Torque sensor

A torque sensor that detects moment about a Z-axis in an XYZ three-dimensional coordinate system, comprising:

• a first structure formed around the Z-axis;
• a second structure formed around the Z-axis;
• a strain body provided between the first structure and the second structure, the strain body connecting the first structure and the second structure, and producing elastic deformation by the action of the moment;
• two first structure Y-axis connecting portions that connect the first structure and the strain body;
• two second structure X-axis connecting portions that connect the strain body and the second structure;
• a detection element;
• a detection circuit that outputs an electric signal indicating the moment, based on a detection result of the detection element;
• two first structure X-axis connecting portions that connect the first structure and the strain body;
• and
• two second structure Y-axis connecting portions that connect the strain body and the second structure, wherein
• the first structure Y-axis connecting portions are disposed on a positive side and a negative side of a Y-axis relative to the strain body,
• the second structure X-axis connecting portions are disposed on a positive side and a negative side of an X-axis relative to the second structure,
• the strain body includes four deformable bodies each including a displacement portion that is displaced in a Z-axis direction by elastic deformation,
• the deformable bodies are respectively disposed in a first quadrant, a second quadrant, a third quadrant, and a fourth quadrant,
• the detection element includes a capacitive element that detects a change in capacitance value by a displacement of the displacement portion of each of the deformable bodies in the Z-axis direction,
• the second structure is disposed inside the first structure when seen along the Z-axis,
• the first structure Y-axis connecting portion extends along the Y-axis and the Z-axis,
• the dimension of the first structure Y-axis connecting portion in the Z-axis direction is greater than the dimension of the first structure Y-axis connecting portion in the Y-axis direction,
• the second structure X-axis connecting portion extends along the X-axis and the Z-axis,
• the dimension of the second structure X-axis connecting portion in the Z-axis direction is greater than the dimension of the second structure X-axis connecting portion in the X-axis direction,
• when seen along the Z-axis, the first structure X-axis connecting portions are disposed on a positive side and a negative side of the X-axis relative to the strain body, and the second structure Y-axis connecting portions are disposed on a positive side and a negative side of the Y-axis relative to the second structure,
• the first structure X-axis connecting portion extends along the X-axis, and
• the second structure Y-axis connecting portion extends along the Y-axis.