CN111853216A

CN111853216A - Lubricating structure on hydraulic transmission

Info

Publication number: CN111853216A
Application number: CN202010669383.7A
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: 2020-07-13
Filing date: 2020-07-13
Publication date: 2020-10-30

Abstract

The invention relates to the field of vehicle transmission, in particular to a lubricating structure on a hydraulic transmission, which comprises a transmission shell, a transmission input shaft, a forward clutch device, a reverse clutch device and an output shaft device, wherein the transmission input shaft, the forward clutch device, the reverse clutch device and the output shaft device are arranged in the transmission shell; the forward clutch device comprises a forward clutch gear and a forward fixed gear; the in-vehicle clutch gear is connected with the input shaft of the gearbox or the in-vehicle fixed gear through an inner friction plate pair and an outer friction plate pair; a first lubricating oil channel is arranged inside the side wall of the input shaft of the gearbox, the outer end of the first lubricating oil channel is communicated with the shaft end of the central rotating shaft, and at least two second radial oil holes which are formed in the outer wall surface of the input shaft of the gearbox and face towards the inner friction plate pair, the outer friction plate pair and the bearing respectively are formed in the inner end of the first lubricating oil channel. The structure can realize the targeted lubrication of the inner and outer friction plate pairs and the bearing in the clutch device; the lubrication efficiency is higher, i.e. the lubrication is achieved by a smaller amount of lubricating oil.

Description

Lubricating structure on hydraulic transmission

Technical Field

The invention relates to the field of vehicle transmission, in particular to a lubricating structure on a hydraulic transmission.

Background

In the material handling industry, diesel fork lift trucks are widely used. The gearboxes for the internal combustion forklift include common mechanical gearboxes and hydraulic gearboxes. Because the hydraulic transmission case transfers energy through hydraulic medium (transmission oil), compared with the mechanical transmission case, the hydraulic transmission case has the advantages of stable transmission, low noise, comfortable operation and the like, thereby having wider application. A traditional hydraulic transmission adopts a multi-plate wet clutch, and forward or backward movement is realized by a single clutch under the action of hydraulic oil.

The lubrication of the clutch device in the existing hydraulic transmission can refer to the clutch hub for the automatic transmission disclosed in the Chinese utility model patent text with the publication number of "CN 202301537U", and comprises a first clutch inner hub, a second clutch outer hub and a piston, wherein the first clutch inner hub is provided with an oil outlet, the second clutch outer hub is provided with a second clutch outer hub supporting shaft, the second clutch outer hub is provided with an extension part, and the extension part extends between the first clutch inner hub and the piston; the first clutch inner hub, the extension part and the second clutch outer hub support shaft form an oil pocket. This technical scheme is through oil outlet and pocket oil duct intercommunication, has solved the not enough and difficult problem of processing of a plurality of clutch spatial arrangement in traditional many grades of gearbox design, has compressed the space of many grades of automatic gearbox, makes its structure compacter, and processing is more simple and convenient, and the low cost more of cost has solved the lubrication problem of friction disc in the first clutch simultaneously under the condition of practicing thrift the space and reducing the processing degree of difficulty. However, in the scheme, the oil outlet hole and the oil pocket oil channel are far away from the inner and outer friction plate pairs, so that the friction plates cannot be directly lubricated, namely, the friction plates can be lubricated by a large amount of lubricating oil.

On the basis, due to the stable and comfortable characteristic of hydraulic drive, the hydraulic drive is more and more 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. Different PTO transmission routes and transmission structures not only influence the compactness of the whole gearbox structure, but also influence the whole transmission efficiency; there is room for improvement in existing PTO transmission routes.

The hydraulic transmission gearbox disclosed in the patent publication of Chinese invention with the reference publication number "CN 104315109A" comprises a gearbox assembly, a reducer drive axle assembly and a proportional hydraulic control system, wherein the gearbox assembly and the reducer drive axle assembly are in power transmission connection through a universal coupling, and the gearbox assembly and the reducer drive axle assembly are in box body connection through an elastic support component; the transmission assembly comprises a transmission case shell and a torque converter shell which are fixed together, the torque converter assembly is arranged in the torque converter shell, an output gear, an output flange, an intermediate shaft assembly, an input shaft assembly, an oil inlet shaft sleeve assembly, a driving gear, a PTO gear and an inner pump gear are arranged in the transmission case shell, the input shaft assembly comprises a forward gear clutch, and the intermediate shaft assembly comprises a backward gear clutch. As shown in fig. 2 of the patent, the PTO shaft and its gears are connected to the input shaft assembly, which then transmits power to the oil pump assembly through the internal pump gears.

