Harmonic speed reducer
The harmonic drive mechanism addresses the complexity and high maintenance costs of cross-roller bearings by using a flexible bearing and novel internal/external ring arrangement with axial and radial bearings, achieving reduced production and maintenance costs and fluid leakage prevention.
Patent Information
- Application Number
- CN202422582239.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-25
- Publication Date
- 2025-07-15
- Estimated Expiration
- 2034-10-25
AI Technical Summary
The cross roller bearings in existing harmonic reducers have complex structures, high manufacturing costs and complex maintenance, resulting in increased downtime and cost.
Flexible bearings, flexible wheels and rigid wheel structures are adopted, and axial and radial roller bearings are arranged through the design between the outer ring and the extension wall to achieve simultaneous support of radial and axial stresses, and at the same time, the maze sealing structure is used to prevent lubricating fluid leakage.
It reduces the production and maintenance costs of harmonic reducers, and effectively prevents lubricant from leaking out, improving the operating efficiency and service life of the equipment.
Smart Images
Figure CN223105193U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a speed reducer, in particular to a harmonic speed reducer. Background Art
[0002] The existing harmonic speed reducer is configured with crossed roller bearings according to requirements to bear radial and axial loads. However, the crossed roller bearings have some obvious disadvantages. Specifically, the structure of the crossed roller bearings is complex and the manufacturing cost is relatively high. Secondly, when the crossed roller bearings fail or need to be replaced, the maintenance process of the crossed roller bearings is complicated, resulting in increased downtime and costs.
[0003] Therefore, the inventor of the present utility model believes that the above defects can be improved. After painstaking research and in combination with the application of scientific principles, a design reasonable and effectively improving the above defects is finally proposed for the present utility model. Summary of the Utility Model
[0004] The technical problem to be solved by the present utility model is to provide a harmonic speed reducer in view of the deficiencies of the prior art.
[0005] An embodiment of the present utility model discloses a harmonic speed reducer, comprising: a camshaft; a flexible bearing mechanically connected to the camshaft; a flexspline connected to the outer edge of the flexible bearing, the flexspline being drivable by the camshaft through the flexible bearing; a rigid gear connected to the outer edge of the flexspline, the rigid gear being engageable with the flexspline; a first inner ring member disposed on one side of the rigid gear, the first inner ring member comprising: a first body mechanically connected to the rigid gear; and a first extension wall; a second inner ring member disposed on one side of the first inner ring member, the second inner ring member comprising: a second body mechanically connected to the first inner ring member; and a second extension wall; an outer ring member mounted on the flexspline, a part of the outer ring member extending towards the flexspline and located between the first extension wall and the second extension wall; wherein, there is a first radial space between the outer ring member and the first extension wall, there is a second radial space between the outer ring member and the second extension wall, and the outer ring member has an axial space communicating the first radial space and the second radial space; two axial roller bearings disposed in the first radial space and the second radial space; a radial roller bearing disposed in the axial space; two ball bearings fixed on the camshaft; and a first outer cover and a second outer cover, the first outer cover being mounted on one of the ball bearings and mechanically connected to the rigid gear, the second outer cover being mounted on the other ball bearing and mechanically connected to the flexspline.
[0006] Optionally, the harmonic reducer further includes: a first rotary shaft seal abutting against the camshaft and the first outer cover; a second rotary shaft seal abutting against the camshaft and the second outer cover; a third rotary shaft seal abutting against the first inner ring member and the outer ring member; wherein, there is a liquid storage space for accommodating a lubricating liquid between the first rotary shaft seal, the second rotary shaft seal, the camshaft, the flexspline, the first outer cover and the second outer cover, and the liquid storage space communicates with the second radial space.
[0007] Optionally, the outer ring member includes: a first sub-ring member surrounding the first inner ring member; a second sub-ring member mechanically connected to one side of the first sub-ring member along an axial direction and surrounding the second body, the second sub-ring member having a protrusion extending towards the second body, the protrusion being located between the first extension wall and the second extension wall; wherein, there is the first radial space between the protrusion and the first extension wall, there is the second radial space between the protrusion and the second extension wall, and there is the axial space between the protrusion and the second body; a third sub-ring member mechanically connected to one side of the second sub-ring member along the axial direction and surrounding the second inner ring member.
