Transmission mechanism for electric vehicle, range extending device, range extending system and electric vehicle

Abstract

The invention provides a transmission mechanism, a range extending device and a range extending system for an electric vehicle and the electric vehicle. The transmission mechanism comprises a first input shaft; a second input shaft; a first clutch disposed between the first input shaft and the second input shaft; a differential provided with an input gear; an intermediate shaft; a first intermediate gear (24) and a second intermediate gear (25) on the intermediate shaft, the first intermediate gear being in power connection with a second rotating component (22) of the first clutch and the second intermediate gear being capable of being in power connection with the first intermediate gear (24) and meshing with an input gear (70) of the differential (7); one end part of each output shaft is in power connection with the differential mechanism; and a second clutch (6) provided between the first intermediate gear and the second intermediate gear, whereby transmission of power between the first and second intermediate gears can be allowed or disengaged.

Description

Technical Field

[0001] This application relates to the field of new energy vehicles, and more particularly to a transmission mechanism for an electric vehicle, a range extender for an electric vehicle, a range extender system for an electric vehicle, and an electric vehicle. Background Technology

[0002] With the depletion of petroleum resources and the increasing environmental awareness of the public, there is an urgent need for green and environmentally friendly vehicles that can save energy and achieve low or even zero emissions. Therefore, new energy vehicles, such as electric vehicles, are receiving increasing attention. Compared with the internal combustion engines of traditional vehicles, the traction motors of electric vehicles have a wider operating range, and their constant torque at low speeds and constant power at high speeds are more suitable for vehicle operation requirements. In recent years, the power drive systems for electric vehicles and their operating modes have become a research hotspot.

[0003] Existing technology discloses a power coupling system for electric vehicles, including an internal combustion engine, a generator, and a drive motor. This technology employs both a generator and a drive motor, resulting in a complex vehicle structure, larger footprint, and increased manufacturing costs. Furthermore, the prior art directly connects the internal combustion engine and generator, preventing flexible control of both components.

[0004] Therefore, there is a need for improvements to electric vehicles, especially range extenders for electric vehicles. Summary of the Invention

[0005] The purpose of this invention is to provide a simple and space-saving transmission mechanism, range extender and range extender system for electric vehicles, as well as an electric vehicle.

[0006] To address the aforementioned technical problems, this disclosure provides a transmission mechanism for an electric vehicle, comprising: a first input shaft; a second input shaft; a first clutch disposed between the first input shaft and the second input shaft, the first clutch having a first rotating component and a second rotating component capable of engaging and disengaging from each other, the first rotating component of the first clutch being connected to the first input shaft and the second rotating component of the first clutch being connected to the second input shaft, thereby enabling a power connection between the first input shaft and the second input shaft; a differential, the differential being disposed on a differential housing and having an input gear; an intermediate shaft; a first intermediate gear and a second intermediate gear, the first intermediate gear and the second intermediate gear being located on the intermediate shaft, the first intermediate gear being power-connected to the second rotating component of the first clutch, and the second intermediate gear being capable of being power-connected to the first intermediate gear on one hand and engaging with the input gear of the differential on the other hand, thereby enabling a power connection between the input gear and the second rotating component of the first clutch; two output shafts, one end of each of the two output shafts being power-connected to the differential, thereby enabling the transmission of power from the differential; and a second clutch disposed between the first intermediate gear and the second intermediate gear, thereby enabling or disengaging the transmission of power between the first intermediate gear and the second intermediate gear.

[0007] The transmission mechanism for electric vehicles disclosed herein is compact in structure, improves the utilization of interior space, and can quickly disconnect the power transmission from the drive unit to the wheels.

[0008] The second clutch is a jaw clutch.

[0009] The transmission mechanism for the electric vehicle includes a third intermediate gear, which is arranged anti-rotationally on the second rotating component of the first clutch and is poweredly connected to the first intermediate gear, thereby enabling it to be poweredly connected to the input gear of the differential. Specifically, the intermediate gear directly meshes with the input gear of the differential.

[0010] The transmission mechanism for electric vehicles further includes a planetary gear mechanism, which includes a sun gear, planet gears, a ring gear, and a planet carrier supporting the planet gears. The sun gear is poweredly connected to the second input shaft, the ring gear is fixed, and the planet carrier is poweredly connected to the second rotating component of the first clutch.

[0011] Preferably, the second rotating component of the first clutch includes a main body portion and a rotating shaft connected to the main body portion, the main body portion being capable of direct engagement with the first rotating component of the first clutch, and a third intermediate gear being arranged anti-rotationally on the rotating shaft.

[0012] Preferably, the second rotating component of the first clutch includes a main body and a rotating shaft connected to the main body, the main body being capable of direct engagement with the first rotating component of the first clutch, and the planetary carrier being poweredly connected to the rotating shaft.

