TORQUE SENSOR

• US 20130167661A1
• Filed: 07/27/2011
• Published: 07/04/2013
• Est. Priority Date: 08/05/2010
• Status: Active Grant

• Current Assignee: Tri-Force Management Corporation
• Original Assignee: Tri-Force Management Corporation
• Inventors: Okada, Kazuhiro, Nishioki, Nobuhisa
• Granted Patent: US 8,667,854 B2
• Time in Patent Office: Days
• US Class Current: 73/862.337
• CPC Class Codes: G01L 3/10 involving electric or magnetic means for indicating
• CPC Class Codes: G01L 3/106 involving electrostatic means

Abstract

A small, high-stiffness torque sensor. An annular deformable body is disposed between left and right side supports. Convex sections protruding from the left side support in a rightward direction are joined to the left side surface of the annular deformable body, and convex sections protruding from the right side support in a leftward direction are joined to the right side surface of the annular deformable body. When force is applied to the right side support and torque around the Z axis acts on the left side support, the annular deformable body is elliptically deformed and the long-axis position of the inner peripheral surface of the annular deformable body moves away from the Z axis while the short-axis position moves closer to the Z axis. The acting torque is detected as a variation in the capacitance value of capacitive elements formed by displacement electrodes and fixed electrodes.

Claims

1. A torque sensor for detecting torque about a predetermined rotation axis (Z), comprising:

an annular deformation body (30;

30A) made of a material that produces elastic deformation due to exertion of torque to be detected, having a through-opening portion (H30) through which the rotation axis (Z) is inserted;

a left side support body (10) disposed at a position adjacent to a left side of the annular deformation body (30;

30A), when viewed in such a reference observation direction that the rotation axis (Z) creates a horizontal line extending left and right;

a right side support body (20) disposed at a position adjacent to a right side of the annular deformation body (30;

30A), when viewed in the reference observation direction;

a left side connection member (11, 12) for connecting a left side connection point (P11, P12) on a left-hand side surface of the annular deformation body (30;

30A) to the left side support body (10);

a right side connection member (21, 22) for connecting a right side connection point (P21, P22) on a right-hand side surface of the annular deformation body (30;

30A) to the right side support body (20);

a displacement electrode (E31 to E34;

E31A to E34A;

E31L to E34L) fixed to an inner peripheral surface or an outer peripheral surface of the annular deformation body (30;

30A), for producing displacement caused by elastic deformation of the annular deformation body (30;

30A);

a fixed electrode (E21 to E24;

E21A to E24A;

E21S to E24S;

E24B) disposed at a position opposed to the displacement electrode (E31 to E34;

E31A to E34A;

E31L to E34L), fixed to the left side support body (10) or the right side support body (20); and

a detector circuit (41 to 43, 51 to 55) for outputting an electrical signal indicating torque about the rotation axis (Z) exerted on one of the right side support body (10) and the left side support body (20) with the other loaded, based on an amount of fluctuation in capacitance value of a capacitive element (C1 to C4;

C4A, C4B;

C1-1 to C4-2) composed of the displacement electrode (E31 to E34;

E31A to E34A;

E31L to E34L) and the fixed electrode (E21 to E24;

E21A to E24A;

E21S to E24S;

E24B), wherein

an orthogonal projection image of the left side connection point (P11, P12) and an orthogonal projection image of the right side connection point (P21, P22) with respect to a plane of projection orthogonal to the rotation axis (Z) are formed at different positions.

2. The torque sensor according to claim 1, wherein

a first left side connection point (P11) and a second left side connection point (P12) are provided on the left-hand side surface of the annular deformation body (30;

30A),

the left side connection member (11, 12) includes a first left side connection member (11) for connecting the first left side connection point (P11) to the left side support body (10) and a second left side connection member (12) for connecting the second left side connection point (P12) to the left side support body (10),

a first right side connection point (P21) and a second right side connection point (P22) are provided on the right-hand side surface of the annular deformation body (30;

30A),

the right side connection member (21, 22) includes a first right side connection member (21) for connecting the first right side connection point (P21) to the right side support body (20) and a second right side connection member (22) for connecting the second right side connection point (P22) to the right side support body (20), and

when orthogonal projection images are obtained by projecting the annular deformation body (30;

30A) on a plane of projection orthogonal to the rotation axis (Z), the orthogonal projection images of the connection points are disposed on an annular path along an outline of the annular deformation body (30;

30A) in an order of the first left side connection point (P11), the first right side connection point (P21), the second left side connection point (P12), and the second right side connection point (P22).

