Electric motor commutator

• US 5,925,962 A
• Filed: 05/05/1998
• Issued: 07/20/1999
• Est. Priority Date: 12/19/1995
• Status: Expired due to Term

• Current Assignee: TI Group Automotive Systems LLC
• Original Assignee: Walbro Corporation (Sun Capital Partners Incorporated)
• Inventors: Kobman, Richard L., Ruprecht, Marc B., Westendorf, Dirk G., Mercer, Michael L., Birchenough, Arthur J., George, James A., Tuckey, deceased, J. D.
• Primary Examiner(s): Enad, Elvin G.
• Application Number:
  US09/072,933
• Time in Patent Office: 441 Days
• Field of Search: 310/231, 310/235, 310/236, 310/237, 29/597
• US Class Current: 310/237
• CPC Class Codes: F02M 2037/082 Details of the entry of the current supply lines into the pump housing, e.g. wire connectors, grommets, plugs or sockets
• CPC Class Codes: F02M 37/10 submerged in fuel, e.g. in reservoir
• CPC Class Codes: H01R 39/06 other than with external cylindrical contact surface, e.g. flat commutators
• CPC Class Codes: H01R 43/08 in which segments are not separated until after assembly
• CPC Class Codes: H02K 5/132 Submersible electric motors H02K5/128 takes precedence
• CPC Class Codes: Y10T 29/49009 Dynamoelectric machine
• CPC Class Codes: Y10T 29/49011 Commutator or slip ring assembly
• CPC Class Codes: Y10T 29/49012 Rotor

Abstract

A flat commutator for an electric motor of a vehicle fuel pump. The commutator, is made with a one-piece carbon ring having a flat outer face, a one-piece conductor ring underlying the outer face of and embedded in the carbon ring, and a housing of a plastic insulating material molded on the rear face and the inner and outer edges of the carbon ring and adapted to mount the commutator on a motor armature. A plurality of circumferentially spaced apart grooves extend radially and axially completely through both the carbon ring and the conductor ring to provide a plurality of individual sintered carbon segments each with a separate conductor for electrically connecting the segments with armature coils.

Claims

1. A commutator for an electric motor of a fuel pump which comprises:

an annular ring of sintered carbon having a planar front face and a back face, a conductor ring embedded in the carbon ring between and spaced from the front and back faces of the carbon ring prior to sintering the carbon ring and having a plurality of circumferentially spaced apart tangs adjacent the outer periphery of the carbon ring forming electrical connectors and a plurality of mounting projections which are circumferentially spaced apart, disposed radially inward of the tangs and project generally axial outwardly of the back face of the carbon ring, the conductor ring being securely attached to and bonded in the carbon ring by sintering of the carbon ring and its tangs electrically connected with the carbon ring, a housing of an electrically insulating plastic material molded over the back face of the carbon ring after sintering of the carbon ring and with the mounting projections of the conductor ring embedded and interlocked in the housing, the housing having a bore coaxial with the carbon ring, and a plurality of equally circumferentially spaced apart grooves extending radially and axially completely through the carbon ring and the metal conductor ring and forming a plurality of spaced apart separate sintered carbon segments each with a separate electrical conductor embedded and bonded therein by sintering to serve as commutator segments for contact with brushes with the grooves being formed only after the carbon ring has been sintered and after the housing has been molded onto the back face of the carbon ring to permanently fix and secure each of the carbon segments to the housing.

2. The commutator of claim 1 wherein a portion of the conductor ring is exposed in each groove and the radial extent of the exposed portion of the conductor ring is less than one half of the radial extent of the groove through the carbon ring.

3. The commutator of claim 1 wherein a portion of the conductor ring is exposed in each radial groove and the exposed portion has a surface area which is less than one-third of the surface area of the face of the carbon ring in the groove in which the conductor ring is exposed.

4. The commutator of claim 1 wherein the housing has an integral annular portion projecting into and bearing on the side wall of a central opening through the carbon ring.

5. The commutator of claim 1 wherein the conductor ring has circumferentially spaced through openings defining in part between them radially extending segments embedded in and bonded to the carbon ring.

6. A commutator for an electric motor of a fuel pump which comprises:

an annular ring of sintered carbon having a planar front face and a back face, a conductor ring embedded within the carbon ring between and spaced from the front and back faces of the carbon ring prior to sintering the carbon ring and having a plurality of circumferentially spaced apart tangs adjacent the outer periphery of the carbon ring, said conductor ring being securely attached and bonded to the carbon ring by sintering of the carbon ring with its tangs electrically connected with the sintered carbon ring, a housing of an electrically insulating plastic material molded over at least the back face of the sintered carbon ring after sintering of the carbon ring with the conductor ring embedded therein, the housing having a bore coaxial with the carbon ring, and a plurality of equally circumferentially spaced apart grooves extending radially and axially completely through the sintered carbon ring and the conductor ring and forming a plurality of spaced apart separate sintered carbon segments each with a separate electrical conductor embedded and bonded therein by sintering, to serve as commutator segments for contact with brushes with the grooves being formed only after the housing has been molded onto the sintered carbon ring to permanently fix and secure each of the carbon segments to the housing.

7. The commutator of claim 6 which also comprises circumferentially spaced openings through the conductor ring defining in part between them radially extending spokes embedded in the carbon ring.

8. The commutator of claim 7 wherein the radial spokes have generally outward arcuate edges that define bulges in the spokes, and through holes are located in the area of said bulges, and the sintered carbon of the carbon ring extends through said holes through said spokes.

9. The commutator of claim 6 wherein the housing is molded over the peripheral outside surface of the carbon ring between the front face and back faces as well as over the back face.

10. The commutator of claim 6 wherein a portion of the conductor ring is exposed in each groove and the radial extent of the exposed portion of the conductor ring is less than one half of the radial extent of the groove through the carbon ring.

11. The commutator of claim 6 wherein a portion of the conductor ring is exposed in each radial groove and the exposed portion has a surface area which is less than one-third of the surface area of the face of the carbon ring in the groove in which the conductor ring is exposed.

12. The commutator of claim 6 wherein the housing has an integral annular portion projecting into and bearing on the side wall of a central opening through the carbon ring.

13. The commutator of claim 6 wherein at least part of the portion of the conductor ring embedded within the carbon ring has a textured surface bonded to the carbon ring by sintering.

14. The commutator of claim 6 wherein the housing has an integral outer sidewall molded over and bearing on the outer peripheral wall of the sintered carbon ring with the tang of the conductor ring embedded in and extending through the outer wall of the housing.

15. The commutator of claim 14 wherein the outer sidewall of the housing has a plurality of circumferentially spaced apart recesses and part of each tang of the conductor ring is received in an associated one of the recesses.

16. The commutator of claim 14 wherein the housing has an integral inner annular sidewall projecting into and bearing on the sidewall of a central opening through the carbon ring.