Gear shifting mechanism and gear shifting method

Abstract

A gear shifting mechanism, comprising a controller (1), an intermediate shaft (3), a drive shaft (5), a clutch assembly (6), a first gear pair (8) and a second gear pair (4). The intermediate shaft (3) is in transmission connection with a motor shaft of a motor (100); the drive shaft (5) is in transmission connection with a housing of a differential (200), the differential (200) being mounted on a wheel axle between two wheels (300); and the motor (100) and the clutch assembly (6) are both electrically connected to the controller (1). The controller (1) is configured to control, in response to a gear shifting instruction, the motor (100) to be switched from a torque control mode to a rotating speed control mode, and to adjust the rotating speed of the motor (100) until the current gear meets a gear disengaging condition; the clutch assembly (6) drives the intermediate shaft (3) to move axially, so as to disengage the current gear, and adjusting the rotating speed of the motor (100) continues until a target gear meets a gear engaging condition; and the clutch assembly (6) drives the intermediate shaft (3) to move axially, such that the target gear is engaged. Instead of using a synchronizer to adjust the speed, the gear shifting mechanism adjusts the rotating speed of the motor. The gear shafting mechanism has a simple structure and low cost, and reduces the gear shifting time, thereby achieving more rapid gear shifting. Also disclosed is a gear shifting method.

Description

Gear shifting mechanism and gear shifting method Technical Field

[0001] The present application relates to the field of vehicle technology, and in particular to a gear shifting mechanism and a gear shifting method. Background Art

[0002] The shortcomings of single-stage reducers in electric vehicles are as follows: 1. They cannot take into account the efficient operation of the motor in both low-speed starting and high-speed driving conditions, and the motor utilization efficiency is relatively low. 2. In terms of power performance, acceleration is weak when driving at high speeds. 3. Compared with the two-speed transmission solution, the requirements for the motor are significantly higher, and the motor needs to have higher power and speed. The core reason is that the single-stage reducer has only one fixed gear ratio and can only make the vehicle run at high speed by increasing the motor speed. However, the increase in speed will lead to a decrease in motor efficiency and torque. If a multi-speed transmission is used, this problem can be effectively avoided. At present, electric vehicles are gradually upgrading from low-end products. Users are pursuing performance, efficiency and driving range, and are less sensitive to weight and cost. Multi-speed transmissions should be the future development trend of electric vehicle transmission systems.

[0003] Prior art often utilizes gear pairs with varying speed ratios, switching between these gear pairs and ultimately achieving gear and speed ratio changes through a shift system consisting of a shift motor, shift drum, shift fork, or synchronizer. However, existing shift systems are complex, and there is a speed difference between the two sides of the synchronizer, requiring time for both speeds to converge. This results in lengthy shift times and a poor driving experience. Summary of the Invention

[0004] The purpose of this application is to provide a gear shifting mechanism and a gear shifting method, which have a simple structure, low cost, shorten the gear shifting time, make the gear shifting process faster, and improve the driving experience.

[0005] To achieve the above objectives, in a first aspect, the present application provides a shift mechanism comprising a controller, an intermediate shaft, a transmission shaft, a clutch assembly, a first gear gear pair, and a second gear gear pair, wherein the intermediate shaft is drivingly connected to a motor shaft of a motor, the transmission shaft is drivingly connected to a housing of a differential, the differential is mounted on a wheel axle between two wheels, and the motor and the clutch assembly are both electrically connected to the controller;

[0006] The clutch assembly is configured to drive the intermediate shaft to move axially, so that the intermediate shaft can be connected to the transmission shaft through the first gear pair or the second gear pair; the transmission ratio of the first gear pair is greater than the transmission ratio of the second gear pair;

[0007] The controller is configured to, in response to a gear shift command, control the motor to switch from a torque control mode to a speed control mode, and adjust the speed of the motor until the current gear meets a gear disengagement condition, drive the intermediate shaft to move axially via the clutch assembly to disengage the current gear, and continue to adjust the speed of the motor until the target gear meets a gear engagement condition, drive the intermediate shaft to move axially via the clutch assembly to engage the target gear;

[0008] When the current gear is the intermediate shaft connected to the drive shaft via the first gear gear pair, the target gear is the intermediate shaft connected to the drive shaft via the second gear gear pair. When the current gear is the intermediate shaft connected to the drive shaft via the second gear gear pair, the target gear is the intermediate shaft connected to the drive shaft via the first gear gear pair. During the shifting process, the motor speed is adjusted by the controller rather than by a synchronizer. This simplifies the structure, reduces costs, shortens shifting time, and makes the shifting process faster, thereby improving the driving experience.

