Similar articles

Abstract: A good efficiency performance of a pump over a wide range of displacement conditions is crucially important for variable pump control systems to save energy. However, according to the literature, less attention has been paid to the understanding of the efficiency, leakage flow, and compression flow characteristics of the pump with respect to displacement conditions. In this study, a test bench was built, and a novel explicit volumetric loss model was proposed to investigate these problems. The overall efficiency is found to drop considerably with the decreasing displacement. The volumetric losses range from 13% to 47% of the total power losses of pump at the rated speed, under the conditions of pressure ranging from 5 to 35 MPa and displacement ranging from 13% to 100% of full displacement. The highest proportion of compression flow losses in the total volumetric losses of pump at the rated speed can reach up to 41% when the pressure and displacement are greater than 30 MPa and 88% of full displacement, respectively; after that, the proportion gradually decreases with decreasing displacement. However, the leakage flow generally increases with decreasing displacement, or may decrease first and begin to increase after the minimum with the further decrease of displacement. In the components of leakage of slipper/swash plate pair, the squeeze leakage is found to reach a magnitude equal to that of the Poiseuille leakage. The findings can guide the further research and design of pumps with better efficiency performance.

This work uses well-established theory as documented in the references. The useful aspect of the paper is that it shows the effect of varying displacement on the different losses. I am not aware of this appearing in any other paper so it makes this paper particularly useful. Both theoretical and experimental results are presented, my long-standing view being that fluid power analysis is only useful if it is supported by practical data.

宽幅排量工况下轴向柱塞泵容积损失及效率变化特征

[1]Bergada, J.M., Kumar, S., Davies, D.L., et al., 2012a. A complete analysis of axial piston pump leakage and output flow ripples. Applied Mathematical Modelling, 36(4):1731-1751.

[2]Bergada, J.M., Davies, D.L., Kumar, S., et al., 2012b. The effect of oil pressure and temperature on barrel film thickness and barrel dynamics of an axial piston pump. Meccanica, 47(3):639-654.

[3]Edge, K.A., Darling, J., 1989. The pumping dynamics of swash plate piston pumps. Journal of Dynamic Systems, Measurement, and Control, 111(2):307-312.

[4]Ericson, L., Palmberg, J.O., 2012. Unsteady flow through a valve plate restrictor in a hydraulic pump/motor unit. Proceedings of 8th International Fluid Power Conference, IFK, Dresden, Germany, B6:1-13.

[5]Fang, Y., Ikeya, M., 1992. Lubrication condition between the piston and cylinder for low-speed ranges of swashplate type axial pistons pump and motors: spin of the piston and its influence. Hydraulics & Pneumatics, 23(4):420-426 (in Japanese).

[6]Guan, C.H., Jiao, Z.X., He, S.Z., 2014. Theoretical study of flow ripple for an aviation axial-piston pump with damping holes in the valve plate. Chinese Journal of Aeronautics, 27(1):169-181.

[7]Huang, J.H., Quan, L., Zhang, X.G., 2014. Development of a dual-acting axial piston pump for displacement-controlled system. Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture, 228(4):606-616.

[8]Ivantysyn, J., Ivantysynova, M., 2001. Hydrostatic Pumps and Motors. Academia Books International, New Delhi, India, p.130-133.

[9]Kazama, T., 2008. Mixed lubrication simulation of hydrostatic spherical bearings for hydraulic piston pumps and motors. Journal of Advanced Mechanical Design, Systems, and Manufacturing, 2(1):71-82.

[10]Kumar, S., Bergada, J.M., 2013. The effect of piston grooves performance in an axial piston pumps via CFD analysis. International Journal of Mechanical Sciences, 66:168-179.

[11]Lin, S., Hu, J.B., 2015. Tribo-dynamic model of slipper bearings. Applied Mathematical Modelling, 39(2):548-558.

[12]Ma, J.E., Xu, B., Zhang, B., et al., 2010a. Flow ripple of axial piston pump with computational fluid dynamic simulation using compressible hydraulic oil. Chinese Journal of Mechanical Engineering, 23(01):45-52.

[13]Ma, J.E., Fang, Y.T., Xu, B., et al., 2010b. Optimization of cross angle based on the pumping dynamics model. Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 11(3):181-190.

[14]Mandal, N.P., Saha, R., Sanyal, D., 2012. Effects of flow inertia modelling and valve-plate geometry on swash plate axial piston pump performance. Proceeding of the Institution of Mechanical Engineers, Part I: Journal of Systems and Control Engineering, 226(4):451-465.

[15]Manring, N.D., 2000. The discharge flow ripple of an axial piston swash plate type hydrostatic pump. Journal of Dynamic Systems, Measurement, and Control, 122(2):263-268.

[16]Mizell, D., Ivantysynova, M., 2014. Material combinations for the piston-cylinder interface of axial piston machines: a simulation study. Proceeding of the 8th FPNI PhD Symposium, Lappeenranta, Finland.

[17]Tanaka, K., Nakahara, T., Kyogoku, K., 2003. Half-frequency whirl of pistons in axial piston pumps and motors under mixed lubrication. Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology, 217(2):93-102.

[18]Wegner, S., Gels, S., Murrenhoff, H., 2014. Simulation of the tribological contact cylinder block valve plate and influence of geometry and operating points on the friction torque in axial piston machines. 9th International Fluid Power Conference, Aachen, Germany, p.13-19.

[19]Xu, B., Zhang, J.H., Yang, H.Y., 2012. Investigation on structural optimization of anti-overturning slipper of axial piston pump. Science China Technological Sciences, 55(11):3010-3018.

[20]Xu, B., Zhang, J.H., Yang, H.Y., et al., 2013. Investigation on the radial micro-motion about piston of axial piston pump. Chinese Journal of Mechanical Engineering, 26(2):325-333.

[21]Xu, B., Sun, Y.H., Zhang, J.H., et al., 2015a. A new design method for the transition region of the valve plate for an axial piston pump. Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 16(3):229-240.

[22]Xu, B., Ye, S.G., Zhang, J.H., 2015b. Effects of index angle on flow ripple of a tandem axial piston pump. Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 16(5):404-417.

[23]Xu, B., Wang, Q.N., Zhang, J.H., 2015c. Effect of case drain pressure on slipper/swashplate pair within axial piston pump. Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 16(12):1001-1014.

[24]Zecchi, M., Mehdizadeh, A., Ivantysynova, M., 2013. A novel approach to predict the steady state temperature in ports and case of swash plate type axial piston machines. Proceedings of the 13th Scandinavian International Conference on Fluid Power, Linkoping, Sweden.