Linear joint motor assembly, joint assembly and robot
By setting the torque sensor at the head end of the lead screw shaft in the linear joint motor assembly and positioning outside the housing, combining the split structure and the connection mechanism, the problem of induction delay of the torque sensor data is solved, and the effect of high dynamic control is achieved.
Patent Information
- Application Number
- CN202422321066.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-23
- Publication Date
- 2025-08-05
- Estimated Expiration
- 2034-09-23
AI Technical Summary
In the existing linear joint motor components, the data sensing delay problem of the torque sensor affects the implementation of high dynamic control.
The torque sensor is set at the head end of the screw shaft. The torque sensor is located outside the housing when the screw shaft is retracted to the initial position. The torque sensor is connected to the screw shaft through a connecting mechanism. The torque sensor includes a plurality of strain gauges. The sensor sleeve covers the strain gauge. The split structure of the screw shaft is a push rod and a screw, and the connecting mechanism is connected by a fixing member.
The transmission chain of force is short, avoids data sensing delay, and improves fast response and precise control capabilities.
Smart Images
Figure CN223186520U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of motor technology, and in particular to a linear joint motor assembly, a joint assembly and a robot. Background Art
[0002] The linear joint motor assembly includes a linear joint motor and a torque sensor. The linear joint motor pushes the load through the screw shaft. For example, in the field of robotics, the linear joint motor can be used in the robot's legs (thigh or calf) or wrist. By controlling the linear joint motor, the extension and bending of the legs can be precisely controlled, thereby achieving more efficient gait control for more natural and smooth walking or movement. In the landing gear system of an aircraft, the linear joint motor can be used to extend and retract the landing gear. For example, in a missile servo, the linear joint motor can improve the missile's maneuverability and control accuracy.
[0003] In the above applications, the control of the linear shutdown motor needs to be based on the data of the torque sensor. Therefore, how to shorten the transmission chain of the force detected by the torque sensor to avoid data sensing delay and thus facilitate high dynamic control is a technical requirement that needs to be met. Utility Model Content
[0004] The purpose of this application is to disclose a linear joint motor assembly, a joint assembly, and a robot. The linear joint motor assembly has a short transmission chain for detecting force, which can avoid data sensing delay and is conducive to high dynamic control.
[0005] In a first aspect, the present application discloses a linear joint motor assembly. The linear joint motor assembly includes a linear joint motor and a torque sensor. The linear joint motor includes a housing, a screw shaft, a rotor, and a stator, wherein the rotor and the stator are located within the housing; the stator and the rotor cooperate to drive the screw shaft to rotate; the housing includes a housing front end from which the screw shaft extends; the screw shaft includes a screw shaft head end remote from the housing front end. The torque sensor is disposed on the screw shaft to sense the force applied to the screw shaft head end.
[0006] In some embodiments, when the screw shaft is retracted to an initial position, the torque sensor is located outside the housing.
[0007] In some embodiments, the screw shaft includes a push rod having a head end of the screw shaft and a screw driven by the rotor; the screw and the push rod are connected by a connecting mechanism; or, the screw and the push rod are constructed as one piece.
[0008] In some embodiments, the connecting mechanism includes a first socket provided on the push rod, a second socket provided on the lead screw, and a fixing member; the lead screw and the push rod are inserted, and the fixing member passes through the first socket and the second socket to connect the lead screw and the push rod.
[0009] In some embodiments, the screw shaft is provided with a plurality of mounting grooves, and the plurality of mounting grooves are evenly distributed around the circumference of the screw shaft; the torque sensor includes a plurality of strain gauges; and the plurality of strain gauges are located in the mounting grooves in a one-to-one correspondence.
[0010] In some embodiments, the screw shaft includes a receiving groove, and the mounting groove is arranged at the bottom of the receiving groove; the torque sensor includes a sensor sleeve; and the sensor sleeve is arranged in the receiving groove to cover the plurality of strain gauges.
[0011] In some embodiments, the linear joint motor assembly includes a stroke limiter fixed to the screw shaft; when the screw shaft is extended to a maximum stroke, the stroke limiter abuts against the front end of the housing.
[0012] In some embodiments, the linear joint motor assembly includes a bearing mounting member, and the bearing mounting member is integrally constructed with the first end of the screw shaft, or the bearing mounting member is threadedly connected to the first end of the screw shaft.
[0013] In a second aspect, the present application discloses a joint assembly, which includes any one of the aforementioned linear joint motor assemblies.
[0014] In some embodiments, the joint assembly becomes the lower limb of the robot, including a sole and a sole sensor arranged on the sole, and the wiring harness of the torque sensor and the wiring harness of the sole sensor are connected to the same connector.
[0015] In a third aspect, the present application discloses a robot comprising any one of the aforementioned joint assemblies.
