CN117628149A - Multi-gear transmission and new energy vehicle - Google Patents

Abstract

The invention belongs to the technical field of transmission devices, and particularly relates to a multi-gear transmission and a new energy vehicle. The multi-speed transmission of the present invention includes: a multi-speed transmission, comprising: the main input shaft assembly is provided with a main input shaft, a first-gear input gear, a second-gear input gear, a third-gear input gear and a fourth-gear input gear; the output shaft assembly is provided with an output shaft, a first-gear output gear meshed with the first-gear input gear, a second-gear output gear meshed with the second-gear input gear, a third-gear output gear meshed with the third-gear input gear and a fourth-gear output gear meshed with the fourth-gear input gear, and the fourth-gear output gear can rotate relative to the output shaft; the auxiliary input shaft assembly is provided with an auxiliary input shaft and a four-gear input gear; a gear shifting mechanism arranged on the output shaft; the main driving motor and the auxiliary driving motor are used for driving the auxiliary input shaft to rotate. The invention can obviously improve the efficiency of the transmission driven by double motors.

Description

Multi-gear transmission and new energy vehicle

Technical Field

The invention relates to the technical field of transmission devices, in particular to a multi-gear transmission and a new energy vehicle.

Background

To protect the resource environment, commercial vehicles are increasingly being converted from conventional fuel drives to electric motor drives. Unlike the pure transmission of a passenger car, the commercial car needs larger torque and better economy, the single-gear pure transmission is not suitable for the development of the commercial car, and the multi-gear transmission of the commercial car is a main development direction. Wherein the use of a two motor solution provides a further cost advantage. A two-motor transmission and vehicle are disclosed in, for example, publication No. CN 215751864U. The transmission in the patent adopts two motors for driving, a plurality of groups of gear pairs and at least two clutches are arranged, the gear positions are switched through the cooperation of the clutches and the gear pairs, and the power of the two motors is combined and output. However, this patent requires two intermediate shafts to assist in the transmission of two electric power, and is therefore relatively complex in construction. And the idler gear of this patent is provided on the intermediate shaft, the efficiency of the transmission is therefore low.

Disclosure of Invention

In view of the above, the embodiment of the invention provides a multi-gear transmission and a new energy vehicle, which are used for solving the technical problems of complex transmission structure and low efficiency of the existing transmission driven by two motors.

The technical scheme adopted by the invention is as follows:

in a first aspect, the present invention provides a multi-speed transmission comprising:

the main input shaft assembly is provided with a main input shaft, a first-gear input gear, a second-gear input gear, a third-gear input gear and a fourth-gear input gear;

the output shaft assembly is provided with an output shaft, a first-gear output gear meshed with the first-gear input gear, a second-gear output gear meshed with the second-gear input gear, a third-gear output gear meshed with the third-gear input gear, a fourth-gear output gear meshed with the fourth-gear input gear, and the fourth-gear output gear can rotate relative to the output shaft;

the auxiliary input shaft assembly is provided with an auxiliary input shaft and a four-gear input gear meshed with the four-gear output gear;

a shift mechanism for shifting a gear of the transmission;

the main driving motor is used for driving the main input shaft to rotate;

the auxiliary driving motor is used for driving the auxiliary input shaft to rotate;

wherein the transmission ratio of the fourth gear is smaller than the transmission ratios of the other gears.

Preferably, the first gear input gear, the second gear input gear, the third gear input gear and the fourth gear input gear of the main input shaft assembly are fixedly connected with the main input shaft respectively.

Preferably, the fourth gear input gear is fixedly connected with the auxiliary input shaft;

preferably, the first gear output gear, the second gear output gear and the third gear output gear can rotate respectively relative to the output shaft.

Preferably, the first gear output gear, the second gear output gear, the third gear output gear and the fourth gear output gear are respectively connected with the output shaft in a rotating way through needle bearings.

Preferably, the gear shifting mechanism comprises at least one first synchronizer and at least one second synchronizer, wherein the first synchronizer is arranged on the output shaft and is used for enabling the output shaft of the transmission to synchronously rotate with the second-gear input gear or the fourth-gear input gear, and the second synchronizer is used for enabling the output shaft of the transmission to synchronously rotate with the first-gear output gear or the third-gear output gear.

Preferably, the output shaft is provided with a shaft hole, the shaft hole penetrates through one end of the output shaft, lubricating oil is contained in the shaft hole, a first oil guide channel and a third oil guide channel are formed on the first synchronizer and the output shaft, a second oil guide channel and a fourth oil guide channel are formed on the second synchronizer and the output shaft, each oil guide channel corresponds to each needle bearing on the output shaft one by one, and each oil guide channel is communicated with the corresponding needle bearing and the corresponding shaft hole;

The first synchronizer is provided with a blocking piece connected with the synchronizing ring, and when the first synchronizer is in a state of being combined with the first gear output gear, the blocking piece moves along with the step ring to block the first oil guide channel, so that the third oil guide channel is in an open position; when the first synchronizer is in a state of being combined with the three-gear output gear, the blocking piece moves to a position for blocking the third oil guide channel along with the step ring, so that the first oil guide channel is opened; when the first synchronizer is in a neutral state, the blocking piece moves to a position where the first oil guide channel and the third oil guide channel are opened along with the step ring;

the second synchronizer is provided with a blocking piece connected with the synchronizing ring, and when the second synchronizer is in a state of being combined with the second gear output gear, the blocking piece moves along with the step ring to block the second oil guide channel, so that the fourth oil guide channel is in an open position; when the second synchronizer is in a state of being combined with the four-gear output gear, the blocking piece moves to a position for blocking the fourth oil guide channel along with the step ring, so that the second oil guide channel is opened; when the second synchronizer is in a neutral state, the blocking piece moves along with the step ring to a position where the second oil guide channel and the fourth oil guide channel are both opened.

Preferably, the stroke of the first oil guide channel from the blocking state to the opening state is smaller than the stroke of the first gear output gear and the first synchronizer from the complete combination to the complete separation state by the synchronous ring; the stroke of the third oil guide channel from the blocking state to the opening state is smaller than the stroke of the three-gear output gear and the first synchronizer from the complete combination to the complete separation state by the synchronous ring; the stroke of the second oil guide channel from the blocking state to the opening state is smaller than the stroke of the second gear output gear and the second synchronizer from the complete combination to the complete separation state by the synchronous ring; the plugging piece enables the stroke of the first oil guide channel from the plugging state to the opening state to be smaller than the stroke of the synchronous ring enabling the four-gear output gear and the second synchronizer to be completely combined to the complete separation state.

