torque sensor
By combining the first and second annular components, the problem of the difficulty in arranging the torque transmission component and the strain gauge in parallel is solved, thus achieving the weight reduction of the torque sensor and the improvement of the strain gauge sensitivity.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NIDIKEKOZHIBO ELECTRONICS CO LTD
- Filing Date
- 2025-11-20
- Publication Date
- 2026-07-14
AI Technical Summary
In the prior art, it is difficult to simply equip the components that transmit torque and the strain generating components that configure strain gauges in a structure that extends parallel to the axis, and the torque sensor has not been able to achieve lightweight design.
The structure employs a combination of a first annular component and a second annular component, wherein the first annular component is fixed to the rotating body, the second annular component is connected to the first annular component through multiple beams, the strain generating component extends parallel to the central axis and is fixed to the annular component by screws, and the strain gauge is disposed on the strain generating component, thereby achieving torque transmission and weight reduction.
This technology enables easy assembly of torque-transmitting components and strain gauges, and allows for lightweighting of the torque sensor, thereby improving the sensitivity of the strain gauge and the overall performance of the sensor.
Smart Images
Figure CN122385031A_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to torque sensors. Background Technology
[0002] Patent Document 1 discloses a torque meter having a deformation section disposed between a rotating input shaft and an output shaft. The deformation section includes multiple components for transmitting torque from the input shaft to the output shaft, and multiple components with strain gauges disposed thereon. The torque-transmitting components and the strain gauge-distributed components extend parallel to the axis. Existing technical documents Patent documents
[0003] Patent Document 1: International Publication No. 2005 / 075950 Summary of the Invention The problem the invention aims to solve
[0004] Patent document 1 does not specifically disclose how to assemble the torque-transmitting component and the component equipped with strain gauges to the input shaft and the output shaft.
[0005] The torque-transmitting component and the strain-generating component for mounting the strain gauges are preferably easy to equip. However, a technique has not yet been proposed for easily equipping these components in a structure where the torque-transmitting component and the strain-generating component for mounting the strain gauges extend parallel to the axis. In addition, there is high hope for lightweight torque sensors.
[0006] Therefore, the purpose of this disclosure is to provide a torque sensor in which the torque-transmitting component and the strain-generating component for configuring the strain gauge extend parallel to the axis, and these components can be easily equipped, and a lightweight design can be achieved. Solution for solving the problem
[0007] According to one aspect of this disclosure, a torque sensor is provided between a first rotating body rotating about a central axis and a second rotating body rotating about the central axis according to the rotation of the first rotating body. The torque sensor comprises: a first annular member having a first flat plate portion fixed to the first or second rotating body, the first flat plate portion having an annular shape centered on the central axis; a second annular member having a plurality of second flat plate portions fixed to the second or first rotating body, a plurality of third flat plate portions fixed to the first annular member, and a plurality of beam portions extending parallel to the central axis and connected to the second and third flat plate portions, and integrally having an annular shape centered on the central axis; at least one strain generating member extending parallel to the central axis, assembled to the first and second annular members, capable of elastic deformation; and at least one strain gauge disposed on the strain generating member. Each beam portion is connected to one end of one of the plurality of second flat plate portions and one end of one of the plurality of third flat plate portions. Invention Effects
[0008] In this disclosed embodiment, a first annular member and a second annular member constitute a single assembly. The second annular member has a second plate portion and a third plate portion, respectively fixed to a first rotating body and a second rotating body. Furthermore, the second annular member has multiple beam portions connecting the second plate portion and the third plate portion, extending parallel to the central axis, and transmitting torque. A strain generating member extending parallel to the central axis is assembled to the first and second annular members. Thus, multiple beam portions transmitting torque and a strain generating member are provided in a single assembly having the first and second annular members. Therefore, by assembling the second annular member together with the first annular member to the first and second rotating bodies, multiple beam portions and a strain generating member can be easily provided. Furthermore, in the first annular member, the first flat plate is fixed to and supported by the rotating body. Therefore, the first annular member does not need to have high rigidity, thus enabling its weight reduction. In the second annular member, the second flat plate is fixed to and supported by another rotating body. Therefore, the second annular member does not need to have high rigidity, thus enabling its weight reduction. Consequently, the overall torque sensor can be lightweight. Attached Figure Description
