As an important part of the motor, the motor housing has strict requirements for its dimensional accuracy in many aspects.
1. Inner diameter accuracy
The inner diameter accuracy of the motor housing is crucial. For the part where the rotor is installed, the inner diameter size must be accurate, and its tolerance range is usually controlled within a very small value. For example, in a small motor casing processing, the inner diameter tolerance may be within ±0.05 mm. This is because the gap between the rotor and the housing directly affects the performance of the motor. If the inner diameter is too small, the rotor may not be installed smoothly, and may even rub against the housing during operation, causing the motor to overheat, reduce efficiency, and excessive wear of parts. On the contrary, if the inner diameter is too large, the air gap of the motor will be uneven, affecting the magnetic field distribution, and then affecting the torque output and operation stability of the motor.
2. Outer diameter accuracy
The outer diameter accuracy of the housing should not be ignored. During the assembly process of the motor, the housing needs to cooperate with other components (such as end covers, etc.). Excessive deviation in the outer diameter dimensional accuracy may cause assembly difficulties or unstable overall structure of the motor after assembly. Generally speaking, the dimensional tolerance of the outer diameter also needs to be controlled within ±0.1 mm to ensure close fit with other components, ensure the sealing and integrity of the motor during operation, and prevent impurities such as dust and moisture from entering the motor and affecting the normal operation of the motor.
3. Length Accuracy
The length accuracy of the motor casing is also strictly required. The length of the casing determines the spatial layout inside the motor, which has an important impact on the installation of the stator winding and the overall axial size of the motor. If the casing length is too long or too short, it will affect the installation position and tension of the stator winding, and then affect the electrical performance of the motor. During the processing, the tolerance of the casing length may be limited to ±0.2 mm to ensure the reasonable axial layout of the various components inside the motor.
4. Concentricity Requirements
Concentricity is one of the extremely strict dimensional accuracy requirements in Motor Casing Processing. A high degree of concentricity needs to be maintained between the inner hole, outer circle and mounting surface of the casing. For example, if the concentricity deviation between the inner hole and the outer circle is too large, the motor will generate unbalanced force during operation, causing vibration and noise, and reducing the service life of the motor. The concentricity deviation is usually required to be controlled within 0.03-0.05 mm to ensure the smooth operation of the motor.
5. Flatness and verticality
The installation plane of the housing and the verticality between the parts are also within the strict requirements of dimensional accuracy. Poor flatness will affect the close fit of components such as the end cover and the housing, resulting in poor sealing. The verticality deviation may affect the relative position relationship between the components inside the motor, and thus affect the performance of the motor. For these precision requirements, the deviation is usually controlled within a very small value to ensure the rationality of the overall structure of the motor and the reliability of operation.
