CN219946269U - Robot joint module and robot - Google Patents

Abstract

The application provides a robot joint module and a robot. The torque sensor comprises a first flange and a second flange, wherein the first flange and the second flange are coaxially arranged, the second flange is surrounded by the first flange, and the first flange is fixedly connected with the joint output end. The harmonic reducer comprises a flexible gear and a crossed roller bearing, wherein a fixed flange of the flexible gear is fixedly connected with the second flange, and an outer ring of the crossed roller bearing is fixedly connected with the first flange. The torque sensor only bears the transmission torque between the harmonic reducer and the joint output end and does not bear the bending moment under the support of the crossed roller bearing, so that the influence of the bending moment on the sensing signal of the torque sensor can be avoided, the output torque of the joint module can be accurately measured, and the positioning precision of the joint output end cannot be reduced due to the bending deformation of an output flange of a conventional torque sensor, namely, the first flange.

Description

Robot joint module and robot

Technical Field

The application relates to the technical field of robots, in particular to a robot joint module and a robot.

Background

The collaborative robot needs to interact with a person and needs to have torque sensing capability for interaction security. The power unit of the cooperative robot usually adopts an integrated joint, the moment sensing capability of the cooperative robot usually depends on motor current feedback of the integrated joint or an additional moment sensor is arranged, and different sensing schemes have larger influence on moment sensing precision; meanwhile, the transmission efficiency of the integrated joint is related to the load capacity of the cooperative robot. The existing cooperative robot joint generally adopts a harmonic reducer for transmission, a torque sensor is arranged between a harmonic reducer flexible gear output flange and a joint output end, and the torque sensor is often bent during measurement, namely the torque sensor also bears bending moment during measurement, so that the measurement precision of the torque sensor is greatly affected, and the practical service life of the torque sensor is shortened.

Disclosure of Invention

In order to solve the technical problems, the utility model provides a robot joint module and a robot, which can effectively improve the sensing precision of a moment sensor and prolong the service life of the moment sensor.

One aspect of the utility model is: the robot joint module comprises a joint output end, a moment sensor and a harmonic reducer, wherein the moment sensor comprises a first flange and a second flange which are coaxially arranged, the first flange surrounds the second flange, and the first flange is fixedly connected with the joint output end; the harmonic reducer comprises a flexible gear and a crossed roller bearing, the flexible gear comprises a fixed flange, the crossed roller bearing comprises an inner ring and an outer ring, the fixed flange is fixedly connected with the second flange, and the outer ring is fixedly connected with the first flange.

Further, the torque sensor further comprises a fixed end plate, and the first flange and the second flange are formed by extending from a first end face of the fixed end plate; the moment sensor further comprises a connecting journal and a strain reinforcement beam, wherein the connecting journal is used for connecting the first flange and the fixed end plate; the strain reinforcement beam is secured to the connection journal and is connected to the fixed end plate and the first flange.

Further, a second end face of the fixed end plate opposite to the first end face is convexly provided with a protection check ring, and a signal processing plate is further fixed on the second end face.

Further, the robot joint module further comprises an oil seal and a sealing sliding ring; the seal sliding ring is fixedly sleeved on the second flange, the oil seal comprises an oil seal sleeve, the oil seal sleeve comprises a first end part and a second end part which are oppositely arranged, the first end part is fixed in the inner ring, and the flexible wheel is accommodated in the first end part; the sealing slip ring is received within the second end portion, and an inner wall of the second end portion is in sliding contact with the sealing slip ring.

Further, the device also comprises a sealing element arranged in the flexible wheel; the sealing element comprises a connecting flange and an annular sealing tooth part, and the annular sealing tooth part is connected to one side end of the connecting flange; the harmonic reducer further comprises a wave generator connected with the flexible gear, the wave generator comprises an annular clamping tooth part, wherein the annular sealing tooth part comprises an annular end face and a tooth groove, and the tooth groove is arranged on the annular end face; the annular latch part comprises a tooth root and a latch convexly arranged by the tooth root, wherein the latch is accommodated in the tooth slot; the tooth root and the annular end face form a first gap, the tooth slot and the tooth latch form a second gap, and the first gap and the second gap are mutually communicated to form a labyrinth channel.

Further, the width of the labyrinth passage is 0.2-1 mm.

Further, the harmonic reducer further comprises a fastening gasket and a fastening piece; the fastening gasket is arranged on one side of the connecting flange, which is away from the fixing flange; the fastening piece comprises a fastening head, the fastening piece fixes the fixing flange, the connecting flange and the second flange, and the fastening head abuts against the fastening gasket.

Further, the device also comprises a low-speed shaft and a sealing ring; the wave generator further comprises an inner hole, the connecting flange is provided with a fixing hole, one end of the low-speed shaft is fixed in the fixing hole, and the other end of the low-speed shaft penetrates through the inner hole; the sealing ring is sleeved on the low-speed shaft, and the sealing ring is propped against the end face of the fastening gasket and the low-speed shaft.

Further, the robot joint module further comprises a motor and a low-speed shaft; the harmonic reducer further comprises a steel wheel, the steel wheel is connected with one end of the inner ring, which is opposite to the oil jacket, and the motor is connected with the steel wheel; the connecting flange is provided with a fixing hole, the wave generator further comprises an inner hole, one end of the low-speed shaft is fixed in the fixing hole, and the other end of the low-speed shaft penetrates through the inner hole; the motor comprises a motor output shaft sleeved on the low-speed shaft; the oil containing channel is formed among the outer wall of the low-speed shaft, the inner wall of the motor output shaft and the inner wall of the inner hole, and is communicated with the labyrinth channel.

Further, the width of the oil containing channel is 0.2-0.8 mm.

Further, a sealing gasket is arranged between the first end part and the inner ring.

Further, an oil seal check ring is convexly arranged at the first end part, and the oil seal check ring is resisted on the end face of the inner ring.

Further, the oil seal further comprises an oil seal framework, wherein the oil seal framework is fixed in the first end part, and the oil seal framework abuts against the sealing sliding ring.

Further, a friction pad is included; the friction pad is disposed between the opposing end faces of the fixed flange and the second flange.

