Motor bearing use and installation
Motor bearings, also known as motor bearings or motor bearings, are special bearings for motors or motors. The bearing used in the motor is a part that supports the shaft and can guide the rotation of the shaft as well as the parts that are idle on the shaft. There are four types of bearings commonly used in motors, namely rolling bearings, plain bearings, joint bearings and oil-impregnated bearings. The most common motor bearings are rolling bearings, ie bearings with rolling elements.
working principle
Motor bearings use smooth metal balls or rollers and lubricated inner and outer ring metal faces to reduce friction. These balls or rollers "bear" the load and support the motor shaft so that the motor (rotor) can rotate smoothly.
Bearing type
Most of the small and medium-sized motors use rolling bearings. Large and medium-sized motors also use rolling bearings. Ball bearings (such as deep groove ball bearings) are used for the bearings at both ends of the small motor. 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 are used for non-load ends (but the opposite is true, such as 1050 kW motors). Rolling bearings are lubricated with grease but 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 bearing, that is, install the motor bearing in accordance with the operating standards including the following items.
● Clean the motor bearings and related parts. (For grease-lubricated bearings and double-sided oil seals or dust caps, seal bearings are not required to be cleaned before installation.)
●Check the size and finishing of related parts
installation method
The installation of the motor bearing should be based on the bearing structure, size and the matching nature of the bearing components. The pressure should be directly applied to the end face of the ferrule. The pressure should not be transmitted through the rolling element. The motor bearing installation generally adopts the following methods:
1, press fit
The inner ring of the motor bearing is tightly matched with the shaft. When the outer ring and the bearing housing hole are loosely fitted, the motor bearing can be first press-fitted on the shaft by the press, and then the shaft is fitted into the bearing housing hole together with the bearing, and the press fit is performed. On the end face of the inner ring of the motor bearing, a mounting sleeve (copper or mild steel) made of soft metal material is used.
The outer ring of the motor bearing is tightly matched with the bearing housing hole. When the inner ring and the shaft are loosely fitted, the motor bearing can be first pressed into the bearing housing hole. At this time, the outer diameter of the assembly sleeve should be slightly smaller than the diameter of the housing hole.
If the motor bearing ring is tightly fitted with the shaft and the seat hole, the inner ring and the outer ring should be pressed into the shaft and the seat hole at the same time during installation. The structure of the assembly sleeve should be able to simultaneously tighten the end faces of the inner ring and the outer ring of the bearing. .
2, heating and cooperation
By heating the motor bearings or housings, thermal expansion is used to transform the tight fit into a loose fit installation method. It is a common and labor-saving installation method. This method is suitable for the installation of motor bearings with large interference. Before the hot assembly, put the motor bearing or the ferrule of the separable bearing into the fuel tank and heat it evenly at 80-100 °C, then remove it from the oil and load it on the shaft as soon as possible. In order to prevent the inner ring end face and the shoulder from sticking tightly after cooling, the motor bearing can be axially tightened after cooling. When the outer ring of the motor bearing is tightly matched with the bearing seat made of light metal, the hot mounting method of the heated bearing seat can avoid the abrasion of the mating surface.
When heating the motor bearing with the fuel tank, there should be a grid at a certain distance from the bottom of the box, or the motor bearing should be hung with a hook. The motor bearing can not be placed on the bottom of the box to prevent the sinking of impurities into the motor bearing or uneven heating, in the fuel tank. There must be a thermometer, and the oil temperature should not be strictly controlled to exceed 100 °C to prevent the tempering effect and reduce the hardness of the ferrule.