3. The torque sensor according to claim 2, wherein when two mutually orthogonal straight lines to pass through a projection point of the rotation axis (Z) are drawn on the plane of projection orthogonal to the rotation axis (Z), the orthogonal projection images of the first left side connection point (P11) and the second left side connection point (P12) are disposed on a first straight line (Y), and the orthogonal projection images of the first right side connection point (P21) and the second right side connection point (P22) are disposed on a second straight line (X).

4. The torque sensor according to claim 1, wherein as the left side support body (10) and the right side support body (20), annular structures each having a through-opening portion (H10, H20) at a center portion are used, and an insertion hole that penetrates through the through-opening portions (H10, H30, H20) of the left side support body (10), the annular deformation body (30), and the right side support body (20) is secured along the rotation axis (Z).

5. The torque sensor according to claim 1, wherein the annular deformation body (30;

30A) is made of a circular annular member that is obtained by forming, in a central portion of a disk disposed about the rotation axis (Z) as a central axis, a through-opening portion (H30) being in a shape of a concentric disk having a smaller diameter.

6. The torque sensor according to claim 1, wherein the left side support body (10) and the right side support body (20) are made of circular annular members each of which is obtained by forming, in a central portion of a disk disposed about the rotation axis (Z) as a central axis, a through-opening portion (H10, H20) being in a shape of a concentric disk having a smaller diameter.

7. The torque sensor according to claim 1, wherein

the displacement electrode (E31 to E34;

E31A to E34A;

E31L to E34L) is constructed by a conductive layer formed on an inner peripheral surface of the annular deformation body (30), and

the fixed electrode (E21 to E24;

E21A to E24A;

E21S to E24S;

E24B) is constructed by a conductive plate disposed at a position opposed to the conductive layer and projecting in a direction along the rotation axis (Z) from the left side support body (10) or the right side support body (20).

8. The torque sensor according to claim 1, including a first displacement electrode (E31) fixed to, out of respective parts of the annular deformation body (30), a first part that is displaced in a direction to approach the rotation axis (Z) when torque in a predetermined rotating direction is exerted, a second displacement electrode (E32) fixed to a second part that is displaced in a direction to separate from the rotation axis (Z) when torque in the predetermined rotating direction is exerted, a first fixed electrode (E21) disposed at a position opposed to the first displacement electrode (E31), and a second fixed electrode (E22) disposed at a position opposed to the second displacement electrode (E32), wherein

the detector circuit outputs an electrical signal corresponding to a difference between a capacitance value of a first capacitive element (C1) composed of the first displacement electrode (E31) and the first fixed electrode (E21) and a capacitance value of a second capacitive element (C2) composed of the second displacement electrode (E32) and the second fixed electrode (E22) as an electrical signal indicating exerted torque.

9. The torque sensor according to claim 8, wherein mutually opposed displacement electrodes and fixed electrodes are disposed offset from each other so that, when torque in a predetermined rotating direction is exerted, an effective opposing area of a pair of electrodes (E21, E31) composing a capacitive element (C1) an electrode interval of which is reduced is increased, and an effective opposing area of a pair of electrodes (E22, E32) composing a capacitive element (C2) an electrode interval of which is increased is reduced.

10. The torque sensor according to claim 1, wherein an area of one of fixed electrode (E21S to E24S) and displacement electrode (E31L to E34L) is set larger than that of the other so that, even when a relative position of the displacement electrode to the fixed electrode changes as a result of exertion of torque in a predetermined rotating direction, an effective opposing area of a pair of electrodes composing a capacitive element (C1 to C4) does not change.

11. The torque sensor according to claim 1, further comprising:

an inner annular deformation body (90) made of a material that produces elastic deformation due to exertion of torque to be detected, having a through-opening portion (H90) through which the rotation axis (Z) is inserted, disposed inside of the annular deformation body (80);

an inner left side connection member (63, 64) for connecting an inner left side connection point on a left-hand side surface of the inner annular deformation body (90) to the left side support body (60);

an inner right side connection member (72) for connecting an inner right side connection point on a right-hand side surface of the inner annular deformation body (90) to the right side support body (70);

an inner displacement electrode fixed to an inner peripheral surface or an outer peripheral surface of the inner annular deformation body (90), for producing displacement caused by elastic deformation of the inner annular deformation body (90); and

an inner fixed electrode disposed at a position opposed to the inner displacement electrode, fixed to the left side support body (60) or the right side support body (70), wherein

an orthogonal projection image of the inner left side connection point and an orthogonal projection image of the inner right side connection point with respect to a plane of projection orthogonal to the rotation axis (Z) are formed at different positions, and

the detector circuit outputs an electrical signal indicating torque about the rotation axis (Z) by further using an amount of fluctuation in capacitance value of a capacitive element composed of the inner displacement electrode and the inner fixed electrode.

