Harmonic reducer

Abstract

The harmonic reducer comprises a wave generator, a flexible gear, a rigid gear, an input end cover, an input flange, an output end cover and an output flange, the input end cover and the output end cover are arranged on the two sides of the rigid gear respectively, the flexible gear is arranged in the rigid gear and connected with the rigid gear in a meshed mode, the wave generator is arranged in the flexible gear, the input flange is connected with the wave generator, and the output flange is connected with the input flange. The output flange is connected with the flexible gear, the wave generator comprises an elliptic cam and a sheath, the elliptic cam is wrapped by the sheath in a detachable mode, a retention area is arranged on the peripheral face of the sheath, and a space capable of providing lubricant retention is formed in the retention area. By means of the design of the retention area, more lubricating agents can be stored, and the lubricating effect is improved; the sheath is arranged between the wave generator and the flexible gear to form a buffer layer, so that direct contact friction between the elliptic cam and the flexible gear is avoided, the abrasion loss of the elliptic cam and the flexible gear is reduced, the sheath can be replaced without replacing the whole wave generator when the screw is disassembled and the buckle is loosened during maintenance, and the maintenance cost is reduced.

Description

Technical Field

[0001] This utility model relates to the field of speed reducer technology, and in particular to a harmonic speed reducer. Background Technology

[0002] A harmonic reducer consists of a flexible wheel, a rigid wheel, and a wave generator. The flexible wheel is a part with an external gear that can undergo elastic deformation. The rigid wheel is a part with an internal gear that mainly works with the flexible wheel to perform meshing transmission. The two gears, the flexible wheel and the rigid wheel, mesh with each other with the same pitch but a difference of 2 in the number of teeth. The wave generator, as the input component, is generally composed of an elliptical cam and a thin-walled bearing. The wave generator stably transmits controllable elastic deformation to the flexible wheel, causing it to rotate periodically around the fixed rigid wheel.

[0003] In existing harmonic reducers, the cam-type wave generator and flexure rotate together. The carrier wave generator drives the flexure to rotate via a gear that rotates continuously along the inner wall of the flexure. During this process, the flexure undergoes noticeable periodic deformation. Because the wave generator and flexure are in direct metal-to-metal contact, the coefficient of friction is high. After prolonged operation, a fine scratch appears on the inner wall of the flexure, indicating significant wear. The metal particles generated by this wear contaminate the lubrication system, leading to decreased lubrication performance and reduced lifespan of the harmonic reducer. Repairing the entire structure requires replacing the entire wave generator and flexure, which is costly. Summary of the Invention

[0004] The main purpose of this utility model is to overcome the defects of the above-mentioned background technology and provide a harmonic reducer.

[0005] To achieve the above objectives, the present invention proposes a harmonic reducer comprising a wave generator, a flexible wheel, a rigid wheel, an input end cover, an input flange, an output end cover, and an output flange. The input end cover and the output end cover are respectively disposed on both sides of the rigid wheel. The flexible wheel is disposed within the rigid wheel, and the external teeth of the flexible wheel mesh with the internal teeth of the rigid wheel. The wave generator is disposed within the flexible wheel and causes deformation of the flexible wheel. The input flange is connected to the wave generator, and the output flange is connected to the flexible wheel. The wave generator includes an elliptical cam and a sleeve. The sleeve is detachably and tightly wrapped around the outer surface of the elliptical cam. A retention area is provided on the outer circumferential surface of the sleeve. When the wave generator and the flexible wheel are installed together, the retention area forms a space for lubricant retention. By using the sleeve as a buffer layer, direct contact and friction between the elliptical cam and the inner wall of the flexible wheel are avoided, reducing wear. The retention area design can store more lubricant, improving the lubrication effect.

[0006] The technical solution is further optimized by providing several slots on the elliptical cam and buckles on the sleeve that match the slots. During maintenance, the sleeve can be replaced simply by loosening the buckles, without replacing the entire wave generator, thus improving the service life of the wave generator and reducing operating costs.

[0007] To further optimize the technical solution, the elliptical cam is provided with several positioning grooves, and the sleeve is provided with protrusions that match the positioning grooves; this ensures that the sleeve can rotate synchronously with the elliptical cam, thereby improving the stability of the wave generator.

[0008] To further optimize the technical solution, the surface of the retention area is designed with any one of the following: knurled texture, grid texture, or square groove texture, forming a micro oil storage space that allows the lubricant to be stored for a long time and improves lubrication efficiency.

