Torque meter

Abstract

To reduce the influence of centrifugal force in a torque meter for measuring torque transmitted by a rotating shaft.SOLUTION: A torque detection strain gauge TG is fixed in a region ART between an outer peripheral region AR1 to which a first rotating shaft 51 of a first disk part 2 is connected and an inner peripheral region AR2 to which a cylindrical part 1 interlocked with a second rotating shaft 52 is connected, and a centrifugal-force compensation strain gauge CG is fixed in a region ARC located on an outer peripheral side of the region AR1. A strain detection circuit detects strain caused by torque transmitted between the region AR1 and the region AR2 by using the torque-detection strain gauge, in a form in which the influence of centrifugal force is canceled by using the centrifugal-force compensation strain gauge.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to techniques for measuring torque transmitted by a rotating shaft. [Background technology]

[0002] A known technique for measuring torque transmitted by a rotating shaft is to measure torque using a strain gauge fixed on the disk surface of a disk-shaped torque meter in which a first rotating shaft is connected to the inner side and a second rotating shaft is connected to the outer side (for example, Patent Document 1).

[0003] In this technology, the torque meter is configured so that, depending on the magnitude of the torque transmitted between the first and second rotating shafts via the torque meter, the torque meter undergoes deformation in the circumferential direction, with the outer circumferential side displacing relative to the inner circumferential side, and the strain corresponding to this deformation is displayed on a strain gauge.The torque meter is then used to measure the torque transmitted between the first and second rotating shafts from the strain detected by the strain gauge. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-164006 Summary of the Invention [Problem to be solved by the invention]

[0005] Because the torque meter described above rotates together with the first and second rotating shafts, the deformation of the torque meter also includes a component due to centrifugal force (centrifugal acceleration). This centrifugal force acts as a disturbance to the detection of the strain gauge, reducing the accuracy of torque measurement.

[0006] Therefore, an object of the present invention is to suppress a decrease in the accuracy of torque measurement due to centrifugal force in a torque meter that measures torque transmitted by a rotating shaft. [Means for solving the problem]

[0007] To achieve the above object, the present invention provides a torque meter for detecting torque, comprising: a disk-shaped torque transmission disk for transmitting torque between a first rotating shaft and a second rotating shaft; a torque-detecting strain gauge fixed to the torque transmission disk, which is a strain gauge for detecting torque; and a centrifugal-force-compensating strain gauge fixed to the torque transmission disk, which is a strain gauge for centrifugal force compensation. The torque transmission disk has a first region, which is an annular region in the axial direction for directly or indirectly transmitting torque between the torque transmission disk and the first rotating shaft; and a second region, which is an annular or circular region in the axial direction and located inner than the first region for directly or indirectly transmitting torque between the torque transmission disk and the second rotating shaft. The torque-detecting strain gauge is fixed to a region between the first region and the second region. The centrifugal force compensation strain gauge is fixed to a third region of the torque transmission disk, which is neither the first region, the second region, nor a region between the first and second regions, and is a region where centrifugal force acts due to the rotation of the torque transmission disk.

[0008] Here, in this torque meter, the third region may be a region on the outer periphery of the torque transmission disk than the first region, and in this case, the centrifugal force compensation strain gauge may be fixed on the disk surface of the torque transmission disk or on the side surface of the torque transmission disk.

[0009] Furthermore, the above torque meter may be provided with a strain detection means that uses the resistance value of the torque detection strain gauge to detect and output the strain caused by the torque transmitted between the first area and the second area in the area where the torque detection strain gauge is fixed, and the strain detection means may cancel the effect of the centrifugal force caused by the rotation of the torque meter on the detection of the strain using the resistance value of the centrifugal force compensation strain gauge.

[0010] To achieve the above object, the present invention provides a torque meter for transmitting torque between a first rotating shaft and a second rotating shaft, the torque meter including a first disk connected to the first rotating shaft, a second disk connected to the second rotating shaft, a cylindrical portion coaxially connecting the first disk and the second disk, a torque detection strain gauge fixed to the cylindrical portion, and a centrifugal force compensation strain gauge fixed to the first disk. The first disk has a first region that is an annular region in the axial direction for transmitting torque between the first rotating shaft and the first disk, and a second region that is an annular or circular region in the axial direction located inner than the first region for transmitting torque between the first disk and the cylindrical portion. In addition, the centrifugal force compensation strain gauge is fixed to a third region of the first disk portion, which is a region that is neither the first region, the second region, nor a region between the first region and the second region, and is a region where centrifugal force due to the rotation of the first disk portion acts.

