What is the inspection and repair of motor parts?

Update:14 Dec 2019
Summary:

The insulation sleeve of the motor parts is complete wi […]

The insulation sleeve of the motor parts is complete without cracks and looseness. The lead connection should be firm, and the insulation resistance value should not be lower than 0.5MΩ at the working temperature of 75 ℃. In terms of the brush device, the lower edge of the brush box and the surface of the motor accessories are required to be 2 ~ 4mm away. If the distance is too large, the brush will jump in the brush box. If it is a hard brush, it may be broken. The brush should slide flexibly in the brush box, the inner surface of the brush box is smooth, the tolerance of the hole diameter in the brush box is H10, and the tolerance of the axial dimension is H8. Brush width and thickness tolerance d11. The gap between the brush and the wall of the brush box should be 0.1 ~ 0.2mm, the gap is too large, the brush will tangentially swing in the brush box, affecting the normal operation of the motor accessories; the gap is too small, causing the brush to be stuck in the brush box, causing similar Electric arc welding burns the surface of the copper ring.

The motor parts should be carefully inspected during maintenance: whether the motor part-type work surface is smooth, and whether there are defects such as burn marks and streaks. The working surface is required to be smooth and free from rust and grease. The external insulation of the motor parts must be properly bound and sealed well. If it is not handled well, it can be tied with synthetic resin impregnated weft-free glass ribbon to prevent the leakage of mica flakes when the motor is running. The fitting of the motor parts with the shaft and the matching of the rings with the insulation sleeve should be firm. Use a small hammer to tap the copper ring and the sleeve with the copper. There should be a metal sound.

The brush should be in close contact with the ring. The pressure difference between the brushes should not exceed 20% of its average. The wound rotor asynchronous motor with a lifting device, the electric shock on the short-circuit ring and the blade on the motor parts evenly contact, the contact area is more than 60%, to avoid causing the rotor to run in single phase or the contact to overheat and lose its elasticity. For slight burn marks, pitting, brush marks and other defects on the surface of the motor parts, you can use oil stone, fine file to polish, and finally polish with zero-zero emery cloth. Under normal circumstances, motor parts should not be turned easily, because one turn will reduce many lifespans.