A four-gear shift device with fast response

Abstract

This application relates to the field of transmission system technology, and in particular to a fast-response four-speed shifting device, which includes a housing, a gear selection side motor, a shifting side motor, a square shaft assembly, a gear selection / shifting finger, and a connecting sleeve. The gear selection side motor drives a rack via a gear shaft and gears, causing the gear selection / shifting finger to move axially along the square shaft assembly. The shifting side motor drives a shifting sleeve via a shifting screw and screw nut, which, in conjunction with the connecting sleeve, drives the square shaft assembly to rotate. The housing has an interlocking groove with multiple gear slots, allowing the gear selection / shifting finger to be inserted into the slots for locking. A first sensor (gear shaft side), a second sensor (square shaft side), and a TCU control system provide dual-angle detection for high-precision shifting control. A spherical protrusion at the bottom of the connecting sleeve engages with the shifting sleeve's connecting hole to compensate for assembly deviations. This device simplifies the gear selection structure through a gear and rack design, improving shifting response speed. The dual-stabilization and dual-sensor design ensures reliability and accuracy. Furthermore, its simplified structure and strong adaptability make it suitable for various dual-motor driven vehicles.

Description

Technical Field

[0001] This application relates to the field of transmission system technology, and in particular to a fast-response four-speed shifting device. Background Technology

[0002] Existing dual-motor four-speed shifting devices generally adopt a structure where both the selection and shifting sides use lead screw and nut drives to achieve gear changes. While this solution meets basic shifting reliability requirements, it suffers from a core, unresolved technical problem: the lead screw and nut drive system itself consists of multiple complex parts, including the lead screw, nut, guide sleeve, and lubricating components. This results in a large number of parts and cumbersome assembly processes—requiring repeated calibration of the lead screw and nut fit and the additional installation of guide structures to prevent transmission misalignment. This directly increases manufacturing costs and reduces the overall compactness of the device. Furthermore, it necessitates the disassembly of multiple related parts to replace faulty components during later maintenance, leading to low maintenance efficiency. More importantly, lead screw and nut drives inherently possess characteristics of "large inertial load and significant energy loss." Combined with the additional transmission resistance from their complex structure, this results in a severe lag in transmission response during gear selection. In congested urban traffic or complex mountain roads where frequent gear shifts are common, slow gear selection directly causes "shift delays," affecting not only driving smoothness but also potentially reducing vehicle power output efficiency due to untimely gear changes. For a long time, the industry has attempted to improve performance by optimizing the materials of the lead screw and nut (such as using high-strength alloys) and improving machining precision (such as reducing thread tolerances). However, these methods have remained within the core framework of "dual-sided lead screw and nut drives," failing to fundamentally resolve the dual contradiction of "structural complexity" and "slow response," and thus struggling to meet the higher demands of vehicles for timely and economical gear shifts.

[0003] To address this issue, a fast-response four-speed shifting device has been invented to solve the problems mentioned in the background art. Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings of existing dual-motor four-speed shifting devices, which suffer from complex structure and slow transmission response due to the use of lead screw and nut transmission on both sides, and to provide a four-speed shifting device with a faster response.

[0005] This application provides a fast-response four-speed shifting device, employing the following technical solution: It includes a housing, two sets of motors, a square shaft assembly, a shifting finger, and a connecting sleeve; the two sets of motors are a shifting-side motor and a selection-side motor, both fixedly connected to the housing; a gear shaft is fixedly connected to the output end of the selection-side motor, a gear is fixedly connected to the gear shaft, and the gear meshes with a rack; the shifting finger is slidably mounted on the square shaft assembly; the rack is disposed within the housing and fixedly connected to one end of the shifting finger, thereby driving the shifting finger to move axially along the square shaft assembly. The motor on the shifting side is fixedly connected to a shifting screw at its output end. A shifting sleeve is provided inside the housing, and a screw nut is slidably fitted inside the shifting sleeve. The screw nut is threadedly engaged with the shifting screw. One end of the engaging sleeve is fixedly connected to the square shaft assembly, and the other end is engaged with the shifting sleeve to drive the square shaft assembly to rotate. An interlocking groove is provided inside the housing. The interlocking groove includes multiple gear slots corresponding to different gear positions. The multiple gear slots are spaced apart along the axial direction of the square shaft assembly. One end of the shifting finger can be inserted into the corresponding gear slot to achieve gear locking.

