阅读说明：本技术 一种具有多个前进档和多个倒档的变速器 (Transmission with multiple forward gears and multiple reverse gears ) 是由 陈荣文 潘延虹 于 2020-12-16 设计创作，主要内容包括：本发明公开了一种具有多个前进档和多个倒档的变速器。该变速器主要包括换档操纵机构总成、输入轴总成、输出轴总成、中间轴总成、壳体,输入轴总成、输出轴总成和中间轴总成组合成三轴结构的主箱,主箱包括四组档位齿轮和一组前进后退换向齿轮；输入轴总成、输出轴总成组合成两轴结构的副箱,副箱包括快档齿轮组和慢档齿轮组。本发明能够实现前进挡快档和前进档慢档各四个档位,后退档快档和后退档慢档各四个档位共十六个档位的调节。主箱总成和副箱总成的齿轮及齿轮轴组合成具有多个前进档和多个倒档的变速器。本发明的变速器轴向尺寸小、结构简单、空间布置紧凑、实现了整机的正反向操作,提高了整机的性能。(A transmission having a plurality of forward gears and a plurality of reverse gears is disclosed. The transmission mainly comprises a gear shift control mechanism assembly, an input shaft assembly, an output shaft assembly, an intermediate shaft assembly and a shell, wherein the input shaft assembly, the output shaft assembly and the intermediate shaft assembly form a main box of a three-shaft structure, and the main box comprises four groups of gear gears and a group of forward and backward reversing gears; the input shaft assembly and the output shaft assembly are combined into an auxiliary box with a two-shaft structure, and the auxiliary box comprises a fast gear set and a slow gear set. The invention can realize the adjustment of sixteen gears, namely four gears of a forward gear fast gear and a forward gear slow gear, and four gears of a reverse gear fast gear and a reverse gear slow gear. The gears and gear shafts of the main box assembly and the auxiliary box assembly are combined into a transmission with a plurality of forward gears and a plurality of reverse gears. The transmission has the advantages of small axial size, simple structure and compact spatial arrangement, realizes the forward and reverse operation of the whole transmission, and improves the performance of the whole transmission.)

1. A transmission with a plurality of forward gears and a plurality of reverse gears mainly comprises a gear shift control mechanism assembly (1), an input shaft assembly (2), an output shaft assembly (3), an intermediate shaft assembly (4) and a shell (5); the method is characterized in that: three groups of corresponding hole systems are arranged on two sides of the shell (5), and an input shaft assembly (2), an output shaft assembly (3) and an intermediate shaft assembly (4) are respectively arranged on the three groups of corresponding hole systems;

the main body of the input shaft assembly (2) is an input shaft (6) and is fixed on the shell (5) through a bearing; one end of the input shaft (6) is a power input end, and a reverse gear reversing gear (9), a reversing fixed gear seat (12), a forward gear reversing gear (13) and an auxiliary box duplicate gear (15) are sequentially arranged on the input shaft (6) from the direction of the power input end; the reversing fixed tooth holder (12) is fixed on the input shaft (6), and a reversing sliding tooth sleeve (11) is arranged on the reversing fixed tooth holder (12);

the main body of the output shaft assembly (3) is an output shaft (18) and is fixed on the shell (5) through a bearing; the auxiliary box gear shaft (30) is sleeved on the output shaft (18); from the direction of the power input end of the input shaft, a first-gear driven gear (20), a second-gear fixed gear seat (23), a second-gear driven gear (24), a fourth-gear driven gear (26), a third-fourth-gear fixed gear seat (28) and a third-fourth-gear driven gear (29) are sequentially arranged on an auxiliary box gear shaft (30), and a fast-slow gear fixed gear seat (32) and an auxiliary box slow gear (33) are arranged on an output shaft (18); a second-gear fixed tooth holder (23) is fixed on an auxiliary box gear shaft (30), a second-gear sliding tooth sleeve (22) is arranged on the second-gear fixed tooth holder (23), a third-fourth-gear fixed tooth holder (28) is fixed on the auxiliary box gear shaft (30), a third-fourth-gear sliding tooth sleeve (27) is arranged on the third-fourth-gear fixed tooth holder (28), a fast-slow gear fixed tooth holder (32) is fixed on an output shaft (18), and a fast-slow gear sliding tooth sleeve (31) is arranged on the fast-slow gear fixed tooth holder (32);

