A structural component and overload protection mechanism of a torque measuring device

Abstract

The present invention provides a structural component and an overload protection mechanism of a torque measuring device. The structural component includes an outer ring, an inner ring and a first connecting portion; the structural component also includes a second connecting portion arranged between the outer ring and the inner ring, and the second connecting portion is configured as follows: when the structural component is installed in the torque measuring device, the second connecting portion is used to resist the bending moment exerted on the torque measuring device. An overload protection mechanism is arranged between the outer ring and the inner ring, and the overload protection mechanism includes a recessed portion and a raised portion, the head of the raised portion is accommodated in the recessed portion, and there is a gap between the raised portion and the opposite side of the recessed portion. The present invention solves the problem of poor bending moment resistance of the existing torque measuring device. When the load is too large, the overload protection mechanism can effectively solve the damage of the overload corresponding variant during the movement of the robot, improve the service life of the torque measuring device, and reduce the cost.

Description

Technical Field

[0001] The invention relates to a torque measuring device, in particular to a structural component and an overload protection mechanism of the torque measuring device, and belongs to the technical field of robot sensors. Background Art

[0002] The torque sensor installed at the joint of the robot is used to measure the torque in one of the rotation directions. The torque sensor usually has one or more strain bodies. The torque borne by the sensor is calculated by measuring the deformation of the strain body. When designing the sensor, the structural design ensures that the deformation of the strain body and the torque are in an approximately linear relationship. The deformation of the strain body can be measured by resistive (strain gauge), capacitive, electromagnetic and optical methods.

[0003] The torque sensor is installed at the output of the robot joint and can directly measure the output torque of the joint. Compared with the method of calculating the joint torque using the motor current, a more accurate joint output torque value can be obtained. The torque sensor installed on the robot joint has the following requirements: (1) In addition to the torque measurement direction, the stiffness in other directions should be as large as possible, which can improve the stiffness of the robot joint in other directions, thereby improving the positioning accuracy of the robot and reducing the influence of other directional forces generated during the robot movement on the torque sensor output signal; (2) The robot may collide with surrounding objects during movement, and there is also the possibility of soft protection failure in the event of a collision. In order to protect the strain of the torque sensor in the robot joint, the torque sensor needs to have an overload protection function.

[0004] Although the existing torque sensors on the market try to improve the stiffness in other directions during design, they cannot achieve significant improvement. The existing overload protection mechanisms and methods are difficult to assemble. The following patent analysis is made for the current patents that are relatively close.

[0005] US Patent US20170266814A1 discloses a joint torque sensor for a robot, such as Figure 1 As shown, the strain body 301 can be disassembled to facilitate the mounting of the strain sensitive element. In addition to the two strain bodies 301, four beams 401 are added to the inner and outer rings of the sensor. The four beams are only used to connect the inner and outer rings of the sensor, and the sizes of these beams are not specially designed to improve the stiffness of the sensor in other directions.

[0006] US Patent US008291775B2 discloses a torque sensor for a robot, such as Figure 2 As shown in the figure, there are four beams from the inner ring to the outer ring of the sensor, two of which are strain beams used to mount strain gauges. The other two beams are connected to the outer ring of the sensor as shown in the figure. Figure 2In the structure shown in the partially enlarged figure, there is a gap between the concave inner side of the outer ring 102 and the outer side of the end of the raised portion 502. The design of this part is mainly to reduce the influence of the axial and radial runout of the robot joint reducer on the fluctuation of the sensor torque signal.

[0007] Chinese patent CN101118194A discloses a torque sensor with anti-overload function, such as Figure 3 As shown, in addition to the strain body 303, the sensor has a blind hole 203 in the inner ring and a through hole 103 in the outer ring. The blind hole 203 and the through hole 103 are coaxial, wherein the aperture of the through hole 103 is larger than that of the blind hole 203. The pin 503 is driven into the blind hole 203 in the inner ring through the through hole 103 in the outer ring. There is a certain gap between the pin 503 and the through hole 103. When an overload occurs, the pin 503 and the through hole 103 in the outer ring collide with each other, which plays a role in protecting the strain body 303 of the sensor. This method requires very high processing accuracy of the coaxial hole, and due to the flexibility of the sensor, the processing of the coaxial hole is more difficult. In addition, when the pin 503 is assembled, the spacing between the pin 503 and the through hole 103 on the circumference is difficult to control uniformly, which may result in the spacing in one direction being too large to protect the strain body 303, and the spacing in another direction being too small to protect the strain body 303 in advance.