Further, the oil seal also comprises an elastic sealing ring; the elastic sealing ring is arranged in the second end part, and the elastic sealing ring abuts against the end face of the sealing sliding ring and the fixing flange.

In another aspect of the application, a robot is provided, which comprises the robot joint module.

The beneficial effects of the application are as follows: compared with the existing robot joint module, the robot joint module provided by the application comprises a joint output end, a moment sensor and a harmonic reducer. The torque sensor comprises a first flange and a second flange, wherein the first flange and the second flange are coaxially arranged, the second flange is surrounded by the first flange, and the first flange is fixedly connected with the joint output end. The harmonic reducer comprises a flexible gear and a crossed roller bearing, wherein a fixed flange of the flexible gear is fixedly connected with the second flange, and an outer ring of the crossed roller bearing is fixedly connected with the first flange. The torque sensor only bears the transmission torque between the harmonic reducer and the joint output end and does not bear the bending moment under the support of the crossed roller bearing, so that the influence of the bending moment on the sensing signal of the torque sensor can be avoided, the output torque of the joint module can be accurately measured, and the positioning precision of the joint output end cannot be reduced due to the bending deformation of an output flange of a conventional torque sensor, namely, the first flange.

Drawings

For a clearer description of the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments will be briefly introduced below, it being obvious that the drawings in the description below are only some embodiments of the present application, and that other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art, wherein:

fig. 1 is a schematic perspective view of a robot joint module according to the present application; the robot joint module comprises a sealing piece and a moment sensor;

FIG. 2 is a right side schematic view of FIG. 1;

FIG. 3 is a schematic cross-sectional view of the structure in the direction B-B in FIG. 2;

FIG. 4 is a schematic view of the partial enlarged structure of FIG. 3;

FIG. 5 is a schematic perspective view of the seal of FIG. 1;

fig. 6 is a schematic perspective view of the torque sensor of fig. 1.

Detailed Description

The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the application. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are intended to be within the scope of the present disclosure.

In describing embodiments of the present application, it should be noted that, unless explicitly stated and limited otherwise, the terms "coupled," "coupled," and "connected" should be construed broadly, and may be either a fixed connection, a removable connection, or an integral connection, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium. The specific meaning of the above terms in embodiments of the present application will be understood in detail by those of ordinary skill in the art.

In embodiments of the application, unless expressly specified and limited otherwise, a first feature "up" or "down" on a second feature may be that the first and second features are in direct contact, or that the first and second features are in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

In one aspect of the present application, a robot joint module 100 is provided, and referring to fig. 1-2, fig. 1 is a schematic perspective view of a robot joint module provided by the present application; the robot joint module comprises a sealing piece and a moment sensor; FIG. 2 is a right side schematic view of FIG. 1; fig. 3 is a schematic sectional view of the structure in the direction B-B in fig. 2. The robot joint module 100 includes a joint output (not shown), a torque sensor 11, and a harmonic reducer 12. The joint output end is used for being connected with a load and transmitting power of the speed reducer; the torque sensor 11 can detect the torque sensing on various rotating or non-rotating mechanical parts, and convert the physical change of the torque into an accurate electric signal, so that the torque sensor can be used for sensing and measuring the torque of the joint output end; the harmonic reducer 12 is a reducer made by utilizing a harmonic principle and is used for reducing the power of an input end and transmitting the power to an output end of a joint.

The torque sensor 11 includes a first flange 111 and a second flange 112 that are coaxially disposed. The first flange 111 surrounds the second flange 112. The first flange 111 serves as an output of the torque sensor 11, and the second flange 112 serves as an input of the torque sensor 11. The first flange 111 is fixedly connected to the joint output 10 so that the torque of the joint output can be perceived and measured.

The harmonic reducer 12 includes a flexspline 121 and a crossed roller bearing 122. The flexible gear 121 is a thin-walled gear capable of generating large elastic deformation, and the flexible gear 121 comprises a fixed flange 1211. The cross roller bearing 122 is a special type of bearing in which the inner race 1221 is split and the outer race 1222 rotates, i.e., the cross roller bearing 122 includes an inner race 1221 and an outer race 1222. The fixed flange 1211 is fixedly connected to the second flange 112, and preferably, the fixed flange 1211 is fixedly connected coaxially to the second flange 112. Outer ring 1222 is fixedly connected to first flange 111, preferably, outer ring 1222 is fixedly connected coaxially with first flange 111. I.e. the torque sensor 11 is connected between the flexspline 121 and the cross roller bearing 122. It will be appreciated that because the rollers of the crossed roller bearing 122 are arranged in a crossed manner between the inner race 1221 and the outer race 1222, the crossed roller bearing 122 is able to bear loads in all directions, while the first flange 111 of the torque sensor 11 is fixedly connected to the outer race 1222 of the crossed roller bearing 122. Therefore, when the power of the flexible gear 121 is output to the joint output end, the torque sensor 11 only bears the transmission torque between the harmonic reducer 12 and the joint output end and does not bear the bending moment under the support of the crossed roller bearing 122, so that the influence of the bending moment on the sensing signal of the torque sensor 11 can be avoided, the output torque of the joint module can be accurately measured, and the positioning precision of the joint output end cannot be reduced due to the bending deformation of the output flange, namely the first flange 111, of the conventional torque sensor 11.

Therefore, in the robot joint module 100 of the present application, since the torque sensor 11 is disposed between the crossed roller bearing 122 and the flexible wheel 121, and the torque sensor 11 rotates along with the flexible wheel 121 and transmits power, in the transmitting process, the torque sensor 11 only bears the transmission torque between the harmonic reducer 12 and the joint output end and does not bear the bending moment due to the support of the crossed roller bearing 122, so that the influence of the bending moment on the sensing signal of the torque sensor 11 can be avoided, the output torque of the joint module can be accurately measured, and the positioning accuracy of the joint output end is not reduced due to the bending deformation of the output flange of the conventional torque sensor 11, that is, the first flange 111.

In some embodiments, the robot joint module 100 further includes an oil seal 13 and a sealing slip ring 14, and both the oil seal 13 and the sealing slip ring 14 have a sealing effect and prevent grease of the harmonic reducer 12 from contacting the torque sensor 11. It will be appreciated that the harmonic reducer 12 requires grease lubrication during transmission to ensure stable operation and to extend the useful life.

