Buffer type harmonic transmission flexible gear and harmonic reducer

Abstract

The utility model discloses a buffer type harmonic drive flexible gear and harmonic reducer, the harmonic drive flexible gear comprises a cylinder and a flange located at one end of the cylinder, the side wall of the cylinder far away from the flange is provided with an outer gear ring, the side wall of the cylinder close to the outer gear ring abuts against a wave generator, the joint of the cylinder and the flange forms a bending part, and the bending part is connected with the outer gear ring. The bending part is provided with the first buffering holes, the first buffering holes vertically penetrate through the bending part, the first buffering holes are evenly distributed in the circumferential direction of the cylinder body, a deformation space of the bending part is formed, stress concentration of the bending part is dispersed, the local stress level is reduced, the possibility of fatigue crack generation is reduced, and the service life of the flexible gear is prolonged.

Description

Technical Field

[0001] This utility model belongs to the field of harmonic reducer flexure technology, specifically relating to a buffer-type harmonic drive flexure and a harmonic reducer. Background Technology

[0002] Harmonic reducers are high-precision, high-ratio transmission devices widely used in industrial automation, robotics, aerospace, and other fields. They consist of a fixed rigid wheel, a flexible wheel located inside the rigid wheel, and a wave generator that causes radial deformation of the flexible wheel. The wave generator produces an elliptical motion trajectory through an eccentric device, which in turn drives the flexible wheel to deform. The flexible wheel generates a controllable elastic deformation wave, causing relative tooth misalignment between the rigid and flexible wheels to transmit power and motion.

[0003] The flex wheel is the core component of a harmonic reducer. Its structure typically includes a cylinder and a flange at one end of the cylinder. An external gear ring is located on the side of the cylinder wall away from the flange, and a bend is formed at the connection between the cylinder and the flange. The wave generator abuts against the inner wall of the cylinder and is located near the external gear ring. When the wave generator is inserted into the inner bore of the flex wheel's cylinder, the cylinder undergoes radial deformation, forcing the external gears of the cylinder to mesh with the internal gears of the flex wheel. The torque is transmitted to the output shaft through the cylinder, the bend, and the flange.

[0004] However, in the actual use of harmonic reducers, especially under conditions of frequent impacts, the flexspline faces severe challenges. The following problems are prone to occur:

[0005] 1. Material fatigue problem: The flexible wheel undergoes repeated elastic deformation under the action of the wave generator, resulting in periodic stress in the bending part and the cylinder area. Long-term operation can easily lead to fatigue cracks and reduce the service life of the flexible wheel.

[0006] 2. Stress concentration problem: The bending section forms a stress concentration point due to the geometric change at the connection between the cylinder and the flange. Under dynamic load, it is easy to accelerate local material damage and increase the risk of tearing. Utility Model Content

[0007] To address the problems and shortcomings of the existing technology, this utility model provides a buffered harmonic drive flexure and a harmonic reducer, which effectively solves the problems of material fatigue and stress concentration of the flexure under frequent impact conditions, improves the service life and reliability of the flexure, and thus enhances the overall performance of the harmonic reducer.

[0008] This utility model is achieved through the following technical solution:

[0009] A buffered harmonic drive flexure includes a cylinder and a flange located at one end of the cylinder. An external gear ring is provided on the side wall of the cylinder away from the flange. The inner wall of the cylinder abuts against a wave generator on the side near the external gear ring. A bend is formed at the connection between the cylinder and the flange. A first buffer hole is provided in the bend, which penetrates the bend vertically. Multiple first buffer holes are provided and are evenly distributed along the circumferential direction of the cylinder to form a deformation space in the bend, thereby dispersing the stress concentration in the bend, reducing the local stress level, reducing the possibility of fatigue cracks, and extending the service life of the flexure.

[0010] Furthermore, a second buffer hole is provided on the side of the cylinder near the bending section. The second buffer hole penetrates the bottom of the cylinder and connects to the first buffer hole. This further optimizes the stress release path, enhances the buffering capacity of the flexible wheel, and improves fatigue resistance.

