Electrically motorized wheel assembly

• US 5,438,228 A
• Filed: 11/12/1993
• Issued: 08/01/1995
• Est. Priority Date: 07/14/1992
• Status: Expired due to Fees

• Current Assignee: Hydro-Quebec (Province of Québec)
• Original Assignee: Hydro-Quebec (Province of Québec)
• Inventors: Harbec, Germain, Bourgeois, Francois-Xavier, Couture, Pierre, Francoeur, Bruno, Simard, Julien
• Primary Examiner(s): LaBalle, Clayton E.
• Application Number:
  US08/151,192
• Time in Patent Office: 627 Days
• Field of Search: 310/67 R, 310/90, 310/68 B, 310/68 R, 310/217, 310/218, 318/138, 180/65.5, 180/65.6, 180/242
• US Class Current: 310/67.00R
• CPC Class Codes: B60K 2007/0038 the motor moving together with the wheel axle
• CPC Class Codes: B60K 2007/0092 the motor axle being coaxial to the wheel axle
• CPC Class Codes: B60K 7/0007 the motor being electric
• CPC Class Codes: B60L 15/20 for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 2220/44 Wheel Hub motors, i.e. integrated in the wheel hub
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/427 Voltage
• CPC Class Codes: B60L 2240/429 Current
• CPC Class Codes: B60L 2240/527 Voltage
• CPC Class Codes: B60L 2240/529 Current
• CPC Class Codes: H02K 1/18 Means for mounting or fastening magnetic stationary parts on to, or to, the stator structures
• CPC Class Codes: H02K 11/05 Rectifiers associated with casings, enclosures or brackets
• CPC Class Codes: H02K 17/12 for multi-phase current
• CPC Class Codes: H02K 19/10 for multi-phase current
• CPC Class Codes: H02K 21/22 with magnets rotating around the armatures, e.g. flywheel magnetos
• CPC Class Codes: H02K 2205/09 Machines characterised by drain passages or by venting, breathing or pressure compensating means
• CPC Class Codes: H02K 29/10 using light effect devices
• CPC Class Codes: H02K 5/10 with arrangements for protection from ingress, e.g. water or fingers
• CPC Class Codes: H02K 5/18 : with ribs or fins for improving heat transfer
• CPC Class Codes: H02K 5/225 : Terminal boxes or connection arrangements specially adapted for submersible motors H02K5/132
• CPC Class Codes: H02K 7/14 : Structural association with mechanical loads, e.g. with hand-held machine tools or fans with fan or impeller for cooling the machine H02K9/06
• CPC Class Codes: H02K 9/08 : by gaseous cooling medium circulating wholly within the machine casing H02K9/10 takes precedence
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility

Abstract

The electrically motorized wheel assembly comprises a hollow shaft having a first opening at one end thereof and a second opening, the first opening receiving conductors from outside of the assembly; a stator coaxial with and fixedly attached to the shaft, the stator being provided with a hollow portion and coils; a rotor coaxial with the stator and mounted for rotation about the stator; and converting system for converting an input electrical current to a variable AC electrical current, the converting system including power electronics fixedly mounted within the hollow portion, input terminals for receiving the input electrical current and output terminals for delivering the variable AC electrical current; whereby, to provide the variable AC current to the coils of the stator.

Claims

1. An electrically motorized wheel assembly comprising:

a hollow shaft having a first opening at one end thereof and a second opening, said first opening receiving conductors from outside of said assembly;

a stator coaxial with and fixedly attached to said shaft, said stator being provided with coils, said stator comprising a central portion attached to said shaft, a support provided with openings and extending radially from said central portion, and a peripheral circular pole piece wound with said coils, said pole piece being fixed onto peripheral ends of said support;

a rotor coaxial with said stator and mounted for rotation about said stator, said rotor comprising a housing having a cylindrical wall having an inner surface provided with a magnetic means surrounding said stator and separated therefrom by an air-gap, said housing comprising an inner wall, on a side of said cylindrical wall, and an outer wall, on the other side of said cylindrical wall, said shaft extending through said inner wall and centrally thereof, said outer wall of said housing comprising convex and concave sections that alternate along circumference direction thereof, in such a manner that, when said rotor is rotating, an air circulation is produced inside said housing by means of said convex sections, and an air circulation is produced along outside portions of said concave sections, whereby an efficient heat exchange can be obtained through said outer wall; and

converting means for converting an input electrical current to a variable AC electrical current, said converting means including power electronics, input terminals for receiving said input electrical current and output terminals for delivering said variable AC electrical current to said coils of said stator.

