Highly flexible integrated speed reduction device that is easy to maintain

Abstract

This utility model relates to the field of mechanical transmission technology, and in particular to a highly flexible integrated speed reduction device that is easy to maintain, comprising a steel wheel, a flexible wheel, a wave generator, and a motor assembly. By using a splined detachable connection between the motor output shaft and the camshaft, the motor assembly and the wave generator are independently arranged, achieving reliable transmission while facilitating disassembly, replacement, and maintenance. The elliptical structure of the wave generator drives the flexible wheel to produce periodic deformation and mesh with the steel wheel to obtain high-precision speed reduction output. This device has a compact structure and high transmission rigidity, making it suitable for highly integrated applications such as robot joints.

Description

Technical Field

[0001] This utility model relates to the field of mechanical transmission technology, and in particular to a highly flexible integrated speed reduction device that is easy to maintain. Background Technology

[0002] Harmonic reducers are widely used in robot joints, collaborative robotic arms, and high-precision positioning systems due to their advantages such as high reduction ratio, high transmission accuracy, and compact size. Traditional harmonic reducers typically consist of a flexspline, a steel wheel, and a wave generator. The wave generator is generally directly driven by the motor output shaft, causing the flexspline to undergo periodic elliptical deformation to achieve meshing transmission. However, in traditional structures, the motor and wave generator are often connected as a single unit, for example, the motor output shaft is directly machined into the wave generator's input shaft, or it is fixed by a non-removable connection structure. While this connection method can transmit torque, it has the following drawbacks: First, the motor assembly and wave generator assembly are difficult to disassemble independently, resulting in high maintenance and replacement costs; second, the single-unit connection is not conducive to precision upgrades or component replacement. Once the motor output shaft or wave generator camshaft wears or deforms, it is usually necessary to replace the entire motor or the entire reduction gear; third, the axial structure at the motor end is restricted, making it difficult to improve assembly freedom and hindering the overall flexibility of the machine.

[0003] As robots and precision equipment evolve towards miniaturization, lightweighting, and high reliability, speed reduction devices, while maintaining high coaxiality and rigidity transmission, still need to possess higher maintainability and modularity. Therefore, achieving a reliable separate connection between the motor assembly and wave generator assembly while maintaining harmonic drive accuracy and structural rigidity, and solving the problems of difficult disassembly and replacement in traditional structures, has become a crucial technological breakthrough for the industry.

[0004] The above content is only used to help understand the technical solution of this utility model and does not represent an admission that the above content is prior art. Utility Model Content

[0005] The purpose of this utility model is to provide a highly flexible integrated speed reduction device that is easy to maintain, addressing the shortcomings of existing technologies. It aims to achieve a technical solution that allows for separate connection of the motor assembly and the wave generator assembly without reducing harmonic drive performance, enabling independent disassembly and assembly, and facilitating maintenance.

[0006] This utility model achieves the above objectives through the following technical solution: a highly flexible integrated speed reduction device that is easy to maintain, comprising: Steel wheel with rigid internal teeth; A flexible gear has flexible external teeth that mesh with the internal teeth of a rigid gear; The wave generator includes an elliptical camshaft and a flexible bearing installed inside a flexure and fitted onto the camshaft and located on the elliptical structure. The motor assembly has a motor output shaft that is splined to the end of the camshaft away from the flexible bearing.

[0007] Furthermore, the camshaft is provided with an internal spline on the side away from the flexible bearing, and the motor output shaft is provided with an external spline that matches the internal spline.

[0008] Furthermore, an external spline is provided on the side of the camshaft away from the flexible bearing, and an internal spline matching the external spline is provided on the motor output shaft.

[0009] Furthermore, the motor assembly also includes a motor housing, a motor stator disposed on the motor housing, and a motor rotor disposed on the motor output shaft; The end of the flexible wheel away from the external teeth of the flexible wheel has a bottom wall, and one side of the bottom wall abuts against one side of the motor housing; The speed reduction device also includes a speed reduction output shaft connected to the steel wheel, and a cross bearing connected to the side of the bottom wall away from the motor housing.

[0010] Furthermore, the motor assembly also includes: The first oil seal is sleeved on the motor output shaft and installed inside the motor housing; The first deep groove ball bearing is sleeved on the motor output shaft, adjacent to the first oil seal, and installed inside the motor housing; The flange is installed on the side of the motor housing away from the crossed bearing; The second deep groove ball bearing is sleeved on the motor output shaft, located on the side of the first deep groove ball bearing away from the first oil seal, and connected to the flange; The second oil seal is fitted onto the reduction output shaft and connected between the reduction output shaft and the motor output shaft.

