A coaxial dual-output transmission mechanism

Abstract

The present invention discloses a coaxial dual-output transmission mechanism, which belongs to the technical field of transmission devices. The mechanism comprises an active drive shaft and an auxiliary drive shaft, both of which extend out of a housing and a power output end of the housing. The auxiliary drive shaft is a hollow structure and is coaxially sleeved outside the active drive shaft. A worm gear is arranged at the power input end of the auxiliary drive shaft, a worm matched with the worm gear is arranged on the housing, a conical protrusion is arranged on the auxiliary drive shaft, a conical groove matched with the conical protrusion is arranged on the worm wheel, a clamping mechanism for clamping the worm gear against the conical protrusion from the axial direction is arranged on the auxiliary drive shaft; the auxiliary drive shaft and the worm wheel are matched through the conical groove and the conical protrusion to transmit torque. Compared with the flat key connection method, the mechanism has not only a simple structure, but also the auxiliary drive shaft does not need to be machined with a keyway, which can greatly reduce the wall thickness of the auxiliary drive shaft, thereby reducing the weight of the overall force transmission mechanism, providing operability for the weight of the inspection robot, and the conical surface matching method makes the force more uniform and is easy to process and form.

Description

Technical Field

[0001] This invention relates to the field of transmission technology, and in particular to a coaxial dual-output transmission mechanism. Background Art

[0002] With the continuous development of smart grids, increasingly higher requirements have been placed on the inspection of transmission lines, leading to the emergence and vigorous development of transmission line inspection robots. Domestic transmission line inspection robots are mainly divided into dual-arm and single-arm types. Typically, the walking and clamping mechanisms of these robots employ a dual-axis output, parallel-layout force transmission mechanism for drive. However, this layout is not only structurally complex but also bulky, hindering weight control and placing a burden on the lines during inspections.

[0003] Therefore, a coaxial dual-output force transmission mechanism has gradually emerged in the market. For example, the utility model patent with patent number "201620749212.4" and patent name "Dual Input Output Gearbox" discloses a dual input output force transmission mechanism used between the prime mover and the working machine. It can also be used in power line inspection robots. It includes a housing, an input shaft, a transmission mechanism, and an output shaft. The input shaft includes a main transmission input shaft and a driven transmission input shaft. The output shaft includes a main transmission output shaft and a driven transmission output sleeve that rotate independently on the same axis. The driven transmission output sleeve is sleeved outside the main transmission output shaft. The transmission mechanism is divided into a main transmission mechanism that connects the main transmission input shaft and the main transmission output shaft, and a driven transmission mechanism that connects the driven transmission input shaft and the driven transmission output sleeve. The main transmission mechanism includes a bevel gear driving wheel connected to the main transmission input shaft and a bevel gear driven wheel that meshes with the bevel gear driving wheel. The bevel gear driven wheel is connected to the main transmission output shaft. The driven transmission mechanism includes a worm gear connected to the driven transmission input shaft. The aforementioned patent transforms the original two parallel solid dual shafts into a single force transmission shaft coaxially arranged with a hollow shaft and a solid shaft. This arrangement centralizes the drive components, facilitating both overall robot layout and wiring, and simplifying the structure. Consequently, it reduces the volume and weight of the output shaft, thereby lowering the overall weight of the force transmission mechanism. Patents with numbers "201921376093.2" and "201720641705.0" disclose this structure. However, in both these patents and existing force transmission mechanisms, the drive input shaft and worm gear are connected using a flat key connection. This requires machining a keyway on the drive input shaft, which necessitates a certain wall thickness. This limits the wall thickness of the drive input shaft, making it difficult to further reduce the overall weight of the force transmission mechanism. Summary of the Invention

[0004] The purpose of this invention is to solve the above-mentioned technical problems and provide a coaxial dual-output transmission mechanism. The auxiliary drive shaft and the worm gear transmit torque through a tapered groove and a tapered protrusion. Compared with the flat key connection method, it is not only simple in structure, but also eliminates the need to machine the keyway of the auxiliary drive shaft, which can significantly reduce the wall thickness of the auxiliary drive shaft and thus reduce the weight of the overall force transmission mechanism. This provides the possibility for further reducing the weight of the inspection robot. Moreover, the tapered surface fit makes the force more uniform and facilitates the processing and forming.

