Lubrication characteristics of cycloid pin wheel transmission of RV reducer

Abstract

In order to analyze the lubricating characteristics at different meshing points in the cycloid pin wheel transmission process, the cycloid gear teeth were discretized, combined with the kinematic analysis of the cycloid pin gear transmission and the contact analysis of the gear teeth. The progressive mesh densification method (PMD) was used to numerically solve the film thickness. The influence of the design parameters and process parameters on the lubrication characteristics was analyzed. The elastohydrodynamic lubrication and mixed lubrication characteristics at different contact points were obtained. The optimal meshing area of the cycloid gear tooth was determined, and the film thickness ratio, contact load ratio, maximum contact pressure at different points, average film thickness and roughness after contact deformation were analyzed. The conclusion of this study provides effective guidance for the research on the modification of cycloid gear teeth.

Keywords

cycloid pin wheel transmission / tooth modification / lubrication characteristics

References

[1] WangH, ShiZ-y, YuB, XuH. Transmission performance analysis of RV reducers influenced by profile modification and load [J]. Applied Sciences, 2019, 9(19): 4099

[2] ShiX-j, SunW, LuX-q, MaX, ZhuD, ZhaoB, HeT. Three-dimensional mixed lubrication analysis of spur gears with machined roughness [J]. Tribology International, 2019, 140: 105864

[3] ZhaoQ, HeS-J. Analysis of EHL in cycloid planetary gearing [J]. Lubrication Engineering, 1997, 22619-21(in Chinese)

[4] JiangY-z, WangY-q, YuP. The transient EHL analysis of the cycloidal pinwheel planetary gearing mechanism [J]. Lubrication Engineering, 2014, 39(12): 12-1523. (in Chinese)

[5] JIANG Yuan-zhi, WANG You-qiang, LU Xian-jiu. The influence of single rough peak on the elastohydrodynamic lubrication of cycloid pinwheel [J]. Machinery Design & Manufacture, 2014(12): 49–52. (in Chinese)

[6] WeiB, WangJ-x, ZhouG-w, YangR-s, ZhouH-j, HeT. Mixed lubrication analysis of modified cycloidal gear used in the RV reducer [J]. Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology, 2016, 230(2): 121-134

[7] SunZ-d, ZhuC-c, LiuH-j, SongC-s, GuZ-L. Study on starved lubrication performance of a cycloid drive [J]. Tribology Transactions, 2016, 59(6): 1005-1015

[8] ZhuC-c, SunZ-d, LiuH-j, SongC-s, GuZ-L. Effect of tooth profile modification on lubrication performance of a cycloid drive [J]. Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology, 2015, 229(7): 785-794

[9] ZhuD, AiX-L. Point contact EHL based on optically measured three-dimensional rough surfaces [J]. Journal of Tribology, 1997, 119(3): 375-384

[10] ZhuD, HuY-Z. The study of transition fromelastohydrodynamic to mixed and boundary lubrication [C]. Proceedings of the 1999 STLE/ASME Tribology Surveillance, 1999, Park Ridge, STLE/ASME, 150-156

[11] HuY-z, ZhuD. A full numerical solution to the mixed lubrication in point contacts [J]. Journal of Tribology, 2000, 122(1): 1-9

[12] LiuY-c, WangQ J, WangW-z, HuY-z, ZhuD. Effects of differential scheme and mesh density on EHL film thickness in point contacts [J]. Journal of Tribology, 2006, 128(3): 641-653

[13] WangW-z, HuY-z, LiuY-c, WangH. Deterministic solutions and thermal analysis for mixed lubrication in point contacts [J]. Tribology International, 2007, 40(4): 687-693

[14] ZhuD. On some aspects of numerical solutions of thin-film and mixed elastohydrodynamic lubrication [J]. Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology, 2007, 221(5): 561-579

[15] HeT, RenN, ZhuD, WangJ-X. Plasto-elastohydrodynamic lubrication in point contacts for surfaces with three-dimensional sinusoidal waviness and real machined roughness [J]. Journal of Tribology, 2014, 136(3): 031504