Preferably, when the first synchronizer is in a state of being combined with the first-gear output gear and separated from the third-gear output gear, and the second synchronizer is in a state of being separated from the fourth-gear input gear and the second-gear input gear, the power of the main input shaft is transmitted to the output shaft through the first-gear output gear, the power of the second output shaft is transmitted to the main input shaft through the fourth-gear output gear, and then the power of the second output shaft is transmitted to the output shaft through the first-gear output gear;

When the first synchronizer is in a state of being separated from the first-gear output gear and the third-gear output gear, and the second synchronizer is in a state of being combined with the second-gear input gear and separated from the fourth-gear input gear, the power of the main input shaft is transmitted to the output shaft through the second-gear output gear, the power of the second output shaft is transmitted to the main input shaft through the fourth-gear output gear, and the power of the second output shaft is transmitted to the output shaft through the second-gear output gear;

when the first synchronizer is in a state of being combined with the third-gear output gear and separated from the first-gear output gear, and the second synchronizer is in a state of being separated from the fourth-gear input gear and the second-gear input gear, the power of the main input shaft is transmitted to the output shaft through the third-gear output gear, the power of the second output shaft is transmitted to the main input shaft through the fourth-gear output gear, and the power of the second output shaft is transmitted to the output shaft through the third-gear output gear;

when the first synchronizer is in a state of being separated from the first-gear output gear and the third-gear output gear, and the second synchronizer is in a state of being combined with the fourth-gear input gear and separated from the second-gear input gear, the power of the main input shaft is transmitted to the output shaft through the third-gear output gear, and the power of the second output shaft is transmitted to the output shaft through the fourth-gear output gear;

When the first synchronizer is in a state of being separated from the first-gear output gear and the third-gear output gear, and the second synchronizer is in a state of being separated from the second-gear output gear and the fourth-gear output gear, the multi-gear transmission is in a neutral state.

In a second aspect, the present invention provides a new energy vehicle comprising the multi-speed transmission of the first aspect.

The beneficial effects are that: according to the multi-gear transmission and the new energy vehicle, power output by the main driving motor and power output by the auxiliary driving motor are respectively transmitted to the main input shaft assembly and the auxiliary input shaft assembly, the power of the main driving motor is transmitted to the output shaft by utilizing gears which are meshed with each other on the main input shaft and each gear on the output shaft, and the gears of the multi-gear transmission are switched through the gear shifting mechanism arranged on the output shaft. The invention also uses the four-gear output gear which is arranged on the output shaft and can rotate relative to the output shaft as a bridge, so that the power of the auxiliary input shaft can be transmitted to the main input shaft when the transmission is in other gears except the four gears, the power of the main driving motor and the power of the auxiliary driving motor can be stably combined without an intermediate shaft, and then the combined power is transmitted to the output shaft by the main input shaft according to the transmission ratio of the current gear. When the transmission is in the fourth gear, the power of the main input shaft and the auxiliary input shaft is simultaneously transmitted to the output shaft in the transmission ratio of the fourth gear, so that the power of the main driving motor and the auxiliary driving motor is combined and then output in the transmission ratio of the fourth gear. Because the power of the auxiliary input shaft is combined through four-gear transmission, the load is reduced, and the service life is greatly prolonged. And because the four-gear idler gear serving as a power transmission bridge is arranged on the output shaft, the efficiency of the transmission can be further improved. In addition, the four-gear output gear with the lowest transmission ratio is used as a bridge for the power of the auxiliary driving motor, so that the power of the auxiliary driving motor can be transmitted to the output shaft, the stress of the gear is reduced, and the service life of the transmission is prolonged. According to the embodiment, the four-gear output gear is set to be the idler gear, so that the four-gear output gear which is most used when the vehicle runs is always in a stressed state, and the efficiency of the transmission can be further improved.

Drawings

In order to more clearly illustrate the technical solution of the embodiments of the present invention, the drawings required to be used in the embodiments of the present invention will be briefly described, and it is within the scope of the present invention to obtain other drawings according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a front view of a multi-speed transmission of the present invention;

FIG. 2 is a cross-sectional view A-A of FIG. 1;

FIG. 3 is a three-dimensional block diagram of a multi-speed transmission of the present invention;

FIG. 4 is a schematic diagram of an oil guide channel according to the present invention;

FIG. 5 is a schematic view of a partial structure of an oil guide passage when a first synchronizer of the present invention is combined with a first-gear output gear;

FIG. 6 is a schematic view of a partial structure of an oil guide passage when the first synchronizer of the present invention is combined with a three-speed output gear;

FIG. 7 is a schematic view of a partial structure of an oil guide channel of the first synchronizer of the present invention in a neutral state; .

Parts and numbers in the figure:

1. the main input shaft, 2, the main input shaft front bearing, 3, the four-gear input gear, 4 the two-gear input gear, 5 the input shaft rear bearing, 6, the output shaft, 7, the output shaft front bearing, 8, the first gear output gear, 9, the first bearing, 10, the first synchronizer, 11, the three-gear output gear, 12, the third bearing, 13, the four-gear output gear, 14, the fourth bearing, 15 the second synchronizer, 16, the two-gear output gear, 17, the second bearing, 18, the output shaft rear bearing, 19, the auxiliary input shaft, 20, the auxiliary input shaft front bearing, 21 the auxiliary input shaft rear bearing, 22, the first gear input gear, 23, the three-gear input gear, 24, the auxiliary four-gear input gear, 10, the main input shaft assembly, 20, the output shaft assembly, 30, the auxiliary input shaft assembly, 71, the first oil guide channel, 72, the second oil guide channel, 73, the third oil guide channel, 74, the fourth oil guide channel, 75, the shaft hole, 76, the synchronizing ring, 77, the blocking piece, 78 and the guide groove.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. It is noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. In the description of the present invention, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings, merely to facilitate description of the present application and simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising … …" does not exclude the presence of other like elements in a process, method, article or apparatus that comprises the element. If not conflicting, the embodiments of the present invention and the features of the embodiments may be combined with each other, which are all within the protection scope of the present invention.

