CN209979107U

CN209979107U - Torque measuring device and structural part and overload protection mechanism thereof

Info

Publication number: CN209979107U
Application number: CN201920417451.3U
Authority: CN
Inventors: 陈鸿格; 莫喜先
Original assignee: Qinzhe (shanghai) Intelligent Technology Co Ltd
Current assignee: Qinzhe (shanghai) Intelligent Technology Co Ltd
Priority date: 2019-03-29
Filing date: 2019-03-29
Publication date: 2020-01-21
Anticipated expiration: 2029-03-29

Abstract

The utility model provides a torque measuring device and structure and overload protection mechanism thereof. The structural part comprises an outer ring, an inner ring and a first connecting part; the structural member further includes a second connection portion disposed between the outer race and the inner race, the second connection portion configured to: the second connection portion is for resisting a bending moment experienced by the torque measuring device when the structural member is mounted to the torque measuring device. An overload protection mechanism is arranged between the outer ring and the inner ring and comprises a concave part and a convex part, the head of the convex part is accommodated in the concave part, and a gap is reserved between the convex part and the side surface opposite to the concave part. The utility model provides a current torque measurement device's bending resistance moment performance poor problem. When the load is too big, the overload protection mechanism can effectively solve the problem that the overload corresponds to the damage of the variant in the movement process of the robot, the service life of the torque measuring device is prolonged, and the cost is reduced.

Description

Torque measuring device and structural part and overload protection mechanism thereof

Technical Field

The utility model relates to a torque measuring device, concretely relates to torque measuring device's structure and overload protection mechanism belongs to robot sensor technical field.

Background

The torque sensor is installed at a robot joint and used for measuring the torque in one rotation direction, the torque sensor usually comprises one or more strain bodies, and the torque borne by the sensor is calculated by measuring the deformation of the strain bodies. When the sensor is designed, the deformation amount of the strain body and the torque are ensured to be approximately in a linear relation through the design of the structure. The strain amount of the strain body can be measured by a resistance type (strain gauge), a capacitance type, an electromagnetic type, an optical type, or the like.

The torque sensor is arranged at the output end of the robot joint, can directly measure the output torque of the joint, and can obtain a more accurate joint output torque value compared with a method for calculating the joint torque by adopting the motor current. Torque sensors mounted to the robot joints have the following requirements: (1) except for the torque measurement direction, the rigidity in other directions is as large as possible, so that the rigidity of the robot joint in other directions can be improved, the positioning precision of the robot is improved, and the influence of forces in other directions generated in the motion process of the robot on the output signals of the torque sensor can be reduced; (2) the robot has the possibility of colliding with surrounding objects in the moving process and the possibility of soft protection failure in the collision process, and in order to protect a strain body of a torque sensor in a robot joint, the torque sensor needs to have an overload protection function.

Although the existing torque sensor in the market is designed to improve the rigidity in other directions as much as possible, the existing torque sensor cannot be greatly improved. The existing overload protection mechanism and method have certain difficulty in assembly. The following patent analysis is made for the currently relatively close patents.

US20170266814a1 discloses a joint torque sensor for a robot, as shown in fig. 1, a strain body 301 is detachable to facilitate the mounting of a strain sensitive element. Besides two straining bodies 301, four beams 401 are added on the inner ring and the outer ring of the sensor, the four beams are only used for connecting the inner ring and the outer ring of the sensor, and the sizes of the beams are not specially designed to improve the rigidity of the sensor in other directions.

US008291775B2 discloses a torque sensor for a robot, which has 4 beams from the inner ring to the outer ring of the sensor, two of which are strain beams for mounting a strain gauge, as shown in fig. 2. The other two beams and the outer ring of the sensor are made into a structure as shown in a partial enlarged view in fig. 2, a gap is left between the concave inner side surface of the outer ring 102 and the end outer side surface of the convex part 502 in the drawing, and the design of the part is mainly used for reducing the influence of the axial and radial runout of the robot joint reducer on the fluctuation of the torque signal of the sensor.