[0008] Through the analysis of the above similar patents, it can be seen that the existing technical solutions have certain problems in solving the sensor's anti-bending moment capability and overload protection implementation. Summary of the invention

[0009] The technical problems to be solved by the present invention are: (1) the bending moment resistance performance of the torque measuring device; and (2) the overload protection of the torque measuring device.

[0010] In order to solve the above technical problems, the present invention provides a torque measuring device with an anti-bending moment structure and an overload protection mechanism. The specific technical solution is as follows:

[0011] According to a first aspect of the present invention, a structural component of a torque measuring device is disclosed, comprising an outer ring, an inner ring, and a first connecting portion connected between the outer ring and the inner ring, wherein the first connecting portion is integrally formed with the outer ring and the inner ring; the structural component also comprises a second connecting portion arranged between the outer ring and the inner ring, wherein the second connecting portion is configured as follows: when the structural component is installed in the torque measuring device, the second connecting portion is used to resist the bending moment exerted on the torque measuring device, wherein the bending moment refers to a moment whose direction of force does not coincide with the rotating shaft of the torque measuring device.

[0012] In one embodiment, the second connection part includes a second connection part body, and the first body surface of the second connection part body is lower than the first inner ring surface of the inner ring and the first outer ring plane of the outer ring to ensure that the second connection part body does not contact other components connected to the inner ring or the outer ring.

[0013] In one embodiment, the second connection portion is integrally formed with the outer ring and the inner ring.

[0014] In one embodiment, the second connecting portion is split, and two ends of the second connecting portion are respectively fixed to the outer ring and the inner ring.

[0015] In one embodiment, the second connecting portion is a straight connecting piece connected between the outer ring and the inner ring, and the dimension of the straight connecting piece extending in the first direction is greater than the dimension extending in the second direction. The first direction refers to a direction parallel to or overlapping with the axial direction of the inner ring, and the second direction refers to a direction parallel to or overlapping with the tangential direction of the inner ring.

[0016] In one embodiment, the straight connecting piece extends along a third direction, and the third direction coincides with the radial direction of the inner ring.

[0017] In one embodiment, the second connecting portion is a folded connecting piece or a curved connecting piece connected between the outer ring and the inner ring.

[0018] In one embodiment, the structural member includes multiple first connection parts and multiple second connection parts, the number of the second connection parts is N times the number of the first connection parts, N is an integer and ≥1; the first connection parts are evenly distributed between the outer ring and the inner ring, and N second connection parts are distributed in the space between two adjacent first connection parts.

[0019] In one embodiment, the second connection portion includes a connector connecting the outer ring and the inner ring, wherein a first end of the connector is fixed to the outer ring, and a second end of the connector is movable on the surface of the inner ring.

[0020] In one embodiment, the second connection portion includes a connector connecting the outer ring and the inner ring, a first end of the connector is fixed to the inner ring, and a second end of the connector can move on the surface of the outer ring.

[0021] In one embodiment, the second end of the connector is provided with a rolling member, and a rolling surface of the rolling member contacts the surface of the inner race.

[0022] In one embodiment, the rolling component comprises a roller, and the axis of the roller extends along the radial direction of the inner ring.

[0023] In one embodiment, the connectors are arranged in pairs, and the two connectors in each pair of connectors are in contact with two surfaces of the inner ring respectively.

[0024] According to a second aspect of the present invention, an overload protection mechanism for a torque measuring device is disclosed. The torque measuring device comprises an outer ring and an inner ring. An overload protection mechanism is arranged between the outer ring and the inner ring. The overload protection mechanism comprises a recessed portion and a raised portion. The head of the raised portion is accommodated in the recessed portion. There is a gap between the raised portion and the side surfaces opposite to the recessed portion. The recessed portion is integrally formed with the outer ring, and the raised portion is integrally formed with the inner ring. Alternatively, the recessed portion is integrally formed with the inner ring, and the raised portion is integrally formed with the outer ring.

