A lightweight harmonic reducer

Abstract

The utility model relates to harmonic reducer technical field especially relates to a light harmonic reducer, including the casing, still including wave generator and rotating assembly, the casing is composed of lower casing and upper casing, the rotating assembly includes flexspline, rigid wheel and cross bearing, the flexspline is fixedly connected with the lower casing through a plurality of circumferential even distribution's first locking screw, is set up with the intercalation groove of cross bearing adaptation on the lower casing, the lower casing is fixedly connected with upper casing through a plurality of circumferential even distribution's third locking screw, to the cross bearing is embraced tightly fixed between intercalation groove and upper casing. The utility model reduces the number of threaded holes on the cross bearing, directly reduces its wall thickness and volume, reduces the use proportion of high-density metal, the external mounting structure of cross structure all changes to aluminium piece, replaces the traditional heavier metal material, makes harmonic reducer overall weight drop greatly.

Description

Technical Field

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

[0002] Harmonic gear reducers are transmission devices that use a wave generator to produce controllable elastic deformation waves from a flexible gear. These waves interact with a rigid gear to transmit motion and power. They feature simple structure, large transmission ratio (i=30~300 for a single-stage harmonic gear drive), stable transmission, high precision, and low backlash. Harmonic gear reducers are increasingly widely used in aviation, aerospace, energy, navigation, shipbuilding, bionic machinery, robotics, machine tools, instruments, electronic equipment, mining and metallurgy, transportation, textile machinery, and medical devices.

[0003] Currently, existing cross bearings are made of GCr15 material, and both the inner and outer rings have threaded holes for connection. This makes the walls of both the inner and outer rings relatively thick, naturally resulting in a heavier cross bearing. Consequently, the reducer becomes heavier, and the robotic arm equipped with these reducers will have a large moment of inertia when rotating. This large moment of inertia will have a negative impact on the robotic arm, leading to poor performance. Utility Model Content

[0004] The purpose of this invention is to solve the aforementioned problems existing in the prior art by proposing a lightweight harmonic reducer.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a lightweight harmonic reducer, comprising a housing, a wave generator, and a rotating assembly. The housing consists of a lower housing and an upper housing. The rotating assembly includes a flexible wheel, a rigid wheel, and a cross bearing. The flexible wheel is fixedly connected to the lower housing by a plurality of circumferentially evenly distributed first locking screws. The lower housing has a fitting groove adapted to the cross bearing. The lower housing is fixedly connected to the upper housing by a plurality of circumferentially evenly distributed third locking screws to hold and fix the cross bearing between the fitting groove and the upper housing. The rigid wheel is fixedly connected to the cross bearing by a plurality of circumferentially evenly distributed second locking screws.

[0006] Preferably, the wave generator includes a cam and a flexible bearing, the flexible bearing being fixedly mounted on the inner wall of the flexible wheel, the outer ring of the cam being interference-fitted with the inner ring of the flexible bearing, and the number of teeth on the outer ring of the flexible wheel being less than the number of teeth on the inner ring of the rigid wheel.

[0007] Preferably, the lower housing is provided with a boss, and the upper housing is provided with a groove adapted to the boss, and the boss and the groove are fitted together.

[0008] Preferably, a skeleton oil seal is fitted on the outer side of the cross bearing to prevent lubricating oil from seeping out of the harmonic reducer.

[0009] Preferably, a first sealing ring is provided on the side of the lower housing near the upper housing, and a second sealing ring is provided on the side of the lower housing near the flexible wheel.

[0010] Preferably, the cross bearing is combined with the lower housing and the upper housing to form a cross structure, and its external mounting structure is made of aluminum.

[0011] Compared with existing technologies, the advantages of this utility model are: 1. This utility model reduces the number of threaded holes on the cross bearing, thereby directly reducing its wall thickness and volume, reducing the proportion of high-density metal used, and replacing all external mounting structures of the cross structure with aluminum parts, replacing the traditional heavier metal materials. This allows the cross bearing alone to achieve effective weight reduction, ultimately achieving the goal of significantly reducing the overall weight of the harmonic reducer.

[0012] 2. While reducing weight, this utility model ensures the stability and fitting accuracy of core components through multiple structural designs: the lower housing and the upper housing are locked together by a third locking screw, forming a "clamping" structure for the cross bearing, limiting its radial and axial displacement and ensuring its stable position as a reference component; the boss of the lower housing fits into the groove of the upper housing, which not only enhances the tightness of the fit between the two, but also ensures concentricity and avoids the transmission being affected by assembly deviations; the flexible wheel and the lower housing, and the rigid wheel and the cross bearing are all fixed by circumferentially evenly distributed locking screws, ensuring that each core component does not loosen during high-speed operation.