12. The torque sensor according to claim 1, wherein

for detecting torque about a Z-axis in an XYZ three-dimensional coordinate system, the annular deformation body (30) is disposed on an XY plane about an origin O, the left side support body (10) is disposed in a negative Z-axis region, and the right side support body (20) is disposed in a positive Z-axis region,

a first left side connection point (P11) and a second left side connection point (P12) are provided on a negative Z-axis-side side surface of the annular deformation body (30),

the left side connection member includes a first left side connection member (11) for connecting the first left side connection point (P11) to the left side support body (10) and a second left side connection member (12) for connecting the second left side connection point (P12) to the left side support body (10),

a first right side connection point (P21) and a second right side connection point (P22) are provided on a positive Z-axis-side side surface of the annular deformation body (30),

the right side connection member includes a first right side connection member (21) for connecting the first right side connection point (P21) to the right side support body (20) and a second right side connection member (22) for connecting the second right side connection point (P22) to the right side support body (20), and

when orthogonal projection images are obtained by projecting both side surfaces of the annular deformation body (30) on the XY plane, a projection image of the first right side connection point (P21) is disposed on a positive X-axis, a projection image of the second right side connection point (P22) is disposed on a negative X-axis, a projection image of the first left side connection point (P11) is disposed on a positive Y-axis, and a projection image of the second left side connection point (P12) is disposed on a negative Y-axis.

13. The torque sensor according to claim 12, wherein the annular deformation body (30) is made of a circular annular member that is obtained by forming, in a central portion of a disk disposed about the Z-axis as a central axis, a through-opening portion (H30) being in a shape of a concentric disk having a smaller diameter.

14. The torque sensor according to claim 13, including, when a V-axis and a W-axis that pass though the origin O and create 45 degrees with respect to the X-axis and Y-axis are defined on the XY plane, a first displacement electrode (E31) and a first fixed electrode (E21) disposed on the V-axis and a second displacement electrode (E32) and a second fixed electrode (E22) disposed on the W-axis, wherein

the detector circuit (41, 42, 43) outputs an electrical signal corresponding to a difference between a capacitance value of a first capacitive element (C1) composed of the first displacement electrode (E31) and the first fixed electrode (E21) and a capacitance value of a second capacitive element (C2) composed of the second displacement electrode (E32) and the second fixed electrode (E22) as an electrical signal indicating exerted torque.

15. The torque sensor according to claim 14, wherein

when an outline of an orthogonal projection image of the annular deformation body (30) onto the XY plane changes from a circle to an ellipse due to exertion of torque in a predetermined rotating direction, the V-axis is set in a short-axis direction of the ellipse, and the W-axis is set in a long-axis direction thereof, and

with no torque exerted, a position of the first fixed electrode (E21) is shifted by a predetermined offset amount in the predetermined rotating direction relative to a position of the first displacement electrode (E31), and a position of the second fixed electrode (E22) is shifted by a predetermined offset amount in a direction opposite to the predetermined rotating direction relative to a position of the second displacement electrode (E32).

16. The torque sensor according to claim 13, including, when signed V- and W-axes that pass through the origin O and create 45 degrees with respect to the X-axis and Y-axis are defined on the XY plane, a first displacement electrode (E31) and a first fixed electrode (E21) disposed on the positive V-axis, a second displacement electrode (E32) and a second fixed electrode (E22) disposed on the positive W-axis, a third displacement electrode (E33) and a third fixed electrode (E23) disposed on the negative V-axis, and a fourth displacement electrode (E34) and a fourth fixed electrode (E24) disposed on the negative W-axis, wherein

the detector circuit outputs an electrical signal corresponding to a difference between “

a sum of a capacitance value of a first capacitive element (C1) composed of the first displacement electrode (E31) and the first fixed electrode (E21) and a capacitance value of a third capacitive element (C3) composed of the third displacement electrode (E33) and the third fixed electrode (E23)” and

“

a sum of a capacitance value of a second capacitive element (C2) composed of the second displacement electrode (E32) and the second fixed electrode (E22) and a capacitance value of a fourth capacitive element (C4) composed of the fourth displacement electrode (E34) and the fourth fixed electrode (E24)”

as an electrical signal indicating exerted torque.

