Adjusting structure for hypoid gear gap of welding robot

Abstract

The application discloses a kind of for welding robot's hypoid gear gap adjusting structure, including body, sealing tube, big hypoid gear, small hypoid gear and output flange;Output flange is rotatably installed in the one side opening of installation cavity by first bearing, one end of big hypoid gear is connected to one end of output flange by screw thread, big hypoid gear is set to be axially adjustable displacement, sealing tube is rotatably installed in the other side opening of installation cavity by skeleton oil seal, one end of sealing tube is fixedly connected to the other end of big hypoid gear by bolt;Small hypoid gear is rotatably installed in body by second bearing, one end of small hypoid gear is inserted into installation cavity and engaged with big hypoid gear;By this, it can adjust the gap between big and small hypoid gears within reasonable gap range, compact structure, simple installation, improve transmission accuracy, convenient maintenance.

Description

Technical Field

[0001] This invention relates to the field of robotics, and in particular to an adjustment structure for the backlash of a quasi-hyperboloid gear used in a welding robot. Background Technology

[0002] Currently, more and more welding robots are using hypoid gears. The assembly of existing hypoid gears can only rely on machining to ensure the reasonable clearance of the product. The machining accuracy of the product affects the assembly and transmission accuracy. After running for a period of time, the hypoid gears will generate gaps due to the friction between the two gears, which will reduce the transmission accuracy. In some cases, mechanical wear will occur after long-term operation, and the gaps will become larger and larger. Repeatedly adding shims to test assembly and adjust will consume a lot of time and cost, affecting the service life of the robot.

[0003] Existing patent CN206967521U discloses a structure for adjusting the backlash of a gear in the wrist of an industrial robot. Under the premise of fixing the drive gear, the axial movement of the large gear is achieved by adjusting the preload of the bolts to control the compression of the disc spring that engages with the quasi-hyperboloid gear, thereby eliminating interference or backlash during gear meshing. This method achieves the function of adjusting gear backlash to a certain extent. However, since the disc spring is an elastic element, its axial elastic deformation varies depending on the preload and feed rate of the bolts in different directions. Long-term compression of the disc spring will lead to its failure, resulting in a slight misalignment between the end face of the quasi-hyperboloid gear and the axis of the drive gear. This causes periodic wear during gear transmission, reducing transmission accuracy and shortening the gear's lifespan over time. Furthermore, this structure is not a single-sided sleeve or modular design. The number of modular parts engaging on both sides of the five-axis wrist is relatively large, and the requirements for coaxiality are higher, making installation more difficult. It also poses challenges for later maintenance, repair, and parts disassembly and replacement.

[0004] Therefore, a new technology needs to be developed to solve the above problems. Summary of the Invention

[0005] In view of this, the present invention addresses the deficiencies of the existing technology, and its main objective is to provide an adjustment structure for the clearance of quasi-hyperboloid gears for welding robots. This structure can adjust the clearance between large and small quasi-hyperboloid gears within a reasonable clearance range, and features a compact structure, simple installation, improved transmission accuracy, and convenient maintenance.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] An adjustment structure for the backlash of a hypoid gear in a welding robot includes a body, a sealing tube, a large hypoid gear, a small hypoid gear, and an output flange.

[0008] The main body has a mounting cavity with openings at both ends. The output flange is rotatably mounted in one opening of the mounting cavity via a first bearing. The large hypoid gear is rotatably mounted in the mounting cavity, with one end of the large hypoid gear connected to one end of the output flange via a thread. The large hypoid gear is axially adjustable. The sealing tube is rotatably mounted in the other opening of the mounting cavity via a skeleton oil seal, with one end of the sealing tube fixedly connected to the other end of the large hypoid gear via bolts. The small hypoid gear is rotatably mounted in the main body via a second bearing, with one end of the small hypoid gear extending into the mounting cavity and meshing with the large hypoid gear.

[0009] Rotating the sealing tube causes the large hypoid gear to move in conjunction with it. The large hypoid gear can move toward or away from the small hypoid gear, thereby reducing or increasing the gap between the large hypoid gear and the small hypoid gear.

