Double-speed hub reduction gear
By designing a dual-speed wheel-side reducer, combined with a first-, second-, and third-stage planetary reduction mechanism and clutch switching, the problem of traditional wheel-side reducers being unable to change speed is solved, achieving multi-speed ratios and high torque output, making it suitable for heavy-duty scenarios.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-26
- Publication Date
- 2026-03-20
AI Technical Summary
Traditional side wheel reducers can only provide a single output speed ratio and cannot change speed according to demand. This results in low output speed and high torque at high speed ratios, or low output torque at low speed ratios, and difficulty in working under load.
The dual-speed wheel-side reducer design uses a combination of first-stage, second-stage, and third-stage planetary reduction mechanisms. By switching the clutch, two different output speed ratios and torques are achieved, namely the product of the first-stage speed ratio and the second-stage and third-stage speed ratios, and the product of the second-stage speed ratio and the third-stage speed ratio.
It enables speed variation according to demand, obtaining different output speed ratios and torques, improving load-bearing capacity and operational stability, and is suitable for heavy-duty scenarios.
Smart Images
Figure CN224017644U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of speed reduction device technology, specifically a dual-speed wheel-side speed reducer. Background Technology
[0002] Traditional side wheel reducers typically have only one output speed ratio and cannot perform speed changes. In traditional side wheel reducers, if a large speed ratio is used, although the output torque is high, the output speed is low, resulting in a slow rotational speed. If a traditional side wheel reducer uses a small speed ratio, although the output speed is high, the output torque is low. Moreover, traditional side wheel reducers only achieve speed reduction and torque increase through a single-stage planetary reduction gear set, which makes it difficult to operate under heavy loads. Utility Model Content
[0003] The purpose of this invention is to provide a dual-speed wheel-side reducer to overcome the problems existing in the prior art.
[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows: a dual-speed wheel-side reducer, characterized in that: it includes an outer cylinder, a first-stage planetary reduction mechanism, a second-stage planetary reduction mechanism, a third-stage planetary reduction mechanism disposed inside the outer cylinder, a reducer input shaft, a reducer output shaft, an inner cylinder, a clutch one, and a clutch two, wherein the reducer input shaft and the reducer output shaft are arranged coaxially, the inner cylinder is arranged around the reducer input shaft, and a second internal gear ring is provided on the inner wall of the outer cylinder corresponding to the second-stage planetary reduction mechanism and the third-stage planetary reduction mechanism;
[0005] The first-stage planetary reduction mechanism includes a first sun gear, a first planet gear, a first internal gear ring, a first left planet carrier, and a first right planet carrier. The first sun gear is located at the output end of the reducer's input shaft. The first left planet carrier includes a first annular flange and a first axial protrusion. The first right planet carrier includes a second annular flange and a second axial protrusion. A first planet gear shaft is connected between the first annular flange and the second annular flange. The first planet gear is rotatably mounted on the first planet gear shaft and meshes with the first sun gear and the first internal gear ring. The first axial protrusion is mounted on the input end of the reducer's output shaft. A receiving groove is provided inside the second axial protrusion. Clutch 1 is located in the receiving groove and mounted on the output end of the reducer's input shaft. Clutch 1 can be engaged or disengaged from the second axial protrusion. The first internal gear ring includes a first left internal gear ring and a first right internal gear ring. Clutch 2 is mounted on the first right internal gear ring. Clutch 2 can be engaged or disengaged from the inner cylinder.
[0006] The tertiary planetary reduction mechanism comprises a third sun gear, a third planetary gear and a third planetary carrier, the third sun gear is rotatably sleeved on the reduction mechanism output shaft, the third planetary carrier is provided with a third planetary gear shaft on one side, the third planetary gear is rotatably sleeved on the third planetary gear shaft and meshes with the third sun gear and the second inner gear ring, and the other side of the third planetary carrier is fixedly connected with one end of an inner cylinder body, and the other end of the inner cylinder body is fixedly connected with an outer cylinder body;
[0007] The secondary planetary reduction mechanism comprises a second sun gear, a second planetary gear and an annular second planetary carrier, the second sun gear is arranged on the output end of the reduction mechanism output shaft, the second planetary carrier is provided with a second planetary gear shaft on one side, the second planetary carrier is sleeved on the third sun gear and meshes with the third sun gear, and the second planetary gear is rotatably sleeved on the second planetary gear shaft and meshes with the second sun gear and the second inner gear ring.
