Power-interruption-free electric vehicle two-gear transmission adopting two-stage planetary gears

Abstract

The invention discloses a power-interruption-free electric vehicle two-gear transmission adopting two-stage planetary gears. The power-interruption-free electric vehicle two-gear transmission 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 mechanism, a friction clutch, a transmission shell and the like. The torque output by the driving motor is transmitted to the intermediate shaft after passing through the first reduction gear set; and the intermediate shaft is fixedly connected with the first sun gear. The controllable one-way clutch is used for connecting the transmission shell and the first planet carrier; the friction clutch is used for connecting the first gear ring and the intermediate shaft. And the second reduction gear set is used for reducing the speed and increasing the torque output by the first gear ring and then transmitting the torque to the differential shell. According to the two-gear transmission, six states of first-gear driving, second-gear driving, neutral gear, first-gear regenerative braking, second-gear regenerative braking and reverse running can be achieved by controlling the friction clutch and the controllable one-way clutch in a coordinated mode. And power-interruption-free gear shifting between the first gear and the second gear can be achieved.

Description

Technical Field

[0001] The invention belongs to the field of electric vehicle transmission, and in particular relates to a highly integrated two-speed transmission for electric vehicles without power interruption and adopting a two-stage planetary gear. Background Art

[0002] In recent years, with the development and progress of society, electric vehicles with zero fuel consumption, high integration, fast power response and high driving performance have been vigorously developed and gradually recognized by the market. With the development and popularization of the market, electric vehicles will also develop in the direction of high-end, high-performance, diversified and personalized in the future, so the demand for advanced drive technology that can improve chassis performance is increasing. The power-interruption-free shifting technology of two-speed transmissions for electric vehicles is one of them.

[0003] At present, the two-speed transmission of electric vehicles has attracted great attention from many scholars and manufacturers. Compared with the single-motor acceleration and deceleration drive mode, the use of a two-speed transmission can, on the one hand, greatly reduce the maximum torque and maximum speed requirements of the drive motor, thereby reducing the size cost of the motor; on the other hand, through the optimization of the transmission ratio of the two-speed transmission, the high-efficiency range utilization of the drive motor can be greatly improved, thereby improving the economy of the vehicle and increasing the cruising range.

[0004] However, the use of a stepped two-speed transmission is accompanied by the problem of power interruption during gear shifting. To solve the problem of power interruption during gear shifting in a two-speed transmission, some scholars have proposed a two-speed transmission solution of "friction clutch + one-way overrunning clutch". However, if this solution is applied to a single-axle drive electric vehicle, it cannot achieve reverse operation and first-gear regenerative braking energy recovery. Therefore, someone has proposed a two-speed transmission solution of "friction clutch + one-way overrunning clutch + claw clutch". However, this solution has many actuators and a complex structure. In addition, in the process of regenerative braking without regenerative braking force interruption, it is not easy to switch between the first-gear regenerative braking state and the second-gear regenerative braking state. Therefore, to solve the above problems, the present invention proposes a new configuration solution of "friction clutch + controllable one-way clutch".

[0005] At the same time, in order to make the wheel end torque external characteristic curve change continuously, give full play to the high efficiency range of the motor, and reduce the difficulty of shifting, the ratio of the first gear ratio to the second gear ratio should not be too large, and should be designed to be around 1.7-2. The two-stage planetary gear system can achieve a 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. The transmission 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 to achieve 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 achieve 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 using a two-stage planetary gear, which can realize six different driving states, namely, a first-gear driving state, a second-gear driving state, a neutral state, a first-gear regenerative braking state, a second-gear regenerative braking state, and a gear-car driving state; 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 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 an electric vehicle without power interruption using a two-stage planetary gear, characterized in that it includes: 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 comprises 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 to reduce the speed and increase the torque output by the driving motor and then output it to the intermediate shaft, and comprises: a first driving gear and a first driven gear; the first driving gear and the first driven gear are externally meshed for transmission; the first driving gear is spline-fixedly connected to the motor output shaft; the first driven gear is spline-fixedly connected to the intermediate shaft.

