Energy-saving multi-plate clutch two-speed transmission and energy-saving shifting method thereof

Abstract

The present invention discloses an energy-saving multi-plate clutch two-speed transmission and an energy-saving shifting method thereof, comprising a hydraulic control system, a first accumulator connected to a first hydraulic chamber, and a second accumulator connected to a second hydraulic chamber; when the first multi-plate clutch needs to be kept in an engaged state, the first multi-plate clutch can be kept in an engaged state by the hydraulic pressure stored in the first accumulator; when the second multi-plate clutch needs to be kept in an engaged state, the second multi-plate clutch can be kept in an engaged state by the hydraulic pressure stored in the second accumulator; during the period when the first accumulator or the second accumulator outputs hydraulic pressure, the hydraulic control system is in a shutdown state, which not only effectively reduces energy consumption and improves the overall cruising range, but also reduces fatigue of the hydraulic control system and greatly reduces the frequency of failures of the hydraulic control system, thereby extending the maintenance cycle and reducing usage and maintenance costs.

Description

Technical Field

[0001] The present invention relates to the technical field of speed change systems, and in particular to an energy-saving multi-plate clutch two-speed transmission and an energy-saving shifting method thereof. Background Art

[0002] With the rapid advancement of electric drive technology, more and more equipment's powertrains are adopting electric motors. To improve the drive motor's power output efficiency, enhance sustained acceleration performance, and provide a broader, high-efficiency platform to fully meet the diverse and complex operating conditions of vehicle acceleration, climbing, and high-speed driving, more and more electric drive systems are adding transmissions.

[0003] Among them, multi-plate clutch two-speed transmissions are widely used due to their low cost, compact structure, and stable and reliable performance. Please refer to Chinese invention patent application publication number CN112238745A. Existing multi-plate clutch two-speed transmissions require a hydraulic control system to continuously supply hydraulic pressure to the multi-plate clutch when engaged. This not only results in high energy consumption and affects overall range, but also, because at least one multi-plate clutch remains engaged in forward or reverse gear, the hydraulic control system has no downtime, resulting in a high frequency of hydraulic control system failures and a short maintenance cycle.

[0004] Solving the above problems has become a top priority. Summary of the Invention

[0005] In view of this, the present invention provides an energy-saving multi-plate clutch two-speed transmission and an energy-saving shifting method thereof.

[0006] The technical solution is as follows:

[0007] The first aspect of the present application relates to an energy-saving multi-plate clutch two-speed transmission, comprising a housing and an input shaft and an output shaft coaxially arranged in the housing, wherein the input shaft has a sun gear that rotates synchronously with the output shaft at one end close to the output shaft, and the output shaft has a planet carrier that rotates synchronously with the input shaft at one end close to the input shaft, the planet carrier being rotatably mounted on at least three planet gears distributed circumferentially around the sun gear, each planet gear being meshed with the sun gear, the housing being clutch-connected to an inner gear ring that is simultaneously meshed with each planet gear via a first multi-plate clutch, the input shaft being clutch-connected to the planet carrier via a second multi-plate clutch, the housing being provided with a first hydraulic chamber and a second hydraulic chamber, the first hydraulic chamber being provided with a first hydraulic cylinder for controlling the engagement or disengagement of the first multi-plate clutch, the second hydraulic chamber being provided with a second hydraulic cylinder for controlling the engagement or disengagement of the second multi-plate clutch, and the housing further comprising a hydraulic control system, a first accumulator connected to the first hydraulic chamber, and a second accumulator connected to the second hydraulic chamber;

[0008] When the hydraulic control system pressurizes the first hydraulic chamber to put the first multi-plate clutch in an engaged state via the first hydraulic cylinder and simultaneously relieves pressure from the second hydraulic chamber to put the second multi-plate clutch in a disengaged state, the hydraulic control system disconnects the first accumulator from the first hydraulic chamber after completing energy storage, and maintains a high pressure in the first hydraulic chamber via the hydraulic pressure stored in the first accumulator, thereby keeping the first multi-plate clutch in an engaged state via the first hydraulic cylinder;

[0009] When the hydraulic control system pressurizes the second hydraulic chamber and puts the second multi-plate clutch in an engaged state through the second hydraulic cylinder, and simultaneously relieves pressure on the first hydraulic chamber to put the first multi-plate clutch in a disengaged state, the hydraulic control system disconnects the second accumulator from the second hydraulic chamber after completing energy storage, and maintains high pressure in the second hydraulic chamber through the hydraulic pressure stored in the second accumulator, thereby keeping the second multi-plate clutch in an engaged state through the second hydraulic cylinder.

[0010] With the above energy-saving multi-plate clutch two-speed transmission, when the first multi-plate clutch needs to be kept in the engaged state, the liquid pressure can be first stored in the first accumulator, and then the liquid pressure stored in the first accumulator is used to continuously act on the first hydraulic cylinder, and the first multi-plate clutch is kept in the engaged state through the first hydraulic cylinder; when the second multi-plate clutch needs to be kept in the engaged state, the liquid pressure can be first stored in the second accumulator, and then the liquid pressure stored in the second accumulator is used to continuously act on the second hydraulic cylinder, and the second multi-plate clutch is kept in the engaged state through the second hydraulic cylinder; whether the first accumulator outputs liquid pressure or the second accumulator outputs liquid pressure, the hydraulic control system is in a shutdown state, which not only effectively reduces energy consumption and improves the overall cruising range, but also the hydraulic control system has more downtime and rest time, thereby reducing the fatigue of the hydraulic control system and greatly reducing the frequency of failures of the hydraulic control system, thereby extending the maintenance cycle and reducing usage and maintenance costs.

[0011] In some embodiments, the first accumulator includes a first accumulator housing mounted on a housing and a first solenoid valve mounted on the first accumulator housing. The first accumulator housing has a first energy storage chamber, a first hydraulic oil flow channel connecting the first hydraulic chamber and the hydraulic control system, and a first energy storage flow channel connecting the first energy storage chamber and the first hydraulic oil flow channel. The first solenoid valve can block or open the first energy storage flow channel. The first energy storage chamber is provided with a first piston capable of approaching or moving away from the first energy storage flow channel, a first energy storage spring for driving the first piston to approach the first energy storage flow channel, a first position sensor for detecting whether the first piston has reached an energy storage completion position, and a first pressure sensor for detecting whether the first piston has reached an energy storage start position. The hydraulic control system can drive the first piston to compress the first energy storage spring through hydraulic pressure.

[0012] The second accumulator includes a second accumulator housing mounted on the box body and a second solenoid valve mounted on the second accumulator housing. The second accumulator housing has a second energy storage chamber, a second hydraulic oil flow channel connecting the second hydraulic chamber and the hydraulic control system, and a second energy storage flow channel connecting the second energy storage chamber and the second hydraulic oil flow channel. The second solenoid valve can block or conduct the second energy storage flow channel. The second energy storage chamber is provided with a second piston that can approach or move away from the second energy storage flow channel, a second energy storage spring for driving the second piston to approach the second energy storage flow channel, a second position sensor for detecting whether the second piston has reached the energy storage completion position, and a second pressure sensor for detecting whether the second piston has reached the energy storage start position. The hydraulic control system can drive the second piston to compress the second energy storage spring through hydraulic pressure.