[0011] Furthermore, it also includes a drive assembly mounted on the side of the flange away from the motor housing, the drive assembly including a drive mounting plate and a drive end cover; The camshaft is provided with a first threaded hole, and the motor output shaft is provided with a second threaded hole at one end of the external spline that matches the first threaded hole. The motor output shaft is inserted into the camshaft to achieve spline connection by aligning the external spline and the internal spline. The connection is then fastened by screws passing through the first threaded hole and the second threaded hole.

[0012] The beneficial effects of this utility model are: By incorporating a motor output shaft with a splined connection and detachably engaging it with the end of the camshaft, the motor assembly and wave generator are arranged in a separate structural configuration. The motor output shaft is no longer rigidly connected to the wave generator; instead, torque transmission is achieved through spline engagement. The spline structure provides excellent angular positioning capability and torsional stiffness, ensuring sufficient transmission rigidity and coaxiality when the wave generator drives the flexspline to undergo elliptical deformation, thus not compromising the accuracy of the harmonic drive.

[0013] Meanwhile, the splined connection is detachable, allowing the motor assembly and camshaft to be removed independently from the device. When the motor output shaft, camshaft, or wave generator part wears or deforms, the corresponding component can be replaced individually without replacing the entire reduction gear. This structure not only significantly reduces maintenance costs and downtime but also improves the overall configurability of the device, allowing users to select motor or wave generator components of different precision levels according to their needs, thus giving the reduction gear greater flexibility and adaptability.

[0014] Furthermore, since the motor end and wave generator end no longer use an integral structure, the device has greater freedom in assembly layout, allowing the entire deceleration system to achieve more compact space utilization efficiency while maintaining high torsional stiffness. This structure is particularly suitable for robot joint systems with high requirements for reliability, maintainability, and modularity. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0016] Figure 2 This is an exploded view of the structure of this utility model.

[0017] Figure 3 This is an exploded view of another structure of this utility model.

[0018] Figure 4 This is another exploded view of the structure of this utility model.

[0019] Figure 5 This is a schematic diagram of the camshaft structure of this utility model.

[0020] Figure 6 This is a cross-sectional structural diagram of the present invention.

[0021] The reference numerals in the figures include: 11—Steel wheel, 12—Flexible wheel, 13—Wave generator, 14—Reduction output shaft, 15—Cross bearing 121—Bottom wall, 131—Camshaft, 132—Flexible bearing, 131a—Internal spline, 131b—First threaded hole; 2—Motor assembly, 21—Motor output shaft; 22—Motor housing; 23—Motor stator; 24—Motor rotor; 25—First oil seal; 26—First deep groove ball bearing; 27—Second deep groove ball bearing; 28—Flange; 29—Second oil seal. 211—External spline, 212—Second threaded hole; 3—Driver components, 31—Driver mounting plate, 32—Driver end cover. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present utility model, and not all of them. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present utility model. It is understood that the accompanying drawings are provided for reference and illustration only, and are not intended to limit the present utility model. The connection relationships shown in the drawings are only for clear description and do not limit the connection method.

[0023] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this utility model 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, and therefore should not be construed as a limitation of this utility model. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In addition, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances. The terminology used in this specification of this utility model is only for the purpose of describing specific embodiments and is not intended to limit this utility model.

[0024] like Figures 1-6 As shown, this embodiment of the invention provides a highly flexible integrated speed reduction device that is easy to maintain, comprising: Steel wheel 11 has rigid internal teeth; The flexible gear 12 has flexible external teeth that mesh with the internal teeth of the rigid gear; The wave generator 13 includes an elliptical camshaft 131 and a flexible bearing 132 installed inside the flexible wheel 12, sleeved on the camshaft 131, and located on the elliptical structure. The motor assembly 2 has a motor output shaft 21 that is splinedly connected to the end of the camshaft 131 away from the flexible bearing 132.

[0025] Furthermore, the camshaft 131 is provided with an internal spline 131a on the side away from the flexible bearing 132, and the motor output shaft 21 is provided with an external spline 211 that matches the internal spline 131a.

