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

Abstract

The application 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 (10), a second input shaft (12), a first clutch (2) arranged between the first and second input shafts, a reduction device (3) comprising a sun gear (31), a planetary gear pair comprising inner and outer planetary gears, a ring gear (33) having inner and outer teeth, and a planet carrier (34), the sun gear being connected to the second input shaft, the ring gear being connected to a second rotating part of the first clutch and the planet carrier being fixed, a differential (7), an intermediate shaft, first and second intermediate gears arranged on the intermediate shaft, two output shafts (71), one end of each output shaft being power-connected to the differential, and a second clutch (6) arranged in a power transmission path between the first intermediate gear and the other end of each output shaft opposite to the one end.

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 direct power connection between the internal combustion engine and generator in this prior art prevents flexible control of both components. The drive motor's output needs to be reduced in speed; however, existing technologies typically use conventional planetary gear sets to reduce the motor's output, leading to a bulky system and reduced transmission efficiency.

[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 a reduction gear disposed between the first clutch and the second input shaft, the reduction gear comprising a sun gear, at least one planetary gear pair including an internal planetary gear and an external planetary gear, a ring gear, and a planet carrier supporting the planetary gear pair, the sun gear being connected to the second input shaft, the ring gear having internal teeth on its radially inner surface and external teeth on its radially outer surface, the ring gear being connected to the second rotating component of the first clutch, and the planet carrier being fixed, thereby transmitting power from the first input shaft and from the second input shaft. The power can be coupled at the ring gear; a differential, the differential having an input gear on the differential housing; an intermediate shaft; a first intermediate gear and a second intermediate gear, the first intermediate gear and the second intermediate gear being arranged on the intermediate shaft, the first intermediate gear meshing with the external teeth of the ring gear, and the second intermediate gear being able to be powered by the first intermediate gear on one hand and powered by the input gear of the differential on the other hand, thereby the input gear being able to be powered by the ring gear; two output shafts, one end of each of the two output shafts being powered by the differential, thereby being able to transmit power from the differential; and a second clutch, the second clutch being disposed on the power transmission path of the transmission mechanism between the first intermediate gear and the other end of each of the two output shafts opposite to the first end, thereby allowing or disconnecting the power transmission between the first intermediate gear and the other end of each output shaft.

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

[0008] Preferably, the external planetary gear of one planetary gear pair of the reduction gear meshes with the internal teeth of the gear ring on the side of the gear ring closest to the first intermediate gear.

[0009] Preferably, when viewed in the radial direction of the gear ring, the meshing point of the outer planetary gear of the first planetary gear pair of the reduction gear with the inner teeth of the gear ring and the meshing point of the first intermediate gear with the outer teeth of the gear ring overlap.

[0010] Preferably, when the reduction gear includes multiple planetary gear pairs and the number of planetary gear pairs is even, the planetary gear pair is a first planetary gear pair, and the outer planetary gear of the second planetary gear pair among the multiple planetary gear pairs meshes with the inner teeth of the gear ring on the side of the gear ring away from the first intermediate gear.

[0011] Preferably, the inner planetary gear and outer planetary gear of the planetary gear pair, the gear ring and the first intermediate gear are arranged in a straight line.

[0012] The transmission mechanism for electric vehicles disclosed herein is compact in structure, and by making the meshing point of the outer planetary gear of one planetary gear pair of the reduction device with the inner teeth of the gear ring and the meshing point of the first intermediate gear with the outer teeth of the gear ring overlap in the radial direction of the gear ring, the forces acting on the gear ring can be effectively counteracted.

[0013] The second clutch can be a jaw clutch. The first clutch can be a friction clutch.

[0014] Preferably, the second clutch is a jaw clutch, and the first clutch is a friction clutch.

[0015] According to an aspect of this disclosure, the second clutch is disposed between the first intermediate gear and the second intermediate gear, thereby enabling or disabling the transmission of power between the first intermediate gear and the second intermediate gear.

[0016] According to an aspect of this disclosure, the second clutch is disposed on either of the two output shafts, thereby enabling the disconnection of power transmission between the differential and the other end.

[0017] 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.

[0018] The damper is a torsional damper.

[0019] This disclosure provides a range extender for an electric vehicle, comprising: an electric generator; and the aforementioned transmission mechanism for the electric vehicle, wherein a second input shaft of the transmission mechanism for the electric vehicle is poweredly connected to the electric generator.

