Harmonic speed reducer with double rigid wheels
By adopting an external rotor motor and connecting components in the dual rigid wheel harmonic reducer, the enclosed space and the accommodating space are isolated, solving the problem of the difficulty in reducing the overall thickness and realizing the thinness of the device, which is suitable for equipment such as robotic arms and self-propelled vehicles.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-05
- Publication Date
- 2026-03-10
AI Technical Summary
The overall thickness of existing dual rigid wheel harmonic reducers is difficult to reduce, making it impossible to achieve a thinner design.
The design employs an external rotor motor and connecting components, combined with the structure of the front cover, rear cover, and wave generator, to form an isolation between the enclosed space and the accommodating space, thereby reducing the overall thickness.
The dual rigid wheel harmonic reducer has been made thinner and is suitable for various robotic arms and self-propelled vehicles.
Smart Images
Figure CN121630983A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to a harmonic reducer, in particular to a double rigid wheel harmonic reducer. BACKGROUND
[0002] The conventional double rigid wheel harmonic reducer has a problem of difficult reduction of the overall thickness when assembled with a motor. SUMMARY
[0003] The present application discloses a double rigid wheel harmonic reducer, which is mainly used to solve the problem of difficult reduction of the overall thickness of the conventional double rigid wheel harmonic reducer.
[0004] One embodiment of the present application discloses a double rigid wheel harmonic reducer, which comprises: a static rigid wheel, two opposite sides of which are defined as a front side and a back side; a back cover, which comprises a ring-shaped sheet and a cylindrical structure, the ring-shaped sheet has a side protruding to form the cylindrical structure, the ring-shaped sheet has a through hole, and the cylindrical structure has a hollow channel, one end of the hollow channel being in communication with the through hole; the ring-shaped sheet is fixed to the back side of the static rigid wheel; a front cover, which is fixedly arranged on the front side of the static rigid wheel, the front cover comprising an opening, the inner diameter of the opening being greater than the outer diameter of the cylindrical structure; a dynamic rigid wheel, which is fixedly arranged with the front cover, the dynamic rigid wheel being located between the front cover and the back cover; a flexible wheel, which is arranged between the back cover and the front cover, the static rigid wheel and the dynamic rigid wheel being capable of engaging with the flexible wheel; a wave generator, which comprises: a flexible bearing, which is connected with the flexible wheel; a connecting member, which comprises a ring-shaped bottom and a ring-shaped wall, the ring-shaped wall being extended to one side from the periphery of the ring-shaped bottom, the ring-shaped bottom having a through hole penetrating through the ring-shaped bottom, the inner diameter of the through hole being greater than the outer diameter of the cylindrical structure, and the through hole being capable of being sleeved on the outer side of the cylindrical structure; the ring-shaped wall being pivotally connected with the front cover and the back cover, the connecting member being connected with the flexible bearing, and the ring-shaped wall, the outer side of the cylindrical structure and the ring-shaped sheet jointly forming a containing space; an external rotor motor, which is arranged in the containing space, the external rotor motor comprising an external rotor and an internal stator, the external rotor being fixedly arranged with the connecting member, and the internal stator being fixedly arranged with the back cover; wherein the wave generator is arranged around the cylindrical structure, and the hollow channel is arranged through the double rigid wheel harmonic reducer, the hollow channel being used for containing at least one electric wire; wherein the length of the outer side surface of the front cover to the outer side surface of the back cover along an axial direction is defined as a total length, the length of the external rotor motor along the axial direction is less than the length of the ring-shaped wall along the axial direction, and the length of the ring-shaped wall along the axial direction is less than the total length.
[0005] Optionally, a ring-shaped oil seal structure is arranged between the through hole and the outer side of the cylindrical structure, the ring-shaped oil seal structure being used for sealing the gap between the through hole and the cylindrical structure.