[0008] Optionally, on a side of the first extension wall facing the protrusion, the first extension wall and the protrusion clamp the axial roller bearing located in the first radial space; on a side of the second extension wall facing the protrusion, the second extension wall and the protrusion clamp the axial roller bearing located in the second radial space; neither the first extension wall nor the second extension wall contacts the protrusion.
[0009] Optionally, a side surface of the third sub-ring member facing the second inner ring member has a bump, and the second body and the bump are spaced apart from each other; there is a bent flow passage section between the second radial space and the bump and the second inner ring member.
[0010] Optionally, the width of the bent flow passage section is a first predetermined value, the width of the gap between the first radial space and a third rotary shaft seal of the harmonic reducer located between the first extension wall is a second predetermined value, and the first predetermined value and the second predetermined value are the minimum radial gaps in a labyrinth seal.
[0011] In summary, the harmonic reducer disclosed in the embodiments of the present utility model can, through the design of "there is a first radial space between the outer ring member and the first extended wall, there is a second radial space between the outer ring member and the second extended wall, and the outer ring member has an axial space communicating the first radial space and the second radial space", and "the two axial roller bearings are arranged in the first radial space and the second radial space, and the radial roller bearing is arranged in the axial space", not only realize the simultaneous support of radial and axial stresses through the two axial roller bearings and the radial roller bearing, but also greatly reduce the manufacturing and maintenance costs.
[0012] To further understand the features and technical content of the present utility model, please refer to the following detailed description and drawings of the present utility model. However, these descriptions and drawings are only used to illustrate the present utility model and do not impose any limitation on the protection scope of the present utility model. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 Stereoscopic schematic diagram of the harmonic reduction device of the present utility model.
[0014] Figure 2 Another stereoscopic schematic diagram of the harmonic reduction device of the present utility model.
[0015] Figure 3 Exploded schematic diagram of the harmonic reduction device of the present utility model.
[0016] Figure 4 Partial stereoscopic schematic diagram of the harmonic reduction device of the present utility model.
[0017] Figure 5 For Figure 4 exploded schematic diagram.
[0018] Figure 6 For Figure 1 Cross-sectional schematic diagram along the VI-VI cutting line.
[0019] Figure 7 For Figure 6 partial enlarged schematic diagram.
[0020] Figure 8 For Figure 7 enlarged schematic diagram of area VIII. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0021] The following are specific embodiments to illustrate the disclosed embodiments of the present utility model. Those skilled in the art can understand the advantages and effects of the present utility model from the content disclosed in this specification. The present utility model can be implemented or applied through other different specific embodiments, and various details in this specification can also be modified and changed based on different viewpoints and applications without departing from the concept of the present utility model. In addition, the drawings of the present utility model are only for simple schematic illustration and are not drawn according to actual dimensions. The following embodiments will further detail the related technical content of the present utility model, but the disclosed content is not used to limit the protection scope of the present utility model.
[0022] It should be understood that although terms such as "first", "second", "third", etc. may be used herein to describe various components or signals, these components or signals should not be limited by these terms. These terms are mainly used to distinguish one component from another, or one signal from another. In addition, the term "or" used herein should, depending on the actual situation, possibly include any one or a combination of more of the associated listed items. Furthermore, the term "electrically coupled" used herein refers to one of "indirect electrical connection" and "direct electrical connection".
[0023] Referring to Figures 1 to 8 As shown, this embodiment provides a harmonic reducer 100. As Figures 1 to 3 shown, the harmonic reducer 100 includes a camshaft 1, a flexible bearing 2 mechanically connected to the camshaft 1, a flexspline 3 connected to the outer edge of the flexible bearing 2, a rigid gear 4 meshed with the flexspline 3, a first inner ring member 5 provided on one side of the rigid gear 4, a second inner ring member 6 provided on one side of the first inner ring member 5, an outer ring member 7 surrounding the outer edges of the first inner ring member 5 and the second inner ring member 6, two axial roller bearings 8A and a radial roller bearing 8B provided between the first inner ring member 5, the second inner ring member 6 and the outer ring member 7, two ball bearings 9 mechanically connected to the camshaft 1, a first outer cover 10A provided between one of the ball bearings 9 and the rigid gear 4, and a second outer cover 10B provided between the other ball bearing 9 and the flexspline 3.
