In-wheel motor unit

Patent metadata

Field	Value
Publication number	US-10384530-B2
Application number	US-201715688273-A
Country	US
Kind code	B2
Filing date	Aug 28, 2017
Priority date	Aug 29, 2016
Publication date	Aug 20, 2019
Grant date	Aug 20, 2019

Abstract

An in-wheel motor unit comprises a housing, a motor, a speed reducer including a rotating body and an output shaft fixed to the rotating body and penetrating the housing to extend to outside of the housing in an axle outward direction, and a hub bearing including a bearing part and a hub part integrated with the bearing part. A part of the output shaft positioned at an axle outward direction side of the rotating body is supported only by the bearing part. A part of the bearing part is positioned inside the housing. Inside of this part is disposed a first seal member which fluid-tightly seals a gap between an inner race and an outer race at a position positioned at an axle inward direction side of a group of rolling elements.

First claim

The invention claimed is:

1. An in-wheel motor unit comprising:
a housing supported by a vehicle body and disposed inside a wheel of a vehicle;
a motor supported by said housing and accommodated inside said housing;
a speed reducer including a rotating body with a cylindrical shape configured to be rotated by said motor on an inside of said housing and lubricated by a lubricating oil and an output shaft fixed to or integrated with said rotating body;
a hub bearing provided on a part of said output shaft positioned at an axle outward direction side of said rotating body, allowing a rotation of said wheel while supporting a vehicle weight, and including one or a plurality of groups of rolling elements comprised of a plurality of rolling elements disposed in a circumferential direction thereof; and
a first seal member,
said in-wheel motor unit rotating said wheel by transmitting torque of said motor to said wheel via said speed reducer and said hub bearing,
wherein,
said hub bearing includes a bearing part lubricated by a grease with a higher viscosity than said lubricating oil and a hub part to which a brake rotor disposed outside said housing is fixed, wherein said bearing part and said hub part are integrated with each other,
said housing includes a wall surface on said axle outward direction side, said wall surface expanding on a plane substantially perpendicular to a central axis of said hub bearing,
an opening is provided in said wall surface,
said output shaft penetrates said opening to extend to outside of said housing in an axle outward direction,
said bearing part penetrates said wall surface via said opening and at least a part of said one or a plurality of groups of rolling elements is positioned inside said housing so that a part of said bearing part is positioned on an inside of said housing with respect to said wall surface via said opening,
said part of said output shaft positioned at said axle outward direction side of said rotating body is rotatably supported with respect to said housing only by said bearing part,
a first recessed part recessing in an axle inward direction is provided on one end surface in said axle outward direction of said rotating body,
said first recessed part includes a center of said one end surface and a central axis thereof coincides with a central axis of said rotating body,
one end part in said axle inward direction of said bearing part is positioned in said first recessed part, and
said first seal member is disposed inside said part of said bearing part, fluid-tightly seals a gap between an inner race and an outer race of said hub bearing at a position positioned at an axle inward direction side of said one or a plurality of groups of said rolling elements of said hub bearing, and divides an inside of said housing into a first space where said motor and said rotating body are disposed and a second space surrounded by said inner race, said outer race, said first seal member, and a virtual plane including said opening of said housing.

2. An in-wheel motor unit according to claim 1 , wherein,
said bearing part has a cylindrical shape where at least more than or equal to two groups of said rolling elements are disposed side by side in an axle direction,
said output shaft is supported only by said hub bearing, and a part of said output shaft positioned at said axle inward direction side of said rotating body is not supported by any bearings.

3. An in-wheel motor unit according to claim 1 , wherein,
a part of said output shaft positioned at said axle inward direction side of said rotating body is rotatably supported with respect to said housing by a taper roller bearing.

4. An in-wheel motor unit according to claim 3 , wherein,
a second recessed part recessing in said axle outward direction is provided on an other end surface in said axle inward direction of said rotating body,
one end part in said axle outward direction of said taper roller bearing is positioned in said second recessed part.

Assignees

• Toyota Motor Co Ltd

Inventors

• Fukudome Hideki

Classifications

• B60K7/0007 Primary

  the motor being electric · CPC title

• B60L2220/42

  with use of more than one motor · CPC title

• H02K7/116

  with gears · CPC title

• B60K2007/0038

  the motor moving together with the wheel axle · CPC title

• B60K17/043

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