A crank-connecting rod mechanism capable of automatically adjusting length

Abstract

The present invention discloses a crank-connecting rod mechanism capable of automatically adjusting the length, comprising a crank rod structure and a connecting rod assembly; the crank rod structure comprises a support unit and a motion unit arranged on the support unit, the motion unit comprises a ring gear with internal teeth rotatably mounted on the support unit, a planetary carrier rotatably mounted on the support unit, and a planetary gear with external teeth rotatably mounted on the planetary carrier, and the rotation axis of the ring gear and the rotation axis of the planetary carrier are colinear, and the planetary gear and the inner teeth of the ring gear are meshed with each other. The present invention can automatically adjust the length of the crank rod structure in the crank-connecting rod mechanism, thereby achieving the purpose of enabling the crank-connecting rod mechanism to output a more accurate trajectory.

Description

Technical Field

[0001] The invention relates to a transmission device, in particular to a crank-connecting rod mechanism capable of automatically adjusting the length. Background Art

[0002] At present, robot manufacturing has become a research hotspot, and most of the robots developed need to use a crank-connecting rod mechanism for transmission. However, the length of the crank rod in the traditional crank-connecting rod mechanism cannot be adjusted, or can only be adjusted manually, which not only greatly affects the transmission requirements of the mechanism and makes it impossible for the mechanism to obtain an accurate output trajectory, but also manually adjusting the length increases the workload of the staff and reduces work efficiency.

[0003] Therefore, it is particularly important to develop a crank-connecting rod mechanism that can automatically adjust the length. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a crank-connecting rod mechanism which can automatically adjust the length.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions: a crank-connecting rod mechanism capable of automatically adjusting the length, comprising a crank rod structure and a connecting rod assembly;

[0006] The crank rod structure includes a supporting unit and a moving unit arranged on the supporting unit, the moving unit includes a ring gear with internal teeth rotatably mounted on the supporting unit, a planetary carrier rotatably mounted on the supporting unit, and a planetary gear with external teeth rotatably mounted on the planetary carrier, and the rotating axis of the ring gear and the rotating axis of the planetary carrier are colinear, and the planetary gears are meshed with the internal teeth of the ring gear.

[0007] Furthermore, it also includes a sun gear with external teeth rotatably mounted on the support unit, the rotation axis of the sun gear and the rotation axis of the ring gear are colinear, and the planetary gears are meshed with the sun gear.

[0008] Further, the support unit includes a support frame, on which a first mounting shaft is rotatably mounted, the sun gear is rotatably mounted on the first mounting shaft, and the planetary carrier is fixedly mounted on the first mounting shaft, or the sun gear is fixedly mounted on the first mounting shaft, and the planetary carrier is rotatably mounted on the first mounting shaft.

[0009] Furthermore, the support frame includes two support plates arranged at an interval from each other, a first bearing seat is fixedly installed on the top of the support plate, and the first installation shaft is rotatably installed in the first bearing seat through a bearing.

[0010] Furthermore, a pulley, a sprocket or a gear is fixedly mounted on the first installation shaft to indirectly drive the first installation shaft, or the first installation shaft is directly driven by a motor including a reduction device.

[0011] Furthermore, the annular gear is rotatably mounted on the support unit through the following structure: a side surface of the annular gear is provided with an annular guide rail coaxial with the annular gear, a support block is fixed on the support unit, a guide groove matching the annular guide rail is opened on the support block, and the annular guide rail is inserted into the guide groove.

[0012] Furthermore, a worm is also included, and the ring gear also has external teeth, and the worm is meshed with the external teeth of the ring gear.

[0013] Furthermore, a second mounting shaft is rotatably mounted on the planet carrier, and the planetary gear is fixedly mounted on the second mounting shaft, so that the planetary gear is rotatably mounted on the planet carrier.

[0014] Furthermore, it also includes a motion output unit, which includes a crank, an output shaft and a second bearing seat, one end of the crank is fixedly mounted on the second mounting shaft, the output shaft is fixedly mounted on the other end of the crank, the second bearing seat is rotatably mounted on the output shaft through a bearing, and one end of the connecting rod assembly is fixedly connected to the second bearing seat.

