CN115264009A - A two-speed automatic transmission - Google Patents

Abstract

The invention discloses a two-gear automatic transmission which comprises an input shaft, an output shaft, a first-gear driving gear, a second-gear driving gear, a first-gear driven gear and a second-gear driven gear, a clutch, a connector and a one-way clutch, wherein the first-gear driving gear and the second-gear driving gear are arranged on the input shaft, the first-gear driven gear and the second-gear driven gear are arranged on the output shaft, the clutch is connected with the input shaft and the second-gear driving gear, the connector is used for controlling the connection and the disconnection between the output shaft and the first-gear driven gear, the one-way clutch is connected with the first-gear driven gear and is used for transmitting power between the first-gear driven gear and the output shaft, and the installation state of the one-way clutch is set to be a free state when the rotating speed of the output shaft is higher than that of the first-gear driven gear when a vehicle runs forwards. The two-gear automatic transmission can avoid drag torque loss of a clutch when the transmission works at the second gear on the premise of ensuring the function of no power interruption during gear shifting, thereby improving the efficiency.

Description

A two-speed automatic transmission

technical field

The invention belongs to the technical field of automobile transmissions, in particular, the invention relates to a two-speed automatic transmission.

Background technique

When the performance of the driving motor is certain, the type and performance of the pure electric vehicle's transmission directly determine the power performance and energy consumption level of the pure electric vehicle. At present, the transmission of pure electric vehicles mostly uses a single-speed reducer, which has a simple structure, small size, light weight, and low cost. There is no need to shift gears during operation, and there is no power interruption.

However, when a single-speed reducer is used, the requirements for the drive motor are relatively high, and the drive motor is required to provide both high drive torque in the constant torque area and high speed in the constant power area to meet the needs of vehicle acceleration. , climbing and high-speed driving requirements. At the same time, the use of a single-speed reducer is not conducive to improving the efficiency of the electric drive assembly system. This is because a single transmission ratio usually cannot take into account the power and economy of a pure electric vehicle at the same time, and the driving motor cannot be at a high-efficiency operating point in most cases during driving, especially at the highest or lowest speed and low load conditions, the driving motor will be Running at the low-efficiency operating point, thereby wasting electric energy and reducing driving mileage. In order to make pure electric vehicles take full advantage of their advantages and reduce the requirements for drive motors and batteries, the electric drive system of pure electric vehicles should use a multi-speed transmission. Work in an ideal high-efficiency area, thereby improving the vehicle's power, economy and other indicators.

Compared with automatic transmissions with more gears, two-speed automatic transmissions have a simpler and more compact structure, higher power density, and can realize gear shifting without power interruption. The technology is relatively mature, the requirements for motors are lower, and the overall cost of electric drive systems is lower. , At the same time, it can ensure high transmission efficiency, and the possibility of large-scale promotion and application in the field of pure electric vehicles is higher, and it can be industrialized and marketized faster, so it has greater feasibility.

Fig. 2 has shown a kind of automobile two-speed automatic transmission of shifting without power interruption known at present, mainly includes:

The input shaft and the first clutch, the second clutch, the first-speed driving gear and the second-speed driving gear arranged on the input shaft. Among them, the input ends of the first clutch and the second clutch are connected with the input shaft without relative rotation, and the driving gear of the first gear is arranged on the input shaft so as to be relatively rotatable and connected with the driven end of the first clutch without relative rotation, and the driving gear of the second gear It is relatively rotatable and arranged on the input shaft and is connected with the passive ends of the two clutches without relative rotation.

The output shaft and the first gear driven gear, the second gear driven gear and the final reduction driving gear arranged on the output shaft. The first-gear driven gear, the second-gear driven gear and the main deceleration driving gear are respectively connected to the output shaft without relative rotation, the first-gear driven gear meshes with the first-gear driving gear, and the second-gear driven gear meshes with the second-gear driving gear.

The differential and the main reduction and driven gears arranged on the differential, the main reduction and passive gears and the differential have no relative rotation connection, and the main reduction and passive gears mesh with the main reduction and driving gears.

