Effects of Lubricant Properties on Lubricating Performance of Tripod Sliding Universal Joints under Thermal Condition

The effects of the lubricant properties on the lubricating performance of the tripod sliding universal joint were studied under thermal condition by numerical method. The obtained results show that increasing lubricant viscosity increases the film thickness whereas increasing viscosity-pressure coefficient or viscosity-temperature coefficient is just the reverse. The pressure hardly depends on the viscosity-pressure coefficient or viscosity-temperature coefficient, and a larger lubricant viscosity induces only a remarkable second pressure peak. Increasing lubricant viscosity or viscosity-pressure coefficient increases the temperature whereas the increasing viscosity-temperature coefficient reduces it.