[0009] In some embodiments of the present application, based on the above solution, the current gear position is that the intermediate shaft is connected to the transmission shaft through the first gear gear pair, and the target gear position is that the intermediate shaft is connected to the transmission shaft through the second gear gear pair;

[0010] The controller is specifically configured as follows:

[0011] In response to the upshift command, the motor is controlled to switch from the torque control mode to the speed control mode and reduce the speed of the motor until the two gears of the first gear gear pair are relatively stationary and there is no relative load. The intermediate shaft is driven axially from the first gear gear pair to the second gear gear pair through the clutch assembly, so that the first gear gear pair is disengaged;

[0012] The motor speed is then reduced until the two gears of the second-gear pair are relatively stationary and meshing conditions are met. The clutch assembly then drives the intermediate shaft axially from the first-gear pair toward the second-gear pair, engaging the second-gear pair. During upshifts, the motor speed is adjusted by the controller, rather than by a synchronizer. This results in a simpler, lower-cost design, shorter shift times, and a more rapid shifting process, improving the driving experience.

[0013] In some embodiments of the present application, based on the above solution, the current gear position is that the intermediate shaft is connected to the transmission shaft through the second gear gear pair, and the target gear position is that the intermediate shaft is connected to the transmission shaft through the first gear gear pair;

[0014] The controller is specifically configured as follows:

[0015] In response to the downshift command, the motor is controlled to switch from the torque control mode to the speed control mode and reduce the speed of the motor until the two gears of the second gear pair are relatively stationary and there is no relative load. The intermediate shaft is driven axially from the second gear pair to the first gear pair through the clutch assembly, so that the second gear pair is disengaged;

[0016] The motor speed is increased until the two gears of the first-gear pair are relatively stationary and meshing conditions are met. The clutch assembly then drives the intermediate shaft axially from the second-gear pair toward the first-gear pair, engaging the first-gear pair. During downshifts, the motor speed is adjusted by the controller, rather than by a synchronizer. This results in a simpler, lower-cost design, shorter shift times, and a more rapid shifting process, improving the driving experience.

[0017] In some embodiments of the present application, based on the aforementioned solution, the shift mechanism further includes a first phase sensor mounted on the transmission shaft and a second phase sensor mounted on the intermediate shaft, the first phase sensor and the second phase sensor being electrically connected to the controller, the first phase sensor and the second phase sensor each including a matching ring gear with missing teeth, and based on a missing tooth signal detected per unit time, the controller obtains the rotational speed of the transmission shaft or the intermediate shaft based on the missing tooth signal, and then obtains the current vehicle speed or the current motor speed based on the corresponding transmission ratio;

[0018] The controller is further configured to obtain the current vehicle speed via a first phase sensor and the current motor speed via a second phase sensor. Therefore, during gear shifting, the controller reduces or increases the motor speed based on the relationship between the current vehicle speed and the current motor speed, ensuring the gear shifting process is completed.

[0019] In some embodiments of the present application, based on the aforementioned solution, the transmission ratio of the first gear pair is in the range of 11 to 13, and the transmission ratio of the second gear pair is in the range of 4 to 9. Thus, the first gear pair has a lower speed when in transmission connection, and the second gear pair has a higher speed when in transmission connection.

[0020] In some embodiments of the present application, based on the aforementioned solution, the clutch assembly includes a first clutch and a second clutch, the first clutch being disposed at an end of the intermediate shaft proximate to the first gear gear pair, and the second clutch being disposed at an end of the intermediate shaft proximate to the second gear gear pair. The first clutch is configured to drive the intermediate shaft to move axially from the first gear gear pair toward the second gear gear pair, and the second clutch is configured to drive the intermediate shaft to move axially from the second gear gear pair toward the first gear gear pair. This facilitates selection of the first clutch and the second clutch as needed to drive the intermediate shaft to move axially from the first gear gear pair toward the second gear gear pair, or to drive the intermediate shaft to move axially from the second gear gear pair toward the first gear gear pair.