[0026] Furthermore, the camshaft 131 is provided with an external spline 211 on the side away from the flexible bearing 132, and the motor output shaft 21 is provided with an internal spline 131a that matches the internal spline 131a.

[0027] Furthermore, the motor assembly 2 also includes a motor housing 22, a motor stator 23 disposed on the motor housing 22, and a motor rotor 24 disposed on the motor output shaft 21; The flexible wheel 12 has a bottom wall 121 at the end away from the external teeth of the flexible wheel, and one side of the bottom wall 121 abuts against one side of the motor housing 22; The speed reduction device also includes a speed reduction output shaft 14 connected to the steel wheel 11, and a cross bearing 15 connected to the side of the bottom wall 121 away from the motor housing 22.

[0028] Furthermore, motor assembly 2 also includes: The first oil seal 25 is sleeved on the motor output shaft 21 and installed inside the motor housing 22; The first deep groove ball bearing 26 is sleeved on the motor output shaft 21, adjacent to the first oil seal 25, and installed inside the motor housing 22; Flange 28 is installed on the side of the motor housing 22 away from the cross bearing 15; The second deep groove ball bearing 27 is sleeved on the motor output shaft 21, located on the side of the first deep groove ball bearing 26 away from the first oil seal 25, and is connected to the flange 28; The second oil seal 29 is sleeved on the reduction output shaft 14 and connected between the reduction output shaft 14 and the motor output shaft 21.

[0029] Furthermore, it also includes a driver assembly 3 installed on the side of the flange 28 away from the motor housing 22, the driver assembly 3 including a driver mounting plate 31 and a driver end cover 32; The camshaft 131 is provided with a first threaded hole 131b, and the motor output shaft 21 is provided with a second threaded hole 212 that matches the first threaded hole 131b on the end face of one end of the external spline 211. The motor output shaft 21 is inserted into the camshaft 131 to achieve spline connection by aligning the external spline 211 and the internal spline 131a. The connection is then fastened by screws passing through the first threaded hole 131b and the second threaded hole 212.

[0030] In detail: The integrated speed reduction device provided by this utility model integrates the motor assembly 2, the wave generator 13 and the speed reduction mechanism into a single structure and adopts a detachable spline-type split connection method, which enables the device to achieve excellent maintenance convenience and assembly flexibility while maintaining high structural rigidity and high coaxiality.

[0031] In this invention, the camshaft 131 and the motor output shaft 21 are connected by a spline, and the spline is a detachable, modular structure. Unlike traditional harmonic reducers where the motor shaft, wave generator 13 shaft, and encoder shaft are mostly independent components requiring multi-stage connections for power transmission, this invention simplifies the power chain, resulting in a more compact structure and improved torque transmission efficiency through direct spline engagement between the motor output shaft 21 and the camshaft 131. Furthermore, the spline's excellent torsional resistance and angular positioning capability ensure that the wave generator 13 maintains a stable elliptical excitation shape under high loads, thereby guaranteeing the accuracy of the harmonic transmission.

[0032] To ensure the reliability of the spline connection during assembly and replacement, the camshaft 131 has a first threaded hole 131b at its end, and the motor output shaft 21 has a matching second threaded hole 212 on its spline end face. After the spline is aligned, it can be axially tightened by screws passing through the two threaded holes to further prevent axial movement of the spline during long-term operation, improve connection stability, and facilitate subsequent quick disassembly, replacement, and maintenance of the motor assembly 2.

[0033] This invention further employs a multi-layered sealing and support structure to improve the overall assembly density and sealing performance. The first oil seal 25 and the first deep groove ball bearing 26, installed in the motor assembly 2, together with the second deep groove ball bearing 27 mounted on the flange 28, form a two-stage support for the motor output shaft 21. The second oil seal 29, located between the reduction output shaft 14 and the motor output shaft 21, is used to prevent grease from permeating between the wave generator 13 and the motor cavity. Through this structure, a stable grease isolation zone can be formed, preventing grease from entering the motor cavity from the harmonic drive cavity or from leaking in the reverse direction.