[0013] Alternatively, the transmission mechanism for the electric vehicle further includes a planetary gear mechanism, which includes a sun gear, planet gears, a ring gear, and a planet carrier supporting the planet gears. The sun gear is poweredly connected to the second input shaft, and the planet carrier is fixed. The ring gear is poweredly connected to the second rotating component of the first clutch, and the ring gear has external teeth in the circumferential direction that mesh with the first intermediate gear.

[0014] The transmission mechanism for electric vehicles further includes a shock absorber, which is disposed between the first input shaft and the first clutch. The input end of the shock absorber is poweredly connected to the first input shaft, and the output end of the shock absorber is poweredly connected to the first rotating component of the first clutch.

[0015] The damper is a torsional damper.

[0016] At least one of the first and second intermediate gears is rotatable relative to the intermediate shaft.

[0017] This disclosure provides a range extender for electric vehicles, characterized in that it includes: an electric generator; and the aforementioned transmission mechanism for electric vehicles, wherein the second input shaft of the transmission mechanism for electric vehicles is poweredly connected to the electric generator.

[0018] The electric generator is a permanent magnet synchronous motor.

[0019] This disclosure provides a range extender system for electric vehicles, characterized in that it includes: an internal combustion engine; and the aforementioned range extender for electric vehicles, wherein the first input shaft of the transmission mechanism for electric vehicles is poweredly connected to the internal combustion engine.

[0020] The internal combustion engine is an inline 4-cylinder internal combustion engine.

[0021] This disclosure provides an electric vehicle, characterized in that it includes: the range extender system for the electric vehicle; and a pair of wheels, the pair of wheels being a pair of front wheels or a pair of rear wheels of the electric vehicle, wherein the other end of each of the two output shafts of the transmission mechanism for the electric vehicle is poweredly connected to a corresponding wheel of the pair of wheels.

[0022] The electric vehicle includes a main drive unit, which includes a main drive motor and a main reducer poweredly connected to the main drive motor, wherein the main drive unit is used to drive a pair of wheels different from the pair of wheels driven by the range extender system for the electric vehicle.

[0023] When the range extender for an electric vehicle drives the pair of front wheels of the electric vehicle, the main drive drives the pair of rear wheels of the electric vehicle. While the vehicle is in motion, the main drive is typically always operational, and the range extender for the electric vehicle operates as needed, depending on the vehicle's condition and road conditions, for driving, generating electricity, or both.

[0024] This disclosure also provides a method for controlling the range extender for an electric vehicle, characterized by comprising: step S21: determining the relationship between the state of charge (SOC) of the power battery of the electric vehicle and the SOC threshold, or simultaneously determining the relationship between the SOC of the power battery of the electric vehicle and the SOC threshold, and the relationship between the vehicle speed of the electric vehicle and the vehicle speed threshold; step S22: selecting the operating mode of the range extender based on the determination result.

[0025] Preferably, when it is determined in step S21 that the SOC of the power battery is higher than the first SOC threshold, step S22 includes: controlling the internal combustion engine to stop working, disengaging the first clutch, and engaging the second clutch, so that the electric generator drives the pair of wheels after being transmitted to the differential via the third intermediate gear, the first intermediate gear, and the second intermediate gear, thereby the range extender for electric vehicles enters pure electric mode.

[0026] Preferably, when it is determined in step S21 that the SOC of the power battery is lower than the first SOC threshold but higher than the second SOC threshold, and the vehicle speed is greater than the first vehicle speed threshold, step S22 includes: controlling the first clutch and the second clutch to be closed, so that the internal combustion engine and the electric generator jointly drive the pair of wheels via the third intermediate gear, the first intermediate gear and the second intermediate gear and the differential, thereby the range extender for electric vehicles enters the hybrid drive mode.

[0027] Preferably, when it is determined in step S21 that the SOC of the power battery is lower than the second SOC threshold but higher than the third SOC threshold, and the vehicle speed is greater than the vehicle speed threshold, step S22 includes: controlling both the first clutch and the second clutch to be closed, so that a portion of the power of the internal combustion engine is transmitted to the electric generator for power generation, and another portion of the power of the internal combustion engine drives the pair of wheels via the first clutch, the third intermediate gear, the first intermediate gear and the second intermediate gear and the differential, thereby the range extender for the electric vehicle enters the first range extender mode.

[0028] Preferably, when it is determined in step S21 that the SOC of the power battery is lower than the third SOC threshold and the vehicle speed is lower than the vehicle speed threshold, step S22 includes: controlling the first clutch to close and the second clutch to disengage, so that the power of the internal combustion engine is only transmitted to the electric generator for power generation, thereby the range extender for electric vehicles enters the second range extender mode.

[0029] Preferably, the method further includes: step S23: when starting the vehicle, controlling the first clutch to close and the second clutch to disengage, and starting the internal combustion engine using power from the electric generator.

[0030] This disclosure also provides a program product comprising a program containing a plurality of instructions, wherein, when the program is run on an onboard computer, the instructions execute a method for controlling the aforementioned range extender for an electric vehicle. The program product may be, for example, a program carrier, such as a hard disk.

