Abstract: Even in the even that, when a steering torque is applied to a steering wheel 11 of an electric power steering system, a pinion shaft 21 of a rack-and-pinion steering gear box 16 is curved by a bending moment generated by a reaction force which a pinion 20 receives from a rack 18, since a steering shaft 14 on which a magnetostriction torque sensor 34 is provided is connected to the pinion shaft 21 via a universal joint 15, the transmission of the bending moment to the steering shaft 14 is made difficult to occur. As a result, the effect imposed by the bending moment on the detection accuracy of the magnetostriction torque sensor 34 provided on the steering shaft 14 can be suppressed to a minimum level.

Abstract: This electric power steering apparatus is provided with: a motor; a worm gear provided on a rotational shaft of the motor so as not to rotate with respect to the rotational shaft; a worm wheel gear which meshes with the worm gear and links to a steering system; a gear housing to which a motor housing of the motor is attached, and which accommodates the worm gear and the worm wheel gear; and a decentering device which makes the rotational shaft approach to or depart from a rotational axis of the worm wheel gear in a parallel manner thereto, by rotating the motor housing with respect to the gear housing.

Abstract: The torque sensor includes a plurality of coil units having a substantially cylindrical shape, the coil units including a plurality of detection coils arranged to face a magnetic characteristic change portion formed on a rotary shaft. The coil units include a first coil unit and a second coil unit, and the first coil unit and the second coil unit are disposed in the axial direction of the shaft. The first coil unit and the second coil unit are fixed in an integrally molded resin. Thereby, there is provided a torque sensor having a high productivity and an easy configuration and a method of manufacturing the torque sensor.

Abstract: This magnetostrictive torque sensor includes: a shaft made of a magnetized material; a magnetostrictive portion provided on the shaft at a position distanced for a predetermined length from an end of the shaft; a detection coil that is arranged so as to face the magnetostrictive portion, and detects a change in a magnetic characteristic of the magnetostrictive portion; and a plating made of an nonmagnetic material, that is provided on the end of the shaft.

Abstract: An electric power steering apparatus includes a worm gear mechanism for transmitting the torque generated by an electric motor to a steered road wheel of the vehicle. The worm gear mechanism has a worm gear made of metal and a worm wheel formed of plastic material and meshing with the worm gear. The worm gear has a tooth profile including a dedendum part formed in an involute shape and an addendum part formed in a circular arc shape with a center located on a line of action.

Abstract: An electric motor having a rotation shaft includes a motor housing into which the electric motor is accommodated, at least one pair of rolling bearings positioned in the motor housing and rotatably supporting both ends of the rotation shaft, and a displacement restriction member provided inside the motor housing and restricting a displacement of the rolling bearing in an axial direction of the rolling bearing. Each rolling bearing includes an inner race, an outer race, and rolling elements rotatably supported between the inner race and the outer race. The inner race is press fitted without any gaps onto an outer peripheral surface of the rotation shaft, and the outer race is press fitted without any gaps into a bearing attachment portion provided inside the motor housing.

Abstract: The present invention provides a method and a system for searching for relationships between base sequences in order to efficiently analyze the relationship between a sample base sequence and known base sequences. In the system, a theoretical value calculating portion calculates theoretical restriction fragment length values based on restriction enzyme data. The comparing portion produces analysis result data by comparing theoretical restriction fragment patterns with measured restriction fragment patterns, calculating the degree of similarity of the sample base sequence to known base sequences.

Abstract: Electric power steering apparatus includes an electric motor for producing steering assist torque corresponding to steering torque applied to a steering system, and a worm gear mechanism for transmitting the steering assist torque to the steering system. The worm of the worm gear mechanism has a pressure angle greater than a pressure angle of the worm wheel, so as to reduce an actual meshing pitch circle diameter of the worm in the worm gear mechanism.

Abstract: A cable type steering system includes an operation cable having an outer tube and inner cable slidably received in the outer tube. A drive pulley coupled to a steering wheel for rotation and a driven pulley coupled to a steering gear box for steering wheels for rotation are connected to end portions of the inner cable. A steering torque inputted to the steering wheel is transmitted to the steering gear box via the inner cable of the operation cable. At least one of a first portion of the system extending from the drive pulley to a first position of the outer tube and a second portion of the system extending from the driven pulley to a second position of the outer tube is accommodated within a waterproof space formed by a cover, such as a rubber cover or a cover molded of synthetic resin.

Abstract: Worm gear mechanism includes a driving worm, a torque delivering worm wheel meshing with the worm, and an auxiliary worm wheel superimposed on the torque delivering worm wheel. The auxiliary worm wheel has a pitch diameter greater than that of the torque delivering worm wheel. The auxiliary worm wheel is biased against the driving worm wheel via a biasing member in the form of a leaf spring.

