Pure electric vehicle two-gear transmission

Abstract

The application discloses a two-gear transmission of a pure electric vehicle, which comprises a motor, an input shaft, an intermediate shaft, an output shaft, a first driving gear, a synchronizer assembly, a wet clutch, a second driving gear, a first driven gear, a multi-mode clutch, a constantly meshing gear, a second driven gear and a main reduction gear; the input shaft is connected with the motor; the first driving gear is fixedly connected with the input shaft, the first driven gear is fixedly connected with the multi-mode clutch, the multi-mode clutch is connected with the intermediate shaft, and the first driving gear is in mesh with the first driven gear; and the wet clutch and the second driving gear are sleeved on the input shaft. In the application, power interruption does not occur in the gear shifting process, the control difficulty is relatively small, the drag torque is reduced, the transmission efficiency is effectively improved, and the vehicle cruising range is improved.

Description

Technical Field

[0001] This invention relates to pure electric vehicles, and more specifically to a two-speed transmission for pure electric vehicles. Background Technology

[0002] Currently, most pure electric vehicles use single-speed reducers. Although these reducers are simple in structure and low in cost, the drive motor cannot always operate in its high-efficiency range, resulting in high energy consumption and short lifespan. This fails to improve the power and economy of the target vehicle model. Furthermore, high motor speeds easily cause vibration and noise, which not only reduces driving comfort but also lowers energy efficiency and shortens the driving range. Among the four main types of automatic transmissions (AT / CVT / DCT / AMT) currently available, AMT has advantages such as high efficiency, low cost, simple structure, good production continuity, and convenient maintenance. A common two-speed AMT pure electric vehicle transmission includes a clutch, synchronizer, shifting mechanism, and transmission system. However, existing automotive transmissions lose power during clutch disengagement, with the power interruption time lasting from the start of clutch disengagement to the clutch engagement point. The relatively long shift interruption time in AMT significantly impacts driving and passenger comfort.

[0003] CN112145634A discloses a two-speed pure electric transmission with uninterrupted power shifting, comprising: an input shaft, an intermediate shaft, and an output shaft disposed within a housing. The second-speed drive gear, clutch, and first-speed drive gear are sequentially mounted on the input shaft connected to a motor. The second-speed driven gear, synchronizer, parking gear, first-speed driven gear, and output drive gear are sequentially mounted on the intermediate shaft. The parking gear is fixedly connected to the housing. The synchronizer is connected to a shift parking motor via a lead screw. The main reduction gear is connected to a differential, which is disposed on the output shaft. The clutch and synchronizer cooperate to achieve uninterrupted power shifting. This two-speed pure electric transmission can achieve uninterrupted power shifting, and the technical solution disclosed in the aforementioned patent document is undoubtedly a beneficial attempt in the relevant technical field. However, the clutch of this two-speed pure electric transmission generates drag torque when not in operation, affecting the efficiency of the automatic transmission and thus reducing the driving range of the electric vehicle. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a two-speed transmission for pure electric vehicles that does not interrupt power during gear shifting, is easier to control, reduces drag torque, effectively improves transmission efficiency, and increases vehicle range.

[0005] The present invention provides a two-speed transmission for a pure electric vehicle, comprising a motor, an input shaft, an intermediate shaft, an output shaft, a first drive gear, a synchronizer assembly, a wet clutch, a second drive gear, a first driven gear, a multi-mode clutch, a constant mesh gear, a second driven gear, and a main reduction gear.

[0006] The input shaft is connected to the motor;

[0007] The first driving gear is fixedly connected to the input shaft, the first driven gear is fixedly connected to the multi-mode clutch, the multi-mode clutch is connected to the intermediate shaft, and the first driving gear meshes with the first driven gear;

[0008] The wet clutch and the second drive gear are loosely fitted on the input shaft. The wet clutch and the second drive gear are fixedly connected. The synchronizer assembly can disconnect or connect the power between the wet clutch and the input shaft. The second drive gear meshes with the second driven gear, and the second driven gear is fixedly connected to the intermediate shaft.

[0009] The constant meshing gear meshes with the main reduction gear, the constant meshing gear is fixedly connected to the intermediate shaft, and the main reduction gear is fixedly connected to the output shaft.

[0010] Furthermore, the wet clutch includes a clutch driving end, a friction plate assembly, and a clutch driven end, all loosely fitted on the input shaft. The clutch driving end can cooperate with the synchronizer assembly, the friction plate assembly can disconnect or connect the power between the clutch driving end and the clutch driven end, and the clutch driven end is fixedly connected to the second driving gear.

