Transmission

Abstract

The present application discloses a transmission device, including an external transmission device, which is cylindrical, has an outer wall and an inner wall, and the inner wall is provided with a plurality of arc-shaped protrusions extending inward; an internal transmission device, which is arranged inside the inner wall of the external transmission device, has an outer circumferential surface, and the outer circumferential surface is provided with a plurality of arc-shaped protrusions extending outward; and a spacer, which is located between the arc-shaped protrusions of the external transmission device and the arc-shaped protrusions of the internal transmission device, and can contact the arc-shaped protrusions of the external transmission device and the arc-shaped protrusions of the internal transmission device at the same time; when the rotational driving torque between the external transmission device and the internal transmission device is greater than a predetermined torque, the deformation of the arc-shaped protrusions of the external transmission device or the arc-shaped protrusions of the internal transmission device can cause the external transmission device to slip and rotate relative to the internal transmission device. The transmission device of the present application can protect the driving device when overloaded.

Description

Technical Field

[0001] The present application relates to the field of machinery, and in particular to the field of transmission devices. Background Art

[0002] The driving device can drive the load to rotate. When the load is too large, the driving device will be blocked and damaged. Therefore, a transmission device is needed to protect the driving device when the load is too large. Summary of the invention

[0003] Exemplary embodiments of the present application can solve at least some of the above problems. The present application provides a transmission device, including an external transmission device, the external transmission device is cylindrical, the external transmission device has an outer wall and an inner wall, and the inner wall is provided with a plurality of arc-shaped protrusions extending inwardly; an internal transmission device, the internal transmission device is arranged inside the inner wall of the external transmission device, the internal transmission device has an outer circumferential surface, and the outer circumferential surface is provided with a plurality of arc-shaped protrusions extending outwardly; and an isolation ring, the isolation ring is located between the arc-shaped protrusion of the external transmission device and the arc-shaped protrusion of the internal transmission device, and the isolation ring can contact the arc-shaped protrusion of the external transmission device and the arc-shaped protrusion of the internal transmission device at the same time; wherein, when the rotational driving torque between the external transmission device and the internal transmission device is greater than a predetermined torque, the deformation of the arc-shaped protrusion of the external transmission device or the arc-shaped protrusion of the internal transmission device can cause the external transmission device to slip and rotate relative to the internal transmission device.

[0004] According to the above transmission device, when the rotational driving torque between the external transmission device and the internal transmission device is not greater than a predetermined torque, the external transmission device and the internal transmission device can rotate together.

[0005] According to the above transmission device, transmission teeth are provided on the outer wall of the external transmission device, so that the external transmission device is an external gear.

[0006] According to the above transmission device, the outer wall of the external transmission device is provided with helical teeth.

[0007] According to the above transmission device, the external transmission device can be driven to rotate by the motor, and the rotation of the internal transmission device can drive the load to rotate; or the internal transmission device can be driven to rotate by the motor, and the rotation of the external transmission device can drive the load to rotate.

[0008] According to the above transmission device, the outer transmission device and the inner transmission device are made of plastic, and the isolation ring is made of metal.

[0009] According to the above transmission device, the arc-shaped protrusion of the external transmission device and the arc-shaped protrusion of the internal transmission device are arc-shaped.

[0010] According to the above transmission device, the top end of the arc-shaped protrusion of the inner transmission device is located between two adjacent arc-shaped protrusions of the outer transmission device.

[0011] According to the above transmission device, the arc-shaped protruding portion of the external transmission device or the arc-shaped protruding portion of the internal transmission device is hollowed out.

[0012] According to the above transmission device, the number of the arc-shaped protruding portions of the inner transmission device is the same as the number of the arc-shaped protruding portions of the outer transmission device.

