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.

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.

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.

Static and Dynamic Characteristics of Aerostatic Circular Porous Thrust Bearings (Effect of the Shape of the Air Supply Area)

2000 ◽  
Vol 123 (3) ◽  
pp. 501-508 ◽  
Author(s):  
S. Yoshimoto ◽  
K. Kohno
Keyword(s):  
Porous Material ◽  
Dynamic Characteristics ◽  
Thrust Bearing ◽  
Aerostatic Bearing ◽  
Bearing Surface ◽  
Static And Dynamic Characteristics ◽  
Thrust Bearings ◽  
Porous Bearing ◽  
Air Supply ◽  
Bearing Design

Recently, graphite porous material has been used successfully in an aerostatic bearing. In actual bearing design, it is often necessary to reduce the thickness of porous material to make the bearing smaller. However, a reduction in thickness results in a reduction in the strength of the porous material. In particular, when the diameter of porous material is large, it is difficult to supply the air through the full pad area of porous material because it deforms. Therefore, in this paper, two types of air supply method (the annular groove supply and the hole supply) in a circular aerostatic porous thrust bearing are proposed to avoid the deflection of the bearing surface. The static and dynamic characteristics of aerostatic porous bearing with these air supply methods are investigated theoretically and experimentally. In addition, the effects of a surface restricted layer on the characteristics are clarified.

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.

A semianalytical method for studying the performances of aerostatic thrust bearing

2018 ◽  
Vol 233 (4) ◽  
pp. 628-637
Author(s):  
Jianbo Zhang ◽  
Chunxiao Jiao ◽  
Donglin Zou ◽  
Na Ta ◽  
Zhushi Rao
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Film Thickness ◽  
Reynolds Equation ◽  
Thrust Bearing ◽  
Separation Of Variables ◽  
Orifice Diameter ◽  
Thrust Bearings ◽  
Supply Pressure ◽  
Semianalytical Method

The solution of Reynolds equation and computational fluid dynamics are widely employed for the lubrication performance analysis of aerostatic thrust bearing. However, the solution of Reynolds equation may be inaccurate and cannot present detailed performance near orifice, while computational fluid dynamics method has low computational efficiency with time consumption in mesh generation and solving Navier–Stokes equations. In order to overcome the drawbacks of Reynolds equation and computational fluid dynamics, based on the method of separation of variables, a semianalytical method is developed for describing the characteristics of aerostatic bearings available. The method of separation of variables considering the initial and viscous effect is more accurate than the Reynolds equation and can present detailed performance near orifice in the aerostatic thrust bearings, while method of separation of variables has great computational efficiency compared to computational fluid dynamics. Meanwhile, the pressure distribution calculated by method of separation of variables is compared to the published experimental data and the results obtained by computational fluid dynamics. The comparative results indicate validity of the method. Furthermore, the influences of flow and geometry parameters, such as supply pressure, orifice diameter, film thickness, and bearing radius, on the characteristics of aerostatic thrust bearings with single orifice are studied. The results show that there exists pressure depression phenomenon near orifice. The depression phenomenon is strengthened with increase of film thickness and supply pressure and decrease of orifice diameter and bearing radius, while the maximum speed increases with strengthening of pressure depression due to decrease of minimum local pressure near orifice. Moreover, the bearing capacity increases with increase of supply pressure, orifice diameter, and bearing radius and decreases with increase of film thickness, while mass flow rate increases with supply pressure, orifice diameter, and film thickness and it is not sensitive to bearing radius.

An Externally Pressurized Supersonic Gas Thrust Bearing (2nd Report, Dynamic Characteristics in Supersonic Operations and Static Characteristics in Sonic Operations)

1984 ◽  
Vol 106 (1) ◽  
pp. 169-173
Author(s):  
Y. Miyake ◽  
T. Inaba ◽  
T. Matsuoka
Keyword(s):  
Dynamic Characteristics ◽  
Thrust Bearing ◽  
Load Capacity ◽  
Damping Factor ◽  
Static Characteristics ◽  
Supply Pressure

The dynamic characteristics of a newly proposed supersonic gas thrust bearing are analyzed under supersonic operations. Its static characteristics in sonic operations are also investigated. It is concluded that the load capacity, the stiffness factor, and the damping factor are increased proportionally to the supply pressure in either supersonic or sonic operation range which is determined according to the magnitude of the clearance.

Dynamic Characteristics of Aerostatic Thrust Bearings with Porous Inserts

1980 ◽  
Vol 22 (2) ◽  
pp. 55-58 ◽  
Author(s):  
B. C. Majumdar
Keyword(s):  
Perturbation Method ◽  
Dynamic Characteristics ◽  
Dynamic Behaviour ◽  
Thrust Bearing ◽  
Thrust Bearings ◽  
First Order ◽  
Design Variables ◽  
Stiffness And Damping ◽  
Film Stiffness ◽  
First Order Perturbation

A first-order perturbation method is adopted to find the dynamic behaviour of an aerostatic circular thrust bearing having a central porous insert as a restrictor. The linearized gas film stiffness and damping are derived and used to study their behaviour with other design variables.