[0011] Here, the torque meter may be provided with a strain detection means that uses the resistance value of the torque detection strain gauge to detect and output the strain caused by the torque transmitted through the cylindrical portion, and the strain detection means may cancel the effect of the centrifugal force caused by the rotation of the torque meter on the detection of the strain using the resistance value of the centrifugal force compensation strain gauge.

[0012] Alternatively, the torque meter may be provided with a plurality of the torque-detecting strain gauges and a strain detection circuit. The strain detection circuit may include a bridge circuit incorporating the centrifugal force compensation strain gauge and a plurality of the torque-detecting strain gauges to detect strain in the region where the torque-detecting strain gauges are fixed. However, the centrifugal force compensation strain gauges are incorporated into the bridge circuit so that the resistance value of the centrifugal force compensation strain gauge reduces the influence of centrifugal force caused by the rotation of the torque meter from the output of the bridge circuit.

[0013] With these torque meters, while torque-detecting strain gauges detect strain that includes components due to torque and centrifugal force, centrifugal force-compensating strain gauges can detect strain that includes only the component due to centrifugal force, but not the component due to torque. Therefore, the effect of centrifugal force on strain detection using torque-detecting strain gauges can be canceled out using the detection value of the centrifugal force-compensating strain gauge, thereby preventing a decrease in torque measurement accuracy due to centrifugal force. [Effects of the Invention]

[0014] As described above, according to the present invention, in a torque meter that measures torque transmitted by a rotating shaft, it is possible to suppress a decrease in the accuracy of torque measurement due to centrifugal force. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a diagram showing a configuration of a torque meter according to an embodiment of the present invention; [Figure 2] FIG. 2 is a diagram showing the arrangement of strain gauges according to an embodiment of the present invention. [Figure 3] 1 is a diagram illustrating an example of the configuration of a distortion detection circuit according to an embodiment of the present invention. [Figure 4] FIG. 10 is a diagram illustrating another configuration example of the distortion detection circuit according to the embodiment of the present invention. [Figure 5] FIG. 10 is a diagram illustrating another configuration example of a torque meter according to an embodiment of the present invention. [Figure 6]FIG. 10 is a diagram illustrating another configuration example of a torque meter according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, an embodiment of the present invention will be described. FIG. 1a1 shows a perspective view of the torque meter according to this embodiment, FIG. 1a2 shows a front view of the torque meter, FIG. 1a3 shows a side view of the torque meter, and FIG. 1a4 shows a rear view of the torque meter. As shown in each figure, the torque meter comprises a hollow cylindrical portion 1, a disk-shaped first disk portion 2 connected to the front side of the cylindrical portion 1 and coaxial with the cylindrical portion 1, and a disk-shaped second disk portion 3 connected to the back side of the cylindrical portion 1 and coaxial with the cylindrical portion 1. However, the first disk portion 2 and the second disk portion 3 may be hollow disks provided as flanges of the hollow cylindrical portion 1. Furthermore, the cylindrical portion 1 may be a solid columnar portion.

[0017] The first disk portion 2 has eight screw holes arranged in an annular area on the outer periphery, and the second disk portion 3 has eight screw holes arranged in an annular area on the outer periphery. Next, as shown schematically in the oblique view of Figure 1b1 and the side view of Figure 1b2, the flange at the end of the first rotating shaft 51 is connected to the front of the first disc portion 2 using eight bolts and eight screw holes in the first disc portion 2, and the flange at the end of the second rotating shaft 52 is connected to the back of the second disc portion 3 using eight bolts and eight screw holes in the second disc portion 3.

[0018] 2a, in the torque meter described above, the first disk portion 2 relays torque transmitted between the first rotating shaft 51 and the second rotating shaft 52 between a first region AR1, which is an annular region on the outer periphery where a screw hole to which the first rotating shaft 51 is connected is arranged, and a second region AR2, which is an annular region to which the cylindrical portion 1 is connected. However, if the cylindrical portion 1 is not hollow, the second region AR2 will be a circular region.

