Skateboard brushless DC motor bearing, also known as motor bearing or motor bearing, is a special bearing specially applied to the motor or motor. The bearing used in the motor is a part that supports the shaft. It can guide the rotation of the shaft and can also withstand the idling parts on the shaft. The concept of the bearing is very broad. There are four types of bearings commonly used in motors, namely rolling bearings, sliding bearings, joint bearings and oil-impregnated bearings. Common motor bearings are rolling bearings, and DC brushless motors use rolling bearings.
Today we will briefly analyze the precautions when selecting bearings for brushless DC motors:
Used in a low temperature environment, the design of the bearing radial clearance will cause abnormal noise in the motor, that is, loud noise. Under low temperature conditions, the outer ring of the bearing shrinks, causing the radial clearance to become smaller, and the radial clearance of the bearing goes down to tolerance during manufacturing. The brushless DC motor will cause the ball to run and hard friction with the raceway, which will cause abnormal noise. When the bearing is assembled, the inner ring of the bearing is squeezed, which will also cause the radial clearance to become smaller.
1.Check whether the assembly process of the skateboard brushless DC motor bearing is abnormal, including the bearing size of the motor shaft and the R angle of the shaft end;
2.Adjust the bearing radial clearance. Increase the bearing radial clearance (for example, adjust the tolerance from 5-12μ to 8-15μ), replace the bearing on the initial abnormal feedback DC brushless motor, and then run at low temperature to check whether the same abnormal noise occurs. The plan is demonstrated. If the radial clearance is adjusted too large, the bearing is prone to runout problems (especially in a high temperature environment). The synchronization of the adjustment of the radial clearance of the bearing requires an increase in the assembly pre-pressure of the bearing. The rectification design plan of the DC brushless motor Certain adjustments are required; the radial clearance of the bearing is reduced to simulate the hard friction between the ball running and the raceway. On the motor with abnormal feedback at the initial stage, check whether there will be similar differences when running at low temperature when the motor is powered on at room temperature. Demonstration of the plan based on the impact of the situation.
3.Perform difference analysis on the physical characteristics of bearing grease. The grease of the abnormal noise motor bearing generally increases the viscosity of the base oil at low temperatures, and the excessively high oil viscosity affects the centrifugal oil separation and migration flow. This kind of grease is prone to wear in the anti-vibration packaging of long-distance transportation, which further leads to the appearance of low-temperature abnormal noise.