Transmission mechanism for an electric vehicle, range extender device, range extender system and electric vehicle

Abstract

The present invention provides a transmission mechanism for an electric vehicle, a range extender device and a range extender system, and an electric vehicle. The transmission mechanism comprises: a first input shaft (10) and a second input shaft (12); a first clutch (2) and a second rotating part (22); a reduction device (3) comprising a first input gear (32) and a ring gear (33), the ring gear having internal and external teeth, the first input gear being connected to the second input shaft and meshing with the internal teeth, and the ring gear being connected to the first clutch; a differential (7); an intermediate shaft; a first intermediate gear and a second intermediate gear arranged on the intermediate shaft; two output shafts (71), one end of each output shaft being driven by the differential;and a second clutch (6) arranged on a power transmission path of the transmission mechanism between the first intermediate gear and each other end of the output shafts, opposite one end.

Description

Technical field

[0001] The present application relates to the field of new energy vehicles, in particular a transmission mechanism for an electric vehicle, a range extender device for an electric vehicle and a range extender system for an electric vehicle, as well as an electric vehicle. State of the art

[0002] Given the scarcity of oil resources and increasing awareness of environmental protection, there is an urgent need for environmentally friendly vehicle products that can conserve energy and produce low or no emissions. As a result, vehicles with new energy sources, such as electric vehicles, are gaining increasing attention. An electric vehicle's traction motor has a wider operating range than a conventional vehicle's internal combustion engine, and its characteristic of constant torque at low speeds and constant power at high speeds is better suited to the vehicle's operational requirements. In recent years, the power drive system for electric vehicles and its operating modes have become key areas of research.

[0003] The prior art discloses a range extender system, or power coupling system, for an electric vehicle, comprising an internal combustion engine, a generator, and a drive motor. In this technology, both the generator and the drive motor are used, resulting in a complex vehicle structure, a large footprint, and increased manufacturing costs. Furthermore, in the prior art, the internal combustion engine and the generator are directly coupled, preventing flexible control of the engine and generator. The drive motor's output power must be reduced. However, the prior art typically uses a conventional planetary gear set for this reduction, leading to a bulky system and reduced transmission efficiency.

[0004] This creates a need to improve electric vehicles, especially the electric vehicle's range extender system. Disclosure of the invention

[0005] One object of the present invention is to provide a transmission mechanism for an electric vehicle, a range extender device and a range extender system, as well as an electric vehicle, which have a simple structure and save space.

[0006] To solve the above technical problem, the present disclosure provides a transmission mechanism for an electric vehicle, characterized in that it comprises: a first input shaft; a second input shaft; a first coupling arranged between the first input shaft and the second input shaft; and a first rotating part and a second rotating part that can be engaged and disengaged from each other, wherein the first rotating part of the first coupling is connected to the first input shaft;a reduction device, wherein the reduction device is arranged between the first clutch and the second input shaft and the reduction device comprises a first input gear and a ring gear, wherein the ring gear has internal teeth on a radially inner surface of the ring gear and external teeth on a radially outer surface of the ring gear, wherein the first input gear is connected on one side to the second input shaft and on the other side engages with the internal teeth, and wherein the ring gear is connected to the second rotating part of the first clutch so that the power from the first input shaft and the power from the second input shaft can be coupled to each other at the ring gear; a differential which is provided with a second input gear on a differential housing; an intermediate shaft;a first intermediate gear and a second intermediate gear, wherein the first intermediate gear and the second intermediate gear are arranged on the intermediate shaft, the first intermediate gear being in mesh with the external teeth of the ring gear, and wherein the second intermediate gear is driveably connected on one side to the first intermediate gear and on the other side to the second input gear of the differential, so that the second input gear is driveably connected to the ring gear; two output shafts, wherein one end of each of the two output shafts is driveably connected to the differential, so that the power from the differential can be transmitted;and a second clutch arranged on a power transmission path of the transmission mechanism between the first intermediate gear and each other end of the two output shafts, opposite one end, so that power transmission between the first intermediate gear and the other end of each of the two output shafts can be allowed or disconnected.

[0007] The transmission mechanism for an electric vehicle according to the present disclosure has a compact structure, increases the space utilization in the vehicle, enables a reduction of the motor power with a simple design and can quickly disconnect the power transmission from a drive device to the wheels.

[0008] Preferably, it is provided that in the radial direction of the gear ring, the point of engagement between the first input gear and the internal teeth of the gear ring overlaps with the point of engagement between the first intermediate gear and the external teeth of the gear ring.

[0009] According to one aspect of the present disclosure, the first input gear engages with the internal teeth of the gear ring on a side of the gear ring facing the first intermediate gear.

[0010] According to a further aspect of the present disclosure, it is provided that the first input gear engages with the internal teeth of the gear ring on a side of the gear ring facing away from the first intermediate gear; and that the reduction device further comprises a first transition gear with a fixed center point and a second transition gear with a fixed center point, wherein the first transition gear is arranged between the first input gear and the second transition gear and engages with both the first input gear and the second transition gear, and wherein the second transition gear engages with the internal teeth of the gear ring.

[0011] Preferably, the first transition gear and the second transition gear are supported by a common gear carrier. Furthermore, the gear centers of the first input gear, the ring gear, the first transition gear, the second transition gear, and the first intermediate gear are preferably arranged on a straight line.

[0012] The second clutch could be a dog clutch. The first clutch could be a friction clutch.

[0013] The transmission mechanism for an electric vehicle according to the present disclosure has a compact structure. By overlapping, in the radial direction of the ring gear, the engagement point between the first input gear and the internal teeth of the ring gear with the engagement point between the first intermediate gear and the external teeth of the ring gear, the forces acting on the ring gear can be effectively canceled out.