The first gear working state and the power transmission path of the known disclosed two-speed automatic transmission: the first clutch engages, the second clutch disengages, the input power passes through the input shaft, the first clutch, the first gear driving gear, the first gear driven gear, The output shaft, main deceleration driving gear, main deceleration driven gear and differential assembly are routed, and finally output to the left and right drive wheels through the differential assembly.

The second gear working state and the power transmission path of the known disclosed two-speed automatic transmission: the second clutch is engaged, the first clutch is separated, and the input power passes through the input shaft, the second clutch, the second gear driving gear, the second gear driven gear, The output shaft, main deceleration driving gear, main deceleration driven gear and differential assembly are routed, and finally output to the left and right drive wheels through the differential assembly.

Switching between two gears of the known two-speed automatic transmission is known:

Switching from first gear to second gear: the first clutch is initially in the engaged state, the first clutch is driven and controlled, and the engaging torque of the first clutch is gradually reduced; at the same time, the second clutch is driven and controlled, and the engaging torque of the second clutch is gradually increased; Afterwards, the engagement torque of the first clutch decreases to zero while the engagement torque of the second clutch increases to a certain value, and finally the second clutch makes the input end and the output end rotate at the same speed under the action of the engagement torque, and the shift ends.

Switching from the second gear to the first gear: the second clutch is initially in the engaged state, the second clutch is driven and controlled, and the engaging torque of the second clutch is gradually reduced; at the same time, the first clutch is driven and controlled, and the engaging torque of the first clutch is gradually increased; Afterwards, the engagement torque of the second clutch decreases to zero while the engagement torque of the first clutch increases to a certain value, and finally the first clutch makes the input end and the output end rotate at the same speed under the action of the engagement torque, and the shift ends.

The points to be improved in the above-mentioned known and disclosed two-speed automatic transmission are: 1. When it is in the second gear, the first clutch is engaged and the second clutch is disengaged, and the second clutch in the disengaged working state will generate certain drag Torque, resulting in losses resulting in a reduction in transmission efficiency. 2. During the switching process of the two gears, it is necessary to carry out cooperative driving control on the two clutches at the same time, which increases the difficulty of the clutch driving control. Three, it needs two sets of clutches and corresponding drive control parts thereof, which is not conducive to the reduction of cost and weight.

Contents of the invention

The present invention aims to solve at least one of the technical problems existing in the prior art. Therefore, the present invention provides a two-speed automatic transmission, the purpose of which is to improve efficiency without clutch drag torque loss when the transmission is in the second gear operation under the premise of ensuring that there is no power interruption function for gear shifting.

In order to achieve the above object, the technical solution adopted by the present invention is: a two-speed automatic transmission, including an input shaft, an output shaft, a first-speed driving gear arranged on the input shaft, a second-speed driving gear, and a first-speed slave gear arranged on the output shaft. Driven gear, second-speed driven gear, and a clutch arranged on the input shaft connected with the input shaft and the second-speed driving gear, used to control the connection between the output shaft and the first-speed driven gear to engage and disengage and a one-way clutch connected to the first-speed driven gear and used for power transmission between the first-speed driven gear and the output shaft. The installation state of the one-way clutch is set to It is a free state when it is higher than the speed of the first gear driven gear.

The input end of the clutch is connected with the input shaft without relative rotation, the driving gear of the first gear is connected with the input shaft without relative rotation, and the driving gear of the second gear is relatively rotatably sleeved on the input shaft and is connected with the input shaft. There is no relative rotational connection at the output end of the clutch.

The second-speed driven gear and the connector are connected to the output shaft without relative rotation, and the first-speed driven gear is relatively rotatably sleeved on the output shaft and arranged adjacent to the connector. The driven gear is coupled with the output shaft or with other fixed parts arranged on the output shaft through the one-way clutch.

The connector has an engaging gear sleeve that is not connected to the output shaft in relative rotation and can move axially. The engaging gear sleeve has two working state positions, and the two working state positions are respectively connected with the first gear slave The engaged position where the driven gear is engaged and the disengaged position where the first gear driven gear is disengaged.

