Gearbox and vehicle with gear shift buffer structure

Abstract

The present invention relates to a gearbox and a vehicle with a shift buffer structure. The gearbox with the shift buffer structure comprises a housing, a gear ring, a shift assembly, a baffle and a buffer structure, wherein the housing has a cavity; the gear ring is arranged in the cavity, and the gear ring is used to be movably sleeved on the outer periphery of the transmission assembly along a first direction to have a high gear state and a low gear state; the shift assembly has a driving part movably arranged in the cavity along the first direction, the driving part is connected to the gear ring, and the baffle is arranged on one side of the gear ring, so that when in the low gear state, the baffle is used to limit the gear ring; the buffer structure has a damping part that is telescopically arranged, and the damping part and the driving part are arranged at intervals along the first direction, so that when in the low gear state, the driving part abuts against the damping part to block the movement of the shift assembly. The present invention reduces the impact force of the gear ring hitting the baffle through the damping part blocking the drive, reduces the impact sound between the gear ring and the baffle, and improves the driving experience of the user.

Description

Technical Field

[0001] The present invention relates to the technical field of gearboxes, and in particular to a gearbox and a vehicle with a gear shift buffer structure. Background Art

[0002] Medium and heavy-duty trucks often need to be equipped with more than ten gearboxes due to their large loads and long transportation distances. It is difficult for an independent gearbox to achieve multi-speed shifting, so multi-speed gearboxes mostly adopt a main and auxiliary box structure to meet the needs of different loads and different road conditions. Planetary gear trains are mostly used in the transmission auxiliary box speed change system due to their compact structure, small size, small mass, large load-bearing capacity, large power transmission range and transmission range, low operating noise, high efficiency and long life. The synchronizer high and low gear assembly is used to control the inner gear ring of the planetary gear train to connect with the box or planetary carrier, thereby achieving high and low gear shifting.

[0003] Patent CN204267701U discloses a planetary gear train auxiliary box of a gearbox, comprising a box body, a shift cylinder assembly mounted on the box body, a shift fork fixedly connected to the shift cylinder assembly, a synchronizer shifted by the shift fork, a power input shaft mounted on the box body, and a planetary gear train; the synchronizer sleeve is arranged on the output shaft of the planetary carrier in the planetary gear train, the sliding sleeve in the synchronizer is connected to the inner gear ring in the planetary gear train, the low-speed synchronizer cone ring is directly fixed on the box body, the high-speed synchronizer cone ring is connected to the planetary carrier in the planetary gear train, and the high-speed synchronizer cone ring is located between the planetary gear train and the low-speed synchronizer cone ring; the power input shaft is a gear shaft, the gear at the top of the gear shaft is the sun gear of the planetary gear train, and the output shaft of the planetary carrier is the power output shaft of the auxiliary box.

[0004] However, the above-mentioned prior art is usually provided with a baffle plate located on the low gear side. When the ring gear moves from the high gear to the low gear, the ring gear and the baffle plate will collide with each other to limit the movement of the ring gear. The ring gear collides with the baffle plate, producing a loud impact sound, and the user's driving experience is poor. Summary of the invention

[0005] In view of this, it is necessary to provide a gearbox with a gear shift buffer structure to solve the technical problem that in the prior art, a baffle is usually provided on the low gear side. When the ring gear moves from a high gear to a low gear, the ring gear and the baffle will collide with each other to limit the movement of the ring gear. The ring gear collides with the baffle, producing a loud impact sound, resulting in a poor driving experience for users.