[0014] Preferably, the second coupling is a claw coupling, and the first coupling is a friction coupling.

[0015] According to one aspect of the present disclosure, the second coupling is arranged between the first intermediate gear and the second intermediate gear, so that power transmission between the first intermediate gear and the second intermediate gear can be allowed or disconnected.

[0016] According to one aspect of the present disclosure, the second coupling is arranged on any one of the two output shafts, so that a power transmission between the differential and the other end can be separated.

[0017] The transmission mechanism for an electric vehicle further comprises: a damper arranged between the first input shaft and the first clutch, wherein an input of the damper is drivenly connected to the first input shaft, and wherein an output of the damper is drivenly connected to the first rotating part of the first clutch.

[0018] The damper is a torsional damper.

[0019] The present disclosure provides a range extender device for an electric vehicle, characterized in that it comprises: a motor generator; and the above transmission mechanism for an electric vehicle, wherein the second input shaft of the transmission mechanism for an electric vehicle is drivenly connected to the motor generator.

[0020] The motor generator is a permanent magnet synchronous motor.

[0021] The present disclosure provides a range extender system for an electric vehicle, characterized in that it comprises: an internal combustion engine; and the above range extender device for an electric vehicle, wherein the first input shaft of the transmission mechanism for an electric vehicle is drivenly connected to the internal combustion engine.

[0022] The combustion engine is an inline four-cylinder combustion engine.

[0023] The present disclosure provides an electric vehicle characterized in that it comprises: the above range-extender system for an electric vehicle, a traction battery in which the current generated by the range-extender system is stored; and a pair of wheels, wherein the pair of wheels is a pair of front wheels or a pair of rear wheels of the electric vehicle, and wherein the other end of each of the two output shafts of the transmission mechanism for an electric vehicle is drivenly connected to one wheel of the pair of wheels.

[0024] The electric vehicle comprises a main drive consisting of a main drive motor and a main reduction gearbox connected to the main drive motor, the main drive being powered by the electric vehicle's drive battery, and the main drive being used to drive a different pair of wheels than the pair of wheels driven by the electric vehicle's range extender system.

[0025] When the range extender device for an electric vehicle is used to drive a pair of the vehicle's front wheels, the main drive powers a pair of the vehicle's rear wheels. While the vehicle is in motion, the main drive is typically always engaged, and the range extender device operates as needed, depending on the vehicle's situation, road surface conditions, etc., to provide propulsion, power generation, or both.

[0026] The present disclosure further provides a method for controlling the range extender device for an electric vehicle, characterized in that it comprises: Step S21: Determining a relationship between a state of charge (SOC) and an SOC threshold of the electric vehicle's traction battery, or determining both the relationship between SOC and an SOC threshold of the electric vehicle's traction battery and a relationship between a vehicle speed and a vehicle speed threshold of the electric vehicle; and Step S22: Selecting an operating mode of the range extender device depending on the result of the determination.

[0027] The present disclosure further provides a computer-readable medium comprising a program containing several instructions, wherein, when the program is executed on an on-board computer, the instructions perform the method for controlling the above range-extender system for an electric vehicle. For example, the computer-readable medium is a program carrier such as a hard drive.

[0028] The reduction gear, range extender device, and / or range extender system for an electric vehicle according to the present disclosure have a compact structure, increase space utilization in the vehicle, enable a reduction of engine power with a simple design, and can quickly disconnect the power transmission from a drive device to the wheels. The method for controlling the range extender device for an electric vehicle according to the present disclosure allows several operating modes to be automatically switched depending on the state of charge (SOC) of the drive battery and the vehicle speed. Brief description of the characters

[0029] The features, advantages, technologies, and industrial significance of exemplary embodiments of the present invention are described below with reference to the accompanying drawings, where the same reference numerals denote the same elements. Obviously, the accompanying drawings described below represent only some embodiments of the present invention. A person skilled in the art can modify these accompanying drawings without inventive step. Fig. Figure 1 shows a schematic structural representation of a transmission mechanism for an electric vehicle, a range extender device and a range extender system according to a first embodiment; Fig. Figure 2 shows a schematic representation of a state of the gear mechanism according to the first embodiment, in which a first input gear, a ring gear and a first intermediate gear are in engagement with each other; Fig. Figure 3 shows a schematic structural representation of the transmission mechanism for an electric vehicle, the range extender device and the range extender system according to a second embodiment; Fig. Figure 4 shows a schematic structural representation of the transmission mechanism for an electric vehicle, the range extender device and the range extender system according to a third embodiment; Fig. Figure 5 shows a schematic representation of a state of the transmission mechanism according to the third embodiment, in which a first input gear, a ring gear, a first transition gear and a second transition gear are in mesh with each other; and Fig. Figure 6 shows a schematic structural representation of the transmission mechanism for an electric vehicle, the range extender device and the range extender system according to a fourth embodiment. Detailed descriptions

[0030] The following section describes individual embodiments of the present invention with reference to the accompanying drawings, in order to illustrate specific embodiments that can be carried out by the present invention. The terms "left" and "right," etc. (where applicable) in the description serve only to describe the present application with reference to the accompanying drawings and do not limit the present invention. Furthermore, it is understood that the terms "left" or "right" represent only one direction and can be used in reverse. The terms used in the description serve only for simplification and are not to be understood as limiting. The terms "axial," "radial," "circumferential direction," "outward," "inward," "above," and "below," etc. (where applicable), denote directions with respect to the accompanying drawings.Unless expressly stated otherwise, all values, ranges, and shapes (where provided) are to be understood as approximate, as if the terms "approximately," "about," or "essentially" preceded the respective values ​​or ranges. The terms "approximately" and "essentially," etc., are intended to denote ranges that largely or predominantly, but not necessarily completely (though possibly completely), cover the specified areas. [System configuration]First example:

[0031] Fig. Figure 1 shows a schematic structural representation of a transmission mechanism for an electric vehicle, a range extender device, and a range extender system according to a first embodiment. As in Fig. As shown in Figure 1, the range extender system for an electric vehicle according to the first embodiment comprises: an internal combustion engine 1; a motor-generator 4; and a transmission mechanism located between the internal combustion engine 1 and the motor-generator 4, as indicated by a dashed block. The transmission mechanism can extract power from the internal combustion engine 1 and the motor-generator 4. The internal combustion engine 1 and the motor-generator 4 are preferably located on two opposite sides of the transmission mechanism.

