Transmission device with buffering and self-locking functions for new energy automobile

Abstract

The invention discloses a transmission device with buffering and self-locking functions for a new energy automobile, and belongs to the technical field of new energy transmission devices. The input shaft and the output shaft are coaxially and rotationally arranged on the box body shell, the involute cam is arranged on the input shaft in a sliding and non-rotating mode, the composite sun gear is arranged outside the involute cam in a one-way rotating and sleeving mode, and the planet carrier is fixedly arranged on the output shaft. The compound planet wheel and the reversing planet wheel are rotationally arranged on the planet carrier, the axes of the compound planet wheel and the reversing planet wheel are parallel to each other, the transmission inner gear ring is internally meshed with the compound planet wheel, the sun wheel axial driving assembly is used for driving the involute cam to slide in the axial direction, and the rotation self-locking assembly is used for allowing or forbidding rotation of the output shaft. And the self-locking switching power assembly is used for switching the working state of the rotary self-locking assembly. The transmission device can isolate and buffer inertia rotation of a load, has a synchronous braking and self-locking function and can be used for a new energy automobile.

Description

Technical Field

[0001] The present invention mainly relates to the technical field of new energy transmission devices, and in particular to a transmission device with buffering and self-locking for new energy vehicles. Background Art

[0002] Compared to internal combustion engine vehicles, new energy vehicles (NEVs) are becoming a trend in future automotive development due to their zero-pollution operation. As a core component of new energy vehicles, the performance of their transmission system determines their market success. Traditional transmission systems typically utilize gear trains for speed change to achieve input and output transmission. Because gear meshing in the transmission chain cannot be quickly disconnected, the output shaft continues to rotate due to load inertia after the input motor shaft suddenly stops. This inertial rotation of the load is transmitted back through the gear meshing to the stationary motor shaft, shortening the motor's service life. In prior art, Document 1 (Application Number: 202210405281.3) provides a dedicated transmission housing for new energy vehicles that effectively disconnects load inertial rotation after the motor shaft stops, protecting the motor shaft. Although the existing technology protects the motor shaft by rotation isolation, it still has the following technical defects: after the motor input shaft is braked, the output shaft connected to the load will continue to rotate for a while due to rotational inertia before stopping, so the input braking and the input braking are not synchronized, that is, the transmission device of the existing technology cannot achieve synchronous braking self-locking during the transmission process. Summary of the Invention

[0003] The technical problem to be solved by the present invention is: In response to the technical problems existing in the prior art, the present invention provides a transmission device that can be used for new energy vehicles, with unidirectional input and positive and negative bidirectional output, which can isolate and buffer the inertial rotation of the load and has a synchronous braking and self-locking function.

[0004] To solve the above problems, the present invention proposes a solution: a transmission device with buffering and self-locking for new energy vehicles, comprising a housing, and an input shaft and an output shaft coaxially mounted on the housing and extending outward at one end; further comprising: an involute cam mounted on the input shaft for sliding but not rotating, a compound sun gear unidirectionally mounted and non-sliding on the outside of the involute cam, a planet carrier fixedly mounted on the output shaft, at least one set of compound planetary gears and reversing planetary gears rotatably mounted on the planet carrier with axes parallel to each other, a transmission inner ring gear fixedly mounted on the inner wall of the housing and internally meshing with the compound planetary gears, a sun gear axial drive assembly mounted on the input shaft for driving the involute cam to slide axially, a rotation self-locking assembly mounted on the output shaft for allowing or prohibiting rotation of the output shaft, and a self-locking switching power assembly mounted on the inner wall of the housing; the reversing planetary gear is externally meshed with the compound planetary gear for transmission, and the compound sun gear can be externally meshed with the reversing planetary gear and the compound planetary gear respectively after sliding left and right.

[0005] When the rotation self-locking component is in a non-self-locking state, the output shaft is allowed to rotate; when the rotation self-locking component is in a self-locking state, the output shaft is prohibited from rotating; the self-locking switching power component is used to switch the rotation self-locking component between the self-locking state and the non-self-locking state.

[0006] Furthermore, the rotating self-locking component includes: a directional gear fixedly mounted on the output shaft, a switching plate rotatably mounted inside the box shell, a switching gear A, a switching gear B and a reversing gear rotatably mounted on the switching plate and with axes parallel to each other, and a damping inner gear ring that is simultaneously engaged with the directional gear and the reversing gear; the switching plate is coaxially mounted with the reversing gear, and the switching gear B is simultaneously externally engaged with the switching gear A and the reversing gear; rotating the switching plate can switch the switching gear A that is externally engaged with the directional gear to the switching gear B.