[0008] On the basis of the above technical scheme, the utility model further can make improvements as follows:
[0009] As further improvement of the above technical scheme, the first left planetary carrier and the first right planetary carrier are arranged on the left and right sides of the first sun gear respectively, the first annular flange of the first left planetary carrier and the second annular flange of the first right planetary carrier are fixedly connected together through bolts, the first planetary gear can rotate around the first planetary gear shaft, and the first planetary gear shaft passes through the first annular flange and the second annular flange and is fixedly connected with the first annular flange and the second annular flange.
[0010] As further improvement of the above technical scheme, the first inner gear ring is arranged on the outer side of the first left planetary carrier and the first right planetary carrier, the first left inner gear ring and the first right inner gear ring are integrally made, the inner side of the first left inner gear ring meshes with the first planetary gear, and the diameter of the first left inner gear ring is greater than the diameter of the first right inner gear ring.
[0011] As further improvement of the above technical scheme, the outer circumferential surface of the first right inner gear ring and the inner circumferential surface of the inner cylinder body are provided with a clutch two, and the inner circumferential surface of the first right inner gear ring and the outer circumferential surface of the reduction mechanism input shaft are provided with a bearing.
[0012] As further improvement of the above technical scheme, the inner cylinder body and the outer cylinder body are in a cylindrical shape, the inner cylinder body is arranged on the inner side of the right end of the outer cylinder body, a bearing is arranged between the inner cylinder body and the outer cylinder body, the inner cylinder body extends outward to form an annular flange at one end, and the annular flange is fixedly connected to the inner wall of the right end of the outer cylinder body.
[0013] As further improvement of the above technical scheme, the other end of the outer cylinder body is provided with a second inner gear ring corresponding to the secondary planetary reduction mechanism and the tertiary planetary reduction mechanism, the left end of the outer cylinder body is provided with a first cover body, and the right end of the inner cylinder body is provided with a second cover body.
[0014] As a further improvement of the above technical solution, the first cover body is centrally provided with a protruding part, the output end face of the reducer output shaft is provided with a groove, the protruding part is placed in the groove, and a bearing is arranged between the protruding part and the groove; the second cover body is centrally provided with a bearing seat, the bearing seat is sleeved on the input end of the reducer input shaft, and a bearing is arranged between the bearing seat and the input end of the reducer input shaft.
[0015] As a further improvement of the above technical solution, the inner circumferential surface of the first axial protruding part is in interference fit or fixedly connected with the input end of the reducer output shaft through splines, and a bearing is arranged between the outer circumferential surface of the first axial protruding part and the third planet carrier.
[0016] As a further improvement of the above technical solution, the outer circumferential surface of the outer cylinder body is fixedly provided with an annular brake disc through a screw, and two brake calipers are arranged on opposite sides of the brake disc.
[0017] As a further improvement of the above technical solution, the input end of the reducer output shaft is provided with a protrusion, the output end face of the reducer input shaft is provided with a recess, the protrusion is placed in the recess, and the reducer output shaft is rotatable around the reducer input shaft through the cooperation of the protrusion and the recess.