Example 1

As shown in fig. 1, the present embodiment provides a multi-speed transmission including: a main input shaft assembly 10, an output shaft assembly 20, a secondary input shaft assembly 30, a gear shifting mechanism, a main drive motor and a secondary drive motor. The multi-gear transmission of the embodiment adopts at least two motors for driving, wherein the motors for driving comprise a main driving motor and an auxiliary driving motor, and the main driving motor is used for driving the main input shaft 1 to rotate; wherein the secondary drive motor is used to drive the secondary input shaft 19 in rotation. The multi-speed transmission in the embodiment can be selectively driven by the main driving motor alone or by both the main driving motor and the auxiliary driving motor according to the use situation of the vehicle.

In this embodiment, the power of the main driving motor is transmitted to the output shaft 6 through the main input shaft 1, and the main input shaft assembly 10 mainly includes the main input shaft 1, a first gear input gear 22, a second gear input gear 4, a third gear input gear 23, and a fourth gear input gear 3; two ends of the main input shaft 1 are respectively provided with a bearing which is fixed on the box body to support the input shaft assembly, and the two bearings are respectively a main input shaft front bearing 2 and a main input shaft rear bearing 5.

The main input shaft 1 can be rotated by a main drive motor. The main input shaft 1 can be in transmission connection with an output shaft 6 of the main drive motor through a coupling, a spline and the like, so that the power of the main drive motor can be transmitted to the main input shaft 1.

The output shaft assembly 20 in this embodiment is used to output power from the primary drive motor and/or the secondary drive motor to the drive shaft. Wherein the output shaft assembly 20 mainly comprises an output shaft 6, a first-gear output gear 8 meshed with the first-gear input gear 22, a second-gear output gear 16 meshed with the second-gear input gear 4, a third-gear output gear 11 meshed with the third-gear input gear 23, a fourth-gear output gear 13 meshed with the fourth-gear input gear 3, and the fourth-gear output gear 13 can rotate relative to the output shaft 6; wherein the output shaft 6 can be in driving connection with the transmission shaft through a coupling, a flange plate, a spline and the like, so that the power of the output shaft 6 can be transmitted to the transmission shaft. Two ends of the output shaft 6 are respectively provided with a bearing which is fixed on the box body and supports the output shaft assembly 20, and the two bearings are respectively an output shaft front bearing 7 and an output shaft rear bearing 18.

In this embodiment, the transmission provides for shifting four different gear steps, which are first gear, second gear, third gear and fourth gear respectively, the different gear steps corresponding to different gear ratios, wherein the gear ratio of the fourth gear step is smaller than the gear ratios of the other gear steps.

The present embodiment utilizes four gears on the main input shaft 1 and four gears on the output shaft 6 to achieve different gear ratios. The gears on the main input shaft 1 for realizing the four gears are respectively corresponding to a first gear input gear 22, a second gear input gear 4, a third gear input gear 23 and a fourth gear input gear 3. The gears on the output shaft 6 for realizing the four gears are respectively corresponding to a first gear output gear 8, a second gear output gear 16, a third gear output gear 11 and a fourth gear output gear 13. Wherein gears with the same gear position on the main input shaft 1 and the output shaft 6 are meshed with each other, namely, a first gear input gear 22 is meshed with a first gear output gear 8, a second gear input gear 4 is meshed with a second gear output gear 16, a third gear input gear 23 is meshed with a third gear output gear 11, and a fourth gear input gear 3 is meshed with a fourth gear output gear 13.

When the input gear of one gear on the main input shaft 1 rotates, the output gear of the corresponding gear can be driven to rotate.

In this embodiment, the fourth-gear output gear 13 is rotatable with respect to the output shaft 6; the four-gear output gear 13 in this embodiment is rotatably connected to the output shaft 6, for example, the four-gear output gear 13 may be sleeved on the output shaft 6, so that the four-gear output gear 13 may rotate relative to the output shaft 6.

Wherein the output shaft 6 can be in driving connection with the transmission shaft through a coupling, a flange plate, a spline and the like, so that the power of the output shaft 6 can be transmitted to the transmission shaft.

In the present embodiment, the power of the sub-drive motor is transmitted to the output shaft 6 through the sub-input shaft 19. The auxiliary input shaft 19 can be in transmission connection with the auxiliary drive electric output shaft 6 through a coupling, a spline and the like, so that the power of the auxiliary drive motor can be transmitted to the auxiliary input shaft 19. Two bearings are respectively arranged at two ends of the auxiliary input shaft 19 and are fixed on the box body to support the input shaft assembly, and the two bearings are respectively a front auxiliary input shaft bearing 20 and a rear auxiliary input shaft bearing 21.

Wherein the secondary input shaft assembly 30 mainly comprises a secondary input shaft 19 and a four-speed input gear meshed with the four-speed output gear 13, the four-speed input gear of the secondary input shaft assembly 30 is also referred to as a secondary four-speed input gear 24 for convenience of description; since the four-speed output gear 13 in the present embodiment is rotatable relative to the output shaft 6, the four-speed input gear of the auxiliary input shaft 19 can drive the four-speed output gear 13 engaged with it to idle relative to the output shaft 6 when the gear of the transmission is not in four-speed, and the four-speed output gear 13 is engaged with the four-speed input gear 3 of the main input shaft 1, so that the power of the auxiliary input shaft 19 can be combined with the power of the main input shaft 1 to realize that the main drive motor and the auxiliary drive motor jointly drive the output shaft 6 in other three gears than four-speed.

When the gear of the transmission is in the fourth gear, the four-gear input gear of the auxiliary input shaft 19 and the four-gear input gear 3 of the main input shaft 1 simultaneously drive the four-gear output gear 13 on the output shaft 6 to rotate, so that the power of the auxiliary input shaft 19 and the power of the main input shaft 1 are combined on the output shaft 6 through the four-gear output gear 13, and the main drive motor and the auxiliary drive motor jointly drive the output shaft 6 in the fourth gear. In this embodiment, the first gear input gear 22 of the main input shaft assembly 10 is fixedly connected with the main input shaft 1, the second gear input gear 4 is fixedly connected with the main input shaft 1, the third gear input gear 23 is fixedly connected with the main input shaft 1, and the fourth gear input gears 3 are respectively fixedly connected with the main input shaft 1.