[0006] Optionally, it also includes a first sensor, a second sensor, and a TCU control system. The first sensor is a gear shaft angle sensor, which is fixed on the housing and connected to one end of the gear shaft. The second sensor is a square shaft angle sensor, which is fixed on the housing and connected to the end of the square shaft assembly. Both the first and second sensors are electrically connected to the TCU control system, respectively feeding back the detected gear shaft angle data and square shaft rotation angle data to the TCU control system. The TCU control system is also electrically connected to the two sets of motors to control the rotation degree of the output shafts of the two sets of motors.

[0007] Optionally, a motor side cover is provided between the gear selection side motor and the housing. One side of the motor side cover is attached to the end face of the gear selection side motor, and the other side is attached to the side cover support surface of the housing. The motor side cover is detachably and fixedly connected to the gear selection side motor and the housing respectively.

[0008] Optionally, rack sleeves are fixed to both sides of the rack along its length by threaded pins, and rack slots are provided on the housing. The rack sleeves slide in cooperation with the rack slots on the housing, and the rack slots extend along the moving direction of the rack.

[0009] Optionally, disc springs are provided at both ends of the lead screw nut, one end of the disc spring abuts against the end face of the nut, and the other end abuts against the inner axial end face of the shift sleeve; an elongated hole is provided on the inner wall of the shift sleeve, and a threaded pin is provided on the nut to be inserted into the elongated hole.

[0010] Optionally, the square shaft assembly includes a square shaft, and the end of the square shaft is sequentially fitted with a small opening retaining ring, a needle roller bearing, and a square shaft washer, and the outer ring of the needle roller bearing is fixedly connected to the inner partition of the housing.

[0011] Optionally, the housing is provided with a vent plug, two sensor mounting points, and two motor mounting points; the vent plug is fixedly connected to the housing and communicates with the inner cavity of the housing; the first sensor and the second sensor are respectively fixedly assembled at the two sensor mounting points; the two motor mounting points correspond one-to-one with the gear selection side motor and the gear shift side motor and are fixedly connected.

[0012] Optionally, the bottom of the engagement sleeve is provided with a spherical protrusion, and the top of the shift sleeve is provided with an engagement hole, wherein the spherical protrusion can move within the engagement hole.

[0013] In summary, this application includes the following beneficial technical effects: 1. Faster shift response: The gear selector side adopts a gear and rack drive, which has less transmission inertia and higher efficiency compared with the traditional double-sided screw and nut structure. It can quickly convert the motor rotation into the axial movement of the gear selector finger, significantly shortening the shift response time and meeting the smoothness requirements of frequent gear shifting in vehicles. 2. More reliable gear locking: The interlocking protrusion inside the housing has slots corresponding to different gears. After the gear selector is inserted into the slot, radial movement can be restricted. This, combined with the motor locking, forms a double stable gear. The movable fit between the spherical protrusion of the engagement sleeve and the engagement hole of the gear shift sleeve can compensate for assembly deviations, ensure smooth power transmission, and reduce the risk of gear skipping. 3. Better cost and maintenance: The complex structure of the lead screw nut on the gear selection side is simplified, reducing the number of parts and lowering manufacturing costs; the motor side cover, rack and pinion sleeve and other components are detachable and fixed, and most of the core parts are standard parts, making it convenient for later maintenance and disassembly, thus reducing maintenance costs.

[0014] 4. More precise shifting: The square shaft end sensor and the gear shaft side sensor form a dual angle detection. The TCU combines the two sets of data to calibrate the motor control commands, avoiding gear offset caused by the error of a single sensor, and further improving shifting accuracy.