[0031] The reducer, range extender, and / or range extender system for electric vehicles disclosed herein are compact in structure, improving the utilization of vehicle interior space. Using the method disclosed for controlling the range extender for electric vehicles, multiple operating modes can be automatically switched based on the SOC of the power battery and the vehicle speed. Attached Figure Description

[0032] The features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, wherein like symbols denote like elements. It is obvious that the drawings described below are merely some embodiments of the present invention, and those skilled in the art can make changes to these drawings without creative effort.

[0033] Figure 1 This is a structural schematic diagram of the transmission mechanism, range extender, and range extender system for an electric vehicle according to the first embodiment.

[0034] Figure 2This is a diagram illustrating one operating mode of the transmission mechanism, range extender, and range extender system for an electric vehicle according to the first embodiment.

[0035] Figure 3 This is a diagram showing another operating mode of the transmission mechanism, range extender, and range extender system for an electric vehicle according to the first embodiment.

[0036] Figure 4 This is a diagram showing another operating mode of the transmission mechanism, range extender, and range extender system for an electric vehicle according to the first embodiment.

[0037] Figure 5 This is a diagram showing another operating mode of the transmission mechanism, range extender, and range extender system for an electric vehicle according to the first embodiment.

[0038] Figure 6 This is a schematic diagram of the transmission mechanism, range extender, and range extender system for an electric vehicle according to the second embodiment. Detailed Implementation

[0039] The following description of various embodiments of the present invention with reference to the accompanying drawings illustrates specific embodiments in which the present invention can be implemented. The terms "left" and "right," etc., appearing in the specification are merely for describing this application with reference to the drawings and are not intended to limit the invention. It is understood that the terms "left" or "right" merely indicate a direction and are reversible.

[0040] First embodiment:

[0041] Figure 1 This is a structural schematic diagram of the transmission mechanism, range extender, and range extender system for an electric vehicle according to the first embodiment. Figure 1 As shown, the range extender system for an electric vehicle according to the first embodiment includes: an internal combustion engine 1; an electric generator 4; and a transmission mechanism located between the internal combustion engine 1 and the electric generator 4. This transmission mechanism is capable of coupling and outputting power from the internal combustion engine 1 and the electric generator 4. The internal combustion engine 1 and the electric generator 4 are preferably located on opposite sides of the transmission mechanism.

[0042] The transmission mechanism includes 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 supported. The first input shaft 10 and the second input shaft 12 are used to receive power input from corresponding power sources.

[0043] The transmission mechanism also includes a first clutch 2, which is disposed between the first input shaft 10 and the second input shaft 12. The first clutch 2 includes a first rotating component 21 and a second rotating component 22 capable of engaging and disengaging from each other. The first rotating component 21 is connected to the first input shaft 10, and thereby connected to the internal combustion engine 1, specifically the crankshaft of the internal combustion engine. The second rotating component 22 is connected to the second input shaft 12, and thereby connected to the electric generator 4, specifically the output shaft of the electric generator. Thus, the first clutch 2 can powerly connect the first input shaft 10 and the second input shaft 12. Accordingly, the first clutch 2 can powerly connect the internal combustion engine 1 and the electric generator 4.

[0044] The transmission mechanism for electric vehicles also includes a differential 7, which has an input gear 70 on its housing. The input gear 70 of the differential is power-connected to the second rotating component 22 of the first clutch 2, thereby receiving power from the second rotating component 22.

[0045] The transmission mechanism for the electric vehicle also includes 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, and at least one of the intermediate gears is rotatable relative to the intermediate shaft. The axis of the intermediate shaft 222 is different from the axis of the first clutch 2 and the axis of the differential 7. The first intermediate gear 24 is poweredly connected to the second rotating component of the first clutch. The second intermediate gear 25 is poweredly connected to the first intermediate gear 24 to receive power from it and is also poweredly connected to the input gear 70 of the differential, preferably meshing with the input gear 70. Thus, the input gear 70 is poweredly connected to the second rotating component 70 of the first clutch 2. Specifically, the intermediate shaft 222 can be rotatably supported, with one of the intermediate gears, the first intermediate gear 24 and the second intermediate gear 25, arranged anti-rotatably on or integral with the intermediate shaft 222, while the other intermediate gear is rotatably arranged on the intermediate shaft 222.

[0046] The transmission mechanism for the electric vehicle also includes two output shafts 71. One end of each of the two output shafts 71 is poweredly connected to the differential 7, thereby enabling the transmission of power from the differential 7. For example, the output shafts 71 are used to transmit power to a pair of wheels of the electric vehicle. Specifically, each output shaft 71 can be connected to a corresponding wheel of a pair of wheels 8 of the electric vehicle to transmit power from the differential 7 to the pair of wheels 8. This pair of wheels 8 is either a pair of front wheels or a pair of rear wheels of the electric vehicle.