the main body of the intermediate shaft assembly (4) is an intermediate shaft (36) and is fixed on the shell (5) through a bearing; the gear mechanism comprises an intermediate shaft first-gear (21), an intermediate shaft second-gear (37), an intermediate shaft fourth-gear (38), a gear spacer sleeve (39) and an intermediate shaft third-gear (40) which are sequentially arranged from the direction of a power input end of an input shaft, wherein the four gears are all fixed on an intermediate shaft (36), and three shafts are parallel to each other.

2. A transmission having a plurality of forward gears and a plurality of reverse gears as defined in claim 1 wherein: a reverse gear reversing gear (9) of the input shaft (6) is meshed with a middle shaft four-gear (38) of a middle shaft (36); a forward gear reversing gear (13) of the input shaft (6) is meshed with a third-gear driven gear (29) of the output shaft (18), a large gear 25 of an auxiliary box duplicate gear (15) is meshed with an auxiliary box fast gear (16) of an auxiliary box gear shaft (30), and a small gear (42) of the auxiliary box duplicate gear (15) is meshed with an auxiliary box slow gear (33); a first-gear driven gear (20) of the output shaft (18) is meshed with a first-gear (21) of an intermediate shaft (36), a second-gear driven gear (24) is meshed with a second-gear (37) of the intermediate shaft, a fourth-gear driven gear (26) is meshed with a fourth-gear (38) of the intermediate shaft, and a third-gear driven gear (29) is meshed with a third-gear (40) of the intermediate shaft.

Technical Field

The invention relates to a transmission with a plurality of forward gears and a plurality of reverse gears, belonging to the technical field of manufacturing of transmission systems of tractors and engineering machinery.

Background

The machine such as tractor, engineering machine tool need only set up a plurality of forward gears and one to two and retreat the gear and just can satisfy daily use demand under the ordinary condition. With the continuous popularization and application of mechanization, machines such as tractors and engineering machinery need to bear multiple operation modes, and in order to improve the working efficiency, the multipurpose machine is provided with a rotary seat to realize a two-end driving mode. When the driving mode is in a reverse driving mode, the reverse gear is too few to meet the use requirement, and a transmission which can realize forward and reverse driving and meets the high-efficiency driving requirement in gear number is needed to be designed.

Disclosure of Invention

The invention aims to provide a transmission with a plurality of forward gears and a plurality of reverse gears, and solve the problem that the reverse gears of the conventional transmission are insufficient.

