MOTOR FOR INJECTION MOLDING MACHINE, ROTOR OF BURIED MAGNET MOTOR

摘要

A motor for injection molding machine exhibiting excellent durability, and a rotor of a buried magnet motor. In a plate (22) constituting the rotor (20) of a servo motor, a columnar portion (25) formed between adjacent holding holes (24, 24) serves, at a portion between the inner circumferential end (25a) and the intermediate portion (25c) thereof, as a holding portion (30) coming into line contact with a permanent magnet (23) which is thereby locked even during acceleration/deceleration of the servo motor and prevented from moving. Since the permanent magnet (23) does not butt against a specific part of the columnar portion (25) even after a long term use, the columnar portion (25) is protected against abrasion and fracture and its durability is enhanced sharply. The gap between the holding portion (30) of the columnar portion (25) and the permanent magnet (23) may be filled with filler such as electric insulating varnish, adhesive or resin to thereby close the gap between the holding portion (30) and the permanent magnet (23). Consequently, the permanent magnet (23) does not move in the holding hole (24) even during acceleration/deceleration of the servo motor and above-mentioned effect becomes more prominent.