CN111005999A

CN111005999A - Gear box

Info

Publication number: CN111005999A
Application number: CN201911405020.6A
Authority: CN
Inventors: 陆立峰; 金刚强
Original assignee: Zhejiang Jindao Technology Co ltd
Current assignee: Zhejiang Jindao Technology Co ltd
Priority date: 2019-12-30
Filing date: 2019-12-30
Publication date: 2020-04-14

Abstract

The invention discloses a gearbox, which comprises a first shell, a second shell, a differential assembly, a gear shifting assembly, a torque converter assembly and a PTO assembly, wherein the torque converter assembly comprises a hydraulic torque converter and a turbine shaft; the PTO shaft is installed inside the second shell, the inner gearing oil pump is meshed with the oil pump driving gear, the inner gearing oil pump and the oil pump end cover are fixedly connected with the second shell, one end, close to the oil pump end cover, of the first through hole is provided with an inner spline and is a PTO interface, and the PTO interface is used for installing an external oil pump.

Description

Gear box

Technical Field

The invention relates to the technical field of forklifts, in particular to a gearbox.

Background

Due to the characteristics of stability and comfort of hydraulic drive, hydraulic drive is increasingly widely applied to various machines.

The pressure of most mechanical hydraulic systems comes from a hydraulic pump, and the driving modes of the hydraulic pump are divided into two modes of direct driving of an engine and transmission of a belt pulley of the whole vehicle. The power take-off device is widely used in a small-tonnage forklift through a direct driving mode of a diesel engine, so that a PTO output interface used for driving a hydraulic pump needs to be designed on the diesel engine matched with the small-tonnage forklift to realize power transmission of the PTO.

Therefore, chinese patent publication No. CN200978935Y discloses a forklift hydraulic transmission gearbox with a power take-off (i.e., PTO interface) that has a larger crude oil filtering area and is convenient for mounting an external oil pump. The forklift hydraulic transmission gearbox with the power take-off port comprises a differential, a gear shift gearbox and a hydraulic torque converter, wherein the differential is connected with the gear shift gearbox, a second shell is arranged on the gear shift gearbox, the hydraulic torque converter is arranged in the second shell, an internal meshing oil pump is arranged on the second shell, and a first power take-off port for driving an external oil pump is arranged on the internal meshing oil pump; the utility model has the advantages that: the hydraulic device on the forklift can be arranged on the two power take-off ports, and the power of the oil pump is obtained through the power take-off ports, so that the hydraulic device of the forklift is greatly convenient to arrange; a connecting seat with an oil channel is arranged between the guide wheel shaft and the second shell, so that the oil channel of the hydraulic torque converter is communicated with the oil channel of the gear shifting gearbox, and an oil inlet channel and an oil return channel of the torque converter are formed; the mounting position of the crude oil filter is changed from mounting on the upper part of the gear shifting gearbox to mounting on the lower part of the gear shifting gearbox, so that the filtering area of the crude oil filter is increased, and the resistance of the crude oil filter is reduced; the gear tooth width of the internal meshing oil pump is increased, and the oil supply capacity of the internal meshing oil pump is improved.

However, those skilled in the art find that the above invention has the following technical problems in the process of use:

1) the PTO transmission structure of the invention is not compact enough, and has improved space;

2) the installation directions of the screws cannot be guaranteed to be consistent in the assembling process of the gearbox body due to the gearbox body structure of the gearbox and the PTO transmission structure, so that the assembling reference of the whole gearbox cannot be unified, the matching precision and the installation precision of the assembled gearbox cannot be guaranteed, and the efficiency of the PTO transmission structure is seriously influenced;

3) in the structure of external oil pump's mounting structure PTO interface promptly, the internal gearing oil pump is located the outside, leads to the PTO interface unstable easily, and assembles the difficulty, and assembly cost is great.

Disclosure of Invention

In order to solve the technical problem, the invention provides a gearbox which has a very compact transmission structure, is convenient to install and is provided with a stable PTO interface.

In order to achieve the purpose, the invention adopts the following technical scheme:

a gearbox comprises a first shell, a second shell, a differential assembly, a gear shifting assembly and a transmission assembly, wherein the first shell and the second shell are fixedly connected through a plurality of first bolts and third bolts;

the transmission assembly comprises a torque converter assembly and a PTO assembly, the torque converter assembly comprises a hydraulic torque converter, a pump hub, a first gear and a turbine shaft, the hydraulic torque converter is connected with the gear shifting assembly through the turbine shaft, the pump hub is fixedly connected with the hydraulic torque converter, and the first gear is fixedly connected with the pump hub; it is characterized in that the preparation method is characterized in that,

the PTO assembly comprises a first shaft sleeve, an intermediate shaft and a PTO shaft, wherein the intermediate shaft is sleeved with an intermediate gear, the PTO shaft is sleeved with an oil pump driven gear, an oil pump driving gear, an internal meshing oil pump and an oil pump end cover, the PTO shaft is provided with a first through hole along the axis direction, the first shaft sleeve is fixedly connected with a second shell, the first shaft sleeve is sleeved on a turbine shaft, one end of the first shaft sleeve is positioned in a pump hub, the intermediate gear is respectively meshed with the oil pump driven gear and the first gear, and the intermediate shaft is fixedly connected with the second shell; the PTO shaft is arranged in the second shell, the internal meshing oil pump is meshed with the oil pump driving gear, the internal meshing oil pump and the oil pump end cover are fixedly connected with the second shell, one end, close to the oil pump end cover, of the first through hole is provided with an internal spline and is a PTO interface, and the PTO interface is used for installing an external oil pump;