In this embodiment, the first gear input gear 22, the second gear input gear 4, the third gear input gear 23 and the fourth gear input gear 3 in the main input shaft assembly 10 are all fixed gears, that is, the four gears can be fixedly connected with the main input shaft 1, so that the first gear input gear 22, the second gear input gear 4, the third gear input gear 23 and the fourth gear input gear 3 can synchronously rotate along with the main input shaft 1. The first-gear input gear 22 and the main input shaft assembly 10 are fixedly connected with the main input shaft 1 in an interference fit mode, the second-gear input gear 4 and the main input shaft assembly 10 are fixedly connected with the main input shaft 1 in an interference fit mode, the third-gear input gear 23 and the main input shaft assembly 10 are fixedly connected with the main input shaft 1 in an interference fit mode, the fourth-gear input gear 3 and the main input shaft assembly 10 are fixedly connected with the main input shaft 1 in an interference fit mode, and therefore when the first-gear input gear 22, the second-gear input gear 4, the third-gear input gear 23 and the fourth-gear input gear 3 in the main input shaft assembly 10 are assembled, the four gears can be arranged on the input shaft through interference hot pressing.

In this embodiment, the fourth gear input gear 3 of the auxiliary input shaft assembly 30 is fixedly connected to the auxiliary input shaft 19, so that the fourth gear input gear 3 of the auxiliary input shaft assembly 30 can rotate synchronously with the auxiliary input shaft 19.

In this embodiment, the first gear output gear 8, the second gear output gear 16, and the third gear output gear 11 are rotatable with respect to the output shaft 6, respectively. In this embodiment, the first gear output gear 8, the second gear output gear 16 and the third gear output gear 11 are rotatably connected to the output shaft 6, for example, the first gear output gear 8 may be sleeved on the output shaft 6 in an empty manner, so that the first gear output gear 8 may rotate relative to the output shaft 6, the second gear output gear 16 may be sleeved on the output shaft 6 in an empty manner, so that the second gear output gear 16 may rotate relative to the output shaft 6, and the third gear output gear 11 may be sleeved on the output shaft 6 in an empty manner, so that the third gear output gear 11 may rotate relative to the output shaft 6.

In this embodiment, to enable the first gear output gear 8 in the output shaft assembly 20 to rotate better relative to the output, the output shaft assembly 20 further includes a first bearing 9, a second bearing 17, a third bearing 12, and a fourth bearing 14. The first bearing 9 is arranged on the output shaft 6, and the first gear output gear 8 is rotationally connected with the output shaft 6 through the first bearing 9; the second bearing 17 is arranged on the output shaft 6, and the second gear output gear 16 is rotationally connected with the output shaft 6 through the second bearing 17; the third bearing 12 is arranged on the output shaft 6, and the three-gear output gear 11 is rotationally connected with the output shaft 6 through the third bearing 12; the fourth bearing 14 is disposed on the output shaft 6, and the third gear output gear 11 is rotatably connected to the output shaft 6 through a first bearing. Wherein the first bearing 9, the second bearing 17, the third bearing 12 and the fourth bearing 14 are preferably needle bearings. In other embodiments, the first bearing 9, the second bearing 17, the third bearing 12 and the fourth bearing 14 may be other types of bearings, which are not limited herein.

Wherein a gear shifting mechanism is arranged on the output shaft 6, and the gear shifting mechanism is used for switching gears of the output shaft 6. In the present embodiment, the gear shift mechanism includes at least one first synchronizer 10 and at least one second synchronizer 15 provided on the output shaft 6, the second synchronizer 15 being for synchronizing rotation of the output shaft 6 of the transmission with the second-gear in-out gear or the fourth-gear output gear 13, and the first synchronizer 10 being for synchronizing rotation of the output shaft 6 of the transmission with the first-gear output gear 8 or the third-gear output gear 11.

In this embodiment, the second synchronizer 15 gear and the output shaft 6 may be connected in a synchronous transmission manner, that is, the second synchronizer 15 gear and the output shaft 6 may be connected in a connection manner that enables the second synchronizer 15 gear and the output shaft 6 to rotate synchronously, for example, the second synchronizer 15 gear may be connected in a synchronous transmission manner with the output shaft 6 through a spline. During implementation, a spline can be arranged on the outer diameter of the output shaft 6, a key groove matched with the spline is arranged on the inner wall of the second synchronizer 15 gear, the spline on the output shaft 6 is inserted into the key groove of the second synchronizer 15 gear along the axial direction, the second synchronizer 15 gear is connected with the output shaft 6, and the second synchronizer 15 gear can synchronously rotate with the output shaft 6 by means of the matching of the spline and the key groove. Because the second synchronizer 15 keeps off and rotates with the output shaft 6 synchronously, therefore after the second synchronizer 15 keeps off and combines with the second gear output gear 16, the output shaft 6 keeps off and rotates with the second gear output gear 16 synchronously through the second synchronizer 15 under the drive of the second gear output gear 16, in order to realize the power output of the second gear transmission ratio. After the second synchronizer 15 is combined with the fourth-gear output gear 13, the output shaft 6 is driven by the fourth-gear output gear 13 through the second synchronizer 15 to synchronously rotate with the fourth-gear output gear 13 so as to realize power output of a fourth-gear transmission ratio.

Similarly, in this embodiment, the first synchronizer 10 may be in a synchronous transmission connection with the output shaft 6, that is, the first synchronizer 10 and the output shaft 6 are connected in a connection manner that enables the first synchronizer 10 to rotate synchronously with the output shaft 6, for example, the first synchronizer 10 may be in a synchronous transmission connection with the output shaft 6 through a spline. In specific implementation, a spline can be arranged on the outer diameter of the output shaft 6, a key groove matched with the spline is arranged on the inner wall of the first synchronizer 10 gear, the spline on the output shaft 6 is inserted into the key groove of the first synchronizer 10 gear along the axial direction, so that the first synchronizer 10 gear is connected with the output shaft 6, and the first synchronizer 10 gear can synchronously rotate with the output shaft 6 by means of the matching of the spline and the key groove. Because the first synchronizer 10 gear and the output shaft 6 rotate synchronously, after the first synchronizer 10 gear is combined with the first gear output gear 8, the output shaft 6 and the first gear output gear 8 synchronously rotate under the drive of the second gear output gear 16 through the first synchronizer 10 gear, so that the power output of the first gear transmission ratio is realized. After the first synchronizer 10 is combined with the third-gear output gear 11, the output shaft 6 is driven by the third-gear output gear 11 through the first synchronizer 10 to synchronously rotate with the third-gear output gear 11 so as to realize power output of a third-gear transmission ratio.

