A variable speed device, a gearbox

Abstract

The present invention provides a stepless speed change device and a gearbox. The speed change device includes a driving conical disk, at least one first driving conical pulley in contact transmission with the driving conical disk, a driven conical disk, at least one second driving conical pulley in contact transmission with the driven conical disk, and a transmission mechanism. Wherein the first driving conical pulley can be displaced between the maximum circumference and the minimum circumference of the driving conical disk, the second driving conical pulley can be displaced between the maximum circumference and the minimum circumference of the driven conical disk, and the first driving conical pulley is connected to the second driving conical pulley through the transmission mechanism. The present invention has the advantages of large torque transmission, high reliability and low cost at the same time.

Description

Technical Field

[0001] The present invention belongs to the technical field of variable speed, and particularly relates to a continuously variable transmission device and a gearbox. Background Art

[0002] The gearboxes of fuel vehicles generally include MT (manual transmission), AMT (automated mechanical transmission), AT (automatic transmission), CVT (continuously variable transmission), and DCT (dual clutch transmission). Among them, CVT (continuously variable transmission) is used by more and more vehicles due to its excellent shift smoothness and fuel economy.

[0003] The existing CVT continuously variable transmission devices mainly include four types: belt (chain) CVT, wheel CVT, ring CVT, and ball CVT.

[0004] In the belt (chain) CVT, there are defects such as a small contact area between the steel belt (or steel chain) and the transmission conical surface, easy slipping, extremely easy wear of the steel belt (or steel chain) resulting in breakage in extreme conditions, limited transmitted torque, and relatively high cost of the steel belt (steel chain).

[0005] In the wheel CVT, there are defects such as complex shapes of the driving and driven wheels and the variable speed rollers, high machining accuracy requirements, complex control of the angles of the variable speed rollers, and high costs.

[0006] In the ring CVT, there are defects such as a very small friction contact area of the variable speed ring, limited transmitted torque, and inability to be applied to large vehicles.

[0007] The ball CVT is a line contact, and its force transmission contact area is much smaller than the above-mentioned forms of solutions. The machining accuracy requirements of the transmission components are higher, and its application scenarios are greatly limited.

[0008] The existing CTV continuously variable transmission devices all have the defect of being unable to balance the contradictions among "transmitted torque", "reliability", and "cost". Based on this, the present invention provides a brand-new continuously variable transmission device and a gearbox to solve the problems in the prior art. Summary of the Invention

[0009] Aiming at the defects of the prior art, the present invention provides a variable speed device and a gearbox, which have the advantages of large transmitted torque, high reliability, and low cost at the same time.

[0010] To achieve the above object, on the one hand, the present invention provides a variable speed device, which includes:

[0011] A driving conical disk;

[0012] At least one first transmission conical wheel in contact with the driving conical disk for transmission;

[0013] The first driving conical pulley can be displaced between the maximum circumference and the minimum circumference of the driving conical disc;

[0014] Driven conical disc;

[0015] At least one second driving conical pulley in contact transmission with the driven conical disc;

[0016] The second driving conical pulley can be displaced between the maximum circumference and the minimum circumference of the driven conical disc;

[0017] And

[0018] A transmission mechanism, the first driving conical pulley is connected to the second driving conical pulley through the transmission mechanism.

[0019] In the above technical solution of the present invention, there is a frictional contact between the driving conical disc and the first driving conical pulley. The driving conical disc has a series of relatively large circumferential contact friction surfaces, and the first driving conical pulley has relatively small circumferential contact friction surfaces. The driving conical disc rotates at a certain speed. When the first driving conical pulley is located at the smaller circumference of the driving conical disc, the rotational speed obtained by the first driving conical pulley is smaller. When the first driving conical pulley is located at the larger circumference of the driving conical disc, the rotational speed obtained by the first driving conical pulley is larger.