the gear shifting assembly comprises an input shaft, an output shaft, a gear assembly, a forward gear clutch and a backward gear clutch which are positioned in a first shell, wherein a third gear is fixedly installed on the output shaft, the gear assembly comprises a first gear shaft and a spiral bevel gear which are fixedly connected, the input shaft is in transmission fit with a turbine shaft, the output shaft is in transmission fit with the input shaft, the third gear is in transmission fit with the spiral bevel gear, and the first gear shaft is in transmission fit with a differential assembly.

Preferably, the first shaft sleeve is fixedly connected with the second shell through a third bolt, and the intermediate shaft is fixedly connected with the second shell through a second bolt; wherein the first bolt, the second bolt and the third bolt are all installed towards the direction far away from the hydraulic torque converter.

Preferably, a second platform is arranged in the second shell, the second platform is higher than the bottom in the second shell, the third bolts are mounted on the second platform, the first bolts are mounted on the bottom in the second shell, the intermediate shaft is mounted in the second shell through one of the third bolts, and the third bolts and the first bolts enclose a shape with the cross section of the first shell on the vertical plane.

Preferably, the second platform is provided with a first mounting hole, the bottom in the second shell is provided with a second mounting hole, and the second mounting hole is a stepped hole and is coaxial with the first mounting hole; one end of the middle shaft is abutted to the plane of the second mounting hole;

the middle shaft is sequentially sleeved with a first sealing ring, a first sealing gasket, a first bearing and a second sealing ring along the direction far away from the first shell, the first sealing ring is positioned between the bottom of the first sealing gasket and the second shell and the middle shaft, the inner surface of the first bearing is tightly matched with the middle shaft, and the outer surface of the first bearing is tightly matched with the middle gear; the upper end surface of the first bearing abuts against the intermediate shaft, and the lower end surface of the first bearing abuts against the first sealing pad; the second sealing ring is positioned between the intermediate shaft and the second platform;

the second shell is provided with a first oil inlet and a first oil outlet, the first shaft sleeve is provided with a first oil duct, a first gap is reserved between the first shaft sleeve and the turbine shaft, the first oil duct is communicated with the first oil outlet, and the first gap is communicated with the interior of the hydraulic torque converter and the first oil inlet respectively.

Preferably, the oil pump end cover is located outside the internal meshing oil pump.

Preferably, a fourth bearing and a fifth sealing ring are further sleeved at one end, close to the turbine shaft, of the input shaft, the inner surface of the fourth bearing is in tight fit with the input shaft, the outer surface of the fourth bearing is in tight fit with the second shell, and the fifth sealing ring abuts against the second shell and the input shaft.

Preferably, the gear shifting assembly further comprises an idler shaft, a second gear is fixedly mounted on the output shaft, a forward gear and a backward gear are fixedly mounted on the idler shaft, one end of the input shaft is sleeved on the turbine shaft through a spline, the other end of the input shaft is rotatably mounted on the first shell, one end of the output shaft is rotatably mounted on the second shell, two ends of the first gear shaft are rotatably mounted on the first shell, one end of the idler shaft is rotatably mounted on the second shell, the other end of the idler shaft is rotatably mounted on the first shell, the forward gear clutch is in transmission fit with the forward gear, the backward gear clutch is in transmission fit with the backward gear, and the second gear is meshed with the forward gear.

Preferably, the first shell is internally divided into a first space and a second space by the first platform, the input shaft, the idler shaft and the output shaft are positioned in the first space, and the gear assembly and the third gear on the output shaft are positioned in the second space;

the input shaft, the idler shaft and the output shaft are parallel to the turbine shaft, and the first gear shaft is perpendicular to the turbine shaft;

the deep groove ball bearings are sleeved at two ends of the input shaft;

the two ends of the idler shaft are respectively sleeved with a deep groove ball bearing, the forward gear and the idler shaft are integrally formed, and the backward gear is arranged on the idler shaft through a spline;

one end of the output shaft, which is arranged on the second shell, is also sleeved with a deep groove ball bearing, the third gear is positioned at the other end of the output shaft and is integrally formed with the output shaft, the third gear is a helical gear, and the second gear is arranged on the output shaft through a spline;

the output shaft is also sleeved with two conical roller bearings in pair, the inner surfaces of the two conical roller bearings are tightly matched with the output shaft, and the outer surfaces of the two conical roller bearings are tightly matched with the first platform;

two paired tapered roller bearings are sleeved at two ends of the first gear shaft, the inner surfaces of the two tapered roller bearings are in tight fit with the first gear shaft, and the outer surfaces of the two tapered roller bearings are in tight fit with the first shell.