[0016] A two-stage planetary gear system, comprising: 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 via a spline, the inner planetary gear is externally meshed with the sun gear, the outer planetary gear is externally meshed with the inner planetary gear, the ring gear is internally meshed with the outer planetary gear, the inner planetary gear and the outer planetary gear are rotatably supported on the inner planetary gear shaft and the outer planetary gear shaft, respectively, 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 via bearings. The characteristic parameters of the planetary row of the two-stage planetary gear system are designed to be about 1.7 to 2.1, so as to ensure the continuity of the external characteristics of the wheel end torque while adapting to the high efficiency interval characteristics of the electric vehicle motor;

[0017] The controllable one-way clutch comprises the inner ring, the outer ring, a plurality of first ratchets, a plurality of second ratchets, a plurality of return springs, a control disk, and a control mechanism; the controllable one-way clutch can be controlled to achieve a one-way locking state, and can be controlled to switch 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 a two-way ratchet protrusion is machined on the outer surface; the outer surface of the outer ring is machined with a spline and fixedly connected to the transmission housing, and a plurality of the first ratchets and a plurality of the second ratchets arranged evenly and staggered are installed on the inner surface Pawl, the first pawl and the second pawl are installed in opposite directions, and the movable ends of the first pawl and the second pawl are respectively fixedly installed with a control pin; the reset spring is installed between the first pawl and the outer ring and between the second pawl and the outer ring; the control pin cooperates with the control disk, and can move radially in the space defined by the control disk under the drive of the control mechanism, and the movable ends of the first pawl and the second pawl can contact the bidirectional ratchet protrusion on the outer surface of the inner ring under the action of the reset spring, thereby locking the inner ring in counterclockwise and clockwise rotation respectively.

[0018] The control disk is mounted on the side surfaces of the inner ring and the outer ring and can rotate around the intermediate shaft; the control disk is processed with multiple groups of control grooves of two different shapes arranged alternately on the circumference, which respectively cooperate with the control pin of the first pawl and the control pin of the second pawl to constrain the spatial range in which the respective control pins can move, and the total number of the control pins is the same as the total number of the control grooves; the constraint relationship is specifically expressed as follows:

[0019] When the control disk is in the middle position, the first pawl control pin is not controlled by the corresponding control groove, and the movable end of the first pawl is pushed toward the bidirectional ratchet protrusion on the outer surface of the inner ring under the action of the return spring, while the second pawl control pin is controlled by the corresponding control groove, and the movable end of the second pawl is pulled outward under the action of the control groove and does not contact the bidirectional ratchet protrusion on the outer surface of the inner ring. At this time, the controllable one-way clutch is in a one-way locked state in which the inner ring is locked in counterclockwise rotation;

[0020] When the control disk 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 corresponding control grooves, and the first pawl movable end and the second pawl movable end are pushed toward the bidirectional ratchet protrusion on the outer surface of the inner ring under the action of the return spring, and the controllable one-way clutch is in a bidirectional locked state;

[0021] When the control disk rotates clockwise from the middle position by a certain angle, the first pawl control pin and the second pawl control pin are both controlled by the corresponding control grooves, and the first pawl movable end and the second pawl movable end are both pulled outwards under the action of the control grooves and do not contact the bidirectional ratchet protrusion on the outer surface of the inner ring. At this time, the inner and outer rings of the controllable one-way clutch are completely separated, and the controllable one-way clutch is in a bidirectional overrunning state.

[0022] The control mechanism includes: a worm wheel, a worm, and a control motor. The worm wheel is a fan-shaped spoke structure, and its spoke is fixedly connected to the control disk. The worm is meshed with the worm wheel for transmission. The control motor is fixedly connected to the worm. The output torque of the control motor is reduced in speed and increased in torque by the worm wheel and the transmission direction is vertically changed to realize the rotation control of the control disk.

[0023] The second reduction gear set reduces the torque on the gear ring and then outputs it; it includes: a second driving gear and a second driven gear; the second driving gear and the gear ring can be made into one piece and are rotatably supported on the intermediate shaft through a needle bearing, and the second driven gear and the second driving gear are externally meshed for transmission.

[0024] The differential receives the torque from the second reduction gear set and distributes it evenly to the left output shaft and the right output shaft of the transmission; it includes a differential case, a plurality of asteroid bevel gears, a left output shaft bevel gear, and a right output shaft bevel gear; the transmission case is rotatably supported on the left output shaft and the right output shaft of the transmission; the plurality of asteroid bevel gears are rotatably supported on the differential case; the left output shaft bevel gear and the right output shaft bevel gear are meshed with the plurality of asteroid bevel gears for transmission, and are respectively connected to the left drive wheel and the right drive wheel universal transmission shaft through the left output shaft and the right output shaft of the transmission; the second driven gear is fixedly connected to the differential case by a spline.