[0020] Similarly, there is also a frictional contact between the driven conical disc and the second driving conical pulley. The driven conical disc has a series of relatively large circumferential contact friction surfaces, and the second driving conical pulley has relatively small circumferential contact friction surfaces. The rotational speed of the first driving conical pulley is transmitted to the second driving conical pulley through the transmission mechanism. Assuming that the rotational speed of the first driving conical pulley does not change, then when the second driving conical pulley is located at the smaller circumference of the driven conical disc, the speed transmitted from the second driving conical pulley to the driven conical disc is larger. When the second driving conical pulley is located at the larger circumference of the driven conical disc, the speed transmitted from the second driving conical pulley to the driven conical disc is smaller.

[0021] Specifically, the displacement of the first driving conical pulley relative to the driving conical disc can be carried out simultaneously with the displacement of the second driving conical pulley relative to the driven conical disc. That is, when the driving conical disc rotates at a certain speed, when the first driving conical pulley is located at the minimum circumference of the driving conical disc and the second driving conical pulley is located at the maximum circumference of the driven conical disc at the same time, the rotational speed of the driven conical disc is the smallest; when the first driving conical pulley is located at the maximum circumference of the driving conical disc and the second driving conical pulley is located at the minimum circumference of the driven conical disc at the same time, the rotational speed of the driven conical disc is the largest.

[0022] By adjusting the contact positions of the first driving conical pulley and the driving conical disc, and the contact positions of the second driving conical pulley and the driven conical disc, the stepless speed change process of the entire device is carried out.

[0023] According to another specific embodiment of the present invention, the axis of the first driving conical pulley is perpendicular to the axis of the driving conical disc, and the axis of the second driving conical pulley is perpendicular to the axis of the driven conical disc.

[0024] Preferably, the axes of the driving conical disc and the driven conical disc are parallel or collinear.

[0025] According to another specific embodiment of the present invention, both the driving conical disc and the first driving bevel gear can perform axial displacement, and both the driven conical disc and the second driving bevel gear can perform axial displacement.

[0026] According to another specific embodiment of the present invention, the transmission mechanism at least includes a gear / sprocket / pulley transmission group.

[0027] The gear / sprocket / pulley transmission group in this solution can transmit power.

[0028] According to another specific embodiment of the present invention, the transmission mechanism further includes a first driving bevel gear, a second driving bevel gear, a first driven bevel gear, a second driven bevel gear, a first lead screw and a second lead screw;

[0029] The first driving bevel gear and the second driving bevel gear rotate synchronously;

[0030] The first driven bevel gear meshes with the first driving bevel gear. The first lead screw is connected to the first driven bevel gear and rotates with the first driven bevel gear. The first driven bevel wheel is arranged to be driven by the first lead screw and can be displaced along the axial direction of the first lead screw;

[0031] The second driven bevel gear meshes with the second driving bevel gear. The second lead screw is connected to the second driven bevel gear and rotates with the second driven bevel gear. The second driven bevel wheel is arranged to be driven by the second lead screw and can be displaced along the axial direction of the second lead screw.

[0032] In this solution, the synchronous rotation of the first driving bevel gear and the second driving bevel gear can synchronously drive the rotation of the first driven bevel gear and the second driven bevel gear. Among them, the same-direction rotation or reverse rotation of the first lead screw and the second lead screw can be realized according to whether the first driving bevel gear and the second driving bevel gear are mirror-distributed or array-distributed.

[0033] In the solution of the linkage between the first lead screw and the second lead screw, preferably, the first lead screw and the second lead screw rotate in the reverse direction to finally drive the first driving bevel wheel and the second driving bevel wheel to realize a fast adjustment process of one rising and one falling, and can cover the designed maximum transmission efficiency.