[0007] Furthermore, the composite sun gear includes a sun gear A and a sun gear B fixedly connected together coaxially. Sliding the composite sun gear can switch the external meshing transmission state between the sun gear A and the reversing planetary gear to the external meshing transmission state between the sun gear B and the composite planetary gear.

[0008] Furthermore, the composite planetary gear is composed of a planetary gear A and a planetary gear B which are coaxially and synchronously rotated on the planetary carrier. The planetary gear B is externally meshed with the reversing planetary gear for transmission, and the planetary gear A can be engaged or disengaged with the sun gear B.

[0009] Furthermore, the switching gear B is composed of a coaxial and synchronously rotating coaxial gear A and a coaxial gear B installed on the switching plate. The coaxial gear A is externally meshed with the switching gear A, and the coaxial gear B is externally meshed with the reversing gear. By rotating the switching plate, the switching gear A externally meshed with the directional gear can be switched to the coaxial gear A.

[0010] Furthermore, the sun gear axial drive assembly includes: a bracket plate A fixedly mounted on the input shaft, and an electric telescopic rod with two ends respectively connected to the bracket plate A and the involute cam.

[0011] Furthermore, the self-locking switching power assembly includes: a bracket plate B fixedly mounted on the inner wall of the box shell, a hollow shaft rotatably mounted on the bracket plate B, and a power source for driving the hollow shaft to rotate; the switching plate is fixedly mounted on the hollow shaft, and the reversing gear is coaxial with the hollow shaft.

[0012] Furthermore, the right end of the involute cam is a hollow cylindrical structure, and the circumferential outer edge of the left end of the involute cam is composed of a number of axially symmetrically distributed involute surfaces, and a gradual gap with a gradually changing width is formed between the involute surface and the inner edge of the composite sun gear. A number of rollers and elastic elements are installed in the gradual gap, one end of the elastic element is connected to the involute cam, and the other end is in conflict with the roller; the diameter of the roller is greater than the minimum width of the gradual gap.

[0013] Furthermore, when the elastic element is in a static equilibrium state, a plurality of the rollers simultaneously conflict with the outer edge of the involute cam and the inner edge of the composite sun gear.

[0014] Compared with the prior art, the present invention has the following advantages and beneficial effects: the present invention provides a transmission device with buffered self-locking for new energy vehicles, which is provided with a compound sun gear that allows axial sliding and a reversing planetary gear and a compound planetary gear that can be switched to engage with the compound sun gear. The meshing object of the compound sun gear is switched by the sun gear axial driving component, and the reversing output of the output shaft can be achieved without changing the rotation direction of the input shaft, that is, the present invention achieves the transmission effect of one-way rotation input and forward and reverse bidirectional rotation output; the compound sun gear adopts a plurality of rollers mounted on the involute cam, and the rollers installed in the involute gap formed between the compound sun gear and the involute cam allow the compound sun gear to rotate counterclockwise relative to the involute cam, but prohibit the compound sun gear from rotating clockwise relative to the involute cam, so the input shaft is reversed. When the gear shifts clockwise, the composite sun gear can be driven to rotate counterclockwise synchronously. After the input shaft stops suddenly, the composite sun gear can continue to rotate counterclockwise around the stationary involute cam under the action of inertial rotation, that is, the present invention achieves the isolation and buffering effect of inertial rotation after input braking; in addition, the present invention is also provided with a rotation self-locking component that can switch between a self-locking state and a non-self-locking state. The self-locking switching power component switches the rotation self-locking component to the non-self-locking state, and the input shaft rotates counterclockwise, and the output shaft can be driven forward or reversely by the planetary carrier; when the input shaft is braked, it only needs to switch the rotation self-locking component to the self-locking state at the same time, and the output shaft will be immediately locked and prevented from rotating by the directional gear and the damping inner ring gear. Therefore, the output shaft is braked immediately after the input shaft is braked, that is, the present invention achieves the effect of synchronous braking and self-locking of the input and output. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The present invention is a schematic diagram of the structural principle of a transmission device with buffering and self-locking for new energy vehicles.

