Cycloidal gear tooth profile optimization method and small RV speed reducer

Abstract

The invention discloses a cycloidal gear tooth profile optimization method and a small RV speed reducer. The invention discloses a small RV speed reducer, which relates to the technical field of speed reducers, and comprises an input shaft, a planetary gear assembly, a cycloid speed reduction assembly and an output assembly, the output end part of the input shaft is sleeved with a transmission sun gear, the input shaft and the transmission sun gear are concentrically arranged, and the cycloid speed reduction assembly is fixedly connected with the output assembly. After the input shaft penetrates through the cycloid speed reduction assembly, the transmission sun gear is meshed with the crank planetary gear set to form transmission, so that the cycloid speed reduction assembly synchronously generates planetary rotation, and speed reduction output is conducted through the cycloid speed reduction assembly by means of the output assembly. According to the cycloidal gear, the assembly structure is simple, the axial length needed by a traditional cycloidal gear is reduced, the size is greatly reduced, meanwhile, the minimum curvature radius is 0.5 mm after optimization treatment is conducted on the obtained tooth profile curve through the cycloidal gear tooth profile optimization method, the machining production pain point encountered in the speed reducer production and manufacturing industry is successfully solved, and the production efficiency is improved. Batch production is facilitated, the cost is greatly reduced, and the service life of the product is prolonged.

Description

Technical Field

[0001] This invention relates to the field of speed reduction equipment technology, and more specifically, to a method for optimizing the tooth profile of a cycloidal gear and a small RV reducer. Background Technology

[0002] Current RV reducers, due to their multi-stage gear reduction structure, are bulky and difficult to miniaturize. The market currently offers RV reducers ranging from a small 150mm diameter to over 400mm in diameter, leaving a gap in the market for RV reducers with diameters under 100mm. The cycloidal gear, as a core component of the RV reducer, directly affects its transmission accuracy, efficiency, load capacity, lifespan, and reliability. Because the cycloidal gear profile in smaller reducers is sharp, stress concentration issues often arise. Furthermore, research has found that the difficulty in miniaturizing RV reducers lies in the cycloidal gear profile. While this profile is relatively easy to machine when the overall size of the RV reducer is large, sharp corners and other machining dead points appear when the overall size is small, leading to machining difficulties and causing the cycloidal gear to wear easily and have a shortened lifespan. Therefore, this application develops a novel cycloidal gear profile to reduce machining difficulty and achieve the goal of miniaturizing RV reducers. Summary of the Invention

[0003] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a cycloidal gear tooth profile optimization method and a small RV reducer to solve one or more of the above-mentioned problems.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] This application provides a method for optimizing the tooth profile of a cycloidal gear, including the following steps:

[0006] (1) Obtain the reference radius and undulation radius of the outer and inner cycloidal wheel profiles;

[0007]

[0008] u in =A·K·sin(Z) in ·T)

[0009] u out =A·K·sin(Z) out ·T)

[0010] Where, r in u is the reference radius of the cycloidal wheel profile. in Let r be the undulation radius of the cycloidal wheel profile. inis the reference radius of the outer cycloid gear profile, u in is the fluctuation radius of the outer cycloid gear profile; Zin is the number of teeth of the inner cycloid coil, Zout is the number of teeth of the outer cycloid coil, M is the module of the cycloid teeth, 0 < M ≤ 3, A is the crank eccentric shaft, 0 < A ≤ 3, K is the tooth amplitude coefficient, 0 < K ≤ 1, T is the angular amplitude, 0 ≤ T ≤ 2π, Rout is the polar radius length of the outer cycloid gear profile at T radians, Rin is the polar radius length of the inner cycloid gear profile at T radians;

[0011] (2) Establish the gear equation of the cycloid gear in the polar coordinate system to obtain the polar radius length Rout of the outer cycloid gear profile and the polar radius length Rin of the inner cycloid gear profile. The specific formulas are as follows:

[0012]

[0013]

[0014] Rout is the polar radius length of the outer cycloid gear profile at T radians, Rin is the polar radius length of the inner cycloid gear profile at T radians;

[0015] (3) Convert the polar radius length Rout of the outer cycloid gear profile and the polar radius length Rin of the outer cycloid gear profile obtained in the polar coordinate system into rectangular coordinates respectively. The conversion formulas are as follows:

[0016] X out =R out ·cos(T)

[0017] Yout = Rout·sin(T)

[0018] X in =R in ·cos(T)

[0019] (4) Obtain the outer cycloid profile curve set Pout and the inner cycloid profile curve set Pin through the obtained rectangular coordinates;

[0020]

[0021]

[0022] This application also provides a small RV reducer, which uses the above-mentioned cycloidal gear tooth profile optimization method to prepare a cycloidal reducer assembly. The reducer includes an input shaft, a cycloidal reducer assembly, and an output assembly. A transmission sun gear is sleeved on the output end of the input shaft. The input shaft and the transmission sun gear are arranged on the same central axis. The cycloidal reducer assembly and the output assembly are fixedly connected. After the input shaft passes through the cycloidal reducer assembly, the transmission sun gear meshes with the crank planetary gear set to form a transmission, thereby causing the cycloidal reducer assembly to generate planetary rotation synchronously, so as to reduce the output speed through the output assembly.

[0023] As a preferred feasible method, the cycloidal reduction gear assembly includes a cycloidal coil, an upper cycloidal gear, and a lower cycloidal gear. An internal gear ring is provided inside the cycloidal coil. The upper cycloidal gear and the lower cycloidal gear are mirror images of each other and rotate eccentrically. The upper cycloidal gear, the lower cycloidal gear, and the internal gear ring of the cycloidal coil form a cycloidal gear set and realize planetary transmission.

[0024] As a preferred embodiment, the crankshaft includes a first connecting post and a second connecting post disposed near the side of the lower cycloidal gear. The first and second connecting posts are eccentrically arranged, and the diameter of the first connecting post is larger than the diameter of the second connecting post. The lower cycloidal gear rotates eccentrically around a plurality of first connecting posts, and the upper cycloidal gear rotates eccentrically around a plurality of second connecting posts.

[0025] As a preferred feasible method, the crank-planetary gear set includes three planetary gears that mesh with the transmission sun gear. Each planetary gear is fixedly mounted with a crankshaft, which is an eccentric shaft. Each planetary gear is connected to the lower cycloidal gear and the upper cycloidal gear in sequence through the corresponding eccentric shaft.

[0026] As a preferred and feasible embodiment, the cycloidal reduction gear assembly also includes a gear end cover, the gear end cover having a first hole at its center, the lower cycloidal gear having a center hole at its center, and the input shaft passing through the first hole and the center hole before mounting the transmission sun gear.

[0027] As a preferred and feasible approach, both the upper and lower cycloidal gears are symmetrically provided with multiple second holes around their center, and the gear end caps are symmetrically provided with multiple third holes around their center. The crankshaft passes through the second and third holes in sequence to achieve a transmission connection with the upper and lower cycloidal gears.

[0028] As a preferred and feasible approach, a matching second bearing is provided in the second hole of the upper cycloidal gear and the lower cycloidal gear, and a matching third bearing is provided in the third hole of the gear end cover.

[0029] As a preferred embodiment, the output component includes an output end cover, on which multiple connecting shafts are provided. Each connecting shaft has a pin hole along its axial direction. Multiple fourth holes are provided on the upper cycloidal gear and the lower cycloidal gear respectively. Multiple pins that cooperate with the pin holes are provided on the gear end cover. After the connecting shaft passes through the fourth hole, the gear end cover and the output end cover are fixedly connected.

[0030] As a preferred and feasible approach, the output end cover is provided with multiple fifth holes on the side near the planetary gear, and one end of the crankshaft is inserted into the fifth hole.

[0031] As a preferred and feasible option, the reducer also includes an input housing and an output housing, which are fixedly connected by bolts.

[0032] As a preferred feasible method, the RV reducer has a width A, a length B, and a thickness H, with a value of 50mm≤A≤60mm, 50mm≤B≤60mm, and 20mm≤H≤30mm.

[0033] As a preferred feasible method, the RV reducer is cylindrical with a diameter D and a thickness H of 60mm≤D≤80mm, 20mm≤H≤40mm, and 20mm≤H≤30mm.

