Journal articles: 'Torque speed characteristics'

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Kucheruk, V. Yu, I. P. Kurytnik, Ye Z. Oshanov, P. I. Kulakov, A. A. Semenov, D. Zh Karabekova, and A. K. Khassenov. "Computer-measuring system of the induction motor’s dynamical torque-speed characteristics." Bulletin of the Karaganda University. "Physics" Series 94, no. 2 (June 28, 2019): 92–100. http://dx.doi.org/10.31489/2019ph2/92-100.

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Inaguma, Y. "Friction torque characteristics of an internal gear pump." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 225, no. 6 (April 11, 2011): 1523–34. http://dx.doi.org/10.1177/0954406211399659.

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This paper describes the influence of pump operating conditions, such as operating pressures, pump speeds, and oil temperatures, on the friction torque characteristics of internal gear pumps for automobiles. Additionally, it presents a new mathematical model reflecting the influence of the oil temperature on the friction torque. In an internal gear pump, the friction torque was affected by oil temperature as well as operating pressure and pump speed. When the operating pressure was high, the influence of oil temperature on friction torque at a pump speed of less than 1000 r/min was contrary to that at a pump speed of greater than 1000 r/min. It was considered that the friction torque is fundamentally composed of three components: the component dependent on the operating pressure, dependent on the pump speed, and independent of both the operating pressure and the pump speed. However, the component dependent on the operating pressure was affected significantly by not only the pump speed but also the oil temperature. In addition, another factor besides the viscosity of the oil existed in the component dependent on the pump speed. A mathematical model for the friction torque characteristic of the internal gear pump was newly established by adding factors including the oil temperature to the Wilson’s model. The new model was able to represent with accuracy the experimental friction torque characteristic in the internal gear pump under various pump operating conditions.

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Dolgih, Antonina, and Vladimir Martemyanov. "Speed-Torque Characteristics of Torque Motor with Tape Winding Stator." Известия высших учебных заведений. Электромеханика 64, no. 1 (2021): 37–42. http://dx.doi.org/10.17213/0136-3360-2021-1-37-42.

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The speed-torque characteristics of a torque motor with a new type of active element – the tape winding is considered. The analytical studies of the motor speed-torque characteristics determination is difficult because it is required to take into account the distributed current flowing through the winding elements. This leads to the numerical methods application, in particular, COMSOL Multiphysics software based on the finite element method (FEM). Attention is paid to the changing of the motor developed torque in the presence of EMF created in the winding during the rotor rotation. It is shown that the motor torque with a rotor rotation frequency changing depends mainly on the nature of the distributed current lines flowing through the winding elements, despite the fact that the consumed current value changes to a lesser extent. The obtained speed-torque characteristics of the torque motor has a form similar to ones of separately excited DC motors. The research results allow assessing the expected characteristics of the motor model and are an integral part of the developed design policy of the torque motor with the tape winding stator.

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Han, Zhao Lin, and Feng Liu. "Research on Power Diffluence and Conflux Mechanism of Hydro-Mechanical Transmission." Advanced Materials Research 479-481 (February 2012): 921–24. http://dx.doi.org/10.4028/www.scientific.net/amr.479-481.921.

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Abstract. Hydro-Mechanical Transmission (HMT) is a dual-power flow transmission system in which power is transferred parallel by mechanical transmission and hydraulic transmission. There are four types of HMT: torque-diffluence and torque-conflux, torque-diffluence and speed-conflux, speed-diffluence and speed-conflux, speed-diffluence and torque-conflux, when gear pair and planetary train are used as power diffluence or conflux mechanism respectively. And the result of kinematics characteristics analysis indicates that only torque-diffluence and speed-conflux type of HMT can be used as the vehicle transmission system because its output speed characteristics and pump speed characteristics can meet the requirements of the vehicle drive.

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Wang, Dagang, Ruixin Wang, and Jun Zhang. "Dynamic brake characteristics of disc brake during emergency braking of the kilometer deep coal mine hoist." Advances in Mechanical Engineering 12, no. 5 (May 2020): 168781402091809. http://dx.doi.org/10.1177/1687814020918097.

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Dynamic brake characteristics of disc brake during emergency braking of the kilometer deep coal mine hoist were investigated in the present study. The theoretical model of dynamic brake torque of disc brake during emergency braking was given to explore dynamic brake torque properties of disc brake. The three-dimensional thermo-mechanical coupled finite element model of brake disc–brake shoe was established to explore thermo-mechanical characteristics of disc brake during emergency braking. Effects of effective mass, hoisting acceleration and deceleration, and maximum hoisting speed on dynamic brake torques, equivalent von Mises stress, and temperature fields of disc brake during emergency braking were presented. The results show that the evolutions of brake torque, equivalent stress, and temperature of disc brake present fluctuating characteristics. The dynamic brake torque shows the largest change amplitude during emergency braking in the hoisting stage of constant speed. The largest equivalent stress and temperature are both located near the third brake shoe along the rotational direction at each side. An increase in effective mass causes overall decreases in the peak values of brake torque, equivalent stress, and temperature during emergency braking. Increases in hoisting acceleration/deceleration and maximum hoisting speed cause the increases in the maximum equivalent stress and temperature during emergency braking as compared to the slight decrease in the maximum brake torque.

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Pan, Hui, and Xing Cai. "Study on Characteristics of Metal V-Belt Infinitely Variable Power-Split Transmission." Advanced Materials Research 383-390 (November 2011): 785–89. http://dx.doi.org/10.4028/www.scientific.net/amr.383-390.785.

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Six kinds of torque-splitting and speed-converging metal V-belt IVPST were raised; their global speed ratio and torque ratio of metal V-belt CVT output to metal V-belt IVPST output were derived. Two different torque-splitting and speed-converging metal V-belt IVPSTs were sum up: series and parallel metal V-belt IVPSTs. In series metal V-belt IVPST, speed ratio changing rate and torque ratio were related to gear ratio of planetary gear train and fixed gear transmission, but in parallel metal V-belt IVPST, that were only related to gear ratio of planetary gear train.

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Wang, Gui Juan. "The Experimental Study on "Soft Start" of Mine Permanent Magnet Coupling." Applied Mechanics and Materials 727-728 (January 2015): 403–5. http://dx.doi.org/10.4028/www.scientific.net/amm.727-728.403.