Preferably, the hydraulic control system is further provided with a valve assembly and a cooler which are installed on the outer surface of the first shell, the valve assembly, the internal meshing oil pump, the external oil pump and the cooler jointly form a proportional hydraulic control system of the gearbox, and the internal meshing oil pump and the external oil pump form an oil pump assembly of the gearbox;

the valve assembly comprises a two-position three-way electromagnetic reversing valve, an electro-hydraulic proportional reversing valve A, an electro-hydraulic proportional reversing valve B, a main pressure regulating valve, a hydraulic torque converter and an overflow valve, the output end of the oil pump assembly is connected with the main pressure regulating valve, the hydraulic torque converter, the overflow valve and a cooler, the oil pump assembly is connected to a lubricating oil way through the main pressure regulating valve, the hydraulic torque converter and the cooler, and the oil pump assembly is connected to an oil return oil way through the main pressure regulating valve and the overflow valve; the forward gear clutch is connected with the two-position three-way electro-hydraulic proportional reversing valve A, the reverse gear clutch is connected with the two-position three-way electro-hydraulic proportional reversing valve B, and the electro-hydraulic proportional reversing valve A and the electro-hydraulic proportional reversing valve B are connected in parallel and then connected with the output end of the oil pump assembly through the two-position three-way electromagnetic reversing valve.

the valve assembly comprises a main pressure regulating valve, an overflow valve, a inching valve, a buffer valve, a gear shifting valve and a compensating valve, the oil pump assembly is connected to a lubricating oil way through the main pressure regulating valve, the torque converter and the cooler, and the oil pump assembly is connected to an oil return oil way through the main pressure regulating valve and the overflow valve; the gear shifting valve is a three-position four-way valve, the forward gear clutch and the backward gear clutch are respectively connected with two working oil ports of the gear shifting valve, an oil return port of the gear shifting valve is connected with an oil return path, an oil inlet of the gear shifting valve is connected with an oil outlet of the inching valve, an oil inlet of the inching valve is connected to the oil pump assembly through a damping hole A, an oil return port of the inching valve is connected with the oil return path, an oil inlet of the buffer valve is connected with an oil outlet of the inching valve, an oil inlet of the compensation valve is connected to the oil pump assembly through a damping hole B.

The invention has the technical effects that:

1) the invention has compact transmission structure, reasonable layout and high space utilization rate.

2) The oil pump end cover is arranged at the outer end of the internally-meshed oil pump, so that the internally-meshed oil pump is protected from being interfered by external factors, and vibration generated by the internally-meshed oil pump in the working process is relieved to a certain extent, so that a PTO (power take off) interface is more stable.

3) The first bolt, the second bolt and the third bolt are arranged in the same direction, so that the assembly standard of the whole gearbox has a unified standard, and the assembly efficiency and the assembly precision are improved.

Drawings

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

FIG. 2 is a second schematic structural view of the transmission of the present invention (with the first and second housings omitted);

FIG. 3 is a partial cross-sectional view of the transmission of the present invention;

FIG. 4 is a partial cross-sectional view of the transmission PTO drive configuration of the transmission of the present invention;

FIG. 5 is an enlarged view of a portion of FIG. 4 of the present invention;

FIG. 6 is a left side view of FIG. 1;

FIG. 7 is a schematic view of the first housing of the present invention;

FIG. 8 is a right side view of FIG. 7;

FIG. 9 is a schematic structural view of a second housing of the present invention;

fig. 10 is a right side view of fig. 9.

Description of reference numerals: 101. a first bolt; 102. a third bolt; 1. a first housing; 11. a first platform; 12. a second oil inlet; 2. a second housing; 30. a differential assembly; 31. a hydraulic torque converter; 32. a pump hub; 33. a first gear; 34. a turbine shaft; 35. a first bushing; 36. an intermediate shaft; 37. a PTO shaft; 38. an intermediate gear; 39. an oil pump driven gear; 40. an oil pump drive gear; 41. an internal engagement oil pump; 42. an oil pump end cover; 103. a second bolt; 43. an input shaft; 44. an idler shaft; 45. an output shaft; 151. a forward clutch; 131. a reverse gear clutch; 48. a forward gear; 49. a reverse gear; 50. a second gear; 51. a third gear; 52. a first gear shaft; 53. a spiral bevel gear; 21. a second platform; 22. a first oil inlet; 23. a first oil outlet; 361. a first oil passage; 362. a first gap; 311. an elastic plate; 201. a filter; 202. a filter; 20. an oil pump assembly; 10. a valve assembly.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be considered as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, unless otherwise specified, "a plurality" means two or more unless explicitly defined otherwise.

In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

A transmission as shown in fig. 1-3, 4 and 6, comprising a first housing 1 and a second housing 2 fixedly connected by a plurality of first bolts 101 and third bolts 102, a differential assembly 30 and a gear shift assembly mounted on the first housing 1, and a transmission assembly mounted on the second housing 2, wherein the differential assembly 30 and the transmission assembly are respectively located at two opposite sides of the first housing 1, and the gear shift assembly is located in the first housing 1;

the transmission assembly comprises a torque converter assembly and a PTO assembly, the torque converter assembly comprises a hydraulic torque converter 31, a pump hub 32, a first gear 33 and a turbine shaft 34, the hydraulic torque converter 31 is connected with the gear shifting assembly through the turbine shaft 34, the pump hub 32 is fixedly connected with the hydraulic torque converter 31, and the first gear 33 is fixedly connected with the pump hub 32;