[0025] In one embodiment, the length of the protrusion accommodated in the recess is greater than one third of the total length of the protrusion itself.

[0026] In one embodiment, when the overload protection mechanism is triggered to perform a protection function, the first side surface of the recessed portion is in surface contact with the second side surface of the raised portion.

[0027] In one embodiment, virtual extension surfaces of the first side surface and the second side surface intersect at the axis of the inner ring.

[0028] The third aspect of the present invention discloses a torque measuring device, wherein the anti-bending moment structure and the overload protection mechanism can be used separately to play their respective roles; or they can be used simultaneously in the same torque measuring device to play their respective roles.

[0029] The beneficial effects of the present invention are as follows: the present invention improves the structure of the torque measuring device. On the one hand, the method of using the first connecting part and the second connecting part together solves the problem of poor bending moment resistance of the torque sensor of the existing resistance strain gauge spoke structure. During use, it not only ensures the flexibility of the robot and the dynamic monitoring of the joint torque, but also improves the overall robot accuracy. On the other hand, an overload protection mechanism is added between the outer ring and the inner ring of the torque measuring device. When the load is too large, the two parts of the overload protection mechanism mesh and fit together, transferring the overload torque from the strain body to the fitting surface, which can effectively solve the damage of the overload corresponding variant during the movement of the robot, increase the service life of the torque measuring device, and reduce costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the structure of the first torque measuring device structural component in the prior art;

[0031] Figure 2 It is a structural schematic diagram and a partial enlarged diagram of the structural parts of the torque measuring device in the second prior art;

[0032] Figure 3 is a schematic structural diagram of a torque measuring device structural component in a third prior art;

[0033] Figure 4 It is a schematic diagram of the overall structure of the torque measuring device structural parts in a preferred embodiment of the present invention;

[0034] Figure 5 It is a structural schematic diagram and a partial enlarged diagram of a connecting beam in a preferred embodiment of the present invention;

[0035] Figure 6 It is a schematic cross-sectional structure diagram of a strain body in a preferred embodiment of the present invention at a viewing angle A;

[0036] Figure 7 is a partial enlarged view of a strain sensor in a preferred embodiment of the present invention;

[0037] Figure 8 is a circuit diagram of a strain gauge sensor in a preferred embodiment of the present invention;

[0038] Fig. 9 is a schematic diagram of signal processing of a torque measuring device in a preferred embodiment of the present invention;

[0039] Fig.10 is a schematic diagram of the overall structure of a torque measuring device in another preferred embodiment of the present invention and a partially enlarged schematic diagram of a folding connecting member therein;

[0040] Fig.11 is a schematic diagram of a partial structure (including a connector) of a torque measuring device in another preferred embodiment of the present invention;

[0041] Fig.12 yes Fig.11 A schematic diagram of the cross-section structure of the middle connector at perspective A;

[0042] Fig.13 It is a structural schematic diagram and a partial enlarged diagram of an overload protection mechanism in a preferred embodiment of the present invention.

[0043] The reference numerals are as follows:

[0044] 102 outer ring

[0045] 103 through hole (located on the outer ring)

[0046] 110 outer ring

[0047] 203 Blind hole (in the inner circle)

[0048] 210 Inner Circle

[0049] 301 strain

[0050] 303 strain

[0051] 310 strain

[0052] 310' strain

[0053] 311 Strain Gauge Sensor

[0054] 312 Strain Gauge Sensor

[0055] 401 Liang

[0056] 410 straight connector

[0057] 420 Folding connector

[0058] 430 Connectors

[0059] 431 Connector body

[0060] 432 Roller

[0061] 433 Screw

[0062] 502 raised part

[0063] 503 Pin

[0064] 510 Overload protection mechanism

[0065] 511 Raised part

[0066] 512 Depression

[0067] 610 Operational Amplifier Circuit

[0068] 620 single-ended to differential module

[0069] 630 Collection Terminal

[0070] 631 Differential to Single-Ended Module

[0071] 632 Analog / Digital Conversion Module DETAILED DESCRIPTION

[0072] The concept, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings to fully understand the purpose, characteristics and effects of the present invention.

