Nsk Corporation

Ryoichi Otaki

Hisashi Machida

Shinichi Natsumeda

Hideki Hashitani

Hiroya Achiha

Koichi Sakai

Hiroyuki Ito

Koji Hashimoto

Hiroshi Eda

Kazuo Chikaraishi

Toshihiro Fukuda

Tomofumi Yamashita

Atsushi Ozawa

A rotary shaft and a rotation driven member are connected as to transmit motive power when the rotary shaft rotates relatively to the rotation driven member. A roller gets displaced to a first position where a frictional force with an outer race and the rotation driven member decreases, thereby permitting transmission of a rotational force from the rotary shaft to the rotation driven member. When the rotation driven member rotates relatively to the rotary shaft, the roller gets displaced to a second position where the frictional force with the outer race and the rotation driven member increases, thereby rotationally fixing the rotation driven member with respect to the outer race. The power transmission from a brake apparatus to an electric motor can be hindered while permitting the power transmission to the brake apparatus from the electric motor by using either a worm exhibiting a relatively low transmission efficiency or a worm wheel.

Linear actuator

An actuator has an electric motor, a screw shaft connected to a rotational shaft of the electric motor in such a manner as to be capable of transmitting power, a nut member disposed on peripherally of the screw shaft and connected to the rotational shaft of the electric motor in such a manner as to be capable of transmitting the power and a ball rolling within a spiral groove formed between the screw shaft and the nut member, characterized in that the rotational speed of the screw shaft and the rotational speed of the nut member are different.

Actuator and brake device

A ball screw mechanism that can drive a movable pulley disk in an axial direction includes a screw cylinder and a nut member. A stopper pin is inserted through the screw cylinder from one end surface of the circumferential wall of the screw cylinder to the other end surface. As an end portion of the stopper pin is engaged with a notch portion of a transmission case, the rotation of the screw cylinder is inhibited. A stopper projection is provided on the nut member. As the other end portion of the stopper pin abuts against the stopper projection, the rotation range of the nut member is regulated. The stopper projection and the stopper pin function as excessive fastening preventing means for preventing the excessive fastening of the ball screw mechanism.

Pulley width adjusting device for continuously variable transmission

In an actuator device which comprises a screw shaft, a nut member, and balls, the nut member moves relatively to the screw shaft in a first axial direction and a second axial direction opposite thereto in a manner such that it is continually subjected to a load in the first axial direction. A ball screw groove of the screw shaft is formed having a loaded surface which is pressed against the balls, on the side of a groove base in the first axial direction. A ball screw groove of the nut member is having a loaded surface which is pressed against the balls, on the side of its groove base in the second axial direction. These loaded surfaces are finished so that their surface roughness is lower than that of the unloaded surfaces.

Actuator device for manipulating movable member

The present invention provides a traction coefficient measurement device having a driving roller rotated around a driving shaft, a driven shaft is rotated together with a driven shaft, corresponding to the rotation of the driving roller, based on the engagement with the driving roller, and a load device for applying a resistance to the driven shaft against the rotation, wherein the driving shaft is fixed in position and the driven shaft is supported so as to move to and from the driving shaft, and a press apparatus is used to force the driven shaft to the driving shaft for measurement operation, and the driven shaft is positioned lower than the driving shaft in height, and the traction force acting on the engagement portion between the driving roller and the driven roller is directed in a direction to push the driven shaft downward.

Traction coefficient measurement device

An auxiliary equipment of driving force for bicycle is provided wherein a reduction gear of the traction roller type is adopted, and the contact pressure between the outer peripheral surfaces of the traction rollers and the outer peripheral surface of the rotatable shaft and the inner peripheral surface of the outer ring is controlled corresponding to the torque to be transmitted, so that the battery is less exhausted and that the traveling distance of the electrically power augmented bicycle is prolonged.

Auxiliary device for bicycle with traction roller type gear

A frictional transmission comprises first and second rotary shafts arranged in directions in which the central axes thereof crossed each other, a roller supported coaxially with the first rotary shaft for rotating with the first rotary shaft, a first frictional surface provided on the roller coaxially with the first rotary shaft, a disc supported coaxially with the second rotary shaft for rotating with the second rotary shaft, and a second frictional surface provided on this disc coaxially with the second rotary shaft. The second frictional surface and the first frictional surface are brought into frictional engagement with each other. A loading cam device is arranged so as to press the second frictional surface toward the first frictional surface at the time of driving. A further disc coaxial with the aforementioned disc is disposed in the environs of the second rotary shaft, and the roller is sandwiched by and between the two discs. This further disc is rotatably supported by an angular-type ball bearing relative to the second rotary shaft and the first-mentioned disc in the environs of the second rotary shaft in a state that this further disc is prevented from being displaced in a direction to be separated from the first-mentioned disc.

Frictional transmission

A friction-roller speed changer has three intermediate rollers (12a, 12b, 12c). Two rollers (12a, 12b) of which act as a wedge roller and can be moved into the narrower area of an annular space (10) by the transmission of power, wherein during power transmission from the input side in the normal state to the output side. The other intermediate roller (12a or 12b), which does not act as the wedge roller, moves into the wider area of the annular space (10) against the elastic force of the spring (14) whereby transmission efficiency for bidirectional rotation is maintained while preventing backflow of power.

Growing community of inventors

Fujisawa, Japan

Ryoichi Otaki