[0019] Therefore, deformation of the first disk portion 2 due to torque occurs within the area ART shown by diagonal hatching in Figure 2b2, which consists of the first area AR1, the second area AR2, and the area between them, and does not occur outside the area ART. As shown in Figure 2c, eight torque detection strain gauges TG_A, TG_B, TG_C, TG_D, TG_E, TG_F, TG_G, and TG_H and two centrifugal force compensation strain gauges CG_A and CG_B are fixed to the front of the first disk portion 2. The eight torque-detecting strain gauges are arranged in the region between the first region AR1 and the second region AR2 within the region ART where deformation due to torque occurs. The eight torque-detecting strain gauges are also arranged at equal angular intervals of 45° on a circle concentric with the first disk portion 2. On the other hand, the two strain gauges for centrifugal force compensation are placed in the gray area ARC in Figure 2b2, which is located on the outer periphery of the area ART and where no deformation due to torque occurs. The two strain gauges for centrifugal force compensation are also placed symmetrically with respect to the center of the first disk portion 2. However, the two centrifugal force compensating strain gauges may be arranged on the side surfaces of the first disk portion 2 as shown in FIG. 2d. As the strain gauge for torque detection, a two-axis strain gauge is used, which has two measurement grids: measurement grid R, which has sensitivity in a direction tilted 45° clockwise from the central axis direction indicated by the solid arrow in Figure 2e1, and measurement grid L, which has sensitivity in a direction tilted 45° counterclockwise from the central axis direction.

[0020] Furthermore, each torque detecting strain gauge is arranged so that its central axis direction is in the radial direction toward the outer periphery. When the torque transmitted between the first region AR1 and the second region AR2 applies a force indicated by the dotted arrow in Figure 2e2 to the area where the torque detection strain gauge is placed, causing it to deform as shown in Figure 2e3, the measurement grid L of the torque detection strain gauge expands, increasing its resistance value, and the measurement grid R contracts, decreasing its resistance value.

[0021] Next, as the two strain gauges for centrifugal force compensation, uniaxial strain gauges having a measurement grid with sensitivity in the direction of the central axis indicated by the solid arrow shown in FIG. 2f1 are used. Furthermore, each centrifugal force compensation strain gauge is arranged so that its central axis direction is tangent to a circle concentric with the first disk that passes through the centrifugal force compensation strain gauge. However, the central axis direction does not necessarily have to coincide with the tangent direction, and the central axis direction may be inclined from the tangent direction. As the radius of the first disk increases due to centrifugal force, a force indicated by the dotted arrow in Figure 2f2 is applied to the area where the centrifugal force compensation strain gauge is located, causing it to deform as shown in Figure 2f3. This causes the measurement grid of the centrifugal force compensation strain gauge to stretch, increasing its resistance value. However, the type of the two centrifugal force compensation strain gauges and their arrangement and orientation within the region ARC do not necessarily have to be as described above, and any type may be used as long as it can detect the magnitude of deformation of the region ARC due to centrifugal force. Actually, the deformation of the area where the torque detecting strain gauges are arranged includes a component due to centrifugal force in addition to a component due to torque transmitted between the first area AR1 and the second area AR2. On the other hand, the deformation of the arrangement region of the centrifugal force compensating strain gauges does not include a component due to torque transmitted between the first region AR1 and the second region AR2, but includes only a component due to centrifugal force. Therefore, the effect of centrifugal force on strain detection using the change in resistance value of the torque detection strain gauge can be canceled out using the change in resistance value of the centrifugal force compensation strain gauge, thereby suppressing the decrease in accuracy of torque measurement due to centrifugal force. The cancellation of such centrifugal force components may be performed by calculating the torque using a torque detection strain gauge, and then removing the centrifugal force components, which are calculated using a centrifugal force compensation strain gauge, from the calculated torque. Alternatively, this cancellation may be achieved by configuring a strain detection circuit by incorporating a centrifugal force compensation strain gauge into a well-known bridge circuit that outputs a change in the resistance value of a torque detection strain gauge as a voltage signal. Although not shown in the figure, the distortion detection circuit is a circuit built into the torque meter. The torque meter also has built-in power receiving circuits that receive power supplied to the distortion detection circuit via wireless power supply, and transmitters that wirelessly transmit the output voltage value of the distortion detection circuit to an external measuring device. Now, Figure 3a1 shows a typical bridge circuit using the four-gauge method when using two torque-detecting strain gauges TG_A and TG_E positioned symmetrically about the center of the first disk portion 2 in Figure 3a2, where TG_*-R represents the measurement grid R of the torque-detecting strain gauge TG_*, and TG_*-L represents the measurement grid L of the torque-detecting strain gauge TG_*.

