Journal articles: 'Bearings (Machinery) Design and construction'

1

Li, Peng, Min Wang, Xiao Li Qi, Jian You Feng, Xiao Hui Liu, Run Qiu Tang, and Wen Ying Zhao. "Analysis of the Mechanical Properties of Slewing Bearings Using Finite Element Method." Applied Mechanics and Materials 224 (November 2012): 286–94. http://dx.doi.org/10.4028/www.scientific.net/amm.224.286.

Full text

Abstract:

Slewing bearings are the basic structural components widely used in construction machinery industry. Their stress status and distribution have great influence on the service life. A finite element approach for a single-row slewing bearing is established based on the bilinear isotropic model. The stress status at different loading conditions is simulated with the bearing geometric and material parameters. The result shows that the numerical simulation is reasonable in comparison with the analytical result obtained by Hertz’s theory and provides reliable design guideline for slewing bearings.

APA, Harvard, Vancouver, ISO, and other styles

2

Amrhein, W., S. Silber, K. Nenninger, G. Trauner, and R. Schöb. "Mechatronical Design Studies on Small Brushless Motors." International Journal of Rotating Machinery 9, no. 2 (2003): 127–33. http://dx.doi.org/10.1155/s1023621x03000113.

Full text

Abstract:

Brushless DC- and AC-permanent-magnet motors controlled by powerful micro-controller electronics have opened up a significant share of the small motor market in the last years. Based on the mechanical low cost construction of single-phase motor the paper presents electronic drive concepts to improve the performance and for special applications also the lifetime of brushless motors. The tangential and radial forces acting on the rotor are controlled by special phase current curves to reduce the torque ripple and to avoid expendable machinery parts like ball or sliding bearings.

APA, Harvard, Vancouver, ISO, and other styles

3

Gunter, Edgar J., and Brian K. Weaver. "Kaybob Revisited: What We Have Learned about Compressor Stability from Self-Excited Whirling." Advances in Acoustics and Vibration 2016 (December 20, 2016): 1–17. http://dx.doi.org/10.1155/2016/7368787.

Full text

Abstract:

The Kaybob compressor failure of 1971 was an excellent historic example of rotordynamic instability and the design factors that affect this phenomenon. In the case of Kaybob, the use of poorly designed bearings produced unstable whirling in both the low and high pressure compressors. This required over five months of vibration troubleshooting and redesign along with over 100 million modern U.S. dollars in total costs and lost revenue. In this paper, the history of the Kaybob compressor failure is discussed in detail including a discussion of the ineffective bearing designs that were considered. Modern bearing and rotordynamic analysis tools are then employed to study both designs that were considered along with new designs for the bearings that could have ultimately restored stability to the machine. These designs include four-pad, load-between-pad bearings and squeeze film dampers with a central groove. Simple relationships based on the physics of the system are also used to show how the bearings could be tuned to produce optimum bearing stiffness and damping of the rotor vibration, producing insights which can inform the designers as they perform more comprehensive analyses of these systems.

APA, Harvard, Vancouver, ISO, and other styles

4

ŻOCHOWSKI, Tomasz, and Artur OLSZEWSKI. "ANALYSIS OF BEARING CLEARANCE AND WIDTH OF AN OIL GROOVE ON THE CHARACTERISTIC OF FLUID FILM IN HYDRODYNAMIC MAIN CRANKSHAFT BEARINGS." Tribologia 281, no. 5 (November 1, 2018): 159–67. http://dx.doi.org/10.5604/01.3001.0012.7669.

Full text

Abstract:

Paper represents an analysis of the influence of oil groove width and bearing clearance on the characteristics of oil film in a hydrodynamic journal main crankshaft bearing. Analysis was performed to define the influence of bearing clearance and dimensions of oil grooves on static characteristics and manufacturability of half-shelf bearings in industrial high-volume production. Computer simulations were made using an ARTbear program, which was developed in Department of Machine Construction and Vehicle Design in Gdańsk Technical University. The analysis allowed defining the correlation between groove geometry and load capacity and working conditions of bearings. Potential opportunities of possible shortening of production time in high-volume production were also indicated.

APA, Harvard, Vancouver, ISO, and other styles

5

Jurecki, Rafał, Edward Pokropiński, Dariusz Więckowski, and Łukasz Żołądek. "Design of a Test Rig for the Examination of Mechanical Properties of Rolling Bearings." Management Systems in Production Engineering 25, no. 1 (March 1, 2017): 22–28. http://dx.doi.org/10.1515/mspe-2017-0003.

Full text

Abstract:

AbstractThe paper presents a design basis adopted for the construction of a test facility for the rig testing of rolling bearings. One of the methods of inspection of the bearings is the testing of the bearings as components having already been mounted in a specific machine component unit and tested in the conditions of operation of the unit as a whole. This article presents preliminary engineering requirements and the design of a special test rig for the examination of rolling bearings without the necessity of mounting the bearings in a specific machine component unit. The rig testing is widely used in consideration of numerous good points of such a method. The simulation testing of bearings (on test rigs) consists in reproducing as accurately as possible the real conditions of operation of the bearings when mounted in the device for which they are intended. The rigs used for such tests are complicated and expensive, but the results of such tests are more “reliable” and more accurately represent the impact of various operational factors (loads) on the durability of the bearings under test.

APA, Harvard, Vancouver, ISO, and other styles

6

Murthy, T. S. R. "Construction and design of self adjusting hydrodynamic bearings for precision machine tool spindles." International Journal of Machine Tool Design and Research 26, no. 2 (January 1986): 179–89. http://dx.doi.org/10.1016/0020-7357(86)90218-0.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Wang, Cheng-Chi, Rong-Mao Lee, Chih-Jer Lin, Chih-Yung Huang, and Tsui-Er Lee. "Research on the nonlinear dynamic characteristics of opposed high-speed gas bearing systems." Journal of Low Frequency Noise, Vibration and Active Control 39, no. 3 (March 7, 2019): 502–22. http://dx.doi.org/10.1177/1461348419834758.