[0013] The transmission device of the present application can protect the driving device when overloaded. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] These and other features and advantages of the present application may be better understood by reading the following detailed description with reference to the accompanying drawings, in which like reference numerals refer to like parts throughout, wherein:

[0015] Figure 1 is a schematic diagram of the assembly of a power system using a transmission device according to an embodiment of the present application;

[0016] Figure 2A yes Figure 1 An exploded schematic diagram of the transmission shown;

[0017] Figure 2B yes Figure 1 A top view of the transmission shown;

[0018] Figure 3A yes Figure 1 A schematic diagram of the structure of the internal transmission device shown;

[0019] Figure 3B yes Figure 3A Rear view of the internal transmission shown;

[0020] Figure 4A yes Figure 1 A schematic diagram of the structure of the external transmission device shown;

[0021] Figure 4B yes Figure 4A A front view of the external transmission shown;

[0022] Figure 5A yes Figure 2A The structural schematic diagram of the isolation ring shown;

[0023] Figure 5B yes Figure 2A A front view of the isolator shown;

[0024] Figure 6 yes Figure 2B Sectional view of section AA;

[0025] Figure 7A-7B yes Figure 6 The enlarged part in the dotted box;

[0026] Fig. 8A is an assembly schematic diagram of a power system using a transmission device of another embodiment of the present application;

[0027] Figure 8B yes Fig. 7A An exploded schematic diagram of the power system is shown. DETAILED DESCRIPTION

[0028] Various specific embodiments of the present application will be described below with reference to the accompanying drawings that form a part of this specification. It should be understood that although terms indicating directions, such as "front", "rear", "upper", "lower", "left", "right", "top", "bottom" and other directions or orientations are used in this application to describe various example structural parts and elements of the present application, these terms are used here only for the purpose of convenience of explanation and are determined based on the example orientations shown in the accompanying drawings. Since the embodiments disclosed in the present application can be set in different directions, these terms indicating directions are only for illustration and should not be regarded as limitations. In the following drawings, the same figure numbers are used for the same parts and similar figure numbers are used for similar parts.

[0029] Figure 1 FIG. 1 is a schematic diagram of the assembly of a power system 100 using a transmission device 104 according to an embodiment of the present application. Figure 1 As shown, the power system 100 includes a driving device 102, a transmission device 104, and a load device 106. The driving device 102 is used to provide a driving torque. The transmission device 104 is used to transmit the driving torque to the load device 106, thereby driving the load device 106 to rotate. Figure 1 In the illustrated embodiment, the driving device 102 is a motor, and the load device 106 is a thermostat. In other embodiments, the driving device 102 may be a device other than a motor, and the load device 106 may be a device other than a thermostat.

[0030] like Figure 1 As shown, the motor includes a rotating shaft 112 and a driving wheel 114, and the driving wheel 114 is connected to the rotating shaft 112. When the motor is powered, the driving wheel 114 can rotate together with the rotating shaft 112. The driving wheel 114 is a spur gear.

[0031] The thermostat includes a gear 142, a rotating shaft 144, a housing 146 and a valve body (not shown). The valve body is accommodated in the housing 146. The valve body is connected to the rotating shaft 144, and the rotating shaft 144 is connected to the gear 142. When the gear 142 rotates, the valve body and the rotating shaft 144 can rotate together with the gear 142. The gear 142 is a helical gear.