[0047] The transmission mechanism for electric vehicles also includes a second clutch 6, which is located on the intermediate shaft 222 and disposed between the first intermediate gear 24 and the second intermediate gear 25, thereby enabling or disabling the transmission of power between the first intermediate gear 24 and the second intermediate gear 25.

[0048] The type of the second clutch 6 is not limited. However, preferably, the second clutch 6 is a dog clutch (also known as a canine clutch or claw clutch). The dog clutch can be a radial tooth dog clutch or an axial tooth dog clutch. The dog clutch includes a first external spline (not shown) disposed on the first intermediate gear 24, a second external spline (not shown) disposed on the second intermediate gear 25, and a sliding sleeve (not shown) provided with an internal spline. The sliding sleeve is slidably disposed on one of the external splines of the first and second external splines via its internal spline, and is axially actuated when engagement is required to make its internal spline mesh with the other external spline, thereby realizing the synchronous rotation of the first and second intermediate gears. The structural features of the dog clutch are simple structure, low drag loss, small size, and no relative rotation of the two shafts after engagement; convenient operation, ability to transmit large torque, effective prevention of overload and overheating, and extension of equipment service life; and fast response characteristics. Using this jaw clutch, the transmission mechanism for electric vehicles according to this disclosure is smaller in size and can rapidly drive the electric vehicle (main drive or auxiliary drive). In the case where an intermediate gear is arranged anti-rotationally on or integral with the intermediate shaft 222, an external spline of the jaw clutch can be formed on the intermediate shaft 222.

[0049] The first clutch 2 can be any type of clutch, such as a friction clutch. Friction clutches have the advantages of simple construction and low cost. As described above, the second rotating component 22 of the first clutch 2 is poweredly connected to the second input shaft 12 and / or the electric generator 4. It is readily understood that the second rotating component 22 of the first clutch 2 can be directly poweredly connected to the output shaft of the electric generator 4, and in this case, the second rotating component 22 includes the second input shaft 12. Alternatively, the second rotating component 22 of the first clutch 2 can be poweredly connected to the output shaft of the electric generator 4 via a reduction gear.

[0050] Differential 7 is a conventional type of differential. Each output shaft 71 of the transmission mechanism is powered at one end to a corresponding wheel 8 of the electric vehicle and at the other end to the differential 7. In this case, the output shaft 71 of the transmission mechanism can also be regarded as the output shaft of the differential 7 itself. The specific construction of the differential is known and will not be described in detail herein.

[0051] The drive connection between the first intermediate gear 24 and the first clutch 2 can be achieved in various ways. For example, the outer peripheral edge of the second rotating component 22 of the first clutch 2 can have teeth that directly mesh with the first intermediate gear 24. The second rotating component 22 of the first clutch 2 can be provided with a third intermediate gear 23, which is integrally connected to the second rotating component 22. Alternatively or preferably, the second rotating component 22 of the first clutch 2 includes a main body and a rotating shaft 221 connected to the main body, the main body being capable of directly engaging with the first rotating component 21 of the first clutch 2, and the third intermediate gear 23 is arranged anti-rotationally on the rotating shaft 221. The third intermediate gear 23 meshes with the first intermediate gear 24, so that power from the first clutch 2 can be transmitted to the differential 7 via the third intermediate gear 23 and the first intermediate gear 24.

[0052] As described above, a speed reduction device can be provided between the first clutch 2 and the electric generator 4, and this speed reduction device can be, for example, a planetary gear mechanism 3. That is, the transmission mechanism includes a speed reduction device such as a planetary gear mechanism 3. The planetary gear mechanism 3 includes a sun gear 31, planet gears 32, a ring gear 33, and a planet carrier 34 supporting the planet gears. The sun gear 31 is poweredly connected to the second input shaft 12, thereby being poweredly connected to the output shaft of the electric generator 4. The ring gear 33 is fixed, for example, fixed relative to the frame of the electric vehicle, and the planet carrier 34 is poweredly connected to the second rotating component 22 of the first clutch 2. In particular, if the second rotating component 22 is provided with a rotating shaft 221, the planet carrier 34 can be poweredly connected to the rotating shaft 221. Thus, the planetary gear mechanism 3 can transmit power between the first clutch 2 and the electric generator 4 and can reduce the rotation of the electric generator 4.

[0053] Please note that, with the third intermediate gear 23 provided as described above and the ring gear 33 of the planetary gear mechanism 3 fixed, the first intermediate gear 24 is not limited to being powered by the third intermediate gear 23, but can be powered by any part integrally provided on the second rotating component 22 or the rotating shaft 221 of the first clutch 2.

