A dual-motor multi-gear electric drive system

Abstract

The application provides a double-motor multi-gear electric drive system, adopts an electric drive bridge scheme arranged coaxially at two positions, through more coaxial arrangement, space utilization can be improved, the volume and occupied space of the electric drive system are reduced, internal structures are reduced, the mass of the vehicle body is reduced, through three shaft nesting formed by the first half shaft, the intermediate shaft and the second motor input shaft, the power density can be further improved; through changing the positions of the first and second clutch devices, four gear positions in which the double motors work simultaneously can be combined, when each adjacent gear position is switched, it is ensured that one motor continuously outputs power, the occurrence of interrupting conditions in gear shifting is avoided, and the comfort of gear shifting is ensured; the fourth forward gear position can be directly shifted back to the first forward gear position, and this process is also without power interruption.

Description

Technical Field

[0001] This invention relates to the technical field of electric motor-driven vehicle transmission systems, and specifically to a dual-motor multi-speed electric drive system. Background Technology

[0002] Most current motor drive systems combine a motor and a reducer or a motor and a two-speed transmission. Motor drive systems capable of more than two speeds are relatively rare.

[0003] Motors are classified into low-speed and medium-speed motors and high-speed motors. Generally, low-speed and medium-speed motors can be made with hollow motor shafts to achieve coaxial arrangement with the differential half-shaft, thereby reducing the size of the electric drive axle. High-speed motors usually have thinner motor shafts. If they cannot be arranged coaxially with the differential half-shaft, they need to be offset and the number of shafts should be reduced as much as possible to reduce the size of the electric drive axle.

[0004] In a motor drive system, there are usually one or two motors. Motor drive systems with two or more speeds require shifting. Single-motor drive systems have a power interruption problem when shifting gears, while dual-motor drive systems can solve the power interruption problem by alternating between the two power sources.

[0005] The drawback of existing technology is that current electric drive axle solutions typically involve two or three stages of gear reduction from the drive motor to the differential. While two or three stages are sufficient for low- to medium-speed drive motors, these motors are inherently larger and heavier, making high-speed motors more preferred in practical applications. To achieve the same torque output, high-speed motors require a higher gear ratio. This ratio can be increased by using planetary gear pairs or by increasing the number of parallel shafts.

[0006] Using planetary gear pairs undoubtedly increases the complexity and manufacturing difficulty of the motor drive system. Increasing the number of parallel shafts will increase the size and weight of the motor drive system, which may not meet the usage requirements.

[0007] At the same time, the more gears a motor drive system has, the more gear pairs and shifting components are needed, which can lead to a mismatch between the achieved effect and the increased cost. Summary of the Invention

[0008] In order to overcome the defects and shortcomings of the existing technology, the present invention provides a dual-motor multi-speed electric drive system.

[0009] The specific solution provided by this invention is as follows:

[0010] A dual-motor multi-speed electric drive system, the system comprising:

[0011] A first motor, the output shaft of the first motor is connected to the input shaft of the first motor, and the input shaft of the first motor is connected to the input shaft through an input gear pair;

[0012] A second motor, the output shaft of which is connected to the input shaft of the second motor;

[0013] The first clutch device is fixedly mounted on the input shaft and can selectively engage with the first or second gear of the first or second gear pair on both sides or be in the middle position.

[0014] The second clutch device is fixedly mounted on the input shaft of the second motor and can selectively engage with the output driving gear of the output gear pair on both sides or the main reduction driven gear of the main reduction gear pair, or be in the neutral position.

[0015] The intermediate shaft is connected to the first motor via a first-speed gear pair or a second-speed gear pair, and the intermediate shaft is connected to the output shaft via an output gear pair;

[0016] An output shaft, which is connected to the differential via a main reduction gear pair;

[0017] A differential, wherein the differential is connected to the wheels via a first half-shaft and a second half-shaft on each side; characterized in that:

[0018] The second motor input shaft is sleeved on the outer circumference of the first half-shaft;

[0019] Furthermore, the intermediate shaft is sleeved on the outer periphery of the second motor input shaft.

[0020] In a further preferred embodiment of the present invention, the output shaft is sleeved on the outer periphery of the input shaft.

[0021] As a further preferred embodiment of the present invention, the input gear pair includes a corresponding meshing input driving gear and an input driven gear, wherein the input driving gear is fixedly disposed on the first motor input shaft, and the input driven gear is fixedly disposed on the input shaft.

[0022] As a further preferred embodiment of the present invention, the first gear pair includes a first gear driving gear and a first gear driven gear that mesh with each other; the first gear driving gear is movably sleeved on the input shaft, and the first gear driven gear is fixedly mounted on the intermediate shaft.