[0015] Instruction manual illustrations Figure 1 This is a schematic diagram of the overall structure of the device. Figure I ; Figure 2 This is a top view of the device; Figure 3 This is a cross-sectional schematic diagram of the overall structure of this device; Figure 4 This is a schematic diagram of the internal structure of the housing of this device. Figure I ; Figure 5This is a schematic diagram of the internal structure of the housing of this device. Figure II ; Figure 6 Schematic diagram of the housing of this device Figure I ; Figure 7 Schematic diagram of the housing of this device Figure II ; Figure 8 This is a bottom view of the device; Among them, 1. Housing, 2. Motor, 3. Square shaft assembly, 4. Gear selector finger, 5. Engaging sleeve, 62. Gear selector side motor, 72. Gear shifting side motor, 8. Gear shaft, 9. Gear, 10. Gear shifting screw, 11. Gear shifting sleeve, 12. Screw nut, 13. Interlocking protrusion, 14. Gear position slot, 151. First sensor, 152. Second sensor, 16. Motor side cover, 17. Rack sleeve, 18. Rack slot, 19. Disc spring, 20. Oblong hole, 21. Threaded pin, 22. Square shaft, 23. Open retaining ring, 24. Needle roller bearing, 25. Square shaft washer, 26. Vent plug, 27. Sensor mounting point, 28. Motor mounting point, 29. Spherical protrusion, 30. Engaging hole, 31. Rack. Detailed Implementation

[0016] The present application will be further described in detail below with reference to the accompanying drawings. In the description of the present utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present utility model.

[0017] Reference Figure 1 , Figure 3 , Figure 4 , Figure 5 As shown: This four-speed shifting device includes a housing 1 for supporting all components, two sets of motors 2 (selection side motor 62 and shift side motor 72) for providing power, a square shaft assembly 3 as the transmission center, a selection / shifting finger 4 for realizing gear switching action, and a coupling sleeve 5 for transmitting rotational power; In this embodiment, both the selection side motor 62 and the shift side motor 72 are DC servo motors, which are detachably and fixedly connected to the motor mounting boss on the housing 1 through a flange. The motor mounting boss is based on the central axis of the housing 1, the end face of the boss is perpendicular to the outer wall of the housing 1, and four circumferentially arranged threaded holes are evenly distributed on the end face. The output end of the motor 2 faces the inside of the housing 1. The output end of the gear selector motor 62 is coaxially fixed to one end of the gear shaft 8 via a flat key. A spur gear 9 is fitted and fixed to the outer wall of the gear shaft 8 via an interference fit. The teeth of the gear 9 are fully meshed with the tooth groove of the rack 31. The rack 31 is made of 40Cr and has undergone heat treatment. A square through hole adapted to the square shaft assembly 3 is opened in the middle of the gear selector finger 4. The rack 31 is slidably assembled on the square shaft assembly 3 through the square through hole. A rectangular connecting block is integrally formed on the top of the rack 31. The connecting block is fixedly connected to one end of the gear selector finger 4 by screws to ensure that when the rack 31 moves in a straight line, it can drive the gear selector finger 4 to slide synchronously along the axial direction of the square shaft assembly 3. The output end of the shift motor 72 is coaxially fixed to one end of the shift screw 10 via a threaded connection. The shift screw 10 has a trapezoidal thread, is made of 40Cr steel, and has undergone heat treatment. A shift sleeve 11 (made of 40Cr steel, with chrome plating) is installed inside the housing 1 via a bearing support. A screw nut 12 (made of 45 steel, with heat treatment) is slidably fitted inside the shift sleeve 11. The screw nut 12 is threadedly engaged with the shift screw 10. One end of the connecting sleeve 5 is fixedly connected to the square shaft 22 of the square shaft assembly 3 via a key connection. A spherical protrusion 29 is integrally formed at the bottom of the connecting sleeve 5. A connecting hole 30 that matches the spherical protrusion 29 is opened at the top of the shift sleeve 11. The spherical protrusion 29 is embedded in the connecting hole 30 and can move within the hole, thereby realizing the mating connection between the connecting sleeve 5 and the shift sleeve 11. The inner wall of the housing 1 is provided with an interlocking protrusion 13 along the vertical direction. The interlocking protrusion 13 includes four gear slots 14 corresponding to gears 1 to 4. The spacing of the slots is adapted to the axial movement stroke of the shift finger 4. The end of the shift finger 4 away from the rack 31 is a wedge-shaped structure, which can be inserted into the corresponding gear slot 14. The radial movement of the shift finger 4 is restricted by the side wall of the slot, thereby achieving gear locking.

