TWI888301B - Harmonic reducer - Google Patents

Abstract

A harmonic reducer is provided. The harmonic reducer includes a camshaft, a flexible bearing, a flexspline, a rigid spline, first and second inner ring components, an outer ring component, two first roller bearings, a second roller bearing, two ball bearings, and first and second outer covers. The flexible bearing is mechanically connected to the camshaft. The flexspline is connected to the outer edge of the flexible bearing. The rigid spline meshes with the outer edge of the flexspline. The first inner ring component is positioned on one side of the rigid spline. The second inner ring component is positioned on one side of the first inner ring component. Both the first and second inner ring components each include a main body and an extending wall connected to the main body. The outer ring component is installed on the outer edges of the first and second inner ring components. Part of the outer ring component is located between the extending walls of the first and second inner ring components, forming two radial spaces to accommodate the two first roller bearings and an axial space to accommodate the second roller bearing.

Description

Harmonic reducer

The present invention relates to a speed reducer, and more particularly to a harmonic speed reducer.

Existing harmonic reducers are equipped with crossed roller bearings as required to bear radial and axial loads. However, crossed roller bearings have some obvious disadvantages. Specifically, the crossed roller bearings have a complex structure and high manufacturing costs. 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.

Therefore, the inventors of the present invention believe that the above defects can be improved, and have conducted intensive research and applied scientific principles to finally propose the present invention which has a reasonable design and effectively improves the above defects.

The technical problem to be solved by the present invention is to provide a harmonic reducer to address the deficiencies of the prior art.

The embodiment of the present invention discloses a harmonic reducer, comprising: a camshaft; a flexible bearing mechanically connected to the camshaft, the flexible bearing mechanically connected to the camshaft; a flexwheel connected to the outer edge of the flexible bearing, the flexwheel can be driven by the camshaft through the flexible bearing; a conical wheel connected to the outer edge of the flexwheel, the conical wheel can engage the flexwheel; a first An inner ring is disposed on one side of the rebar, the first inner ring comprises: a first body, mechanically connected to the rebar; and a first extension wall; a second inner ring is disposed on one side of the first inner ring, the second inner ring comprises: a second body, mechanically connected to the first inner ring; and a second extension wall; an outer ring is mounted on the flexible wheel and mechanically connected to the outer ring, A portion of the outer ring extends toward the flexible wheel and is located between the first extension wall and the second extension wall; wherein a first radial space is provided between the outer ring and the first extension wall, a second radial space is provided between the outer ring and the second extension wall, and the outer ring has an axial space connecting the first radial space and the second radial space; two axial roller bearings , arranged in the first radial space and the second radial space; a radial roller bearing, arranged in the axial space; two ball bearings, fixed on the cam shaft; and a first outer cover and a second outer cover, the first outer cover is installed on one of the ball bearings and mechanically connected to the steel wheel, and the second outer cover is installed on the other ball bearing and mechanically connected to the flexible wheel.

Preferably, the outer ring component includes: a first sub-ring component, which surrounds the first inner ring component; a second sub-ring component, which is mechanically connected to one side of the first sub-ring component along an axial direction and surrounds the second main body, and the second sub-ring component has a protrusion extending toward the second main body, and the protrusion is located between the first extension wall and the second extension wall; wherein, the first radial space is between the protrusion and the first extension wall, the second radial space is between the protrusion and the second extension wall, and the axial space is between the protrusion and the second body; a third sub-ring component, which is mechanically connected to one side of the second sub-ring component along the axial direction and surrounds the second inner ring component.

Preferably, the first extension wall faces one side of the protrusion, and the first extension wall and the protrusion clamp the axial roller bearing located in the first radial space; the second extension wall faces one side of the protrusion, and the second extension wall and the protrusion clamp the axial roller bearing located in the second radial space; the first extension wall and the second extension wall do not contact the protrusion.

Preferably, the third sub-ring has a protrusion on a side surface facing the second inner ring, and the second body and the protrusion are spaced apart from each other; the second radial space has a curved flow section between the protrusion and the second inner ring.

Preferably, the width of the curved flow channel section is a first predetermined value, the width of the gap between the first radial space and the third rotary shaft seal is a second predetermined value, and the first predetermined value and the second predetermined value are a minimum radial gap of the labyrinth seal.