If chinese utility model patent that publication number is CN210591394U discloses a take tractor power take-off of wet clutch again, include the power input shaft of being connected with engine drive, still establish including establishing in proper order the power output shaft and the power connecting axle of power input shaft, the power output shaft transmission is connected with variable speed output system, slip the cover between power output shaft and the power connecting axle and be equipped with the cover that slides, the power input shaft is connected with the mount pad that is used for installing the inner plate on the wet clutch, the power connecting axle is connected the shell that is used for installing the outer piece on the wet clutch, PTO power take-off is connected in the shell transmission, still including being used for slide the cover with the control system of wet clutch work. The PTO power take off system of this solution also employs a separate drive tooth attached to the power coupling shaft.

The scheme is that on the basis of optimizing the transmission mode of the PTO shaft, the interior of the hydraulic transmission gearbox is optimized by combining the in-vehicle clutch device, and a lubricating structure is provided.

Disclosure of Invention

In order to solve the above problems, an object of the present invention is to provide a lubrication structure for a hydraulic transmission, which can perform targeted lubrication of an inner and outer friction plate pair and a bearing in a clutch device; the lubrication efficiency is higher, i.e. the lubrication is achieved by a smaller amount of lubricating oil.

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

a lubrication structure on a hydraulic transmission comprises a transmission shell, and a transmission input shaft, a forward clutch device, a reverse clutch device and an output shaft device which are arranged in the transmission shell; the forward clutch device comprises a forward clutch gear and a first gear, wherein the forward clutch gear is sleeved on an input shaft of the gearbox through a bearing, and the first gear is connected with the input end of the reverse clutch device; the forward clutch gear is connected with the input shaft of the gearbox or the first gear through an inner friction plate pair and an outer friction plate pair; the method is characterized in that: the side wall of the input shaft of the gearbox is internally provided with a first lubricating oil channel, the outer end of the first lubricating oil channel is communicated with the shaft end of the central rotating shaft, the inner end of the first lubricating oil channel is provided with at least two second radial oil holes which are arranged on the outer wall surface of the input shaft of the gearbox, the two second radial oil holes respectively face the inner friction plate pair and the outer friction plate pair, and a bearing between the sequential clutch gear and the input shaft of the gearbox.

The invention adopts the technical scheme, which relates to a lubricating structure on a hydraulic transmission, wherein the lubricating structure is used for lubricating a forward clutch device connected to an input shaft of the transmission, and particularly the forward clutch device comprises a forward clutch gear sleeved on the input shaft of the transmission through a bearing and a first gear connected with the input end of the reverse clutch device; the sequential clutch gear is connected with the input shaft of the gearbox or the first gear through an inner friction plate pair and an outer friction plate pair. In the traditional scheme, a lubricating oil hole in the clutch device is formed in a clutch hub, and the inner and outer friction plate pairs and bearings in the clutch device cannot be lubricated through the lubricating oil hole. In the scheme, a first lubricating oil channel is arranged in the side wall of the input shaft of the gearbox, and the outer end of the first lubricating oil channel is arranged at the shaft end of the central rotating shaft and can be used for connecting an oil circuit; two second radial oil holes are formed in the inner end of the first lubricating oil channel, face the inner friction plate pair and the outer friction plate pair respectively, and a bearing is arranged between the forward clutch gear and the input shaft of the gearbox. By the structure, the scheme can realize the targeted lubrication of the inner and outer friction plate pairs and the bearing in the clutch device; the lubrication efficiency is higher, i.e. the lubrication is achieved by a smaller amount of lubricating oil.