[0054] The first rotating component 21 of the first clutch 2 can be directly powered to a power source, such as an internal combustion engine 1. Preferably, to buffer and dampen the output of the external power source, such as the internal combustion engine 1, the transmission mechanism for the electric vehicle can be provided with a damper 11, which is disposed between the first input shaft 10 and the first clutch 2. The input end of the damper 11 is powered to the first input shaft 10, thereby connecting to the crankshaft of the internal combustion engine 1, and the output end of the damper 11 is powered to the first rotating component 21 of the first clutch 2. The damper is preferably a torsional damper. However, the damper can be other types of dampers, such as hydraulic dampers.

[0055] Preferably, the transmission mechanism may include a housing B to house one or more components of the transmission mechanism. Preferably, the internal combustion engine 1 and the electric generator 4 may be located outside the housing B and on opposite sides of the housing B, respectively. The housing B may, for example, be fixed to the frame of an electric vehicle. With the transmission mechanism housed in the housing B, a first input shaft 10 is rotatably supported in the wall on one side of the housing B, and a second input shaft 12 is rotatably supported in the wall on a second side of the housing B opposite to the first side. For example, the engine 1 is located on this side, and the electric generator 4 is located on the other side. The shock absorber 11 and the planetary gear mechanism 3 may be located inside or outside the housing B. The first clutch 2 is preferably located inside the housing B. The differential 7 is preferably located inside the housing B. One of the two output shafts 71 is rotatably supported in the wall on one side of the housing B, and the other output shaft is rotatably supported in the wall on the other side of the housing B. It should be understood that the positional relationship of all components of the transmission mechanism relative to the housing B is not limiting, but can be appropriately selected according to actual needs. The construction of housing B is unrestricted; for example, housing B may not have any walls in the axial direction of the input or output shaft.

[0056] The above-mentioned transmission mechanism for electric vehicles has a reasonable layout of its components, a compact structure, which facilitates assembly, saves space, and improves the utilization rate of interior space.

[0057] The range extender for electric vehicles disclosed herein includes the aforementioned transmission mechanism and electric generator 4. The second input shaft 12 of the transmission mechanism for electric vehicles is poweredly connected to the electric generator 4.

[0058] The electric generator 4 is a motor that can be used as both a motor and a generator. The electric generator 4 is equipped with an inverter 5 for controlling its operation. This electric generator is preferably a permanent magnet synchronous motor (PSM). However, it should be understood that the type of electric generator 4 is not limited.

[0059] The range extender system for electric vehicles disclosed herein includes the aforementioned range extender and an internal combustion engine 1. The first input shaft 10 of the transmission mechanism for the electric vehicle is specifically poweredly connected to the crankshaft of the internal combustion engine 1. The specific type of the internal combustion engine 1 is not limited; for example, it can be an inline four-cylinder internal combustion engine, a horizontally opposed six-cylinder internal combustion engine, or a V12 internal combustion engine. The output parameters of the internal combustion engine, such as maximum output power, are also not limited but are selected as needed. Thus, the internal combustion engine 1 and the electric generator 4 can work together to power the electric vehicle.

[0060] Existing range extender devices and / or systems typically use two motors, one dedicated to generating electricity and the other dedicated to driving the vehicle to achieve the range extension function. This makes the device bulky and increases costs. However, the range extender device and / or system described above in this disclosure requires only one motor, namely the electric generator 4, to achieve both power generation and vehicle driving functions, thereby realizing the range extension function at low cost and with a small footprint.

[0061] The electric vehicle disclosed herein includes the aforementioned range extender system and a pair of wheels 8, which are 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 the electric vehicle is power-connected to a corresponding wheel in the pair of wheels 8. The range extender system according to the invention can be the only drive unit for the electric vehicle. Thus, efficient power generation and driving of the electric vehicle can be achieved without an additional drive unit, thereby reducing costs.

[0062] It is readily understood that the range extender system according to the invention can be used as an auxiliary drive for an electric vehicle. Therefore, additionally, the electric vehicle of this disclosure may include a main drive. The main drive includes a main drive motor and a main reducer poweredly 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 for the electric vehicle. For example, the main drive can be used to drive a pair of rear wheels of the electric vehicle, and the range extender system according to this disclosure can be used to drive a pair of front wheels of the electric vehicle. Since the main drive itself enables two-wheel drive for the electric vehicle, the electric vehicle of this disclosure can easily achieve four-wheel drive for the electric vehicle.

[0063] With the range extender and / or range extender system of the electric vehicle using the above structure, the shock absorber can be easily mounted on the internal combustion engine, achieving high power density and good smoothness. Furthermore, the entire range extender and / or range extender system is highly integrated and compact, thereby achieving low drag loss when the electric vehicle is coasting.

[0064] The range extender system for electric vehicles according to the first embodiment has multiple operating modes, including pure electric mode, hybrid drive mode, first range extender mode, and second range extender mode, and can automatically switch between multiple modes according to the SOC of the power battery and the vehicle speed requirement. Therefore, this disclosure also provides a method for controlling a range extender system for electric vehicles, the method comprising: step S21, determining the relationship between the SOC of the power battery of the electric vehicle and a SOC threshold, or simultaneously determining the relationship between the SOC of the power battery of the electric vehicle and a SOC threshold and the relationship between the vehicle speed of the electric vehicle and a vehicle speed threshold; and step S22, selecting the operating mode of the range extender system based on the determination result.