Full text

Abstract:

In recent years, the opposed high-speed gas bearing system has been gradually valued and used in the field of precision machinery, especially for precision instruments and mechanisms requiring high speed, high precision, and high rigidity. Although the bearing capacity is not as good as the oil film bearings, it can provide a working environment where the rotor can generate high speed and low heat without deformation of the shaft, and the gas pressure distribution of clearance in bearing also has better stability. Due to the strong nonlinearity of the gas film pressure function of gas bearings and the fact that the actual shaft system possesses dynamic problems including critical speed, spindle imbalance or improper bearing design, it will cause the rotation process of the shaft to produce a nonperiodic motion and instability, and even chaotic motion under certain parameters. And these irregular movements can even cause machine damage or process delays when serious, so in order to understand the process of working under the conditions where the system will have a nonperiodic phenomenon and to avoid the occurrence of irregular vibration especially chaos. In this paper, the opposed high-speed gas bearing system feature will be discussed in detail with three different numerical analysis methods, i.e. the finite difference method, perturbation method, and mixing method. The relevant theories include dynamic trajectories, spectrum analysis, bifurcation diagram, Poincare map, and the maximum Lyapunov exponents. From the results of nonlinear dynamic behavior of the rotor center, periodic and nonperiodic motions occur at different rotor masses and bearing parameters, respectively. Especially, for the chaos of shaft exists at specific intervals and can be distinguished efficiently. Meanwhile, it is found to ensure that the bearing system can suppress the phenomena of chaos actively by adjusting the bearing parameters, and reduce the system loss caused by irregular vibration. It is expected to be an important basis for designing a precision shaft or mechanism and to enhance the stability and performance of bearing system.

APA, Harvard, Vancouver, ISO, and other styles

8

Boral, Piotr. "The design of the CNC milling machine." MATEC Web of Conferences 254 (2019): 01003. http://dx.doi.org/10.1051/matecconf/201925401003.

Full text

Abstract:

CNC machine tools are currently predominating in the machine-building industry. Generally, these machine tools are equipped with control systems supplied by the world's leading manufacturers, such as Siemens, Fanuc or HeidenHein, and are very expensive. In parallel, many cheap amateur and semi-professional CNC machine tool solutions are being developed. Below, a CNC milling machine of welded construction is described, which is intended to be, at the same time, a test stand. The design of the milling machine is based on steel closed sections of a large cross-section and a big wall thickness. This has allowed a rigid frame structure to be obtained. To obtain high displacement accuracy, high-accuracy profiled rail slideways have been used, along which pre-stressed linear ball bearings move. The machine tool has been furnished with a fourth numerically controlled axis, which is demountable.

APA, Harvard, Vancouver, ISO, and other styles

9

D. Holt, Gary, and David J. Edwards. "Machinery transportation management: case study of “plant-trailer” H&S incidents." Built Environment Project and Asset Management 4, no. 3 (July 7, 2014): 264–80. http://dx.doi.org/10.1108/bepam-01-2014-0001.

Full text

Abstract:

Purpose – The purpose of this paper is to investigate causal agents of health and safety (H&S) incidents among “plant-trailers” (as used by construction and utility contractors to transport mechanical machinery); including the relationship(s) of such incidents to routine safety inspections and, plant maintenance functions. Design/methodology/approach – H&S plant-trailer incident data, from a collaborating UK-based case study utility company are analysed using inductive, interpretative and descriptive statistical methods. Findings – Principal incident occurrences relate to trailer wheels, wheel bearings, tyres and braking systems. All forms of incidents observed harbour significant risk and especially, if they occur during travel on public highways. Derived recommendations for incident mitigation and control, suggest a requirement for improved human behaviour, machinery inspection regimes and maintenance systems. Research limitations/implications – The findings will be valuable to academia as a basis for advancing this new research subject, both empirically and internationally. Direction is offered in this respect. Practical implications – Recommendations will be of practical relevance to machinery management practitioners generally and to plant-trailer stakeholders more specifically. For the latter, the study encourages introspective consideration of plant-trailer H&S systems. Originality/value – No previous research has targeted these issues relating to plant-trailers.

APA, Harvard, Vancouver, ISO, and other styles

10

Gutzwiller, Les, and Mark A. Corbo. "Vibration and Stability of 3000-hp, Titanium Chemical Process Blower." International Journal of Rotating Machinery 9, no. 3 (2003): 197–217. http://dx.doi.org/10.1155/s1023621x03000186.

Full text

Abstract:

This 74-in-diameter blower had an overhung rotor design of titanium construction, operating at 50 pounds per square inch gauge in a critical chemical plant process. The shaft was supported by oil-film bearings and was directdriven by a 3000-hp electric motor through a metal disk type of coupling. The operating speed was 1780 rpm. The blower shaft and motor shaft motion was monitored by Bently Nevada proximity probes and a Model 3100 monitoring system.Although the blowers showed very satisfactory vibration levels during test runs at the manufacturer's plant, the vibration levels in situ had always been higher than was desirable. After several months of monitoring showed ever increasing vibration levels, one of the blowers was shut down in order to diagnose and resolve the problem.Several steps were taken to diagnose the problem: (1) The rotor was removed and the shop balance was checked and corrected. (2) The bearing support movement due to thermal expansion was measured. Then the shafts were misaligned in the cold condition in order to achieve near-perfect shaft alignment during normal operation. (3) The expected shaft vibration at the bearings was determined using lateral rotor dynamics analysis, including critical speed mapping. (4) A heavy sleeve was added to the blower shaft to increase the radial load on the drive-end bearing. (5) The metal disk type of coupling was replaced by a gear coupling. (6) The finite element and impact of the bearing support pedestal were tested to determine the stiffness of the bearing support. (7) The shaft movement was measured during a coast-down. (8)Tilting-pad bearings were evaluated as a possible replacement for the original standard sleeve type of hydrodynamic oil-film bearings.The final solution showed the importance of coupling angular stiffness (often rarely considered in machine design), rotor dynamic analysis, and field alignment.

APA, Harvard, Vancouver, ISO, and other styles

11

Gürbüz, Riza. "Mechatronics Approach for Desk-Top CNC Milling Machine Design." Solid State Phenomena 144 (September 2008): 175–80. http://dx.doi.org/10.4028/www.scientific.net/ssp.144.175.

Full text

Abstract:

The marriage of computer, electronic technology and traditional machining disciplines has given birth to revolutionary new disciplines, Mechatronics. Therefore Mechatronics requires mechanical, electronic and computer knowledge together. The main aim of this article is to present the mechatronics approach for desk-top CNC milling machine design. Construction of computer controlled (CNC) Machine differs greatly from that of conventional machine tools. This difference arises from the requirement of higher performance levels. Machine Structure, guide ways, feed drives, spindle and spindle bearings, measuring systems, machine control unit, software and operator interface, gauging and tool monitoring should be considered as mechatronics approach. Servo motors, motor drivers and motor control unit were used in this CNC milling machine to make it flexible and easy programming. Ball screws were used to X-Y –Z axes to eliminate backlash of the slides. Non-contact home and Limit switches were used to prevent possible damages against over travels. Necessary torque and power have been calculated to select the motors by taking care of the load, ball screws, motor inertia and required cutting tools and etc. and developed CNC milling machine has been tested several times for reliable machining of machine parts.

