Test And Analysis Of Gear Wear Response Under Alternating Load

Gear transmission has many advantages such as compact structure,accurate transmission ratio,and high transmission efficiency.It is a widely used transmission method in mechanical equipment.Under many operating conditions,the impact of alternating loads will lead to shortened gear life,cause equipment failure and safety accidents,and cause unnecessary economic losses.Therefore,in this paper,by establishing a gear friction and wear test bench capable of realizing dynamic loading,the failure form and evolution mechanism of gears under alternating loads are studied.Construct a friction and wear test bench for alternating load gears.According to the experimental requirements,specific design schemes for power input,resistance loading,and oil circulation of the test platform are proposed.The power input mainly introduces the motor selection design and the realization of stepless speed change.It is required to meet the simple and adjustable speed and stable power output.In terms of resistance loading,the design scheme of dynamic load loading of three springs and constant load loading of half coupling is proposed.Numerical calculations were carried out.The oil circulation scheme of the peristaltic pump was designed to achieve the requirements of preventing uneven distribution of oil abrasive particles and real-time collection of oil samples without stopping.Taking the experimental helical gear as the research object,a three-dimensional simulation model with the same parameters as the experimental gear was established.The finite element dynamics was used to analyze the stress distribution during the gear meshing process.The results show that during the gear meshing process,the pinion receives maximum stress at the tooth root and is prone to fracture Failure.Based on the maximum stress,the gear’s alternating load spectrum is simulated and the gear’s fatigue specific curve is derived.The nominal fatigue method is used to calculate the gear’s fatigue life under near experimental conditions.The analysis results meet the fatigue design requirements.Gear friction and wear experiments were conducted to explore the evolution mechanism of gear wear under alternating loads.The article analyzes the experimental results in terms of wear rate,oil abrasive particles,and tooth surface morphology.It is found that due to the impact of alternating loads,there are a lot of abnormal gear running and period,and the initial running state is easy to be unbalanced.The stable wear period is small.The number of abrasive particles is much higher than the small amount of abrasive particles under a constant load,and the stable running time is short;the gears have strong adhesive wear and sliding wear in the later period of operation.A new oil pollution assessment model is proposed,which has better accuracy and flexibility,and can predict the wear state of gears.From the perspective of the tooth surface morphology,the tooth tip and root of the gear are dominated by adhesive wear,and the pitting at the index circle is serious.Under the influence of alternating load,the pitting area at the index circle is relatively large,and the pitting is more extensive;the wear at the tooth root is the most serious,and the brittleness of the surface material is greatly increased.Fluid intensifies the wear process.