[0005] To achieve the above objectives, the present invention provides the following solution: The present invention provides a coaxial dual-output transmission mechanism, including a housing, an active drive shaft and an auxiliary drive shaft, both of which have their power output ends extending from the housing. The auxiliary drive shaft is a hollow structure and is coaxially sleeved outside the active drive shaft. The power input end of the auxiliary drive shaft is provided with a worm gear. The housing is provided with a worm that cooperates with the worm gear. The auxiliary drive shaft is provided with a conical protrusion. The worm gear is provided with a conical groove that cooperates with the conical protrusion. The auxiliary drive shaft is provided with a clamping mechanism that presses the worm gear against the conical protrusion from the axial direction.

[0006] Preferably, the diameter of the tapered protrusion gradually decreases from the power output end to the power input end of the auxiliary drive shaft. The clamping mechanism includes a bearing nut threadedly connected to the power input end of the auxiliary drive shaft. A clamping ring and a first bearing are sequentially sleeved on the auxiliary drive shaft between the worm gear and the bearing nut. The auxiliary drive shaft is rotatably connected to the housing through the first bearing.

[0007] Preferably, the inner wall of the housing is provided with a first limiting boss that restricts the movement of the first bearing toward the power output end of the auxiliary drive shaft.

[0008] Preferably, a second bearing is provided between the housing and the auxiliary drive shaft. The second bearing is located between the output end of the auxiliary drive shaft and the tapered protrusion. A second limiting boss is provided on the inner wall of the housing to restrict the movement of the second bearing toward the power input end of the auxiliary drive shaft.

[0009] Preferably, the power output end of the auxiliary drive shaft is provided with an auxiliary drive pulley, and an annular positioning block is provided between the auxiliary drive pulley and the second bearing.

[0010] Preferably, a first flanged oil-free bushing and a second flanged oil-free bushing are provided between the auxiliary drive shaft and the active drive shaft. The input end of the auxiliary drive shaft abuts against the inner flanged surface of the flanged edge of the first flanged oil-free bushing, and the output end of the auxiliary drive shaft abuts against the inner flanged surface of the flanged edge of the second flanged oil-free bushing.

[0011] Preferably, the power input end and power output end of the active drive shaft are respectively provided with a first limiting protrusion and a second limiting protrusion. The first limiting protrusion abuts against the outer surface of the first flanged oilless bushing flange, and an active drive pulley is provided between the second limiting protrusion and the outer surface of the second flanged oilless bushing flange.

[0012] Preferably, the housing is provided with a walking drive motor connecting frame, and the walking drive motor connecting frame is provided with a first through hole for connecting the power input end of the active drive shaft to the output shaft of the walking drive motor.

[0013] Preferably, the housing is provided with an auxiliary drive motor connecting bracket, and the auxiliary drive motor connecting bracket is provided with a second through hole for connecting the worm gear and the auxiliary drive motor.

[0014] Preferably, the worm gear is rotatably connected to the housing via a third bearing, and a bearing end cap is provided on the housing on the other side of the auxiliary drive motor connecting frame.

[0015] The present invention achieves the following technical effects compared to the prior art:

[0016] 1. The coaxial dual-output transmission mechanism proposed in this invention has two independent and coaxially arranged transmission systems. The active drive shaft and the auxiliary drive shaft are used to drive the walking mechanism and the auxiliary clamping mechanism of the power transmission line inspection robot, respectively. This arrangement concentrates the drive parts, which not only facilitates the overall layout and wiring of the robot, but also simplifies the structure, reduces the volume and weight of the output shaft, and reduces the weight of the overall force transmission mechanism. The auxiliary drive shaft and the worm gear transmit torque through the cooperation of the conical groove and the conical protrusion. Compared with the flat key connection, it is not only simple in structure, but also does not require the auxiliary drive shaft to be machined with a keyway, realizing the keyless connection function, which greatly reduces the wall thickness of the auxiliary drive shaft, thereby reducing the weight of the overall force transmission mechanism, providing operability for the inspection robot, and the conical surface cooperation makes the force more uniform and easy to process and form.

[0017] 2. In this invention, the preload torque of the tapered engagement between the worm gear and the auxiliary drive shaft is provided by the bearing nut. Compared with the keyless bushing, it has the advantages of small size and compact structure, which makes it possible to further reduce weight. Moreover, the assembly and disassembly are relatively simple, which is beneficial for maintenance and replacement of worn parts.