the PTO assembly comprises a first shaft sleeve 35, an intermediate shaft 36 and a PTO shaft 37, wherein the intermediate shaft 36 is sleeved with an intermediate gear 38, the PTO shaft 37 is sequentially sleeved with an oil pump driven gear 39, an oil pump driving gear 40, an internal meshing oil pump 41 and an oil pump end cover 42 along the same direction, the oil pump driving gear 40 is installed on the PTO shaft 37 through a flat key, the oil pump driven gear 39 is installed on the PTO shaft 37 through a spline, the PTO shaft 37 is provided with a first through hole along the axial direction of the PTO shaft, the first shaft sleeve 35 is fixedly connected with the second shell 2 through a second bolt 103, the first shaft sleeve 35 is sleeved on the turbine shaft 34, one end of the first shaft sleeve is located in the pump hub 32, the intermediate gear 38 is respectively meshed with the oil pump driven gear 39 and the first gear 33, and the intermediate shaft 36; the PTO shaft 37 is mounted inside the second housing 2, the internal meshing oil pump 41 is meshed with the oil pump driving gear 40, the internal meshing oil pump 41 and the oil pump end cover 42 are fixedly connected with the second housing 2, and one end of the first through hole, which is close to the oil pump end cover 42, is provided with an internal spline and is a PTO interface; the PTO interface is used for connecting an external oil pump;

through addding oil pump driven gear 39 and making when installing PTO axle 37 need not be too big with the port internal diameter that is used for installing crescent oil pump 41 on the second casing 2, just so have the space directly at second casing 2 surface mounting crescent oil pump 41, install oil pump end cover 42 in crescent oil pump 41's the outside again, so both had fine guard action to crescent oil pump 41, oil pump end cover 42 also can be more convenient cooperate with external oil pump simultaneously.

The gear shift assembly comprises an input shaft 43, an idler shaft 44, an output shaft 45 and a gear assembly which are positioned in the first shell 1, as well as a forward gear clutch 151 and a backward gear clutch 131 which are arranged on the input shaft 43, a forward gear 48 and a backward gear 49 which are fixedly arranged on the idler shaft 44, and a second gear 50 and a third gear 51 which are fixedly arranged on the output shaft 45, wherein the gear assembly comprises a first gear shaft 52 and a spiral bevel gear 53 which are fixedly connected, one end of the input shaft 43 is sleeved on the turbine shaft 34 through a spline, the other end of the input shaft is rotatably arranged on the first shell 1, one end of the idler shaft 44 is rotatably arranged on the second shell 2, the other end of the idler shaft is rotatably arranged on the first shell 1, one end of the output shaft 45 is rotatably arranged on the second shell 2, and both ends of the first gear shaft 52 are rotatably arranged on the first shell 1, the forward gear clutch 151 is in transmission fit with the forward gear 48, the reverse gear clutch 131 is in transmission fit with the reverse gear 49, the second gear 50 is meshed with the forward gear 48, the third gear 51 is in transmission fit with the spiral bevel gear 53, and the first gear shaft 52 is in transmission fit with the differential assembly 30;

the first bolt 101, the second bolt 103, and the third bolt 102 are mounted in the same direction, i.e., in a direction away from the torque converter 31.

So set up, when a plurality of spare parts in the installation second casing 2, only need install towards a direction, in the installation promptly, need not rotate the gearbox that turns in order to adjust the direction, both easy to assemble can obtain very high assembly precision again.

In the embodiment of the present application, as shown in fig. 9 and 10, a second platform 21 is arranged in the second casing 2, the second platform 21 is higher than the bottom in the second casing 2, the third bolts 102 are mounted on the second platform 21, the first bolts 101 are mounted on the bottom in the second casing 2, the intermediate shaft 36 is mounted in the second casing 2 through one of the third bolts 102, and the third bolts 102 and the first bolts 101 enclose a shape that is consistent with the cross section of the first casing 1 in the vertical plane; further preferably, the cross section of the first casing 1 on the vertical surface is rectangular, and the plurality of third bolts 102 and the plurality of first bolts 101 enclose a rectangular shape; with such a configuration, the intermediate shaft 36 is installed in the second housing 2 through the third bolt 102 for fixing the second housing 2 to the first housing 1, so that firstly, the assembly reference of the bolts is unified, and then, the assembly precision of the transmission is improved, and secondly, the intermediate shaft 36 is stably installed in the second housing 2.

In the embodiment of the present application, a first mounting hole is formed in the second platform 21, a second mounting hole is formed in the bottom of the second casing 2, and the second mounting hole is a stepped hole and is coaxial with the first mounting hole; one end of the middle shaft 36 is abutted in the plane of the second mounting hole;

the middle shaft 36 is sequentially sleeved with a first sealing ring, a first sealing gasket, a first bearing and a second sealing ring along the direction far away from the first shell 1, the first sealing ring is positioned between the bottom of the first sealing gasket and the second shell 2 and the middle shaft 36, the inner surface of the first bearing is tightly matched with the middle shaft 36, and the outer surface of the first bearing is tightly matched with the middle gear 38; the upper end surface of the first bearing abuts against the intermediate shaft 36 and the lower end surface of the first bearing abuts against the first sealing gasket; the second sealing ring is positioned between the intermediate shaft 36 and the second platform 21; the first bearing is a short cylindrical roller bearing. So set up, reach sealed purpose through first sealing washer and second sealing washer, and the second sealing washer is very short with the friction route of second platform 21 in the installation, the effectual sealing performance who guarantees the second sealing washer.