[0009] Figure 1 This is a perspective view showing a torque sensor according to an embodiment of the present disclosure. Figure 2 This shows the input and output shafts fixed to torque. Figure 1 The image shows a 3D view of the torque sensor. Figure 3 It is shown Figure 1 A perspective view of the combination of the first and second annular components of the torque sensor. Figure 4 yes Figure 3 The top view of the second annular component shown. Figure 5 This is a top view showing an example of the configuration of strain gauges on a strain generating component. Figure 6 This is a top view showing other examples of strain gauge configurations on strain generating components. Figure 7 This is a top view showing other examples of strain gauge configurations on strain generating components. Figure 8 This is a top view showing other examples of strain gauge configurations on strain generating components. Figure 9 This is a schematic top view showing the configuration of the strain generating component in the torque sensor according to the embodiment. Figure 10 This is a schematic side view showing a portion of the torque sensor before it is subjected to torque. Figure 11 It shows that torque has been applied. Figure 10 A rough side view of the portion shown. Figure 12 This is a schematic top view showing other examples of the configuration of the strain generating element in a torque sensor. Figure 13 This is a schematic top view showing other examples of the configuration of the strain generating element in a torque sensor. Figure 14 This is a schematic top view showing other examples of the configuration of the strain generating element in a torque sensor. Figure 15 This is a schematic top view showing other examples of the configuration of the strain generating element in a torque sensor. Figure 16 This is a perspective view showing a combination of a first annular member and a second annular member of a torque sensor according to a variation of an embodiment of the present disclosure. Figure 17 yes Figure 16 The top view of the second annular component shown. Explanation of reference numerals in the attached figures Ax: Central axis, 100: Torque sensor, 2: First rotating body, 3: Second rotating body, 10: First annular component, 11: First flat plate, 11a: Through hole (first through hole), 11b: Cutout, 12: First assembly piece, 20: Second annular component, 22: Second flat plate, 23: Third flat plate, 23a: Through hole (second through hole), 24: Beam, 25: Second assembly piece, 40, 40A, 40B: Strain generating components, 42: Strain gauge. Detailed Implementation
[0010] The various embodiments of this disclosure will now be described with reference to the accompanying drawings. The scale of the drawings is not necessarily accurate, and some features may be exaggerated or omitted.
[0011] like Figure 1 and Figure 2 As shown, the torque sensor 100 according to the embodiments of this disclosure has a first annular member 10, a second annular member 20 and a plurality of strain generating members 40. The torque sensor 100 is positioned between a first rotating body 2 that rotates about a central axis Ax and a second rotating body 3 that rotates about the central axis Ax according to the rotation of the first rotating body 2. The first rotating body 2 is a torque input shaft or a component mounted on an input shaft, such as the output shaft of a motor or reducer. The second rotating body 3 is a torque output shaft or a component mounted on an output shaft, such as an axis provided on the hand or arm of a robot. The first rotating body 2 and the second rotating body 3 share a common central axis Ax and are spaced apart along the central axis Ax. The axial end of the second rotating body 3 is opposite to the axial end of the first rotating body 2, and a torque sensor 100 is disposed between them.
[0012] like Figure 3 As shown, the first annular member 10 has a first flat plate portion 11 and a plurality of first assembly pieces 12 connected to the first flat plate portion 11. The material of the first annular member 10 can be, for example, a metal such as stainless steel, or a resin with high mechanical strength. When the first annular member 10 is made of metal, it is preferably manufactured from a single sheet by bending and punching. When the first annular member 10 is made of resin, it is preferably manufactured by stamping or injection molding using a forming die.
[0013] The first plate portion 11 has a closed annular shape centered on the central axis Ax. The first plate portion 11 is disposed on an imaginary plane orthogonal to the central axis Ax. Multiple first assembly pieces 12 are arranged at predetermined intervals (preferably equal angular intervals) along a circumferential direction centered on the central axis Ax. In this embodiment, the first annular member 10 has eight first assembly pieces 12, but as described later, the number of first assembly pieces 12 is not limited to eight, and may be one or more other numbers. The first assembly piece 12 is disposed radially inside the first flat plate portion 11. Specifically, each first assembly piece 12 is bent from the inner periphery of the first flat plate portion 11 and extends perpendicular to the first flat plate portion 11 and parallel to the central axis Ax. Each first assembly piece 12 is a flat plate disposed on the tangent plane of an imaginary cylinder centered on the central axis Ax. Thus, a plurality of first assembly pieces 12 are arranged surrounding the imaginary cylinder. A through hole 12a for assembling the strain generating member 40 is formed in the center of each first assembly piece 12.
[0014] like Figure 3 and Figure 4 As shown, the second annular member 20 has multiple second flat plate portions 22, multiple third flat plate portions 23, multiple beam portions 24, and multiple second assembly pieces 25. The second annular member 20 as a whole has a closed annular shape centered on the central axis Ax. The material of the second annular member 20 can be, for example, a metal such as stainless steel, or a resin with high mechanical strength. When the second annular member 20 is made of metal, it is preferably manufactured from a single sheet by bending and punching. When the second annular member 20 is made of resin, it is preferably manufactured by stamping or injection molding using a forming die.
