阅读说明：本技术 一种换挡机构、变速机构和动力输出机构 (Gear shifting mechanism, speed change mechanism and power output mechanism ) 是由 李平 冯伟 张先锋 张涛 周玉华 湛小梅 李亚丽 曹中华 于 2020-12-02 设计创作，主要内容包括：本发明公开了一种换挡机构,包括动力输入轴和套接固定在动力输入轴上的传动套,传动套上设置有刚性传动齿轮和换挡环,动力输入轴的圆周表面设置有传动槽,传动套贯穿设置有限位孔,传动槽内搁置有可活动并部分穿过限位孔的换挡钢球。当动力输入轴运转时,换挡球受到离心力的作用脱离动力输入轴,动力输入轴和刚性传动齿轮处于分离状态,不传递动力；在需要换挡时,横向移动换挡环将换挡球压入传动槽中,动力输入轴和刚性传动齿轮传递动力,退回空挡后,由回位弹簧将换挡环推回原位,这时该换挡机构又处于空挡状态,该机构减少了换挡过程中拉离合器浪费的时间,从根本上解决了因用户操作原因导致的变速箱换挡机构或者变速箱齿轮的人为损坏或报废。(The invention discloses a gear shifting mechanism which comprises a power input shaft and a transmission sleeve fixedly sleeved on the power input shaft, wherein a rigid transmission gear and a gear shifting ring are arranged on the transmission sleeve, a transmission groove is formed in the circumferential surface of the power input shaft, a limiting hole is formed in the transmission sleeve in a penetrating mode, and a gear shifting steel ball which can move and partially penetrates through the limiting hole is placed in the transmission groove. When the power input shaft runs, the gear shifting ball is separated from the power input shaft under the action of centrifugal force, and the power input shaft and the rigid transmission gear are in a separated state and do not transmit power; when gear shifting is needed, the gear shifting ball is pressed into the transmission groove by transversely moving the gear shifting ring, the power input shaft and the rigid transmission gear transmit power, the gear shifting ring is pushed back to the original position by the return spring after returning to the neutral position, and the gear shifting mechanism is in the neutral position state.)

1. The utility model provides a gearshift, includes power input shaft (1) and cup joints to be fixed transmission cover (2) on power input shaft (1), fixedly connected with rigidity drive gear (3), characterized by on transmission cover (2): the transmission sleeve (2) is further sleeved with a shifting ring (4) capable of moving transversely, a plurality of transmission grooves (5) arranged circumferentially are formed in the surface of the power input shaft (1), a limiting hole (6) located above the transmission grooves (5) penetrates through the transmission sleeve (2), a shifting ball (7) which can move and partially penetrates through the limiting hole (6) is placed in the transmission grooves (5), and the shifting ring (4) is located on one side of the limiting hole (6); and a return spring (8) sleeved on the transmission sleeve (2) is clamped between the gear shifting ring (4) and the rigid transmission gear (3).

2. The shift mechanism and transmission of claim 1 wherein: one side of the gear shifting ring (4) and a limit cavity (9) extending axially is arranged between the transmission sleeve (2), the bottom of the limit cavity (9) is integrally provided with an extrusion part (10) facing the limit hole (6) in an inclined mode, and the height of the limit cavity (9) is smaller than the diameter of the gear shifting ball (7).

3. The shift mechanism and transmission of claim 1 wherein: the gear shifting ring (4) is connected with a shifting fork (11) which extends outwards.

4. The shift mechanism of claim 1, wherein: a transition groove (12) is further arranged between two adjacent transmission grooves (5) for connection, and the depth of the transition groove (12) is smaller than that of the transmission groove (5).

5. A transmission mechanism using the gear shift mechanism according to any one of claims 1 to 4, characterized in that: the gear shifting mechanism comprises an intermediate shaft (13) and a power output shaft (14) which are arranged in parallel with the power input shaft (1), wherein the axes of the power input shaft (1), the intermediate shaft (13) and the power output shaft (14) are arranged in an equilateral triangle, four groups of gear shifting mechanisms are arranged outside the power input shaft (1), and the four groups of gear shifting mechanisms are respectively arranged on the power input shaft (1) in a pairwise opposite mode;

