Energy-saving multi-disc clutch type two-gear transmission and energy-saving gear shifting method thereof

Abstract

The invention discloses an energy-saving multi-disc clutch type two-gear transmission and an energy-saving gear shifting method thereof. The energy-saving multi-disc clutch type two-gear transmission comprises a hydraulic control system, a first energy storage device connected with a first hydraulic cavity and a second energy storage device connected with a second hydraulic cavity. When the first multi-plate clutch needs to be kept in the combined state, the first multi-plate clutch can be kept in the combined state through hydraulic force stored by the first energy storage device; when the second multi-plate clutch needs to be kept in the combined state, the second multi-plate clutch can be kept in the combined state through the hydraulic force stored by the second energy storage device; when the first energy storage device or the second energy storage device outputs hydraulic pressure, the hydraulic control system is in a shutdown state, energy consumption is effectively reduced, the overall endurance mileage is increased, the fatigue degree of the hydraulic control system is reduced, the fault frequency of the hydraulic control system is greatly reduced, the maintenance period can be prolonged, and the maintenance efficiency is improved. And the use and maintenance cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of speed change systems, and in particular to an energy-saving multi-disc 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 beginning to adopt electric motor drive. In order to improve the power output efficiency of the drive motor, enhance the continuous acceleration performance, and have a wider high-efficiency platform to fully meet the requirements of various complex working conditions such as vehicle acceleration, climbing and high-speed driving, more and more electric drive systems choose to add transmissions.

[0003] Among them, multi-disc clutch two-speed transmissions have been widely used due to their low cost, compact structure, stability and reliability. Please refer to the Chinese invention patent application with publication number CN112238745A. When the multi-disc clutch of the existing multi-disc clutch two-speed transmission is in the engaged state, the hydraulic control system needs to continuously provide hydraulic pressure to the multi-disc clutch, which not only leads to high energy consumption and affects the overall cruising range, but also because at least one multi-disc clutch is always in the engaged state when in the forward gear or reverse gear, the hydraulic control system has no downtime and rest time, resulting in a high frequency of failure of the hydraulic control system 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-disc 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 type 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 rotating synchronously with the output shaft at one end close to the output shaft, and the output shaft has a planet carrier rotating synchronously with the input shaft at one end close to the input shaft, and at least three planet gears rotatably mounted on the planet carrier and distributed around the sun gear in the circumferential direction, and each planet gear is meshed with the sun gear, and the housing is clutch-connected with an inner gear ring meshed with each planet gear at the same time through a first multi-plate clutch, and the input shaft is clutch-connected with the planet carrier through a second multi-plate clutch, and a first hydraulic chamber and a second hydraulic chamber are arranged in the housing, and a first hydraulic cylinder for controlling the engagement or disconnection of the first multi-plate clutch is arranged in the first hydraulic chamber, and a second hydraulic cylinder for controlling the engagement or disconnection of the second multi-plate clutch is arranged in the second hydraulic chamber, and also includes 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 through the first hydraulic cylinder, and simultaneously releases pressure from the second hydraulic chamber to put the second multi-plate clutch in a disconnected state, the hydraulic control system disconnects the communication between the first accumulator and the first hydraulic chamber after the first accumulator completes energy storage, and keeps the first hydraulic chamber at a high pressure through the hydraulic pressure stored in the first accumulator, thereby keeping the first multi-plate clutch in an engaged state through the first hydraulic cylinder;

[0009] When the hydraulic control system pressurizes the second hydraulic chamber to put 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 connection between the second accumulator and the second hydraulic chamber after the second accumulator completes 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] By adopting 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 the liquid pressure or the second accumulator outputs the 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 the use and maintenance costs.

[0011] In some embodiments, the first accumulator includes a first accumulator housing mounted on a box body and a first solenoid valve mounted on the first accumulator housing, the first accumulator housing having a first energy storage chamber, a first hydraulic oil flow channel connected to 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 conduct 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 by hydraulic pressure;

[0012] The second accumulator includes a second accumulator shell installed on the box body and a second solenoid valve installed on the second accumulator shell. The second accumulator shell 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 port opened on the box body through pipelines.

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

[0017] The second multi-plate clutch comprises 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, 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, and a second return spring for driving the second clamping piston away from the fixed clamping seat is arranged between the second clamping piston and the input shaft.