[0015] Furthermore, the output shaft is fixedly mounted on the other end of the crank by the following structure: a circular mounting hole with a notch is opened at the other end of the crank, and the other end of the crank is located at both sides of the notch of the circular mounting hole with clamps extending outward respectively, a disc matching the circular mounting hole is placed in the circular mounting hole, and the clamps on both sides are clamped by clamping bolts to tighten the disc in the circular mounting hole, and the output shaft is eccentrically fixed on the disc.

[0016] The beneficial effects of the present invention are embodied in:

[0017] The present invention can automatically adjust the length of the crank rod structure in the crank-connecting rod mechanism, thereby achieving the purpose of enabling the crank-connecting rod mechanism to output a more accurate trajectory.

[0018] The invention has a simple structure, is easy to manufacture, is economical and practical, is easy to operate, has good functions and is highly practical. It is suitable for use in the connecting rod mechanism of a lower limb rehabilitation robot, etc., outputs a more precise trajectory, simulates a person's precise gait, and helps users recover their health. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of an embodiment of the present invention.

[0020] Figure 2 yes Figure 1 Left view of .

[0021] Figure 3 It is a schematic structural diagram of a support unit and a planet carrier in one embodiment of the present invention.

[0022] Figure 4 and Figure 5 They are schematic diagrams of the structure of the motion output unit in one embodiment of the present invention from different perspectives.

[0023] Figure 6 It is a schematic structural diagram of the first installation shaft in one embodiment of the present invention.

[0024] Figure 7 It is a schematic structural diagram of the second installation shaft in one embodiment of the present invention.

[0025] Figure 8 It is a working principle diagram of an embodiment of the present invention.

[0026] Fig. 9 It is a structural schematic diagram of an embodiment of the present invention without a sun gear.

[0027] Fig.10 It is a working principle diagram of an embodiment of the present invention without a sun gear.

[0028] The components in the accompanying drawings are marked as: 100 crank rod structure, 200 connecting rod assembly, 11 support plate, 12 first bearing seat, 13 first mounting shaft, 14 support block, 141 guide groove, 15 first end cover, 16, 17 flat keys, 21 ring gear, 211 ring guide rail, 22 sun gear, 23 planetary gear, 24 planetary carrier, 25 second mounting shaft, 26 second end cover, 31 crank, 32 output shaft, 33 second bearing seat, 34 disc, 311 circular mounting hole, 312 clamping plate, 313 clamping bolt, 314 tightening bolt, 315, 316 flat keys, 41 pulley, 42 worm. DETAILED DESCRIPTION

[0029] The present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other.

[0030] See below Figures 1 to 7 .

[0031] The crank-connecting rod mechanism capable of automatically adjusting the length of the present invention comprises a crank-rod structure 100 and a connecting rod assembly 200;

[0032] The crank rod structure 100 includes a supporting unit and a moving unit arranged on the supporting unit, the moving unit includes a ring gear 21 with internal teeth rotatably mounted on the supporting unit, a planetary carrier 24 rotatably mounted on the supporting unit, and a planetary gear 23 with external teeth rotatably mounted on the planetary carrier 24, and the rotating axis of the ring gear 21 and the rotating axis of the planetary carrier 24 are colinear, and the planetary gear 23 is meshed with the internal teeth of the ring gear 21.

[0033] In one embodiment, it further comprises a sun gear 22 with external teeth rotatably mounted on the support unit, the rotation axis of the sun gear is colinear with the rotation axis of the ring gear 21, and the planetary gears 23 are also meshed with the sun gear 22. The sun gear can make each component bear force better, the overall structure is more reasonable and stable, and the stability of the mechanism is ensured.

[0034] like Figure 8 As shown, the sun gear is circle I, the planetary gear is circle II, the ring gear is circle III, the center of the first mounting axis is point O, the center of the second mounting axis is point A, BC is the connecting rod assembly, when in use, the planet carrier is driven to rotate, because the planetary gear is meshed with the ring gear and the sun gear, the planetary gear can make circular motion between the ring gear and the sun gear around the rotation axis O of the planet carrier, and can also rotate around its own rotation axis A, and drive the ring gear to rotate at the same time, then the mechanism generates two degrees of freedom, because in a plane, the two degrees of freedom can reach any position, so through different eccentric positions B, and then by changing the speed relationship between the planetary gear and the ring gear, any trajectory can be output in the motion plane, and the connecting rod assembly is hinged at position B, and the crank rod structure is adjusted so that the output trajectory of the crank rod structure is the same as the crank rod length change trajectory required in the crank-connecting rod mechanism, which is equivalent to enabling the crank rod to automatically adjust its length, so that the crank-connecting rod mechanism obtains a more accurate output trajectory.