[0009] To further optimize the technical solution, the knurled pattern, grid pattern, and square groove pattern are all provided with inwardly extending baffles. When the baffles are running at high speed, they form a lubricant blocking structure, which effectively inhibits the lubricant from migrating outward due to centrifugal force, ensuring that the lubricant is stably retained in the groove and maintaining long-term lubrication.

[0010] To further optimize the technical solution, the casing is made of plastic material and manufactured using injection molding, thereby reducing manufacturing costs.

[0011] To further optimize the technical solution, the plastic material is any one of nylon, polyoxymethylene, polyphenylene sulfide, polyamide imide, polyethyleneimine, polyetheretherketone, and polyethersulfone resin. The plastic material has excellent wear resistance and high temperature resistance, and also has the property of heat reshaping, so that the products made from the plastic material can be recycled and reused multiple times.

[0012] To further optimize the technical solution, several blind holes are provided on the retention area. The blind holes form independent oil storage chambers, which can store additional lubricant and serve as a supplementary oil source for the main retention area channel. When the component is running, centrifugal force causes the lubricant in the blind holes to slowly seep out, achieving automatic oil replenishment.

[0013] To further optimize the technical solution, the outer ring of the rigid wheel is provided with an oil injection hole, and the flexible wheel is provided with an oil passage hole; this facilitates the lubricant to penetrate to the contact surface between the wave generator and the flexible wheel, thereby improving lubrication efficiency.

[0014] To further optimize the technical solution, O-rings are provided between the input end cover, the output end cover, and the rigid wheel to ensure sealing and prevent lubricant leakage.

[0015] The beneficial effects of this utility model include: by using a sleeve made of plastic material to tightly wrap the working surface of the elliptical cam, a flexible buffer interface layer is formed; when the elliptical cam and the flexure rotate, the sleeve acts as a buffer medium, avoiding direct contact and friction between the elliptical cam and the inner wall of the flexure, thus reducing the amount of wear between the wave generator and the flexure; through the retention area set on the sleeve, the wave generator can store more lubricant when the wave generator drives the flexure to rotate periodically, ensuring sufficient lubrication and improving the lubrication effect; the elliptical cam and the sleeve are connected in a detachable manner, so that the worn sleeve can be replaced separately during maintenance without replacing the entire wave generator, effectively reducing maintenance costs. Attached Figure Description

[0016] Figure 1 This is an exploded view of the assembly of the harmonic reducer in an embodiment of this utility model.

[0017] Figure 2 This is a schematic diagram of the flexible wheel in an embodiment of this utility model.

[0018] Figure 3 This is a schematic diagram of the rigid wheel in an embodiment of this utility model.

[0019] Figure 4 This is a schematic diagram of the elliptical cam in an embodiment of this utility model.

[0020] Figure 5 This is a schematic diagram of the sleeve in an embodiment of this utility model.

[0021] Figure 6 This is a schematic diagram of the blind hole in an embodiment of this utility model.

[0022] Figure 7 This is a schematic diagram of the retaining edge in an embodiment of this utility model.

[0023] Reference numerals: 1. Input end cover; 2. O-ring; 3. Oil seal; 4. Screw; 5. Input flange; 6. Rigid wheel; 601. Oil injection hole; 7. Wave generator; 701. Elliptical cam; 7011. Positioning groove; 7012. Slot; 702. Sleeve; 7021. Raised strip; 7022. Snap fastener; 7023. Retention area; 7024. Blind hole; 7025. Side flange; 8. Flexible wheel; 801. Oil passage hole; 9. Output flange; 10. Output end cover. Detailed Implementation Plan