[0015] Multiple third plate portions 23 are arranged at predetermined intervals (preferably equal angular intervals) along a circumferential direction centered on the central axis Ax. Each third plate portion 23 has an arc shape centered on the central axis Ax. In this embodiment, the second annular member 20 has eight third plate portions 23, but the number of third plate portions 23 is not limited to eight, and may be one or more other numbers. Multiple third plate sections 23 are arranged on an imaginary plane orthogonal to the central axis Ax and are flush with each other. Each third plate section 23 is in contact with the surface of the first plate section 11 and is connected (i.e. fixed) to the first plate section 11.
[0016] The plurality of second plate portions 22 are also arranged at predetermined intervals (preferably equal angular intervals) along a circumferential direction centered on the central axis Ax. Each second plate portion 22 has a generally arcuate shape centered on the central axis Ax. In this embodiment, the second annular member 20 has eight second plate portions 22, but the number of second plate portions 22 is not limited to eight, and may be one or more other numbers. The second plate portion 22 is also disposed on an imaginary plane orthogonal to the central axis Ax, and is flush with it. That is, the second plate portion 22 is parallel to the third plate portion 23 and the first plate portion 11. Thus, the second plate portion 22 is intermittently arranged in a circumferential direction centered on the central axis Ax, and the third plate portion 23 is also intermittently arranged in a circumferential direction centered on the central axis Ax. The second plate portion 22 does not overlap with the third plate portion 23 when viewed along the central axis Ax.
[0017] Each beam portion 24 is a flat plate, arranged on an imaginary plane containing the central axis Ax. Therefore, the multiple beam portions 24 are arranged radially. Furthermore, each beam portion 24 extends parallel to the central axis Ax. Each beam portion 24 is connected to one end of one of the multiple second flat plate portions 22 and one end of one of the multiple third flat plate portions 23. Each beam portion 24 is orthogonal to both the second flat plate portions 22 and the third flat plate portions 23.
[0018] A plurality of intermittently arranged second flat plate portions 22, a plurality of intermittently arranged third flat plate portions 23, and a plurality of beam portions 24 form a closed annular shape. Since each beam portion 24 is a flat plate, when the second annular member 20 is made of metal, the second annular member 20 having the second flat plate portions 22, third flat plate portions 23, and beam portions 24 can be easily formed by bending a single plate. Since each beam portion 24 is a flat plate, when the second annular member 20 is made of resin, the second annular member 20 can be easily formed by stamping or injection molding using a forming die. Furthermore, the third plate portion 23 does not overlap with the second plate portion 22 when viewed along the central axis Ax. Therefore, when the second annular member 20 is made of metal, a second annular member 20 having multiple intermittently arranged second plate portions 22 and multiple intermittently arranged third plate portions 23 can be easily formed by bending a single plate. Furthermore, when the second annular member 20 is made of resin, the second annular member 20 can be easily formed by stamping or injection molding using a forming die.
[0019] Multiple second assembly pieces 25 are arranged at predetermined intervals (preferably equal angular intervals) along a circumferential direction centered on the central axis Ax. In this embodiment, the second annular member 20 has eight second assembly pieces 25, but as described later, the number of assembly pieces 12 of the second assembly pieces 25 is not limited to eight, and may be one or more other numbers.
[0020] like Figure 4As shown, the second assembly piece 25 is disposed radially inside the second flat plate portion 22. Specifically, each second assembly piece 25 is bent from the inner periphery of the second flat plate portion 22 and extends perpendicular to the second flat plate portion 22 and parallel to the central axis Ax. Each second assembly piece 25 is a flat plate disposed on the tangent plane of an imaginary cylinder centered on the central axis Ax. Thus, a plurality of second assembly pieces 25 are arranged to surround the imaginary cylinder.
[0021] A through hole 25a for assembling the strain generating member 40 is formed in the center of each second assembly piece 25. Each second assembly piece 25 is located on the extension line of one first assembly piece 12 when viewed along the central axis Ax. That is, when viewed in the direction of the central axis Ax, the plane extending from each second assembly piece 25 coincides with the plane extending from one first assembly piece 12. Thus, in this embodiment, eight groups including first assembly pieces 12 and second assembly pieces 25 are provided, and the strain generating member 40 is provided in each group.
[0022] like Figure 1 As shown, each strain generating component 40 is disposed radially inside the first annular component 10 and radially inside the second annular component 20. Each strain generating component 40 is assembled to the first assembly piece 12 and the second assembly piece 25 in a manner extending parallel to the central axis Ax. Each strain generating component 40 is inserted into the through hole 12a (… Figure 3 Screw 50 is fixed to the first assembly piece 12 by being inserted into the through hole 25a. Figure 3 The screw 51 is fixed to the second assembly piece 25. In this way, each strain generating member 40 is mounted on the first assembly piece 12 and the second assembly piece 25.