[0035] In one embodiment, the support unit includes a support frame, on which a first mounting shaft 13 is rotatably mounted, the sun gear 22 is rotatably mounted on the first mounting shaft 13, and the planet carrier 24 is fixedly mounted on the first mounting shaft 13, or the sun gear 22 is fixedly mounted on the first mounting shaft 13, and the planet carrier 24 is rotatably mounted on the first mounting shaft 13. Such a design has a reasonable structure, and is reliable and stable. When in use, the first mounting shaft is driven to rotate by the motor, the first mounting shaft transmits the rotation speed to the planet carrier, and the planet carrier drives the planetary gear to revolve, or the first mounting shaft transmits the rotation speed to the sun gear, and the sun gear drives the planetary gear to revolve.

[0036] Of course, there is a case where there is no sun gear. In this case, for the above-mentioned support frame, the planet carrier 24 is fixedly mounted on the first mounting shaft 13.

[0037] Preferably, in order to facilitate the transmission of drive, a pulley 41, a sprocket or a gear is fixedly mounted on the first installation shaft 13. The pulley, sprocket or gear can be used as a power input mechanism of the mechanism to indirectly drive the first installation shaft. When in use, the motor provides a speed to the pulley to drive the first installation shaft to rotate. The higher the speed, the faster the mechanism runs; or the first installation shaft 13 can be directly driven by a motor with a reduction device.

[0038] More preferably, the pulley 14 is disposed between the two support plates 11 described below, so that the acting force is more reasonable.

[0039] In one embodiment, the annular gear 21 is rotatably mounted on the support unit through the following structure: a side surface of the annular gear 21 is provided with an annular guide rail 211 coaxial with the annular gear 21, a support block 14 is fixed to the support unit, a guide groove 141 matching the annular guide rail 211 is formed on the support block 14, and the annular guide rail 211 is inserted into the guide groove 141. This implementation method has a simple structure, is easy to manufacture and install, does not cause any interference to the movement of the planetary gear, and has very good practicality.

[0040] In one embodiment, a worm 42 is further included, and the ring gear 21 also has external teeth, and the worm 42 meshes with the external teeth of the ring gear 21. The worm also serves as a power input mechanism of the mechanism, and the worm and the ring gear form a worm gear mechanism. When in use, the motor provides a speed to the worm, which can drive the ring gear to rotate, and when the mechanism is stopped, the mechanism can be self-locked, thereby preventing the initial phase of the mechanism from changing.

[0041] In one embodiment, the support frame includes two support plates 11 arranged at intervals from each other, a first bearing seat 12 is fixedly mounted on the top of the support plate 11, and the first installation shaft 13 is rotatably mounted in the first bearing seat 12 via a rolling bearing. This design is simple and reasonable, easy to manufacture and install, and can ensure the stability of the structure and ensure that the first installation shaft rotates stably and smoothly.

[0042] In a specific implementation, the sun gear 22 is also rotatably mounted on the first mounting shaft 13 through a rolling bearing to ensure stable and smooth rotation of the sun gear; preferably, a first end cover 15 is respectively provided on both sides of the first bearing seat 12 on the first mounting shaft 13 and between the planetary carrier 24 and the sun gear 22, so that the structure of the mechanism can be more compact, and the end cover can also increase the sealing of the rolling bearing and the accuracy of the bearing positioning.

[0043] In one embodiment, the planet carrier 24 and the pulley 14 are fixedly mounted on the first mounting shaft 13 by means of a flat key. This fixing method is easy to operate and the mounting is stable and reliable. Specifically, a matching keyway is provided on the first mounting shaft 13, which is connected to the keyways on the pulley and the planet carrier by means of common flat keys 16 and 17, so that the rotation speeds of the first mounting shaft, the planet carrier and the pulley are consistent.

[0044] In one embodiment, the planet carrier 24 is rotatably mounted with a second mounting shaft 25, and the planetary gear 23 is fixedly mounted on the second mounting shaft 25, so that the planetary gear 23 is rotatably mounted on the planet carrier 24. This design has a simple structure and reliable and stable mechanism operation.