[0006] The present invention provides a gearbox with a gear shift buffer structure, the gearbox with a gear shift buffer structure comprising:

[0007] A housing having a cavity;

[0008] A gear ring, disposed in the cavity, and used to be movably sleeved on the outer periphery of the transmission assembly along a first direction to have a high gear state and a low gear state;

[0009] A shift assembly, comprising a driving part movably disposed in the cavity along the first direction, the driving part being connected to the ring gear and used for driving the ring gear to switch between the high gear state and the low gear state;

[0010] a baffle plate, disposed on one side of the gear ring, so that when the gear ring is in the low gear state, the baffle plate is used to limit the position of the gear ring;

[0011] The buffer structure has a telescopic damping part, wherein the damping part and the driving part are arranged at intervals along the first direction, so that in the low gear state, the driving part abuts against the damping part to block the movement of the shift assembly.

[0012] Optionally, the housing is provided with a piston cavity, the front end of the piston cavity is connected to the cavity through a channel, and the piston cavity is filled with lubricating oil;

[0013] The buffer structure includes a piston assembly, which is movably installed in the piston cavity along a first direction, and one end of the piston assembly extends from the channel into the cavity. The piston assembly divides the piston cavity into a first chamber and a second chamber connected to the channel, and the second chamber is filled with lubricating oil. The piston assembly constitutes the damping part.

[0014] Optionally, the piston assembly includes a piston rod and a piston head disposed at one end of the piston rod, the piston head is movably mounted in the piston cavity, one end of the piston rod extends from the channel into the cavity and is coaxially arranged with the driving part.

[0015] Optionally, the piston rod is provided with an air passage connecting the first chamber and the cavity.

[0016] Optionally, the housing is provided with an oil inlet passage and an oil return passage communicating with the cavity and the second chamber;

[0017] The buffer structure also includes a first one-way valve and a second one-way valve. The first one-way valve is arranged in the oil inlet channel, and the first one-way valve is used to allow the lubricating oil in the cavity to flow to the piston cavity. The second one-way valve is arranged in the oil return channel, and the second one-way valve is used to allow the lubricating oil in the piston cavity to flow to the cavity.

[0018] Optionally, the first one-way valve comprises a first steel ball and a first elastic member, the first steel ball is movably installed in the oil inlet channel through the first elastic member, and the first steel ball is used to block or open the oil inlet channel;

[0019] The second one-way valve includes a second steel ball and a second elastic member, wherein the second steel ball is movably installed in the oil inlet channel through the second elastic member, and the second steel ball is used to block or open the oil return channel, wherein the elastic force of the second elastic member is greater than the elastic force of the first elastic member.

[0020] Optionally, the diameter of the oil inlet passage is larger than the diameter of the oil return passage, and the diameter of the oil return passage is smaller than the diameter of the piston chamber.

[0021] Optionally, the gearbox with the shift buffer structure further includes an oil pump, which is connected to the oil inlet channel and is used to pump the lubricating oil in the cavity into the second chamber.

[0022] Optionally, the buffer structure also includes a third elastic member, which is arranged in the second chamber, one end of the third elastic member is connected to the bottom of the second chamber, and the other end of the third elastic member is connected to the piston head, and the third elastic member is used to drive the piston head to move toward the direction of the shift assembly.

[0023] In addition, the present invention also provides a vehicle, comprising a gearbox with a shift buffer structure as described in any one of the above technical solutions.

[0024] Compared with the prior art, the present invention provides a gearbox with a shift buffer structure, wherein the housing has a cavity, the gear ring is arranged in the cavity, the gear ring is movably sleeved on the outer periphery of the transmission assembly along a first direction, and is respectively meshed with different gear trains, so that the gearbox has a high gear state and a low gear state, and the shift assembly has a driving part movably arranged in the cavity along the first direction, the driving part is connected to the gear ring, and the gear ring is driven to move by the driving part to realize the switching between the high gear state and the low gear state; the baffle is arranged on one side of the gear ring, and the gear ring is switched from the high gear state to the low gear state. When in the low gear state, the baffle plate contacts the gear ring to limit the gear ring. The buffer structure has a telescopic damping portion. The damping portion and the driving portion are spaced apart along the first direction. During specific use, when the driving portion drives the gear ring to move, the driving portion itself is also moving. When moving to the low gear state, the driving portion abuts against the damping portion. The damping portion blocks the drive, thereby reducing the impact force of the gear ring hitting the baffle plate and reducing the impact sound between the gear ring and the baffle plate, thereby avoiding affecting the user's driving comfort and improving the user's driving experience.