[0032] Figure 2A yes Figure 1 The exploded schematic diagram of the transmission device 104 is shown to illustrate various components in the transmission device 104 . Figure 2B yes Figure 1 FIG. 1 is a top view of the transmission device 104. Figure 2A-2B As shown, the transmission device 104 includes an external transmission device 116, an annular isolating ring 218, an internal transmission device 120 and a rotating shaft 222. The rotating shaft 222 is inserted into the internal transmission device 120, and both ends of the rotating shaft 222 can extend from the internal transmission device 120. The isolating ring 218 is sleeved on the proximal end 234 of the internal transmission device 120. The isolating ring 218 and the proximal end 234 of the internal transmission device 120 are accommodated in the external transmission device 116. Thus, the external transmission device 116, the annular isolating ring 218 and the internal transmission device 120 are all sleeved on the rotating shaft 222. The transmission device 104 also includes a bracket 224 and a pair of gaskets 2141, 2142. The opposite ends of the bracket 224 are respectively provided with an annular bearing portion 2261 and an annular bearing portion 2262, and the bearing portions 2261, 2262 are used to receive the rotating shaft 222. The two ends of the rotating shaft 222 are respectively fitted with gaskets 2141, 2142 and then inserted into the bearing parts 2261, 2262 of the bracket 224. Thus, the external transmission device 116, the annular isolation ring 218 and the internal transmission device 120 are supported by the bracket 224 through the rotating shaft 222, and the external transmission device 116, the annular isolation ring 218 and the internal transmission device 120 can rotate around the rotating shaft 222. The outer wall 402 of the external transmission device 116 is provided with straight teeth (see Figure 4A-4B ), which can mesh with the straight teeth on the driving wheel 114, so that when the driving wheel 114 rotates, the external transmission device 116 can rotate together with the driving wheel 114. The spiral groove 308 (see Figure 3A-3B ). It can mesh with the helical teeth on the gear 142, so that when the internal transmission device 120 rotates, the gear 142 can rotate together with the internal transmission device 120.

[0033] Figure 3A yes Figure 1 The three-dimensional structural schematic diagram of the internal transmission device 120 is shown. Figure 3B yes Figure 3AThe rear view of the internal transmission device 120 is shown to illustrate the specific structure of the proximal end 234. Figure 3A-3B As shown, the internal transmission device 120 is cylindrical, and has an internal cavity 304 and an outer circumferential surface 302. The internal cavity 304 is used to accommodate the rotating shaft 222. The outer circumferential surface 302 of the proximal end 134 of the internal transmission device 120 is provided with 12 arc-shaped protrusions 306 extending radially outward. As an example, the arc-shaped protrusions 306 are arc-shaped, and the 12 arc-shaped protrusions 306 are evenly arranged on the outer circumferential surface 302. The distance from the vertex of the arc-shaped protrusion 306 to the rotation center O of the internal transmission device 120 is r. The outer circumferential surface 302 of the remaining part of the internal transmission device 120 is also provided with a spiral groove 308 to mesh with the gear 142 of the thermostat. The internal transmission device 120 can be made of metal (e.g., iron, copper, stainless steel) or plastic.

[0034] Figure 4A yes Figure 1 A three-dimensional schematic diagram of the structure of the external transmission device 116 is shown. Figure 4B yes Figure 4A FIG. 1 is a front view of the external transmission device 116 to illustrate the specific structure of the external transmission device 116. Figure 4A-4B As shown, the external transmission device 116 is cylindrical, and has an outer wall 402 and an inner wall 404. The outer wall 402 is provided with a transmission tooth 406 to engage with the drive wheel 114. The inner wall 404 is provided with 12 arc-shaped protrusions 408 extending radially inward. As an example, the arc-shaped protrusions 408 are arc-shaped and hollowed out. A cavity 410 is formed at the hollowed-out part so that the arc-shaped protrusions 408 can be greatly deformed when subjected to external force. When the arc-shaped protrusions 408 are not deformed, the distance from the vertex of the arc-shaped protrusions 408 to the rotation center O' of the external transmission device 116 is R. The external transmission device 116 can be made of metal (e.g., iron, copper, stainless steel) or plastic.

[0035] Figure 5A yes Figure 2A A three-dimensional structural schematic diagram of the isolation ring 218 is shown. Figure 5B yes Figure 5A The front view of the isolation ring 218 is shown to illustrate the specific structure of the isolation ring 218. Figure 5A-5B As shown, the isolating ring 218 is annular and has 12 bends 510 evenly arranged along its circumference, so that its radial cross section is a regular dodecagon. The thickness of the isolating ring 218 is h. The isolating ring 218 is made of metal (eg, iron, copper, stainless steel).