[0011] Furthermore, the second buffer holes are vertically oriented, and the number of the second buffer holes is the same as the number of the first buffer holes. The second buffer holes are evenly distributed along the circumferential direction of the cylinder. This forms a uniform stress relief channel in the vertical direction, improving the buffering and fatigue resistance performance of the flexible wheel at various circumferential positions.

[0012] Furthermore, the second buffer holes are inclinedly disposed in the cylinder, and the number of second buffer holes is twice the number of first buffer holes. Every two second buffer holes are connected to one first buffer hole, and the two second buffer holes and one first buffer hole form a Y-shaped hole structure. The Y-shaped hole structure can disperse stress from multiple directions, more effectively absorb impact energy, and further reduce the degree of stress concentration.

[0013] Furthermore, the top wall of the second buffer hole is arc-shaped. The arc-shaped top wall can guide the stress to be distributed more evenly, avoiding the formation of new stress concentration points at the top wall of the hole and improving the buffering effect.

[0014] Furthermore, deformation grooves are formed on the outer wall of the cylinder. These grooves are aligned with and extend in the same direction as the tooth grooves of the outer gear ring. The deformation grooves and the tooth grooves of the outer gear ring are interconnected, and the number of deformation grooves is equal to the number of tooth grooves of the outer gear ring. This increases the flexibility of the flexible wheel, making its deformation under stress more uniform, reducing local stress concentration, and improving the smoothness of inter-tooth meshing.

[0015] Furthermore, a flange ring is fixed to the outer side of the flange, and a connecting hole is provided on the flange ring, which mates with the output shaft. This ensures the stability and reliability of the connection between the flexible gear and the output shaft, achieving efficient power transmission.

[0016] Furthermore, a cavity is formed within the bending section, and the cavity is filled with a highly elastic polymer. This absorbs and buffers stress, further improving the fatigue resistance and cushioning capacity of the flexible wheel.

[0017] Furthermore, a temperature sensor is installed on the side of the flange near the bend. This sensor monitors the operating temperature of the flexspline in real time, indirectly reflecting the stress state and operating condition of the flexspline, and providing data support for equipment maintenance and fault early warning.

[0018] A buffer-type harmonic reducer includes a wave generator, a rigid wheel, and a harmonic drive flexure. The rigid wheel is mounted on the outside of the harmonic drive flexure. The rigid wheel contains an internal gear ring that mates with an external gear ring; the number of teeth on the internal gear ring is greater than the number of teeth on the external gear ring. The harmonic drive flexure is mounted on the outside of the wave generator. By coordinating the improved flexure with the wave generator and the rigid wheel, the overall performance of the harmonic reducer under frequent impact conditions is improved, including increased transmission accuracy, enhanced stability, and extended service life.

[0019] The beneficial effects of this utility model are:

[0020] 1. Improve the service life of the flexible wheel: Through the design of the first buffer hole, the second buffer hole, the deformation groove and the high elastic polymer filling, the stress concentration of the flexible wheel is effectively reduced, the generation of fatigue cracks is reduced, and the service life of the flexible wheel is significantly extended in different embodiments, with an average extension of more than 100%.

[0021] 2. Enhanced fatigue resistance: The multi-stage buffer hole structure and deformation groove design optimize the stress distribution of the flexible wheel, improve its fatigue resistance, and enable it to work stably under frequent impact conditions, greatly reducing equipment failures caused by fatigue damage.

[0022] 3. Improve transmission stability: The deformation groove makes the flexure deform more evenly under force and the inter-tooth meshing more stable. Combined with the reliable connection between the flange ring and the output shaft, it effectively improves the transmission stability of the harmonic reducer and reduces vibration and noise.

[0023] 4. Real-time monitoring and early warning: The installation of temperature sensors enables real-time monitoring of the flexible wheel's operating temperature, providing data support for equipment maintenance and fault early warning, preventing equipment failures in advance, and improving production efficiency and equipment reliability. Attached Figure Description

[0024] Figure 1 This is a schematic structural diagram illustrating one embodiment of a buffer-type harmonic drive flexure in this utility model.

[0025] Figure 2 Used to explain Figure 1 Enlarged view of a portion of point A in the middle;

[0026] Figure 3 Used to explain Figure 1 Enlarged view of a portion of point B in the middle;

[0027] Figure 4This is a schematic diagram illustrating another embodiment of a buffer-type harmonic drive flexure in this utility model.