[0025] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the preferred embodiments of the present invention are described in detail as follows with reference to the accompanying drawings. The specific implementation of the present invention is given in detail by the following embodiments and their accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0027] Figure 1 A schematic structural diagram of an embodiment of a gearbox with a shift buffer structure provided by the present invention;

[0028] Figure 2 for Figure 1 A partial cross-sectional view of a gearbox with a shift buffer structure, wherein the lubricating oil is in the stage of entering the buffer cylinder;

[0029] Figure 3 for Figure 1 A partial cross-sectional view of a gearbox having a shift buffer structure, wherein the gearbox is in a buffering action stage;

[0030] Figure 4 for Figure 1 A partial cross-sectional view of a gearbox having a gear shift buffer structure, wherein the gearbox is at the end of a high-gear to low-gear shift;

[0031] Figure 5 for Figure 1 A partial cross-sectional view of a gearbox with a gear shift buffer structure, wherein it is in the stage of shifting from low gear to high gear.

[0032] Description of reference numerals:

[0033] 1-housing, 11-cavity, 12-piston cavity, 121-first chamber, 122-second chamber, 13-oil inlet channel, 14-oil return channel, 2-gear ring, 3-shift assembly, 31-shift cylinder, 311-push rod, 32-shift fork, 4-baffle, 5-buffer assembly, 51-piston assembly, 511-piston rod, 5111-air channel, 512-piston head, 52-first one-way valve, 53-second one-way valve, 54-third elastic member. DETAILED DESCRIPTION

[0034] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0035] The present invention provides a vehicle, comprising a gearbox with a shift buffer structure 5 as described in any one of the above technical solutions.

[0036] See also Figures 1 to 5 The gearbox with a shift buffer structure 5 includes a housing 1, a ring gear 2, a shift assembly 3, a baffle 4 and a buffer structure 5, wherein the housing 1 has a cavity 11; the ring gear 2 is arranged in the cavity 11, and the ring gear 2 is used to be movably sleeved on the outer periphery of the transmission assembly along a first direction to have a high gear state and a low gear state; the shift assembly 3 has a driving part movably arranged in the cavity 11 along the first direction, and the driving part is connected to the ring gear 2 to drive the ring gear 2 to switch between the high gear state and the low gear state; the baffle 4 is arranged on one side of the ring gear 2, so that when in the low gear state, the baffle 4 is used to limit the ring gear 2; the buffer structure 5 has a telescopic damping part, and the damping part and the driving part are arranged at intervals along the first direction, so that when in the low gear state, the driving part abuts against the damping part to block the movement of the shift assembly 3.

[0037] The gearbox with a shift buffer structure 5 provided by the present invention comprises: a housing 1 having a cavity 11, a gear ring 2 arranged in the cavity 11, and a gear ring 2 movably sleeved on the outer periphery of a transmission assembly along a first direction, respectively meshing with different gear trains, so that the gearbox has a high gear state and a low gear state; the shift assembly 3 comprises a driving part movably arranged in the cavity 11 along the first direction, the driving part being connected to the gear ring 2, and the gear ring 2 is driven to move by the driving part to realize switching between the high gear state and the low gear state; the baffle 4 is arranged on one side of the gear ring 2, and the gear ring 2 is switched from the high gear state to the low gear state; When in the low gear state, the baffle plate 4 is in contact with the ring gear 2 to limit the position of the ring gear 2. The buffer structure 5 has a telescopic damping portion. The damping portion and the driving portion are spaced apart along the first direction. During specific use, when the driving portion drives the ring gear 2 to move, it itself is also moving. When moving to the low gear state, the driving portion abuts against the damping portion. The damping portion blocks the drive, thereby reducing the impact force of the ring gear 2 hitting the baffle plate 4 and reducing the impact sound between the ring gear 2 and the baffle plate 4, thereby avoiding affecting the user's driving comfort and improving the user's driving experience.

