阅读说明：本技术 电动汽车纵向驱动自适应锥度离合自动变速系统 (Longitudinal driving self-adaptive taper clutch automatic speed changing system of electric automobile ) 是由 薛荣生 张引航 陈俊杰 王靖 陈同浩 舒雷 谭志康 邓天仪 邓云帆 梁品权 颜昌 于 2020-12-16 设计创作，主要内容包括：本发明公开了一种电动汽车纵向驱动自适应锥度离合自动变速系统,包括高速挡传动机构、低速挡传动机构、倒挡换挡机构、同轴设置的输入轴和输出轴以及与输入轴平行的副轴,其中,摩擦离合器包括同步转动地套装在螺旋滚道套上的主动摩擦盘和同步转动地套装在超越离合器的内心轮上的从动摩擦盘。采用以上技术方案,不仅能够根据阻力情况自适应换挡,而且结构相对前代产品更为简单、紧凑、可靠,零部件更少,外形尺寸更小,更易于布置,能够大幅降低装配难度和生产制造成本。(The invention discloses a longitudinal driving self-adaptive taper clutch automatic speed changing system of an electric automobile, which comprises a high-speed gear transmission mechanism, a low-speed gear transmission mechanism, a reverse gear shifting mechanism, an input shaft, an output shaft and an auxiliary shaft parallel to the input shaft, wherein a friction clutch comprises a driving friction disc and a driven friction disc, the driving friction disc is sleeved on a spiral roller way sleeve in a synchronous rotating mode, and the driven friction disc is sleeved on an inner core wheel of an overrunning clutch in a synchronous rotating mode. By adopting the technical scheme, the gear shifting device can self-adaptively shift gears according to the resistance condition, has a simpler, more compact and more reliable structure compared with the prior products, has fewer parts and smaller overall dimension, is easier to arrange, and can greatly reduce the assembly difficulty and the production and manufacturing cost.)

1. The utility model provides an electric automobile longitudinal drive self-adaptation tapering separation and reunion automatic transmission system, includes high-speed gear drive mechanism, low-speed gear drive mechanism, reverse gear gearshift, coaxial setting's input shaft (1) and output shaft (3) and countershaft (4) parallel with input shaft (1), its characterized in that: the high-speed gear transmission mechanism comprises a friction clutch (5) and an elastic element group (6) for applying pretightening force to the friction clutch (5), the friction clutch (5) comprises a driving friction disc (5a) and a driven friction disc (5b), the driving friction disc (5a) is sleeved on a spiral roller sleeve (7) in a synchronous rotating mode, the driven friction disc (5b) is sleeved on an inner core wheel (9c) of the overrunning clutch (9) in a synchronous rotating mode, the spiral roller sleeve (7) is sleeved on an input shaft (1) and forms a spiral transmission pair with the input shaft (1) so as to slide along the axial direction of the input shaft (1), and the input shaft (1) can transmit power to the inner core wheel (9c) of the overrunning clutch (9) through the spiral roller sleeve (7), the driving friction disc (5a) and the driven friction disc (5b) in sequence;

the low-speed gear transmission mechanism comprises an inner core wheel sleeve (8) which is rotatably sleeved on the input shaft (1), an overrunning clutch (9) which is sleeved on the inner core wheel sleeve (8) and a countershaft transmission assembly with the countershaft (4), wherein the inner core wheel (9c) and the inner core wheel sleeve (8) rotate synchronously, and the spiral raceway sleeve (7) can transmit power to the inner core wheel sleeve (8) through the countershaft transmission assembly and the overrunning clutch (9) in sequence;

the reverse gear shifting mechanism comprises a middle transmission sleeve (10) forming a spiral transmission pair with the output shaft (3), a reverse gear driven gear (11) sleeved on the middle transmission sleeve (10) and a reverse gear driving gear (12) rotating coaxially with the auxiliary shaft (4), the reverse gear driving gear (12) is meshed with the reverse gear driven gear (11), and the middle transmission sleeve (10) can be combined with one of the inner core wheel sleeve (8) and the reverse gear driven gear (11) under the action of the gear shifting assembly.