Chinese patent CN101118194A discloses a torque sensor with overload resistance, as shown in fig. 3, except for a strain body 303, a blind hole 203 is formed in an inner ring of the sensor, a through hole 103 is formed in an outer ring of the sensor, 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 of the inner ring through the through hole 103 of the outer ring. A certain gap is formed between the pin 503 and the through hole 103, and when overload occurs, the pin 503 collides with the through hole 103 of the outer ring to play a role in protecting the strain body 303 of the sensor. The mode has high requirement on the machining precision of the coaxial hole, and the machining of the coaxial hole is more difficult due to the flexibility of the sensor. In addition, when the pins 503 are assembled, the distance between the pins 503 and the through holes 103 on the circumference is difficult to control uniformly, which may cause that the excessive distance in one direction does not play a role of protecting the straining bodies 303, and the excessive distance in the other direction protects the straining bodies 303 in advance.

Through analyzing the similar patents, the technical scheme in the prior art has certain problems in solving the bending moment resistance and overload protection of the sensor.

SUMMERY OF THE UTILITY MODEL

The utility model discloses the technical problem who solves: (1) the bending moment resistance of the torque measuring device; (2) overload protection of a torque measuring device.

In order to solve the technical problem, the utility model provides a torque measuring device has bending moment resistance structure and overload protection mechanism, and concrete technical scheme is as follows:

the utility model discloses a first aspect of the utility model discloses a structure of a torque measuring device, which comprises an outer ring, an inner ring and a first connecting part connected between the outer ring and the inner ring, wherein the first connecting part is integrally formed with the outer ring and the inner ring; the structural member further includes a second connection portion disposed between the outer race and the inner race, the second connection portion configured to: when the structural member is installed on the torque measuring device, the second connecting part is used for resisting a bending moment applied to the torque measuring device, and the bending moment refers to a moment with a moment direction not coincident with a rotating shaft of the torque measuring device.

In one embodiment, the second connecting part comprises a second connecting part body, and the first body surface of the second connecting part body is lower than the first inner ring surface of the inner ring and the first outer ring plane of the outer ring so as to ensure that the second connecting part body does not contact with other parts connected to the inner ring or the outer ring.

In one embodiment, the second connecting portion is integrally formed with the outer race and the inner race.

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

In one embodiment, the second connection portion is a straight connection member connected between the outer ring and the inner ring, the straight connection member extending in a first direction parallel to or coinciding with the axial direction of the inner ring over a larger dimension than in a second direction parallel to or coinciding with the tangential direction of the inner ring.

In one embodiment, the straight connection extends in a third direction, which third direction coincides with a radial direction of the inner ring.

In one embodiment, the second connection is a dog-leg or curved connection between the outer race and the inner race.

In one embodiment, the structural member comprises a plurality of first connecting parts and a plurality of second connecting parts, the number of the second connecting parts is N times of the number of the first connecting parts, N is an integer and is more than or equal to 1; first connecting portion evenly distributed is between outer lane and inner circle, and the spatial distribution N second connecting portion between two adjacent first connecting portions.

In one embodiment, the second connecting portion comprises a connector connecting the outer race and the inner race, a first end of the connector being fixed to the outer race and a second end of the connector being movable on the surface of the inner race.

In one embodiment, the second connecting portion comprises a connector connecting the outer race and the inner race, a first end of the connector being fixed to the inner race and a second end of the connector being movable on a surface of the outer race.

In one embodiment, the second end of the connector carries a rolling member, the rolling surface of which is in contact with the surface of the inner race.

In one embodiment, the rolling member comprises a roller, the axis of the roller extending in a radial direction of the inner race.

In one embodiment, the connectors are arranged in pairs, with the two connectors of each pair contacting two surfaces of the inner race, respectively.