[0013] In some embodiments, the first accumulator housing is provided with a first oil return port for returning the hydraulic oil to the hydraulic control system, and the first oil return port is located at an end of the first energy storage spring away from the first piston;

[0014] The second accumulator housing is provided with a second oil return port for returning the hydraulic oil to the hydraulic control system, and the second oil return port is located at an end of the second energy storage spring away from the second piston;

[0015] The first oil return port and the second oil return port are both connected to the oil inlet opened on the box body through pipelines.

[0016] In some embodiments, the first multi-plate clutch includes a first outer plate mounting seat surrounding an outer ring gear, a plurality of first inner friction plates axially movably mounted on an outer circumferential surface of the inner ring gear, and a plurality of first outer friction plates axially movably mounted on an inner circumferential surface of the first outer plate mounting seat, the first outer plate mounting seat being fixedly mounted in a housing, the housing having a fixed clamping surface, the first inner friction plates and the first outer friction plates being alternately arranged between the fixed clamping surface and a first clamping piston of a first hydraulic cylinder, and a first return spring being arranged between the first clamping piston and the housing for driving the first clamping piston away from the fixed clamping surface;

[0017] The second multi-plate clutch includes a second outer plate mounting seat fixedly mounted on the planetary carrier, a plurality of second inner friction plates axially movably mounted on the outer circumference of the input shaft, and a plurality of second outer friction plates axially movably mounted on the inner circumference of the second outer plate mounting seat. A fixed clamping seat is synchronously rotated on the input shaft, and each second inner friction plate and each second outer friction plate are alternately arranged between the fixed clamping seat and the second clamping piston of the second hydraulic cylinder. A second return spring is arranged between the second clamping piston and the input shaft for driving the second clamping piston away from the fixed clamping seat.

[0018] In some embodiments, the inner edge of the first inner friction plate is spline-matched with the outer circumference of the inner gear ring, and the outer edge of the first outer friction plate is spline-matched with the inner circumference of the first outer plate mounting seat;

[0019] The inner edge of the second inner friction plate is spline-fitted with the outer circumference of the input shaft, and the outer edge of the second outer friction plate is spline-fitted with the inner circumference of the second outer plate mounting seat.

[0020] In some embodiments, a first conducting hole adapted to the first energy storage flow channel is formed on the piston rod of the first solenoid valve. When the first conducting hole is located in the first energy storage flow channel by the extension and contraction of the piston rod of the first solenoid valve, the first energy storage flow channel is in a conducting state. When the first conducting hole is offset from the first energy storage flow channel by the extension and contraction of the piston rod of the first solenoid valve, the first energy storage flow channel is in a disconnected state.

[0021] A second conducting hole adapted to the second energy storage flow channel is provided on the piston rod of the second solenoid valve. When the second conducting hole is located in the second energy storage flow channel through the extension and contraction of the piston rod of the second solenoid valve, the second energy storage flow channel is in a conducting state. When the second conducting hole is staggered with the second energy storage flow channel through the extension and contraction of the piston rod of the second solenoid valve, the second energy storage flow channel is in a disconnected state.

[0022] In some embodiments, the hydraulic control system includes a first, two-position, three-way valve, a second, two-position, three-way valve, a three-position, four-way valve, and a gear pump, wherein the first, two-position, three-way valve and the second, two-position, three-way valve each have a through position and a reflux position, and the three-position, four-way valve has a forward conducting position, a cutoff position, and a phase-changing conducting position. The housing is provided with an oil outlet for delivering hydraulic oil to the gear pump, and a driving gear of the gear pump is synchronously rotatably mounted on the input shaft.

[0023] Furthermore, when the input shaft rotates forward, the gear pump that pumps hydraulic oil in the forward direction can, under the coordinated control of the first solenoid valve, the second solenoid valve, the first two-position three-way valve, the second two-position three-way valve, and the three-position four-way valve:

[0024] applying hydraulic pressure to the first hydraulic cylinder and the first accumulator;

[0025] or,

[0026] applying hydraulic pressure to the second hydraulic cylinder and the second accumulator;

[0027] When the input shaft is reversed, the gear pump that pumps hydraulic oil in reverse can apply hydraulic pressure to the first hydraulic cylinder and the first accumulator under the coordinated control of the first solenoid valve, the second solenoid valve, the first two-position three-way valve, the second two-position three-way valve and the three-position four-way valve.

[0028] In some embodiments, a power output tooth is integrally formed on the output shaft, and the power output tooth is engaged with a differential power input gear of the differential.

[0029] A second aspect of the present application relates to an energy-saving shifting method for the above-mentioned energy-saving multi-plate clutch two-speed transmission, which is performed according to the following steps:

[0030] S1. Detect the rotation direction of the input shaft: if the input shaft rotates forward, proceed to step S2; if the input shaft rotates reversely, proceed to step S5;

[0031] S2. Check whether the speed of the input shaft is higher than the set value: if not, go to step S3; if yes, go to step S3;

[0032] S3. Enter low forward gear and follow the steps below:

[0033] S31, the first solenoid valve makes the first energy storage flow channel conductive, the first two-position three-way valve and the second two-position three-way valve are both in the straight-through position, and the three-position four-way valve is in the forward conducting position;

[0034] S32, the hydraulic oil output from the oil outlet is pumped into the first hydraulic oil flow channel by the gear pump of the forward pumping oil. A portion of the hydraulic oil in the first hydraulic oil flow channel flows into the first hydraulic chamber, causing the first clamping piston of the first hydraulic cylinder to press the first inner friction plates and the first outer friction plates, thereby keeping the inner gear ring stationary. At this time, the second clamping piston of the second hydraulic cylinder releases the second inner friction plates and the second outer friction plates. At the same time, another portion of the hydraulic oil in the first hydraulic oil flow channel flows into the first energy storage chamber through the first energy storage flow channel, pushing the first piston to compress the first energy storage spring until the first position sensor detects the first piston, and then proceeds to the next step;

[0035] S33, the three-position four-way valve is switched to the cut-off position. Simultaneously, the gear pump is stopped. The elastic potential energy of the first energy storage spring provides the hydraulic pressure for the first clamping piston of the first hydraulic cylinder to press the first inner friction plates and the first outer friction plates until the first pressure sensor detects the first piston. Then, the three-position four-way valve is switched to the forward conducting position, and the process returns to step S32;

[0036] S4. Enter high-speed forward gear and follow the steps below:

[0037] S41, the second solenoid valve makes the second energy storage flow channel conductive, the first two-position three-way valve and the second two-position three-way valve are both in the straight-through position, and the three-position four-way valve is in the disguised conduction position;

