Two-speed transmission for electric vehicles with no power interruption using a double planetary gear

Abstract

The application discloses a two-gear transmission of a non-powered interrupt electric vehicle adopting a two-stage planetary gear, which comprises a driving motor, a first reduction gear set, an intermediate shaft, a two-stage planetary gear train, a controllable one-way clutch, a second reduction gear set, a differential, a friction clutch and a transmission housing. The torque output by the driving motor is transmitted to the intermediate shaft through the first reduction gear set; the intermediate shaft is fixedly connected with a first sun gear. The controllable one-way clutch is used for connecting the transmission housing and a first planet carrier; the friction clutch is used for connecting a first ring gear and the intermediate shaft. The second reduction gear set is used for transmitting the torque output by the first ring gear to the differential housing after reducing the torque and increasing the torque. The two-gear transmission can realize six states, i.e., one-gear driving, two-gear driving, neutral gear, one-gear regenerative braking, two-gear regenerative braking and reverse driving, by coordinately controlling the friction clutch and the controllable one-way clutch; and the two-gear transmission can realize non-powered interrupt gear shifting between the one-gear and the two-gear.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of electric vehicle transmission, and particularly relates to a high-integration two-gear electric vehicle transmission without power interruption adopting a double-stage planetary gear. BACKGROUND

[0002] In recent years, with the development and progress of society, electric vehicles characterized by zero oil consumption, high integration, fast power response, high driving performance and the like have been greatly developed and gradually recognized by the market. With the development and popularization of the market, electric vehicles in the future will also develop towards high-end high performance, diversification and individualization, and therefore the demand for advanced drive technologies capable of improving chassis performance is increasing. The power interruption-free shifting technology of the two-gear electric vehicle transmission is one of the technologies.

[0003] At present, the two-gear electric vehicle transmission has attracted the attention of many scholars and manufacturers. Compared with the single motor plus speed reducer driving mode, the use of the two-gear transmission can greatly reduce the maximum torque and highest speed demand of the driving motor, thereby reducing the size and cost of the motor, and can greatly improve the utilization rate of the high efficiency interval of the driving motor through the transmission ratio optimization of the two-gear transmission, thereby improving the economy of the vehicle and increasing the cruising range.

[0004] However, the use of the two-gear transmission will be accompanied by the problem of power interruption during shifting. To solve the problem of power interruption during shifting of the two-gear transmission, some scholars have proposed a two-gear transmission scheme of "friction clutch + one-way overrunning clutch", but this scheme cannot realize the reverse working condition and one-gear regenerative braking energy recovery if applied to a single-axle driving electric vehicle. Therefore, some people have proposed a two-gear transmission scheme of "friction clutch + one-way overrunning clutch + claw clutch", but this scheme has many actuators and a complex structure, and the one-gear regenerative braking state and two-gear regenerative braking state are not easy to switch during the regenerative braking process without regenerative braking power interruption. Therefore, to solve the above problems, the application proposes a new "friction clutch + controllable one-way clutch" configuration scheme.

[0005] At the same time, to make the wheel end torque external characteristic curve change continuously, fully exert the high efficiency interval of the motor, and reduce the shifting difficulty, the ratio of the one-gear transmission ratio and the two-gear transmission ratio should not be too large, and should be designed around 1.7-2. The double-stage planetary gear train can realize the speed ratio change of 1.7-2 by designing its characteristic parameters.

[0006] In view of the above background content, existing technical defects and technical expectations, the present invention proposes a two-speed transmission for electric vehicles without power interruption using a two-stage planetary gear. It only uses two pairs of gears and a two-stage planetary gear system, and cooperates with the use of a controllable one-way clutch and a friction clutch. It can realize six different driving states: first gear driving state, second gear driving state, neutral state, first gear regenerative braking, second gear regenerative braking, and gear driving, and can realize gear shifting without power interruption. Summary of the Invention

[0007] The present invention provides a two-speed transmission for an electric vehicle without power interruption, which adopts a two-stage planetary gear. The transmission can realize six different driving states: first gear driving state, second gear driving state, neutral state, first gear regenerative braking, second gear regenerative braking, and vehicle driving; the two-speed transmission can realize free switching of different driving modes based on a controllable one-way clutch and a friction clutch, and the switching control difficulty is low; at the same time, the two-speed transmission can make the ratio of the first gear transmission ratio to the second gear transmission ratio be about 1.7-2.1 by using a two-stage planetary gear system with a characteristic parameter of about 1.7-2.1, thereby reducing the difficulty of gear shifting, ensuring the continuity of the external characteristics of the wheel end torque, and effectively improving the utilization rate of the high efficiency range of the motor.

[0008] In order to achieve the above purpose, the following technical solutions are adopted:

[0009] A two-speed transmission for electric vehicles without power interruption using a two-stage planetary gear is characterized by including: a drive motor, an intermediate shaft, a first reduction gear set, a two-stage planetary gear system, a controllable one-way clutch, a second reduction gear set, a differential, a friction clutch, a transmission housing, a left transmission output shaft, a right transmission output shaft, etc.