As a preferred embodiment, in the present embodiment, the first-gear output gear 8, the third-gear output gear 11, the fourth-gear output gear 13, and the second-gear output gear 16 are disposed in this order along the axial direction of the output shaft 6. The first gear input gear 22, the third gear input gear 23, the fourth gear input gear 3 and the second gear input gear 4 of the corresponding main input shaft assembly 10 are sequentially arranged along the axial direction of the input shaft.

In this embodiment, the arrangement sequence of the four gears is omitted and is arranged according to the sequence of step-by-step upshift of the first gear, the second gear, the third gear and the fourth gear, but a mode of cross arrangement of the connected gears is adopted, wherein the first gear and the second gear are separated by the third gear, the third gear and the fourth gear are separated by the second gear, and the third gear and the fourth gear are arranged in the middle of the shafting. The present embodiment utilizes a shift mechanism to shift gears of the transmission. Because the first gear and the second gear are separated, the first gear and the second gear can be respectively engaged without interference and influence, so that the comfort of the engaged gears is improved. And in the same way, the two gears and the three gears can be respectively engaged without interference and influence, so that the comfort of engaged gears is improved. The adoption of the mode also enables the multi-gear transmission to have greater safety redundancy. When the first synchronizer or the first gear and the third gear shift actuating mechanism are damaged, the second gear can independently finish starting, and the limp home function of the commercial vehicle is ensured.

After the mode is adopted, the first synchronizer 10 and the second synchronizer 15 can be located on the same output shaft 6, so that the occupied space of a shafting is reduced, the two synchronizers can be driven by a shifting fork conveniently, and the two synchronizers can not interfere with each other during gear shifting. The first gear and the second gear are staggered, the first synchronizer 10 is used when the first gear is engaged, and the second synchronizer 15 is used when the second gear is engaged, so that the first gear and the second gear can be engaged respectively and are not interfered with each other. The second gear and the third gear are staggered, the second synchronizer 15 is used when the second gear is engaged, and the first synchronizer 10 is used when the third gear is engaged, so that the second gear and the third gear can be engaged respectively and are not interfered with each other. Since the first synchronizer 10 is used when the third gear is engaged and the second synchronizer 15 is used when the fourth gear is engaged, the third gear and the fourth gear can be engaged separately and without interference. According to the embodiment, the arrangement mode of the gears and the synchronizers is adopted, so that different synchronizers are adopted for two adjacent gears when the gears are shifted step by step, and the shifting process of each gear is not affected.

In the present embodiment, the second synchronizer 15 is located between the second gear output gear 16 and the fourth gear output gear 13 and/or the first synchronizer 10 is located between the first gear output gear 8 and the third gear output gear 11. According to the embodiment, the synchronizer is arranged between the output gears corresponding to the shifted gears, so that the synchronizer can realize the shifting between the gears controlled by the synchronizer only by moving a short distance along the axial direction, and the gear shifting process is faster and more convenient.

The speed reducer of the embodiment can realize five gear states, namely a first gear, a second gear, a third gear, a fourth gear and a neutral gear.

When the first synchronizer 10 is in a state of being combined with the first-gear output gear 8 and separated from the third-gear output gear 11, and the second synchronizer 15 is in a state of being separated from the fourth-gear output gear 13 and the second-gear output gear 16, the power of the main driving motor is transmitted to the main input shaft 1, the main input shaft 1 drives the first-gear input gear 22 to synchronously rotate, the first-gear input gear 22 drives the first-gear output gear 8 meshed with the first-gear input gear 22 to synchronously rotate, and the first-gear output gear 8 drives the output shaft 6 to rotate through the first synchronizer 10, so that the power of the main input shaft 1 is transmitted to the output shaft 6 through the first-gear output gear 8. The power of the auxiliary driving motor is transmitted to the auxiliary input shaft 19 so that the auxiliary input shaft 19 drives the four-gear input gear of the auxiliary input shaft 19 to rotate, the four-gear input gear of the auxiliary input shaft 19 drives the four-gear output gear 13 meshed with the four-gear input gear to rotate relative to the output shaft 6, the four-gear output gear 13 drives the main input shaft 1 to rotate through the four-gear input gear 3 of the main input shaft 1 meshed with the four-gear output gear 13, and thus the power of the auxiliary input shaft 19 is transmitted to the main input shaft 1 through the four-gear output gear 13 and then transmitted to the output shaft 6 through the first-gear output gear 8. At this time, the power of the main driving motor and the auxiliary driving motor are combined and transmitted to the output shaft 6 together, and then transmitted to the wheels by the output shaft 6, and the transmission is in a first gear engaging state.

When the first synchronizer 10 is in a state of being separated from the first-gear output gear 8 and the third-gear output gear 11, and the second synchronizer 15 is in a state of being combined with the second-gear output gear 16 and separated from the fourth-gear output gear 13, the power of the main driving motor is transmitted to the main input shaft 1, the main input shaft 1 drives the second-gear input gear 4 to synchronously rotate, the second-gear input gear 4 drives the second-gear output gear 16 meshed with the second-gear input gear 4 to synchronously rotate, and the second-gear output gear 16 drives the output shaft 6 to rotate through the second synchronizer 15, so that the power of the main input shaft 1 is transmitted to the output shaft 6 through the second-gear output gear 16. The power of the auxiliary driving motor is transmitted to the auxiliary input shaft 19 so that the auxiliary input shaft 19 drives the four-gear input gear of the auxiliary input shaft 19 to rotate, the four-gear input gear of the auxiliary input shaft 19 drives the four-gear output gear 13 meshed with the four-gear input gear to rotate relative to the output shaft 6, the four-gear output gear 13 drives the main input shaft 1 to rotate through the four-gear input gear 3 of the main input shaft 1 meshed with the four-gear output gear 13, the power of the auxiliary input shaft 19 is transmitted to the main input shaft 1 through the four-gear output gear 13, and then the power of the main driving motor and the power of the auxiliary driving motor are combined and transmitted to the output shaft 6 together at the moment through the two-gear output gear 16, and then the transmission is in a two-gear shift state.

