Magnet-retaining structure for motor

Claim 1

In a motor comprising a cylindrical blind casing (2) having an opening (9) formed at one end thereof, an end bracket (13) attached to said opening (9) and adapted to close said opening (9), two semicircular magnets (4, 4) inserted in said casing (2), an armature (14) rotated across the magnetic lines of flux formed by said magnets (4, 4), a brush (16) for supplying electric current to said armature (14) through the medium of a commutator (15), and a coupler (17) for supplying external electric current to said brush (16), a magnet-retaining structure which is characterized by the fact that a coupler insertion hole (12) for permitting attachment of said coupler (17) is formed in said casing (2) by incising a passage down said opening (9) of said casing (2), first stoppers (5a, 5b) respectively abutting axial end faces (23b) of each of said magnets (4, 4) which are on the side remote from said opening (9) and regulating the positions in the axial direction of said magnets (4, 4) on the side remote from said opening (9) and second stoppers (6a, 6b) respectively abutting opposed first circumferential end faces (7a) of each of said magnets (4, 4) and regulating the positions in the circumferential direction of said magnets (4,4) formed on the inner wall surface of said casing (2), a resilient retainer (8) which is formed by bending a resilient material in the general shape of the letter U and adapted to urge said magnets (4, 4) with the resilient force tending to press said magnets (4,4) outwardly in the radial direction inserted between opposed second circumferential end faces (7b) of each of said magnets (4, 4), with the open leg side (8b) thereof disposed on said opening (9) side, said coupler (17) having formed integrally therewith a retainer part (43) adapted to abut the neighboring parts of said opposed second circumferential end faces (7b) of axial end faces (23a) on the opening (9) side of each of said magnets (4, 4) which admit the insertion of said resilient retainer (8), said coupler (17) being slid home in said coupler insertion hole (12) from said opening (9) side so as to be nipped between said axial end faces (23a) of each of said magnets (4, 4) and the inner wall surface of said end bracket (13).