Distribution characteristics and impact on pump’s efficiency of hydro-mechanical losses of axial piston pump over wide operating ranges

Abstract

A novel performance model of losses of pump was presented, which allows an explicit insight into the losses of various friction pairs of pump. The aim is to clarify that to what extent the hydro-mechanical losses affect efficiency, and to further gain an insight into the variation and distribution characteristics of hydro-mechanical losses over wide operating ranges. A good agreement is found in the comparisons between simulation and experimental results. At rated speed, the hydro-mechanical losses take a proportion ranging from 87% to 89% and from 68% to 97%, respectively, of the total power losses of pump working under 5 MPa pressure conditions, and 13% of full displacement conditions. Furthermore, within the variation of speed ranging from 48% to 100% of rated speed, and pressure ranging from 14% to 100% of rated pressure, the main sources of hydro-mechanical losses change to slipper swash plate pair and valve plate cylinder pair at low displacement conditions, from the piston cylinder pair and slipper swash plate pair at full displacement conditions. Besides, the hydro-mechanical losses in ball guide retainer pair are found to be almost independent of pressure. The derived conclusions clarify the main orientations of efforts to improve the efficiency performance of pump, and the proposed model can service for the design of pump with higher efficiency performance.

Keywords

axial piston pump / efficiency / hydro-mechanical losses / digital prototyping / distribution characteristics / over wide operating ranges

References

[1] BergadaJ M, KumarS, DaviesD L. A complete analysis of axial piston pump leakage and output flow ripples [J]. Applied Mathematical Modelling, 2012, 36(4): 1731-1751

[2] ManringN D. Friction forces within the cylinder bores of swash plate type axial piston pumps and motors [J]. ASME Journal of Dynamic Systems, Measurement and Control, 1999, 121(1): 531-537

[3] JeongH S, KimH E. On the instantaneous and average piston friction of swash plate type hydraulic axial piston machines [J]. Journal of Mechanical Science and Technology, 2004, 18(10): 1700-1711

[4] NilsV, HubertusM, UlrichB, DavidB. Mechanical losses in the piston-bushing contact of axial piston units [C]. Proceedings of the 9th JFPS International Symposium on Fluid Power. Matsue: The Japan Fluid Power System Society (JFPS), 2014368-375

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

[6] JonathanE BPower losses in the lubricating gap between cylinder block and valve plate of swash plate type axial piston machines [D], 2008est Lafayette, USAPurdue University

[7] WangB, ZhouH, YangH-yong. Experimental study of frictional torque properties of plane port pairs in axial piston pump [J]. Journal of Zhejiang University (Engineering Science), 2009, 43(11): 2091-2095

[8] CanbulutF, SinanogluC, KocE. Experimental analysis of frictional power loss of hydrostatic slipper bearings [J]. Industrial lubrication and Tribology, 2009, 61(3): 123-131

[9] LinS, HuJ-bin. Tribo-dynamic model of slipper bearings [J]. Applied Mathematical Modelling, 2015, 39(2): 548-558

[10] SunY, JiangJ-H, LiuJ-long. Relative position and friction power loss between slipper retainer and ball guide in axial piston pump [J]. Journal of South China University of Technology, 2011, 39(4): 82-87

[11] SunY, LiY, JiangJ-hai. Stress analysis and experiments for slipper retainer and ball guide in axial piston pump [J]. Journal of Xi’an Jiaotong University, 2013, 47(2): 103-108

[12] WilsonW E. Performance criteria for positive displacement pumps and fluid motors [C]. ASME Semi-annual meeting. Chicago, USA: ASME, 194814-48

[13] MikeskaD, IvantysynovaM. A precise steady state model of displacement machines for the application in virtual prototyping of power split drives [C]. 2nd FPNI-PhD Symposium. Modena, Italy Center for Compact and Efficient Fluid Power, 200295-111

[14] PaceyD A, TurnquistR O, ClarkS J. The development of a coefficient model for hydrostatic transmissions [C]. Proceedings of the 35th national conference on fluid power. Chicago: IIIinois Institute of Technology, 1979173-178

[15] ZarottiG L. Pump efficiencies approximation and modeling [C]. 6th BHRA Fluid Power Symposium. Cambridge, England BHRA Fluid Engineering, 1981145-164

[16] MccandlishD, DoreyR E. The mathematical modeling of hydrostatic pumps and motors [J]. Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture, 1984, 198(1): 165-174

[17] DoreyR E. Modeling of losses in pumps and motors [C]. Proceedings of the First Bath International Fluid Workshop. England: Research Studies Press, 198871-97

[18] GrandallD RThe performance and efficiency of hydraulic pumps and motors [D], 2010Twin Cities, USAUniversity of Minnesota

[19] RydbergK E. Efficiencies for variable hydraulic pumps and motors—Mathematical models and operation conditions [C]. IEI/Flu-MeS. Linkoping, Sweden: Linköping University, 20091-37

[20] IvantysynJ, IvantysynovaMHydrostatic pumps and motors [M], 2001New DelhiAcademic Books International

[21] GuanC-b, JiaoZ-x, HeS-zhan. Theoretical study of flow ripple for an aviation axial piston pump with damping holes in the valve plate [J]. Chinese Journal of Aeronautics, 2014, 27(1): 169-181

[22] XuB, ZhangJ-h, YangH-y, ZhangBin. Investigation on the radial micro-motion about piston of axial piston pump [J]. Chinese Journal of Mechanical Engineering, 2011, 26(2): 325-333

[23] XuB, ZhangJ-h, YangH-yong. Investigation on structural optimization of anti-overturning slipper of axial piston pump [J]. Sci China Tech Sci, 2012, 55(8): 1-9

[24] HuangJ-h, QuanL, ZhangX-gang. Development of a dual-acting axial piston pump for displacement-controlled system [J]. Proc Inst Mech Eng, Part B: J Eng Manuf, 2014, 228(4): 606-616

[25] XuB, HuM, ZhangJ-hui. Impact of typical steady-state conditions and transient conditions on flow ripple and its test accuracy for axial piston pump [J]. Chinese Journal of Mechanical Engineering, 2015, 28(5): 1012-1022

[26] HoppermannA. Laser structured contact surfaces—Effects on the tribological behaviour of hydraulic material combinations [J]. Ölhydraulik und Pneumatik, 2004, 48(1): 1-13

[27] IvantysynovaM. The piston cylinder assembly in piston machines—A long journey of discovery [C]. Proceedings of 8th IFK International Conference on Fluid Power. Dresden, Germany: HIDROSTATICNI POGONI, 2012307-332

[28] SunYiResearch on lubrication and power loss of slipper and its matching parts within axial piston pump [D], 2013Xi’an, ChinaHarbin Institute of Technology

[29] ChenQ-P S H-y, FangW-q, HeL-g, YangM-ju. Fluid structure interaction for circulation valve of hydraulic shock absorber [J]. Journal of Central South University, 2013, 20(3): 648-654