[0016] Figure 2 It is a schematic diagram of the assembly of the composite sun gear and the involute cam in the present invention.

[0017] Figure 3 It is a schematic diagram of the structural principle of the rotary self-locking component of the present invention when it is in a self-locking state.

[0018] Figure 4 It is a schematic diagram of the structural principle of the rotary self-locking component of the present invention when it is in a non-self-locking state.

[0019] Figure 5 yes Figure 3 AA rotated section view in.

[0020] Figure 6 yes Figure 4 BB rotated section view in .

[0021] In the figure, 11 is the housing; 12 is the input shaft; 13 is the output shaft; 14 is the planet carrier; 141 is the main planet shaft; 142 is the auxiliary planet shaft; 15 is the compound planet gear; 151 is the planet gear A; 152 is the planet gear B; 16 is the involute cam; 161 is the involute surface; 162 is the gradual gap; 17 is the compound sun gear; 171 is the sun gear A; 172 is the sun gear B; 18 is the reversing planet gear; 19 is the transmission inner ring gear; 21 is the bracket plate A; 22—electric telescopic rod; 31—directional gear; 32—damping inner ring gear; 33—reversing gear; 34—switching plate; 35—switching gear A; 36—switching gear B; 361—co-diameter gear A; 362—co-diameter gear B; 41—bracket plate B; 42—hollow shaft; 43—power source; 51—rotating shaft A; 52—rotating shaft B; 53—rotating shaft C; 54—roller; 55—elastic element; 56—axial positioning plate; 57—bearing baffle. DETAILED DESCRIPTION

[0022] The present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments. Figure 1 The direction from left to right in the figure is recorded as the X-axis direction; in the following description, all concepts related to the directionality or orientation of up, down, left, right, front and back are based on Figure 1 The position is used as a reference, and thus it cannot be understood as a special limitation on the technical solution provided by the present invention.

[0023] See also Figure 1The present invention provides a transmission device with buffering and self-locking for new energy vehicles, which includes a housing 11, an input shaft 12 and an output shaft 13 coaxially mounted on the housing 11 and extending outward at one end, an involute cam 16 mounted on the input shaft 12 and sliding without rotating, a compound sun gear 17 unidirectionally rotating and sleeved on the outside of the involute cam 16, a planetary carrier 14 fixedly mounted on the output shaft 13, at least one set of compound planetary gears 15 and reversing planetary gears 18 rotatably mounted on the planetary carrier 14 and with axes parallel to each other, a transmission inner ring gear 19 fixedly mounted on the inner wall of the housing 11 and meshing with the compound planetary gears 15, a sun gear axial drive assembly mounted on the input shaft 12 for driving the involute cam 16 to slide axially, a rotation self-locking assembly mounted on the output shaft 13 for allowing or prohibiting the output shaft 13 from rotating, and a self-locking switching power assembly mounted on the inner wall of the housing 11. The reversing planetary gear 18 is externally meshed with the compound planetary gear 15 for transmission. The compound sun gear 17 can then externally mesh with the reversing planetary gear 18 and the compound planetary gear 15, respectively, after sliding left and right. In specific implementation, the housing 11 is a casting, consisting of a bottom plate, a top plate, a left plate, a right plate, a front plate, and a rear plate. The input shaft 12 is rotatably mounted on the left plate through a rolling bearing, while the output shaft 13 is mounted on the right plate through a rolling bearing. A rectangular keyway is axially defined on the input shaft 12, and a long guide key is installed in the rectangular keyway using a transition fit. The inner hole of the involute cam 16 is axially defined with a guide groove that matches the guide key, thereby enabling the involute cam 16 to slide without rotating. Installation; Several main planetary shafts 141 and several auxiliary planetary shafts 142 are arranged on the planetary carrier 14 along the X-axis direction; the main planetary shafts 141 and the auxiliary planetary shafts 142 are parallel to each other, the compound planetary gear 15 is rotatably mounted on the main planetary shaft 141, and the reversing planetary gear 18 is rotatably mounted on the auxiliary planetary shaft 142; Several main planetary shafts 141 are axially symmetrically distributed about the input shaft 12, and Several auxiliary planetary shafts 142 are axially symmetrically distributed about the input shaft 12; The number of main planetary shafts 141 is greater than or equal to the number of auxiliary planetary shafts 142. In the first embodiment, the number of main planetary shafts 141 and the number of auxiliary planetary shafts 142 are equal, both being two; in the second embodiment, the number of main planetary shafts 141 is four, and the number of auxiliary planetary shafts 142 is two. An axial positioning plate 56 is installed on the right side of the compound sun gear 17, and an axial positioning bearing is installed in the axial positioning plate 56. The cylindrical right end of the involute cam 16 passes through the axial positioning bearing and is fixedly installed with a bearing baffle 57. The bearing baffle 57 presses against the inner ring of the axial positioning bearing, thereby ensuring that axial relative sliding cannot occur between the compound sun gear 17 and the involute cam 16.