[0010] As a preferred embodiment, the other end face of the sealing tube is provided with a wrench hole for rotating the sealing tube.

[0011] As a preferred embodiment, the first bearing is a crossed roller bearing, which is fixed inside one side opening of the mounting cavity. One end of the output flange passes through the crossed roller bearing and extends to the end of the crossed roller bearing facing the large hypoid gear. The crossed roller bearing and the large hypoid gear are spaced apart. The outer peripheral sidewall of the other end of the output flange has an annular connecting wall extending circumferentially. The end of the crossed roller bearing facing away from the large hypoid gear is constrained by the annular connecting wall. The annular connecting wall is fixed to the crossed roller bearing by a first connecting screw.

[0012] As a preferred embodiment, one end of the output flange includes a first pressure block and a second pressure block, the second pressure block extending axially and passing through the first bearing at one end;

[0013] The second pressure block has an annular structure, and a semi-circular groove ring is formed on the outer peripheral sidewall of the second pressure block facing the large hypoid gear; the semi-circular groove ring extends circumferentially, and the two ends of the semi-circular groove ring are not connected. The semi-circular groove ring penetrates the inner cavity of the second pressure block, so that the first pressure block is formed on the side of the second pressure block facing the large hypoid gear.

[0014] Both the first and second pressure blocks have external threads on their outer peripheral sidewalls. One end of the large hyperboloid gear is recessed into a first connecting cavity. The inner peripheral sidewall of the first connecting cavity is provided with an internal thread. The external thread is adapted to connect with the internal thread.

[0015] As a preferred embodiment, the other end of the large hypoid gear is recessed with a second connecting cavity. The bottom of the second connecting cavity is provided with a plurality of first connecting holes arranged in a ring at uniform intervals. The first connecting holes extend into the first connecting cavity. One end face of the output flange is provided with a plurality of second connecting holes arranged in a ring at uniform intervals. Some of the second connecting holes extend through the first pressure block and the second pressure block in sequence. The first connecting holes and the second connecting holes are connected by a second connecting screw. One end of the second connecting screw passes through the first connecting hole and is locked inside the second connecting hole. When the second connecting screw is tightened, the axial force causes the first pressure block to move closer to the second pressure block.

[0016] As a preferred embodiment, the effective thread depth of the second connecting screw within the second pressure block is greater than twice the axial thickness of the first pressure block.

[0017] As a preferred embodiment, a first locking hole is provided on the end face of one end of the sealing tube, and a second locking hole is provided on the other end of the large hyperboloid gear. The first locking hole and the second locking hole are connected by a locking screw.

[0018] As a preferred embodiment, the sealing tube is provided with a first bolt hole that passes through both ends of the sealing tube, and the large hypoid gear is provided with a second bolt hole, and the first bolt hole and the second bolt hole are connected by the bolt.

[0019] As a preferred embodiment, the lower end of the main body has a mounting through hole, the upper end of which is connected to the mounting cavity. The small hypoid gear is located inside the mounting through hole, and the upper end of the small hypoid gear extends into the mounting cavity through the mounting through hole. The second bearing is sleeved on the lower end of the small hypoid gear, and the upper end of the second bearing is constrained by the limiting wall inside the mounting through hole. The lower end of the second bearing is fixedly connected to the main body by a bearing cap, and the inner ring of the second bearing is fixed by a locking nut, which is sleeved on the lower end of the small hypoid gear.

[0020] As a preferred embodiment, a motor is fixedly connected to the lower end of the main body, and the other end of the small hypoid gear is connected to the output shaft of the motor.

[0021] Compared with the prior art, the present invention has obvious advantages and beneficial effects. Specifically, as can be seen from the above technical solution, it mainly involves connecting one end of a large hypoid gear to one end of an output flange via a thread, and setting the large hypoid gear to be axially adjustable. One end of a sealing tube is fixedly connected to the other end of the large hypoid gear via bolts. Thus, by rotating the sealing tube, the sealing tube is linked to the movement of the large hypoid gear, which can move towards or away from the small hypoid gear, thereby reducing or expanding the gap between the large and small hypoid gears. This allows the gap between the large and small hypoid gears to be adjusted within a reasonable range. Furthermore, the structure is compact, the installation is simple, the transmission accuracy is improved, maintenance is convenient, and the service life of the gears is extended.

