Cooling system for electric motor with internal shaft passage and cooling medium reservoir

• US 9,660,502 B2
• Filed: 10/19/2012
• Issued: 05/23/2017
• Est. Priority Date: 09/25/2012
• Status: Expired due to Fees

• Current Assignee: Komatsu Ltd.
• Original Assignee: Komatsu Ltd.
• Inventors: Matsuki, Yasuhiko, Minamiura, Akira
• Primary Examiner(s): Kenerly, Terrance
• Assistant Examiner(s): Moraza, Alexander
• Application Number:
  US14/233,262
• Publication Number:
  US 20150015099A1
• Time in Patent Office: 1,677 Days
• Field of Search: 310 61, 310 52, 310 54, 310 57, 310227, 310 53, 310 58, 310 60 A, 310 60 R, 310 62, 310 63, 310 59
• CPC Class Codes: H02K 1/32 with channels or ducts for flow of cooling medium
• CPC Class Codes: H02K 11/21 Devices for sensing speed or position, or actuated thereby specially adapted for machines having non-mechanical commutating devices H02K29/06, H02K29/14
• CPC Class Codes: H02K 11/225 Detecting coils
• CPC Class Codes: H02K 9/00 Arrangements for cooling or ventilating channels or ducts in parts of the magnetic circuit H02K1/20, H02K1/32; channels or ducts in or between conductors H02K3/22, H02K3/24
• CPC Class Codes: H02K 9/19 for machines with closed casing and closed-circuit cooling using a liquid cooling medium, e.g. oil
• CPC Class Codes: H02K 9/193 with provision for replenishing the cooling medium; with means for preventing leakage of the cooling medium

Abstract

A motor includes: a shaft to which a rotor is attached and having an internal cooling medium passage in an inside of the shaft, a cooling medium passing through the internal cooling medium passage; a housing including the shaft disposed therein and configured to rotatably support the shaft; and a cooling medium reservoir provided in the housing and provided on an upstream side of an inlet of the internal cooling medium passage in a flowing direction of the cooling medium, the cooling medium reservoir being configured to store the cooling medium and then flow the cooling medium to the internal cooling medium passage.

Claims

1. A motor comprising:

a shaft to which a rotor is attached and having an internal cooling medium passage in an inside of the shaft, a cooling medium passing through the internal cooling medium passage;

a housing including the shaft disposed therein and configured to rotatably support the shaft;

a cooling medium reservoir provided in the housing and provided on a rest system of an upstream side of an inlet of the internal cooling medium passage in a flowing direction of the cooling medium, the cooling medium reservoir being configured to store the cooling medium and then flow the cooling medium to the internal cooling medium passage,

wherein the cooling medium reservoir is provided on a rotational center axis of the shaft, and the rotational center axis is in parallel with a gravitational direction, and the cooling medium reservoir is provided with a restriction section which has an internal diameter which gradually reduces in diameter along a length to a minimum diameter followed by increasing in diameter before connecting to the internal cooling medium passage.

2. The motor according to claim 1, wherein a passage including a restriction section is provided between the cooling medium reservoir and the internal cooling medium passage.

3. The motor according to claim 2, further comprising:

a cooling medium inlet provided on the housing and configured to introduce the cooling medium into the cooling medium reservoir; and

a cooling medium introduction member that is a member disposed between the cooling medium inlet and the inlet, in which the cooling medium reservoir is provided on a side of the cooling medium inlet, and the passage penetrates from the cooling medium reservoir toward the inlet.

4. The motor according to claim 3, further comprising a rotation angle detection sensor mounted on an end portion side of the shaft, the end portion at which the inlet is opened, the rotation angle detection sensor being configured to detect a rotation angle of the shaft,

wherein the cooling medium introduction member presses the rotation angle detection sensor from the end portion side of the shaft.

5. The motor according to claim 1, wherein:

the shaft is supported on the housing on both sides in a longitudinal direction through a bearing; and

the motor further comprises a bearing cooling medium passage configured to supply the cooling medium stored in the cooling medium reservoir to the bearing on an end portion side of the shaft at which the inlet is opened.

6. A motor comprising:

a shaft to which a rotor is attached and having an internal cooling medium passage in an inside of the shaft, a cooling medium passing through the internal cooling medium passage;

a housing including the shaft disposed therein and configured to rotatably support the shaft;

a cooling medium reservoir provided in the housing and provided on an upstream side of an inlet of the internal cooling medium passage in a flowing direction of the cooling medium, the cooling medium reservoir being configured to store the cooling medium and then flow the cooling medium to the internal cooling medium passage;

a cooling medium inlet provided on the housing and configured to introduce the cooling medium into the cooling medium reservoir; and

a cooling medium introduction member that is a member disposed between the cooling medium inlet and the inlet, in which the cooling medium reservoir is provided on a side of the cooling medium inlet, and a passage including a restriction section penetrates from the cooling medium reservoir toward the inlet, and the cooling medium reservoir being provided with the restriction section which has an internal diameter which gradually reduces in diameter along a length to a minimum diameter followed by increasing in diameter before connecting to the internal cooling medium passage.