Dog-tooth synchronizer, transmission

Abstract

A dog tooth type synchronizer and transmission, comprising a gear, a synchronizer hub, a sliding shift sleeve, a combination tooth, an output shaft, the gear is rotatably connected on the output shaft and is axially immovable, the synchronizer hub is fixedly connected on the output shaft, the sliding shift sleeve is connected on the synchronizer hub through a spline and is reciprocally movable in the axial direction, the driven gear and the sliding shift sleeve are both provided with the combination tooth and form a combination tooth pair, the combination tooth is provided with a first and a second contact surface, the first contact surface is perpendicular to the output shaft, the second contact surface is at an angle with the first contact surface, a clearance L1 is provided between the two key surfaces of the spline connecting the sliding shift sleeve and the synchronizer hub, a spring hole A is provided in the radial direction of the synchronizer hub, a spring A and a top block A are provided in the spring hole A, and a V-shaped groove A is provided on the sliding shift sleeve.

Description

Technical Field

[0001] This invention relates to the field of transmission technology, and in particular to the field of transmissions for new energy vehicles. Background Technology

[0002] The characteristics of electric motors in new energy vehicles mean they don't need as many gears as traditional transmissions, so most new energy vehicles currently use fixed-gear transmissions. However, fixed-gear transmissions require motors with high power and a wide speed range, making it difficult to effectively control the motor's operation. In contrast, two-gear transmissions can reduce motor output torque, decrease motor size and cost, optimize motor operation, and improve the high-speed performance of new energy vehicles. Currently, many manufacturers are designing two-gear transmissions for new energy vehicles. The mainstream two-gear transmission designs include synchronized transmissions, single-clutch transmissions, and dual-clutch transmissions. Synchronized transmissions have a simple structure and mature technology, but they have disadvantages such as long shift times and power interruptions affecting comfort. Single-clutch transmissions offer smooth shifting and good comfort, but they are larger, heavier, and more expensive. Dual-clutch transmissions are easier to manufacture and develop, but they suffer from poor heat dissipation, high failure rates, and high prices.

[0003] Dog-tooth synchronizers, also known as claw clutches, achieve rapid and direct gear shifting through their dog-tooth-shaped engagement teeth structure, without interrupting power, thus demonstrating their unique advantages in high-performance applications such as racing. However, their disadvantages are equally obvious. The engagement teeth of a dog-tooth transmission can engage at any speed difference, inevitably causing severe gear grinding, resulting in strong jerking and loud noise. Therefore, dog-tooth synchronizers are difficult to operate and require professional training, and they also cause significant damage to the gear set, severely affecting its lifespan. To improve these shortcomings, corresponding technologies have been developed both domestically and internationally, such as application number CN200610006229.1 and the improved CN202110024549.4. These technologies use a large play between the engagement gear and the drive shaft, combined with a central spring, to delay the transmission of power after the gear and synchronizer hub mesh. However, since they can still engage at any speed difference, the delay time may be insufficient or too long. Whether the delay time is insufficient or too long, it will cause shifting shock and vehicle jerking. Summary of the Invention

[0004] This invention provides a dog-tooth synchronizer and a transmission, which mainly solves the problem of severe tooth breakage caused by the engagement of the meshing teeth under arbitrary speed differences in existing dog-tooth synchronizer technology, as well as the resulting defects such as strong jerking, huge noise and shortened life.