[0024] In cooperation with Figure 2 、 Figure 3 、and Figure 6 shown, the camshaft 1 has an axial direction D1 and a radial direction D2. The camshaft 1 includes a shaft body 11 having a hollow structure and an outer convex portion 12 on the outer edge of the shaft body 11.
[0025] Referring back to Figure 3 and Figure 6As shown, the flexible bearing 2 is mechanically connected to the outer protrusion 12. The inner edge of the flexible bearing 2 is mechanically connected to the outer protrusion 12 of the camshaft 1, and the outer edge of the flexible bearing 2 is mechanically connected to the inner edge of the flexible wheel 3, so that the flexible wheel 3 can be driven by the camshaft 1 through the flexible bearing 2. The rigid wheel 4 meshes with the outer teeth of the flexible wheel 3, so that the rigid wheel 4 is driven by the flexible wheel 3. Among them, the mechanical connection referred to in the utility model can be any physical method that can fix two components to each other, such as friction and interference fit.
[0026] Re-reference Figure 3 , Figure 6 and Figure 7 As shown, in this embodiment, the flexible wheel 3 includes a radial portion 32 and an axial portion 31, and the radial portion 32 is clamped by the second outer cover 10B and the outer ring 7. The axial portion 31 is mechanically connected to the flexible bearing 2 and meshes with the rigid wheel 4.
[0027] like Figures 5 to 7 As shown, the first inner ring member 5 is arranged on one side of the rigid wheel 4, so that the first inner ring member 5 can rotate synchronously with the rigid wheel 4. The first inner ring member 5 is located on the left side of the rigid wheel 4.
[0028] In this embodiment, the first inner ring member 5 further includes a first body 51 and a first extension wall 52 connected to the first body 51. The first body 51 is mechanically connected to the rigid wheel 4 at one side in the axial direction D1, the first extension wall 52 extends from the first body 51 in a radial direction away from the flexible wheel 3, and the first extension wall 52 is located on a side of the first body 51 facing the protrusion 721.
[0029] Re-reference Figures 6 to 8 As shown, the second inner ring member 6 is arranged on the left side of the first inner ring member 5 , so that the second inner ring member 6 can rotate synchronously with the first inner ring member 5 .
[0030] In this embodiment, the second inner ring member 6 further includes a second body 61 and a second extension wall 62 connected to the second body 61. The second body 61 is mechanically connected to the other side of the first inner ring member 5 in the axial direction D1 on one side of the axial direction D1, and the second extension wall 62 extends from the second body 61 in a radial direction away from the flexible wheel 3, and the second extension wall 62 is spaced from the first extension wall 52. The second extension wall 62 is located on the side of the second body 61 facing the protrusion 721. Figures 4 to 6As shown, the outer ring member 7 surrounds the first inner ring member 5 and the second inner ring member 6, and the outer ring member 7 is mechanically connected to the flexspline 3. Among them, the second sub-ring member 72 extends towards the second body 61 and is located between the first extension wall 52 and the second extension wall 62, such that there is a first radial space SP1 between the protrusion 721 and the first extension wall 52, there is a second radial space SP2 between the protrusion 721 and the second extension wall 62, and the outer ring member 7 has an axial space communicating the first radial space SP1 and the second radial space SP2. That is to say, the first radial space SP1, the second radial space SP2, and the axial space SP3 are generally configured in a C shape.
[0031] In this embodiment, the outer ring member 7 is a combined structure. Specifically, the outer ring member 7 includes a first sub-ring member 71, a second sub-ring member 72, and a third sub-ring member 73 that are assembled with each other. The first sub-ring member 71 surrounds the first inner ring member 5. The second sub-ring member 72 is mechanically connected to one side of the first sub-ring member 71 and surrounds the second body 61. The third sub-ring member 73 is mechanically connected to one side of the second sub-ring member 72 and surrounds the second inner ring member 6.