[0036] Figure 6 yes Figure 2BThe sectional view of the AA section in FIG. 1 is to show the positional relationship between the drive wheel 114, the external transmission device 116, the isolation ring 218 and the internal transmission device 120. Figure 6 As shown, the rotation center O′ of the outer transmission 116 coincides with the rotation center O of the inner transmission 120 . The spacer 218 is located between the arcuate protrusion 508 of the outer transmission 116 and the arcuate protrusion 306 of the inner transmission 120 .

[0037] The dimensions of the isolating ring 218, the arcuate protrusion 508 of the external transmission device 116, and the arcuate protrusion 306 of the internal transmission device 120 are set such that the outer wall 504 of the isolating ring 218 contacts the arcuate protrusion 408 of the external transmission device 116, and the inner wall 502 of the isolating ring 218 contacts the arcuate protrusion 306 of the internal transmission device 120 at the bending portion 510. Specifically, when the arcuate protrusion 408 of the external transmission device 116 is not deformed, the sum of the distance r from the vertex of the arcuate protrusion 306 of the internal transmission device 120 to the rotation center O (O') and the thickness h of the isolating ring 218 is greater than the distance R from the vertex of the arcuate protrusion 408 of the external transmission device 116 to the rotation center O (O'), that is, r+h>R.

[0038] Furthermore, the arc-shaped protrusion 408 of the external transmission device 116 is configured such that when the rotational driving torque M between the external transmission device 116 and the internal transmission device 120 is less than or equal to a predetermined torque M P When the arc-shaped protrusion 408 can only produce a small deformation or no deformation, so that the external transmission device 116 will not rotate relative to the internal transmission device 120, but the internal transmission device 120 can be driven to rotate by the external transmission device 116; and when the rotational driving torque M between the external transmission device 116 and the internal transmission device 120 is greater than a predetermined torque M P When the arc-shaped protrusion 408 is deformed, the deformation is sufficient to make the external transmission device 116 rotate relative to the internal transmission device 120, so that the external transmission device 116 cannot drive the internal transmission device 120 to rotate. The rotational driving torque M between the external transmission device 116 and the internal transmission device 120 is less than or equal to a predetermined torque M P The situation occurs when the power system 100 is operating normally (for example, the load of the load device 106 is less than or equal to the stall torque of the drive device 102). At this time, the external transmission device 116 can drive the internal transmission device 120 to rotate. The rotational driving torque M between the external transmission device 116 and the internal transmission device 120 is greater than a predetermined torque M PThe situation occurs when, for example, the load of the load device 106 is greater than the stall torque of the drive device 102 (i.e., overload). At this time, the external transmission device 116 cannot drive the internal transmission device 120 to rotate, and the power system 100 is not operating normally. P is the rotational driving torque M between the external transmission device 116 and the internal transmission device 120 when the load of the load device 106 is equal to the stall torque of the driving device 102. As an example, when the stall torque of the driving device 102 is 11 N*m, the predetermined torque M P It is 11N*m.

[0039] Figure 7A-7B yes Figure 6 Enlarged view of the part in the dashed box. Fig. 7A A more detailed positional relationship of the outer transmission 116 , the cage 218 , and the inner transmission 120 is shown when the power system 100 is operating normally. Figure 7B The figure shows a more detailed positional relationship of the outer transmission device 116 , the cage 218 , and the inner transmission device 120 when the power system 100 is not operating normally.