APA, Harvard, Vancouver, ISO, and other styles

12

Chao, Paul C. P., Chi-Wei Chiu, J. S. Huang, and Chien-Ming Chen. "Design and construction of an in situ inspection machine for ensuring the dynamic performance of fluid bearings in data storage devices." Microsystem Technologies 15, no. 10-11 (February 21, 2009): 1547–56. http://dx.doi.org/10.1007/s00542-009-0803-8.

Full text

APA, Harvard, Vancouver, ISO, and other styles

13

Kurniawan, Dicky, Safril Safril, and Bukhari Bukhari. "RANCANG BANGUN MESIN PUNTIR UNTUK PEMBUAT BESI TERALIS MODEL SPIRAL SPESIFIKASI BESI KOTAK 10X10X1000 mm." Jurnal Teknik Mesin 11, no. 1 (July 11, 2019): 16–21. http://dx.doi.org/10.30630/jtm.11.1.174.

Full text

Abstract:

Today the need for housing (home) is increasing. Touch of beauty and support in terms of security are widely used in the construction of the house, one of the trellis. One of the production processes in processing iron trellis is the process of forming spiral iron trellis models of a certain size, in the process special machines are needed that can alleviate, simplify, and accelerate human work. This process is also called cold work because without the heat treatment process. The specifications of the trellis iron torsion machine are 1500x500x800 mm. This machine has several driving units, namely: Motor as a driver, and reducer to reduce the rotation of the shaft on the swivel chuck, and use belt transmission and chains. From the calculation and design of the engine, the motor power of ½ Hp is obtained, the production capacity is 10x10x1000 mm, the shaft diameter is 25.4 mm. The production time of this machine is 7 times / workpiece or ± 2 minutes / Pcs or 29 to 30 Pcs / hour. This trellis iron torsion machine works well and gets a better and stronger spiral model iron box. The components contained in this machine include: Electric motors, pulleys, belts, frames, sprocket, chains, chucks, bearings and speed reducers.

APA, Harvard, Vancouver, ISO, and other styles

14

LAGUNOVA, Yuliya Andreevna, Stanislav Anatol’evich MAYOROV, and Gennadiy Alexeevich BOYARSKIH. "Statistical analysis of stress-strain state of bearing jaw crusher." NEWS of the Ural State Mining University 1, no. 2 (June 15, 2020): 159–71. http://dx.doi.org/10.21440/2307-2091-2020-2-159-171.

Full text

Abstract:

The relevance of the work. When creating particularly large machines and systems, in the case of their 3D modeling and detailed study, the load on the central processor of the computer, as well as on the graphic and RAM modules, increases, which significantly slows down the design process and calculations. In the article, a statistical analysis of the stress-strain state of the jaw crusher bearing is carried out to establish the correspondence of the theoretical and actual structural models taking into account all workloads. The objectives of the study. Consider the task of selecting a simpler and “easier” for the calculation model programs, not difficult to parameterize, compared with the original bearing model, but providing accuracy in the calculation in an acceptable range of errors. To analyze the stress-strain state of the bearing assembly with various geometric parameters. Research methodology. In the calculations, the finite element method was used. Used specialized software package APM WinMachine. A computational experiment was conducted. A correlation analysis of the theoretical and actual structural model of the bearing is carried out. Results. Mathematical models of the metal structures of bearings of various sections are given and the locations of the highest stresses are identified. Calculation errors and correlation dependencies of stresses are established taking into account the Pearson, Fisher criteria and the construction of the Taylor series. Conclusions. The results of a computational experiment satisfy the requirements and can be used to solve further problems of designing bearing assemblies. In the future, a parameter-dependent model can be created that makes it easier to calculate using any type of bearing

APA, Harvard, Vancouver, ISO, and other styles

15

Anishсhenko, O., V. Kukhar, A. Pryisyazhnyi, and I. Takhtamysh. "Analysis of roller designs for sintering and firing machines." Problems of tribology 97, no. 3 (September 28, 2020): 32–38. http://dx.doi.org/10.31891/2079-1372-2020-97-3-32-38.

Full text

Abstract:

The article analyzes the known constructions of roller units of carts for the manufacture of agglomerate and pellets on conveyor lines. The article points out the advantages and disadvantages of roller designs, the lack of standard technical solutions for the design of roller assemblies, as well as reliable methods for calculating their parts for strength and durability. To increase the life of the rollers, the authors, after successful industrial tests, offer innovative technical solutions: seals in the form of stuffing boxes made of expanded graphite fibers reinforced with steel thread; bearing antifriction filler made from polytetrafluoroethylene, carbon fiber and graphite. The article shows that due to axial loads during the operation of the bogies, it is impractical to use ball bearings in the ball, they should be replaced with roller bearings. The authors propose an approximate method for calculating the durability of bearings, which additionally takes into account the elastic deformation of the material of the bogies during their thermal expansion and the gaps in the nodes of the bogies. The authors use the calculation of experimental results on the size of the gaps in the nodes of the bogies, the curvature of the body of the heated bogies on the conveyor line and their movement on three rollers instead of four, take into account the change in the coefficient of linear expansion of the material of the bogie depending on the increase in the heating temperature of the case.

APA, Harvard, Vancouver, ISO, and other styles

16

Paden, Brad, Nelson Groom, and James F. Antaki. "Design Formulas for Permanent-Magnet Bearings." Journal of Mechanical Design 125, no. 4 (December 1, 2003): 734–38. http://dx.doi.org/10.1115/1.1625402.

Full text

Abstract:

As the energy densities in permanent magnet materials increases, permanent magnet (PM) bearings are becoming increasingly attractive machine elements for applications ranging from turbo machinery to energy storage flywheels. Desirable qualities include high speed, low wear, energy savings, and freedom from lubricants that can degrade or contaminate other system components. In this paper we develop analytical expressions for stiffness and peak load in stacked-structure radial magnetic bearings that extend the seminal work of Backers, and Yonnet and co-workers. In addition to the derivation of simple design rules, the axial peak force and negative axial stiffness are calculated.

APA, Harvard, Vancouver, ISO, and other styles

17

Rajczyk, Jarosław. "Rate of Regeneration of Construction Machinery." Applied Mechanics and Materials 405-408 (September 2013): 3235–38. http://dx.doi.org/10.4028/www.scientific.net/amm.405-408.3235.