[0023] Each strain generating member 40 is a thin plate capable of elastic deformation. Each strain generating member 40 is formed, for example, from metals such as aluminum and stainless steel, ceramic materials, or resin materials. The plurality of strain generating members 40, respectively assembled on the first assembly piece 12 and the second assembly piece 25, are arranged at predetermined intervals (preferably equal angular intervals) in a circumferential direction centered on the central axis Ax. Each strain generating component 40 is assembled to the first assembly piece 12 and the second assembly piece 25, and is positioned on the tangential plane of an imaginary cylinder centered on the central axis Ax. Thus, the plurality of strain generating components 40 are arranged to surround the imaginary cylinder. When viewed along the central axis Ax, the spacing between the two beams 24 located at both ends of each second plate portion 22 is smaller than the spacing between the two beams 24 located at both ends of each third plate portion 23. Each strain generating member 40, when viewed along the central axis Ax, is positioned between two adjacent beams 24 located at the ends of the second plate portion 22 with a smaller spacing. Therefore, the second annular member 20 surrounding the strain generating member 40 has high rigidity. Thus, unexpected deformation of the strain generating member 40 can be prevented.
[0024] like Figure 2 As shown, the second plate portion 22 of the second annular member 20 is fixed to the axial end of the first rotating body 2 (the member on the input shaft side of the torque) by screws 53. The first plate portion 11 of the first annular member 10 is fixed to the axial end of the second rotating body 3 (the member on the output shaft side of the torque) by screws 54. like Figure 3 and Figure 4 As shown, each of the second plate portions 22 has a through hole 22a for inserting a screw 53 for fixing the second annular member 20 to the first rotating body 2.
[0025] The first plate portion 11 has a plurality of through holes (first through holes) 11a for inserting a plurality of screws 54 for fixing the first annular member 10 to the second rotating body 3. Furthermore, each of the third plate portions 23 of the second annular member 20 has a through hole (second through hole) 23a overlapping the through hole 11a. The through hole 23a is a threaded hole for fastening screws 54. Each third plate portion 23 has a cylindrical protrusion 23b formed around each through hole 23a. The cylindrical protrusion 23b extends toward the opposite side of the through hole 11a, reinforcing the through hole 23a, which is a threaded hole. A plurality of screws 54 are inserted into the first through hole 11a and the second through hole 23a, fixing the third plate portion 23 together with the first plate portion 11 to the second rotating body 3. Therefore, both the first annular member 10 and the second annular member 20 can be simultaneously assembled to the first rotating body 2. In addition, the first annular member 10 is lightweighted through the first through hole 11a, and the second annular member 20 is lightweighted through the second through hole 23a.
[0026] As described above, the first annular member 10 is fixed to the end of the second rotating body 3, and the second annular member 20 is fixed to the end of the first rotating body 2. Alternatively, the first annular member 10 can be fixed to the end of the first rotating body 2, and the second annular member 20 can be fixed to the end of the second rotating body 3.
[0027] In this embodiment, the second flat plate portion 22 of the second annular member 20 is fixed to the first rotating body 2 (the member on the input shaft side of the torque), and the third flat plate portion 23 of the second annular member 20 is fixed to the first annular member 10 and the second rotating body 3 (the member on the output shaft side of the torque). A beam portion 24, located between the second flat plate portion 22 and the third flat plate portion 23, transmits torque between the first rotating body 2 and the second rotating body 3. The beam portion 24, extending parallel to the central axis Ax, undergoes elastic deformation (deflection) under circumferential load as the torque is transmitted. Furthermore, the strain generating member 40, assembled on the first assembly piece 12 of the first annular member 10 and the second assembly piece 25 of the second annular member 20, also transmits torque between the first rotating body 2 and the second rotating body 3. The strain generating member 40, extending parallel to the central axis Ax, also undergoes elastic deformation (torsion) under circumferential loads. At least one strain gauge 42 is disposed on each strain generating member 40 (see reference). Figures 5-8 ).
[0028] In this embodiment, the first annular member 10 and the second annular member 20 constitute a single assembly. The second annular member 20 has a second flat plate portion 22 and a third flat plate portion 23, which are respectively fixed to the first rotating body 2 and the second rotating body 3. Furthermore, the second annular member 20 has a plurality of beam portions 24 that connect the second flat plate portion 22 and the third flat plate portion 23, extend parallel to the central axis Ax, and transmit torque. A strain generating member 40 extending parallel to the central axis Ax is assembled to the first annular member 10 and the second annular member 20. Therefore, multiple beam portions 24 for transmitting torque and multiple strain generating members 40 are provided in a single assembly having a first annular member 10 and a second annular member 20. Thus, by assembling the second annular member 20 together with the first annular member 10 to the first rotating body 2 and the second rotating body 3, multiple beam portions 24 and multiple strain generating members 40 can be easily provided.
[0029] Furthermore, in the first annular member 10, the first flat plate portion 11 is fixed to and supported on the axial end of the second rotating body 3 (or the first rotating body 2). Therefore, the first annular member 10 does not need to have high rigidity, thus enabling the first annular member 10 to be lightweight. In the second annular member 20, the second flat plate portion 22 is fixed to and supported on the axial end of the first rotating body 2 (or the second rotating body 3). Therefore, the second annular member 20 does not need to have high rigidity, thus enabling the second annular member 20 to be lightweight. Consequently, the torque sensor 100 as a whole can be lightweight.