[0038] Further, for the convenience of explanation, in the present embodiment, the first direction is left and right, that is, the gear ring 2 is arranged to move along the left and right directions. When the gear ring 2 moves to the left, it is in the high gear state, and when the gear ring 2 moves to the right, it is in the low gear state. The baffle 4 is arranged on the right side of the gear ring 2, and when the gear ring 2 moves to the low gear state, the right side of the gear ring 2 abuts against the left side of the baffle 4, thereby achieving the purpose of limiting the gear ring 2 from continuing to move to the right. Correspondingly, when the driving part drives the gear ring 2 to move left and right, the driving part also moves left and right. When the driving part moves to the right, it abuts against the damping part, driving the damping part to move to the right. When the damping part blocks the telescopic part, the purpose of blocking the gear ring 2 can be achieved, thereby reducing the impact force between the gear ring 2 and the baffle 4.

[0039] Furthermore, the shift assembly 3 includes a shift cylinder 31 and a shift fork 32, the shift cylinder 31 is arranged in the housing 1, and a push rod 311 of the shift cylinder 31 extends into the cavity 11 and is fixedly connected to the shift fork 32, the push rod 311 is extended along the first direction, the shift fork 32 is connected to the ring gear 2, the push rod 311 constitutes the driving part, the shift fork 32 is driven to move by the shift cylinder 31, and then the ring gear 2 is driven to move along the first direction, the push rod 311 and the damping part are arranged at intervals from left to right, and the push rod 311 can be connected to the damping part in a disengageable manner, that is, when the push rod 311 moves to the right, it can abut against the damping part and push the damping part to move to the right, and when the push rod 311 moves to the left, it can be disengaged from the damping part to avoid the damping part affecting the movement of the push rod 311.

[0040] Furthermore, the specific form of the buffer structure 5 is not limited, and it can be a pneumatic damping structure or a hydraulic damping structure. In the present embodiment, the shell 1 is provided with a piston cavity 12, the front end of the piston cavity 12 is connected to the cavity 11 through a channel, and the piston cavity 12 is filled with lubricating oil; the buffer structure 5 includes a piston assembly 51, the piston assembly 51 is movably installed in the piston cavity 12 along a first direction, and one end extends from the channel into the cavity 11, the piston assembly 51 divides the piston cavity 12 into a first chamber 121 connected to the channel and a second chamber 122, the second chamber 122 is filled with lubricating oil, and the piston assembly 51 constitutes the damping part. Specifically, the push rod 311 and the piston assembly 51 are coaxially arranged from left to right and spaced apart. When the push rod 311 moves to the right, the push rod 311 abuts against the piston assembly 51, driving the piston assembly 51 to move in the piston cavity 12 to compress the volume of the second chamber 122. Since the second chamber 122 is filled with lubricating oil, a blocking effect is achieved.

[0041] Furthermore, in this embodiment, the piston assembly 51 includes a piston rod 511 and a piston head 512 provided at one end of the piston rod 511, the piston head 512 is movably installed in the piston cavity 12, one end of the piston rod 511 extends from the channel into the cavity 11 and is coaxially arranged with the driving part.

[0042] Furthermore, the diameter of the channel is matched with the diameters of the piston rod 511 and the push rod 311. Such a configuration can limit the position of the piston rod 511 to prevent the piston rod 511 from shaking when it moves.

[0043] Furthermore, since the channel is adapted to the piston rod 511 , in order to prevent the gas in the first chamber 121 from affecting the movement of the piston head 512 , in this embodiment, the piston rod 511 is provided with an airway 5111 connecting the first chamber 121 and the cavity 11 .