[0021] In a second aspect, the present application provides a shifting method, which is applied to the shifting mechanism of the first aspect. The shifting method includes:

[0022] In response to the shift command, the controller controls the motor to switch from the torque control mode to the speed control mode and adjusts the speed of the motor until the current gear meets the gear disengagement condition, and drives the intermediate shaft to move axially through the clutch assembly to disengage the current gear;

[0023] The controller continues to adjust the motor speed until the target gear meets the gear engagement conditions, and drives the intermediate shaft to move axially through the clutch assembly, so that the target gear is engaged;

[0024] When the current gear is the intermediate shaft connected to the drive shaft via the first gear gear pair, the target gear is the intermediate shaft connected to the drive shaft via the second gear gear pair. When the current gear is the intermediate shaft connected to the drive shaft via the second gear gear pair, the target gear is the intermediate shaft connected to the drive shaft via the first gear gear pair. During the shifting process, the motor speed is adjusted by the controller rather than by a synchronizer. This simplifies the structure, reduces costs, shortens shifting time, and makes the shifting process faster, thereby improving the driving experience.

[0025] In some embodiments of the present application, based on the above solution, the current gear position is that the intermediate shaft is connected to the transmission shaft through the first gear gear pair, and the target gear position is that the intermediate shaft is connected to the transmission shaft through the second gear gear pair. The gear shifting method specifically includes:

[0026] In response to the upshift command, the controller controls the motor to switch from the torque control mode to the speed control mode and reduce the speed of the motor until the two gears of the first gear gear pair are relatively stationary and there is no relative load. The intermediate shaft is driven axially from the first gear gear pair to the second gear gear pair through the clutch assembly, so that the first gear gear pair is disengaged.

[0027] The controller continues to reduce the motor speed until the two gears of the second-gear pair are relatively stationary and meet the meshing conditions. The clutch assembly then drives the intermediate shaft axially from the first-gear pair toward the second-gear pair, engaging the second-gear pair. During upshifts, the motor speed is adjusted by the controller, rather than by a synchronizer. This simplifies the structure, reduces costs, and shortens shift times, making the shift process faster and improving the driving experience.

[0028] In some embodiments of the present application, based on the above solution, the current gear position is that the intermediate shaft is connected to the transmission shaft through the second gear pair, and the target gear position is that the intermediate shaft is connected to the transmission shaft through the first gear pair. The gear shifting method specifically includes:

[0029] In response to the downshift command, the controller controls the motor to switch from the torque control mode to the speed control mode and reduce the speed of the motor until the two gears of the second gear pair are relatively stationary and free of relative load, and drives the intermediate shaft to move axially from the second gear pair toward the first gear pair through the clutch assembly, so that the second gear pair is disengaged;

[0030] The controller increases the motor speed until the two gears of the first-gear pair are relatively stationary and meshing conditions are met. The clutch assembly then drives the intermediate shaft axially from the second-gear pair toward the first-gear pair, engaging the first-gear pair. During downshifts, the motor speed is adjusted by the controller, rather than by a synchronizer. This results in a simpler, lower-cost design, shorter shift times, and a more rapid shift process, improving the driving experience.

[0031] In some embodiments of the present application, based on the above solution, before the step of adjusting the speed of the motor, the shifting method further includes:

[0032] The controller uses the first phase sensor to obtain the current vehicle speed and the second phase sensor to obtain the current motor speed. Therefore, during the gear shifting process, the controller reduces or increases the motor speed accordingly based on the relationship between the current vehicle speed and the current motor speed, ensuring the gear shifting process is completed.

[0033] The technical solution of the present application provides a shift mechanism and shift method. The shift mechanism includes a controller, an intermediate shaft, a drive shaft, a clutch assembly, a first gear pair, and a second gear pair. The intermediate shaft is drivingly connected to the motor shaft of the motor, and the drive shaft is drivingly connected to the housing of the differential. The differential is mounted on the wheel axle between two wheels. The motor and the clutch assembly are both electrically connected to the controller. The controller is configured to, in response to a shift command, control the motor to switch from a torque control mode to a speed control mode, and adjust the motor speed until the current gear meets the disengagement condition. The clutch assembly drives the intermediate shaft to move axially to disengage the current gear. The motor speed is then continuously adjusted until the target gear meets the engagement condition. The clutch assembly drives the intermediate shaft to move axially to engage the target gear. The present application uses the controller to adjust the motor speed instead of using a synchronizer for speed regulation, resulting in a simple structure and low cost. Furthermore, since a synchronizer is not used, the time required for the speeds on both sides of the synchronizer to reach consistency is reduced, thereby shortening the shift time, making the shift process faster, and improving the driving experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings are incorporated into and constitute a part of the specification, illustrating embodiments consistent with the present application and, together with the specification, explaining the principles of the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can derive other drawings based on these drawings without inventive effort. In the drawings:

[0035] FIG1 is a schematic structural diagram of a shift mechanism according to an embodiment of the present application, wherein the gear position in FIG1 is in a neutral state;

[0036] FIG2 is a schematic diagram of the electrical connection between the first phase sensor, the second phase sensor, the motor, the clutch assembly, and the controller according to an embodiment of the present application;

[0037] FIG3 is a schematic structural diagram of a shift mechanism according to an embodiment of the present application, wherein the gear position in FIG3 is in the second gear state;

[0038] FIG4 is a schematic structural diagram of a shift mechanism according to an embodiment of the present application, wherein the gear position in FIG4 is in the first gear state;

[0039] FIG5 is a flow chart of a shifting method according to an embodiment of the present application. Specific best mode of implementation

[0040] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0041] The following will describe some embodiments of the present application in detail with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features therein may be combined with each other.

[0042] Referring to Figures 1 and 2 , an embodiment of the present application provides a shift mechanism, wherein the shift mechanism is mounted on a vehicle and is used to shift the vehicle into gear and thereby change the vehicle's speed. Specifically, the shift mechanism includes a controller 1, an intermediate shaft 3, a transmission shaft 5, a clutch assembly 6, a first phase sensor 7, a second phase sensor 9, a first gear gear pair 8, and a second gear gear pair 4. The intermediate shaft 3 is drivingly connected to the motor shaft of a motor 100, and the transmission shaft 5 is drivingly connected to the housing of a differential 200. The differential 200 is mounted on a wheel axle between two wheels 300. The first phase sensor 7, the second phase sensor 9, the motor 100, and the clutch assembly 6 are all electrically connected to the controller 1.

[0043] The clutch assembly 6 is used to drive the intermediate shaft 3 to move axially, so that the intermediate shaft 3 can be connected to the transmission shaft 5 through the first gear pair 8 or the second gear pair 4. The transmission ratio of the first gear pair 8 is greater than the transmission ratio of the second gear pair 4.

[0044] The first phase sensor 7 is mounted on the transmission shaft 5 and is used to obtain the current vehicle speed in real time. The controller 1 obtains the current vehicle speed through the first phase sensor 7. The second phase sensor 9 is mounted on the intermediate shaft 3 and is used to obtain the current rotational speed of the motor 100 in real time. The controller 1 obtains the current rotational speed of the motor 100 through the second phase sensor 9. It should be noted that the first phase sensor 7 and the second phase sensor 9 each include a matching ring gear with missing teeth. Based on the missing tooth signal detected per unit time, the controller 1 obtains the rotational speed of the transmission shaft 5 or the intermediate shaft 3 based on the missing tooth signal, and then obtains the current vehicle speed or the current rotational speed of the motor 100 based on the corresponding transmission ratio.

[0045] The controller 1 is used to respond to the gear shift instruction, control the motor 100 to switch from the torque control mode (making the motor rotate at a given torque) to the speed control mode (making the motor rotate at a given speed), and adjust the speed of the motor 100 until the current gear meets the first preset condition, drive the intermediate shaft 3 to move axially through the clutch assembly 6, so that the current gear is disengaged, and continue to adjust the speed of the motor 100 until the target gear meets the second preset condition, drive the intermediate shaft 3 to move axially through the clutch assembly 6, so that the target gear is engaged.

[0046] The current gear position is that the intermediate shaft 3 is connected to the transmission shaft 5 through the first gear gear pair 8 or the intermediate shaft 3 is connected to the transmission shaft 5 through the second gear gear pair 4. The target gear position is that the intermediate shaft 3 is connected to the transmission shaft 5 through the first gear gear pair 8 or the intermediate shaft 3 is connected to the transmission shaft 5 through the second gear gear pair 4. The current gear position is different from the target gear position.