[0005] To address the aforementioned problems, this invention provides a dog-tooth synchronizer, comprising a driven gear, a synchronizer hub, a sliding shift sleeve, engagement teeth, and an output shaft. The driven gear is rotatably connected to the output shaft and is axially immovable. The synchronizer hub is fixedly connected to the output shaft. The sliding shift sleeve is splined to the synchronizer hub and axially reciprocates. Multiple engagement teeth are provided on opposite sides of both the driven gear and the sliding shift sleeve, forming engagement tooth pairs. Each engagement tooth has first and second contact surfaces. The first contact surface is perpendicular to the axis of the output shaft, and the second contact surface forms an angle with the first contact surface. The extension of the line connecting the second and first contact surfaces intersects the axis of the output shaft. A play L1 is provided between the two key surfaces of the spline of the sliding shift sleeve and the synchronizer hub. Multiple spring holes A are provided in the radial direction of the synchronizer hub. A spring A and a top block A are provided within each spring hole A. The top block A has a trapezoidal top and a rectangular bottom. The sliding shift sleeve has V-grooves A in the same number as the spring holes A. The scanning path of the cross-section of the V-grooves A is parallel to the axis of the output shaft. The characteristic feature is that when the second contact surface of the engaging tooth on the driven gear presses against the second contact surface of the engaging tooth on the sliding shift sleeve, its tangential component forms a torque T1, which acts on the sliding shift sleeve. Under the action of torque T1, the top block A generates a torque T2 on the V-groove A that is equal in magnitude and opposite in direction to T1.

[0006] Optionally: The sliding shift sleeve has multiple movable tooth holes on the same circumference. The cross-sectional scanning path of the movable tooth holes is parallel to the axis of the sliding shift sleeve. Movable engaging teeth and a spring C are disposed within each movable tooth hole. The movable tooth holes are divided into multiple groups, each group consisting of N movable tooth holes. The relationship between the distance L between two adjacent movable tooth holes in the same group and the tooth pitch L2 of the engaging teeth on the driven gear is: L = The distance between the live teeth at the same position in each group of live teeth is an integer multiple of the tooth pitch L2 of the engaging teeth on the driven gear. The movable engaging teeth on the sliding shift sleeve and the engaging teeth on the driven gear form a pair of engaging teeth.

[0007] Optionally: The synchronizer hub has multiple spring holes B in the radial direction, and a spring B and a top block B are provided in the spring holes B. The top of the top block B is trapezoidal at the top and rectangular at the bottom. The sliding shift sleeve has two sets of V-grooves B along the axial direction. The scanning path of the cross section of the V-grooves B is perpendicular to the axis of the sliding shift sleeve 3. The number of V-grooves B in each set is the same as the number of spring holes B.

[0008] The present invention also provides a transmission including the synchronizer described above.

[0009] This invention provides a dog-tooth type synchronizer and transmission, which can prevent the engagement of gear teeth under large speed differences, and the resulting drawbacks such as severe gear grinding, strong jerking, loud noise, and shortened transmission life. At the same time, this invention has the advantages of smooth and rapid gear shifting, simple structure, small size, mature technology, and low cost, and is especially suitable for new energy vehicles. Attached Figure Description

[0010] Figure 1 This is a front view of the transmission in Example 1.

[0011] Figure 2 It is a toothed structure.

[0012] Figure 3 Working principle of dog tooth synchronizer 1.

[0013] Figure 4 Working principle of dog tooth synchronizer 2.

[0014] Figure 5 The working principle of the dog-tooth synchronizer 3.

[0015] Figure 6 4. Working principle of the dog tooth synchronizer.

[0016] Figure 7 This shows the positional relationship between the five active tooth holes in group A and the first active tooth hole in group B in Example 1.

[0017] Figure 8 The front view and right view show the structural relationship between spring hole B, spring B, top block B, and V-groove B.

[0018] Figure 9 These are three-view diagrams of the movable engagement teeth in Examples 1 and 2.

[0019] Figure 10 This is a front view of the synchronizer hub and sliding shift sleeve of Embodiment 1.

[0020] Figure 11 This is a left view of the synchronizer hub and sliding shift sleeve of Embodiment 1.

[0021] Figure 12 This is a front view of the transmission in Example 2.

[0022] Figure 13 This is a left view of the transmission in Example 2.