[0034] In summary, the present invention has the following beneficial effects:

[0035] First, the components of this application are simple, the structural design is compact, and the size of the RV reducer produced is greatly reduced;

[0036] Secondly, the tooth profile curve obtained by optimizing the cycloidal gear tooth profile using the method described in this application achieves a minimum radius of curvature of 0.5 mm. This method successfully solves the processing and production pain points encountered in the reducer manufacturing industry, facilitates mass production, significantly reduces costs, and extends the product's service life. Attached Figure Description

[0037] Figure 1 This is an exploded structural diagram of a small RV reducer provided by the present invention; Figure 2 An exploded structural diagram of a small RV reducer provided by the present invention from another perspective; Figure 3 This is a simplified structural diagram of a small RV reducer provided by the present invention; Figure 4 This is a schematic cross-sectional view of a small RV reducer provided by the present invention; Figure 5 This invention provides a schematic diagram of the overall structure of a small RV reducer. Figure 6 A schematic diagram of the internal three-dimensional structure of a small RV reducer provided by the present invention; Figure 7 This invention provides a schematic diagram of the planetary gear connection structure in a small RV reducer. Figure 8 The existing cycloidal gear tooth profile diagram; Figure 9 The image shows the cycloidal gear tooth profile generated using a cycloidal gear tooth profile optimization method provided by this invention. Detailed Implementation

[0047] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0048] It should be noted that all uses of "first", "second", "third" and "fourth" in the embodiments of the present invention are for the purpose of distinguishing two entities with the same name but different names or different parameters. It is clear that "first", "second", "third" and "fourth" are only for the convenience of expression and should not be construed as limiting the embodiments of the present invention. Subsequent embodiments will not explain this in detail.

[0049] In the description of this invention, it should be understood that the terms "center," "lateral," "longitudinal," "front," "rear," "left," "right," "upper," "lower," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this invention.

[0050] The following is in conjunction with the appendix Figure 1-9 The present invention will be described in further detail below.

[0051] This application provides a method for optimizing the tooth profile of a cycloidal gear, specifically including the following steps:

[0052] (1) Obtain the reference radius and the fluctuation radius of the epicycloid gear profile and the hypocycloid gear profile;

[0053]

[0054] u in = A·K·sin(Z in ·T)

[0055] u out = A·K·sin(Z out ·T)

[0056] Where, r in is the reference radius of the hypocycloid gear profile, u in is the fluctuation radius of the hypocycloid gear profile, r in is the reference radius of the epicycloid gear profile, u in is the fluctuation radius of the epicycloid gear profile; Zin is the number of teeth of the internal cycloid coil, Zout is the number of teeth of the external cycloid coil, M is the module of the cycloid teeth, 0 < M ≤ 3, A is the crank eccentric shaft, 0 < A ≤ 3, K is the tooth amplitude coefficient, 0 < K ≤ 1, T is the angular amplitude, 0 ≤ T ≤ 2π, Rout is the polar radius length of the epicycloid gear profile at T radians, Rin is the polar radius length of the hypocycloid gear profile at T radians;

[0057] (2) Establish the gear equation of the cycloid gear in the polar coordinate system, and obtain the polar radius length Rout of the epicycloid gear profile and the polar radius length Rin of the hypocycloid gear profile. The specific formulas are as follows:

[0058]

[0059]

[0060] Rout is the polar radius length of the epicycloid gear profile at T radians, Rin is the polar radius length of the hypocycloid gear profile at T radians;

[0061] (3) Correspondingly convert the polar radius length Rout of the epicycloid gear profile and the polar radius length Rin of the hypocycloid gear profile obtained in the polar coordinate system into rectangular coordinates. The conversion formulas are as follows: X out = R out ·cos(T)

[0062] Yout = Rout·sin(T)

[0063] X in = R in ·cos(T)

[0064] Y in = R in ·sin(T)

[0065] (4) Obtain the set of epicycloid contour curves Pout and the set of incycloid contour curves Pin by obtaining the rectangular coordinates;

[0066]

[0067]

[0068] The principle will be explained in detail below with reference to the attached diagram: It should be noted that, compared to sharp contour curves, rounded contour curves have higher machinability. Here, higher machinability means that, by detecting the minimum radius of curvature of the curve, the larger the minimum radius of curvature, the easier it is to process.