[0047] Specifically, the gear shift instructions include upshift instructions and downshift instructions. In the actual process, when the gear shift speed requirement range is met, the vehicle controller recognizes that the user has a need to increase or decrease the speed (for example, stepping on the accelerator pedal or releasing the accelerator pedal, etc.), and sends a gear shift instruction to the controller 1.

[0048] In some embodiments, as shown in FIG4 , the current gear position is that the intermediate shaft 3 is connected to the transmission shaft 5 via the first gear gear pair 8 , and the target gear position is that the intermediate shaft 3 is connected to the transmission shaft 5 via the second gear gear pair 4 ;

[0049] The controller 1 is specifically configured as follows:

[0050] Shift-off process: In response to the shift-up command, the motor 100 is controlled to switch from the torque control mode to the speed control mode and reduce the speed of the motor 100 until the two gears of the first-gear gear pair 8 are relatively stationary and free of relative load. The intermediate shaft 3 is driven axially from the first-gear gear pair 8 to the second-gear gear pair 4 via the clutch assembly 6, as shown in FIG1 , thereby disengaging the first-gear gear pair 8.

[0051] Gear shifting process: Continue to reduce the speed of motor 100 until the two gears of second gear pair 4 are relatively stationary and meet the meshing condition. Then, continue to drive intermediate shaft 3 axially from first gear pair 8 toward second gear pair 4 via clutch assembly 6, as shown in FIG3 , so that second gear pair 4 engages. The meshing condition is met when the tooth tops of the two gears of second gear pair 4 align with the tooth bottoms and the tooth backlash meets the meshing requirements.

[0052] In some embodiments, as shown in FIG3 , the current gear position is that the intermediate shaft 3 is connected to the transmission shaft 5 via the second gear gear pair 4 , and the target gear position is that the intermediate shaft 3 is connected to the transmission shaft 5 via the first gear gear pair 8 ;

[0053] The controller 1 is specifically configured as follows:

[0054] Shift-off process: In response to the downshift command, the motor 100 is controlled to switch from the torque control mode to the speed control mode and reduce the speed of the motor 100 until the two gears of the second-gear gear pair 4 are relatively stationary and free of relative load. The intermediate shaft 3 is driven to move axially from the second-gear gear pair 4 toward the first-gear gear pair 8 via the clutch assembly 6, as shown in FIG1 , thereby disengaging the second-gear gear pair 4.

[0055] Gear shifting process: Increase the speed of motor 100 until the two gears of first gear pair 8 are relatively stationary and meet the meshing condition. Then, continue to drive intermediate shaft 3 axially from second gear pair 4 toward first gear pair 8 via clutch assembly 6, as shown in FIG4 , so that first gear pair 8 engages. The meshing condition is met when the tooth tops of the two gears of first gear pair 8 are aligned with the tooth bottoms and the tooth backlash meets the meshing requirements.

[0056] It should be noted that during the upshift and downshift processes, the motor 100 no longer provides torque to the vehicle, and the vehicle speed decreases slightly. Therefore, the controller 1 first reduces the speed of the motor 100. During the gear shift process, the controller 1 reduces or increases the speed of the motor 100 accordingly based on the relationship between the current vehicle speed and the current speed of the motor 100, ensuring the gear shift process is completed.

[0057] In some embodiments, the transmission ratio of the first gear pair 8 is in the range of 11-13, which can be referred to as a low-speed gear. The transmission ratio of the second gear pair 4 is in the range of 4-9, which can be referred to as a high-speed gear. Of course, more gear pairs can be provided between the intermediate shaft 3 and the transmission shaft 5, such as a third gear pair or a fourth gear pair, but with different transmission ratios.

[0058] Specifically, the first gear gear pair 8 includes a first driving gear and a first driven gear, and the second gear gear pair 4 includes a second driving gear and a second driven gear. The first and second driving gears are axially fixed to the intermediate shaft 3, and the first and second driven gears are axially fixed to the transmission shaft 5. The first driving gear meshes with the first driven gear, and the second driving gear meshes with the second driven gear. The spacing between the first and second driving gears is smaller than the spacing between the first and second driven gears.

[0059] In some embodiments, the first and second driving wheels have an interference fit with the intermediate shaft 3, and the first and second driven wheels have an interference fit with the transmission shaft 5, to achieve a fixed effect. In other embodiments, the first and second driving wheels and the intermediate shaft 3 are integrally formed gear shafts, and the first and second driven wheels and the transmission shaft 5 are integrally formed gear shafts.