[0013] 3. This utility model prevents internal lubricating oil leakage and ensures long-term stable operation of the reducer through a multi-seal design: the skeleton oil seal sleeved on the outside of the cross bearing has an internal spring that can fix its own position, effectively preventing grease from flowing out from the gap between the inner ring of the cross structure and the upper housing; a first sealing ring is set between the lower housing and the upper housing, and a second sealing ring is set between the lower housing and the flexible wheel, respectively sealing two key gaps to form a comprehensive anti-leakage system, ensuring that the grease always remains in the internal cavity, reducing component wear and extending the service life of the reducer. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of a lightweight harmonic reducer proposed in this utility model. Figure 2 This is a schematic diagram of the second locking screw and rigid wheel structure of a lightweight harmonic reducer proposed in this utility model; Figure 3 This is a cross-sectional view of a lightweight harmonic reducer proposed in this utility model. Figure 4for Figure 3 Enlarged detail image of point A in the middle; Figure 5 A cross-sectional view of the flex wheel and lower housing of a lightweight harmonic reducer proposed in this utility model; Figure 6 This is a cross-sectional view of the lower housing, upper housing, and cross bearing of a lightweight harmonic reducer proposed in this utility model.

[0015] In the diagram: 1. Flexible wheel, 2. Lower housing, 3. Upper housing, 4. First locking screw, 5. Flexible bearing, 6. Rigid wheel, 7. Second locking screw, 8. Skeleton oil seal, 9. Cross bearing, 10. First sealing ring, 11. Second sealing ring, 12. Third locking screw. Detailed Implementation

[0016] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0017] Reference Figures 1 to 6 A lightweight harmonic reducer includes a wave generator, a rotating assembly, a lower housing 2, and an upper housing 3. The rotating assembly includes a flexible wheel 1, a rigid wheel 6, and a cross bearing 9. The flexible wheel 1 is fixedly connected to the lower housing 2 by multiple first locking screws 4, which are evenly distributed around the circumference of the flexible wheel 1. The lower housing 2 has a fitting groove adapted to the cross bearing 9. The lower housing 2 is fixedly connected to the upper housing 3 by multiple third locking screws 12, which are evenly distributed around the circumference of the lower housing 2 and the upper housing 3. In actual assembly, after the cross bearing 9 is embedded in the pre-set fitting groove of the lower housing 2 and the upper housing 3 covers the lower housing 2, tightening the third locking screws 12 forms a "clamping" structure for the cross bearing 9, which restricts the radial and axial displacement of the cross bearing 9 and ensures the positional stability of the cross bearing 9 as a core reference component. The upper housing 3 and lower housing 2 form a complete outer shell, providing protection and support for internal components and ensuring the integrity of the entire reducer housing. The cross bearing 9, together with the lower housing 2 and upper housing 3, forms a complete cross structure. The external mounting structure of this cross structure is made of aluminum. By reducing the number of threaded holes required on the cross bearing 9, the wall thickness of the cross bearing 9 is reduced, greatly reducing the volume of the cross bearing 9 and the proportion of high-density metal, thereby reducing the weight of the harmonic reducer. The lower housing 2 is provided with a boss, and the upper housing 3 is provided with a groove that matches the boss. The fit between the boss and the groove makes the lower housing 2 and the upper housing 3 fit more tightly and ensures their concentricity. The rigid wheel 6 is fixedly connected to the cross bearing 9 by multiple second locking screws 7, which are evenly distributed along the circumference of the rigid wheel 6.

[0018] The wave generator includes a cam and a flexible bearing 5. The outer surface of the cam has an elliptical structure with major and minor axes. The flexible bearing 5 is fixedly installed on the inner wall of the flexible wheel 1. The outer ring of the cam and the inner ring of the flexible bearing 5 are interference-fitted and closely fitted. When the cam rotates, the flexible bearing 5 undergoes elastic deformation along with the elliptical structure of the cam, thereby driving the flexible wheel 1 to generate radial deformation synchronously (forming major and minor axes corresponding to the cam). The outer ring of the flexible wheel 1 is provided with teeth (the number of teeth is the reduction ratio × 2), and the inner ring of the rigid wheel 6 is provided with teeth (the number of teeth is the reduction ratio × 2 + 2). After the deformation of the flexible wheel 1, the external teeth at the major axis mesh precisely with the internal teeth of the rigid wheel 6. Due to the difference in the number of teeth between the flexible wheel 1 and the rigid wheel 6, a reduction output is achieved. After the harmonic reducer is assembled, its internal cavity is filled with a sufficient amount of grease for lubrication during meshing. A skeleton oil seal 8 is fitted on the outside of the cross bearing 9. The spring inside the skeleton oil seal 8 fixes its position. The skeleton oil seal 8 can prevent grease from flowing out from the gap between the inner ring of the cross structure and the upper housing 3 during normal operation of the harmonic reducer. A first sealing ring 10 is provided on the side of the lower housing 2 near the upper housing 3. The first sealing ring 10 is used to prevent grease leakage caused by the gap between the lower housing 2 and the upper housing 3. A second sealing ring 11 is provided on the side of the lower housing 2 near the flexible wheel 1. The second sealing ring 11 is used to prevent grease leakage from the gap between the lower housing 2 and the flexible wheel 1.

