Motor Quality Problems Caused by Unsuitable Bearings

      Motor bearings are always a topic of more discussion in motor products, different motor products need to match the corresponding bearings, bearing selection is not appropriate, there may be noise, vibration and other problems that directly affect the performance of the motor, serious, affect the service life of the motor.

      Deep groove ball bearing is one of the most widely used bearing types, special operating environment of the motor will have different requirements for bearings, if necessary, bearing materials, manufacturing process and other specific requirements.

      Deep groove ball bearing noise can be transmitted through structural conduction or air media. The deep groove ball bearing in rotation is itself the source of sound or vibration, resulting in bearing vibration or noise, mainly from the natural vibration of the bearing and the vibration generated by the relative movement of the bearing inside.

      In the actual use process, the selection of bearing grease, the filling amount, the installation and later maintenance and use of bearings have a direct impact on the bearing operation. Therefore, in the design stage of the motor, the manufacturing stage and the use and maintenance stage of the customer, the bearing should be necessary and standardized maintenance to avoid the motor quality problems caused by the

Motor bearing selection should pay attention to the elements

the selection of special specifications of motor bearings

● Special materials: requiring excellent anti-rust performance, or working in corrosive environments such as salt water, stainless steel bearings are recommended;

● High temperature tempering treatment: the use of temperature is relatively high, more than 150 degrees, the bearing ring is required to use high temperature tempering heat treatment, the normal heat treatment tempering temperature is 160 degrees for 3 hours, then the high temperature tempering according to the actual situation choose 180 degrees or 220 degrees, or 250 degrees.

● Freezing treatment: After quenching, before tempering, increase a low temperature minus 70 degrees freezing treatment process, the main purpose is to reduce the residual austenite content inside the ring, improve the stability of bearing dimensional accuracy.

Motor bearing seal structure and material selection

The purpose of the bearing seal is to prevent the leakage of the lubricant in the bearing part, and to prevent the intrusion of external dust, moisture, foreign bodies and other harmful objects into the bearing interior, so that the bearing can operate safely and permanently under the required conditions. In the following cases, priority can be given to the selection of sealed bearings that are pre-filled with grease.

● Bearings are not required to operate permanently.

● Medium and low speed, load, temperature operating conditions.
● Low production costs are required.

● Where it is difficult to add lubricant, or where it is not necessary to add lubricant in the future.

Using such bearings, the bearing housing (box) and its seal design can be simplified, greatly reducing manufacturing costs: when the use conditions are not harsh, it can even be operated for a long time, and it is widely used in household appliances, vehicles, motors and other industries.

Selection of grease for motor bearings

In addition to rolling contact, deep groove ball bearings have considerable sliding contact. Therefore, the main purpose of bearings is to reduce the friction and wear of various parts of bearings, and do not produce high temperature melting. Whether the lubrication method and lubricant are appropriate or not directly affects the performance and durability of the bearing. In general, grease has the following functions.

● Reduce friction and wear;

● Friction heat conduction, removal of the bearing due to friction heat, the need to rely on the medium of the lubricant to conduct the heat to it or take away, so that the bearing temperature drops, the lubricant, the bearing can maintain long-term operation.
● Ease the concentration of local stress.

Installation and use of motor bearings.

Rolling bearings are precision components and should be installed and used in a standardized manner. When the bearing is installed, the matching ring should be stressed, that is, when the bearing is pressed on the shaft, the bearing inner ring should be stressed, otherwise the bearing outer ring is stressed; When the shaft and bearing chamber are assembled at the same time, the bearing inner and outer rings must be stressed at the same time. Bearing cages should not be subjected to external forces under any conditions.