[0032] The transmission mechanism comprises two input shafts, namely a first input shaft 10 and a second input shaft 12. Both the first input shaft 10 and the second input shaft 12 are rotatably mounted. The first input shaft 10 and the second input shaft 12 serve to receive power inputs from corresponding power sources, for example, the internal combustion engine 1 and the motor-generator 4.

[0033] The transmission mechanism further comprises a first clutch 2, which is arranged between the first input shaft 10 and the second input shaft 12. The first clutch 2 comprises a first rotating part 21 and a second rotating part 22, which can be engaged and disengaged from one another. The first rotating part 21 is connected to the first input shaft 10 to receive power from it and is thereby connected to the internal combustion engine 1, in particular to a crankshaft of the internal combustion engine. The connection between the first rotating part 21 and the first input shaft 10 can be a direct connection, such as a positive-locking connection or a friction-locking connection, or an indirect connection, such as a connection via a conventional coupler.The second rotating part 22 is drive-connected to the second input shaft 12, for example via a reduction device 3 as described below, and is thereby drive-connected to the motor-generator 4, in particular to an output shaft of the motor-generator. This allows the first coupling 2 to drive-connect the first input shaft 10 to the second input shaft 12. Accordingly, the first coupling 2 can drive-connect the internal combustion engine 1 to the motor-generator 4. In the present disclosure, the term "drive-connected" refers to a type of connection in which two parts are directly or indirectly connected to each other so that power transmission between them is possible.

[0034] The transmission mechanism for an electric vehicle further comprises a reduction device 3. The reduction device 3 is arranged between the first clutch 2 and the second input shaft 12, which can be connected to the motor-generator 4. The reduction device 3 comprises a first input gear 32 and a ring gear 33. The first input gear 32 is located radially inside the ring gear 33. The ring gear 33 has internal teeth 331 on a radially inner surface and external teeth 333 on a radially outer surface of the ring gear. The first input gear 32 is connected to the second input shaft 12 on one side and engages with the internal teeth 331 on the other. The ring gear 33 is connected to the second rotating part 22 of the first clutch 2. This allows the power from the first input shaft 10 and the power from the second input shaft 12 to be coupled to each other at the ring gear 33.

[0035] The transmission mechanism for an electric vehicle further comprises a differential 7, which is provided with a second input gear 70 on a differential housing. The second input gear 70 can be driven by the reduction device 3, so that it can receive power from the reduction device 3.

[0036] The transmission mechanism for an electric vehicle further comprises an intermediate shaft 222, a first intermediate gear 24, and a second intermediate gear 25. The first intermediate gear 24 and the second intermediate gear 25 are located on the intermediate shaft 222, with at least one of the intermediate gears being rotationally fixed to the intermediate shaft 222. The axis of the intermediate shaft 222 differs from the axis of rotation of the ring gear 33 of the reduction device 3 and from the axis of rotation of an output shaft 71 of the differential 7 and lies between these two axes. The first intermediate gear 24 meshes with the external teeth 332 of the ring gear 33. The second intermediate gear 25 is driven by the first intermediate gear 24 to receive power from it. It is also driven by the second input gear 70 of the differential.Preferably, it engages with the second input gear 70. This allows the second input gear 70 to be driven by the ring gear 33, in particular by the external teeth 332 of the ring gear 33. In particular, the intermediate shaft 222 can be rotatably mounted as required, wherein one of the first intermediate gear 24 and the second intermediate gear 25 is fixed to the intermediate shaft 222 or formed integrally with it, while the other intermediate gear is rotatably mounted on the intermediate shaft 222. Alternatively, both the first intermediate gear 24 and the second intermediate gear 25 are fixed to the intermediate shaft 222 or formed integrally with it. The term "fixed to rotation" refers to a type of connection in which two parts are rigidly connected to each other so that they cannot rotate relative to each other.

[0037] The transmission mechanism for an electric vehicle further comprises two output shafts 71. One end of each of the two output shafts 71 is drive-connected to the differential 7 so that power from the differential 7 can be transmitted. The output shaft 71 is used, for example, to transmit the power to a pair of wheels of the electric vehicle. In particular, the other end of each of the output shafts 71, opposite the end drive-connected to the differential 7, can be connected to one wheel of a pair of wheels 8 of the electric vehicle to transmit the power from the differential 7 to the pair of wheels 8. The pair of wheels 8 is either a pair of front wheels or a pair of rear wheels of the electric vehicle.

[0038] The transmission mechanism for an electric vehicle further comprises a second clutch 6, which is arranged on a power transmission path of the transmission mechanism between the first intermediate gear 24 and the other end of each of the two output shafts 71, which is opposite to one end, so that a power transmission between the first intermediate gear 24 and the other end of each of the two output shafts can be allowed or disconnected.

[0039] In particular, the Fig. It can be seen from Figure 1 that the second clutch 6 is located on the intermediate shaft 222 and is arranged between the first intermediate gear 24 and the second intermediate gear 25, so that power transmission between the first intermediate gear 24 and the second intermediate gear 25 can be allowed or disconnected.