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The "soft start" problem was studied for magnetic coupling in coal mine by experimental method. At first, the starting condition of magnetic coupling was analysed. Aaccording to the load characteristics of conveyor. Secondly, the torque characteristic curve, speed characteristic curve and current starting curve were plotted using the experimental data. From three kinds of characteristic curve we have conclusion that the output torque and output speed is much less than the input torque and input speed, the starting current value with the load was less than the starting current value when directly connected. That means magnetic coupling with the soft start characteristic.

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Zhang, Lin, Chao Wei, and Ji Bin Hu. "Model for the prediction of drag torque characteristics in wet clutch with radial grooves." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 233, no. 12 (November 28, 2018): 3043–56. http://dx.doi.org/10.1177/0954407018814959.

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Drag torque can cut down the efficiency of the vehicle transmission system. So it should be reduced on the premise of normal vehicle lubrication and heat dissipation. The purpose of this paper is to analyze the variation rule of drag torque in single-plate wet clutch from the perspective of flow rate, density, and viscosity. In the theoretical model of drag torque, the flow field is divided into oil film area and cavitation zone. Based on the mass flow conservation and viscosity–pressure equation, the equivalent density and viscosity of each node in each region are obtained. Then the total drag torque is calculated through the sum of each node’s torque. Finally, the curves of drag torque with rotational speed under different working conditions are obtained by numerical calculation, and they have been tested and verified. Through this research, the following conclusions can be reached: the rotational speed of the peak of drag torque is near the maximum speed where full oil film lubrication is realized. While temperature declines, it will lead to higher viscosity, then the speed of the lubricant along the radial direction will decrease, resulting in the increase in maximum speed of full oil film lubrication under the same oil supply; accordingly, the peak of drag torque will rise. If the flow rate of oil supply is increased, the maximum speed where full oil film lubrication is realized will be higher; consequently, the maximum drag torque will be improved. When clearance becomes wider, the cross-sectional area of the radial flow will be larger, then the maximum speed of full oil film lubrication under the same oil supply will be decreased, thus the peak of drag torque will decline.

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Jeong, S. S., J. K. Park, and T. G. Park. "Speed and Torque Characteristics of Three-Phase Ultrasonic Motor." Ferroelectrics 466, no. 1 (May 9, 2014): 110–18. http://dx.doi.org/10.1080/00150193.2014.895171.

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Nelatury, S. R. "Uniqueness of Torque-Speed Characteristics of an Induction Motor." IEEE Transactions on Magnetics 40, no. 5 (September 2004): 3431–33. http://dx.doi.org/10.1109/tmag.2004.831628.

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Zhu, Z. Q., and Z. Azar. "Torque speed characteristics of switched flux permanent magnet machines." COMPEL - The international journal for computation and mathematics in electrical and electronic engineering 31, no. 1 (December 30, 2011): 22–39. http://dx.doi.org/10.1108/03321641211184805.

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Baranov, Pavel R., Sergey N. Kladiev, Stanislav V. Borisov, and Alexander A. Filipas. "Studying Characteristics of Traction Induction Motors for Variable-Speed Mine Electric Locomotive." Applied Mechanics and Materials 770 (June 2015): 378–83. http://dx.doi.org/10.4028/www.scientific.net/amm.770.378.

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The analysis of torque-speed characteristics of induction motors has been carried out in order to choose the base design for variable speed traction electric drives of underground mine electric locomotives. For constant dimensions of active part of series-produced electric motors the influence of the diverse conductivity’s materials for manufacturing the squirrel-cage rotor on speed-torque and speed-current characteristics. The designs are compared according to speed-up dynamics, power indexes and key design features of the studied electric motors.

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Song, Young-Youn, Jung-Yul Cha, and Chung-Ju Hwang. "Mechanical Characteristics of Various Orthodontic Mini-screws in Relation to Artificial Cortical Bone Thickness." Angle Orthodontist 77, no. 6 (November 1, 2007): 979–85. http://dx.doi.org/10.2319/090606-363.1.

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Abstract Objective: To evaluate the effect of cortical bone thickness on the maximum insertion and removal torque of different types of self-drilling mini-screws and to determine if torque depends on the screw design. Materials and Methods: Three different types of self-drilling mini-screws (cylindrical type [Cl], taper type [Ta], taper type [Tb]) were inserted with the use of a driving torque tester at a constant speed of 3 rotations per minute. Experimental bone blocks with different cortical bone thicknesses were used as specimens. Results: Differences in the cortical bone thickness had little effect on the maximum insertion and removal torque in Cl. However, with Ta and Tb, the maximum insertion torque increased as the cortical bone thickness increased. The maximum insertion torque of Tb was highest in all situations, followed by Ta and Tb, in that order. Cl showed less torque loss in all cortical bone thicknesses and a longer removal time compared to Ta or Tb. There were significant relationships between cortical bone thickness, maximum insertion and removal torque, and implantation time in each type of self-drilling mini-screw. Conclusion: Since different screw designs showed different insertion torques with increases in cortical bone thickness, the suitable screw design should be selected according to the cortical thickness at the implant site.

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Agapiou, J. S. "Evaluation of the Effect of High Speed Machining on Tapping." Journal of Engineering for Industry 116, no. 4 (November 1, 1994): 457–62. http://dx.doi.org/10.1115/1.2902128.

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This paper summarizes tapping characteristics at speeds as high as 9,000 rpm (180 m/min surface speed) as compared to traditional tapping done at speeds from 500 to 1,500 rpm (20–30 m/min). High speed tapping was achieved by synchronizing the spindle rotation and the feed motion of a specially built machine at extremely high speeds and acceleration/deceleration rates. This investigation analyzes the performance of roll and cut tap geometries in the high speed tapping of 319 aluminum. The torque required by the different tap geometries at several speeds and percent threads combination is evaluated. The relationship between pretapped hole diameter and minor diameter of the thread and the estimation of percent thread are analyzed. The thread quality generated at high speeds is also evaluated. It is shown that the cutting speed does not affect the steady state torque and the shear strength. The torque for roll forming taps is higher than that for cut taps. The shear strength of roll forming threads increased with percent thread.

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Irasari, Pudji, Ketut Wirtayasa, Puji Widiyanto, Muhammad Fathul Hikmawan, and Muhammad Kasim. "Characteristics analysis of interior and inset type permanent magnet motors for electric vehicle applications." Journal of Mechatronics, Electrical Power, and Vehicular Technology 12, no. 1 (July 31, 2021): 1–9. http://dx.doi.org/10.14203/j.mev.2021.v12.1-9.