In order to solve the problems, the following technical scheme is adopted: a transmission with a plurality of forward gears and a plurality of reverse gears mainly comprises a gear shift control mechanism assembly, an input shaft assembly, an output shaft assembly, an intermediate shaft assembly and a shell; three groups of corresponding hole systems are arranged on two sides of the shell, and an input shaft assembly, an output shaft assembly and a middle shaft assembly are respectively arranged on the two sides of the shell; the input shaft assembly main body is an input shaft and is fixed on the shell through a bearing; one end of the input shaft is a power input end, and a reverse gear reversing gear, a reversing fixed gear seat, a forward gear reversing gear and an auxiliary box duplicate gear are sequentially arranged on the input shaft from the direction of the power input end; the reversing fixed tooth holder is fixed on the input shaft, and a reversing sliding tooth sleeve is arranged on the reversing fixed tooth holder; the output shaft assembly main body is an output shaft and is fixed on the shell through a bearing; the auxiliary box gear shaft is sleeved on the output shaft; from the direction of the power input end of the input shaft, a first-gear driven gear, a second-gear fixed gear seat, a second-gear driven gear, a fourth-gear driven gear, a third-fourth-gear fixed gear seat and a third-gear driven gear are sequentially arranged on the gear shaft of the auxiliary box, and a fast-slow gear fixed gear seat and an auxiliary box slow gear are arranged on the output shaft; a second-gear fixed tooth holder is fixed on the auxiliary box gear shaft, a second-gear sliding tooth sleeve is arranged on the second-gear fixed tooth holder, a third-fourth-gear fixed tooth holder is fixed on the auxiliary box gear shaft, a third-fourth-gear sliding tooth sleeve is arranged on the third-fourth-gear fixed tooth holder, a fast-slow-gear fixed tooth holder is fixed on the output shaft, and a fast-slow-gear sliding tooth sleeve is arranged on the fast-slow-gear fixed tooth holder; the intermediate shaft assembly main body is an intermediate shaft and is fixed on the shell through a bearing; starting from the direction of the power input end of the input shaft, an intermediate shaft first-gear, an intermediate shaft second-gear, an intermediate shaft fourth-gear, a gear spacer bush and an intermediate shaft third-gear are sequentially arranged, and all the four gears are fixed on the intermediate shaft; the three axes are parallel to each other.

A reverse gear reversing gear of the input shaft is meshed with a middle shaft four-gear of the middle shaft; a forward gear reversing gear of the input shaft is meshed with a third-gear driven gear of the output shaft, a large gear of an auxiliary box duplicate gear is meshed with an auxiliary box gear shaft and an auxiliary box fast gear, and a small gear of the auxiliary box duplicate gear is meshed with an auxiliary box slow gear; the first-gear driven gear of the output shaft is meshed with the first-gear of the intermediate shaft, the second-gear driven gear is meshed with the second-gear of the intermediate shaft, the fourth-gear driven gear is meshed with the fourth-gear of the intermediate shaft, and the third-gear driven gear is meshed with the third-gear of the intermediate shaft.

The invention has the beneficial effects that: the invention adopts a three-shaft structure design, the input shaft assembly, the output shaft assembly and the intermediate shaft assembly are combined into a main box with a three-shaft structure, the input shaft assembly and the output shaft assembly form an auxiliary box with a two-shaft structure, gears of the main box assembly and the auxiliary box assembly are integrated in a box body, and gears of the transmission are increased, so that the gears of the transmission reach sixteen gears which are four gears respectively, namely a forward gear fast gear, a backward gear fast gear, a forward gear full gear and a backward gear slow gear, and the transmission assembly can be designed to be smaller and more compact, thereby achieving the purposes of reliable use and light weight manufacture. Meanwhile, power can be directly output from the other end of the input shaft assembly to drive other working devices. The power can be output from two ends of the output shaft after speed change to drive the tractor, the engineering machinery and other machines to walk.

Drawings

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

FIG. 2 is an expanded view of the left side view structure of FIG. 1;

FIG. 3 is a schematic view of the input shaft assembly and the output shaft assembly of the present invention;

FIG. 4 is a schematic structural view of an output shaft assembly and a countershaft assembly of the present invention;

FIG. 5 is a schematic view of the input shaft assembly and the intermediate shaft assembly of the present invention.