Abstract: A worm gear mechanism includes a worm, a torque-transmitting worm wheel meshing with the worm, and an auxiliary worm wheel disposed concentrically with the torque-transmitting worm wheel. The auxiliary worm wheel has a pitch circle diameter set to be greater than a pitch circle diameter of the torque-transmitting worm wheel and hence meshes with the worm in a meshing phase different from that of the torque-transmitting worm wheel. A screw thread provided on the worm actually meshes with teeth of the torque-transmitting worm wheel along a length defined as an actual meshing length. The screw thread has an effective length reduced to be approximately equal to the actual meshing length.

Abstract: An improvement to an electric power steering apparatus which applies an assisting torque produced by an electric motor in correspondence with a steering torque to a rack shaft by way of a belt type transmission mechanism. A driving pulley of the belt type transmission mechanism is mounted to an output shaft part of the motor shaft of the electric motor. This output shaft part is rotatably supported at locations on both sides of the driving pulley.

Abstract: The electric power steering device such that the characteristic vibration of the rack shaft is adjusted by providing a hollow portion at the rack shaft, resulting in that the characteristic vibration of the rack shaft does not resonate with the vibration of the rack caused by the wheels and/or the motor.

Abstract: An electric power steering apparatus with an electric motor generating an assistant steering force for transmission to the steering system, a worm shaft rotated by the electric motor, a worm gear on the worm shaft that rotates therewith, a worm wheel rotated by the worm gear, a pinion shaft that rotates with the worm gear, supporting units that support both ends of the worm shaft so as to allow rotation thereof, and a distortion prevention unit that prevents distortion of the worm shaft. The supporting units may support the ends of the worm shaft without play.

Abstract: Worm gear mechanism is provided which includes a worm, a torque-transmitting worm wheel and an auxiliary worm wheel. In order to secure a sufficient face width of the torque-transmitting worm wheel, a pitch diameter of the auxiliary worm wheel is set to be greater than a pitch diameter of the torque-transmitting worm wheel. Thus, undesired backlash can be eliminated by the auxiliary worm wheel meshing with the worm with a different meshing phase from the torque-transmitting worm wheel.

Abstract: A cable-type steering device in which a driving pulley coupled to a first pulley shaft connected to a steering wheel and a follower pulley coupled to a second pulley shaft connected to a steering gear box are connected to each other by operating cables, whereby a steering torque input to the steering wheel is transmitted through the operating cables to the steering gear box. At least one of transmission of a steering torque between the driving pulley and the first pulley shaft and transmission of a steering torque between the follower pulley and the second pulley shaft is carried out through a tapered coupling portion including a tapered surface formed on an outer periphery of at least one of the first and second pulley shafts and a tapered surface formed on an inner periphery of at least one of the driving pulley and the follower pulley.

Abstract: A cable type steering system includes a drive pulley coupled to a steering wheel for rotation and having a drive pulley main body, a driven pulley coupled to a steering gear box for steering wheels for rotation and having a driven pulley main body, and an operation cable connecting the drive pulley with the driven pulley, so that a steering torque inputted to the steering wheel is transmitted to the steering gear box via the operation cable. At least one of the drive pulley main body and the driven pulley main body may be molded of a synthetic resin in such a manner as to cover a detent portion formed on an outer circumference of a pulley boss made of a metal both from an axial direction and a radial direction, and at least part of the covered detent portion is visible from outside of the covering pulley main body.

Abstract: To provide the electric motor assist type power steering apparatus, which can prevent the aggravation of the feeling of the steering, and which can transmit the assist steering force brought by the electric motor to the steering shaft completely, by preventing the flexure of the worm shaft of the electric motor assist type power steering apparatus, preferably the pinion assist type electric power steering apparatus.

Abstract: The invention is a polyimide, random copolymer having repeating units of the formula (1): wherein R1 and R2 each represent a divalent group selected from and R1 and R2 may be the same or different; and x=0.60 to 0.80, y+z=0.40 to 0.20, and x+y+z=1.00, and a linear expansion coefficient at 100 to 200° C. is in the range of from 10 to 20 ppm/K. This is a useful polyimide that can be a polyimide circuit substrate material capable of keeping flat, neither shrinking nor expanding in its laminate.

Abstract: Disclosed are a polyamic acid having repeating units represented by the formula (1): wherein the norbornane skeleton of comprises four components of and their contents satisfy the following: 1%≦2,5-[diexo]≦90%, 1%≦2,5-[exo,endo]≦90%, 1%≦2,6-[diexo]≦90%, 1% ≦2,6-[exo,endo]≦90%, provided that (2,5-[diexo])+(2,5-[exo,endo])+(2,6-[diexo])+(2,6-[exo,endo])=100%, R represents from 4 to 27 carbon atoms, and represents a tetravalent group selected from the group consisting of an aliphatic group, a monocyclic aliphatic group, a condensed polycyclic aliphatic group, a monocyclic aromatic group, a condensed polycyclic aromatic group, and a non-condensed polycyclic aliphatic or aromatic group which is composed of cycloaliphatic or aromatic groups mutually bonded to each other either directly or via a crosslinking member; and a polyimide