2. The longitudinal driving self-adaptive taper clutch automatic speed changing system of the electric automobile according to claim 1, characterized in that: the auxiliary shaft transmission assembly comprises an elastic element driving ring (13) and a first-level speed reduction driving gear (14) which are sleeved on the spiral roller way sleeve (7) and a first-level speed reduction driven gear (15) which is sleeved on the auxiliary shaft (4) in a synchronous rotating mode, the first-level speed reduction driving gear (14) is meshed with the first-level speed reduction driven gear (15), the elastic element driving ring (13) and the spiral roller way sleeve (7) rotate synchronously, and the elastic element driving ring (13) is matched with one end cam profile close to the first-level speed reduction driving gear (14) to form an end face cam transmission pair; the auxiliary shaft (4) is provided with a speed reduction secondary driving tooth (4a), an outer ring (9a) of the overrunning clutch (9) is provided with a speed reduction secondary driven tooth (9b) meshed with the speed reduction secondary driving tooth (4a), and the reverse gear driving gear (12) is sleeved at one end of the auxiliary shaft (4) in a synchronous rotating mode.

3. The longitudinal driving self-adaptive taper clutch automatic speed changing system of the electric automobile according to claim 2, characterized in that: the overrunning clutch (9) further comprises rolling bodies arranged between the outer ring (9a) and the inner core wheel (9c), the inner core wheel (9c) comprises an inner core wheel main body (9c1) and an inner core wheel input sleeve (9c2) which are integrally formed, the driven friction disc (5b) is sleeved on the inner core wheel input sleeve (9c2) in a synchronous rotating mode, and the inner core wheel main body (9c1) is sleeved on the inner core wheel sleeve (8) in a synchronous rotating mode.

4. The longitudinal driving self-adaptive taper clutch automatic speed changing system of the electric automobile according to claim 3, characterized in that: the inner core wheel main body (9c1) is in spline fit with the inner core wheel sleeve (8), the driven friction disc (5b) is in spline fit with the inner core wheel input sleeve (9c2), and the driving friction disc (5a) is welded on the spiral roller way sleeve (7).

5. The longitudinal driving self-adaptive taper clutch automatic speed changing system of the electric automobile according to claim 4, characterized in that: the friction clutch (5) further comprises a driven disc support sleeve (5c) which synchronously rotates with the driven friction disc (5b), and bearings are arranged at the ends, far away from each other, of the driven friction disc (5b) and the driven disc support sleeve (5 c).

6. The longitudinal driving self-adaptive taper clutch automatic speed changing system of the electric automobile according to claim 2, characterized in that: the elastic element driving ring (13) is in key connection with the spiral raceway sleeve (7) and is locked on the spiral raceway sleeve (7) through a plurality of bolts.

7. The longitudinal driving self-adaptive taper clutch automatic speed changing system of the electric automobile according to claim 1, characterized in that: the subassembly of shifting is including can driving middle transmission cover (10) endwise slip's the combination cover of shifting (16) and being used for the drive to shift fork (17) of shifting of combination cover (16), the one end terminal surface that middle transmission cover (10) and interior heart wheel cover (8) are close to each other all is provided with the fender combination tooth (a) that advances of mutual adaptation, the one end terminal surface that combination cover (16) and reverse gear driven gear (11) are close to each other of shifting all is provided with reverse gear combination tooth (b) of mutual adaptation.

8. The longitudinal driving self-adaptive taper clutch automatic speed changing system of the electric automobile according to claim 7, characterized in that: the tooth crest of the forward gear combination tooth (a) and/or the reverse gear combination tooth (b) is a bevel ratchet tooth structure.