The second aspect of the utility model discloses an overload protection mechanism of a torque measurement device, the torque measurement device comprises an outer ring and an inner ring, the overload protection mechanism is arranged between the outer ring and the inner ring, the overload protection mechanism comprises a concave part and a convex part, the head of the convex part is accommodated in the concave part, and a gap is arranged between the opposite side surfaces of the convex part and the concave part; the concave part and the outer ring are integrally formed, and the convex part and the inner ring are integrally formed; or the concave part and the inner ring are integrally formed, and the convex part and the outer ring are integrally formed.

In one embodiment, the length of the projection received in the recess is greater than one third of the overall length of the projection itself.

In one embodiment, the first side of the recess is in face contact with the second side of the projection when the overload protection mechanism is triggered for protection.

In one embodiment, the imaginary extension planes of the first and second side planes intersect at the axis of the inner ring.

The third aspect of the utility model discloses a torque measuring device, the bending moment resisting structure and the overload protection mechanism can be used independently, and the functions of the bending moment resisting structure and the overload protection mechanism are achieved respectively; the torque measuring device can also be used in the same torque measuring device and can play respective roles simultaneously.

The utility model has the advantages that: the utility model discloses improve the structure torque measuring device. On one hand, the method of combining the first connecting part and the second connecting part is adopted, and the problem that the bending moment resistance performance of the existing torque sensor with the resistance strain gauge spoke type structure is poor is solved. In use, the flexibility of the robot and the dynamic monitoring of the joint torque are ensured, and the overall robot precision is improved. On the other hand, an overload protection mechanism is added between an outer ring and an inner ring of the torque measuring device, when the load is overlarge, two parts of the overload protection mechanism are meshed and attached, and the overload torque is transferred to an attaching surface from the strain body, so that the damage of the overload strain body in the movement process of the robot can be effectively solved, the service life of the torque measuring device is prolonged, and the cost is reduced.

Drawings

FIG. 1 is a schematic structural view of a first prior art torque measuring device structure;

FIG. 2 is a schematic and partially enlarged view of a second prior art torque measuring device structural member;

FIG. 3 is a schematic structural view of a third prior art torque measuring device structure;

fig. 4 is a schematic view of the overall structure of the structural member of the torque measuring device according to a preferred embodiment of the present invention;

fig. 5 is a schematic structural view and a partially enlarged view of a connection beam according to a preferred embodiment of the present invention;

fig. 6 is a schematic structural diagram of a strain body according to a preferred embodiment of the present invention;

fig. 7 is a partially enlarged view of a strain gauge sensor according to a preferred embodiment of the present invention;

fig. 8 is a circuit diagram of a strain gauge sensor according to a preferred embodiment of the present invention;

fig. 9 is a schematic signal processing diagram of a torque measuring device according to a preferred embodiment of the present invention;

FIG. 10 is a schematic view of the entire structure of a torque measuring device according to another preferred embodiment of the present invention and an enlarged view of a portion of a zigzag connecting member thereof;

FIG. 11 is a schematic view of a partial structure of a torque measuring device (including a connector) according to yet another preferred embodiment of the present invention;

FIG. 12 is a sectional view of the connector of FIG. 11 at view A;

fig. 13 is a schematic structural diagram and a partial enlarged view of an overload protection mechanism according to a preferred embodiment of the present invention.

The reference numbers are as follows:

102 outer ring

103 through hole (on the outer ring)

110 outer ring

203 Blind hole (in the inner circle)

210 inner ring

301 strain body

303 strain body

310 strain body

310' strain body

311 strain gauge sensor

312 strain gage sensor

401 beam

410 straight connecting piece

420-fold connecting piece

430 connector

431 connector body

432 roller

433 screw

502 convex part

503 Pin

510 overload protection mechanism

511 convex part

512 concave part

610 operational amplifier circuit

620 single end to differential module

630 acquisition terminal

631 differential to single-ended module

632 analog/digital conversion module

Detailed Description

The conception, the specific structure and the technical effects of the present invention will be further described with reference to the accompanying drawings, so as to fully understand the objects, the features and the effects of the present invention.

