scholarly journals Analysis of the dynamic characteristics of downsized aerostatic thrust bearings with different pressure equalizing grooves at high or ultra-high speed

2021 ◽  
Vol 13 (5) ◽  
pp. 168781402110180
Author(s):  
Ruzhong Yan ◽  
Haojie Zhang
Keyword(s):  
Dynamic Characteristics ◽  
High Speed ◽  
Rotation Speed ◽  
Dynamic Stiffness ◽  
Simulation Method ◽  
Perturbation Amplitude ◽  
Thrust Bearings ◽  
Supply Pressure ◽  
Ultra High Speed ◽  
Air Film

This study adopts the DMT(dynamic mesh technology) and UDF(user defined functions) co-simulation method to study the dynamic characteristics of aerostatic thrust bearings with equalizing grooves and compare with the bearing without equalizing groove under high speed or ultra high speed for the first time. The effects of air film thicness, supply pressure, rotation speed, perturbation amplitude, perturbation frequency, and cross section of the groove on performance characteristics of aerostatic thrust bearing are thoroughly investigated. The results show that the dynamic stiffiness and damping coefficient of the bearing with triangular or trapezoidal groove have obvious advantages by comparing with that of the bearing without groove or with rectangular groove for the most range of air film thickness, supply pressure, rotation speed, perturbation amplitude, especially in the case of high frequency, which may be due to the superposition of secondary throttling effect and air compressible effect. While the growth range of dynamic stiffness decreases in the case of high or ultra-high rotation speed, which may be because the Bernoulli effect started to appear. The perturbation amplitude only has little influence on the dynamic characteristic when it is small, but with the increase of perturbation amplitude, the influence becomes more obvious and complex, especially for downsized aerostatic bearing.

The Dynamic Optimization Analysis of High-Speed Hybrid Thrust Bearing

2010 ◽  
Vol 118-120 ◽  
pp. 507-511
Author(s):  
Kai Sun ◽  
Lan Wang ◽  
Xin Jun Zhao
Keyword(s):  
Dynamic Optimization ◽  
Dynamic Characteristics ◽  
High Speed ◽  
Thrust Bearing ◽  
Orifice Diameter ◽  
Optimization Analysis ◽  
Angular Misalignment ◽  
Thrust Bearings ◽  
Supply Pressure ◽  
Dynamic Moment

In this paper, the dynamic characteristics of high-speed hybrid thrust bearing with four-recesses are optimized for different orifice diameter and supply pressure at a given speed condition, the dynamic moment coefficients of hybrid thrust bearing are analyzed, considering the thrust collar angular misalignment case to determine the optimization of orifice diameter and supply pressure under a given speed. The results provide certain reference to the hybrid thrust bearings used in high speed precision spindle.

Switchmode Hydraulic Power Supply Theory

2005 ◽  
Author(s):  
Jianwei Cao ◽  
Linyi Gu ◽  
Feng Wang ◽  
Minxiu Qiu
Keyword(s):  
Flow Rate ◽  
Dynamic Characteristics ◽  
Power Supply ◽  
Power Loss ◽  
High Speed ◽  
Hydraulic Pressure ◽  
Hydraulic Systems ◽  
Hydraulic Pump ◽  
Hydraulic Power ◽  
Supply Pressure

Switchmode hydraulic power supply is a new kind of energy-saving pressure converting system, which is originally proposed by the authors. It is mainly applied in multiple-actuator hydraulic systems, and installed between hydraulic pump and actuators (one switchmode hydraulic power supply for one actuator). It can provide pressure or flow rate that is adapted to the consumption of each actuator in the system by boosting or bucking the pressure, with low power loss, and conveniently, through high-speed switch valves, just like a hydraulic pressure transformer. There are two basic types of switchmode hydraulic power supply: pressure boost and pressure buck. Their structures and working principles are introduced. The dynamic characteristics of two typical types of switchmode hydraulic power supply, the pressure boost type and the pressure buck type, were analyzed through simulations and experiments. The performances were evaluated, and improvements on the efficiency of switchmode hydraulic power supply were proposed.

Dynamic Analysis of High-Speed Hybrid Thrust Bearings

2013 ◽  
Vol 365-366 ◽  
pp. 304-308
Author(s):  
Lei Wang
Keyword(s):  
Dynamic Analysis ◽  
High Speed ◽  
Reynolds Equation ◽  
Thrust Bearing ◽  
Dynamic Performance ◽  
Orifice Diameter ◽  
Thrust Bearings ◽  
Supply Pressure ◽  
Bearing Stiffness ◽  
Stiffness And Damping

An analysis is conducted and solutions are provided for the dynamic performance of high speed hybrid thrust bearing. By adopting bulk flow theory, the turbulent Reynolds equation is solved numerically with the different orifice diameter and supply pressure. The results show that increasing supply pressure can significantly improve the bearing stiffness and damping, while the orifice diameters make a different effect on the bearing stiffness and damping.

Difference between SFMR and SITMR 1 compensation for hydrostatic thrust bearing

2021 ◽  
pp. 1-18
Author(s):  
Yuanpeng Sha ◽  
Shujiang Chen ◽  
Changhou Lu ◽  
Wei Pan
Keyword(s):  
Dynamic Characteristics ◽  
Thrust Bearing ◽  
Single Action ◽  
Thrust Bearings ◽  
Supply Pressure ◽  
Outlet Pressure ◽  
Island Type ◽  
Flat Membrane ◽  
The Difference ◽  
Static Flow

Abstract Both flat and island type membranes are used in single-action membrane restrictors. But the difference between the single-action flat membrane restrictor (SFMR) and the single-action island type membrane restrictor (SITMR) has rarely been reported in the literature. In this study, we first compared the static and dynamic characteristics of SFMR and SITMR, and found that there is a little difference between them when the difference between supply pressure ps and outlet pressure pr is not large. Then, we investigated the dynamic characteristics of hydrostatic thrust bearings using both SFMR and SITMR compensation, and found SITMR having a better dynamic bearing performance. The reason for this phenomenon is that the mass of the membrane in SITMR is smaller than that of the membrane in SFMR. When the difference between supply pressure ps and outlet pressure pr becomes large, SFMR reduces the static flow rate of the lubricant of bearing systems more significantly than SITMR.

Dynamic Identification of Convergent Externally Pressurized Gas-Bearing Gaps

1988 ◽  
Vol 110 (2) ◽  
pp. 263-270 ◽  
Author(s):  
P. Plessers ◽  
R. Snoeys
Keyword(s):  
Frequency Response ◽  
Response Function ◽  
Frequency Response Function ◽  
Dynamic Stiffness ◽  
Test Procedure ◽  
Dynamic Identification ◽  
Thrust Bearings ◽  
Stiffness And Damping ◽  
Air Film ◽  
Gas Bearing

The dynamic behavior of externally pressurized gas bearings is described by means of frequency response functions, from which dynamic stiffness and damping coefficients are derived. A numerical method is presented to calculate the frequency response function for plane circular thrust bearings with convergent gap geometry. A test procedure is described for measuring the frequency response function of an air film in order to verify computational, results. The comparison reveals a fairly good agreement between measured and calculated frequency responses. Finally, the effect of bearing parameters on the frequency response function of the air film is investigated.

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