When the connector is in the engagement position engaged with the first-speed driven gear, the connector and the first-speed driven gear are coupled without relative rotation; when the connector is in the disengaged position separated from the first-speed driven gear , both operate independently of each other.

When the two-speed automatic transmission is in the first gear, the clutch is in the disengaged state, the engaging gear sleeve of the connector is in the disengaged position, and the input power passes through the input shaft, the first gear driving gear, and the first gear driven gear sequentially. A gear and a one-way clutch are transmitted to the output shaft.

When the two-speed automatic transmission is in the first gear, the clutch is in the disengaged state, the engaging tooth sleeve of the connector is in the engaged position, and the input power passes through the input shaft, the first gear driving gear and the first gear driven gear sequentially. The gear is transmitted to both the coupler and the one-way clutch, and then to the output shaft.

When the two-speed automatic transmission is in the second gear, the clutch is in the engaged state, the engaging tooth sleeve of the connector is in the disengaged position, and the input power passes through the input shaft, the second-speed driving gear and the second-speed driven gear sequentially. The gear transmits to the output shaft.

When the two-speed automatic transmission is in reverse gear, the clutch is in a disengaged state, the engaging tooth sleeve of the connector is in an engaged position, and the input power passes through the input shaft, the first-speed driving gear, and the first-speed driven gear in sequence. Gears and connectors pass to the output shaft.

The first gear driving gear and the first gear driven gear form a first gear pair, the second gear driving gear and the second gear driven gear form a second gear pair, and the transmission ratio of the first gear pair is set to Greater than the transmission ratio of the second gear pair.

The two-speed automatic transmission of the present invention has the following advantages:

1. Under the premise of ensuring that there is no power interruption function for shifting, there is no drag torque loss of the clutch when the transmission is in the second gear, which can improve the efficiency of the transmission;

2. On the premise of ensuring that there is no power interruption function for shifting, only one clutch is used, and there is no need to carry out coordinated drive control on two clutches at the same time, which relatively significantly reduces the difficulty of clutch drive control;

3. Under the premise of ensuring no power interruption function for shifting, only one clutch is used, which relatively reduces the number of clutches and their drive control components, and reduces the cost.

Description of drawings

This manual includes the following drawings, the contents shown are:

Fig. 1 is the structural representation of two-speed automatic transmission of the present invention;

Fig. 2 is the structural representation of prior art two-speed automatic transmission;

The marks in the figure are: 1. Input shaft; 2. Clutch; 3. Second gear driving gear; 4. First gear driving gear; 5. First gear driven gear; 6. Connector; 7. Output shaft; 8. One-way Clutch; 9, second gear driven gear; 10, main deceleration driving gear; 11, main deceleration driven gear; 12, differential; 13, first clutch; 14, second clutch.

Detailed ways

The specific embodiment of the present invention will be described in further detail by describing the embodiments below with reference to the accompanying drawings, the purpose is to help those skilled in the art to have a more complete, accurate and in-depth understanding of the concept and technical solutions of the present invention, and contribute to its implementation.

As shown in Figure 1, the present invention provides a two-speed automatic transmission, including an input shaft, an output shaft, a first-speed driving gear arranged on the input shaft, a second-speed driving gear, and a first-speed driven gear arranged on the output shaft. gears and second-speed driven gear, clutch connected with input shaft and second-speed driven gear, connector for controlling engagement and disengagement between said output shaft and first-speed driven gear, and connection with first-speed driven gear And the one-way clutch used to transmit power between the first-speed driven gear and the output shaft, the installation state of the one-way clutch is set to be higher than the first-speed driven gear when the speed of the output shaft is higher than that of the first-speed driven gear when the vehicle is moving forward. is in a free state.

Specifically, the non-limiting innovations and advantages of the present invention lie in that, on the premise of ensuring that there is no power interruption function for shifting, it provides a dual gear shifter with higher efficiency, lower control difficulty, lower cost, and lower weight. gear automatic transmission.