Description of reference numerals: the gear-shifting control mechanism assembly 1, the input shaft assembly 2, the output shaft assembly 3, the intermediate shaft assembly 4, the transmission shell 5, the input shaft 6, the input shaft first bearing 7, the gear bushing 8, the reverse reversing gear 9, the needle bearing 10, the reversing sliding gear sleeve 11, the reversing fixed gear seat 12, the forward reversing gear 13, the duplicate gear bearing 14, the auxiliary box duplicate gear 15, the auxiliary box fast gear 16, the input shaft second bearing 17, the output shaft 18, the output shaft first bearing 19, the first gear driven gear 20, the intermediate shaft first gear 21, the second gear sliding gear sleeve 22, the second gear fixed gear seat 23, the second gear driven gear 24, the large gear 25, the fourth gear driven gear 26, the third and fourth gear sliding gear sleeve 27, the third and fourth gear fixed gear seat 28, the third gear driven gear 29, the auxiliary box gear shaft 30, the fast and slow gear sliding gear sleeve 31, the fast and slow gear fixed gear seat 32, the auxiliary box slow gear 33, the reverse gear and the reverse gear, An output shaft second bearing 34, an intermediate shaft first bearing 35, an intermediate shaft 36, an intermediate shaft second gear 37, an intermediate shaft fourth gear 38, a gear spacer 39, an intermediate shaft third gear 40, an intermediate shaft second bearing 41 and a pinion 42.

Detailed Description

The invention is further described with reference to the following figures and embodiments.

As shown in fig. 1, 2, 3, 4 and 5, a transmission with multiple forward gears and multiple reverse gears mainly comprises a gear shift control mechanism assembly 1, an input shaft assembly 2, an output shaft assembly 3, an intermediate shaft assembly 4 and a shell 5;

the housing 5 is provided with three sets of corresponding hole systems, which are respectively provided with an input shaft assembly 2, an output shaft assembly 3 and an intermediate shaft assembly 4. The gear shifting control mechanism assembly 1 comprises a vertical control mechanism and a lateral control mechanism, the vertical control mechanism comprises a vertical rocker and a vertical shifting fork, and the lateral control mechanism comprises a lateral rocker and a lateral shifting fork.

As shown in fig. 1-3 and 5, the input shaft assembly 2 is mainly an input shaft 6 and is fixed on the housing 5 through an input shaft first bearing 7 and an input shaft second bearing 17; one end of the first input shaft bearing 7 is a power input end, and a reverse gear reversing gear 9, a reversing fixed gear seat 12, a forward gear reversing gear 13 and an auxiliary box duplicate gear 15 are sequentially arranged on the input shaft 6 from the direction of the power input end; a reversing fixed toothholder 12 is fixed on the input shaft 6, a reversing sliding toothholder 11 is arranged on the reversing fixed toothholder 12, two sides of the reversing fixed toothholder 12 are respectively provided with a gear bushing 8, each gear bushing 8 is provided with a needle bearing 10, and a backward gear reversing gear 9 and a forward gear reversing gear 13 are respectively arranged on the two needle bearings 10; an auxiliary box duplicate gear 15 is sleeved on the input shaft 6, a duplicate gear bearing 14 and a needle bearing 10 are arranged between the auxiliary box duplicate gear 15 and the input shaft 6, and an input shaft second bearing 17 is sleeved on the auxiliary box duplicate gear 15.

As shown in fig. 1-4, the output shaft assembly 3 is mainly an output shaft 18, and is fixed on the housing 5 through an output shaft first bearing 19 and an output shaft second bearing 34; the auxiliary box gear shaft 30 is sleeved on the output shaft 18, and two needle roller bearings 10 are arranged between the auxiliary box gear shaft 30 and the output shaft 18; after the auxiliary box gear shaft is positioned at the first bearing 19, a first-gear driven gear 20, a second-gear fixed tooth holder 23, a second-gear driven gear 24, a fourth-gear driven gear 26, a third-fourth-gear fixed tooth holder 28, a third-gear driven gear 29, a fast-slow gear fixed tooth holder 32 and an auxiliary box slow-gear 33 are sequentially arranged on the auxiliary box gear shaft 30 from the direction of the first bearing 19;