[0010] A transmission housing, used to accommodate and support all components of the two-speed transmission;

[0011] The left output shaft of the transmission is used to transmit power to the left drive wheel;

[0012] The right output shaft of the transmission is used to transmit power to the right drive wheel;

[0013] The drive motor is coaxially arranged with the left output shaft of the transmission, and includes the stator, rotor, motor output shaft and motor housing; the stator is fixed inside the motor housing; the rotor is fixed on the motor output shaft; the motor output shaft is rotatably supported on the motor housing; the motor output shaft is a hollow shaft, and the left output shaft of the transmission passes through the inside of the motor output shaft.

[0014] The intermediate shaft is arranged in parallel with the left output shaft of the transmission and is rotatably supported on the transmission housing through bearings.

[0015] The first reduction gear set is used for outputting the torque of the driving motor after speed reduction and torque increase to the intermediate shaft, and comprises a first driving gear and a first driven gear.

[0016] The double-stage planetary gear train comprises a sun gear, an inner planetary gear, an outer planetary gear, an inner planetary gear shaft, an outer planetary gear shaft, a ring gear and a planet carrier, the sun gear is fixedly connected to the intermediate shaft through a spline, the inner planetary gear is in external meshing transmission with the sun gear, the outer planetary gear is in external meshing transmission with the inner planetary gear, the ring gear is in internal meshing transmission with the outer planetary gear, the inner planetary gear and the outer planetary gear are respectively rotatably supported on the inner planetary gear shaft and the outer planetary gear shaft, the inner planetary gear shaft and the outer planetary gear shaft are supported on the planet carrier, and the planet carrier is rotatably supported on the intermediate shaft through a bearing.

[0017] The controllable one-way clutch comprises the inner ring, the outer ring, a plurality of first pawls, a plurality of second pawls, a plurality of reset springs, a control disc and a control mechanism, and can be controlled to realize a one-way locking state and be switched from the one-way locking state to a two-way locking state or a two-way overrunning state. There is a certain gap between the inner ring and the outer ring. The inner ring is fixedly connected to the planet carrier and has a two-way ratchet protrusion on an outer surface. The outer ring is fixedly connected to the transmission housing through a spline on an outer surface and has a plurality of first pawls and a plurality of second pawls mounted on an inner surface in a uniform staggered manner. The first pawls and the second pawls are arranged in opposite directions, and each of the first pawls and the second pawls has a control pin fixedly mounted on a movable end. The reset springs are mounted between the first pawls and the outer ring and between the second pawls and the outer ring. The control pins are matched with the control disc and can move radially within a space defined by the control disc under the driving of the control mechanism. The movable ends of the first pawls and the second pawls can be in contact with the two-way ratchet protrusion on the outer surface of the inner ring under the action of the reset springs, so as to lock the counterclockwise rotation and the clockwise rotation of the inner ring, respectively.

[0018] The control disc is installed on the side surface of the inner ring and the outer ring and can rotate around the intermediate shaft; a plurality of groups of control grooves with two different shapes are arranged alternately on the control disc, which are matched with the control pin of the first pawl and the control pin of the second pawl respectively, so as to restrict the space range in which the respective control pin can move, and the total number of the control pins is the same as the total number of the control grooves; the restriction relationship is specifically shown as follows:

[0019] When the control disc is in the intermediate position, the first pawl control pin is not controlled by the corresponding control groove, the movable end of the first pawl is pushed to the outer surface double-directional ratchet protrusion of the inner ring under the action of the reset spring, and at this time, the second pawl control pin is controlled by the corresponding control groove, the movable end of the second pawl is pulled outward under the action of the control groove, and does not contact the outer surface double-directional ratchet protrusion of the inner ring, at this time, the controllable one-way clutch is in the one-way locking state of locking the rotation of the inner ring counterclockwise;

[0020] When the control disc rotates counterclockwise from the intermediate position by a certain angle, the first pawl control pin and the second pawl control pin are not controlled by the respective corresponding control grooves, the movable end of the first pawl and the movable end of the second pawl are both pushed to the outer surface double-directional ratchet protrusion of the inner ring under the action of the reset spring, at this time, the controllable one-way clutch is in the double-directional locking state;

[0021] When the control disc rotates clockwise from the intermediate position by a certain angle, the first pawl control pin and the second pawl control pin are both controlled by the respective corresponding control grooves, the movable end of the first pawl and the movable end of the second pawl are both pulled outward under the action of the control groove, and do not contact the outer surface double-directional ratchet protrusion of the inner ring, at this time, the inner ring and the outer ring of the controllable one-way clutch are completely separated, and the controllable one-way clutch is in the double-directional overrun state.

[0022] The control mechanism comprises a worm wheel, a worm and a control motor, the worm wheel is a fan spoke structure, the spoke of the worm wheel is fixedly connected with the control disc, the worm is in meshing transmission with the worm wheel, the control motor is fixedly connected with the worm, and the output torque of the control motor is reduced and increased in torque by the worm wheel and worm, and then the transmission direction is changed vertically to realize the rotation control of the control disc.