Full text

Abstract:

All kinds of products can be conditionally divided into two types, ie. those that can be regenerated and those without the possibility of undergoing regeneration. Regeneratives are those products which, in the event of failure are eligible for repair. To this category, almost all types of machines, mechanisms and devices can be assigned to. Products that are not regenerative are those that, which in the event of failure do not qualify for regeneration in a given situation or because of principle. These include gears, springs, bearings and electronic components. Indicators for the reliability of products that can be regenerated differ from those which may be defined for parts or elements that are not to be regenerated. The concept of reliability index is understood as the quantitative characterization or evaluation of one or more of their characteristics or features. The length of work or the volume of work accomplished can be called work done during that time is assessed over time or related to its indicators. Parts, until they become defective, may work 100 hours, 10 cycles, 10000 km, etc. However, in terms of related concepts distinguish between work done to the first failure, the work between defects (for parts which are subject to regeneration). Given that the regenerable and non-regenerable calculation of indicators are different and will be subject to separate consideration.

APA, Harvard, Vancouver, ISO, and other styles

18

Chen, Xi, Ying Sun, and Yi Qi Zhou. "Establishing Brand Image through Product Color Design: Exploring Color Design Principles of Construction Machinery Products." Applied Mechanics and Materials 437 (October 2013): 922–25. http://dx.doi.org/10.4028/www.scientific.net/amm.437.922.

Full text

Abstract:

Product color design is a powerful tool for establishing brand image. This paper analyzed the development status of construction machinery industry, and on the basis of that presented the necessity of establishing brand image through product color design in the construction machinery industry. Then after analyzing the special environment and people-related elements to be considered when designing construction equipment, and combined with successful brand image construction cases, proposed three principles for the product color design of construction machinery products.

APA, Harvard, Vancouver, ISO, and other styles

19

Mildebrath, Maximilian, Hans Jürgen Maier, Thomas Hassel, Timm Coors, Florian Pape, Gerhard Poll, Alexander Barroi, Marius Lammers, Jörg Hermsdorf, and Ludger Overmeyer. "Herstellungsprozess und Wälzfestigkeit von hybriden Hochleistungsbauteilen/Manufacturing of Hybrid High-Performance Components under Rolling Contact Fatigue." Konstruktion 70, no. 09 (2018): 84–89. http://dx.doi.org/10.37544/0720-5953-2018-09-84.

Full text

Abstract:

Inhalt: Moderne Massivbauteile werden herkömmlich aus Monomaterialien gefertigt. Viele Bauteile besitzen dabei Funktions- und Strukturbereiche, welche durch unterschiedliche Beanspruchungsprofile sehr unterschiedliche Anforderungen an den Konstruktionswerkstoff stellen. Somit ermöglicht das eingesetzte Material oft nur einen Kompromiss hinsichtlich der geforderten Materialeigenschaften und der Leistungsfähigkeit des Bauteils. Im Sonderforschungsbereich 1153 „Tailored Forming“ an der Leibniz Universität Hannover (LUH) werden neue Prozessketten zur Realisierung hoch belastbarer hybrider Massivbauteile entwickelt. In Zusammenarbeit des Instituts für Werkstoffkunde (IW) und des Instituts für Maschinenkonstruktion und Tribologie (IMKT) wurden hybride Lagerscheiben zum Einsatz als Axial-Zylinderrollenlagern entwickelt. Diese wurden mittels Plasma-Pulver-Auftragschweißen (PPA) aus Vergütungsstahl hergestellt (Bild 1) und anschließend bezüglich Ihrer Wälzfestigkeit untersucht. Diese Untersuchungen dienen als Grundlage zur Evaluierung von Leistungsfähigkeit und Qualität des Beschichtungsprozesses sowie der Materialeigenschaften. Mit ersten hybrid hergestellten Rohlingen werden Maschinenelemente gefertigt, um die Eignung des Prozesses für industrielle Anwendungen zu bewerten.   Abstract: Modern solid components are conventionally manufactured from monomaterials. Many components are equipped with functional and structural areas, which have to fulfil various demands regarding the construction material due to different stress profiles. Thus, the applied material offers a trade-off concerning the required material properties and the performance of the component. The Collaborative Research Center 1153 „Tailored Forming“ at Leibniz Universität Hannover (LUH) is developing new process chains for the realization of highly resilient hybrid solid components. In cooperation with the Institute of Materials Science (IW) and the Institute of Machine Design and Tribology (IMKT), multi-material bearing discs were developed for use as cylindrical roller thrust bearings. These were produced by plasma powder deposition welding (PPA) from heat treatable steel (Figure 1) on a steel substrate and then tested under rolling contact loads. These investigations serve as a basis for evaluating the performance and quality of the coating process as well as the material properties. In this publication, the above concept was proven for first hybrid produced workpieces in order to assess the suitability of the process for industrial applications.

APA, Harvard, Vancouver, ISO, and other styles

20

Salikhov, R. F., V. V. Akimov, A. F. Mishurov, and G. N. Musagitova. "TECHNOLOGY IMPROVEMENT OF PLAIN BEARINGS’ TECHNICAL CONTROL IN CONSTRUCTION MACHINERY AND EQUIPMENT." Russian Automobile and Highway Industry Journal 15, no. 6 (January 11, 2019): 854–65. http://dx.doi.org/10.26518/2071-7296-2018-6-854-865.

Full text

Abstract:

Introduction. The creation of new machinery and development of modern technologies of its repair in many respects with generation of materials with required properties are defined. Special attention is paid to the economy and widespread introduction of resource-saving and environmentally friendly technologies and to the problems of obtaining and exploitation of new materials, improvement of the goods’ quality.The quality control of materials, which have been used for plain bearings manufacture, during repair action of construction machinery and equipment, as well as reduction of cost and duration of technical control operations implementation are among the issues for repair service organizations. Their solution would enable to increase post-repair resource, cut down failures number, and reduce costs of faults removal in warranty period.Materials and methods. The authors suggest a thermal method of plain bearings materials quality assessment in internal combustion engines. This method is remarkable for its comparative simplicity; it does not require destruction of the material and application of expensive equipment.Results. The dependences of “Cummins” and “Mahle” bushings thickness change on the heating temperature as well as samples warming temperature dependence on test duration have been obtained. According to the derived results such parameters as specific heat and thermal conductivity coefficient are defined. The results of carried out tests show that thermal physic parameters of unoriginal bushings differ from original ones by 11% in thermal conductivity coefficient and by 1.56 times in specific heat.Discussion and conclusions. The calculation of specific heat, thermal conductivity of plain bearings allows to determine the probability of their failure at the stage of entrance control and therefore, to make a more correct decision when choosing parts for execution high-quality repair. As a consequence of temperature change comparison, when bushings samples of “Cummins” and “Mahle” companies are heated, it could be concluded that heating intensity of an original bushing is 17% higher and the reciprocal of bushing temperature gradient under warming is 1.27 times lower in comparison with an unoriginal plain bearing.

APA, Harvard, Vancouver, ISO, and other styles

21

Zhou, Yan. "Appearence Design of Construction Machinery Based on Perspective of Industrial Design." Applied Mechanics and Materials 416-417 (September 2013): 1861–65. http://dx.doi.org/10.4028/www.scientific.net/amm.416-417.1861.

