Wheel drive motor and in-wheel motor drive assembly

Patent metadata

Field	Value
Publication number	US-2016355084-A1
Application number	US-201515116521-A
Country	US
Kind code	A1
Filing date	Jan 27, 2015
Priority date	Feb 18, 2014
Publication date	Dec 8, 2016
Grant date	—

Abstract

The wheel drive motor according to the invention includes a motor shaft ( 35 ) having a large diameter portion ( 35 d ) located at a central part in the axial direction and a small diameter portion ( 35 b ) located on a first side in the axial direction, a bearing ( 36 b ) rotatably supporting the small diameter portion ( 35 b ), and a rotor ( 24 ) secured to an outer circumferential surface ( 35 j ) of the large diameter portion ( 35 d ). An end part ( 24 p ) of the rotor ( 24 ) located on the first side in the axial direction projects over an end face ( 35 e ) of the large diameter portion ( 35 d ) located on the first side in the axial direction toward the side on which the small diameter portion ( 35 b ) is.

First claim

1 . A wheel drive motor, comprising:
a motor shaft, for outputting drive force to rotate a wheel, extending in an axial direction and including a large diameter portion located at a central part in the axial direction and a small diameter portion located on a first side in the axial direction, the small diameter portion having a diameter smaller than that of the large diameter portion, a bearing rotatably supporting the small diameter portion, and a rotor secured to an outer circumferential surface of the large diameter portion and facing a stator, wherein an end part of the rotor located on the first side in the axial direction projects over an end face of the large diameter portion located on the first side in the axial direction toward the side on which the small diameter portion is.

2 . The wheel drive motor according to claim 1 , wherein the large diameter portion has an outer diameter greater than the outer diameter of the bearing, and the end part of the rotor projects over an end part of the bearing located on a second side in the axial direction toward the side on which the small diameter portion is.

3 . The wheel drive motor according to claim 2 , wherein the outer circumferential surface of the large diameter portion includes a large diameter portion's fitting surface that fits with a radially inner part of the rotor, the small diameter portion has a small diameter portion's fitting surface on its outer circumference, the small diameter portion's fitting surface fitting with an inner ring member of the bearing, and the positions of the large diameter portion's fitting surface and the small diameter portion's fitting surface are adjacent to each other so as not to overlap with each other in the axial direction.

4 . The wheel drive motor according to claim 1 , further comprising
an end member that is fixedly attached to the large diameter portion, projects from the end face of the large diameter portion located on the first side in the axial direction, and covers an end face of the rotor located on the first side in the axial direction.

5 . The wheel drive motor according to claim 4 , wherein
the end member is positioned to be coaxial with the motor shaft at an attachment position on the large diameter portion, and the end member includes an outer circumferential fitting surface that fits with a radially inner part of the end part_of the rotor located on the first side in the axial direction.

6 . The wheel drive motor according to claim 4 , further comprising
an edge member that is interposed between the end member and the end face of the rotor located on the first side in the axial direction, and includes a lubricating oil passage.

7 . An in-wheel motor drive assembly comprising:
a wheel drive motor according to claim 1 , a speed reducing section including an input shaft coupled to the motor shaft and an output shaft reducing the rotational speed of the input shaft and outputting it, and a wheel hub bearing section including a wheel hub coupled to the output shaft.

Assignees

• Ntn Toyo Bearing Co Ltd

Inventors

• Uozumi Tomohisa
• Kuroda Masaru
• Suzuki Kenichi

Classifications

• H02K9/19

  for machines with closed casing and closed-circuit cooling using a liquid cooling medium, e.g. oil · CPC title

• B60K17/043

  Transmission unit disposed in on near the vehicle wheel, or between the differential gear unit and the wheel · CPC title

• H02K1/32

  with channels or ducts for flow of cooling medium · CPC title

• B60K7/0007 Primary

  the motor being electric · CPC title

• B60B27/00

  Hubs (non-metallic B60B5/00; of high resiliency B60B9/00) · CPC title