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Permanent magnet motors (PMMs) are widely used in electric vehicles because of their benefits. Based on the permanent magnet topologies on the rotor, PMMs are classified into three types: surface mounted PMM, inset PMM, and interior PMM. This paper discusses a comparison of the characteristics of interior and inset types of PMMs for electric vehicle applications. The study aims to find out the effect of the rotor construction on the magnetic characteristics, torque-speed characteristics, and cogging torque. Simulations were carried out analytically and numerically using the FEMM 4.2 software. The simulation results at the base speed show that the interior PMM generates a higher torque but with a lower rotation, namely 56.47 Nm and 3162 rpm, respectively, while the inset PMM produces higher rotation 4200 rpm but lower output torque of 46.01 Nm. However, with a higher saliency ratio, the interior PMM produces higher maximum torque and speed at both constant torque and field weakening regions than the PMM inset, which is 92.87 Nm and 6310 rpm, consecutively. In terms of cogging torque, the interior PMM raises it slightly higher (2.90 Nm) than the inset PMM (1.93 Nm). The results conclude that, in general, the interior PMM shows better performance in all studied regions and is preferable for electric vehicle applications.

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El-Ghobashy El-Hagar, Mahmoud Mohamed. "Performance Characteristics of a Reciprocating Piston Pump Driven by a Wind Machine." WSEAS TRANSACTIONS ON POWER SYSTEMS 15 (January 14, 2021): 265–69. http://dx.doi.org/10.37394/232016.2020.15.31.

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The torque applied by a reciprocating pump on a wind machine axis is a fluctuating torque. The energy furnished by the pump on the wind machine axis is absorbed mainly in raising the water and the piston when the latter moves up. This has a direct adverse effect on the starting speed. The lower the maximum torque to be overcome, the easier will the wind machine start. If the necessary torque is high, a faster wind speed is required to start the wind machine. The operating time of the machine is consequently reduced. It is therefore desirable to reduce the starting torque, and hence to make the starting easier. This paper presents a theoretical study to reduce the starting torque of a non-conventional reciprocating piston pump by controlling the stroke volume of the pump or by controlling the flow rate of the piston pump. These two methods are the best to control, smooth and reduce the starting torque of the pump by drilling a very small hole in the piston. The effect of this hole is that at very low speed (at starting) all water that could be pumped is leaked through the hole. This is the main important of the hole which made the pressure on the piston is very low and as a result the starting torque is low. The quantity of water leaking through the hole is small compared to the normal output of the pump. Finally the comparison between normal and leakhole piston pump and the effect of this leakhole on the cavitation phenomena are studied

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Wang, Hao, and Zhi Hong Yin. "Analysis and Calculation of a Gravity Turbine Torque, Speed." Applied Mechanics and Materials 740 (March 2015): 65–68. http://dx.doi.org/10.4028/www.scientific.net/amm.740.65.

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In order to understand the operation of the water turbine generating by gravity .With the method of Linearization, equivalent and torque balance, this paper analysed, drove and calculated the water turbine’s rotational torque and speed theoretically ,and calculated by using examples according the motion characteristics of the turbine. By calculating, the factors of the water turbine’s capacity, the expression of the rotational torque and the turbine’s speed were obtained.

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Martnez, Sergio, and Carlos Veganzones. "Uncertainty in Estimating Torque-Speed Characteristics of Induction Rotating Machines From Noisy Direct Torque Measurements." IEEE Transactions on Magnetics 43, no. 3 (March 2007): 1124–26. http://dx.doi.org/10.1109/tmag.2006.888075.

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Liu, Cancan, Xigui Zheng, Niaz Muhammad Shahani, Peng Li, Cong Wang, and Xiaowei Guo. "An experimental investigation into the borehole drilling and strata characteristics." PLOS ONE 16, no. 7 (July 20, 2021): e0253663. http://dx.doi.org/10.1371/journal.pone.0253663.

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Measurement while drilling is an important part of the intelligent development of coal mines. The main purpose of this paper is to comprehensively analyze the response characteristics of borehole drilling parameters and find a better method to predict rock mechanical properties based on drilling parameters. Firstly, six concrete blocks and multiple specimens were prepared with different material ratios. Next, the concrete specimens were tested for mechanical properties in the laboratory. Meanwhile, the displacement, rotation speed, torque, and sound pressure level (SPL) were observed during the drilling of the concrete blocks. Finally, the response characteristics of drilling parameters such as rotation speed, rate of penetration (ROP), torque, and SPL were analyzed. Besides, multiple prediction models of rock mechanical parameters were obtained by data analysis. The research results indicate that the drilling process can be classified into the initial stage of drilling (fast speed) and the steady stage of drilling (slow speed). The torque work ratio accounts for more than 99%, which increases with the increase in rock strength. The penetration depth per revolution and torque work ratio are significantly related to rock uniaxial compressive strength, Brazilian tensile strength, cohesion, and elastic modulus. The ROP is the best choice for estimating rock mechanical parameters. This research provides an important reference for laboratory rock mechanics parameter testing and geological features detection based on drilling parameters.

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Geng, Guo Qing, Hao Bin Jiang, Jia Yin Dong, Tao Jiang, and Tao Liu. "Modeling and Characteristics Research of Proportional-Valve Hydraulic Power Steering of Commercial Vehicle." Advanced Materials Research 765-767 (September 2013): 357–60. http://dx.doi.org/10.4028/www.scientific.net/amr.765-767.357.

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Dynamics model of mechanical system and hydraulic system inclued electro-hydraulic proportional valve of Proportional-Valve Hydraulic Power Steering were established.and simulation model of assisted characteristic of PVHPS system was build .Response characteristic of proportional valve bypass flow was analyzed at different speed, and higher of the speed, greater of the flow in the bypass flow is . Steering wheel torque increases gradually as vehicle speed increases at the same wheel angle, and driver's better steering road feeling can be ensured. As wheel steering torque increases, assisted oil pressure increases and higher the speed is , slowly oil pressure increases, and assisted oil pressure increases quickly at low-speed steering condition, and increases slowly at high-speed condition,which meet the requirement of low-speed steering agility and high-speed road feeling.

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Brockhurst, P. J., and Roya Shams. "Dynamic measurement of the torque-speed characteristics of dental high speed air turbine handpieces." Australian Dental Journal 39, no. 1 (February 1994): 33–38. http://dx.doi.org/10.1111/j.1834-7819.1994.tb05544.x.