[0018] The beneficial effects of the double-speed hub reduction machine are as follows: when the clutch one is combined and the clutch two is separated, the primary planetary reduction mechanism is disconnected, the rotation speed input to the reducer input shaft is output only after being reduced by the secondary planetary reduction mechanism and the tertiary planetary reduction mechanism, the final output speed ratio of the reducer is the product of the secondary rotation speed ratio and the tertiary rotation speed ratio, and thus the first gear output rotation speed is obtained; when the clutch one is separated and the clutch two is combined, the rotation speed input to the reducer input shaft is output after being reduced by the primary planetary reduction mechanism, the secondary planetary reduction mechanism, and the tertiary planetary reduction mechanism, the final output speed ratio of the reducer is the product of the primary rotation speed ratio, the secondary rotation speed ratio, and the tertiary rotation speed ratio, and thus the second gear output rotation speed is obtained. Therefore, the double-speed hub reduction machine can be varied in speed according to requirements to obtain different output speed ratios and torques, has high carrying capacity, runs stably, and the double-speed hub reduction machine can provide greater reduction ratio and higher torque output through the tertiary planetary reduction mechanism, and is suitable for heavy load scenes. BRIEF DESCRIPTION OF DRAWINGS
[0019] The utility model is further described below in combination with the drawings and examples.
[0020] Figure 1 is a structural schematic view of the double-speed hub reduction machine provided by the preferred embodiment of the utility model;
[0021] Figure 2 is Figure 1 the double-speed hub reduction machine in the front side view;
[0022] Figure 3 is Figure 1 the double-speed wheel-side reduction machine in the left side view in
[0023] Figure 4 is Figure 1 the structural schematic diagram of the planetary reduction mechanism in the double-speed wheel-side reduction machine in
[0024] Figure 5 is Figure 1 the internal structure diagram of the double-speed wheel-side reduction machine in
[0025] In the figure: 1, primary planetary reduction mechanism; 11, first sun gear; 12, first planetary gear; 13, first inner gear ring; 131, first left inner gear ring; 132, first right inner gear ring; 14, first left planet carrier; 141, first annular flange; 142, first axial protrusion; 15, first right planet carrier; 151, second annular flange; 152, second axial protrusion; 16, first planetary gear shaft; 2, secondary planetary reduction mechanism; 21, second sun gear; 22, second planetary gear; 23, second planetary gear shaft; 24, second planet carrier; 3, tertiary planetary reduction mechanism; 31, third sun gear; 32, third planetary gear; 34, third planet carrier; 35, third planetary gear shaft; 4, reduction machine input shaft; 5, reduction machine output shaft; 53, protrusion; 6, outer cylinder body; 61, first cover body; 62, second inner gear ring; 63, protrusion; 64, brake disc; 65, brake caliper; 7, inner cylinder body; 71, bearing; 72, second cover body; 73, flange; 8, clutch one; 9, clutch two. DETAILED DESCRIPTION
[0026] The utility model will be further explained in detail in combination with the drawings and embodiments, these drawings are all simplified schematic diagrams, only with the schematic way to illustrate the basic structure of the utility model, therefore it only shows the relevant constitution with the utility model.
[0027] In the description of the utility model, need understanding is, the term "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "internal", "external" and so on the orientation or positional relation indicated is based on the orientation or positional relation shown in the drawing, just is for the convenience of describing the utility model and simplifying the description, and it is not indicated or implied that the device or element indicated must have a particular orientation, a particular orientation configuration and operation, therefore can not be understood as the restriction of the utility model. In addition, the term "first", "second" and so on are just for the description purpose, and can not be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features limited by "first", "second" and so on can be explicitly or implicitly include one or more features. In the description of the utility model, unless otherwise specified, the meaning of "a plurality of" is two or more than two.
[0028] In the description of the utility model, it needs to be explained that, unless otherwise specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, can be fixed connection, can also be detachable connection, or integrally connected, can be mechanical connection, can also be electrical connection, can be directly connected, can also be indirectly connected through intermediate medium, can be the communication inside two elements. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood through specific circumstances.
[0029] As Figures 1 to 5 The utility model provides a kind of double-speed wheel edge reduction gear, including outer cylinder 6, be arranged in the inside of outer cylinder 6 first planetary reducer 1, second planetary reducer 2, third planetary reducer 3, reduction gear input shaft 4, reduction gear output shaft 5, inner cylinder 7, clutch one 8 and clutch two 9, reduction gear input shaft 4 and reduction gear output shaft 5 coaxial arrangement, inner cylinder 7 is arranged around reduction gear input shaft 4, outer cylinder 6 inner wall is equipped with second inner gear ring 62 corresponding second planetary reducer 2 and third planetary reducer 3.