As shown in FIG. 1 , the two-speed automotive automatic transmission capable of shifting without power interruption of the present invention includes an input shaft component, an output shaft component and a differential gear component.

The input shaft components include: input shaft 1, clutch 2, first-speed driving gear 4 and second-speed driving gear 3, clutch 2, first-speed driving gear 4 and second-speed driving gear 3 are arranged concentrically with input shaft 1, and the input of clutch 2 end and the input shaft 1 without relative rotation connection, the first gear driving gear 4 has no relative rotation connection with the input shaft 1, and the second gear driving gear 3 is relatively rotatable on the input shaft 1 and has no connection with the output end of the clutch 2 Relatively rotating joints.

The output shaft components include: output shaft 7, first gear driven gear 5, second gear driven gear 9, one-way clutch 8, main deceleration driving gear 10 and connector 6, first gear driven gear 5, second gear driven gear 9. The one-way clutch 8, the main deceleration driving gear 10 and the connector 6 are arranged concentrically with the output shaft 7 respectively, and the second gear driven gear 9, the main deceleration driving gear 10 and the connector 6 are not connected to the output shaft 7 for relative rotation. The first gear driven gear 5 is idly sleeved on the output shaft 7 and is arranged adjacent to the connector 6, and the first gear driven gear 5 is also connected to the output shaft 7 through the one-way clutch 8 or arranged on the output shaft 7 The other fixed parts on the output shaft 7 are connected to other fixed parts. The other fixed parts arranged on the output shaft 7 refer to parts that rotate synchronously with the output shaft 7. The installation state of the one-way clutch 8 is set to be when the speed of the output shaft 7 is high when the vehicle is moving forward. It is in a free state at the speed of the first gear driven gear 5 .

The first gear driven gear 5 meshes with the first gear driving gear 4 on the input shaft part, and the second gear driven gear 9 meshes with the second gear driving gear 3 on the input shaft part.

The differential components include: a differential assembly 12 and a final reduction driven gear 11 , the differential assembly 12 and the final reduction driven gear 11 are arranged concentrically and have no relative rotational connection. The final reduction driven gear 11 meshes with the final reduction driving gear 10 on the output shaft member.

The transmission ratio of the first gear pair is set to be greater than the transmission ratio of the second gear pair. The first gear pair is composed of the first gear driving gear 4 and the first gear driven gear 5. The second gear pair is composed of the second gear driving gear 3 and the second gear pair. Block driven gear 9 constitutes.

The connector 6 is provided with an engaging tooth sleeve that is not connected to the output shaft in relative rotation and can move axially. The engaging tooth sleeve has two working state positions, and the two working state positions are the engagement positions engaged with the first-speed driven gear 5 respectively. And the disengagement position that is separated from the driven gear 5 of the first gear.

When the connector 6 is in the engagement position engaged with the driven gear 5 of the first block, the connector 6 and the driven gear 5 of the first block are coupled without relative rotation. position, the connector 6 and the first gear driven gear both operate independently of each other.

The two-speed automobile automatic transmission of the present invention has two forward gears, which are respectively a first gear and a second gear.

When the two-speed automatic transmission is in the first gear, the automatic transmission has the following two working modes:

When the gear position of the automatic transmission is the first gear and it is in the first working mode: the clutch 2 is in the disengaged state, the connector 6 is in the disengaged position, that is, the connector 6 is in the engaged position separated from the first gear driven gear 5, and the input power Through the input shaft 1, the first gear driving gear 4, the first gear driven gear 5, the one-way clutch 8, the output shaft 7, the main deceleration driving gear 10, the main deceleration driven gear 11 and the differential assembly 12, the final Output to the left and right drive wheels through the differential assembly.