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Pan, Xiong, Chen Xinyuan, Sun Hongjun, Zhong Jiping, and Zhen Chenping. "Effect of internal leakage on torque converter characteristics." Advances in Mechanical Engineering 12, no. 9 (September 2020): 168781402095996. http://dx.doi.org/10.1177/1687814020959969.

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To understand the effect of internal leakage on the torque field and characteristics of a torque converter (TC), a transient analysis was performed on the internal flow of a TC and the pressure pulsation characteristics of monitoring points in the convection channel. It was found that dividing the leakage area of the TC into a separate watershed improved simulation accuracy by 4%. When there was a leakage area, there were distinct collision, mixing, and assimilation stages between the leakage flow and the main flow. These phenomena caused energy loss that was highest at low speed ratios. However, the leakage flow always accounted for 12% of the main flow regardless of the speed ratio. At the same time, the leakage flow had a larger influence on pressure pulsation inside the TC and especially the low frequency band was more substantial. This shows that the leakage area has a large influence on the TC performance, energy loss, and flow state. Analysis of the leakage area showed that reducing the leakage area helps to improve powertrain performance and fuel economy.

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Cui, Jun Guo, Wen Sheng Xiao, Jian Bo Zhao, Jing Xi Lei, Xiao Dong Wu, and Zhi Gang Wang. "Development and Application of Low-Speed and High-Torque Permanent Magnet Synchronous Motor." Applied Mechanics and Materials 229-231 (November 2012): 888–94. http://dx.doi.org/10.4028/www.scientific.net/amm.229-231.888.

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To meet the demands of direct-drive petroleum equipment, developed a low-speed and high-torque permanent magnet synchronous motor. By analyzing and identifying the suitable key parameters such as permanent magnet structure parameters, air gap length, type and size of Stator Slot and so on, designed permanent magnet synchronous motor with the torque 10800 Nm, the rated speed 30 r/min and high efficiency and power factor. Obtained the flux density distribution situation and characteristic curves under no-load working condition through simulation and analysis. Manufactured the low-speed and high-torque permanent magnet synchronous motor and applied it to pumping unit. Test results show that this motor has many advantages such as wide range of speed regulation, small torque ripple, smooth operation and other characteristics. The Direct-drive Pumping Unit used this permanent magnet synchronous motor can save 20% energy than the beam pumping unit, so its social and economic benefits are significant.

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Su, Shi Bin, Yi Kai Shi, Kang Han, and Xiao Qing Yuan. "Optimal Design of Transverse Flux Permanent Motor with Reducing Cogging Torque." Applied Mechanics and Materials 385-386 (August 2013): 1197–200. http://dx.doi.org/10.4028/www.scientific.net/amm.385-386.1197.

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Transverse Flux Permanent-magnet Motor has low speed, high torque density characteristics. In order to reduce cogging torque, a novel topology model of transverse flux motor has been designed for electric vehicle wheel in this paper. Its remarkable characteristic is sufficient to reduce the cogging torque, raise motor output torque and raise utilization ratio to the space in electric vehicle wheel. The cogging torque of the prototype model is calculated through the three dimensional finite element analysis methods. The result shows that the theoretical research method is effective and topology model rationality.

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NURJANAH, SENI, NASRUN HARIYANTO, and SABAT ANWARI. "Torka Motor Induksi pada Mesin CNC di PT. Dirgantara Indonesia menggunakan Software PSIM." MIND Journal 6, no. 1 (August 1, 2021): 73–88. http://dx.doi.org/10.26760/mindjournal.v6i1.73-88.

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AbstrakMesin CNC digunakan untuk membuat kerangka pesawat terbang, motor induksi sebagai tenaga penggerak diatur kecepatan putarnya untuk menghasilkan torka sesuai kebutuhan dikendalikan oleh VSD. Pengendalian VSD pada mesin CNC menggunakan software PSIM untuk mengetahui karakteristik mesin CNC dengan tegangan dan frekuensi yang divariasikan agar menghasilkan torka konstan. Analisis karakteristik motor induksi digunakan rangkaian pengganti dan perhitungan matematis. Untuk mengetahui rentan kerja mesin CNC maka arus starting 61,83Ampere; torka starting 23,28N.m; torka maksismum 14,1N.m; putaran sinkron 1500rpm. Pengolahan data dilakukan secara matematis, pada pengukuran mendapatkan torka 35N.m sedangkan simulasi beban 30% menghasilkan torka 4.2N.m; beban 60% menghasilkan torka 8.3N.m; beban 90% menghasilkan torka 12.5N.m. Dapat disimpulkan kendali V/f menghasilkan torka konstan sepanjang pengaturan kecepatan putar. Kata kunci: PSIM, Variable Speed Drive, Torka Motor Induksi, Mesin CNCAbstractCNC machines are used to make aircraft frames, the induction motor as the driving force is set to rotate its speed to produce torque as needed, controlled by a variable speed drive. VSD control on CNC machines uses PSIM software to determine the characteristics of CNC machines with varied voltages and frequencies to produce constant torque. Analysis of the characteristics of the induction motor used a replacement circuit and mathematical calculations to determine the working range of the CNC machine. Then the starting current is 61.83Amperes; starting torque 23.28N.m; maximum torque 14.1N.m; synchronous speed 1500rpm. Data processing is done mathematically, the measurement gets 35N.m of torque while the 30% load simulation produces 4.2N.m of torque; 60% load produces 8.3N.m torque; 90% load produces 12.5N.m of torque. It can be concluded that the V/f control produces constant torque throughout the rotational speed setting.Keywords: PSIM, Variable Speed Drive, Induction Motor Torque, CNC Machine

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Lovell, M. R., M. M. Khonsari, and R. D. Marangoni. "Evaluation of Ultra-Low-Speed Jitter in Rolling Balls." Journal of Tribology 114, no. 3 (July 1, 1992): 589–94. http://dx.doi.org/10.1115/1.2920921.

