Permanent magnet motor

Claim 2

A synchronous motor with stator and rotor parts axially aligned in a casing formed of electrical insulation material, said casing comprising a shell with a top rim and having a bottom portion formed with pilot means, the axis of said assembled stator and rotor parts being aligned with reference to said pilot means, and a cover of electrical insulation material having a deformable resilient inner convex face for the top of the shell, said cover having a projection on the inner convex face thereof directly engageable with an adjacent stator part, said cover being deformed about said projection into engagement with said top rim and secured to said top rim of said shell such that said projection maintains said parts in centered relation with the said pilot means.

Claim 3

The invention defined in claim 1, wherein said stator parts include upstanding pole pieces engaged with the bottom portion of said casing; and wherein said defomed cover imparts axial thrust to said assembled motor parts through said projection to forcably engage said pole pieces with said bottom portion of said casing.

Claim 4

The invention defined in claim 1, wherein said motor parts include nested pole pieces having axially spaced base portions formed with aligned center openings, core means between said base portions, boss projections at each end of the said core means engaged snugly in each of said aligned center openings of the spaced base portions, a stator coil bobbin on said core between said base portions having coil leads extending therefrom, salient pole fingers axially extending in alternately spaced relation from each of said pole pieces with their ends terminating adjacent the interior of the bottom waLl of the casing to define an annular area, a permanent magnet rotor within the axially extending alternately spaced pole fingers, said rotor including a hollow rotor shaft centered in said annular area, said hollow rotor shaft being mounted to rotate with said rotor on a stub shaft centrally extending from an end of said core means, a thrust bearing on an end of said rotor shaft engageable with said end of said core, a second thrust bearing formed on a surface of said rotor opposite to said first mentioned thrust bearing, said second bearing being engageable with the interior bottom wall of the casing.

Claim 5

The invention defined in claim 3, wherein said rotor comprises a disc with a permanent magnet ring secured thereon and centered around said hollow shaft.

Claim 6

The invention defined in claim 4, wherein said permanent magnet ring is formed of elastic material and stretch-fitted over said rotor disc.

Claim 7

The invention defined in claim 4, wherein said permanent magnet ring and said rotor disc further include interlocking spline means maintaining said magnet ring in predetermined indexed position on said rotor disc.

Claim 8

The invention defined in claim 3, wherein said rotor comprises a rotor disc formed with a countersunk inboard side face and an outboard side face, said countersunk side providing a chamber to receive a lug projecting from the outboard side of said bobbin and shaft means coaxial with said disc; and a direction control lever mounted on said lug engageable with said shaft means to block rotation of said rotor in one direction to provide a one-way drive to said rotor disc from an indexed start position between the salient pole fingers and the permanent magnet on said rotor disc.

Claim 9

The invention defined in claim 3, wherein said casing shell rim at the open end thereof is formed with spaced cut-outs and said cover includes an inward projecting portion with spaced cut-outs for registry with said cut-outs in the shell rim; said coil leads from said coil bobbin being clenched by the walls of the cut-outs to hold the said leads and thereby preclude stress on the lead connections to said stator coil.

Claim 10

The invention defined in claim 3, wherein said stator parts include upstanding pole pieces engaged with the bottom portion of said casing; and wherein said deformed cover imparts axial thrust to said assembled motor parts through said projection to forceably engage said pole pieces with said bottom portion of said casing.

Claim 11

The invention defined in claim 7, wherein said stator parts include upstanding pole pieces engaged with the bottom portion of said casing; and wherein said deformed cover imparts axial thrust to said assembled motor parts through said projection to forceably engage said pole pieces with said bottom portion of said casing.

Claim 12

The invention defined in claim 8, wherein said stator parts include upstanding pole pieces engaged with the bottom portion of said casing; and wherein said deformed cover imparts axial thrust to said assembled motor parts through said projection to forceably engage said pole pieces with said bottom portion of said casing.

Claim 13

A synchronous motor as described in claim 1, in combination with a gear case having a top plate, and a guide opening formed in the said top plate; said pilot means formed on the bottom portion of said housing fitting snugly in said guide opening in the top plate of the gear case to provide centered driving connection to a gear of a gear train in the gear case.

Claim 14

A synchronous motor as described in claim 2, in combination with a gear case having a top plate, and a guide opening formed in the said top plate; said pilot means formed on the bottom portion of said housing fitting snugly in said guide opening in the top plate of the gear case to provide centered driving connection to a gear of a gear train in the gear case.

Claim 15

A synchronous motor as described in claim 3, in combination with a gear case having a top plate and a guide opening formed in the said top plate; said pilot means formed on the bottom portion of said housing fitting snugly in said guide opening in the top plate of the gear case to provide centered driving connection to a gear of a gear train in the gear case.

Claim 16

A synchronous motor as described in claim 1, wherein said pilot means formed on the bottom of said housing comprises a hollow guide boss and wherein one of said rotor parts includes a shaft with a rotor pinion.

Claim 17

A synchronous motor as described in claim 15, in combination with a gear case having a top plate with a guide opening in mating relation with said hollow guide boss permitting central projection of said rotor shaft with a pinion through said guide opening and said holow guide boss into drive connection with a gear train in said gear case.