[0022] In this bridge circuit, each measurement grid is affected by centrifugal force, so the output characteristics relative to the actual torque change depending on the magnitude of the centrifugal force, as if the offset increases in the positive or negative direction as the centrifugal force increases. Next, FIG. 3a2 shows another example of a strain detection circuit in which a centrifugal force compensation strain gauge CG_A shown in FIG. 3b2 is incorporated into the bridge circuit shown in FIG. 3a1. The strain detection circuit of Figure 3a2 is obtained by replacing TG_E-R of the bridge circuit of Figure 3a1 with a circuit element in which a centrifugal force compensation strain gauge CG_A and a first variable resistor VR1 are connected in parallel and TG_E-R are connected in series, and by replacing TG_A-L of the bridge circuit with a circuit element in which a counter resistor CR and TG_A-L are connected in series.

[0023] The counter resistor CR is provided to prevent the zero point of the bridge circuit output from shifting, and its resistance value is set equal to the resistance value of the circuit element consisting of the centrifugal force compensation strain gauge CG_A and the first variable resistor VR1 connected in parallel when there is no centrifugal force. In this strain detection circuit, when the resistance value of the centrifugal force compensating strain gauge CG_A increases due to centrifugal force, the centrifugal force compensating strain gauge CG_A acts to increase the output of the bridge circuit, and the amount of increase increases the stronger the centrifugal force, i.e., the greater the resistance value of the centrifugal force compensating strain gauge CG_A. Conversely, if the output of the bridge circuit is to decrease as the resistance value of the centrifugal force compensating strain gauge CG_A increases due to centrifugal force, then the position of the counter resistor CR can be swapped with the circuit element in which the centrifugal force compensating strain gauge CG_A and the first variable resistor VR1 are connected in parallel.

[0024] Therefore, by using such a distortion detection circuit, the output characteristics of the distortion detection circuit with respect to the actual torque can be made to approach a constant characteristic that is not dependent on centrifugal force. In addition, in Figure 3b1, TG_A-R of the bridge circuit may be replaced with a circuit element in which counter resistors CR and TG_A-R are connected in series, and TG_E-L of the bridge circuit may be replaced with a circuit element in which counter resistors CR and TG_E-L are connected in series. In the above, the case where two torque detection strain gauges TG_A and TG_E are used in the strain detection circuit has been described, but the strain detection circuit may be configured to include even more torque detection strain gauges. As an example, when using eight torque detection strain gauges TG_A to TG_H shown in Figure 4a and two centrifugal force compensation strain gauges CG_A and CG_B, the strain detection circuit can be configured, for example, as shown in Figure 4b. The strain detection circuit of Figure 4b is obtained by replacing TG_A-L of the bridge circuit of Figure 3a1 with a circuit element in which a centrifugal force compensation strain gauge CG_A and a second variable resistor VR2 are connected in parallel and DCR1 are connected in series, replacing TG_A-R with DCR2, replacing TG_E-L with DCR3, and replacing TG_E-R with a circuit element in which a centrifugal force compensation strain gauge CG_B and a third variable resistor VR3 are connected in parallel and DCR4 are connected in series.