[0022] Secondly, by setting a first locking hole on one end face of the sealing tube and a second locking hole on the other end of the large hyperboloid gear, the first locking hole and the second locking hole are connected by a locking screw. In this way, the large hyperboloid gear can be prevented from moving and rotating axially upward during operation after the clearance is adjusted. Compared with the fixing method of side set screws, which is very easy to damage the threads, this method can effectively protect the internal and external threads while ensuring installation, thereby ensuring structural stability and reliability and quick adjustment.

[0023] Furthermore, by providing a wrench hole on the end face of the other end of the sealing tube, the gear clearance can be adjusted by twisting the sealing tube to rotate it, making assembly and maintenance convenient;

[0024] Furthermore, by using crossed roller bearings instead of thin-walled bearings, rigidity is increased by 3 to 4 times, bearing clearance is adjustable, rotational inertia is low, starting torque is low, and high-precision rotational motion can be obtained even when preloaded.

[0025] Furthermore, the combination design of the skeleton oil seal with the first O-ring and the second O-ring can prevent the lubricating oil inside the body from leaking out or splashing out, resulting in good sealing performance.

[0026] To more clearly illustrate the structural features, technical means, and specific objectives and functions achieved by the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0027] Figure 1 This is a three-dimensional schematic diagram of the overall structure of an embodiment of the present invention;

[0028] Figure 2 This is a three-dimensional schematic diagram of the overall structure from another angle of an embodiment of the present invention;

[0029] Figure 3 This is a three-dimensional structural diagram of an embodiment of the present invention after the main body has been removed;

[0030] Figure 4 yes Figure 3 Another angle view of the structure shown;

[0031] Figure 5 This is an exploded view of an embodiment of the present invention;

[0032] Figure 6 This is another exploded view of an embodiment of the present invention;

[0033] Figure 7 This is a cross-sectional view of an embodiment of the present invention;

[0034] Figure 8 This is a three-dimensional schematic diagram of the output flange according to an embodiment of the present invention.

[0035] Explanation of reference numerals in the attached diagram:

[0036] 10. Main body; 11. Mounting cavity

[0037] 12. Mounting through hole; 13. Bearing cover

[0038] 20. Sealing tube; 21. First locking hole

[0039] 22. Locking screw 23. Second O-ring

[0040] 30. Large hyperboloid gear; 31. First connecting cavity

[0041] 32. Second connecting cavity; 33. Second connecting screw

[0042] 40. Small hypoid gear

[0043] 50. Output flange; 51. Annular connecting wall

[0044] 52. First connecting screw; 53. First O-ring seal

[0045] 54. First pressing block 55. Second pressing block

[0046] 56. Semicircular grooved ring; 60. Crossed roller bearing.

[0047] 70. Oil seal with skeleton; 80. Angular contact bearing.

[0048] 90. Motor; 91. Output shaft

[0049] 101. Tighten the nut. Detailed Implementation

[0050] Please refer to Figures 1 to 8 As shown, it illustrates the specific structure of an embodiment of the present invention.

[0051] An adjustment structure for the backlash of a hypoid gear in a welding robot includes a body 10, a sealing tube 20, a large hypoid gear 30, a small hypoid gear 40, and an output flange 50.