[0065] As shown in the figure below, the SOC threshold includes three thresholds: a first SOC threshold S1, a second SOC threshold S2 that is less than the first SOC threshold S1, and a third SOC threshold S3 that is less than the second SOC threshold S2. The operating mode of the range extender system is selected based on the relationship between the SOC of the electric vehicle's power battery and each SOC threshold, as well as the relationship between vehicle speed V and vehicle speed threshold V1.

[0066] Comparison chart of SOC and vehicle speed with their respective thresholds

[0067]

[0068] Figure 2 This is a diagram of an operating mode of a range extender system for electric vehicles according to the first embodiment. Figure 3 This is a diagram of another operating mode of the range extender system for electric vehicles according to the first embodiment. Figure 4 This is a diagram of another operating mode of the range extender system for electric vehicles according to the first embodiment. Figure 5 This is a diagram of another operating mode of the range extender system for electric vehicles according to the first embodiment.

[0069] Specifically, such as Figure 2 As shown, when step S21 determines that the SOC of the electric vehicle's power battery is higher than the first SOC threshold S1, step S22 includes: controlling the internal combustion engine 1 to stop working while the electric generator 4 works as a drive motor; disengaging the first clutch 2 and engaging the second clutch 6; the power from the electric generator 4 is transmitted through the second rotating component 22 of the first clutch 2 (or the third intermediate gear 23 that rotates integrally with the second rotating component 22), the first intermediate gear 24, and the second intermediate gear 25 to the differential 7, and then to a pair of wheels 8 to drive the electric vehicle. At this time, the range extender system for the electric vehicle operates in pure electric mode, and the power transmission route is as follows: Figure 2As indicated by the dashed arrow. At this time, the main drive unit (not shown) of the electric vehicle is typically used to drive another pair of wheels of the electric vehicle, different from the pair of wheels 8. Therefore, when the range extender system for the electric vehicle operates in pure electric mode, the electric vehicle achieves four-wheel drive.

[0070] like Figure 3 As shown, when step S21 determines that the SOC of the power battery is lower than the first SOC threshold S1 but higher than the second SOC threshold S2, and the vehicle speed V is higher than the vehicle speed threshold V1, step S22 includes: controlling the internal combustion engine 1 to work and the electric generator 4 to work as a drive motor, with both the first clutch 2 and the second clutch 6 closed. The power of the internal combustion engine 1 and the power of the electric generator 4 are coupled through the second rotating component 22 of the first clutch 2. Then, the coupled power is transmitted to the differential 7 through the third intermediate gear 23, the first intermediate gear 24, and the second intermediate gear 25, and then to a pair of wheels 8. At this time, the range extender system for the electric vehicle operates in hybrid mode, and the power transmission route is as follows: Figure 3 As indicated by the dashed arrow. At this point, the main drive unit of the electric vehicle is typically used to drive a different pair of wheels than the first pair (8). Therefore, when the range extender system for the electric vehicle operates in hybrid mode, the electric vehicle achieves four-wheel drive.

[0071] like Figure 4 As shown, when step S21 determines that the SOC of the power battery is lower than the second SOC threshold S2 but higher than the third SOC threshold S3, and the vehicle speed V is higher than the vehicle speed threshold V1, step S22 includes: controlling the internal combustion engine 1 to operate and the electric generator 4 to operate as a generator; both the first clutch 2 and the second clutch 6 are closed; a portion of the power from the internal combustion engine 1 is transmitted to the electric generator 4 via the first clutch 2 to generate electricity, while the other portion of the power from the internal combustion engine 1 is transmitted to a pair of wheels 8 via the first clutch 2, the third intermediate gear 23, the first intermediate gear 24, the second intermediate gear 25, and the differential 7. The electricity generated by the electric generator 4 is stored in the power battery (not shown) of the electric vehicle. At this time, the range extender system for the electric vehicle operates in the first range extender mode, and the power transmission route is as follows: Figure 4 As indicated by the dashed arrow. At this time, the main drive unit of the electric vehicle is typically used to drive a different pair of wheels than the first pair of wheels 8. Therefore, when the range extender system for the electric vehicle operates in the first range extender mode, the electric vehicle also achieves four-wheel drive.

[0072] like Figure 5As shown, when step S21 determines that the SOC of the power battery is lower than the third SOC threshold S3 and the vehicle speed is lower than the vehicle speed threshold V1, step S22 includes: controlling the first clutch 2 to close and the second clutch 6 to disengage, the internal combustion engine 1 drives the electric generator 4 to generate electricity via the first clutch 2 to charge the power battery. At this time, the range extender system for the electric vehicle operates in the second range extender mode, in which only electricity generation is performed. The electricity generated by the electric generator 4 is stored in the power battery (not shown) of the electric vehicle. At this time, if the main drive of the electric vehicle is driving a different pair of wheels than the pair of wheels 8, when the range extender system for the electric vehicle operates in the second range extender mode, the electric vehicle travels in a low-speed area in a two-wheel drive mode. The power transmission route is as follows: Figure 5 As shown by the dashed arrow on the upper middle side.