A first oil inlet 22 and a first oil outlet 23 are formed in the second shell 2, a first oil duct 361 is formed in the first shaft sleeve 35, a first gap 362 is reserved between the first shaft sleeve 35 and the turbine shaft 34, the first oil duct 361 is communicated with the first oil outlet 23, and the first gap 362 is respectively communicated with the interior of the hydraulic torque converter 31 and the first oil inlet 22; further preferably, the first shaft sleeve 35 includes a first base, a first shaft body and a second shaft body which are integrally formed, the first base is fixedly connected with the second housing 2 through a plurality of second bolts 103, and the first shaft body and the first base are provided with a first oil passage 361 together. With this arrangement, only one first oil channel 361 is provided on the first sleeve 35, and the first gap 362 is left as the second oil channel, so that the first base, the first shaft body, and the second shaft body can be integrally formed without being fixedly connected by bolts, and the installation direction of the second bolt 103 can be the same as the installation direction of the first bolt 101 and the third bolt 102.

In the embodiment of the present application, a fourth bearing and a fifth seal ring are further sleeved on one end of the input shaft 43 close to the turbine shaft 34, an inner surface of the fourth bearing is tightly fitted with the input shaft 43, an outer surface of the fourth bearing is tightly fitted with the second housing 2, and the fifth seal ring abuts against the second housing 2 and the input shaft 43; more preferably, the fourth bearing is a deep groove ball bearing. This is because the pressure oil passes along the surface of the turbine shaft 34, and therefore, it is necessary to ensure the sealing property between the input shaft 43 and the second housing 2 to ensure that no pressure oil in the first gap 362 enters the first housing 1.

In the embodiment of the present application, the pump hub 32 is fixedly connected to the torque converter 31 by welding, the first gear 33 is fixedly connected to the pump hub 32 by a bolt, a third seal ring is further provided between the pump hub 32 and the first gear 33, and a first oil seal is further provided between the first gear 33 and the second housing 2. The arrangement can ensure the stability of the pump hub 32 and the first gear 33 in the transmission process and ensure the sealing performance.

It should be noted that, although the mounting direction of the bolts between the first gear 33 and the pump hub 32 is different from that of the first bolt 101, the second bolt 103, and the third bolt 102, the first gear 33, the pump hub 32, and the torque converter 31 are integrally mounted on the second housing 2 during the assembly process of the embodiment of the present application, and therefore, the mounting reference of the entire transmission is not affected.

In the embodiment of the present application, as shown in fig. 5, there are further provided a fourth sealing ring, a second bearing and a third bearing, the inner surface of the second bearing is tightly fitted with the PTO shaft 37, and the outer surface of the second bearing is tightly fitted with the second housing 2, the inner surface of the third bearing is tightly fitted with the PTO shaft 37, and the outer surface of the third bearing is tightly fitted with the second housing 2, the fourth sealing ring is abutted against the PTO shaft 37 and the second housing 2 and is located between the second bearing and the third bearing; preferably, the second bearing and the third bearing are both deep groove ball bearings; so set up, make PTO installation convenient, guaranteed the axiality between PTO axle 37 and PTO interface again.

In the embodiment of the present application, as shown in fig. 7 and 8, the first platform 11 divides the interior of the first casing 1 into a first space and a second space, the input shaft 43, the idler shaft 44 and the output shaft 45 are located in the first space, and the gear assembly and the third gear 51 on the output shaft 45 are located in the second space;

the input shaft 43, the idler shaft 44 and the output shaft 45 are parallel to the turbine shaft 34, and the first gear shaft 52 is perpendicular to the turbine shaft 34;

the two ends of the input shaft 43 are sleeved with deep groove ball bearings;

the two ends of the idler shaft 44 are respectively sleeved with a deep groove ball bearing, the forward gear 48 and the idler shaft 44 are integrally formed, and the backward gear 49 is arranged on the idler shaft 44 through a spline;

the output shaft 45 is further sleeved with a deep groove ball bearing at one end of the second shell 2, the third gear 51 is located at the other end of the output shaft 45 and is integrally formed with the output shaft 45, the third gear 51 is a helical gear, and the second gear 50 is mounted on the output shaft 45 through a spline;

the output shaft 45 is also sleeved with two conical roller bearings in pair, the inner surfaces of the two conical roller bearings are tightly matched with the output shaft 45, and the outer surfaces of the two conical roller bearings are tightly matched with the first platform 11;

two paired tapered roller bearings are sleeved at two ends of the first gear shaft 52, the inner surfaces of the two tapered roller bearings are tightly matched with the first gear shaft 52, and the outer surfaces of the two tapered roller bearings are tightly matched with the first shell 1.