Unless otherwise defined, technical or scientific terms used in the claims and the specification of this patent shall have the ordinary meaning as understood by those of ordinary skill in the art to which this patent belongs.

As used in this specification and the appended claims, the terms "first," "second," and the like do not denote any order, quantity, or importance, but rather are used to distinguish one element from another.

In the description of the present invention, "a" or "an" and the like do not denote a limitation of quantity, but rather denote the presence of at least one. In the description of this patent, unless otherwise indicated, "a plurality" means two or more. The word "comprising" or "having", and the like, means that the element or item appearing before "comprises" or "having" covers the element or item listed after "comprising" or "having" and its equivalent, but does not exclude other elements or items.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "axial", "radial", "circumferential", and the like, indicate orientations and positional relationships based on the orientations and positional relationships shown in the drawings, and are used merely for convenience in describing the present invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present invention.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In order to solve the problems of weak bending moment resistance and the like of the conventional torque measuring device, the patent designs the torque measuring device with a plurality of bending-resistant connecting pieces.

The torque measuring device mainly comprises a structural part, a strain sensor and a circuit. The structural member has a shape different from a structure, and a typical shape of the structural member in this patent is shown in fig. 4, and the structural member is composed of an outer ring 110, an inner ring 210, a strain body 310, a straight-line connector 410, and an overload protection mechanism 510. The outer ring 110 and the inner ring 210 share a common axis, the strain body 310 is connected between the outer ring 110 and the inner ring 210, and preferably, the strain body 310 is integrally formed with the outer ring 110 and the inner ring 210. A groove is formed in the middle of the strain body 310, and the groove can be used for mounting a strain gauge sensor. When the outer ring 110 and the inner ring 210 are twisted relatively, the strain body 310 is slightly deformed, and the deformation is detected by the strain sensor, so as to obtain a torque value.

The structural member further includes a bending moment resistant connection disposed between the outer race 110 and the inner race 210. There are several specific implementations of the bending moment resistant connection, and the straight connection 410 in fig. 4 is the simplest and most common implementation of the bending moment resistant connection. The torque measuring device is installed at a robot joint, and under an ideal state, the torque measuring device is only acted by torques, the torque directions of the torques are coincided with the rotating shaft, and the torque measuring device is used for measuring the torques. However, in fact, the robot arm's own weight is not small, which causes bending moment to occur in the inner ring 210 relative to the plane of the outer ring 110, and the moment direction of these bending moments is not coincident with the rotation axis of the torque measuring device, which is destructive to the entire torque measuring device, and at least causes measurement error of the strain gauge sensor. Therefore, the present invention has the bending moment resistant connection portion installed between the outer ring 110 and the inner ring 210. When the torque measuring device is installed at the joint of the robot, the bending-resistant connecting part is used for resisting bending moment applied to the torque measuring device.

Each structural member is provided with a plurality of strain bodies and a plurality of bending moment resistant connecting parts. Usually, the bending moment resistant connection part and the strain body are arranged in multiples, namely the number of the bending moment resistant connection parts is N times of the number of the strain bodies, and N is an integer and is more than or equal to 1. As shown in fig. 4, the straining bodies 310 are uniformly distributed between the outer ring 110 and the inner ring 210, and two straight connectors 410 are distributed in a space between two adjacent straining bodies 310. The strain body 310 and the straight connecting piece 410 are uniformly distributed, so that the accuracy of the measurement data of the uniform resistance bending moment and the torque is ensured.

If a large torque occurs between the outer ring 110 and the inner ring 210, for example, when a robot joint is in a severe collision, the range of the strain gauge 310 may be exceeded, which may cause damage to the strain gauge and failure of the entire torque measuring apparatus. To avoid this problem, the present invention provides an overload protection device 510 between the outer ring 110 and the inner ring 210 for protecting the strain gauge sensor. The overload protection device 510 can have a plurality of implementation modes, and the utility model provides one of them is the simplest and most feasible.

