Pressure-flow analytical formulas of lubrication film of slipper pairs on camshaft connecting rod type low speed high torque （LSHT） hydraulic motors are put forward. The bottom surface of slipper pairs is rectangle,...Pressure-flow analytical formulas of lubrication film of slipper pairs on camshaft connecting rod type low speed high torque （LSHT） hydraulic motors are put forward. The bottom surface of slipper pairs is rectangle, and the effect of squeeze flow and pressure differential flow is considered. The dynamic process of lubrication film formation through squeezing is numerically studied by computer simulation. Effects of supply pressure, initial lubrication film thickness, velocity damping coefficient, loading impact and gravity, etc are studied. Advantages of novel slipper pairs with large oil cavity area are pointed out.展开更多
An induction motor with its speed modulated by frequency features wide transfer speed range, high systematie efficiency, simple structure and long life, and it therefore becomes one of the best driving motors used in ...An induction motor with its speed modulated by frequency features wide transfer speed range, high systematie efficiency, simple structure and long life, and it therefore becomes one of the best driving motors used in electrical vehicles. The present research trend of it is high power, high speed, high efficiency and long life. How to meet the above requirements by using the electromagnetic design, structure design and beat design, becomes a matter that needs to be resolved now. In this paper, the characters of the motor in operation are analyzed, all kinds of factors that relate to life are laid out, its heating and loss are discussed and analyzed. The key reasons affecting the motor life are presented, and different characters of a high induction motor are compared with these of a general induction motor. A design idea is described, that is : we should consider how to improve the efficiency and reliability as well as bow to reduce the heating by changing the electromagnet, structure, dissipation and operation of the motor. How to reduce its losses and to improve its dissipation has been presented in the paper.展开更多
Calnetix has recently completed the design and development of the next generation medium voltage,megawatt high speed motor drive system using 10 kVSilicon Carbide power devices.A1.6MWmedium voltage motor supported by ...Calnetix has recently completed the design and development of the next generation medium voltage,megawatt high speed motor drive system using 10 kVSilicon Carbide power devices.A1.6MWmedium voltage motor supported by active magnetic bearings has been designed as a test platform for the system.The heteropolar radial magnetic bearings feature a winding topology with separate bias,cos(x-control)and sin(y-control)coils on each pole.This approach is shown to produce a more uniform load capacity versus angle than the conventional bi-quadrant winding scheme.This paper describes the design and motivation for the machine with primary emphasis on the magnetic bearing system.Preliminary bench test results of the actuator are described and compared to predictions.Future applications for this type machine in wastewater recovery,exhaust gas remediation,and natural gas compression are discussed.展开更多
Adjustable speed AC Motor drives have been used extensively in modern industry and transportation which calls for electrical and mechanical energy conversion with wide output power range applications.Because of its mo...Adjustable speed AC Motor drives have been used extensively in modern industry and transportation which calls for electrical and mechanical energy conversion with wide output power range applications.Because of its modularity and scalability,the drive system can be extended to many different application areas.More recently,adjustable speed AC motor drive applications are spreading not only in industry applications,but also sky and the marine.In this paper,after summarizing the history of adjustable speed AC motor drives and applications,the main issues of AC drive technologies are reviewed and investigated in the paper.Technical issues of adjustable speed AC motor drives including its standardization are surveyed and analyzed for more advancement.Finally,the paper provides the latest technical trends on adjustable speed AC motor drives technologies,and discusses the development of high speed high power PM motor.展开更多
文摘Pressure-flow analytical formulas of lubrication film of slipper pairs on camshaft connecting rod type low speed high torque （LSHT） hydraulic motors are put forward. The bottom surface of slipper pairs is rectangle, and the effect of squeeze flow and pressure differential flow is considered. The dynamic process of lubrication film formation through squeezing is numerically studied by computer simulation. Effects of supply pressure, initial lubrication film thickness, velocity damping coefficient, loading impact and gravity, etc are studied. Advantages of novel slipper pairs with large oil cavity area are pointed out.
文摘An induction motor with its speed modulated by frequency features wide transfer speed range, high systematie efficiency, simple structure and long life, and it therefore becomes one of the best driving motors used in electrical vehicles. The present research trend of it is high power, high speed, high efficiency and long life. How to meet the above requirements by using the electromagnetic design, structure design and beat design, becomes a matter that needs to be resolved now. In this paper, the characters of the motor in operation are analyzed, all kinds of factors that relate to life are laid out, its heating and loss are discussed and analyzed. The key reasons affecting the motor life are presented, and different characters of a high induction motor are compared with these of a general induction motor. A design idea is described, that is : we should consider how to improve the efficiency and reliability as well as bow to reduce the heating by changing the electromagnet, structure, dissipation and operation of the motor. How to reduce its losses and to improve its dissipation has been presented in the paper.
文摘Calnetix has recently completed the design and development of the next generation medium voltage,megawatt high speed motor drive system using 10 kVSilicon Carbide power devices.A1.6MWmedium voltage motor supported by active magnetic bearings has been designed as a test platform for the system.The heteropolar radial magnetic bearings feature a winding topology with separate bias,cos(x-control)and sin(y-control)coils on each pole.This approach is shown to produce a more uniform load capacity versus angle than the conventional bi-quadrant winding scheme.This paper describes the design and motivation for the machine with primary emphasis on the magnetic bearing system.Preliminary bench test results of the actuator are described and compared to predictions.Future applications for this type machine in wastewater recovery,exhaust gas remediation,and natural gas compression are discussed.
文摘Adjustable speed AC Motor drives have been used extensively in modern industry and transportation which calls for electrical and mechanical energy conversion with wide output power range applications.Because of its modularity and scalability,the drive system can be extended to many different application areas.More recently,adjustable speed AC motor drive applications are spreading not only in industry applications,but also sky and the marine.In this paper,after summarizing the history of adjustable speed AC motor drives and applications,the main issues of AC drive technologies are reviewed and investigated in the paper.Technical issues of adjustable speed AC motor drives including its standardization are surveyed and analyzed for more advancement.Finally,the paper provides the latest technical trends on adjustable speed AC motor drives technologies,and discusses the development of high speed high power PM motor.
