ELECTRIC STARTER MOTOR

• US 3,791,684 A
• Filed: 08/24/1972
• Issued: 02/12/1974
• Est. Priority Date: 08/24/1972
• Status: Expired due to Term

• Current Assignee: Lyle J. Hamman
• Original Assignee: Lyle J. Hamman
• Inventors: Hamman, Lyle J.
• Primary Examiner(s): Simmons, G. R.
• Application Number:
  US05/283,559
• Time in Patent Office: 537 Days
• Field of Search: 310/254,258,259,179,180 293/37,38,48 123/179
• US Class Current: 290/38.00R
• CPC Class Codes: H02K 1/185 to outer stators
• CPC Class Codes: H02K 5/148 Slidably supported brushes

Abstract

An electric starter motor for starting small internal combustion engines characterized by its high torque and compact size having a housing including four sides of convex configuration facilitating the winding of four field coils formed of mechanically interconnected and nested laminations defining a stack having annular synthetic insulators at the ends wherein the field wire coils are wrapped about both the poles defined by the laminations and aligned recessed insulators. The motor brushes are mounted upon a brush card, and the armature includes an extension extending from the housing upon which Bendix type starter apparatus is mounted. Four field coils and brushes are employed, and in the DC energized embodiment, two of the field coils are mounted in parallel and connected to one brush, while the other two field coils are connected in parallel with each other, and connected to an opposing brush. The coil connected brushes are shunted to equalize the voltage at the armature commutator.

Claims

1. An electric starter motor characterized by its compact size and ability to produce high torque forces comprising, in combination, an elongated housing having ends, an axis and four sidewalls, said sidewalls being of a convex configuration having an axis of generation parallel to said housing axis, adjacent sidewalls intersecting and defining a corner, a field coil defined within said housing within each corner, an end cap mounted upon each housing end, an armature extending through said housing having a commutator and rotatably supported on said end caps, a brush card of dielectric material within said housing adjacent an end thereof, a plurality of electrical conducting brushes mounted on said card engaging said armature commutator, engine starter drive means operatively connected to said armature, said field coils being defined by a stack of metal laminations having ends, a dielectric insulator within said housing located adjacent each end of said stack and a coil of electrical conductive wire wrapped about each field coil and its associated end insulators.

2. In an electric starter motor as in claim 1 wherein four brushes are mounted upon said brush card, two diametrically opposed brushes being grounded to said housing and each of the other two diametrically opposed brushes being connected in series with two parallel connected field coils.

3. In an electric starter motor as in claim 2, a shunt interconnecting said other two brushes to equalize the voltage at said commutator.

4. In an electric starter motor as in claim 1 wherein said field laminations each include an indentation nesting with and frictionally engaging a like indentation in the adjacent lamination whereby said inDentations constitute mechanical connection means between said laminations.

5. An electric starter motor characterized by its compact size and ability to produce high torque forces comprising, in combination, an elongated tubular housing having ends and a central region, a plurality of field laminations forming a stack located within said central region, said stack having ends within the length of said housing, poles defined upon said laminations, an annular synthetic plastic insulator located within said housing located adjacent each end of said stack, said insulators each including an axially extending recess opening toward the adjacent housing end, said recesses being defined by axially extending projections aligned with said poles whereby said recesses are aligned with said poles, a coil of wire coiled about each field pole and received within the insulator recesses defined at the end of each pole, an end cap mounted on each end of said housing, an armature rotatably mounted on said end caps extending through said field stack and said insulators, said armature having an extension extending exteriorly of said housing, brushes within said housing engaging a commutator defined on said armature, and starter drive means mounted on said armature extension.

6. In an electric starter motor as in claim 5 wherein said brushes are mounted upon a brush card of dielectric material.

7. In an electric starter motor as in claim 6 wherein four brushes are mounted upon said brush card, two diametrically opposed brushes being grounded to said housing and each of the other two diametrically opposed brushes being connected in series with two parallel connected field coils.

8. In an electric starter motor as in claim 7, a shunt interconnecting said other two brushes to equalize the voltage at said commutator.