[0016] For the above-mentioned linear joint motor assembly, joint assembly, and robot, since the torque sensor is provided on the lead screw shaft, the force transmission chain is the part of the joint connected to the lead screw shaft head end - the lead screw shaft - the torque sensor. Therefore, the force transmission is short, which can avoid data sensing delay and is conducive to high dynamic control (for example, fast response capability and precise control capability). BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 is a schematic diagram of a linear drive device according to an embodiment of the present application;
[0018] Figure 2is a cross-sectional view of a first linear joint motor assembly shown in an embodiment of the present application, illustrating that the lead screw shaft is an integral structure;
[0019] Figure 3 This is a schematic diagram showing an embodiment of the present application in which the screw shaft is in a split structure and a torque sensor is arranged on the push rod. DETAILED DESCRIPTION
[0020] Here, the technical solutions in the embodiments (or "implementations") of the present application will be clearly and completely described in conjunction with the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements.
[0021] If there are terms related to directional indications or positional relationships in the embodiments of this application (such as up, down, left, right, front, back, inside, outside, top, bottom, center, vertical, horizontal, longitudinal, transverse, length, width, counterclockwise, clockwise, axial, radial, circumferential, etc.), such terms are only used to explain the relative positional relationship, movement, etc. between the components in a specific posture (as shown in the accompanying drawings); if the specific posture changes, the directional indication or positional relationship will also change accordingly. In addition, the terms "first" and "second" in the embodiments of this application are only used for the purpose of convenience of description and should not be understood as indicating or implying relative importance.
[0022] Figure 1 A joint assembly 100 is shown schematically, representing a robot's lower limb (also understood as the calf). The joint assembly comprises a linear joint motor assembly 10, a lower limb body 20, and a foot 30. In other embodiments, the joint assembly 100 can also be used in a robot wrist, thigh, aircraft landing gear, or missile servo. Regardless of the joint assembly 100, it includes any of the following linear joint motor assemblies 10.
[0023] See also Figure 2 and Figure 3, the linear joint motor assembly 10 includes a linear joint motor 1 and a torque sensor 2. The linear joint motor 1 includes a housing 11, a screw shaft 12, a rotor 13 and a stator 14. The screw shaft 12 is not limited, for example, it can be a roller screw. The housing 11 includes a front housing 111, a middle housing 112 and a tail housing 113. The front housing 111, the middle housing 112 and the tail housing 113 form a cavity for accommodating the rotor 13 and the stator 14. In an embodiment of the present application, the rotor 13 is a rotor 13 with a screw nut. The rotor 13 can rotate relative to the housing 11 through a bearing assembly 19. When the rotor 13 rotates, the screw shaft 12 can be extended or retracted by the screw nut and the thread on the screw shaft 12, combined with the limiting structure (such as flat position) between the push rod 121 and the front end 110 of the housing. Of course, the extension or retraction of the screw shaft 12 can adopt any structure, which will not be repeated. In addition to driving the screw shaft 12 in the manner shown in the figure, the rotor 13 can also be driven by a planetary gear reduction assembly. In this case, the output of the planetary gear reduction assembly drives the screw shaft 12. The housing 11 includes a housing front end 110 for the screw shaft 12 to extend. The screw shaft 12 includes a screw shaft head end 1211 away from the housing front end 110. Figure 3 and combined Figure 2 The torque sensor 2 is provided on the screw shaft 12 and is used to sense the force from the screw shaft head end 1211 and obtain data. Figure 2 and Figure 3 and combined Figure 1 The first end 1211 of the screw shaft is connected to a bearing mounting part, which is rotatably connected to the lower limb body 20 approximately at the ankle, and the lower limb body 20 is connected to the foot 30. In this way, during walking, the first end 1211 of the screw shaft will be subjected to force and detected by the torque sensor 2.
[0024] As described above, since the torque sensor 2 is arranged on the screw shaft 12, the force transmission chain is the part of the joint connected to the screw shaft head end 1211 (at Figure 1 The sole of the foot is in the middle) - screw shaft 12 - torque sensor 2, so the force transmission is short, which can avoid data sensing delay and is conducive to high dynamic control (for example, fast response capability and precise control capability).
[0025] When the screw shaft 12 is retracted to its initial position, the torque sensor 2 is located outside the housing 11. In this way, during the process of the screw shaft 12 extending from the initial position to the maximum stroke, or during the process of retracting from the maximum stroke to the initial position, the torque sensor 2 moves outside the housing 11. Figure 2It illustrates that when the screw shaft 12 moves from the initial position to the maximum stroke, the torque sensor 2 is located outside the housing 11. Based on this illustration, technicians can deduce that in the initial position, the torque sensor 2 is located outside the housing 11.