Full text

Abstract:

This paper combined with their actual project experience and industrial design point of view, based on the role of construction machinery design, working methods, evaluation methods, the authors put forward three ideas and opinions, and thus to provide some ideas and information for china's construction machinery enterprises in the development of industrial design.

APA, Harvard, Vancouver, ISO, and other styles

22

Kirk, R. G. "Evaluation of AMB Turbomachinery Auxiliary Bearings." Journal of Vibration and Acoustics 121, no. 2 (April 1, 1999): 156–61. http://dx.doi.org/10.1115/1.2893958.

Full text

Abstract:

The use of active magnetic bearings (AMB) for turbomachinery has experienced substantial growth during the past two decades. The advantages for many applications make AMB’s a very attractive solution for potentially low loss and efficient support for both radial and thrust loads. New machinery must be shop tested prior to shipment to the field for installation on-line. For AMB turbomachinery, one additional test is the operation of the auxiliary drop or overload bearings. A major concern is ability of the selected auxiliary bearing to withstand the contact forces following an at speed rotor drop. The proper design of AMB machinery requires the calculation of the anticipated loading for the auxiliary bearings. Analytical techniques to predict the rotor transient response are reviewed. Results of transient response evaluation of a full-size compressor rotor are presented to illustrate some of the important parameters in the design for rotor drop.

APA, Harvard, Vancouver, ISO, and other styles

23

Shen, Yue Guo, Liang Liang Dai, Nai Yan Zhang, and Guo Wei Wei. "Camouflage Coatings Design and Optimization of Construction Machinery." Advanced Materials Research 139-141 (October 2010): 472–76. http://dx.doi.org/10.4028/www.scientific.net/amr.139-141.472.

Full text

Abstract:

Camouflage coatings method and its features are described. Concrete way of camouflage for construction machinery is presented. Aiming at the actual situation and in association with practical experiences, concrete methods to design and optimize camouflage for construction machinery are suggested.

APA, Harvard, Vancouver, ISO, and other styles

24

Hou, Yu, Qi Zhao, Yu Guo, Xionghao Ren, Tianwei Lai, and Shuangtao Chen. "Application of Gas Foil Bearings in China." Applied Sciences 11, no. 13 (July 5, 2021): 6210. http://dx.doi.org/10.3390/app11136210.

Full text

Abstract:

Gas foil bearing has been widely used in high-speed turbo machinery due to its oil-free, wide temperature range, low cost, high adaptability, high stability and environmental friendliness. In this paper, state-of-the-art investigations of gas foil bearings are reviewed, mainly on the development of the high-speed turbo machinery in China. After decades of development, progress has been achieved in the field of gas foil bearing in China. Small-scale applications of gas foil bearing have been realized in a variety of high-speed turbo machinery. The prospects and markets of high-speed turbo machinery are very broad. Various high-speed turbomachines with gas foil bearings have been developed. Due to the different application occasions, higher reliability requirements are imposed on the foil bearing technology. Therefore, its design principle, theory, and manufacturing technology should be adaptive to new application occasions before mass production. Thus, there are still a number of inherent challenges that must be addressed, for example, thermal management, rotor-dynamic stability and wear-resistant coatings.

APA, Harvard, Vancouver, ISO, and other styles

25

Goodwin, M. J., J. L. Nikolajsen, and P. J. Ogrodnik. "Reciprocating machinery bearing analysis: Theory and practice." Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology 217, no. 6 (June 1, 2003): 409–26. http://dx.doi.org/10.1243/135065003322620246.

Full text

Abstract:

The aim of this paper is to review theoretical and experimental work undertaken on the design and performance assessment of bearings in reciprocating machinery. The review details the most recent developments in theoretical approaches to design and also describes the practical work that has been undertaken to validate theoretical models. The limitations of both areas of work are identified.

APA, Harvard, Vancouver, ISO, and other styles

26

Liu, Wei, Jianhua Wei, Jinhui Fang, and Shizhen Li. "Hydraulic-feedback proportional valve design for construction machinery." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 229, no. 17 (February 5, 2015): 3162–78. http://dx.doi.org/10.1177/0954406214568822.

Full text

Abstract:

Due to the increasing demand for large-tonnage construction machinery, the manufacturers call for a reliable and inexpensive proportional control valve with large flow capacity. In this work, a novel throttle poppet valve based on hydraulic-feedback principle has been studied comprehensively and optimized to meet the requirements of the construction machinery. A detailed and precise mathematical model has been developed and validated through experiments. According to the model, basic status of the valve under different working conditions has been analyzed, and the impacts of the parameters on the performances of response speed and the pressure stiffness have been studied through the root locus method. To find the optimal parameters suitable for construction machinery, an optimization based on non-dominated sorting genetic algorithm II was carried out, and the performances have been significantly improved. Finally, by adopting the analysis on the parameters and the optimization results, guidelines for designing the hydraulic-feedback proportional valve in various sizes are presented.

APA, Harvard, Vancouver, ISO, and other styles

27

Burrows, C. R., P. S. Keogh, and M. N. Sahinkaya. "Progress towards smart rotating machinery through the use of active bearings." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 223, no. 12 (April 16, 2009): 2849–59. http://dx.doi.org/10.1243/09544062jmes1487.

Full text

Abstract:

The design of a smart rotating machine involves the integration of controllable bearings, actuators, and sensors to measure a defined set of physical variables, an on-line adaptive controller, a control algorithm to achieve the desired performance, and an algorithm to re-configure the system in the event of faults. This review discusses each of these issues, and highlights the progress that has been made. The key role played by active magnetic bearings in the evolution of smart or self-adaptive machine design is described.

APA, Harvard, Vancouver, ISO, and other styles

28

Qian, Xue Ming, Lan Duan, and Chen Chen Yi. "Research on Expert System of Bearing Design." Applied Mechanics and Materials 556-562 (May 2014): 1267–70. http://dx.doi.org/10.4028/www.scientific.net/amm.556-562.1267.

Full text

Abstract:

In the design of machinery, Calculating and validating of bearings are exertive. Artificial Intelligence is the requirement of future design. This paper proposes a bearing expert system based on multiple reasoning, which highly improves the efficiency and quality of bearing design. The system and implementing method can be farther used in intelligent mechanical design.

APA, Harvard, Vancouver, ISO, and other styles

29

Schweitzer, G. "Safety and Reliability Aspects for Active Magnetic Bearing Applications - A Survey." Proceedings of the Institution of Mechanical Engineers, Part I: Journal of Systems and Control Engineering 219, no. 6 (September 1, 2005): 383–92. http://dx.doi.org/10.1243/095965105x33491.