In summary, the harmonic reducer disclosed in the embodiment of the present invention can achieve the following advantages: "a first radial space is provided between the outer ring and the first extension wall, a second radial space is provided between the outer ring and the second extension wall, and the outer ring has an axial space connecting the first radial space and the second radial space", "the two radial spaces are provided between the outer ring and the second extension wall, and the outer ring has an axial space connecting the first radial space and the second radial space". The axial roller bearing is arranged in the first radial space and the second radial space, and the radial roller bearing is arranged in the axial space". The harmonic reducer can not only support radial and axial stresses at the same time through the two axial roller bearings and the radial roller bearing, but also greatly reduce the manufacturing and maintenance costs.

To further understand the features and technical contents of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings provided are only used for reference and description and are not used to limit the present invention.

The following is a specific embodiment to illustrate the implementation of the "harmonic reducer" disclosed in the present invention. The technical personnel in this field can understand the advantages and effects of the present invention from the content disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments. The details in this specification can also be modified and changed in various ways based on different viewpoints and applications without deviating from the concept of the present invention. In addition, the drawings of the present invention are only for simple schematic illustration and are not depicted according to actual size. Please note in advance. The following implementation will further explain the relevant technical content of the present invention in detail, but the disclosed content is not used to limit the scope of protection of the present invention.

It should be understood that, although the terms "first", "second", "third", etc. may be used in this document 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 component, or one signal from another signal. In addition, the term "or" used in this document may include any one or more combinations of the related listed items depending on the actual situation.

In addition, in the following description, if it is indicated to refer to a specific figure or as shown in a specific figure, it is only used to emphasize that most of the related content described in the subsequent description appears in the specific figure, but it does not limit the subsequent description to only refer to the specific figure.

Referring to FIGS. 1 to 8 , the present embodiment provides a harmonic reducer 100. As shown in FIGS. 1 to 3 , the harmonic reducer 100 comprises a camshaft 1, a flexible bearing 2 mechanically connected to the camshaft 1, a flexible wheel 3 connected to the outer edge of the flexible bearing 2, a steel wheel 4 engaged with the flexible wheel 3, a first inner ring 5 disposed on one side of the steel wheel 4, a second inner ring 6 disposed on one side of the first inner ring 5, and a plurality of outer rings surrounding the outer edge of the first inner ring 5 and the second inner ring. An outer ring member 7 is provided on the outer edge of the first inner ring member 5, the second inner ring member 6 and the outer ring member 7, two axial roller bearings 8A and a radial roller bearing 8B are arranged between the first inner ring member 5, the second inner ring member 6 and the outer ring member 7, two ball bearings 9 are mechanically connected to the cam shaft 1, a first outer cover 10A is provided between one of the ball bearings 9 and the steel wheel 4, and a second outer cover 10B is provided between the other ball bearing 9 and the flexible wheel 3.

2 , 3 , and 6 , the camshaft 1 has an axial direction D1 and a radial direction D2 . The camshaft 1 includes a shaft body 11 with a hollow structure and an outer protrusion 12 on the outer edge of the shaft body 11 .

Referring again to FIG. 3 and FIG. 6 , 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 cam shaft 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 cam shaft 1 through the flexible bearing 2. The rebar 4 engages with the outer teeth of the flexible wheel 3, so that the rebar 4 is driven by the flexible wheel 3. The mechanical connection referred to in the present invention can be any physical method that can fix two elements to each other, such as friction and tight fit.

Referring again to FIG. 3 , FIG. 6 and FIG. 7 , 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 engages the rebar 4 .

As shown in Figures 5 to 7, the first inner ring member 5 is disposed on one side of the conical wheel 4 so that the first inner ring member 5 can rotate synchronously with the conical wheel 4. The first inner ring member 5 is located on the left side of the conical wheel 4.

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 reed 4 on 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 flex spline 3, and the first extension wall 52 is located on a side of the first body 51 facing the protrusion 721.

Referring again to FIGS. 6 to 8 , the second inner ring member 6 is disposed 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 .