[0023] The reference numerals in the attached drawings are as follows: 1. Engaging tooth; 11. Engaging tooth A; 12. Engaging tooth B; 13. First contact surface; 14. Second contact surface; 15. Working surface; 2. Synchronizer hub; 21. Spring hole A; 211. Spring A; 212. Top block A; 22. Spring hole B; 221. Spring B; 222. Top block B; 223. Rectangular groove; 3. Sliding shift sleeve; 31. Left half; 32. Right half; 33. V-groove A; 34. V-groove B; 35. Screw; 36. Locating pin; 37. Spring C; 41. Driving gear; 42. Driven gear; 43. Gear ring; 51. Input shaft; 52. Output shaft; 53. Shift fork; 61. Spline; 62. Spline groove; 7. Live gear hole; 71. Movable engagement gear; 7A1. First live gear hole of group A; 7A2. Second live gear hole of group A; 7A3. Third live gear hole of group A; 7A4. Fourth live gear hole of group A; 7A5. Fifth live gear hole of group A; 7B1. First live gear hole of group B; 81. Planetary support; 811. Planetary gear; 9. Sun gear. Detailed Implementation

[0024] In the description of this invention, it should be understood that directional terms such as "up, down, left, right", "parallel, vertical" and "top, bottom" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and simplifying the description. Unless otherwise stated, these directional terms 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, and therefore should not be construed as a limitation on the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner and outer contours of each component itself.

[0025] To facilitate drawing and description Figure 3 , Figure 4 , Figure 5 The diagram is presented using two synchronized graphs. The x-axis is the axis along the tangent of the output shaft 52, the Y1 axis is the axial direction of the sliding shift sleeve 3, and the Y2 axis is the radial direction of the output shaft 52. Figure 2 , Figure 6 , Figure 7 The X-axis is obtained by unfolding along the tangent direction of the output shaft 52, and the Y-axis is the axial direction of the output shaft 52; in Figure 8 In the diagram, X1 axis represents the axial direction of synchronizer hub 2, X2 axis is obtained by unfolding along the tangent direction of output shaft 52, and Y axis represents the radial direction of synchronizer hub 2; Figure 3 , Figure 4 , Figure 5 , Figure 6The synchronizer hub 2 is set as the reference point. The driven gear 42 moves to the right with an initial velocity Vo, which is equal to the speed difference between the driven gear 42 and the sliding shift sleeve 3 at the start of shifting. The driven gear 42 is simultaneously subjected to a leftward acceleration a. For ease of distinction and concise writing, the "engaging tooth 1 on the sliding shift sleeve 3" is abbreviated as "engaging tooth A", and the "engaging tooth 1 on the driven gear 42" is abbreviated as "engaging tooth B". "Engaging tooth A" and "engaging tooth B" are identical except for their positions. The phrase "the working surfaces of engaging tooth A11 and engaging tooth B12 begin to contact each other" is abbreviated as "the synchronizer begins to synchronize". Unless otherwise stated, the synchronizer and transmission mentioned below refer to the dog-tooth synchronizer and transmission provided by this invention.

[0026] Furthermore, it should be noted that the use of suffixes such as "A", "B", and "C" to define components in this invention is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above words have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0027] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the present invention; at the same time, it should be understood that, for ease of description and drawing, the dimensions of the various parts shown in the drawings are not drawn exactly according to actual scale; techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification.

[0028] like Figure 2-1 The connecting gear 1 shown has a first contact surface 13, two second contact surfaces 14, and two working surfaces 15. The first contact surface 13 is perpendicular to the axis of the sliding shift sleeve 3. The second contact surfaces 14 are symmetrically distributed on both sides of the first contact surface 13 and form an angle with the first contact surface. The extension line of the intersection of the second contact surface and the first contact surface intersects the axis of the output shaft. The height of the second contact surface 14 is L3 and the width is L4. Figure 2-2 Another type of engagement tooth 1 is provided, which has a first contact surface 13, a second contact surface 14, and two working surfaces 15. The first contact surface 13 is perpendicular to the central axis of the output shaft 52. The second contact surface 14 forms an angle with the first contact surface 13, and the extension line of the intersection of the second contact surface 14 and the first contact surface 13 intersects the axis of the output shaft 52. The height of the second contact surface 14 is L3 and the width is L4.