[0018] The implementation principle is as follows: The gear selection side motor 62 drives the gear 9 to rotate through the gear shaft 8. The meshing transmission between the gear 9 and the rack 31 converts the rotational motion into the linear motion of the rack 31, which in turn drives the gear selection finger 4 to move axially along the square shaft assembly 3 until the wedge-shaped end of the gear selection finger 4 is inserted into the slot corresponding to the target gear, thus completing the gear positioning; The gear shifting side motor 72 drives the shifting screw 10 to rotate, which drives the screw nut 12 to move axially along the shifting sleeve 11 through the threaded engagement. The shifting sleeve 11 drives the engagement sleeve 5 and the square shaft assembly 3 to rotate through the engagement of the spherical protrusion 29 of the engagement sleeve 5 and the engagement hole 30, thereby driving the gear selection finger 4 to rotate and lock, ensuring gear stability; The gear slot 14 of the interlocking protrusion 13 restricts the disorderly movement of the gear selection finger 4, and together with the locking function of the motor 2, realizes reliable four-gear switching.

[0019] This shifting device also includes a first sensor 151 and a second sensor 152 for angle detection, and a control core TCU control system. In this embodiment, the selection and installation positioning reference of the first sensor 151 are as follows: the first sensor 151 is a rotary angle sensor (model range WDD35D4~WDD35D8), with an operating voltage of 5V±0.5V, a detection accuracy of ±0.1°, an output signal of 0~5V analog voltage signal, and a sampling frequency ≥100Hz. The first sensor 151 is fixed to the sensor mounting location 27 of the housing 1 by screws. The detection end of the first sensor 151 is coaxially aligned with the end of the gear shaft 8 away from the shifting side motor 62. Taking the end face of the gear shaft 8 as the axial reference, the distance between the detection end and the end face is the effective detection distance of the first sensor 151. Taking the axis of the gear shaft 8 as the radial reference, the positioning groove of the sensor mounting location 27 of the housing 1 ensures that the axis of the detection end is coaxial with the axis of the gear shaft 8. Zero-point calibration is performed when the shifting index 4 is in neutral. The 2.5V±0.1V output of sensor 151 serves as a reference value; after adjustment, it is locked in place. An annular positioning groove is formed on the outer wall of the square shaft 22 assembly 3 at the end furthest from housing 1 (the end adjacent to shift sleeve 11). The second sensor 152 (model range consistent with the first sensor 151, WDD35D4~WDD35D8, conforming to GB / T26802-2011 standard) is fixed to the second sensor mounting position 27 of housing 1 with screws. The detection end of the sensor 152 is coaxially aligned with the end face of the square shaft 22; the distance between the detection end and the end face of the square shaft 22 is the effective detection distance of the sensor (determined according to the model manual) with the axis of the square shaft 22 as the radial reference; the positioning groove of the housing 1 corresponding to the sensor mounting position 27 ensures that the axis of the detection end is coaxial with the axis of the square shaft 22; the zero point calibration is based on the output value of 2.5V±0.1V of the second sensor 152 when the shift finger 4 is in neutral, and is locked and fixed after adjustment.