[0023] The second reduction gear set reduces and increases the torque on the gear ring and then outputs; it comprises a second driving gear and a second driven gear; the second driving gear can be integrated with the gear ring and is rotatably supported on the intermediate shaft by a needle bearing, and the second driven gear is in external meshing transmission with the second driving gear.

[0024] A differential, receiving torque from the second reduction gear set and distributing the torque equally to the transmission left output shaft and the transmission right output shaft; it comprises a differential housing, a plurality of planetary bevel gears, a left output shaft bevel gear, a right output shaft bevel gear; the differential housing is rotatably supported on the transmission left output shaft and the transmission right output shaft; the plurality of planetary bevel gears are rotatably supported on the differential housing; the left output shaft bevel gear and the right output shaft bevel gear are in meshing transmission with the plurality of planetary bevel gears, and are connected with the left drive wheel and the right drive wheel cardan shaft respectively through the transmission left output shaft and the transmission right output shaft respectively; the second driven gear is fixedly connected with the differential housing through a spline.

[0025] A friction clutch, comprising a clutch driving part and a clutch driven part, the clutch driving part is fixedly connected with the intermediate shaft, the clutch driven part is fixedly connected with the ring gear;

[0026] When the two-gear transmission is in one-gear driving state, the friction clutch is controlled to be in a separated state, the controllable one-way clutch is in a bidirectional locking state, and the driving motor outputs driving torque in a positive direction; when the two-gear transmission is in two-gear driving state, the friction clutch is in a combined state, the controllable one-way clutch is in a bidirectional overrunning state, and the driving motor outputs driving torque in a positive direction; when the two-gear transmission is in neutral state, the friction clutch is in a separated state, the controllable one-way clutch is in a bidirectional overrunning state, and the driving motor does not output any torque; when the two-gear transmission is in one-gear regenerative braking state, the friction clutch is in a separated state, the controllable one-way clutch is in a bidirectional locking state, and the driving motor outputs electromagnetic braking torque in a positive direction; when the two-gear transmission is in two-gear regenerative braking state, the friction clutch is in a combined state, the controllable one-way clutch is in a bidirectional overrunning state, and the driving motor outputs electromagnetic braking torque in a positive direction; when the two-gear transmission is in reverse state, the friction clutch is in a separated state, the controllable one-way clutch is in a bidirectional locking state, and the driving motor outputs driving torque in a reverse direction.

[0027] The bidirectional locking state of the controllable one-way clutch is a transition state when the two-gear transmission is switched between one-gear driving and two-gear driving.

[0028] The power interruption free shifting process of the two-gear transmission is as follows:

[0029] When power interruption free upshifting is performed, torque phase control is performed first, and then inertia phase control is performed; in the torque phase, the torque T of the driving motor is gradually increased to the two-gear required torque T2. m One-gear required torque Gradually increased to two-gear required torque The friction clutch gradually tightens and enters a semi-clutch sliding state, and the following relationship is satisfied: Where, T c The torque transmitted by the friction clutch is i g1 is the first gear transmission ratio, i g2 is the second gear ratio, is the desired wheel end torque; at the end of the torque phase, the output torque of the drive motor is The friction clutch transmits torque During the inertia phase, the friction clutch maintains the torque it transmits unchanged, and the drive motor appropriately reduces the output torque so that the speed of the clutch active part is synchronized with the speed of the clutch driven part. When the speed difference between the clutch active part and the clutch driven part is less than a certain threshold, the friction clutch is fully clamped and enters the second gear state; the controllable one-way clutch needs to be switched from the two-way locking state to the one-way overrunning state before the speed of the clutch active part is synchronized with the speed of the clutch driven part. When the friction clutch is fully clamped, the controllable one-way clutch needs to be switched from the one-way overrunning state to the two-way overrunning state.

[0030] When downshifting without power interruption, inertia phase control is performed first, and then torque phase control is performed; in the inertia phase, the friction clutch enters the semi-clamped sliding state from the fully clamped state, and its torque is The drive motor requires torque from the second gear Appropriately increase the torque so that the inner ring speed approaches zero; the controllable one-way clutch needs to switch from the two-way overrunning state to the one-way overrunning state before the inner ring speed approaches zero. When the inner ring speed reaches zero, the controllable one-way clutch needs to switch from the one-way overrunning state to the two-way locking state; when the inner ring speed reaches zero, it enters the torque phase stage, and the torque of the drive motor is changed from the second gear required torque to the second gear required torque. Gradually reduce to the required torque of the first gear The friction clutch is gradually released so that the output torque of the drive motor and the torque transmitted by the friction clutch satisfy the following relationship: When the friction clutch is completely released, the vehicle enters the first gear state.

[0031] The beneficial effects of the present invention are:

[0032] 1. The two-gear transmission of the application, which is a power interruption-free electric vehicle two-gear transmission using double planetary gears, can realize six different driving states, namely, one-gear driving state, two-gear driving state, neutral state, one-gear regenerative braking state, two-gear regenerative braking state, and reverse driving state. The two-gear transmission can realize free switching of different driving modes based on the controllable one-way clutch and the friction clutch, and the switching control is difficult.