[0038] S42: The hydraulic oil output from the oil outlet is pumped into the second hydraulic oil flow channel by the gear pump of the forward pumping oil. A portion of the hydraulic oil in the second hydraulic oil flow channel flows into the second hydraulic chamber, causing the second clamping piston of the second hydraulic cylinder to press the second inner friction plates and the second outer friction plates, thereby causing the planetary carrier to rotate synchronously with the input shaft. At this time, the first clamping piston releases the first inner friction plates and the first outer friction plates. At the same time, another portion of the hydraulic oil in the second hydraulic oil flow channel flows into the second energy storage chamber through the second energy storage flow channel, pushing the second piston to compress the second energy storage spring until the second position sensor detects the second piston, and then proceeds to the next step;

[0039] S43, the three-position four-way valve is switched to the cut-off position. At the same time, the gear pump is stopped. The elastic potential energy of the second energy storage spring provides the hydraulic pressure for the second clamping piston of the second hydraulic cylinder to press the second inner friction plates and the second outer friction plates until the second pressure sensor detects the second piston. Then, the three-position four-way valve is switched to the phase-change conduction position, and the process returns to step S42;

[0040] S5. Enter reverse gear and follow the steps below:

[0041] S51, the first solenoid valve makes the first energy storage flow channel conductive, the first two-position three-way valve and the second two-position three-way valve are both in the backflow position, and the three-position four-way valve is in the forward conduction position;

[0042] S52: The hydraulic oil output from the oil outlet is pumped into the first hydraulic oil flow channel by the gear pump of the reverse pumping oil. A portion of the hydraulic oil in the first hydraulic oil flow channel flows into the first hydraulic chamber, causing the first clamping piston of the first hydraulic cylinder to press the first inner friction plates and the first outer friction plates, thereby keeping the inner gear ring stationary. At this time, the second clamping piston of the second hydraulic cylinder releases the second inner friction plates and the second outer friction plates. At the same time, another portion of the hydraulic oil in the first hydraulic oil flow channel flows into the first energy storage chamber through the first energy storage flow channel, pushing the first piston to compress the first energy storage spring until the first position sensor detects the first piston, and then proceeds to the next step.

[0043] S53, the three-position four-way valve is switched to the cut-off position. At the same time, the gear pump is shut down. The elastic potential energy of the first energy storage spring provides the first clamping piston of the first hydraulic cylinder with the liquid pressure to press each first inner friction plate and each first outer friction plate until the first pressure sensor detects the first piston. Then, the three-position four-way valve is switched to the forward conducting position and returns to step S52.

[0044] The energy-saving shifting method of the above energy-saving multi-plate clutch type two-speed transmission is adopted in combination with the energy-saving multi-plate clutch type two-speed transmission to achieve all the advantages of the energy-saving multi-plate clutch type two-speed transmission.

[0045] In some embodiments, in step S31 and step S51, the second solenoid valve blocks the second energy storage flow channel; in step S41, the first solenoid valve blocks the first energy storage flow channel. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a schematic diagram of the structure of an energy-saving multi-plate clutch two-speed transmission;

[0047] Figure 2 It is a structural diagram of the gear pump;

[0048] Figure 3 This is a schematic diagram of the hydraulic control system in working state when in low-speed forward gear;

[0049] Figure 4 This is a schematic diagram of the hydraulic control system in a shutdown state when in low-speed forward gear;

[0050] Figure 5 This is a schematic diagram of the hydraulic control system in working condition when in high-speed forward gear;

[0051] Figure 6 This is a schematic diagram of the hydraulic control system in a shutdown state when in high-speed forward gear;

[0052] Figure 7 This is a schematic diagram of the hydraulic control system in working state when in reverse gear;

[0053] Figure 8 This is a schematic diagram showing the hydraulic control system in shutdown state when in reverse gear. DETAILED DESCRIPTION

[0054] The present invention will be further described below with reference to the embodiments and accompanying drawings.

[0055] Example 1:

[0056] like Figure 1 and Figure 2 As shown, an energy-saving multi-plate clutch two-speed transmission mainly includes a case 1, an input shaft 2 and an output shaft 3; wherein, the input shaft 2 is used for power input, usually connected to the motor shaft of the drive motor, and can also be directly the motor shaft of the drive motor; the output shaft 3 is used for power output, which can directly drive the wheels or transmit power to the transmission mechanism. In this embodiment, the transmission mechanism is a differential 20, and a power output tooth 3a is integrally formed on the output shaft 3, and the power output tooth 3a is engaged with the differential power input gear 20a of the differential 20.

[0057] Specifically, the input shaft 2 and the output shaft 3 are coaxially mounted within the housing 1 and are both rotatable relative to the housing 1. The input shaft 2 has a sun gear 2a at its end, near the output shaft 3, which rotates synchronously with the output shaft 3. Sun gear 2a can be independent and fixedly mounted on the input shaft 2, or it can be integrally formed with the input shaft 2. The output shaft 3 has a planetary carrier 4 at its end, near the input shaft 2, which rotates synchronously therewith. This planetary carrier 4 rotatably mounts at least three planetary gears 5 circumferentially distributed around the sun gear 2a, each planetary gear 5 meshing with the sun gear 2a. The housing 1 is clutched and connected to an internal gear ring 7, which simultaneously meshes with each of the planetary gears 5, via a first multi-plate clutch 6. The input shaft 2 is clutched and connected to the planetary carrier 4 via a second multi-plate clutch 8. The housing 1 is provided with a first hydraulic chamber 11 and a second hydraulic chamber 12. The first hydraulic chamber 11 houses a first hydraulic cylinder 13 for controlling the engagement or disengagement of the first multi-plate clutch 6. The second hydraulic chamber 12 houses a second hydraulic cylinder 14 for controlling the engagement or disengagement of the second multi-plate clutch 8. Thus, a two-speed reduction gear mechanism based on a planetary gear train is formed.

[0058] When the input shaft 2 rotates forward, the first hydraulic cylinder 13 controls the first multi-plate clutch 6 to be in the engaged state, and the second hydraulic cylinder 14 controls the second multi-plate clutch 8 to be in the disengaged state, it is in the low-speed forward gear, the internal gear 7 is locked, and when the input shaft 2 rotates, each planetary gear 5 rotates while also revolving along the sun gear 2a. The revolution of each planetary gear 5 drives the planetary carrier 4 to rotate at the same speed, and the planetary carrier 4 drives the output shaft 3 to rotate synchronously with it. Since the revolution speed of each planetary gear 5 is less than the rotation speed of the input shaft 2, a reduction transmission is achieved.

[0059] When the input shaft 2 rotates forward, the first hydraulic cylinder 13 controls the first multi-plate clutch 6 to be in the disconnected state, and the second hydraulic cylinder 14 controls the second multi-plate clutch 8 to be in the engaged state, it is in the high-speed forward gear, and the internal gear ring 7 is not locked. When the input shaft 2 rotates, the second multi-plate clutch 8 drives the planetary carrier 4 to rotate synchronously with it, and the planetary carrier 4 drives the output shaft 3 to rotate synchronously with it. Therefore, the rotation speed of the input shaft 2 and the output shaft 3 is the same, realizing high-speed direct drive.