2. An electrically motorized wheel assembly according to claim 1, wherein:

said stator is provided with a hollow portion; and

said power electronics are fixedly mounted within said hollow portion.

3. An assembly according to claim 1, wherein said housing sealingly encloses said shaft, said stator and said converting means.

4. An assembly according to claim 1, comprising a first bearing associated with said inner wall, and a second bearing associated with said outer wall, said bearings being respectively mounted on both sides of said shaft so that said rotor can be rotated with respect to said stator by means of said bearings.

5. An assembly according to claim 1, wherein said magnetic means surrounding said stator include a series of permanent magnets.

6. An assembly according to claim 5, wherein said converting means comprises:

a DC/AC converter having an input for receiving a direct current from said input terminals, and three outputs for generating three phase AC currents into said output terminals; and

a microprocessor unit connected to said converter for controlling its operation.

7. An assembly according to claim 6, wherein:

said stator is cross-shaped and has four arms;

said converter is made of three converter units that generate respectively said three phase AC currents, said units being fixed respectively onto three of said four arms; and

said microprocessor unit is fixed onto the fourth of said arms;

said assembly further comprising two circular supply distribution bus connected to said converter and microprocessor units, whereby said direct current can be distributed to said converter and microprocessor units by means of said bus.

8. An assembly according to claim 1, wherein said stator comprises a lightweight heat conductive material.

9. An assembly according to claim 8, wherein said material is aluminum alloy.

10. An assembly according to claim 1, further comprising a rim fixed around an outer surface of said housing, and a layer made of elastomer and mounted between said rim and said housing, said rim being adapted to receive a tire.

11. An assembly according to claim 10, wherein said rim is flat.

12. An assembly according to claim 1, wherein said peripheral circular pole piece includes metallic strips.

13. An assembly according to claim 12, wherein said support comprises at least two arms between said openings.

14. An assembly according to claim 13, wherein said support comprises at least three equally spaced arms extending radially to said peripheral ends of said support.

15. An assembly according to claim 14, wherein said equally spaced arms comprise four equally spaced arms.

16. An assembly according to claim 12, wherein said peripheral ends of said support are fixed onto the pole piece of said stator by means of a circular member that is solid with said peripheral ends, said circular member having an outer surface provided with recesses, said circular pole piece of said stator having an inner surface provided with projecting tongues that can be fitted into said recesses for fixing said pole piece of said stator onto said circular member, said circular member having an inner surface provided with projections, whereby an efficient heat exchange can be obtained by means of said projections when an air circulation is produced inside said housing.

17. An assembly according to claim 1, wherein said inner wall of said housing has a concave-shaped outer surface to produce, when said rotor is rotating, an air circulation toward periphery of said inner wall, said outer surface being provided with a series of parallel elongated strips extending in the direction of said shaft, said strips having their free side defining a space in which brake means can be mounted, whereby an efficient heat exchange can be obtained through said inner wall, and said brake means can be cooled down by the air circulation produced along said inner wall.

18. An assembly according to claim 1, further comprising drying means including an air pipe having an end disposed inside said housing, a chamber disposed at the other end of said pipe, and a desiccating material disposed inside said chamber, whereby, when said rotor is rotating, air circulation is produced inside said pipe and through said chamber to dry air inside said housing.

19. An assembly according to claim 18, wherein:

said chamber is an annular elongated chamber disposed inside said hollow shaft, said chamber being open at both of its ends;

said first opening of said shaft is airtight; and

said other end of said pipe is disposed between said airtight first opening and said chamber.

20. An assembly according to claim 18, wherein;

said chamber is disposed outside of said assembly; and

said first opening of said shaft is airtight;

whereby said pipe is used as an outlet from an inlet into said chamber.