9. The longitudinal driving self-adaptive taper clutch automatic speed changing system of the electric automobile according to claim 7, characterized in that: the gear shifting combination sleeve (16) is welded and fixed on the intermediate transmission sleeve (10).

10. The longitudinal driving self-adaptive taper clutch automatic speed changing system of the electric automobile according to claim 1, characterized in that: the periphery of the driving friction disc (5a) is embedded with a plurality of permanent magnets (25), and the inner wall of the shell of the speed changing system is provided with Hall elements matched with the permanent magnets (25).

Technical Field

The invention relates to the technical field of electric automobile transmission systems, in particular to a longitudinal driving self-adaptive taper clutch automatic speed changing system for an electric automobile.

Background

The existing electric vehicle is controlled according to experience completely by a driver under the condition that the driving resistance cannot be accurately known due to the limitation of a transmission structure of the existing electric vehicle in the driving process, so that the condition that the working state of a motor is not matched with the actual driving condition of the vehicle often inevitably occurs, and the motor is locked. Especially, when the vehicle is in low-speed heavy-load conditions such as starting, climbing, headwind and the like, the motor usually needs to work under the conditions of low efficiency, low rotating speed and high torque, the motor is easy to be damaged accidentally, the maintenance and replacement cost is increased, and meanwhile, the endurance mileage of the battery can be directly influenced. For vehicle types with high economic requirements, such as electric logistics vehicles, the traditional variable speed transmission structure obviously cannot well meet the use requirements.

In order to solve the problems, the inventor designs a series of cam self-adaptive automatic speed changing systems, drives the cam by using the driving resistance, achieves the purposes of automatically shifting gears and adaptively matching the vehicle speed output torque according to the driving resistance, and has a good application effect.

However, in the practical application process, the inventor finds that the structure of the adaptive automatic speed changing and self-adapting automatic speed changing system is complex and the number of parts is large due to the fact that the transmission path and the gear shifting path of the existing scheme are complex, so that the assembly difficulty is high, and the cost is high.

Therefore, a set of brand-new longitudinal driving adaptive taper clutch automatic speed change system for the electric automobile is urgently needed to be designed, so that adaptive gear shifting can be performed under the influence of resistance, the structure is compact, parts are few, and the assembly difficulty and the production and manufacturing cost can be reduced.

Disclosure of Invention

In order to solve the technical problems, the invention provides a longitudinal driving self-adaptive taper clutch automatic speed changing system for an electric automobile.

The technical scheme is as follows:

the utility model provides an electric automobile longitudinal drive self-adaptation tapering separation and reunion automatic speed changing system, includes high-speed gear drive mechanism, low-speed gear drive mechanism, reverse gear gearshift, the input shaft and the output shaft of coaxial setting and the countershaft parallel with the input shaft, its main points lie in: the high-speed gear transmission mechanism comprises a friction clutch and an elastic element group for applying pretightening force to the friction clutch, the friction clutch comprises a driving friction disc and a driven friction disc, the driving friction disc is sleeved on a spiral raceway sleeve in a synchronous rotating mode, the driven friction disc is sleeved on an inner core wheel of the overrunning clutch in a synchronous rotating mode, the spiral raceway sleeve is sleeved on an input shaft, a spiral transmission pair is formed between the spiral raceway sleeve and the input shaft and can slide along the axial direction of the input shaft, and the input shaft can transmit power to the inner core wheel of the overrunning clutch through the spiral raceway sleeve, the driving friction disc and the driven friction disc in sequence;

the low-speed gear transmission mechanism comprises an inner core wheel sleeve which is rotatably sleeved on the input shaft, an overrunning clutch which is sleeved on the inner core wheel sleeve and a countershaft transmission assembly with the countershaft, the inner core wheel and the inner core wheel sleeve synchronously rotate, and the spiral raceway sleeve can transmit power to the inner core wheel sleeve through the countershaft transmission assembly and the overrunning clutch in sequence;

the reverse gear shifting mechanism comprises a middle transmission sleeve forming a spiral transmission pair with the output shaft, a reverse gear driven gear sleeved outside the middle transmission sleeve and a reverse gear driving gear coaxially rotating with the auxiliary shaft, the reverse gear driving gear is meshed with the reverse gear driven gear, and the middle transmission sleeve can be combined with one of the inner core wheel sleeve and the reverse gear driven gear under the action of the gear shifting assembly.