[0028] Figure 5 Used to explain Figure 4 A magnified view of a portion of point C in the middle.

[0029] List of components and reference numerals:

[0030] 1. Cylinder body; 11. External gear ring; 12. Second buffer hole; 121. Arc-shaped surface; 13. Deformation groove; 2. Flange; 21. Flange ring; 22. Connecting hole; 3. Bending part; 31. First buffer hole. Detailed Implementation

[0031] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0032] It should be noted that the directional terms such as left, right, up, down, front, and back in the embodiments of this utility model are only relative concepts or are based on the normal use state of the product, i.e., the direction of the product's movement, and should not be considered as limiting.

[0033] In addition, it should be noted that the dynamic terms such as "relative motion" mentioned in the embodiments of this utility model not only refer to changes in position, but also include movements such as rotation and rolling in which the position does not change relative to the position, but the state changes.

[0034] Finally, it should be noted that when a component is said to be "located on" or "set on" another component, it can be on the other component or may have an intervening component at the same time. When a component is said to be "connected to" another component, it can be directly connected to the other component or may have an intervening component at the same time.

[0035] like Figures 1 to 5The diagram shows a buffered harmonic drive flexure, comprising a cylinder 1 and a flange 2 located at one end of the cylinder 1. An external gear ring 11 is provided on the side wall of the cylinder 1 away from the flange 2. The inner wall of the cylinder 1 abuts against a wave generator on the side close to the external gear ring 11. A bend 3 is formed at the connection between the cylinder 1 and the flange 2. The bend 3 has a first buffer hole 31, which vertically penetrates the bend 3. Multiple first buffer holes 31 are provided and are evenly distributed along the circumferential direction of the cylinder 1, forming a deformation space for the bend 3, dispersing the stress concentration in the bend 3, reducing the local stress level, reducing the possibility of fatigue cracks, and extending the service life of the flexure.

[0036] In one embodiment, a flexible wheel for a joint of an industrial robot is made of high-strength alloy steel. The diameter of the cylinder 1 is 100mm, and 12 first buffer holes 31 with a length of 1mm are evenly opened in the circumferential direction at the bending part 3. Through finite element analysis and actual testing, the stress concentration factor of the bending part 3 is reduced by 30%, and the fatigue life is extended by 50% under the same working conditions.

[0037] Preferably, a second buffer hole 12 is provided on the side of the cylinder 1 near the bending portion 3. The second buffer hole 12 penetrates the bottom of the cylinder 1 and is connected to the first buffer hole 31. This further optimizes the stress release path, enhances the buffering capacity of the flexible wheel, and improves fatigue resistance.

[0038] In one embodiment, a second buffer hole 12 is provided on the flexible wheel for the joint of the industrial robot described above. The second buffer hole 12 is 12mm long, vertically penetrates the bottom of the cylinder 1, and communicates with the first buffer hole 31. Through experimental comparison, the flexible wheel with the second buffer hole 12 installed has a more uniform internal stress distribution when subjected to impact load, and its fatigue life is increased by 20% compared with the case where only the first buffer hole 31 is provided.

[0039] Preferably, the second buffer holes 12 are vertically oriented, and the number of second buffer holes 12 is the same as the number of first buffer holes 31. The second buffer holes 12 are evenly distributed along the circumferential direction of the cylinder 1. This forms a uniform stress relief channel in the vertical direction, improving the buffering and fatigue resistance performance of the flexible wheel at various circumferential positions.

[0040] Preferably, the second buffer holes 12 are inclinedly disposed on the cylinder 1, and the number of second buffer holes 12 is twice the number of first buffer holes 31. Every two second buffer holes 12 are connected to one first buffer hole 31, and the two second buffer holes 12 and one first buffer hole 31 form a Y-shaped hole structure. The Y-shaped hole structure can disperse stress from multiple directions, more effectively absorb impact energy, and further reduce the degree of stress concentration.

[0041] In one embodiment, a Y-shaped structure is formed in a flexible wheel for a medical surgical robot using a tilted second buffer hole 12. Through actual surgical operation simulation tests, the flexible wheel exhibits excellent stability and fatigue resistance under frequent start-stop and minor impact conditions, ensuring the accuracy of surgical operations and the reliability of the equipment.