When the first synchronizer 10 is in a state of being combined with the third-gear output gear 11 and separated from the first-gear output gear 8, and the second synchronizer 15 is in a state of being separated from the fourth-gear output gear 13 and the second-gear output gear 16, the power of the main driving motor is transmitted to the main input shaft 1, the main input shaft 1 drives the third-gear input gear 23 to synchronously rotate, the third-gear input gear 23 drives the third-gear output gear meshed with the third-gear input gear 23 to synchronously rotate, and the third-gear output gear 11 drives the output shaft 6 to rotate through the first synchronizer 10, so that the power of the main input shaft 1 is transmitted to the output shaft 6 through the third-gear output gear. The power of the auxiliary driving motor is transmitted to the auxiliary input shaft 19 so that the auxiliary input shaft 19 drives the four-gear input gear of the auxiliary input shaft 19 to rotate, the four-gear input gear of the auxiliary input shaft 19 drives the four-gear output gear 13 meshed with the four-gear input gear to rotate relative to the output shaft 6, the four-gear output gear 13 drives the main input shaft 1 to rotate through the four-gear input gear 3 of the main input shaft 1 meshed with the four-gear output gear 13, the power of the auxiliary input shaft 19 is transmitted to the main input shaft 1 through the four-gear output gear 13, the power of the main driving motor and the power of the auxiliary driving motor are combined at the moment and transmitted to the output shaft 6 together, the power is transmitted to wheels through the output shaft 6, and the transmission is in a three-gear shift state.

When the first synchronizer 10 is in a state of being separated from the first-gear output gear 8 and the third-gear output gear 11, and the second synchronizer 15 is in a state of being combined with the fourth-gear output gear 13 and separated from the second-gear output gear, the power of the main driving motor is transmitted to the main input shaft 1, the main input shaft 1 drives the third-gear input gear 23 to synchronously rotate, the third-gear input gear 23 drives the third-gear output gear meshed with the third-gear input gear 23 to synchronously rotate, and the third-gear output gear 11 drives the output shaft 6 to rotate through the first synchronizer 10, so that the power of the main input shaft 1 is transmitted to the output shaft 6 through the third-gear output gear. The power of the auxiliary driving motor is transmitted to the auxiliary input shaft 19 so that the auxiliary input shaft 19 drives the four-gear input gear of the auxiliary input shaft 19 to rotate, the four-gear input gear of the auxiliary input shaft 19 drives the four-gear output gear 13 meshed with the four-gear input gear to synchronously rotate with the output shaft 6, the power of the auxiliary input shaft 19 is transmitted to the output shaft 6 through the four-gear output gear 13, at the moment, the power of the main driving motor and the power of the auxiliary driving motor are combined and transmitted to the output shaft 6 together, and then the power is transmitted to wheels through the output shaft 6, and the transmission is in a four-gear engaged state.

When the first synchronizer 10 is in a state of being separated from the first-speed output gear 8 and the third-speed output gear 11, and the second synchronizer 15 is in a state of being separated from the second-speed output gear 16 and the fourth-speed output gear 13, the multi-speed transmission is in a neutral state. At this time, the power of the electric main driving motor and the auxiliary driving motor cannot be transmitted to the wheels.

In this embodiment, the output gears of the four gears are rotatably connected to the output shaft through needle bearings provided on the output shaft, respectively. Needle bearings need to be well lubricated at high rotational speeds or otherwise fail easily. In the case of a transmission operating in different gears, the rotation of the needle bearings is different, some of the needle bearings rotating at high speed and some of the needle bearings not rotating. While needle bearings in those high-speed rotations require more lubrication oil.

In this regard, as shown in fig. 4, in the present embodiment, the output shaft 6 is provided with a shaft hole 75, the shaft hole 75 penetrates through one end of the output shaft 6, the shaft hole 75 contains lubricating oil, the first synchronizer 10 and the output shaft 6 are formed with a second oil guide channel 71 and a third oil guide channel 73, the second synchronizer 15 and the output shaft 6 are formed with a second oil guide channel 72 and a fourth oil guide channel 74, each oil guide channel corresponds to each needle bearing on the output shaft 6 one by one, and the oil guide channels communicate with the corresponding needle bearing and the shaft hole 75;

lubricating oil can be introduced into the shaft holes 75 from the end of the output shaft 6, and the lubricating oil in the shaft holes 75 enters the corresponding shaft holes 75 through the oil guide passage.

As shown in fig. 5, the first synchronizer 10 is provided with a blocking piece 77 connected with the synchronizing ring 76, when the first synchronizer 10 is in a state of being combined with the first gear output gear 8, the blocking piece 77 moves along with the synchronizing ring 76 to block the second oil guide channel 71, so that the third oil guide channel 73 is in an open position; at this time, the transmission works in the first gear state, the first gear output gear 8 and the output shaft 6 rotate synchronously, the needle bearings corresponding to the first gear output gear 8 do not rotate, and other needle bearings rotate, and because the second oil guide channel 71 is blocked, the lubricating oil in the shaft hole 75 does not flow to the needle bearings corresponding to the first gear output gear 8, and only flows to the needle bearings corresponding to other output gears through other channels.

As shown in fig. 6, when the first synchronizer 10 is in the engaged state with the third-gear output gear 11, the blocking member 77 moves with the synchronizing ring 76 to a position to block the third oil guide passage 73, leaving the second oil guide passage 71 open; at this time, the transmission works in the third gear state, the second gear output gear 16 and the output shaft 6 rotate synchronously, the needle bearings corresponding to the third gear output gear 11 do not rotate, and other needle bearings rotate, and because the third oil guide channel 73 is blocked, the lubricating oil in the shaft hole 75 does not flow to the needle bearings corresponding to the third gear output gear 11, and only flows to the needle bearings corresponding to other output gears through other channels.

As shown in fig. 7, when the first synchronizer 10 is in the neutral state, the blocking member 77 moves with the synchronizing ring 76 to a position where both the second oil guide passage 71 and the third oil guide passage 73 are opened; at this time, the lubricating oil in the shaft hole 75 may flow to the needle bearings corresponding to the first output gear and the third output gear.

The transmission is engaged by shifting the synchronizer ring 76 on the synchronizer, and the blocking member 77 is connected with the synchronizer ring 76 in an embodiment, so that the blocking member 77 can move along with the step member when the synchronizer ring 76 is shifted to engage. In order to enable the blocking member 77 to move, the present embodiment may further provide a guide groove 78 on the first synchronizer 10, so that the blocking member 77 moves in the moving groove of the first synchronizer 10.

