Assembly including an electric motor and a load

• US 20050191178A1
• Filed: 02/26/2004
• Published: 09/01/2005
• Est. Priority Date: 02/26/2004
• Status: Abandoned Application

• Current Assignee: A. O. Smith Corporation
• Original Assignee: A. O. Smith Corporation
• Inventors: Lin, Chih Min, Watkins, William James
• Application Number:
  US10/788,092
• Publication Number:
  US 20050191178A1
• Time in Patent Office: Days
• US Class Current: 415/216.1
• CPC Class Codes: F04D 29/20 Mounting rotors on shafts
• CPC Class Codes: F04D 29/263 mounting fan or blower rotors on shafts
• CPC Class Codes: F04D 29/266 mounting compressor rotors on shafts

Abstract

An assembly including an electric motor, a load, and a retainer. The electric motor can include a shaft that defines a first cross-section that is non-circular and substantially normal to the shaft axis. The load can include a rotating member that defines a bore and first and second apertures in communication with the bore. The bore can be configured to receive at least a portion of the shaft. An opening of the bore can be fully enclosed by a continuous portion of the rotating member. A portion of the bore can define a second cross-section that is non-circular and that corresponds to at least a portion of the first cross-section. The retainer can extend through the first and second apertures and engage the shaft and thereby substantially prevent axial movement of the shaft relative to the rotating member during normal operation of the electric motor.

Claims

1. An assembly comprising:

an electric motor comprising

a first housing,

a stator fixed relative to the first housing,

a shaft supported by the first housing for rotation about a shaft axis, the shaft extending from the first housing, a portion of the shaft defining a first cross-section, the first cross-section being non-circular and substantially normal to the shaft axis, and

a rotor connected to the shaft for rotation with the shaft relative to the stator;

a load comprising

a second housing,

a rotating member configured to be driven by the electric motor for rotation relative to the second housing, the rotating member defining a bore and first and second apertures in communication with the bore, the bore being configured to receive at least a portion of the shaft, an opening of the bore being fully enclosed by a continuous portion of the rotating member, a portion of the bore defining a second cross-section, the second cross-section being non-circular and corresponding to at least a portion of the first cross-section; and

a retainer extending through the first and second apertures and engaging the shaft, the retainer substantially preventing axial movement of the shaft relative to the rotating member during normal operation of the electric motor.

2. An assembly as claimed in claim 1 wherein the load is a fluid pump, and wherein the rotating member is an impeller.

3. An assembly as claimed in claim 2 wherein the impeller is a molded plastic component.

4. An assembly as claimed in claim 1 wherein an end portion of the shaft is chamfered for guiding the shaft into the bore.

5. An assembly as claimed in claim 1 wherein the shaft comprises a shaft flat, and wherein the first cross-section comprises a sectional portion of the shaft flat.

6. An assembly as claimed in claim 1 wherein the shaft defines a surface having a substantially axially facing component, and wherein the retainer extends through the first and second apertures and engages the surface.

7. An assembly as claimed in claim 6 wherein the shaft defines a groove extending circumferentially around at least a portion of the shaft, wherein a portion of the groove is chamfered for guiding the retainer in to and out of the groove, and wherein the groove comprises the surface.

8. An assembly as claimed in claim 1 wherein the retainer comprises a C-shaped retaining ring, and wherein the C-shaped retaining ring is formed of metal.

9. An assembly as claimed in claim 1 wherein the retainer comprises an O-shaped retaining ring, and wherein the O-shaped retaining ring is formed of a elastomeric material.

10. An assembly as claimed in claim 1 wherein the retainer comprises a partially O-shaped retaining ring, and wherein the partially O-shaped retaining ring is formed of a plastic material.

11. An assembly as claimed in claim 1 wherein the portion of the bore defining the second cross-section comprises a sectional portion of the opening of the bore.

12. An assembly as claimed in claim 1 wherein the rotating member defines a groove, wherein the first and second apertures are in communication with the groove, and wherein the groove is sized to receive a portion of the retainer.

13. A method of drivingly connecting an electric motor to a rotating member, the method comprising:

providing an electric motor comprising

a stator,

a shaft supported for rotation about a shaft axis, a portion of the shaft defining a first cross-section, the first cross-section being non-circular and substantially normal to the shaft axis, the shaft defining a groove, and

a rotor connected to the shaft for rotation with the shaft relative to the stator;

providing a rotating member configured to be driven by the electric motor, the rotating member defining a bore and first and second apertures in communication with the bore, the bore being configured to receive at least a portion of the shaft, an opening of the bore being fully enclosed by a continuous portion of the rotating member, a portion of the bore defining a second cross-section, the second cross-section being non-circular and configured to engage at least a portion of the shaft that defines the first cross-section;

inserting the shaft into the bore so the groove is at least partially axially aligned with the first and second apertures;

providing a resilient lock member; and

deflecting the resilient lock member relative to the rotating member so the resilient lock member engages the groove through the first and second apertures.

14. A method as claimed in claim 13 and further comprising inserting the lock member through the first and second apertures prior to inserting the shaft into the bore, and wherein inserting the shaft into the bore comprises moving at least one of the rotating member and the shaft axially so the lock member deflects relative to the shaft and then engages the groove through the first and second apertures.

15. An assembly comprising:

an electric motor comprising

a first housing,

a stator fixed relative to the first housing,

a motor shaft supported by the first housing for rotation about a shaft axis, the motor shaft extending from the first housing, a portion of the motor shaft defining a first cross-section, the first cross-section being non-circular and substantially normal to the shaft axis, the motor shaft defining a groove; and

a rotor connected to the motor shaft for rotation with the motor shaft relative to the stator;

a fluid pump comprising

a second housing,

a molded plastic impeller configured to be driven by the electric motor for rotation relative to the second housing, the impeller comprising a hollow shaft, the hollow shaft defining a bore and first and second apertures in communication with the bore, the bore being configured to receive at least a portion of the motor shaft, an opening of the bore being fully enclosed by a continuous portion of the hollow shaft, a portion of the bore defining a second cross-section, the second cross-section being non-circular, the portion of the bore defining the second cross-section configured to engage at least a portion of the motor shaft that defines the first cross-section; and

a retaining member extending through the first and second apertures and engaging the groove, the retaining member substantially preventing axial movement of the motor shaft relative to the hollow shaft during normal operation of the electric motor.

16. An assembly as claimed in claim 15 wherein an end portion of the shaft is chamfered for guiding the shaft into the bore, and wherein a portion of the groove is chamfered for guiding the retaining member in to and out of the groove.

17. An assembly as claimed in claim 15 wherein the hollow shaft defines a second groove, wherein the first and second apertures are in communication with the second groove, and wherein the second groove is sized to receive a portion of the retaining member.

18. An assembly as claimed in claim 17 wherein the retaining member comprises a retaining ring, and wherein the retaining ring is at least partially O-shaped.

19. An assembly as claimed in claim 15 wherein the retaining member is disposed in the second housing during normal operation of the fluid pump.