By adopting the structure, the actual driving working condition and the motor working condition of the pure electric vehicle can be matched in a self-adaptive manner according to the resistance condition, so that the electric vehicle has strong climbing and heavy-load capacity, meanwhile, the motor is always positioned on a high-efficiency platform, the efficiency of the motor under the climbing and heavy-load conditions is greatly improved, the energy consumption of the motor is reduced, the three-gear speed change function of reverse gear, forward high-speed gear and forward low-speed gear is realized, and particularly, the high-speed and low-speed gear shift speed change of the forward gear can be automatically carried out along with the driving resistance change in a self-adaptive manner under the condition of not cutting off the driving force; and the whole system structure is simpler, more compact and more reliable than the prior products, has fewer parts and smaller overall dimension, is easier to arrange, and can greatly reduce the assembly difficulty and the production and manufacturing cost.

Preferably, the method comprises the following steps: the auxiliary shaft transmission assembly comprises an elastic element driving ring and a speed reduction primary driving gear which are sleeved on the spiral raceway sleeve, and a speed reduction primary driven gear which is sleeved on the auxiliary shaft in a synchronous rotating manner, wherein the speed reduction primary driving gear is meshed with the speed reduction primary driven gear, the elastic element driving ring and the spiral raceway sleeve rotate synchronously, and the elastic element driving ring is matched with one end cam profile close to the speed reduction primary driving gear to form an end face cam transmission pair; the auxiliary shaft is provided with a speed reduction secondary driving tooth, the outer ring of the overrunning clutch is provided with a speed reduction secondary driven tooth meshed with the speed reduction secondary driving tooth, and the reverse gear driving gear is sleeved at one end of the auxiliary shaft in a synchronous rotating mode. With the above structure, the power can be stably and reliably transmitted at a reduced speed, and the transmission efficiency is high.

Preferably, the method comprises the following steps: the overrunning clutch further comprises a rolling body arranged between the outer ring and the inner core wheel, the inner core wheel comprises an inner core wheel main body and an inner core wheel input sleeve which are integrally formed, the driven friction disc is sleeved on the inner core wheel input sleeve in a synchronous rotating mode, and the inner core wheel main body is sleeved on the inner core wheel sleeve in a synchronous rotating mode. By adopting the structure, not only can one part be reduced, the cost is reduced, but also the design is ingenious, and the stability and the reliability of the matching between the parts are improved.

Preferably, the method comprises the following steps: the inner core wheel main body is in spline fit with the inner core wheel sleeve, the driven friction disc is in spline fit with the inner core wheel input sleeve, and the driving friction disc is welded on the spiral roller path sleeve. By adopting the structure, the stability and the reliability of the matching between the parts are ensured, and the assembly is easy.

Preferably, the method comprises the following steps: the friction clutch further comprises a driven disc supporting sleeve which rotates synchronously with the driven friction disc, and bearings are arranged at the ends, far away from each other, of the driven friction disc and the driven disc supporting sleeve. By adopting the structure, the driven friction disc can be reliably positioned and supported, and the stability and the reliability of the friction clutch are improved.

Preferably, the method comprises the following steps: the elastic element driving ring is in key connection with the spiral raceway sleeve and is locked on the spiral raceway sleeve through a plurality of bolts. With the above structure, the elastic element drive ring can be stably and reliably mounted on the spiral raceway sleeve.