[0006] Optionally, the rear cover also includes a rear annular protrusion structure, which surrounds the cylindrical structure, and the inner diameter of the rear annular protrusion structure is larger than the outer diameter of the annular wall of the connecting member; the wave generator also includes a rear bearing, which is located between the rear annular protrusion structure and the annular wall, and the connecting member can rotate relative to the rear cover through the rear bearing; the rear bearing, the connecting member, the annular oil seal structure and the rear cover together enclose the accommodating space so that the accommodating space is not connected to the space where the flexible bearing is located.
[0007] Optionally, the front cover has a front annular protrusion structure formed around the opening; the wave generator also includes a front bearing located between the front annular protrusion structure and the connecting member, the connecting member being rotatable relative to the front cover via the front bearing.
[0008] Optionally, an annular boss protrudes from the outer side of the annular wall of the connecting member. The thickness of the annular wall at the annular boss is greater than the thickness at other locations. The flexible bearing is connected to the annular boss. The rear bearing and the front bearing are located on both sides of the annular boss, respectively. The front bearing, the rear bearing, the annular boss, the flexible bearing, the front annular protrusion structure, the rear annular protrusion structure, the front cover, the rear cover, the dynamic rigid wheel, and the static rigid wheel together form a closed space. The closed space is not connected to the accommodating space.
[0009] Optionally, the static rigid wheel has an outer ring sidewall, and the dual rigid wheel harmonic reduction device also includes an outer ring oil seal structure. The outer ring oil seal structure is located on the outer ring sidewall and the outer sidewall of the dynamic rigid wheel. The outer ring oil seal structure is used to assist in sealing the enclosed space.
[0010] Optionally, the front bearing is a rubber-capped bearing, which helps to seal the enclosed space.
[0011] Optionally, the rear bearing is a rubber-capped bearing, which helps to prevent the enclosed space from communicating with the accommodating space.
[0012] Optionally, the annular bottom of the connecting member has multiple mounting holes for engaging with multiple mounting components to fix the outer rotor to the annular bottom.
[0013] Optionally, the front cover and the annular bottom are located on one side of the dual rigid wheel harmonic reducer, and the rear cover is located on the other side of the dual rigid wheel harmonic reducer; the rear cover or cylindrical structure also includes at least one wire outlet hole for providing wires of the external rotor motor to pass through.
[0014] In summary, the dual rigid wheel harmonic reducer of the present invention, through the design of the connecting components included in the wave generator and the external rotor motor, and the design of placing the external rotor motor in the accommodating space, allows the dual rigid wheel harmonic reducer to have a relatively thin overall thickness.
[0015] To further understand the features and technical content of this invention, please refer to the following detailed description and accompanying drawings. However, these descriptions and drawings are only for illustrating the invention and are not intended to limit the scope of protection of the invention in any way. Attached Figure Description
[0016] Figure 1 and Figure 2 These are schematic diagrams from different perspectives of the dual rigid wheel harmonic deceleration device of the present invention.
[0017] Figure 3 The dual rigid wheel harmonic deceleration device of the present invention is along Figure 1 A schematic diagram of the cross section III-III.
[0018] Figure 4 yes Figure 3 A magnified view of a portion of the image.
[0019] Figures 5 to 9 These are partial exploded schematic diagrams of the dual rigid wheel harmonic deceleration device of the present invention. Detailed Implementation
[0020] In the following description, if a specific drawing is indicated or shown in a specific drawing, it is only to emphasize that most of the relevant content mentioned in the following description appears in that specific drawing, but does not limit the following description to refer only to that specific drawing.
[0021] Please refer to the following: Figures 1 to 9 , Figure 1 and Figure 2 These are schematic diagrams from different perspectives of the dual rigid wheel harmonic deceleration device of the present invention. Figure 3 The dual rigid wheel harmonic deceleration device of the present invention is along Figure 1 A schematic diagram of the cross-section along section III-III. Figure 4 yes Figure 3 A partially enlarged schematic diagram, Figures 5 to 9 These are partial exploded schematic diagrams of the dual rigid wheel harmonic deceleration device of the present invention.