[0030] Figures 5-8Various examples of the configuration of strain gauges 42 on strain generating members 40 are shown. Each strain generating member 40 has two wide portions 43 and a long portion 44. The long portion 44 is connected to the two wide portions 43. Each wide portion 43 overlaps with a first mounting piece 12 or a second mounting piece 25 and is pressed against the first mounting piece 12 or the second mounting piece 25 by the head of a screw 50 or 51. Through holes 45 for inserting screws 50 or 51 are formed in each wide portion 43.
[0031] At least one strain gauge 42 is disposed on the elongated portion 44. The strain gauge 42 can also be attached to the elongated portion 44 of the strain generating member 40 with an adhesive, but it is preferable to form it as a thin film on the elongated portion 44. For example, sputtering can be used as a thin film forming technique. When the strain generating member 40 is made of ceramic or resin, the strain gauge 42 can be directly formed on the elongated portion 44 using a thin film forming technique. When the strain generating member 40 is made of metal, an electrically insulating film can be formed on the elongated portion 44, and the strain gauge 42 can be formed on the electrically insulating film using a thin film forming technique.
[0032] exist Figures 5-8 In any of the examples, the strain gauge 42 is preferably arranged to extend along the long side of the strip 44. Thus, when the strain generating member 40 is assembled to the assembly pieces 12, 25, the strain gauge 42 is arranged parallel to the central axis Ax. The strain gauge 42 is positioned near one or both ends of the elongated section 44, thereby improving the sensitivity of strain measurement.
[0033] Preferably, such as Figure 5 or Figure 6 As shown, four strain gauges 42 are installed in each strain generating component 40. The strain gauges 42 in each strain generating component 40 constitute a Wheatstone bridge circuit (full-bridge circuit), thereby improving the sensitivity of strain measurement. Figure 5 As shown, the four strain gauges 42 constituting the full-bridge circuit can be positioned near both ends of the elongated section 44. Alternatively, as... Figure 6 As shown, the four strain gauges 42 constituting the full-bridge circuit can also be arranged near one end of the elongated section 44.
[0034] like Figure 7 As shown, each strain generating component 40 can also be equipped with two strain gauges 42 forming a half-bridge circuit. For example... Figure 7 As shown, the two strain gauges 42 constituting the half-bridge circuit can be arranged near both ends of the elongated portion 44. Alternatively, although not shown, the two strain gauges 42 constituting the half-bridge circuit can also be arranged near one end of the elongated portion 44. like Figure 8As shown, each strain generating component 40 can also be equipped with a single strain gauge 42. When the sensitivity of each strain gauge 42 is high, such as... Figure 7 and Figure 8 As shown, the number of strain gauges 42 disposed on each strain generating member 40 can be one or two.
[0035] Figure 9 This is a schematic top view showing the configuration of the strain generating member 40 in the torque sensor 100. (See attached image.) Figure 9 As shown, in the torque sensor 100, eight strain generating elements 40 are arranged with equal angular spacing (45 degrees). The eight strain generating elements 40 are classified into four strain generating elements 40A and four strain generating elements 40B. The four strain generating elements 40A are arranged with equal angular spacing (90 degrees), and the four strain generating elements 40B are also arranged with equal angular spacing (90 degrees). The group of strain generating elements 40B is offset by 45 degrees relative to the group of strain generating elements 40A. All four strain generating elements 40A are used together for torque measurement and are connected to a computational circuit (not shown). The computational circuit calculates the torque from the strain values measured by these strain generating elements 40A. Four strain generating elements 40B are used independently of strain generating element 40A for torque measurement and are connected to other computing circuits (not shown). The computing circuits calculate the torque from the strain values measured by these strain generating elements 40B. Neither the group of strain generating components 40A nor the group of strain generating components 40B is absolutely necessary, but is provided as a backup in case the other fails. In other words, the torque sensor 100 has a dualized, or redundant, group of strain generating components 40.
[0036] In addition to the torque to be measured, the strain gauges 42 disposed in each strain generating member 40 are also subjected to undesirable torques and undesirable translational forces in the direction of the central axis Ax, radially, and circumferentially. In each group, the multiple strain generating members 40 (four strain generating members 40 in this embodiment) are arranged with equal angular spacing. With this arrangement, the computing circuits connected to the multiple strain gauges 42 corresponding to these strain generating members 40 can cancel out the effects of the undesirable torques and undesirable translational forces.
[0037] As described above, each strain generating member 40 is disposed radially inside the first annular member 10 and radially inside the second annular member 20. Since the strain generating member 40 of the strain gauge 42 is disposed radially inside the annular members 10 and 20, the strain gauge 42 can be easily connected to the calculation circuit when the aforementioned calculation circuit electrically connected to the strain gauge 42 is disposed radially inside the annular members 10 and 20.