[0026] As set up above, since the screw shaft 12 is retracted to its initial position, the torque sensor 2 is located outside the housing 11, that is, the torque sensor 2 is not inside the housing 11 during the movement of the screw shaft 12, thereby avoiding the interference generated by the friction between the front end 110 of the housing and the screw shaft 12 on the force collection of the torque sensor 2, and the data of the torque sensor 2 is more accurate.
[0027] See also Figure 3 The screw shaft 12 includes a push rod 121 having a screw shaft head end 1211 and a screw 122. Figure 2 The screw 122 is driven by the rotor 13 of the linear joint motor 1, thereby extending or retracting the screw shaft 12. Figure 3 The lead screw 122 and the push rod 121 are connected by a connecting mechanism, and the connecting mechanism is not limited to the structure described below. Figure 2 The lead screw 122 and the push rod 121 are integrally constructed.
[0028] As described above, the screw shaft 12 is a split structure including a push rod 121 and a screw 122. The push rod 121 and the screw 122 can be processed separately, thereby reducing processing costs and increasing processing precision. Because the screw shaft 12 is an integrated structure, the length is too long, which increases the processing difficulty. The distance between the ejector pin holes is too long, and during grinding, the coaxiality of the screw and the form and position tolerances of the thread cannot be guaranteed. By splitting the screw shaft 12 into the push rod 121 and the screw 122, they can be processed separately to ensure processing precision and ease of processing. Furthermore, after splitting into the push rod 121 and the screw 122, the screw manufacturer can only process the screw 122, and the sensor manufacturer only needs to process the push rod and the sensor. Each manufacturer can focus on their respective areas of expertise and ensure precision and production efficiency. For example, this helps with the mass production of screws and the mass production of assemblies consisting of push rods and torque sensors.
[0029] See also Figure 3 The connecting mechanism includes a first socket provided on the push rod 121, a second socket provided on the lead screw 122, and a fixing member 123; the lead screw 122 is inserted into the push rod 121, and the fixing member 123 passes through the first and second sockets to connect the lead screw 122 and the push rod 121. Figure 3 The first and second jacks are not shown in FIG. Figure 3The assembly state of the fixing member 123, the push rod 121, and the lead screw 122 shown in the figure can undoubtedly infer the structure of the first and second receptacles. Based on the function of the fixing member 123, the structure of the fixing member 123 is not limited, as long as it can connect the push rod 121 and the lead screw 122, and is not limited to the pin shown in the figure.
[0030] As described above, the fixing member 123 passes through the first insertion hole and the second insertion hole to connect the lead screw 122 and the push rod 121 , and the difficulty of assembling the push rod 121 and the lead screw 122 is low.
[0031] See also Figure 3 The screw shaft 12 is provided with a plurality of mounting grooves. The mounting grooves are evenly distributed around the circumference of the screw shaft 12. Figure 3 The strain gauges 21 are evenly distributed around the circumference of the push rod 121. The torque sensor 2 includes a plurality of strain gauges 21. The plurality of strain gauges 21 are located in the mounting groove in a one-to-one correspondence.
[0032] As described above, since multiple strain gauges 21 are located one-to-one in the mounting groove 1221 of the screw shaft 12, the strain gauges 21 are set inside the push rod 121, the push rod 121 has a beautiful appearance, and the number of parts of the linear joint motor assembly 10 is reduced.
[0033] Continue reading Figure 3 and combined Figure 2 The screw shaft 12 includes a receiving groove 1222. The mounting groove is provided at the bottom of the receiving groove 1222. The torque sensor 2 includes a sensor sleeve 22. The sensor sleeve 22 is sleeved on the receiving groove 1222 to cover the plurality of strain gauges 21. Figure 3 and Figure 2 In the variation of the torque sensor installation method shown, when the sensor sleeve 22 is not included, the accommodating groove 1222 is not provided, and the installation groove is directly formed on the screw shaft 12 .
[0034] As described above, the sensor sleeve 22 is sleeved on the receiving groove 1222 to cover the plurality of strain gauges 21, which not only protects the strain gauges 21 but also makes the appearance of the push rod 121 beautiful. For example, from the appearance, it is no different from an ordinary push rod.
[0035] See also Figure 2 The linear joint motor assembly 10 includes a stroke limiter 16. The stroke limiter 16 is fixed to the screw shaft 12. When the screw shaft 12 moves linearly to a maximum stroke, the stroke limiter 16 abuts against the front end 110 of the housing.
[0036] As described above, the screw shaft 12 is limited by the stroke limiter 16 , and the stroke of the screw shaft 12 is limited by a simple structure, which does not increase the complexity of the structure of the linear joint motor assembly 10 .