17. The torque sensor according to claim 16, wherein

when an outline of an orthogonal projection image of the annular deformation body (30) onto the XY plane changes from a circle to an ellipse due to exertion of torque in a predetermined rotating direction, the V-axis is set in a short-axis direction of the ellipse, and the W-axis is set in a long-axis direction thereof, and

with no torque exerted, a position of the first fixed electrode (E21) is shifted by a predetermined offset amount in the predetermined rotating direction relative to a position of the first displacement electrode (E31), a position of the second fixed electrode (E22) is shifted by a predetermined offset amount in a direction opposite to the predetermined rotating direction relative to a position of the second displacement electrode (E32), a position of the third fixed electrode (E23) is shifted by a predetermined offset amount in the predetermined rotating direction relative to a position of the third displacement electrode (E33), and a position of the fourth fixed electrode (E24) is shifted by a predetermined offset amount in a direction opposite to the predetermined rotating direction relative to a position of the fourth displacement electrode (E34).

18. The torque sensor according to claim 14, wherein

an area of one of the fixed electrode (E21S to E24S) and displacement electrode (E31L to E34L) is set larger than that of the other so that, even when a relative position of the displacement electrode to the fixed electrode changes as a result of exertion of torque in a predetermined rotating direction, an effective opposing area of a pair of electrodes composing a capacitive element (C1 to C4) does not change.

19. The torque sensor according to claim 18, wherein displacement electrodes are constructed by a common conductive layer formed on an inner peripheral surface of the annular deformation body.

20. The torque sensor according to claim 19, wherein the annular deformation body (30A) is constructed by a conductive elastic material so as to use an inner peripheral surface itself of the annular deformation body (30A) as a common conductive layer (E35).

21. The torque sensor according to claim 12, further comprising an inner annular deformation body (90) made of a material that produces elastic deformation due to exertion of torque to be detected, having a through-opening portion (H90) through which the Z-axis is inserted, disposed on the XY plane about the origin O so as to be located inside of the annular deformation body (80),

a first inner left side connection point and a second inner left side connection point being provided on a negative Z-axis-side side surface of the inner annular deformation body (90),

a first inner right side connection point and a second inner right side connection point being provided on a positive Z-axis-side side surface of the inner annular deformation body (90), and further comprising:

a first inner left side connection member (63) for connecting the first inner left side connection point to the left side support body (60), a second inner left side connection member (64) for connecting the second inner left side connection point to the left side support body (60), a first inner right side connection member for connecting the first inner right side connection point to the right side support body (70), a second inner right side connection member for connecting the second inner right side connection point to the right side support body (70);

an inner displacement electrode fixed to an inner peripheral surface or an outer peripheral surface of the inner annular deformation body (90), for producing displacement caused by elastic deformation of the inner annular deformation body (90); and

an inner fixed electrode disposed at a position opposed to the inner displacement electrode, fixed to the left side support body (60) or the right side support body (70), wherein

when orthogonal projection images are obtained by projecting both side surfaces of the inner annular deformation body (90) on the XY plane, a projection image of the first inner right side connection point is disposed on a positive Y-axis, a projection image of the second inner right side connection point is disposed on a negative Y-axis, a projection image of the first inner left side connection point is disposed on a positive X-axis, and a projection image of the second inner left side connection point is disposed on a negative X-axis, and

the detector circuit outputs an electrical signal indicating torque about the rotation axis (Z) by further using an amount of fluctuation in capacitance value of a capacitive element composed of the inner displacement electrode and the inner fixed electrode.

30. The torque sensor according to claim 1, wherein the left side connection member (11, 12;

61 to 64) is constructed by a projecting portion projecting rightward from a right side surface of the left side support body (10;

60), the right side connection member (21, 22;

72) is constructed by a projecting portion projecting leftward from a left side surface of the right side support body (20;

70), and top surfaces of the projecting portions are joined to the connection points of the annular deformation body (30;

80, 90).