When the gear position of the automatic transmission is the first gear and it is in the second working mode: the clutch 2 is in the disengaged state, the connector 6 is in the combined position, that is, the connector 6 is in the engaged position with the driven gear 5 of the first gear, and the first gear is driven by the gear 5. The driving gear 5 and the output shaft 7 can rotate synchronously, and the input power passes through the input shaft 1, the first gear driving gear 4, the first gear driven gear 5, the one-way clutch 8 and the connector 6, the output shaft 7, and the main deceleration driving gear 10 , the main reduction driven gear 11 and the differential gear assembly 12, and finally output to the left and right drive wheels through the differential gear assembly.

The difference between the first working mode of the first gear and the second working mode of the first gear is that when the gear of the automatic transmission is the first gear and is in the first working mode, the one-way clutch 8 cannot transmit power in two directions, but can only transmit power in one direction. To transmit power, the one-way clutch 8 can only transmit the power from the first-speed driven gear 5 to the output shaft 7, that is, the vehicle can only drive the wheels in one direction by the power source during forward driving, and cannot input power through the reverse drive of the wheels The source, that is, the vehicle cannot drive the input motor in the reverse direction when the vehicle is moving forward, so that the braking energy cannot be recovered.

When the gear position of the automatic transmission is the first gear and it is in the second working mode, the transmission can transmit power in both forward and reverse directions. The forward power transmission of the transmission is realized through the one-way clutch 8 or the connector 6, and the reverse transmission of the transmission The power is realized through the connector 6. Therefore, the vehicle can reversely drive the motor at the input end (the motor is connected to the input shaft) during forward running, and the automatic transmission drives the motor to run to generate electricity, thereby enabling braking energy recovery.

When the transmission of the present invention is in the second gear, the clutch 2 is in the engaged state, and the connector 6 is in the disengaged state, that is, the engaging tooth sleeve of the connector 6 is in the disengaged position separated from the first gear driven gear 5, and the input power is input through the Shaft 1, second-speed driving gear 3, second-speed driven gear 9, output shaft 7, main deceleration driving gear 10, main deceleration driven gear 11 and differential assembly 12 are routed, and finally output through the differential assembly Drive the wheels to the left and right. At this time, the one-way clutch 8 is in the overrunning working mode, that is, it is in a free state and does not transmit power.

When the transmission of the present invention is in reverse gear, the clutch 2 is in the disengaged state, and the connector 6 is in the combined position, that is, the engaging tooth sleeve of the connector 6 is in the engaged position with the first gear driven gear 5. At this time, the input power changes relative to The forward gear is driven in the opposite direction, and the input power passes through the input shaft 1, the first gear driving gear 4, the first gear driven gear 5, the connector 6, the output shaft 7, the main deceleration driving gear 10, the main deceleration driven gear 11 and the differential gear. Transmission assembly 12 paths, and finally output to the left and right drive wheels through the differential assembly.

When the vehicle is moving forward, according to the state of the input power when shifting gears, the shifting of gears is divided into positive torque shifting and negative torque shifting. Positive torque shifting refers to the torque value of input power when shifting gears is a positive value, that is, the torque rotation direction of the input power is the same as the rotation direction of the input shaft 1, negative torque shift means that the torque value of the input power is negative when switching gears, that is, the torque rotation direction of the input power is the same as that of the input shaft 1 The shaft 1 is placed in the opposite direction of rotation, and the gear switching process between the first gear and the second gear is as follows:

Positive torque shifting, the process of shifting from first gear to second gear is as follows: first, switch the engaging tooth sleeve of connector 6 to the disengaged position, and then control and drive clutch 2 to gradually increase the engaging torque of clutch 2, correspondingly, single The transmission torque to the clutch 8 is gradually reduced, that is, the one-way clutch 8 is automatically switched from the locked state to the free rotation state. There is a mutual speed difference and engagement torque between the input end and the output end of the clutch 2, and the clutch 2 is in the "slip" state. After that, the speed of the input end of the clutch 2 is gradually reduced to the same speed as the output end of the clutch 2 under the action of the engagement torque of the clutch 2, and the shifting process ends. Since the input power is continuous during the shifting process, there is no power interruption during the shifting process.