[0020] TCU Control System Selection and Control Logic: The TCU can be a dedicated automotive transmission controller (model range TCU-2000~TCU-3000), with an operating voltage compatible with the vehicle's 12V / 24V power supply specifications, and a built-in 32-bit microprocessor (main frequency ≥100MHz); the first sensor 151 and the second sensor 152 are electrically connected to the TCU's CAN bus interface via shielded wires, and the TCU is electrically connected to the two sets of motors 2 via a PWM control interface; the control logic is set as follows: the TCU simultaneously receives signals from the first sensor 151 (gear shaft 8 side) and the second sensor 152 (square shaft 22 side). The sampling frequency is ≥100Hz, and the data is converted into digital angle data after being filtered by moving average (window length 5 sampling points). When determining the gear position, the gear position is double-verified by combining the 'gear shaft 8 angle data derived from the rack 31 travel' and the 'square shaft 22 angle data derived from the gear selector 4 rotation state'. When the motor 2 control command is generated, the rotation angle and speed are calibrated based on the deviation between the two sets of data (allowable deviation ≤0.3°). If the deviation exceeds the threshold, the fine-tuning program is started. When providing fault feedback, if any sensor has 5 consecutive abnormal sampling points, or if the deviation between the two sets of data is ≥0.5°, a fault signal is output to the vehicle instrument panel.

[0021] The implementation principle is as follows: the first sensor 151 detects the angle of the gear shaft 8 in real time and provides feedback on the axial movement position of the gear selector finger 4 driven by the rack 31; the second sensor 152 detects the rotation angle of the square shaft 22 in real time and provides feedback on the locked rotation state of the gear selector finger 4; the TCU receives the two sets of data and cross-verifies them, accurately controlling the rotation amplitude and locking timing of the two motors 2 to ensure that the gear position is without deviation; at the same time, the interlocking convex groove 13 restricts the movement of the gear selector finger 4, and works with the motor 2 to lock, preventing gear shifting during vehicle operation, and achieving high-precision and stable four-gear switching.

[0022] Reference Figure 1 , Figure 2 As shown: A motor side cover (made of Q235 steel) is provided between the gear selection side motor 62 and the housing 1 of this gear shifting device; in this embodiment, one end face of the motor side cover is completely fitted with the flange end face of the gear selection side motor 62, and is detachably fixed by four circumferentially distributed GB / T70.1 hexagon socket head cap screws. The screws pass through the screw holes of the motor side cover and then engage with the threaded holes of the flange end of the motor 2; the other end face of the motor side cover is fitted with the side cover support surface of the housing 1, and a nitrile rubber annular sealing gasket (the cross-section is consistent with the inner and outer diameters of the motor side cover, and the Shore hardness is 50~60A) is provided between the mating surfaces; the motor side cover is fixed to the housing 1 by bolts. The bolts pass through the bolt holes of the motor side cover and then engage with the threaded holes of the side cover support surface of the housing 1. The inner hole of the motor side cover is clearance fitted with the output end of the motor 2 to ensure smooth passage of the output end.

[0023] The implementation principle is as follows: the side cover of motor 2 forms a stable support through double fixing to prevent motor 2 from vibrating and shifting, and to ensure the coaxiality of the output end of motor 2 and gear shaft 8; the sealing gasket works with the side cover of motor 2 to achieve dustproof and oil-proof sealing, and extend the service life of internal parts.

[0024] Reference Figure 4 , Figure 5 , Figure 6 , Figure 7 As shown: rack 31 of this shifting device has rack sleeves 17 fixed on both sides along its length; two parallel rack slots 18 are provided on the inner wall of the housing 1 along the moving direction of rack 31, and the outer wall of rack sleeve 17 slides with the inner wall of the slot to ensure that rack 31 moves only in a straight line along the slot direction.

[0025] The implementation principle is as follows: the cooperation between the rack sleeve 17 and the rack slot 18 restricts the lateral displacement of the rack 31, ensuring the stable meshing of the gear 9 and the rack 31, thereby ensuring the accuracy of the axial movement of the gear selection finger 4 and avoiding gear selection deviation caused by the wobbling of the rack 31.