[0032] It should be particularly noted that referring to Figure 6 and Figure 7 As shown, in practice, the outer diameters of the first sub-ring member 71, the second sub-ring member 72, and the third sub-ring member 73 are the same as each other in this embodiment, and the second sub-ring member 72 has a protrusion 721 extending towards the second body 61. The protrusion 721 is located between the first extension wall 52 and the second extension wall 62, and there can be the first radial space SP1 between the protrusion 721 and the first extension wall 52, there can be the second radial space SP2 between the protrusion 721 and the second extension wall 62, and there is the axial space SP3 between the protrusion 721 and the second body 61, but the present invention is not limited thereto.
[0033] For example, in other embodiments not shown in the present invention, the first sub-ring member 71, the second sub-ring member 72, and the third sub-ring member 73 can also be integrally connected, such that the outer ring member 7 is a single-piece member. Optionally, as Figure 8 shown, the first extension wall 52 and the second extension wall 62 can be designed to be stepped.
[0034] Referring to Figure 8As shown, two of the axial roller bearings 8A are respectively disposed within the first radial space SP1 and the second radial space SP2. Among them, the axial roller bearing 8A located within the first radial space SP1 abuts against the protruding portion 721 and the first extension wall 52. The axial roller bearing 8A located within the second radial space SP2 abuts against the protruding portion 721 and the second extension wall 62.
[0035] In practice, the axial roller bearing 8A includes a retaining member 81A and a plurality of rollers 82A disposed on the retaining member 81A, and the rollers 82A are not affected by the retaining member 81A to roll, so that the outer ring member 7 can rotate relative to the first inner ring member 5 and the second inner ring member 6 through the two axial roller bearings 8A and is provided with a supporting force in the axial direction D1.
[0036] As Figure 8 shown, the radial roller bearing 8B is disposed within the axial space SP3, and the radial roller bearing 8B abuts against the protruding portion 721 and the second body 61.
[0037] In practice, the radial roller bearing 8B includes a retaining member 81B and a plurality of rollers 82B disposed on the retaining member 81B, and the rollers 82B are not affected by the retaining member 81B to roll, so that the outer ring member 7 can rotate relative to the first inner ring member 5 and the second inner ring member 6 through the radial roller bearing 8B and is provided with a supporting force in the radial direction D2.
[0038] As Figure 3 and Figure 6 shown, the inner rims of two of the ball bearings 9 are mechanically connected to the outer rim of the camshaft 1, and the outer rims of the two ball bearings 9 are respectively mechanically connected to the first outer cover 10A and the second outer cover 10B. Among them, the first outer cover 10A is mechanically connected to the rigid gear 4. Additionally, the second outer cover 10B is mechanically connected to the flexible gear 3.
[0039] It is worth noting that, as Figure 3 and Figure 7 shown, in order to ensure that the components within the harmonic speed reducer 100 can operate smoothly and extend the service life, the harmonic speed reducer 100 may further include a first rotary shaft seal 11A, a second rotary shaft seal 11B, and a third rotary shaft seal 11C to ensure that a lubricating fluid (not shown) can be accommodated within the harmonic speed reducer 100.
[0040] Specifically, the first rotary shaft seal 11A is disposed on the outer edge of the camshaft 1 and located between one of the ball bearings and the first outer cover 10A to ensure that the lubricating fluid can pass through one of the ball bearings 9 and does not leak out from the gap between the camshaft 1 and the first outer cover 10A.
[0041] The second rotary shaft seal 11B is disposed on the outer edge of the camshaft 1 and located between the other ball bearing 9 and the second outer cover 10B to ensure that the lubricating fluid can pass through the other ball bearing 9 and does not leak out from the gap between the camshaft 1 and the second outer cover 10B.
[0042] The third rotary shaft seal 11C is disposed on the first body 51 of the first inner ring member 5. The third rotary shaft seal 11C can abut against the first inner ring member 5 and the inner edge of the outer ring member 7, so that the lubricating fluid does not leak out from the gap between the first extension wall 52 and the inner edge of the outer ring member 7.