[0024] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0025] In the description of this invention, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0026] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. In this invention, unless otherwise explicitly specified and limited, the terms "installed," "connected," "joined," "fixed," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two elements or the interaction between two elements. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0027] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0028] Please see Figures 1 to 7As shown in the embodiments of this application, the harmonic reducer includes a wave generator 7, a flexible wheel 8, a rigid wheel 6, an input end cover 11, an input flange 5, an output flange 10, and an output flange 9. The wave generator 7 is composed of a sleeve 702 that is detachably wrapped around the outer peripheral surface of an elliptical cam 701. Specifically, the sleeve 702 is made of any one of the wear-resistant plastic materials selected from nylon, polyoxymethylene, polyphenylene sulfide, polyamide-imide, polyethyleneimine, polyetheretherketone, and polyethersulfone resin. The plastic material not only has excellent wear resistance and high temperature resistance, but also has the property of being thermoformed, making the plastic... Products made of rubber materials can be recycled multiple times. Several buckles 7023 are provided on the inner circumferential surface of the sleeve 702, and a matching groove 7012 is provided on the outer circumferential surface of the elliptical cam 701. The buckles 7023 adopt a square protrusion structure, with the top edge of the protrusion chamfered. The chamfer angle is controlled within 30°~50°. This chamfer design effectively reduces insertion resistance during assembly. Two symmetrical rectangular through-type stress relief grooves are machined axially on both sides of the protrusion structure, giving the buckles 7023 elastic deformation capability. 7012 employs a U-shaped groove structure that matches the snap fastener 7023, set on the outer circumferential surface of the elliptical cam 701. The groove 7012 achieves precise alignment with the protruding part of the snap fastener 7023 through its axial depth, realizing axial positioning constraint after assembly and effectively suppressing the risk of axial displacement. Both side walls of the groove 7012 are designed as slightly inclined surfaces, reducing the contact angle and lowering the frictional resistance of the snap fastener 7023 sliding in. The sleeve 702 is fixed by snapping the snap fastener 7023 into the groove 7012 on the elliptical cam 701. During maintenance, simply loosening the snap fastener 7023 allows for replacement of the sleeve. The sleeve 702 eliminates the need to replace the entire wave generator 7, effectively reducing maintenance costs. The outer working surface of the sleeve 702 features knurled, checkered, or square groove patterns as a retention area 7023. These recessed patterns create microscopic oil storage spaces, effectively storing and retaining lubricant. During relative movement of the friction pairs, lubricant is continuously released, significantly improving lubrication durability, reducing friction and wear, and thus extending component lifespan. The elliptical cam 701 is made of metal, and the ratio of its major axis to its minor axis is 1.05 to 1.2. To ensure effective deformation of the flexible wheel 8, an involute tooth shape is machined on the inner wall of the rigid wheel 6. The input end cover 1 and the output flange 10 are fixed to both sides of the rigid wheel 6 by screws 4. An oil injection hole 601 is provided on the outer ring of the rigid wheel 6 for injecting lubricating oil into the harmonic reducer. An oil passage hole 801 is provided on the flexible wheel 8, allowing lubricant to enter the contact surface between the harmonic generator 7 and the flexible wheel 8 through the gap between the rigid wheel 6 and the flexible wheel 8. The flexible wheel 8 is nested inside the rigid wheel 6, and the outer teeth of the flexible wheel 8 mesh with the inner teeth of the rigid wheel 6. The difference in the number of teeth between the outer teeth of the flexible wheel 8 and the inner teeth of the rigid wheel 6 is usually 2 teeth to achieve harmonic transmission. The harmonic generator 7 is located inside the flexible wheel 8. The input flange 5 is fixedly connected to one side of the elliptical cam 701 by screws 4. The inner hole of the input flange 5 is connected to the output shaft of the motor (not shown) by a key connection. The output flange 9 is connected and fixed to the flexible wheel 8 by screws 4, outputting the decelerated motion.

[0029] During operation, the input flange 5 is driven to rotate by a motor (not shown), which in turn drives the wave generator 7 to rotate. The sleeve 702 on the elliptical cam 701 contacts the flexure 8, causing the flexure 8 to undergo periodic elastic deformation and mesh with the internal teeth of the rigid wheel 6 to achieve speed reduction transmission. Lubricant is injected through the oil injection hole 601 and enters the retention area 7023 through the oil passage hole 801 of the flexure 8, forming an oil film at the friction interface to reduce wear. The sleeve 702 acts as a buffer layer to prevent the elliptical cam 701 from directly contacting and rubbing against the inner wall of the flexure 8, thus reducing wear. The design of the retention area 7023 can store more lubricant, improving the lubrication effect. During maintenance, the sleeve 702 can be replaced simply by removing the screw 4 and loosening the clip 7023, without replacing the entire harmonic wave generator 7, thus reducing the operating cost of the harmonic reducer.

[0030] The knurled, grid, and square groove patterns all have inner-extending baffles 7025. When rotating at high speed, the baffles 7025 form a physical barrier to prevent excessive lubricant from leaving the retention area 7023 due to centrifugal force. Some of the lubricant that is thrown out is retained in the retention area 7023 after being blocked by the baffles 7025, thus improving the lubricant utilization rate.