the transmission sleeve (2) comprises a first transmission sleeve, a second transmission sleeve, a third transmission sleeve and a fourth transmission sleeve which are sequentially arranged from left to right, and the rigid transmission gear (3) comprises a first output gear (301) arranged at the left end of the first transmission sleeve, a second output gear (302) arranged at the right end of the second transmission sleeve, a third output gear (303) arranged at the left end of the third transmission sleeve and a fourth output gear (304) arranged at the right end of the fourth transmission sleeve;

a first intermediate transmission gear (130), a second intermediate transmission gear (131), a third shifting fork (132), a third intermediate transmission gear (133), a fourth intermediate transmission gear (134), a fifth intermediate transmission gear (135) and a sixth intermediate transmission gear (136) are sequentially arranged on the intermediate shaft (13) from left to right, the first intermediate transmission gear (130), the fourth intermediate transmission gear (134), the fifth intermediate transmission gear (135) and the sixth intermediate transmission gear (136) are all fixedly connected with the intermediate shaft (13), the third fork (132) is clamped between the second intermediate transmission gear (131) and the third intermediate transmission gear (133) and is integrally arranged, the second intermediate transmission gear (131) and the third intermediate transmission gear (133) are fixedly connected to the intermediate shaft (13) in the radial direction and are connected to the intermediate shaft (13) in an axial sliding manner;

a first output gear (140), a first chain wheel (141), a second output gear (142), a third output gear (143) and a fourth output gear (144) are sequentially sleeved and fixed on the power output shaft (14) from left to right;

the first output gear (301) is meshed with the first intermediate transmission gear (130), the second output gear (302) is meshed with the fourth intermediate transmission gear (134) and the fourth output gear (144), the third output gear (303) is meshed with the fourth intermediate transmission gear (134) and the fourth output gear (144), the fourth output gear (304) is meshed with the sixth intermediate transmission gear (136), the second intermediate transmission gear (131) is meshed with the first output gear (140), the third intermediate transmission gear (133) is meshed with the second output gear (142), the fourth intermediate transmission gear (134) is meshed with the third output gear (143), and the fifth intermediate transmission gear (135) is meshed with the fourth output gear (144).

6. The gearshift mechanism of claim 5, wherein: the gear shifting ring (4) comprises a first gear shifting ring (401) arranged at the right end of the first transmission sleeve, a second gear shifting ring (402) arranged at the left end of the second transmission sleeve, a third gear shifting ring (403) arranged at the right end of the third transmission sleeve and a fourth gear shifting ring (404) arranged at the left end of the fourth transmission sleeve, wherein a first shifting fork (110) is clamped between the first gear shifting ring (401) and the second gear shifting ring (402), and a second shifting fork (111) is clamped between the third gear shifting ring (403) and the fourth gear shifting ring (404);

the return spring (8) includes a first return spring (801) disposed between the first shift ring (401) and the first output gear (301), a second return spring (802) disposed between the second shift ring (402) and the second output gear (302), a third return spring (803) disposed between the third shift ring (403) and the third output gear (303), and a fourth return spring (804) disposed between the fourth shift ring (404) and the fourth output gear (304).

7. A power output mechanism using the speed change mechanism according to claim 5 or 6, characterized in that: comprises a second chain wheel (15), the second chain wheel (15) is connected with the first chain wheel (141) through a matched chain (16); second sprocket (15) cup joints fixed mounting on power output tube (17) that both ends symmetry opening set up about one, output semi-axis (19) that each other becomes the mirror image setting are installed respectively to the both ends opening of power output tube (17), be provided with slide (20) of a plurality of axial trends in power output tube (17), output semi-axis (19) insert the tip of power output tube (17) is provided with hemisphere motion portion (21), division board (18) be provided with sphere recess (22) that hemisphere motion portion (21) suited, middle part on power output tube (17) is provided with division board (18), the surperficial arch of hemisphere motion portion (21) is provided with the embedding transmission ball (23) of slide (20).

8. A power take-off mechanism as defined in claim 7, wherein: still the cover is installed at the cover in axle sleeve pipe (17) location axle sleeve (24) on hemisphere motion portion (21), slide (20) set up on the inside wall of location axle sleeve (24), the lateral wall of location axle sleeve (24) is provided with holding down groove (25) that a plurality of circumference was arranged, the lateral wall of power output tube (17) runs through to be provided with and is located hold down hole (26) of holding down groove (25) top, but holding down groove (25) rest has partially passed hold down ball (27) of holding down hole (26), but axial displacement has been cup jointed on power output tube (17) and has been covered hold down ring (28) of holding down hole (26), the terminal surface of holding down ring (28) with be provided with between the terminal surface of second sprocket (15) and cup joint return spring (29) on axle sleeve pipe (17).