[0073] Furthermore, such as Figure 5 As shown, when the electric vehicle starts, the electric generator 4 can be used as a drive motor to start the internal combustion engine 1. The power transmission route is as follows: Figure 5 As shown by the dashed arrow at the bottom center. Accordingly, the method for controlling the range extender system of the electric vehicle in this embodiment further includes: step S23, controlling the electric generator 4 to generate starting torque and start the internal combustion engine 1 during startup.

[0074] In the first and second range-extending modes mentioned above, since the SOC of the power battery is low, the internal combustion engine 1 drives the electric generator 4 to charge the power battery in order to quickly increase the SOC of the power battery.

[0075] The above working mode is illustrated in Table 1 below:

[0076] Table 1

[0077]

[0078] The aforementioned SOC thresholds are used to determine the SOC level of the power battery, and the vehicle speed threshold is used to determine the vehicle speed. In this embodiment, no specific values ​​are limited for the SOC and vehicle speed thresholds. Typically, they can be freely set according to the specific control strategy, and the values ​​of either the SOC or vehicle speed thresholds will differ under different control strategies. After setting the SOC and vehicle speed thresholds, the electric vehicle automatically makes judgments and automatically switches between multiple modes based on the judgment results.

[0079] Furthermore, when the vehicle brakes, the first clutch 2 disengages and the second clutch 6 engages to generate braking torque using the electric generator 4 to brake the wheels. This induces a current in the windings of the electric generator 4 to charge the power battery, thus recovering braking energy. Therefore, the control method of this embodiment further includes controlling the second clutch 6 to generate braking torque and inducing a current in the windings of the electric generator 4 to charge the power battery of the electric vehicle during braking.

[0080] Furthermore, according to the range extender system for electric vehicles constructed as described above, by simply disengaging the second clutch 6, both the internal combustion engine and the electric generator can be disconnected from the wheels 8 of the electric vehicle, thereby easily interrupting the transmission of driving force.

[0081] Second embodiment:

[0082] Figure 6 This is a schematic diagram of the transmission mechanism, range extender, and range extender system for an electric vehicle according to the second embodiment. The parts identical to those in the first embodiment are omitted here; only the differences are described.

[0083] Unlike the first embodiment, as Figure 6 As shown, in the second embodiment, the third intermediate gear 23 is not provided, and the structure and transmission relationship of the planetary gear mechanism 3 are changed.

[0084] Specifically, instead of the gear ring 33, the planetary carrier 34 is fixed, and the gear ring 33 has external teeth in the circumferential direction. The gear ring 33 is poweredly connected to the rotation shaft 221 of the second rotating component 22 of the first clutch 2, and the external teeth of the gear ring 33 mesh with the first intermediate gear 24. Thus, power can be transmitted from the gear ring 33 to the first intermediate gear 24.

[0085] According to the second embodiment, the various operating modes of the range extender system for electric vehicles include the operating states of each component and the direction of power flow, compared with the first embodiment. Figure 2-5 The various operating modes shown are corresponding. Therefore, the various operating modes of the range extender system for electric vehicles according to the second embodiment will not be described in detail.

[0086] Furthermore, this disclosure also provides a program product, such as a program carrier or computer medium, the program product including a program containing a plurality of instructions, wherein, when the program is run on an on-board computer, the instructions execute the method for controlling a range extender system for an electric vehicle.

[0087] Preferred embodiments of the present invention have been described above, but these embodiments are not intended to limit the scope of the invention. Therefore, modifications may be made to the various embodiments without departing from the spirit of the invention and its equivalents, and without exceeding the scope of protection defined by the claims.

Claims

1. A transmission mechanism for an electric vehicle, characterized by comprising: a first input shaft (10); a second input shaft (12); a first clutch (2) provided between the first input shaft (10) and the second input shaft (12), the first clutch having a first rotary member (21) and a second rotary member (22) capable of being engaged and disengaged from each other, the first rotary member (21) of the first clutch being connected to the first input shaft (10) and the second rotary member (22) of the first clutch being connected to the second input shaft (12), whereby the first input shaft (10) and the second input shaft (12) can be power connected; a differential (7) provided with an input gear (70) on a differential housing; an intermediate shaft (222); a first intermediate gear (24) and a second intermediate gear (25) arranged on the intermediate shaft (222), the first intermediate gear (24) being power connected to the second rotary member (22) of the first clutch (2), and the second intermediate gear (25) being power connectable to the first intermediate gear (24) on one hand and to the input gear (70) of the differential (7) on the other hand, whereby the input gear (70) can be power connected to the second rotary member (22) of the first clutch; two output shafts (71), one end of each of the two output shafts being power connected to the differential (7), whereby power from the differential (7) can be transmitted; and a second clutch (6) provided between the first intermediate gear (24) and the second intermediate gear (25), whereby transmission of power between the first intermediate gear (24) and the second intermediate gear (25) can be allowed or interrupted.