[0044] Furthermore, since the length of the channel is greater than the length of the piston rod 511, when the push rod 311 moves, the push rod 311 extends into the channel and abuts against the channel. In order to prevent the push rod 311 from blocking the airway 5111, a connecting airway 5111 is also provided on the push rod 311. The connecting airway 5111 can connect the airway 5111 and the cavity 11, so as to discharge the gas in the first chamber 121 into the cavity 11, thereby facilitating the resetting of the piston head 512.

[0045] Furthermore, in the present embodiment, the shell 1 is provided with an oil inlet passage 13 and an oil return passage 14 connecting the cavity 11 and the second chamber 122; the buffer structure 5 also includes a first one-way valve 52 and a second one-way valve 53, the first one-way valve 52 is provided in the oil inlet passage 13, and the first one-way valve 52 is used to allow the lubricating oil in the cavity 11 to flow to the piston cavity 12, and the second one-way valve 53 is provided in the oil return passage 14, and the second one-way valve 53 is used to allow the lubricating oil in the piston cavity 12 to flow to the cavity 11. During specific use, the lubricating oil in the cavity 11 is first pumped into the second chamber 122 through the oil inlet passage 13, so that the second chamber 122 is filled with lubricating oil, and the piston head 512 is pushed to move to the left end of the piston cavity 12. The first one-way valve 52 can limit the lubricating oil in the second chamber 122 from the oil inlet passage 13 to flow back into the cavity 11. When the push rod 311 drives the piston rod 511 to move to the right, the piston head 512 squeezes the lubricating oil in the second chamber 122, so that the lubricating oil flows into the cavity 11 through the oil return passage 14, which is convenient for repeated use. The second one-way valve 53 can limit the lubricating oil in the cavity 11 from the oil return passage 14 to flow into the second chamber 122. In this way, the push rod 311 is blocked by the circulation of lubricating oil between the cavity 11 and the piston cavity 12.

[0046] Furthermore, the specific forms of the first one-way valve 52 and the second one-way valve are not limited. In the present embodiment, the first one-way valve 52 comprises a first steel ball and a first elastic member, the first steel ball is movably mounted in the oil inlet channel 13 through the first elastic member, and the first steel ball is used to block or open the oil inlet channel 13; the second one-way valve 53 comprises a second steel ball and a second elastic member, the second steel ball is movably mounted in the oil inlet channel 13 through the second elastic member, and the second steel ball is used to block or open the oil return channel 14, wherein the elastic force of the second elastic member is greater than the elastic force of the first elastic member. During specific use, when the lubricating oil is injected into the second chamber 122 through the oil inlet channel 13, the lubricating oil pushes the first steel ball to move, so that the first steel ball opens the oil inlet channel 13. At this time, the first steel ball compresses the first elastic member, so that the lubricating oil smoothly enters the second chamber 122. After the injection is completed, the first elastic member drives the first steel ball back to the initial position, so that the first steel ball blocks the oil inlet channel 13 to prevent leakage. During the buffering process, the piston head 512 compresses the lubricating oil in the second chamber 122, so that the lubricating oil pushes the second steel ball to move, so that the second steel ball opens the oil return channel 14, and the lubricating oil flows from the oil return channel 14 to the cavity 11. After the buffering is completed, the second elastic member drives the second steel ball back to the initial position, so that the second steel ball blocks the oil return channel 14.

[0047] Furthermore, specific forms of the first elastic member and the second elastic member are not limited. In the present embodiment, both the first elastic member and the second elastic member are springs.

[0048] Further, in this embodiment, the diameter of the oil inlet passage 13 is greater than the diameter of the oil return passage 14 , and the diameter of the oil return passage 14 is smaller than the diameter of the piston chamber 12 .

[0049] Furthermore, in the present embodiment, the gearbox with the shift buffer structure 5 further includes an oil pump, which is connected to the oil inlet channel 13 , and is used to pump the lubricating oil in the cavity 11 into the second chamber 122 .