[0040] Fig. Figure 2 shows a schematic representation of a state of the gear mechanism according to the first embodiment, in which a first input gear, a ring gear, and a first intermediate gear are meshed with each other. In connection with Fig. 2 and Fig. As can be seen in Figure 1, the engagement point between the first input gear 32 and the gear ring 33, in particular its internal teeth 331, overlaps substantially with the engagement point between the first intermediate gear 24 and the gear ring 33, in particular its external teeth 333, in the radial direction of the gear ring 33. This means that these two engagement points are arranged substantially on a straight line in the radial direction of the gear ring 33, as shown in Figure 1. Fig. 2 is represented by a dashed line. In other words, the two points of engagement are located in the circumferential direction of the gear ring at essentially the same position or the same circumferential angle on the circumference of the gear ring.

[0041] Furthermore, the Fig. As can be seen from Figure 2, the first input gear 32 engages with the internal teeth 331 of the gear 33 on the side of the gear 33 facing the first intermediate gear 24. This means that, during the transmission of power from the first input gear 32 via the gear 33 to the first intermediate gear 24, the forces acting on the gear 33, particularly radial and axial forces, are canceled out due to the overlapping arrangement of these two engagement points in the radial direction of the gear 33. Accordingly, the reduction device according to the present disclosure can reduce the rotational power of a drive source with a simple design and in a stable manner. This further reduces costs.

[0042] The type of the second coupling 6 is also not limited. Preferably, however, the second coupling 6 is also a jaw coupling (also referred to as a serrated coupling or pawl coupling). The jaw coupling can be either a radial jaw coupling or an axial jaw coupling. The jaw coupling comprises a first outer splined section (not shown) provided on the first intermediate gear 24, a second outer splined section (not shown) provided on the second intermediate gear 25, and a sliding sleeve (not shown) with an inner splined section.The sliding sleeve, with its internal splined teeth, is slidably arranged on one of the first and second external splined teeth. When engagement is required, it is axially actuated to bring its internal splined teeth into contact with the other external splined teeth, thus achieving synchronous rotation of the first and second intermediate gears. The jaw coupling has the following design features: a simple structure, low drag loss, compact dimensions, no relative rotation between two meshing, connected shafts; ease of operation, the ability to transmit high torque, effective prevention of overload and overheating, extended service life of the device, and a fast response characteristic.With the jaw coupling, the transmission mechanism for an electric vehicle according to the present disclosure has a small size. Furthermore, the electric vehicle can be driven quickly (by a main drive or an auxiliary drive). In a case where one of the intermediate gears is fixedly arranged on the intermediate shaft 222 or is formed integrally with the intermediate shaft 222, an external splined connection of the jaw coupling associated with this intermediate gear can be formed directly on the intermediate shaft 222.

[0043] The first coupling 2 can be any type of coupling, for example, a friction coupling. Friction couplings offer advantages such as simple design and low cost. As described above, the second rotating part 22 of the first coupling 2 is drivenly connected to the gear ring 33 of the reduction device 3. However, it is easy to understand that the second rotating part 22 of the first coupling 2 can be rigidly connected to the gear ring 33 of the reduction device 3 or formed integrally with it.

[0044] The differential 7 is a conventional type of differential. As described above, each output shaft 71 of the transmission mechanism is driven by the differential 7 at one end and by a corresponding wheel 8 of the electric vehicle at the other end. In this case, the output shaft 71 of the transmission mechanism can also be considered the output shaft of the differential 7 itself. The specific design of the differential may be known and is not described in detail here.

[0045] The first rotating part 21 of the first clutch 2 can be directly driven by a power source, such as the internal combustion engine 1. Preferably, the output of an external power source, such as the internal combustion engine 1, is buffered or damped. The transmission mechanism for an electric vehicle can be equipped with a damper 11, which is arranged between the first input shaft 10 and the first clutch 2. The inlet of the damper 11 is driven by the first input shaft 10 and thus connectable to the crankshaft of the internal combustion engine 1, and the outlet of the damper 11 is driven by the first rotating part 21 of the first clutch 2. The damper is preferably a torsional damper. However, the type of damper is not limited and can also be another type of damper, for example, a hydraulic damper.

[0046] Preferably, the transmission mechanism can include a housing to accommodate one or more parts of the transmission mechanism. Preferably, the internal combustion engine 1 and the motor-generator 4 can be located outside the housing and on two opposite sides of the housing. The housing can, for example, be attached to the frame of the electric vehicle. In a transmission mechanism provided with the housing, the first input shaft 10 is rotatably mounted in a wall on one side of the housing, and the second input shaft 12 is rotatably mounted in a wall on the opposite side of the housing. For example, the engine 1 is located on one side and the motor-generator 4 on the other side. The damper 11 and the reduction gear 3 can be arranged inside or outside the housing. The first clutch 2 is preferably arranged inside the housing.The differential 7 is preferably arranged inside the housing. One of the two output shafts 71 is rotatably mounted in a wall on one side of the housing, and the other output shaft is rotatably mounted in a wall on the other side of the housing. It is understood that the positional relationships of all parts of the transmission mechanism relative to the housing are not restricted, but can be selected appropriately according to the actual requirements. The design of the housing is not restricted. For example, the housing may have no wall in the axial direction of the input shaft and / or the output shaft.

[0047] Individual parts of the transmission mechanism for an electric vehicle, constructed as described above, feature a practical layout and compact structure, facilitating assembly, saving space, and increasing space utilization within the vehicle. In particular, by using the reduction device 3 according to the present disclosure, the rotational power of a drive source can be reduced with a simple and stable design, and by using the second clutch 6 according to the present disclosure, the power transmission from a drive device to the wheels of the electric vehicle can be quickly disconnected. Second example:

[0048] Fig. Figure 3 shows a schematic structural representation of the transmission mechanism for an electric vehicle, the range extender device, and the range extender system according to a second embodiment. The elements of the second embodiment, which are identical to those of the first embodiment, are designated with the same reference numerals and are not described again here. Only the different elements are explained.