[0045] Preferably, the second mounting shaft 25 is rotatably mounted on the planetary carrier 24 via a rolling bearing to ensure stable and smooth rotation of the second mounting shaft; more preferably, second end covers 26 are respectively provided on both sides of the planetary carrier 24 to increase the sealing of the rolling bearing and the accuracy of the bearing positioning.

[0046] In one embodiment, a motion output unit is further included, and the motion output unit includes a crank 31, an output shaft 32, and a second bearing seat 33. One end of the crank 31 is fixedly mounted on the second mounting shaft 25, and the output shaft 32 is fixedly mounted on the other end of the crank 31. The second bearing seat 33 is rotatably mounted on the output shaft 32 through a bearing, and one end of the connecting rod assembly 200 is fixedly connected to the second bearing seat 33. In such a mechanism, since the crank is fixedly mounted on the second mounting shaft, the rotation speeds of the second mounting shaft, the planetary gear, and the crank are consistent, which is equivalent to an integrated motion, and the output shaft is at a certain eccentric position of the planetary gear.

[0047] In one embodiment, the output shaft 32 is fixedly mounted on the other end of the crank 31 by the following structure: a circular mounting hole 311 with a notch is opened at the other end of the crank 31, and the other end of the crank 31 is located on both sides of the notch of the circular mounting hole 311 and has clamps 312 extending outwards respectively, a disc 34 matching the circular mounting hole 311 is placed in the circular mounting hole 311, and the clamps 312 on both sides are clamped by clamping bolts 313, so that the disc 34 is clamped in the circular mounting hole 311, and the output shaft 32 is eccentrically fixed on the disc 34. With this design, the angle of the disc can be adjusted by loosening the clamping bolts, and the position of the output shaft can also be adjusted, so that the position adjustment range of the output shaft is larger, and after the clamping bolts are tightened, the clamping effect is reliable, which can prevent the position of the disc from changing and avoid causing the motion trajectory to change. Preferably, a threaded hole is opened on the disc 34 for fixing the output shaft.

[0048] Preferably, the other end of the crank 31 is further provided with one or more threaded through holes communicating with the circular mounting hole 311 , and the threaded through holes are threadedly connected with tightening bolts 314 for further tightening the disc.

[0049] In one embodiment, one end of the crank 31 is fixedly mounted on the second mounting shaft 25 by a flat key. This fixing method is easy to operate and the installation is stable and reliable. Specifically, two key slots are provided on the second mounting shaft 25, and the planetary gear and the crank are fixedly connected to the second mounting shaft by ordinary flat keys 315 and 316.

[0050] See also Figure 8 , which is a schematic diagram of a sun gear mechanism, where the sun gear is circle I, the planetary gear is circle II, the ring gear is circle III, the center of the first mounting shaft is point O, the center of the second mounting shaft is point A, the center of the output shaft is point B, and BC is a connecting rod assembly. Before using the mechanism, adjust the position of the disc, and then tighten the disc with the clamping bolts, that is, change the distance from point O to point B and the size of ∠OAB. At different eccentric positions B, by changing the speed relationship between the planetary gear and the ring gear, the output component can output any trajectory in the motion plane, thereby achieving the requirement of obtaining an elliptical trajectory that simulates the normal gait of the human lower limbs.

[0051] From the schematic diagram, we can see that the crank rod has four active components, four low pairs and two high pairs. According to the degree of freedom calculation formula F = 3n-2P L -P H , it can be obtained that the degree of freedom of the crank rod is 2.

[0052] See also Fig.10, which is a schematic diagram of a mechanism without a sun gear, in which the ring gear is circle I, the planetary gear is circle II, the center of the first mounting shaft is point O, the center of the second mounting shaft is point A, the center of the output shaft is point B, and BC is a connecting rod assembly. Before using the mechanism, adjust the position of the disc, and then tighten the disc with the clamping bolts, that is, change the distance from point O to point B and the size of ∠OAB. At different eccentric positions B, by changing the speed relationship between the planetary gear and the ring gear, the output component can output any trajectory in the motion plane, thereby achieving the requirement of obtaining an elliptical trajectory that simulates the normal gait of the human lower limbs.

[0053] From the schematic diagram, we can see that the mechanism has three active components, three low pairs and one high pair. According to the degree of freedom calculation formula F = 3n-2P L -P H , we can get that the degree of freedom of the mechanism is 2.