[0030] The first planetary reduction mechanism 1 comprises a first sun gear 11, a first planetary gear 12, a first inner ring gear 13, a first left planetary carrier 14 and a first right planetary carrier 15, the first sun gear 11 is arranged on the output end of the reduction machine input shaft 4, the first left planetary carrier 14 comprises a first annular flange 141 and a first axial protrusion 142, the first right planetary carrier 15 comprises a second annular flange 151 and a second axial protrusion 152, the first annular flange 141 and the second annular flange 151 are connected with the first planetary gear shaft 16, the first planetary gear 12 is rotatably sleeved on the first planetary gear shaft 16 and is in mesh with the first sun gear 11 and the first inner ring gear 13, the first axial protrusion 142 is sleeved on the input end of the reduction machine output shaft 5, the inner side of the second axial protrusion 152 is provided with a receiving groove, the clutch one 8 is arranged in the receiving groove and is sleeved on the output end of the reduction machine input shaft 4, and the clutch one 8 can be combined or separated with the second axial protrusion 152. The first inner ring gear 13 comprises a first left inner ring gear 131 and a first right inner ring gear 132, the clutch two 9 is sleeved on the first right inner ring gear 132, and the clutch two 9 can be combined or separated with the inner cylinder body 7.
[0031] The third planetary reduction mechanism 3 comprises a third sun gear 31, a third planetary gear 32 and a third planetary carrier 34, the third sun gear 31 is rotatably sleeved on the reduction machine output shaft 5, one side of the third planetary carrier 34 is provided with a third planetary gear shaft 35, the third planetary gear 32 is rotatably sleeved on the third planetary gear shaft 35 and is in mesh with the third sun gear 31 and the second inner ring gear 62, the other side of the third planetary carrier 34 is fixedly connected with one end of the inner cylinder body 7, and the other end of the inner cylinder body 7 is fixedly connected with the outer cylinder body 6.
[0032] The second planetary reduction mechanism 2 comprises a second sun gear 21, a second planetary gear 22 and an annular second planetary carrier 24, the second sun gear 21 is arranged on the output end of the reduction machine output shaft 5, one side of the second planetary carrier 24 is provided with a second planetary gear shaft 23, the second planetary carrier 24 is sleeved on the third sun gear 31 and is in mesh with the third sun gear 31, and the second planetary gear 22 is rotatably sleeved on the second planetary gear shaft 23 and is in mesh with the second sun gear 21 and the second inner ring gear 62.
[0033] Preferably, the first left planetary carrier 14 and the first right planetary carrier 15 are arranged on the left and right sides of the first sun gear 11 respectively, the first annular flange 141 of the first left planetary carrier 14 and the second annular flange 151 of the first right planetary carrier 15 are fixedly connected together through bolts, the first planetary gear 12 can rotate around the first planetary gear shaft 16, and the first planetary gear shaft 16 penetrates through the first annular flange 141 and the second annular flange 151 and is fixedly connected with the first annular flange 141 and the second annular flange 151.
[0034] Preferably, the first inner ring gear 13 is arranged outside the first left and right planet carriers 14 and 15, and the first left and right inner ring gears 131 and 132 are integrally formed, the inner side of the first left inner ring gear 131 is engaged with the first planet gear 12, the first right inner ring gear 132 is located on the right side of the first right planet carrier 15, the diameter of the first left inner ring gear 131 is larger than that of the first right inner ring gear 132, and the outer circumferential surface of the first right inner ring gear 132 is provided with the clutch 9 between the inner circumferential surface of the inner cylinder 7, and the inner circumferential surface of the first right inner ring gear 132 is provided with a bearing between the outer circumferential surface of the input shaft 4 of the speed reducer.