[0034] According to another specific embodiment of the present invention, the transmission mechanism further includes a first frame, a second frame, a first spline shaft, a second spline shaft, a first transmission gear group and a second transmission gear group;

[0035] The first spline shaft is parallel to the first lead screw. The first frame is arranged on the first lead screw. One transmission gear in the first transmission gear set is slidably sleeved on the first spline shaft and rotatably arranged on the first frame. The other transmission gear in the first transmission gear set rotates synchronously with the first transmission cone pulley;

[0036] The second spline shaft is parallel to the second lead screw. The second frame is arranged on the second lead screw. One transmission gear in the second transmission gear set is slidably sleeved on the second spline shaft and rotatably arranged on the second frame. The other transmission gear in the second transmission gear set rotates synchronously with the second transmission cone pulley;

[0037] Two transmission wheels in the gear / sprocket / belt pulley transmission set are respectively arranged on the first spline shaft and the second spline shaft.

[0038] According to another specific embodiment of the present invention, there are provided more than two first transmission cone pulleys and second transmission cone pulleys. The more than two first transmission cone pulleys are distributed in an array or relatively centered on the axis of the driving cone disc. The more than two second transmission cone pulleys are distributed in an array or relatively centered on the axis of the driven cone disc.

[0039] The relative distribution here is, for example, distributed in a grouped manner or distributed according to other rules.

[0040] According to another specific embodiment of the present invention, there are provided more than two first driven bevel gears having the same number as the first transmission cone pulleys. The more than two first driven bevel gears are all meshed with the first driving bevel gear; there are provided more than two second driven bevel gears having the same number as the second transmission cone pulleys. The more than two second driven bevel gears are all meshed with the second driving bevel gear.

[0041] In this solution, a group of first driving bevel gears and second driving bevel gears can drive the rotation of different first driven bevel gears and second driven bevel gears, and finally realize the adjustment of the contact positions of different first transmission cone pulleys and second transmission cone pulleys by driving the rotation of multiple lead screws.

[0042] According to another specific embodiment of the present invention, the first lead screw is replaced with a first speed adjustment slider with end face threads, and the second lead screw is replaced with a second speed adjustment slider with end face threads; the transmission modes of the first speed adjustment slider and the first frame, and the second speed adjustment slider and the second frame in this solution are end face thread pairs.

[0043] On the other hand, the present invention provides a gearbox, which includes at least one set of front-speed transmission devices, and this gearbox is a continuously variable transmission.

[0044] Among the structures with two or more sets of speed change devices, two adjacent conical discs are respectively the driving conical disc and the driven conical disc. For example, in a transmission with three conical discs, namely the first conical disc, the second conical disc, and the third conical disc, the first conical disc and its mating structure, and the second conical disc and its mating structure form the first set of speed change devices. At the same time, the second conical disc and its mating structure, and the third conical disc and its mating structure form the second set of speed change devices.

[0045] The present invention has the following beneficial effects:

[0046] The present invention does not use flexible transmission elements such as steel belts, steel chains, or belts, can withstand large torque loads, and there is no risk of breakage of flexible transmission elements;

[0047] Compared with other technical solutions in the prior art, the friction contact area between the friction transmission pairs (the friction contact between the driving conical disc and the first transmission conical wheel, and the friction contact between the driven conical disc and the second transmission conical wheel) in the present invention is large, the transmission is reliable, and it is not easy to slip and wear;

[0048] The present invention uses a lead screw pair or an end face thread pair as the speed regulation operation structure, can achieve pure mechanical speed regulation control, does not require precision components such as hydraulic solenoid valve spool boxes, has a low requirement for the cleanliness of the oil, and can greatly reduce the problem of solenoid valve core failure caused by oil impurities;

[0049] The present invention does not require the metal transmission belt with complex process and high cost in the chain type CVT continuously variable transmission, can transmit a large torque, and at the same time has the advantages of simple structure and low manufacturing cost;

[0050] The present invention can significantly reduce the number of components and costs while improving the service life and reliability of the transmission, significantly reducing the overall cost of the transmission, and is conducive to large-scale market promotion and application.