[0060] When in reverse gear, the input shaft 2 reverses, the first hydraulic cylinder 13 controls the first multi-plate clutch 6 to be in the engaged state, and the second hydraulic cylinder 14 controls the second multi-plate clutch 8 to be in the disengaged state. Except that the rotation directions of each component are opposite, the transmission path is exactly the same as the low-speed forward gear.

[0061] The first multi-plate clutch 6 includes a first outer plate mounting seat 6a surrounding the outer periphery of the inner ring gear 7, multiple first inner friction plates 6b axially movably mounted on the outer periphery of the inner ring gear 7, and multiple first outer friction plates 6c axially movably mounted on the inner periphery of the first outer plate mounting seat 6a. The first outer plate mounting seat 6a is fixedly mounted in the housing 1, which has a fixed clamping surface 1c. The first inner friction plates 6b and first outer friction plates 6c are alternately positioned between the fixed clamping surface 1c and a first clamping piston 13a of a first hydraulic cylinder 13. A first return spring 13b is positioned between the first clamping piston 13a and the housing 1 to urge the first clamping piston 13a away from the fixed clamping surface 1c. When the hydraulic control system applies hydraulic pressure to the first clamping piston 13a of the first hydraulic cylinder 13, the first inner friction plates 6b and first outer friction plates 6c are clamped between the fixed clamping surface 1c and the first clamping piston 13a, thereby locking the inner ring gear 7 and preventing it from rotating. When the hydraulic control system does not apply hydraulic pressure to the first clamping piston 13a of the first hydraulic cylinder 13, the first clamping piston 13a releases the first inner friction plates 6b and the first outer friction plates 6c, thereby unlocking the inner ring gear 7 and allowing the inner ring gear 7 to rotate relative to the housing 1.

[0062] The second multi-plate clutch 8 comprises a second outer plate mounting seat 8a fixedly mounted on the planetary carrier 4, a plurality of second inner friction plates 8b axially movably mounted on the outer circumference of the input shaft 2, and a plurality of second outer friction plates 8c axially movably mounted on the inner circumference of the second outer plate mounting seat 8a. A fixed clamping seat 19 is mounted on the input shaft 2 for synchronous rotation. The second inner friction plates 8b and the second outer friction plates 8c are alternately positioned between the fixed clamping seat 19 and the second clamping piston 14a of the second hydraulic cylinder 14. A second return spring 14b is positioned between the second clamping piston 14a and the input shaft 2 to urge the second clamping piston 14a away from the fixed clamping seat 19. When the hydraulic control system applies hydraulic pressure to the second clamping piston 14a of the second hydraulic cylinder 14, the second inner friction plates 8b and the second outer friction plates 8c are clamped between the fixed clamping seat 19 and the second clamping piston 14a, thereby locking the planetary carrier 4 and enabling synchronous rotation of the planetary carrier 4 and the input shaft 2. When the hydraulic control system does not apply hydraulic pressure to the second clamping piston 14a of the second hydraulic cylinder 14, the second clamping piston 14a releases the second inner friction plates 8b and the second outer friction plates 8c, thereby unlocking the planetary carrier 4 and allowing the planetary carrier 4 to rotate relative to the input shaft 2.

[0063] Furthermore, the inner edge of the first inner friction plate 6b is splined to the outer circumference of the inner ring gear 7, and the outer edge of the first outer friction plate 6c is splined to the inner circumference of the first outer plate mounting seat 6a. Similarly, the inner edge of the second inner friction plate 8b is splined to the outer circumference of the input shaft 2, and the outer edge of the second outer friction plate 8c is splined to the inner circumference of the second outer plate mounting seat 8a. This structure allows the first inner friction plate 6b, the first outer friction plate 6c, the second inner friction plate 8b, and the second outer friction plate 8c to rotate synchronously with the counterpart and move axially along the counterpart, while also facilitating easy assembly and ensuring stability and reliability.

[0064] See Figures 1-8 The energy-saving multi-plate clutch two-speed transmission also includes a hydraulic control system, a first energy accumulator 9 connected to the first hydraulic chamber 11, and a second energy accumulator 10 connected to the second hydraulic chamber 12. The first energy accumulator 9 is used to store energy in low-speed forward gear and reverse gear, and the second energy accumulator 10 is used to store energy in high-speed forward gear.

[0065] When the energy-saving multi-plate clutch two-speed transmission is in low-speed forward gear or reverse gear, the second hydraulic chamber 12 is depressurized, disengaging the second multi-plate clutch 8. The hydraulic control system first pressurizes the first hydraulic chamber 11, engaging the first multi-plate clutch 6 via the first hydraulic cylinder 13. Simultaneously, the first accumulator 9 simultaneously accumulates energy. After the first accumulator 9 has completed its energy accumulation, the hydraulic control system disconnects it from the first hydraulic chamber 11. At this point, the stored hydraulic pressure in the first accumulator 9 maintains high pressure in the first hydraulic chamber 11, thereby maintaining the first multi-plate clutch 6 in its engaged state via the first hydraulic cylinder 13.

[0066] When the energy-saving multi-plate clutch two-speed transmission is in a high-speed forward gear, the first hydraulic chamber 11 is depressurized, disengaging the first multi-plate clutch 6. The hydraulic control system first pressurizes the second hydraulic chamber 12, engaging the second multi-plate clutch 8 via the second hydraulic cylinder 14. Simultaneously, the second accumulator 10 simultaneously accumulates energy. After the second accumulator 10 has completed its energy accumulation, the hydraulic control system disconnects it from the second hydraulic chamber 12. At this point, the stored hydraulic pressure in the second accumulator 10 maintains high pressure in the second hydraulic chamber 12, thereby maintaining the second multi-plate clutch 8 in its engaged state via the second hydraulic cylinder 14.

[0067] As can be seen from the above, the hydraulic control system is in a shutdown state regardless of whether the first accumulator 9 or the second accumulator 10 is outputting hydraulic pressure. This not only effectively reduces energy consumption and improves the overall cruising range, but also provides the hydraulic control system with more downtime, thereby reducing fatigue of the hydraulic control system and significantly reducing the frequency of failures in the hydraulic control system, thereby extending the maintenance cycle and reducing usage and maintenance costs.

[0068] See Figure 1 The first accumulator 9 includes a first accumulator shell 9a installed on the box body 1 and a first solenoid valve 9e installed on the first accumulator shell 9a. The first accumulator shell 9a has a first energy storage chamber 9b, a first hydraulic oil flow channel 9c connecting the first hydraulic chamber 11 and the hydraulic control system, and a first energy storage flow channel 9d connecting the first energy storage chamber 9b and the first hydraulic oil flow channel 9c. The first solenoid valve 9e can block or conduct the first energy storage flow channel 9d. The first energy storage chamber 9b is provided with a first piston 9f that can approach or move away from the first energy storage flow channel 9d, a first energy storage spring 9g for driving the first piston 9f to approach the first energy storage flow channel 9d, a first position sensor 9h for detecting whether the first piston 9f has reached the energy storage completion position, and a first pressure sensor 9i for detecting whether the first piston 9f has reached the energy storage start position. The hydraulic control system can drive the first piston 9f to compress the first energy storage spring 9g through hydraulic pressure.