22. A torque sensor for detecting torque about a predetermined rotation axis (Z), comprising:

an outer annular deformation body (80) made of a material that produces elastic deformation due to exertion of torque to be detected, having a through-opening portion (H80) through which the rotation axis (Z) is inserted;

an inner annular deformation body (90) made of a material that produces elastic deformation due to exertion of torque to be detected, having a through-opening portion (H90) through which the rotation axis (Z) is inserted, disposed inside of the outer annular deformation body (80);

a left side support body (60) disposed at a position adjacent to a left side of the outer annular deformation body (80) and the inner annular deformation body (90), when viewed in such a reference observation direction that the rotation axis (Z) creates a horizontal line extending left and right;

a right side support body (70) disposed at a position adjacent to a right side of the outer annular deformation body (80) and the inner annular deformation body (90), when viewed in the reference observation direction;

an outer left side connection member (61, 62) for connecting an outer left side connection point on a left-hand side surface of the outer annular deformation body (80) to the left side support body (60);

an outer right side connection member (72) for connecting an outer right side connection point on a right-hand side surface of the outer annular deformation body (80) to the right side support body (70);

an inner left side connection member (63, 64) for connecting an inner left side connection point on a left-hand side surface of the inner annular deformation body (90) to the left side support body (60);

an inner right side connection member for connecting an inner right side connection point on a right-hand side surface of the inner annular deformation body (90) to the right side support body (70);

an outer displacement electrode (E81, E82) fixed to an inner peripheral surface of the outer annular deformation body (80), for producing displacement caused by elastic deformation of the outer annular deformation body (80);

an inner displacement electrode (E91, E92) fixed to an outer peripheral surface of the inner annular deformation body (90) so as to be opposed to the outer displacement electrode (E81, E82), for producing displacement caused by elastic deformation of the inner annular deformation body (90); and

a detector circuit for outputting an electrical signal indicating torque about the rotation axis (Z) exerted on one of the right side support body (70) and the left side support body (60) with the other loaded, based on an amount of fluctuation in capacitance value of a capacitive element (C1 to C4) composed of the outer displacement electrode (E81, E82) and the inner displacement electrode (E91, E92), wherein

with respect to a plane of projection orthogonal to the rotation axis (Z), an orthogonal projection image of the outer left side connection point and an orthogonal projection image of the outer right side connection point are formed at different positions, and an orthogonal projection image of the inner left side connection point and an orthogonal projection image of the inner right side connection point are formed at different positions.

23. A torque sensor for detecting torque about a Z-axis in an XYZ three-dimensional coordinate system, comprising:

an outer annular deformation body (80) made of a material that produces elastic deformation due to exertion of torque to be detected, having a through-opening portion (H80) through which the Z-axis is inserted, disposed on an XY plane about an origin O;

an inner annular deformation body (90) made of a material that produces elastic deformation due to exertion of torque to be detected, having a through-opening portion (H90) through which the Z-axis is inserted, disposed on the XY plane about the origin O and disposed within the through-opening portion (H80) of the outer annular deformation body (80);

a left side support body (60) disposed at a position adjacent to a negative Z-axis region side of the outer annular deformation body (80) and the inner annular deformation body (90); and

a right side support body (70) disposed at a position adjacent to a positive Z-axis region side of the outer annular deformation body (80) and the inner annular deformation body (90),

a first outer left side connection point and a second outer left side connection point being provided on a negative Z-axis-side side surface of the outer annular deformation body (80), and a first outer right side connection point and a second outer right side connection point being provided on a positive Z-axis-side side surface of the outer annular deformation body (80),

a first inner left side connection point and a second inner left side connection point being provided on a negative Z-axis-side side surface of the inner annular deformation body (90), and a first inner right side connection point and a second inner right side connection point being provided on a positive Z-axis-side side surface of the inner annular deformation body (90), and further comprising;

a first outer left side connection member (61) for connecting the first outer left side connection point to the left side support body (60), a second outer left side connection member (62) for connecting the second outer left side connection point to the left side support body (60), a first outer right side connection member for connecting the first outer right side connection point to the right side support body (70), a second outer right side connection member (72) for connecting the second outer right side connection point to the right side support body (70);

a first inner left side connection member (63) for connecting the first inner left side connection point to the left side support body (60), a second inner left side connection member (64) for connecting the second inner left side connection point to the left side support body (60), a first inner right side connection member for connecting the first inner right side connection point to the right side support body (70), a second inner right side connection member for connecting the second inner right side connection point to the right side support body (70);

an outer displacement electrode (E81, E82) fixed to an inner peripheral surface of the outer annular deformation body (80), for producing displacement caused by elastic deformation of the outer annular deformation body (80);

an inner displacement electrode (E91 to E94) fixed at a position opposed to the outer displacement electrode (E81 to E84) in an outer peripheral surface of the inner annular deformation body (90), for producing displacement caused by elastic deformation of the inner annular deformation body (90); and