[0033] 2. The two-gear transmission of the application, which is a power interruption-free electric vehicle two-gear transmission using double planetary gears, uses the controllable one-way clutch to connect the transmission housing and the planet carrier, and uses the friction clutch to connect the gear ring and the sun gear (connecting the sun gear through the intermediate shaft). The controllable one-way clutch and the friction clutch are not connected to the same position of the double planetary gear train, so that the torque output by the two-gear transmission during the inertia phase of the power interruption-free gear shifting depends only on the clutch clamping force, thereby effectively ensuring the control effect of the power interruption-free gear shifting.

[0034] 3. The two-gear transmission of the application, which is a power interruption-free electric vehicle two-gear transmission using double planetary gears, uses a double planetary gear train, and the characteristic parameters of the planetary gear train can be designed to be about 1.7-2.1, so that the ratio of the one-gear transmission ratio to the two-gear transmission ratio is about 1.7-2.1, thereby ensuring the continuity of the wheel end torque external characteristic, reducing the gear shifting difficulty, and improving the utilization rate of the motor high efficiency interval. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 The structure diagram of the two-gear transmission of the application, which is a power interruption-free electric vehicle two-gear transmission using double planetary gears.

[0036] Figure 2 The structure diagram of the two-gear transmission of the application, which is a power interruption-free electric vehicle two-gear transmission using double planetary gears.

[0037] Figure 3 The local structure diagram of the controllable one-way clutch of the two-gear transmission of the application, which is a power interruption-free electric vehicle two-gear transmission using double planetary gears.

[0038] Figure 4 The structure diagram of the controllable one-way clutch control mechanism of the two-gear transmission of the application, which is a power interruption-free electric vehicle two-gear transmission using double planetary gears.

[0039] Figure 5 The schematic diagram of the one-way locking state of the controllable one-way clutch of the two-gear transmission of the application, which is a power interruption-free electric vehicle two-gear transmission using double planetary gears.

[0040] Figure 6A schematic diagram of a controllable one-way clutch bidirectional locking state principle of a two-gear transmission of a power interruption-free electric vehicle adopting a two-stage planetary gear according to the present application

[0041] Figure 7 A schematic diagram of a controllable one-way clutch bidirectional overrun state principle of a two-gear transmission of a power interruption-free electric vehicle adopting a two-stage planetary gear according to the present application

[0042] Figure 8 A schematic diagram of torque flow in a first-gear driving state of a two-gear transmission of a power interruption-free electric vehicle adopting a two-stage planetary gear according to the present application

[0043] Figure 9 A schematic diagram of torque flow in a second-gear driving state of a two-gear transmission of a power interruption-free electric vehicle adopting a two-stage planetary gear according to the present application

[0044] Figure 10 A schematic diagram of torque flow in a first-gear regenerative braking state of a two-gear transmission of a power interruption-free electric vehicle adopting a two-stage planetary gear according to the present application

[0045] Figure 11 A schematic diagram of torque flow in a second-gear regenerative braking state of a two-gear transmission of a power interruption-free electric vehicle adopting a two-stage planetary gear according to the present application DETAILED DESCRIPTION

[0046] The present application will be further described in conjunction with the accompanying drawings so that those skilled in the art can implement the present application according to the description and drawings. An embodiment of a two-gear transmission of a power interruption-free electric vehicle adopting a two-stage planetary gear according to the present application is described as follows:

[0047] As shown in Figure 1 , Figure 2 A two-gear transmission of a power interruption-free electric vehicle adopting a two-stage planetary gear, characterized in that it comprises a driving motor 100, an intermediate shaft 803, a first reduction gear set 200, a two-stage planetary gear train 400, a controllable one-way clutch 300, a second reduction gear set 600, a differential 700, a friction clutch 500, a transmission left housing 809, a transmission right housing 808, a transmission left output shaft 801, a transmission right output shaft 802, and the like.

[0048] The transmission left housing 809 and the transmission right housing 808 are used to accommodate and support all components of the two-gear transmission;

[0049] The transmission left output shaft 801 is used to transmit power to the left driving wheel;

[0050] The transmission right output shaft 802 is used to transmit power to the right driving wheel;

[0051] The driving motor 100 is coaxially arranged with the transmission left output shaft 801, and includes the stator 101, the rotor 102, the motor output shaft 103 and the motor housing 104; the stator 101 is fixed inside the motor housing 104; the rotor 102 is fixed on the motor output shaft 103; the motor output shaft 103 is rotationally supported on the motor housing 104; the motor output shaft 103 is a hollow shaft, and the transmission left output shaft 801 passes through the inside of the motor output shaft 103.

[0052] The intermediate shaft 803 is arranged in parallel with the transmission left output shaft 801 and is rotationally supported on the transmission left housing 809 and the transmission right housing 808 by bearings.

[0053] The first reduction gear set 200 is used to output the torque of the driving motor 100 after speed reduction and torque increase to the intermediate shaft 803, and includes a first driving gear 201 and a first driven gear 202; the first driving gear 201 and the first driven gear 202 are externally meshed to transmit power; the first driving gear 201 is fixedly connected to the motor output shaft 103 by splines; and the first driven gear 202 is fixedly connected to the intermediate shaft 803 by splines.