[0051] The following further describes the present invention in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 is a schematic diagram of the principle of Embodiment 1 of the speed change device of the present invention, showing a low-speed state;

[0053] Figure 2 is a schematic diagram of the principle of Embodiment 1 of the speed change device of the present invention, showing a high-speed state;

[0054] Figure 3 is a schematic structural diagram of Embodiment 1 of the speed change device of the present invention;

[0055] Figure 4 is a schematic diagram of the mechanism of Embodiment 2 of the transmission of the present invention;

[0056] Figure 5 isFigure 4 Enlarged view of the middle transmission mechanism part;

[0057] Figure 6 It is a schematic structural diagram of Embodiment 2 of the speed change device of the present invention;

[0058] Figure 7 is Figure 4 Schematic diagram of the contact positions of multiple first transmission cone pulleys and second transmission cone pulleys in the low and medium speed states;

[0059] Figure 8 is Figure 4 Schematic diagram of the contact positions of multiple first transmission cone pulleys and second transmission cone pulleys in the high speed state;

[0060] Figure 9 It is a schematic structural diagram of another transmission mechanism in Embodiment 2 of the transmission of the present invention;

[0061] Figure 10 It is a schematic diagram of the mechanism of Embodiment 3 of the transmission of the present invention;

[0062] Figure 11 It is a schematic diagram of the mechanism of Embodiment 4 of the transmission of the present invention. Detailed implementation manners

[0063] In order to be able to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention will be further described in detail below in conjunction with the drawings and specific implementation manners. It should be noted that, without conflict, the embodiments of the present application and the features in the embodiments can be combined with each other.

[0064] Many specific details are set forth in the following description in order to fully understand the present invention. However, the present invention can also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the limitations of the specific embodiments disclosed below.

[0065] Example 1

[0066] A speed change device, as Figure 1 shown in FIG. -3, includes a driving cone disk 101, a first transmission cone pulley 102, a driven cone disk 103, a second transmission cone pulley 104 and a transmission mechanism 105.

[0067] Among them, the driving cone disk 101 rotates at a set input speed, the first transmission cone pulley 102 is in contact with the driving cone disk 101 for transmission, the second transmission cone pulley 104 is in contact with the driven cone disk 103 for transmission, the first transmission cone pulley 102 is connected to the second transmission cone pulley 104 through the transmission mechanism 105, wherein the axis of the first transmission cone pulley 102 is perpendicular to the axis of the driving cone disk 101, and the axis of the second transmission cone pulley 104 is perpendicular to the axis of the driven cone disk 103, asFigure 1 as shown;

[0068] Furthermore, the axes of the driving conical disc 101 and the driven conical disc 103 are collinear (coaxial).

[0069] The transmission mechanism 105 in this embodiment can be a gear transmission group, a sprocket transmission group, or a pulley transmission group. For example Figure 1 the shown gear transmission group.

[0070] Among them, the first transmission conical pulley 102 can be displaced between the maximum circumference and the minimum circumference of the driving conical disc 101. Specifically, as Figure 1 , 2 shown, the driving conical disc 101 can perform an axial displacement to the right, and the first transmission conical pulley 102 can perform an axial displacement upward and always maintain the contact friction transmission between the driving conical disc 101 and the first transmission conical pulley 102.

[0071] The second transmission conical pulley 104 can be displaced between the maximum circumference and the minimum circumference of the driven conical disc 103. Specifically, as Figure 1 , Figure 2 shown, the driven conical disc 103 can perform an axial displacement to the right, and the second transmission conical pulley 104 can perform an axial displacement downward and always maintain the contact friction transmission between the driven conical disc 103 and the second transmission conical pulley 104.

[0072] In this embodiment, the driving conical disc 101 rotates at a certain speed. When the first transmission conical pulley 102 is located at the smaller circumference of the driving conical disc 101, as Figure 1 shown, the rotational speed obtained by the first transmission conical pulley 102 is smaller. When the first transmission conical pulley 102 is located at the larger circumference of the driving conical disc 101, as Figure 2 shown, the rotational speed obtained by the first transmission conical pulley 102 is larger.