[0025] Here, DCR1 is a circuit element in which TG_A-L, TG_C-L, TG_E-L, and TG_G-L are connected in series as shown in Figure 4c1, and DCR2 is a circuit element in which TG_A-R, TG_C-R, TG_E-R, and TG_G-R are connected in series as shown in Figure 4c2. Furthermore, DCR3 is a circuit element in which TG_B-L, TG_D-L, TG_F-L, and TG_H-L are connected in series as shown in Figure 4c3, and DCR4 is a circuit element in which TG_B-R, TG_D-R, TG_F-R, and TG_H-R are connected in series as shown in Figure 4c4. In FIG. 4b, DCR2 of the bridge circuit may be replaced with a circuit element in which counter resistors CR and DCR2 are connected in series, and DCR3 of the bridge circuit may be replaced with a circuit element in which counter resistors CR and DCR3 are connected in series. The above has shown an example of constructing a strain detection circuit by incorporating a centrifugal force compensation strain gauge into a bridge circuit, but the strain detection circuit may have any configuration as long as the influence of centrifugal force on detection in the bridge circuit is reduced using a centrifugal force compensation strain gauge. In the above embodiment, the cylindrical portion 1 and the second disk portion 3 may be omitted, and the torque meter may be configured using only the first disk portion 2. Figure 5a1 shows an oblique view of a torque meter consisting only of the first disk portion 2, Figure 5a2 shows a front view of the torque meter, Figure 5a3 shows a side view of the torque meter, Figure 5a4 shows a rear view of the torque meter, and Figure 5a5 shows a cross section along the cross section line AA in Figure 5a2. As shown in the figure, this torque meter is the same as the torque meter in Figure 1 except that the cylindrical portion 1 and the second disk portion 3 are eliminated, and a screw hole is provided in the first disk portion 2 for connecting the second rotating shaft 52 to the back surface of the first disk portion 2, as shown in Figure 5b. In addition, a recess shown as D1 in Figure 5c is provided in an area on the front surface of the first disk portion 2 that is outer than the first area AR1, and each centrifugal force compensation strain gauge CG_* is arranged within this outer recess D1, and a recess shown as D2 in Figure 5c is provided in an area on the front surface of the first disk portion 2 that is inner than the first area AR1, and each torque detection strain gauge TG_* is arranged in an area on the outer side of the screw hole in this inner recess D2 that is used to connect the second rotating shaft 52.

[0026] In this torque meter, the arrangement of the torque detection strain gauges and centrifugal force compensation strain gauges may be the same as that shown in FIG. 2c. 2a, 2b, and 2c, the centrifugal force compensating strain gauges have been placed in the region ARC, which is located on the outer periphery of the region ART where torque-induced deformation of the first disk portion 2 occurs, and where no torque-induced deformation occurs. However, if there are other regions where torque-induced deformation does not occur and where centrifugal force-induced distortion that can be detected by the centrifugal force compensating strain gauges occurs, the centrifugal force compensating strain gauges may be placed in those other regions. Also, while the torque-detecting strain gauges have been placed in front of the first disk portion 2, the torque-detecting strain gauges may be placed anywhere on the torque meter where torque-induced deformation occurs.

[0027] For example, if the cylindrical portion 1 is made hollow and cylindrical, the area inside the second annular area AR2 will not be deformed by torque. Therefore, if distortion due to centrifugal force that can be detected by a centrifugal force compensation strain gauge occurs within this inner area, the centrifugal force compensation strain gauge may be placed at the location where the distortion occurs.

[0028] Alternatively, the torque meter may be configured as shown in Figures 6a1-a4. FIG. 6a1 shows a perspective view of the torque meter, FIG. 6a2 shows a front view of the torque meter, FIG. 6a3 shows a side view of the torque meter, and FIG. 6a4 shows a rear view of the torque meter. As shown in each figure, this torque meter is the torque meter shown in Figures 1a1-a4, with the outer edge portion on the back surface of the first disk portion 2, which is outer than the first area AR1, and the outer edge portion on the front surface of the second disk portion 3, which is outer than the screw hole for connecting the second rotating shaft 52, recessed. In addition, in this torque meter, a centrifugal force compensation strain gauge is placed in a recess on the outer edge of the back surface of the first disk portion 2, indicated by E1 in Fig. 6b1, and multiple torque detection strain gauges are placed on the outer peripheral surface of the cylindrical portion 1, indicated by F1 in Fig. 6c. In Fig. 6c, each of the multiple rectangles within the outer peripheral surface F1 represents a torque detection strain gauge.

[0029] Here, as shown in Fig. 6d, with the torque meter connected to the first rotating shaft 51 and the second rotating shaft 52, the cylindrical portion 1 relays the torque transmitted between the first rotating shaft 51 and the second rotating shaft 52 via the first disk portion 2 and the second disk portion 3. Then, torsional deformation of the cylindrical portion 1 occurs according to the magnitude of the torque being relayed, and the strain is detected by a torque detection strain gauge arranged on the outer circumferential surface of the cylindrical portion 1.