[0026] Reference Figure 3 As shown: The lead screw nut 12 of this shifting device is provided with disc springs 19 at both ends (model range 60Si2Mn-D12×d5×t0.8~D16×d8×t1.0); In this embodiment, the disc springs 19 are made of 60Si2Mn spring steel, which has been quenched and tempered at medium temperature, with an elastic modulus of 15~25N / mm and a rated working load of 5~10N. They are respectively abutted between the two end faces of the lead screw nut 12 and the inner axial end face of the shifting sleeve 11; The inner side wall of the shifting sleeve 11 is provided with a rectangular elongated hole 20 along the axial direction (the center line is parallel to the axis of the shifting sleeve 11), and the bottom of the lead screw nut 12 is provided with a threaded hole. After the threaded pin 21 passes through the threaded hole, the other end is inserted into the elongated hole 20 and can slide in the elongated hole 20.

[0027] The implementation principle is as follows: the disc spring 19 absorbs the impact force between the lead screw nut 12 and the shift sleeve 11 through elastic deformation, provides axial preload, and avoids rigid collision; the threaded pin 21 and the elongated hole 20 restrict the rotation of the nut, so that the nut only moves along the axial direction of the shift sleeve 11, ensuring that the shift sleeve 11 moves smoothly and synchronously with the nut, and improving the smoothness of shifting.

[0028] Reference Figure 1 , Figure 4As shown: The square shaft assembly 3 of this shifting device is based on a square columnar square shaft 22 (material 40CrNiMoA, heat-treated, hardness HRC30~35). In this embodiment, an annular groove is provided on the outer side wall of one end of the square shaft 22, and an open retaining ring 23 is inserted into the annular groove to achieve axial fixation. A needle roller bearing 24 is sleeved on the inner side of the open retaining ring 23. The inner ring of the bearing is interference-fitted with the outer side wall of the square shaft 22, and the outer ring is interference-fitted with the bearing mounting hole of the inner side plate of the housing 1. A square shaft washer 25 made of Q235 steel (inner diameter matches the square shaft 22, outer diameter matches the inner ring of the bearing) is sleeved between the needle roller bearing 24 and the open retaining ring 23. The inner side wall of the square shaft washer 25 fits against the square shaft 22, and the outer side wall abuts against the end face of the inner ring of the bearing.

[0029] The implementation principle is as follows: the needle roller bearing 24 provides stable rotational support for the square shaft 22 and reduces rotational resistance; the open retaining ring 23 and the square shaft washer 25 restrict the axial movement of the bearing, prevent the bearing from falling out of the installation position, ensure the stable transmission of the square shaft assembly 3, and improve the smoothness of the shifting action.

[0030] Reference Figure 6 , Figure 7 , Figure 8 As shown: The housing 1 of this shifting device (made of ADC12 aluminum alloy, die-cast and anodized) integrates ventilation and mounting structures; in this embodiment, the top of the housing 1 has an internally threaded ventilation hole, and the ventilation plug 26 is fixed in the ventilation hole by threaded engagement, and its internal ventilation channel connects the inner cavity of the housing 1 with the outside; the two sensor mounting locations 27 are rectangular grooves on the outer side wall of the housing 1, and the inner side wall of the groove is provided with 4 M4 threaded holes; the first sensor 151 is fixed to the sensor mounting location 27 near the gear shaft 8, and the second sensor 152 is fixed to the sensor mounting location 27 near the square shaft 22 assembly 3. The detection ends of both extend through the corresponding through holes of the housing 1 to the inner side, and are aligned one-to-one with the ends of the gear shaft 8 and the square shaft 22; the two motor 2 mounting locations are circular bosses protruding from the outer side wall of the housing 1.

[0031] The implementation principle is as follows: the vent plug 26 balances the air pressure inside and outside the housing 1, avoiding the component jamming or sealing failure caused by the air pressure difference due to temperature changes; the sensor mounting point 27 provides a precise installation benchmark to ensure the accuracy of angle detection; the motor mounting point 28 ensures the coaxiality of the output end of the motor 2 and the transmission component, reducing power loss and improving transmission efficiency.