[0073] For example, if the first transmission conical pulley 102 transmits power to the second transmission conical pulley 104 through a gear transmission group with a transmission ratio of 1, then when the second transmission conical pulley 104 is located at the smaller circumference of the driven conical disc 103, the speed transmitted from the second transmission conical pulley 104 to the driven conical disc 103 is larger. When the second transmission conical pulley 104 is located at the larger circumference of the driven conical disc 103, the speed transmitted from the second transmission conical pulley 104 to the driven conical disc 103 is smaller.

[0074] In this embodiment, by adjusting the contact positions of the first transmission conical pulley 102 with the driving conical disc 101 and the contact position of the second transmission conical pulley 104 with the driven conical disc 103, the stepless speed change process of the entire device is carried out.

[0075] Example 2

[0076] This embodiment provides a transmission, as Figure 4 shown in FIG. -9, including an input shaft 201, an output shaft 202, a driving cone disk 203, more than two first driving cone wheels 204, a driven cone disk 205, more than two second driving cone wheels 206, and more than two transmission mechanisms 207, wherein the number of the first driving cone wheels 204, the second driving cone wheels 206, and the transmission mechanisms 207 is the same and they correspond to each other one by one.

[0077] In this embodiment, for example, eight first driving cone wheels 204 and eight second driving cone wheels 206 are provided. Among them, the eight first driving cone wheels 204 are arrayed in the axial direction around the axis of the driving cone disk 203, and the eight second driving cone wheels 206 are arrayed in the axial direction around the axis of the driven cone disk 205. Based on the same principle as in Embodiment 1, combined with Figure 7 , 8 shown in FIG., by adjusting the contact position between the first driving cone wheel 204 and the driving cone disk 203 and / or the contact position between the second driving cone wheel 206 and the driven cone disk 205, different and continuously variable rotational speeds of the driven cone disk 205 are obtained, realizing its stepless speed change function.

[0078] The following takes one of the transmission mechanisms 207 as an example to introduce the transmission process in detail:

[0079] As Figure 4 , 5 shown in FIG., the transmission mechanism 207 includes a first driving bevel gear 208, a second driving bevel gear 209, a first driven bevel gear 210, a second driven bevel gear 211, a first lead screw 212, a second lead screw 213, a first frame 214, a second frame 215, a first spline shaft 216, a second spline shaft 217, a first transmission gear set 218, a second transmission gear set 219, and a third transmission gear set 220.

[0080] Among them, the first driving bevel gear 208 and the second driving bevel gear 209 rotate synchronously, and preferably they are fixed together as a whole;

[0081] The first driven bevel gear 210 meshes with the first driving bevel gear 208. A connection is provided between the first lead screw 212 and the first driven bevel gear 210, and the first lead screw 212 rotates with the first driven bevel gear 210. The second driven bevel gear 211 meshes with the second driving bevel gear 209. A connection is provided between the second lead screw 213 and the second driven bevel gear 211, and the second lead screw 213 rotates with the second driven bevel gear 211;

[0082] The first spline shaft 216 is parallel to the first lead screw 212. The first frame 214 is arranged on the first lead screw 212 to form a nut-screw pair. One transmission gear in the first transmission gear set 219 is slidably sleeved on the first spline shaft 216 and rotatably arranged on the first frame 214, so as to form synchronous rotation between the one transmission gear and the first spline shaft 216 while being able to relatively slide. Another transmission gear in the first transmission gear set 218 and the first transmission cone pulley 204 rotate synchronously;

[0083] The second spline shaft 217 is parallel to the second lead screw 213. The second frame 215 is arranged on the second lead screw 213 to form a nut-screw pair. One transmission gear in the second transmission gear set is slidably sleeved on the second spline shaft 217 and rotatably arranged on the second frame 215, so as to form synchronous rotation between the one transmission gear and the second spline shaft 217 while being able to relatively slide. Another transmission gear in the second transmission gear set 219 and the second transmission cone pulley 206 rotate synchronously;

[0084] Two transmission gears in the third transmission gear set 220 are respectively arranged on the first spline shaft 216 and the second spline to rotationally transmit power.

