# US 2019/0173352 A1 · Motor unit

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- Number: US 2019/0173352 A1
- Document ID: US20190173352A1
- Status: Published application
- Kind: A1
- Application number: 16/323,930
- Filed: 2017-08-07
- Published: 2019-06-06
- Earliest claimed: 2016-08-09
- Assignees: Nidec Corporation
- Applicants: Nidec Corporation
- Inventors: Yasuo YAMAGUCHI; Takayuki MIGITA; Yuki ISHIKAWA
- Web page: https://patentgrep.com/patent/US20190173352A1

## CPC

- H02K 9/19: for machines with closed casing and closed-circuit cooling using a liquid cooling medium, e.g. oil
- H02K 5/20: with channels or ducts for flow of cooling medium
- H02K 5/203: {specially adapted for liquids, e.g. cooling jackets}
- H02K 2209/00: Specific aspects not provided for in the other groups of this subclass relating to systems for cooling or ventilating
- H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53})

## Abstract

A motor unit includes a motor, a housing including a housing space to house the motor, oil in a vertically lower region of the housing space, and an oil passage to lead the oil from the vertically lower region of the housing space through the motor to the vertically lower region of the housing space. The oil passage includes a first oil passage extending through an inside of the motor, and a second oil passage extending through an outside of the motor. One of the first oil passage and the second oil passage is includes a cooler to cool the oil therein.

## Claims

### Claim at position 1

1-7. (canceled)

### Claim at position 2

8: A motor unit comprising:
a motor;
a housing including a housing space to house the motor;
oil in a vertically lower region of the housing space; and
an oil passage to lead the oil from the vertically lower region of the housing space through the motor to the vertically lower region of the housing space; wherein
the oil passage includes a first oil passage extending through an inside of the motor, and a second oil passage extending through an outside of the motor; and
one of the first oil passage and the second oil passage includes a cooler to cool the oil therein.

### Claim at position 3 (depends on 8)

9: The motor unit according to claim 8, wherein
each of the first oil passage and the second oil passage includes a circulation channel extending from the vertically lower region of the housing space back to the vertically lower region of the housing space through the motor; and
the first oil passage and the second oil passage are joined at the vertically lower region of the housing space.

### Claim at position 4 (depends on 8)

10: The motor unit according to claim 8, wherein the motor includes:
a rotor including a shaft extending along a motor axis, and a rotor core surrounding the shaft from radially outside, the rotor being rotatable about the motor axis; and
a stator radially outside of the rotor; and
the first oil passage includes a channel extending from an interior of the shaft through the rotor core.

### Claim at position 5 (depends on 10)

11: The motor unit according to claim 10, further comprising a gear in the housing space and connected to the motor, wherein
at least a portion of the gear is lower than a liquid surface of the oil in the vertically lower region of the housing space;
a channel of the first oil passage includes a first reservoir in the housing space; and
the first oil passage includes:
an oil flow passage to lead the oil from the first reservoir to the interior of the shaft; and
a scraping-up channel along which the oil in the vertically lower region of the housing space is scraped up by rotation of the gear to be received by the first reservoir.

### Claim at position 6 (depends on 8)

12: The motor unit according to claim 8, wherein the second oil passage is structured to feed the oil in the vertically lower region of the housing space to the motor through an upper side of the motor.

### Claim at position 7 (depends on 12)

13: The motor unit according to claim 12, wherein
a channel of the second oil passage includes a second reservoir to store the oil therein, the second reservoir being located on the upper side of the motor; and
the second reservoir includes an outflow port to feed a portion of the oil in the second reservoir to the motor.

### Claim at position 8 (depends on 12)

14: The motor unit according to claim 12, wherein a channel of the second oil passage includes a pump and the oil cooler therein, the pump and the oil cooler being arranged one under another in an up-down direction, each of the pump and the oil cooler being fixed to an outer peripheral surface of the housing.