[0023] As a further preferred embodiment of the present invention, the two-speed gear pair includes a second-speed driving gear and a second-speed driven gear; the second-speed driving gear is movably sleeved on the input shaft, and the second-speed driven gear is fixedly mounted on the intermediate shaft.

[0024] As a further preferred embodiment of the present invention, the output gear pair includes a corresponding meshing output driving gear and an output driven gear; the output driving gear is fixedly disposed on the intermediate shaft, and the output driven gear is fixedly disposed on the output shaft.

[0025] As a further preferred embodiment of the present invention, the main reduction gear pair includes a main reduction driving gear and a main reduction driven gear that mesh with each other; the main reduction driving gear is fixedly mounted on the output shaft, and the main reduction driven gear is fixedly mounted on the differential housing of the differential.

[0026] As a further preferred embodiment of the present invention, the differential includes a differential housing, a differential bevel gear fixedly connected inside the differential housing, and half-shaft gears corresponding to and connected to the first half-shaft and the second half-shaft respectively provided on both sides of the differential bevel gear.

[0027] As a further preferred embodiment of the present invention, the system includes the following operating modes:

[0028] Mode N: The first clutch is in the neutral position, the second clutch is in the neutral position, and this is the neutral mode;

[0029] Mode 1: The first clutch engages with the first gear drive gear of the first gear pair on one side, and the second clutch engages with the output drive gear of the output gear pair on one side. At this time, it is the first forward gear.

[0030] Mode 2: The first clutch engages with the second drive gear of the second gear pair on the other side, and the second clutch engages with the output drive gear of the output gear pair on one side. At this time, it is the second forward gear.

[0031] Mode 3: The first clutch engages with the second gear drive gear of the second gear pair on the other side, and the second clutch engages with the main reduction driven gear of the main reduction gear pair on the other side. At this time, it is the third forward gear.

[0032] Mode 4: The first clutch engages with the first gear drive gear of the first gear pair on one side, and the second clutch engages with the main reduction driven gear of the main reduction gear pair on the other side. At this time, it is the fourth forward gear.

[0033] Compared with existing technologies, the technical effects that this invention can achieve include:

[0034] 1) This invention provides a dual-motor multi-speed electric drive system, which adopts a two-coaxial electric drive axle scheme. By using more coaxial arrangements, the space utilization rate can be improved, the volume and space occupied by the electric drive system can be reduced, the internal structure can be reduced, and the vehicle weight can be reduced. Through the three-axis nesting formed by the first half-shaft, the intermediate shaft and the second motor input shaft, the power density can be further improved.

[0035] 2) This invention provides a dual-motor multi-speed electric drive system. By changing the positions of the first and second clutch devices, four gears in which the dual motors work simultaneously can be combined. When switching between adjacent gears, it is ensured that one motor is always continuously outputting power, avoiding the occurrence of gear shifting interruption and ensuring the comfort of gear shifting. The fourth forward gear can be directly switched back to the first forward gear, and this process is also without power interruption. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the structure of the first embodiment of the present invention.

[0037] Figure 2 This is a power route diagram for the first forward gear in the first embodiment of the present invention.

[0038] Figure 3 This is a power route diagram for the second forward gear in the first embodiment of the present invention.

[0039] Figure 4 This is a power route diagram for the third forward gear in the first embodiment of the present invention.

[0040] Figure 5 This is a power route diagram for the fourth forward gear in the first embodiment of the present invention. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0043] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0044] [First Embodiment]

[0045] This invention provides a dual-motor multi-speed electric drive system, such as... Figure 1 The first embodiment of the present invention is shown, which includes:

[0046] A first motor EM1 has its output shaft connected to a first motor input shaft 1, and the first motor input shaft 1 is connected to an input shaft 7 via an input gear pair; for example... Figure 1 As shown, in this embodiment, the input gear pair includes a corresponding meshing input driving gear 2 and an input driven gear 3. The input driving gear 2 is fixedly mounted on the first motor input shaft 1, and the input driven gear 3 is fixedly mounted on the input shaft 7. The input gear pair can transmit the output power of the first motor EM1 to the input shaft 7.

[0047] The second motor EM2 has its output shaft connected to the second motor input shaft 16 to transmit the output power of the second motor EM2 to the second motor input shaft 16.

[0048] This embodiment also includes a first clutch device A, which is fixedly mounted on the input shaft 7 and can selectively engage with the driving gears of the first or second gear pairs on both sides or be in the neutral position; for example Figure 1 As shown, the first clutch device A includes a first gear hub 5, which engages or disengages with the first or second gear drive gear of the first or second gear pair on both sides to achieve the engagement or disengagement of the power transmission route.