[0038] Reference Figure 10 and Figure 11 This will explain the principle of strain measurement by strain gauge 42. Figure 10 This shows a portion of the torque sensor 100 before torque is applied. Figure 11 This shows the part to which torque has been applied. In Figure 10 and Figure 11 In this configuration, two strain gauges 42 are arranged in one strain generating member 40. However, as described above, one strain gauge 42 may also be arranged in one strain generating member 40, or four strain gauges 42 may be arranged in one strain generating member 40.
[0039] When the first rotating body 2 rotates about its central axis Ax, it imparts a torque about the central axis Ax to the torque sensor 100. The beam portion 24, located between the second plate portion 22 and the third plate portion 23, transmits torque from the first rotating body 2 to the second rotating body 3. Furthermore, the strain generating member 40, disposed between the beam portions 24, also transmits torque from the first rotating body 2 to the second rotating body 3. At this time, as... Figure 11 As shown, the beam 24 undergoes elastic deformation (deflection) under a circumferential load L, and the strain generating member 40 also undergoes elastic deformation (torsion) under a circumferential load L. Therefore, each strain gauge 42 disposed in the strain generating member 40 is subjected to tensile or compressive force. For example, in Figure 11 In the example, near the upper strain gauge 42, the strain generating member 40 extends, thus stretching the upper strain gauge 42. On the other hand, near the lower strain gauge 42, the strain generating member 40 contracts, thus compressing the lower strain gauge 42. In this way, by deforming the strain gauge 42, strain can be measured.
[0040] In this embodiment, since the strain generating member 40 is arranged between the two beam portions 24 that undergo elastic deformation, the strain generating member 40 is easily elastically deformed (easily torsional) with the deformation of the beam portions 24. Therefore, the sensitivity of the strain gauge 42 is improved. Each beam 24 is a flat plate, arranged on an imaginary plane containing the central axis Ax, and the multiple beams 24 are arranged radially. This arrangement of the beams 24 enhances their resistance to compressive and tensile forces in the direction of the central axis Ax, and makes them more susceptible to flexing under circumferential loads centered on the central axis Ax. Consequently, the strain generating member 40, positioned between two beams 24, readily twists with the flexing of the beams 24, thus increasing the sensitivity of the strain gauge 42.
[0041] Each strain generating member 40 is assembled to one of the plurality of first assembly pieces 12 of the first annular member 10 and one of the plurality of second assembly pieces 25 of the second annular member 20. The first assembly piece 12 extends from the first flat plate portion 11 perpendicular to the first flat plate portion 11 and parallel to the central axis Ax, and the second assembly piece 25 extends from the second flat plate portion 22 perpendicular to the second flat plate portion 22 and parallel to the central axis Ax. Therefore, even if the flat plate portions 11 and 22 are parallel to each other, the strain generating member 40 can be easily assembled to the flat plate portions 11 and 22.
[0042] Each strain generating member 40, assembled on the first assembly piece 12 and the second assembly piece 25, is a flat plate arranged on a tangent plane of an imaginary cylinder centered on the central axis Ax. By arranging each strain generating member 40, which extends parallel to the central axis Ax, on a tangent plane of the imaginary cylinder centered on the central axis Ax, each strain generating member 40 is easily twisted along this tangent plane. Consequently, the sensitivity of the strain gauge 42 arranged on the strain generating member 40 is improved.
[0043] As described above, the first annular member 10 is formed from a single plate, and the second annular member 20 is also formed from a single plate. The first annular member 10 can be manufactured by bending and blanking a single plate, or by stamping or injection molding using a forming die. The second annular member 20 can also be manufactured by bending and blanking a single plate, or by stamping or injection molding using a forming die. The first annular member 10 and the second annular member 20 can also be manufactured by casting or forging. In either case, manufacturing costs can be reduced compared to manufacturing the annular members 10 and 20 from an ingot by machining. Furthermore, compared to the case where the first annular member 10 and the second annular member 20 are each formed from multiple parts, the annular members 10 and 20 can be processed more easily, and the number of parts can be minimized. Furthermore, if the first annular member 10 and the second annular member 20 are made of resin, the first annular member 10 and the second annular member 20 can also be integrally formed.
[0044] like Figure 1 and Figure 3As shown, a plurality of cuts 11b are formed on the outer periphery of the first flat plate portion 11 of the first annular member 10. The cuts 11b are formed on the radially outer side of the first assembly piece 12. Through the cuts 11b, the first annular member 10 is made lighter. In this embodiment, since each strain generating member 40 is disposed radially inside the first annular member 10 and the second annular member 20, the assembly pieces 12 and 25 are disposed radially inside the first flat plate portion 11 and the second flat plate portion 22. Therefore, a cutout 11b located on the opposite side of the first assembly piece 12 is formed at the outer periphery of the first flat plate portion 11. However, although not shown, when each strain generating member 40 is arranged radially outside the annular members 10 and 20, the assembly pieces 12 and 25 are arranged radially outside the first flat plate portion 11 and the second flat plate portion 22. In this case, the cutout 11b located on the opposite side of the first assembly piece 12 can be formed on the inner periphery of the first flat plate portion 11.