[0032] Reference Figure 3As shown: The bottom of the engagement sleeve 5 of this shifting device is integrally formed with a spherical protrusion 29; in this embodiment, the top of the shifting sleeve 11 is provided with a circular engagement hole 30 that matches the spherical protrusion 29. The inner diameter of the engagement hole 30 is slightly larger than the diameter of the spherical protrusion 29, ensuring that the spherical protrusion 29 can move flexibly in the hole; the top of the engagement sleeve 5 is fixed to the square shaft 22 by a key connection, and the spherical protrusion 29 is embedded in the engagement hole 30 of the shifting sleeve 11, and the spherical surface of the protrusion is fully fitted with the hole wall of the engagement hole 30, realizing the movable connection between the two; during installation, the engagement sleeve 5 is first fixed to the square shaft 22, and then the spherical protrusion 29 is aligned with the engagement hole 30 of the shifting sleeve 11 and embedded, ensuring that the engagement sleeve 5 can rotate synchronously with the axial movement of the shifting sleeve 11 after assembly.

[0033] The implementation principle is as follows: the movable fit between the spherical protrusion 29 and the engagement hole 30 can compensate for the slight coaxiality deviation during the assembly process, ensuring that the axial movement of the shift sleeve 11 can be smoothly converted into the rotational movement of the engagement sleeve 5, thereby driving the square shaft assembly 3 to rotate and realize the locking action of the shift finger 4; the spherical contact reduces frictional resistance and improves power transmission efficiency and shifting smoothness.

[0034] The working principle of this device is as follows: Gear selection and positioning: The gear selection side motor 62 starts, driving the gear shaft 8 and gear 9 to rotate. Gear 9 meshes with rack 31 to transmit the rotational motion, converting the rotational motion into the linear motion of rack 31. Rack 31 is fixedly connected to gear selection finger 4, driving gear selection finger 4 to slide along the axial direction of square shaft assembly 3 until one end of gear selection finger 4 is inserted into the target gear slot 14 of interlocking protrusion 13 in housing 1, thus completing gear selection. Shift lock: The shift side motor 72 starts synchronously, driving the shift screw 10 to rotate. The screw nut 12 is threadedly engaged with the shift screw 10 and is restricted from rotating by the shift sleeve 11, only moving along the sleeve axis. The shift sleeve 11 drives the engagement sleeve 5 and the square shaft assembly 3 to rotate through the engagement of the ball protrusion 29 of the engagement sleeve 5 and the engagement hole 30, thereby driving the shift finger 4 to rotate, so that the shift finger 4 is tightly engaged with the target gear slot 14, completing the shift. Precise and stable gear shifting: The first sensor 151 detects the angle of the gear shaft 8 in real time and provides feedback on the axial movement position of the gear selector finger 4 driven by the rack 31; the second sensor 152 detects the rotation angle of the square shaft 22 in real time and provides feedback on the locked rotation state of the gear selector finger 4; the TCU receives the two sets of data and cross-verifies them to precisely control the rotation amplitude and locking timing of the two motors 2 to ensure that the gear position is without deviation; at the same time, the interlocking convex groove 13 restricts the movement of the gear selector finger 4 and locks it in conjunction with the motor 2 to prevent gear shifting during vehicle operation, thus achieving high-precision and stable four-gear switching.