[0043] There is a liquid storage space M for accommodating the lubricating fluid between the first rotary shaft seal 11A, the second rotary shaft seal 11B, the camshaft 1, the flexspline 3, the rigid gear 4, the first inner ring member 5, the second inner ring member 6, the first outer cover 10A and the second outer cover 10B. The liquid storage space M communicates with the second radial space SP2.
[0044] As Figure 8 shown, when the harmonic reducer 100 starts, the lubricating fluid suddenly accumulates in the outer space (i.e., the first radial space SP1, the second radial space SP2, and the axial space SP3) due to rotational inertia. Therefore, the second radial space SP2 may also have a bent flow passage section G at the place where it communicates with the liquid storage space M to control the flow rate and flow volume of the lubricating fluid entering the second radial space SP2.
[0045] Specifically, one side of the third sub-ring member 73 facing the second inner ring member 6 has a convex block 731, and the convex block 731 and the second extension wall 62 are spaced apart from each other. Accordingly, there is the bent flow passage section G between the second radial space SP2, the convex block 731, and the second extension wall 62.
[0046] It should be noted that the width of the bent flow channel section G is designed such that the lubricating fluid is not easily passed through, that is, the lubricating fluid can generally stay in the first radial space SP1, the second radial space SP2, and the axial space SP3. Of course, the width of the gap between the first extension wall 52 and the third rotary shaft seal 11C where the first radial space SP1 is located can also be designed such that the lubricating fluid is not easily passed through, so as to achieve the effect of "staying in the first radial space SP1, the second radial space SP2, and the axial space SP3".
[0047] In addition, it should be emphasized that the first radial space SP1, the second radial space SP2, the axial space SP3, the bent flow channel section G, and the "gap between the first radial space SP1 located between the first extension wall 52 and the third rotary shaft seal 11C" can be designed in the structure of a "Labyrinth Seal".
[0048] Specifically, the principle of the "Labyrinth Seal" is as follows: It is composed of multiple layers of staggered grooves and protrusions, forming a structure similar to a labyrinth, thereby increasing the volume change of the path of the lubricating fluid passing through the seal and changing the flow resistance. When the liquid flows from the high-pressure end to the low-pressure end, it will pass through a series of small gaps and cavities in the labyrinth seal. When the liquid passes through these small gaps, the flow velocity will increase, and the pressure and temperature will decrease. Then, when the liquid enters the larger cavity, the velocity will suddenly slow down, generating eddies, so that the kinetic energy will be converted into heat, the pressure remains unchanged but the temperature will rise to the previous level. This process will repeat in each pair of gaps and cavities in the labyrinth seal. Each time the liquid passes through a gap, the pressure will drop a little, and as the volume of the liquid increases, the flow velocity will also become faster and faster. When reaching the downstream of the labyrinth seal, the decrease in pressure will become more obvious. Finally, when the liquid passes through all the gaps and cavities, the pressure is almost close to the external back pressure (low pressure), and the temperature remains unchanged. In this way, the liquid is effectively sealed and will not leak easily. In practice, the width of the bent flow channel section G is a first predetermined value, the width of the gap between the first radial space SP1 located between the first extension wall 52 and the third rotary shaft seal 11C is a second predetermined value, and the first predetermined value and the second predetermined value are the minimum radial gaps in the labyrinth seal.
[0049] In addition, in order to prevent the lubricating fluid from leaking from the first radial space SP1, the second radial space SP2, the axial space SP3, and the liquid storage space M, the harmonic reducer 100 can also have a rubber ring (not marked) between each component, but the present invention is not limited thereto.
[0050] [Technical effects of the embodiments of the present utility model]
[0051] The harmonic reducer disclosed in the embodiments of the present utility model can, through the design of "there is a first radial space between the outer ring member and the first extended wall, there is a second radial space between the outer ring member and the second extended wall, and the outer ring member has an axial space connecting the first radial space and the second radial space", and "two axial roller bearings are arranged in the first radial space and the second radial space, and the radial roller bearings are arranged in the axial space", not only realize the simultaneous support of radial and axial stresses through the two axial roller bearings and the radial roller bearings, but also greatly reduce the manufacturing and maintenance costs. In addition, the aforementioned design can also effectively prevent the lubricating fluid from unexpectedly leaking out from the interior of the harmonic reducer (for example: the third rotary shaft seal).