[0069] Therefore, in low-speed forward and reverse gears, the hydraulic control system first applies hydraulic pressure to the first hydraulic chamber 11 through the first hydraulic oil flow channel 9c. High-pressure hydraulic oil also enters the first energy storage chamber 9b through the first energy storage flow channel 9d, pushing the first piston 9f away from the first pressure sensor 9i to compress the first energy storage spring 9g, converting the hydraulic pressure into the elastic potential energy of the first energy storage spring 9g. When the first position sensor 9h detects the first piston 9f, energy storage in the first accumulator 9 is complete. At this point, the hydraulic control system shuts down and no longer applies hydraulic pressure to the first hydraulic chamber 11 through the first hydraulic oil flow channel 9c. The hydraulic pressure in the first hydraulic chamber 11 is instead provided by the elastic potential energy of the first energy storage spring 9g. During this process, the hydraulic oil in the first energy storage chamber 9b gradually decreases until the first pressure sensor 9i detects the first piston 9f. The hydraulic control system then restarts, and the first accumulator 9 begins to store energy again, repeating this cycle.

[0070] The second accumulator 10 includes a second accumulator housing 10a installed on the box body 1 and a second solenoid valve 10e installed on the second accumulator housing 10a. The second accumulator housing 10a has a second energy storage chamber 10b, a second hydraulic oil flow channel 10c connecting the second hydraulic chamber 12 and the hydraulic control system, and a second energy storage flow channel 10d connecting the second energy storage chamber 10b and the second hydraulic oil flow channel 10c. The second solenoid valve 10e can block or conduct the second energy storage flow channel 10d. The second energy storage chamber 10b is provided with a second piston 10f that can approach or move away from the second energy storage flow channel 10d, a second energy storage spring 10g for driving the second piston 10f to approach the second energy storage flow channel 10d, a second position sensor 10h for detecting whether the second piston 10f has reached the energy storage completion position, and a second pressure sensor 10i for detecting whether the second piston 10f has reached the energy storage start position. The hydraulic control system can drive the second piston 10f to compress the second energy storage spring 10g through hydraulic pressure.

[0071] Therefore, in high-speed forward gear, the hydraulic control system first applies hydraulic pressure to the second hydraulic chamber 12 via the second hydraulic oil flow channel 10c. High-pressure hydraulic oil also enters the second energy storage chamber 10b via the second energy storage flow channel 10d, pushing the second piston 10f away from the second pressure sensor 10i, compressing the second energy storage spring 10g, converting the hydraulic pressure into the elastic potential energy of the second energy storage spring 10g. When the second position sensor 10h detects the second piston 10f, energy storage in the second accumulator 10 is complete. At this point, the hydraulic control system shuts down, no longer applying hydraulic pressure to the second hydraulic chamber 12 via the second hydraulic oil flow channel 10c. The hydraulic pressure in the second hydraulic chamber 12 is instead provided by the elastic potential energy of the second energy storage spring 10g. During this process, the hydraulic oil in the second energy storage chamber 10b gradually decreases until the second pressure sensor 10i detects the second piston 10f. The hydraulic control system then restarts, and the second accumulator 10 begins to store energy again, repeating this cycle.

[0072] Furthermore, the first accumulator housing 9a is provided with a first oil return port 9j for returning the hydraulic oil to the hydraulic control system. The first oil return port 9j is located at the end of the first energy storage spring 9g away from the first piston 9f. The hydraulic oil that seeps through the first piston 9f is returned to the box body 1 through the first oil return port 9j. Specifically, the internal space of the box body 1 serves as an oil storage tank for the hydraulic oil of the hydraulic control system. Therefore, the box body 1 is provided with an oil inlet 1b and an oil outlet 1a connected to the oil storage tank, and the first oil return port 9j is connected to the oil inlet 1b through a pipeline.

[0073] Similarly, the second accumulator housing 10a is provided with a second oil return port 10j for returning the hydraulic oil to the hydraulic control system. The second oil return port 10j is located at the end of the second energy storage spring 10g away from the second piston 10f. The hydraulic oil that seeps through the second piston 10f is returned to the tank 1 through the second oil return port 10j, that is, the second oil return port 10j is connected to the oil inlet 1b through a pipeline.

[0074] See Figure 1 A first conducting hole 9e1 is provided on the piston rod of the first solenoid valve 9e, which is compatible with the first energy storage flow channel 9d. When the first solenoid valve 9e extends and contracts the piston rod so that the first conducting hole 9e1 is located in the first energy storage flow channel 9d, the first energy storage flow channel 9d is in a conducting state. When the first solenoid valve 9e extends and contracts the piston rod so that the first conducting hole 9e1 is offset from the first energy storage flow channel 9d, the first energy storage flow channel 9d is in a disconnected state. The on-off control of the first energy storage flow channel 9d by the first solenoid valve 9e is simple and reliable.

[0075] Similarly, a second conducting hole 10e1 is provided on the piston rod of the second solenoid valve 10e, which is compatible with the second energy storage channel 10d. When the second solenoid valve 10e causes the second conducting hole 10e1 to be located in the second energy storage channel 10d through the extension and contraction of the piston rod, the second energy storage channel 10d is in a conducting state. When the second solenoid valve 10e causes the second conducting hole 10e1 to be offset from the second energy storage channel 10d through the extension and contraction of the piston rod, the second energy storage channel 10d is in a disconnected state. The on-off control of the second energy storage channel 10d by the second solenoid valve 10e is simple and reliable.

[0076] See Figures 1-8 The hydraulic control system includes a first, second, third, and fourth-way valve 16, a second, second, third, and fourth-way valve 17, a third, fourth-way valve 18, and a gear pump 15. Both the first, second, third, and fourth-way valves 16 and 17 have a through position a and a return position b. The third, fourth-way valve 18 has a forward conducting position c, a cutoff position d, and a reverse conducting position e. Hydraulic oil output from an oil outlet 1a on the housing 1 flows to the gear pump 15. The gear pump 15 comprises a driving gear 15a, which is synchronously mounted on the input shaft 2, and a driven gear 15b meshing with the driving gear 15a. Oil grooves are provided on the circumferential outer edges of the driving gear 15a and the driven gear 15b. An oil suction port 15c and an oil pump port 15d are respectively provided on either side of the meshing position between the driving gear 15a and the driven gear 15b. When the driving gear 15a rotates forward, hydraulic oil is drawn into the oil grooves of the driving gear 15a and the driven gear 15b through the oil suction port 15c and then pumped out through the oil pump port 15d. When the driving gear 15a rotates reversely, the hydraulic oil is sucked into the oil grooves of the driving gear 15a and the driven gear 15b through the oil pump port 15d, and then pumped out from the oil suction port 15c.