[0049] This embodiment also includes a second clutch device B, which is fixedly mounted on the second motor input shaft 16 and can selectively engage with the output driving gear of the output gear pair on both sides or the main reduction driven gear of the main reduction gear pair, or be in the neutral position; such as Figure 1As shown, the second clutch device B includes a second gear hub 17. The second gear hub 17 engages or disengages with the output driving gear of the output gear pair on both sides or the main reduction driven gear of the main reduction gear pair to realize the engagement or disengagement of the power transmission route. By controlling the second clutch device B to engage to the right or to the left, the second motor EM2 can be directly connected to the differential or transmitted through gears.

[0050] like Figure 1 As shown, in this embodiment, the first gear pair includes a first gear drive gear 6 and a first gear driven gear 8 that mesh with each other; the first gear drive gear 6 is movably sleeved on the input shaft 7, and the first gear driven gear 8 is fixedly mounted on the intermediate shaft 10.

[0051] like Figure 1 As shown, in this embodiment, the second gear pair includes a second-gear drive gear 4 and a second-gear driven gear 9 that mesh with each other; the second-gear drive gear 4 is movably sleeved on the input shaft 7, and the second-gear driven gear 9 is fixedly mounted on the intermediate shaft 10.

[0052] The output power of the first motor EM1 can be transmitted from the input shaft 7 to the intermediate shaft 10 through the first gear pair and the second gear pair.

[0053] Intermediate shaft 10, the first motor EM1 is connected to the intermediate shaft 10 via a first gear pair and a second gear pair, and the intermediate shaft 10 is connected to the output shaft 13 via an output gear pair; as follows Figure 1 As shown, in this embodiment, the output gear pair includes a corresponding meshing output driving gear 11 and an output driven gear 12; the output driving gear 11 is fixedly mounted on the intermediate shaft 10, and the output driven gear 12 is fixedly mounted on the output shaft 13; the output gear pair can transmit the output power of the first and second motors to the output shaft 13 via the intermediate shaft 10.

[0054] Output shaft 13, which is connected to differential 18 via a main reduction gear pair; as Figure 1 As shown, in this embodiment, the main reduction gear pair includes a main reduction drive gear 14 and a main reduction driven gear 15 that mesh with each other; the main reduction drive gear 14 is fixedly mounted on the output shaft 13, and the main reduction driven gear 15 is fixedly mounted on the differential housing of the differential 18, and the power is transmitted to the differential through the main reduction gear pair.

[0055] Differential 18, the differential being connected to the wheels via first half-shafts 20 and second half-shafts 19 on both sides; in this embodiment, as... Figure 1As shown, the differential 18 includes a differential housing, a differential bevel gear fixedly connected inside the differential housing, and half-shaft gears corresponding to the first half-shaft 20 and the second half-shaft 19 respectively provided on both sides of the differential bevel gear; power is transmitted to the wheels on both sides through the differential.

[0056] The key contribution of this embodiment compared to existing technologies is:

[0057] The second motor input shaft 16 is sleeved on the outer periphery of the first half-shaft 20; and the intermediate shaft 10 is sleeved on the outer periphery of the second motor input shaft 16. This electric drive axle scheme, with its two coaxial locations, improves space utilization, reduces the size and space occupied by the electric drive system, decreases internal structure, and lightens vehicle weight. Furthermore, the three-axis nesting formed by the first half-shaft, intermediate shaft, and second motor input shaft further enhances power density.

[0058] As a preferred embodiment, the output shaft (13) is sleeved on the outer periphery of the input shaft (7). Through another coaxial arrangement, the space utilization rate is further improved, the volume and space occupied by the electric drive system are reduced, the internal structure is reduced, and the vehicle body weight is reduced.

[0059] This embodiment can combine four gears with dual motors working simultaneously by changing the positions of the first and second clutches. Under the premise that the second clutch remains unchanged, when switching between adjacent gears, it is ensured that one motor is always continuously outputting power, avoiding the occurrence of gear shifting interruption and ensuring the comfort of gear shifting. At the same time, it can realize the direct shift back to the first forward gear from the fourth forward gear.

[0060] As shown in Table 1, the system includes the following operating modes:

[0061] Mode N: The first clutch device A is in the neutral position, the second clutch device B is in the neutral position, and this is the neutral mode N;

[0062] Mode 1: The first clutch device A engages with the first gear drive gear of the first gear pair on one side, and the second clutch device B engages with the output drive gear of the output gear pair on one side. This is the first forward gear D1; the power transmission route in this gear is as follows... Figure 2 As shown;

[0063] Mode 2: The first clutch device A engages with the second drive gear of the second gear pair on the other side, and the second clutch device B engages with the output drive gear of the output gear pair on one side. This is the second forward gear, D2. The power transmission route in this gear is as follows: Figure 3 As shown;

[0064] Mode 3: The first clutch device A engages with the second drive gear of the second gear pair on the other side, and the second clutch device B engages with the driven gear of the main reduction gear pair on the other side. This is the third forward gear, D3. The power transmission route in this gear is as follows: Figure 4 As shown;

[0065] Mode 4: The first clutch device A engages with the first gear drive gear of the first gear pair on one side, and the second clutch device B engages with the main reduction driven gear of the main reduction gear pair on the other side. This is the fourth forward gear, D4. The power transmission route in this gear is as follows: Figure 5 As shown.