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 first inner ring member 5 on the other side of the axial direction D1 on one side of the axial direction D1, 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 a side of the second body 61 facing the protrusion 721. As shown in FIGS. 4 to 6, 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 flexible wheel 3. The second sub-ring 72 extends toward the second body 61 and is located between the first extension wall 52 and the second extension wall 62, so that there is a first radial space SP1 between the protrusion 721 and the first extension wall 52, a second radial space SP2 between the protrusion 721 and the second extension wall 62, and the outer ring 7 has an axial space connecting the first radial space SP1 and the second radial space SP2. In other words, the first radial space SP1, the second radial space SP2, and the axial space SP3 are arranged in a substantially C-shaped configuration.

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, and 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.

It should be particularly noted that, referring to FIG. 6 and FIG. 7 again, in practice, the outer diameters of the first sub-ring 71, the second sub-ring 72, and the third sub-ring 73 are the same in this embodiment, and the second sub-ring 72 has a protrusion 721 extending toward the second body 61. The protrusion 721 is located between the first extension wall 52 and the second extension wall 62, and the protrusion 721 and the first extension wall 52 can have the first radial space SP1, the protrusion 721 and the second extension wall 62 can have the second radial space SP2, and the protrusion 721 and the second body 61 have the axial space SP3, but the present invention is not limited thereto.

For example, in other embodiments of the present invention not shown, the first sub-ring member 71, the second sub-ring member 72, and the third sub-ring member 73 may also be integrally connected, so that the outer ring member 7 is a single-piece component. Preferably, as shown in FIG8 , the first extension wall 52 and the second extension wall 62 may be designed in a stepped shape.

Referring again to FIG. 8 , the two axial roller bearings 8A are respectively disposed in the first radial space SP1 and the second radial space SP2. The axial roller bearing 8A in the first radial space SP1 abuts against the protrusion 721 and the first extension wall 52. The axial roller bearing 8A in the second radial space SP2 abuts against the protrusion 721 and the second extension wall 62.

In practice, the axial roller bearing 8A includes a supporting member 81A and a plurality of rollers 82A placed on the supporting member 81A, and the rollers 82A are not affected by the supporting member 81A in rolling, so that the outer ring 7 can rotate relative to the first inner ring 5 and the second inner ring 6 through the two axial roller bearings 8A and be provided with support force in the axial direction D1.

As shown in FIG. 8 , the radial roller bearing 8B is disposed in the axial space SP3 , and the radial roller bearing 8B abuts against the protrusion 721 and the second body 61 .

In practice, the radial roller bearing 8B includes a supporting member 81B and a plurality of rollers 82B placed on the supporting member 81B, and the rollers 82B are not affected by the supporting member 81B in rolling, so that the outer ring 7 can rotate relative to the first inner ring 5 and the second inner ring 6 through the radial roller bearing 8B and be provided with support force in the radial direction D2.

As shown in FIG3 and FIG6 , the inner edges of the two ball bearings 9 are mechanically connected to the outer edges of the cam shaft 1, and the outer edges of the two ball bearings 9 are mechanically connected to the first outer cover 10A and the second outer cover 10B, respectively. The first outer cover 10A is mechanically connected to the steel wheel 4. In addition, the second outer cover 10B is mechanically connected to the flexible wheel 3.

It is worth noting that, as shown in FIG. 3 and FIG. 7 , in order to ensure that each component in the harmonic reducer 100 can operate smoothly and extend the service life, the harmonic reducer 100 can 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 contained in the harmonic reducer 100.

Specifically, the first rotary shaft seal 11A is disposed on the outer edge of the camshaft 1 and is 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 seep out from the gap between the camshaft 1 and the first outer cover 10A.

The second rotary shaft seal 11B is disposed on the outer edge of the camshaft 1 and is 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.

The third rotary shaft seal 11C is disposed on the first body 51 of the first inner ring 5 , and the third rotary shaft seal 11C can abut against the first inner ring 5 and the inner edge of the outer ring 7 , so that the lubricating fluid does not seep out from the gap between the first extension wall 52 and the inner edge of the outer ring 7 .

A liquid storage space M for accommodating the lubricating fluid is provided between the first rotary shaft seal 11A, the second rotary shaft seal 11B, the cam shaft 1, the flexible wheel 3, the steel wheel 4, the first inner ring 5, the second inner ring 6, the first outer cover 10A and the second outer cover 10B, and the liquid storage space M is connected to the second radial space SP2.