Preferably, the gearbox input shaft is a hollow shaft rod, a PTO shaft penetrates through the interior of the gearbox input shaft, and the PTO is positioned in the interior of the gearbox input shaft at least through bearings at two end parts of the PTO shaft and is arranged concentrically with the gearbox input shaft; the outer end of the PTO shaft is connected with the torque converter, and the inner end of the PTO shaft is connected with the oil pump. Compared with the prior art, the PTO shaft and the input shaft assembly are in a gear transmission mode. According to the scheme, the torque converter can directly drive the oil pump through the PTO shaft, so that the transmission mode of the PTO shaft is optimized; in addition, in the installation mode, the transmission box does not need to be connected with the input shaft of the transmission box through a gear, so that the installation structure is simplified, the transmission box can be more compact, and the space optimization of the transmission structure on the whole machine is facilitated. Furthermore, the PTO shaft in the scheme is arranged in the input shaft of the gearbox in a penetrating mode, even the PTO shaft is arranged without occupying other space in the gearbox, and the space occupied by the PTO shaft device in the traditional gearbox is saved.

Preferably, a first lubricating oil channel is arranged in the side wall of the input shaft of the gearbox, the outer end of the first lubricating oil channel is communicated with the shaft end of the central rotating shaft, a first radial oil hole is formed in the inner end of the first lubricating oil channel and communicated with a gap between the input shaft of the gearbox and the PTO shaft of the gearbox, and the first radial oil hole is formed in the inner wall surface of the input shaft of the gearbox between the two groups of bearings. In addition to the above-described solution, the solution also needs to solve the problem of bearing lubrication provided between the inner and outer end side walls of the PTO shaft and the shaft hole inner wall of the transmission input shaft. Therefore, furthermore, the first lubricating oil channel is arranged inside the side wall of the input shaft of the gearbox, and the outer end of the first lubricating oil channel is arranged at the shaft end of the central rotating shaft and can be used for connecting an oil circuit; the inner end of the first lubricating oil channel is arranged on the inner wall surface of the input shaft of the gearbox, and the lubricating oil can enter a gap between the PTO shaft and the input shaft of the gearbox from the inner end of the first lubricating oil channel and flows to two axial ends to lubricate bearings on two sides respectively.

Preferably, an outer end of the PTO shaft is connected to the torque converter, and an inner end of the PTO shaft is connected to the oil pump coupling.

Preferably, a sealing component is arranged between the side wall of the outer end part of the PTO shaft and the inner wall of the shaft hole of the input shaft of the gearbox; or a bearing between the side wall of the outer end part of the PTO shaft and the inner wall of the shaft hole of the input shaft of the gearbox is a sealing bearing assembly so as to realize the sealing between the PTO shaft and the input shaft of the gearbox. In the technical scheme, the PTO shaft penetrates into the transmission input shaft and can realize circumferential relative rotation of the PTO shaft and the transmission input shaft, and the PTO shaft can be realized by adopting two groups of bearings at the inner end part and the outer end part of the PTO shaft. In addition, in order to prevent oil in the torque converter from flowing between the PTO shaft and the transmission input shaft, it is necessary to seal the outer end side wall of the PTO shaft and the shaft hole inner wall of the transmission input shaft. Two sealing schemes are provided, one is to directly arrange a sealing part (such as a sealing ring) for sealing; alternatively, the bearing is selected as a sealing bearing assembly, such as a bimetallic sliding bearing, which can also achieve the purpose of sealing.

Preferably, the forward clutch gear is fixedly connected with a clutch hub, and the clutch hub is connected with the input shaft of the gearbox through an inner friction plate pair and an outer friction plate pair; the inner friction plate pair and the outer friction plate pair comprise a plurality of outer friction plates and inner friction plates which are arranged at intervals, the outer friction plates and the clutch hub are circumferentially positioned and can axially move relatively, and the inner friction plates and the transmission input shaft are circumferentially positioned and can axially move relatively. The technical scheme is one embodiment, and in the embodiment, the clutch hub is fixedly connected with the forward clutch gear. In the existing scheme, the clutch hub and the central rotating shaft are welded and fixed. Therefore, compared with the prior art, the installation mode of the clutch hub in the scheme is simplified, the clutch hub does not need to be integrally welded and is carburized, the width of the sliding groove in the clutch hub can be accurately controlled, the width of the sliding groove in the clutch hub is matched with the width of the outer friction plate, axial movement can be achieved, and shaking in the using process caused by circumferential looseness can be avoided.