In the embodiment of the present application, the first housing 1 is provided with a second oil inlet 12, the input shaft 43 is provided with a second oil passage, a third oil passage and a fourth oil passage along the axial direction, the second oil passage, the third oil passage and the fourth oil passage are arranged in a shape of Chinese character 'pin', the side surface of the input shaft 43 is provided with a plurality of passages respectively communicated with the second oil passage, the third oil passage and the fourth oil passage, and the second oil passage is communicated with the second oil inlet 12.

In the embodiment of the present application, an elastic plate 311 is disposed on the side of the torque converter 31 away from the first housing 1, and the elastic plate 311 is connected to a flywheel of the engine; further, the power transmission relationship of the PTO is as follows:

engine → pump hub 32 → first gear 33 → intermediate shaft 36 → oil pump driven gear 39 → PTO shaft 37 → external oil pump;

meanwhile, the internal meshing oil pump 41 can also work normally, and the power transmission relationship is as follows:

engine → pump hub 32 → first gear 33 → intermediate shaft 36 → oil pump driven gear 39 → PTO shaft 37 → oil pump drive gear 40 → internal gear oil pump 41;

in the embodiment of the present application, the torque converter 31 is driven by the engine through the elastic plate 311, drives the pump wheel to rotate, and makes the fluid flow into the turbine wheel at high speed along the blade direction, and pushes the turbine wheel to rotate, and the stator wheel makes the torque converter generate the torque conversion effect, and transmits the torque to the hydraulic transmission gearbox input shaft 43 through the turbine shaft 34, and when the forward gear is engaged, the reverse gear clutch 131 idles, and the power transmission sequence is:

input shaft 43 → forward clutch 151 → forward gear 48 → second gear 50 → output shaft 45 → third gear 51 → spiral bevel gear 53 → differential output;

when the reverse gear is engaged, the forward clutch 151 idles, and the power transmission sequence is:

input shaft 43 → reverse clutch 131 → reverse gear 49 → idler shaft 44 → forward gear 48 → second gear 50 → output shaft 45 → third gear 51 → spiral bevel gear 53 → differential output;

in the embodiment of the present application, a valve assembly 10 and a cooler 141 installed on the outer surface of the first housing 1 are further provided, the valve assembly 10, the internal oil pump 41, the external oil pump and the cooler 141 jointly form a proportional hydraulic control system of the transmission, and the internal oil pump 41 and the external oil pump form an oil pump assembly 20 of the transmission.

The first specific structure of the valve assembly 10 comprises a two-position three-way electromagnetic directional valve, an electro-hydraulic proportional directional valve A, an electro-hydraulic proportional directional valve B, a main pressure regulating valve, a hydraulic torque converter and an overflow valve, wherein the output end of the oil pump assembly is connected with the main pressure regulating valve, the hydraulic torque converter, the overflow valve and a cooler; the forward gear clutch is connected with the two-position three-way electro-hydraulic proportional reversing valve A, the backward gear clutch is connected with the two-position three-way electro-hydraulic proportional reversing valve B, and the electro-hydraulic proportional reversing valve A and the electro-hydraulic proportional reversing valve B are connected in parallel and then connected with the output end of the oil pump assembly through the two-position three-way electromagnetic reversing valve;

the working principle is as follows: when the two-position three-way electromagnetic reversing valve, the electro-hydraulic proportional reversing valve A and the electro-hydraulic proportional reversing valve B do not work, the forward gear clutch and the backward gear clutch are both connected with an oil return path and are in a separated state, no power is transmitted, and the gearbox is in a neutral position state; when the two-position three-way electromagnetic reversing valve and the electro-hydraulic proportional reversing valve A work, part of power oil enters the forward gear clutch through the two-position three-way electromagnetic reversing valve and the electro-hydraulic proportional reversing valve A, the forward gear clutch is connected, the electro-hydraulic proportional reversing valve B does not work, the backward gear clutch is connected with an oil return oil path and is in a separation state, power is transmitted to the forward direction, and the gearbox is in a forward gear state; when the two-position three-way electromagnetic reversing valve and the electro-hydraulic proportional reversing valve B work, part of power oil enters the backward gear clutch through the two-position three-way electromagnetic reversing valve and the electro-hydraulic proportional reversing valve B, the backward gear clutch is connected, the electro-hydraulic proportional reversing valve A does not work, the forward gear clutch is connected with return oil and is in a separated state, power is transmitted in the backward direction, and the gearbox is in the backward gear state.

The second specific structure of the valve assembly 10 comprises a main pressure regulating valve, an overflow valve, a inching valve, a buffer valve, a gear shifting valve and a compensating valve, wherein an oil pump assembly is connected to a lubricating oil path through the main pressure regulating valve, a torque converter and a cooler, and is connected to an oil return path through the main pressure regulating valve and the overflow valve; the gear shifting valve is a three-position four-way valve, the forward gear clutch and the backward gear clutch are respectively connected with two working oil ports of the gear shifting valve, an oil return port of the gear shifting valve is connected with an oil return path, an oil inlet of the gear shifting valve is connected with an oil outlet of the inching valve, an oil inlet of the inching valve is connected to the oil pump assembly through a damping hole A, an oil return port of the inching valve is connected with the oil return path, an oil inlet of the buffer valve is connected with an oil outlet of the inching valve, an oil inlet of the compensation valve is connected to the oil pump assembly through a damping hole B. The inching valve is a three-position three-way valve, and the compensating valve is a two-position two-way valve;

the working principle is as follows: the oil pump assembly 20 provides power oil for the hydraulic system. The main pressure regulating valve controls the system pressure, the pressure is set to be 0.9-1.1 MPa, and redundant hydraulic oil overflows through the main pressure regulating valve, flows through the torque converter and the cooler and then enters the lubricating oil way; the pressure of the torque converter oil path is controlled by an overflow valve at 0.3-0.6 MPa.