[0077] Specifically, when the input shaft 2 rotates forward, the gear pump 15 pumping hydraulic oil in the forward direction can, under the coordinated control of the first solenoid valve 9e, the second solenoid valve 10e, the first two-position three-way valve 16, the second two-position three-way valve 17, and the three-position four-way valve 18: if it is in the low-speed forward gear, apply hydraulic pressure to the first hydraulic cylinder 13 and the first accumulator 9; if it is in the high-speed forward gear, apply hydraulic pressure to the second hydraulic cylinder 14 and the second accumulator 10;

[0078] When the input shaft 2 reverses, the gear pump 15 that pumps hydraulic oil in reverse can apply hydraulic pressure to the first hydraulic cylinder 13 and the first accumulator 9 under the coordinated control of the first solenoid valve 9e, the second solenoid valve 10e, the first two-position three-way valve 16, the second two-position three-way valve 17 and the three-position four-way valve 18.

[0079] Furthermore, the hydraulic control system also includes a filter 22 and a pressure relief valve 21. The hydraulic oil output from the oil outlet 1a is filtered by the filter 22 and then enters the gear pump 15. The hydraulic oil pumped out by the gear pump 15 is output at a constant pressure after the pressure is adjusted by the pressure relief valve 21, thereby ensuring the stability and reliability of the operation of the first hydraulic cylinder 13, the first accumulator 9, the second hydraulic cylinder 14 and the second accumulator 10.

[0080] Example 2:

[0081] See Figures 1-8 An energy-saving shifting method for an energy-saving multi-plate clutch two-speed transmission according to embodiment 1 is performed according to the following steps:

[0082] S1. Detect the rotation direction of the input shaft 2: if the input shaft 2 rotates forward, proceed to step S2; if the input shaft 2 rotates reversely, proceed to step S5.

[0083] S2. Check whether the rotation speed of input shaft 2 is higher than the set value: if not, go to step S3; if yes, go to step S3.

[0084] S3, enter low speed forward gear (see Figure 3 and Figure 4 ) and follow these steps:

[0085] S31: The first solenoid valve 9e conducts the first energy storage flow channel 9d, the first two-position three-way valve 16 and the second two-position three-way valve 17 are both in the straight-through position a, and the three-position four-way valve 18 is in the forward conducting position c. At this time, the second solenoid valve 10e blocks the second energy storage flow channel 10d, which can preserve the hydraulic energy in the second accumulator 10, thereby further improving the energy-saving effect.

[0086] S32. The hydraulic oil output from the oil outlet 1a is pumped into the first hydraulic oil flow channel 9c through the gear pump 15 of the forward pumping oil. A part of the hydraulic oil in the first hydraulic oil flow channel 9c flows into the first hydraulic chamber 11, so that the first clamping piston 13a of the first hydraulic cylinder 13 presses each first inner friction plate 6b and each first outer friction plate 6c, thereby keeping the inner gear ring 7 stationary. At this time, the second clamping piston 14a of the second hydraulic cylinder 14 releases each second inner friction plate 8b and each second outer friction plate 8c. At the same time, another part of the hydraulic oil in the first hydraulic oil flow channel 9c flows into the first energy storage chamber 9b through the first energy storage flow channel 9d, and pushes the first piston 9f to compress the first energy storage spring 9g until the first position sensor 9h detects the first piston 9f. The energy storage of the first accumulator 9 is completed, and the next step is entered.

[0087] S33, the three-position four-way valve 18 is switched to the cut-off position d. At the same time, the gear pump 15 is shut down. The elastic potential energy of the first energy storage spring 9g provides the first clamping piston 13a of the first hydraulic cylinder 13 with the hydraulic pressure to press the first inner friction plates 6b and the first outer friction plates 6c until the first pressure sensor 9i detects the first piston 9f. The hydraulic energy in the first accumulator 9 is released, the three-position four-way valve 18 is switched to the forward conduction position c, and returns to step S32.

[0088] Step S3 is repeated in this way until a gear shift is required.

[0089] S4, enter high speed forward gear (see Figure 5 and Figure 6 ) and follow these steps:

[0090] In step S41, the second solenoid valve 10e opens the second energy storage flow channel 10d, the first two-position three-way valve 16 and the second two-position three-way valve 17 are both in the straight-through position a, and the three-position four-way valve 18 is in the disguised conduction position e. At this time, the first solenoid valve 9e blocks the first energy storage flow channel 9d, thereby preserving the hydraulic energy in the first accumulator 9 and further improving the energy-saving effect.

[0091] S42. The hydraulic oil output from the oil outlet 1a is pumped into the second hydraulic oil flow channel 10c through the gear pump 15 of the forward pumping oil. A part of the hydraulic oil in the second hydraulic oil flow channel 10c flows into the second hydraulic chamber 12, so that the second clamping piston 14a of the second hydraulic cylinder 14 presses each second inner friction plate 8b and each second outer friction plate 8c, thereby making the planetary carrier 4 rotate synchronously with the input shaft 2. At this time, the first clamping piston 13a releases each first inner friction plate 6b and each first outer friction plate 6c. At the same time, another part of the hydraulic oil in the second hydraulic oil flow channel 10c flows into the second energy storage chamber 10b through the second energy storage flow channel 10d, and pushes the second piston 10f to compress the second energy storage spring 10g until the second position sensor 10h detects the second piston 10f. The second accumulator 10 completes energy storage and enters the next step.

[0092] S43, the three-position four-way valve 18 is switched to the cut-off position d. At the same time, the gear pump 15 is shut down. The elastic potential energy of the second energy storage spring 10g provides the second clamping piston 14a of the second hydraulic cylinder 14 with the liquid pressure to press each second inner friction plate 8b and each second outer friction plate 8c until the second pressure sensor 10i detects the second piston 10f. The hydraulic energy in the second accumulator 10 is released, the three-position four-way valve 18 is switched to the disguised conduction position e, and the process returns to step S42.

[0093] Step S4 is repeated in this way until a gear shift is required.

[0094] S5, enter reverse gear (see Figure 7 and Figure 8) and follow these steps:

[0095] S51: The first solenoid valve 9e opens the first energy storage flow channel 9d, the first two-position three-way valve 16 and the second two-position three-way valve 17 are both in the return position b, and the three-position four-way valve 18 is in the forward conduction position c. At this time, the second solenoid valve 10e blocks the second energy storage flow channel 10d, which can preserve the hydraulic energy in the second accumulator 10, thereby further improving the energy-saving effect.

[0096] S52. The hydraulic oil output from the oil outlet 1a is pumped into the first hydraulic oil flow channel 9c through the reverse pumping gear pump 15. A part of the hydraulic oil in the first hydraulic oil flow channel 9c flows into the first hydraulic chamber 11, causing the first clamping piston 13a of the first hydraulic cylinder 13 to press each first inner friction plate 6b and each first outer friction plate 6c, thereby keeping the inner gear ring 7 stationary. At this time, the second clamping piston 14a of the second hydraulic cylinder 14 releases each second inner friction plate 8b and each second outer friction plate 8c. At the same time, another part of the hydraulic oil in the first hydraulic oil flow channel 9c flows into the first energy storage chamber 9b through the first energy storage flow channel 9d, and pushes the first piston 9f to compress the first energy storage spring 9g until the first position sensor 9h detects the first piston 9f. The energy storage of the first accumulator 9 is completed, and the next step is entered.