As shown in FIG8 , when the harmonic reducer 100 is started, the lubricating fluid is suddenly accumulated 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 curved flow channel section G at the location connected to the liquid storage space M to control the flow velocity and flow rate of the lubricating fluid entering the second radial space SP2.

Specifically, the third sub-ring member 73 has a protrusion 731 on one side facing the second inner ring member 6, and the protrusion 731 and the second extension wall 62 are spaced apart from each other. Accordingly, the second radial space SP2 has the curved flow channel section G between the protrusion 731 and the second extension wall 62.

It should be noted that the width of the curved channel section G is designed so that the lubricant cannot easily pass through, that is, the lubricant can be generally retained 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 in the first radial space SP1 can also be designed so that the lubricant cannot easily pass through, thereby achieving the effect of "retaining in the first radial space SP1, the second radial space SP2, and the axial space SP3".

In addition, it should be emphasized that the first radial space SP1, the second radial space SP2, the axial space SP3, the curved channel section G, and "the gap between the first radial space SP1 and the first extension wall 52 and the third rotary shaft seal 11C" can be designed with a "labyrinth seal" structure.

Specifically, the principle of the "labyrinth seal" is that it is composed of multiple layers of interlaced grooves and protrusions to form a maze-like structure, thereby increasing the volume change of the path of the lubricating fluid through the seal and changing the resistance to flow. When the liquid flows from the high-pressure end to the low-pressure end, it passes through a series of small gaps and cavities in the labyrinth seal. When the liquid passes through these small gaps, the flow speed will increase, and the pressure and temperature will decrease. After that, when the liquid enters the larger cavity, the speed will suddenly slow down, forming a vortex, so that the kinetic energy will be converted into heat, the pressure will remain unchanged but the temperature will rise to the previous level. This process will be repeated in every 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 rate will become faster and faster. When it reaches the downstream of the labyrinth seal, the pressure reduction 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 curved flow channel section G is a first predetermined value, and the gap width of the first radial space SP1 between the first extension wall 52 and the third rotary shaft seal 11C is a second predetermined value. The first predetermined value and the second predetermined value are a minimum radial gap in the labyrinth seal.

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 may further have a rubber ring (not shown) between each component, but the present invention is not limited thereto.

[Technical Effects of the Embodiments of the Invention]

The harmonic reducer disclosed in the embodiment of the present invention can be realized by "a first radial space between the outer ring and the first extension wall, a second radial space between the outer ring and the second extension wall, and an axial space connecting the first radial space and the second radial space" and "the two axial spaces The radial roller bearing is arranged in the first radial space and the second radial space, and the radial roller bearing is arranged in the axial space". The harmonic reducer can not only support radial and axial stresses simultaneously through the two axial roller bearings and the radial roller bearing, but also greatly reduce the manufacturing and maintenance costs. In addition, the above-mentioned design can also effectively prevent the lubricating fluid from unexpectedly seeping out from the inside of the harmonic reducer (for example, the third rotating shaft seal).

The contents disclosed above are only preferred feasible embodiments of the present invention and are not intended to limit the scope of the patent application of the present invention. Therefore, all equivalent technical changes made using the contents of the specification and drawings of the present invention are included in the scope of the patent application of the present invention.

100: Harmonic reducer 1: Camshaft 11: Shaft 12: Outer protrusion 2: Flexible bearing 3: Flexwheel 31: Axial part 32: Radial part 4: Cone 5: First inner ring 51: First body 52: First extension wall 6: Second inner ring 61: Second body 62: Second extension wall 7: Outer ring 71: First sub-ring 72: Second sub-ring 721: Protrusion 73: Third sub-ring 731: Boss 8A: Axial roller bearing 81A: Supporting member 82A: Roller 8B: radial roller bearing 81B: support 82B: roller 9: ball bearing 10A: first outer cover 10B: second outer cover 11A: first rotary shaft seal 11B: second rotary shaft seal 11C: third rotary shaft seal D1: axial direction D2: radial direction SP1: first radial space SP2: second radial space SP3: axial space G: curved flow section M: liquid storage space

FIG1 is a three-dimensional schematic diagram of the harmonic deceleration device of the present invention.