[0060] Specifically, the motor shaft of the motor 100 always maintains a transmission connection with the intermediate shaft 3 through the gear pair 2.

[0061] Specifically, the clutch assembly 6 includes a first clutch and a second clutch. The first clutch is provided at one end of the intermediate shaft 3 close to the first gear gear pair 8, and the second clutch is provided at one end of the intermediate shaft 3 close to the second gear gear pair 4. The first clutch is configured to drive the intermediate shaft 3 to move axially from the first gear gear pair 8 toward the second gear gear pair 4, and the second clutch is configured to drive the intermediate shaft 3 to move axially from the second gear gear pair 4 toward the first gear gear pair 8.

[0062] Based on the same inventive concept, an embodiment of the present application further provides a shifting method, which is applied to the shifting mechanism of the aforementioned embodiment. As shown in FIG5 , the shifting method includes:

[0063] Step S1: In response to a shift command, the controller 1 controls the motor 100 to switch from a torque control mode to a speed control mode, and adjusts the speed of the motor 100 until the current gear meets the gear disengagement condition, and drives the intermediate shaft 3 to move axially through the clutch assembly 6, so that the current gear is disengaged;

[0064] Step S2: The controller 1 continues to adjust the speed of the motor 100 until the target gear position meets the gear engagement condition, and drives the intermediate shaft 3 to move axially through the clutch assembly 6, so that the target gear position is engaged.

[0065] The current gear position is that the intermediate shaft 3 is connected to the transmission shaft 5 through the first gear gear pair 8 or the intermediate shaft 3 is connected to the transmission shaft 5 through the second gear gear pair 4. The target gear position is that the intermediate shaft 3 is connected to the transmission shaft 5 through the first gear gear pair 8 or the intermediate shaft 3 is connected to the transmission shaft 5 through the second gear gear pair 4. The current gear position is different from the target gear position.

[0066] In some embodiments, before step S1, the shifting method further includes:

[0067] The controller 1 obtains the current vehicle speed through the first phase sensor 7 and obtains the current rotation speed of the motor 100 through the second phase sensor 9 .

[0068] In some embodiments, the current gear position is that the intermediate shaft 3 is connected to the transmission shaft 5 via the first gear gear pair 8, and the target gear position is that the intermediate shaft 3 is connected to the transmission shaft 5 via the second gear gear pair 4. The gear shifting method specifically includes:

[0069] In response to the upshift command, the controller 1 controls the motor 100 to switch from the torque control mode to the speed control mode and reduce the speed of the motor 100 until the two gears of the first gear gear pair 8 are relatively stationary and free of relative load. The intermediate shaft 3 is driven axially from the first gear gear pair 8 to the second gear gear pair 4 via the clutch assembly 6, so that the first gear gear pair 8 is disengaged.

[0070] The controller 1 continues to reduce the speed of the motor 100 until the two gears of the second gear pair 4 are relatively stationary and the engagement condition is met, and continues to drive the intermediate shaft 3 to move axially from the first gear pair 8 to the second gear pair 4 through the clutch assembly 6, so that the second gear pair 4 is engaged.

[0071] In some embodiments, the current gear position is that the intermediate shaft 3 is connected to the transmission shaft 5 via the second gear gear pair 4, and the target gear position is that the intermediate shaft 3 is connected to the transmission shaft 5 via the first gear gear pair 8. The gear shifting method specifically includes:

[0072] In response to the downshift command, the controller 1 controls the motor 100 to switch from the torque control mode to the speed control mode and reduce the speed of the motor 100 until the two gears of the second gear gear pair 4 are relatively stationary and free of relative load. The intermediate shaft 3 is driven axially from the second gear gear pair 4 to the first gear gear pair 8 via the clutch assembly 6, so that the second gear gear pair 4 is disengaged.

[0073] The controller 1 increases the speed of the motor 100 until the two gears of the first gear gear pair 8 are relatively stationary and meet the engagement conditions, and continues to drive the intermediate shaft 3 to move axially from the second gear gear pair 4 to the first gear gear pair 8 through the clutch assembly 6, so that the first gear gear pair 8 is engaged.

