| 摘要 |
PURPOSE:To make it possible to have a stable separation of a conductive body and a core constantly at conducting a heat shock treatment, by installing a ring of a specified material on a circumferencial portion contacting both end surfaces of a core and performing diecasting upon it. CONSTITUTION:A ring 4 of a high electric resistance and a heat expansion coefficienct, for instance, of iron is installed on a circumferencial portion contacting both end surfaces of a laminated core 1 which has half-closed grooves, and a cage rotor is formed by diecasting a conductive body 2 and an end ring 2a. This method makes it possible to separate the core 1 and the conductive body 2 at all times without being pressed to stick together, even if conducting a heat shock treatment separating the core 1 and the conductive body 2 by heating and cooling the rotor rapidly. |