[0019] In operation, the cross bearing 9 is positioned between the lower housing 2 and the upper housing 3. Since the lower housing 2 and the upper housing 3 are locked together by the third locking screw 12, the cross bearing 9 is held tightly by the lower housing 2 and the upper housing 3, forming a complete cross structure. The external mounting structure of this cross structure is made entirely of aluminum, which not only ensures structural stability but also reduces the weight of the cross bearing 9 by more than 40%, thus achieving an overall weight reduction effect for the harmonic reducer. The flexible wheel 1 is locked to the lower housing 2 by the first locking screw 4, and the rigid wheel 6 is locked to the cross bearing 9 by the second locking screw 7. The upper boss of the lower housing 2 fits into the upper groove of the upper housing 3, ensuring a tight fit between the lower housing 2 and the upper housing 3. In operation, the cam extends into the inner side of the flexible bearing 5. The elliptical cam has long and short axes, which are used to deform the flexible wheel 1. The cam and the flexible bearing 5 combine to form a wave generator, which is used to deform the flexible wheel 1. After deformation, the flexible wheel 1 has long and short axes. The external teeth at the long axis will mesh with the internal teeth of the rigid wheel 6. Due to the difference in the number of teeth between the rigid wheel 6 and the flexible wheel 1, there is a difference in the rotational speed between the flexible wheel 1 and the rigid wheel 6, thus achieving deceleration. The first sealing ring 10 is used to seal the gap between the upper housing 3 and the cross bearing 9 to prevent oil leakage. The second sealing ring 11 is used to seal the gap between the lower housing 2 and the flexible wheel 1. The skeleton oil seal 8 is sleeved on the outside of the cross bearing 9 to prevent grease from flowing out of the internal cavity of the harmonic reducer.

[0020] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. 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 lightweight harmonic reducer, comprising a housing, characterized in that, It also includes a wave generator and a rotating assembly. The housing consists of a lower housing (2) and an upper housing (3). The rotating assembly includes a flexible wheel (1), a rigid wheel (6), and a cross bearing (9). The flexible wheel (1) is fixedly connected to the lower housing (2) by a plurality of circumferentially evenly distributed first locking screws (4). The lower housing (2) has a fitting groove adapted to the cross bearing (9). The lower housing (2) is fixedly connected to the upper housing (3) by a plurality of circumferentially evenly distributed third locking screws (12) to hold the cross bearing (9) tightly between the fitting groove and the upper housing (3). The rigid wheel (6) is fixedly connected to the cross bearing (9) by a plurality of circumferentially evenly distributed second locking screws (7).

2. The lightweight harmonic reducer according to claim 1, characterized in that, The wave generator includes a cam and a flexible bearing (5). The flexible bearing (5) is fixedly installed on the inner wall of the flexible wheel (1). The outer ring of the cam is interference-fitted with the inner ring of the flexible bearing (5). The number of teeth on the outer ring of the flexible wheel (1) is less than the number of teeth on the inner ring of the rigid wheel (6).

3. The lightweight harmonic reducer according to claim 1, characterized in that, The lower housing (2) is provided with a boss, and the upper housing (3) is provided with a groove that matches the boss. The boss and the groove fit together.

4. A lightweight harmonic reducer according to claim 1, characterized in that, The cross bearing (9) is fitted with a skeleton oil seal (8) on its outer side, which is used to prevent lubricating oil from seeping out of the harmonic reducer.

5. A lightweight harmonic reducer according to claim 1, characterized in that, The lower housing (2) is provided with a first sealing ring (10) on the side near the upper housing (3), and the lower housing (2) is provided with a second sealing ring (11) on the side near the flexible wheel (1).

6. A lightweight harmonic reducer according to claim 1, characterized in that, The cross bearing (9) is combined with the lower housing (2) and the upper housing (3) to form a cross structure, and its external mounting structure is made of aluminum.

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