How to use and install the bearings of the electric motor?
Motor bearings, also known as electric motor bearings or motor bearings, are a specialized type of bearing that is specifically applied to electric motors or motors. A bearing used in an electric motor is a part that supports the shaft, which guides the rotation of the shaft and also withstands the empty rotation of the shaft. There are four types of bearings commonly used in electric motors, namely, rolling bearings, plain bearings, spherical bearings, and oiled bearings. Common motor bearings are rolling bearings, i.e. bearings with rolling elements.
Principle of operation:
Motor bearings utilize smooth metal balls or rollers and lubricated metal surfaces on the inner and outer rings to reduce friction. These balls or rollers “carry” the load and support the motor spindle, allowing the motor (rotor) to rotate smoothly.
Types of Bearings Used
Most small and medium-sized motors use rolling bearings. Large and medium-sized motors also use rolling bearings. Small motors use ball bearings (e.g. deep groove ball bearings) for both ends of the bearing. Medium-sized motors use roller bearings (e.g. cylindrical roller bearings, tapered roller bearings) at the load end. Generally used for high load conditions), non-load end of the ball bearings (but also the opposite situation, such as 1050kW motor). Rolling bearings are lubricated with grease, but also with lubricant.
Mounting of bearings
Good or bad mounting of motor bearings will directly affect the accuracy, life and performance of the bearings. Therefore, please fully study the mounting of the bearings, i.e., please perform the motor bearing mounting in accordance with the operation standards that include the following items.
●Cleaning of motor bearings and related parts (Cleaning is not required before mounting of bearings that have been grease lubricated and bearings that have oil seals or dust caps and seals on both sides.)
●Checking the dimensions and finish of related parts.
Mounting method
Motor bearing mounting should be based on the bearing structure, size and bearing parts with the nature of the determination, the pressure should be added directly in the tight fit to the collar end face, not through the rolling body to transfer the pressure, the motor bearing mounting is generally used as follows:
1, press fit motor bearing inner ring and shaft is a tight fit, the outer ring and bearing hole is loose fit, can be used to press the motor bearing first pressure mounted on the shaft, and then the shaft together with the bearing into the bearing hole, pressure mounting in the motor bearing inner ring end face, pad a soft metal material to do the assembly of the casing (copper or soft steel).
Motor bearing outer ring and bearing hole with a tight fit, the inner ring and the shaft for the looser fit, the motor bearing can be pressed into the bearing hole first, when the outer diameter of the assembly sleeve should be slightly smaller than the diameter of the seat hole.
If the motor bearing collar and shaft and seat holes are tight fit, the installation of the inner ring and outer ring should be pressed into the shaft and seat holes at the same time, the structure of the assembly casing should be able to simultaneously tighten the bearing inner ring and the outer ring of the end face.
2、Heating fit
By heating the motor bearing or bearing seat, the use of thermal expansion will be changed from a tight fit to a loose fit installation method. Is a commonly used and labor-saving installation method. This method is suitable for the installation of motor bearings with a large amount of interference, before the hot installation of motor bearings or separable bearings of the collar into the oil tank uniformly heated 80-100 ℃, and then removed from the oil as soon as possible mounted on the shaft, in order to prevent the cooling of the inner ring end face and the shoulder of the shaft is not tightly adhered to the motor bearings can be cooled and then axially tightened. When the outer ring of the motor bearing is tightly fitted with the bearing housing made of light metal, the hot-fitting method of heating the bearing housing can avoid the fitted surface from being scratched.
When heating the motor bearings with the oil tank, there should be a mesh fence at a certain distance from the bottom of the box, or the motor bearings should be hung by hooks, and the motor bearings should not be put on the bottom of the box to prevent the sinking impurities from entering into the motor bearings or uneven heating, and there must be a thermometer in the oil tank, and the temperature of the oil should not be more than 100 ℃ under strict control to prevent the occurrence of the tempering effect, which can reduce the hardness of the rings.