[0011] Furthermore, the synchronizer assembly includes a clutch hub and a sliding sleeve. The clutch hub is fixedly connected to the input shaft, and the sliding sleeve can move along the axis to realize the power disconnection or connection between the clutch hub and the clutch driving end.

[0012] Furthermore, the wet clutch is a normally closed wet clutch.

[0013] Furthermore, when the two-speed transmission of the pure electric vehicle is in first gear or reverse gear, the multi-mode clutch is locked in both directions, the synchronizer assembly cuts off the power between the wet clutch and the input shaft, and the wet clutch is in an engaged state.

[0014] Furthermore, when the two-speed transmission of the pure electric vehicle is in second gear, the multi-mode clutch is open in both directions, the synchronizer assembly enables the power connection between the wet clutch and the input shaft, and the wet clutch is in the engaged state.

[0015] The beneficial effects of this invention are as follows: During gear shifting, the multi-mode clutch, wet clutch, and synchronizer assembly can be controlled independently without power interruption, thus reducing control difficulty. Furthermore, because the wet clutch is designed to be normally closed, it has no drag torque when not in operation, and the multi-mode clutch has almost no drag torque when not in operation, effectively improving transmission efficiency and increasing vehicle range. Moreover, when used in conjunction with the synchronizer assembly, the multi-mode clutch mechanism is no longer limited by speed, meaning that speed adjustment of the power source is no longer required before the mechanism operates. Simultaneously, when the transmission is in the rear axle position of a four-wheel-drive pure electric vehicle, with both the multi-mode clutch and synchronizer assembly in a non-engaged state, the transmission can disengage the drive system, thereby avoiding oil churning losses when the rear axle drive system is not in operation and optimizing the energy consumption of four-wheel-drive pure electric vehicles. Attached Figure Description

[0016] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the following figures are provided for illustration:

[0017] Figure 1 This is a schematic diagram of the structure of the present invention.

[0018] The following labels are used in the attached diagram: 1-Motor, 2-Input shaft, 3-Intermediate shaft, 4-Output shaft, 5-First drive gear, 6-Synchronizer assembly, 61-Clutch hub, 62-Sliding sleeve, 7-Wet clutch, 71-Clutch driving end, 72-Friction plate assembly, 73-Clutch driven end, 8-Second drive gear, 9-First driven gear, 10-Multimode clutch, 11-Constant mesh gear, 12-Second driven gear, 13-Main reduction gear. Detailed Implementation

[0019] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0020] like Figure 1 As shown, a two-speed transmission for a pure electric vehicle in this embodiment includes a motor 1, an input shaft 2, an intermediate shaft 3, an output shaft 4, a first drive gear 5, a synchronizer assembly 6, a wet clutch 7, a second drive gear 8, a first driven gear 9, a multi-mode clutch 10, a constant mesh gear 11, a second driven gear 12, and a main reduction gear 13.

[0021] The input shaft 2 is connected to the motor 1;

[0022] The first driving gear 5 is fixedly connected to the input shaft 2, the first driven gear 9 is fixedly connected to the multi-mode clutch 10, the multi-mode clutch 10 is connected to the intermediate shaft 3, and the first driving gear 5 meshes with the first driven gear 9;

[0023] The wet clutch 7 and the second drive gear 8 are loosely fitted on the input shaft 2. The wet clutch 7 and the second drive gear 8 are fixedly connected. The synchronizer assembly 6 can disconnect or connect the power between the wet clutch and the input shaft 2. The second drive gear 8 meshes with the second driven gear 12. The second driven gear 12 is fixedly connected to the intermediate shaft 3.

[0024] The constant meshing gear 11 meshes with the main reduction gear 13, the constant meshing gear 11 is fixedly connected to the intermediate shaft 3, and the main reduction gear 13 is fixedly connected to the output shaft 4.

[0025] In this embodiment, the wet clutch includes a clutch driving end 71, a friction plate assembly 72, and a clutch driven end 73, all loosely fitted on the input shaft 2. The clutch driving end 71 can cooperate with the synchronizer assembly 6. The friction plate assembly 72 can disconnect or connect the power between the clutch driving end 71 and the clutch driven end 73. The clutch driven end 73 is fixedly connected to the second driving gear 8.

