Tribology Performance Optimization Of Gear Pairs With Solid Lubrication

Gear drive is one of the most important driving modes in modern machineries.With the development of industrialization and the extension of gear application area,gears are forward to be developed with advantages such as overloading, high-speed,high precision, high efficiency, high reliability, which requires to improve theperformance of gear in the way of design theory, material, manufacturing processes,experimental technique, etc. Lubrication and friction are important aspects in theresearch of gear performance. Traditional lubricant oil （or grease） can hardly meet thelubrication requirements of gears operating under special and extreme circumstancessuch as high （low） temperature, high vacuum, high load and strong radiation, thus thesolid lubrication technology is developed and applied to gear drive. In this paper,transmission parts of solid lubrication precision filtering driving mechanism （PatentNumber: CN101042180A） invented by Professor Wang Jiaxu in the State KeyLaboratory of Mechanical Transmission of Chongqing University are studied, andanalysis and optimization of tribological properties in gear pair have been carried out,aiming at reducing the friction and wear, as well as shock and vibration, improvingreliability and prolonging the service life. The main research contents are summarizedas follows:①MoS₂acting as solid lubricant film on gear surface is studied. Briefly introducethe structure, properties and preparation principle of MoS₂and quality characterizationmethods of solid lubricant film. Research of stress distribution in solid lubricant film isan important means of evaluating the bonding strength between base body and lubricantfilm. Stress distributions in the film/base body system with different thickness anddifferent elastic moduli amount of lubricant film are calculated using the finite elementmethod.②Explain the structure and working principle of the filtering reducer, and revealthe main tribological behaviors occurred in gear pair including rolling and slidingfriction, meshing impact. A three-dimensional solid model of solid lubrication filteringreducer is built up, then dynamic contact finite element analysis of the model is carriedout. The distribution and variation of stress and strain of gears in the process of meshingare obtained.③Based on the understanding of the finite element theory and method for calculating the distribution of gear temperature field, loading parameter for finiteelement thermal analysis of the filtering reducer is determined. Distributions oftemperature and thermal strain in gear body are calculated, providing reference fordetermination of the amount of gear modification.④Aiming at reducing the friction and wear, preventing meshing impact andoptimizing the tribological properties, tooth profile modification of filtering reducergear is carried out. Based on the gear modification theory and finite element results,tooth modification parameters are determined. Performances of filtering reducer beforeand after profile modification are calculated and compared by finite element analysis.