[0040] like Fig. 7A As shown, when the power system 100 operates normally, the driving torque provided by the driving device 102 can drive the load device 106 to rotate. Specifically, each arc-shaped protrusion 306 of the internal transmission device 120 is engaged in a corresponding bent portion 510 on the isolation ring 218, so that the internal transmission device 120 and the isolation ring 218 are immobile relative to each other. The top of the arc-shaped protrusion 306 of the internal transmission device 120 and its corresponding bent portion 510 are engaged between two adjacent arc-shaped protrusions 408 of the external transmission device 116. Each arc-shaped protrusion 408 of the external transmission device 116 is located between two adjacent bent portions 510 of the isolation ring 218. When the external transmission device 116 starts to rotate and the internal transmission device 120 does not rotate, a rotational driving torque (i.e., torque generated by friction) is generated between the arc-shaped protrusion 408 of the external transmission device 116 and the isolation ring 218 and the arc-shaped protrusion 306 of the internal transmission device 120. When the power system 100 is not overloaded, the rotational driving torque M is less than or equal to the predetermined torque M P The rotational driving torque can drive the isolation ring 218 and the internal transmission device 120 to rotate, thereby causing the external transmission device 116, the isolation ring 218 and the internal transmission device 120 to rotate together.

[0041] like Figure 7BAs shown, when the power system 100 is not operating normally, for example, when the load in the load device 106 is too large, the driving torque provided by the driving device 102 is not large enough, and therefore cannot drive the load device 106 to rotate. Specifically, when the external transmission device 116 starts to rotate and the internal transmission device 120 does not rotate, a rotational driving torque (i.e., a torque generated by friction) is generated between the arc-shaped protrusion 408 of the external transmission device 116 and the arc-shaped protrusion 306 of the internal transmission device 120 of the isolation ring 218. Since the load of the load device 106 connected to the internal transmission device 120 is greater than the driving power transmitted by the external transmission device 116 from the driving device 102, the rotational driving torque M is greater than the predetermined torque M P , the rotational driving torque cannot drive the isolation ring 218 and the internal transmission device 120 to rotate. Since the hollowed-out part of the arc-shaped protrusion 408 forms a cavity 410, the rotational driving torque will cause the arc-shaped protrusion 408 to produce a large deformation, and the arc-shaped protrusion 408 can no longer remain between the two adjacent bent parts 510 of the isolation ring 218, but rotates along the outer wall 504 of the isolation ring 218 relative to the isolation ring 218 and the internal transmission device 120. At this time, only the driving wheel 114 drives the external transmission device 116 to rotate, while the isolation ring 218 and the internal transmission device 120 do not rotate. In other words, at this time, the external transmission device 116 rotates with slippage relative to the isolation ring 218 and the internal transmission device 120.

[0042] The transmission device 104 in the present application can provide good power transmission when the power system 100 is operating normally, and is in a slipping rotation state when the load of the load device 106 is too large, so as to prevent the drive device 102 from being directly stuck by the load device 106 and causing a stall, thereby protecting the drive device 102. In addition, the present application can reduce the wear generated when the internal transmission device 120 and the external transmission device 116 rotate by setting an isolation ring 218 between the internal transmission device 120 and the external transmission device 116, thereby increasing the operating stability of the transmission device 104 and increasing the service life. It can be understood by those skilled in the art that the number and shape of the arc-shaped protrusions 306 on the internal transmission device 120, the shape of the isolation ring 218, and the number and shape of the arc-shaped protrusions 408 on the external transmission device 116 can be set according to the size of the required predetermined torque. Those skilled in the art may also understand that the arcuate protrusion 408 of the external transmission device 116 may not be hollowed out, but the arcuate protrusion 306 of the internal transmission device 120 may be hollowed out, which can also enable the external transmission device 116 to be in a slipping rotation state relative to the internal transmission device 120 when the load of the load device 106 is too large.