Preferably, the method comprises the following steps: the subassembly of shifting is including driving the middle transmission cover axial gliding combination cover of shifting and being used for the drive shift fork of shifting of combination cover of shifting, the preceding fender combination tooth that all is provided with mutual adaptation on the one end terminal surface that middle transmission cover and interior heart-piece cover are close to each other, the combination cover of shifting all is provided with the reverse fender combination tooth of mutual adaptation on the one end terminal surface that reverse gear driven gear is close to each other. By adopting the structure, the structure is simple and reliable, and the gear shifting operation is easy.

Preferably, the method comprises the following steps: the tooth top surfaces of the forward gear combination teeth and/or the reverse gear combination teeth are in a bevel ratchet structure. By adopting the structure, the gear shifting is easier.

Preferably, the method comprises the following steps: the gear shifting combination sleeve is welded and fixed on the intermediate transmission sleeve. With the structure, the gear shifting combination sleeve can be stably and reliably arranged on the intermediate transmission sleeve.

Preferably, the method comprises the following steps: the periphery of the driving friction disc is embedded with a plurality of permanent magnets, and the inner wall of the shell of the speed changing system is provided with a Hall element matched with the permanent magnets. By adopting the structure, the output rotating speed of the forward gear can be monitored in real time.

Compared with the prior art, the invention has the beneficial effects that:

the longitudinal driving self-adaptive taper clutch automatic speed change system of the electric automobile adopting the technical scheme has the advantages of novel structure, ingenious design and easy realization, not only can self-adaptively match the actual driving working condition and the motor working condition of a pure electric vehicle according to the resistance condition, and ensure that the electric automobile has strong climbing and heavy-load capacity and is always positioned on a high-efficiency platform, thereby greatly improving the efficiency of the motor under the climbing and heavy-load conditions, reducing the energy consumption of the motor, having three-gear speed change functions of reverse gear, forward high-speed gear and forward low-speed gear, and particularly being capable of self-adaptively automatically carrying out high-speed and low-speed gear change of the forward gear along with the driving resistance change under the condition of not cutting off the driving force; and the structure is simpler, compact, reliable than the previous generation product, spare part is still less, and overall dimension is littleer, changes to arrange, can reduce the assembly degree of difficulty and production manufacturing cost by a wide margin.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic diagram of a first embodiment of the present invention;

FIG. 3 is a schematic view of a second embodiment of the present invention;

FIG. 4 is a schematic view of the internal structure of the overrunning clutch;

fig. 5 is a development view of the forward gear engaging teeth or the reverse gear engaging teeth.

Detailed Description

The present invention will be further described with reference to the following examples and the accompanying drawings.

As shown in fig. 1, the longitudinal driving adaptive taper clutch automatic speed change system for the electric vehicle mainly comprises a high-speed gear transmission mechanism, a low-speed gear transmission mechanism, a reverse gear shifting mechanism, an input shaft 1 and an output shaft 3 which are coaxially arranged, and a counter shaft 4 parallel to the input shaft 1.

Referring to fig. 1-3, the high-speed gear transmission mechanism includes a friction clutch 5 and an elastic element group 6 for applying a pre-tightening force to the friction clutch 5, the friction clutch 5 includes a driving friction disc 5a synchronously rotatably sleeved on a spiral roller sleeve 7 and a driven friction disc 5b synchronously rotatably sleeved on an inner core wheel 9c of an overrunning clutch 9, the spiral roller sleeve 7 is sleeved on the input shaft 1 and forms a spiral transmission pair with the input shaft 1 so as to be capable of axially sliding along the input shaft 1, and the input shaft 1 is capable of sequentially transmitting power to the inner core wheel 9c of the overrunning clutch 9 through the spiral roller sleeve 7, the driving friction disc 5a and the driven friction disc 5 b.