[0074] In summary, embodiments of the present application provide a shift mechanism and shift method. The shift mechanism includes a controller, an intermediate shaft, a drive shaft, a clutch assembly, a first gear pair, and a second gear pair. The intermediate shaft is drivingly connected to the motor shaft of the motor, and the drive shaft is drivingly connected to the housing of the differential. The differential is mounted on the wheel axle between two wheels. The motor and clutch assembly are both electrically connected to the controller. The controller is configured to, in response to a shift command, control the motor to switch from a torque control mode to a speed control mode, and adjust the motor speed until the current gear meets the disengagement condition. The clutch assembly then drives the intermediate shaft to move axially, disengaging the current gear. The motor speed is then continuously adjusted until the target gear meets the engagement condition. The clutch assembly then drives the intermediate shaft to move axially, engaging the target gear. Embodiments of the present application utilize a controller to adjust the motor speed, rather than using a synchronizer for speed regulation. This results in a simple structure and low cost. Furthermore, the lack of a synchronizer reduces the time required for the speeds on both sides of the synchronizer to reach consistency, thereby shortening shift time and making the shifting process faster, thereby improving the driving experience.

[0075] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the embodiments disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present application that follow the general principles of the present application and include common knowledge or customary techniques in the art that are not disclosed in this application. It should be understood that the present application is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from the scope thereof. The scope of this application is limited only by the appended claims.

Claims

1. A gear shifting mechanism, characterized in that: It includes a controller, an intermediate shaft, a transmission shaft, a clutch assembly, a first gear gear pair and a second gear gear pair, wherein the intermediate shaft is drivingly connected to the motor shaft of the motor, the transmission shaft is drivingly connected to the housing of the differential, the differential is installed on the wheel shaft between the two wheels, and the motor and the clutch assembly are both electrically connected to the controller; The clutch assembly is configured to drive the intermediate shaft to move axially, so that the intermediate shaft can be connected to the transmission shaft through the first gear pair or the second gear pair; the transmission ratio of the first gear pair is greater than the transmission ratio of the second gear pair; The controller is configured to control the motor to switch from a torque control mode to a speed control mode in response to a gear shift instruction, and adjust the speed of the motor until the current gear meets a gear disengagement condition, drive the intermediate shaft to move axially through the clutch assembly, so that the current gear is disengaged, and continue to adjust the speed of the motor until the target gear meets a gear engagement condition, drive the intermediate shaft to move axially through the clutch assembly, so that the target gear is engaged; When the current gear position is that the intermediate shaft is connected to the transmission shaft through the first gear gear pair, the target gear position is that the intermediate shaft is connected to the transmission shaft through the second gear gear pair; when the current gear position is that the intermediate shaft is connected to the transmission shaft through the second gear gear pair, the target gear position is that the intermediate shaft is connected to the transmission shaft through the first gear gear pair.

2. The shift mechanism according to claim 1, characterized in that: The current gear position is that the intermediate shaft is connected to the transmission shaft through the first gear pair, and the target gear position is that the intermediate shaft is connected to the transmission shaft through the second gear pair; The controller is specifically configured as follows: In response to the upshift instruction, the motor is controlled to switch from the torque control mode to the speed control mode, and the speed of the motor is reduced until the two gears of the first gear gear pair are relatively stationary and have no relative load, and the intermediate shaft is driven to move axially from the first gear gear pair to the second gear gear pair through the clutch assembly, so that the first gear gear pair is disengaged; Continue to reduce the speed of the motor until the two gears of the second gear pair are relatively stationary and meet the meshing condition, and continue to drive the intermediate shaft to move axially from the first gear pair to the second gear pair through the clutch assembly, so that the second gear pair is engaged.

3. The shift mechanism according to claim 1, characterized in that: The current gear position is that the intermediate shaft is connected to the transmission shaft through the second gear pair, and the target gear position is that the intermediate shaft is connected to the transmission shaft through the first gear pair; The controller is specifically configured as follows: In response to the downshift instruction, the motor is controlled to switch from the torque control mode to the speed control mode, and the speed of the motor is reduced until the two gears of the second gear gear pair are relatively stationary and have no relative load, and the intermediate shaft is driven to move axially from the second gear gear pair to the first gear gear pair through the clutch assembly, so that the second gear gear pair is disengaged; The rotation speed of the motor is increased until the two gears of the first gear gear pair are relatively stationary and meet the meshing condition, and the intermediate shaft is continuously driven to move axially from the second gear gear pair to the first gear gear pair through the clutch assembly, so that the first gear gear pair is engaged.

