Miniature motor with a frequency generator

Claim 1

A miniature motor and frequency generator arrangement, comprising: a bell-shaped housing portion; an end plate portion connected to an open end of said bell-shaped housing; a first motor shaft bushing connected to said bell-shaped housing; a second motor shaft bushing connected to said end plate; a motor shaft supported by said first housing and said second bushing for rotation; a rotor core support on said rotor shaft; a stator including a permanent magnet connected to said bell-shaped housing; said stator being positioned radially outwardly of said rotor core; rotor windings wound on said rotor core to form a rotor; a commutator positioned on said rotor shaft within said bell-shaped housing; brushes supported in said bell-shaped housing extending to engage said commutator by making sliding contact with said commutator; a disk-shaped frequency generator rotor portion formed of soft magnetic material, said disk-shaped frequency generator rotor including magnetic-pole teeth on an outer periphery thereof; an annular disk internal-gear core, formed of a soft magnetic material, an outer periphery of said annular-disk internal-gear core being connected to and supported by said bell-shaped housing, said annular-disk internal gear core having an inner periphery defining a plurality of magnetic-pole teeth, said annular-disk internal gear core magnetic-pole teeth being positioned facing said disk-shaped frequency generator rotor magnetic-pole teeth, said annular-disk internal gear core magnetic-pole teeth being spaced away from said disc-shaped frequency generator rotor magnetic-pole teeth to define a gap; at least one frequency generator stator permanent magnet positioned adjacent said gap, said at least one frequency generator stator permanent magnet being connected to said end plate for defining a magnetic field between said disc-shaped frequency generator rotor and said annular-disc internal gear core magnetic-pole teeth; and, a frequency generator stator including frequency-detecting coils for detecting the changes in magnetic flux and generating an induced voltage proportional to the revolution of the rotor, said frequency generator is disposed in a space defined by said brushes and said motor housing.