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The frictional resistance generated by a ball bearing, when starting from rest, increases to a free rolling value in a finite amount of time instead of experiencing an instantaneous step increase. This is due to the complex ball dynamics involved. A change in the direction of rotation results in a reversal of the bearings dynamic torque characteristics. When a traversing process is continuously repeated, the friction torque of the bearing traces out hysteresis loops. This phenomenon is often described as ball jitter. An apparatus was built to study the ultra-low-speed hysteresis behavior found in jittering ball bearings. This behavior was first modeled by P. R. Dahl (1968). He found torque hysteresis loops to be characterized by the steady rolling friction torque, Ts, and the reversal torque slope, σ. A theoretical expression for Ts has been verified in previous research by Lovell et al. (1991), but no expression for σ has currently been determined at low speeds. Therefore, the experimental testing apparatus was canonically designed to incorporate three balls, rather than a full bearing. This was done in order that the characteristics of σ could be more readily determined, as many additional friction elements which occur in full bearings were eliminated. The effects of normal load, rotational rate, and lubrication regime on σ were all investigated using the testing apparatus. The experimental values obtained for the rest slope were coupled with previously determined values of Ts, so that empirical Dahl hysteresis curves could be generated. Excellent correlation was found to exist between the experimental jitter torque data and Dahl predicted dynamic torque behavior.

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Krykowski, Krzysztof, and Janusz Hetmańczyk. "Constant Current Models of Brushless DC Motor." Electrical, Control and Communication Engineering 3, no. 1 (August 1, 2013): 19–24. http://dx.doi.org/10.2478/ecce-2013-0010.

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Abstract Two constant current models of Permanent Magnet Brushless Direct Current Motor (PM BLDC) are presented in the paper. In the first part of the paper principle of operation, basic properties and mathematical equations describing PM BLDC models are given. Then, two different constant current models of PM BLDC motor are considered: In the first model, PM BLDC motor is approximated with dc motor; in the second model, modified constant current model is applied with additional block, which is used to take into account the impact of inductance on torque-speed characteristics. In order to verify these models, torque-speed characteristics have been determined and compared for different motor supply voltages. After running a series of simulation and laboratory tests, we have found that this modified model (which makes allowance for the influence of inductance on torque-speed characteristics) ensures obtaining torque-speed characteristics identical to those of the real motor. Therefore, this model may be recommended for those simulation tests which do not consider effects occurring inside the electronic commutator-motor circuit. However, approximation of PM BLDC motor with dc motor is not recommended in computer tests.

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Kishore, M. L. P., Vijay K. Singh, R. K. Behra, Chandra S. Saran, Manikant Paswan, and Kapil Kumar. "Hydrodynamic characteristics of marine composite propeller blade using a numerical approach." International Journal of Advances in Applied Sciences 10, no. 1 (March 1, 2021): 20. http://dx.doi.org/10.11591/ijaas.v10.i1.pp20-27.

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<p>The aim of the present research work is to investigate the hydrodynamic characteristics (pressure distribution, rotational speed, thrust and torque) of the conventional B-series composite propeller blade. The open water efficiency for the scaled model of composite propeller blade is computed using computational fluid dynamics (CFD) fluent simulation tool. The obtained numerical results show that the propeller will operate at optimum efficiency for the given speed condition and perform with reduced efficiency at other operational speeds. The computed responses are also validated with the standard B-series data which verifies the accuracy and robustness of the present numerical approach in analyzing the performance characteristics of propellers. The deviation in solution ranges from 5 to 15% in the case of thrust, 10-20% in case of torque. Pressure estimation is usually quite accurate with a 5-8% variation. The tabular data of pressure distribution over the propeller blade may be used for further structural analysis</p>

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Peng, Xiao, Mo Fa Li, and Yong Jian Li. "Direct Torque Control for Brushless Doubly-Fed Machine Based on Fuzzy-PI Regulator." Advanced Materials Research 614-615 (December 2012): 1185–89. http://dx.doi.org/10.4028/www.scientific.net/amr.614-615.1185.

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The inverter switch state is based on the torque error and the stator flux amplitude error in the hysteretic controller which is adopted on the traditional direct torque control for the brushless doubly-fed machine, in this way, current and flux are distorted that results torque ripple in low speed range, even more influents control effect of the whole system. According to this problem, a new direct torque control method with fuzzy-PI regulator for the brushless doubly-fed machine is presented in this paper, applying the fuzzy theory to design controller parameters. The simulation results show that the method is effective to improve the dynamic characteristics of the motor, reduce the torque ripple, improve the speed and the torque control precision, and expand the direct torque control system of speed range.

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Sato, Mitsuhide, Keigo Takazawa, Manabu Horiuchi, Ryoken Masuda, Ryo Yoshida, Masami Nirei, Yinggang Bu, and Tsutomu Mizuno. "Reducing Rotor Temperature Rise in Concentrated Winding Motor by Using Magnetic Powder Mixed Resin Ring." Energies 13, no. 24 (December 20, 2020): 6721. http://dx.doi.org/10.3390/en13246721.

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The demand for high-speed servomotors is increasing, and minimal losses in both high-speed and high-torque regions are required. Copper loss reduction in permanent magnet motors can be achieved by configuring concentrated winding, but there are more spatial harmonics compared with distributed winding. At high-speed rotation, the eddy current loss of the rotor increases, and efficiency tends to decrease. Therefore, we propose a motor in which a composite ring made from resin material mixed with magnetic powder is mounted on the stator to suppress spatial harmonics. This paper describes three characteristic motor types, namely, open-slot motors, composite-ring motors, and closed-slot motors. Spatial harmonics are reduced significantly in composite-ring motors, and rotor eddy current loss is reduced by more than 50% compared with open-slot motors. Thermal analysis suggests that the saturation temperature rise value is reduced by more than 30 K. The use of a composite ring is effective in reducing magnet eddy current loss during high-speed rotation. Conversely, the torque characteristics in the closed-slot motor are greatly reduced as well as the efficiency. Magnetic circuits and simulations show that on electrical steel sheets with high relative permeability, the ring significantly reduces the torque flux passing through the stator, thus reducing the torque constant. To achieve reduced eddy current loss during high-speed rotation while ensuring torque characteristics with the composite ring, it is necessary to set the relative permeability and thickness of the composite ring according to motor specifications.

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Inaguma, Yoshiharu. "Oil temperature influence on friction torque characteristics in hydraulic pumps." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 226, no. 9 (December 1, 2011): 2267–80. http://dx.doi.org/10.1177/0954406211430572.