[0054] The double-stage planetary gear train 400 includes a sun gear 401, an inner planetary gear 402, an outer planetary gear 403, an inner planetary gear shaft 404, an outer planetary gear shaft 405, a ring gear 406 and a planet carrier 407; the sun gear 401 is fixedly connected to the intermediate shaft 803 by splines; the inner planetary gear 402 is externally meshed to transmit power with the sun gear 401; the outer planetary gear 403 is externally meshed to transmit power with the inner planetary gear 402; the ring gear 406 is internally meshed to transmit power with the outer planetary gear 403; the inner planetary gear 402 and the outer planetary gear 403 are respectively rotationally supported on the inner planetary gear shaft 404 and the outer planetary gear shaft 405; the inner planetary gear shaft 404 and the outer planetary gear shaft 405 are supported on the planet carrier 407; and the planet carrier 407 is rotationally supported on the intermediate shaft 803 by bearings. The planetary row characteristic parameter of the double-stage planetary gear train 400 is designed to be about 1.7-2.1, so as to ensure the continuity of the wheel end torque external characteristic and adapt to the high efficiency interval characteristic of the electric motor of the electric vehicle;

[0055] As Figure 3 , Figure 4As shown, the controllable one-way clutch 300 comprises the inner ring 301, the outer ring 302, a plurality of first pawls 303, a plurality of second pawls 304, a plurality of reset springs 305, a control disc 306, and a control mechanism; the controllable one-way clutch 300 can be controlled to achieve a one-way lock state, and can be controlled to switch from the one-way lock state to a two-way lock state or a two-way overrun state; there is a certain gap between the inner ring 301 and the outer ring 302; the inner ring 301 is integrated with the planetary carrier 407, and the outer surface is processed with a two-way ratchet protrusion; the outer surface of the outer ring 302 is processed with a spline fixedly connected with the transmission left housing 809, and the inner surface is installed with a plurality of uniformly staggered first pawls 303 and a plurality of second pawls 304, the installation direction of the first pawls 303 and the second pawls 304 is opposite, and the movable end of each of the first pawls 303 and the second pawls 304 is fixedly installed with a control pin 303(a) and 304(a) respectively; the reset spring 305 is installed between the first pawl 303 and the outer ring 302 and the second pawl 304 and the outer ring 302; the control pins 303(a) and 304(a) cooperate with the control disc 306, and can move radially within the space defined by the control disc under the driving of the control mechanism, the movable end of the first pawl 303 and the movable end of the second pawl 304 can contact the two-way ratchet protrusion on the outer surface of the inner ring 301 under the action of the reset spring 305, thereby locking the counterclockwise rotation and clockwise rotation of the inner ring 301 respectively.

[0056] The control disc 306 is installed on the side surface of the inner ring 301 and the outer ring 302, and can rotate around the intermediate shaft 803; a plurality of groups of control grooves with two different shapes are processed on the control disc 306 and are circumferentially arranged alternately, which cooperate with the control pins 303(a) of the first pawls 303 and the control pins 304(a) of the second pawls 304 respectively to constrain the space range in which each control pin can move, and the total number of control pins is the same as the total number of control grooves; the constraint relationship is specifically as follows:

[0057] As shown in Figure 5 When the control disc 306 is in the middle position, the first pawl control pin 303(a) is not controlled by the corresponding control groove, and the movable end of the first pawl 303 is pushed to the two-way ratchet protrusion on the outer surface of the inner ring 301 under the action of the reset spring 305, while the second pawl control pin 304(a) is controlled by the corresponding control groove, and the movable end of the second pawl 304 is pulled outward under the action of the control groove, and does not contact the two-way ratchet protrusion on the outer surface of the inner ring 301, at this time, the controllable one-way clutch 300 is in the one-way lock state of locking the counterclockwise rotation of the inner ring 301;

[0058] AsFigure 6 As shown, when the control disc 306 is rotated counterclockwise from the intermediate position by a certain angle, the first pawl control pin 303(a) and the second pawl control pin 304(a) are not controlled by the corresponding control grooves, and the active ends of the first pawl 303 and the second pawl 304 are pushed to the outer surface double-direction ratchet protrusions of the inner ring 301 under the action of the reset spring 305. At this time, the controllable one-way clutch 300 is in a double-direction locked state.

[0059] As shown, when the control disc 306 is rotated counterclockwise from the intermediate position by a certain angle, the first pawl control pin 303(a) and the second pawl control pin 304(a) are not controlled by the corresponding control grooves, and the active ends of the first pawl 303 and the second pawl 304 are pushed to the outer surface double-direction ratchet protrusions of the inner ring 301 under the action of the reset spring 305. At this time, the controllable one-way clutch 300 is in a double-direction locked state. Figure 7 As shown, when the control disc 306 is rotated clockwise from the intermediate position by a certain angle, the first pawl control pin 303(a) and the second pawl control pin 304(a) are controlled by the corresponding control grooves, and the active ends of the first pawl 303 and the second pawl 304 are pulled outward under the action of the control grooves and do not contact the double-direction ratchet protrusions of the outer surface of the inner ring 301. At this time, the inner ring 301 and the outer ring 302 of the controllable one-way clutch 300 are completely separated, and the controllable one-way clutch 300 is in a double-direction overrunning state.