[0024] See also Figure 1 and Figure 2Preferably, the compound sun gear 17 comprises a coaxially fixed sun gear A171 and a sun gear B172. Sun gear A171 has a smaller diameter than sun gear B172, and sun gear B172 is located to the right of sun gear A171. Sliding the compound sun gear 17 switches the external meshing transmission state between sun gear A171 and the reversing planetary gear 18 to an external meshing transmission state between sun gear B172 and the compound planetary gear 15. The compound planetary gear 15 comprises planetary gears A151 and B152, which are coaxially mounted on the main planetary shaft 141 and rotate synchronously therewith. Planetary gear A151 is located to the right of planetary gear B152. Both planetary gears A151 and B152 are internally meshed with the transmission inner ring gear 19. The diameter of planetary gear A151 is equal to the diameter of planetary gear B152. Planetary gear B152 is externally meshed with the reversing planetary gear 18, and planetary gear A151 can engage or disengage with sun gear B172. The sun gear axial drive assembly includes a support plate A21 fixedly mounted on the input shaft 12, and an electric telescopic rod 22, each connected to the support plate A21 and the involute cam 16 at both ends. In specific implementation, the fixed end of the electric telescopic rod 22 is fixedly connected to the support plate A21, and the movable end of the electric telescopic rod 22 is fixedly connected to the left end of the involute cam 16. In specific application, the movable rod of the electric telescopic rod 22 extends outward, pushing the involute cam 16 and the compound sun gear 17 to slide synchronously to the right, causing the compound sun gear 17 to slide to the right limit position. At this time, the sun gear A171 disengages from the reversing planetary gear 18, and the sun gear B172 engages externally with the planetary gear A151. The movable rod of the electric telescopic rod 22 retracts inward, pulling the involute cam 16 and the compound sun gear 17 to slide synchronously to the left, causing the compound sun gear 17 to slide to the left limit position. At this time, the sun gear A171 engages externally with the reversing planetary gear 18, and the sun gear B172 disengages from the planetary gear A151.

[0025] See also Figures 3 to 6When the rotating self-locking component is in a non-self-locking state, the output shaft 13 is allowed to rotate; when the rotating self-locking component is in a self-locking state, the output shaft 13 is prohibited from rotating; preferably, the rotating self-locking component includes: a directional gear 31 fixedly mounted on the output shaft 13, a switching plate 34 rotatably mounted inside the box shell 11, a switching gear A35, a switching gear B36 and a reversing gear 33 rotatably mounted on the switching plate 34 and with axes parallel to each other, and a damping inner gear ring 32 that is simultaneously engaged with the directional gear 31 and the reversing gear 33 for transmission; the switching plate 34 is coaxially mounted with the reversing gear 33, and the switching gear B36 is simultaneously engaged with the switching gear A35 and the reversing gear 33 for external transmission; by rotating the switching plate 34, the switching gear A35 that is externally engaged with the directional gear 31 can be switched to the switching gear B36. The switching gear B36 is composed of a coaxial and synchronously rotating coaxial gear A361 and a coaxial gear B362 mounted on the switching plate 34. The coaxial gear A361 is externally meshed with the switching gear A35 for transmission, and the coaxial gear B362 is externally meshed with the reversing gear 33 for transmission. By rotating the switching plate 34, the switching gear A35, which is externally meshed with the directional gear 31, can be switched to the coaxial gear A361. The self-locking switching power assembly is used to switch the rotating self-locking assembly between a self-locking state and a non-self-locking state. The self-locking switching power assembly includes: a bracket plate B41 fixedly mounted on the inner wall of the box shell 11, a hollow shaft 42 rotatably mounted on the bracket plate B41, and a power source 43 that drives the hollow shaft 42 to rotate; the switching plate 34 is fixedly mounted on the hollow shaft 42, and the reversing gear 33 is coaxial with the hollow shaft 42. During specific implementation, a rolling bearing is used inside the left end of the hollow shaft 42 to be rotatably connected to the right end of the rotating shaft C53, and the right end of the hollow shaft 42 is rotatably mounted on the bracket plate B41 through a rolling bearing; the power source 43 is mounted on the bracket plate B41, and the power source 43 is a rotating motor, and the motor shaft of the rotating motor is connected to the right end of the hollow shaft 42. The switching plate 34 is rotatably mounted with a rotating shaft A51 and a rotating shaft B52 whose axes are parallel to the output shaft 13, the switching gear A35 is fixedly mounted on the rotating shaft A51, the co-diameter gears A361 and the co-diameter gears B362 are fixedly mounted on the rotating shaft B52, and the co-diameter gear B362 is located on the right side of the co-diameter gear A361, and the reversing gear 33 is fixedly mounted on the rotating shaft C53; the radius of the directional gear 31 is equal to the radius of the reversing gear 33, the radius of the switching gear A35, and the radius of the switching gear B36, so that when the rotating self-locking assembly is in a non-self-locking state, the damping inner gear ring 32 can rotate freely; the use of the co-diameter gears A361 and the co-diameter gears B362 to form a switching gear B36 can make the switching gear A35 and the reversing gear 33 staggered in space, that is, there will be no motion interference between the two. The damping inner gear ring 32 is made of a damping non-metallic material that can undergo a certain elastic deformation, and can also be made of an elastic metal thin ring, so that the kinetic energy is quickly dissipated when the output shaft 13 is braked and self-locked.