4. The shift mechanism according to claim 2 or 3, characterized in that: The shift mechanism further includes a first phase sensor mounted on the transmission shaft and a second phase sensor mounted on the intermediate shaft, the first phase sensor and the second phase sensor are both electrically connected to the controller, the first phase sensor and the second phase sensor respectively include a matching gear ring with missing teeth, according to the missing tooth signal detected within a unit time, and then, the controller obtains the rotation speed of the transmission shaft or the intermediate shaft according to the missing tooth signal, and then obtains the current vehicle speed or the current rotation speed of the motor according to the corresponding transmission ratio; The controller is further configured to obtain a current vehicle speed through the first phase sensor, and obtain a current rotation speed of the motor through the second phase sensor.

5. The shift mechanism according to claim 1, characterized in that: The transmission ratio of the first gear gear pair ranges from 11 to 13, and the transmission ratio of the second gear gear pair ranges from 4 to 9.

6. The shift mechanism according to claim 1, characterized in that: The clutch assembly includes a first clutch and a second clutch, the first clutch is arranged at one end of the intermediate shaft close to the first gear gear pair, and the second clutch is arranged at one end of the intermediate shaft close to the second gear gear pair, the first clutch is configured to drive the intermediate shaft to move axially from the first gear gear pair to the second gear gear pair, and the second clutch is configured to drive the intermediate shaft to move axially from the second gear gear pair to the first gear gear pair.

7. A gear shifting method, characterized in that: Applicable to the shift mechanism according to any one of claims 1 to 6, the shift method comprising: In response to the shift command, the controller controls the motor to switch from the torque control mode to the speed control mode, and adjusts the speed of the motor until the current gear meets the first preset condition, and drives the intermediate shaft to move axially through the clutch assembly, so that the current gear is disengaged; The controller continues to adjust the speed of the motor until the target gear meets a second preset condition, and drives the intermediate shaft to move axially through the clutch assembly, so that the target gear is engaged; When the current gear position is that the intermediate shaft is connected to the transmission shaft through the first gear gear pair, the target gear position is that the intermediate shaft is connected to the transmission shaft through the second gear gear pair; when the current gear position is that the intermediate shaft is connected to the transmission shaft through the second gear gear pair, the target gear position is that the intermediate shaft is connected to the transmission shaft through the first gear gear pair.

8. The shifting method according to claim 7, characterized in that: The current gear position is that the intermediate shaft is connected to the transmission shaft through the first gear pair, and the target gear position is that the intermediate shaft is connected to the transmission shaft through the second gear pair. The gear shifting method specifically includes: In response to the upshift instruction, the controller controls the motor to switch from the torque control mode to the speed control mode, and reduces the speed of the motor until the two gears of the first gear gear pair are relatively stationary and have no relative load, and drives the intermediate shaft to move axially from the first gear gear pair to the second gear gear pair through the clutch assembly, so that the first gear gear pair is disengaged; The controller continues to reduce the speed of the motor until the two gears of the second gear pair are relatively stationary and meet the meshing condition, and continues to drive the intermediate shaft to move axially from the first gear pair to the second gear pair through the clutch assembly, so that the second gear pair is engaged.

9. The shifting method according to claim 7, characterized in that: The current gear position is that the intermediate shaft is connected to the transmission shaft through the second gear pair, and the target gear position is that the intermediate shaft is connected to the transmission shaft through the first gear pair. The gear shifting method specifically includes: In response to the downshift instruction, the controller controls the motor to switch from the torque control mode to the speed control mode, and reduces the speed of the motor until the two gears of the second gear gear pair are relatively stationary and have no relative load, and drives the intermediate shaft to move axially from the second gear gear pair to the first gear gear pair through the clutch assembly, so that the second gear gear pair is disengaged; The controller increases the speed of the motor until the two gears of the first gear gear pair are relatively stationary and meet the meshing condition, and continues to drive the intermediate shaft to move axially from the second gear gear pair to the first gear gear pair through the clutch assembly, so that the first gear gear pair is engaged.

10. The shifting method according to claim 8 or 9, characterized in that: Before the step of adjusting the rotation speed of the motor, the shifting method further includes: The controller obtains the current vehicle speed through the first phase sensor, and obtains the current rotation speed of the motor through the second phase sensor.

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