Electric motor magnetic flux path structure

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENT With reference to FIGS.
1-3, a permanent magnet electric motor is shown generally indicated at 10.
The motor 10 is preferably configured for use in vehicle HVAC systems.
The electric motor 10 includes an armature 12 having windings 14.
The armature 12 is constructed and arranged to rotate a shaft 16.
An axis of rotation of the shaft 16 of the motor is shown at A.
The motor 10 includes a commutator 18 and brushes 20 to engage the commutator 18 and conduct electrical current to the windings 14.
Permanent magnets 21 are disposed about the armature 12.
A frame assembly 22 carries the permanent magnets 21.
As shown in FIGS.
3 and 4, the frame assembly 22, preferably molded from plastic or other non-magnetic material, is of clam-shell configuration having a first half 24 (FIG.
3) and a mating second half 24' (FIG.
4).
The plastic material for the frame assembly is preferably glass-filled NYLON.
RTM.
.
The first half 24 includes a plurality of protrusions 26 extending from an edge 28 thereof and the second half 24' includes a plurality of recess 30 in edge 32.
Each recess 30 receives an associated protrusion 26.
Thus, once assembled, edges 28 and 32 are in abutting relation with the frame assembly 22 defining a generally open cylindrical structure.
The frame assembly 22 includes a plurality of retaining tabs 34 for locating and retaining the permanent magnets 21 with respect to the inside of the frame assembly 22.
An electrical connector body 35 is also molded into the frame assembly for housing an electrical connector 25 of the motor 10.
Brush tubes 23 are defined in the frame assembly to hold brushes 20 so that no brush card is required.
The frame assembly 22 incorporates the brush tubes 23, an end cap 25, bearing retainers 27 and the electrical connector body 35 (FIG.
2).
As best shown in FIGS.
1 and 2, a coil spring structure 36 is provided about the outer periphery of a portion of the frame assembly 22 and thus permanent magnets 21 to define a flux path