Preferably, the first gear is fixedly connected with a clutch hub, and the clutch hub is connected with the gear clutch gear through an inner friction plate pair and an outer friction plate pair; the inner friction plate pair and the outer friction plate pair comprise a plurality of outer friction plates and inner friction plates which are arranged at intervals, the outer friction plates and the clutch hub are circumferentially positioned and can axially move relatively, and the inner friction plates and the forward clutch gear are circumferentially positioned and can axially move relatively. This solution is another embodiment in which the clutch hub is connected to the first gear as in the prior art, but the central rotating shaft and the fixed gear integrally connected thereto form an area for mounting the hydraulic drive assembly, so that the clutch hub and the fixed gear can be detachably connected, such as by bolts, without using the welding and fixing method in the prior art; therefore, compared with the mode that the clutch hub and the central rotating shaft are welded and fixed in the prior art, the scheme also simplifies the installation mode of the clutch hub.

Preferably, the reversing clutch device comprises a reversing shaft, a reversing clutch gear sleeved on the reversing shaft through a bearing, and a second gear meshed with the first gear; the reversing clutch gear is connected with the reversing shaft or the second gear through an inner friction plate pair and an outer friction plate pair; and a second lubricating oil channel is arranged in the shaft rod of the reversing shaft, the outer end of the second lubricating oil channel is communicated with the shaft end of the reversing shaft, and the inner end of the second lubricating oil channel is communicated with a bearing which is provided with an oil hole and is respectively communicated with the inner friction plate pair, the outer friction plate pair and the bearing between the reversing clutch gear and the reversing shaft. The technical scheme further limits the lubricating mode in the reversing clutch device, and has the effect of realizing the targeted lubrication of the inner and outer friction plate pairs and the bearings in the clutch device similar to the forward clutch device; the lubrication efficiency is higher, i.e. the lubrication is achieved by a smaller amount of lubricating oil.

Preferably, the reversing clutch gear is fixedly connected with a clutch hub, and the clutch hub is connected with the reversing axle through an inner friction plate pair and an outer friction plate pair; the inner friction plate pair and the outer friction plate pair comprise a plurality of outer friction plates and inner friction plates which are arranged at intervals, the outer friction plates and the clutch hub are circumferentially positioned and can axially move relatively, and the inner friction plates and the reversing shaft are circumferentially positioned and can axially move relatively.

Preferably, the second gear is fixedly connected with a clutch hub, and the clutch hub is connected with the reversing clutch gear through an inner friction plate pair and an outer friction plate pair; the inner friction plate pair and the outer friction plate pair comprise a plurality of outer friction plates and inner friction plates which are arranged at intervals, the outer friction plates and the clutch hub are circumferentially positioned and can axially move relatively, and the inner friction plates and the reversing clutch gear are circumferentially positioned and can axially move relatively.

The structure and effect of the clutch in the reverse clutch device can refer to the forward clutch device, and will not be described in detail herein.

Drawings

Fig. 1 is a schematic structural diagram of a hydraulic transmission case related to the invention.

Fig. 2 is an enlarged view of a portion a of fig. 1.

Fig. 3 is a schematic view of a clutch device according to the invention.

Fig. 4 is a schematic structural view of a parking brake device in the hydraulic transmission.

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 hydrodynamic transmission as shown in FIGS. 1-4 includes a transmission assembly and a torque converter assembly. The gearbox assembly comprises a gearbox shell 1, and a gearbox input shaft 2, a forward clutch device, a reverse clutch device, an output shaft device and a parking brake device which are arranged in the gearbox shell 1. The forward clutch device and the reverse clutch device in the embodiment have commonality in structure. The clutch device adopted by the forward clutch device and the reverse clutch device is as follows:

as shown in fig. 3, the clutch device includes a central rotating shaft 10, a gear clutch gear 20 sleeved on the central rotating shaft 10 through a bearing, and a fixed gear 30 for transmitting external power to the central rotating shaft 10 or outputting power of the central rotating shaft 10 outwards. Based on the difference of the application positions of the clutch devices, the central rotating shaft 10 can be a transmission input shaft 2, a forward shaft or a reverse shaft 51, namely when the clutch devices are reverse clutch devices, the central rotating shaft 10 is the reverse shaft 51; when the clutch device is an in-vehicle clutch device, the central rotating shaft 10 is an in-vehicle shaft; of course, it is also possible to refer to the existing gearbox, in which the sequential clutch device is mounted on the gearbox input shaft 2, and the central rotating shaft 10 is the gearbox input shaft 2. Similarly, the gear clutch gear 20 and the fixed gear 30 are referred to as a forward clutch gear 41 and a first gear 42 in the forward clutch device; the gear clutch gear 20 and the fixed gear 30 are referred to as a reverse clutch gear 52 and a second gear 53 in the reverse clutch device.