Negative torque shifting, the process of shifting from first gear to second gear is as follows: first, switch the engaging tooth sleeve of connector 6 to the disengaged position, and then control and drive clutch 2 to gradually increase the engaging torque of clutch 2, due to the input power If the torque is negative, the one-way clutch 8 is in a free state and does not transmit power, and then the input and output speeds of the clutch 2 gradually become the same under the action of the engaging torque, and the shifting process ends.

Positive torque shift, the process of shifting from the second gear to the first gear is as follows: firstly switch the engaging tooth sleeve of the connector 6 to the disengaged position, and then control and drive the clutch 2 so that the engaging torque of the clutch 2 gradually decreases, when the clutch 2 When the engagement torque is reduced to less than the torque of the input power, the clutch 2 enters the "slip grinding" state, and the speed of the input end of the clutch 2 increases relative to the speed of the output end of the clutch 2. When the speed of the input end of the clutch 2 continues to increase until it reaches its When the rotational speed of the driven first gear driven gear 5 reaches the rotational speed of the output shaft 7, the one-way clutch 8 is automatically switched to the locked state from the free transition state, after which the engagement torque of the clutch 2 continues to be reduced to zero, and the shifting process ends. Since the input power is continuous during the shifting process, there is no power interruption during the shifting process.

Negative torque shifting, the process of shifting from second gear to first gear is as follows: first, switch the engaging tooth sleeve of connector 6 to the disengaged position, and then control and drive clutch 2 to gradually reduce the engaging torque of clutch 2, when clutch 2 The shifting process ends when the engagement torque decreases to zero.

For two-speed automatic transmissions of electric vehicles, the first gear is usually set to a transmission ratio of a large value (usually the transmission ratio is set between 10 and 15), which is mainly used for starting, rapid acceleration at low speeds, and large slopes The driving time of these working conditions accounts for a very low proportion in the total driving time of the vehicle, and the second gear is usually set to a transmission ratio with a small value (usually the transmission ratio is set to 4 to 8 Between), it is mainly used in most of the driving conditions of users, that is, electric vehicles with two-speed transmissions work in the second gear most of the time, so the improvement of the efficiency of the second gear of the transmission is conducive to saving the electric energy of the whole vehicle and thus Increase the cruising range of the vehicle. In the known two-speed automatic transmission in the prior art, when it is in the second gear, the first clutch is engaged and the second clutch is disengaged, and the second clutch in the disengaged state will generate a certain drag torque, which will cause Relative reduction in transmission efficiency. The speed changer of the present invention only adopts one clutch, and when the second gear is working, the clutch is in an engaged state, and there is no clutch dragging torque. Therefore, the speed changer of the present invention improves the deficiency of the aforementioned known open speed changer.

In the known two-speed automatic transmissions disclosed in the prior art, the switch between the two gears requires simultaneous driving control of the two clutches, that is, one clutch increases the engagement torque, and at the same time decreases the engagement of the other clutch in association. Torque, thereby increasing the difficulty of clutch actuation control. The transmission of the present invention only uses one clutch, and only one clutch needs to be driven and controlled when shifting gears, which reduces the difficulty of control. And it is beneficial to the improvement of the gear shifting comfort of the whole vehicle.

Known disclosed two-speed automatic transmission in the prior art, it has two sets of clutches and corresponding drive control parts thereof, and the cost of clutches and corresponding drive control parts (with solenoid valves, piston parts, hydraulic oil circuit parts, etc.) Occupy a larger proportion in the total cost of the transmission, the transmission of the present invention only adopts one clutch, and the quantity of the clutch and its corresponding drive control components is reduced by half relative to the quantity of the corresponding components of the aforementioned known disclosed two-speed automatic transmission, so The transmission of the present invention has relatively low cost and low weight advantages.

According to the above description of the specific implementation of the transmission of the present invention, it can be found that the non-limiting innovations and advantages of the present invention lie in that, under the premise of ensuring that there is no power interruption function for shifting, it provides a higher efficiency, lower control difficulty, and more Low cost, lower weight two-speed automatic transmission.