[0097] S53, the three-position four-way valve 18 is switched to the cut-off position d. At the same time, the gear pump 15 is shut down. The elastic potential energy of the first energy storage spring 9g provides the first clamping piston 13a of the first hydraulic cylinder 13 with the liquid pressure to press each first inner friction plate 6b and each first outer friction plate 6c until the first pressure sensor 9i detects the first piston 9f. The hydraulic energy in the first accumulator 9 is released, the three-position four-way valve 18 is switched to the forward conduction position c, and returns to step S52.

[0098] Step S5 is repeated in this way until a gear shift is required.

[0099] Finally, it should be noted that the above description is only a preferred embodiment of the present invention. Under the guidance of the present invention, ordinary technicians in this field can make various similar expressions without violating the purpose and claims of the present invention. Such changes fall within the scope of protection of the present invention.

Claims

1. An energy-saving multi-plate clutch two-speed transmission, comprising a housing and an input shaft and an output shaft coaxially arranged in the housing, wherein the input shaft has a sun gear that rotates synchronously with the output shaft at one end close to the output shaft, and the output shaft has a planet carrier that rotates synchronously with the input shaft at one end close to the input shaft, the planet carrier having at least three planet gears rotatably mounted on the planet carrier and distributed circumferentially around the sun gear, each planet gear being meshed with the sun gear, the housing having an internal gear ring that is meshed with each planet gear at the same time via a first multi-plate clutch, the input shaft being clutched with the planet carrier via a second multi-plate clutch, the housing having a first hydraulic chamber and a second hydraulic chamber, the first hydraulic chamber being provided with a first hydraulic cylinder for controlling the engagement or disengagement of the first multi-plate clutch, and the second hydraulic chamber being provided with a second hydraulic cylinder for controlling the engagement or disengagement of the second multi-plate clutch, characterized in that: Also included is a hydraulic control system, a first accumulator connected to the first hydraulic chamber, and a second accumulator connected to the second hydraulic chamber; When the hydraulic control system pressurizes the first hydraulic chamber to put the first multi-plate clutch in an engaged state via the first hydraulic cylinder and simultaneously relieves pressure from the second hydraulic chamber to put the second multi-plate clutch in a disengaged state, the hydraulic control system disconnects the first accumulator from the first hydraulic chamber after completing energy storage, and maintains a high pressure in the first hydraulic chamber via the hydraulic pressure stored in the first accumulator, thereby keeping the first multi-plate clutch in an engaged state via the first hydraulic cylinder; When the hydraulic control system pressurizes the second hydraulic chamber and puts the second multi-plate clutch in an engaged state through the second hydraulic cylinder, and simultaneously relieves pressure on the first hydraulic chamber to put the first multi-plate clutch in a disengaged state, the hydraulic control system disconnects the second accumulator from the second hydraulic chamber after completing energy storage, and maintains high pressure in the second hydraulic chamber through the hydraulic pressure stored in the second accumulator, thereby keeping the second multi-plate clutch in an engaged state through the second hydraulic cylinder.

2. The energy-saving multi-plate clutch two-speed transmission according to claim 1, characterized in that: The first accumulator includes a first accumulator housing mounted on a housing and a first solenoid valve mounted on the first accumulator housing. The first accumulator housing has a first energy storage chamber, a first hydraulic oil flow channel connecting the first hydraulic chamber and the hydraulic control system, and a first energy storage flow channel connecting the first energy storage chamber and the first hydraulic oil flow channel. The first solenoid valve is capable of blocking or conducting the first energy storage flow channel. The first energy storage chamber is provided with a first piston capable of approaching or moving away from the first energy storage flow channel, a first energy storage spring for driving the first piston to approach the first energy storage flow channel, a first position sensor for detecting whether the first piston has reached an energy storage completion position, and a first pressure sensor for detecting whether the first piston has reached an energy storage start position. The hydraulic control system is capable of driving the first piston to compress the first energy storage spring through hydraulic pressure. The second accumulator includes a second accumulator housing mounted on the box body and a second solenoid valve mounted on the second accumulator housing. The second accumulator housing has a second energy storage chamber, a second hydraulic oil flow channel connecting the second hydraulic chamber and the hydraulic control system, and a second energy storage flow channel connecting the second energy storage chamber and the second hydraulic oil flow channel. The second solenoid valve can block or conduct the second energy storage flow channel. The second energy storage chamber is provided with a second piston that can approach or move away from the second energy storage flow channel, a second energy storage spring for driving the second piston to approach the second energy storage flow channel, a second position sensor for detecting whether the second piston has reached the energy storage completion position, and a second pressure sensor for detecting whether the second piston has reached the energy storage start position. The hydraulic control system can drive the second piston to compress the second energy storage spring through hydraulic pressure.

3. The energy-saving multi-plate clutch two-speed transmission according to claim 2, characterized in that: The first accumulator housing is provided with a first oil return port for returning the hydraulic oil to the hydraulic control system, and the first oil return port is located at an end of the first energy storage spring away from the first piston; The second accumulator housing is provided with a second oil return port for returning the hydraulic oil to the hydraulic control system, and the second oil return port is located at an end of the second energy storage spring away from the second piston; The first oil return port and the second oil return port are both connected to the oil inlet opened on the box body through pipelines.

4. The energy-saving multi-plate clutch two-speed transmission according to claim 2, characterized in that: The first multi-plate clutch includes a first outer plate mounting seat surrounding an inner gear ring, a plurality of first inner friction plates axially movably mounted on an outer circumferential surface of the inner gear ring, and a plurality of first outer friction plates axially movably mounted on an inner circumferential surface of the first outer plate mounting seat, the first outer plate mounting seat being fixedly mounted in a housing, the housing having a fixed clamping surface, the first inner friction plates and the first outer friction plates being alternately arranged between the fixed clamping surface and a first clamping piston of a first hydraulic cylinder, and a first return spring being arranged between the first clamping piston and the housing for driving the first clamping piston away from the fixed clamping surface; The second multi-plate clutch includes a second outer plate mounting seat fixedly mounted on the planetary carrier, a plurality of second inner friction plates axially movably mounted on the outer circumference of the input shaft, and a plurality of second outer friction plates axially movably mounted on the inner circumference of the second outer plate mounting seat. A fixed clamping seat is synchronously rotated on the input shaft, and each second inner friction plate and each second outer friction plate are alternately arranged between the fixed clamping seat and the second clamping piston of the second hydraulic cylinder. A second return spring is arranged between the second clamping piston and the input shaft for driving the second clamping piston away from the fixed clamping seat.

5. The energy-saving multi-plate clutch two-speed transmission according to claim 4, characterized in that: The inner edge of the first inner friction plate is spline-fitted with the outer circumference of the inner gear ring, and the outer edge of the first outer friction plate is spline-fitted with the inner circumference of the first outer plate mounting seat; The inner edge of the second inner friction plate is spline-fitted with the outer circumference of the input shaft, and the outer edge of the second outer friction plate is spline-fitted with the inner circumference of the second outer plate mounting seat.

