Ntn Corporation

Hirokazu Ooba

Keisuke Sone

Kazuhiko Yoshida

Yusuke Ohata

Satoshi Utsunomiya

Taisuke Igi

Norio Ishihara

Hiroki Mukai

Kiyohiro Itou

Tomomi Ishikawa

Kentaro Nishikawa

Takashi Nozaki

Arito Matsui

Provided is a steering system capable of enhancing traveling stability when a vehicle drives straight and improving small-turn performance. The steering system includes: a first steering device; a second steering device including a mechanical section configured to individually steer each of left and right wheels by driving a steering actuator and a control section configured to control the steering actuator; and a vehicle information detection section configured to detect a velocity of the vehicle and a steering angle. The control section includes a turning angle control module configured to control the steering actuator pursuant to a predetermined rule in accordance with the velocity of the vehicle and the steering angle so as to control turning angles of the left and right wheels.

Steering system and vehicle equipped with same

The steering function-equipped hub unit includes: a turning shaft-equipped hub bearing including an inner ring, an outer ring, and rolling elements in double rows interposed between the inner ring and the outer ring, the turning shaft-equipped hub bearing having a turning shaft extending in a vertical direction; a unit support member rotatably supporting the turning shaft-equipped hub bearing () about a turning axis of the turning shaft; and a steering actuator configured to rotationally drive the turning shaft-equipped hub bearing about the turning axis (A). The unit support member and the steering actuator include a flange and an end portion, respectively, to be removably fixed to a knuckle which is a chassis frame component of a vehicle.

Hub unit having steering function, and vehicle equipped with same

Provided are a steering function-equipped hub unit that has a simple structure, high rigidity and a reduced size, a steering system, as well as a vehicle including the steering function-equipped hub unit. The steering function-equipped hub unit includes: a hub unit main body including a hub bearing supporting a wheel; a unit support member provided to a knuckle of a suspension device and rotatably supporting the hub unit main body about a turning axis extending in a vertical direction; and a steering actuator configured to rotationally drive the hub unit main body about the turning axis. The hub unit main body is supported by the unit support member through a preloaded rolling bearing.

Hub unit with steering function, steering system, and vehicle

Provided is a turning function-equipped having a reduced size and having improved strength to an external shock force and improved reliability. The turning function-equipped hub unit includes: a hub unit main body; a unit support member; and a turning actuator. The unit support member is provided to a chassis frame component. The unit support member includes an abutment part with which a part of the hub unit main body is brought into abutment in a vertical direction during non-normal time, the abutment part being separated from the hub unit main body in the vertical direction during normal time, and the non-normal time in which the abutment is caused, is a time when an impact load equal to or greater than a predetermined value acts on the hub unit main body in the vertical direction due to an external force from the wheel.

Hub unit having steering function, and vehicle provided with said hub unit

A supplemental turning function-equipped hub unit includes: a hub unit body including a hub bearing; and a unit support member configured to be mounted through a suspension device, the unit support member supporting the hub unit body through rotation-permitting support components at two upper and lower portions of the hub unit body such that the hub unit body is rotatable about a supplemental turning axis. A supplemental turning force receiving part is provided on a side part of the hub unit body, which part is configured to receive a force that causes the hub unit body to rotate about the supplemental turning axis.

Supplemental turning function-equipped hub unit and vehicle

The retainer is provided so as to be prevented from being rotatable with respect to the rotary shaft, and rotation of the input-side rotary member is reduced in speed and transmitted to the output-side rotary member through intermediation of the balls which engage with both of the ball engagement grooves. A raceway center line of the second ball engagement groove is formed of a wave-shaped curve. When a speed reduction ratio of the speed reducer is represented by 'i', the wave-shaped curve has such a shape that the balls which engage with the first ball engagement groove engage with the second ball engagement groove at a given rotation angle (&#x3b8;) of the input-side rotary member in a state in which the output-side rotary member is at a rotation angle (i&#x3b8;).

Speed reducer

An in-wheel motor drive device is provided including a brake caliper which can be easily mounted in position and dismounted. The in-wheel motor drive device includes a hub to which the wheel body of a vehicle wheel is mounted, an electric motor arranged inside of the hub in the width direction of the vehicle so as to be coaxial with the hub, a motor housing in which are received the electric motor, and the brake caliper, which is arranged to clamp a brake disk through a pair of brake pads disposed on both sides of the brake disk. The brake caliper is fixed to the outer periphery of the motor housing by driving bolts radially inwardly, from radially outside, of the motor housing.

In-wheel motor drive device

A hollow shaft, which is usable with a constant velocity universal joint, has an increased static torsional strength and torsional fatigue strength of a small diameter portion (small diameter portion having a smooth outer peripheral surface) formed near a spline at an end portion of the hollow shaft, and has a reduced manufacturing cost. The hollow shaft is molded by plastic working from a tubular blank, and subjected to quench hardening treatment. The quench hardening treatment includes carburizing and quenching treatment. The hollow shaft includes a softened section formed in a part of the hollow shaft by local heating treatment after carrying out the carburizing and quenching treatment.