Example 1

The structure of this embodiment is as shown in fig. 5, the bending moment resistant connecting part is a straight connecting part 410, and the straight connecting part 410 can also be called as a connecting beam. The structural member is composed of an outer ring 110, an inner ring 210, a strain body 310 and a straight connecting piece 410. The above components are integrally formed by the same material, wherein the straight connecting piece 410 is processed by wire cutting or laser cutting in order to improve the bending moment resisting rigidity of the robot. The outer ring 110 and the inner ring 210 are concentric circles, and the gap between the outer ring 110 and the inner ring 210 is approximately a circular ring, and the straight-line connector 410 connects the outer ring 110 and the inner ring 210, that is, the straight-line connector 410 is arranged at the gap position between the outer ring 110 and the inner ring 210. The distribution of the straight connecting members 410 in the circumferential direction is required to ensure that the bending stiffness of the structural member in the circumferential direction is as uniform as possible.

The enlarged partial views of a and b in fig. 5 are cross-sectional views of the straight-line connecting member 410 from the view angle a in the main view of fig. 5. The enlarged detail view marked c in fig. 5 is a top view of the straight connecting member 410 in the main view of fig. 5. According to the calculation formula of the beam deflection, the bending moment resistance rigidity of the straight connecting piece 410 is in direct proportion to the third power of the axial size a thereof, and the torque rigidity thereof is in direct proportion to the third power of the thickness b thereof. Therefore, the straight connecting member 410 is designed to have an axial dimension a greater than the thickness b to ensure that the bending stiffness is increased by a magnitude greater than the torsional torque stiffness. The length c of the straight connecting member 410 in the radial direction can be adjusted, that is, the concave limit of the straight connecting member 410 extending to the outer ring 110 or the inner ring 210 of the sensor can be adjusted to control the rigidity of the structural member in the bending moment and torque torsion directions. Straight connector 410 is generally out of plane with outer race 110 and inner race 210. The straight connecting member 410 is generally arranged to be lower than the plane where the inner ring 210 and the outer ring 110 are located, so that the installation is convenient, and the problem that the measuring accuracy of the sensor and the bending moment resistance effect of the structural member are affected due to friction generated by the contact between the straight connecting member 410 and external parts when the structural member is installed is avoided.

As shown in fig. 6, the torque measuring device body is designed in a spoke type structure, and one or more strain bodies 310 are arranged between the outer ring 110 and the inner ring 210. The straining body 310 is a straining body that can be micro-deformed by a torque. Grooves are respectively arranged in the middle of the strain bodies 310, and the grooves can be used for mounting the strain gauge sensors 311. When there are a plurality of straining bodies 310, the straining bodies are generally uniformly arranged along the circumference, or may be non-uniformly arranged, and the rigidity at different angular positions is balanced by other structures. The strain body 310 is not in the same plane with 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, so that the installation is convenient, and the problem that the measurement accuracy is affected due to friction generated by contact between the strain body 310 and external parts when a structural member is installed is avoided. Typically, inner race 210 and outer race 110 are also not in a single plane.

As shown in fig. 6, 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' may enhance the rigidity to some extent. A strain gauge sensor 311 may be disposed in the groove for detecting a strain signal. When the outer ring of the torque measuring device and the outer ring bear opposite torques, shear strain is generated at the groove of the strain body 310, and the magnitude of the shear strain is in a linear relation with the applied torque force. The strain gauge sensor 311 mounted at the groove for measuring shear strain is naturally also subjected to the torque load, and generates a shear strain signal.

As shown in fig. 7, the 2-piece strain gauge sensor 311 and the strain gauge sensor 312 are generally mounted at positions 180 degrees apart, or the strain gauge sensors are mounted at 4 positions simultaneously. The change in shear strain at the groove is first converted into a change in resistance signal by the strain gauge sensor 311. There are two strain gauges in each strain gauge sensor 311 that measure the strain signals separately so that the two strain gauges placed one above the other as shown in FIG. 7 form a Wheatstone bridge, the bridge being shown in FIG. 8. When strain occurs, the resistance on the bridge arms of the bridge changes, the balance of the Wheatstone bridge is broken, and the output voltage changes at Vout. In fig. 7, two other strain gauge sensors placed left and right can also form a bridge, and the torque signals are measured through two groups of wheatstone bridges, so that the measurement error can be reduced, and the measurement precision can be improved.

