It is known from the test results that for the low-speed and heavy-duty lubricated gears with circumferential velocity v = 1-4m / s, the tooth wear rate is related to the circumferential velocity, and there is a worst value. When the gear moves at the worst speed, the wear rate is the highest. When the speed is lower than the worst speed, the wear rate decreases rapidly. When the speed is higher than the worst speed, the wear rate decreases slowly.
The results also show that the wear loss and the worst speed decrease with the increase of material strength, tooth surface hardness and lubricant viscosity. For the nitrided quenched and tempered gear pair, the wear loss is obviously reduced. The wear curve tends to be flat, the influence of circumferential velocity on wear rate is weakened, and the worst velocity value does not decrease.
Under the test conditions, the worst speed of the first pair of test gears is around v = 1.41m/s, and the worst speed of the second and third pair of test gears is around v = 1.13m/s, as shown in the figure.