[0022] like Figures 1 to 4 As shown, the dual rigid wheel harmonic deceleration device 100 of the present invention includes a static rigid wheel 1, a front cover 2, a dynamic rigid wheel 3, a flexible wheel 4, a wave generator 5, and a rear cover 6. The two opposite sides of the static rigid wheel 1 are defined as a front side 1A and a rear side 1B, respectively.
[0023] like Figure 7As shown, the static rigid wheel 1 includes an annular body 11, an outer annular sidewall 12, and a rigid wheel body 13. The outer annular sidewall 12 is formed around the periphery of the annular body 11. The annular body 11 has multiple mounting holes 111, each of which penetrates the annular body 11. The rigid wheel body 13 is located on the side of the annular body 11 where the outer annular sidewall 12 is formed. Multiple first inner tooth-like structures 131 are formed on the inner side of the rigid wheel body 13.
[0024] like Figure 8 and Figure 9 As shown, the rear cover 6 includes an annular sheet 61, a cylindrical structure 62, and a rear annular protrusion 63. The annular sheet 61 has a through hole 611 that penetrates the annular sheet 61. The cylindrical structure 62 and the rear annular protrusion 63 protrude from one side of the annular sheet 61. The annular sheet 61 can be fixed to the rear side 1B of the static rigid wheel 1 by multiple screws Q engaging with multiple mounting holes 111 of the annular body 11, and the annular sheet 61 will cover the rear side 1B of the static rigid wheel 1.
[0025] like Figure 8 and Figure 9 As shown, the cylindrical structure 62 has a hollow channel 621, one end of which is connected to the perforation 611. A rear annular protrusion 63 is arranged around the cylindrical structure 62. The rear annular protrusion 63 is along an axial direction (e.g., along...). Figure 3 The direction of the axis AX shown is less than the length of the cylindrical structure 62 along the axial direction.
[0026] like Figures 3 to 5 As shown, the front cover 2 is fixed to the dynamic rigid wheel 3 by multiple screws Q, and the front cover 2 and the dynamic rigid wheel 3 are fixedly disposed on the front side 1A of the static rigid wheel 1, while the dynamic rigid wheel 3 is located between the front cover 2 and the rear cover 6. The front cover 2 includes an opening 21, the inner diameter of which is larger than the outer diameter of the cylindrical structure 62. A front annular protrusion 22 is formed around the opening 21 on the front cover 2.
[0027] The inner side of the dynamic rigid wheel 3 has multiple second inner tooth-like structures 31. The rigid wheel body 13 of the dynamic rigid wheel 3 and the static rigid wheel 1 is also connected to a crossed roller bearing 9, which is located between the outer ring sidewall 12 and the dynamic rigid wheel 3 and the rigid wheel body 13. In practical applications, the crossed roller bearing 9 can also be a four-point contact ball bearing.
[0028] like Figures 3 to 6As shown, the flexible wheel 4 is disposed within the static rigid wheel 1 and is located between the rear cover 6 and the front cover 2. The outer side of the flexible wheel 4 has multiple first tooth-like structures 41 and multiple second tooth-like structures 42, with a groove 43 between the first tooth-like structures 41 and the second tooth-like structures 42. The multiple first tooth-like structures 41 and multiple second tooth-like structures 42 are respectively used to mesh with multiple first inner tooth-like structures 131 of the static rigid wheel 1 and multiple second inner tooth-like structures 31 of the dynamic rigid wheel 3. The number of teeth in the first inner tooth-like structures 131 of the static rigid wheel 1 is the same as the number of teeth in the first tooth-like structures 41 of the flexible wheel 4, while the number of teeth in the second inner tooth-like structures 31 of the dynamic rigid wheel 3 is different from the number of teeth in the second tooth-like structures 42 of the flexible wheel 4.