[0069] like Figure 8 As shown in the figure, for example, if the known parameters of the cycloidal wheel include: a reference diameter of 50 mm, a fluctuation amplitude of 1 mm, and 50 teeth, as shown in the figure, in the tooth profile curve obtained without the optimization processing method of this application, 0.06 and 1.94 are the curvature diameters of the concave and convex parts, and the minimum curvature radius is 0.03 mm, which is very difficult to process.

[0070] The cycloidal gear tooth profile obtained using the optimization method of this application is as follows: Figure 9 As shown, the tooth profile curve obtained by the optimization process of this application has a curvature diameter of 50mm, a fluctuation amplitude of 1mm, and 50 teeth. The curve is smooth and without sharp points. After optimization, the curvature diameter of both the concave and convex parts is 1mm, and the minimum curvature radius is found to be 0.5mm, which facilitates machining. This method successfully solves the machining and production pain points encountered in the reducer manufacturing industry, facilitates mass production, greatly reduces costs, and extends the product's service life.

[0071] This application also provides a small RV reducer, which includes an input housing 11, an input shaft 1, a cycloidal reduction assembly, and an output assembly 2. A transmission sun gear 3 is sleeved on the output end of the input shaft. The input end of the input shaft is fixedly connected to the output end of the motor shaft to receive the power output by the motor. The input shaft 1 and the transmission sun gear 3 are arranged concentrically. The cycloidal reduction assembly and the output assembly 2 are fixedly connected. After the input shaft 1 passes through the cycloidal reduction assembly, the transmission sun gear 3 meshes with the crank planetary gear set to form a transmission, thereby causing the cycloidal reduction assembly to synchronously generate planetary rotation, so as to reduce the output speed through the output assembly 2.

[0072] like Figure 1-2As shown, it should be noted that the cycloidal reduction gear assembly in this application includes a cycloidal coil 4, an upper cycloidal gear 5, a gear end cover 7, and a lower cycloidal gear 6. An internal gear ring 41 is provided inside the cycloidal coil 4. The cycloidal coil 4, input housing 11, and output housing 12 are fixedly connected by bolts. The upper cycloidal gear 5 and lower cycloidal gear 6 are mirror images of each other and rotate eccentrically. The upper and lower cycloidal gears are respectively mounted on the crankshaft of the crank planetary gear set. The upper cycloidal gear 5, lower cycloidal gear 6, and the internal gear ring of the cycloidal coil 4 form a cycloidal gear set and achieve planetary transmission. The output housing is connected by an output end bearing and an output end cover.

[0073] like Figure 7 As shown, the crankshaft 9 includes a first connecting post 91 and a second connecting post 92 disposed near the side of the lower cycloidal gear 6. The first connecting post 91 and the second connecting post 92 are eccentrically arranged, and the diameter of the first connecting post 91 is larger than the diameter of the second connecting post 92. The lower cycloidal gear 6 rotates eccentrically around multiple first connecting posts, and the upper cycloidal gear 5 rotates eccentrically around multiple second connecting posts. Specifically, each tooth on the upper cycloidal gear 5 and the lower cycloidal gear 6 in this application advances alternately on the internal gear ring. For example, the internal gear ring has 50 teeth, and for every revolution of the crank planetary gear, the cycloidal gear advances one tooth angle on the internal gear ring, i.e., 360 / 50 = 7.2 degrees.

[0074] In this application, the gear end cover 7 has a first hole 71 at its center. The upper cycloidal gear 5, the lower cycloidal gear 6, and the gear end cover are arranged on the same central axis. After the input shaft 1 passes through the first hole 71, the transmission sun gear 3 is fixedly installed on the output shaft. Based on the above, it should be noted that the RV reducer in this application has a width A, a length B, and a thickness H, with a range of 50mm ≤ A ≤ 60mm, 50mm ≤ B ≤ 60mm, and 20mm ≤ H ≤ 30mm. The RV reducer is cylindrical, with a diameter D and a thickness H, with a range of 60mm ≤ D ≤ 80mm, 20mm ≤ H ≤ 40mm, and 20mm ≤ H ≤ 30mm.

[0075] Therefore, the structure of this application is compact and ingenious. Power is output sequentially to the transmission sun gear 3, crank planetary gear set, hypocycloidal gear 6, supercycloidal gear 5, and output component through the input shaft, thereby achieving deceleration output.