[0042] Preferably, the top wall of the second buffer hole 12 is an arc-shaped surface 121. The arc-shaped top wall can guide the stress to be distributed more evenly, avoid the formation of new stress concentration points at the top wall of the hole, and improve the buffering effect.

[0043] In one embodiment, in the flexible wheel of a harmonic reducer used in an automated production line, the top wall of the second buffer hole 12 is designed as an arc-shaped surface 121 with a radius of 0.5 mm. Stress test analysis shows that compared with a conventional flat-topped second buffer hole 12, the arc-shaped top wall reduces the stress concentration factor around the buffer hole by 15%, effectively improving the durability of the flexible wheel.

[0044] Preferably, the outer wall of the cylinder 1 is further provided with deformation grooves 13. The deformation grooves 13 are aligned with the tooth grooves of the outer gear ring 11 and extend in the same direction. The deformation grooves 13 and the tooth grooves of the outer gear ring 11 are interconnected. The number of deformation grooves 13 is equal to the number of tooth grooves of the outer gear ring 11. This increases the flexibility of the flexible wheel, makes the deformation of the flexible wheel more uniform under force, reduces local stress concentration, and improves the smoothness of inter-tooth meshing.

[0045] In one embodiment, in a flexible wheel for an industrial handling robot, the outer gear ring 11 has 80 teeth, and correspondingly, 80 deformation grooves 13 are formed on the outer wall of the cylinder 1. Through actual operation monitoring, the flexible wheel with deformation grooves 13 installed has smoother inter-tooth meshing during power transmission, significantly reduces vibration and noise, and significantly improves the operational stability of the equipment.

[0046] Preferably, a flange ring 21 is fixed to the outer side of the flange 2, and a connecting hole 22 is provided on the flange ring 21. The flange ring 21 cooperates with the output shaft. This ensures the stability and reliability of the connection between the flexible gear and the output shaft, and realizes efficient power transmission.

[0047] In one embodiment, in a robot joint flexible wheel used in an automobile manufacturing production line, the flange ring 21 is made of high-strength aluminum alloy, and the connecting hole 22 is an M8 threaded hole, which is fastened to the output shaft by bolts. During long-term high-load operation, the connection is firm and reliable, and no loosening occurs, ensuring the precise movement and efficient operation of the robot joint.

[0048] Preferably, the bent portion 3 has a cavity filled with a highly elastic polymer. This absorbs and buffers stress, further improving the fatigue resistance and cushioning capacity of the flexible wheel.

[0049] In one embodiment, the cavity formed by the bending portion 3 in the flexible wheel of a harmonic reducer for high-speed packaging equipment is filled with polyurethane elastomer. Fatigue testing showed that the flexible wheel filled with highly elastic polymer had a 30% longer fatigue life when subjected to high-frequency impacts, effectively reducing the number of downtimes caused by fatigue damage to the flexible wheel.

[0050] Preferably, a temperature sensor is installed on the side of the flange 2 near the bend 3. This allows for real-time monitoring of the flexspline's operating temperature, indirectly reflecting the flexspline's stress state and operating condition, and providing data support for equipment maintenance and fault early warning.

[0051] In one embodiment, a high-precision thermistor temperature sensor is installed in the flexure of a harmonic reducer for a CNC machine tool. The equipment control system collects temperature data in real time, and when the temperature exceeds a set threshold, the system issues an early warning signal, prompting the operator to inspect and maintain the equipment. In practical applications, temperature monitoring has effectively prevented numerous equipment failures caused by flexure overheating, improving production efficiency and equipment reliability.

[0052] A buffer-type harmonic reducer includes a wave generator, a rigid wheel, and a harmonic drive flexure. The rigid wheel is fitted outside the harmonic drive flexure, and the rigid wheel contains an internal gear ring that mates with an external gear ring 11. The number of teeth on the internal gear ring is greater than the number of teeth on the external gear ring 11. The harmonic drive flexure is fitted outside the wave generator. By coordinating the improved flexure with the wave generator and the rigid wheel, the overall performance of the harmonic reducer under frequent impact conditions is improved, including increased transmission accuracy, enhanced stability, and extended service life.

