Ntn Corporation

Tomohisa Uozumi

Shiro Tamura

Shinya Taikou

Kenichi Suzuki

Masaru Kuroda

Tomoyoshi Izutsu

An in-wheel motor drive device includes an electric motor section, a speed reducer section having a speed-reduction structure using parallel shaft gears, a wheel bearing section, and a casing. The parallel shaft gears include at least one intermediate shaft each having an input-side and output-side intermediate gears, and an output shaft having a final output gear. The at least one intermediate shaft and the output shaft each have both end portions supported by rolling bearings to be rotatable. Among the rolling bearings, at least one rolling bearing arranged close to the input-side intermediate gear or a rolling bearing arranged close to the final output gear is arranged in a radially-inner-side recess portion of the gear, which is arranged close to the corresponding rolling bearing.

In-wheel motor drive device

Provided is an in-wheel motor drive device () including: a motor (); a wheel bearing (); and a speed reducer (). The speed reducer () comprises: a speed reducer input shaft (S) including an input gear (); a speed reducer output shaft (S) including an output gear (); and an intermediate shaft (S) including a small-diameter intermediate gear () and a large-diameter intermediate gear (). The large-diameter intermediate gear () has a circumscribed circle which is superimposed with a pitch circle of a plurality of rolling elements () of the wheel bearing () when viewed from an axial direction.

The wheel drive motor according to the invention includes a motor shaft () having 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, a bearing () rotatably supporting the small diameter portion (), and a rotor () secured to an outer circumferential surface () of the large diameter portion (). 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.

Wheel drive motor and in-wheel motor drive assembly

An in-wheel motor drive device includes: a motor part; a speed reduction part; a wheel bearing part; and a casing, the motor part including: a stator, which is fixed to the casing; a rotation shaft of a motor, which is rotatably supported on the casing through intermediation of a plurality of rolling bearings; and a rotor, which is mounted to the rotation shaft of the motor, the rotation shaft of the motor being configured to rotationally drive an input shaft of a speed reducer, the speed reduction part being configured to reduce a speed of rotation of the input shaft of the speed reducer to transmit the rotation to an output shaft of the speed reducer, the wheel bearing part being connected to the output shaft of the speed reducer, the rotation shaft of the motor being made of case hardening steel and subjected to carburizing, quenching, and tempering.

A rolling bearing includes inner and outer races rotatable relative to each other, a plurality of rolling elements interposed between the inner and outer races, and a retainer arranged between the inner and outer races for retaining the plurality of rolling elements equiangularly. Flange portions are formed on a radially inner side and a radially outer side of an axial end portion of the retainer so as to extend radially. Recessed grooves are formed in a region of the inner race and a region of the outer race corresponding to the respective flange portions so as to form labyrinths together with the flange portions. Inner side surfaces of the flange portions and axial end surfaces of the recessed grooves, which are opposed to the inner side surfaces of the flange portions, are inclined radially so as to generate a flow of lubricant.

Rolling bearing

A rolling includes an inner race and an outer race, which rotate relative to each other, balls, which are interposed between the inner and outer races, and a retainer, which is arranged between the inner and outer races, for retaining the balls equiangularly. The retainer includes two annular members facing each other in an axial direction and having opposing surfaces each including hemispherical pockets formed in a plurality of circumferential positions, for receiving the balls, the two annular members being coupled together so that the opposing surfaces are brought into abutment on each other. A flange portion extends radially and is provided on a radially inner or outer side of an axial end portion of each of the two annular members.

Growing community of inventors

Shizuoka, Japan

Tomohisa Uozumi