[0034] The need for such a high level of sealing and oil prevention capability stems primarily from the following technical reasons: the flexible bearing 132 of the wave generator 13, and the meshing area of ​​the steel wheel 11 and the flexible wheel 12 need to be filled with grease to reduce friction and wear. The internal pressure and temperature rise are relatively high in these areas. If grease enters the motor, it will cause contamination of the motor coils, increased damping of the motor rotor 24, and increased heat generation, severely impacting the motor's lifespan. Furthermore, the spline connection is located between the motor end and the wave generator 13 end. Without strict sealing and isolation, grease may seep into the motor cavity along the spline gap. Therefore, this invention designs the spline connection area as a sealing isolation zone, constructing a double-layer protective structure through the first oil seal 25 and the second oil seal 29, ensuring that the grease is always kept within the wave generator 13 cavity, thereby guaranteeing long-term reliable operation.

[0035] In terms of structure, this invention further provides a reduction output shaft 14 form that facilitates the arrangement of the output structure. This shaft has a "T"-shaped cross-section, including an upper disc-shaped component and a lower tubular component. The tubular component is inserted into the motor output shaft 21 and sealed by a second oil seal 29. This structure not only enhances the supporting rigidity of the output section but also allows for a compact arrangement of the reduction output shaft 14 and the motor assembly 2, which is beneficial for further shortening the overall axial dimension and improving integration.

[0036] In summary, this utility model achieves a comprehensive effect of high coaxiality, high torsional stiffness, high sealing performance, and easy maintenance through split spline connection, double oil seal and multi-bearing support structure, and T-shaped cross-section output shaft. It is particularly suitable for integrated harmonic deceleration systems with high precision and high reliability requirements.

[0037] Furthermore, in this invention, the camshaft 131 and the motor output shaft 21 are connected by a detachable spline, making the motor assembly 2 and the wave generator 13 assembly arranged in a separate structure. Since the two transmit torque through a spline rather than a permanent interference fit or welding structure, the motor output shaft 21 and the camshaft 131 are structurally independent and can be disassembled and replaced separately.

[0038] Specifically, during assembly, the external spline 211 of the motor output shaft 21 and the internal spline 131a (or the opposite spline form) of the camshaft 131 are aligned and inserted into each other. Then, they are secured with screws through the first threaded hole 131b and the second threaded hole 212 at their ends, thus forming a reliable and removable axial positioning method. During disassembly, only the screws need to be removed to separate the motor output shaft 21 from the camshaft 131, and any part can be replaced as needed without replacing the entire reduction gear.

[0039] Because this invention modularizes and separates components such as the motor output shaft 21, camshaft 131, flexible bearing 132, and motor assembly 2, and makes the power transmission path detachable through spline connections, the corresponding component can be replaced individually when a certain part wears, deforms, or fails. For example, when the motor output shaft 21 wears or the bearing area becomes abnormal, the motor assembly 2 can be directly separated from the camshaft 131, and the motor output shaft 21 or the entire motor module can be replaced separately; when the camshaft 131 suffers shape errors or spline wear due to long-term stress, only the camshaft 131 can be disassembled and replaced without replacing the motor assembly 2.

[0040] This discrete, detachable structure significantly reduces maintenance costs and downtime, avoiding the major drawback of traditional integrated harmonic reducers that require complete replacement due to the high coupling between the input shaft, motor shaft, and wave generator 13 shaft. Furthermore, the spline positioning method of this invention ensures high coaxiality and torsional stiffness while also providing good assembly repeatability, allowing the repaired device to maintain its original precision performance.

[0041] Based on the above structural design, this utility model realizes the independent replacement of modular components, making it more convenient to replace and maintain key components such as motor component 2, wave generator 13 component and output component of the speed reduction device, greatly improving reliability and service life, and reducing operation and maintenance costs.

[0042] When this device is in operation, the motor assembly 2 serves as the power input source, providing rotational driving force to the camshaft 131 through its motor output shaft 21. As the motor output shaft 21 rotates, its splined portion engages synchronously with the splined portion of the camshaft 131, causing the camshaft 131 to rotate at an angular velocity consistent with the motor speed. Because the camshaft 131 has an elliptical structure on its outer circumference, when the camshaft 131 rotates, this elliptical structure drives the flexible bearing 132 to produce a periodic eccentric motion.

[0043] The flexible bearing 132 is installed inside the flexible wheel 12 and fitted onto the elliptical structure of the camshaft 131. Therefore, under the periodic deformation of the flexible bearing 132, the external teeth of the flexible wheel 12 synchronously deform into an elliptical shape. As the camshaft 131 rotates continuously, the external teeth of the flexible wheel 12 mesh with the rigid internal teeth of the steel wheel 11 at the major axis of the ellipse, and disengage at the minor axis, thus forming two opposing meshing areas circumferentially around the internal teeth of the steel wheel 11. These meshing areas gradually move along the inner circumference of the steel wheel 11 as the camshaft 131 rotates, causing a slight reverse rotation difference between the flexible wheel 12 and the steel wheel 11.