[0073] Unless otherwise defined, the technical or scientific terms used in the claims and specification of this patent shall have the common meanings understood by persons having ordinary skills in the technical field to which this patent belongs.

[0074] The words “first”, “second” and similar terms used in this specification and claims do not indicate any order, quantity or importance but are only used to distinguish different components.

[0075] In the description of the present invention, "one" or "an" and other similar words do not indicate a quantity limitation, but indicate the existence of at least one. In the description of this patent, unless otherwise specified, "multiple" means two or more. "Including" or "having" and other similar words mean that the elements or objects appearing before "including" or "having" include the elements or objects listed after "including" or "having" and their equivalent elements, and do not exclude other elements or objects.

[0076] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0077] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0078] In order to solve the problems of weak bending moment resistance of existing torque measuring devices, this patent designs a torque measuring device with multiple bending-resistant connectors.

[0079] The torque measuring device is mainly composed of structural parts, strain sensors and circuits. The shapes and structures of the structural parts vary. The typical shapes of the structural parts in this patent are as follows: Figure 4 As shown, the structural member is composed of an outer ring 110, an inner ring 210, a strain body 310, a straight connection member 410, and an overload protection mechanism 510. The outer ring 110 and the inner ring 210 rotate together, and the strain body 310 is connected between the outer ring 110 and the inner ring 210. Preferably, the strain body 310 is integrally formed with the outer ring 110 and the inner ring 210. A groove is provided in the middle of the strain body 310, and the groove can be used to mount a strain sensor. When relative torsion occurs between the outer ring 110 and the inner ring 210, the strain body 310 also undergoes a slight deformation, which is detected by the strain sensor, and the torque value is obtained.

[0080] The structural member further includes a moment-resistant connection portion disposed between the outer ring 110 and the inner ring 210. The moment-resistant connection portion may be implemented in a variety of specific ways. Figure 4The straight connector 410 in the figure is the simplest and most common way to realize the anti-bending moment connection. The torque measuring device is installed at the joint of the robot. In an ideal state, the torque measuring device is only affected by torque, and the torque direction of these torques coincides with the rotating shaft. The torque measuring device is used to measure these torques. But in fact, the robot arm has a considerable gravity, which causes the inner ring 210 to have a bending moment relative to the plane where the outer ring 110 is located. The torque direction of these bending moments does not coincide with the rotating shaft of the torque measuring device, which is destructive to the entire torque measuring device and at least causes measurement errors of the strain sensor. Therefore, the present invention installs an anti-bending moment connection between the outer ring 110 and the inner ring 210. When the torque measuring device is installed at the joint of the robot, the anti-bending moment connection is used to resist the bending moment exerted on the torque measuring device.

[0081] Each structural member has multiple strain bodies and multiple moment-resisting connections. Usually, the moment-resisting connections are arranged in multiples of the strain bodies, that is, the number of moment-resisting connections is N times the number of strain bodies, where N is an integer and ≥ 1. Figure 4 As shown in , the strain bodies 310 are evenly distributed between the outer ring 110 and the inner ring 210, and two straight connectors 410 are distributed in the space between two adjacent strain bodies 310. The strain bodies 310 and the straight connectors 410 are evenly distributed to ensure uniform resistance to bending moment and accurate torque measurement data.

[0082] If a large torque occurs between the outer ring 110 and the inner ring 210, for example, when the robot joint is subjected to a severe collision, it is possible that the measuring range of the strain body 310 is exceeded, resulting in damage to the strain sensor and failure of the entire torque measuring device. In order to avoid this problem, the present invention sets an overload protection device 510 between the outer ring 110 and the inner ring 210 for protecting the strain sensor. The overload protection device 510 can be implemented in a variety of ways, and the present invention provides the simplest and most feasible one.