[0026] See also Figure 2 The circumferential outer edge of the left end of the involute cam 16 is composed of several axially symmetrically distributed involute surfaces 161. A gradual gap 162 with a gradually changing width is formed between the involute surfaces 161 and the inner edge of the compound sun gear 17. Several rollers 54 and elastic elements 55 are installed in the gradual gap 162. One end of the elastic element 55 is connected to the involute cam 16, and the other end contacts the roller 54. The diameter of the roller 54 is greater than the minimum width of the gradual gap 162. Preferably, when the elastic element 55 is in a static equilibrium state, the several rollers 54 simultaneously contact the involute surfaces 161 of the involute cam 16 and the inner edge of the compound sun gear 17. In a specific embodiment, the rollers 54 are cylindrical rollers, the elastic element 55 is a metal coil spring, and the portion of the involute cam 16 extending rightward beyond the right end of the compound sun gear 17 is a hollow cylindrical structure.

[0027] The self-locking working principle of the present invention is as follows: Figure 3 and Figure 5 , the power source 43 drives the switching plate 34 to rotate clockwise to the first position. At this time, the directional gear 31 and the switching gear A35 are externally meshed, and the directional gear 31 and the switching gear B36 are disengaged, that is, the rotation self-locking assembly enters the self-locking working state. The external meshing transmission path on the output shaft 13 is as follows: the directional gear 31 drives the switching gear A35 to rotate, the switching gear A35 drives the switching gear B36 to rotate, and the switching gear B36 drives the reversing gear 33 to rotate. Therefore, according to the external meshing transmission path, the directional gear 31 and the reversing gear 33 must rotate at the same speed and in opposite directions. However, since the directional gear 31 and the reversing gear 33 are both internally meshed with the damping inner ring gear 32, the internal meshing transmission path on the output shaft 13 is as follows: the directional gear 31 drives the damping inner ring gear 32 to rotate in the same direction, and the damping inner ring gear 32 drives the reversing gear 33 to rotate in the same direction. Therefore, according to the internal meshing transmission path, the directional gear 31 and the reversing gear 33 must rotate at the same speed and in the same direction. The superposition of the two different meshing transmission paths prevents the reversing gear 33 from rotating. If the reversing gear 33 cannot rotate, the directional gear 31 and the output shaft 13 cannot rotate either. Therefore, when the rotation self-locking assembly is in the self-locking state, the output shaft 13 is locked by the reversing gear 33 and cannot rotate.