[0052] The sealing tube 20, the hyperboloid gear 30, and the output flange 50 are all axially connected in the middle. The body 10 has a mounting cavity 11 with openings at both ends. The output flange 50 is rotatably mounted in one opening of the mounting cavity 11 via a first bearing. The hyperboloid gear 30 is rotatably mounted in the mounting cavity 11, with one end of the hyperboloid gear 30 threadedly connected to one end of the output flange 50. The hyperboloid gear 30 is axially adjustable. The sealing tube 20 is rotatably mounted in the other opening of the mounting cavity 11 via a skeleton oil seal 70. One end of the sealing tube 20 is bolted to the other end of the hyperboloid gear 30. The sealing tube 20 has a first bolt hole penetrating both ends, and the hyperboloid gear 30 has a second bolt hole. The first bolt hole and the second bolt hole are connected by bolts. The small hypoid gear 40 is rotatably mounted in the body 10 via a second bearing. One end of the small hypoid gear 40 extends into the mounting cavity 11 and meshes with the large hypoid gear 30. A motor 90 is fixedly connected to the lower end of the body 10, and the other end of the small hypoid gear 40 is connected to the output shaft 91 of the motor 90. Here, rotating the sealing tube 20 causes the large hypoid gear 30 to move in conjunction with it. The large hypoid gear 30 can move towards or away from the small hypoid gear 40, thereby reducing or increasing the gap between the large hypoid gear 30 and the small hypoid gear 40. This allows the gap between the large and small hypoid gears to be adjusted within a reasonable range. The structure is compact, installation is simple, transmission accuracy is improved, maintenance is convenient, and the service life of the gears is extended.

[0053] The first bearing is a crossed roller bearing 60, which is fixed inside one side opening of the mounting cavity 11. One end of the output flange 50 passes through the crossed roller bearing 60 and extends to the end of the crossed roller bearing 60 facing the large hypoid gear 30. The crossed roller bearing 60 and the large hypoid gear 30 are spaced apart. An annular connecting wall 51 protrudes circumferentially from the outer peripheral sidewall of the other end of the output flange 50. The end of the crossed roller bearing 60 facing away from the large hypoid gear 30 is constrained by the annular connecting wall 51. The annular connecting wall 51 is fixed to the crossed roller bearing 60 by a first connecting screw 52. A first O-ring seal 53 is provided between the annular connecting wall 51 and the crossed roller bearing 60.

[0054] The second bearing is an angular contact bearing 80. The lower end of the body 10 has a mounting through hole 12. The upper end of the mounting through hole 12 is connected to the mounting cavity 11. The small hypoid gear 40 is located inside the mounting through hole 12. The upper end of the small hypoid gear 40 passes through the mounting through hole 12 and extends into the mounting cavity 11. The second bearing is sleeved on the lower end of the small hypoid gear 40. The upper end of the second bearing is restricted by the limiting wall inside the mounting through hole 12. The lower end of the second bearing is limited and fixedly connected to the body 10 by the bearing cap 13. The inner ring of the second bearing is fixed by a locking nut 101. The locking nut 101 is sleeved on the lower end of the small hypoid gear 40.

[0055] One end of the output flange 50 includes a first pressure block 54 and a second pressure block 55. The second pressure block 55 extends axially and one end passes through the crossed roller bearing 60. The second pressure block 55 has an annular structure. A semi-circular groove ring 56 is formed on the outer peripheral sidewall of the second pressure block 55 facing the large hypoid gear 30. The semi-circular groove ring 56 extends circumferentially, and the two ends of the semi-circular groove ring 56 are not connected. The semi-circular groove ring 56 penetrates the inner cavity of the second pressure block 55, so that the first pressure block 54 is formed on the side of the second pressure block 55 facing the large hypoid gear 30. External threads are provided on the outer peripheral sidewalls of the first pressure block 54 and the second pressure block 55. A first connecting cavity 31 is recessed at one end of the large hypoid gear 30. An internal thread is provided on the inner peripheral sidewall of the first connecting cavity 31. The external thread and the internal thread are adapted to be connected. One end of the second pressure block 55 extends into the first connecting cavity 31, and a brass gasket is provided between one end of the second pressure block 55 and the bottom of the first connecting cavity 31.

[0056] The other end of the large hypoid gear 30 is recessed with a second connecting cavity 32. The bottom of the second connecting cavity 32 is provided with a plurality of first connecting holes arranged in a ring at uniform intervals. These first connecting holes extend into the first connecting cavity 31. One end face of the output flange 50 is provided with a plurality of second connecting holes arranged in a ring at uniform intervals. Some of these second connecting holes sequentially pass through the first pressure block 54 and the second pressure block 55. The first connecting holes and the second connecting holes are connected by a second connecting screw 33. One end of the second connecting screw 33 passes through the first connecting hole and is locked inside it. Here, the effective thread depth of the second connecting screw 33 within the second pressure block 55 is greater than twice the axial thickness of the first pressure block 54. When the second connecting screw 33 is tightened, the axial force causes the first pressure block 54 to move closer to the second pressure block 55. The axial force acting on the internal and external threads prevents relative rotation between the output flange 50 and the large hypoid gear 30.