[0083] Example 1

[0084] The structure of this embodiment is as follows Figure 5 The moment-resistant connection part is a straight connector 410, which can also be called a connecting beam. The structural member is composed of an outer ring 110, an inner ring 210, a strain body 310 and a straight connector 410. The above-mentioned components are obtained by integrally processing the same material, wherein the straight connector 410 is processed by wire cutting or laser cutting in order to improve the moment-resistant stiffness of the robot. The outer ring 110 and the inner ring 210 are concentric circles, and the gap between the two is roughly a circular ring. The straight connector 410 connects the outer ring 110 and the inner ring 210, that is, the straight connector 410 is arranged at the gap position between the outer ring 110 and the inner ring 210. The distribution requirement of the straight connector 410 in the circumferential direction is to ensure that the circumferential stiffness of the structural member is as consistent as possible.

[0085] Figure 5 The enlarged pictures marked with a and b are Figure 5 A cross-sectional view of the straight connecting member 410 from the perspective of direction A in the main figure. Figure 5 The enlarged part marked with c is Figure 5 The main figure shows an enlarged top view of the straight connector 410. According to the calculation formula for beam disturbance, the bending moment stiffness of the straight connector 410 is proportional to the cube of its axial dimension a, and its torque stiffness is proportional to the cube of its thickness b. Therefore, when designing the straight connector 410, the axial dimension a is required to be greater than the thickness b to ensure that the increase in its bending stiffness is greater than the torque stiffness. The length c of the straight connector 410 in the radial direction can be adjusted, that is, the concave limit of the straight connector 410 extending toward the outer ring 110 or the inner ring 210 of the sensor can be adjusted to control the stiffness of the structural member in the bending moment and torque directions. The straight connector 410 is usually not in the same plane as the outer ring 110 and the inner ring 210. Generally, the straight connector 410 is arranged to be lower than the plane where the inner ring 210 and the outer ring 110 are located, which facilitates installation and avoids friction between the straight connector 410 and external parts when the structural parts are installed, thereby affecting the measurement accuracy of the sensor and the bending moment resistance of the structural parts.

[0086] like Figure 6 As shown, the main body of the torque measuring device adopts a spoke-type structural design, and there is one or more strain bodies 310 between the outer ring 110 and the inner ring 210. The strain body 310 is a strain body that can undergo micro-deformation under the action of torque. Grooves are respectively provided in the middle of the strain body 310, and the grooves can be used to mount strain gauge sensors 311. When there are multiple strain bodies 310, the strain bodies are generally arranged uniformly along the circumference, or they can be arranged non-uniformly, and the stiffness at different angles is balanced through other structures. The strain body 310 is not in the same plane as the outer ring 110 and the inner ring 210, and is generally lower than the plane where the inner ring 210 and the outer ring 110 are located, which facilitates installation to avoid friction caused by contact between the strain body 310 and external parts when the structural parts are installed, thereby affecting the measurement accuracy. Generally, the inner ring 210 and the outer ring 110 are not in the same plane.

[0087] like Figure 6 As shown, the side section formed by the strain body 310 and the groove is in an "I" shape or a "concave" shape. The "I" shape 310 or the "concave" shape 310' can improve the stiffness to a certain extent. A strain gauge sensor 311 can be placed at the groove to detect the strain signal. When the outer ring and the outer ring of the torque measuring device are subjected to relative torque, shear strain is generated at the groove of the strain body 310, and the magnitude of the shear strain is linearly related to the applied torque force. The strain gauge sensor 311 mounted at the groove for measuring shear strain is naturally also affected by the torque load, and a shear strain signal will be generated.

[0088] like Figure 7 As shown, two strain gauge sensors 311 and 312 are generally mounted at positions 180 degrees apart, or strain gauge sensors are mounted at four positions at the same time. The shear strain change at the groove is first converted into a resistance signal change by the strain gauge sensor 311. Each strain gauge sensor 311 has two strain grids, which measure the strain signal respectively. Figure 7 The two strain gauges placed one above the other in the figure form a Wheatstone bridge. Figure 8 When strain occurs, the resistance on the bridge arm changes, the balance of the Wheatstone bridge is broken, and the output voltage at Vout changes. Figure 7 The other two strain gauge sensors placed on the left and right can also form an electric bridge. By measuring the torque signal through two sets of Wheatstone bridges, the measurement error can be reduced and the measurement accuracy can be improved.

