Study on the surface durability of grease lubrication gears. A comparison of the surface failure and tooth temperature between grease and oil lubrication.

To compare grease lubrication with oil bath lubrication, observation of the tooth surface and measurement of the temperature rise were carried out using grease material with very similar properties to oil material. The value of the loading force was changed from Pn = 0.0 kN/m to 471.9 kN/m in steps, and the value of the pitch line velocity was also changed from V = 1.59 m/s to 6.19 m/s. The main results of the present investigation were as follows : (1) In the case of grease lubrication, the scoring was observed at a lower load condition compared with the load condition of the pitting in the oil bath lubrication. (2) The temperature of the grease rose rapidly and the temperature rise of the tooth in the grease increased about 1.7 times more than in the oil bath.