The present invention has been exemplarily described above with reference to the accompanying drawings. Apparently, the specific implementation of the present invention is not limited by the above methods. As long as various insubstantial improvements are made using the method concept and technical solution of the present invention; or without improvement, the above-mentioned concept and technical solution of the present invention are directly applied to other occasions, all within the protection scope of the present invention within.

Claims (10)

1. A two-speed automatic transmission, comprising an input shaft, an output shaft, a first gear driving gear arranged on the input shaft, a second gear driving gear, a first gear driven gear and a second gear driven gear arranged on the output shaft, and The clutch connected with the input shaft and the second-speed driving gear is characterized in that it also includes a connector for controlling the engagement and disengagement between the output shaft and the first-speed driven gear and is connected with the first-speed driven gear. And the one-way clutch used to transmit power between the first-speed driven gear and the output shaft, the installation state of the one-way clutch is set to be higher than the first-speed driven gear when the speed of the output shaft is higher than that of the first-speed driven gear when the vehicle is moving forward. is in a free state. 2. The two-speed automatic transmission according to claim 1, characterized in that: the input end of the clutch is connected with the input shaft without relative rotation, and the driving gear of the first gear is connected with the input shaft without relative rotation. The second-speed driving gear is relatively rotatably sleeved on the input shaft and is connected with the output end of the clutch without relative rotation. 3. The two-speed automatic transmission according to claim 1, characterized in that: the second-speed driven gear and the connector are connected without relative rotation to the output shaft, and the first-speed driven gear can be relatively The rotating idler is arranged on the output shaft and adjacent to the connector, and the first gear driven gear is coupled with the output shaft or other fixed parts arranged on the output shaft through the one-way clutch. 4. The two-speed automatic transmission according to any one of claims 1 to 3, characterized in that: the connector has an engaging tooth sleeve that is not coupled to the output shaft in relative rotation and can move axially, the engaging The gear sleeve has two working state positions, and the two working state positions are respectively an engaged position engaged with the first-speed driven gear and a disengaged position separated from the first-speed driven gear. 5. The two-speed automatic transmission according to claim 4, characterized in that: when the connector is in the engagement position engaged with the first-speed driven gear, the connector and the first-speed driven gear do not rotate relative to each other When the connector is in the disengaged position separated from the driven gear of the first gear, the two operate independently of each other. 6. The two-speed automatic transmission according to claim 4, characterized in that: when the two-speed automatic transmission is in the first gear, the clutch is in the disengaged state, the engaging tooth sleeve of the connector is in the disengaged position, and the input The power is transmitted to the output shaft through the input shaft, the first gear driving gear, the first gear driven gear and the one-way clutch in sequence. 7. The two-speed automatic transmission according to claim 4, characterized in that: when the two-speed automatic transmission is in the first gear, the clutch is in the disengaged state, the engaging tooth sleeve of the connector is in the engaged position, and the input The power is transmitted to the connector and the one-way clutch simultaneously through the input shaft, the first-speed driving gear and the first-speed driven gear, and then to the output shaft. 8. The two-speed automatic transmission according to claim 4, characterized in that: when the two-speed automatic transmission is in the second gear, the clutch is in the engaged state, the engaging gear sleeve of the connector is in the disengaged position, and the input The power is transmitted to the output shaft through the input shaft, the second gear driving gear and the second gear driven gear sequentially. 9. The two-speed automatic transmission according to any one of claims 1 to 8, characterized in that: when the two-speed automatic transmission is in reverse gear, the clutch is in a disengaged state, and the engaging gear sleeve of the connector is in In the engaged position, the input power is sequentially transmitted to the output shaft through the input shaft, the first-speed driving gear, the first-speed driven gear and the connector. 10. The two-speed automatic transmission according to any one of claims 1 to 8, characterized in that: the first-speed driving gear and the first-speed driven gear form a first-speed gear pair, and the second-speed driving gear and the first-speed driven gear The second-speed driven gear constitutes a second-speed gear pair, and the transmission ratio of the first-speed gear pair is set to be greater than that of the second-speed gear pair.

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