Denso Corporation

Jtekt Corporation

Koyo Seiko Company, Ltd.

Favess Co., Ltd.

Toshiharu Ishihara

Naoki Nakane

Yoshitomo Tokumoto

Taisuke Tsujimoto

Akio Osuka

Takeshi Izumi

Tetsuya Murakami

Norio Nakatani

Kaname Joushita

Noriyuki Yahata

Takashi Kaoku

Sinji Hakamata

Tomoharu Horiuchi

Takanori Hamada

Takeshi Izumu

A torque detection device has a magnetic flux collecting ring, arranged outside an outer periphery of a magnetic circuit forming member which is provided in a rotating body applied with a torque, for collecting a magnetic flux generated by the magnetic circuit forming member; a detector for detecting the torque applied to the rotating body based on a density of the magnetic flux collected by the magnetic flux collecting ring; and a holding ring for holding the magnetic flux collecting ring and the detector and including an attachment part to be attached to a stationary object on an outer periphery on one side in a radial direction. An attachment-preventing convex part for preventing attachment to the stationary object by contacting the stationary object is formed on one end face in an axis line direction of the holding ring.

Torque detection device and electric power steering apparatus using the same

There is provided a torque detecting device including: magnetic flux concentrating rings which locate on a magnetic circuit forming member provided in a rotating body to which a torque is exerted, the rings concentrating a magnetic flux generated by the member; a detecting part which detects the torque to the rotating body based on a density of the magnetic flux concentrated by the rings; and a holding ring which holds the magnetic flux concentrating rings and the detecting part and includes an attachment portion attaching to a stationary substance, on a circumference of the holding ring. Both end faces of the holding ring in an axial direction of the holding ring are substantially parallel. The attachment portion includes a fitting groove into which a sealing ring, which seals a gap between the attachment portion and the stationary substance, fits.

Torque detecting device and electric power steering apparatus using the same

A torque detecting apparatus for detecting rotational torque applied to a first and a second shafts which are coaxially connected to each other by a torsion bar by using a relative angular displacement between a cylindrical magnet fixedly fitted onto the first shaft and integrally rotating with the first shaft and yoke rings surrounding an outer circumference of the first rotating member and integrally rotating with the second shaft. A facing portion is provided between the first and second shafts, and faces each other in the axial direction by a space smaller than a space between a lower end face of the first rotating member and the upper end face of the second shaft. Positioning in the axial direction of the cylindrical magnet and the yoke rings is carried out referring position where the space of the facing surface becomes zero.

Torque detecting apparatus, and method for assembling torque detecting apparatus

A magnetic shield made of magnetic material in the shape of a thin cylinder is externally fitted and fixed on a cylindrical mold member holding magnetic flux collecting rings so that it has extended sections with appropriate length on both sides in the axial direction, and therefore magnetic noise from outside in the radial direction is shielded directly by the outer surface of the magnetic shield, magnetic noise from both sides in the axial direction is shielded by concentrating the magnetic noise on the end faces of the magnetic shield, and the influence on the magnetic flux collecting rings held in the mold member is eliminated.

Torque detecting device having magnetic shield for shielding magnetic noise

A torque detecting apparatus is provided which is capable of easily positioning a magnetic sensor in relation to a corresponding pair of magnetism collecting projections and thus improving the detection accuracy of the magnetic sensor without increasing the number of assembling and processing steps. A pair of magnetism collecting projectionsandof each magnetism collecting ringare arranged to extend not in their respective radial directions but substantially in parallel to each other while two magnetic sensorsandare mounted to a circuit boardand inserted along the direction of projection of the magnetism collecting projectionsandinto the air gaps respectively between the two magnetism collecting projectionandof one magnetism collecting ringand the two magnetism collecting projectionandof the other magnetism collecting ring

Torque detecting apparatus

Magnetic pole nails. . . aligned on magnetic yokesthat integrally rotate with the second shaftare formed in a rectangular shape, and the circumferential width and alignment pitch of the magnetic pole nails. . . are appropriately determined with respect to the magnetization pitch of the N-poles. . . and the S-poles. . . circumferentially aligned on the cylindrical magnetthat integrally rotates with the first shaftso that a variation in magnetic flux generated on the magnetic yokein accordance with the relative displacement between the cylindrical magnetand the magnetic yokeuniformly takes place in a larger amplitude. Thus, a torque detecting apparatus that achieves higher detection accuracy with a simple structure can be provided.

