Mounting laminated core on shaft of small electric motor - eroding surfaces of shaft in electrical discharge machining process to increase diameter

摘要

The process is used for fixing the laminated iron core of a small electric motor to a shaft such that the shaft diameter is large enough for the loading and is secured adequately. The core is fixed in a pressing operation in which an interference fit is obtained. The diameter of the shaft is increased above the nominal size using an electrical discharge process to erode the surface. This causes pits and craters to be formed with the result that the diameter is enlarged by some 20 to 50 microns. ADVANTAGE - Reduced reject rate within usual mfg. tolerances due to too limited free refractive torque or bowed shafts.