[0029] like Figure 3As shown, the synchronizer hub 2 is fixedly connected to the output shaft 52. The sliding shift sleeve 3 and the synchronizer hub 2 are connected by a spline 61 and a spline groove 62. Both spline surfaces of the spline 61 and the spline groove 62 are provided with play L1. The sliding shift sleeve 3 and the driven gear 42 are respectively provided with engagement teeth A11 and engagement teeth B12. The synchronizer hub 2 is provided with a spring hole A21 in the radial direction. The spring hole A21 is provided with a spring A211 and a top block A212. The top of the top block A212 is trapezoidal at the top and rectangular at the bottom. The sliding shift sleeve 3 is provided with a V-groove A33. The scanning path of the V-groove A33 is shown in the figure. Parallel to the central axis of the output shaft 52, when the top block A212 is in the middle position of the V-groove A33, the spline 61 is also in the middle position of the spline groove 62; when the second contact surfaces 14 of the engaging teeth A11 and B12 press against each other, the pressure on the second contact surface 14 of the engaging teeth A11 can be decomposed into two forces F3 and F4 on the X-axis and Y1 axis, where F3 generates torque T1. Under the action of torque T1, the top block A212 generates a force on the V-groove A33, which can be decomposed into two forces F1 and F2 on the X-axis and Y2 axis, where F1 generates torque T2. The sliding shift sleeve 3 is simultaneously subjected to torques T1 and T2. Since the technical feature of this invention sets T1 and T2 to be equal in magnitude and opposite in direction, the sum of the torques on the sliding shift sleeve 3 is zero and it remains stationary. Before the synchronizer starts to synchronize, the driven gear 42 will only move up and down repeatedly.

[0030] like Figure 4 As shown, when the synchronizer starts to synchronize, since the torque of the working surface 15 of the engagement gear B12 comes from the engine, the torque output by the engine is obviously much greater than T1. Therefore, the engagement gear B12 pushes the engagement gear A11 to move to the right and continues to move downward at the same time until the speed V of the driven gear 42 is equal to zero under the action of acceleration a.

[0031] like Figure 5 As shown, the driven gear 42 moves to the left under the continued action of acceleration a, and pushes the sliding shift sleeve 3 to move to the left. In the subsequent process, the engaging gear A11 and engaging gear B12 first complete the engagement depth of L8. When the play on the left side of the spline 61 and spline groove 62 is zero, the entire shifting process is completed.

[0032] like Figure 6-1 As shown, after passing the position of engagement tooth B12 (shown by the solid line), engagement tooth B12 (shown by the dashed line) will move downwards and to the right simultaneously. The condition for the synchronizer to start synchronizing is that the time taken for engagement tooth B12 to traverse distance L6 is less than the time taken to traverse distance L7. Therefore, by setting an appropriate shifting force F and the angular acceleration of the driven gear 41, the synchronizer can achieve the desired synchronization. The condition for synchronizer synchronization to begin is that the speed difference is less than a predetermined value. For ease of description, it is assumed that there is a specific engagement tooth B12 on the driven gear 42. At the instant when the speed difference between the driven gear 42 and the sliding shift sleeve 3 is equal to zero, the landing point of this engagement tooth B12 must be any position within a tooth pitch range. This interval where the landing point is located is named S1, and the second-to-last tooth pitch interval is named S2. Obviously, the shifting impact generated when synchronizer synchronization begins is minimal in interval S1. To ensure that engagement tooth B12 only lands in interval S1, the time taken for engagement tooth B12 to travel the distance L6 in interval S2 must be greater than the time taken to travel the distance L7, and the time taken for engagement tooth B12 to travel the distance L6 in interval S1 must be less than the time taken to travel the distance L7. The shifting impact is greatest when engagement tooth B12 lands on the rightmost side of interval S1, and the speed difference Vmax between the driven gear 42 and the sliding shift sleeve 3 is Vmax when synchronizer synchronization occurs. The shift shock is minimized when the engaging gear B12 falls on the leftmost side of interval s1 at revolutions per minute. The speed difference Vmin between the driven gear 42 and the sliding shift sleeve 3 during synchronizer synchronization is... Revolutions per minute, and L1 = in It equals the velocity of engagement gear B12 after traveling a distance L2 with an initial velocity of zero and acceleration a, where t is the time taken for engagement gear B12 to travel a distance L8, and a is the acceleration of driven gear 42.