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

[0019] The inner edge of the second inner friction plate is spline-matched with the outer circumference of the input shaft, and the outer edge of the second outer friction plate is spline-matched 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 provided on the piston rod of the first solenoid valve, and 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, and 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 matched with 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 offset from 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 straight-through position and a reflux position, and the three-position four-way valve has a forward conduction position, a cut-off position and a phase-changing conduction position, an oil outlet for conveying hydraulic oil to the gear pump is provided on the box body, and a driving gear of the gear pump is synchronously rotated and sleeved on the input shaft;

[0023] Furthermore, when the input shaft rotates forward, the gear pump that pumps hydraulic oil in the forward direction can be controlled by 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 meshed with a differential power input gear of the differential.

[0029] A second aspect of the present application relates to an energy-saving shifting method of the above-mentioned energy-saving multi-disc 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, go to step S2; if the input shaft rotates reversely, go 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 the low speed 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 through the gear pump of the forward pumping oil, and a part of the hydraulic oil in the first hydraulic oil flow channel flows into the first hydraulic cavity to make the first clamping piston of the first hydraulic cylinder press each first inner friction plate and each first outer friction plate, so that the inner gear ring remains stationary, and at this time, the second clamping piston of the second hydraulic cylinder releases each second inner friction plate and each second outer friction plate, and at the same time, another part of the hydraulic oil in the first hydraulic oil flow channel flows into the first energy storage cavity through the first energy storage flow channel, and pushes the first piston to compress the first energy storage spring until the first position sensor detects the first piston, and then enters the next step;

[0035] S33, the three-position four-way valve is switched to the cut-off position, and at the same time, the gear pump is stopped, and the elastic potential energy of the first energy storage spring provides the first clamping piston of the first hydraulic cylinder with the hydraulic pressure to press each first inner friction plate and each first outer friction plate until the first pressure sensor detects the first piston, and 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 conductive position;

[0038] S42, the hydraulic oil output from the oil outlet is pumped into the second hydraulic oil flow channel through the gear pump of the forward pumping oil, and a part of the hydraulic oil in the second hydraulic oil flow channel flows into the second hydraulic cavity to make the second clamping piston of the second hydraulic cylinder press each second inner friction plate and each second outer friction plate, so that the planet carrier and the input shaft rotate synchronously, and at this time, the first clamping piston releases each first inner friction plate and each first outer friction plate, and at the same time, another part of the hydraulic oil in the second hydraulic oil flow channel flows into the second energy storage cavity through the second energy storage flow channel, and pushes the second piston to compress the second energy storage spring until the second position sensor detects the second piston, and then enters the next step;

[0039] S43, the three-position four-way valve is switched to the cut-off position, and at the same time, the gear pump is stopped, and the elastic potential energy of the second energy storage spring provides the second clamping piston of the second hydraulic cylinder with the hydraulic pressure to press each second inner friction plate and each second outer friction plate until the second pressure sensor detects the second piston, and the three-position four-way valve is switched to the phase-changing 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 reflux 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 through the gear pump of the reverse pump oil, and a part of the hydraulic oil in the first hydraulic oil flow channel flows into the first hydraulic cavity to make the first clamping piston of the first hydraulic cylinder press each first inner friction plate and each first outer friction plate, so that the inner gear ring remains stationary, and at this time, the second clamping piston of the second hydraulic cylinder releases each second inner friction plate and each second outer friction plate, and at the same time, another part of the hydraulic oil in the first hydraulic oil flow channel flows into the first energy storage cavity through the first energy storage flow channel, and pushes the first piston to compress the first energy storage spring until the first position sensor detects the first piston, and then enters 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 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 conduction 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 channel; in step S41, the first solenoid valve blocks the first energy storage channel. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

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

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

[0051] Figure 6 This is a schematic diagram of the hydraulic control system being 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 of the hydraulic control system being in a shutdown state when in reverse gear. DETAILED DESCRIPTION

[0054] The present invention is further described below in conjunction with embodiments and drawings.

[0055] Embodiment 1:

[0056] like Figure 1 and Figure 2 As shown, an energy-saving multi-plate clutch two-speed transmission mainly includes a housing 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, and can directly drive the wheels, or transmit the power to the transmission mechanism. In this embodiment, the transmission mechanism is a differential 20, and the output shaft 3 is integrally formed with a power output tooth 3a, which is meshed with the differential power input gear 20a of the differential 20.