[0050] Further, the oil inlet passage 13 includes a first oil inlet section, a first mounting section, and a second oil inlet section which are connected in sequence, one end of the first oil inlet section is connected to the oil pump through a pipeline, the diameter of the first mounting section is larger than the diameter of the first oil inlet section, so that a step is formed between the first oil inlet section and the first mounting section, the first oil inlet section and the first mounting section are both extended in the left-right direction, one end of the second oil inlet section is connected to the middle of the first mounting section, the other end of the second oil inlet section is connected to the second chamber 122, and the second oil inlet section is gradually inclined from left to right in the direction toward the second chamber 122, the first steel ball and the first elastic member are sequentially installed in the first mounting section from left to right, and the diameter of the first steel ball is adapted to the diameter of the first mounting section, so that the first steel ball plays a blocking role, and the first steel ball, under the action of the first elastic member, is pressed against the step to separate the first oil inlet section and the first mounting section, and when pumping oil into the second chamber 122, the lubricating oil pushes the first steel ball to move, so that the first oil inlet section, the first mounting section, and the second oil inlet section are connected.

[0051] Further, the oil return passage 14 includes a first oil return section, a second mounting section, and a second oil return section which are connected in sequence, one end of the first oil return section is connected to the second chamber 122, the diameter of the second mounting section is larger than the diameter of the first oil return section, so that a step is formed between the first oil return section and the second mounting section, the first oil return section and the second mounting section are both extended in the vertical direction, one end of the second oil return section is connected to the middle of the second mounting section, the other end of the second oil return section is connected to the cavity 11, and the second oil inlet section is extended in the left and right directions, the second steel ball and the second elastic member are sequentially installed in the second mounting section from bottom to top, and the diameter of the second steel ball is adapted to the diameter of the second mounting section, so that the second steel ball plays a blocking role, and the second steel ball is pressed against the step under the action of the second elastic member to separate the first oil return section and the second mounting section. During buffering, the lubricating oil in the second chamber 122 pushes the second steel ball to move, so that the first oil return section, the second mounting section, and the second oil return section are connected.

[0052] Furthermore, in this embodiment, the buffer structure 5 further includes a third elastic member 54, which is disposed in the second chamber 122, one end of the third elastic member 54 is connected to the bottom of the second chamber 122, and the other end of the third elastic member 54 is connected to the piston head 512, and the third elastic member 54 is used to drive the piston head 512 to move toward the shift assembly 3. The third elastic member 54 is provided to facilitate the resetting of the piston head 512.

[0053] Furthermore, the specific form of the third elastic member 54 is not limited. In this embodiment, the third elastic member 54 is a spring.

[0054] Furthermore, this embodiment includes the following stages:

[0055] The lubricating oil enters the buffer cylinder stage: in the initial state, it is in a high gear state, the lubricating oil passes through the oil pump, passes through the oil inlet channel 13, pushes the first steel ball, and enters the second chamber 122, so that the second chamber 122 is filled with lubricating oil, and at this time, the second steel ball in the return oil channel 14 can block the return oil channel 14 under the elastic force of the second elastic member, preventing the lubricating oil from returning to the cavity 11 from the return oil channel 14.

[0056] At this time, the buffer structure 5 satisfies the following conditions:

[0057] P1×S1>F1;and,

[0058] P2×S2<F2;and,

[0059] F2>F1;

[0060] Among them, P1 is the oil pressure in the oil inlet channel 13, S1 is the surface area of ​​the lubricating oil in the oil inlet channel 13 in contact with the first steel ball, F1 is the elastic force of the first elastic member, P2 is the oil pressure in the second chamber 122, S2 is the surface area of ​​the lubricating oil in contact with the second steel ball, and F2 is the elastic force of the second spring.