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

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

[0027] The one-way locking state of the controllable one-way clutch is a transition state when the two-speed transmission switches between the first-gear drive and the second-gear drive.

[0028] The two-speed transmission shifting process without power interruption is as follows:

[0029] When upshifting without power interruption is performed, torque phase control is performed first, and then inertia phase control is performed; in the torque phase, the torque T of the drive motor m Torque required by first gear Gradually increase to the torque required for the second gear The friction clutch is gradually clamped into a semi-linked sliding state and satisfies the following relationship: Where, T c is the torque transmitted by the friction clutch, i g1 is the first gear transmission ratio, i g2 is the second gear transmission 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 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 be switched from a one-way overrunning state to a two-way overrunning state.

[0030] When downshifting without power interruption is performed, inertia phase control is performed first, and then torque phase control is performed; in the inertia phase stage, the friction clutch enters a semi-clamped sliding state from a fully clamped state, and its torque is The drive motor requires torque from the second gear The torque is appropriately increased to make the inner ring speed approach zero; the controllable one-way clutch needs to be switched from the two-way overrunning state to the one-way overrunning state before the inner ring speed approaches zero, and when the inner ring speed reaches zero, the controllable one-way clutch needs to be switched from the one-way overrunning state to the two-way locking state; when the inner ring speed reaches zero, the torque phase stage is entered, 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 first gear required torque 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 first gear state is entered.

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

[0032] 1. The two-speed transmission of an electric vehicle without power interruption using a two-stage planetary gear described in the present invention can realize six different driving states: first gear driving state, second gear driving state, neutral state, first gear regenerative braking state, second gear regenerative braking state, and reverse driving state; 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.

[0033] 2. The present invention describes a two-speed transmission for an electric vehicle with no power interruption and using a two-stage planetary gear, wherein a controllable one-way clutch is used to connect the transmission housing and the planetary carrier, and a friction clutch is used to connect the ring gear and the sun gear (the sun gear is connected via an intermediate shaft), that is, the controllable one-way clutch and the friction clutch are not connected to the same position of the two-stage planetary gear system, so that the torque output by the two-speed transmission in the inertia phase of the no power interruption gear shifting only depends on the clutch clamping force, thereby effectively ensuring the control effect of the no power interruption gear shifting.

[0034] 3. The two-speed transmission of an electric vehicle without power interruption using a two-stage planetary gear described in the present invention uses a two-stage planetary gear system, and the characteristic parameters of the planetary gear can be designed to be about 1.7-2.1, so that the ratio of the first gear transmission ratio to the second gear transmission ratio is about 1.7-2.1, thereby ensuring the continuity of the external characteristics of the wheel end torque, reducing the difficulty of shifting, and improving the utilization rate of the high efficiency range of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The present invention is a simplified structural diagram of a two-speed transmission for an electric vehicle without power interruption that adopts a two-stage planetary gear.

[0036] Figure 2 The present invention is a structural diagram of a two-speed transmission for an electric vehicle without power interruption that adopts a two-stage planetary gear.

[0037] Figure 3 The present invention is a partial structural diagram of a controllable one-way clutch of a two-speed transmission for an electric vehicle without power interruption and using a two-stage planetary gear.

[0038] Figure 4 This is a structural diagram of a controllable one-way clutch control mechanism of a two-speed transmission of an electric vehicle without power interruption using a two-stage planetary gear according to the present invention.

[0039] Figure 5 A schematic diagram of the one-way locking state of a controllable one-way clutch of a two-speed transmission of an electric vehicle without power interruption using a two-stage planetary gear according to the present invention

[0040] Figure 6A schematic diagram of the bidirectional locking state of a controllable one-way clutch of a two-speed transmission of an electric vehicle without power interruption using a two-stage planetary gear according to the present invention

[0041] Figure 7 A schematic diagram of the bidirectional overrunning state of a controllable one-way clutch of a two-speed transmission of an electric vehicle without power interruption using a two-stage planetary gear according to the present invention

[0042] Figure 8 The present invention is a schematic diagram of torque flow of a two-speed transmission of a non-power-interruption electric vehicle using a two-stage planetary gear in a first-speed driving state.

