Jtekt Corporation

Tohru Onozaki

Tsune Kobayashi

Kunihiko Suzuki

Hiroshi Takuno

Motoyasu Yamamori

Keita Nomura

Masaharu Tagami

Hideki Shibata

Atsushi Ando

Naomasa Mukaide

Akira Saito

Tomoyoshi Takai

Tomohiko Haruyama

Katsuhito Yoshinaga

In a reduction-transmission mechanism, an input member is arranged at such a position that a size obtained by adding a fitting clearance formed between a ball bearing and an outer periphery of an eccentric portion, a fitting clearance formed between the ball bearing and an inner periphery of the input member, which defines a center hole, and a radial internal clearance of the ball bearing is smaller than a size obtained by adding a fitting clearance formed between an outer periphery of each of a plurality of output members and a corresponding one of needle roller bearings, a fitting clearance formed between each of the needle roller bearings and an inner periphery of the input member, which defines a corresponding one of a plurality of pin insertion holes, and a radial internal clearance of each of the needle roller bearings.

Speed reduction mechanism, and motor torque transmission device including the speed reduction mechanism

In an in-wheel motor driving device, since an involute speed reduction gear with a small difference in number of teeth which can be made small in size can be disposed on an inner side of an inner rotor type motor, a size of the in-wheel motor driving device in the direction of a rotational axis can be reduced. Further, in the inner rotor type motor, since a first stator is disposed so as to face a radially outer side of a large-diameter rotor, heat generated in the first stator is easily dissipated. On the other hand, in an outer rotor type motor, since a second stator is disposed so as to face a radially inner side of a small-diameter rotor, a torque radius of the small-diameter rotor can be made large, thereby making it possible to ensure a large torque capacity. Because of this, the outer rotor type motor can be made smaller in diameter than the inner rotor type motor, thereby making it possible to ensure a large space within a wheel.

In-wheel motor driving device

When an outer ring is fitted to an inner periphery of an input member, which defines a center hole, and an inner ring is fitted to an eccentric portion with clearances in a reduction-transmission mechanism, in a state where tooth tips of the input member contact bottomlands of a rotation force applying member on a line perpendicular to a second axis and a fourth axis, a size between the second axis and a third axis is set to a size that is smaller than or equal to half of a size obtained by adding a diameter difference between an outside diameter of a ball bearing and an inside diameter of the input member, which defines the center hole, a diameter difference between an inside diameter of the ball bearing and an outside diameter of the eccentric portion and an operating clearance of the ball bearing.

Speed reduction mechanism, and motor torque transmission device including the same

When a bearing includes outer and inner rings and the outer ring is fitted to the inner periphery of an input member, which defines a center hole, with a clearance and the inner ring is fitted to an eccentric portion with a clearance, a size between a second axis and a third axis is set to a size that is smaller than or equal to half of a size obtained by adding a diameter difference between an outside diameter of the bearing and an inside diameter of the input member, which defines the center hole, a diameter difference between an inside diameter of the bearing and an outside diameter of the eccentric portion and an operating clearance of the bearing in a state where the input member has been moved to contact the housing on a line perpendicular to the second axis and a fourth axis.

A speed change gear device is provided with a housing, a first member supported rotatably about a predetermined rotational axis, a shaft member formed with an external gear, an annular member formed with an internal gear meshing with the external gear, and a transmission mechanism for transmitting a rotational component only of the annular member to the shaft member or a disc member arranged to be rotatable relative to the housing. The external gear differs from the internal gear in the number of teeth. Further, the first member is formed with a receiving hole that receives the annular member at a position where the center of the annular member is at a predetermined distance from the rotational axis. Then, the annular member is received in the receiving hole rotatably relative to the first member.

Speed change gear device

An easily structured swing internal contact type planetary gear device is proposed which can achieve a higher meshing ratio when an involute tooth profile is adapted. Each of an internal tooth of an internally toothed gear wheel and an external tooth of an externally toothed gear wheel is formed with an involute tooth profile. Under a driving condition, one of an internal tooth body of the internally toothed gear wheel and an external tooth body of the externally toothed gear wheel is elastically deformed in an extending direction and the other thereof is elastically deformed in a contracting direction so that the number of meshing teeth becomes larger than the number of meshing teeth under a non-driving condition.

Growing community of inventors

Nagoya, Japan

Tohru Onozaki