The oil seal 13 includes an oil jacket 131, and the oil jacket 131 includes a first end 1311 and a second end 1312 that are disposed opposite to each other. The first end 1311 is fixed within the inner ring 1221, and the flexspline 121 is housed within the first end 1311. That is, the oil jacket 131 is disposed between the torque sensor 11 and the harmonic reducer 12, and can isolate the torque sensor 11 from grease of the harmonic reducer 12.

The sealing slip ring 14 is fixedly sleeved on the second flange 112, and the sealing slip ring 14 is received in the second end 1312. The sealing slip ring 14 and the second flange 112 may be secured together using an interference fit, adhesive, O-ring seal, or the like. That is, the second flange 112 is fixedly connected to the fixed flange 1211, and the sealing slip ring 14 is fixedly sleeved on the second flange 112, the first end 1311 of the oil jacket 131 is fixed to the inner ring 1221, and the inner wall of the second end 1312 is in sliding contact with the sealing slip ring 14 fixedly connected to the torque sensor 11. Wherein sliding contact refers to a relative movement between the first end 1311 of the oil jacket 131, which is connected to the torque sensor 11, and the torque sensor 11. The sealing sliding ring 14 can cooperate with the oil jacket 131 to seal grease of the harmonic reducer 12, isolate the grease on one side of the oil jacket 131 away from the torque sensor 11, prevent the torque sensor 11 from directly contacting the grease of the harmonic reducer 12, and effectively reduce the sealing and corrosion resistance of the torque sensor 11; and the temperature drift of the signals of the moment sensor 11 caused by the temperature change of grease can be prevented, and the accuracy of the moment sensor 11 is prevented from being influenced. In addition, since the inner wall of the second end 1312 is in sliding contact with the sealing slip ring 14, the tightness of the oil jacket 131 and the sealing slip ring 14 in the relative rotation process is ensured, and meanwhile, the friction force between the oil jacket 131 and the torque sensor 11 is reduced, so that the sensing measurement precision of the torque sensor 11 in sensing the torque of the output end of the joint can be further improved, and the sensing capability of the integrated joint torque is improved. And the friction force between the oil jacket 131 and the moment sensor 11 is reduced, so that the transmission efficiency of the robot joint module 100 can be improved, and the load capacity of the robot can be effectively improved.

Referring to fig. 3 and 4, fig. 4 is a schematic view of a partial enlarged structure in fig. 3. In some embodiments, the robotic joint module 100 further includes a seal 15 disposed within the flex gear 121. The seal 15 is used for sealing grease in the flexspline 121. The seal 15 includes a connecting flange 151 and annular seal teeth 152. The connection flange 151 and the annular seal tooth 152 are both accommodated in the flexspline 121. The connection flange 151 is fixed to the fixing flange 1211 and rotates together with the fixing flange 1211, and the annular seal tooth portion 152 is connected to one side end of the connection flange 151.

The harmonic reducer 12 further includes a wave generator 123 connected to the flexspline 121. The wave generator 123 is a member for controllably elastically deforming the flexible gear 121, and is installed in the flexible gear 121. And the diameter of the inner hole of the flexible wheel 121 is slightly smaller than the total length of the wave generator 123, when the wave generator 123 is installed in the flexible wheel 121, the wave generator 123 forces the section of the flexible wheel 121 to be changed from the original round shape to the oval shape, teeth near the two ends of the long shaft of the flexible wheel are completely engaged, and teeth near the two ends of the short shaft of the flexible wheel are completely disengaged, so that the power of the input end is transmitted to the joint output end through the speed reduction of the flexible wheel 121. The wave generator 123 includes an annular latch 1231, the annular latch 1231 and the annular seal tooth 152 cooperating with each other such that a labyrinth passage is formed by a gap between the annular latch 1231 and the annular seal tooth 152. Labyrinth passage means that annular latch 1231 does not abut or contact annular seal tooth 152, and the gap between the two still allows a small portion of grease to pass through, and the gap between the two changes direction at least once in the radial direction. Accordingly, the flexible wheel 121 connecting flange 151 is fixedly connected with the fixing flange 1211, a seal can be formed at the fixing flange 1211, and the labyrinth passage is sealed in the flexible wheel 121 of the wave generator 123, so that grease can be effectively sealed between the flexible wheel 121 and the wave generator 123. The annular latch 1231 may be provided according to practical situations, as long as it can prevent leakage of grease in the flexible gear 121 that lubricates the flexible gear 121 and the wave generator 123. It will be appreciated that the flexspline 121 needs to interact with the wave generator 123, and thus, lubricating grease is provided inside the flexspline 121, and the seal 15 provided in the flexspline 121 can effectively seal the flexspline 121 from the grease required by the wave generator 123, so as to ensure that the flexspline 121 and the wave generator 123 are always in a lubricating state.

It will also be appreciated that in order to ensure the sealing effect of the labyrinth passage, i.e. the labyrinth passage is a curved passage, it is necessary to change direction a plurality of times, whereby the path length of the labyrinth passage may be increased and the speed of the grease passing through the labyrinth passage in the direction of extension of the labyrinth may be effectively slowed down. The labyrinth passage needs to change the direction at least three times, so that a good sealing effect can be achieved. It should be noted that the labyrinth passage is a bent passage with a better sealing effect than a smooth bent passage.

In some embodiments, the annular seal tooth 152 includes an annular end face 1521 and a tooth groove 1522, the tooth groove 1522 being disposed on the annular end face 1521. The tooth grooves 1522 may be annular grooves, and the side walls of the annular grooves or portions between every two adjacent tooth grooves 1522 are annular teeth. The annular latch portion 1231 includes a tooth root portion 1232 and a latch 1233 protruding from the tooth root portion 1232, wherein the latch 1233 is an annular protrusion, and the latch 1233 may be a plurality of latches, and a latch groove is formed between the two latches 1233, and the latch groove is also annular. Wherein, latch 1233 is received in tooth slot 1522 and annular teeth are received in the latch slot. A first gap is formed between the tooth root 1232 and the annular end face 1521, a second gap is formed between the tooth slot 1522 and the tooth 1233, and a third gap is formed between the side wall of the annular tooth and the side wall of the tooth opposite the tooth 1233. And the first gap and the second gap are communicated with each other through the third gap to form a labyrinth passage. It will be appreciated that when the annular latch portion 1231 has one latch 1233 and the annular seal tooth 152 has one annular tooth, the latch 1233 and the annular tooth may form two corners after being staggered. Preferably, the number of the latch 1233 and the number of the annular teeth are two, so that the labyrinth passage formed by the cooperation of the latch 1233 and the annular teeth can be formed with five corners, and each corner is a right angle. Of course, the number of the latch 1233 and the ring teeth may be greater than two, and may be specifically selected according to practical situations, which is not limited herein.