2. The transmission mechanism for an electric vehicle according to claim 1, characterized by, The second clutch (6) is a dog clutch.

3. The transmission mechanism for an electric vehicle according to claim 1 or 2, characterized by, The transmission mechanism for an electric vehicle comprises a third intermediate gear (23), the third intermediate gear (23) being arranged non-rotatably on the second rotary member (22) of the first clutch (2), and the third intermediate gear (23) being in mesh with the first intermediate gear (24), whereby power connection to the input gear (70) of the differential (7) is possible.

4. The transmission mechanism for an electric vehicle according to claim 3, characterized by, The transmission mechanism for an electric vehicle further comprises a planetary gear mechanism (3) comprising a sun gear (31), a planet gear (32), a ring gear (33) and a carrier (34) supporting the planet gear, the sun gear (31) being power connected to the second input shaft (12), the ring gear (33) being stationary, and the carrier (34) being power connected to the second rotary member (22) of the first clutch (2).

5. The transmission mechanism for an electric vehicle according to claim 3, characterized by, The second rotary member (22) of the first clutch (2) comprises a main body portion and a rotary shaft (221) connected to the main body portion, the main body portion being capable of direct engagement with the first rotary member (21) of the first clutch (2), and the rotary shaft (221) being power connected to the second input shaft (12). The third intermediate gear (23) is arranged anti-rotationally on the rotation shaft (221).

6. The transmission mechanism for an electric vehicle according to claim 4, characterized by, The second rotation component (22) of the first clutch (2) comprises a main body part and a rotation shaft (221) connected to the main body part, the main body part is capable of being directly engaged with the first rotation component (21) of the first clutch (2), and The planet carrier (34) is power connected with the rotation shaft (221).

7. The transmission mechanism for an electric vehicle according to claim 1 or 2, characterized by, The transmission mechanism for electric vehicles further comprises a planetary gear mechanism (3), the planetary gear mechanism (3) comprises a sun gear (31), a planet wheel (32), a ring gear (33) and a planet carrier (34) supporting the planet wheel, The sun gear (31) is power connected with the second input shaft (12), and The planet carrier (34) is fixed; The ring gear (33) is power connected with the second rotation component (22) of the first clutch (2), the ring gear (33) is provided with external teeth in the circumferential direction and the external teeth of the ring gear (33) are engaged with the first intermediate gear (24).

8. The transmission mechanism for an electric vehicle according to claim 1 or 2, characterized by, The transmission mechanism for electric vehicles further comprises: A damper (11) is arranged between the first input shaft (10) and the first clutch (2), the input end of the damper (11) is power connected with the first input shaft (10), and the output end of the damper (11) is power connected with the first rotation component (21) of the first clutch (2).

9. The transmission mechanism for an electric vehicle according to claim 8, characterized by, The damper (11) is a torsional damper.

10. The transmission mechanism for an electric vehicle according to claim 1 or 2, characterized by, At least one of the first intermediate gear (24) and the second intermediate gear (25) is capable of rotating relative to the intermediate shaft.

11. A range extending device for an electric vehicle, characterized in that Comprise: An electric motor generator (4); And The transmission mechanism for electric vehicles according to any one of the preceding claims, Wherein the second input shaft (12) of the transmission mechanism for electric vehicles is power connected with the electric motor generator (4).

12. The range extending device for an electric vehicle of claim 11, wherein, The electric motor generator is a permanent magnet synchronous motor.

13. A range extending system for an electric vehicle, characterized by Comprise: An internal combustion engine (1); The range extending device for electric vehicles according to the preceding claim 11 or 12, Wherein the first input shaft (10) of the transmission mechanism for electric vehicles is power connected with the internal combustion engine (1).

14. The range extending system for an electric vehicle of claim 13, wherein, The internal combustion engine is an in-line 4-cylinder internal combustion engine.

15. An electric vehicle characterized by Comprise: The range extending system for electric vehicles according to claim 13 or 14; And A pair of wheels (8), the pair of wheels are a pair of front wheels or a pair of rear wheels of the electric vehicle, Wherein the other end of each of the two output shafts of the transmission mechanism for electric vehicles is power connected with a corresponding one of the pair of wheels (8).

16. The electric vehicle of claim 15, wherein Comprise: A main drive, the main drive comprises a main drive motor and a main speed reducer power connected with the main drive motor, Wherein the main drive is used to drive a pair of wheels different from the pair of wheels (8) driven by the range extending system for electric vehicles.

Images