Technical Field

The invention relates to the technical field of mechanical transmission, in particular to a gear shifting mechanism, a speed change mechanism and a power output mechanism.

Background

The existing agricultural machinery gearbox mainly comprises a box body, a speed changing and operating mechanism and an intermediate transmission and output part. Power is transmitted into the input shaft through the belt pulley, gear shifting is achieved through the operating mechanism of the gearbox to achieve different output rotating speeds of the output end, and requirements of different working conditions such as climbing, operation and walking are met.

However, the existing agricultural machinery gearbox also has the following problems and disadvantages:

1. the existing speed change method adopts an operating mechanism to push a shifting fork to drive a shifting gear to realize shifting, and agricultural machinery belongs to low-speed high-torque moment during operation, so that the phenomena of difficult shifting and gear beating can be caused in the shifting process. In the gear shifting process, the gear shifting can be realized only by separating the clutch, so that firstly, the operation time is wasted; secondly, due to the limitation of user knowledge and operation level, the risk that the gear shifting is directly carried out without pulling the clutch, the transmission mechanism or the transmission gear is damaged, and even the gearbox is scrapped exists.

2. The semi-axis all adopts coaxial output about current agricultural machine gearbox output, and the semi-axis center all is the collinear about promptly, and when rotary tillage, weeding operation like this, the middle gearbox box part of its left and right semi-axis can not install the rotary blade, leads to this part soil to carry out the rotary tillage operation, forms the no tillage, needs the manual work to carry out the additional tillage, has increased artifical labour cost.

3. The traditional mechanical gearbox adopts an idler wheel as intermediate transmission to realize reverse gear design, and the manufacturing cost is increased in the manufacturing and installation processes. And the weight increases. Because the idler wheel is of a cantilever structure, the problem of deformation of an idler wheel shaft can be caused during high-torque transmission operation.

4. The gearbox in the operation process of the existing rotary cultivator is provided with 4 gears which comprise three forward gears and a reverse gear, the gear selection is less under the condition of composite operation, and particularly when the operation precision requirement is high, the operation requirement can not be met.

Therefore, those skilled in the art are dedicated to develop a gear shifting mechanism with smooth gear shifting, a speed change mechanism with a simplified structure and a power output mechanism capable of being adjusted at multiple angles.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, an object of the present invention is to provide a shifting mechanism with smooth shifting.

In order to achieve the purpose, the invention provides a gear shifting mechanism, which comprises a power input shaft and a transmission sleeve sleeved and fixed on the power input shaft, wherein a rigid transmission gear is fixedly connected onto the transmission sleeve, a gear shifting ring capable of moving transversely is sleeved on the transmission sleeve, a plurality of transmission grooves arranged circumferentially are formed in the surface of the power input shaft, a limiting hole positioned above the transmission grooves is arranged in the transmission sleeve in a penetrating manner, a movable gear shifting ball partially penetrating through the limiting hole is placed in the transmission grooves, and the gear shifting ring is positioned on one side of the limiting hole; and a return spring sleeved on the transmission sleeve is clamped between the gear shifting ring and the rigid transmission gear.

An axially extending limiting cavity is arranged between one side of the gear shifting ring and the transmission sleeve, an extruding part obliquely facing the limiting hole is integrally arranged at the bottom of the limiting cavity, and the height of the limiting cavity is smaller than the diameter of the gear shifting ball.

The gear shifting ring is connected with a shifting fork extending outwards.

And a transition groove is also arranged between two adjacent transmission grooves for connection, and the depth of the transition groove is less than that of the transmission groove.

The invention also provides a speed change mechanism adopting the gear shift mechanism, which comprises a transmission shaft and a power output shaft which are arranged in parallel with the power input shaft, wherein the axes of the power input shaft, the transmission shaft and the power output shaft are arranged in an equilateral triangle, and the gear shift mechanism is provided with four groups except the power input shaft, and the four groups are respectively arranged on the power input shaft in a pairwise opposite manner.