[0049] As in Fig. As shown in Figure 1, in the first embodiment described above, the second coupling 6 is located on the intermediate shaft 222 and is arranged between the first intermediate gear 24 and the second intermediate gear 25. In contrast to the first embodiment, in the second embodiment the second coupling 6 is arranged on one of the two output shafts 71, as shown in Figure 1. Fig. Figure 3 shows that this allows the power transmission from the differential 7 to the other end of either of the two output shafts 71 to be disconnected. It is understood that regardless of which of the two output shafts 71 the second coupling 6 is located on, the same effect of disconnecting the power transmission can be achieved. Third example:

[0050] Fig. Figure 4 shows a schematic structural representation of the transmission mechanism for an electric vehicle, the range extender device and the range extender system according to a third embodiment. Fig. Figure 5 shows a schematic representation of a state of the transmission mechanism according to the third embodiment, in which a first input gear, a ring gear, a first transition gear, and a second transition gear are meshed with one another. The elements of the third embodiment, which are identical to those of the first embodiment, are designated with the same reference numerals and are not described again here. Only the different elements are explained.

[0051] As in Fig. As shown in Figure 2, in the first embodiment described above, the first input gear 32 engages with the internal teeth 331 of the gear ring 33 on a side of the gear ring 33 facing the first intermediate gear 24. In contrast to the first embodiment, in the third embodiment, the first input gear 32 engages with the internal teeth 331 of the gear ring 33 on a side of the gear ring 33 facing away from the first intermediate gear 24, as shown in Figure 2. Fig. 4 to Fig. 5 shown.

[0052] Apart from the first input gear 32, the reduction device 3, particularly in the third embodiment, also comprises a first transition gear 34 and a second transition gear 35. The centers of the first transition gear 34 and the second transition gear 35 are each fixed. The first transition gear 34 and the second transition gear 35 are located radially within the gear ring 33 and can be mounted independently of each other. Preferably, however, the first transition gear 34 and the second transition gear 35 can be supported by a common gear carrier 36, which is fixed, for example, attached to a stator 42 of the electric motor 4.The first transition gear 34 is arranged between the first input gear 32 and the second transition gear 35 and is in mesh with both the first input gear 32 and the second transition gear 35, with the second transition gear 35 meshing with the internal teeth 331 of the gear ring 33. As in . Fig. As can be clearly seen in Figure 5, the first input gear 32 is located on the side of the gear ring 33 facing away from the first intermediate gear 24 (see Figure 5). Fig. 4), while the second transition gear 35 is located on the side of the gear ring 33 facing the first intermediate gear 24 and engages with the internal teeth 331 of the gear ring 33.

[0053] The dimensions and arrangement of the first input gear 32, the first transition gear 34, and the second transition gear 35 are not particularly restricted, as long as these three gears—namely, the first input gear 32, the first transition gear 34, and the second transition gear 35—engage in such a way that the first input gear 32 and the second transition gear 35 each engage with the internal teeth 331 of the gear ring 33. Preferably, the centers, i.e., the gear centers, of the first input gear 32, the gear ring 33, the first transition gear 34, the second transition gear 35, and the first intermediate gear 24 (not shown) are arranged on a straight line L, as shown in Fig. 5 shown. This allows the radial force acting on the gear ring to be better balanced.

[0054] When power is transmitted from the first input gear 32 via the ring gear 33 to the first intermediate gear 24, the forces acting on the ring gear are balanced by the radial overlap of the engagement point between the second transition gear 35 and the ring gear 33, in particular its internal teeth 331, with the engagement point between the first intermediate gear 24 and the ring gear 33, in particular its external teeth 333, in the radial direction of the ring gear 33. Accordingly, the reduction device according to the present disclosure can reduce the rotational power of a drive source with a simple design and in a stable manner. In this way, costs are further reduced. Fourth example:

[0055] Fig. Figure 6 shows a schematic structural representation of the transmission mechanism for an electric vehicle, the range extender device, and the range extender system according to a fourth embodiment. The elements of the fourth embodiment, which are identical to those of the third embodiment, are designated with the same reference numerals and are not described again here. Only the different elements are explained.

[0056] As in Fig. As shown in Figure 4, in the third embodiment described above, the second coupling 6 is located on the intermediate shaft 222 and is arranged between the first intermediate gear 24 and the second intermediate gear 25. In contrast to the third embodiment, in the fourth embodiment the second coupling 6 is arranged on one of the two output shafts 71, as shown in Figure 4. Fig.Figure 6 shows that this allows the power transmission from the differential 7 to the other end of either of the two output shafts 71 to be disconnected. It is understood that regardless of which of the two output shafts 71 the second coupling 6 is located on, the same effect of disconnecting the power transmission can be achieved.

[0057] The range extender device for an electric vehicle according to the present disclosure comprises a transmission mechanism according to any one of the first to fourth embodiments described above and a motor generator 4. The second input shaft 12 of the transmission mechanism for an electric vehicle is drivenly connected to the motor generator 4.

[0058] The motor-generator 4 can be used both as an electric motor and as a generator. The motor-generator 4 is equipped with an inverter (not shown) which serves to control its operation. The motor-generator is preferably a permanent magnet synchronous motor (PSM). However, it is understood that the type of motor-generator 4 is not limited.