The hydraulic oil supplied to the clutch oil path by the oil pump assembly 20 flows through the inching valve after being throttled by the damping hole, and simultaneously fills the buffer valve with liquid; when the charging pressure (shown as the pressure at the point A) reaches the set pressure, the compensation valve is converted from the normally closed function to the normally open function. The hydraulic oil supplied to the clutch oil path by the oil pump flows through the damping hole, passes through the compensating valve and then merges with the oil flowing out of the inching valve to an oil inlet (point A in the figure) of the shift valve. When the current gear shifting valve is in a neutral position, oil inlets of a forward gear clutch piston and a backward gear clutch piston are communicated with an oil return path, the clutches are in a release state, and the gearbox is in a neutral position state. When the gear shifting valve is in a left functional position, the oil path at the point A is communicated with the reverse gear clutch piston, the forward gear clutch piston is communicated with the oil return oil path, the reverse gear clutch is in an engaged state, the forward gear clutch is in a released state, and the gearbox is in a reverse gear engaged state. When the gear shifting valve is in the right functional position, the oil path at the point A is communicated with the forward gear clutch piston, and the reverse gear clutch piston is communicated with the oil return path. The forward gear clutch is in an engaged state, the reverse gear clutch is in a released state, and the gearbox is in a forward gear engaged state.

The two ends of the oil pump assembly 20 are respectively connected with a filter 202 and a filter 201, wherein the filter 202 is installed inside the first casing 1, and the filter 201 is transversely installed outside the first casing 1 and on the side of the valve assembly 10. So configured, it is easier to replace than a conventional upright filter 201.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made in the above embodiments by those of ordinary skill in the art without departing from the principle and spirit of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A gearbox comprises a first shell (1) and a second shell (2) which are fixedly connected through a plurality of first bolts (101) and third bolts (102), a differential assembly (30) and a gear shifting assembly which are installed on the first shell (1), and a transmission assembly which is installed on the second shell (2), wherein the differential assembly (30) and the transmission assembly are respectively positioned on two opposite sides of the first shell (1), and the gear shifting assembly is positioned in the first shell (1);

the transmission assembly comprises a torque converter assembly and a PTO assembly, the torque converter assembly comprises a hydraulic torque converter (31), a pump hub (32), a first gear (33) and a turbine shaft (34), the hydraulic torque converter (31) is connected with the gear shifting assembly through the turbine shaft (34), the pump hub (32) is fixedly connected with the hydraulic torque converter (31), and the first gear (33) is fixedly connected with the pump hub (32); it is characterized in that the preparation method is characterized in that,

the PTO assembly comprises a first shaft sleeve (35), an intermediate shaft (36) and a PTO shaft (37), wherein the intermediate shaft (36) is sleeved with an intermediate gear (38), the PTO shaft (37) is sleeved with an oil pump driven gear (39), an oil pump driving gear (40), an internal meshing oil pump (41) and an oil pump end cover (42), the PTO shaft (37) is provided with a first through hole along the axis direction, the first shaft sleeve (35) is fixedly connected with a second shell (2), the first shaft sleeve (35) is sleeved on a turbine shaft (34) and one end of the first shaft sleeve is positioned in a pump hub (32), the intermediate gear (38) is respectively meshed with the oil pump driven gear (39) and a first gear (33), and the intermediate shaft (36) is fixedly connected with the second shell (2); the PTO shaft (37) is mounted inside the second shell (2), the internal meshing oil pump (41) is meshed with the oil pump driving gear (40), the internal meshing oil pump (41) and the oil pump end cover (42) are fixedly connected with the second shell (2), one end, close to the oil pump end cover (42), of the first through hole is provided with an internal spline and is a PTO interface, and the PTO interface is used for mounting an external oil pump;

the gear shifting assembly comprises an input shaft (43), an output shaft (45), a gear assembly, a forward gear clutch (151) and a backward gear clutch (131) which are positioned in a first shell (1), wherein a third gear (51) is fixedly mounted on the output shaft (45), the gear assembly comprises a first gear shaft (52) and a spiral bevel gear (53) which are fixedly connected, the input shaft (43) is in transmission fit with a turbine shaft (34), the output shaft (45) is in transmission fit with the input shaft (43), the third gear (51) is in transmission fit with the spiral bevel gear (53), and the first gear shaft (52) is in transmission fit with a differential assembly (30).

2. A gearbox according to claim 1, characterised in that said first sleeve (35) is fixedly connected to the second casing (2) by means of a third bolt (102), said intermediate shaft (36) being fixedly connected to the second casing (2) by means of a second bolt (103); wherein the first bolt (101), the second bolt (103) and the third bolt (102) are all installed towards the direction far away from the hydraulic torque converter (31).