Full text

Abstract:

The application of magnetic bearings for rotating machinery has become state of the art and spans from research prototypes to industrial series. Users are aware that beyond functionality the aspects of safety and related areas become increasingly important. This survey addresses the issues of safety and reliability, being a part of dependability. It gives a review on existing approaches, and it shows numerous examples of problems and solutions. Review topics are safety-oriented design methods, software tools, redundancy, robust control, and retainer bearings. Finally, the concept of smart machines is introduced as a way for further improving safety and dependability of machinery with active magnetic bearings.

APA, Harvard, Vancouver, ISO, and other styles

30

Srinivasan, S., E. H. Maslen, and L. E. Barrett. "Optimization of Bearing Locations for Rotor Systems With Magnetic Bearings." Journal of Engineering for Gas Turbines and Power 119, no. 2 (April 1, 1997): 464–68. http://dx.doi.org/10.1115/1.2815597.

Full text

Abstract:

This paper presents a method for quickly evaluating the effect of changes in bearing location on bearing design for stability of rotating machinery. This method is intended for use by rotating machinery designers to select the “best” bearing locations prior to the bearing design process. The purpose of the method is to improve the design process by separating the problem of determining the “best” bearing locations from that of determining the actual bearing design. The method is independent of the type of bearing employed. For each candidate bearing configuration, the method provides a scalar measure of the relative ability of bearings to meet stability specifications. Within certain limits, the stability specifications are defined by the designer. The scalar measure is used to rank the candidate bearing locations and thereby select the best one. The scalar measure is compared to a practical measure of magnetic bearing design such as the infinity norm of the controller for an example design of a multistage centrifugal compressor.

APA, Harvard, Vancouver, ISO, and other styles

31

Wang, Zhong Heng, and Jian Gong Zhu. "Design of New Hydraulic Lifts for Construction Machinery Assembly." Advanced Materials Research 189-193 (February 2011): 2172–76. http://dx.doi.org/10.4028/www.scientific.net/amr.189-193.2172.

Full text

Abstract:

In this paper, according to the domestic construction machinery market，bulldozers，the representative machinery assembling with hydraulic lifts make mechanical, electrical, hydraulic innovative design. AMESim software will use for its modeling and simulation. AMESim simulation results show that the new design of the hydraulic lift is more stability and synchronization than the traditional one.

APA, Harvard, Vancouver, ISO, and other styles

32

Shutin, Denis, Leonid Savin, and Alexander Babin. "A Review on Active Bearings and Perspectives of Using Them in Rotating Machinery." Applied Mechanics and Materials 630 (September 2014): 181–87. http://dx.doi.org/10.4028/www.scientific.net/amm.630.181.

Full text

Abstract:

The paper examines the issues of improving the rotor units by means of using support units with actively changeable characteristics. An overview of the known solutions related to the use of active bearings in various types of turbomachinery is provided. A closer look is given at the design and features of active radial bearings, the main elements of which are fluid film bearings. The results of mathematical modeling of active hybrid bearings are presented. The prospects of the use of this type of supports to improve the dynamic characteristics of rotating machinery, including reducing vibrations caused by various factors, are analyzed. Promising directions of development of active bearings are considered, which primarily involves the modification of system components and rotor motion control system algorithms, including intelligent technologies and artificial intelligence methods.

APA, Harvard, Vancouver, ISO, and other styles

33

Tian, Qiaoping, and Honglei Wang. "An Ensemble Learning and RUL Prediction Method Based on Bearings Degradation Indicator Construction." Applied Sciences 10, no. 1 (January 2, 2020): 346. http://dx.doi.org/10.3390/app10010346.

Full text

Abstract:

The prediction of the remaining life of a bearing plays a vital role in reducing the accident-related maintenance costs of machinery and in improving the reliability of machinery and equipment. To predict bearing remaining useful life (RUL), the abilities of statistical characteristics to reflect the bearing degradation state differ, and the single prediction model has low generalization ability and a poor prediction effect. An ensemble robust prediction method is proposed here to predict bearing RUL based on the construction of a bearing degradation indicator set: the initial bearing degradation indicator subsets were constructed using the Fast Correlation-Based Filter with Approximate Markov Blankets (FCBF-AMB) and Maximal Information Coefficient (MIC) selection methods. Through the cross-operation of the obtained subsets, we obtained a set of robust degradation indicators. These selected degradation indicators were fed into the long short-term memory (LSTM) neural network prediction model enhanced by the AdaBoost algorithm. We found through calculation that the average prediction accuracy of the proposed method is 91.40%, 92.04%, and 93.25% at 2100, 2250, and 2400 rpm, respectively. Compared with other methods, the proposed method improves the prediction accuracy by 1.8% to 14.87% at most. Therefore, the method proposed in this paper is more accurate than the other methods in terms of RUL prediction.

APA, Harvard, Vancouver, ISO, and other styles

34

Yang, J. R. "The Research of Design Method on Green Modular that Oriented Construction Machinery." Advanced Materials Research 1049-1050 (October 2014): 828–32. http://dx.doi.org/10.4028/www.scientific.net/amr.1049-1050.828.

Full text

Abstract:

The aim of this study was to obtain the method of the green design and modular design that oriented construction machinery products. A variety of modern design tools such as the finite element analysis software package and optimize design package and a two-factor evaluation fuzzy modelare used to analyze and Evaluation the green degree and the module degree of the construction machinery. Some modern mathematical tools such as AHP and fuzzy comprehensive evaluation method are used to calculate and evaluate the green degree and the module degree in construction machinery design. The proposed design method can meet the requirements of the green degree and the module degree of the construction machinery.

APA, Harvard, Vancouver, ISO, and other styles

35

Shevchenko, S. V., and O. S. Krol. "CONSTRUCTION MODIFICATION OF RADIAL THRUST ROLLER BEARINGS." Globus: technical sciences 7, no. 1(37) (February 19, 2021): 4–8. http://dx.doi.org/10.52013/2713-3079-37-1-1.

Full text

Abstract:

Analytical relationships have been developed for the design of modified tapered roller bearings based on standard bearings of the 7000 type. The modification consists in replacing the rolling elements in the form of tapered rollers with a straight generatrix by concave rollers with an arc generatrix, which are in contact with the convex raceways of the rings. By calculation, the advantage of modified roller bearings in terms of service life in comparison with standard roller bearings of similar overall dimensions is shown.