[0059] The range extender system for an electric vehicle of the present disclosure comprises the range extender device described above and the internal combustion engine 1. The first input shaft 10 of the transmission mechanism for an electric vehicle is driven by the internal combustion engine 1, in particular by its crankshaft. The type of internal combustion engine 1 is not limited and can, for example, be an inline four-cylinder internal combustion engine, a boxer six-cylinder internal combustion engine, or a V-shaped twelve-cylinder internal combustion engine. The output parameters of the internal combustion engine, such as the maximum torque or the maximum output power, are also not limited and are selected as required. This allows the internal combustion engine 1 and the motor-generator 4 to jointly deliver power to the output shaft 71 of the range extender system.However, it is easy to understand that the mechanical power output of the combustion engine 1 can be limited to the output shaft 71, so that only the motor generator 4 supplies power to the output shaft 71 to ensure a pure electric drive mode of the range extender system.

[0060] Prior art range extender devices and / or range extender systems typically use two electric motors, one for power generation and the other for driving the vehicle to perform the range extender function. This makes the device bulky and increases costs. The range extender device and / or range extender system of the present disclosure, described above, requires only one electric motor, namely the motor-generator 4, to perform two functions: power generation and vehicle propulsion. This allows the range extender function to be implemented with low cost and a small footprint.Furthermore, by using the reduction device 3 according to the present disclosure, the rotational power of a drive source can be reduced with a simple construction and in a stable manner, and by using the second coupling 6 according to the present disclosure, the power transmission from a drive device to the output shafts or the wheels of the electric vehicle can be quickly disconnected.

[0061] The electric vehicle of the present disclosure comprises the above range-extender system, a traction battery, and a pair of wheels 8, wherein the pair of wheels is either a pair of front wheels or a pair of rear wheels of the electric vehicle. The other end of each of the two output shafts of the transmission mechanism for an electric vehicle is driven by one wheel of the pair of wheels 8. The electricity generated by the range-extender system can be stored in the traction battery of the electric vehicle. The range-extender system of the present invention can be a single drive system for the electric vehicle. This eliminates the need for an additional drive system to enable efficient electricity generation and propulsion of the electric vehicle, thus reducing costs.

[0062] However, it is readily apparent that the range extender system of the present invention can serve as an auxiliary drive for the electric vehicle. Thus, the electric vehicle of the present disclosure can additionally include a main drive. The main drive comprises a main drive motor and a main reduction gear connected to the main drive motor. The main drive is used to drive a different pair of wheels than the pair of wheels 8 driven by the range extender system of the electric vehicle. For example, the range extender system according to the present disclosure can be used to drive a pair of front wheels of the electric vehicle, while the main drive can be used to drive a pair of rear wheels of the electric vehicle.Because the main drive itself can achieve two-wheel drive of the electric vehicle, the electric vehicle of the present disclosure can easily achieve four-wheel drive of the electric vehicle by means of the range extender system.

[0063] With the electric vehicle's range extender device and / or range extender system, designed as above, the damper can be easily mounted on the combustion engine, resulting in high power density and smooth operation, and the entire range extender device and / or range extender system being highly integrated and compact, leading to low resistance loss when the electric vehicle coasts. [Tax strategy]

[0064] The range extender system for an electric vehicle according to a first embodiment has a variety of operating modes, including a pure electric drive mode, a hybrid drive mode, a first range extender mode, and a second range extender mode. Furthermore, several modes can be automatically switched depending on the state of charge (SOC) of the traction battery and the required vehicle speed.Thus, the present disclosure further provides a method for controlling the range extender system for an electric vehicle, comprising: Step S21: Determining a magnitude relationship between SOC and an SOC threshold of the electric vehicle's traction battery, or determining both the magnitude relationship between SOC and an SOC threshold of the electric vehicle's traction battery and a magnitude relationship between a vehicle speed and a vehicle speed threshold of the electric vehicle; and Step S22: Selecting an operating mode of the range extender system depending on the result of the determination.

[0065] As shown in the following diagram, the SOC threshold comprises three thresholds: a first SOC threshold S1, a second SOC threshold S2 (which is lower than the first SOC threshold S1), and a third SOC threshold S3 (which is lower than the second SOC threshold S2). The operating mode of the range extender system is selected based on the relationship between the SOC and the respective SOC thresholds (S1, S2, and S3) of the traction battery and the relationship between a vehicle speed V and a vehicle speed threshold V1 of the electric vehicle.

[0066] Diagram showing SOC and vehicle speed compared to the respective thresholds:

[0067] If, in step S21, it is determined that the state of charge (SOC) of the electric vehicle's traction battery is higher than the first SOC threshold S1, step S22 specifically includes: controlling the internal combustion engine 1 and the motor-generator 4 by disengaging the internal combustion engine while operating the motor-generator as the traction motor; disengaging the first clutch 2 and engaging the second clutch 6; and transferring the power from the motor-generator 4 via a reduction mechanism 3, the first intermediate gear 24, and the second intermediate gear 25 to the differential 7 and then to a pair of wheels 8 to propel the electric vehicle. In this case, the electric vehicle range extender system operates in pure electric drive mode. The electric vehicle's main drive (not shown, if present) is typically used to power the other pair of wheels besides the one pair of wheels 8 of the electric vehicle.This allows the electric vehicle to achieve four-wheel drive when the range extender system for an electric vehicle is operated in pure electric drive mode.

[0068] If, in step S21, it is determined that the state of charge (SOC) of the traction battery is lower than the first SOC threshold S1 but higher than the second SOC threshold S2, and that the vehicle speed V is higher than the vehicle speed threshold V1, step S22 comprises: controlling the internal combustion engine 1 and the motor-generator 4 by operating the internal combustion engine and the motor-generator as the traction engine; engaging the first clutch 2 and the second clutch 6; coupling the power of the internal combustion engine 1 and the power of the motor-generator 4 via the reduction mechanism 3; and then transmitting the coupled power via the first intermediate gear 24 and the second intermediate gear 25 to the differential 7 and then to a pair of gears 8. In this case, the range extender system for an electric vehicle operates in hybrid drive mode.The main drive (not shown, if present) of the electric vehicle is typically used to power the other pair of wheels besides the one pair of wheels 8 of the electric vehicle. This gives the electric vehicle four-wheel drive when the range extender system for an electric vehicle is operating in hybrid drive mode.