[0057] Specifically, the input shaft 2 and the output shaft 3 are coaxially installed in the housing 1 and can rotate relative to the housing 1. The input shaft 2 has a sun gear 2a that rotates synchronously with the output shaft 3 at one end thereof, and the sun gear 2a can be independent and fixedly mounted on the input shaft 2; the sun gear 2a can also be integrally formed on the input shaft 2. The output shaft 3 has a planet carrier 4 that rotates synchronously with the input shaft 2 at one end thereof, and at least three planetary gears 5 that are circumferentially distributed around the sun gear 2a are rotatably mounted on the planet carrier 4, and each planetary gear 5 is meshed with the sun gear 2a. The housing 1 is clutch-connected with an inner gear ring 7 that is simultaneously meshed with each planetary gear 5 through a first multi-plate clutch 6, and the input shaft 2 is clutch-connected with the planet carrier 4 through a second multi-plate clutch 8. The housing 1 is provided with a first hydraulic chamber 11 and a second hydraulic chamber 12, and the first hydraulic chamber 11 is provided with a first hydraulic cylinder 13 for controlling the first multi-plate clutch 6 to engage or disengage, and the second hydraulic chamber 12 is provided with a second hydraulic cylinder 14 for controlling the second multi-plate clutch 8 to engage or disengage. Therefore, a two-speed reduction 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 an engaged state, and the second hydraulic cylinder 14 controls the second multi-plate clutch 8 to be in a disconnected state, it is in a low-speed forward gear, and the inner ring gear 7 is locked. 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 a disconnected state, and the second hydraulic cylinder 14 controls the second multi-plate clutch 8 to be in a connected state, it is in a 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, so 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 an engaged state, and the second hydraulic cylinder 14 controls the second multi-plate clutch 8 to be in a disengaged state. Except that the rotation directions of the components are opposite, the transmission path is exactly the same as the low-speed forward gear.

[0061] The first multi-plate clutch 6 comprises a first outer plate mounting seat 6a surrounding the inner gear ring 7, a plurality of first inner friction plates 6b axially movably mounted on the outer peripheral surface of the inner gear ring 7, and a plurality of first outer friction plates 6c axially movably mounted on the inner peripheral surface of the first outer plate mounting seat 6a. The first outer plate mounting seat 6a is fixedly mounted in the housing 1, and the housing 1 has a fixed clamping surface 1c. Each first inner friction plate 6b and each first outer friction plate 6c are alternately arranged between the fixed clamping surface 1c and the first clamping piston 13a of the first hydraulic cylinder 13. A first return spring 13b for driving the first clamping piston 13a away from the fixed clamping surface 1c is arranged between the first clamping piston 13a and the housing 1. When the hydraulic control system applies hydraulic pressure to the first clamping piston 13a of the first hydraulic cylinder 13, each first inner friction plate 6b and each first outer friction plate 6c can be clamped between the fixed clamping surface 1c and the first clamping piston 13a, thereby locking the inner gear ring 7 so that the inner gear ring 7 will not rotate. 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 gear ring 7 and allowing the inner gear ring 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 planet 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 synchronously rotated on the input shaft 2. Each second inner friction plate 8b and each second outer friction plate 8c are alternately arranged between the fixed clamping seat 19 and the second clamping piston 14a of the second hydraulic cylinder 14. A second return spring 14b for driving the second clamping piston 14a away from the fixed clamping seat 19 is arranged between the second clamping piston 14a and the input shaft 2. When the hydraulic control system applies hydraulic pressure to the second clamping piston 14a of the second hydraulic cylinder 14, each second inner friction plate 8b and each second outer friction plate 8c can be clamped between the fixed clamping seat 19 and the second clamping piston 14a, thereby locking the planet carrier 4 and making the planet carrier 4 rotate synchronously with 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 with the outer circumference of the inner gear ring 7, and the outer edge of the first outer friction plate 6c is splined with the inner circumference of the first outer plate mounting seat 6a; similarly, the inner edge of the second inner friction plate 8b is splined with the outer circumference of the input shaft 2, and the outer edge of the second outer friction plate 8c is splined with the inner circumference of the second outer plate mounting seat 8a. The above structure enables 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, and is easy to assemble, stable and reliable.

[0064] See also Figure 1-Figure 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 the low-speed forward gear and reverse gear, and the second energy accumulator 10 is used to store energy in the high-speed forward gear.