FIG. 2 is another three-dimensional schematic diagram of the harmonic deceleration device of the present invention.

FIG3 is an exploded schematic diagram of the harmonic speed reducer of the present invention.

FIG. 4 is a partial three-dimensional schematic diagram of the harmonic deceleration device of the present invention.

FIG. 5 is an exploded schematic diagram of FIG. 4 .

FIG. 6 is a schematic cross-sectional view along line VI-VI of FIG. 1 .

FIG. 7 is a partial enlarged schematic diagram of FIG. 6 .

FIG. 8 is an enlarged schematic diagram of region VIII in FIG. 7 .

100: Harmonic reducer

1: Camshaft

11: Axis

12: Outer convex part

2: Flexible bearings

3: Flexwheel

31: Axial part

32: Radial part

4: Ganglun

5: First inner ring

6: Second inner ring

7: Outer ring parts

71: First sub-ring

72: Second sub-ring

73: The third sub-ring

8A: Axial roller bearings

8B: Radial roller bearings

9: Ball bearings

10A: First outer cover

10B: Second outer cover

11A: First rotary shaft seal

11B: Second rotary shaft seal

11C: Third rotary shaft seal

D1: Axial direction

D2: radial direction

M: Liquid storage space

Claims (6)

A harmonic reducer comprises: a camshaft; a flexible bearing mechanically connected to the camshaft, the flexible bearing being mechanically connected to the camshaft; a flexible wheel connected to the outer edge of the flexible bearing, the flexible wheel being able to be driven by the camshaft through the flexible bearing; a steel wheel connected to the outer edge of the flexible wheel, the steel wheel being able to engage the flexible wheel; a first inner ring disposed on one side of the steel wheel, the first inner ring comprising: a first body mechanically connected to the steel wheel; and a first extension wall; a second inner ring disposed on one side of the first inner ring, the second inner ring comprising: A second body, mechanically connected to the first inner ring; and A second extension wall; An outer ring, mounted on the flexible wheel and mechanically connected to the outer ring, a portion of the outer ring extends toward the flexible wheel and is located between the first extension wall and the second extension wall; wherein a first radial space is provided between the outer ring and the first extension wall, a second radial space is provided between the outer ring and the second extension wall, and the outer ring has an axial space connecting 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 cam shaft; 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 steel wheel, and the second outer cover is mounted on the other ball bearing and mechanically connected to the flexible wheel. The harmonic reducer according to claim 1, further comprising: 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 and the outer ring; wherein a liquid storage space for accommodating a lubricant is provided between the first rotary shaft seal, the second rotary shaft seal, the camshaft, the flexible wheel, the first outer cover and the second outer cover, and the liquid storage space is connected to the second radial space. According to the harmonic reducer described in claim 1, the outer ring comprises: a first sub-ring, surrounding the first inner ring; a second sub-ring, mechanically connected to one side of the first sub-ring in an axial direction and surrounding the second body, the second sub-ring having a protrusion extending toward the second body, the protrusion being located between the first extension wall and the second extension wall; wherein the first radial space is between the protrusion and the first extension wall, the second radial space is between the protrusion and the second extension wall, and the axial space is between the protrusion and the second body; a third sub-ring, mechanically connected to one side of the second sub-ring in the axial direction and surrounding the second inner ring. The harmonic reducer according to claim 3, wherein the first extension wall faces one side of the protrusion, and the first extension wall and the protrusion clamp the axial roller bearing located in the first radial space; the second extension wall faces one side of the protrusion, and the second extension wall and the protrusion clamp the axial roller bearing located in the second radial space; the first extension wall and the second extension wall do not contact the protrusion. According to the harmonic reducer described in claim 4, the third sub-ring has a protrusion on a side facing the second inner ring, and the second body and the protrusion are spaced apart from each other; the second radial space has a curved flow section between the protrusion and the second inner ring. The harmonic reducer according to claim 5, wherein the width of the curved flow channel section is a first predetermined value, the width of the gap between the first radial space and a third rotating shaft seal of the harmonic reducer is a second predetermined value, and the first predetermined value and the second predetermined value are a minimum radial gap in the labyrinth seal.

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