节流器是液体静压主轴的核心元件，其节流特性对液体静压主轴的刚度和回转精度具有直接影响。针对现有节流器在主轴工作时节流特性不可控的不足，提出一款预压预调型可控节流器。在分析可控节流器工作原理和节流特性基础上，根据流体润滑理论，建立基于可控节流器的液体静压轴承承载性能的理论模型，研究可控节流器供油压力、弹簧刚度和控制油腔压力等参数对液体静压轴承承载性能的影响规律，并与固定节流液体静压轴承的承载性能进行对比。研究发现，在其他结构参数及工作参数一定的条件下，可控节流器能够显著地提高液体静压轴承的油膜刚度；在不同偏心率条件下，可控节流液体静压轴承的最佳油膜刚度对应的节流参数不同。在开发的液体静压电主轴试验台上进行了试验研究，通过对油腔压力和油膜刚度的理论计算值与试验测量值的对比，证实了可控节流方案的有效性。
A restrictor is one of the most important components of hydrostatic spindles and its throttling behavior has a significant effect on both stiffness and rotational precision of hydrostatic spindles. There is a shortage exhibited by the existing restrictors whose throttling characteristics cannot be controlled when hydrostatic spindles are working. A pre-pressure and pre-conditioning controllable restrictor is proposed. The operating principle of the proposed restrictor and its throttling behavior are analyzed qualitatively, and then a theoretical analysis model of hydrostatic journal bearings with a controllable restrictor is established based on fluid lubrication theory. The influences of controllable restrictor parameters including oil pressure, spring stiffness and controllable chamber pressure on the load characteristics of hydrostatic bearings are studied by using the established model. The load characteristics of the hydrostatic bearing with a controllable restrictor are compared with those of the hydrostatic bearing with a gap restrictor. It is found that the controllable restrictor can significantly improve the oil film stiffness of hydrostatic bearings under the condition that all other parameters of hydrostatic bearings are not changed. Moreover, the optimal oil film stiffness values of hydrostatic bearings are different under different eccentricities because the controllable throttle parameters are changed with a change in an eccentricity. The validity of the theoretical analysis model is verified by comparing theoretical values with experimental results.
[1] 袁巨龙,张飞虎,戴一帆,等. 超精密加工领域科学技术发展研究[J]. 机械工程学报,2010,46(15):161-177. YUAN Julong,ZHANG Feihu,DAI Yifan,et al. Development research of science and technologies in ultra-precision machining field[J]. Journal of Mechanical Engineering,2010,46(15):161-177.
[2] ROWE W B. Advances in hydrostatic and hybrid bearing technology[J]. Journal of Mechanical Engineering Science,1989,203(43):225-242.
[3] 丁振乾. 流体静压支撑设计[M]. 上海:上海科学技术文献出版社,1989. DING Zhenqian. Fluid hydrostatic support design[M]. Shanghai:Science and Technology Documents Press of Shanghai,1989.
[4] 熊万里,阳雪冰,吕浪,等. 液体动静压电主轴关键技术综述[J]. 机械工程学报,2009,45(9):1-18. XIONG Wanli,YANG Xuebing,LÜ Lang,et al. Review on key technology of hydrodynamic and hydrostatic high-frequency motor spindles[J]. Journal of Mechanical Engineering,2009,45(9):1-18.
[5] 熊万里,侯志泉,吕浪. 液体静压主轴回转误差的形成机理研究[J]. 机械工程学报,2014,50(7):112-119. XIONG Wanli,HOU Zhiquan,LÜ Lang. Study on the mechanism of hydrostatic spindle rotational error motion[J]. Journal of Mechanical Engineering,2014,50(7):112-119.
[6] 侯志泉,熊万里,吕浪,等. 轴颈形状误差对液体静压主轴回转精度的影响[J]. 机械工程学报,2016,52(15):147-154. HOU Zhiquan,XIONG Wanli,LÜ Lang. Study on the influence of the journal shape error for hydrostatic spindle rotational error motion[J]. Journal of Mechanical Engineering,2016,52(15):147-154.
[7] CHEN C H,KANG Y,CHANG Y P,et al. Influence of restrictor on the stability of the rigid rotor-hybrid bearing system[J]. Journal of Sound and Vibration,2006,297:635-648.
[8] SINGH N,SHARMA S C,JAIN S C,et al. Performance of membrane compensated multirecess hydrostatic/hybrid flexible journal bearing system considering various recess shapes[J]. Tribology International,2004,37:11-24.
[9] PHALLE V M,SHARMA S C,JAIN S C. Performance analysis of a 2-lobe worn multi-recess hybrid journal bearing system using different flow control devices[J]. Tribology International,2012,52(3):101-116.
[10] 朱有红,刘建亭,杨建玺,等. 液体静压轴承薄膜节流新结构的设计分析[J]. 轴承,2008(3):27-30. ZHU Youhong,LIU Jianting,YANG Jianxi,et al. Design analysis on new thin film restrictor of liquid hydrostatic bearing[J]. Bearing,2008(3):27-30.
[11] KANG Y,SHEN P C,CHANG Y P,et al. Modified predictions of restriction coefficient and flow resistance for membrane-type restrictors in hydrostatic bearing by using regression[J]. Tribology International,2007,40:1369-1380.
[12] GAO D R. Theoretical analysis and numerical simulation of the static and dynamic characteristics of hydrostatic guides based on progressive mengen flow controller[J]. Chinese Journal of Mechanical Engineering,2010,23(6):709-716.
[13] KANG Y,CHEN C,LEE H,et al. Design for static stiffness of hydrostatic bearings single-action variable compensations[J]. Industrial Lubrication and Tribology,2011,63(2):103-118.
[14] KANE N R,SIHLER J,SLOCUM A H. A hydrostatic rotary bearing with angled surface self-compensation[J]. Precision Engineering,2003,27(2):125-139.
[15] ZUO X B,WANG J M,YIN Z Q,et al. Self-compensated precision hydrostatic rotary bearing[J]. Advanced Materials Research,2013,662:674-677.
[16] 王勇勤,周巡,刘志芳. 基于伺服控制节流的静压推力轴承性能分析与研究[J]. 四川大学学报,2012,44(2):201-205. WANG Yongqin,ZHOU Xun,LIU Zhifang. Study on dynamic characteristics of hydrostatic thrust bearing with servo control[J]. Journal of Sichuan University,2012,44(2):201-205.
[17] HAUGAARD A M,SANTOS I F. Multi-orifice active tilting-pad journal bearings-harnessing of synergetic coupling effects[J]. Tribology International,2010,43(8):1374-1391.
[18] 熊万里. 可控节流器:中国,102562828A[P]. 2012-07-11. XIONG Wanli. Controllable restrictor:China,102562828A[P]. 2012-07-11.