[0018] 3. In this invention, the active drive shaft is supported by a flanged oil-free bushing, which has the advantages of simple structure and small size. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of a coaxial dual-output transmission mechanism.

[0021] Figure 2 This is a longitudinal sectional view of a coaxial dual-output transmission mechanism;

[0022] Figure 3 This is a cross-sectional view of a coaxial dual-output transmission mechanism.

[0023] Explanation of reference numerals in the attached drawings: 1. Housing; 2. Active drive shaft; 3. Auxiliary drive shaft; 4. Worm gear; 5. Worm; 6. Conical protrusion; 7. Bearing nut; 8. Pressure ring; 9. First bearing; 10. First limiting boss; 11. Second bearing; 12. Second limiting boss; 13. Auxiliary drive pulley; 14. Annular positioning block; 15. First flanged oil-free bushing; 16. Second flanged oil-free bushing; 17. First limiting protrusion; 18. Second limiting protrusion; 19. Active drive pulley; 20. Travel drive motor connecting frame; 21. First through hole; 22. Auxiliary drive motor connecting frame; 23. Second through hole; 24. Bearing end cap; 25. Third limiting boss; 26. Fourth limiting boss; 27. Third bearing. Detailed Implementation

[0024] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0025] This embodiment provides a coaxial dual-output transmission mechanism, such as Figures 1 to 3As shown, the system includes a housing 1, an active drive shaft 2, and an auxiliary drive shaft 3. Both the active drive shaft 2 and the auxiliary drive shaft 3 are located inside the housing 1. The auxiliary drive shaft 3 is a hollow structure and is sleeved outside the active drive shaft 2. The active drive shaft 2 and the auxiliary drive shaft 3 are used to drive the walking mechanism and auxiliary clamping mechanism of the inspection robot, respectively. The power output ends of both the active drive shaft 2 and the auxiliary drive shaft 3 extend out of the housing 1. The power input end of the auxiliary drive shaft 3, which is used to connect to the auxiliary drive motor, is equipped with a worm gear 4. The housing 1 is equipped with a worm 5, which is perpendicular to the axis of the auxiliary drive shaft 3. The worm gear transmission structure composed of the worm gear 4 and the worm 5 has good mechanical self-locking capability, which can provide good safety protection for the auxiliary clamping mechanism of the power transmission line inspection robot without the need for an additional locking mechanism, thereby reducing energy consumption. The auxiliary drive shaft 3 has a conical protrusion 6 on its outer wall, and the worm gear 4 has a conical groove that mates with the conical protrusion 6. The auxiliary drive shaft 3 also has a clamping mechanism that can press the worm gear 4 axially onto the conical protrusion 6. The worm gear 4 and the auxiliary drive shaft 3 transmit torque through the conical groove and the conical protrusion 6. Compared with the flat key connection, this method is not only simpler in structure, but also eliminates the need to machine a keyway for the auxiliary drive shaft 3, which can significantly reduce the wall thickness of the auxiliary drive shaft 3, thereby reducing the weight of the overall force transmission mechanism and improving the operability of the inspection robot. Furthermore, the conical surface mating method makes the force distribution more uniform and facilitates machining.

[0026] Furthermore, in this embodiment, as Figures 1 to 3As shown, the diameter of the conical protrusion 6 gradually decreases from the power output end to the power input end of the auxiliary drive shaft 3. The clamping mechanism includes a clamping ring 8, a first bearing 9, and a bearing nut 7. The bearing nut 7 is threadedly connected to the power input end of the auxiliary drive shaft 3. The clamping ring 8 and the first bearing 9 are sequentially arranged between the worm gear 4 and the bearing nut 7. The auxiliary drive shaft 3 and the housing 1 are rotatably connected through the first bearing 9. During installation, the worm gear 4 is first inserted from the power input end of the auxiliary drive shaft 3 and moved from the small diameter end to the large diameter end of the conical protrusion 6 until the conical groove in the middle of the worm gear 4 and the conical protrusion 6 are wedged together. Then, the clamping ring 8 and the first bearing 9 are sequentially inserted from the power input end of the auxiliary drive shaft 3. Finally, the bearing nut 7 is screwed into the power input end of the auxiliary drive shaft 3. As the bearing nut 7 is screwed, the first bearing 9 presses the clamping ring 8 against the side of the worm gear 4. The bearing nut 7 provides an axial preload torque to the worm gear 4, ensuring the stability of the worm gear 4. By selecting worm gears 4 with different widths and tapered grooves, the axial position of the worm gear on the auxiliary drive shaft 3 can be changed, thereby adjusting the axial position of the worm gear 4 in the entire transmission system. This ensures the fitting accuracy between the worm gear 4 and the worm 5. The width of the corresponding clamping ring 8 is selected according to the different worm gears 4 to ensure that each specification of worm gear 4 can be stably installed on the tapered protrusion 6. The first bearing 9 adopts an angular contact ball bearing, preferably a double-row angular contact ball bearing, which can withstand both radial and axial forces.