The gear clutch gear 20 is connected to the central shaft 10 or the fixed gear 30 via inner and outer friction plate pairs. The fixed gear 30 is integrally connected with the central rotating shaft 10, and an axially extending part 31 is arranged at the radial outer end part of the fixed gear 30; a hydraulic driving assembly is arranged in an area enclosed by the axial extension part 31, the body part and the outer wall of the central rotating shaft 10 of the fixed gear 30; the output end of the hydraulic driving assembly can axially move along the central rotating shaft 10 and acts on the inner and outer friction plate pairs, a hydraulic cavity is formed between the hydraulic driving assembly and the body part of the fixed gear 30, and the driving end of the hydraulic driving assembly is in sealing fit with the axial extension part 31 of the fixed gear 30 and the outer wall of the central rotating shaft 10. When the clutch device operates, the central rotating shaft 10 and the fixed gear 30 thereon rotate, and the gear clutch gear 20 is selectively driven to rotate through the inner and outer friction plate pairs, so that the on or off of the clutch device is controlled. As described in the background art, in the conventional clutch device, a region for mounting the piston is formed between the clutch hub and the intermediate rotating shaft body and between the clutch hub and the radially extending portion of the intermediate rotating shaft, and the piston needs to form a hydraulic pressure chamber between the clutch hub and the radially extending portion of the intermediate rotating shaft. However, in this embodiment, the central rotating shaft 10 and the fixed gear 30 integrally connected thereto form a region for mounting the hydraulic driving assembly, the axial extension 31 of the fixed gear 30 and the outer wall of the central rotating shaft 10 can be in sealing fit with the driving end of the hydraulic driving assembly, and a hydraulic cavity is formed between the hydraulic driving assembly and the body of the fixed gear 30. Because the central rotating shaft 10 and the fixed gear 30 (the body and the axial extension part 31) are integrally formed, the problems of welding seams and gaps can be avoided, the strength and the sealing requirements required by the hydraulic cavity are ensured, and the potential safety hazard is eliminated.

The clutch device can adopt the following two clutch connection structures:

in the first structure, as shown in fig. 3, a clutch hub 32 is fixedly connected to the shift position clutch gear 20, and the shift position clutch gear 20 and the clutch hub 32 are fixed by rivets in the drawing. The clutch hub 32 is connected with the central rotating shaft 10 through an inner friction plate pair and an outer friction plate pair; the inner and outer friction plate pairs comprise a plurality of outer friction plates 33 and inner friction plates 34 which are arranged at intervals, the outer friction plates 33 and the clutch hub 32 are circumferentially positioned and can axially move relatively, and the inner friction plates 34 and the central rotating shaft 10 are circumferentially positioned and can axially move relatively. In this embodiment, clutch hub 32 is connected and fixed to range clutch gear 20. In the prior art, the clutch hub 32 is welded to the central rotating shaft 10. Therefore, in comparison, the installation mode of the clutch hub 32 in the scheme is simplified, the clutch hub 32 does not need to be integrally welded and is carburized, and the width of the sliding groove in the clutch hub 32 can be accurately controlled, so that the width of the sliding groove is matched with that of the outer friction plate 33, the axial movement can be realized, and the shaking in the use process caused by circumferential looseness can be avoided.

For a second structure diagram, reference may be made to the structure disclosed in patent publication No. CN 104315109A. Specifically, a clutch hub 32 is fixedly connected to the fixed gear 30, and the clutch hub 32 is connected to the shift clutch gear 20 via inner and outer friction plates 33. The inner and outer friction plates 33 include a plurality of outer friction plates 33 and inner friction plates 34 arranged at intervals, the outer friction plates 33 are circumferentially positioned and axially movable relative to the clutch hub 32, and the inner friction plates 34 are circumferentially positioned and axially movable relative to the gear clutch gear 20. Although the clutch hub 32 is connected to the fixed gear 30 as in the prior art, the above-described embodiment forms an area for mounting the hydraulic drive assembly by virtue of the central rotating shaft 10 and the fixed gear 30 integrally connected thereto. The clutch hub 32 need not be welded to the fixed gear 30 and instead may be a removable connection such as a bolt/rivet connection. Therefore, compared with the prior art that the clutch hub 32 and the central rotating shaft 10 are welded and fixed, the scheme also simplifies the installation mode of the clutch hub 32.