[0037] See also Figure 3 The linear joint motor assembly 10 includes a bearing mounting member 3, the bearing mounting member 3 and the lead screw shaft head end 1211 are integrally constructed, or, see Figure 2 The bearing mounting member 3 is threadedly connected to the lead screw shaft head end 1211. The bearing mounting member 3 is used to mount a bearing, such as a ball bearing.
[0038] As described above, by threaded connection or integral structure, it is easy to simply and conveniently connect the bearing mounting member 3. In comparison, the bearing mounting member 3 is integrally constructed with the lead screw shaft head end 1211, which is more convenient to manufacture and does not require installation steps.
[0039] In a second aspect, the present application discloses a joint assembly. The joint assembly includes any of the aforementioned linear joint motor assemblies. As previously described, the joint assembly can be a robot's lower limb (such as a calf), thigh, or wrist, or it can also be an aircraft landing gear or missile servo, etc.
[0040] See also Figure 1 and combined Figure 3 In some embodiments, the joint assembly becomes the lower limb of the robot, including the sole of the foot 30 and a sole sensor (not shown in the figure) arranged on the sole of the foot, and the wiring harness of the torque sensor 2 and the wiring harness of the sole sensor are connected to the same connector. Figure 3 FIG. 2 simply illustrates the routing of the wiring harness 23 of the torque sensor 2 .
[0041] As described above, the wiring harness 23 of the torque sensor 2 and the wiring harness of the sole sensor are converged into the same connector, so that the wiring harness of the torque sensor 2 and the wiring harness of the sole sensor can be better managed and routed.
[0042] In a third aspect, the present application discloses a robot. The robot includes any of the aforementioned joint assemblies. The robot includes a humanoid robot, a robot dog, and the like.
[0043] It should be noted that the technical solutions or technical features described in the above embodiments can be combined or supplemented with each other without conflict. The scope of protection of this application is not limited to the precise structures described in the above embodiments and shown in the accompanying drawings; all modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of this application shall be included in the scope of protection of this application.
Claims
1. A linear joint motor assembly, characterized in that: The linear joint motor assembly includes a linear joint motor and a torque sensor, wherein: The linear joint motor includes a housing, a screw shaft, a rotor and a stator, wherein the rotor and the stator are located in the housing; the stator and the rotor cooperate to drive the screw shaft to move; the housing includes a housing front end for the screw shaft to extend; the screw shaft includes a screw shaft head end away from the housing front end; The torque sensor is arranged on the screw shaft and is used to sense the force from the head end of the screw shaft.
2. The linear joint motor assembly according to claim 1, characterized in that: When the lead screw shaft is retracted to an initial position, the torque sensor is located outside the housing.
3. The linear joint motor assembly according to claim 1, characterized in that: The screw shaft includes a push rod having a head end of the screw shaft and a screw driven by the rotor; the screw and the push rod are connected by a connecting mechanism; or, the screw and the push rod are constructed as one piece.
4. The linear joint motor assembly according to claim 3, characterized in that: The connecting mechanism includes a first socket provided on the push rod, a second socket provided on the lead screw, and a fixing member; the lead screw and the push rod are inserted, and the fixing member passes through the first socket and the second socket to connect the lead screw and the push rod.
5. The linear joint motor assembly according to claim 1, characterized in that: The screw shaft is provided with a plurality of mounting grooves, and the plurality of mounting grooves are evenly distributed around the circumference of the screw shaft; the torque sensor includes a plurality of strain gauges; and the plurality of strain gauges are located in the mounting grooves in a one-to-one correspondence.
6. The linear joint motor assembly according to claim 5, characterized in that: The screw shaft includes a receiving groove, and the mounting groove is arranged at the bottom of the receiving groove; the torque sensor includes a sensor sleeve; the sensor sleeve is arranged in the receiving groove to cover the plurality of strain gauges.
7. The linear joint motor assembly according to claim 1, characterized in that: The linear joint motor assembly includes a stroke limiter, which is fixed to the screw shaft; when the screw shaft extends to a maximum stroke, the stroke limiter abuts against the front end of the housing.
8. The linear joint motor assembly according to claim 1, characterized in that: The linear joint motor assembly includes a bearing mounting member, which is integrally constructed with the first end of the lead screw shaft, or the bearing mounting member is threadedly connected to the first end of the lead screw shaft.
9. A joint assembly, characterized in that: A linear joint motor assembly comprising any one of claims 1 to 8.
10. The joint assembly according to claim 9, characterized in that: The joint assembly forms the lower limb of the robot, including a sole and a sole sensor arranged on the sole. The wiring harness of the torque sensor and the wiring harness of the sole sensor are connected to the same connector.
11. A robot, characterized in that: The robot comprises the joint assembly according to claim 9 or 10.