a second-gear fixed tooth holder 23 is fixed on the auxiliary box gear shaft 30, a second-gear sliding tooth sleeve 22 is arranged on the first-gear fixed tooth holder 23, two gear bushings 8 are respectively fixed on two sides of the second-gear fixed tooth holder 23, and a first-gear driven gear 20 and a second-gear driven gear 24 are respectively arranged on the two gear bushings 8; a third-fourth gear fixed tooth holder 28 is fixed on an auxiliary box gear shaft 30, a third-fourth gear sliding tooth sleeve 27 is arranged on the third-fourth gear fixed tooth holder 28, two sides of the third-fourth gear fixed tooth holder 28 are respectively fixed with a gear bush 8, and a fourth gear driven gear 26 and a third gear driven gear 29 are respectively arranged on the two gear bushes 8; the fast-slow gear fixed tooth holder 32 is positioned behind the auxiliary box gear shaft 30 and fixed on the output shaft 18, a fast-slow gear sliding tooth sleeve 31 is arranged on the fast-slow gear fixed tooth holder 32, one side of the fast-slow gear fixed tooth holder 32 is tightly attached to the auxiliary box fast gear 16 of the auxiliary box gear shaft 30, the other side of the fast-slow gear fixed tooth holder 32 is provided with a gear bushing 8 fixed on the output shaft 18, and the gear bushing 8 is provided with an auxiliary box slow gear 33.

As shown in fig. 1, 2, 4 and 5, the main body of the intermediate shaft assembly 4 is an intermediate shaft 36 fixed to the housing 5 through an intermediate shaft first bearing 35 and an intermediate shaft second bearing 41; an intermediate shaft first gear 21, an intermediate shaft second gear 37, an intermediate shaft fourth gear 38, a gear spacer 39 and an intermediate shaft third gear 40 are sequentially arranged between the intermediate shaft first bearing 35 and the intermediate shaft second bearing 41, and all the four gears are fixed on the intermediate shaft 36;

the reverse gear reversing gear 9 of the input shaft 6 is meshed with a countershaft fourth gear 38 of the countershaft 36; the forward gear reversing gear 13 of the input shaft 6 is meshed with the third-gear driven gear 29 of the output shaft 18, the large gear 25 of the auxiliary box duplicate gear 15 is meshed with the auxiliary box fast gear of the auxiliary box gear shaft 30, and the small gear 42 of the auxiliary box duplicate gear 15 is meshed with the auxiliary box slow gear 33; the first-speed driven gear 20 of the output shaft 18 is meshed with the first-speed counter gear 21 of the counter shaft 36, the second-speed driven gear 24 is meshed with the second-speed counter gear 37, the fourth-speed driven gear 26 is meshed with the fourth-speed counter gear 38, and the third-speed driven gear 29 is meshed with the third-speed counter gear 40.

The three shafts are parallel to each other, the input shaft assembly 2, the output shaft assembly 3 and the intermediate shaft assembly 4 are combined into a main box with a three-shaft structure, and the main box comprises four groups of gear gears and a group of forward and backward reversing gears; the input shaft assembly 2 and the output shaft assembly 3 are combined into an auxiliary box with a two-shaft structure, and the auxiliary box comprises a fast gear set and a slow gear set. The invention can realize the adjustment of sixteen gears, namely four gears of a forward gear fast gear and a forward gear slow gear, and four gears of a reverse gear fast gear and a reverse gear slow gear.

The operation of the present invention will be described by selecting the first gear with slow forward gear, the second gear with fast reverse gear, the third gear with fast forward gear and the fourth gear with slow reverse gear.

The working process of the invention is as follows:

when the reversing sliding gear sleeve 11 is positioned on the reversing fixed gear seat 12, the first-gear sliding gear sleeve 22 is positioned on the first-gear fixed gear seat 23, the third-fourth sliding gear sleeve 27 is positioned on the third-fourth fixed gear seat 28, and the fast-slow sliding gear sleeve 31 is positioned on the fast-slow fixed gear seat 32, all gears are positioned in the neutral position, and all gears on the input shaft 6 and the output shaft 18 and the auxiliary box gear shaft 30 can idle.