[0033] like Figure 6-2 As shown, relative Figure 6-1 The distances L6 and L7 in the middle are obviously... Figure 6-2The intermediate distance L6 remains essentially constant, while the distance L7 equals the tooth gap width. The time taken for the engaging tooth B12 to traverse distance L7 becomes extremely short. Therefore, except for a very few engaging teeth B12 whose landing point is closest to the left side of interval S1, which can achieve synchronizer synchronization, engaging teeth B12 whose landing points are elsewhere cannot achieve synchronizer synchronization before the driven gear 42 moves to the left. After the driven gear 42 moves to the left, the distance L6 becomes zero, so synchronizer synchronization will definitely occur within interval S1. At this point, it is only necessary to ensure that the time taken for the engaging tooth B12 to traverse distance L8 is less than that of the sliding shift sleeve 3-way. The time taken for the play L1 is sufficient, and we can easily change the time taken for the engagement tooth B12 to pass through the distance L8 by adjusting the shifting force F, thereby reducing the play L1 and thus reducing the shifting shock. Obviously, the speed difference during shifting is much smaller when the engagement tooth 1 has only one second contact surface 14 than when the engagement tooth 1 has two second contact surfaces 14. It is also easier to implement technically, especially suitable for two-speed transmissions where the same gear is always upshifted (or downshifted). Engagement tooth 1 with two second contact surfaces 14 is suitable for transmissions with more than two gears, where engaging the intermediate gear may be either upshifting or downshifting.

[0034] like Figure 7 As shown, taking a group of 5 movable tooth holes 7 as an example, the positional relationship between the movable tooth holes 7 within the group and the positional relationship between the movable tooth holes 7 outside the group are described. The distance L between two adjacent movable tooth holes 7 within the same group is... The distance between live tooth holes 7 in different groups but at the same sequential position is an integer multiple of the tooth pitch L2. When using the live tooth hole 7 structure, the maximum speed difference Vmax during synchronization of the synchronizer is = Rotational speed per minute, where N in the formula represents the number of live tooth holes 7 in each group.

[0035] like Figure 8-1 The diagram shows the front and right views of the structural relationship between spring hole B22, spring B221, top block B222, and V-groove B34. Multiple spring holes B22 are arranged radially on the synchronizer hub 2. Spring B221 and top block B222 are installed within each spring hole B22. The top block B222 has a trapezoidal top and a rectangular bottom. Two sets of V-grooves B34 are arranged along the axial direction on the sliding shift sleeve 3. The number of V-grooves B34 in each set is the same as the number of spring holes B22. The scanning path of the V-groove B34 is a circle perpendicular to the axis of the synchronizer hub 2. The two sets of V-grooves B34 correspond to two different gear positions. When the sliding shift sleeve 3 moves along the axial direction, causing one of the V-grooves B34 to reach the position of top block B222, top block B222 engages the V-groove B34, thus locking it with the corresponding gear position. Figure 8-2 The figures shown are a front view and a right view illustrating another structural relationship between spring hole B, spring B, top block B, and V-groove B. Figure 8-1The design features a rectangular groove 223 at the top of the spring hole B22, perpendicular to the axis of the synchronizer hub 2. The top of the top block B222 is trapezoidal, and the bottom is rectangular. The scanning path of the V-groove B34 is a straight line perpendicular to the axis of the synchronizer hub 2. When the sliding shift sleeve 3 rotates slightly relative to the synchronizer hub 2, the top block B222 can follow the sliding shift sleeve 3 within the rectangular groove 223. Figure 8-1 Line contact between the center block B222 and the V-groove B34 Figure 8-2 The top block B222 and the V-groove B34 are in surface contact, which is suitable for applications requiring large axial forces. Example 1