[0044] Because of the tooth difference transmission relationship between the flexible wheel 12 and the steel wheel 11, and because the number of teeth on the flexible wheel 12 is less than that on the steel wheel 11, the flexible wheel 12 only undergoes a very small cumulative change in angle relative to the steel wheel 11 during each complete input cycle. After multiple cyclic deformations, the output end of the flexible wheel 12 forms a stable low-speed, high-torque output. The steel wheel 11 is fixed to the output end structure, and the deceleration effect is achieved through the relative motion of the flexible wheel 12.

[0045] Throughout the operation, the motor output shaft 21 and the camshaft 131 are connected by a detachable spline, which ensures both the coaxiality and rigidity of the rotary transmission and allows the motor assembly 2 to be disassembled independently without affecting components such as the wave generator 13 or the flexure 12 when maintenance is required. This structure not only ensures continuous stability during operation but also gives the device higher maintainability and operational efficiency.

[0046] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A high-flexibility integrated deceleration device that is easy to maintain, characterized by, include: A steel wheel (11) has rigid internal teeth; The flexible wheel (12) has flexible external teeth that mesh with the internal teeth of the rigid wheel; The wave generator (13) includes a camshaft (131) with an elliptical structure and a flexible bearing (132) installed inside the flexible wheel (12) and sleeved on the camshaft (131) and located on the elliptical structure; The motor assembly (2) has a motor output shaft (21) that is splined to the end of the camshaft (131) away from the flexible bearing (132).

2. The high-flexibility integrated reduction device convenient to maintain according to claim 1, characterized in that, An internal spline (131a) is provided on the side of the camshaft (131) away from the flexible bearing (132), and an external spline (211) matching the internal spline (131a) is provided on the motor output shaft (21).

3. The high-flexibility integrated reduction device convenient to maintain according to claim 1, characterized in that, The camshaft (131) has an external spline (211) on the side away from the flexible bearing (132), and the motor output shaft (21) has an internal spline (131a) that matches the external spline (211).

4. The high-flexibility integrated reduction device convenient to maintain according to claim 2, characterized in that, The motor assembly (2) also includes a motor housing (22), a motor stator (23) disposed on the motor housing (22), and a motor rotor (24) disposed on the motor output shaft (21); The flexible wheel (12) has a bottom wall (121) at the end away from the external teeth of the flexible wheel, and one side of the bottom wall (121) abuts against one side of the motor housing (22); The speed reduction device also includes a speed reduction output shaft (14) connected to the steel wheel (11) and a cross bearing (15) connected to the side of the bottom wall (121) away from the motor housing (22).

5. The high-flexibility integrated reduction device for ease of maintenance according to claim 4, characterized by, The motor assembly (2) also includes: The first oil seal (25) is sleeved on the motor output shaft (21) and installed inside the motor housing (22); The first deep groove ball bearing (26) is sleeved on the motor output shaft (21), adjacent to the first oil seal (25), and installed inside the motor housing (22); Flange (28) is installed on the side of the motor housing (22) away from the cross bearing (15); The second deep groove ball bearing (27) is sleeved on the motor output shaft (21), located on the side of the first deep groove ball bearing (26) away from the first oil seal (25), and connected to the flange (28); The second oil seal (29) is sleeved on the reduction output shaft (14) and connected between the reduction output shaft (14) and the motor output shaft (21).

6. The high-flexibility integrated reduction device for ease of maintenance according to claim 5, characterized by, It also includes a drive assembly (3) installed on the side of the flange (28) away from the motor housing (22), the drive assembly (3) including a drive mounting plate (31) and a drive end cover (32); The camshaft (131) is provided with a first threaded hole (131b), and the motor output shaft (21) is provided with a second threaded hole (212) that matches the first threaded hole (131b) on the end face of one end of the external spline (211). The motor output shaft (21) is inserted into the camshaft (131) to achieve spline connection by aligning the external spline (211) and the internal spline (131a). The connection is then fastened by screws passing through the first threaded hole (131b) and the second threaded hole (212).

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