The forward gear is one gear slower: the power is transmitted from the input shaft 6, and is engaged into the forward gear through the reversing control lever of the gear shift control mechanism assembly 1, namely, the reversing sliding gear sleeve 11 is shifted to the forward gear reversing gear 13 and is meshed with the joint teeth of the forward gear reversing gear 13, when the input shaft 6 rotates, the forward gear reversing gear 13 is driven to rotate through the reversing fixed gear seat 12, the forward gear reversing gear 13 transmits the power to the three-gear driven gear 29 on the output shaft assembly 3, and the power of the three-gear driven gear 29 is transmitted to the intermediate shaft three-gear 40 on the intermediate shaft assembly 4. Since all the gears on the intermediate shaft assembly 4 are fixed on the intermediate shaft 36, power can be transmitted to the intermediate shaft 36, the intermediate shaft first gear 21 on the intermediate shaft 36 transmits power to the first gear driven gear 20 on the output shaft assembly 3, at this time, the gear is selected through the operating lever of the gear shift operating mechanism assembly 1, the first and second gear sliding gear sleeves 22 are shifted to the first gear driven gear 20 to be meshed with the joint teeth of the first gear driven gear 20 to be shifted into the first gear, the first gear driven gear 20 drives the auxiliary box gear shaft 30 to rotate through the first and second gear fixing tooth holders 23, the auxiliary box fast gear 16 of the auxiliary box gear shaft 30 is meshed with the big gear 25 of the auxiliary box duplicate gear 15, power is transmitted to the auxiliary box duplicate gear 15, the small gear 42 of the auxiliary box duplicate gear is meshed with the auxiliary box slow gear 33, the auxiliary box duplicate gear 15 transmits power to the auxiliary box slow gear 33, at this time, gear is selected through the side operating mechanism in the gear shift operating mechanism assembly 1, the fast-slow gear sliding gear sleeve 31 is shifted to the auxiliary box slow gear 33, the joint teeth of the fast-slow gear sliding gear sleeve 31 and the auxiliary box slow gear 33 are meshed with and engaged with the slow gear, the auxiliary box slow gear 33 transmits power to the fast-slow gear fixed gear seat 32 through the fast-slow gear sliding gear sleeve 31, and the fast-slow gear fixed gear seat 32 is fixed with the output shaft 18 through a spline, so that the power can be output from two ends of the output shaft.

Reverse gear fast second gear: the power is transmitted from the input shaft 6, and is engaged into the backward gear through the reversing control lever of the gear-shifting control mechanism assembly 1, namely the reversing sliding gear sleeve 11 is shifted to the backward gear reversing gear 9 and is meshed with the joint teeth of the backward gear reversing gear 9, the input shaft 6 drives the backward gear reversing gear 9 to rotate through the reversing fixed gear seat 12, the backward gear reversing gear 9 transmits the power to the intermediate shaft fourth gear 38 on the intermediate shaft assembly 4, as all the gears on the intermediate shaft assembly 4 are fixed on the intermediate shaft 36, the power can be transmitted to the intermediate shaft 36, the intermediate shaft second gear 37 on the intermediate shaft 36 transmits the power to the second gear driven gear 24 on the output shaft assembly 3, at this time, the gear is selected through the control lever of the gear-shifting control mechanism assembly 1, the first-second gear sliding gear sleeve 22 is shifted to the second gear driven gear 24 and is meshed with the joint teeth of the second gear driven gear, the second-gear driven gear 24 drives the auxiliary box gear shaft 30 to rotate through the first-gear and second-gear fixed tooth holders 23, at this time, the side control mechanism in the gear shift control mechanism assembly 1 is used for selecting gears, the fast-slow gear sliding tooth sleeve 31 is shifted to the auxiliary box fast-gear 16 of the auxiliary box gear shaft 30, the engaging teeth of the fast-slow gear sliding tooth sleeve 31 and the auxiliary box fast-gear 16 are meshed and engaged into the fast gear, the auxiliary box fast-gear 16 transmits power to the fast-slow gear fixed tooth holders 32 through the fast-slow gear sliding tooth sleeve 31, and the fast-slow gear fixed tooth holders 32 are fixed with the output shaft 18 through splines, so that the power can be output from two ends of the output shaft.