[0053] In a harmonic reducer used in a large industrial robotic arm, the aforementioned buffer-type harmonic drive flexure is employed, with the inner gear ring of the rigid gear having two more teeth than the outer gear ring of the flexure. Actual operational testing showed that under conditions of frequent starts and stops and exposure to large impact loads, the transmission accuracy of this harmonic reducer remained within ±1 arcminute, and its service life was extended by more than two times compared to traditional harmonic reducers, effectively meeting the high-precision and high-reliability transmission requirements of industrial robotic arms.

[0054] When the aforementioned buffer-type harmonic drive flexure and harmonic reducer are used, the buffer-type harmonic reducer includes a wave generator, a rigid wheel, and the aforementioned buffer-type harmonic drive flexure. The rigid wheel is fitted onto the outside of the harmonic drive flexure, and the rigid wheel has an internal gear ring that mates with the external gear ring 11. The number of teeth on the internal gear ring is greater than the number of teeth on the external gear ring 11. The harmonic drive flexure is fitted onto the outside of the wave generator. By applying the improved flexure to the harmonic reducer, combined with the synergistic work of the rigid wheel and the wave generator, a significant improvement in the performance of the harmonic reducer under frequent impact conditions is achieved.

[0055] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A buffer-type harmonic drive flexible wheel, comprising a cylindrical body and a flange located at one end of the cylindrical body, wherein an external gear ring is provided on the side wall of the cylindrical body away from the flange, and the inner wall of the cylindrical body abuts against a wave generator on the side near the external gear ring, wherein a bend is formed at the connection between the cylindrical body and the flange, characterized in that, The bending section is provided with a first buffer hole, which penetrates the bending section vertically. Multiple first buffer holes are provided and are evenly distributed along the circumferential direction of the cylinder.

2. The buffer-type harmonic drive flexible wheel according to claim 1, characterized in that, A second buffer hole is provided on the side of the cylinder near the bending part. The second buffer hole penetrates the bottom of the cylinder and is connected to the first buffer hole.

3. The buffer-type harmonic drive flexible wheel according to claim 2, characterized in that, The second buffer hole is opened vertically, and the number of the second buffer hole is the same as the number of the first buffer hole. The second buffer hole is evenly distributed along the circumferential direction of the cylinder.

4. A buffer-type harmonic drive flexible wheel according to claim 2, characterized in that, The second buffer hole is inclinedly disposed on the cylinder, and the number of the second buffer hole is twice the number of the first buffer hole. Every two second buffer holes are connected to one first buffer hole, and the two second buffer holes and one first buffer hole form a Y-shaped hole structure.

5. A buffer-type harmonic drive flexible wheel according to claim 2, characterized in that, The top wall of the second buffer hole has an arc-shaped surface.

6. A buffer-type harmonic drive flexible wheel according to claim 1, characterized in that, The outer wall of the cylinder is also provided with deformation grooves, which are aligned with the tooth grooves of the outer gear ring and extend in the same direction. The deformation grooves are interconnected with the tooth grooves of the outer gear ring, and the number of deformation grooves is equal to the number of tooth grooves of the outer gear ring.

7. A buffer-type harmonic drive flexible wheel according to claim 1, characterized in that, A flange ring is fixed to the outer side of the flange, and a connecting hole is provided on the flange ring. The flange ring and the output shaft cooperate with each other.

8. A buffer-type harmonic drive flexible wheel according to claim 1, characterized in that, The bending section has a cavity, which is filled with a highly elastic polymer.

9. A buffer-type harmonic drive flexible wheel according to claim 1, characterized in that, A temperature sensor is installed on the side of the flange near the bend.

10. A buffer-type harmonic reducer, characterized in that, The harmonic reducer includes a wave generator, a rigid wheel, and a harmonic drive flexible wheel as described in any one of claims 1-9. The rigid wheel is fitted on the outside of the harmonic drive flexible wheel, and the rigid wheel has an internal gear ring that mates with the external gear ring. The number of teeth on the internal gear ring is greater than the number of teeth on the external gear ring. The harmonic drive flexible wheel is fitted on the outside of the wave generator.

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