The driving friction disk 5a is welded on the spiral roller sleeve 7, a spiral transmission pair is formed between the spiral roller sleeve 7 and the input shaft 1, the spiral roller sleeve 7 can slide along the axial direction of the input shaft 1, and the elastic element driving ring 13 is driven to compress the elastic element group 6, so that the driving friction disk 5a and the driven friction disk 5b are formed. Specifically, the screw transmission pair includes an inner screw raceway circumferentially distributed on an inner wall of the screw raceway sleeve 7 and an outer screw raceway circumferentially distributed on an outer wall of the input shaft 1, and a plurality of balls protruding outward are embedded in each outer screw raceway, and each ball can roll in the corresponding inner screw raceway and outer screw raceway. When the helical raceway sleeve rotates relative to the input shaft, it can move axially relative to the input shaft, and thereby the friction clutch 5, i.e., the driving friction disk 5a and the driven friction disk 5b, can be pressed or released, so that the friction clutch 5 is in an engaged or disengaged state.

The elastic element group 6 can apply pre-tightening force to the spiral roller way sleeve 7 to press the driving friction disc 5a and the driven friction disc 5b, so that the friction clutch 5 keeps a combined state. In this embodiment, the elastic element group 6 preferably adopts a disc spring, which is stable and reliable and has low cost.

Further, the friction clutch 5 further includes a driven plate support sleeve 5c which rotates synchronously with the driven friction plate 5b, and bearings are arranged at the ends of the driven friction plate 5b and the driven plate support sleeve 5c which are far away from each other, so as to reliably support the driven friction plate 5b and ensure the stability and reliability of the combination or separation of the friction clutch 5.

Referring to fig. 1-4, the low-speed transmission mechanism includes an inner core wheel sleeve 8 rotatably sleeved on the input shaft 1, an overrunning clutch 9 sleeved on the inner core wheel sleeve 8, and a countershaft transmission assembly having a countershaft 4, the inner core wheel 9c and the inner core wheel sleeve 8 rotate synchronously, and the spiral raceway sleeve 7 can transmit power to the inner core wheel sleeve 8 sequentially through the countershaft transmission assembly and the overrunning clutch 9.

The auxiliary shaft transmission assembly comprises an elastic element driving ring 13 and a first-stage speed reduction driving gear 14 which are sleeved on the spiral roller way sleeve 7 and a first-stage speed reduction driven gear 15 which is sleeved on the auxiliary shaft 4 in a synchronous rotating mode, the elastic element driving ring 13 and the spiral roller way sleeve 7 rotate synchronously, the first-stage speed reduction driving gear 14 is meshed with the first-stage speed reduction driven gear 15, and the elastic element driving ring 13 is matched with one end cam profile close to the first-stage speed reduction driving gear 14 to form an end face cam transmission pair; the auxiliary shaft 4 is provided with a speed reduction secondary driving tooth 4a, an outer ring 9a of the overrunning clutch 9 is provided with a speed reduction secondary driven tooth 9b meshed with the speed reduction secondary driving tooth 4a, and a reverse driving gear 12 is sleeved at one end of the auxiliary shaft 4 in a synchronous rotating manner.

In this embodiment, the elastic element drive ring 13 is fixed to the spiral raceway sleeve 7 by bolts. Not only is convenient to assemble, but also is stable and reliable.

The overrunning clutch 9 further includes rolling bodies disposed between the outer race 9a and the inner core 9c, the inner core 9c includes an integrally formed inner core body 9c1 and an inner core input sleeve 9c2, the driven friction disk 5b is synchronously rotatably fitted over the inner core input sleeve 9c2, and the inner core body 9c1 is synchronously rotatably fitted over the inner core sleeve 8. The inner core wheel main body 9c1 is in spline fit with the inner core wheel sleeve 8, and the driven friction disc 5b is in spline fit with the inner core wheel input sleeve 9c 2.