[0026] In this embodiment, the synchronizer assembly 6 includes a clutch hub 61 and a sliding sleeve 62. The clutch hub 61 is fixedly connected to the input shaft 2, and the sliding sleeve 62 can move along the axis to realize the power cut-off or connection between the clutch hub 61 and the clutch driving end 71.

[0027] In this embodiment, the wet clutch is a normally closed wet clutch.

[0028] In this embodiment, when the two-speed transmission of the pure electric vehicle is in first gear or reverse gear, the multi-mode clutch 10 is locked in both directions, the synchronizer assembly 6 cuts off the power between the wet clutch and the input shaft 2, and the wet clutch is in the engaged state.

[0029] In this embodiment, when the two-speed transmission of the pure electric vehicle is in second gear, the multi-mode clutch 10 is opened in both directions, the synchronizer assembly 6 enables the power connection between the wet clutch and the input shaft 2, and the wet clutch is in the engaged state.

[0030] The multi-mode clutch 10 is existing technology. Its structure includes an inner ring, an outer ring, and an actuator that can change the power transmission mode between the inner and outer rings. This actuator can achieve unidirectional locking, bidirectional locking, or bidirectional opening between the inner and outer rings. When unidirectionally locked, the inner ring cannot transmit torque to the outer ring when rotating, so the inner ring cannot drive the outer ring to rotate. However, when the outer ring rotates, it can transmit torque to the inner ring, so the outer ring can drive the inner ring to rotate. When bidirectionally locked, both the inner and outer rings can transmit torque to each other, allowing both the inner and outer rings to rotate. When bidirectionally open, neither the inner nor outer ring can transmit torque to the outer ring, so neither the inner nor outer ring can drive the outer ring to rotate. In use, in this embodiment, the outer ring of the multi-mode clutch 10 is fixedly connected to the first driven gear 9, and the inner ring is fixedly connected to the intermediate shaft 3.

[0031] The shifting process of this embodiment will be described in detail below.

[0032] Shifting from first to second gear: When the two-speed transmission of a pure electric vehicle is in first gear, the multi-mode clutch 10 is locked in both directions, and the sliding sleeve 62 is separated from the clutch driving end 71, thereby realizing the power cut-off between the wet clutch and the input shaft 2 by the synchronizer assembly 6. The wet clutch is in the engaged state, and at this time, both the forward torque and the reverse torque of the motor 1 can be transmitted to the output shaft 4, and the transmission path is as follows: motor 1 → input shaft 2 → first driving gear 5 → first driven gear 9 → multi-mode clutch 10 → intermediate shaft 3 → constant mesh gear 11 → main reduction gear 13 → output shaft 4. When a shift command is received, the multi-mode clutch 10 is controlled to change to one-way locking, and then the wet clutch is in the disengaged state. After the wet clutch is opened, the synchronizer assembly 6 slides through the sliding sleeve 62 to the position engaged with the clutch driving end 71. Then the wet clutch is restored to the engaged state. At this time, the positive torque of the motor 1 can be transmitted to the output shaft 4, and the transmission path is as follows: motor 1 → input shaft 2 → synchronizer assembly → wet clutch → second driving gear 8 → second driven gear 12 → intermediate shaft 3 → constant mesh gear 11 → main reduction gear 13 → output shaft 4, realizing the shift from first gear to second gear. After the shift is completed, the multi-mode clutch 10 is controlled to change to bidirectional opening to avoid the impact of forward and reverse drag switching on the multi-mode clutch 10, and at the same time reduce the loss.

[0033] Shifting from second gear to first gear: When the two-speed transmission of a pure electric vehicle is in second gear, the multi-mode clutch 10 is open in both directions, and the sliding sleeve 62 engages with the clutch drive end 71, thereby realizing the power connection between the wet clutch and the input shaft 2 through the synchronizer assembly 6. The wet clutch is in the engaged state, and at this time, the positive torque of the motor 1 can be transmitted to the output shaft 4, and the transmission path is as follows: motor 1 → input shaft 2 → synchronizer assembly → wet clutch → second drive gear 8 → second driven gear 12 → intermediate shaft 3 → constant mesh gear 11 → main reduction gear 13 → output shaft 4. When a shift command is received, the multi-mode clutch 10 is changed to one-way lock-up, and then the wet clutch is disengaged. After the wet clutch is opened, the synchronizer assembly 6 slides through the sliding sleeve 62 to the position separated from the clutch driving end 71. Then the wet clutch is restored to the engaged state. At this time, both the forward and reverse torques of the motor 1 can be transmitted to the output shaft 4, and the transmission path is as follows: motor 1 → input shaft 2 → first driving gear 5 → first driven gear 9 → multi-mode clutch 10 → intermediate shaft 3 → constant mesh gear 11 → main reduction gear 13 → output shaft 4. Finally, the wet clutch is changed to the engaged state, and the multi-mode clutch 10 is changed to two-way lock-up, realizing the shift from first gear to second gear.