Similarly, a blocking piece 77 connected with the synchronizing ring 76 is arranged on the second synchronizer 15, and when the second synchronizer 15 is in a state of being combined with the second gear output gear 16, the blocking piece 77 moves along with the synchronizing ring 76 to block the second oil guide channel 72, so that the fourth channel is in an open position; at this time, the transmission works in the second gear state, the second gear output gear 16 and the output shaft 6 rotate synchronously, the needle bearings corresponding to the second gear output gear 16 do not rotate, and other needle bearings rotate, and because the second oil guide channel 72 is blocked, the lubricating oil in the shaft hole 75 does not flow to the needle bearings corresponding to the second gear output gear 16, and only flows to the needle bearings corresponding to other output gears through other channels.

When the second synchronizer 15 is in a state of being combined with the fourth-gear output gear 13, the blocking piece 77 moves along with the synchronizing ring 76 to a position for blocking the fourth channel, so that the second oil guide channel 72 is opened; at this time, the transmission works in a four-gear state, the first-gear output gear 8 and the output shaft 6 synchronously rotate, the needle bearings corresponding to the four-gear output gear 13 do not rotate, and other needle bearings rotate, and as the fourth channel is blocked, lubricating oil in the shaft hole 75 cannot flow to the needle bearings corresponding to the four-gear output gear 13, and only can flow to the needle bearings corresponding to other output gears through other channels.

When the second synchronizer 15 is in the neutral state, the blocking member 77 moves with the synchronizing ring 76 to a position where both the second oil guide passage 72 and the fourth passage are opened. At this time, the lubricating oil in the shaft hole 75 may flow to the needle bearings corresponding to the first output gear and the third output gear.

In order to allow the blocking element 77 to move, the present embodiment may also provide guides on the second synchronizer 15, such that the blocking element 77 moves within the guides of the second synchronizer 15.

According to the embodiment, the structure can be utilized to control the flow direction of the lubricating oil in the shaft hole 75 when the gear is engaged, so that the lubricating oil in the shaft hole 75 only flows to the rotating needle bearings and does not flow to the needle bearings which do not rotate, reasonable distribution of the lubricating oil of each needle bearing in the actual installation working condition is realized, the needle bearings can be lubricated more fully when rotating, and the service life of each needle bearing is prolonged. In addition, the embodiment skillfully utilizes the gear engaging action of the synchronizer to drive the plugging piece to move to control the oil way of the lubricating oil, so that the oil way of the lubricating oil can be controlled according to the gear engaging condition without adding other driving mechanisms.

In the present embodiment, the stroke of the blocking member 77 from the blocking state to the open state of the first oil guide passage 71 is smaller than the stroke of the synchronizing ring 76 from the fully engaged state to the fully disengaged state of the first gear output gear and the first synchronizer; the stroke of the third oil guide channel 73 from the blocking state to the opening state is smaller than the stroke of the synchronizing ring 76 from the full combination of the three-gear output gear and the first synchronizer to the full separation state by the blocking member 77; the stroke of the blocking piece 77 from the blocking state to the open state of the second oil guide channel 72 is smaller than the stroke of the synchronous ring 76 from the complete combination of the second gear output gear and the second synchronizer to the complete separation state; the blocking member 77 makes the stroke of the first oil guide passage from the blocking state to the open state smaller than the stroke of the synchronizing ring 76 to fully couple the four-speed output gear and the second synchronizer to the fully decoupled state.

Because the stroke of the blocking member 77 from the blocking state to the open state of the first oil guide channel 71 is smaller than the stroke of the synchronizing ring 76 from the completely combined state to the completely separated state of the first gear output gear and the first synchronizer, the first oil guide channel 71 can be opened before the synchronizing ring 76 moves to completely separate the first gear output gear and the first synchronizer, so that lubricating oil is introduced into the first oil guide channel 71 in advance, and the problem that lubricating oil cannot be introduced into the bearing position corresponding to the first gear output gear immediately when the first gear output gear and the first synchronizer are completely separated is effectively avoided.

Similarly, because the stroke of the blocking member 77 from the blocking state to the open state of the third oil guiding channel 73 is smaller than the stroke of the synchronizing ring 76 from the completely combined state to the completely separated state of the third gear output gear and the first synchronizer, the third oil guiding channel 73 can be opened before the synchronizing ring 76 moves to completely separate the first gear output gear and the first synchronizer, so that lubricating oil is introduced into the third oil guiding channel 73 in advance, and the problem that lubricating oil cannot be introduced into the bearing position corresponding to the first gear output gear immediately when the third gear output gear and the first synchronizer are completely separated is effectively avoided.

Similarly, because the stroke of the blocking member 77 from the blocking state to the open state of the second oil guiding channel 72 is smaller than the stroke of the synchronizing ring 76 from the completely combined state to the completely separated state of the second gear output gear and the second synchronizer, the second oil guiding channel 72 can be opened before the synchronizing ring 76 moves to completely separate the second gear output gear and the second synchronizer, so that lubricating oil is introduced into the second oil guiding channel 72 in advance, and the problem that lubricating oil cannot be introduced into the bearing position corresponding to the first gear output gear immediately when the second gear output gear and the second synchronizer are completely separated is effectively avoided.

Similarly, because the stroke of the blocking member 77 from the blocking state to the open state of the fourth oil guide channel 74 is smaller than the stroke of the synchronizing ring 76 from the completely engaged state to the completely disengaged state of the fourth gear output gear and the second synchronizer, the fourth oil guide channel 74 can be opened before the synchronizing ring 76 moves to completely disengage the fourth gear output gear and the second synchronizer, so that lubricating oil is introduced into the fourth oil guide channel 74 in advance, and the problem that lubricating oil cannot be introduced into the bearing position corresponding to the fourth gear output gear immediately when the fourth gear output gear and the second synchronizer are completely disengaged is effectively avoided.

Example 3

The present embodiment provides a new energy vehicle including the multi-speed transmission described in embodiment 1.

In the foregoing, only the specific embodiments of the present invention are described, and it will be clearly understood by those skilled in the art that, for convenience and brevity of description, the specific working processes of the systems, modules and units described above may refer to the corresponding processes in the foregoing method embodiments, which are not repeated herein. It should be understood that the scope of the present invention is not limited thereto, and any equivalent modifications or substitutions can be easily made by those skilled in the art within the technical scope of the present invention, and they should be included in the scope of the present invention.