[0029] like Figure 3 , Figure 4 , Figures 7 to 9 As shown, the wave generator 5 includes: a flexible bearing 51, a connecting member 52, an external rotor motor 53, a front bearing 54, and a rear bearing 55. The flexible bearing 51 is connected to the flexure 4. The connecting member 52 includes an annular bottom 521 and an annular wall 522. The annular bottom 521 has a plurality of mounting holes 5211 for engaging with a plurality of mounting components (e.g., screws Q) to fix the external rotor 531 to the annular bottom 521. The annular wall 522 extends to one side around the annular bottom 521 and has a through hole 5212 that penetrates the annular bottom 521. The inner diameter of the through hole 5212 is larger than the outer diameter of the cylindrical structure 62, and the through hole 5212 can be fitted onto the outside of the cylindrical structure 62. The annular wall 522 is pivotally connected to the front cover 2 and the rear cover 6. The connecting member 52 is connected to the flexible bearing 51. The annular wall 522, the outer side of the cylindrical structure 62 and the annular sheet 61 together form an accommodating space SP1.
[0030] In practical applications, the front bearing 54 is located between the front annular protrusion structure 22 and the connecting member 52, and the connecting member 52 can rotate relative to the front cover 2 via the front bearing 54. The rear bearing 55 is located between the rear annular protrusion structure 63 and the annular wall 522, and the connecting member 52 can rotate relative to the rear cover 6 via the rear bearing 55.
[0031] An annular boss 5221 protrudes from the outer side of the annular wall 522 of the connecting member 52, and the thickness of the annular wall 522 at the annular boss 5221 is greater than the thickness at other locations. The inner diameter of the rear annular protrusion structure 63 is greater than the outer diameter of the annular boss 5221 of the annular wall 522 of the connecting member 52, and the inner diameter of the front annular protrusion structure 22 is greater than the outer diameter of the annular boss 5221 of the annular wall 522 of the connecting member 52.
[0032] like Figure 3 and Figure 4As shown in the cross-sectional view of the double-rigid-ring harmonic speed reducer 100, the annular boss 5221 of the connecting member 52 generally presents a structure similar to a convex shape. The flexible bearing 51 is connected to the annular boss 5221, and the rear bearing 55 and the front bearing 54 are respectively located on both sides of the annular boss 5221. By designing the thickness of the annular boss 5221 to be greater than the thickness of the other positions of the connecting member 52, and in cooperation with the design of placing the rear bearing 55 and the front bearing 54 on both sides of the annular boss 5221, the annular boss 5221 can assist in restricting the movement range of the rear bearing 55 and the front bearing 54 in the axial direction.
[0033] As Figure 3 and Figure 4 shown, in the cross-sectional view of the double-rigid-ring harmonic speed reducer 100, the front bearing 54 is disposed between one side of the front annular protrusion structure 22 and the annular boss 5221 of the connecting member 52, and the rear bearing 55 is disposed between the other side of the rear annular protrusion structure 63 and the annular boss 5221 of the connecting member 52. The annular boss 5221 of the connecting member 52, the front annular protrusion structure 22, and the rear annular protrusion structure 63 are designed to jointly hold the front bearing 54 and the rear bearing 55.
[0034] The front bearing 54, the rear bearing 55, the annular boss 5221, the flexible bearing 51, the front annular protrusion structure 22, the rear annular protrusion structure 63, the front cover 2, the rear cover 6, the dynamic rigid ring 3, and the static rigid ring 1 jointly form a closed space SP2, and the closed space SP2 is not connected to the accommodation space SP1. In an optional embodiment, the front bearing 54 can be a rubber-covered bearing, and the rubber-covered bearing can assist in closing the closed space SP2; the rear bearing 55 can also be a rubber-covered bearing, and the rubber-covered bearing can assist in blocking the communication between the closed space SP2 and the accommodation space SP1.
[0035] In practical applications, between the through hole 5212 (as Figure 8 shown) and the outer side of the cylindrical structure 62, an annular oil seal structure 7 is further provided, and the annular oil seal structure 7 is used to seal the gap between the through hole 5212 and the cylindrical structure 62. The rear bearing 55, the connecting member 52, the annular oil seal structure 7, and the rear cover 6 jointly enclose the accommodation space SP1, so that the accommodation space SP1 is not connected to the closed space SP2. Since lubricating oil is provided in the closed space SP2, through the design of not allowing the accommodation space SP1 and the closed space SP2 to communicate with each other, it can effectively prevent the lubricating oil located in the accommodation space SP1 from flowing into the accommodation space SP1. If the lubricating oil flows into the accommodation space SP1, it may cause damage to the outer rotor motor 53.