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

[0021] This disclosure provides a range extender system for an electric vehicle, comprising: an internal combustion engine; and the aforementioned range extender for an electric vehicle, wherein a first input shaft of the transmission mechanism for the electric vehicle is poweredly connected to the internal combustion engine.

[0022] The internal combustion engine is an inline 4-cylinder internal combustion engine.

[0023] This disclosure provides an electric vehicle, comprising: a range extender system for the electric vehicle; a power battery in which the power generated by the range extender system is stored; 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.

[0024] The electric vehicle includes a main drive unit, which includes a main drive motor and a main reducer powered by the main drive motor. The main drive unit is powered by the electric vehicle's battery. The main drive unit is used to drive a pair of wheels that are different from the pair of wheels driven by the range extender system for the electric vehicle.

[0025] 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.

[0026] 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. They allow for simple deceleration of the motor output and enable rapid disconnection of power transmission from the drive unit to the wheels. Using the method disclosed for controlling the range extender for electric vehicles, multiple operating modes can be automatically switched based on the state of charge (SOC) of the power battery and the vehicle speed. Attached Figure Description

[0027] 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.

[0028] 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.

[0029] Figure 2 This is a schematic diagram of the state of engagement of the sun gear, the inner planetary gear and the outer planetary gear of a planetary gear pair, and the ring gear of the transmission mechanism according to the first embodiment.

[0030] Figure 3 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

[0031] Various embodiments of the invention are described below with reference to the accompanying drawings, illustrating specific embodiments in which the invention can be implemented. The expressions “left” and “right” (if any) appearing in the specification are merely for describing the application with reference to the drawings and are not intended to limit the invention. It is understood that the expression “left” or “right” simply indicates a direction and is reversible. Certain terms used in this specification are for convenience only and not for limitation. The terms “axial,” “radial,” “circumferential,” “outward,” “inward,” “upward,” and “downward” (if any) indicate direction in the referenced drawings. Unless otherwise expressly stated, each value and range, as well as shape (if any), should be interpreted as approximate, as if preceded by the terms “about,” “approximately,” or “substantially.” The terms “about,” “substantially,” etc., are intended to mean a range that is considerably large or largely, but not necessarily entirely (but may fully encompass), the specified range.

[0032] It should be understood that although the terms “first,” “second,” etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, without departing from the scope of this disclosure, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element.

[0033] <System Configuration>

[0034] First embodiment:

[0035] 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, as indicated by the dashed box. 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. The electric generator 4 has a rotor 41 and a stator 42, the stator 42 being fixed and the rotor 41 being rotatable relative to the stator 41. The operating principle of the electric generator is well known and will not be described further here.

[0036] 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, such as an internal combustion engine 1 and an electric generator 4.

[0037] 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 to the internal combustion engine 1, specifically the crankshaft of the internal combustion engine. The connection between the first rotating component 21 and the first input shaft 10 can be a direct connection, such as a form-fit connection or a friction-fit connection, or an indirect connection, such as a connection via a conventional coupling. The second rotating component 22 is poweredly connected (e.g., via a reduction gear 3, as described below) to the second input shaft 12, and thereby poweredly connected to the electric generator 4, specifically the output shaft of the electric generator. Thus, the first clutch 2 is capable of powerly connecting the first input shaft 10 and the second input shaft 12. Accordingly, the first clutch 2 is capable of powerly connecting the internal combustion engine 1 to the electric generator 4. The term "powered connection" is a connection in which two components are directly or indirectly connected in a manner capable of transmitting power.

[0038] The transmission mechanism for the electric vehicle also includes a reduction gear 3. The reduction gear 3 is disposed between the first clutch 2 and a second input shaft 12 capable of connecting to an electric generator 4. The reduction gear 3 has a spur planetary gear configuration. Specifically, the reduction gear 3 includes a sun gear 31, at least one planetary gear pair including an inner planetary gear 321 and an outer planetary gear 322, a planet carrier 34 supporting the planetary gear pair, and a ring gear 33. The sun gear 31 is connected to the second input shaft 12. The planetary gear pair is located radially inward of the ring gear 33. The ring gear 33 has inner teeth 331 located on the radially inner surface of the ring gear and outer teeth 333 located on the radially outer surface of the ring gear. The inner planetary gear 321 of the planetary gear pair meshes with the sun gear 31 on one hand and with the outer planetary gear 322 on the other hand, and the outer planetary gear 322 meshes with the inner teeth 331 of the ring gear 33. The ring gear 33 is poweredly connected to the second rotating component 22 of the first clutch 2. The planet carrier 34 is fixed. Thus, the power from the first input shaft 10 and the power from the second input shaft 12 can be coupled together at the gear ring 33.