[0027] Furthermore, in this embodiment, as Figures 1 to 3 As shown, a first limiting boss 10 is provided on the inner wall of the outer casing 1. The first limiting boss 10 can prevent the first bearing 9 from moving toward the power output end of the auxiliary drive shaft 3.

[0028] In this embodiment, Figures 1 to 3 As shown, a second bearing 11 is also provided between the outer casing 1 and the auxiliary drive shaft 3. The second bearing 11 is located between the output end of the auxiliary drive shaft 3 and the tapered protrusion 6. A second limiting boss 12 is provided on the inner wall of the outer casing 1 to restrict the movement of the second bearing 11 toward the power input end of the auxiliary drive shaft 3. Preferably, the second bearing 11 is a deep groove ball bearing to withstand the radial force of the auxiliary drive shaft.

[0029] Furthermore, in this embodiment, as Figures 1 to 3 As shown, the power output end of the auxiliary drive shaft 3 is equipped with an auxiliary drive pulley 13, which is connected to the auxiliary clamping mechanism of the inspection robot. Of course, it can be replaced with other transmission structures, such as sprockets or gears, according to different usage requirements. An annular positioning block 14 is provided between the auxiliary drive pulley 13 and the second bearing 11, which presses the second bearing 11 onto the second limiting boss 12.

[0030] In this embodiment, Figures 1 to 3As shown, a first flanged oilless bushing 15 and a second flanged oilless bushing 16 are provided between the auxiliary drive shaft 3 and the active drive shaft 2. After the auxiliary drive shaft 3 is fitted onto the first flanged oilless bushing 15 and the second flanged oilless bushing 16, the input end of the auxiliary drive shaft 3 abuts against the inner flanged surface of the flange of the first flanged oilless bushing 15, and the output end of the auxiliary drive shaft 3 abuts against the inner flanged surface of the flange of the second flanged oilless bushing 16. The arrangement of the first flanged oilless bushing 15 and the second flanged oilless bushing 16 can effectively reduce the volume of the output shaft system, and has the characteristics of simple layout and compact structure.

[0031] In this embodiment, Figures 1 to 3 As shown, the power input end and power output end of the active drive shaft 2 are respectively provided with a first limiting protrusion 17 and a second limiting protrusion 18. The first limiting protrusion 17 abuts against the outer surface of the flange of the first flanged oilless bushing 15. An active drive pulley 19 is provided between the second limiting protrusion 18 and the outer surface of the flange of the second flanged oilless bushing 16. One side of the active drive pulley 19 abuts against the second limiting protrusion 18, and the other side abuts against the outer surface of the flange of the second flanged oilless bushing 16. The active drive pulley 19 is used to connect with the walking mechanism of the inspection robot. Of course, it can be replaced with other transmission mechanisms such as sprockets and gears according to the actual structure of the robot, which has the advantage of strong versatility.

[0032] In this embodiment, Figures 1 to 3 As shown, a drive motor connecting frame 20 is provided on the end of the outer casing 1. The drive motor connecting frame 20 is threadedly connected to the outer casing 1 by bolts. A third limiting boss 25 is provided on the end of the drive motor connecting frame 20. The third limiting boss 25 presses against the first bearing 9. A first through hole 21 is provided in the middle of the drive motor connecting frame 20. The output shaft of the drive motor can be coaxially connected to the power input end of the drive shaft 2 through the first through hole 21.

