Test study on the effect of lubricants on E-axle power loss

Abstract

ObjectiveThe typical input speed of the electric drive axle is 12 000-22 000 r/min, but the existing research work basically focuses on the gearbox, drive axle and other gear transmission devices used in traditional internal combustion engines. The difference in operating conditions will lead to the difference in the impact law of power loss. At the same time, the existing research has not classified and analyzed the oil mixing loss and the loss of different transmission levels. Based on the above issues, power loss tests were conducted on a high-speed electric drive axle for a certain light commercial vehicle under different oil types, oil temperatures, oil levels, and other conditions.MethodsBased on bench tests, this article studied the influence of lubricating oil on the power loss of a certain electric drive bridge, and analyzed the influence of lubricating oil formula, oil temperature, and oil quantity factors on the transmission efficiency of the drive system.ResultsThe test results show that the E-axle power loss is significantly influenced byoperating conditions, oil formulations, oil temperatures, and oil levels. Under nominal operating conditions of the E-axle, the no-load power loss accounts for more than 80% of the total power loss, of which the first stage component accounts for more than 80% of the no-load power loss. Selecting appropriate lubricant formulas, reducing the oil level, and adjusting the oil temperature are effective measures for power loss reduction, with a potential efficiency improvement of more than 1.04%, 3.90%, and 1.60%, respectively. The achieved results can be utilized to improve the E-axle.

Keywords

• Power loss
• Lubricating oil
• E-axle
• Bench test
• Churning loss