[0057] One end of the sealing tube 20 extends into the second connecting cavity 32. A first locking hole 21 is provided on the end face of one end of the sealing tube 20, and a second locking hole is provided on the other end of the large hyperboloid gear 30. The first locking hole 21 and the second locking hole are connected by a locking screw 22. This prevents the large hyperboloid gear 30 from moving or rotating axially upwards during operation after the clearance has been adjusted. Compared to the fixing method using side set screws, which easily damages the threads, this method effectively protects the internal and external threads while ensuring installation, thus guaranteeing structural stability, reliability, and rapid adjustment. The second locking hole is formed at the bottom of the second connecting cavity 32. A second O-ring 23 is provided between one end of the sealing tube 20 and the bottom of the second connecting cavity 32.

[0058] The other end of the sealing tube 20 is provided with a wrench hole for rotating the sealing tube 20, which can be used to rotate the sealing tube 20 to adjust the gear clearance, making assembly and maintenance convenient.

[0059] In summary, the key design feature of this invention lies in its ability to axially adjust the displacement of one end of a large hypoid gear to one end of an output flange via a threaded connection. One end of a sealing tube is bolted to the other end of the large hypoid gear. By rotating the sealing tube, the large hypoid gear moves in tandem with the sealing tube, allowing it to move towards or away from the small hypoid gear. This reduces or expands the gap between the large and small hypoid gears, thus adjusting the gap between them to a reasonable range. The invention also features a compact structure, simple installation, improved transmission accuracy, convenient maintenance, and extended gear lifespan. Furthermore, by providing a first locking hole on one end of the sealing tube and a second locking hole on the other end of the large hypoid gear, the first locking hole... The locking hole and the second locking hole are connected by a locking screw. This prevents the large hypoid gear from moving or rotating axially upwards during operation after the clearance is adjusted. Compared to the fixing method of side set screws, which easily damages the threads, this method effectively protects the internal and external threads while ensuring installation, thus ensuring structural stability and reliability, and allowing for quick adjustment. Furthermore, a wrench hole is provided on the end face of the other end of the sealing tube, which can be used to rotate the sealing tube to adjust the gear clearance, making assembly and maintenance convenient. In addition, by using crossed roller bearings, thin-walled bearings can be replaced, increasing rigidity by 3 to 4 times. The bearing clearance is adjustable, the moment of inertia is low, and the starting torque is low. Even when preloaded, high-precision rotational motion can be obtained. Finally, the combination design of the skeleton oil seal with the first O-ring and the second O-ring prevents the lubricating oil inside the body from leaking or splashing out, resulting in good sealing performance.

[0060] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the technical scope of the present invention. Therefore, any minor modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. An adjustment structure for the backlash of a quasi-hypoid gear used in a welding robot, characterized in that: It includes the main body, sealing tube, large hypoid gear, small hypoid gear, and output flange; The main body has a mounting cavity with openings at both ends. The output flange is rotatably mounted in one opening of the mounting cavity via a first bearing. The large hypoid gear is rotatably mounted in the mounting cavity, with one end of the large hypoid gear connected to one end of the output flange via a thread. The large hypoid gear is axially adjustable. The sealing tube is rotatably mounted in the other opening of the mounting cavity via a skeleton oil seal, with one end of the sealing tube fixedly connected to the other end of the large hypoid gear via bolts. The small hypoid gear is rotatably mounted in the main body via a second bearing, with one end of the small hypoid gear extending into the mounting cavity and meshing with the large hypoid gear. Rotating the sealing tube causes the large hypoid gear to move in conjunction with it. The large hypoid gear can move toward or away from the small hypoid gear, thereby reducing or increasing the gap between the large hypoid gear and the small hypoid gear.