[0085] In this embodiment, the distance between the driving cone disk 203 and the driven cone disk 205 is preferably a constant value. They slide synchronously to the left or right. When the first lead screw 212 in the same transmission mechanism 207 rises, the second lead screw 213 descends, or vice versa.

[0086] The power transmission process in this embodiment is as follows:

[0087] Input shaft 201 → Driving cone disk 203 → First transmission cone pulley 204 → First transmission gear set 218 → First spline shaft 216 → Third transmission gear set 220 → Second spline shaft 217 → Second transmission gear set 219 → Second transmission cone pulley 206 → Driven cone disk 205 → Output shaft 202.

[0088] The preferred speed change process in this embodiment is (taking the adjustment from the highest speed to the lowest speed as an example):

[0089] The driving cone disc 203 and the driven cone disc 205 slide to the right under the drive of the hydraulic cylinder 228 and the hydraulic cylinder 318 respectively, while driving the first driving bevel gear 208 and the second driving bevel gear 209 to rotate → the first driven bevel gear 210 and the second driven bevel gear 211 reverse → the first screw rod 212 and the second screw rod 213 reverse → the first frame 214 descends, and the second frame 215 rises → the first transmission cone wheel 204 descends while maintaining contact friction with the driving cone disc 203, and the second transmission cone wheel 206 rises while maintaining contact friction with the driven cone disc 205 → the contact position of the first transmission cone wheel 204 and the driving cone disc 203 changes, and the contact position of the second transmission cone wheel 206 and the driven cone disc 205 changes → the rotation speed decreases.

[0090] In other examples of the present invention, different numbers of first transmission cone wheels 204 and second transmission cone wheels 206 can be designed according to design requirements, such as Figure 9 shown.

[0091] In this embodiment, the Figure 4 The other components and connection relationships involved are applicable to the prior art. For example, the active cone disc 203 and the input shaft 201 are connected by a spline sleeve 221, and there is a transmission structure and a differential 222 between the driven cone disc 205 and the output shaft 202, as well as the related clutch 223, clutch input shaft 224, reverse gear 225, synchronizer slip ring 226 and starting forward gear 227.

[0092] Example 3

[0093] This embodiment provides a transmission, such as Figure 10 As shown, the difference between this embodiment and embodiment 2 is that the first screw rod is replaced by a first speed regulating slider 301 with an end face thread in the transmission mechanism to form an end face thread pair between the first speed regulating slider 301 and the first frame 302, and the second screw rod is replaced by a second speed regulating slider 303 with an end face thread to form an end face thread pair between the second speed regulating slider 303 and the second frame 304.

[0094] Example 4

[0095] This embodiment provides a transmission, such as Figure 10 As shown, the difference between this embodiment and embodiment 3 is that the input shaft of the active cone disc and the output shaft of the driven cone disc are arranged in parallel to form a vertically parallel structure, and other transmission structures are adaptively adjusted, which will not be described in detail here.

[0096] This embodiment can effectively save lateral space and is particularly suitable for large torque variable speed output occasions.

[0097] The power transmission process in this embodiment is as follows:

[0098] Input shaft 401 → First transmission gear set 418 → Driving cone disc 403 → First transmission cone pulley 404 → Second transmission gear set 419 → First spline shaft 416 → Third transmission gear set 420 → Fourth transmission gear set 421 → Fifth transmission gear set 422 → Second spline shaft 417 → Sixth transmission gear set 423 → Second transmission cone pulley 406 → Driven cone disc 405 → Output shaft 402.