Forward gear third gear: the power is transmitted from the input shaft 6, and is engaged into the forward gear through the reversing control lever of the gear shift control mechanism assembly 1, namely, the reversing sliding gear sleeve 11 is shifted to the forward gear reversing gear 13 and is engaged with the joint teeth of the forward gear reversing gear 13, when the input shaft 6 rotates, the reversing fixed gear base 12 drives the forward gear reversing gear 13 to rotate, the forward gear reversing gear 13 transmits the power to the three-gear driven gear 29 on the output shaft assembly 3, at the moment, the gear is selected through the control lever of the gear shift control mechanism assembly 1, the three-fourth gear sliding gear sleeve 27 is shifted to the three-gear driven gear 29, the third gear driven gear 29 is engaged with the joint teeth of the three-gear driven gear 29 to be engaged into the third gear, the three-gear driven gear 29 drives the auxiliary box gear shaft 30 to rotate through the three-fourth gear fixed gear base 28, at the moment, the gear is selected through the side control mechanism in the gear shift control mechanism assembly 1, the fast-slow gear sliding gear sleeve, the fast and slow gear sliding gear sleeve 31 is meshed with the joint teeth of the auxiliary box fast gear 16 to be shifted into the fast gear, the auxiliary box gear shaft 30 transmits power to the fast and slow gear fixed gear seat 32 through the fast and slow gear sliding gear sleeve 31, and the fast and slow gear fixed gear seat 32 is fixed with the output shaft 18 through a spline, so that the power can be output from two ends of the output shaft.

Reverse gear slow fourth gear: the power is transmitted from the input shaft 6, and is engaged into the reverse gear through the reversing control lever of the gear shift control mechanism assembly 1, namely the reversing sliding gear sleeve 11 is shifted to the reverse gear reversing gear 9, the reversing sliding gear sleeve 11 is engaged with the engaging teeth of the reverse gear reversing gear 9, the power of the input shaft 6 is transmitted to the reverse gear reversing gear 9, the reverse gear reversing gear 9 transmits the power to the intermediate shaft four-gear 38 on the intermediate shaft assembly 4, as all the gears on the intermediate shaft assembly 4 are fixed on the intermediate shaft 36, the power can be transmitted to the intermediate shaft 36, the intermediate shaft four-gear 38 on the intermediate shaft 36 transmits the power to the four-gear driven gear 26 on the output shaft assembly 3, at this time, the gear is selected through the control lever of the gear shift control mechanism assembly 1, the three-four-gear sliding gear sleeve 27 is shifted to the four-gear driven gear 26, the three-four-gear sliding gear sleeve 27 is, the four-gear driven gear 26 drives the auxiliary box gear shaft 30 to rotate through the three-four-gear fixed gear seat 28, the auxiliary box fast gear 16 of the auxiliary box gear shaft 30 is meshed with the large gear 25 of the auxiliary box duplicate gear 15 to transmit power to the auxiliary box duplicate gear 15, the small gear 42 of the auxiliary box duplicate gear is meshed with the auxiliary box slow gear 33, the auxiliary box duplicate gear 15 transmits power to the auxiliary box slow gear 33, at the moment, the gear is selected through the side operating mechanism in the gear shifting operating mechanism assembly 1, the fast-slow gear sliding gear sleeve 31 is shifted to the auxiliary box slow gear 33, the fast-slow gear sliding gear sleeve 31 is meshed with the joint teeth of the auxiliary box slow gear 33 to be shifted into the slow gear, the auxiliary box slow gear 33 transmits power to the fast-slow gear fixed gear seat 32 through the fast-slow gear sliding gear sleeve 31, and the fast-slow gear fixed gear seat 32 is fixed with the output shaft 18 through splines, and therefore power can be output from two ends of the output shaft.