[0065] When the energy-saving multi-plate clutch two-speed transmission is in the low-speed forward gear and reverse gear, the second hydraulic chamber 12 has no pressure, so the second multi-plate clutch 8 is in the disconnected state. The hydraulic control system first pressurizes the first hydraulic chamber 11, so that the first multi-plate clutch 6 is in the engaged state through the first hydraulic cylinder 13, and at the same time, the first accumulator 9 will synchronously store energy. And, after the first accumulator 9 completes the energy storage, the hydraulic control system will disconnect the communication between it and the first hydraulic chamber 11. At this time, the first hydraulic chamber 11 is kept at high pressure by the hydraulic pressure stored in the first accumulator 9, so that the first multi-plate clutch 6 is kept in the engaged state through the first hydraulic cylinder 13.

[0066] When the energy-saving multi-plate clutch two-speed transmission is in the high-speed forward gear, there is no pressure in the first hydraulic chamber 11, so the first multi-plate clutch 6 is in the disconnected state. The hydraulic control system first pressurizes the second hydraulic chamber 12, so that the second multi-plate clutch 8 is in the engaged state through the second hydraulic cylinder 14, and at the same time, the second accumulator 10 will synchronously store energy. And, after the second accumulator 10 completes the energy storage, the hydraulic control system will disconnect the communication between it and the second hydraulic chamber 12. At this time, the second hydraulic chamber 12 is kept at high pressure by the hydraulic pressure stored in the second accumulator 10, so that the second multi-plate clutch 8 is kept in the engaged state through the second hydraulic cylinder 14.

[0067] From the above, it can be seen that no matter when the first accumulator 9 outputs hydraulic pressure or the second accumulator 10 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 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 period and reducing the use and maintenance costs.

[0068] See also Figure 1 The first accumulator 9 includes a first accumulator housing 9a installed on the box body 1 and a first solenoid valve 9e installed on the first accumulator housing 9a. The first accumulator housing 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 reaches the energy storage completion position, and a first pressure sensor 9i for detecting whether the first piston 9f reaches the energy storage start position. The hydraulic control system can drive the first piston 9f to compress the first energy storage spring 9g through the hydraulic pressure.

[0069] Therefore, in the low-speed forward gear and reverse gear, first, the hydraulic control system applies hydraulic pressure to the first hydraulic chamber 11 through the first hydraulic oil flow channel 9c, and the high-pressure hydraulic oil also enters 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 in the direction away from the first pressure sensor 9i, and converts 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, it means that the first energy accumulator 9 has completed energy storage. At this time, the hydraulic control system stops 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 the process, the hydraulic oil in the first energy storage chamber 9b will gradually decrease until the first pressure sensor 9i detects the first piston 9f, and the hydraulic control system starts again, and the first energy accumulator 9 starts to store energy again, and so on.

[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 the high-speed forward gear, first, the hydraulic control system applies hydraulic pressure to the second hydraulic chamber 12 through the second hydraulic oil flow channel 10c, and the high-pressure hydraulic oil also enters 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 in the direction away from the second pressure sensor 10i, and converts 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, it means that the second energy accumulator 10 has completed energy storage. At this time, the hydraulic control system stops and no longer applies hydraulic pressure to the second hydraulic chamber 12 through 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 the process, the hydraulic oil in the second energy storage chamber 10b will gradually decrease until the second pressure sensor 10i detects the second piston 10f, and the hydraulic control system is started again, and the second energy accumulator 10 starts to store energy again, and this goes back and forth.

[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 an end of the first energy storage spring 9g away from the first piston 9f. The hydraulic oil that has seeped through the first piston 9f is returned to the housing 1 through the first oil return port 9j. Specifically, the internal space of the housing 1 serves as an oil storage tank for the hydraulic oil of the hydraulic control system. Therefore, the housing 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 has seeped 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 also Figure 1 A first conducting hole 9e1 matched with the first energy storage channel 9d is provided on the piston rod of the first solenoid valve 9e. When the first solenoid valve 9e causes the first conducting hole 9e1 to be located in the first energy storage channel 9d through the extension and contraction of the piston rod, the first energy storage channel 9d is in an on state. When the first solenoid valve 9e causes the first conducting hole 9e1 to be offset from the first energy storage channel 9d through the extension and contraction of the piston rod, the first energy storage channel 9d is in an off state. The on-off control of the first energy storage channel 9d by the first solenoid valve 9e is simple and reliable.

[0075] Similarly, a second conducting hole 10e1 adapted to the second energy storage channel 10d is provided on the piston rod of the second solenoid valve 10e. 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 an on 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 an off state. The on-off control of the second energy storage channel 10d by the second solenoid valve 10e is simple and reliable.

