Abstract: 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 Tmax (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·n·Tmax/k<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.

Abstract: 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.

Abstract: Magnetic pole nails 51, 51 . . . aligned on magnetic yokes 5, 5 that integrally rotate with the second shaft 2 are formed in a rectangular shape, and the circumferential width and alignment pitch of the magnetic pole nails 51, 51 . . . are appropriately determined with respect to the magnetization pitch of the N-poles 40, 40 . . . and the S-poles 41, 41 . . . circumferentially aligned on the cylindrical magnet 4 that integrally rotates with the first shaft 1, so that a variation in magnetic flux generated on the magnetic yoke 5, 5 in accordance with the relative displacement between the cylindrical magnet 4 and the magnetic yoke 5, 5 uniformly takes place in a larger amplitude. Thus, a torque detecting apparatus that achieves higher detection accuracy with a simple structure can be provided.

Abstract: 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 projections 60 and 60 of each magnetism collecting ring 6 are arranged to extend not in their respective radial directions but substantially in parallel to each other while two magnetic sensors 7 and 7 are mounted to a circuit board 70 and inserted along the direction of projection of the magnetism collecting projections 60 and 60 into the air gaps respectively between the two magnetism collecting projection 60 and 60 of one magnetism collecting ring 6 and the two magnetism collecting projection 60 and 60 of the other magnetism collecting ring 6.

Abstract: An angular position sensor is provided which is designed to an angular position of a rotary shaft. The angular position sensor has a magnet affixed to the rotary shaft. The magnet has an N-pole and an S-pole and is so geometrically shaped as to produce magnetic flux which is substantially uniform in amount within a range extending around each of centers of the N-pole and the S-pole. This improves the linearity of a change in sensor output upon rotation of the rotary shaft.

Abstract: 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.

Abstract: 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.

Abstract: An inventive torque detection device includes: a magnetic circuit forming member having a tubular magnet provided at an outer circumferential portion of a first rotating body, and a magnetic ring that is located circumferentially of the tubular magnet and rotated together with a second rotating body connected to the first rotating body; a magnetic flux collecting ring part for collecting a magnetic flux generated by the magnetic circuit forming member; and a detection part for detecting, based on a density of the magnetic flux collected by the magnetic flux collecting ring part, a torque applied to the first or second rotating body, wherein the tubular magnet is formed by curing and magnetizing a synthetic resin, into which a magnetic powder is mixed, around the outer circumferential portion of the first rotating body.

Abstract: 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 Tmax (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·n·Tmax /k<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.

Abstract: An inventive torque detection device includes: a magnetic circuit forming member having a tubular magnet provided at a first rotating body, and a magnetic ring that is located circumferentially of the tubular magnet and rotated together with a second rotating body connected to the first rotating body; a magnetic flux collecting ring part for collecting a generated magnetic flux; a detection part for detecting, based on a density of the collected magnetic flux, a torque applied to the first or second rotating body; and a molded body that is molded at an outer circumferential portion of the first rotating body, and is joined to longitudinal both sides of the tubular magnet so as to fix the tubular magnet to the first rotating body. A molding pressure, generated when the tubular magnet is molded, is applied in the longitudinal direction of the tubular magnet.

Abstract: A torque detecting apparatus includes two magnetism collecting rings cylindrical portions enclosing a magnetic circuit forming member provided on a rotating body and a magnetism sensitive device disposed between the protruding pieces protruding from parts of the cylindrical portions in an radially outward direction of the cylindrical portions. It includes a regulating body for regulating a relative position between the magnetism sensitive device and the protruding pieces respectively. This regulating body includes two inserting recesses into which each of protruding pieces is inserted respectively, each recess having a prismatic shape. It also has a connecting part connecting inner edges of apertures of the inserting recesses to each other. It also has a holding part holding the magnetism sensitive device between the inserting recesses.

Abstract: 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.