[0035] Preferably, the inner cylinder 7 and the outer cylinder 6 are cylindrical, the inner cylinder 7 is arranged inside the right end of the outer cylinder 6, a bearing 71 is arranged between the inner cylinder 7 and the outer cylinder 6, the right end of the inner cylinder 7 extends outward to form an annular flange 73, the annular flange 73 is connected to the inner wall of the right end of the outer cylinder 6, and the left end of the outer cylinder 6 is provided with a second inner ring gear 62 corresponding to the second and third planetary reduction mechanisms 2 and 3, the left end of the outer cylinder 6 is provided with a first cover 61, and the right end of the inner cylinder 7 is provided with a second cover 72.
[0036] Preferably, the outer circumferential surface of the outer cylinder 6 is fixed with an annular brake disc 64 through a screw, two brake calipers 65 are arranged on opposite sides of the brake disc 64, and the brake function of the double-speed rim reduction machine can be realized through the brake disc 64 and the brake calipers 65.
[0037] Preferably, the first sun gear 11 and the input shaft 4 of the speed reducer are integrally formed, and the second sun gear 21 and the output shaft 5 of the speed reducer are integrally formed.
[0038] Preferably, the input end of the output shaft 5 of the speed reducer is provided with a protrusion 53, the output end surface of the input shaft 4 of the speed reducer is provided with a recess, the protrusion 53 is arranged in the recess, and the output shaft 5 of the speed reducer is installed to rotate around the input shaft 4 of the speed reducer through the cooperation of the protrusion 53 and the recess. The central part of the second cover 72 is provided with a bearing seat, the bearing seat is sleeved on the input end of the input shaft 4 of the speed reducer, and a bearing is arranged between the bearing seat and the input end of the input shaft 4 of the speed reducer. The central part of the first cover 61 is provided with a protruding part 63, the output end surface of the output shaft 5 of the speed reducer is provided with a groove, the protruding part 63 is arranged in the groove, and a bearing is arranged between the protruding part 63 and the groove.
[0039] Specifically, the third planet gear 32 is arranged in multiple, the inner circumferential surface of the first axial protruding part 142 is fixedly connected with the input end of the output shaft 5 of the speed reducer through interference fit or spline, and the outer circumferential surface of the first axial protruding part 142 is provided with a bearing between the third planet carrier 34.
[0040] In use, the above-mentioned dual-speed wheel-side reducer is installed on the drive axle of a vehicle. A wheel is provided on the outer side of the outer cylinder 6. The power output from the drive axle is transmitted to the input end of the reducer input shaft 4. When clutch 1 8 is separated from the second axial protrusion 152 of the first right planetary carrier 15 and clutch 2 9 is engaged with the inner cylinder 7, the reducer input shaft 4 is disengaged from the first left and right planetary carriers. When the reducer input shaft 4 rotates, it drives the first sun gear 11 to rotate. The first sun gear 11 transmits motion to the first planetary gear 12. The first planetary gear 12 both rotates on its own axis and revolves around the sun. The first planetary gear 12 revolves around the sun, driving the first left and right planetary carriers to rotate. The first internal gear ring 13 is fixed and outputs the first-stage speed ratio. The output speed of the first left and right planetary carriers is used as the input speed of the second-stage planetary reduction mechanism 2.
[0041] When clutch 18 engages with the second axial protrusion 152 of the first right planetary carrier 15 and clutch 29 disengages from the inner cylinder 7, the reducer input shaft 4 is integrated with the first left and right planetary carriers. When the reducer input shaft 4 rotates, it drives the first left and right planetary carriers and the first sun gear 11 to rotate synchronously. The first left and right planetary carriers and the first sun gear 11 drive the first planetary gear 12 to rotate synchronously. The first planetary gear 12 drives the first internal gear ring 13 to rotate synchronously. The reducer input shaft 4 and the reducer output shaft 5 have the same speed. At this time, the first-stage speed ratio is 1, and the output speed of the first-stage planetary reduction mechanism 1 is used as the input speed of the second-stage planetary reduction mechanism 2.