The transmission cover includes from a left side to the right side in proper order first transmission cover, second transmission cover, third transmission cover and fourth transmission cover, rigidity drive gear is including setting up the first output gear of first transmission cover left end, setting are in the second output gear of second transmission cover right-hand member, setting are in the third output gear of third transmission cover left end and setting are in the fourth output gear of fourth transmission cover right-hand member.

The transmission shaft is provided with a first intermediate transmission gear, a second intermediate transmission gear, a third shifting fork, a third intermediate transmission gear, a fourth intermediate transmission gear, a fifth intermediate transmission gear and a sixth intermediate transmission gear from left to right in sequence, the first intermediate transmission gear, the fourth intermediate transmission gear, the fifth intermediate transmission gear and the sixth intermediate transmission gear are all fixedly connected with the transmission shaft, the third shifting fork is clamped between the second intermediate transmission gear and the third intermediate transmission gear and integrally arranged, the second intermediate transmission gear and the third intermediate transmission gear are fixedly connected on the transmission shaft in the radial direction, and the axial sliding connection is arranged on the transmission shaft.

And a first output gear, a first chain wheel, a second output gear, a third output gear and a fourth output gear are sequentially sleeved and fixed on the power output shaft from left to right.

The first output gear is meshed with the first intermediate transmission gear, the second output gear is meshed with the fourth intermediate transmission gear and the fourth output gear, the third output gear is meshed with the fourth intermediate transmission gear and the fourth output gear, the fourth output gear is meshed with the sixth intermediate transmission gear, the second intermediate transmission gear is meshed with the first output gear, the third intermediate transmission gear is meshed with the second output gear, the fourth intermediate transmission gear is meshed with the third output gear, and the fifth intermediate transmission gear is meshed with the fourth output gear.

The gear shifting ring comprises a first gear shifting ring arranged at the right end of the first transmission sleeve, a second gear shifting ring arranged at the left end of the second transmission sleeve, a third gear shifting ring arranged at the right end of the third transmission sleeve and a fourth gear shifting ring arranged at the left end of the fourth transmission sleeve, wherein a first shifting fork is clamped between the first gear shifting ring and the second gear shifting ring, and a second shifting fork is clamped between the third gear shifting ring and the fourth gear shifting ring.

The reset spring comprises a first reset spring arranged between the first gear shifting ring and the first output gear, a second reset spring arranged between the second gear shifting ring and the second output gear, a third reset spring arranged between the third gear shifting ring and the third output gear and a fourth reset spring arranged between the fourth gear shifting ring and the fourth output gear.

The invention also provides a power output mechanism adopting the speed change mechanism, which comprises a second chain wheel, wherein the second chain wheel is connected with the first chain wheel through a chain matched with the first chain wheel; the second sprocket cup joints fixed mounting and on the power output tube that both ends symmetry opening set up about one, the output semi-axis that becomes the mirror image setting each other is installed respectively to the both ends opening of power output tube, be provided with the slide of a plurality of axial trends in the power output tube, the output semi-axis inserts the tip of power output tube is provided with hemisphere motion portion, the division board be provided with the sphere recess that hemisphere motion portion suited, the last middle part of power output tube is provided with the division board, the surperficial arch of hemisphere motion portion is provided with the embedding the transmission ball of slide.

The intraductal cover of axle sleeve is still installed the cover and is in location axle sleeve on the hemisphere motion portion, the slide sets up on the inside wall of location axle sleeve, the lateral wall of location axle sleeve is provided with the indent that pushes down of a plurality of circumference range, the lateral wall of power output tube runs through to be provided with and is located the indent top pushes down, but the indent rest has partly passed push down the ball in indent, but the last axial displacement that has cup jointed of power output tube just covers push down the lower ring in indent, the terminal surface of lower ring with be provided with between the terminal surface of second sprocket and cup joint return spring on the axle sleeve.