A detecting unit for detecting a torque applied to a rotor according to rotation of the rotor having an input shaft and an output shaft connected with each other by a torsion bar and a detection circuit board connected with the detecting unit are molded with synthetic resin material to form a mold member. The installation of the mold member into a housing, which has a cylinder portion to surround the rotor and a retainer having an opening formed at the peripheral wall of the cylinder portion, is achieved by inserting the mold member into the retainer from the radial direction through the opening of the retainer.

Torque detecting apparatus and manufacturing method thereof

An inventive torque detection device includes: a magnetic circuit forming member provided at a rotating body to which a torque is applied; a magnetic flux collecting ring for collecting a generated magnetic flux; a detection part for detecting, based on the density of the collected magnetic flux, the torque applied to the rotating body; a holding ring, having a flange, for holding the magnetic flux collecting ring and the detection part; and a sealing ring for sealing between the flange and a housing. The holding ring further has: a concave portion for equalizing the thickness of the holding ring at a region thereof close to the flange; and a prevention wall that is continuous with the flange and brought into contact with an inner circumferential face of the sealing ring so as to prevent the displacement of the sealing ring into the concave portion

Torque detection device

The number n of N-poles and S-poles circumferentially aligned on the cylindrical magnet that integrally rotates with the first shaft is determined so as to be a greatest integer that satisfies the following formula that includes a maximum value T(Nm) of the torque to be detected and a torsion spring constant k (Nm/deg) of the torsion bar connecting the first shaft and the second shaft: 2&#xb7;n&#xb7;T/k&#x3c;360. The cylindrical magnet includes teeth-shaped portions in which portions corresponding to the N-poles and the S-poles are of a protruding shape, so that adhesion of magnetic dust concentrates at the protruding portions. Thus, a torque detecting apparatus is provided that reduces the effect of the adhesion of the magnetic dust, so as to attain higher detection sensitivity and thereby improve the detection accuracy, without incurring an increase in cost.

A torque detecting apparatus according to the present invention includes a first shaft and a second shaft connected coaxially to each other through a connecting shaft, a permanent magnet fixed to the first shaft, a plurality of soft magnetic members having a collar provided therein, fitted by pressing with the second shaft and disposed in a magnetic field of the permanent magnet to form a magnetic circuit, and a detector for detecting magnetic flux generated from the soft magnetic members, wherein the soft magnetic members are integrally molded with a mold body made of synthetic resin, and when a torque is applied to the first shaft or the second shaft, the torque is detected based on an output of the detector. The collar is made of a non-magnetic material.

Torque detecting apparatus and electric power steering apparatus

A torque detecting apparatus having a permanent magnet fixed to an input shaft, magnetic yokes fixed to an output shaft coaxially connected to the input shaft via a torsion bar and disposed within a magnetic field of the permanent magnet to form a magnetic circuit, and a Hall IC for detecting a magnetic flux induced by the magnetic yokes. The permanent magnet is of a truncated conical shape, and the bevel circumference surface thereof is magnetized by magnetic poles alternately in a reverse polarities along circumference direction, so as to oppose the magnetic yokes. A torque applied to the input shaft or the output shaft can be detected through detection by the Hall IC of the magnetic flux generated between the magnetic yokes. The configuration allows reducing the length in an axial direction of the input shaft.

In a torque detecting apparatus, in each of two flux concentrating rings, a portion along a circumferential direction is raised outward in a radial direction so that a flux concentrating section is provided that has a plate shape extending on one side in an axial direction. These flux concentrating rings are fixedly arranged such that the flux concentrating sections should oppose to each other in the circumferential direction with a predetermined gap in between. Leakage flux between opposing surfaces of the flux concentrating sections is detected by magnetic sensors aligned in an axial direction between these opposing surfaces. This improves the utilization of materials for the flux concentrating rings including the flux concentrating sections, and hence reduces the product cost.

Growing community of inventors

Kashiwara, Japan

Toshiharu Ishihara