[0089] The voltage signal from the Wheatstone bridge is generally weak and needs to be amplified by the operational amplifier circuit 610 to make the signal reach a suitable amplitude. Since the distance from the sensor to the acquisition circuit is generally long, in order to reduce the influence of interference during signal transmission, a single-ended to differential module 620 is required to convert the signal into differential transmission. At the sensor signal acquisition end 630, the differential signal must first be converted into a single-ended signal by a differential to single-ended module 631, and then the analog signal of the sensor must be converted into a digital signal by an analog / digital conversion module 632. Fig. 9 shown.

[0090] In a variation of this embodiment, the moment-resistant connection part may also be a split type, with its two ends fixed to the outer ring 110 and the inner ring 210 respectively by fasteners (e.g., screws). The advantage of this method is that the number of moment-resistant connection parts can be increased or decreased according to actual needs, and it is particularly suitable for large torque measuring devices. The disadvantage is that the moment-resistant connection part has a fixing part, which occupies additional space and is not as compact as the straight connection part 410 integrally formed with the outer ring and the inner ring. In addition, the split type also increases the processing cost and debugging difficulty.

[0091] Example 2

[0092] The function of the moment-resistant connection is to resist bending moment, which requires that its axial dimension of the structural part be as large as possible, that is, as "thick" as possible, so that it has a higher bending stiffness; on the other hand, it is required to reduce the impact on the measured torque as much as possible, that is, the moment-resistant connection is required to be as "thin" as possible in this direction; this is a contradiction. Moreover, it is not only difficult to process the moment-resistant connection to be very thin, but also there is a risk of fracture. Under cost-acceptable processing conditions, the minimum thickness of the moment-resistant connection is about 0.5mm.

[0093] In order to resolve the above contradiction, Fig.10 As shown, the moment-resistant connection part is processed into a folded connection piece 420 connected between the outer ring 110 and the inner ring 210. Of course, the moment-resistant connection part can also be processed into other shapes, including but not limited to a curved connection piece, as long as the total length of the connection piece is greater than the distance between the outer ring 110 and the inner ring 210, so as to ensure that the moment-resistant stiffness of the moment-resistant connection part is significantly greater than the torque-resistant stiffness. The other parts of the structural member and their functions are the same as those in Example 1, and will not be repeated here.

[0094] Example 3

[0095] like Fig.11 and Fig.12 As shown, this embodiment is another alternative solution for improving the bending moment resistance of the torque measuring device. A detachable connector 430 is added between the outer ring 110 and the inner ring 210. One end of the body 431 of the connector 430 is fixed to the outer ring 110 by means of a screw 433. The other end of the body 431 is installed with a roller 432, and the shaft of the roller 432 is installed in the body 431. The rolling surface of the roller 432 contacts a surface of the inner ring 210, which can appropriately increase the preload contact force. The axis of the roller 432 extends along the radial direction of the inner ring, that is, the axis of the roller 432 is perpendicular to and intersects with the rotating axis of the torque measuring device. When the outer ring 110 and the inner ring 210 move relative to each other under the action of torque, the roller 432 rolls on the surface of the inner ring 210 without affecting the transmission of torque. When the torque measuring device is subjected to bending moment, the connector 430 can eliminate or weaken the displacement and deformation of the torque measuring device caused by the bending moment.

[0096] Furthermore, there are two methods to improve the bending resistance: (1) placing multiple connectors 430 on the circumference of the inner and outer rings; (2) in order to improve the bending resistance in two directions, a pair of connectors 430 can be respectively arranged on the upper surface and the lower surface of the inner and outer rings.

[0097] If the torque measuring device is relatively large and has sufficient installation space, the connector 430 may be fixed to the inner ring 210 , and the roller 432 may roll on the surface of the outer ring 110 .

