Miniature motor.

摘要

A miniature motor comprises a motor case (1) in the form of a tubular body closed at one end with a case cap (6) fitted to the open end. Permanent magnets (2) are fitted within the case (1), and a rotor (5) having an armature (3) and a commutator (4), is mounted in bearings (9,10) in the case cap (6) and the closed end of the case to rotate with the armature in the magnetic field created by the magnets (2). Brushes (7) making sliding contact with the commutator (4) and connected to supply terminals (8). According to the invention, the atmosphere within the motor case (1) comprises at least one conditioning compound selected from polymethacrylate, polyacrylate, polyisobutylene, low molecular weight polyethylene, low molecular weight polypropylene, ethylene-propylene copolymer, polyvinyl acetate and polybutene. Typically, the atmosphere in the motor case (1) comprises more than two said conditioning compounds. <IMAGE>