In a further embodiment, the hydraulic drive assembly includes a piston 35, and a hold down spring 36 that drives the piston 35 back. A hydraulic cavity 37 is formed between the piston 35 and the body of the fixed gear 30, and two side walls of the piston 35 are in sealing fit with the axial extension 31 of the fixed gear 30 and the outer wall of the central rotating shaft 10. In a specific embodiment, a spring seat 38 is fixed on an outer wall of the central rotating shaft 10, spring installation grooves 39 are respectively formed on opposite side walls of the piston 35 and the spring seat 38, and two end portions of the compression spring 36 are respectively installed in the spring seat 38 and the spring installation groove 39 of the piston 35. In the above technical solution, the hydraulic driving assembly includes a piston 35 and a hold-down spring 36, wherein the piston 35 is driven by hydraulic pressure to approach the inner and outer friction plate pairs, so as to hold down the outer friction plate 33 and the inner friction plate 34, increase the friction force between the outer friction plate 33 and the inner friction plate 34, and at this time, the clutch device is in a closed state. The hold-down spring 36 pushes the piston 35 away from the inner and outer friction plate pairs after the hydraulic pressure is removed, so as to reduce the friction force between the outer friction plate 33 and the inner friction plate 34, and the clutch device is in a disconnected state.

The hydraulic oil conveying path of the clutch device is that a hydraulic oil channel 101 is arranged inside a shaft rod of the central rotating shaft 10, the outer end of the hydraulic oil channel 101 is communicated with the shaft end of the central rotating shaft 10, and the inner end of the hydraulic oil channel 101 is communicated with the hydraulic cavity 37. As described above, since the central rotating shaft 10, the fixed gear 30 (the body and the axially extending portion 31) are formed integrally, and the hydraulic chamber 37 stroke-tightly with the piston 35 is required. In order to realize hydraulic oil supply to the hydraulic chamber 37, a hydraulic oil passage 101 is provided inside the shaft of the central rotating shaft 10, and the hydraulic oil passage 101 can be provided while ensuring strength.

The lubricating oil conveying path of the clutch device is that a second lubricating oil channel 102 is arranged inside a shaft rod of the central rotating shaft 10, the outer end of the second lubricating oil channel 102 is communicated with the shaft end of the central rotating shaft 10, and the inner end of the second lubricating oil channel 102 is provided with at least two third radial oil holes 103 which are respectively communicated with the inner friction plate pair and the outer friction plate pair and a bearing between the gear clutch gear 20 and the central rotating shaft 10. In the technical scheme, the second lubricating oil channel 102 is arranged in the shaft rod of the central rotating shaft 10, so that the lubrication of the bearing and the inner and outer friction plate pairs is realized, and the arrangement of a lubricating oil channel is simplified.

The hydraulic transmission in the present embodiment specifically adopts the following structure, and the following part is the first clutch connection structure adopting the clutch device in combination with the accompanying drawings, and since the above clutch device is described in detail for the second clutch connection structure, it can be understood by those skilled in the art that the clutch device is applied to the hydraulic transmission. In addition, since the clutch device is adopted, the effects described in the above aspects can be applied to the forward clutch device and/or the reverse clutch device in the same manner.

The outer end part of the gearbox input shaft 2 extends into the torque converter 9 and is connected with the worm wheel, and an elastic plate 91 of the torque converter 9 is connected with an engine flywheel. The following clutch device in this embodiment is mounted on the transmission input shaft 2 and is not provided with a following shaft separately. Specifically, the forward clutch device comprises a forward clutch gear 41 which is sleeved on the transmission input shaft 2 through a bearing, a first gear 42 which is connected to the transmission input shaft 2, and a clutch hub 32 which is fixedly connected with the forward clutch gear 41. The clutch hub 32 is connected to the transmission input shaft 2 by inner and outer friction plate pairs. Wherein, the inner and outer friction plate pairs comprise a plurality of outer friction plates 33 and inner friction plates 34 which are arranged at intervals. In the sequential clutch device, an inner friction plate 34 and the transmission input shaft 2 are circumferentially positioned and axially movable relative to each other, and an outer friction plate 33 and the clutch hub 32 are circumferentially positioned and axially movable relative to each other. The sequential clutch device also comprises a hydraulic driving assembly, the output end of the hydraulic driving assembly can axially move along the input shaft 2 of the gearbox and acts on the inner and outer friction plate pairs to adjust the friction force between the outer friction plate 33 and the inner friction plate 34.