It will be appreciated that the width of the first, second, and third gaps may affect the tightness of the labyrinth passage, and that when the widths of the first, second, and third gaps are too large, the tightness may be poor even though the corners of the corner labyrinth passage are greater than three. Thus, in some embodiments, the width of the labyrinth passage is set to 0.2-1 mm. Specifically, the width may be 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm. The widths of the first gap, the second gap and the third gap may be the same or different. Of course, it is also possible that the width of the labyrinth passage increases gradually, or decreases gradually, or increases first and then decreases, or decreases first and then increases in a radially outward direction along the seal 15; it is also possible that the width of each of the first gap, the second gap and the third gap is gradually increased, or gradually decreased, or is increased before being decreased, or is decreased before being increased.

To facilitate the secure connection of the connection flange 151 and the second flange 112 with the fixation flange 1211, the connection flange 151, the fixation flange 1211, and the second flange 112 may be secured together, and in some embodiments, the harmonic reducer 12 further includes fasteners (not shown), including fastening heads. The fastening members fix the fixing flange 1211, the connecting flange 151 and the second flange 112, and the fastening heads are abutted against the connecting flange 151. The fastening piece may be a bolt, the fastening head may be a nut, and the fastening head may abut against an end surface of the connecting flange 151 facing away from the fixing flange 1211. Of course, the fastening member may be a screw, a pin, or the like, as long as the fixing flange 1211, the connecting flange 151, and the second flange 112 can be fastened together.

In order to avoid that the fastening head is in direct contact with the connection flange 151, which would damage the connection flange 151, the harmonic reducer 12 further comprises a fastening washer 16, the fastening washer 16 being arranged on the side of the connection flange 151 facing away from the fixing flange 1211. That is, the fastening gasket 16 is disposed between the fastening head and the connection flange 151, and the fastening head abuts against the fastening gasket 16. Therefore, the direct contact between the fastening head and the connecting flange 151 can be avoided, the area of the fastening gasket 16 is larger than that of the fastening head, and the contact surface can be increased, so that the friction force between the fastening gasket 16 and the connecting flange 151 is increased, and the connection tightness of the connecting piece is further improved.

In some embodiments, the robotic joint module 100 further includes a low speed shaft 17 and a seal ring 18. The low-speed shaft 17 is partially accommodated in the harmonic reducer 12, is connected with the flexible gear 121, and can rotate along with the flexible gear 121. The sealing ring 18 may be an O-ring and is sleeved on the low-speed shaft 17, so as to prevent grease in the harmonic reducer 12 from affecting the tightness of the connection of the low-speed shaft 17.

Specifically, the wave generator 123 further includes an inner hole 1234, and the connecting flange 151 is provided with a fixing hole 153. One end of the low speed shaft 17 is fixed in the fixing hole 153, and the other end of the low speed shaft 17 passes through the inner hole 1234. That is, the inner hole 1234 of the wave generator 123 is communicated with the fixing hole 153, one end of the low-speed shaft 17 passes through the inner hole 1234, and can be fixedly accommodated in the fixing hole 153 by adopting interference fit, adhesion or elastic structural members with the fixing hole 153, and rotates along with the sealing member 15, so that an additional encoder is conveniently arranged on the low-speed shaft 17 for positioning. It is understood that the low speed shaft 17 may be a hollow cylinder, and the inner hole 1234 and the fixing hole 153 may be circular holes, and since the low speed shaft 17, the second flange 112 and the connecting flange 151 all rotate along with the fixing flange 1211 of the flexspline 121, the low speed shaft 17, the second flange 112, the fixing hole 153 and the inner hole 1234 may have a certain coaxiality.

The seal ring 18 abuts against the end face of the tightening washer 16 and the low-speed shaft 17. That is, the side of the seal ring 18 away from the low speed shaft 17 abuts against the fastening washer 16, and the side of the seal ring 18 close to the low speed shaft 17 abuts against the fastening washer 16. It will be appreciated that the fastening washer 16 in this case has not only the function of protecting the seal 15, fastening the connection, but also the function of sealing. Because the fastening gasket 16 and the sealing ring 18 are in abutting sealing on the same cross section, a small amount of grease leaking from the labyrinth passage can be effectively prevented from entering the fixing hole 153, so that the connection between the low-speed shaft 17 and the fixing hole 153 is affected, and the sliding of the low-speed shaft 17 is caused.

Optionally, the sealing ring 18 is sleeved on the low-speed shaft 17, and the sealing ring 18 abuts against the inner walls of the low-speed shaft 17 and the fixing hole 153. At this time, the sealing ring 18 is installed in the fixing hole 153 to abut against and seal one side of the fixing hole 153 close to the torque sensor 11, thereby preventing a small amount of grease leaking in the labyrinth passage from entering, thereby affecting the connection between the low speed shaft 17 and the fixing hole 153, resulting in sliding of the low speed shaft 17. It will be appreciated that at this point the tightening washer 16 does not cooperate with the sealing ring 18 and therefore has only the effect of protecting the seal 15, the tightening connection.

To facilitate the positioning of the seal ring 18, in some embodiments, a groove 171 may also be provided on the low speed shaft 17, the groove 171 may be an annular groove, and the seal ring 18 is mounted in the groove 171. Thus, the sealing ring 18 can be positioned in the mounting process, and the sliding of the sealing ring 18 in the mounting process can be prevented, so that the sealing ring 18 is always positioned in the mounting position.