The voltage signals from the wheatstone bridge are generally weak and need to be amplified by the operational amplifier circuit 610, so that the signals reach a proper amplitude value, and since a longer distance is generally needed from the sensor to the acquisition circuit, in order to reduce the influence of interference in the signal transmission process, the signals need to be converted into differential transmission by the single-ended to differential module 620. At the acquisition end 630 of the sensor signal, a differential-to-single-ended module 631 is used to convert the differential signal into a single-ended signal, and an analog/digital conversion module 632 is used to convert the analog signal of the sensor into a digital signal, as shown in fig. 9.

In a modification of this embodiment, the bending moment-resistant connecting portion may be a split type, and both ends thereof are fixed to the outer ring 110 and the inner ring 210 by fasteners (e.g., screws), respectively. The mode has the advantages that the number of the bending moment resisting connecting parts can be increased or decreased according to actual requirements, and the method is particularly suitable for large-scale torque measuring devices. The disadvantage is that the bending moment resistant connection part with the fixing part occupies extra space, which 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 the debugging difficulty.

Example 2

The bending-resistant connecting part is used for resisting bending moment, and the axial size of the connecting part in the structural member is required to be as large as possible, namely as thick as possible, so that the connecting part has higher bending rigidity; in the other direction, the influence on the measured torque is required to be reduced as much as possible, namely the bending moment resistant connecting part is required to be as thin as possible in the other direction; this is a contradiction. Moreover, the bending moment resistant connecting part is difficult to process to be thin and has the risk of fracture. Under the processing condition that the cost is acceptable, the thickness of the bending-resistant connecting part is about 0.5mm at the minimum.

In order to solve the above-mentioned contradiction, as shown in fig. 10, the bending moment resistant connecting part is processed into a zigzag connecting part 420 connected between the outer ring 110 and the inner ring 210. Of course, the bending moment resisting connection portion may be processed into other shapes, including but not limited to a curved connection member, as long as the total length of the connection member is greater than the distance between the outer ring 110 and the inner ring 210, so as to ensure that the bending moment resisting rigidity of the bending moment resisting connection portion is substantially greater than the torque resisting rigidity. The other parts of the structure and their functions are the same as those in embodiment 1, and are not described herein again.

Example 3

As shown in fig. 11 and 12, this embodiment is another alternative to improve the bending moment resistance of the torque measuring device. A detachable connector 430 is additionally arranged between the outer ring 110 and the inner ring 210, one end of a body 431 of the connector 430 is fixed on the outer ring 110 by a screw 433, the other end of the body 431 is provided with a roller 432, and the shaft of the roller 432 is arranged in the body 431. The rolling surface of the roller 432 is in contact with one surface of the inner race 210, and the preload contact force can be increased appropriately. The axis of the roller 432 extends in the radial direction of the inner ring, i.e. the axis of the roller 432 is perpendicular to and intersects the rotation axis of the torque measuring device. When the outer ring 110 and the inner ring 210 are relatively moved by the torque, the roller 432 rolls on the surface of the inner ring 210 without affecting the transmission of the torque. When the torque measuring device is subjected to a bending moment, the connector 430 can eliminate or reduce the displacement and deformation of the torque measuring device caused by the bending moment.

Further, there are two methods for improving the bending resistance: (1) a plurality of connectors 430 are arranged on the circumference of the inner ring and the outer ring; (2) to improve bending resistance in both directions, a pair of connectors 430 may be provided on the upper and lower surfaces of the inner and outer races, respectively.