APA, Harvard, Vancouver, ISO, and other styles

36

Bluff, Elizabeth. "Safety in machinery design and construction: Knowledge and performance." Safety Science 74 (April 2015): 59–69. http://dx.doi.org/10.1016/j.ssci.2014.10.011.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

Nakada, Kuniaki. "Kansei engineering research on the design of construction machinery." International Journal of Industrial Ergonomics 19, no. 2 (February 1997): 129–46. http://dx.doi.org/10.1016/s0169-8141(96)00009-1.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Gosiewski, Zdzisław, and Arkadiusz Mystkowski. "The Robust Control of Magnetic Bearings for Rotating Machinery." Solid State Phenomena 113 (June 2006): 125–30. http://dx.doi.org/10.4028/www.scientific.net/ssp.113.125.

Full text

Abstract:

The fast progress in the applications of active magnetic suspension systems needs to apply the modern control theory. This paper deals with H∞ and H2 control of rigid rotor movement, which is supported in magnetic bearings. The robust control of magnetic bearings is investigated analytically. The nominal model of active magnetic suspension of rotor and the uncertainty model were derived. The standard PID control and robust control are compared and performance of nominal feedback configuration with weights is presented. We propose a robust control with a multi-objective controller to achieve good robust stability when the model of a plant is uncertain. The behavior of multiplicative uncertainty of magnetic suspension system is shown. The aim of optimal robust control is to improve the magnetic suspension taking into account the energy limitation (i.e., to avoid the saturation of actuators). The H2 performance and H∞ performance depend on a proper selection of weighting functions. So a very important step in the controller design process is to choose the appropriate weight functions: We, Wu, Wd. The influence of noise is limited by weight functions. We also put limits on input and output signals. The stability of a system with disturbance interaction is discussed. The simulations of a well-posed and internally stable magnetic system are presented. The success of the robust control is demonstrated through results of numerical simulations.

APA, Harvard, Vancouver, ISO, and other styles

39

Pilyushina, Galina, Pavel Pyrikov, Evgeny Pamfilov, Aleksey Danilyuk, and Vladimir Kapustin. "Improving the Performance of Wood-Metal Slide Bearings for Forestry Machinery." Lesnoy Zhurnal (Forestry Journal), no. 2 (April 4, 2021): 156–68. http://dx.doi.org/10.37482/0536-1036-2021-2-156-168.

Full text

Abstract:

The performance of slide bearings in forestry machines and equipment is largely determined by the load-carrying capacity and antifriction qualities that depend on the bearing capacity of the sleeve (insert) material, the design rigidity and the nature of the forces during operation. As a result, the bearing materials undergo cyclic changes in the state of the sleeve material, as well as the elements that provide reinforcing, heat-conducting and anti-wear functions. The paper shows the results of research on the stress-strain behavior of anisotropic composite materials in the structures of wood-metal slide bearings. A method for ensuring vibration stability is proposed. It is based on maintaining the damping properties of the support that change in the course of wearing. The functionality of the developed program, which is used to solve the contact and thermal issues in the design of slide bearings, is described. A wood-metal material for making bearing sleeves and inserts from laminated compositions was created and studied. The compositions include a vibration-absorbing and fine-fractional component in a vibration-weighted state and a layered structure heterogeneous in thickness of the sleeve, characterized by a variable elastic modulus, that provides damping properties. The proposed design of a slide bearing using this material is focused on its use mainly in the conditions of shock-cyclic loading, which is typical for operation of most forestry machines and equipment.

APA, Harvard, Vancouver, ISO, and other styles

40

Zhou, Ke, and Xiao Dong Li. "Design and Application of a Whole Machine Test Service Platform of Construction Machinery." Advanced Materials Research 694-697 (May 2013): 2400–2403. http://dx.doi.org/10.4028/www.scientific.net/amr.694-697.2400.

Full text

Abstract:

In order to reduce the pressure of test resource in whole machine tests of construction machinery and provide more efficient service of test and analysis, a whole machine test service platform was designed and applied. Firstly whole machine tests of construction machinery were analyzed. Secondly whole machine test service of construction machinery was analyzed. Thirdly the architecture, function structure and database were designed. Then the application steps of the system were discussed. Feasibility and effectiveness of the system were verified by a case of enterprise application.

APA, Harvard, Vancouver, ISO, and other styles

41

Imlach, J., B. J. Blair, and P. E. Allaire. "Measured and Predicted Force and Stiffness Characteristics of Industrial Magnetic Bearings." Journal of Tribology 113, no. 4 (October 1, 1991): 784–88. http://dx.doi.org/10.1115/1.2920693.

Full text

Abstract:

Closed-loop stiffness and load capacity (force) equations have been developed for industrial magnetic bearings. Two sets of magnetic bearings have been constructed using these equations as a design basis. These bearings have been installed in two canned motor pumps. The predicted force and stiffness values from the equations are compared to experimental measurements to determine their validity. When obvious sources of error were eliminated, agreement within 10 percent was obtained for development pump’s magnetic bearings. Agreement was generally better for this pump than for the demonstration pump. By employing these equations, along with easily measured current and displacement information from magnetic bearing equipped machinery, actual stiffness’ and bearing loadings can be determined for operating equipment. Thus, the range of information available from magnetic bearings is extended to include static and dynamic loadings as well as shaft orbits and critical speed and damping information (Humphris et al., 1989). This enhances their use as diagnostic and preventative maintenance tools which are built into machinery and can be used on line.

APA, Harvard, Vancouver, ISO, and other styles

42

Kodnyanko, V. A. "Modeling Movement of Gas-Static Bearings." Mechanical Engineering and Computer Science, no. 1 (March 1, 2019): 13–28. http://dx.doi.org/10.24108/0119.0001450.

Full text

Abstract:

The competitiveness of gas-static sliding bearings, which are assemblies of cutting-edge machines, in particular, precision metal-cutting machines, largely depends on their creation rapidity, which is determined by their mobility of modeling and quality of theoretical study for the later use in designing constructions. The objective is to develop a computer-aided mobile modeling technology for designing the gas-static bearings, which enables quick calculation and study of their static characteristics, quality criteria for their dynamics, and drawing-up recommendations for rapid designing of bearings to ensure performance characteristics and appropriate dynamics quality of designs through automation of procedures, their mathematical modeling, and theoretical study. As a result, there has been developed a technology concept for modeling of gas-static bearings and numerical methods, which allow us to find a solution for exploring tasks with a desirable accuracy. Based on the approximate and proposed numerical methods, the developed modeling technology rapidity was studied, and high comparative efficiency of this technology was found. Practical relevance of technology lies in significant acceleration of modeling processes, calculation and study of static and dynamic characteristics of gas-static bearings that is provided by application of developed methods, algorithms, and modeling technology. There are also reducing the complexity of research processes, and the capability for quick learning of complex bearing structures rapid exploration of which is hard or inconceivable using the traditional “manual” technology.