The invention has the beneficial effects that:

1. the gear shifting mechanism comprises a power input shaft and a transmission sleeve sleeved and fixed on the power input shaft, wherein a rigid transmission gear is fixedly connected onto the transmission sleeve, a gear shifting ring capable of moving transversely is sleeved on the transmission sleeve, a plurality of circumferentially arranged transmission grooves are formed in the surface of the power input shaft, limiting holes located above the transmission grooves are formed in the transmission sleeve in a penetrating mode, and a movable gear shifting ball partially penetrating through the limiting holes is placed in the transmission grooves. When the power input shaft is in a high-speed rotation state, the shifting ball is separated from the power input shaft under the action of centrifugal force, so that the power input shaft and the rigid transmission gear are in a separation state and do not transmit power; when gear shifting is needed, the gear shifting ball is driven to press into the transmission groove by the gear shifting ring which is moved transversely, the power input shaft and the rigid transmission gear start to transmit power, the gear shifting ring is pushed back to the original position by the return spring after the gear shifting ring returns to the neutral position, and at the moment, the gear shifting mechanism is in the neutral position again.

In the actual agricultural machinery production process, firstly, the time wasted by a user for pulling the clutch in the gear shifting process is reduced. And secondly, the manual damage or the scrapping of a gear shifting mechanism or a gear of the gearbox caused by the operation of the user is fundamentally solved because the user does not pull the clutch or forgets to pull the clutch to shift the gear in the use process due to the limited operation level or the non-strict training of the user.

2. The speed change mechanism comprises a transmission shaft and a power output shaft which are arranged in parallel with a power input shaft, wherein the axes of the power input shaft, the transmission shaft and the power output shaft are arranged in an equilateral triangle, and four groups of the gear shift mechanism except the power input shaft are arranged on the power input shaft and are respectively arranged on the power input shaft in a pairwise opposite manner; the existing idler wheel mechanism is cancelled, the production cost is reduced, and the reliability of the structure is higher; the whole machine of the gearbox is more compact, and the harsh requirement of the hilly and mountainous areas on the whole machine of the agricultural machinery is met, wherein the harsh requirement is as light as possible.

The design of any angle of the output half shaft fundamentally solves the problem that the operation cutter can not operate in all directions due to the width of the box body of the machine tool carrying the gearbox in agricultural production such as rotary tillage, weeding and the like, and can realize the inclined parallel installation of the output left half shaft and the output right half shaft when the gearbox is used for the mini-tiller in the use process, thereby greatly reducing the operation stability of the mini-tiller and greatly reducing the labor intensity and solving the problem of missing tillage.

3. Power take-off mechanism of the invention

The elimination of reverse gear idler mechanism, the first manufacturing cost who reduces the enterprise from the perspective of manufacturer, and the reliability of structure is higher. And secondly, the whole machine of the gearbox is more compact, and the harsh requirement of the hilly and mountainous areas on the whole machine of the agricultural machinery is met, wherein the weight of the whole machine is as light as possible.

4. The design of auxiliary speed change mechanism makes the variable speed interval of gearbox bigger, can satisfy the demand of the different operations of agricultural production such as ridging, tectorial membrane, plough, rotary tillage, weeding, transportation simultaneously, and this design has only increased a pair of auxiliary change gear when satisfying many gears design, has satisfied hills mountain area agricultural machine to the harsh requirement of structure and weight. Not only reduces the production cost, but also improves the market competitiveness of the product due to lower manufacturing cost.

Drawings

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

FIG. 2 is a structural side view of the shift mechanism of the present invention;

FIG. 3 is a cross-sectional view taken at A-A of FIG. 2;

FIG. 4 is an exploded view of the shift mechanism of the present invention;

FIG. 5 is a schematic structural view of the shifting mechanism of the present invention;

FIG. 6 is a structural side view of the shifting mechanism of the present invention;

FIG. 7 is an exploded view of the shifting mechanism of the present invention;

FIG. 8 is a schematic structural view of a power output mechanism of the invention;

FIG. 9 is a structural side view of the power output mechanism of the invention;

FIG. 10 is a cross-sectional view taken at B-B of FIG. 9;

fig. 11 is an exploded view of the power output mechanism of the invention.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and examples, wherein the terms "upper", "lower", "left", "right", "inner", "outer", and the like, as used herein, refer to an orientation or positional relationship indicated in the drawings, which is for convenience and simplicity of description, and does not indicate or imply that the referenced devices or components must be in a particular orientation, constructed and operated in a particular manner, and thus should not be construed as limiting the present invention. The terms "first," "second," "third," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