[0028] The non-self-locking working principle of the present invention is as follows: Figure 4 and Figure 6, the power source 43 drives the switching plate 34 to rotate counterclockwise to the second position. At this time, the directional gear 31 is disengaged from the switching gear A35, and the directional gear 31 is externally meshed with the co-diameter gear A361, that is, the rotation self-locking component enters the non-self-locking working state. The external meshing transmission path on the output shaft 13 is: the directional gear 31 drives the switching gear B36 to rotate, and the switching gear B36 drives the reversing gear 33 to rotate. Therefore, according to the external meshing transmission path, the directional gear 31 and the reversing gear 33 must rotate at the same speed and in the same direction. At this time, the internal meshing transmission path is still: the directional gear 31 drives the damping inner ring gear 32 to rotate in the same direction, and the damping inner ring gear 32 drives the reversing gear 33 to rotate in the same direction. That is, according to the internal meshing transmission path, the directional gear 31 and the reversing gear 33 also have the same speed and in the same direction. The two different meshing transmission paths will not cause the reversing gear 33 to have a conflicting direction, so the reversing gear 33 can rotate normally. Therefore, when the rotation self-locking assembly enters the non-self-locking state, the output shaft 13 can be driven to rotate by the input shaft 12 through the planet carrier 14 .

[0029] The operating principles of the present invention's co-directional and reverse-directional outputs are as follows: First, the self-locking switching power assembly is used to disengage the self-locking assembly. For co-directional output, the sun gear axial drive assembly causes the compound sun gear 17 to slide to its right limit position. The input shaft 12 rotates counterclockwise, and the involute cam 16, via roller 54, drives the compound sun gear 17 counterclockwise. This in turn causes the compound planetary gears 15 to rotate clockwise. Since the transmission ring gear 19 is stationary, the planetary carrier 14 and output shaft 13 rotate counterclockwise, meaning the output shaft 13 and input shaft 12 rotate in the same direction. For reverse-directional output, the sun gear axial drive assembly causes the compound sun gear 17 to slide to its left limit position. The input shaft 12 rotates counterclockwise, and this counterclockwise rotation of the compound sun gear 17 drives the reversing planetary gears 18 clockwise, which in turn drives the compound planetary gears 15 counterclockwise. Since the transmission ring gear 19 is stationary, the planetary carrier 14 and output shaft 13 rotate clockwise. That is, the output shaft 13 and the input shaft 12 rotate in opposite directions.

[0030] The buffered self-locking principle of the output brake of the present invention is that regardless of the rotation direction of the output shaft 13, the input shaft 12 and the compound sun gear 17 always rotate counterclockwise. During normal rotation of the output shaft 13 driven by the input shaft 12, if braking is required, the input shaft 12 is first stopped, and then the rotational self-locking assembly is immediately switched to the self-locking state. This braking process involves a very small time delay. During this very small time delay, after the input shaft 12 is braked, the output shaft 13 continues to rotate counterclockwise due to inertia. At this time, the roller 54 moves from a small gap to a large gap in the gradually changing gap 162, compressing the elastic element 55. The compound sun gear 17 can continue to rotate around the stationary involute cam 16 without driving the involute cam 16, thus isolating and buffering the output inertial rotation. Once the rotational self-locking assembly switches to the self-locking state, the output shaft 13 is immediately locked by the directional gear 31 and the damping inner ring gear 32, preventing further rotation. The time difference in the above braking process can be completely ignored. Therefore, the present invention realizes input-output synchronous self-locking braking.

[0031] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or replacements that are not conceived through creative work should fall within the protection scope of the present invention.

Claims

1. A transmission device with a buffer and self-locking function for a new energy vehicle, comprising a housing (11), and an input shaft (12) and an output shaft (13) coaxially rotatably mounted on the housing (11) and with one end extending outward; characterized in that: Also includes: An involute cam (16) mounted on the input shaft (12) and slidingly but not rotating, a composite sun gear (17) mounted on the involute cam (16) and rotating in one direction but not sliding, a planet carrier (14) fixedly mounted on the output shaft (13), at least one set of composite planetary gears (15) and reversing planetary gears (18) rotatably mounted on the planet carrier (14) and having axes parallel to each other, a transmission inner gear ring (19) fixedly mounted on the inner wall of the housing (11) and meshing with the composite planetary gear (15), and a gear mounted on the output shaft. The input shaft (12) includes a sun gear axial drive assembly for driving the involute cam (16) to slide axially, a rotation self-locking assembly installed on the output shaft (13) for allowing or prohibiting the output shaft (13) from rotating, and a self-locking switching power assembly installed on the inner wall of the housing (11); the reversing planetary gear (18) is externally meshed with the compound planetary gear (15) for transmission, and the compound sun gear (17) can be externally meshed with the reversing planetary gear (18) and the compound planetary gear (15) after sliding left and right; When the rotation self-locking component is in a non-self-locking state, the output shaft (13) is allowed to rotate; when the rotation self-locking component is in a self-locking state, the output shaft (13) is prohibited from rotating; and the self-locking switching power component is used to switch the rotation self-locking component between the self-locking state and the non-self-locking state.

