Calculating method of the fatigue life for the main supporting bearing of mixing drum in concrete mixing truck when considering drum's vibration

It has been observed that there are many studies focusing on the vibration properties of bearings caused by manufacturing errors, assembly related errors, out-of-balance rotor rotation, cage instability, etc. But there are fewer research studies on the effect of rotor's vibration on double-row rolling element bearings' mechanical properties. In this paper, a calculating method has been established for bearing's roller load and fatigue life when considering rotor's vibration. And this model is applied to study the main supporting bearing of the mixing drum of a certain type of concrete mixing truck with the consideration of the mixing drum's vibration. The effects of rotating speed, inclination angle, concrete liquid level, and rolling wheels' supporting position on the roller load and bearing's fatigue life are studied with a specific example with and without considering the mixing drum's vibration. Results show that with the increase in the rotating speed, the bearing roller's maximum load decreases, while the fatigue life of main supporting bearing increases. With the decrease of the concrete liquid level, there is increase in the inclination angle and the movement of rolling wheel from left to right, and the bearing roller's maximum load increases, while the fatigue life of main supporting bearing decreases. The changes of the mixing drum's inclination angle have tremendous effect on bearing's fatigue life, while the change in the rolling wheel's supporting position has little influence on the fatigue life of the main supporting bearing. When considering the mixing drum's vibration, the roller's maximum load is larger than that without considering mixing drum's vibration, while the fatigue life of the main supporting bearing is shorter than that without considering mixing drum's vibration.