As shown in fig. 1 to 8, a gear shift mechanism includes a power input shaft 1 and a transmission sleeve 2 sleeved and fixed on the power input shaft 1, a rigid transmission gear 3 is fixedly connected to the transmission sleeve 2, a gear shift ring 4 capable of moving transversely is further sleeved on the transmission sleeve 2, a plurality of transmission grooves 5 arranged circumferentially are arranged on the surface of the power input shaft 1, a limit hole 6 located above the transmission grooves 5 is arranged in the transmission sleeve 2 in a penetrating manner, a gear shift ball 7 which can move and partially passes through the limit hole 6 is placed in the transmission groove 5, and the gear shift ring 4 is located on one side of the limit hole 6; a return spring 8 sleeved on the transmission sleeve 2 is clamped between the gear shifting ring 4 and the rigid transmission gear 3. In this embodiment, the shift balls 7 are steel balls, and generally there are 6 shift balls arranged at equal intervals; an axially extending limiting cavity 9 is arranged between one side of the gear shifting ring 4 and the transmission sleeve 2, an extruding part 10 facing the limiting hole 6 in an inclined mode is integrally arranged at the bottom of the limiting cavity 9, the height of the limiting cavity 9 is smaller than the diameter of the gear shifting ball 7, as shown in fig. 3, the height of the limiting cavity 9 is h, the diameter of the gear shifting ball 7 is d, and h is smaller than d, so that the gear shifting ball 7 is ensured not to fall off from the limiting cavity 9.

When the gear shifting ring 4 retracts to the middle position, the reset spring 8 automatically compresses the gear shifting ring 4 to retract to the original position. 6 steel balls mainly play a role in transmitting power in the gear shifting mechanism. When the gear shifting operation is carried out, the power input shaft 1 is in a high-speed rotating state, the gear shifting ball 7, namely the steel ball, is subjected to centrifugal force, the gear shifting ball 7 is separated from the transmission groove 5, at the moment, the power input shaft 1, the transmission sleeve 2 and the rigid transmission gear 3 are in a separated state, power is not transmitted, and at the moment, the power input shaft is in a neutral gear; when the power input shaft 1 needs to be shifted to transmit power downwards, the shifting ring 4 is pushed to move transversely, the shifting ring 4 forces the shifting balls 7 to be embedded into the transmission groove 5, so that the power input shaft 1 is connected with the transmission sleeve 2 and the rigid transmission gear 3, and the power input shaft 1 and the rigid transmission gear 3 start to transmit power. After the shifting mechanism is returned to the neutral position, the shifting ring 4 is pushed back to the original position by the return spring 8, and the shifting mechanism is in the neutral position again.

The gear shifting ring 4 is connected with a shifting fork 11 which extends outwards and is a device commonly used in the field, the production cost is low, and the gear shifting ring is convenient to disassemble and assemble. The shifting fork 11 shifts the gear shifting ring 4 to move transversely.

The transition grooves 12 are further arranged between two adjacent transmission grooves 5 for connection, the depth of each transition groove 12 is smaller than that of each transmission groove 5, and each transition groove 12 is a steel ball slideway and is used for ensuring that a steel ball runs smoothly in the gear shifting process, so that the buffering effect in the gear shifting process is achieved, and the service lives of the steel ball and the power input shaft 1 are prolonged.

As shown in fig. 1 to 7, a speed change mechanism using the above gear shift mechanism includes a transmission shaft 13 and a power output shaft 14 which are arranged in parallel with a power input shaft 1, axes of the power input shaft 1, the transmission shaft 13 and the power output shaft 14 are arranged in an equilateral triangle, and four groups of gear shift mechanisms except the power input shaft 1 are arranged on the power input shaft 1 and are respectively arranged two by two in an opposite manner.

The transmission sleeve 2 comprises a first transmission sleeve, a second transmission sleeve, a third transmission sleeve and a fourth transmission sleeve which are arranged in sequence from left to right, and the rigid transmission gear 3 comprises a first output gear 301 arranged at the left end of the first transmission sleeve, a second output gear 302 arranged at the right end of the second transmission sleeve, a third output gear 303 arranged at the left end of the third transmission sleeve and a fourth output gear 304 arranged at the right end of the fourth transmission sleeve;