[0043] Fig. 8AIt is a schematic assembly diagram of a power system 200 using a transmission device 804 according to another embodiment of the present application. Figure 8B yes Fig. 8A The exploded schematic diagram of the power system 200 shown in FIG. 1 is used to illustrate the various components in the power system 200. Figures 8A-8B As shown, the power system 200 includes a driving device 802, a transmission device 804, and a load device 806. The driving device 802 is used to provide a driving torque. The transmission device 804 is used to transmit the driving torque to the load device 806, thereby driving the load device 806 to rotate. Figures 8A-8B In the illustrated embodiment, the driving device 802 is a motor, and the load device 806 is a thermostat. The motor includes a rotating shaft 812 and a driving wheel 814, and the driving wheel 814 is connected to the rotating shaft 812. When the motor is energized, the rotating shaft 812 can rotate together with the driving wheel 814. The driving wheel 814 is a worm. The transmission device 804 includes an external transmission device 816, an annular isolation ring 818 and an internal transmission device 820. The thermostat includes a rotating shaft 844, a housing 846 and a valve body (not shown). The valve body is accommodated in the housing 846. The valve body is connected to the rotating shaft 844, and the rotating shaft 844 is connected to the internal transmission device 820. The internal transmission device 820 can rotate together with the rotating shaft 844 and the valve body. It should be noted that the isolation ring 818 and Figure 2A The isolation ring 218 is similar to the external transmission device 816; Figure 2A The external transmission device 116 is substantially the same as that in FIG. Figure 2A The internal transmission device 120 in FIG. 1 is substantially the same as that in FIG. 1 , and the same parts are not described in detail here. The external transmission device 816 is Figure 2A The external transmission device 116 in the embodiment is different in that: Figure 2A The outer wall 402 of the external transmission device 116 is provided with straight teeth that mesh with the driving wheel 114, and Fig. 8A The outer wall of the external transmission device 816 is provided with helical teeth that mesh with the driving wheel 814. The internal transmission device 820 is Figure 2A The internal transmission 120 in the embodiment is different in that: Figure 2A The outer circumferential surface 302 of the internal transmission device 120 is provided with a spiral groove to mesh with the gear 142 of the thermostat to drive the rotating shaft 144. Fig. 8A The internal transmission device 820 is directly connected to the rotating shaft 844 of the thermostat to drive the rotating shaft 844. The transmission device 804 also includes a bracket 824, which is used to accommodate the motor, the external transmission device 816, the isolation ring 818 and the internal transmission device 820.

[0044] Figures 8A-8BThe transmission device 804 can also provide good power transmission when the power system 200 operates normally, and is in a slipping rotation state when the load of the load device 806 is too large, thereby preventing the drive device 802 from being directly stuck by the load device 806 and causing a stall, thereby protecting the drive device 802.

[0045] Those skilled in the art can understand that the transmission device can be set according to the difference between the driving device and the load device to set the transmission connection mode between the external transmission device and the driving device, and the transmission connection mode between the internal transmission device and the load device. In addition, those skilled in the art can also understand that in addition to the mode shown in the present application in which the external transmission device is connected (or engaged) with the driving device and the internal transmission device is connected (or engaged) with the load device, the mode in which the external transmission device is connected (or engaged) with the load device and the internal transmission device is connected (or engaged) with the driving device also falls within the protection scope of the present application.

[0046] Although only some features of the present application have been illustrated and described herein, various modifications and changes may be made to those skilled in the art. Therefore, it should be understood that the appended claims are intended to cover all the above modifications and changes that fall within the spirit and scope of the present application.

Claims

1. A transmission device (104), characterized in that include: An external transmission device (116), the external transmission device (116) is cylindrical, the external transmission device (116) has an outer wall (402) and an inner wall (404), and the inner wall (404) is provided with a plurality of arc-shaped protrusions (408) extending inwardly; An internal transmission device (120), the internal transmission device (120) being disposed within an inner wall (404) of the external transmission device (116), the internal transmission device (120) having an outer circumferential surface (302), the outer circumferential surface (302) being provided with a plurality of arc-shaped protrusions (306) extending outward; and an isolating ring (218), the isolating ring (218) being located between the arc-shaped protruding portion (308) of the external transmission device (116) and the arc-shaped protruding portion (306) of the internal transmission device (120), the isolating ring (218) being capable of contacting the arc-shaped protruding portion (408) of the external transmission device (116) and the arc-shaped protruding portion (306) of the internal transmission device (120) at the same time; When the rotational driving torque between the external transmission device (116) and the internal transmission device (120) is greater than a predetermined torque, the deformation of the arc-shaped protrusion (408) of the external transmission device (116) or the arc-shaped protrusion (306) of the internal transmission device (120) can cause the external transmission device (116) to slip and rotate relative to the internal transmission device (120).