[0043] Fig. 9 The present invention is a schematic diagram of torque flow of a two-speed transmission of a power-interruption-free electric vehicle using a two-stage planetary gear in a second-speed driving state.

[0044] Fig.10 The present invention is a schematic diagram of torque flow of a two-speed transmission of a non-power-interruption electric vehicle using a two-stage planetary gear in a first-speed regenerative braking state.

[0045] Fig.11 The present invention is a schematic diagram of torque flow of a two-speed transmission of a power-interruption-free electric vehicle using a two-stage planetary gear in a second-speed regenerative braking state. DETAILED DESCRIPTION

[0046] The present invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description. An embodiment of a two-speed transmission for an electric vehicle without power interruption using a two-stage planetary gear according to the present invention is as follows:

[0047] like Figure 1 , Figure 2 As shown, a two-speed transmission for an electric vehicle without power interruption using a double-stage planetary gear is characterized in that it includes: a drive motor 100, an intermediate shaft 803, a first reduction gear set 200, a double-stage planetary gear system 400, a controllable one-way clutch 300, a second reduction gear set 600, a differential 700, a friction clutch 500, a left transmission housing 809, a right transmission housing 808, a left transmission output shaft 801, a right transmission output shaft 802, etc.

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

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

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

[0051] The drive motor 100 is coaxially arranged with the left output shaft 801 of the transmission, 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 rotatably supported on the motor housing 104; the motor output shaft 103 is a hollow shaft, and the left output shaft 801 of the transmission passes through the inside of the motor output shaft 103.

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

[0053] The first reduction gear set 200 is used to reduce the torque output by the driving motor 100 and then output it 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 for transmission; the first driving gear 201 is spline-fixedly connected to the motor output shaft 103; the first driven gear 202 is spline-fixedly connected to the intermediate shaft 803.

[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 via a spline. The inner planetary gear 402 is externally meshed with the sun gear 401 for transmission. The outer planetary gear 403 is externally meshed with the inner planetary gear 402 for transmission. The ring gear 406 is internally meshed with the outer planetary gear 403 for transmission. The inner planetary gear 402 and the outer planetary gear 403 are rotatably supported on the inner planetary gear shaft 404 and the outer planetary gear shaft 405, respectively. The inner planetary gear shaft 404 and the outer planetary gear shaft 405 are supported on the planet carrier 407. The planet carrier 407 is rotatably supported on the intermediate shaft 803 via bearings. The planetary gear characteristic parameters of the dual-stage planetary gear train 400 are designed to be about 1.7 to 2.1, so as to ensure the continuity of the wheel end torque external characteristics while adapting to the high efficiency range characteristics of the electric vehicle motor;

[0055] like Figure 3 , Figure 4As shown, the controllable one-way clutch 300 includes the inner ring 301, the outer ring 302, a plurality of first ratchet pawls 303, a plurality of second ratchet pawls 304, a plurality of return springs 305, a control disk 306, and a control mechanism; the controllable one-way clutch 300 can be controlled to achieve a one-way locking state, and can be controlled to switch 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 301 and the outer ring 302; the inner ring 301 is made into one piece with the planet carrier 407, and a two-way ratchet protrusion is machined on the outer surface; the outer surface of the outer ring 302 is machined with a spline fixedly connected to the left housing 809 of the transmission, and a plurality of the first ratchet pawls 303 and a plurality of the second ratchet pawls 304 arranged evenly and staggered are installed on the inner surface, and the first ratchet pawls The installation directions of the first pawl 303 and the second pawl 304 are opposite, and the movable ends of the first pawl 303 and the second pawl 304 are respectively fixedly installed with control pins 303(a) and 304(a); 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 disk 306, and can move radially in the space defined by the control disk under the drive of the control mechanism, and the movable ends of the first pawl 303 and the second pawl 304 can contact the bidirectional ratchet protrusions on the outer surface of the inner ring 301 under the action of the reset spring 305, thereby locking the inner ring 301 in counterclockwise and clockwise rotation respectively.

