Torque sensor

A torque sensor comprising:

• a rotational member including a first shaft and a second shaft connected to each other via a torsion bar;
• a magnet provided at the first shaft rotatably according to a rotation of the first shaft, the magnet being annularly formed, the magnet being arranged in such a manner that an N pole and an S pole are disposed alternately in a circumferential direction,
• a first yoke member provided at the second shaft rotatably according to a rotation of the second shaft, the first yoke member being made from a magnetic material, the first yoke member including first claw portions, which are a plurality of plate-like members disposed so as to face the magnet, and a first annular portion formed annularly and connecting the first claw portions to one another;
• a second yoke member provided at the second shaft rotatably according to the rotation of the second shaft, the second yoke member being made from a magnetic material, the second yoke member including second claw portions, which are a plurality of plate-like members disposed so as to face the magnet, and a second annular portion formed annularly and connecting the second claw portions to one another, the second yoke member being disposed in such a manner that each of the second claw portions is disposed so as to be arranged alternately between the respective claw portions of the first claw portions;
• a first magnetic collection mechanism provided so as to face the first annular portion and be spaced apart from the first annular portion, the first magnetic collection mechanism being formed into a circular-arc shape along a direction around a rotational axis of the rotational member with use of a magnetic material;
• a second magnetic collection mechanism provided so as to face the second annular portion and be spaced apart from the second annular portion, the second magnetic collection mechanism being formed into a circular-arc shape along the direction around the rotational axis of the rotational member with use of a magnetic material;
• a surface-mount first magnetic sensor provided between the first magnetic collection mechanism and the second magnetic collection mechanism in a radial direction of the rotational axis of the rotational member, and including a Hall element configured to detect a magnetic field between the first magnetic collection mechanism and the second magnetic collection mechanism;
• a surface-mount second magnetic sensor provided between the first magnetic collection mechanism and the second magnetic collection mechanism in the radial direction of the rotational axis of the rotational member, and including a Hall element configured to detect a change in the magnetic field between the first magnetic collection mechanism and the second magnetic collection mechanism;
• and
• a sensor substrate on which the first magnetic sensor and the second magnetic sensor are mounted,
• wherein the torque sensor detects a torque generated on the rotational member based on an output signal of the first magnetic sensor or the second magnetic sensor.

A torque sensor comprising:

• a rotational member including a first shaft and a second shaft connected to each other via a torsion bar;
• a magnet provided at the first shaft rotatably according to a rotation of the first shaft, the magnet being annularly formed, the magnet being arranged in such a manner that an N pole and an S pole are disposed alternately in a circumferential direction,
• a first yoke member provided at the second shaft rotatably according to a rotation of the second shaft, the first yoke member being made from a magnetic material, the first yoke member including first claw portions, which are a plurality of plate-like members disposed so as to face the magnetic member;
• a second yoke member provided at the second shaft rotatably according to the rotation of the second shaft, the second yoke member being made from a magnetic material, the second yoke member including second claw portions, which are a plurality of plate-like members disposed so as to face the magnetic member;
• a surface-mount magnetic sensor including a plurality of Hall elements configured to detect a magnetic field between the first yoke member and the second yoke member;
• and
• a sensor substrate on which the magnetic sensor is mounted,
• wherein the torque sensor detects a torque generated on the rotational member based on an output signal of the magnetic sensor.