2. The transmission device (104) according to claim 1, characterized in that: in, When the rotational driving torque between the external transmission device (116) and the internal transmission device (120) is not greater than a predetermined torque, the external transmission device (116) and the internal transmission device (120) can rotate together.

3. The transmission device (104) according to claim 1, characterized in that: Transmission teeth are provided on the outer wall (402) of the external transmission device (116), so that the external transmission device (116) is an external gear.

4. The transmission device (104) according to claim 1, characterized in that: The outer wall (402) of the external transmission device (116) is provided with helical teeth.

5. The transmission device (104) according to claim 1, characterized in that: The external transmission device (116) can be driven by the motor to rotate, and the internal transmission device (120) can drive the load to rotate; or The internal transmission device (120) can be driven by the motor to rotate, and the external transmission device (116) can drive the load to rotate.

6. The transmission device (104) according to claim 1, characterized in that: The outer transmission device (116) and the inner transmission device (120) are made of plastic, and the isolation ring (218) is made of metal.

7. The transmission device (104) according to claim 1, characterized in that: The arc-shaped protrusion (408) of the external transmission device (116) and the arc-shaped protrusion (306) of the internal transmission device (120) are in the shape of circular arcs.

8. The transmission device (104) according to claim 1, characterized in that: When the rotational driving torque between the external transmission device (116) and the internal transmission device (120) is not greater than a predetermined torque, the top end of the arc-shaped protrusion (306) of the internal transmission device (120) is located between two adjacent arc-shaped protrusions (408) of the external transmission device (116).

9. The transmission device (104) according to claim 1, characterized in that: The arc-shaped protrusion (408) of the external transmission device (116) or the arc-shaped protrusion (306) of the internal transmission device (120) is hollowed out.

10. The transmission device (104) according to claim 1, characterized in that: The number of the arc-shaped protrusions (306) of the internal transmission device (120) is the same as the number of the arc-shaped protrusions (408) of the external transmission device (116); The isolation ring (218) includes a plurality of bent portions (510), and the number of the bent portions (510) is the same as the number of the arc-shaped protruding portions (306) of the internal transmission device (120).

11. The transmission device (104) according to claim 1, characterized in that: in, When the rotational driving torque between the external transmission device (116) and the internal transmission device (120) is greater than a predetermined torque, the arc-shaped protrusion (408) of the external transmission device (116) performs rotational motion relative to the isolation ring (218) and the internal transmission device (120) along the outer wall (504) of the isolation ring (218); The cavity formed by the arc-shaped protrusion (408) of the external transmission device (116) or the arc-shaped protrusion (306) of the internal transmission device (120) allows the arc-shaped protrusion (408) of the external transmission device (116) or the arc-shaped protrusion (306) of the internal transmission device (120) to deform; Each arc-shaped protrusion (408) of the external transmission device (116) includes an inward vertex, and the distance between the inward vertex and the center of the external transmission device (116) is a first radius R; each arc-shaped protrusion (306) of the internal transmission device (120) includes an outward vertex, and the distance between the outward vertex and the center of the internal transmission device (120) is a second radius r; the isolation ring thickness of the isolation ring (218) is h; and when the arc-shaped protrusion (408) of the external transmission device (116) or the arc-shaped protrusion (306) of the internal transmission device (120) is not deformed, the first radius R is smaller than the sum of the second radius r and the isolation ring thickness h; Wherein, the number of the arc-shaped protrusions (408) of the external transmission device (116) is twelve, and the number of the arc-shaped protrusions (306) of the internal transmission device (120) is twelve; The radial cross section of the isolation ring (218) is a regular polygon, and the radial cross section of the isolation ring (218) is a regular dodecagon.

Images