[0076] See also Figure 1-Figure 8 The hydraulic control system includes a first two-position three-way valve 16, a second two-position three-way valve 17, a three-position four-way valve 18 and a gear pump 15. The first two-position three-way valve 16 and the second two-position three-way valve 17 both have a straight-through position a and a reflux position b. The three-position four-way valve 18 has a forward conduction position c, a cut-off position d and a phase-changing conduction position e. The hydraulic oil output from the oil outlet 1a on the housing 1 flows to the gear pump 15. The gear pump 15 is composed of a driving gear 15a mounted on the input shaft 2 in synchronous rotation and a driven gear 15b meshing with the driving gear 15a. An oil groove is provided on the circumferential outer edge of the driving gear 15a and the driven gear 15b. An oil suction port 15c and an oil pumping port 15d are respectively provided on both sides of the meshing position of the driving gear 15a and the driven gear 15b. When the driving gear 15a rotates forward, the hydraulic oil is sucked into the oil grooves of the driving gear 15a and the driven gear 15b through the oil suction port 15c, and then pumped out from the oil pumping 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 pump oil 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] Embodiment 2:

[0081] See also Figure 1-Figure 8 , an energy-saving shifting method of an energy-saving multi-disc clutch two-speed transmission of 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 makes the first energy storage flow channel 9d conductive, 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 to further improve 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 forward pumping oil, and a part of the hydraulic oil in the first hydraulic oil flow channel 9c flows into the first hydraulic chamber 11 to make the first clamping piston 13a of the first hydraulic cylinder 13 press each first inner friction plate 6b and each first outer friction plate 6c, so that the inner gear ring 7 remains 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 liquid 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] S41, the second solenoid valve 10e makes the second energy storage channel 10d conductive, 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 conductive position e; at this time, the first solenoid valve 9e blocks the first energy storage channel 9d, which can preserve the hydraulic energy in the first accumulator 9 to further improve 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 forward pumping oil, and a part of the hydraulic oil in the second hydraulic oil flow channel 10c flows into the second hydraulic chamber 12 to make the second clamping piston 14a of the second hydraulic cylinder 14 press each second inner friction plate 8b and each second outer friction plate 8c, so that the planetary carrier 4 and the input shaft 2 rotate synchronously, and at this time, the first clamping piston 13a releases each first inner friction plate 6b and each first outer friction plate 6c, and 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, and the second energy 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 the second inner friction plates 8b and the second outer friction plates 8c until the second pressure sensor 10i detects the second piston 10f. The hydraulic energy in the second accumulator 10 is released, and the three-position four-way valve 18 is switched to the disguised conduction position e, and 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 makes the first energy storage flow channel 9d conductive, the first two-position three-way valve 16 and the second two-position three-way valve 17 are both in the reflux 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 to further improve 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 gear pump 15 of reverse pumping oil, and a part of the hydraulic oil in the first hydraulic oil flow channel 9c flows into the first hydraulic chamber 11 to make the first clamping piston 13a of the first hydraulic cylinder 13 press each first inner friction plate 6b and each first outer friction plate 6c, so that the inner gear ring 7 remains 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 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 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, and such changes all fall within the scope of protection of the present invention.

Claims

1. An energy-saving multi-disc 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 rotating synchronously therewith at one end close to the output shaft, and the output shaft has a planet carrier rotating synchronously therewith at one end close to the input shaft, wherein at least three planet gears circumferentially distributed around the sun gear are rotatably mounted on the planet carrier, and each planet gear is meshed with the sun gear, the housing is clutch-connected with an inner gear ring simultaneously meshed with each planet gear through a first multi-disc clutch, the input shaft is clutch-connected with the planet carrier through a second multi-disc clutch, a first hydraulic chamber and a second hydraulic chamber are arranged in the housing, a first hydraulic cylinder for controlling the engagement or disconnection of the first multi-disc clutch is arranged in the first hydraulic chamber, and a second hydraulic cylinder for controlling the engagement or disconnection of the second multi-disc clutch is arranged in the second hydraulic chamber, 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 through the first hydraulic cylinder, and simultaneously releases pressure from the second hydraulic chamber to put the second multi-plate clutch in a disconnected state, the hydraulic control system disconnects the communication between the first accumulator and the first hydraulic chamber after the first accumulator completes energy storage, and keeps the first hydraulic chamber at a high pressure through the hydraulic pressure stored in the first accumulator, thereby keeping the first multi-plate clutch in an engaged state through the first hydraulic cylinder; When the hydraulic control system pressurizes the second hydraulic chamber to put 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 connection between the second accumulator and the second hydraulic chamber after the second accumulator completes 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-disc clutch two-speed transmission according to claim 1, characterized in that: The first accumulator comprises a first accumulator housing mounted on a box body and a first solenoid valve mounted on the first accumulator housing, wherein the first accumulator housing has a first energy storage chamber, a first hydraulic oil flow channel connected to 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 conduct 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, and the hydraulic control system can drive the first piston to compress the first energy storage spring by hydraulic pressure; The second accumulator includes a second accumulator shell installed on the box body and a second solenoid valve installed on the second accumulator shell. The second accumulator shell 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-disc 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 port opened on the box body through pipelines.