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This article presents a practical approach to the investigation of the influence of oil temperature on the friction torque in various types of hydraulic pumps using a mathematical model. Currently, an external gear, an internal gear or a vane pump is commonly used for an automatic transmission. These pumps have their own friction torque characteristics, which depend not only on pump-operating conditions such as operating pressures, pump speeds and oil temperature but also on structures and dimensions of the pumps. For various pumps, however, the friction torque characteristics can be represented by an identical mathematical model. In the pump-operating conditions, the oil temperature significantly and complicatedly affects them. The pump should be operated under conditions to obtain a higher mechanical efficiency, and the mathematical model is helpful to analyse how the oil temperature influences the friction torque. It is found that with an increase in oil temperature, the friction torque at a high pump speed decreases in a low oil temperature region, but it would not decrease in a high oil temperature region for all the tested pumps. This fact suggests that the pump overall efficiency would not improve at a high oil temperature, even if the volumetric efficiency does not go down.

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Li, Ye Ni, Shui Xuan Chen, and Hu Xiu Xu. "Speed Control System Research on Hydraulic Torque Forklift." Applied Mechanics and Materials 666 (October 2014): 188–93. http://dx.doi.org/10.4028/www.scientific.net/amm.666.188.

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By researching the characteristics of hydraulic torque forklifts, developed a device which achieved inching function. It can detect position of the handle, using Delta PLC controlled stepper motor driven screw movement, to achieve the control of the engine speed, and modify the control parameters via touch-screen on-site commissioning, to achieve a truck at idle operation, through the manipulation of the handle can Smooth and stable pan, lift or tilt operation, making operation more convenient forklift and reduces the operator's labor intensity, a high value market applications.

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Le Moal, Patrice, Patrice Minotti, Gilles Bourbon, and Eric Joseph. "On-Chip Investigation of Torque/Speed Characteristics on New High-Torque Micrometer-Size Polysilicon Electrostatic Actuators." Japanese Journal of Applied Physics 40, Part 2, No. 6B (June 15, 2001): L596—L599. http://dx.doi.org/10.1143/jjap.40.l596.

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Agamloh, Emmanuel B., Andrea Cavagnino, and Silvio Vaschetto. "Accurate Determination of Induction Machine Torque and Current Versus Speed Characteristics." IEEE Transactions on Industry Applications 53, no. 4 (July 2017): 3285–94. http://dx.doi.org/10.1109/tia.2017.2675984.

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MENG, YONGGANG, YU TIAN, and HONG JI. "STUDY ON CHARACTERISTICS OF AN ELECTRORHEOLOGICAL FLUID COUPLING." International Journal of Modern Physics B 21, no. 28n29 (November 10, 2007): 4929–39. http://dx.doi.org/10.1142/s0217979207045852.

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A prototype of a cylindrical ERF coupling was fabricated, and its transmission capability in steady and unsteady running conditions was investigated. The torque transmitted by the coupling with viscous force in wide ranges of driving speed and field strength was measured. The relationship between the transmission torque, the zero field viscosity of ERF and the shear yield stress of ERF under field was obtained, and was compared with theoretical prediction. Moreover, by modulating the strength of the applied DC field, under a fixed load and input speed, the output speed of the coupling was controlled in the range of transmission ratio from 0 to 1. This provides a means to construct transmission systems in which the output speed can be conveniently adjusted and controlled. Further, square wave electric pulses were applied on the ERF coupling, with a fixed external load added on the output shaft, a uniform stepping rotation of the output shaft has been realized. Experiments showed that under certain conditions the rotation angle of the output axle can be precisely controlled.

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36

Jin, Yuan Qiang, and Yu Li Zang. "Optimal Design of Rotation Shaft Torque Testing System." Advanced Materials Research 476-478 (February 2012): 1987–90. http://dx.doi.org/10.4028/www.scientific.net/amr.476-478.1987.

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Torque measuring in the extra-high rotation speed has not been resolved ideally yet, due to the restriction of the rough conditions. The dynamic characteristics of the developed digital plane grating angular-torquer measuring system are analyzed in this paper. The paper mainly calculates and designs the parameters of elastic shafts with different cross-section. Via the compare of dynamic characteristics and compactness of the elastic shafts with different cross-section, the optimized design is proposed at the end of the paper. The achievements of this paper can supply references to the study and design, maintaining and improvement of relative instruments.

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Abunike, E. C., G. D. Umoh, I. E. Nkan, and O. I. Okoro. "Investigating the Magnetic Characteristics of 12/8 Switched Reluctance Motor for Enhanced Starting Torque." Nigerian Journal of Technological Development 18, no. 1 (June 24, 2021): 70–75. http://dx.doi.org/10.4314/njtd.v18i1.10.

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The switched reluctance motor (SRM) is among the special purpose electric machine family. It is simple in construction and avoids use of magnet so it is cheap to manufacture. The magnetic characteristics and simulation of three phase 12/8 switched reluctance motor (SRM) for enhanced starting torque is presented. The motor was analyzed using finite element technique (FET) and it was improved by focusing on the impact of important geometrical parameters on torque and efficiency. From the simulated results, the motor attained maximum efficiency of 91.7% at a speed of 1648.6 rpm and recorded a maximum torque of 321.1 Nm at a speed of 34.4 rpm. The magnetic flux lines and densities were also recorded. The maximum and minimum magnetic flux lines of the motor as observed were 1.2x10-3 Wb/m and -8.5x10-4 Wb/m respectively while the respective values of the maximum and minimum magnetic flux density of the motor were 3.8x10-1 T and 2.11x10-9 T. The results show that most of the field energy is confined within the motor and also concentrated in the air gap region of the motor. Dynamic analysis of the motor was performed for 0.02 s at a damping coefficient of 0.71 μNms/rad. The results showed that the motor has lower torque ripple. The preference to use this type of motor where high speed operation and better starting torque are needed has been highlighted in this study. Keywords: Switched reluctance motor, static characteristics, transient analysis, torque, magnetic flux

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Agrawal, Ankit, Rakesh Singh Lodhi, and Pragya Nema. "Indirect vector control for induction motor drive using two level and five level inverter." International Journal of Applied Power Engineering (IJAPE) 8, no. 2 (August 1, 2019): 134. http://dx.doi.org/10.11591/ijape.v8.i2.pp134-144.