6. The energy-saving multi-plate clutch two-speed transmission according to claim 2, characterized in that: A first conducting hole adapted to the first energy storage flow channel is formed on the piston rod of the first solenoid valve. When the first conducting hole is located in the first energy storage flow channel by the extension and contraction of the piston rod of the first solenoid valve, the first energy storage flow channel is in a conducting state. When the first conducting hole is offset from the first energy storage flow channel by the extension and contraction of the piston rod of the first solenoid valve, the first energy storage flow channel is in a disconnected state. A second conducting hole adapted to the second energy storage flow channel is provided on the piston rod of the second solenoid valve. When the second conducting hole is located in the second energy storage flow channel through the extension and contraction of the piston rod of the second solenoid valve, the second energy storage flow channel is in a conducting state. When the second conducting hole is staggered with the second energy storage flow channel through the extension and contraction of the piston rod of the second solenoid valve, the second energy storage flow channel is in a disconnected state.

7. The energy-saving multi-disc clutch two-speed transmission according to any one of claims 2 to 6, characterized in that: The hydraulic control system includes a first two-position three-way valve, a second two-position three-way valve, a three-position four-way valve, and a gear pump. The first two-position three-way valve and the second two-position three-way valve each have a through position and a reflux position. The three-position four-way valve has a forward conducting position, a cut-off position, and a phase-changing conducting position. The housing is provided with an oil outlet for delivering hydraulic oil to the gear pump. The driving gear of the gear pump is synchronously rotated and sleeved on the input shaft. Furthermore, when the input shaft rotates forward, the gear pump that pumps hydraulic oil in the forward direction can, under the coordinated control of the first solenoid valve, the second solenoid valve, the first two-position three-way valve, the second two-position three-way valve, and the three-position four-way valve: applying hydraulic pressure to the first hydraulic cylinder and the first accumulator; or, applying hydraulic pressure to the second hydraulic cylinder and the second accumulator; When the input shaft is reversed, the gear pump that pumps hydraulic oil in reverse can apply hydraulic pressure to the first hydraulic cylinder and the first accumulator under the coordinated control of the first solenoid valve, the second solenoid valve, the first two-position three-way valve, the second two-position three-way valve and the three-position four-way valve.

8. The energy-saving multi-plate clutch two-speed transmission according to claim 1, characterized in that: A differential is also included, and a power output tooth is integrally formed on the output shaft, and the power output tooth is engaged with a differential power input gear of the differential.

9. An energy-saving shifting method for an energy-saving multi-plate clutch two-speed transmission according to claim 7, characterized in that: Follow these steps: S1. Detect the rotation direction of the input shaft: if the input shaft rotates forward, proceed to step S2; if the input shaft rotates reversely, proceed to step S5; S2. Check whether the speed of the input shaft is higher than the set value: if not, go to step S3; if yes, go to step S3; S3. Enter low forward gear and follow the steps below: S31, the first solenoid valve makes the first energy storage flow channel conductive, the first two-position three-way valve and the second two-position three-way valve are both in the straight-through position, and the three-position four-way valve is in the forward conducting position; S32, the hydraulic oil output from the oil outlet is pumped into the first hydraulic oil flow channel by the gear pump of the forward pumping oil. A portion of the hydraulic oil in the first hydraulic oil flow channel flows into the first hydraulic chamber, causing the first clamping piston of the first hydraulic cylinder to press the first inner friction plates and the first outer friction plates, thereby keeping the inner gear ring stationary. At this time, the second clamping piston of the second hydraulic cylinder releases the second inner friction plates and the second outer friction plates. At the same time, another portion of the hydraulic oil in the first hydraulic oil flow channel flows into the first energy storage chamber through the first energy storage flow channel, pushing the first piston to compress the first energy storage spring until the first position sensor detects the first piston, and then proceeds to the next step; S33, the three-position four-way valve is switched to the cut-off position. Simultaneously, the gear pump is stopped. The elastic potential energy of the first energy storage spring provides the hydraulic pressure for the first clamping piston of the first hydraulic cylinder to press the first inner friction plates and the first outer friction plates until the first pressure sensor detects the first piston. Then, the three-position four-way valve is switched to the forward conducting position, and the process returns to step S32; S4. Enter high-speed forward gear and follow the steps below: S41, the second solenoid valve makes the second energy storage flow channel conductive, the first two-position three-way valve and the second two-position three-way valve are both in the straight-through position, and the three-position four-way valve is in the disguised conduction position; S42: The hydraulic oil output from the oil outlet is pumped into the second hydraulic oil flow channel by the gear pump of the forward pumping oil. A portion of the hydraulic oil in the second hydraulic oil flow channel flows into the second hydraulic chamber, causing the second clamping piston of the second hydraulic cylinder to press the second inner friction plates and the second outer friction plates, thereby causing the planetary carrier to rotate synchronously with the input shaft. At this time, the first clamping piston releases the first inner friction plates and the first outer friction plates. At the same time, another portion of the hydraulic oil in the second hydraulic oil flow channel flows into the second energy storage chamber through the second energy storage flow channel, pushing the second piston to compress the second energy storage spring until the second position sensor detects the second piston, and then proceeds to the next step; S43, the three-position four-way valve is switched to the cut-off position. At the same time, the gear pump is stopped. The elastic potential energy of the second energy storage spring provides the hydraulic pressure for the second clamping piston of the second hydraulic cylinder to press the second inner friction plates and the second outer friction plates until the second pressure sensor detects the second piston. Then, the three-position four-way valve is switched to the phase-change conduction position, and the process returns to step S42; S5. Enter reverse gear and follow the steps below: S51, the first solenoid valve makes the first energy storage flow channel conductive, the first two-position three-way valve and the second two-position three-way valve are both in the backflow position, and the three-position four-way valve is in the forward conduction position; S52: The hydraulic oil output from the oil outlet is pumped into the first hydraulic oil flow channel by the gear pump of the reverse pumping oil. A portion of the hydraulic oil in the first hydraulic oil flow channel flows into the first hydraulic chamber, causing the first clamping piston of the first hydraulic cylinder to press the first inner friction plates and the first outer friction plates, thereby keeping the inner gear ring stationary. At this time, the second clamping piston of the second hydraulic cylinder releases the second inner friction plates and the second outer friction plates. At the same time, another portion of the hydraulic oil in the first hydraulic oil flow channel flows into the first energy storage chamber through the first energy storage flow channel, pushing the first piston to compress the first energy storage spring until the first position sensor detects the first piston, and then proceeds to the next step. S53, the three-position four-way valve is switched to the cut-off position. At the same time, the gear pump is shut down. The elastic potential energy of the first energy storage spring provides the first clamping piston of the first hydraulic cylinder with the liquid pressure to press each first inner friction plate and each first outer friction plate until the first pressure sensor detects the first piston. Then, the three-position four-way valve is switched to the forward conducting position and returns to step S52.

10. An energy-saving shifting method for an energy-saving multi-plate clutch two-speed transmission according to claim 9, characterized in that: In step S31 and step S51 , the second solenoid valve blocks the second energy storage flow channel; in step S41 , the first solenoid valve blocks the first energy storage flow channel.

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