[0036] In practical applications, the dual rigid wheel harmonic reducer 100 may also include an outer annular oil seal structure 8. The outer annular oil seal structure 8 is located on the outer annular sidewall 12 and the outer sidewall of the dynamic rigid wheel 3. The outer annular oil seal structure 8 is used to help seal the closed space SP2 to prevent the lubricating oil in the closed space SP2 from leaving the closed space SP2.
[0037] like Figure 3 , Figures 7 to 9 As shown, the external rotor motor 53 is disposed in the accommodating space SP1. The external rotor motor 53 includes an external rotor 531 and an inner stator 532. The external rotor 531 is fixed to the connecting member 52, and the inner stator 532 is fixed to the rear cover 6. In one embodiment, the rear cover 6 may also include at least one wire outlet (not shown), which extends through the rear cover 6 and is used to provide a path for the wires of the external rotor motor 53 to pass through. The shape and location of the wire outlet can be designed according to actual needs and are not limited here.
[0038] like Figures 1 to 3 As shown, the front cover 2 and the annular bottom 521 are located on one side of the double rigid wheel harmonic reducer 100, and the rear cover 6 is located on the other side of the double rigid wheel harmonic reducer 100. When the double rigid wheel harmonic reducer 100 is running, the dynamic rigid wheel 3 and the connecting member 52 located on the same side will rotate, while the rear cover 6 will remain stationary. Therefore, by designing the wire hole to be located on the rear cover 6, it is possible to prevent the wire from being caught in the rotating dynamic rigid wheel 3 or the connecting member 52.
[0039] In different embodiments, the wire outlet hole can also be formed in the cylindrical structure 62. Since the hollow channel 621 is used to provide a path for the wires to pass through, directly forming the wire outlet hole in the cylindrical structure 62 facilitates the organization of the wires. In the example where the wire outlet hole is formed in the cylindrical structure 62, since no wires will pass through the rear cover 6, and the rear cover 6 will not rotate when the dual rigid wheel harmonic reducer 100 is running, the space around the rear cover 6 is basically not required when installing the dual rigid wheel harmonic reducer 100 in a device such as a robotic arm. Therefore, it is convenient for the relevant personnel to plan the installation position of the dual rigid wheel harmonic reducer 100 in the robotic arm.
[0040] like Figure 3 and Figure 4As shown, in one practical application, the length from the outer side of the front cover 2 to the outer side of the rear cover 6 along the axial direction is defined as a total length of 100L. The length from the outer side of the rear cover 6 to the end face of the cylindrical structure 62 along the axial direction is 6L, which is not greater than the total length of 100L. The length 53L of the outer rotor motor 53 along the axial direction is less than the length 522 of the annular wall 522 along the axial direction, and the length 522L of the annular wall 522 along the axial direction is less than the total length of 100L. The outer rotor motor 53 is disposed in the connecting member 52 and is located between the front cover 2 and the rear cover 6. This design allows the double rigid wheel harmonic reducer 100 to have a relatively small overall width (i.e., the total length of 100L), thereby allowing the double rigid wheel harmonic reducer 100 to be better applied in various occasions, such as in various sizes of robotic arms.
[0041] When the outer rotor motor 53 is driven, the outer rotor 531 will rotate relative to the inner stator 532, and the outer rotor 531 will drive the connecting member 52 to rotate. The connecting member 52 will drive the flexible bearing 51 to repeatedly flexibly deform. A portion of the plurality of first tooth structures 41 of the flexible wheel 4 will mesh with a portion of the plurality of first inner tooth structures 131 of the static rigid wheel 1. Since the number of first inner tooth structures 131 contained in the static rigid wheel 1 is the same as the number of first tooth structures 41 contained in the flexible wheel 4, when the flexible wheel 4 repeatedly flexibly deforms... The flexible wheel 4 will not rotate relative to the static rigid wheel 1. The second tooth structure 42 of the repeatedly flexibly deformed flexible wheel 4 will mesh with the second inner tooth structure 31 of the dynamic rigid wheel 3. Since the number of second tooth structures 42 contained in the flexible wheel 4 is different from the number of second inner tooth structures 31 of the dynamic rigid wheel 3, the dynamic rigid wheel 3 will be driven to rotate by the repeatedly flexibly deformed flexible wheel 4. In this way, the high-speed power input by the external rotor motor 53 will be output by the dynamic rigid wheel 3 at a relatively low speed, so as to achieve the purpose of deceleration.