[0066] Table 1. Working positions of each clutch device under each working mode in the first embodiment.

[0067]

[0068] Note: √ indicates the current engagement position of the corresponding clutch device.

[0069] The power transmission paths for each speed ratio are as follows Figure 2-5 As shown. D1, D2, D3, and D4 refer to different gears here and do not represent the actual gear sequence.

[0070] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A dual-motor multi-speed electric drive system, the system comprising: The first motor (EM1) has its output shaft connected to its input shaft (1), and its input shaft (1) is connected to its input shaft (7) via an input gear pair. The second motor (EM2) has its output shaft connected to its input shaft (16). The first clutch device (A) is fixedly mounted on the input shaft (7) and can selectively engage with the first or second gear of the first or second gear pair on both sides or be in the middle position. The intermediate shaft (10) is connected to the first motor (EM1) via a first gear pair or a second gear pair, and the intermediate shaft (10) is connected to the output shaft (13) via an output gear pair. Output shaft (13), which is connected to differential (18) via main reduction gear pair; Differential (18), the differential is connected to the wheels via a first half-shaft (20) and a second half-shaft (19) on both sides respectively; Its characteristic is that it also includes: The second clutch device (B) is fixedly mounted on the second motor input shaft (16) and can selectively engage with the output driving gear of the output gear pair on both sides or the main reduction driven gear of the main reduction gear pair or be in the neutral position. The second motor input shaft (16) is sleeved on the outer periphery of the first half-shaft (20); Furthermore, the intermediate shaft (10) is sleeved on the outer periphery of the second motor input shaft (16); The output shaft (13) is sleeved on the outer periphery of the input shaft (7); The system includes the following operating modes: Mode N: The first clutch (A) is in the neutral position, the second clutch (B) is in the neutral position, and this is the neutral mode; Mode 1: The first clutch device (A) engages with the first gear drive gear of the first gear pair on one side, and the second clutch device (B) engages with the output drive gear of the output gear pair on one side. At this time, it is the first forward gear. Mode 2: The first clutch device (A) engages with the second gear drive gear of the second gear pair on the other side, and the second clutch device (B) engages with the output drive gear of the output gear pair on one side. At this time, it is the second forward gear. Mode 3: The first clutch device (A) engages with the second gear drive gear of the second gear pair on the other side, and the second clutch device (B) engages with the main reduction driven gear of the main reduction gear pair on the other side. At this time, it is the third forward gear. Mode 4: The first clutch device (A) engages with the first gear drive gear of the first gear pair on one side, and the second clutch device (B) engages with the main reduction driven gear of the main reduction gear pair on the other side. At this time, it is the fourth forward gear.

2. The dual-motor multi-speed electric drive system according to claim 1, characterized in that: The input gear pair includes a corresponding meshing input driving gear (2) and input driven gear (3). The input driving gear (2) is fixedly mounted on the first motor input shaft (1), and the input driven gear (3) is fixedly mounted on the input shaft (7).

3. The dual-motor multi-gear electric drive system of claim 1, wherein: The first gear pair includes a first gear drive gear (6) and a first gear driven gear (8) that mesh with each other; the first gear drive gear (6) is movably sleeved on the input shaft (7), and the first gear driven gear (8) is fixedly mounted on the intermediate shaft (10).

4. The dual-motor multi-gear electric drive system of claim 1, wherein: The second gear pair includes a second driving gear (4) and a second driven gear (9); the second driving gear (4) is movably sleeved on the input shaft (7), and the second driven gear (9) is fixedly mounted on the intermediate shaft (10).

5. The dual-motor multi-gear electric drive system of claim 1, wherein: The output gear pair includes a corresponding meshing output driving gear (11) and an output driven gear (12); the output driving gear (11) is fixedly mounted on the intermediate shaft (10), and the output driven gear (12) is fixedly mounted on the output shaft (13).

6. The dual-motor multi-gear electric drive system of claim 1, wherein: The main reduction gear pair includes a main reduction drive gear (14) and a main reduction driven gear (15) that mesh with each other; the main reduction drive gear (14) is fixedly mounted on the output shaft (13), and the main reduction driven gear (15) is fixedly mounted on the differential housing of the differential (18).

7. The dual-motor multi-gear electric drive system of claim 1, wherein: The differential (18) includes a differential housing, a differential bevel gear fixedly connected inside the differential housing, and half-shaft gears corresponding to the first half-shaft (20) and the second half-shaft (19) respectively provided on both sides of the differential bevel gear.

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