[0036] Combination Figure 1 , Figure 2-2 , Figure 9 , Figure 10 , Figure 11 In this embodiment, the transmission is a two-speed parallel shaft transmission with the following main parameters: first gear reduction ratio of 3.5 and second gear reduction ratio of 2; the wheelbase between the input shaft and the output shaft is 80 mm; the number of teeth of the engaging tooth B12 on the driven gear 42 is 36; the maximum and minimum radii of the ring containing the engaging tooth B12 are 49 mm and 44 mm, respectively; the engaging tooth B12 has only one second contact surface 14, with the following dimensions at a radius of 46.5 mm: L1 = 1.32 mm, L2 = 8.11 mm, L3 = 0.175 mm, and L4 = 2 mm. The 5 mm, L5=4 mm, L8=4 mm sliding shift sleeve 3 is composed of a left half 31 and a right half 32 and is connected by a screw 35 and a positioning pin 36. There are 30 pairs of movable tooth holes 7 at corresponding positions on the left half 31 and the right half 32. These 30 pairs of movable tooth holes 7 are divided into 6 groups, each group consisting of 5 pairs of movable tooth holes 7. Each pair of movable tooth holes 7 contains a pair of movable engagement teeth 71 and a spring C37. During the meshing process, the average acceleration of the movable engagement teeth 71 is 320 m / s^2, and the meshing time is 0.005 seconds.

[0037] Assuming a gear shift occurs at a motor speed of 5000 rpm, the speed difference between the driven gear 42 and the sliding shift sleeve 3 is approximately 18 rpm. Assuming the driven gear 42 accelerates at 45 rpm² for speed matching, the matching time is 0.4 seconds, and the synchronizer synchronization time is 0.405 seconds. The shift control accuracy between the driven gear 42 and the output shaft 52 is approximately between 42.4 and 56 rpm. Converted to the engine's shift control accuracy, the shift control accuracy from second to first gear is approximately between 148.5 and 196 rpm, and the shift control accuracy from first to second gear is approximately between 85 and 112 rpm. Example 2

[0038] Combination Figure 2-2 , Figure 9 , Figure 12 , Figure 13 In this embodiment, the transmission is a two-speed planetary gear transmission. Compared to embodiment 1, embodiment 2 omits the synchronizer hub 2, moves the spring holes A21 and B22 originally located on the synchronizer hub 2 to the sliding shift sleeve 3, and moves the V-grooves A33 and B34 originally located on the sliding shift sleeve 3 to the output shaft 52. The engaging gear B12 is set on the gear ring of the planetary gear, and the shift fork 53 is moved from the outside of the sliding shift sleeve 3 to the inside of the sliding shift sleeve 3. The output shaft 52 and the sliding shift sleeve 3 are connected by a spline 61 and a spline 62. The keyway 62 is used for connection. Both spline surfaces 61 and spline groove 62 have play L1. In this embodiment, the main parameters of the transmission are: first gear reduction ratio is 4, second gear reduction ratio is 2; the driven gear 42 has 72 teeth on the engaging tooth B12. The maximum and minimum radii of the annulus containing the engaging tooth B12 are 103 mm and 97 mm respectively. The engaging tooth B12 has only one second contact surface 14, with the following values ​​at a radius of 100 mm: L1 = 2.93 mm, L2 = 8.72 mm, L3 = 0.175 mm, L4 = 2.5 mm. L5 = 4.3 mm, L8 = 4 mm; the sliding shift sleeve 3 is composed of a left half 31 and a right half 32 and is connected by a screw 35 and a positioning pin 36. There are 60 pairs of movable tooth holes 7 at corresponding positions on the left half 31 and the right half 32. These 60 pairs of movable tooth holes 7 are divided into 6 groups, each group consisting of 10 pairs of movable tooth holes 7. Each pair of movable tooth holes 7 contains a pair of movable engagement teeth 71 and a spring C37. During the meshing process, the average acceleration of the movable engagement teeth 71 is 320 m / s^2 and the time is 0.005 seconds.