[0056] The control disk 306 is mounted on the side of the inner ring 301 and the outer ring 302 and can rotate around the intermediate shaft 803; the control disk 306 is processed with multiple groups of control grooves of two different shapes arranged alternately on the circumference, which respectively cooperate with the control pin 303 (a) of the first pawl 303 and the control pin 304 (a) of the second pawl 304 to constrain the spatial range in which the respective control pins can move, and the total number of the control pins is the same as the total number of the control grooves; the constraint relationship is specifically expressed as follows:

[0057] like Figure 5 As shown, when the control disk 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 toward the bidirectional 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 outwards under the action of the control groove and does not contact the bidirectional ratchet protrusion on the outer surface of the inner ring 301. At this time, the controllable one-way clutch 300 is in a one-way locked state in which the inner ring 301 is locked in counterclockwise rotation;

[0058] like Figure 6 As shown, when the control disk 306 rotates counterclockwise from the middle 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 movable ends of the first pawl 303 and the second pawl 304 are pushed toward the bidirectional ratchet protrusion on the outer surface of the inner ring 301 under the action of the return spring 305. At this time, the controllable one-way clutch 300 is in a bidirectional locked state;

[0059] like Figure 7 As shown, when the control disk 306 rotates clockwise from the middle position by a certain angle, the first pawl control pin 303 (a) and the second pawl control pin 304 (a) are both controlled by the corresponding control grooves, and the movable ends of the first pawl 303 and the second pawl 304 are both pulled outwards under the action of the control grooves, and do not contact the bidirectional ratchet protrusions on 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 bidirectional overrunning state.

[0060] The control mechanism includes: a worm wheel 307, a worm 308, and a control motor 309. The worm wheel 307 is a fan-shaped spoke structure, and its spoke is fixedly connected to the control disk 306. The worm 308 is meshed with the worm wheel 307 for transmission. The control motor 309 is fixedly connected to the worm 308. The output torque of the control motor 309 is decelerated and increased by the worm 308 and the worm wheel 307, and the transmission direction is vertically changed to realize the rotation control of the control disk 306.

[0061] The second reduction gear set 600 reduces the torque on the gear ring 406 and then outputs it; it includes: a second driving gear 601 and a second driven gear 602; the second driving gear 601 and the gear ring 406 can be made into one piece and are rotatably supported on the intermediate shaft 803 through a needle bearing, and the second driven gear 602 is externally meshed with the second driving gear 601 for transmission.

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

[0063] The friction clutch 500 comprises a clutch driving part 501 and a clutch driven part 502, wherein the clutch driving part 501 is fixedly connected to the intermediate shaft 803, and the clutch driven part 502 is fixedly connected to the ring gear 406 (the second driving gear 601) via a spline;

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

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

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

[0067] When the two-speed transmission is in the first-speed 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 drive motor 100 outputs electromagnetic braking torque in the positive direction. At this time, the power transmission route is as follows: Fig.10 shown.

[0068] When the two-speed transmission is in the second-speed regenerative braking state, the friction clutch 500 is in the engaged state, the controllable one-way clutch 300 is in the bidirectional overrunning state, and the drive motor 100 outputs electromagnetic braking torque in the positive direction. At this time, the power transmission route is as follows: Fig.11 shown.

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

[0070] The one-way locking state of the controllable one-way clutch 300 is a transition state when the two-speed transmission switches between the first-speed driving and the second-speed driving.

[0071] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes, and they can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A two-speed transmission for electric vehicles without power interruption using a two-stage planetary gear, characterized in that: include: A transmission housing, used to accommodate and support all components of the two-speed transmission; The left output shaft of the transmission is used to transmit power to the left drive wheel; The right output shaft of the transmission is used to transmit power to the right drive wheel; A drive motor is coaxially arranged with the left output shaft of the transmission; an intermediate shaft, arranged in parallel with the left output shaft of the transmission; A first reduction gear set, used for reducing the torque output by the driving motor and increasing the torque before outputting it to the intermediate shaft; A two-stage planetary gear train, comprising: a sun gear, an inner planet gear, an outer planet gear, an inner planet gear shaft, an outer planet gear shaft, a ring gear, and a planet carrier, wherein the sun gear is connected to the intermediate shaft via a spline, the inner planet gear is externally meshed with the sun gear for transmission, the outer planet gear is externally meshed with the inner planet gear for transmission, the ring gear is internally meshed with the outer planet gear for transmission, 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 jointly supported on the planet carrier; A controllable one-way clutch, comprising an inner ring and an outer ring, wherein the outer ring is fixed to the transmission housing, and the inner ring is fixedly connected to the planet carrier, wherein the controllable one-way clutch can be controlled to achieve a one-way locking state, and can be controlled to switch from the one-way locking state to a two-way locking state or a two-way overrunning state; The second reduction gear set is used to reduce the torque on the ring gear and increase the torque before outputting it; a differential receiving the torque from the second reduction gear set and evenly distributing the torque to the left output shaft and the right output shaft of the transmission; The friction clutch comprises a clutch driving part and a clutch driven part, wherein the clutch driving part is spline-connected to the intermediate shaft, and the clutch driven part is fixedly connected to the ring gear; the second reduction gear set is arranged at the necked position of the two-stage planetary gear system and the friction clutch intermediate ring gear to reduce the axial size of the transmission.