Claims (10)

1. A multi-speed transmission, comprising:

the main input shaft assembly is provided with a main input shaft, a first-gear input gear, a second-gear input gear, a third-gear input gear and a fourth-gear input gear;

the output shaft assembly is provided with an output shaft, a first-gear output gear meshed with the first-gear input gear, a second-gear output gear meshed with the second-gear input gear, a third-gear output gear meshed with the third-gear input gear, a fourth-gear output gear meshed with the fourth-gear input gear, and the fourth-gear output gear can rotate relative to the output shaft;

the auxiliary input shaft assembly is provided with an auxiliary input shaft and a four-gear input gear meshed with the four-gear output gear;

the gear shifting mechanism is arranged on the output shaft and used for switching gears of the output shaft;

the main driving motor is used for driving the main input shaft to rotate;

the auxiliary driving motor is used for driving the auxiliary input shaft to rotate;

wherein the transmission ratio of the fourth gear is smaller than the transmission ratios of the other gears.

2. The multi-speed transmission of claim 1, wherein the four-speed input gear of the secondary input shaft assembly is fixedly connected to the secondary input shaft.

3. The multi-speed transmission of claim 1, wherein the first, second, third and fourth speed input gears of the main input shaft assembly are fixedly connected to the output shaft, respectively.

4. A multi-speed transmission as recited in claim 3 wherein said first, second and third speed output gears are rotatable relative to said output shaft, respectively.

5. The multi-speed transmission according to claim 4, wherein the first-speed output gear, the second-speed output gear, the third-speed output gear, and the fourth-speed output gear are respectively rotatably connected with the output shaft through needle bearings.

6. The multi-speed transmission according to claim 5, wherein the shift mechanism includes at least one first synchronizer for synchronizing rotation of the output shaft of the transmission with the first-speed output gear or the third-speed output gear and at least one second synchronizer for synchronizing rotation of the output shaft of the transmission with the second-speed output gear or the fourth-speed output gear provided on the output shaft.

7. The multi-speed transmission according to claim 6, wherein the output shaft is provided with a shaft hole penetrating one end of the output shaft, lubricating oil is contained in the shaft hole, a first oil guide channel and a third oil guide channel are formed on the first synchronizer and the output shaft, a second oil guide channel and a fourth oil guide channel are formed on the second synchronizer and the output shaft, each oil guide channel corresponds to each needle bearing on the output shaft one by one, and the oil guide channels are communicated with the corresponding needle bearings and the shaft hole;

The first synchronizer is provided with a blocking piece connected with the synchronizing ring, and when the first synchronizer is in a state of being combined with the first gear output gear, the blocking piece moves along with the step ring to block the first oil guide channel, so that the third oil guide channel is in an open position; when the first synchronizer is in a state of being combined with the three-gear output gear, the blocking piece moves to a position for blocking the third oil guide channel along with the step ring, so that the first oil guide channel is opened; when the first synchronizer is in a neutral state, the blocking piece moves to a position where the first oil guide channel and the third oil guide channel are opened along with the step ring;

the second synchronizer is provided with a blocking piece connected with the synchronizing ring, and when the second synchronizer is in a state of being combined with the second gear output gear, the blocking piece moves along with the step ring to block the second oil guide channel, so that the fourth oil guide channel is in an open position; when the second synchronizer is in a state of being combined with the four-gear output gear, the blocking piece moves to a position for blocking the fourth oil guide channel along with the step ring, so that the second oil guide channel is opened; when the second synchronizer is in a neutral state, the blocking piece moves along with the step ring to a position where the second oil guide channel and the fourth oil guide channel are both opened.

8. The multi-speed transmission of claim 7, wherein the blocking member has a stroke of the first oil gallery from the blocked state to the open state that is less than a stroke of the synchronizer ring to fully engage the first speed output gear and the first synchronizer from the fully engaged to the fully disengaged state; the stroke of the third oil guide channel from the blocking state to the opening state is smaller than the stroke of the three-gear output gear and the first synchronizer from the complete combination to the complete separation state by the synchronous ring; the stroke of the second oil guide channel from the blocking state to the opening state is smaller than the stroke of the second gear output gear and the second synchronizer from the complete combination to the complete separation state by the synchronous ring; the plugging piece enables the stroke of the first oil guide channel from the plugging state to the opening state to be smaller than the stroke of the synchronous ring enabling the four-gear output gear and the second synchronizer to be completely combined to the complete separation state.

9. The multi-speed transmission according to claim 6, wherein:

when the second synchronizer is in a state of being combined with the first-gear output gear and separated from the third-gear output gear, and the first synchronizer is in a state of being separated from the fourth-gear output gear and the second-gear output gear, the power of the main input shaft is transmitted to the output shaft through the first-gear output gear, and the power of the auxiliary input shaft is transmitted to the main input shaft through the fourth-gear output gear and then transmitted to the output shaft through the first-gear output gear;

When the second synchronizer is in a state of being separated from the first-gear output gear and the third-gear output gear, and the first synchronizer is in a state of being combined with the second-gear output gear and separated from the fourth-gear output gear, the power of the main input shaft is transmitted to the output shaft through the second-gear output gear, and the power of the auxiliary input shaft is transmitted to the main input shaft through the fourth-gear output gear and then transmitted to the output shaft through the second-gear output gear;

when the second synchronizer is in a state of being combined with the third-gear output gear and separated from the first-gear output gear, and the first synchronizer is in a state of being separated from the fourth-gear output gear and the second-gear output gear, the power of the main input shaft is transmitted to the output shaft through the third-gear output gear, and the power of the auxiliary input shaft is transmitted to the main input shaft through the fourth-gear output gear and then transmitted to the output shaft through the third-gear output gear;

when the second synchronizer is in a state of being separated from the first-gear output gear and the third-gear output gear, and the first synchronizer is in a state of being combined with the fourth-gear output gear and separated from the second-gear output gear, the power of the main input shaft is transmitted to the output shaft through the third-gear output gear, and the power of the auxiliary input shaft is transmitted to the output shaft through the fourth-gear output gear;

When the second synchronizer is in a state of being separated from the first-gear output gear and the third-gear output gear, and the first synchronizer is in a state of being separated from the second-gear output gear and the fourth-gear output gear, the multi-gear transmission is in a neutral state.

10. New energy vehicle, characterized in that it comprises a multi-speed transmission according to any one of claims 1 to 9.