[0069] If in step S21 it is determined that the SOC of the traction battery is lower than the second SOC threshold S2 but higher than the third SOC threshold S3, and that the vehicle speed V is higher than the vehicle speed threshold V1, step S22 comprises: controlling the internal combustion engine 1 and the motor generator 4 by operating the internal combustion engine and operating the motor generator as a generator; engaging the first clutch 2 and the second clutch 6; and transferring part of the power of the internal combustion engine 1 via the first clutch 2 and the reduction mechanism 3 to the motor generator 4 for power generation, and the other part of the power of the internal combustion engine 1 via the first clutch 2, the reduction mechanism 3, the first intermediate gear 24, the second intermediate gear 25, and the differential 7 to a pair of gears 8.The current generated by the motor-generator 4 is stored in the electric vehicle's traction battery (not shown). In this case, the electric vehicle's range extender system operates in the first range extender mode. The electric vehicle's main drive (not shown, if present) is typically used to power the other pair of wheels besides the one pair of wheels 8. This also gives the electric vehicle four-wheel drive when the electric vehicle's range extender system is operating in the first range extender mode.

[0070] If, in step S21, it is determined that the traction battery's state of charge (SOC) is lower than the third SOC threshold S3 and the vehicle speed is lower than the vehicle speed threshold V1, step S22 comprises: controlling the first clutch 2 to engage and the second clutch 6 to disengage; and controlling the internal combustion engine 1 to put the motor-generator 4 into power generation mode via the first clutch 2 and the reduction mechanism 3 to charge the traction battery. In this mode, the electric vehicle's range extender system operates in a second range extender mode, generating power only (pure power generation mode). The power generated by the motor-generator 4 is stored in the electric vehicle's traction battery (not shown).If the main drive (not shown, if present) of the electric vehicle is currently driving the other pair of wheels than the one pair of wheels 8 of the electric vehicle, the electric vehicle will be driving in two-wheel drive mode in a low-speed range when the range extender system for an electric vehicle is operating in the second range extender mode.

[0071] Furthermore, it is provided that when the range extender system is started up, the motor generator 4 can serve as a drive motor to start the internal combustion engine 1. Accordingly, the method for controlling the range extender system for an electric vehicle according to the present embodiment further comprises: Step S23: Controlling the motor generator 4 to generate a starting torque when starting up the range extender system and starting the internal combustion engine 1.

[0072] Because the SOC of the traction battery is low in the first and second range extender modes described above, the combustion engine 1 puts the motor generator 4 into charging mode to quickly increase the SOC of the traction battery.

[0073] The SOC thresholds mentioned above are used to determine the state of charge (SOC) of the traction battery, and the vehicle speed thresholds are used to determine the vehicle speed. In this embodiment, specific values ​​for the SOC and vehicle speed thresholds are not defined. They can typically be freely set according to specific control strategies, and the values ​​for any one SOC or vehicle speed threshold may differ depending on the control strategy. Once the respective SOC and vehicle speed thresholds have been set, the electric vehicle can automatically perform a determination and switch between several modes depending on the result of the determination.

[0074] Furthermore, when the vehicle brakes, the first clutch 2 is disengaged and the second clutch 6 is engaged to generate a braking torque for braking the wheels using the motor-generator 4. This generates an inductive current in the windings of the motor-generator 4 to charge the electric vehicle's traction battery and recover braking energy. Thus, the control method according to the present embodiment further comprises: controlling the second clutch 6 to generate a braking torque during braking and generating an inductive current in the windings of the motor-generator 4 to charge the electric vehicle's traction battery.

[0075] Furthermore, in the range extender system for an electric vehicle according to the above design, it is possible to disengage both the combustion engine and the motor generator from the wheels 8 of the electric vehicle by simply disengaging the second clutch 6, thus easily interrupting the transmission of the drive power of the range extender system.

[0076] The various operating modes of the range extender system for an electric vehicle were described above using the first embodiment as an example. The respective operating modes of the range extender system for an electric vehicle according to the second to fourth embodiments, including the operating states of the individual components and the direction of power flow, correspond to the operating modes of the first embodiment. Therefore, the operating modes of the range extender system for an electric vehicle according to the second to fourth embodiments are not described in detail here. It should be understood that the operating modes described above are not restrictive and can be modified as needed.

[0077] Furthermore, the present disclosure also provides a computer-readable medium, such as a program carrier like a hard drive, which includes a program containing several instructions, wherein, when the program is executed on an on-board computer, the instructions perform the method for controlling a range-extender system for an electric vehicle.

[0078] Preferred embodiments of the present invention have been described above; however, these embodiments are not intended to limit the scope of the present invention. Therefore, individual embodiments can be modified without exceeding the defined scope of protection of the claims of the present invention and without deviating from the concept of the present invention and its equivalent.