[0039] The transmission mechanism for electric vehicles also includes a differential 7, which has an input gear 70 on its housing. The input gear 70 is power-connected to the reduction gear 3, thereby receiving power from the reduction gear 3.

[0040] The transmission mechanism for electric vehicles 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 rotationally connected to the intermediate shaft 222. The axis of the intermediate shaft 222 is different from the axis of rotation of the gear ring 33 of the reduction gear 3 (or the axis of rotation of the sun gear 31) and the axis of rotation of the output shaft 71 of the differential 7, and is located between the two. The first intermediate gear 24 meshes with the external teeth 332 of the gear ring 33. The second intermediate gear 25 is poweredly connected to the first intermediate gear 24 to receive power from the first intermediate gear 24, 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 gear ring 33, specifically the external teeth 332 of the gear ring 33. Specifically, as needed, the intermediate shaft 222 is rotatably supported, and one of the intermediate gears, the first intermediate gear 24 and the second intermediate gear 25, is rotatably arranged on or integrally with the intermediate shaft 222, while the other intermediate gear is rotatably arranged on the intermediate shaft 222; or both the first intermediate gear 24 and the second intermediate gear 25 are rotatably arranged on or integrally with the intermediate shaft 222. The term "rotatably connected" refers to a connection in which two components are rigidly connected together without being able to rotate relative to each other.

[0041] The transmission mechanism for the electric vehicle also includes two output shafts 71. One end of each output shaft 71 is poweredly connected to the differential 7, thereby enabling the transmission of power from the differential 7. For example, the output shaft 71 is used to transmit power to a pair of wheels of the electric vehicle. Specifically, the other end of each output shaft 71, opposite to the end powered to the differential 7, can be poweredly connected to a corresponding wheel of a pair of wheels 8 of the electric vehicle, for transmitting 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.

[0042] The transmission mechanism for electric vehicles also includes a second clutch 6, which is disposed on the 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 opposite to the first end, thereby enabling or disabling power transmission between the first intermediate gear 24 and the other end of each output shaft.

[0043] Specifically, such as Figure 1 As shown, the second clutch 6 is located on the intermediate shaft 222 and is 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.

[0044] Figure 2 This is a schematic diagram showing the state of engagement of the sun gear, the inner planetary gear and the outer planetary gear of the planetary gear pair, and the ring gear of the speed reduction device of the transmission mechanism according to the first embodiment. Figure 2 The diagram shows only one planetary gear pair; however, it is understood that the reduction gear 3 may include multiple gear pairs, such as 2, 3, 4, or 5. The number of gear pairs is not particularly limited. Figure 2 Combination Figure 1 As shown, the second input shaft 12 is powered by the sun gear 31, which meshes with the inner planetary gear 321 of the planetary gear pair. The inner planetary gear 321 meshes with the outer planetary gear 322, and the outer planetary gear 322 meshes with the inner gear 331 of the ring gear 33. Specifically, in the radial direction of the ring gear 33, the gear centers of the inner planetary gear 321 and the outer planetary gear 322 of the planetary gear pair are approximately aligned on a straight line. That is, the line connecting the gear centers of the inner planetary gear 321 and the outer planetary gear 322 of each planetary gear pair is arranged in the radial direction of the ring gear 33. However, it is conceivable that the straight line connecting the gear centers of the inner planetary gear 321 and the outer planetary gear 322 of each planetary gear pair does not necessarily have to be arranged in the radial direction of the ring gear 33. The planet carrier 34 is fixed, for example, directly connected to the stator 42 of the electric generator 4.

[0045] The outer planetary gear 322 of one planetary gear pair of the reduction gear 3 meshes with the inner teeth 331 of the gear ring 33 on the side of the gear ring 33 near the first intermediate gear 24. Preferably, when viewed in the radial direction of the gear ring 33, the meshing point of the outer planetary gear 322 of the reduction gear 3 with the inner teeth 331 of the gear ring 33 and the meshing point of the first intermediate gear 24 with the outer teeth 333 of the gear ring 33 substantially overlap. That is, the straight line connecting these two meshing points is arranged substantially in the radial direction of the gear ring 33. Or, these two meshing points are located at approximately the same position / same circumferential angle on the circumferential direction of the gear ring.