[0030] If the cylindrical portion 1 is hollow, the torque detection strain gauge may be placed on the inner peripheral surface of the cylindrical portion 1. The centrifugal force compensation strain gauge may also be placed in a recess on the outer edge of the front surface of the second disk portion 3, as shown by E2 in Figure 6b2. [Explanation of symbols]

[0031] 1...cylindrical portion, 2...first disk portion, 3...second disk portion, 51...first rotating shaft, 52...second rotating shaft, CG_A·CG_B...strain gauges for centrifugal force compensation, CR...counter resistor, L·R...measuring grid, SR...resistor, TG_A·TG_B·TG_C·TG_D·TG_E·TG_F·TG_G·TG_H...strain gauges for torque detection, VR1...first variable resistor, VR2...second variable resistor, VR3...third variable resistor.

Claims

1. A torque meter for detecting torque, a torque transmission disk that transmits torque between the first rotating shaft and the second rotating shaft; a torque detection strain gauge fixed to the torque transmission disk, which is a strain gauge for detecting torque; a centrifugal force compensation strain gauge fixed to the torque transmission disk, the torque transmission disk has a first region which is an annular region as viewed in the axial direction and which transmits torque directly or indirectly between the first region and the first rotating shaft, and a second region which is an annular or circular region as viewed in the axial direction and is located on the inner circumferential side of the first region and which transmits torque directly or indirectly between the first region and the second rotating shaft, the torque detection strain gauge is fixed to a region between the first region and the second region, The torque meter is characterized in that the centrifugal force compensation strain gauge is fixed to a third region of the torque transmission disk, which is a region that is neither the first region, the second region, nor a region between the first and second regions, and is a region where centrifugal force due to rotation of the torque transmission disk acts.

2. 2. The torque meter according to claim 1, The torque meter is characterized in that the third region is a region of the torque transmission disk that is more outer circumferential than the first region.

3. 3. The torque meter according to claim 2, A torque meter characterized in that the centrifugal force compensation strain gauge is fixed onto the disk surface of the torque transmission disk.

4. 3. The torque meter according to claim 2, A torque meter characterized in that the centrifugal force compensation strain gauge is fixed to a side surface of the torque transmission disk.

5. 5. A torque meter according to claim 1, 2, 3 or 4, a strain detection means for detecting and outputting a strain caused by a torque transmitted between the first region and the second region in the region where the torque detection strain gauge is fixed, using the resistance value of the torque detection strain gauge; The torque meter according to claim 1, wherein the strain detection means cancels the influence of centrifugal force caused by rotation of the torque meter on the detection of the strain by using the resistance value of the centrifugal force compensation strain gauge.

6. 1. A torque meter for transmitting torque between a first rotatable shaft and a second rotatable shaft, comprising: a first disk portion connected to the first rotary shaft; a second disk portion connected to the second rotary shaft; a cylindrical portion that coaxially connects the first disk portion and the second disk portion; a torque detection strain gauge fixed to the cylindrical portion; a centrifugal force compensation strain gauge fixed to the first disk portion, the first disk portion has a first region which is an annular region as viewed in the axial direction and which transmits torque between the first disk portion and the first rotating shaft, and a second region which is an annular or circular region as viewed in the axial direction and is located on the inner circumferential side of the first region and which transmits torque between the first disk portion and the cylindrical portion, The torque meter is characterized in that the centrifugal force compensation strain gauge is fixed to a third region of the first disk portion, which is a region that is neither the first region, the second region, nor a region between the first region and the second region, and is a region where centrifugal force due to rotation of the first disk portion acts.

7. 7. The torque meter according to claim 6, a strain detection means for detecting and outputting a strain caused by the torque transmitted by the cylindrical portion using the resistance value of the torque detection strain gauge; The torque meter according to claim 1, wherein the strain detection means cancels the influence of centrifugal force caused by rotation of the torque meter on the detection of the strain by using the resistance value of the centrifugal force compensation strain gauge.

8. 7. A torque meter according to claim 1, 2, 3, 4 or 6, The torque detecting device includes a plurality of strain gauges and a strain detection circuit, the strain detection circuit includes a bridge circuit incorporating the centrifugal force compensation strain gauge and a plurality of the torque detection strain gauges, and configured to detect strain in an area where the torque detection strain gauges are fixed; The centrifugal force compensating strain gauge is incorporated into the bridge circuit so that the resistance value of the centrifugal force compensating strain gauge reduces the influence of centrifugal force caused by rotation of the torque meter from the output of the bridge circuit.

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