2. The adjustment structure for the backlash of a quasi-hypoid gear in a welding robot according to claim 1, characterized in that: The other end of the sealing tube is provided with a wrench hole for rotating the sealing tube.

3. The adjustment structure for the backlash of a quasi-hypoid gear in a welding robot according to claim 1, characterized in that: The first bearing is a crossed roller bearing, which is fixed in one side opening of the mounting cavity. One end of the output flange passes through the crossed roller bearing and extends to the end of the crossed roller bearing facing the large hypoid gear. The crossed roller bearing and the large hypoid gear are spaced apart. The outer peripheral sidewall of the other end of the output flange has an annular connecting wall extending circumferentially. The end of the crossed roller bearing facing away from the large hypoid gear is constrained by the annular connecting wall. The annular connecting wall is fixed to the crossed roller bearing by a first connecting screw.

4. The adjustment structure for the backlash of a quasi-hypoid gear in a welding robot according to claim 1, characterized in that: One end of the output flange includes a first pressure block and a second pressure block, the second pressure block extending axially and passing through the first bearing at one end; The second pressure block has an annular structure, and a semi-circular groove ring is formed on the outer peripheral sidewall of the second pressure block facing the large hypoid gear; the semi-circular groove ring extends circumferentially, and the two ends of the semi-circular groove ring are not connected. The semi-circular groove ring penetrates the inner cavity of the second pressure block, so that the first pressure block is formed on the side of the second pressure block facing the large hypoid gear. Both the first and second pressure blocks have external threads on their outer peripheral sidewalls. One end of the large hyperboloid gear is recessed into a first connecting cavity. The inner peripheral sidewall of the first connecting cavity is provided with an internal thread. The external thread is adapted to connect with the internal thread.

5. The adjustment structure for the backlash of a quasi-hypoid gear in a welding robot according to claim 4, characterized in that: The other end of the large hyperboloid gear is recessed with a second connecting cavity. The bottom of the second connecting cavity is provided with a plurality of first connecting holes arranged in a ring at uniform intervals. The first connecting holes extend into the first connecting cavity. One end face of the output flange is provided with a plurality of second connecting holes arranged in a ring at uniform intervals. Some of the second connecting holes extend through the first pressure block and the second pressure block in sequence. The first connecting holes and the second connecting holes are connected by a second connecting screw. One end of the second connecting screw passes through the first connecting hole and is locked inside the second connecting hole. When the second connecting screw is tightened, the axial force causes the first pressure block to move closer to the second pressure block.

6. The adjustment structure for the backlash of a quasi-hypoid gear in a welding robot according to claim 5, characterized in that: The effective thread depth of the second connecting screw within the second pressure block is greater than twice the axial thickness of the first pressure block.

7. The adjustment structure for the backlash of a quasi-hypoid gear in a welding robot according to claim 1, characterized in that: The sealing tube has a first locking hole at one end and the large hyperboloid gear has a second locking hole at the other end. The first locking hole and the second locking hole are connected by a locking screw.

8. The adjustment structure for the backlash of a quasi-hypoid gear in a welding robot according to claim 1, characterized in that: The sealing tube is provided with a first bolt hole that passes through both ends of the sealing tube, and the large hypoid gear is provided with a second bolt hole. The first bolt hole and the second bolt hole are connected by the bolt.

9. The adjustment structure for the backlash of a quasi-hypoid gear in a welding robot according to claim 1, characterized in that: The lower end of the main body has a mounting through hole, the upper end of which is connected to the mounting cavity. The small hypoid gear is located inside the mounting through hole, and the upper end of the small hypoid gear extends into the mounting cavity through the mounting through hole. The second bearing is sleeved on the lower end of the small hypoid gear. The upper end of the second bearing is restricted by the limiting wall inside the mounting through hole. The lower end of the second bearing is fixedly connected to the main body by a bearing cap. The inner ring of the second bearing is fixed by a locking nut, which is sleeved on the lower end of the small hypoid gear.

10. The adjustment structure for the backlash of a quasi-hypoid gear in a welding robot according to claim 1, characterized in that: A motor is fixedly connected to the lower end of the main body, and the other end of the small hypoid gear is connected to the output shaft of the motor.

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