Motor having shaft-grounding arrangement

• US 6,608,410 B2
• Filed: 02/21/2001
• Issued: 08/19/2003
• Est. Priority Date: 02/29/2000
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: ASMO Company Limited (DENSO Corporation)
• Inventors: Gonda, Shuuichi, Sato, Toshihiro
• Primary Examiner(s): Waks, Joseph
• Assistant Examiner(s): Mohandesi, Iraj A.
• Application Number:
  US09/788,542
• Publication Number:
  US 20010017495A1
• Time in Patent Office: 909 Days
• Field of Search: 310/67.R, 310/79, 310/81, 310/239, 310/68.R
• US Class Current: 310/67.00R
• CPC Class Codes: H02K 11/40 Structural association with grounding devices
• CPC Class Codes: H02K 23/04 having permanent magnet excitation
• CPC Class Codes: H02K 5/15 Mounting arrangements for bearing-shields or end plates
• CPC Class Codes: H02K 5/161 radially supporting the rotary shaft at both ends of the rotor H02K5/165, H02K5/167, H02K5/173 take precedence

Abstract

A DC motor has a conductive case and an arrangement for electrically connecting the shaft and case of the DC motor that is grounded. The arrangement includes a conductive member and a pressing member that presses the conductive member against the shaft, thereby grounding the shaft.

Claims

1. A motor comprising:

a rotor;

an armature coil;

a conductive case for accommodating said rotor;

a grounding member for grounding said conductive case;

a shaft having a portion extending outward from conductive case;

a bearing fixed to said case for rotatably supporting said shaft;

a housing for fixing said conductive case;

means, including a conductive member in contact with said shaft and said conductive case, for pressing said conductive member between said shaft and said conductive case, wherein said means comprises;

a resilient contact member integrated with said conductive case; and

a parallel pardon extending in a parallel direction to said shaft;

a slant portion slanting toward a center of said shaft; and

a disk portion held between said conductive case and said housing, wherein said disk portion comprises a plurality of slanted spring members.

2. The motor as claimed in claim 1, wherein

said means comprises a resinous bearing holder for holding said bearing,

said bearing has a spherical outer surface, and

said bearing holder has a spherical inner surface to which said bearing is fitted.

3. A motor comprising:

a rotor;

an armature coil;

a conductive case for accommodating said rotor;

a grounding member for grounding said conductive case;

a shaft having a collar and a portion extending outward from said conductive case;

a bearing directly fixed to said case for rotatably supporting said shaft;

a housing for fixing said conductive case;

means, including a conductive member in contact with said shaft and said conductive case, for pressing said conductive member between said shaft and said conductive case, wherein said means comprises a spring washer held between said bearing and said collar.

4. The motor as claimed in claim 3, further comprising

a bearing-holding washer having a resilient projecting member, wherein

said means comprises resilient projecting member.

5. The motor as claimed in claim 3, further comprising

a housing for fixing said case, wherein

said means further comprises a disk portion held between said case and said housing.

6. The motor as claimed in claim 5, wherein

said disk portion comprises a plurality of slanted spring members.

7. A motor comprising:

a rotor;

an armature coil;

a conductive case for accommodating said rotor;

a grounding member for grounding said conductive case;

a shaft having a portion extending outward from said conductive case;

a bearing fixed to said case for rotatably supporting said shaft;

a housing for fixing said conductive case; and

means, including a conductive member in contact with said shaft and said conductive case, for pressing said conductive member between said shaft and said conductive case, wherein said means comprises a conductive seal member disposed between said shaft and said conductive case.

8. A motor comprising;

a rotor;

an armature coil;

a conductive case for accommodating said rotor;

a grounding member for grounding said conductive case;

a shaft having a portion extending outward from said conductive case;

a bearing fixed to said case for rotatably supporting said shaft;

means, including a conductive member in contact with said shaft and said conductive case, for pressing said conductive member between said shaft and said conductive case, wherein said means comprises;

a parallel portion extending in a parallel direction to said shaft;

a slant portion slanting toward a center of said shaft; and

a disk portion held between said conductive case and said housing, wherein said disk portion comprises a plurality of slanted spring members.

9. A motor comprising:

a rotor;

an armature coil;

a conductive case for accommodating said rotor;

a grounding member for grounding said conductive case;

a shaft having a portion extending outward from said conductive case;

a bearing fixed to said case for rotatably supporting said shaft; and

means, including a conductive member in contact with said shaft and said conductive case, for pressing said conductive member between said shaft and said conductive case, wherein said means comprises a plurality of members surrounding said shaft at equal intervals.