a detector circuit for outputting an electrical signal indicating torque about the Z-axis exerted on one of the right side support body (60) and the left side support body (70) with the other loaded, based on an amount of fluctuation in capacitance value of a capacitive element (C1 to C4) composed of the outer displacement electrode (E81 to E84) and the inner displacement electrode (E91 to E94), wherein

when orthogonal projection images are obtained by projecting both side surfaces of the outer annular deformation body (80) and the inner annular deformation body (90) on the XY plane, a projection image of the first outer right side connection point is disposed on a positive X-axis, a projection image of the second outer right side connection point is disposed on a negative X-axis, a projection image of the first outer left side connection point is disposed on a positive Y-axis, a projection image of the second outer left side connection point is disposed on a negative Y-axis, a projection image of the first inner right side connection point is disposed on a positive Y-axis, a projection image of the second inner right side connection point is disposed on a negative Y-axis, a projection image of the first inner left side connection point is disposed on a positive X-axis, and a projection image of the second inner left side connection point is disposed on a negative X-axis.

24. The torque sensor according to claim 23, wherein the outer annular deformation body (80) and the inner annular deformation body (90) are made of circular annular members each of which is obtained by forming, in a central portion of a disk disposed about the Z-axis as a central axis, a through-opening portion (H80, H90) being in a shape of a concentric disk having a smaller diameter.

25. The torque sensor according to claim 24, wherein as the left side support body (60) and the right side support body (70), annular structures each having a through-opening portion (H60, H70) at a center portion are used, and an insertion hole that penetrates through through-opening portions (H60, H90, H70) of the left side support body (60), the inner annular deformation body (90), and the right side support body (70) is secured along the Z-axis.

26. The torque sensor according to claim 24, including, when a V-axis and a W-axis that pass though the origin O and create 45 degrees with respect to the X-axis and Y-axis are defined on the XY plane, a first outer displacement electrode (E81) and a first inner displacement electrode (E91) disposed on the V-axis and a second outer displacement electrode (E82) and a second inner displacement electrode (E92) disposed on the W-axis, wherein

the detector circuit outputs an electrical signal corresponding to a difference between a capacitance value of a first capacitive element (C1) composed of the first outer displacement electrode (E81) and the first inner displacement electrode (E91) and a capacitance value of a second capacitive element (C2) composed of the second outer displacement electrode (E82) and the second inner displacement electrode (E92) as an electrical signal indicating exerted torque.

27. The torque sensor according to claim 24, including, when signed V- and W-axes that pass through the origin O and create 45 degrees with respect to the X-axis and Y-axis are defined on the XY plane, a first outer displacement electrode (E81) and a first inner displacement electrode (E91) disposed on the positive V-axis, a second outer displacement electrode (E82) and a second inner displacement electrode (E92) disposed on the positive W-axis, a third outer displacement electrode (E83) and a third inner displacement electrode (E93) disposed on the negative V-axis, and a fourth outer displacement electrode (E84) and a fourth inner displacement electrode (E94) disposed on the negative W-axis, wherein

the detector circuit outputs an electrical signal corresponding to a difference between “

a sum of a capacitance value of a first capacitive element (C1) composed of the first outer displacement electrode (E81) and the first inner displacement electrode (E91) and a capacitance value of a third capacitive element (C3) composed of the third outer displacement electrode (E83) and the third inner displacement electrode (E93)” and

“

a sum of a capacitance value of a second capacitive element (C2) composed of the second outer displacement electrode (E82) and the second inner displacement electrode (E92) and a capacitance value of a fourth capacitive element (C4) composed of the fourth outer displacement electrode (E84) and the fourth inner displacement electrode (E94)”

as an electrical signal indicating exerted torque.

28. The torque sensor according to claim 27, wherein outer displacement electrodes are constructed by a common conductive layer (E85) formed on the inner peripheral surface of the outer annular deformation body (80), or inner displacement electrodes are constructed by a common conductive layer formed on the outer peripheral surface of the inner annular deformation body (90).

29. The torque sensor according to claim 28, wherein the outer annular deformation body (80A) is constructed by a conductive elastic material so as to use the inner peripheral surface itself of the outer annular deformation body (80A) as the common conductive layer (E85), or the inner annular deformation body (90) is constructed by a conductive elastic material so as to use the outer peripheral surface itself of the inner annular deformation body (90) as the common conductive layer.