[0046] Furthermore, when the reduction gear 3 includes an odd number of planetary gear pairs, the outer planetary gear 322 of one planetary gear pair meshes with the inner teeth 331 of the gear ring 33 on the side of the gear ring 33 near the first intermediate gear 24, while other planetary gear pairs (if any) are evenly distributed with said one planetary gear pair in the circumferential direction of the gear ring 33. Preferably, the odd number of planetary gear pairs is three planetary gear pairs.

[0047] When the reduction gear 3 includes an even number of planetary gear pairs, the outer planetary gear 322 of the first planetary gear pair meshes with the inner teeth 331 of the gear ring 33 on the side of the gear ring 33 closest to the first intermediate gear 24, and the outer planetary gear 322 of the second planetary gear pair meshes with the inner teeth 331 of the gear ring 33 on the side of the gear ring 33 furthest from the first intermediate gear 24. Other planetary gear pairs (if any) are evenly distributed circumferentially with the first and second planetary gear pairs on the gear ring 33. Particularly and preferably, when the reduction gear 3 includes an even number of planetary gear pairs, the gear centers of the inner planetary gear 321 and outer planetary gear 322 of the first planetary gear pair and the gear centers of the inner planetary gear 321 and outer planetary gear 322 of the second planetary gear pair are arranged in a straight line. Preferably, the even number of planetary gear pairs is 2 or 4 planetary gear pairs.

[0048] Planetary gear sets offer advantages such as high transmission accuracy, high transmission density, small footprint, high transmission efficiency, and long service life. Furthermore, through the gear pair arrangement described above, when power is transmitted from the outer planetary gear 322 through the ring gear 33 to the first intermediate gear 24, the two meshing points are arranged to overlap when viewed radially from the ring gear 33, effectively counteracting the forces on the ring gear, particularly radial and axial forces. Consequently, the reduction device according to this disclosure can reduce the rotational output of the drive source with a simple construction and in a stable manner. This further reduces costs.

[0049] 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 quickly 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 corresponding to the intermediate gear can be directly formed on the intermediate shaft 222.

[0050] 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 gear ring 33 of the reduction gear 3. It is easy to understand that the second rotating component 22 of the first clutch 2 can be fixed together with or integrally formed with the gear ring 33 of the reduction gear 3.

[0051] Differential 7 is a conventional type of differential. As described above, each output shaft 71 of the transmission mechanism is poweredly connected to the differential 7 at one end of the output shaft 71 and poweredly connected to a corresponding wheel 8 of the electric vehicle at the other end of the output shaft 71. 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.

[0052] 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 or dampen the output of the external power source, such as the internal combustion engine 1, the transmission mechanism for the electric vehicle can be equipped 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 type of damper is not limited and can be other types of dampers, such as hydraulic dampers.

[0053] Preferably, the transmission mechanism may include a housing 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 and on opposite sides of the housing, respectively. The housing may, for example, be fixed to the frame of an electric vehicle. With the transmission mechanism provided with a housing, a first input shaft 10 is rotatably supported in a wall on one side of the housing, and a second input shaft 12 is rotatably supported in a wall on a second side of the housing 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. A shock absorber 11 and a reduction gear 3 may be located inside or outside the housing. A first clutch 2 is preferably located inside the housing. A differential 7 is preferably located inside the housing. One of the two output shafts 71 is rotatably supported in a wall on one side of the housing, and the other output shaft is rotatably supported in a wall on the other side of the housing. It should be understood that the positional relationship of all components of the transmission mechanism relative to the housing is not limiting but can be appropriately selected according to actual needs. The construction of the housing is not limited; for example, the housing may not have any walls in the axial direction of the input shafts and / or output shafts.

[0054] The transmission mechanism for electric vehicles described above has a reasonable layout of its components, a compact structure, which facilitates assembly, saves space, and improves the utilization rate of interior space. In particular, the reduction device 3 according to this disclosure can reduce the rotational output of the power source in a stable and high-precision manner, and the second clutch 6 according to this disclosure can quickly disconnect the power transmission from the drive unit to the wheels of the electric vehicle.