Claims

[1] Transmission mechanism for an electric vehicle, characterized by that it includes: a first input wave (10); a second input wave (12); a first coupling (2) arranged between the first input shaft (10) and the second input shaft (12) and comprising a first rotating part (21) and a second rotating part (22) which can be engaged and disengaged from each other, wherein the first rotating part (21) of the first coupling is connected to the first input shaft (10); a reduction device (3), wherein the reduction device (3) is arranged between the first coupling (2) and the second input shaft (12) and the reduction device (3) comprises a first input gear (32) and a gear ring (33), wherein the gear ring (33) has internal teeth (331) on a radially inner surface of the gear ring and external teeth (333) on a radially outer surface of the gear ring, wherein the first input gear (32) is connected on one side to the second input shaft (12) and on the other side engages with the internal teeth (331), and wherein the gear ring (33) is connected to the second rotating part (22) of the first coupling (2) so that the power from the first input shaft (10) and the power from the second input shaft (12) can be coupled to each other at the gear ring (33); a differential (7) which is provided with a second input gear (70) on a differential housing; an intermediate shaft (222); a first intermediate gear (24) and a second intermediate gear (25), wherein the first intermediate gear (24) and the second intermediate gear (25) are arranged on the intermediate shaft (222), wherein the first intermediate gear (24) engages with the external teeth (332) of the ring gear (33), and wherein the second intermediate gear (25) can be driven on one side by the first intermediate gear (24) and on the other side by the second input gear (70) of the differential (7), so that the second input gear (70) can be driven on the ring gear (33); two output shafts (71), wherein one end of each of the two output shafts is drivenly connected to the differential (7) so that power can be transmitted from the differential (7); and a second clutch (6) which is arranged on a power transmission path of the transmission mechanism between the first intermediate gear (24) and each other end of each of the two output shafts, which is opposite to one end, so that a power transmission between the first intermediate gear (24) and the other end of each of the two output shafts can be allowed or disconnected. [2] Transmission mechanism for an electric vehicle according to claim 1, characterized by , that in the radial direction of the gear ring (33) the point of engagement between the first input gear (32) and the internal teeth (331) of the gear ring (33) overlaps with the point of engagement between the first intermediate gear (24) and the external teeth (333) of the gear ring (33). [3] Transmission mechanism for an electric vehicle according to claim 1 or 2, characterized by, that the first input gear (32) engages with the internal teeth (331) of the gear ring (33) on a side of the gear ring (33) facing the first intermediate gear (24). [4] Transmission mechanism for an electric vehicle according to claim 1 or 2, characterized by , that the first input gear (32) engages with the internal teeth (331) of the gear ring (33) on a side of the gear ring (33) facing away from the first intermediate gear (24); and that the reduction device (3) further comprises a first transition gear (34) with a fixed center point and a second transition gear (35) with a fixed center point, wherein the first transition gear (34) is arranged between the first input gear (32) and the second transition gear (35) and is in engagement with both the first input gear (32) and the second transition gear (35), and wherein the second transition gear (35) is in engagement with the internal teeth (331) of the gear ring (33). [5] Transmission mechanism for an electric vehicle according to claim 4, characterized by , that the gear centers of the first input gear (32), the ring gear (33), the first transition gear (34), the second transition gear (35) and the first intermediate gear (24) are arranged on a straight line (L). [6] Transmission mechanism for an electric vehicle according to claim 1 or 2, characterized by, that the second coupling (6) is a claw coupling. [7] Transmission mechanism for an electric vehicle according to claim 1 or 2, characterized by , that the first clutch (2) is a friction clutch. [8] Transmission mechanism for an electric vehicle according to claim 6, characterized by , that the first clutch (2) is a friction clutch. [9] Transmission mechanism for an electric vehicle according to claim 1 or 2, characterized by , that the second coupling (6) is arranged between the first intermediate gear (24) and the second intermediate gear (25) so that power transmission between the first intermediate gear (24) and the second intermediate gear (25) can be allowed or disconnected. [10] Transmission mechanism for an electric vehicle according to claim 1 or 2, characterized by, that the second coupling (6) is arranged on any one of the two output shafts (71) so that a power transmission between the differential (7) and the other end can be disconnected. [11] Transmission mechanism for an electric vehicle according to claim 1 or 2, characterized by , that the transmission mechanism further includes: a damper (11) arranged between the first input shaft (10) and the first clutch (2), wherein an input of the damper (11) is drivenly connected to the first input shaft (10), and wherein an output of the damper (11) is drivenly connected to the first rotating part (21) of the first clutch (2). [12] Transmission mechanism for an electric vehicle according to claim 11, characterized by , that the damper (11) is a torsional damper. [13] Range extender device for an electric vehicle, characterized by that it includes: a motor generator (4); and a transmission mechanism for an electric vehicle according to one of the preceding claims, wherein the second input shaft (12) of the transmission mechanism is connected to the motor generator (4) in a drive manner. [14] Range extender device for an electric vehicle according to claim 13, characterized by that the motor generator is a permanent magnet synchronous motor. [15] Range extender system for an electric vehicle, characterized by , that it includes: an internal combustion engine (1); and a range extender device for an electric vehicle according to the preceding claim 13 or 14, wherein the first input shaft (10) of the transmission mechanism is connected to the internal combustion engine (1) in a drive manner. [16] Range extender system for an electric vehicle according to claim 15, characterized by that the combustion engine is an inline four-cylinder combustion engine. [17] electric vehicle, characterized by , that it includes: a range extender system for an electric vehicle according to claim 15 or 16; a traction battery in which the electricity generated by the range extender system is stored; and a pair of wheels (8), wherein the pair of wheels is a pair of front wheels or a pair of rear wheels of the electric vehicle, and wherein the other end of each of the two output shafts of the transmission mechanism for an electric vehicle is driven by one wheel of the pair of wheels (8). [18] Electric vehicle according to claim 17, characterized by , that it includes: a main drive comprising a main drive motor and a main reduction gearbox connected to the main drive motor, wherein the main drive is powered by the electric vehicle's drive battery, and wherein the main drive is used to drive a different pair of wheels of the electric vehicle than the pair of wheels (8) driven by the range extender system for an electric vehicle.

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