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

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

6. The energy-saving multi-disc clutch two-speed transmission according to claim 2, characterized in that: A first conducting hole adapted to the first energy storage flow channel is provided 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 staggered with 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 matched with 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 offset from 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 comprises 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 both have a straight-through position and a reflux position, and the three-position four-way valve has a forward conduction position, a cut-off position and a phase-changing conduction position, an oil outlet for conveying hydraulic oil to the gear pump is provided on the box body, and 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 be controlled by 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-disc 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 meshed with a differential power input gear of the differential.

9. An energy-saving shifting method for an energy-saving multi-disc clutch two-speed transmission as claimed in claim 7, characterized in that: Follow these steps: S1, detect the rotation direction of the input shaft: if the input shaft rotates forward, go to step S2; if the input shaft rotates reversely, go 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 the low speed 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 through the gear pump of the forward pumping oil, and a part of the hydraulic oil in the first hydraulic oil flow channel flows into the first hydraulic cavity to make the first clamping piston of the first hydraulic cylinder press each first inner friction plate and each first outer friction plate, so that the inner gear ring remains stationary, and at this time, the second clamping piston of the second hydraulic cylinder releases each second inner friction plate and each second outer friction plate, and at the same time, another part of the hydraulic oil in the first hydraulic oil flow channel flows into the first energy storage cavity through the first energy storage flow channel, and pushes the first piston to compress the first energy storage spring until the first position sensor detects the first piston, and then enters the next step; S33, the three-position four-way valve is switched to the cut-off position, and at the same time, the gear pump is stopped, and the elastic potential energy of the first energy storage spring provides the first clamping piston of the first hydraulic cylinder with the hydraulic pressure to press each first inner friction plate and each first outer friction plate until the first pressure sensor detects the first piston, and 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 conductive position; S42, the hydraulic oil output from the oil outlet is pumped into the second hydraulic oil flow channel through the gear pump of the forward pumping oil, and a part of the hydraulic oil in the second hydraulic oil flow channel flows into the second hydraulic cavity to make the second clamping piston of the second hydraulic cylinder press each second inner friction plate and each second outer friction plate, so that the planet carrier and the input shaft rotate synchronously, and at this time, the first clamping piston releases each first inner friction plate and each first outer friction plate, and at the same time, another part of the hydraulic oil in the second hydraulic oil flow channel flows into the second energy storage cavity through the second energy storage flow channel, and pushes the second piston to compress the second energy storage spring until the second position sensor detects the second piston, and then enters the next step; S43, the three-position four-way valve is switched to the cut-off position, and at the same time, the gear pump is stopped, and the elastic potential energy of the second energy storage spring provides the second clamping piston of the second hydraulic cylinder with the hydraulic pressure to press each second inner friction plate and each second outer friction plate until the second pressure sensor detects the second piston, and the three-position four-way valve is switched to the phase-changing 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 reflux 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 through the gear pump of the reverse pump oil, and a part of the hydraulic oil in the first hydraulic oil flow channel flows into the first hydraulic cavity to make the first clamping piston of the first hydraulic cylinder press each first inner friction plate and each first outer friction plate, so that the inner gear ring remains stationary, and at this time, the second clamping piston of the second hydraulic cylinder releases each second inner friction plate and each second outer friction plate, and at the same time, another part of the hydraulic oil in the first hydraulic oil flow channel flows into the first energy storage cavity through the first energy storage flow channel, and pushes the first piston to compress the first energy storage spring until the first position sensor detects the first piston, and then enters 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 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 conduction position and returns to step S52.

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

Images