[0098] Example 4

[0099] like Fig.13As shown, in order to protect the strain body and the moment-resistant connection part of the torque measuring device when the robot is overloaded, an overload protection mechanism 510 is added between the inner ring 210 and the outer ring 110. Specifically, a meshing component is designed between the inner ring 210 and the outer ring 110, and the meshing component is composed of a recessed part 512 and a raised part 511. The head of the raised part 511 is accommodated in the recessed part 512, and there is a certain gap between the raised part 511 and the recessed part 512. When the deformation of the strain body of the torque measuring device is close to the maximum deformation, the relative movement between the inner ring 210 and the outer ring 110 reduces and eliminates a gap between the raised part 511 and the recessed part 512, and the inner ring 210 and the outer ring 110 are tightly attached to each other, and the excessive torque force acts on the fitting part, which plays a role in protecting the strain body.

[0100] like Fig.13 As shown in the upper left partial enlarged view, there is a certain gap d between the side of the protrusion 511 and the side of the recess 512, and there is a certain gap e between the top surface of the protrusion 511 and the top surface of the recess 512. The extended surface of the side of the protrusion 511 and the recess 512 passes through the rotating shaft to ensure that the side of the protrusion 511 and the side of the recess 512 are in surface contact when overloaded. The angle θ between the side of the protrusion 511 and the side of the recess 512 must meet the following requirements: before the torque load reaches the maximum, the two sides are ensured to be in contact to protect the strain body and the moment-resistant connection. The protrusion 511 in the anti-overload meshing component is not in the same plane as the inner ring 210 and the outer ring 110 to avoid the weakening or failure of the protection effect due to contact and friction with other components when the installation protection torque is measured.

[0101] exist Fig.13 In the figure, the raised portion 511 is integrally formed with the inner ring 210 and processed by wire cutting or laser cutting; the recessed portion 512 is integrally formed with the outer ring 110 and also processed by wire cutting or laser cutting. The length of the raised portion 511 contained in the recessed portion 512 is greater than one-third of the total length of the raised portion 511 itself, so that the sides of the two are in greater contact, thereby providing a stronger protective effect. If the raised portion 511 itself is longer, the contact surface between its side and the recessed portion is small, and the raised portion 511 itself may be deformed. In another alternative example, the recessed portion and the raised portion are interchangeable, that is, the recessed portion is integrally formed with the inner ring 210, and the raised portion is integrally formed with the outer ring 110, and the overload protection principle is the same. Fig.13 The above is similar to that shown in the figure and will not be repeated here.

[0102] The overload protection mechanism 510 in this embodiment can be used in conjunction with any of the moment-resistant connection parts in the above-mentioned embodiments 1 to 3. That is, in the same torque measuring device, one of the connecting members 410, 420 or 430 and the overload protection mechanism 510 are provided, and they play their respective roles at the same time. It is also possible to only provide the overload protection mechanism 510 without providing the connecting members 410, 420 or 430. Alternatively, the overload protection mechanism 510 is not provided in the torque measuring device. These are the technical solutions of the torque measuring device claimed to be protected by the present invention.

[0103] This patent uses structural design to add bending moment connection parts to the inner and outer rings of the torque measuring device structure in addition to the strain body to ensure that the stiffness of the bending moment is greater than the stiffness of the torque. Under the premise of ensuring the signal, the bending resistance and positioning accuracy of the robot joint can be increased to be suitable for robot applications. The configuration is improved in the structural design to achieve overload protection of the torque measuring device and solve the overload protection problem of the robot during movement.

[0104] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A structural member of a torque measuring device, comprising an outer ring, an inner ring, and a first connecting portion connected between the outer ring and the inner ring, characterized in that: The first connection portion is integrally formed with the outer ring and the inner ring; the structural member further comprises a second connection portion disposed between the outer ring and the inner ring, the second connection portion being configured such that when the structural member is mounted on the torque measuring device, the second connection portion is used to resist a bending moment to which the torque measuring device is subjected, wherein the bending moment refers to a moment whose direction does not coincide with the rotation axis of the torque measuring device; The second connection portion includes a connector connecting the outer ring and the inner ring, wherein a first end of the connector is fixed to the outer ring, and a second end of the connector is movable on the surface of the inner ring; The second end of the connector is provided with a rolling component, and the rolling surface of the rolling component is in contact with the surface of the inner ring; The rolling component comprises a roller, the axis of which extends along the radial direction of the inner ring; The connectors are arranged in pairs, and the two connectors in each pair of the connectors are in contact with two surfaces of the inner ring respectively.

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