Referring to fig. 3-5, fig. 5 is a schematic perspective view of the seal of fig. 1. In some embodiments, the robot joint module 100 further includes a motor 19 and a low-speed shaft 17, the harmonic reducer 12 further includes a steel wheel 124, and the steel wheel 124 serves to fix the harmonic reducer 12, that is, the steel wheel 124 supports the flexible wheel 121 and the wave generator 123, and the wave generator 123 drives and outputs the flexible wheel 121. It will be appreciated that the flex spline 121 may be a circular barrel-like thin-walled structure, with the outer wall of the barrel-like open end provided with external teeth that engage the steel spline 124. The barrel-shaped closed end face is convexly provided with a fixing flange 1211. The wave generator 123 is accommodated in the flexspline 121 and is located at the barrel-shaped open end. Thus, when the wave generator 123 is mounted in the flexspline 121, the wave generator 123 forces the cross section of the flexspline 121 to change from the original circular shape to the elliptical shape, the teeth near both ends of the long axis of the wave generator are completely engaged with the teeth of the rigid spline, and the teeth near both ends of the short axis of the wave generator are completely disengaged from the rigid spline, so that the power of the input end is transmitted to the joint output end through the speed reduction of the flexspline 121. It will be appreciated that the outer side of the flexspline 121 engages the steel spline 124, so that the oil seal 13 and the seal slip ring 14 between the flexspline 121 and the torque sensor 11 are sealed from grease between the flexspline 121 and the steel spline 124.

The steel wheel 124 is connected to the end of the inner ring 1221 facing away from the oil jacket 131, and the motor 19 is connected to the steel wheel 124. The steel wheel 124 may include a connection hole 1241 and a mounting flange 1242, wherein inner teeth engaged with the flexspline 121 are provided on an inner wall surface of the connection hole 1241, and the mounting flange 1242 is connected with a housing of the motor 19. It will be appreciated that outer race 1222 of cross roller bearing 122 is connected to torque sensor 11 and is rotatable with torque sensor 11, while inner race 1221 of cross roller bearing 122 is connected to steel wheel 124; so that relative rotation also occurs between inner race 1221 and outer race 1222. It will be further appreciated that, in order to facilitate the connection and positioning of the inner ring 1221 and the steel wheel 124, the steel wheel 124 is further provided with positioning protrusions 1243, and the positioning protrusions 1243 are disposed on a side of the mounting flange 1242 near the flexspline 121. When the steel wheel 124 is connected to an end of the inner ring 1221 facing away from the oil jacket 131, the end face of the end abuts against the positioning protrusion 1243, thereby restraining the cross roller bearing 122 between the first flange 111 and the mounting flange 1242 of the steel wheel 124.

The connection flange 151 is provided with a fixing hole 153, the wave generator 123 further includes an inner hole 1234, one end of the low speed shaft 17 is fixed in the fixing hole 153, and the other end of the low speed shaft 17 passes through the inner hole 1234. That is, the inner hole 1234 of the wave generator 123 is communicated with the fixing hole 153, and one end of the low-speed shaft 17 passes through the inner hole 1234, and can be fixedly accommodated in the fixing hole 153 by adopting interference fit, adhesion or elastic structural members with the fixing hole 153, and rotates along with the sealing element 15, the flexible wheel 121 and the sealing sliding ring 14.

The motor 19 may be mounted on the side of the harmonic reducer 12 facing away from the torque sensor 11, the motor 19 may be used as an input, and the motor 19 may include a motor output shaft 191 sleeved on the low speed shaft 17. The motor output shaft 191 may be connected to the wave generator 123 so that power of the motor 19 is transmitted to the joint output through the wave generator 123, the flexspline 121, and the torque sensor 11. And, the other end of the low speed shaft 17 passes through the inner hole 1234 and is partially accommodated in the motor output shaft 191. To avoid grease leaking from the labyrinth passage from accumulating in the harmonic reducer 12 and on one side of the seal ring 18. And since the rotational speeds between the motor output shaft 191 and the low speed shaft 17 are different, there may be a certain gap between the motor output shaft 191 and the low speed shaft 17. Accordingly, an oil-containing passage may be formed between the outer wall of the low speed shaft 17, the inner wall of the motor output shaft 191, and the inner wall of the inner bore 1234, and the oil-containing passage communicates with the labyrinth passage. That is, the grease leaking out of the labyrinth passage may enter the oil accommodating passage, further preventing the grease from entering the fixing hole 153, thereby affecting the stability of the connection of the fixing hole 153 with the low speed shaft 17. And also lubricates the motor output shaft 191 and the low-speed shaft 17 when grease enters between them through the oil accommodating passage.

In order to effectively increase the volume of the accommodating groove 23, in some embodiments, the accommodating groove 23 is formed on any one of the inner wall of the motor output shaft 191 and the outer wall of the low speed shaft 17, and the mounting gap between the low speed shaft 17, the inner hole 1234 and the motor output shaft 191 and the accommodating groove 23 form an oil accommodating channel. Preferably, the receiving groove 23 is provided at a position opposite to the motor output shaft 191 and the low speed shaft 17, that is, the receiving groove 23 is provided between the motor output shaft 191 and the low speed shaft 17. So that grease leaking from the labyrinth passage can be effectively prevented from entering the gap between the fast-exiting shaft of the motor 19 and the low-speed shaft 17 and leaking therefrom.

Further, guide grooves are spirally provided on the inner wall of the motor output shaft 191 and the outer wall of the low speed shaft 17. Because the guide groove is spirally arranged, the path of grease can be greatly increased, so that the grease is less prone to leaking out through the oil containing groove.

In some embodiments, the width of the oil-containing channel is 0.2 to 0.8mm. Specifically, the thickness of the sheet may be 0.3mm, 0.4mm, 0.5mm, 0.6mm, or 0.7mm. Of course, when the receiving groove 23 is formed on any one of the inner wall of the motor output shaft 191 and the outer wall of the low speed shaft 17, the width at the receiving groove 23 may be more than 0.8mm.

To facilitate the mounting and positioning of the torque sensor 11 when fixedly coupled to the flex spline 121, in some implementations, the seal 15 also includes a coupling shaft 154. The torque sensor 11 may be first mounted on the connecting shaft 154.