[0042] As described above, the dual rigid wheel harmonic reducer 100 of the present invention, by designing the wave generator 5 to include the connecting member 52 and the external rotor motor 53, and in conjunction with the cylindrical structure 62 of the rear cover 6, allows the wave generator 5 to be housed between the front cover 2 and the rear cover 6, thereby enabling the dual rigid wheel harmonic reducer 100 to have a relatively thin overall thickness. In other words, the dual rigid wheel harmonic reducer 100 of the present invention can meet the requirement of thinness.
[0043] It is important to emphasize that existing dual-rigid-wheel harmonic reducers use an internal rotor motor. This makes it difficult to reduce the overall thickness of the reducer, thus failing to meet the requirement for a thinner design. Furthermore, because the various components of a dual-rigid-wheel harmonic reducer are interconnected, in practice, an internal rotor motor cannot be directly converted to an external rotor motor. To convert an internal rotor motor to an external rotor motor, the interconnections between all components of the dual-rigid-wheel harmonic reducer must be redesigned to maintain its original functionality. During the redesign process, technicians will plan and design the interconnections of each component based on the intended connection target (e.g., a robotic arm, a self-propelled vehicle). Therefore, in practice, the placement and shape of each component may vary depending on the specific requirements.
[0044] Therefore, for those skilled in the art to which this case pertains, considering existing dual-rigid-wheel harmonic reducers with an internal rotor motor, unless there is explicit instruction or motivation, it is impossible for them to conceive of modifying the internal rotor motor into an external rotor motor. This is because modifying the internal rotor motor into an external rotor motor would require a complete redesign of the dual-rigid-wheel harmonic reducer. In other words, for those skilled in the art, modifying a harmonic reducer with an internal rotor motor into an external rotor motor is neither common knowledge nor a conventional technical means. Conversely, in existing common dual-rigid-wheel harmonic reducers, the use of an internal rotor motor design is the preferred technical approach.
[0045] The above description is only an optional and feasible embodiment of the present invention, and is not intended to limit the patent scope of the present invention. Therefore, all equivalent technical changes made based on the description and drawings of the present invention are included within the protection scope of the present invention.
Claims
1. A dual-rack harmonic speed reduction device, characterized by, The double rigid wheel harmonic reducer comprises: a static rigid wheel, opposite sides of which are defined as a front side and a back side; a back cover, comprising a ring-shaped sheet and a cylindrical structure, one side of the ring-shaped sheet protrudes to form the cylindrical structure, the ring-shaped sheet has a through hole, the cylindrical structure has a hollow channel, one end of the hollow channel communicates with the through hole; the ring-shaped sheet is fixed to the back side of the static rigid wheel; a front cover, fixedly arranged on the front side of the static rigid wheel, the front cover comprises an opening, the inner diameter of the opening is greater than the outer diameter of the cylindrical structure; a dynamic rigid wheel, fixedly arranged with the front cover, the dynamic rigid wheel is located between the front cover and the back cover; a flexible wheel, arranged between the back cover and the front cover, the static rigid wheel and the dynamic rigid wheel can engage with the flexible wheel; a wave generator, comprising: a flexible bearing connected with the flexible wheel; and a connecting member, comprising a ring-shaped bottom and a ring-shaped wall, the ring-shaped wall is extended to one side from the periphery of the ring-shaped bottom, the ring-shaped bottom has a through hole penetrating through the ring-shaped bottom; the inner diameter of the through hole is greater than the outer diameter of the cylindrical structure, and the through hole can be sleeved on the outside of the cylindrical structure; the ring-shaped wall is pivotally connected with the front cover and the back cover, the connecting member is connected with the flexible bearing, and the ring-shaped wall, the outside of the cylindrical structure and the ring-shaped sheet jointly form a containing space; an outer rotor motor arranged in the containing space, the outer rotor motor comprises an outer rotor and an inner stator, the outer rotor is fixedly connected with the connecting member, and the inner stator is fixedly connected with the back cover; wherein the wave generator is arranged around the cylindrical structure, and the hollow channel is arranged through the double rigid wheel harmonic reducer, and the hollow channel is used for containing at least one electric wire; wherein the length of the outer side surface of the front cover along an axial direction to the outer side surface of the back cover is defined as a total length; the length of the outer rotor motor along the axial direction is less than the length of the ring-shaped wall along the axial direction, and the length of the ring-shaped wall along the axial direction is less than the total length.