3. A gearbox according to claim 2, characterised in that a second platform (21) is arranged in said second casing (2), said second platform (21) being higher than the bottom in said second casing (2), said number of third bolts (102) being mounted on said second platform (21), said number of first bolts (101) being mounted on the bottom in said second casing (2), said intermediate shaft (36) being mounted in said second casing (2) by means of one of said third bolts (102), said number of third bolts (102) and said number of first bolts (101) enclosing a shape corresponding to the vertical cross-section of said first casing (1).

4. A gearbox according to claim 3 characterised in that the second platform (21) is provided with a first mounting hole and the bottom of the second housing (2) is provided with a second mounting hole which is a stepped hole and is coaxial with the first mounting hole; one end of the middle shaft (36) is abutted in the plane of the second mounting hole;

the middle shaft (36) is sequentially sleeved with a first sealing ring, a first sealing gasket, a first bearing and a second sealing ring along the direction far away from the first shell (1), the first sealing ring is positioned between the bottom of the first sealing gasket and the second shell (2) and the middle shaft (36), the inner surface of the first bearing is tightly matched with the middle shaft (36), and the outer surface of the first bearing is tightly matched with the middle gear (38); the upper end surface of the first bearing abuts against the intermediate shaft (36) and the lower end surface of the first bearing abuts against the first sealing gasket; the second sealing ring is positioned between the intermediate shaft (36) and the second platform (21);

the hydraulic torque converter is characterized in that a first oil inlet (22) and a first oil outlet (23) are formed in the second shell (2), a first oil duct (361) is formed in the first shaft sleeve (35), a first gap (362) is reserved between the first shaft sleeve (35) and the turbine shaft (34), the first oil duct (361) is communicated with the first oil outlet (23), and the first gap (362) is communicated with the interior of the hydraulic torque converter (31) and the first oil inlet (22) respectively.

5. A gearbox according to claim 1, characterised in that the pump end cover (42) is located outside the internal gearing pump (41).

6. A gearbox according to claim 1 in which the end of the input shaft (43) adjacent to the turbine shaft (34) is also fitted with a fourth bearing having an inner surface that is a close fit with the input shaft (43) and an outer surface that is a close fit with the second housing (2) and a fifth seal that bears against the second housing (2) and the input shaft (43).

7. A gearbox according to claim 1, characterised in that said gear shift assembly further comprises an idler shaft (44), said output shaft (45) is further fixedly mounted with a second gear (50), said idler shaft (44) is further fixedly mounted with a forward gear (48) and a reverse gear (49), said input shaft (43) is splined on a turbine shaft (34) at one end and rotatably mounted on a first housing (1) at the other end, said output shaft (45) is rotatably mounted on a second housing (2) at one end, said first gear shaft (52) is rotatably mounted on the first housing (1) at both ends, said idler shaft (44) is rotatably mounted on the second housing (2) at one end and rotatably mounted on the first housing (1) at the other end, said forward clutch (151) is in driving engagement with the forward gear (48), the reverse gear clutch (131) is in transmission fit with the reverse gear (49), and the second gear (50) is meshed with the forward gear (48).

8. A gearbox according to claim 7 characterised in that the interior of the first housing (1) is divided into a first space and a second space by the first platform (11), the input shaft (43), the idler shaft (44) and the output shaft (45) being located in the first space, the gear assembly and the third gear (51) on the output shaft (45) being located in the second space;

the input shaft (43), the idler shaft (44) and the output shaft (45) are parallel to the turbine shaft (34), and the first gear shaft (52) is perpendicular to the turbine shaft (34);

the two ends of the input shaft (43) are sleeved with deep groove ball bearings;

the deep groove ball bearings are sleeved at two ends of the idler shaft (44), the forward gear (48) and the idler shaft (44) are integrally formed, and the backward gear (49) is arranged on the idler shaft (44) through a spline;

one end of the output shaft (45) mounted on the second shell (2) is further sleeved with a deep groove ball bearing, the third gear (51) is located at the other end of the output shaft (45) and is integrally formed with the output shaft (45), the third gear (51) is a helical gear, and the second gear (50) is mounted on the output shaft (45) through a spline;

the output shaft (45) is also sleeved with two conical roller bearings in pair, the inner surfaces of the two conical roller bearings are tightly matched with the output shaft (45), and the outer surfaces of the two conical roller bearings are tightly matched with the first platform (11);

two paired tapered roller bearings are sleeved at two ends of the first gear shaft (52), the inner surfaces of the two tapered roller bearings are tightly matched with the first gear shaft (52), and the outer surfaces of the two tapered roller bearings are tightly matched with the first shell (1).

9. A transmission according to claim 1, further comprising a valve assembly and a cooler mounted on an outer surface of the first housing, the valve assembly, the internal gearing oil pump, the external oil pump and the cooler together forming a proportional hydraulic control system for the transmission, the internal gearing oil pump and the external oil pump forming an oil pump assembly for the transmission;

10. A transmission according to claim 1, further comprising a valve assembly and a cooler mounted on an outer surface of the first housing, the valve assembly, the internal gearing oil pump, the external oil pump and the cooler together forming a proportional hydraulic control system for the transmission, the internal gearing oil pump and the external oil pump forming an oil pump assembly for the transmission;