2. A two-speed transmission for electric vehicles without power interruption using a two-stage planetary gear as claimed in claim 1, characterized in that: The planetary gear characteristic parameters of the double-stage planetary gear system are designed to be within the range of 1.7 to 2.1 to ensure the continuity of the wheel end torque external characteristics while adapting to the high efficiency range characteristics of the electric vehicle motor.

3. A two-speed transmission for electric vehicles without power interruption using a two-stage planetary gear as claimed in claim 1, characterized in that: The driving motor comprises 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; the motor housing is fixedly connected to the transmission housing by bolts.

4. A two-speed transmission for electric vehicles without power interruption using a two-stage planetary gear as claimed in claim 1, characterized in that: The first reduction gear set is a cylindrical gear set, which includes: a first driving gear and a first driven gear; the first driving gear and the first driven gear are externally meshed for transmission; the first driving gear is spline-connected to the motor output shaft; and the first driven gear is fixedly connected to the intermediate shaft.

5. A two-speed transmission for electric vehicles without power interruption using a two-stage planetary gear as claimed in claim 1, characterized in that: 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 return springs, a control disk, and a control mechanism; Among them, there is a certain gap between the inner ring and the outer ring; the outer surface of the inner ring is processed with a bidirectional ratchet protrusion; the inner surface of the outer ring is installed with a plurality of the first pawls and a plurality of the second pawls that are evenly staggered, and the first pawl and the second pawl are installed in opposite directions, and the movable ends of the first pawl and the second pawl are respectively fixed with a control pin; the reset spring is installed between the first pawl and the outer ring and between the second pawl and the outer ring; the control pin cooperates with the control disk, and can move radially in the space defined by the control disk under the drive of the control mechanism, and the movable ends of the first pawl and the second pawl can contact the bidirectional ratchet protrusion on the outer surface of the inner ring under the action of the reset spring, thereby locking the inner ring in counterclockwise and clockwise rotation respectively.

6. A two-speed transmission for electric vehicles without power interruption using a two-stage planetary gear as claimed in claim 4, characterized in that: The control disk is mounted on the side surfaces of the inner ring and the outer ring and can rotate around the intermediate shaft; the control disk is processed with multiple groups of control grooves of two different shapes arranged alternately on the circumference, which respectively cooperate with the control pin of the first pawl and the control pin of the second pawl to constrain the spatial range in which the respective control pins can move, and the total number of the control pins is the same as the total number of the control grooves; the constraint relationship is specifically expressed as follows: When the control disk is in the middle position, the first pawl control pin is not controlled by the corresponding control groove, and the first pawl movable end is pushed toward the bidirectional ratchet protrusion on the outer surface of the inner ring under the action of the return spring, while the second pawl control pin is controlled by the corresponding control groove, and the second pawl movable end is pulled outward under the action of the control groove and does not contact the bidirectional ratchet protrusion on the outer surface of the inner ring. At this time, the controllable one-way clutch is in a one-way locked state in which the inner ring is locked when rotating counterclockwise and disengaged when rotating clockwise; When the control disk 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 corresponding control grooves, and the first pawl movable end and the second pawl movable end are pushed toward the bidirectional ratchet protrusion on the outer surface of the inner ring under the action of the return spring, and the controllable one-way clutch is in a bidirectional locked state; When the control disk rotates clockwise from the middle position by a certain angle, the first pawl control pin and the second pawl control pin are both controlled by the corresponding control grooves, and the first pawl movable end and the second pawl movable end are both pulled outwards under the action of the control grooves and do not contact the bidirectional ratchet protrusions on the outer surface of the inner ring. At this time, the inner and outer rings of the controllable one-way clutch are completely separated, and the controllable one-way clutch is in a bidirectional overrunning state; The control mechanism includes: a worm wheel, a worm, and a control motor. The worm wheel is a fan-shaped spoke structure, and its spoke is fixedly connected to the control disk. The worm is meshed with the worm wheel for transmission. The control motor is fixedly connected to the worm. The output torque of the control motor is reduced in speed and increased in torque by the worm wheel and the transmission direction is vertically changed to realize the rotation control of the control disk.