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<p>This paper represent modelling & simulation of indirect vector control for induction motor drive using two level and five level inverter. To overcome of lower order harmonics, THD & speed torque characteristics of three phase squirrel cage induction motor. This paper provides solution through indirect vector control & SPWM technique for multilevel inverter. A comparison and performance of two level and five level inverter are used in motor to control speed, current and torque. Matlab simulation environment are taken to simulate indirect vector control for induction motor drive using two level and five level inverter, so torque ripple minimization, lower order harmonics are reduced, constant speed, constant torque and variable speed variable torque are determined through simulation results. The applications under operating conditions are performed better THD, better reliability in AC drives.</p>

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Kodkin, Vladimir L., and Aleksandr S. Anikin. "Experimental study of the VFD’s speed stabilization efficiency under torque disturbances." International Journal of Power Electronics and Drive Systems (IJPEDS) 12, no. 1 (March 1, 2021): 80. http://dx.doi.org/10.11591/ijpeds.v12.i1.pp80-87.

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The article presents a technique for experimental research of variable frequency drives experiencing periodic torque disturbances of variable frequency. The technique is based on the nonlinear transfer function of a link of an asynchronous electric motor, which forms an electromagnetic torque, proposed in previously published articles. The dependence of the transfer function on the frequency of the stator voltage and slip determines the research methodology. Experiments have shown the advantage of the dynamic characteristics of a drive with a positive feedback on the stator current over electric drives with traditional control methods (vector and scalar sensorless), and in terms of dynamic characteristics they also exceed drives with a vector control closed in motor speed. These advantages are retained when the frequency of change of the disturbing torque is changed from 0 to 5 Hz.

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Liu, Jun, Zi-Jie Niu, Hua Zhu, and Chun-Sheng Zhao. "Design and Experiment of a Large-Aperture Hollow Traveling Wave Ultrasonic Motor with Low Speed and High Torque." Applied Sciences 9, no. 19 (September 23, 2019): 3979. http://dx.doi.org/10.3390/app9193979.

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To realize applications involving low speed and high torque in the high-performance actuator industry, especially in the aerospace field, we propose a novel 70H traveling wave rotary ultrasonic motor (TRUM) with an outer diameter of 70 mm and an aperture ratio of 53% (the ratio between the aperture and outer diameter). The power transmission mechanism between the stator and the rotor is analyzed, and a method for realizing low-speed–high-torque characteristics of TRUMs is proposed. ANSYS software is used to simulate the modal parameters of the stator, and the ratio β between the normal amplitude and the tangential vibration velocity of the stator is proposed. The larger the value of β, the lower the speed and the higher the torque. Furthermore, two prototype motors are fabricated, namely, 70HA and 70HB. Compared with 70HA, the maximum no-load speed of the improved 70HB (50 rpm) is decreased by 23.1% and the maximum stall torque (2.4 N∙m) is increased by 100%. Besides this, with a smaller mass of 210 g and a higher torque density of 11.43 N∙m/kg, 70HB has fundamentally different mechanical characteristics.

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Guo, Yan Jie, Li Fang Wang, and Cheng Lin Liao. "Research on Dynamic Conducted EMI Characteristics of Electric Drive System in Electric Vehicles." Advanced Materials Research 773 (September 2013): 3–8. http://dx.doi.org/10.4028/www.scientific.net/amr.773.3.

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This paper represents the conducted electromagnetic interference (EMI) characteristics of the electric drive system in electric vehicles, based on the typical vehicle driving circles. Firstly, the typical vehicle driving circles are introduced, such as Economic Commission of Europe-15 (ECE-15), Extra Urban Driving Cycle (EUDC) and so on. Also, the relationships between motor speed, torque and vehicle speed are calculated according to the mechanical properties of the vehicle. Then, the simulation and experiment platforms are established considering the motor speed and torque as reference inputs. Finally, the dynamic EMI of power electronics device switching processes, system dynamic differential mode (DM) and common mode (CM) EMI are analyzed through the simulation and experiment results.

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Fu, Hui Lin, Yu Cai Zhou, Zhi Xiang Hou, and Yi Zuo. "Study of Vehicle Engine Transient Emissions." Applied Mechanics and Materials 128-129 (October 2011): 1292–300. http://dx.doi.org/10.4028/www.scientific.net/amm.128-129.1292.

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In this paper, the transient emissions from vehicle engines was studied, measurement methods and corrections required for higher precision measurements of transient indirect emissions was discussed. Various operating conditions such as cold start, constant torque increasing speed, constant torque reducing speed emissions were considered and the corresponding emission characteristics were obtained and analyzed.

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Bao, Heyun, Tongjing Xu, Guanghu Jin, and Wei Huang. "Analysis of Dynamic Engaged Characteristics of Wet Clutch in Variable Speed Transmission of a Helicopter." Processes 8, no. 11 (November 17, 2020): 1474. http://dx.doi.org/10.3390/pr8111474.

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The working principle and motion process of an aviation wet clutch are analyzed. The initial velocity before the friction pair engaged is solved. The transient Reynolds equation is modified, and an oil film bearing capacity model and a micro-convex bearing capacity model are derived. The film thickness equation between N friction pairs and a pressure-plate is derived. A dynamic engaged model of springs, pistons, friction pairs, and pressure plates are established. The torque balance equation is established of two pairs of friction pairs. The friction torque, rate of change in the oil film, and law of relative change in speed are obtained. The results demonstrate that the spring preload and the viscosity of the lubricating oil have a significant influence on the engagement characteristics. Increasing the quality of the friction plate will reduce the time of engagement, whereas the quality of the friction plate has slight effect on the friction torque characteristics and oil film thickness. The initial speed generated by the collision process will reduce the output speed, sharply increase the torque peak at the lock, and increase the shift shock.

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Zeng, Liping, Yukun Xu, Jie Huang, and Liquan Song. "Dynamic Characteristics Analysis of a Circumferential Short Spring Dual Mass Flywheel with the Influence of Centrifugal Force and Friction." Symmetry 13, no. 8 (August 16, 2021): 1501. http://dx.doi.org/10.3390/sym13081501.

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Multiple sets of spring, spring seat structures are uniformly arranged in circumferential short spring dual mass flywheel (DMF), which generally have a symmetrical structure. The internal springs and spring seats are constrained by the shape of the primary flywheel and the secondary flywheel. At different rotational speeds, the springs and spring seats have different centrifugal forces. To study the dynamic characteristics of the DMF including torque and stiffness with considering the influence of centrifugal force and friction, the discrete method is used to analyze the mechanical actions of the transmission parts in DMF. The torque action between the spring seat and the secondary flywheel is deduced. The dynamic characteristics of the DMF are obtained through analyzing and calculating. Due to the symmetry of the structure, the torque transmitted and the stiffness of the DMF also have specific symmetrical characteristics. Namely, at two relative rotational angles of the same magnitude and opposite direction, the magnitude of the transmitted torque is the same, the direction is opposite. The magnitude and direction of stiffness are the same. The influence of speed, friction coefficient, spring mass, and spring seat mass on the torque and stiffness characteristics are analyzed. Finally, the theoretical analysis is proved to be valid by the torque characteristics test of DMF.