[0031] To further strengthen the bond between the sleeve 702 and the elliptical cam 701 and ensure the stability of the wave generator 7, a positioning groove 7011 is provided on the outer circumferential surface of the elliptical cam 701. The positioning grooves 7011 are arranged axially at intervals. A protrusion 7021 that cooperates with the positioning groove 7011 is provided on the inner wall of the sleeve 702. During assembly, the protrusion 7021 is embedded in the positioning groove 7011 to prevent the elliptical cam 701 from rotating relative to the sleeve 702 during rotation. At the same time, one side of the sleeve 702 is further fixedly connected to the elliptical cam 701 by screws 4 to ensure stability during high-speed operation.

[0032] To further extend the lubrication cycle of the contact area between the wave generator 7 and the flexible wheel 8, several blind holes 7024 are spaced apart on the surface of the retention area 7023. The blind holes 7024 are radially and evenly arranged on the retention area 7023. The diameter of the blind holes 7024 is 0.8 mm and the depth is 1.5 mm. The blind holes 7024 can further increase the oil storage capacity and extend the oil replenishment cycle.

[0033] To ensure the sealing performance of the harmonic reducer, O-rings 2 are provided between the input end cover 1 and the output end cover 10 and the rigid wheel 6, and shaft oil seals 3 are provided between the input flange 5 and the input end cover 1 and between the output flange 9 and the output end cover 10, so as to improve the sealing performance of the harmonic reducer and prevent lubricant leakage.

[0034] The above description, in conjunction with specific / preferred embodiments, provides a further detailed explanation of the present invention and should not be construed as limiting the specific implementation of the present invention to these descriptions. For those skilled in the art, various substitutions or modifications can be made to these described embodiments without departing from the concept of the present invention, and all such substitutions or modifications should be considered within the protection scope of the present invention. In the description of this specification, the reference to terms such as "an embodiment," "some embodiments," "preferred embodiment," "example," "specific example," or "some examples," etc., indicates that the specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the described specific features, structures, materials, or characteristics can be combined in a suitable manner in any one or more embodiments or examples. Without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification and the features of different embodiments or examples. Although embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions and alterations may be made herein without departing from the scope of protection of the patent application.

Claims

1. A harmonic reducer, comprising a wave generator, a flexible wheel, a rigid wheel, an input end cover, an input flange, an output end cover, and an output flange, wherein the input end cover and the output end cover are respectively disposed on both sides of the rigid wheel, the flexible wheel is disposed within the rigid wheel, and the external teeth of the flexible wheel mesh with the internal teeth of the rigid wheel, the wave generator is disposed within the flexible wheel and causes the flexible wheel to deform, the input flange is connected to the wave generator, and the output flange is connected to the flexible wheel, characterized in that... The wave generator includes an elliptical cam and a sleeve. The sleeve is detachably and tightly wrapped around the outer surface of the elliptical cam. A retention area is provided on the outer circumferential surface of the sleeve. When the wave generator is installed in conjunction with the flexible wheel, the retention area forms a space that can provide lubricant retention.

2. A harmonic reducer as claimed in claim 1, characterized in that: The elliptical cam is provided with several slots, and the sleeve is provided with buckles that match the slots.

3. A harmonic reducer according to claim 2, characterized in that: The outer circumferential surface of the elliptical cam is provided with several positioning grooves, and the sleeve is provided with a protrusion that matches the positioning grooves.

4. A harmonic reducer as claimed in claim 1, characterized in that: The surface of the retention area is provided with any one of the following: knurled pattern, grid pattern, or square groove pattern.

5. A harmonic reducer according to claim 4, characterized in that: The knurled pattern, the grid pattern, and the square groove pattern are all provided with inwardly extending guard edges.

6. A harmonic reducer as claimed in claim 1, characterized in that: The sleeve is made of plastic material.

7. A harmonic reducer as claimed in claim 6, characterized in that: The plastic material is any one of nylon, polyoxymethylene, polyphenylene sulfide, polyamide imide, polyethyleneimine, polyetheretherketone, and polyethersulfone resin.

8. A harmonic drive according to any one of claims 1 to 7, wherein: The retention area is provided with several blind holes.

9. A harmonic reducer as claimed in claim 8, characterized in that: The rigid wheel has an oil injection hole on its outer ring, and the flexible wheel has an oil passage hole.

10. A harmonic reducer according to claim 1, characterized in that: O-rings are provided between the input end cover, the output end cover and the rigid wheel.

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