Abstract: A first shaft and a second shaft are connected coaxially. A torsion bar converts a torque applied between two shafts into a torsion displacement. A multipolar magnet is fixed to the first shaft. One set of magnetic yokes is fixed to the second shaft and disposed in a magnetic field generated by the multipolar magnet. The magnetic yokes are opposed to each other via an air gap in an axial direction. A magnetic sensor is provided for detecting the density of magnetic flux generated in the air gap. A non-magnetic spacer is disposed between the magnetic yokes as a means for positioning the magnetic yokes. The spacer and the magnetic yokes are integrated by resin molding.

Abstract: An angular position determining apparatus is provided which includes a magnet affixed to a rotary shaft and a plurality of magnetic sensor elements and works to determine an angular position of the rotary shaft using outputs of the magnetic sensor elements. The apparatus also includes a malfunction detector which specifies which of the magnetic sensor elements is now malfunctioning and takes an action required to determine the angular position of the rotary shaft correctly in the event of such a malfunction.

Abstract: A torque sensor is provided which consists of a magnet, an assembly of magnetic rings, and a magnetic sensor. The magnetic rings have claws arrayed thereround at regular intervals. Each of the claws of one of the rings is interposed between adjacent two of the claws of the other ring. Upon input of torque, the magnet is rotated relative to the ring assembly, thereby causing the density of magnetic flux to change as a function of the torque which is sensed by the magnetic sensor. Each of the claws is geometrically shaped so as to increase the density of magnetic flux flowing through the ring assembly, thereby improving the sensitivity of the sensor.

Abstract: A torsion bar type torque sensor system is provided with the following: an elastic member that receives a torque and converts the torque to a torsion displacement; a multipolar ring magnet in which N poles and S poles are circumferentially and alternately magnetized; a pair of magnetic yoke halves disposed coaxially with the ring magnet; and a magnetometric sensor that detects magnetic flux generated between the pair of the magnetic yoke halves. The magnetometric sensor is made of a semiconductor that integrates a semiconductor magnetometric sensor, a non-volatile memory, a computation circuit, and an output circuit. This structure provides a torque sensor system that has an excellent maintainability.

Abstract: A torque sensor has a torsion bar coaxially in alignment with input and output shafts, a ring shaped magnet fixed to an axial end of the input shaft, a pair of magnetic yokes fixed to an axial end of the output shaft, and a magnetic sensor for detecting magnetic flux density generated between the pair of magnetic yokes. Each of the magnetic yokes is provided with claws, which are circumferentially spaced at constant intervals, and whose number is equal to that of each of N and S poles alternately arranged circumferentially in the magnet. Each, center of the claws coincides with a boundary between immediately adjacent N and S poles of the magnet, when the torsion bar is not twisted. The magnetic sensor is inserted into an axial gap between the pair of magnetic yokes without contacting the magnetic yokes.

Abstract: 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.

Abstract: A torque sensor has a torsion bar coaxially in alignment with input and output shafts, a ring shaped magnet fixed to an axial end of the input shaft, a pair of magnetic yokes fixed to an axial end of the output shaft, and a magnetic sensor for detecting magnetic flux density generated between the pair of magnetic yokes. Each of the magnetic yokes is provided with claws, which are circumferentially spaced at constant intervals, and whose number is equal to that of each of N and S poles alternately arranged circumferentially in the magnet. Each, center of the claws coincides with a boundary between immediately adjacent N and S poles of the magnet, when the torsion bar is not twisted. The magnetic sensor is inserted into an axial gap between the pair of magnetic yokes without contacting the magnetic yokes.

Abstract: A first shaft and a second shaft are connected coaxially. A torsion bar converts a torque applied between two shafts into a torsion displacement. A multipolar magnet is fixed to the first shaft. One set of magnetic yokes is fixed to the second shaft and disposed in a magnetic field generated by the multipolar magnet. One set of flux collecting rings is disposed along an outer surface of the set of magnetic yokes and opposed to each other via an air gap in an axial direction. A magnetic sensor is provided for detecting the density of magnetic flux generated in the air gap. An outer cylindrical surface of the set of flux collecting rings is surrounded by a magnetic shield.