[0099] Although the present invention is disclosed above in preferred embodiments, it is not intended to limit the scope of implementation of the present invention. Any ordinary person skilled in the art can make some improvements without departing from the scope of the present invention. That is, all equivalent improvements made in accordance with the present invention should be covered by the scope of the present invention.

Claims

1. A speed change device, which comprises: a driving cone disk; at least one first driving cone pulley in contact transmission with the driving cone disk; the first driving cone pulley is capable of shifting between the maximum circumference and the minimum circumference of the driving cone disk; a driven cone disk; at least one second driving cone pulley in contact transmission with the driven cone disk; the second driving cone pulley is capable of shifting between the maximum circumference and the minimum circumference of the driven cone disk; and a transmission mechanism, the first driving cone pulley is connected to the second driving cone pulley through the transmission mechanism; the transmission mechanism further includes a first driving bevel gear, a second driving bevel gear, a first driven bevel gear, a second driven bevel gear, a first lead screw and a second lead screw; the first driving bevel gear and the second driving bevel gear rotate synchronously; the first driven bevel gear meshes with the first driving bevel gear, the first lead screw is connected to the first driven bevel gear and rotates with the first driven bevel gear, and the first driving cone pulley is arranged to be driven by the first lead screw and capable of shifting along the axial direction of the first lead screw; the second driven bevel gear meshes with the second driving bevel gear, the second lead screw is connected to the second driven bevel gear and rotates with the second driven bevel gear, and the second driving cone pulley is arranged to be driven by the second lead screw and capable of shifting along the axial direction of the second lead screw.

2. The speed change device according to claim 1, wherein, the axis of the first driving cone pulley is perpendicular to the axis of the driving cone disk, and the axis of the second driving cone pulley is perpendicular to the axis of the driven cone disk.

3. The speed change device according to claim 2, wherein, both the driving cone disk and the first driving cone pulley are capable of axial displacement, and both the driven cone disk and the second driving cone pulley are capable of axial displacement.

4. The speed change device according to claim 1, wherein, the transmission mechanism at least includes a gear / sprocket / belt pulley transmission group.

5. The speed change device according to claim 1, wherein, the transmission mechanism further includes a first frame, a second frame, a first spline shaft, a second spline shaft, a first transmission gear group and a second transmission gear group; the first spline shaft is parallel to the first lead screw, the first frame is arranged on the first lead screw, one transmission gear in the first transmission gear group is slidably sleeved on the first spline shaft and rotatably arranged on the first frame, and the other transmission gear in the first transmission gear group rotates synchronously with the first driving cone pulley; the second spline shaft is parallel to the second lead screw, the second frame is arranged on the second lead screw, one transmission gear in the second transmission gear group is slidably sleeved on the second spline shaft and rotatably arranged on the second frame, and the other transmission gear in the second transmission gear group rotates synchronously with the second driving cone pulley; two transmission wheels in the gear / sprocket / belt pulley transmission group are respectively arranged on the first spline shaft and the second spline shaft.

6. The speed change device according to claim 1, It is characterized in that there are more than two of the first driving bevel gears and the second driving bevel gears, and the more than two first driving bevel gears are arranged in an array or relatively distributed around the axis of the driving cone disk, and the more than two second driving bevel gears are arranged in an array or relatively distributed around the axis of the driven cone disk.

7. The speed change device according to claim 6, It is characterized in that there are more than two first driven bevel gears with the same number as the first driving bevel gears, and the more than two first driven bevel gears are all meshed with the first driving bevel gear; there are more than two second driven bevel gears with the same number as the second driving bevel gears, and the more than two second driven bevel gears are all meshed with the second driving bevel gear.

8. The speed change device according to claim 7, It is characterized in that the first lead screw is replaced by a first speed adjustment slider with end face threads, and the second lead screw is replaced by a second speed adjustment slider with end face threads.

9. A gearbox, which comprises at least one set of the speed change device according to any one of claims 1-8.

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