scholarly journals Theoretical Disquisition on the Static and Dynamic Characteristics of an Adaptive Stepped Hydrostatic Thrust Bearing with a Displacement Compensator

Mathematics ◽  
2021 ◽  
Vol 9 (22) ◽  
pp. 2949
Author(s):  
Vladimir Kodnyanko ◽  
Andrey Kurzakov ◽  
Olga Grigorieva ◽  
Maxim Brungardt ◽  
Svetlana Belyakova ◽  
...  
Keyword(s):  
Dynamic Characteristics ◽  
Metal Cutting ◽  
Thrust Bearing ◽  
Load Capacity ◽  
Theoretical Research ◽  
Stable Operation ◽  
Adaptive Function ◽  
Main Bearing ◽  
Thrust Bearings ◽  
Wide Range

Stepped hydrostatic thrust bearings used in metal-cutting machines are characterized by high load capacity and damping, which ensure the stable operation of structures. However, in comparison with throttle thrust bearings, they have a high compliance. It is preferable that, in addition to the main bearing function, a modern hydrostatic bearing has the ability to provide low (including negative) compliance for the implementation of an adaptive function in order to actively compensate for the deformation of the machine resilient system, thereby increasing the accuracy of metalworking. This paper considers the design of a stepped hydrostatic thrust bearing, which, in order to reduce the compliance to negative values, features a technical improvement consisting of the use of an active displacement compensator on an elastic suspension. In this paper, the results of mathematical modeling and theoretical research of stationary and non-stationary modes of operation of the adaptive thrust bearing are presented. The possibility of a significant reduction in the static compliance of the structure, including the negative compliance values, is shown. It was found that negative compliance is provided in a wide range of loads, which can be up to 80% of the range of permissible bearing loads. The study of the dynamic characteristics showed that with a targeted selection of parameters that ensure optimal performance, the adaptive thrust bearing is able to operate stably in the entire range of permissible loads. It has been established that an adaptive stepped hydrostatic thrust bearing with a displacement compensator has a high stability margin, sufficient to ensure its operability when implementing the adaptive function.

The Static and Dynamic Characteristics of the Spiral-Grooved Thrust Bearing

1965 ◽  
Vol 87 (3) ◽  
pp. 547-555 ◽  
Author(s):  
S. B. Malanoski ◽  
C. H. T. Pan
Keyword(s):  
Phase Angle ◽  
Dynamic Characteristics ◽  
Thrust Bearing ◽  
Load Capacity ◽  
Radius Ratio ◽  
Oscillatory Motion ◽  
Static And Dynamic Characteristics ◽  
Thrust Bearings ◽  
Rotor Bearing ◽  
Oscillating Motion

A generalized analysis for spiral-grooved thrust bearings is presented. The effects of local radius are considered. For the same grooving geometry and the same inside-to-outside radius ratio, the inflow design is shown to be superior in both stiffness and load capacity. The analysis also treats a relative, transverse, oscillatory motion of the bearing surfaces. Both the magnitude and phase angle (in the temporal sense) of the bearing reaction are dependent on the frequency of the motion. The results for the oscillating motion reveal the possibility of a self-excited, rotor-bearing instability. The criterion for determining the onset of this type of instability is given.

scholarly journals Pneumatic Servo Bearing Actuator with Multiple Bearing Pads for Ultraprecise Positioning

2013 ◽  
Vol 7 (5) ◽  
pp. 498-505 ◽  
Author(s):  
Shuhei Tsujimura ◽  
◽  
Yusuke Hashimoto ◽  
Takashi Matsuoka ◽  
Tomoko Hirayama ◽  
...  
Keyword(s):  
Research And Development ◽  
Dynamic Characteristics ◽  
Large Scale ◽  
Thrust Bearing ◽  
Open Loop ◽  
Open Loop Control ◽  
Positioning Accuracy ◽  
Loop Control ◽  
Positioning Systems ◽  
The Difference

With the increase in demand for semiconductor products, ultrafine linear patterning technologies for Large-Scale Integrations (LSIs) have been making progress. The requested positioning accuracy in such ultraprecise apparatuses is of nanometer order. To meet such specific needs, the research and development of a variety of actuators has been necessary. Our laboratory has developed a ‘Pneumatic Servo Bearing Actuator (PSBA),’ a novel actuator that uses pneumatic servo technology for ultraprecise positioning. Our past studies have showed that the minimum resolution of PSBA was almost 6 nm, even under open loop control; thus, we concluded that the PSBA was a promising actuator in advanced ultraprecise positioning systems. However, the stroke of the PSBA was comparatively short. To expand the stroke of the actuator, we proposed and developed a new PSBA with multiple thin thrust-bearing pads. The main purpose in this study is to investigate the positioning properties of the new PSBA with multiple thrust bearing pads. The obtained characteristics of the PSBA can be enumerated as follows. (1) The PSBA with multiple bearing pads achieves a longer stroke than the PSBA with a single pad. (2) The difference in the thickness of the bearing pads affects the dynamic characteristics of the actuator. (3) The minimum positioning resolution of the developed PSBA with twenty-nine bearing pads is about 2 – 4 nm with feedback control.

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