[0042] When motion is output from the first left and right planetary carriers and transmitted to the reducer output shaft 5, the reducer output shaft 5 transmits motion to the second sun gear 21, and the second sun gear 21 transmits motion to the second planet gear 22. The second planet gear 22 rotates on its own axis and revolves around the sun. The revolving motion of the second planet gear 22 drives the second planetary carrier 24 to rotate, so that the motion of the second-stage planetary reduction mechanism 2 is output from the second planetary carrier 24. At the time of output, a second-stage speed ratio is generated, and the output speed of the second-stage planetary reduction mechanism 2 serves as the input speed of the third-stage planetary reduction mechanism 3.
[0043] When motion is output from the second planetary carrier 24 and transmitted to the third sun gear 31, the third sun gear 31 transmits the motion to the third planetary gear 32. The third planetary gear 32 both rotates on its own axis and revolves around a central point. The revolution of the third planetary gear 32 drives the third planetary carrier 34 to rotate, thus the motion of the three-stage planetary reduction mechanism 3 is output from the third planetary carrier 34, and a three-stage speed ratio is generated during the output. Since the third planetary carrier 34, the inner cylinder 7, and the outer cylinder 6 are fixedly connected as a whole, the third planetary carrier 34 transmits the motion to the outer cylinder 6. A wheel is connected to the outside of the outer cylinder 6, and the motion is finally transmitted to the wheel through the outer cylinder 6.
[0044] The utility model provides a double -speed wheel edge speed reducer, when clutch one 8 combines and clutch two 9 separates, primary planetary reducer 1 disconnects, and the rotational speed of input to speed reducer input shaft 4 only after two -stage planetary reducer 2 and three -stage planetary reducer 3 deceleration export, and the final output speed ratio of speed reducer is two -stage rotational speed ratio and three -stage rotational speed ratio's product, to obtain the first gear output rotational speed of bigger, when clutch one 8 separates and clutch two 9 combines, the rotational speed of input to speed reducer input shaft 4 after primary planetary reducer 1, two -stage planetary reducer 2 and three -stage planetary reducer 3 deceleration export, and the final output speed ratio of speed reducer is primary rotational speed ratio, two -stage rotational speed ratio, three -stage rotational speed ratio three's product, to obtain the second gear output rotational speed of smaller. Therefore, this double -speed wheel edge speed reducer can change speed according to the demand to obtain different output speed ratio and torque, and the carrying capacity is higher, and the operation is more stable.
[0045] The above specific embodiment of the utility model is not involved in the description of the field, and can be implemented by referring to the known technology.
[0046] According to the ideal embodiment of the utility model, the related personnel can make various changes and modifications without deviating from the technical idea of the utility model. The technical scope of the utility model is not limited to the content of the specification, and the technical scope must be determined according to the scope of claims.
Claims
1. A dual-speed wheel-side reducer, characterized in that: It includes an outer cylinder, a first-stage planetary reduction mechanism, a second-stage planetary reduction mechanism, a third-stage planetary reduction mechanism, a reducer input shaft, a reducer output shaft, an inner cylinder, a clutch one, and a clutch two. The reducer input shaft and the reducer output shaft are arranged coaxially. The inner cylinder is arranged around the reducer input shaft. The inner wall of the outer cylinder is provided with a second internal gear ring corresponding to the second-stage planetary reduction mechanism and the third-stage planetary reduction mechanism. The first-stage planetary reduction mechanism includes a first sun gear, a first planet gear, a first internal gear ring, a first left planet carrier, and a first right planet carrier. The first sun gear is located at the output end of the reducer's input shaft. The first left planet carrier includes a first annular flange and a first axial protrusion. The first right planet carrier includes a second annular flange and a second axial protrusion. A first planet gear shaft is connected between the first annular flange and the second annular flange. The first planet gear is rotatably mounted on the first planet gear shaft and meshes with the first sun gear and the first internal gear ring. The first axial protrusion is mounted on the input end of the reducer's output shaft. A receiving groove is provided inside the second axial protrusion. Clutch 1 is located in the receiving groove and mounted on the output end of the reducer's input shaft. Clutch 1 can be engaged or disengaged from the second axial protrusion. The first internal gear ring includes a first left internal gear ring and a first right internal gear ring. Clutch 2 is mounted on the first right internal gear ring. Clutch 2 can be engaged or disengaged from the inner cylinder. The three-stage planetary reduction mechanism includes a third sun gear, a third planet gear, and a third planet carrier. The third sun gear is rotatably mounted on the output shaft of the reducer. A third planet gear shaft is provided on one side of the third planet carrier. The third planet gear is rotatably mounted on the third planet gear shaft and meshes with the third sun gear and the second internal gear ring. The other side of the third planet carrier is fixedly connected to one end of the inner cylinder, and the other end of the inner cylinder is fixedly connected to the outer cylinder. The two-stage planetary reduction mechanism includes a second sun gear, a second planet gear, and a ring-shaped second planet carrier. The second sun gear is located on the output end of the reducer output shaft. A second planet gear shaft is located on one side of the second planet carrier. The second planet carrier is sleeved on the third sun gear and meshes with the third sun gear. The second planet gear is rotatably sleeved on the second planet gear shaft and meshes with the second sun gear and the second internal gear ring.