[0060] The control mechanism includes a worm gear 307, a worm 308, and a control motor 309. The worm gear 307 is a fan spoke structure, and the spoke is fixedly connected with the control disc 306. The worm 308 is in meshing transmission with the worm gear 307. The control motor 309 is fixedly connected with the worm 308. The output torque of the control motor 309 is reduced and increased in torque by the worm 308 and the worm gear 307, and the transmission direction is changed vertically to realize the rotation control of the control disc 306.

[0061] The second reduction gear set 600 reduces and increases the torque on the gear ring 406 and outputs it. It includes a second driving gear 601 and a second driven gear 602. The second driving gear 601 is integrally formed with the gear ring 406 and is rotatably supported on the intermediate shaft 803 by a needle bearing. The second driven gear 602 is in external meshing transmission with the second driving gear 601.

[0062] The differential 700 receives torque from the second reduction gear set 600 and evenly distributes the torque to the transmission left output shaft 801 and the transmission right output shaft 802. The differential 700 includes a differential housing 701, a plurality of planetary bevel gears 704, a left output shaft bevel gear 702, and a right output shaft bevel gear 703. The differential housing 701 is rotatably supported on the transmission left output shaft 801 and the transmission right output shaft 802. The plurality of planetary bevel gears 704 are rotatably supported on the differential housing 701. The left output shaft bevel gear 702 and the right output shaft bevel gear 703 are in meshing transmission with the plurality of planetary bevel gears 704 and are connected to the left drive wheel universal transmission shaft and the right drive wheel universal transmission shaft, respectively, through the transmission left output shaft 801 and the transmission right output shaft 802, respectively. The second driven gear 602 is fixedly connected to the differential housing 701 through the spline.

[0063] The friction clutch 500 includes a clutch driving part 501 and a clutch driven part 502. The clutch driving part 501 is fixedly connected to the intermediate shaft 803. The clutch driven part 502 is fixedly connected to the gear ring 406 (second driving gear 601) through the spline.

[0064] When the two-gear transmission is in the first gear driving state, the friction clutch 500 is controlled to be in the disengaged state, the controllable one-way clutch 300 is in the bidirectional locked state, and the driving motor 100 outputs driving torque in the positive direction. At this time, the power transmission route is as shown in Figure 8 .

[0065] When the two-gear transmission is in the second gear driving state, the friction clutch 500 is in the engaged state, the controllable one-way clutch 300 is in the bidirectional overrunning state, and the driving motor 100 outputs driving torque in the positive direction. At this time, the power transmission route is as shown in Figure 9 .

[0066] When the two-gear transmission is in the neutral state, the friction clutch 500 is in the disengaged state, the controllable one-way clutch 300 is in the bidirectional overrunning state, and the driving motor 100 does not output any torque.

[0067] When the two-gear transmission is in the first gear regenerative braking state, the friction clutch 500 is in the disengaged state, the controllable one-way clutch 300 is in the bidirectional locked state, and the driving motor 100 outputs electromagnetic braking torque in the positive direction. At this time, the power transmission route is as shown in Figure 10 .

[0068] When the two-gear transmission is in the two-gear regenerative braking state, the friction clutch 500 is in the engaged state, the controllable one-way clutch 300 is in the bidirectional overrun state, and the driving motor 100 outputs an electromagnetic braking torque in the forward direction. At this time, the power transmission route is as shown in FIG. 7. Figure 11

[0069] When the two-gear transmission is in the reverse state, the friction clutch 500 is in the disengaged state, the controllable one-way clutch 300 is in the bidirectional locked state, and the driving motor 100 outputs a driving torque in the reverse direction.

[0070] The one-way locked state of the controllable one-way clutch 300 is a transition state when the two-gear transmission switches between the one-gear drive and the two-gear drive.

[0071] Although embodiments of the present application have been disclosed as above, they are not limited only to the applications listed in the specification and the embodiments, and can be applied to various fields suitable for the present application, and additional modifications can be easily made by those skilled in the art, and thus the present application is not limited to specific details and the figures shown and described herein, within the scope of the claims and the equivalent range.​