[0034] During gear shifting, the multi-mode clutch 10, wet clutch, and synchronizer assembly 6 can be controlled independently without power interruption, thus reducing control complexity. Furthermore, because the wet clutch is normally closed, it has no drag torque when not in operation, and the multi-mode clutch 10 has almost no drag torque when not in operation, effectively improving transmission efficiency and increasing vehicle range. Moreover, when used in conjunction with the synchronizer assembly 6, the operation of the multi-mode clutch 10 is no longer limited by speed, meaning that speed adjustment of the power source is no longer required before the mechanism operates. Simultaneously, when the transmission is in the rear axle position of a four-wheel-drive pure electric vehicle, with both the multi-mode clutch 10 and synchronizer assembly 6 in a disengaged state, the transmission can disengage the drive system, thus avoiding oil churning losses when the rear axle drive system is not in operation and optimizing energy consumption in four-wheel-drive pure electric vehicles.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A two-speed transmission for a pure electric vehicle, characterized in that: It includes a motor (1), an input shaft (2), an intermediate shaft (3), an output shaft (4), a first driving gear (5), a synchronizer assembly (6), a wet clutch (7), a second driving gear (8), a first driven gear (9), a multi-mode clutch (10), a constant mesh gear (11), a second driven gear (12), and a main reduction gear (13). The input shaft (2) is connected to the motor (1); The first driving gear (5) is fixedly connected to the input shaft (2), the first driven gear (9) is fixedly connected to the multi-mode clutch (10), the multi-mode clutch (10) is connected to the intermediate shaft (3), and the first driving gear (5) meshes with the first driven gear (9); The wet clutch (7) and the second drive gear (8) are loosely fitted on the input shaft (2). The wet clutch (7) and the second drive gear (8) are fixedly connected. The synchronizer assembly (6) can disconnect or connect the power between the wet clutch and the input shaft (2). The second drive gear (8) meshes with the second driven gear (12). The second driven gear (12) is fixedly connected to the intermediate shaft (3). The constant meshing gear (11) meshes with the main reduction gear (13), the constant meshing gear (11) is fixedly connected to the intermediate shaft (3), and the main reduction gear (13) is fixedly connected to the output shaft (4). During gear shifting, the multi-mode clutch, wet clutch, and synchronizer assembly can be controlled independently without power interruption. The wet clutch is a normally closed wet clutch. After gear shifting, the wet clutch is engaged when the two-speed transmission of the pure electric vehicle is in first gear, reverse gear, or second gear.

2. The two-speed transmission for pure electric vehicles according to claim 1, characterized in that: The wet clutch includes a clutch driving end (71), a friction plate assembly (72), and a clutch driven end (73) that are loosely fitted on the input shaft (2). The clutch driving end (71) can cooperate with the synchronizer assembly (6). The friction plate assembly (72) can cut off or connect the power between the clutch driving end (71) and the clutch driven end (73). The clutch driven end (73) is fixedly connected to the second driving gear (8).

3. The two-speed transmission for pure electric vehicles according to claim 2, characterized in that: The synchronizer assembly (6) includes a clutch hub (61) and a sliding sleeve (62). The clutch hub (61) is fixedly connected to the input shaft (2), and the sliding sleeve (62) can move along the axis to realize the power cut-off or connection between the clutch hub (61) and the clutch driving end (71).

4. The two-speed transmission for pure electric vehicles according to claim 1, characterized in that: When the two-speed transmission of the pure electric vehicle is in first gear or reverse gear, the multi-mode clutch (10) is locked in both directions, and the synchronizer assembly (6) cuts off the power between the wet clutch and the input shaft (2), and the wet clutch is in the engaged state.

5. The two-speed transmission for pure electric vehicles according to claim 4, characterized in that: When the two-speed transmission of the pure electric vehicle is in second gear, the multi-mode clutch (10) is opened in both directions, and the synchronizer assembly (6) enables the power connection between the wet clutch and the input shaft (2), and the wet clutch is in the engaged state.

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