The inner core wheel sleeve 8 is made of a high-strength anti-torsion material, the inner core wheel 9c is made of a compression-resistant wear-resistant material, specifically, the inner core wheel sleeve 8 is made of alloy steel, and the inner core wheel 9c is made of bearing steel or alloy steel or hard alloy. In this embodiment, the inner core wheel sleeve 8 is preferably made of 20CrMnTi, and has high torsion resistance, low cost and high cost performance, and the inner core wheel 9c is preferably made of GCr15, so that the inner core wheel sleeve has high wear resistance and compression resistance, low cost and high cost performance. The torsion resistance and the pressure resistance of the inner core wheel sleeve 8 are high, the reliability and the stability of transmission can be guaranteed, and the abrasion resistance and the pressure resistance of the inner core wheel 9c are high, so that the inner core wheel sleeve 8 and the inner core wheel 9c are made of two different materials, the production cost is effectively saved, and the service life of the multi-row floating combined type heavy-load overrunning clutch is greatly prolonged.

The rolling bodies distributed along the periphery of each inner core wheel 9c are composed of thick rolling bodies 9d and thin rolling bodies 9e which are alternately arranged, two opposite retainers 9f are arranged on the periphery of the inner core wheel 9c, a circle of annular groove 9f1 is formed in the inner wall of each retainer 9f, and two ends of each thin rolling body 9e are slidably inserted into the corresponding annular grooves 9f1 respectively. By adopting the structure, each thin rolling body 9e can follow up, the overall stability and reliability are improved, and the service life is prolonged.

The outer wall of the outer ring 9a is provided with two-stage speed reduction driven teeth 9b arranged along the circumferential direction. The outer wall of the inner hub sleeve 8 is spline fitted to the inner wall of the inner hub body 9c 1. With the above configuration, power transmission can be reliably performed.

The inner core wheel 9c is provided on the outer periphery thereof with external teeth 9c3 corresponding to the thick rolling elements 9d, and the number of internal splines of the inner core wheel 9c is twice the number of internal teeth 9c 3. The installation and debugging are convenient, so that the problem that the inner rings are not synchronous is solved.

The external teeth 9c3 include a top arc section 9c32, and a short side section 9c31 and a long side section 9c33 respectively located at two sides of the top arc section 9c32, the short side section 9c31 is an inwardly concave arc structure, the long side section 9c33 is an outwardly convex arc structure, and the curvature of the short side section 9c31 is smaller than that of the long side section 9c 33. By adopting the structure, the stability and the reliability of the one-way transmission function can be ensured.

Referring to fig. 1, 3 and 5, the reverse gear shift mechanism includes an intermediate transmission sleeve 10 forming a screw transmission pair with the output shaft 3, a reverse gear driven gear 11 sleeved on the intermediate transmission sleeve 10, and a reverse gear driving gear 12 coaxially rotating with the auxiliary shaft 4, the intermediate transmission sleeve 10 can be combined with one of the inner core wheel sleeve 8 and the reverse gear driven gear 11 under the action of the shift assembly, wherein the structure of the screw transmission pair formed between the intermediate transmission sleeve 10 and the output shaft 3 is the same as the structure of the screw transmission pair formed between the screw raceway sleeve 7 and the input shaft 1.

The gear shifting assembly comprises a gear shifting coupling sleeve 16 capable of driving the intermediate transmission sleeve 10 to axially slide and a gear shifting fork 17 for driving the gear shifting coupling sleeve 16. Specifically, the shift coupling sleeve 16 is fitted over the intermediate transmission sleeve 10 and fixed thereto by welding. The end faces, close to each other, of the intermediate transmission sleeve 10 and the inner core wheel sleeve 8 are provided with forward gear engaging teeth a which are mutually matched, and the end faces, close to each other, of the gear shifting engaging sleeve 16 and the reverse gear driven gear 11 are provided with reverse gear engaging teeth b which are mutually matched.

Further, in order to make it easier to advance the gears, the tooth tops of the forward gear engaging teeth a and/or the reverse gear engaging teeth b are formed in a ratchet structure having a slope.