[0033] In this embodiment, Figures 1 to 3 As shown, an auxiliary drive motor connecting bracket 22 is provided on one side of the housing 1. A second through hole 23 is provided in the middle of the auxiliary drive motor connecting bracket 22. The output shaft of the auxiliary drive motor is connected to the worm 5 through the second through hole 23. The worm 5 is coaxially connected to the output shaft of the auxiliary drive motor by means of a flat key. It has the characteristics of strong versatility and can be applied to most motors.

[0034] Furthermore, in this embodiment, as Figures 1 to 3As shown, the worm gear 5 is rotatably connected to the housing 1 via two third bearings 27, both of which are angular contact ball bearings. A fourth limiting boss 26 is provided on one side of the housing 1 that connects to the auxiliary drive motor connecting frame 22, and one of the third bearings 27 is tightly fitted onto the fourth limiting boss 26. A bearing end cap 24 is provided on the other side of the housing 1 that connects to the auxiliary drive motor connecting frame 22, and the bearing end cap 24 presses against the other third bearing 27.

[0035] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A coaxial dual-output transmission mechanism, comprising a housing, an active drive shaft and an auxiliary drive shaft, both power output ends of which extend out of the housing, the auxiliary drive shaft being a hollow structure and coaxially sleeved outside the active drive shaft, a worm gear being provided at the power input end of the auxiliary drive shaft, and a worm gear matched with the worm gear being provided on the housing, characterized in that: The auxiliary drive shaft is provided with a conical protrusion, the worm wheel is provided with a conical groove that cooperates with the conical protrusion, the auxiliary drive shaft is provided with a clamping mechanism that presses the worm wheel onto the conical protrusion from the axial direction, a second bearing is also provided between the housing and the auxiliary drive shaft, a first flanged oil-free bushing and a second flanged oil-free bushing are provided between the auxiliary drive shaft and the active drive shaft, the input end of the auxiliary drive shaft abuts against the inner turning surface of the flange of the first flanged oil-free bushing, the output end of the auxiliary drive shaft abuts against the inner turning surface of the flange of the second flanged oil-free bushing, an auxiliary drive pulley is provided at the power output end of the auxiliary drive shaft, an annular positioning block is provided between the auxiliary drive pulley and the second bearing, the power input end and the power output end of the active drive shaft are respectively provided with a first limiting protrusion and a second limiting protrusion, the first limiting protrusion abuts against the outer turning surface of the flange of the first flanged oil-free bushing, and an active drive pulley is provided between the second limiting protrusion and the outer turning surface of the flange of the second flanged oil-free bushing.

2. A coaxial dual-output transmission mechanism according to claim 1, characterized in that: The diameter of the conical protrusion gradually decreases from the power output end to the power input end of the auxiliary drive shaft. The clamping mechanism includes a bearing nut threadedly connected to the power input end of the auxiliary drive shaft. A clamping ring and a first bearing are sequentially sleeved on the auxiliary drive shaft between the worm gear and the bearing nut. The auxiliary drive shaft is rotatably connected to the outer casing through the first bearing.

3. A coaxial dual-output transmission mechanism according to claim 2, characterized in that: A first limiting boss for limiting the movement of the first bearing toward the power output end of the auxiliary drive shaft is provided on the inner wall of the housing.

4. A coaxial dual-output transmission mechanism according to claim 3, characterized in that: The second bearing is located between the output end of the auxiliary drive shaft and the conical protrusion, and a second limiting boss for limiting the movement of the second bearing toward the power input end of the auxiliary drive shaft is provided on the inner wall of the housing.

5. The coaxial dual-output transmission mechanism according to claim 1, characterized in that: The outer shell is provided with a travel drive motor connecting frame, and the travel drive motor connecting frame is provided with a first through hole for connecting the power input end of the active drive shaft with the output shaft of the travel drive motor.

6. A coaxial dual-output transmission mechanism according to claim 5, characterized in that: An auxiliary drive motor connecting frame is arranged on the shell, and a second through hole for connecting the worm and the auxiliary drive motor is arranged on the auxiliary drive motor connecting frame.

7. A coaxial dual-output transmission mechanism according to claim 6, characterized in that: The worm is rotatably connected to the housing via a third bearing, and a bearing end cover is provided on the housing on the other side of the auxiliary drive motor connecting frame.

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