[0055] Second embodiment:

[0056] Figure 3 This is a schematic diagram of the transmission mechanism, range extender, and range extender system for an electric vehicle according to a second embodiment. The same reference numerals are used for the parts identical to those in the first embodiment, and their descriptions are omitted here; only the different parts are described.

[0057] In the first embodiment described above, as Figure 1 As shown, the second clutch 6 is located on the intermediate shaft 222 and is disposed between the first intermediate gear 24 and the second intermediate gear 25. Unlike the first embodiment, as... Figure 3 As shown, in the second embodiment, the second clutch 6 is disposed on one of the two output shafts 71. This allows the transmission of power from the differential 7 to the other end of either output shaft 71 to be disconnected. It should be understood that disconnecting the power transmission is achieved whether the second clutch 6 is disposed on either of the two output shafts 71.

[0058] The range extender for electric vehicles disclosed herein includes a transmission mechanism and an electric generator 4 according to any one of the first to second embodiments described above. A second input shaft 12 of the transmission mechanism for the electric vehicle is poweredly connected to the electric generator 4.

[0059] The electric generator 4 can be used as both an electric motor and a generator. The electric generator 4 is equipped with an inverter (not shown) for controlling its operation. The 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.

[0060] 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 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 torque and maximum output power, are also not limited but are selected as needed. Thus, the internal combustion engine 1 and the electric generator 4 can together provide power to the output shaft 71 of the range extender system. However, it is readily understood that the mechanical power provided by the internal combustion engine 1 to the output shaft 71 can be limited, while only the electric generator 4 provides power to the output shaft 71, to ensure the pure electric mode of the range extender system.

[0061] 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 cost. 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, thus realizing the range extension function at low cost and in a small footprint. Furthermore, the reduction gear 3 according to this disclosure can reduce the rotational output of the power source in a simple and stable manner, and the second clutch 6 according to this disclosure can quickly disconnect the power transmission from the drive unit to the output shaft or the wheels of the electric vehicle.

[0062] The electric vehicle disclosed herein includes the aforementioned range extender system, a power battery, 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 dynamically connected to a corresponding wheel in the pair of wheels 8. The electricity generated by the range extender system can be stored in the power battery of the electric vehicle. The range extender system according to the invention can be the only drive system for the electric vehicle. Therefore, efficient power generation and driving of the electric vehicle can be achieved without an additional drive system, thereby reducing costs.

[0063] However, 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 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 driven by the range extender system for the electric vehicle, using power from the power battery. For example, the range extender system according to this 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. 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 by means of the range extender system.

[0064] 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.

[0065] The range extender system for electric vehicles according to the first embodiment has multiple operating modes, including pure electric mode, hybrid drive mode, and range extender mode, and can automatically switch between these modes based on the state of charge (SOC) of the power battery and vehicle speed requirements. Specific control strategies can be specified according to the vehicle model; for example, different control strategies can be formulated for pure electric vehicles, hybrid electric vehicles, and range extender vehicles. In this document, the control strategy is not the focus, and therefore its formulation will not be described in detail.

[0066] 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 electric vehicles, characterized in that... include: First input axis (10); Second input axis (12); A first clutch (2) is disposed between the first input shaft (10) and the second input shaft (12). The first clutch has a first rotating part (21) and a second rotating part (22) that can engage and disengage from each other. The first rotating part (21) of the first clutch is connected to the first input shaft (10). A speed reduction device (3) is disposed between the first clutch (2) and the second input shaft (12). The speed reduction device (3) includes a sun gear (31), at least one planetary gear pair including an inner planetary gear (321) and an outer planetary gear (322), a ring gear (33), and a planet carrier (34) supporting the planetary gear pair. The sun gear (31) is connected to the second input shaft (12). The ring gear (33) has internal teeth (331) on the radial inner surface of the ring gear and external teeth (333) on the radial outer surface of the ring gear. The ring gear (33) is connected to the second rotating component (22) of the first clutch (2), and the planet carrier (34) is fixed, so that the power from the first input shaft (10) and the power from the second input shaft (12) can be coupled at the ring gear (33). Differential (7), wherein an input gear (70) is provided on the differential housing. Intermediate shaft (222); A first intermediate gear (24) and a second intermediate gear (25) are arranged on the intermediate shaft (222). The first intermediate gear (24) meshes with the external teeth (332) of the gear ring (33), and the second intermediate gear (25) is powered to the first intermediate gear (24) on one hand and powered to the input gear (70) of the differential (7) on the other hand, thereby the input gear (70) is powered to the gear ring (33). Two output shafts (71), one end of each of the two output shafts being poweredly connected to the differential (7), thereby enabling the transmission of power from the differential (7); and The second clutch (6) is disposed on the power transmission path of the transmission mechanism between the first intermediate gear (24) and the other end opposite to one of the two output shafts, thereby enabling or disabling power transmission between the first intermediate gear (24) and the other end of each output shaft.