[0045] The present disclosure has been described above with reference to preferred embodiments and illustrations. However, those skilled in the art will understand that changes in form and detail can be made without departing from the scope of the invention as set forth in the claims. Such changes, alterations, and modifications should be included within the scope of this disclosure.
[0046] For example, Figures 12-15 Other examples of the configuration of the strain generating elements 40 in the torque sensor 100 are shown. In one embodiment, the torque sensor 100 has eight strain generating elements 40. However, as... Figures 12-15 As shown, the number of strain generating components 40 can be 1, 2, 3, or 4. The number of first assembly pieces 12 of the first annular component 10, the number of flat plate portions 22 and 23 of the second annular component 20, and the number of second assembly pieces 25 can be the same as the number of strain generating components 40. exist Figure 12 In the torque sensor 100 shown, which has two strain generating components 40, the two strain generating components 40 are connected to a single arithmetic circuit. It is difficult for the arithmetic circuit to cancel out the effects of undesirable torque, but it is able to cancel out the effects of undesirable translational forces in the direction of the central axis Ax, radially, and circumferentially. exist Figure 13 In the torque sensor 100 shown, which has four strain generating elements 40, the four strain generating elements 40 are connected to a single processing circuit. This torque sensor 100 does not have a dualized, or redundant, group of strain generating elements 40. However, the processing circuit is capable of canceling out the effects of unwanted torque and unwanted translational forces.
[0047] exist Figure 14In the torque sensor 100 shown, which has three strain generating elements 40, the three strain generating elements 40 are connected to a single processing circuit. The processing circuit is able to cancel out the effects of unwanted torque and unwanted translational force by using a suitable algorithm. exist Figure 15 In the torque sensor 100 shown with one strain generating member 40, the effects of undesirable torque and undesirable translational force cannot be canceled out. However, if the first rotating body 2 and the second rotating body 3 are firmly held and the torque sensor 100 is not subjected to undesirable torque and translational force, then only one strain generating member 40 may be provided.
[0048] In one embodiment, the first annular member 10 is formed from a single plate, and the second annular member 20 is also formed from a single plate. However, as... Figure 16 and Figure 17 As shown, the first annular member 10 can also be formed by joining multiple plate members 10A and 10B using the joint 10C. The second annular member 20 can also be formed by joining multiple plate members 20A and 20B using the joint 20C.
[0049] The technology disclosed herein can be configured as follows. [1] A torque sensor, which is a torque sensor located between a first rotating body rotating about a central axis and a second rotating body rotating about the central axis according to the rotation of the first rotating body, has the following characteristics: The first annular member has a first flat plate portion fixed to the first rotating body or the second rotating body, the first flat plate portion having an annular shape centered on the central axis; The second annular member has a plurality of second plate portions fixed to the second rotating body or the first rotating body, a plurality of third plate portions fixed to the first annular member, and a plurality of beam portions extending parallel to the central axis and connected to the second plate portions and the third plate portions, and as a whole has an annular shape centered on the central axis. At least one strain-generating member, extending parallel to the central axis, is assembled to the first annular member and the second annular member, and is capable of elastic deformation; and At least one strain gauge is disposed on the strain generating member. Each beam is connected to one end of one of the plurality of second plate sections and one end of one of the plurality of third plate sections.
[0050] [2] According to the torque sensor described in [1], wherein, The strain generating component is positioned between the plurality of beams when viewed along the central axis.
[0051] [3] According to the torque sensor described in [1] or [2], wherein, Each beam is a flat plate, arranged on an imaginary plane containing the central axis, and the plurality of beams are arranged radially.
[0052] [4] The torque sensor according to any one of [1] to [3], wherein, The first annular member further includes a first mounting piece that extends from the first flat plate portion perpendicular to the first flat plate portion and parallel to the central axis. The second annular member further comprises a second mounting piece, which extends from the second flat plate portion perpendicular to the second flat plate portion and parallel to the central axis. The strain generating component is assembled to the first assembly piece and the second assembly piece.
[0053] [5] The torque sensor according to any one of [1] to [4], wherein, The strain generating component is disposed on the radially inner side of the first annular component and the radially inner side of the second annular component.
[0054] [6] The torque sensor according to any one of [1] to [5], wherein, The strain generating component is a flat plate arranged on the tangent plane of an imaginary cylinder centered on the central axis.