2. A transmission device with buffer self-locking for new energy vehicles according to claim 1, characterized in that: The rotation self-locking assembly comprises: a directional gear (31) fixedly mounted on the output shaft (13), a switching plate (34) rotatably mounted inside the housing (11), a switching gear A (35), a switching gear B (36) and a reversing gear (33) rotatably mounted on the switching plate (34) and having axes parallel to each other, and a damping inner gear ring (32) that is simultaneously meshed with the directional gear (31) and the reversing gear (33); the switching plate (34) is coaxially mounted with the reversing gear (33), and the switching gear B (36) is simultaneously meshed with the switching gear A (35) and the reversing gear (33); and the switching plate (34) is rotated to switch the switching gear A (35) that is externally meshed with the directional gear (31) to the switching gear B (36).

3. The transmission device with buffer self-locking for new energy vehicles according to claim 2, characterized in that: The composite sun gear (17) comprises a sun gear A (171) and a sun gear B (172) fixedly connected together on a coaxial line. The composite sun gear (17) is slid to switch the external meshing transmission state between the sun gear A (171) and the reversing planetary gear (18) to the external meshing transmission state between the sun gear B (172) and the composite planetary gear (15).

4. The transmission device with buffer self-locking for new energy vehicles according to claim 3, characterized in that: The composite planetary gear (15) is composed of a planetary gear A (151) and a planetary gear B (152) which are coaxially mounted on the planetary carrier (14) and rotate synchronously therewith. The planetary gear B (152) is externally meshed with the reversing planetary gear (18) for transmission, and the planetary gear A (151) can be meshed with or disengaged from the sun gear B (172).

5. The transmission device with buffer self-locking for new energy vehicles according to claim 2, characterized in that: The switching gear B (36) is composed of a coaxial gear A (361) and a coaxial gear B (362) mounted on the switching plate (34) and rotating synchronously. The coaxial gear A (361) is externally meshed with the switching gear A (35), and the coaxial gear B (362) is externally meshed with the reversing gear (33). By rotating the switching plate (34), the switching gear A (35) externally meshed with the directional gear (31) can be switched to the coaxial gear A (361).

6. The transmission device with buffer self-locking for new energy vehicles according to claim 2, characterized in that: The sun gear axial drive assembly comprises: a bracket plate A (21) fixedly mounted on the input shaft (12), and an electric telescopic rod (22) with two ends respectively connected to the bracket plate A (21) and the involute cam (16).

7. The transmission device with buffer self-locking for new energy vehicles according to claim 2, characterized in that: The self-locking switching power assembly comprises: a bracket plate B (41) fixedly mounted on the inner wall of the box shell (11), a hollow shaft (42) rotatably mounted on the bracket plate B (41), and a power source (43) for driving the hollow shaft (42) to rotate; the switching plate (34) is fixedly mounted on the hollow shaft (42), and the reversing gear (33) is coaxial with the hollow shaft (42).

8. The transmission device with buffer self-locking for new energy vehicles according to claim 2, characterized in that: The right end of the involute cam (16) is a hollow cylindrical structure. The circumferential outer edge of the left end of the involute cam (16) is composed of a plurality of axisymmetrically distributed involute curved surfaces (161). A gradual gap (162) with a gradually changing width is formed between the involute curved surface (161) and the inner edge of the composite sun gear (17). A plurality of rollers (54) and elastic elements (55) are installed in the gradual gap (162). One end of the elastic element (55) is connected to the involute cam (16), and the other end is in contact with the roller (54). The diameter of the roller (54) is larger than the minimum width of the gradual gap (162).

9. The transmission device with buffer self-locking for new energy vehicles according to claim 8, characterized in that: When the elastic element (55) is in a static equilibrium state, a plurality of the rollers (54) simultaneously abut against the outer edge of the involute cam (16) and the inner edge of the composite sun gear (17).

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