[0035] The working principle of this device has been explained through the above embodiments. These embodiments only illustrate several implementation methods of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A fast-response four-speed shifting device, characterized in that: The assembly includes a housing (1), two sets of motors (2), a square shaft assembly (3), a shifting finger (4), and a coupling sleeve (5). The two sets of motors (2) are a shifting-side motor (62) and a gear shifting-side motor (72), respectively, and both sets of motors (2) are fixedly connected to the housing (1). The output end of the shifting-side motor (62) is fixedly connected to a gear shaft (8), and a gear (9) is fixedly connected to the gear shaft (8). The gear (9) meshes with a rack (31). The shifting finger (4) is slidably mounted on the square shaft assembly (3). The rack (31) is located inside the housing (1) and is fixedly connected to one end of the shifting finger (4) to drive the shifting finger (4) to move along the axial direction of the square shaft assembly (3). The shifting-side motor (72) has a gear shaft (8) fixedly connected to the gear shaft (8), and a gear ... The output end is fixedly connected to a shift screw (10), and a shift sleeve (11) is provided inside the housing (1). A screw nut (12) is slidably assembled inside the shift sleeve (11). The screw nut (12) is threadedly engaged with the shift screw (10). One end of the connecting sleeve (5) is fixedly connected to the square shaft assembly (3), and the other end is engaged with the shift sleeve (11) to drive the square shaft assembly (3) to rotate. An interlocking groove (13) is provided inside the housing (1). The interlocking groove (13) includes multiple gear slots (14) corresponding to different gear positions. The multiple gear slots (14) are distributed at intervals along the axial direction of the square shaft assembly (3). One end of the shift finger (4) can be inserted into the corresponding gear slot (14) to achieve gear locking.

2. The fast-response four-speed shifting device according to claim 1, characterized in that: It also includes a first sensor (151), a second sensor (152), and a TCU control system. The first sensor (151) is an angle sensor, which is fixed on the housing (1) and connected to one end of the gear shaft (8). The second sensor (152) is an angle sensor, which is fixed on the housing (1) and connected to the end of the square shaft (22) assembly (3). The first sensor (151) and the second sensor (152) are both electrically connected to the TCU control system, and respectively feed back the detected gear shaft (8) angle data and square shaft (22) rotation angle data to the TCU control system. The TCU control system is electrically connected to the two sets of motors (2) to control the rotation degree of the output shaft of the two sets of motors (2).

3. The fast-response four-speed shifting device according to claim 1, characterized in that: A motor (2) side cover is provided between the gear selection side motor (62) and the housing (1). One side of the motor (2) side cover is attached to the end face of the gear selection side motor (62), and the other side is attached to the side cover support surface of the housing (1). The motor (2) side cover is detachably and fixedly connected to the gear selection side motor (62) and the housing (1).

4. The fast-response four-speed shifting device according to claim 1, characterized in that: The rack (31) has rack sleeves (17) fixed on both sides along its length. The housing (1) has rack grooves (18). The rack sleeves (17) and the rack grooves (18) on the housing (1) slide together. The rack grooves (18) extend along the moving direction of the rack (31).

5. A fast-response four-speed shifting device according to claim 1, characterized in that: The screw nut (12) is provided with disc springs (19) at both ends. One end of the disc spring (19) abuts against the end face of the nut, and the other end abuts against the inner axial end face of the shift sleeve (11). The inner wall of the shift sleeve (11) is provided with an elongated hole (20), and the nut is provided with a threaded pin (21) that is inserted into the elongated hole (20).

6. A fast-response four-speed shifting device according to claim 1, characterized in that: The square shaft assembly (3) includes a square shaft (22), and the end of the square shaft (22) is sequentially fitted with an open retaining ring (23), a needle roller bearing (24) and a square shaft washer (25). The outer ring of the needle roller bearing (24) is fixedly connected to the inner side of the housing (1).

7. A fast-response four-speed shifting device according to claim 2, characterized in that: The housing (1) is provided with a vent plug (26), two sensor mounting locations (27) and two motor mounting locations (28); the vent plug (26) is fixedly connected to the housing (1) and communicates with the inner cavity of the housing (1); the first sensor (151) and the second sensor (152) are respectively fixedly assembled at the two sensor mounting locations (27); the two motor mounting locations (28) correspond one-to-one with the gear selection side motor (62) and the gear shift side motor (72) and are fixedly connected.

8. A fast-response four-speed shifting device according to claim 1, characterized in that: The bottom of the engagement sleeve (5) is provided with a spherical protrusion (29), and the top of the shift sleeve (11) is provided with an engagement hole (30). The spherical protrusion (29) can move within the engagement hole (30).

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