[0055] [7] The torque sensor according to any one of [1] to [6], wherein, The plurality of beams, when viewed along the central axis, have two beams with a large gap and two beams with a small gap, and the strain generating member, when viewed along the central axis, is positioned between the two beams with a small gap among the plurality of beams.
[0056] [8] The torque sensor according to any one of [1] to [7], wherein, The plurality of second flat plate portions of the second annular member are arranged intermittently in a circumferential direction centered on the central axis. The plurality of third plate portions of the second annular member are discontinuously arranged in a circumferential direction centered on the central axis and do not overlap with the second plate portion when viewed along the central axis.
[0057] [9] According to the torque sensor described in [5], wherein, A cut is formed at the outer periphery of the first flat plate portion of the first annular member.
[0058]
[10] The torque sensor according to any one of [1] to [4], [6] to [8], wherein, The strain generating component is disposed radially outside the first annular component and radially outside the second annular component. A cut is formed on the inner periphery of the first flat plate portion of the first annular member.
[0059]
[11] The torque sensor according to any one of [1] to
[10] , wherein, A first through hole is formed in the first flat plate portion of the first annular member. A second through hole is formed on the third plate portion of the second annular member, which overlaps with the first through hole. Screws are inserted into the first through hole and the second through hole to fix the third plate portion together with the first plate portion to the first rotating body or the second rotating body.
[0060]
[12] The torque sensor according to any one of [1] to
[11] , wherein, The first annular member is formed from a single plate.
[0061]
[13] The torque sensor according to any one of [1] to
[12] , wherein, The second annular member is formed from a single plate.
Claims
1. A torque sensor, comprising a first rotating body rotating about a central axis and a second rotating body rotating about the central axis according to the rotation of the first rotating body, characterized in that, have: The first annular member has a first flat plate portion fixed to the first rotating body or the second rotating body, the first flat plate portion having an annular shape centered on the central axis; The second annular member has a plurality of second plate portions fixed to the second rotating body or the first rotating body, a plurality of third plate portions fixed to the first annular member, and a plurality of beam portions extending parallel to the central axis and connected to the second plate portions and the third plate portions, and as a whole has an annular shape centered on the central axis. At least one strain generating member, which extends parallel to the central axis, is assembled to the first annular member and the second annular member, and is capable of elastic deformation; as well as At least one strain gauge is disposed on the strain generating member. Each beam is connected to one end of one of the plurality of second plate sections and one end of one of the plurality of third plate sections.
2. The torque sensor according to claim 1, wherein, The strain generating component is positioned between the plurality of beams when viewed along the central axis.
3. The torque sensor according to claim 1 or 2, wherein, Each beam is a flat plate, arranged on an imaginary plane containing the central axis, and the plurality of beams are arranged radially.
4. The torque sensor according to any one of claims 1 to 3, wherein, The first annular member further includes a first mounting piece that extends from the first flat plate portion perpendicular to the first flat plate portion and parallel to the central axis. The second annular member further comprises a second mounting piece, which extends from the second flat plate portion perpendicular to the second flat plate portion and parallel to the central axis. The strain generating component is assembled to the first assembly piece and the second assembly piece.
5. The torque sensor according to any one of claims 1 to 4, wherein, The strain generating component is disposed on the radially inner side of the first annular component and the radially inner side of the second annular component.
6. The torque sensor according to any one of claims 1 to 5, wherein, The strain generating component is a flat plate arranged on the tangent plane of an imaginary cylinder centered on the central axis.
7. The torque sensor according to any one of claims 1 to 6, wherein, The plurality of beams, when viewed along the central axis, have two beams with a large gap and two beams with a small gap, and the strain generating member, when viewed along the central axis, is positioned between the two beams with a small gap among the plurality of beams.
8. The torque sensor according to any one of claims 1 to 7, wherein, The plurality of second flat plate portions of the second annular member are arranged intermittently in a circumferential direction centered on the central axis. The plurality of third plate portions of the second annular member are discontinuously arranged in a circumferential direction centered on the central axis and do not overlap with the second plate portion when viewed along the central axis.
9. The torque sensor according to claim 5, wherein, A cut is formed at the outer periphery of the first flat plate portion of the first annular member.
10. The torque sensor according to any one of claims 1 to 4, 6 to 8, wherein, The strain generating component is disposed radially outside the first annular component and radially outside the second annular component. A cut is formed on the inner periphery of the first flat plate portion of the first annular member.
11. The torque sensor according to any one of claims 1 to 10, wherein, A first through hole is formed in the first flat plate portion of the first annular member. A second through hole is formed on the third plate portion of the second annular member, which overlaps with the first through hole. Screws are inserted into the first through hole and the second through hole to fix the third plate portion together with the first plate portion to the first rotating body or the second rotating body.
12. The torque sensor according to any one of claims 1 to 11, wherein, The first annular member is formed from a single plate.
13. The torque sensor according to any one of claims 1 to 12, wherein, The second annular member is formed from a single plate.