2. The transmission mechanism for electric vehicles according to claim 1, characterized in that, The outer planetary gear (322) of one planetary gear pair of the speed reduction device (3) meshes with the inner teeth (331) of the gear ring (33) on the side of the gear ring (33) near the first intermediate gear (24).

3. The transmission mechanism for electric vehicles according to claim 2, characterized in that, When viewed in the radial direction of the gear ring (33), the meshing point of the outer planetary gear (322) of the one planetary gear pair of the reduction device (3) with the inner tooth (331) of the gear ring (33) and the meshing point of the first intermediate gear (24) with the outer tooth (333) of the gear ring (33) overlap.

4. The transmission mechanism for electric vehicles according to claim 2 or 3, characterized in that, When the reduction gear (3) includes multiple planetary gear pairs and the number of planetary gear pairs is even, the planetary gear pair is the first planetary gear pair. The outer planetary gear (322) of the second planetary gear pair in the plurality of planetary gear pairs meshes with the inner teeth (331) of the gear ring (33) on the side of the gear ring (33) away from the first intermediate gear (24).

5. The transmission mechanism for electric vehicles according to claim 2 or 3, characterized in that, The inner planetary gear (321) and outer planetary gear (322) of the planetary gear pair, the gear ring (33) and the first intermediate gear (24) are arranged in a straight line.

6. The transmission mechanism for electric vehicles according to claim 1 or 2, characterized in that, The second clutch (6) is a jaw clutch.

7. The transmission mechanism for electric vehicles according to claim 1 or 2, characterized in that, The first clutch (2) is a friction clutch.

8. The transmission mechanism for electric vehicles according to claim 6, characterized in that, The first clutch (2) is a friction clutch.

9. The transmission mechanism for electric vehicles according to claim 1 or 2, characterized in that, The second clutch (6) is 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).

10. The transmission mechanism for electric vehicles according to claim 1 or 2, characterized in that, The second clutch (6) is located on either of the two output shafts (71), thereby enabling the disconnection of power transmission between the differential (7) and the other end.

11. The transmission mechanism for electric vehicles according to claim 1 or 2, characterized in that, The transmission mechanism also includes: A shock absorber (11) is disposed between the first input shaft (10) and the first clutch (2). The input end of the shock absorber (11) is poweredly connected to the first input shaft (10), and the output end of the shock absorber (11) is poweredly connected to the first rotating component (21) of the first clutch (2).

12. The transmission mechanism for electric vehicles according to claim 11, characterized in that, The damper (11) is a torsional damper.

13. A range extender for electric vehicles, characterized in that... include: Electric generator (4); and The transmission mechanism for an electric vehicle according to any one of the preceding claims The second input shaft (12) of the transmission mechanism is powered by the electric generator (4).

14. The range extender for electric vehicles according to claim 13, characterized in that, The electric generator is a permanent magnet synchronous motor.

15. A range extender system for electric vehicles, characterized in that... include: Internal combustion engine (1); The range extender for electric vehicles according to claim 13 or 14 above, The first input shaft (10) of the transmission mechanism is powered by the internal combustion engine (1).

16. The range extender system for electric vehicles according to claim 15, characterized in that, The internal combustion engine is an inline 4-cylinder internal combustion engine.

17. An electric vehicle, characterized in that... include: Range extender system for electric vehicles according to claim 15 or 16; The power battery, in which the electricity generated by the range extender system is stored; and A pair of wheels (8), said pair of wheels being 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 electric vehicles is poweredly connected to one of the corresponding wheels of the pair of wheels (8).

18. The electric vehicle according to claim 17, characterized in that... include: The main drive unit includes a main drive motor and a main reducer electrically connected to the main drive motor. The main drive unit is powered by the power battery of the electric vehicle. The main drive is used to drive a pair of wheels of the electric vehicle that are different from the pair of wheels (8) driven by the range extender system for the electric vehicle.

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