[0039] Assuming gear shifting occurs at a motor speed of 5000 rpm, the speed difference between the driven gear 42 and the sliding shift sleeve 3 is approximately 21 rpm. Assuming the driven gear 42 accelerates at 60 rpm², the matching time is 0.35 seconds, and the synchronizer synchronization time is 0.355 seconds. The shift control accuracy between the driven gear 42 and the output shaft 52 is approximately between 24.5 and 42.5 rpm. Converted to the engine's shift control accuracy, the control accuracy from second gear to first gear is approximately between 98 and 170 rpm, and the control accuracy from first gear to second gear is approximately between 49 and 85 rpm.

[0040] The above description is merely a preferred embodiment of the present invention and should not be construed as limiting the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. A dog-tooth synchronizer, comprising a driven gear, a synchronizer hub, a sliding shift sleeve, engagement teeth, and an output shaft, wherein the driven gear is rotatably connected to the output shaft and is axially immovable; the synchronizer hub is fixedly connected to the output shaft; the sliding shift sleeve is connected to the synchronizer hub via a spline and is axially reciprocating; multiple engagement teeth are provided on opposite sides of the driven gear and the sliding shift sleeve, forming an engagement tooth pair; the engagement teeth are provided with first and second contact surfaces, the first contact surface being perpendicular to the axis of the output shaft; the second... The two contact surfaces form an angle with the first contact surface, and the extension line of the intersection of the second contact surface and the first contact surface intersects the axis of the output shaft. A play L1 is provided between the two key surfaces of the spline connecting the sliding shift sleeve and the synchronizer hub. Multiple spring holes A are provided in the radial direction of the synchronizer hub. A spring A and a top block A are provided inside each spring hole A. The top of the top block A is trapezoidal and the bottom is rectangular. The sliding shift sleeve has the same number of V-grooves A as the spring holes A. The scanning path of the cross-section of the V-grooves A is parallel to the axis of the output shaft. Its characteristic is... When the second contact surface of the engagement tooth on the driven gear presses against the second contact surface of the engagement tooth on the sliding shift sleeve, its tangential component force forms a torque T1 and acts on the sliding shift sleeve. Under the action of torque T1, the top block A generates a torque T2 on the V-groove A that is equal in magnitude and opposite in direction to T1.

2. The dog-tooth synchronizer according to claim 1, characterized in that: The sliding shift sleeve has multiple movable tooth holes on the same circumference. The cross-sectional scanning path of the movable tooth holes is parallel to the axis of the sliding shift sleeve. Movable engaging teeth and spring C are provided in the movable tooth holes. The movable tooth holes are divided into multiple groups, each group consisting of N movable tooth holes. The relationship between the distance L between two adjacent movable tooth holes in the same group and the tooth pitch L2 of the engaging teeth on the driven gear is: L = L2 × ((N+1) ÷ N). The distance between the movable tooth holes in the same position in each group is an integer multiple of the tooth pitch L2 of the engaging teeth on the driven gear. The movable engaging teeth on the sliding shift sleeve and the engaging teeth on the driven gear form a tooth pair.

3. The dog-tooth synchronizer according to any one of claims 1 or 2, characterized in that: The synchronizer hub has multiple spring holes B in the radial direction. A spring B and a top block B are installed in each spring hole B. The top of the top block B is trapezoidal at the top and rectangular at the bottom. The sliding shift sleeve has two sets of V-grooves B along the axial direction. The scanning path of the cross-section of the V-grooves B is perpendicular to the axis of the sliding shift sleeve. The number of V-grooves B in each set is the same as the number of spring holes B.

4. A transmission, characterized in that: Includes the dog-tooth synchronizer as described in any one of claims 1 to 3.

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