[0061] It should be noted that when the lubricating oil enters the second chamber 122 from the oil inlet passage 13 , the oil inlet passage 13 is communicated with the second chamber 122 , so at this time P2 = P1 .

[0062] Buffering start stage: in the process of the gearbox shifting from high gear to low gear, the shorter the shifting time, the better; and the realization of the shifting function mainly depends on the rear sub-synchronizer. The working process of the rear sub-synchronizer can be divided into: disengagement, neutral, pre-synchronization, locking, synchronization completion, and combining these steps. In order to reduce the gear shifting shock and avoid the gear shifting time becoming too long due to the buffering effect, the present application sets the buffering intervention time at the time when the synchronization is just completed. The principle of realizing this function is: the working point of the rear sub-synchronizer is directly related to the axial movement position of the ring gear 2, and the ring gear 2 and the shift fork 32 are directly connected to the push rod 311. Therefore, by calculating the axial position of the ring gear 2 when the synchronization is completed, the contact position of the push rod 311 and the piston rod 511 can be determined.

[0063] Buffering stage: After the synchronization of the rear sub-synchronizer is completed, the push rod 311 will continue to push the shift fork 32 to the right. At this time, the piston rod 511 will push the piston head 512. The piston head 512 pushes the lubricating oil in the second chamber 122 into the reflux channel, pushes the second steel ball away, and then flows back to the cavity 11. At this time, the first steel ball blocks the oil inlet channel 13 to prevent the lubricating oil in the second chamber 122 from leaking from the oil inlet channel 13.

[0064] At this time, the buffer structure 5 meets the following conditions:

[0065] The diameter of the oil inlet channel 13 is d, and the value range of d is: 0.5mm≤d≤4mm;

[0066] P2'×S2>F2; and,

[0067] P2'×S1'+F1>P1*S1;

[0068] Among them, P2' is the oil pressure in the second chamber 122 during the buffering process, S2 is the surface area of ​​the lubricating oil in contact with the second steel ball, F2 is the elastic force of the second spring, S1' is the area of ​​the first steel ball in contact with the lubricating oil in the second chamber 122, F1 is the elastic force of the first elastic member, P1 is the oil pressure in the oil inlet channel 13, and S1 is the surface area of ​​the first steel ball in contact with the lubricating oil in the oil inlet channel 13.

[0069] The end stage of shifting from high gear to low gear: the above-mentioned buffering effect will continue to act until the end of the gear shift. At the end of the gear shift, the ring gear 2 will hit the baffle 4. Due to the existence of the buffering effect, the impact force will be much smaller, and therefore the gear shifting impact noise will also be much smaller. After the gear shift is completed, the piston rod 511 no longer pushes the piston head 512 to compress the lubricating oil, and the oil pressure in the second chamber 122 gradually decreases until it is less than the elastic force of the second elastic member. The first steel ball blocks the oil inlet channel 13. Since F2>F1, the oil pump will not continue to fill the second chamber 122 with oil, so as to avoid insufficient lubricating oil in other places due to the continuous consumption of lubricating oil there.

[0070] At this time, the buffer structure 5 satisfies the following conditions:

[0071] F2>F1;

[0072] Wherein, F1 is the elastic force of the first elastic member, and F2 is the elastic force of the second spring.

[0073] Low gear to high gear stage: In order to ensure that the buffering effect can be generated again when shifting to a low gear next time, the piston assembly 51 needs to return to the initial position, the push rod 311 will move quickly to the left until shifting to a high gear, and the piston head 512 will move to the left under the elastic force of the third elastic member 54 and the oil pressure of the lubricating oil until the piston head 512 contacts the left side wall of the piston chamber 12.

[0074] At this time, the buffer structure 5 satisfies the following conditions:

[0075] F4+P2*S3>F3; and,

[0076] P2=P1;and,

[0077] F2>F1;

[0078] Among them, F4 is the elastic force of the third elastic member 54, P2 is the oil pressure in the second chamber 122, P1 is the oil pressure in the oil inlet channel 13, S3 is the surface area of ​​the piston head 512, and F3 is the movement resistance of the piston head 512.