[0052] The above are only the preferred feasible embodiments of the present utility model, and are not intended to limit the protection scope of the present utility model. All equivalent changes and modifications made according to the scope of the patent application of the present utility model shall fall within the protection scope of the claims of the present utility model.
Claims
1. A harmonic reducer, characterized in that, The harmonic reducer includes: A camshaft; A flexible bearing, mechanically connected to the camshaft; A flexspline, connected to the outer edge of the flexible bearing, and the flexspline can be driven by the camshaft through the flexible bearing; A rigid ring, connected to the outer edge of the flexspline, and the rigid ring can mesh with the flexspline; A first inner ring member, disposed on one side of the rigid ring, and the first inner ring member includes: A first body, mechanically connected to the rigid ring; and A first extension wall; A second inner ring member, disposed on one side of the first inner ring member, and the second inner ring member includes: A second body, mechanically connected to the first inner ring member; and A second extension wall; An outer ring member, mounted on the flexspline, and a part of the outer ring member extends towards the flexspline and is located between the first extension wall and the second extension wall; wherein, there is a first radial space between the outer ring member and the first extension wall, there is a second radial space between the outer ring member and the second extension wall, and the outer ring member has an axial space communicating the first radial space and the second radial space; Two axial roller bearings, disposed in the first radial space and the second radial space; A radial roller bearing, disposed in the axial space; Two ball bearings, fixed on the camshaft; and A first outer cover and a second outer cover, the first outer cover is mounted on one of the ball bearings and mechanically connected to the rigid ring, and the second outer cover is mounted on the other ball bearing and mechanically connected to the flexspline.
2. The harmonic speed reducer according to claim 1, wherein, The harmonic reducer further includes: a first rotary shaft seal, abutting against the camshaft and the first outer cover; A second rotary shaft seal, abutting against the camshaft and the second outer cover; A third rotary shaft seal, abutting against the first inner ring member and the outer ring member; Wherein, there is a liquid storage space for accommodating a lubricating liquid between the first rotary shaft seal, the second rotary shaft seal, the camshaft, the flexspline, the first outer cover and the second outer cover, and the liquid storage space communicates with the second radial space.
3. The harmonic reducer according to claim 1, wherein The outer ring member includes: A first sub-ring member, surrounding the first inner ring member; A second sub-ring member, mechanically connected to one side of the first sub-ring member along an axial direction and surrounding the second body, and the second sub-ring member has a protrusion extending towards the second body, and the protrusion is located between the first extension wall and the second extension wall; wherein, there is the first radial space between the protrusion and the first extension wall, there is the second radial space between the protrusion and the second extension wall, and there is the axial space between the protrusion and the second body; A third sub-ring member, mechanically connected to one side of the second sub-ring member along the axial direction and surrounding the second inner ring member.
4. The harmonic speed reducer according to claim 3, characterized in that, On the side of the first extended wall facing the protruding part, the first extended wall and the protruding part clamp the axial roller bearing located in the first radial space; on the side of the second extended wall facing the protruding part, the second extended wall and the protruding part clamp the axial roller bearing located in the second radial space; neither the first extended wall nor the second extended wall contacts the protruding part.
5. The harmonic reducer according to claim 4, wherein One side of the third sub-ring member facing the second inner ring member has a convex block, and the second body and the convex block are spaced apart from each other; there is a bent flow channel section between the second radial space, the convex block, and the second inner ring member.
6. The harmonic speed reducer according to claim 5, wherein, The width of the bent flow channel section is a first predetermined value, and the width of the gap between the first radial space and a third rotary shaft seal of the harmonic reducer located between the first extended wall is a second predetermined value. The first predetermined value and the second predetermined value are the minimum radial gaps in the labyrinth seal.