Claims

1. A two-speed power interruption-free electric vehicle transmission employing a two-stage planetary gear, characterized by, Comprise: Transmission housing for accommodating and supporting all components of the two-speed transmission; Transmission left output shaft for transmitting power to the left drive wheel; Transmission right output shaft for transmitting power to the right drive wheel; Drive motor coaxially arranged with the transmission left output shaft; Intermediate shaft arranged in parallel with the transmission left output shaft; First reduction gear set for reducing the torque output by the drive motor and increasing the torque to the intermediate shaft; Double-stage planetary gear train, comprising: sun gear, inner planet gear, outer planet gear, inner planet gear shaft, outer planet gear shaft, ring gear, planet carrier, the sun gear is connected with the intermediate shaft through spline, the inner planet gear is in external meshing transmission with the sun gear, the outer planet gear is in external meshing transmission with the inner planet gear, the ring gear is in internal meshing transmission with the outer planet gear, the inner planet gear and the outer planet gear are respectively rotatably supported on the inner planet gear shaft and the outer planet gear shaft, and the inner planet gear shaft and the outer planet gear shaft are commonly supported on the planet carrier; Controllable one-way clutch, comprising inner ring and outer ring, the outer ring is fixed on the transmission housing, the inner ring is fixedly connected with the planet carrier, the controllable one-way clutch can be controlled to realize one-way locking state, and can be controlled to switch from one-way locking state to bidirectional locking state or bidirectional overrunning state; Second reduction gear set for reducing the torque on the ring gear and increasing the torque; Differential, receiving torque from the second reduction gear set and distributing it to the transmission left output shaft and the transmission right output shaft; Friction clutch, comprising clutch driving part and clutch driven part, the clutch driving part is splined with the intermediate shaft, and the clutch driven part is fixedly connected with the ring gear; the second reduction gear set is arranged at the position of the double-stage planetary gear train and the friction clutch intermediate ring neck to reduce the axial size of the transmission.

2. The two-speed transmission of claim 1, wherein, The characteristic parameters of the planetary row of the double-stage planetary gear train are designed to be in the range of 1.7-2.1, so as to ensure the continuity of the wheel end torque external characteristic and adapt to the high efficiency interval characteristic of the electric vehicle motor.

3. The two-speed transmission of claim 1, wherein, The drive motor comprises a stator, a rotor, a motor output shaft and a motor housing; the stator is fixed inside the motor housing; the rotor is fixed on the motor output shaft; the motor output shaft is rotatably supported on the motor housing; the motor output shaft is a hollow shaft, and the transmission left output shaft passes through the inside of the motor output shaft; the motor housing and the transmission housing are fixedly connected by bolts.

4. The two-speed transmission of claim 1, wherein, The first reduction gear set is a cylindrical gear set, comprising: a first driving gear and a first driven gear; the first driving gear is in external meshing transmission with the first driven gear; the first driving gear is splined with the motor output shaft; and the first driven gear is fixedly connected with the intermediate shaft.

5. The two-speed transmission of claim 1, wherein, The controllable one-way clutch comprises the inner ring, the outer ring, a plurality of first pawls, a plurality of second pawls, a plurality of reset springs, a control disc and a control mechanism. Wherein, there is a certain gap between the inner ring and the outer ring; The outer surface of the inner ring is processed with bidirectional ratchet protrusions; The inner surface of the outer ring is installed with a plurality of uniformly staggered first pawls and a plurality of second pawls, the installation direction of the first pawl and the second pawl is opposite, the movable end of the first pawl and the second pawl is respectively fixedly installed with a control pin; The reset spring is installed between the first pawl and the outer ring and the second pawl and the outer ring; The control pin cooperates with the control disc and can move radially in the space defined by the control disc under the driving of the control mechanism, the movable end of the first pawl and the second pawl can contact with the bidirectional ratchet protrusions on the outer surface of the inner ring under the action of the reset spring, so as to lock the counterclockwise rotation and clockwise rotation of the inner ring respectively.

6. The two-speed transmission of claim 5, wherein the two-speed transmission is a two-speed power interrupter electric vehicle transmission employing a double planetary gear. The control disc is installed on the side surface of the inner ring and the outer ring and can rotate around the intermediate shaft; A plurality of groups of control grooves with different shapes are arranged on the control disc, which are circumferentially arranged alternately and cooperated with the control pins of the first pawl and the second pawl respectively, so as to restrict the space range in which the respective control pins can move, the total number of the control pins is the same as the total number of the control grooves; The constraint relationship is specifically as follows: When the control disc is in the middle position, the first pawl control pin is not controlled by the corresponding control groove, the movable end of the first pawl is pushed to the bidirectional ratchet protrusions on the outer surface of the inner ring under the action of the reset spring, and at this time the second pawl control pin is controlled by the corresponding control groove, the movable end of the second pawl is pulled up outward under the action of the control groove, and does not contact with the bidirectional ratchet protrusions on the outer surface of the inner ring, at this time the controllable one-way clutch is in the one-way locking state of locking the counterclockwise rotation of the inner ring and disengaging the clockwise rotation; When the control disc rotates counterclockwise from the middle position by a certain angle, the first pawl control pin and the second pawl control pin are not controlled by the respective corresponding control grooves, the movable end of the first pawl and the movable end of the second pawl are pushed to the bidirectional ratchet protrusions on the outer surface of the inner ring under the action of the reset spring, at this time the controllable one-way clutch is in the bidirectional locking state; When the control disc rotates clockwise from the middle position by a certain angle, the first pawl control pin and the second pawl control pin are controlled by the respective corresponding control grooves, the movable end of the first pawl and the movable end of the second pawl are pulled up outward under the action of the control groove, and do not contact with the bidirectional ratchet protrusions on the outer surface of the inner ring, at this time the controllable one-way clutch is in the bidirectional overrunning state; The control mechanism comprises a worm gear, a worm and a control motor, the worm gear is a fan spoke structure, the spoke thereof is fixedly connected with the control disc, the worm is in meshing transmission with the worm gear, the control motor is fixedly connected with the worm, and the output torque of the control motor is transmitted to the control disc after being reduced and increased in torque by the worm gear and worm, and the transmission direction is changed vertically to realize the rotation control of the control disc.

