Bearing assembly method and precautions

Compared to other motor parts, bearings are very precise. In the motor assembly process, the necessary measures should be taken to ensure that the bearing is not contaminated, the bearing cage is not stressed, and finally reach the most ideal state of fit with the associated parts. At present, motor bearing assembly is generally used in two ways, one is the cold press method, the other is the hot set method, two assembly methods have advantages and disadvantages. The cold press method requires the necessary equipment and tooling, and is suitable for mass production of small sizes. The key to the control of this method lies in the coaxiality of the bearing and the rotating shaft during the press-in process; the sleeve for press-in is very critical. On the one hand, every effort should be made to ensure that the sleeve makes the inner and outer rings of the bearing stressed at the same time, and on the other hand, the end face of the bearing sleeve must be maintained regularly to ensure that the shaft bears the force evenly during the press-in process.

Special emphasis must be placed on ensuring that the bearing cage is not subjected to force. For the hot sleeve method, one is oil heat and the other is induction heating. The hot sleeve method is generally used for large-size motor bearings. In comparison, the oil heat method is better and can have effective control of the bearing heating temperature, while induction heating is faster, but the heating temperature and time must be controlled to prevent damage to the bearing material. Bearing knowledge expansion - bearing life under a certain load, the number of revolutions or hours experienced by the bearing before pitting occurs, known as bearing life.

The life of rolling bearing is defined by the number of revolutions or hours of work at a certain speed: within this life, the bearing should not have initial fatigue damage on any of its bearing rings or rolling bodies. Commonly used bearings for electric motors - deep groove ball bearings deep groove ball bearings are the most representative rolling bearings. Compared with other types of bearings of the same size, this type of bearing has a small coefficient of friction, high limiting speed, simple structure, low manufacturing cost, high precision, no need for frequent maintenance, and a large range of sizes and forms, is the most widely used type of bearing. It mainly bears radial load, but also can bear certain axial load. When it only bear radial load, the contact angle is zero.

Deep groove ball bearing installed in the shaft, in the bearing axial clearance range, can limit the shaft or shell two directions of axial displacement, so can be in two directions for axial positioning. When the deep groove ball bearing has a large radial clearance, with angular contact bearing performance, can withstand the larger axial load . In the axial load is very large under high-speed operating conditions, deep groove ball bearings than thrust ball bearings have more superiority.