If the torque measuring device has a large volume and sufficient installation space, the connector 430 may be fixed to the inner ring 210 so that the roller 432 rolls on the surface of the outer ring 110.

Example 4

As shown in fig. 13, in order to protect the strain body and the bending moment resistant connection portion 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 part is designed between the inner ring 210 and the outer ring 110, the meshing part is composed of a concave part 512 and a convex part 511, the head of the convex part 511 is accommodated in the concave part 512, and a certain gap exists between the convex part 511 and the concave 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 convex portion 511 and the concave portion 512, the inner ring 210 and the outer ring 110 are tightly attached to each other, and an excessive torque force acts on the attaching position to protect the strain body.

As shown in the upper left partial enlarged view of fig. 13, a certain gap d is provided between the side surface of the protruding portion 511 and the side surface of the recessed portion 512, and a certain gap e is provided between the top surface of the protruding portion 511 and the top surface of the recessed portion 512. The extension surfaces of the respective sides of the protruding portion 511 and the recessed portion 512 pass through the rotating shaft to ensure surface contact between the side surface of the protruding portion 511 and the side surface of the recessed portion 512 when the overload occurs. The angle θ between the side of the convex portion 511 and the side of the concave portion 512 must satisfy: before the torque load reaches the maximum, the two side surfaces are ensured to be in contact to protect the strain body and the bending moment resistant connection part. The protrusions 511 of the overload prevention engagement member are not in the same plane as the inner ring 210 and the outer ring 110, so that the protection effect is prevented from being weakened or failed due to contact friction with other parts when the overload prevention engagement member is installed for torque measurement.

In fig. 13, the boss 511 is formed integrally with the inner ring 210 to be processed by wire cutting or laser cutting; the recess 512 is integrally formed with the outer race 110, and is also machined by wire cutting or laser cutting. The length of the protrusion 511 contained in the recess 512 is greater than one third of the total length of the protrusion 511 itself, so that the two sides are in more contact with each other for better protection. If the protruding portion 511 itself is long, the contact surface between the side surface and the recessed portion is small, and the protruding portion 511 itself may be deformed. In another alternative, the arrangement of the concave portion and the convex portion may be interchanged, that is, the concave portion is integrally formed with the inner ring 210, and the convex portion is integrally formed with the outer ring 110, so that the principle of the overload protection function is similar to that shown in fig. 13, and will not be described herein again.

The overload protection mechanism 510 in this embodiment can be used in conjunction with any one of the bending moment resistant connection portions in embodiments 1 to 3 described above. That is, in the same torque measuring device, both one of the connecting

members

410, 420 or 430 and the overload protection mechanism 510 are provided, and they simultaneously perform their respective functions. It is also possible to provide only the overload protection mechanism 510 and not the

connection

410, 420 or 430. Alternatively, the overload protection mechanism 510 is not provided in the torque measuring device. These are the torque measuring device technical scheme that the utility model claims.

This patent passes through structural design, and at the inner circle and the outer lane of torque measurement device structure, except meeting an emergency, add moment resistance connecting portion again, ensure that the rigidity that bears the moment of flexure is greater than the rigidity that bears the moment of torsion, can increase the bending resistance and the positioning accuracy of robot joint under the prerequisite of assurance signal to be applicable to the robot and use. The structure is improved in structural design, overload protection of the torque measuring device is achieved, and the problem of overload protection of the robot in the motion process is solved.

The foregoing has described in detail preferred embodiments of the present invention. It should be understood that numerous modifications and variations can be devised by those skilled in the art in light of the teachings of the present invention without undue experimentation. Therefore, the technical solutions that can be obtained by a person skilled in the art through logic analysis, reasoning or limited experiments based on the prior art according to the concepts of the present invention should be within the scope of protection defined by the claims.