7. The two-speed transmission of claim 1, wherein, The second reduction gear set is a cylindrical gear set, which comprises a second driving gear and a second driven gear; the second driving gear is fixedly connected with the ring gear and is rotatably supported on the intermediate shaft by a needle bearing; the second driven gear is in external meshing transmission with the second driving gear.

8. The two-speed transmission of claim 7, wherein the two-speed transmission is a two-speed power interrupter electric vehicle transmission employing a double planetary gear. The differential comprises a differential housing, a plurality of planetary bevel gears, a left output shaft bevel gear and a right output shaft bevel gear; the plurality of planetary bevel gears are rotatably supported on the differential housing; the left output shaft bevel gear and the right output shaft bevel gear are in meshing transmission with the plurality of planetary bevel gears at the same time and are connected with the left driving wheel and the right driving wheel through the respective universal transmission shafts via a transmission left output shaft and a transmission right output shaft respectively; the second driven gear is fixedly connected with the differential housing through a spline.

9. The two-speed transmission of claim 1, wherein, When the two-gear transmission is in the first gear driving state, the friction clutch is controlled to be in the separation state, the controllable one-way clutch is in the bidirectional locking state, the driving motor outputs driving torque in the positive direction, and the middle-low speed acceleration power requirement of the automobile is met; when the two-gear transmission is in the second gear driving state, the friction clutch is in the engagement state, the controllable one-way clutch is in the bidirectional overrunning state, the driving motor outputs driving torque in the positive direction, and the medium-high speed cruising economy requirement of the automobile is met; when the two-gear transmission is in the neutral state, the friction clutch is in the separation state, the controllable one-way clutch is in the bidirectional overrunning state, the driving motor does not output any torque, and the driving requirement of the automobile when the driving axle is used as the driven axle is met; when the two-gear transmission is in the first gear regenerative braking state, the friction clutch is in the separation state, the controllable one-way clutch is in the bidirectional locking state, the driving motor outputs electromagnetic braking torque in the positive direction, and the medium-low speed large braking deceleration requirement of the automobile is met; when the two-gear transmission is in the second gear regenerative braking state, the friction clutch is in the engagement state, the controllable one-way clutch is in the bidirectional overrunning state, the driving motor outputs electromagnetic braking torque in the positive direction, and the high speed small braking deceleration requirement of the automobile is met; when the two-gear transmission is in the reverse gear state, the friction clutch is in the separation state, the controllable one-way clutch is in the bidirectional locking state, the driving motor outputs driving torque in the reverse direction, and the automobile reverse driving requirement is met.

10. The two-speed transmission of claim 1, wherein, When performing upshift without power interruption, torque phase control is performed first, and then inertia phase control is performed; in the torque phase, the torque T m Required torque of first gear Gradually increase to the required torque of the second gear The friction clutch gradually tightens and enters a semi-clutch sliding state, and the following relationship is satisfied: Where, T c The torque transmitted by the friction clutch is i g1 is the first gear transmission ratio, i g2 is the second gear ratio, is the desired wheel end torque; at the end of the torque phase, the output torque of the drive motor is The friction clutch transmits torque During the inertia phase, the friction clutch maintains the torque it transmits unchanged, and the drive motor appropriately reduces the output torque to synchronize the speed of the clutch active part with the speed of the clutch driven part. When the speed difference between the clutch active part and the clutch driven part is less than a certain threshold, the friction clutch is fully clamped and enters the second gear state. The controllable one-way clutch needs to switch from a two-way locking state to a one-way overrunning state before the speed of the clutch active part is synchronized with the speed of the clutch driven part. When the friction clutch is fully clamped, the controllable one-way clutch needs to switch from a one-way overrunning state to a two-way overrunning state. When the unpowered interrupt downshift is performed, the inertia phase control is performed first, and then the torque phase control is performed; in the inertia phase, the friction clutch is switched from the fully clamped state to the semi-locked slip state, and the torque of the friction clutch is The driving motor is switched from the two-gear required torque The torque is appropriately increased so that the inner ring speed approaches zero; the controllable one-way clutch needs to be switched from the bidirectional overrun state to the one-way overrun state before the inner ring speed approaches zero, and the controllable one-way clutch needs to be switched from the one-way overrun state to the bidirectional locked state after the inner ring speed reaches zero; after the inner ring speed reaches zero, the torque phase is entered, and the torque of the driving motor is gradually reduced from the two-gear required torque to the one-gear required torque The friction clutch is gradually released, and the driving motor output torque and the friction clutch transmission torque satisfy the following relationship: When the friction clutch is fully released, the one-gear state is entered.

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