[0076] It should be noted that the crank-planetary gear set includes three planetary gears 8 that mesh with the transmission sun gear 3. Each planetary gear 8 is correspondingly and fixedly mounted with a crankshaft 9. The upper cycloidal gear 5 and the lower cycloidal gear 6 each have three second holes 52 symmetrically arranged around their centers. The gear end cover 7 has three third holes 72 symmetrically arranged around its center. Second bearings 53 are fitted into the second holes 52 of the upper cycloidal gear 5 and the lower cycloidal gear 6, and third bearings 73 are fitted into the third holes 72 of the gear end cover 7. The crankshaft 9 passes through the second holes 52 and the third holes 72 in sequence to achieve a transmission connection with the upper cycloidal gear 5 and the lower cycloidal gear 6. In addition, the gear end cover is also provided with circumferential angular positioning holes, located at the edge of the gear end cover. During the machining process, through cooperation with other parts, machining accuracy and positioning accuracy are ensured, thereby improving the precision and quality of the product.

[0077] In this application, the output assembly 2 includes an output end cover, on which multiple connecting shafts 21 are provided. Each connecting shaft 21 has a pin hole 22 along its axial direction. The upper cycloidal gear 5 and the lower cycloidal gear 6 are respectively provided with multiple fourth holes 54. The gear end cover 7 is provided with multiple pins 74 that cooperate with the pin holes 22. After the connecting shafts 21 pass through the fourth holes, the gear end cover 7 and the output end cover 2 are fixedly connected. Multiple fifth holes are provided on the side of the output end cover near the planetary gear 8, and one end of the crankshaft 9 is inserted into the fifth hole.

[0078] Working Principle: The RV reducer used in this application connects to the output shaft of the motor via an input shaft 1. The rotation of the input shaft drives the transmission sun gear at one end of the input shaft to rotate, which in turn drives the three planetary gears meshing with it. Since the planetary gears are fixedly connected to the upper and lower cycloidal gears via crankshafts, bearings, and other components, they move synchronously relative to each other, causing the upper and lower cycloidal gears to perform cycloidal motion within the internal gear ring of the cycloidal coil. This constitutes a planetary gear transmission. In this application, the gear end cover, upper cycloidal coil, lower cycloidal coil, and output end cover are fixedly connected, thus achieving transmission speed reduction. This application features simple assembly components and a compact structural design, resulting in a significantly reduced RV reducer size that meets practical needs. Furthermore, the use of gear meshing to drive the transmission structure formed by the cycloidal gears within the cycloidal ring improves transmission smoothness and further reduces the axial length required by traditional cycloidal gears, greatly reducing size and significantly improving production efficiency, reducing assembly difficulty, lowering production costs, and increasing practicality.

[0079] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A method for optimizing the tooth profile of a cycloidal gear, characterized in that, Includes the following steps: (1) Obtain the reference radius and undulation radius of the outer and inner cycloidal wheel profiles; u in =A·K·sin(Z in ·T) u out =A·K·sin(Z out ·T) where, r in is the reference radius of the internal cycloid gear profile, u in is the fluctuation radius of the internal cycloid gear profile, r in is the reference radius of the external cycloid gear profile, u in is the fluctuation radius of the external cycloid gear profile; Zin is the number of teeth of the internal cycloid coil, Zout is the number of teeth of the external cycloid coil, M is the module of the cycloid teeth, 0 < M ≤ 3, A is the crank eccentric shaft, 0 < A ≤ 3, K is the tooth amplitude coefficient, 0 < K ≤ 1, T is the angular amplitude, 0 ≤ T ≤ 2π, Rout is the polar radius length of the external cycloid gear profile at T radians, Rin is the polar radius length of the internal cycloid gear profile at T radians; (2) Establish the gear equation of the cycloidal gear in the polar coordinate system, and obtain the polar radius length Rout of the outer cycloidal gear profile and the polar radius length Rin of the inner cycloidal gear profile. The specific formulas are as follows: Rout is the extreme radius length of the outer cycloidal wheel profile when it is in T radians, and Rin is the extreme radius length of the inner cycloidal wheel profile when it is in T radians. (3) Convert the polar radius length Rout and Rin of the epicycloidal wheel profile obtained in the polar coordinate system into rectangular coordinates. The conversion formula is as follows: X out =R out ·cos(T) Yout = Rout·sin(T) X in =R in ·cos(T) Y in =R in ·sin(T) (4) Obtain the set of epicycloid contour curves Pout and the set of incycloid contour curves Pin by obtaining the rectangular coordinates; 2. A small RV reducer, characterized in that, A cycloidal deceleration assembly is prepared using the cycloidal gear tooth profile optimization method described in claim 1. The decelerator includes an input shaft (1), a cycloidal deceleration assembly, and an output assembly (2). A transmission sun gear (3) is sleeved on the output end of the input shaft. The input shaft (1) and the transmission sun gear (3) are arranged in concentric circles. The cycloidal deceleration assembly and the output assembly (2) are fixedly connected. The input shaft (1) passes through the cycloidal deceleration assembly and the transmission sun gear (3) meshes with the crank planetary gear set to form a transmission, thereby causing the cycloidal deceleration assembly to generate planetary rotation synchronously, so as to reduce the output speed through the output assembly (2).