2. The dual-speed wheel-side reducer according to claim 1, characterized in that: The first left planet carrier and the first right planet carrier are respectively disposed on the left and right sides of the first sun gear. The first annular flange of the first left planet carrier and the second annular flange of the first right planet carrier are fixedly connected together by bolts. The first planet gear can rotate around the first planet gear shaft. The first planet gear shaft passes through the first annular flange and the second annular flange respectively and is fixedly connected to the first annular flange and the second annular flange.
3. The dual-speed wheel-side reducer according to claim 2, characterized in that: The first internal gear ring is disposed on the outside of the first left planet carrier and the first right planet carrier. The first left internal gear ring and the first right internal gear ring are integrally formed. The inner side of the first left internal gear ring meshes with the first planet gear. The diameter of the first left internal gear ring is larger than the diameter of the first right internal gear ring.
4. The dual-speed wheel-side reducer according to claim 3, characterized in that: A second clutch is provided between the outer circumferential surface of the first right internal gear ring and the inner circumferential surface of the inner cylinder, and a bearing is provided between the inner circumferential surface of the first right internal gear ring and the outer circumferential surface of the reducer input shaft.
5. The dual-speed wheel-side reducer according to claim 4, characterized in that: The inner cylinder and the outer cylinder are cylindrical. The inner cylinder is located on the inner side of the right end of the outer cylinder. A bearing is provided between the inner cylinder and the outer cylinder. One end of the inner cylinder extends outward to form an annular flange, which is connected and fixed to the inner wall of the right end of the outer cylinder.
6. The dual-speed wheel-side reducer according to claim 5, characterized in that: The inner wall of the other end of the outer cylinder is provided with a second internal gear ring corresponding to the second-stage planetary reduction mechanism and the third-stage planetary reduction mechanism. A first cover is provided at the left end of the outer cylinder, and a second cover is provided at the right end of the inner cylinder.
7. The dual-speed wheel-side reducer according to claim 6, characterized in that: The first cover has a protrusion in the center, and a groove is provided on the output end face of the reducer output shaft. The protrusion is placed in the groove, and a bearing is provided between the protrusion and the groove. The second cover has a bearing seat in the center, which is sleeved on the input end of the reducer input shaft, and a bearing is provided between the bearing seat and the input end of the reducer input shaft.
8. The dual-speed wheel-side reducer according to claim 7, characterized in that: The inner circumferential surface of the first axial protrusion is interference-fitted with the input end of the reducer output shaft or fixedly connected by a spline, and a bearing is provided between the outer circumferential surface of the first axial protrusion and the third planetary carrier.
9. The dual-speed wheel-side reducer according to claim 8, characterized in that: An annular brake disc is fixed to the outer circumference of the outer cylinder by screws, and two brake calipers are set on opposite sides of the brake disc.
10. The dual-speed wheel-side reducer according to claim 9, characterized in that: The input end of the reducer output shaft is provided with a protrusion, and the output end face of the reducer input shaft is provided with a recess. The protrusion is placed in the recess, and the reducer output shaft can rotate around the reducer input shaft through the cooperation of the protrusion and the recess.