The connection shaft 154 is connected to the connection flange 151, and the connection shaft 154 and the annular seal tooth portion 152 are provided on opposite sides of the connection flange 151, respectively. The fixing flange 1211 includes a through-hole 1212, and the connection shaft 154 is disposed in the through-hole 1212 and connected to the second flange 112. Specifically, the connecting shaft 154 is disposed in the through hole 1212 and extends outward to the outside of the fixing flange 1211 of the flexspline 121, that is, the connecting shaft 154 is sleeved in the fixing flange 1211. The torque sensor 11 may be provided with a positioning hole 113, the torque sensor 11 may be sleeved on the connecting shaft 154 through the positioning hole 113, and one end of the connecting shaft 154 after being sleeved is accommodated in the positioning hole 113. It will be appreciated that, in order not to leak the grease in the flexspline 121 from the through hole 1212 and contact the second flange 112, the connecting shaft 154 abuts against the inner hole 1234 and the positioning hole 113, and the seal 15 and the torque sensor 11 rotate under the driving of the flexspline 121, the preferred seal 15 is kept in a coaxial relationship with the flexspline 121 and the second flange 112 by the connecting shaft 154, that is, the second flange 112 has a certain coaxiality with the connecting shaft 154 and the inner hole 1234, the positioning hole 113 and the connecting shaft 154.

It will be appreciated that a portion of the inner race 1221 of the cross roller bearing is connected to the steel wheel 124 of the harmonic reducer 12 and another portion of the inner race 1221 is connected to the first end 1311 of the oil jacket 131. I.e. the inner ring 1221 of the cross roller bearing is sleeved over both the steel wheel 124 and the first end 1311. And the flexible wheel 121 is barrel-shaped and sleeved in the steel wheel 124. One end of the flexible wheel 121, which is far away from the fixed flange 1211, is meshed with the steel wheel 124, and one end of the fixed flange 1211 protrudes out of the steel wheel 124. However, grease is also required to be disposed between the steel wheel 124 and the flexspline 121, so that after the grease leaks from this portion, the grease can contact the torque sensor 11 along the grease jacket 131, thereby affecting the measurement accuracy. Thus, in some embodiments, a sealing gasket 22 is also provided between the first end 1311 and the inner ring 1221. The first end 1311 and the second end 1312 of the oil jacket 131 may be annular sleeves, and the first end 1311 is sleeved inside the inner ring 1221 and sleeved outside the flexspline 121, that is, the first end 1311 is located between the inner ring 1221 and the flexspline 121. The sealing gasket 22 may be an O-ring, and the sealing gasket 22 abuts against an inner wall of the inner ring 1221 and an outer wall of the first end 1311, respectively. Thereby effectively preventing grease between the steel wheel 124 and the flexible wheel 121 from affecting the measurement accuracy of the torque sensor 11. And the oil jacket 131 can be fixedly connected with the inner ring 1221 through the sealing gasket 22, so that the oil jacket 131 is connected with the steel wheel 124 and keeps consistent with the movement of the steel wheel 124. It will be appreciated that the first end 1311 and the second end 1312 have different diameters, i.e., the junction of the first end 1311 and the second end 1312 is stepped so that the second end 1312 is in sliding contact with the sealing slip ring 14.

In some more specific embodiments, first end 1311 is also provided with a sealing gasket groove, in which sealing gasket 22 is partially received. When the first end 1311 is fitted into the inner ring 1221, the inner wall of the seal ring 22 abuts the seal ring groove bottom, and the outer wall of the seal ring 22 abuts the inner wall of the inner ring 1221.

To facilitate the installation and positioning of the oil jacket 131, in some embodiments, the first end 1311 is provided with an oil seal retainer 1313 protruding therefrom, the oil seal retainer 1313 bearing against an end face of the inner ring 1221. Preferably, the oil seal retainer 1313 is disposed on the outer sidewall of the first end 1311 and surrounds the first end 1311, when the inner ring 1221 of the crossed roller bearing 122 is first sleeved on the steel wheel 124, the first end 1311 is then sleeved in the inner ring 1221, an end surface of the oil seal retainer 1313 near the crossed roller bearing 122 abuts against an end surface of the inner ring 1221 of the crossed roller bearing 122 facing the positioning edge 1111, and the oil jacket 131 is stopped and positioned by the positioning edge 1111. It can be appreciated that, after the first end 1311 is sleeved on the inner ring 1221 and stopped and positioned by the oil seal retainer 1313, the projection of the oil seal retainer 1313 onto the inner ring 1221 does not exceed the inner ring 1221, so that the interference between the oil seal retainer 1313 and the outer ring 1222 can be effectively avoided.

Since the inner ring 1221 and the outer ring 1222 of the cross roller bearing 122 rotate relative to each other, grease is required to be provided between the inner ring 1221 and the outer ring 1222 for lubrication. Thus, in some embodiments, there is a felt seal between the inner ring 1221 and the outer ring 1222 of the cross roller bearing 122 to form a low friction seal for sealing the bearing itself from grease. So that grease between the inner ring 1221 and the outer ring 1222 can be prevented from leaking and flowing along the oil jacket 131 to be in contact with the torque sensor 11.

In some embodiments, the oil seal 13 further includes an oil seal skeleton 132, the oil seal skeleton 132 being secured within the second end 1312, and the oil seal skeleton 132 further bearing against the seal slip ring 14. Preferably, the oil seal skeleton 132 may be made of rubber, and the oil seal skeleton 132 is a ring body with a -shaped cross section. It will be appreciated that the sealing slip ring 14 is an annular body and that the inner wall of the sealing slip ring 14 is fixedly connected coaxially to the second flange 112. The upper wall of the oil seal skeleton 132 is fixedly connected coaxially with the inner wall of the second end 1312 and is kept in conformity with the movement of the oil jacket 131, and the lower wall of the oil seal skeleton 132 abuts against the seal slide ring 14 and is kept in coaxial relation with the outer wall of the seal slide ring 14. Therefore, grease can be effectively sealed, and leakage of the grease from between the oil seal framework 132 and the seal sliding ring 14 to the torque sensor 11 is avoided.