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Zhang, Shuowen, Shuqin Fan, Peng Dong, Yangfeng Cao, and Shengdun Zhao. "The importance of forming parameters on rolling process and the performances of component in forming long threads." Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering 234, no. 1 (October 10, 2019): 29–36. http://dx.doi.org/10.1177/0954408919879823.

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The axial self-infeed rolling process is an advanced and efficient process to form long threads such as lead screw and thread shaft. The experiments of axial self-infeed rolling process for the stainless steel were conducted with three blank diameters, forming speeds and two lubrication conditions. The effects of forming speed, blank diameter and lubrication condition on forming torque, microhardness and tooth height of forming threads were analyzed by the design of experiment and analysis of variance. And the characteristics of forming torque, microhardness distribution and tooth height were investigated. The results revealed the forming torque was more influenced by the blank diameter and the forming speed than the lubrication condition. The tooth height was sensitive to all these factors and the microhardness only was affected by the blank diameter.

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Haines, S. N. M., and S. A. Shields. "The Determination of Diesel Engine Friction Characteristics by Electronic Cylinder Disablement." Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power Engineering 203, no. 2 (May 1989): 129–38. http://dx.doi.org/10.1243/pime_proc_1989_203_017_02.

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The use of electronically controlled unit injectors on a high-speed direct injection diesel engine has allowed the development of a new technique for measuring motoring losses. The digital engine controller is programmed to skip successive numbers of injections in a specific circulating sequence, while dynamometer load is adjusted to maintain the desired speed. The linearity between required brake torque and the proportion of disabled to normal injection cycles permits extrapolation of results to find the negative load that would be required to motor the engine at that speed. The method appears to yield more reliable results than traditional approaches, and gives hot motoring values of mean effective torque without the need for external heating or a motoring facility. The equipment and method involved are described, and readings obtained for the whole speed range are presented. These are correlated with losses estimated from pressure measurements, and compared with friction characteristics produced by alternative techniques.

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Han, Wei, Teng Zhang, You Liang Su, Ran Chen, Yan Qiang, and Yang Han. "Transient Characteristics of Water-Jet Propulsion with a Screw Mixed Pump during the Startup Process." Mathematical Problems in Engineering 2020 (May 4, 2020): 1–9. http://dx.doi.org/10.1155/2020/5691632.

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In order to investigate the transient hydrodynamic characteristics of water-jet propulsion with a screw mixed pump during the startup period and to overcome the difficulties in measuring the transient process parameters over a very short period of time, a method based on a flume experiment combined with computational fluid dynamics (CFD) is proposed. The thrust and torque of the pump-jet propulsion according to mooring status at different rotational speeds were measured by the test, which provided a group of data for the boundary and initial conditions of the numerical calculation of the user-defined function (UDF). Consecutive changes in the parameters of the water-jet propulsion dynamics can be captured from the numerical simulation of the startup process with the UDF. Thus, the transient hydrodynamic characteristics of water-jet propulsion according to time or rotation speed were obtained. The results show that the relationship between the thrust or torque of the water-jet propeller and pump rotational speed is close to the quadratic functions. The energy characteristic parameters of screw mixed water-jet pump, such as the flow rate, head, shaft power, and efficiency, rapidly increase and decrease and then remain relatively stable.

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Gao, Lian Xue, and Dian Sheng Sun. "Experimental Study of the Wheel Drive EV with External Rotor Switched Reluctance Motor." Applied Mechanics and Materials 325-326 (June 2013): 472–75. http://dx.doi.org/10.4028/www.scientific.net/amm.325-326.472.

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Equiped with an electronic differential function in double wheel or four wheel electric vehicle drive, it must be driven by motor torque control precisely . Due to the nonlinear characteristics of the motor when the wheels switched reluctance motor drive, it is difficult to ensure motor torque and phase current relationship by the theoretical approach. This paper puts forward the experimental methods to get the different speed motor torque and given the relationship between the current , so as to make table, according to the rotation of the motor speed and torque requirements, the accurate switched reluctance motor torque control through given the current value in the future of the electric vehicle.

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Chai, Hua Wei, Jin Yu Zhou, Wei Ping Zhang, and Zhi Gang Li. "PMSM Servo System Control Based on Disturbance Observer." Applied Mechanics and Materials 44-47 (December 2010): 1090–94. http://dx.doi.org/10.4028/www.scientific.net/amm.44-47.1090.

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In order to realize high speed control of some ac servo system, aimed at all kinds of uncertain factors such as greatly changing moment and torque, and strong impact torque. Therefore, for gaining good speed tracking characteristics, adaptive disturbance observer is adopted to observe load torque disturbance and speed variation. Stability of closed loop system is guaranteed by design of control tractics to satisfy track control requests of rocket launcher servo system. Simulation results indicate that this method can ideally observe disturbance and reduce output of controller, thus control performance of the system is improved and is greatly meaningful.

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Lovell, M. R., M. M. Khonsari, and R. D. Marangoni. "Comparison of the Low-Speed Frictional Characteristics of Silicon Nitride and Steel Balls Using Conventional Lubricants." Journal of Tribology 118, no. 1 (January 1, 1996): 43–51. http://dx.doi.org/10.1115/1.2837091.

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The friction behavior of Si3 N4 ceramic balls operating under ultra-low-speeds with velocity reversal is investigated. Twenty-one sets of exclusively ultra-low-speed operating conditions were examined that include rotational speeds in the range of .01–1 deg/s, normal loads varying from 81.6 to 185.4 N per ball, and two conventional lubricants: DTE 24 and SAE 20 oil. General trends for the friction torque behavior of ceramic balls were established. Theoretical expressions and empirical correlations are presented for evaluation of the steady torque, Ts, and the rest slope, σ. These relationships can be used in Dahl’s model to completely characterize the hysteresis friction behavior of ceramic balls. The results of the ceramic ball friction measurements were compared to that of steel balls operating under identical conditions. In addition, a series of experiments was conducted to extend the operating speeds from .01–500 deg/s. Under the conditions tested, the lubrication regimes from boundary to fluid-film were identified.

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Journal articles on the topic 'Torque speed characteristics'

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