In this embodiment, the shift fork 17 drives the shift coupling sleeve 16 to make the intermediate transmission sleeve 10 in a forward gear transmission state when the intermediate transmission sleeve is coupled with the forward gear coupling teeth a of the inner hub 8.

The elastic element group 6 applies pressure to the inner plate spiral track sleeve 7 to press the driving friction disc 5a and the driven friction disc 5b of the friction clutch 5, at the moment, the friction clutch 5 is in a combined state under the pressure of the elastic element group 6, and the power is in a high-speed gear power transmission path:

the input shaft 1 → the inner plate helical raceway sleeve 7 → the friction clutch 5 → the inner core wheel 9c → the inner core wheel sleeve 8 → the intermediate transmission sleeve 10 → the output shaft 3 outputs power.

At this time, the elastic element group 6 is not compressed. When the resistance torque transmitted to the friction clutch 5 by the input shaft 1 is larger than or equal to the preset load limit of the friction clutch 5, the inner core wheel cam sleeve 7 compresses the elastic element group 6, a gap is formed between the driving friction disc 5a and the driven friction disc 5b of the friction clutch 5, namely, the friction is separated, and the power is transmitted through the following route instead, namely a low-speed power transmission route:

the input shaft 1 → the inner plate spiral raceway sleeve 7 → the elastic element drive ring 13 → the first reduction driving gear 14 → the first reduction driven gear 15 → the auxiliary shaft 4 → the overrunning clutch 9 → the inner core wheel sleeve 8 → the intermediate transmission sleeve 10 → the output shaft 3 outputs power.

At this time, the elastic element group 6 is compressed. As can be seen from the above transmission path, the present invention forms an automatic transmission mechanism that maintains a certain pressure during operation.

The shift fork 17 drives the shift sleeve 16 to make the shift sleeve 16 and the reverse gear driven gear 11 in reverse gear transmission state when they are combined. Reverse gear power transmission route:

the input shaft 1 → the inner piece spiral raceway sleeve 7 → the elastic element drive ring 13 → the reduction primary drive gear 14 → the reduction primary driven gear 15 → the counter shaft 4 → the reverse drive gear 12 → the reverse driven gear 11 → the shift coupling sleeve 16 → the intermediate transmission sleeve 10 → the output shaft 3 outputs power.

In the embodiment, taking an electric automobile as an example, when the whole automobile is started, the resistance is greater than the driving force, the resistance forces the input shaft 1 to rotate for a certain angle relative to the inner-plate spiral roller sleeve 7, under the action of a spiral transmission pair, the inner-plate spiral roller sleeve 7 compresses the elastic element group 6, the outer friction plate 5c is separated from the driven friction plate 5b, namely, the friction clutch 5 is in a disconnected state, and the power rotates at a low-gear speed; therefore, the low-speed starting is automatically realized, and the starting time is shortened. Meanwhile, the elastic element group 6 absorbs the motion resistance moment energy and stores potential energy for restoring the high-speed gear to transmit power.

After the start is successful, the running resistance is reduced, and when the component force is reduced to be smaller than the pressure generated by the elastic element group 6, the driving friction disc 5a and the driven friction disc 5b of the friction clutch 5 are restored to the close contact state by being pushed by the elastic element group 6 which is compressed by the motion resistance and the pressure is rapidly released, and the power rotates at the high-speed gear speed.

In the driving process, the automatic gear shifting principle is the same as the principle of automatic gear shifting along with the change of the motion resistance, gear shifting is realized under the condition of not cutting off power, the whole vehicle runs stably, safety and low consumption are realized, a transmission route is simplified, and the transmission efficiency is improved.

Finally, it should be noted that the above-mentioned description is only a preferred embodiment of the present invention, and those skilled in the art can make various similar representations without departing from the spirit and scope of the present invention.