APA, Harvard, Vancouver, ISO, and other styles

43

Chen, Jie. "Study on an Ontology-Based Design Knowledge Modeling Algorithm." Advanced Materials Research 426 (January 2012): 382–86. http://dx.doi.org/10.4028/www.scientific.net/amr.426.382.

Full text

Abstract:

In this paper, we concentrate on the ontology-Based design knowledge modeling technologies for the construction machinery. For that, we study the ontology modeling theory, the representation of product design knowledge and the ontology modeling of design knowledge, etc. From the design knowledge management’s angle, design knowledge modeling approach is studied to support the design knowledge development, transfer and reuse for the construction machinery.

APA, Harvard, Vancouver, ISO, and other styles

44

Colford, Nick. "Safe design and construction of machinery: regulation, practice and performance." Ergonomics 61, no. 10 (October 3, 2018): 1429–30. http://dx.doi.org/10.1080/00140139.2018.1514990.

Full text

APA, Harvard, Vancouver, ISO, and other styles

45

Gao, Zhu, Xiao Min Ji, and Hun Guo. "An Ontology-Based Design Knowledge Model for the Construction Machinery." Key Engineering Materials 458 (December 2010): 271–76. http://dx.doi.org/10.4028/www.scientific.net/kem.458.271.

Full text

Abstract:

In this paper, we investigated the knowledge modeling and proposed an ontology-based descriptively-logic theory using fuzzy interval in order to support the management and re-usage of the knowledge of design. We also established the methods to classify and present the concept-design knowledge and developed an ontology-based model presenting the knowledge of design as well as a model for modeling cycles. We further applied these methods and models to develop a specific ontology-based design-knowledge model and At last the practicability and validity of these methods are validated in the management system of design knowledge for the construction machinery.

APA, Harvard, Vancouver, ISO, and other styles

46

Panzera, T. H., J. C. Rubio, C. R. Bowen, and P. J. Walker. "Microstructural design of materials for aerostatic bearings." Cement and Concrete Composites 30, no. 7 (August 2008): 649–60. http://dx.doi.org/10.1016/j.cemconcomp.2007.08.013.

Full text

APA, Harvard, Vancouver, ISO, and other styles

47

Zhao, Chang Rong, Xiong Hua Guo, and Xiang Long Zeng. "Research on Engineering Machinery Manufacturing PDM and CAD Integration Solutions." Advanced Materials Research 463-464 (February 2012): 1668–72. http://dx.doi.org/10.4028/www.scientific.net/amr.463-464.1668.

Full text

Abstract:

In the construction machinery manufacture enterprises, the diversified users, individual needs and various products purchasing manners become the market mainstream. Based on the common problems existing in the informatization implementation of current construction machinery manufacture enterprise, this paper focuses on the product design characteristics and production management in construction machinery industry, relies on advanced design and manufacturing technology, modern management technology and information technology, combines with the results and experience of enterprise informatization, analyzes the bottleneck of enterprises and proposes the general plan the construction manufacture enterprise implement information through analyzing the information needs in construction machinery industry and actual situations, also proposes PDM and CAD integration programs according to the situations of PLM software functions and enterprise graphics software.

APA, Harvard, Vancouver, ISO, and other styles

48

Yang, Kezhen, Yefa Hu, Xinhua Guo, Jian Zhou, and Huachun Wu. "Evaluation of Switching Power Amplifier Topology for Active Magnetic Bearings." Actuators 10, no. 6 (June 13, 2021): 131. http://dx.doi.org/10.3390/act10060131.

Full text

Abstract:

Active magnetic bearings (AMBs) have led to great progress in the field of rotating machinery due to their many advantages, such as their non-contact and non-lubrication properties. As the key component of an AMB actuator, the switching power amplifier has an important impact on the performance of magnetic bearings and rotating machinery. In this paper, the topologies of switching power amplifiers for AMBs are introduced. The traditional half-bridge topology and two newly proposed topologies—the three-phase-half-bridge and neutralized-sharing-bridge topology—are analyzed and discussed. The volume, current output performance and cost of the power amplifier with different topologies are comprehensively evaluated, providing a theoretical basis and guidance for the selection and design of the topology of switching power amplifiers for AMBs under different conditions.

APA, Harvard, Vancouver, ISO, and other styles

49

Ravikumar, R. N., K. J. Rathanraj, and V. Arun Kumar. "Experimental Studies on Air Foil Thrust Bearing Load Capabilities Considering the Effect of Foil Configuration." Applied Mechanics and Materials 813-814 (November 2015): 1007–11. http://dx.doi.org/10.4028/www.scientific.net/amm.813-814.1007.

Full text

Abstract:

Abstract. Foil bearings are self-acting hydrodynamics bearings used to support lightly loaded high speed rotating machinery. The advantages that they offer to process fluid lubricated machines usingworking fluid as a lubricant (ambient air) physically non-contacting high speed operation. Foil bearings have been considered as an alternative to conventional bearings with the capacity to cater for high-speeds and hostile environment (high temperature). However, the lack of load carrying capacity at relatively lower speeds limits their applications in heavy turbo machinery and as such are highly suitable in lightly loaded, high speed turbo machinery like small gas turbines.This paper discusses the design and assessment of dynamic characteristics in terms of load carrying capabilities as a function of speed, gap between the bearing and the runner as well as shape of foils for an air foil thrust bearing. The effects of various bearing parameters like foil thickness, number of foils fixed circumferentially and along the axis of rotation and with foil geometry configuration. Characteristics of performance defined essentially in terms of load carrying capabilities and static stiffness have been used for evaluation. Experiments were conducted both for angular foils (with inner edge height less than outer edge height) and square foils by varying number of foils. The experimental results shows that the effect of foil configuration enhances the load carrying capabilities of air foil thrust bearing.

APA, Harvard, Vancouver, ISO, and other styles

50

Kiciński, Jan. "Assessment of Materials and Operational Imperfections in Rotating Machinery." Key Engineering Materials 293-294 (September 2005): 391–400. http://dx.doi.org/10.4028/www.scientific.net/kem.293-294.391.

Full text

Abstract:

Presented have been the methods of modelling of the selected materials and operational imperfections (defects) like rotor cracks and hydrodynamic instability in rotating machines. Despite abundant information on this topic, there are still numerous problems to be solved. This regards primarily to the analysis of characteristic symptoms of such defects in the form of e.g. nonlinear vibrations and coupled forms of lateral, axial and torsional vibrations. The paper presents also author’s opinions concerning the one of the most intriguing operational imperfections, namely the formation of oil whirls and oil whips in slide bearings of a rotating machine. Coupled forms of vibration are generally a result of different kinds of couplings taking place in the system and interactions between construction and material imperfections.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Bearings (Machinery) Design and construction'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles