Motor bearings, also known as motor bearings or motor bearings, are special bearings specially used in motors or motors. The bearing used by the motor is a part that supports the shaft, it can guide the rotation of the shaft, and it can also bear the idling parts on the shaft. There are four types of bearings commonly used in motors, namely rolling bearings, sliding bearings, joint bearings and oil bearings . The most common motor bearings are rolling bearings, ie bearings with rolling elements.

working principle

Electric motor bearings utilize smooth metal balls or rollers and lubricated inner and outer ring metal surfaces to reduce friction. These balls or rollers "carry" the load and support the motor shaft so that the motor (rotor) can spin smoothly.

Bearing use type

Most small and medium-sized motors use rolling bearings, and large and medium-sized motors also use rolling bearings . Bearings at both ends of small motors use ball bearings (such as deep groove ball bearings). Medium-sized motors use roller bearings at the load end (such as cylindrical roller bearings, tapered roller bearings. Generally used for high load conditions), and ball bearings at the non-load end (but there are also opposite cases, such as 1050kW motors). Rolling bearings are lubricated with grease, but they are also lubricated with oil.

Bearing installation

Whether the motor bearing is installed or not will directly affect the accuracy, life and performance of the bearing. Therefore, please fully study the installation of the bearings, that is, please install the motor bearings according to the operating standards including the following items.

●Clean the motor bearings and related parts, (For bearings that have been greased and have oil seals or dust covers on both sides, there is no need to clean the seal ring bearings before installation.)

●Check the dimensions and finishing conditions of related parts

installation method

The installation of the motor bearing should be determined according to the bearing structure, size and the matching properties of the bearing components. The pressure should be directly applied to the end face of the tight fit ring, and the pressure should not be transmitted through the rolling elements. The motor bearing installation generally adopts the following methods:

1. Press fit

When the inner ring of the motor bearing is tightly fitted to the shaft, and the outer ring is loosely fitted to the bearing seat hole, the motor bearing can be first pressed onto the shaft by a press, and then the shaft together with the bearing is put into the bearing seat hole and pressed into place. At the same time, on the end face of the inner ring of the motor bearing, place an assembly sleeve made of soft metal material (copper or mild steel).

When the outer ring of the motor bearing fits tightly with the housing hole and the inner ring fits loosely with the shaft, the motor bearing can be pressed into the bearing housing hole first. At this time, the outer diameter of the fitting tube should be slightly smaller than the diameter of the housing hole.

If the bearing ring of the motor is tightly fitted with the shaft and seat hole, the inner ring and outer ring should be pressed into the shaft and seat hole at the same time during installation, and the structure of the assembly sleeve should be able to press the end faces of the inner ring and outer ring of the bearing at the same time .

2. Heating coordination

It is a common and labor-saving installation method to change the tight fit into loose fit by heating the motor bearing or bearing housing and using thermal expansion. This method is suitable for the installation of motor bearings with large interference. Put the ring of the motor bearing or separable bearing into the oil tank and heat it evenly at 80-100°C before hot fitting, then take it out of the oil and install it on the shaft as soon as possible. , In order to prevent the end face of the inner ring and the shaft shoulder from not being tightly fitted after cooling, the motor bearing can be tightened axially after cooling. When the outer ring of the motor bearing is tightly fitted with the bearing seat made of light metal, the heat-fitting method of heating the bearing seat can be used to avoid the mating surface from being scratched.

When using the oil tank to heat the motor bearing, there should be a grid at a certain distance from the bottom of the tank, or the motor bearing should be hung with a hook. There must be a thermometer to strictly control the oil temperature not to exceed 100°C to prevent the tempering effect and reduce the hardness of the ferrule.