2. The dual-rack wheel harmonic reduction device of claim 1, wherein, A ring-shaped oil seal structure is further arranged between the through hole and the outside of the cylindrical structure, and the ring-shaped oil seal structure is used for closing the gap between the through hole and the cylindrical structure.
3. The dual-geneva harmonic drive of claim 2, wherein, The back cover further comprises a back ring-shaped protruding structure, the back ring-shaped protruding structure is arranged around the cylindrical structure, and the inner diameter of the back ring-shaped protruding structure is greater than the outer diameter of the ring-shaped wall of the connecting member; the wave generator further comprises a back bearing, the back bearing is located between the back ring-shaped protruding structure and the ring-shaped wall, and the connecting member can rotate relative to the back cover through the back bearing; the back bearing, the connecting member, the ring-shaped oil seal structure and the back cover jointly close the containing space, so that the containing space is not communicated with the space where the flexible bearing is located.
4. The dual-rack wheel harmonic reduction device of claim 3, wherein, The front cover generates a front annular protruding structure around the opening; the wave generator further comprises a front bearing, which is located between the front annular protruding structure and the connecting member, and the connecting member can rotate relative to the front cover through the front bearing.
5. The dual-rack harmonic speed reduction apparatus of claim 4, wherein, The outer side of the annular wall of the connecting member protrudes to generate an annular boss, the thickness of the annular wall at the annular boss is greater than that at other positions, the flexible bearing is connected with the annular boss, and the front bearing and the rear bearing are located on two sides of the annular boss respectively; the front bearing, the rear bearing, the annular boss, the flexible bearing, the front annular protruding structure, the rear annular protruding structure, the front cover, the rear cover, the dynamic rigid wheel and the static rigid wheel jointly generate a closed space, and the closed space is not in communication with the accommodation space.
6. The dual-rack wheel harmonic reduction device of claim 5, wherein, The static rigid wheel has an outer ring side wall, and the double-rigid-wheel harmonic reducer further comprises an outer annular oil seal structure located between the outer ring side wall and the outer side wall of the dynamic rigid wheel, which is used to assist in sealing the closed space.
7. The dual-rack wheel harmonic reduction device of claim 5, wherein, The front bearing is a rubber cover bearing, which can assist in sealing the closed space.
8. The dual-rack harmonic speed reduction apparatus of claim 5, wherein, The rear bearing is a rubber cover bearing, which can assist in blocking the closed space from communicating with the accommodation space.
9. The dual-geneva harmonic drive of claim 1, wherein, The annular bottom of the connecting member has a plurality of mounting holes, which are used to cooperate with a plurality of mounting members to fix the outer rotor and the annular bottom.
10. The dual-rack harmonic speed reduction apparatus of claim 1, wherein, The front cover and the annular bottom are located on one side of the double-rigid-wheel harmonic reducer, and the rear cover is located on the other side of the double-rigid-wheel harmonic reducer; the rear cover or the cylindrical structure further comprises at least one wire outlet hole, which is used to provide a wire of the outer rotor motor to pass out.