Claims

1. A structural member of a torque measuring device comprises an outer ring, an inner ring and a first connecting part connected between the outer ring and the inner ring, and is characterized in that the first connecting part is integrally formed with the outer ring and the inner ring; the structure further includes a second connection disposed between the outer race and the inner race, the second connection configured to: when the structural member is installed on the torque measuring device, the second connecting part is used for resisting a bending moment applied to the torque measuring device, and the bending moment refers to a moment of which the moment direction is not coincident with the rotating shaft of the torque measuring device.

2. A structural member of a torque measuring device according to claim 1, wherein the second connecting portion includes a second connecting portion body, and a first body surface of the second connecting portion body is lower than a first inner ring surface of the inner ring and a first outer ring plane of the outer ring so as to ensure that the second connecting portion body does not contact with other components connected to the inner ring or the outer ring.

3. A structural member of a torque measuring device according to claim 2, wherein the second connecting portion is formed integrally with the outer ring and the inner ring.

4. The structural member of a torque measuring device according to claim 2, wherein the second connecting portion is a split type, and both ends of the second connecting portion are fixed to the outer ring and the inner ring, respectively.

5. A structural member for a torque measuring device according to claim 3, wherein the second connecting portion is a straight connecting member connected between the outer race and the inner race, the straight connecting member extending in a first direction parallel to or coincident with the axial direction of the inner race to a greater extent than in a second direction parallel to or coincident with the tangential direction of the inner race.

6. A structural member of a torque measuring device according to claim 5, wherein said straight connecting member extends in a third direction, said third direction coinciding with a radial direction of said inner race.

7. A structural member for a torque measuring device according to claim 3, wherein the second connecting portion is a fold or a curve connecting the outer race and the inner race.

8. A structural member of a torque measuring device according to claim 1,

the structural part comprises a plurality of first connecting parts and a plurality of second connecting parts, the number of the second connecting parts is N times of that of the first connecting parts, and N is an integer and is not less than 1;

the first connecting parts are uniformly distributed between the outer ring and the inner ring, and N second connecting parts are distributed in the space between every two adjacent first connecting parts.

9. A structural member for a torque measuring device according to claim 1, wherein the second connecting portion comprises a connector connecting the outer race and the inner race, a first end of the connector being fixed to the outer race and a second end of the connector being movable on the surface of the inner race.

10. A structural member for a torque measuring device according to claim 1, wherein the second connecting portion comprises a connector connecting the outer race and the inner race, a first end of the connector being fixed to the inner race and a second end of the connector being movable on a surface of the outer race.

11. A structural member for a torque measuring device according to claim 9 wherein the second end of the connector carries a rolling element, the rolling surface of the rolling element being in contact with the surface of the inner race.

12. A structural member for a torque measuring device according to claim 11, wherein said rolling member comprises a roller having an axis extending in a radial direction of said inner race.

13. A structural member for a torque measuring device according to claim 11, wherein said connectors are arranged in pairs, two connectors of each pair contacting two surfaces of said inner race, respectively.

14. An overload protection mechanism of a torque measuring device, the torque measuring device comprises an outer ring and an inner ring, and the overload protection mechanism is arranged between the outer ring and the inner ring and comprises a concave part and a convex part, the head part of the convex part is accommodated in the concave part, and a gap is reserved between the convex part and the side surface opposite to the concave part; the concave part and the outer ring are integrally formed, and the convex part and the inner ring are integrally formed; or, the concave part and the inner ring are integrally formed, and the convex part and the outer ring are integrally formed.

15. The overload protection mechanism for a torque measuring device according to claim 14, wherein the length of the protrusion received in the recess is greater than one third of the total length of the protrusion itself.

16. The overload protection mechanism for a torque measuring device according to claim 14, wherein the first side of the recess is in surface contact with the second side of the protrusion when the overload protection mechanism is triggered for protection.

17. The overload protection mechanism for a torque measuring device according to claim 16, wherein the imaginary extension planes of the first side surface and the second side surface intersect at an axis of the inner race.

18. A torque measuring device comprising a structural member as claimed in any one of claims 1 to 13 and/or an overload protection mechanism as claimed in any one of claims 14 to 17.