a first intermediate transmission gear 130, a second intermediate transmission gear 131, a third shifting fork 132, a third intermediate transmission gear 133, a fourth intermediate transmission gear 134, a fifth intermediate transmission gear 135 and a sixth intermediate transmission gear 136 are sequentially arranged on the intermediate shaft 13 from left to right, the first intermediate transmission gear 130, the fourth intermediate transmission gear 134, the fifth intermediate transmission gear 135 and the sixth intermediate transmission gear 136 are all fixedly connected with the transmission shaft 13, the third shifting fork 132 is clamped between the second intermediate transmission gear 131 and the third intermediate transmission gear 133 and is integrally arranged, the second intermediate transmission gear 131 and the third intermediate transmission gear 133 are fixedly connected to the transmission shaft 13 in the radial direction and are connected to the transmission shaft 13 in an axial sliding manner;

a first output gear 140, a first chain wheel 141, a second output gear 142, a third output gear 143 and a fourth output gear 144 are fixedly sleeved on the power output shaft 14 from left to right in sequence;

the first output gear 301 is meshed with the first intermediate transmission gear 130, the second output gear 302 is meshed with the fourth intermediate transmission gear 134 and the fourth output gear 144, the third output gear 303 is meshed with the fourth intermediate transmission gear 134 and the fourth output gear 144, the fourth output gear 304 is meshed with the sixth intermediate transmission gear 136, the second intermediate transmission gear 131 is meshed with the first output gear 140, the third intermediate transmission gear 133 is meshed with the second output gear 142, the fourth intermediate transmission gear 134 is meshed with the third output gear 143, and the fifth intermediate transmission gear 135 is meshed with the fourth output gear 144.

The above gears can realize 8 different output speeds under the adjustment of the gear shifting ring 4, namely 8 gears, and the power transmission schematic paths of the different gears are as follows.

The transmission path of the first gear is as follows: the power input shaft 1, the fourth output gear 304, the sixth intermediate transfer gear 136, the fifth intermediate transfer gear 135, the fourth output gear 144, the third output gear 143, the fourth intermediate transfer gear 134, the third intermediate transfer gear 133, and the second output gear 142, and finally, the power is output through the first sprocket 141.

The transmission path of the second gear is as follows: the power input shaft 1, the second output gear 302, the fourth intermediate transmission gear 134, the third intermediate transmission gear 133 and the second output gear 142, and finally, the power is output through the first sprocket 141.

The transmission path of the third gear is as follows: the power input shaft 1, the first output gear 301, the third intermediate transmission gear 133, and the second output gear 142, finally, output power through the first sprocket 141.

The reverse gear transmission path is: the power input shaft 1, the third output gear 303, the fourth output gear 144, the third output gear 143, the fourth intermediate transmission gear 134, the third intermediate transmission gear 133, and the second output gear 142, and finally, power is output through the first sprocket 141. The other 4 gear positions are when the subtransmission transmission is required, the third intermediate transmission gear 133 and the second output gear 142 in the above four transmission paths are replaced with the second intermediate transmission gear 131 and the first output gear 140, respectively.

In addition, in order to meet the requirements on the output rotating speed under different working conditions, the first output gear 140 and the second output gear 142 which are respectively meshed with the second intermediate transmission gear 131 and the third intermediate transmission gear 133 of the dual gear are a pair of auxiliary speed changing gears. All the variable speeds of this gearbox are all accomplished at jackshaft 13, consequently when increasing the auxiliary transmission, only need increase a pair of gear can, this design had both satisfied the demand of the different rotational speeds of many gears, had reduced the increase of gear again in a large number, and the weight that alleviates the gearbox body adapts to the severe requirement of hills mountain area agricultural machine to whole quick-witted weight more.

In the design process of reverse gear, the center distance between the output shaft and the input shaft is calculated through design, the power of the input shaft is directly transmitted to the output shaft through the gear shifting mechanism, and the satisfactory reverse gear speed is obtained through speed reduction design.

The design is characterized in that the traditional idler wheel system is omitted; the arrangement of three shafts of the gearbox is designed to be triangular, and the transmission routes of normal 1, 2 and 3 gears of the gearbox are all a power input shaft 1, an intermediate shaft 13 and a power output shaft 14. The transmission route of the reverse gear of the gearbox is the power input shaft 1 and the power output shaft 14. That is, in fig. 5, the third output gear 303, the fourth output gear 144, the third output gear 143, the fourth intermediate transmission gear 134, the third intermediate transmission gear 133 and the second output gear 142 realize reverse transmission, and a satisfactory rotation speed can be achieved through the deceleration of the first output gear 140 and the second output gear 142 respectively engaged with the second intermediate transmission gear 131 and the third intermediate transmission gear 133, so that the need of separately designing an idle gear for reverse gear in the conventional transmission is eliminated. Secondly, the whole gearbox is more compact, smaller in size and lighter in structure, and is more suitable for the situation that the requirement on the whole weight of the whole gearbox is strict in hilly and mountainous areas.

