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: The electric power steering device is disclosed 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 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: 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 detent portion is visible.

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 is connected to one end portion of the inner cable, and a driven pulley coupled to a steering gear box for steering wheels for rotation. A driven pulley is connected to the other end portion 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 extending from the drive pulley to a first optional position of the outer tube and a second portion extending from the driven pulley to a second optional position of the outer tube is accommodated within a waterproof space.

Abstract: An electric power steering apparatus comprising a rack shaft having two racks, a first rack-and-pinion mechanism for transferring a steering torque to the rack shaft, and a second rack-and-pinion mechanism for transferring an assist torque to the rack shaft. The second rack-and-pinion mechanism includes a pinion and a rack both being helical gears so that a large torque can be transmitted to the rack shaft. Teeth of the pinion and rack are arc profiled. The arc profiled teeth mesh with each other through a large contact area of concave and convex surfaces thereof and hence with a reduced contact pressure compared to involute profiled teeth. The arc profiled teeth thus have increased surface fatigue strength, bending strength and bending fatigue strength and can transmit an assist torque sufficiently to the rack shaft. Moreover, they have durability sufficient to withstand a torque load of a motor inertia.

Abstract: In an electric power steering system comprising a worm speed reduction gear unit using an hourglass worm, a pitch diameter of the worm wheel is smaller than that of the hourglass worm. Therefore, when the transmission torque between the worm and worm wheel is relatively small, only one or two of the teeth of the worm wheel engage the worm, and a certain resiliency is produced in the meshing between the worm and worm wheel. Therefore, when the steering angle is small or the transmission torque is small, the electric motor may not be energized but does not apply any substantial resistance to the turning of the steering shaft. Therefore, the vehicle operator is prevented from receiving any undesirable interferences or reaction from the electric motor even when the steering angle is small or the transmission torque is small.

Abstract: The invention is a polyimide, random copolymer having repeating units of the formula (1): 1

Abstract: Disclosed are a polyamic acid having repeating units represented by the formula (1): 1

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: A magnetostrictive torque sensor includes a magnetostrictive film of width W provided along a circumference of a rotational shaft. The film causes magnetostriction in correspondence to a torque applied to the rotational shaft. The torque sensor also includes excitation and detection cores each having substantially U-shaped configuration. These cores are disposed in opposed relation to the film. The excitation core extends through an excitation coil while the detection core extends through a detection coil. The excitation core is disposed on the detection core at right angles. The film has a magnetic path passing therethrough. The magnetic path, the excitation coil, and the detection coil cooperate with each other to provide a magnetic circuit. The excitation coil and the detection coil provides a bridge circuit in cooperation with each other. When a torque is applied to the rotational shaft, the film causes magnetostriction in correspondence to the torque.

Abstract: An electric power steering apparatus having a motor for producing assist torque according to the steering torque, and a rack and pinion mechanism for transferring torque assistance to the rack shaft. The pinion and rack of the rack and pinion mechanism are both helical gears, and transfer high torque to the rack shaft. The helical gears have a curved arc tooth profile. The teeth of a curved arc tooth profile gear set mesh with contact between convex and concave surfaces. The contact area is therefore increased and contact pressure is decreased compared with involute teeth. Surface fatigue strength, bending strength, and bending fatigue strength are thus greater compared with involute teeth. The combined steering torque and assist torque is efficiently transferred to the rack shaft, and durability is sufficient to withstand torque loads from motor inertia.

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: An electric power steering apparatus having a rack shaft supported at opposite end portions thereof by a rack-and-pinion mechanism and a ball-screw mechanism, respectively, includes a plain bearing slidably fitted around a rack shaft to support an intermediate portion of the rack shaft. The plain bearing thus provided considerably reduces a support span of the rack shaft and, hence, shifts a resonance frequency of the rack shaft to a higher frequency range. The rack shaft is, therefore, unlikely to cause vibration when external forces or moments caused due, for example, to a reaction from road surface during a steering operation act on opposite ends of the rack shaft.

Abstract: An electric power steering device includes a steering torque detector for detecting a steering torque in a steering system by detecting relative rotation between an input shaft and an output shaft, an electric motor for generating an auxiliary torque corresponding to a detection signal from the steering torque detector, and a torque transmitting mechanism for transmitting the auxiliary torque from the electric motor to the output shaft. The steering torque detector is composed of a detector body directly attached to the input shaft, and an actuator engaged with the output shaft for activating the detector body. With the steering torque detector thus arranged, an adjustment of the neutral position of the steering torque detector can be performed after the input and output shafts, the steering torque detector, and the torque transmitting mechanism are assembled together to form a single semi-finished steering assembly, and before the semi-finished steering assembly is received in a housing.

Abstract: In an electric power steering device of the type wherein an input member connected to an electric motor and an output shaft including an output member connected to a steering wheel are connected via a plurality of sets of friction clutch mechanisms for transmitting an auxiliary torque from the electric motor to the output shaft, the output member is displaceable in a radial direction relative to the input member. In response to rotation of position control members of the friction clutch mechanisms, one of the friction clutch mechanisms sets is disengaged whereupon a force or pressure exerted from the locking members of the other friction clutch mechanism sets to the output member forces the output member to move in the radial direction relative to the input member. With this movement of the output member, a frictional engagement force acting between the locking members and the input and output members is reduced.

Abstract: A unit-type electric power steering system comprises a steering mechanism having a first shaft and a second shaft. The first shaft has an input shaft for connection to a steering shaft, and an output shaft connected to the input shaft for angular displacement relative thereto and for connection in driving engagement with the second shaft. The second shaft is disposed in a case for displacement therein. A torque sensor detects a steering torque of the steering mechanism, and an electric motor outputs a steering assist force to the first shaft in response to the steering torque detected by the torque sensor. The first shaft, the torque sensor and the electric motor define components integrated into a single unit for removable connection to and disconnection from the second shaft and the case as a single unit without independent connection and disconnection of any one of the components.

Abstract: An electric power steering apparatus transmits an auxiliary torque from an electric motor to a steering system via a mechanical clutch composed of a plurality of sets of friction clutch mechanisms. At least one of the plural clutch mechanism sets is disengageable in advance to the remaining clutch mechanism set. This means that only a part of the clutch mechanisms can be brought to the disengaged state at an advanced timing. When the selected part of the clutch mechanisms is disengaged, the remaining clutch mechanisms are subjected to an unbalanced force tending to disengage the remaining clutch mechanisms. By the effect of the unbalance force, frictional forces acting in the remaining clutch mechanisms are considerably reduced, so that the remaining clutch mechanisms can be disengaged by a small clutch-disengaging force. Thus, the mechanical clutch as a whole can be disengaged by a smaller manual effort or force than as required when all the clutch mechanisms are disengaged at one time.

Abstract: The invention provides a novel preparation process of a polycondensation type polymer, an excellent polymer which is represented by lactic acid and the preparation process of the polymer, a polycondensation agent used for the preparation process, and an intermediate. Specifically, the invention provides a preparation process of the polycondensation type polymer, for example, polyamide, polyimide, polythioester and polyester, comprising bonding a carboxyl group comprising compound with an active hydrogen group comprising compound in the presence of haloiminium salt. The invention provides excellent polylactic acid having a controlled D/L-isomer ratio in the repeating structural units and preparation process of polylactic acid, and further provides a haloiminium salt compound used for the preparation process and an intermediate compound of acid chloride.