Hydrodynamic load carrying capacity analysis of planet gear thrust washer used in high-speed planetary transmission

Aimed at washer in planetary transmission, the wear problem of thrust washer and planet gear due to the force in axis direction was investigated. In order to reduce wear, hydrodynamic lubrication design was studied by way of machining rectangular groove in radial direction into one side of thrust washer. The purpose of hydrodynamic lubrication design is that the relative movement between planet gear and thrust washer results into hydrodynamic pressure, which can separate the contact surface and reduce the wear accordingly. Rectangular groove was chosen to study because of its symmetrical structure, capability to rotate in two directions and easy method. The finite difference method was used to calculate the structural parameter of thrust washer for optimal carrying capacity design. The results show that when the ratio of groove angle to periodic groove angle is about 0.5, the carrying capacity is the best; when the number of grooves is in a range of 20 to 45, the carrying capacity is better; The wider the radial width of washer is, the higher the carrying capacity is. Focus on the less number of grooves in a range of 2 to 12, the carrying capacity analysis was made for guiding engineering practice.