In order to avoid slippage between the torque sensor 11 and the flexspline 121 during high torque impact, i.e. relative rotation between the torque sensor 11 and the flexspline 121, in some embodiments the robotic joint module 100 further comprises friction pads 20. Wherein the friction pad 20 is made of a high friction material, thereby disposing the friction pad 20 between the opposite end surfaces of the fixed flange 1211 and the second flange 112, the friction force between the fixed flange 1211 and the second flange 112 can be increased, and the power transmitted from the flexspline 121 can be stably and effectively transmitted to the second flange 112.

In some embodiments, the robotic joint module 100 further includes an elastic sealing ring 21, the elastic sealing ring 21 is disposed in the second end 1312, and the elastic sealing ring 21 abuts against the end face of the sealing slip ring 14 and the flexspline 121. That is, the sealing slip ring 14 and the elastic seal ring 21 cooperate to seal grease between the flexible gear 121 and the oil seal 13, thereby preventing the grease from coming into contact with the torque sensor 11 from the sealing slip ring 14 to affect the measurement accuracy of the torque sensor 11 and/or from entering the junction of the second flange 112 and the fixed flange 1211 to reduce the frictional force of the connection therebetween. Preferably, the second flange 112 and the fixed flange 1211 are coaxially connected, and the dimensions of the second flange 112 and the fixed flange 1211 are the same, i.e. after the coaxial connection, the projection of the second flange 112 onto the fixed flange 1211 coincides with the fixed flange 1211. The sealing sliding ring 14 is fixedly sleeved on the second flange 112 and covers the connection part of the second flange 112 and the fixed flange 1211. Therefore, grease between the flexible wheel 121 and the oil seal 13 is prevented from entering the joint of the second flange 112 and the fixed flange 1211, and friction force at the joint is reduced, so that the second flange 112 and the fixed flange 1211 rotate relatively. It will be appreciated that the elastic sealing ring 21 needs to have a suitable compression ratio to ensure that the flexspline 121 of the harmonic reducer 12 remains in good contact with the elastic sealing ring 21 throughout the harmonic drive deformation process.

Of course, in other embodiments, the dimensions of the second flange 112 and the fixed flange 1211 are different. For example, the size of the fixing flange 1211 is larger than that of the second flange 112, and both ends of the elastic sealing ring 21 may abut against the end face of the sealing slip ring 14 and the end face of the fixing flange 1211, respectively, to thereby perform sealing. It will be further appreciated that the sealing may be performed only by the sealing slip ring 14, that is, one end of the sealing slip ring 14 is fixed on the second flange 112, and the end surface of the other end abuts against the end surface of the fixed flange 1211 or the flexible wheel 121, so that the grease between the flexible wheel 121 and the oil seal 13 may contact the torque sensor 11 only by the sealing slip ring 14, and even enter the connection portion between the second flange 112 and the fixed flange 1211.

Referring to fig. 1, 2 and 6, fig. 6 is a schematic perspective view of the torque sensor in fig. 1. In some embodiments, torque sensor 11 further includes a stationary end plate 114. The first flange 111 and the second flange 112 are each extended from one end face of the fixed end plate 114. Since the first flange 111 is disposed around the second flange 112, in some applications, the diameter of the first flange 111 is greater than the diameter of the second flange 112. Thus, the first flange 111 is disposed circumferentially outside the second flange 112. Wherein the first flange 111 has a greater extension in length than the second flange 112, so that the torque sensor 11 generally has a C-shaped configuration.

The torque sensor 11 further includes a connecting journal 115 and a strain reinforcement beam 116. Wherein a connecting journal 115 is used to connect the second flange 112 and the fixed end plate 114. The strain reinforcement beams 116 are used to connect the fixed end plate 114 and the first flange 111. Preferably, the connecting journal 115 is the same size as the second flange 112 and is integrally formed. The plurality of strain reinforcement beams 116 are arranged at intervals and enclose a ring shape, and the first flange 111 is connected with the plurality of strain reinforcement beams 116. Therefore, when the robot joint module 100 moves, the power of the motor output shaft 191 is transmitted to the wave generator 123, the power of the wave generator 123 is transmitted to the flexible gear 121, the flexible gear 121 transmits the power to the joint output end through the torque sensor 11, and the torque sensor 11 can measure the joint output torque after the joint output end is stressed.

In some more specific embodiments, the fixed end plates 114 and the strain beams may be provided as thin-walled structures with a wall thickness of no more than 4mm. The second flange 112 of the torque sensor 11 is fixedly connected to the flexspline 121, and transmits power to the second flange 112. Since the first flange 111 is fixedly connected to the outer ring 1222 of the cross roller bearing 122, i.e. the cross roller bearing provides a support for the second flange 112, the torque sensor 11 is not subjected to bending moments. That is, the fixed end plate 114 and the strain-strengthening beam 116 are thin-walled, and bending deformation does not occur, which reduces the positioning accuracy of the joint output end, and the torque sensor 11 can be made smaller in size and lighter in weight.

It will be appreciated that the torque sensor 11 is provided with strain gauges. Strain gauges, also known as strain gauges, are metallic electrical measuring elements that accurately measure forces, loads, torques, etc. in a static area. The resistance of the wire rod is proportionally changed along with the extension state when the strain gauge is stretched or compressed, so that the joint output torque is measured.

In some embodiments, a second end surface 1142 of the fixed end plate 114 opposite the first end surface 1141 is provided with a signal processing plate 117. It can be appreciated that the signal processing board 117 can process signals on the strain gauges and can receive signals from the robot controller, thereby ensuring that the robot joint module 100 operates properly.

The second end surface 1142 is further provided with a protection collar 1143, and the protection collar 1143 is used for protecting the signal processing board 117. Specifically, the protection collar 1143 is an annular body protruding on the second end face 1142, the signal processing board 117 is located in the protection collar 1143, and the projection of the signal processing board 117 onto the protection collar 1143 is in the protection collar 1143, that is, the protruding height of the protection collar 1143 is higher than the height of the signal processing board 117, so that the signal processing board 117 can be prevented from being damaged by compression.