The gear shifting ring 4 comprises a first gear shifting ring 401 arranged at the right end of the first transmission sleeve, a second gear shifting ring 402 arranged at the left end of the second transmission sleeve, a third gear shifting ring 403 arranged at the right end of the third transmission sleeve and a fourth gear shifting ring 404 arranged at the left end of the fourth transmission sleeve, wherein a first shifting fork 110 is clamped between the first gear shifting ring 401 and the second gear shifting ring 402, and a second shifting fork 111 is clamped between the third gear shifting ring 403 and the fourth gear shifting ring 404.

The return springs 8 include a first return spring 801 disposed between the first shift ring 401 and the first output gear 301, a second return spring 802 disposed between the second shift ring 402 and the second output gear 302, a third return spring 803 disposed between the third shift ring 403 and the third output gear 303, and a fourth return spring 804 disposed between the fourth shift ring 404 and the fourth output gear 304.

As shown in fig. 1 to 11, a power output mechanism using the above speed change mechanism includes a second sprocket 15, the second sprocket 15 and a first sprocket 141 are connected by a cooperating chain 16; the second chain wheel 15 is fixedly installed on a power output pipe 17 with symmetrical openings at the left and right ends in a sleeved mode, output half shafts 19 which are arranged in a mirror image mode are installed at the openings at the two ends of the power output pipe 17 respectively, a plurality of axial moving slideways 20 are arranged in the power output pipe 17, hemispherical moving portions 21 are arranged at the end portions, inserted into the power output pipe 17, of the output half shafts 19, spherical grooves 22 matched with the hemispherical moving portions 21 are formed in the partition plate 18, the partition plate 18 is arranged in the middle of the power output pipe 17, and transmission balls 23 embedded into the slideways 20 are arranged on the surface of the hemispherical moving portions 21 in a.

The shaft sleeve 17 is also internally sleeved with a positioning shaft sleeve 24 sleeved on the hemispherical motion part 21, the slide way 20 is arranged on the inner side wall of the positioning shaft sleeve 24, the outer side wall of the positioning shaft sleeve 24 is provided with a plurality of pressing grooves 25 which are circumferentially arranged, the side wall of the power output pipe 17 is provided with a pressing hole 26 which is positioned above the pressing groove 25 in a penetrating manner, the pressing groove 25 is provided with a pressing ball 27 which can partially pass through the pressing hole 26, the power output pipe 17 is sleeved with a pressing ring 28 which can axially move and cover the pressing hole 26, and a return spring 29 sleeved on the shaft sleeve 17 is arranged between the end surface of the pressing ring 28 and the end surface of the second chain wheel 15.

The transmission ball 23 is used as a transmission medium of the hemispherical motion part 21 and the positioning shaft sleeve 24, after all parts are installed, the output half shaft 19 can rotate in any direction around the spherical groove 22, when the rotation angle of the output half shaft 19 needs to be adjusted, the lower pressing ring 28 is shifted, the lower pressing ball 27 is separated from the lower pressing groove 25, the positioning shaft sleeve 24 cannot clamp the hemispherical motion part 21, the 0-10-degree free adjustment of the included angle between the output half shaft 19 and the horizontal direction is realized, the included angle between the two half shafts can be freely adjusted according to the operation requirement, the problem of no-tillage of the gearbox body parts of a rotary cultivator, a weeding machine and the like is effectively solved, and the operations of rotary tillage, weeding and the like are completed at one.

In this embodiment, the power input shaft 1 is further sleeved with a first bearing 30 located beside the rigid transmission gear 3, two ends of the shaft sleeve 17 are further respectively sleeved with a second bearing 31, and the output half shaft 19 is further sleeved with two third bearings 32, so as to ensure smooth rotation.

The foregoing detailed description of the preferred embodiments of the invention has been presented. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions available to those skilled in the art through logic analysis, reasoning and limited experiments based on the prior art according to the concept of the present invention should be within the scope of protection defined by the claims.