[0079] It should be noted that the shift assembly 3, the ring gear 2, the baffle plate 4 and other transmission mechanisms in the gearbox are all existing technologies and will not be described in detail here.

[0080] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A gearbox with a shift buffer structure, characterized in that: It includes: A housing having a cavity; A gear ring, disposed in the cavity, and used to be movably sleeved on the outer periphery of the transmission assembly along a first direction to have a high gear state and a low gear state; A shift assembly, comprising a driving part movably disposed in the cavity along the first direction, the driving part being connected to the ring gear and used for driving the ring gear to switch between the high gear state and the low gear state; a baffle plate, disposed on one side of the gear ring, so that when the gear ring is in the low gear state, the baffle plate is used to limit the position of the gear ring; a buffer structure having a telescopically arranged damping portion, wherein the damping portion and the driving portion are arranged at intervals along the first direction, so that in the low gear state, the driving portion abuts against the damping portion to block the movement of the shift assembly; The housing is provided with a piston cavity, the front end of which is connected to the cavity through a channel, and the piston cavity is filled with lubricating oil; The buffer structure includes a piston assembly, which is movably installed in the piston cavity along a first direction, and one end of the piston assembly extends from the channel into the cavity. The piston assembly divides the piston cavity into a first chamber and a second chamber connected to the channel, and the second chamber is filled with lubricating oil. The piston assembly constitutes the damping part.

2. The gearbox with a shift buffer structure according to claim 1, characterized in that: The piston assembly includes a piston rod and a piston head arranged at one end of the piston rod. The piston head is movably installed in the piston cavity. One end of the piston rod extends from the channel into the cavity and is coaxially arranged with the driving part.

3. The gearbox with a shift buffer structure according to claim 2, characterized in that: The piston rod is provided with an air passage communicating with the first chamber and the cavity.

4. The gearbox with a shift buffer structure according to claim 1, characterized in that: The housing is provided with an oil inlet passage and an oil return passage communicating with the cavity and the second chamber; The buffer structure also includes a first one-way valve and a second one-way valve. The first one-way valve is arranged in the oil inlet channel, and the first one-way valve is used to allow the lubricating oil in the cavity to flow to the piston cavity. The second one-way valve is arranged in the oil return channel, and the second one-way valve is used to allow the lubricating oil in the piston cavity to flow to the cavity.

5. The gearbox with a shift buffer structure according to claim 4, characterized in that: The first one-way valve comprises a first steel ball and a first elastic member, the first steel ball is movably installed in the oil inlet passage through the first elastic member, and the first steel ball is used to block or open the oil inlet passage; The second one-way valve includes a second steel ball and a second elastic member, wherein the second steel ball is movably installed in the oil inlet channel through the second elastic member, and the second steel ball is used to block or open the oil return channel, wherein the elastic force of the second elastic member is greater than the elastic force of the first elastic member.

6. The gearbox with a shift buffer structure according to claim 4, characterized in that: The diameter of the oil inlet passage is larger than the diameter of the oil return passage, and the diameter of the oil return passage is smaller than the diameter of the piston chamber.

7. The gearbox with a shift buffer structure according to claim 4, characterized in that: The gearbox with the shift buffer structure also includes an oil pump, which is connected to the oil inlet channel and is used to pump the lubricating oil in the cavity into the second cavity.

8. The gearbox with a shift buffer structure according to claim 2, characterized in that: The buffer structure also includes a third elastic member, which is arranged in the second chamber, one end of the third elastic member is connected to the bottom of the second chamber, and the other end of the third elastic member is connected to the piston head, and the third elastic member is used to drive the piston head to move toward the shift assembly.

9. A vehicle, characterized in that: The vehicle comprises a gearbox with a shift buffer structure as described in any one of claims 1-8.

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