To facilitate the mounting and positioning of the first flange 111, in some embodiments, the first flange 111 is provided with a positioning edge 1111 protruding therefrom, the positioning edge 1111 cooperating with the outer ring 1222. Specifically, the positioning edge 1111 is annular, and is disposed on a side of the first flange 111 facing away from the strain reinforcement beam 116, that is, the strain reinforcement beam 116 and the positioning edge 1111 are located on two sides of the first flange 111. When the first flange 111 is fixedly connected coaxially with the outer ring 1222 of the cross roller bearing 122, the outer wall of the positioning rim 1111 abuts against the inner wall of the outer ring 1222, and the end surface of the first flange 111 facing away from the stiffening beam abuts against the end surface of the outer ring 1222 near the torque sensor 11.

Another aspect of the present application provides a robot including the robot joint module 100 of any of the above embodiments. It can be understood that the robot in the present application may be a cooperative robot, or may be an industrial robot, and the corresponding robot joint module may be a cooperative robot joint module or an industrial robot joint module. The specific structure of the robot joint module 100 is described in detail above, and will not be described herein.

In the description of the present application, a description of the terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, mechanism, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, mechanisms, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.

The foregoing is only the embodiments of the present application, and therefore, the patent scope of the application is not limited thereto, and all equivalent structures or equivalent processes using the descriptions of the present application and the accompanying drawings, or direct or indirect application in other related technical fields, are included in the scope of the application.

Claims (16)

1. A robot joint module comprises a joint output end, a moment sensor and a harmonic reducer, and is characterized in that,

the torque sensor comprises a first flange and a second flange which are coaxially arranged, wherein the first flange surrounds the second flange, and the first flange is fixedly connected with the joint output end;

the harmonic reducer comprises a flexible gear and a crossed roller bearing, the flexible gear comprises a fixed flange, the crossed roller bearing comprises an inner ring and an outer ring, the fixed flange is fixedly connected with the second flange, and the outer ring is fixedly connected with the first flange.

2. The robotic joint module of claim 1, wherein the torque sensor further comprises a fixed end plate, the first flange and the second flange each extending from a first end face of the fixed end plate; wherein,

The moment sensor further comprises a connecting journal and a strain stiffening beam, wherein the connecting journal is used for connecting the first flange and the fixed end plate;

the strain reinforcement beam is secured to the connection journal and is connected to the fixed end plate and the first flange.

3. The robot joint module according to claim 2, wherein a second end surface of the fixed end plate opposite to the first end surface is provided with a protection retainer ring in a protruding manner, and a signal processing board is further fixed on the second end surface.

4. A robotic joint module as claimed in any one of claims 1 to 3, further comprising an oil seal and a sealing slip ring; the seal sliding ring is fixedly sleeved on the second flange, the oil seal comprises an oil seal sleeve, the oil seal sleeve comprises a first end part and a second end part which are oppositely arranged, the first end part is fixed in the inner ring, and the flexible wheel is accommodated in the first end part;

the sealing slip ring is received within the second end portion, and an inner wall of the second end portion is in sliding contact with the sealing slip ring.

5. The robotic joint module of claim 4, further comprising a seal disposed within the flex gear;

The sealing element comprises a connecting flange and an annular sealing tooth part, and the annular sealing tooth part is connected to one side end of the connecting flange;

the harmonic reducer further comprises a wave generator connected with the flexible gear, the wave generator comprises an annular latch part, wherein,

the annular sealing tooth part comprises an annular end face and a tooth groove, and the tooth groove is arranged on the annular end face;

the annular latch part comprises a tooth root and a latch convexly arranged by the tooth root, wherein the latch is accommodated in the tooth slot; wherein,

a first gap is formed between the tooth root and the annular end face, a second gap is formed between the tooth groove and the tooth latch, and the first gap and the second gap are mutually communicated to form a labyrinth passage.

6. The robotic joint module of claim 5, wherein the width of the labyrinth channel is 0.2-1 mm.

7. The robotic joint module of claim 5, wherein the harmonic reducer further comprises a fastening washer and a fastener; wherein,

the fastening gasket is arranged on one side of the connecting flange, which is away from the fixed flange;

the fastening piece comprises a fastening head, the fastening piece fixes the fixing flange, the connecting flange and the second flange, and the fastening head abuts against the fastening gasket.

8. The robotic joint module of claim 7, further comprising a low speed shaft and a seal ring;

the wave generator further comprises an inner hole, the connecting flange is provided with a fixing hole, one end of the low-speed shaft is fixed in the fixing hole, and the other end of the low-speed shaft penetrates through the inner hole;

the sealing ring is sleeved on the low-speed shaft, and the sealing ring is propped against the end face of the fastening gasket and the low-speed shaft.

9. The robot joint module of claim 7, wherein the robot joint module comprises a plurality of robot joints,

the robot joint module further comprises a motor and a low-speed shaft;

the harmonic reducer further comprises a steel wheel, the steel wheel is connected with one end of the inner ring, which is opposite to the oil jacket, and the motor is connected with the steel wheel;

the connecting flange is provided with a fixing hole, the wave generator further comprises an inner hole, one end of the low-speed shaft is fixed in the fixing hole, and the other end of the low-speed shaft penetrates through the inner hole;

the motor comprises a motor output shaft sleeved on the low-speed shaft; wherein,

an oil containing channel is formed among the outer wall of the low-speed shaft, the inner wall of the motor output shaft and the inner wall of the inner hole, and the oil containing channel is communicated with the labyrinth channel.

10. The robotic joint module of claim 9, wherein the oil-receiving channel has a width of 0.2-0.8 mm.

11. The robotic joint module of claim 4, wherein a sealing gasket is further disposed between the first end and the inner ring.

12. The robot joint module of claim 4, wherein the first end portion is provided with an oil seal retainer ring in a protruding manner, and the oil seal retainer ring is abutted against an end surface of the inner ring.

13. The robotic joint module of claim 4, wherein; the oil seal further comprises an oil seal framework, the oil seal framework is fixed in the first end part, and the oil seal framework abuts against the sealing sliding ring.

14. The robotic joint module of claim 4, further comprising a friction pad;

the friction pad is disposed between the opposing end faces of the fixed flange and the second flange.

15. The robotic joint module of claim 4, wherein the oil seal further comprises an elastic sealing ring;

the elastic sealing ring is arranged in the second end part, and the elastic sealing ring abuts against the end face of the sealing sliding ring and the fixing flange.

16. A robot comprising a robot joint module according to any one of claims 1-15.