[0054] The present invention can be used in a lower limb rehabilitation robot to convert the crank rod of the connecting rod mechanism in the lower limb rehabilitation robot into the crank of the present invention. When the lower limb rehabilitation robot is used, the crank can change the speed ratio of the pulley and the ring gear to make the output component output any trajectory, so that the crank can automatically adjust the length, that is, the connecting rod mechanism outputs an accurate normal human gait trajectory, which is more conducive to the user's lower limb rehabilitation. In the connecting rod mechanism using the crank that can automatically adjust the length, it can also play a role in amplifying the output trajectory.

[0055] It should be understood that the examples and implementation modes described herein are for illustrative purposes only and are not intended to limit the present invention. Those skilled in the art may make various modifications or changes based on the examples and implementation modes. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A crank-connecting rod mechanism capable of automatically adjusting its length, characterized in that: including a crank rod structure and a connecting rod assembly; The crank rod structure comprises a support unit and a motion unit arranged on the support unit, the motion unit comprises a ring gear (21) with internal teeth rotatably mounted on the support unit, a planet carrier (24) rotatably mounted on the support unit, and a planet gear (23) with external teeth rotatably mounted on the planet carrier (24), wherein the rotation axis of the ring gear (21) and the rotation axis of the planet carrier (24) are colinear, and the internal teeth of the planet gear (23) and the ring gear (21) are meshed with each other; The support unit comprises a support frame, on which a first mounting shaft (13) is rotatably mounted; The mechanism has a case where a sun gear (22) is provided and a case where there is no sun gear (22). In the case where there is a sun gear (22), the sun gear (22) is rotatably mounted on the support unit and has external teeth, the rotation axis of the sun gear (22) and the rotation axis of the ring gear (21) are colinear, the planetary gears (23) and the sun gear (22) are meshed with each other, the sun gear (22) is rotatably mounted on the first mounting shaft (13), and the planetary carrier (24) is fixedly mounted on the first mounting shaft (13), or the sun gear (22) is fixedly mounted on the first mounting shaft (13), and the planetary carrier (24) is rotatably mounted on the first mounting shaft (13); in the case where there is no sun gear (22), the planetary carrier (24) is fixedly mounted on the first mounting shaft (13); The invention also comprises a motion output unit, the motion output unit comprising a crank (31), an output shaft (32) and a second bearing seat (33), the output shaft (32) being fixedly mounted on the other end of the crank (31), the second bearing seat (33) being rotatably mounted on the output shaft (32) via a bearing, and one end of the connecting rod assembly (200) being fixedly connected to the second bearing seat (33); The output shaft (32) is fixedly mounted on the other end of the crank (31) by means of the following structure: a circular mounting hole (311) with a notch is formed at the other end of the crank (31), and clamping plates (312) are respectively extended outwards on both sides of the notch of the circular mounting hole (311) at the other end of the crank (31), a circular disk (34) matching the circular mounting hole (311) is placed in the circular mounting hole (311), and the clamping plates (312) on both sides are clamped by clamping bolts (313) to tighten the circular disk (34) in the circular mounting hole (311), and the output shaft (32) is eccentrically fixed on the circular disk (34).

2. The crank-connecting rod mechanism capable of automatically adjusting length according to claim 1, characterized in that: The support frame comprises two support plates (11) arranged at an interval from each other, a first bearing seat (12) is fixedly mounted on the top of the support plate (11), and the first mounting shaft (13) is rotatably mounted in the first bearing seat (12) via a bearing.

3. The crank-connecting rod mechanism capable of automatically adjusting length according to claim 1, characterized in that: A pulley (41) or a sprocket or a gear is fixedly mounted on the first installation shaft (13) to indirectly drive the first installation shaft (13), or the first installation shaft (13) is directly driven by a motor including a reduction device.

4. The crank-connecting rod mechanism capable of automatically adjusting length according to any one of claims 1 to 3, characterized in that: The annular gear (21) is rotatably mounted on the support unit through the following structure: a side surface of the annular gear (21) is provided with an annular guide rail (211) coaxial with the annular gear (21); a support block (14) is fixed on the support unit; a guide groove (141) matching the annular guide rail (211) is formed on the support block (14); and the annular guide rail (211) is inserted into the guide groove (141).

5. The crank-connecting rod mechanism capable of automatically adjusting length according to any one of claims 1 to 3, characterized in that: It also includes a worm (42), and the ring gear (21) also has external teeth, and the worm (42) and the external teeth of the ring gear (21) are meshed with each other.

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