Hollow shaft and constant velocity universal joint

A link actuating device includes input side and output side link hubs, and two sets of link mechanisms. Each of the link mechanisms is a three-link-chain link mechanism including four revolute pairs, and includes input side and output side end links rotatably connected to the input side and output side link hubs and an intermediate links rotatably connected to input side and output side end links. The link mechanism have a positional relationship in which the revolute pair axes between the link hubs and the end links are located on the same plane and cross each other. At least one of the two sets of link mechanisms is provided with interlocking unit that interlocks the input side end link and the output side end link to each other so as to be rotationally displaced.

Link actuating device

A fixed type constant velocity universal joint has pairs of track grooves, each pair forming a wedge angle (&#x3b1;). The wedge angle (&#x3b1;) includes a wedge angle (&#x3b1;) formed, when an operating angle is 0&#xb0;, with respect to each of torque transmitting balls arranged in a joint center plane, and opening to the same side in an axial direction for all pairs of track grooves. Further, the pairs of track grooves are mirror-image symmetrical with each other when the operating angle is 0&#xb0;.

Fixed-type constant velocity universal joint

An eight-ball fixed type constant velocity universal joint of an undercut free type is capable of increasing a torque capacity at high operating angles while securing durability at low operating angles. When a distance between a center of a track groove and a center of a ball is denoted by Rt, and when an axial distance between the center of the track groove and a joint center plane is denoted by F, a ratio R1 of F to Rt is set to fall within a range of 0.061&#x2266;R1&#x2266;0.087. When a radial offset amount, which is a distance between the center of the track groove and a joint center axial line is denoted by fr, a ratio R3 of fr to Rt is set to fall within a range of 0.07&#x2266;R3&#x2266;0.19. When an effective cured-layer depth with Hv 513 is denoted by Di and the diameter of the ball is denoted by d, a bottom surface of a track groove of an inner joint member includes a cured layer with an effective cured-layer depth ratio Di/d of at least 0.111 or more.

Fixed type constant velocity universal joint

A fixed type constant velocity universal joint of an eight-ball undercut-free type has improved torque capacity at high operating angle while ensuring durability at low operating angle. Centers of a track groove () of an outer joint member and a track groove () of an inner joint member are respectively separated from a center plane (P) toward axially different sides, and are offset away from a joint center axis (X) to a radially opposite side relative to grooves (). When Rt represents a distance between a center of a ball () and the center of groove (), and F represents an axial distance between plane (P) and the center of groove (), a ratio Rbetween F and Rt is 0.061&#x2266;R&#x2266;0.087. When fr represents a radial offset amount as a distance between axis (X) and the center of groove (), a ratio Rbetween fr and Rt is 0.07&#x2266;R&#x2266;0.19.

Fixed uniform-motion universal joint

A power transmission shaft includes a torque-transmission teeth portion formed on an outer peripheral surface on an end portion side, and a smooth portion formed on the outer peripheral surface adjacent to the torque-transmission teeth portion so as to have a stepwise reduced diameter. A ratio of a minimum diameter of the smooth portion to a minimum diameter of the torque-transmission teeth portion is set to 0.9 or more and 1.02 or less. Further, the torque-transmission teeth portion and the smooth portion undergo heat treatment so as to form a heat-treated hardened layer. The heat-treated hardened layer is formed to increase in depth from a side of the torque transmission teeth portion to a side of the smooth portion. At least a minimum diameter portion of the smooth portion undergoes full hardening.

Power transmission shaft, drive shaft, and propeller shaft

A constant velocity universal joint has high strength and capable of suppressing deformation caused by quenching at an opening end portion of a track groove of an outer joint member. In an undercut-free constant velocity universal joint in which a track groove in a cup portion of the outer joint member has a hardened layer formed by induction quenching, an opening end surface is protruded by a protruding amount t in an axial direction from a groove bottom of the track groove in a relief surface. The protruding amount t satisfies a relation of t=0.037d to 0.185d when a diameter of a torque transmission ball is represented by d. The opening end surface in a protruded portion and an outer surface of the cup portion continuous to the opening end surface have an unhardened layer free from hardening by quenching.

Constant velocity universal joint

In a fixed type constant velocity universal joint, a center of each of guide grooves of an outer joint member is offset to a position of being spaced apart from a joint central plane to a joint opening side by an axial distance, and is spaced apart from a joint central axis line to an opposite side in a radial direction with respect to each of the guide grooves by a radial distance. Further, a center of each of guide grooves of an inner joint member is offset to a position of being spaced apart from the joint central plane to a joint innermost side by the axial distance, and is spaced apart from the joint central axis line to the opposite side in the radial direction with respect to each of the guide grooves by the radial distance.

Growing community of inventors

Iwata, Japan

Hirokazu Ooba