[16] HeT, WangJ-x, WangZ-j, ZhuD. Simulation of plasto-elastohydrodynamic lubrication in line contacts of infinite and finite length [J]. Journal of Tribology, 2015, 1374041505

[17] HeT, ZhuD, WangJ-x, WangQ J. Experimental and numerical investigations of the Stribeck curves for lubricated counterformal contacts [J]. Journal of Tribology, 2017, 1392021505

[18] OKAMURA H. A contribution to the numerical analysis of isothermal elastohydrodynamic lubrication [C]// Tribology of Reciprocating Engines: Proceedings of the 9th Leeds-Lyon Symposium on Tribology. Butterworths, Guilford, England, 1982: 313–320. https://ci.nii.ac.jp/naid/10027808483.

[19] HughesT G, ElcoateC D, EvansH P. Coupled solution of the elastohydrodynamic line contact problem using a differential deflection method [J]. Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, 2000, 2144585-598

[20] VennerC HMultilevel Solution of the EHL Line and Point Contact Problems [D], 1991, Netherlands, USA, University of Twente

[21] AiX-LNumerical analyses of elastohydrodynamically lubricated line and point contacts with rough surfaces by using semi-system and multigrid methods [D], 1993, Evanston, USA, Northwestern University

[22] PuW, WangJ-x, ZhuD. Progressive mesh densification method for numerical solution of mixed elastohydrodynamic lubrication [J]. Journal of Tribology, 2016, 138(2): 021502

[23] ZhaoJ-x, SadeghiF, HoeprichM H. Analysis of EHL circular contact start up: part II: Surface temperature rise model and results [J]. Journal of Tribology, 2001, 123175-82

[24] ZhaoJ-x, SadeghiF. Analysis of EHL circular contact shut down [J]. Journal of Tribology, 2003, 125(1): 76-90

[25] LuX-q, DongQ-b, ZhouK, ZhaoB, ZhaoB. Numerical analysis of transient elastohydrodynamic lubrication during startup and shutdown processes [J]. Journal of Tribology, 2018, 140(4): 041504

[26] WangZ-z, PuW, HeT, WangJ-x, CaoW. Numerical simulation of transient mixed elastohydrodynamic lubrication for spiral bevel gears [J]. Tribology International, 2019, 13967-77

[27] LiT-x, AnX-t, DengX-z, LiJ-f, LiY-L. A new tooth profile modification method of cycloidal gears in precision reducers for robots [J]. Applied Sciences, 2020, 10(4): 1266

[28] LiL-X. The modification manner for tooth profile and the analysis of forces on the cycloid disk of a cycloid speed reducer [J]. Journal of Dalian Railway Institute, 1984, 5429-40(in Chinese)

[29] ZhuD, WangJ-x, RenN, WangQ J. Mixed elastohydrodynamic lubrication in finite roller contacts involving realistic geometry and surface roughness [J]. Journal of Tribology, 2012, 134(1): 011504

[30] RoelandsC J ACorrelational aspects of the viscosity-temperature-pressure relationship of lubricating oils [D], 1966, The Netherlands, Technische Hogeschool Delft

[31] DowsonD, HigginsonG R. Lubrication of rigid cylinders [M]. Elasto-Hydrodynamic Lubrication, 1977, Amsterdam, Elsevier, 30-44

[32] KumarR, AzamM S, GhoshS K, KhanH. Thermo-elastohydrodynamic lubrication simulation of the Rayleigh step bearing using the progressive mesh densification method [J]. Simulation, 2019, 95(5): 395-410

[33] SunZ-d, RenA-h, WangH-x, SongJ. Analysis of starved lubrication characteristics for a cycloid drive [J]. Lubrication Engineering, 2019, 44(7): 69-77(in Chinese)

[34] WANG Q J, ZHU Dong. Interfacial mechanics: theories and methods for contact and lubrication [M]. CRC Press, 2019.

[35] ZhuD, WangQ J. On the X ratio range of mixed lubrication [J]. Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology, 2012, 226(12): 1010-1022