3. A small RV reducer according to claim 2, characterized in that, The cycloidal deceleration assembly includes a cycloidal coil (4), an inner cycloidal gear (5), and an outer cycloidal gear (6). An inner gear ring (41) is provided inside the cycloidal coil (4). The inner cycloidal gear (5) and the outer cycloidal gear (6) are mirror images of each other and rotate eccentrically. The inner cycloidal gear (5), the outer cycloidal gear (6), and the inner gear ring of the cycloidal coil (4) form a cycloidal gear set and realize planetary transmission.

4. A small RV reducer according to claim 3, characterized in that, The crank planetary gear set includes three planetary gears (8) that mesh with the transmission sun gear (3). Each planetary gear (8) is fixedly mounted with a crankshaft (9). The crankshaft is an eccentric shaft. Each planetary gear (8) is connected to an external cycloidal gear (6) and an internal cycloidal gear (5) in sequence through the corresponding eccentric shaft.

5. A small RV reducer according to claim 3, characterized in that, The crankshaft (9) includes a first connecting post (91) and a second connecting post (92) disposed on the side near the cycloidal gear (6). The first connecting post (91) and the second connecting post (92) are eccentrically disposed. The diameter of the first connecting post (91) is larger than the diameter of the second connecting post (92). The cycloidal gear (6) rotates eccentrically around a plurality of the first connecting posts (91), and the cycloidal gear (5) rotates eccentrically around a plurality of the second connecting posts (92).

6. A small RV reducer according to claim 2, characterized in that, The cycloidal deceleration assembly also includes a gear end cover (7), the gear end cover (7) has a first hole (71) at its center, the inner cycloidal gear (5) and the outer cycloidal gear (6) have a center hole (51) at their center, and the input shaft (1) passes through the first hole (71) and the center hole (51) to install the transmission sun gear (3).

7. A small RV reducer according to claim 3, characterized in that, Both the inner cycloidal gear (5) and the outer cycloidal gear (6) are symmetrically provided with a plurality of second holes (52) around their center. The gear end cap (7) is symmetrically provided with a plurality of third holes (72) around its center. The crankshaft (9) passes through the second holes (52) and the third holes (72) in sequence to realize the transmission connection with the inner cycloidal gear (5) and the outer cycloidal gear (6).

8. A small RV reducer according to claim 3, characterized in that, The inner cycloidal gear (5) and the outer cycloidal gear (6) are provided with matching second bearings (53) in the second hole (52), and the gear end cover (7) is provided with matching third bearings (73) in the third hole (72).

9. A small RV reducer according to claim 3, characterized in that, The output component (2) includes an output end cover, on which a plurality of connecting shafts (21) are provided. Each connecting shaft (21) is provided with a pin hole (22) along its axial direction. The inner cycloidal gear (5) and the outer cycloidal gear (6) are provided with a plurality of fourth holes (54). The gear end cover (7) is provided with a plurality of pins (74) that cooperate with the pin holes (22). The connecting shaft (21) passes through the fourth hole to achieve a fixed connection between the gear end cover (7) and the output end cover (2).

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