7. A two-speed transmission for electric vehicles without power interruption using a two-stage planetary gear as claimed in claim 1, characterized in that: The second reduction gear set is a cylindrical gear set, which includes: a second driving gear and a second driven gear; the second driving gear is fixedly connected to the ring gear and is rotatably supported on the intermediate shaft through a needle bearing, and the second driven gear is externally meshed with the second driving gear for transmission.

8. A two-speed transmission for electric vehicles without power interruption using a two-stage planetary gear as claimed in claim 1, characterized in that: The differential includes a differential case, a plurality of asteroid bevel gears, a left output shaft bevel gear, and a right output shaft bevel gear; the plurality of asteroid bevel gears are rotatably supported on the differential case; the left output shaft bevel gear and the right output shaft bevel gear are simultaneously meshed and transmitted with the plurality of asteroid bevel gears, and are respectively connected to the left drive wheel and the right drive wheel through respective universal joints through the left output shaft and the right output shaft of the transmission; the second driven gear is fixedly connected to the differential case through a spline.

9. A two-speed transmission for electric vehicles without power interruption using a two-stage planetary gear as claimed in claim 1, characterized in that: When the two-speed transmission is in the first gear driving state, the friction clutch is controlled to be in a disengaged state, the controllable one-way clutch is in a two-way locked state, and the drive motor outputs a driving torque in a positive direction to meet the low-speed acceleration power requirements of the vehicle; when the two-speed transmission is in the second gear driving state, the friction clutch is in a coupled state, the controllable one-way clutch is in a two-way overrunning state, and the drive motor outputs a driving torque in a positive direction to meet the high-speed cruising economy requirements of the vehicle; when the two-speed transmission is in a neutral state, the friction clutch is in a disengaged state, the controllable one-way clutch is in a two-way overrunning state, and the drive motor does not output any torque to meet the driving requirements when the vehicle is coasting or the drive axle is used as a driven axle. ; When the two-speed transmission is in the first gear regenerative braking state, the friction clutch is in a disengaged state, the controllable one-way clutch is in a bidirectional locked state, and the drive motor outputs electromagnetic braking torque in the positive direction to meet the large braking deceleration requirements of the vehicle at medium and low speeds; when the two-speed transmission is in the second gear regenerative braking state, the friction clutch is in a coupled state, the controllable one-way clutch is in a bidirectional overrunning state, and the drive motor outputs electromagnetic braking torque in the positive direction to meet the high-speed and small braking deceleration requirements of the vehicle; when the two-speed transmission is in the reverse state, the friction clutch is in a disengaged state, the controllable one-way clutch is in a bidirectional locked state, and the drive motor outputs driving torque in the reverse direction to meet the reverse driving requirements of the vehicle.

10. A two-speed transmission for electric vehicles without power interruption using a two-stage planetary gear as claimed in claim 1, characterized in that: When upshifting without power interruption is performed, torque phase control is performed first, and then inertia phase control is performed; in the torque phase, the torque T of the drive motor m Torque required by first gear Gradually increase to the torque required for the second gear The friction clutch is gradually clamped into a semi-linked sliding state and satisfies the following relationship: Where, T c is the torque transmitted by the friction clutch, i g1 is the first gear transmission ratio, i g2 is the second gear transmission 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 In 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; When downshifting without power interruption is performed, inertia phase control is performed first, and then torque phase control is performed; in the inertia phase stage, the friction clutch enters a semi-clamped sliding state from a fully clamped state, and its torque is The drive motor requires torque from the second gear The torque is appropriately increased to make the inner ring speed approach zero; the controllable one-way clutch needs to be switched from the two-way overrunning state to the one-way overrunning state before the inner ring speed approaches zero, and when the inner ring speed reaches zero, the controllable one-way clutch needs to be switched from the one-way overrunning state to the two-way locking state; when the inner ring speed reaches zero, the torque phase stage is entered, 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 first gear required torque 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 first gear state is entered.

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