The first gear 42 is integrally connected and fixed to the transmission input shaft 2, and an axially extending portion 31 extending axially toward the clutch hub 32 is provided at a radially outer end portion of the first gear 42. The hydraulic drive assembly is disposed in the area enclosed by the axially extending portion 31 of the first gear 42, the body portion and the outer wall of the transmission input shaft 2. A hydraulic cavity 37 is formed between the hydraulic drive assembly and the body part of the first gear 42, and the drive end of the hydraulic drive assembly is in sealing fit with the axial extension part 31 of the first gear 42 and the outer wall of the transmission input shaft 2. Specifically, the hydraulic drive assembly includes a piston 35, and a hold-down spring 36 that drives the piston 35 to return. A hydraulic chamber 37 is formed between the piston 35 and the body of the first gear 42, and two side walls of the piston 35 are in sealing fit with the axial extension 31 of the first gear 42 and the outer wall of the transmission input shaft 2. A spring seat 38 is fixed on the outer wall of the gearbox input shaft 2, spring mounting grooves 39 are formed on the opposite side walls of the piston 35 and the spring seat 38, and two end parts of the compression spring 36 are respectively mounted in the spring mounting grooves 39 of the spring seat 38 and the piston 35.

The reverse clutch device comprises a reverse shaft 51, a reverse clutch gear 52 sleeved on the reverse shaft 51 through a bearing, and a second gear 53 fixedly connected with the reverse shaft 51. The clutch hub 32 is fixedly connected to the reverse clutch gear 52, and the clutch hub 32 is connected to the reverse shaft 51 through inner and outer friction plate pairs. Similarly, the inner and outer friction plate pairs include a plurality of outer friction plates 33 and inner friction plates 34 arranged at intervals, the outer friction plates 33 are circumferentially positioned and axially movable relative to the clutch hub 32, and the inner friction plates 34 are circumferentially positioned and axially movable relative to the countershaft 51. The reverse clutch device further comprises a hydraulic driving assembly, wherein the output end of the hydraulic driving assembly can axially move along the reverse shaft 51 and acts on the inner friction plate pair and the outer friction plate pair to adjust the friction force between the outer friction plate 33 and the inner friction plate 34.

The second gear 53 is integrally connected and fixed to the countershaft 51, and an axially extending portion 31 extending axially toward the clutch hub 32 is provided at a radially outer end of the second gear 53. The hydraulic drive unit is disposed in an area surrounded by the axially extending portion 31 of the second gear 53, the body portion, and the outer wall of the countershaft 51. A hydraulic cavity 37 is formed between the hydraulic drive assembly and the body part of the second gear 53, and the drive end of the hydraulic drive assembly is in sealing fit with the axial extension part 31 of the second gear 53 and the outer wall of the countershaft 51. Specifically, the hydraulic drive assembly includes a piston 35, and a hold-down spring 36 that drives the piston 35 to return. A hydraulic chamber 37 is formed between the piston 35 and the body of the second gear 53, and both side walls of the piston 35 are in sealing engagement with the axially extending portion 31 of the second gear 53 and the outer wall of the countershaft 51. A spring seat 38 is fixed on the outer wall of the axle shaft 51, spring mounting grooves 39 are formed on the opposite side walls of the piston 35 and the spring seat 38, and two end portions of the compression spring 36 are respectively mounted in the spring mounting grooves 39 of the spring seat 38 and the piston 35.

The output shaft arrangement includes an output shaft 61, and an output gear 62 coupled to the output shaft 61. In the above-described embodiment, the second gear 53 is engaged with the first gear 42, and the forward clutch gear 41 and the reverse clutch gear 52 are engaged with the output gear 62, respectively.

1, the sequential power output process of the hydraulic transmission comprises the following steps: the elastic plate 91 on the torque converter 9 is connected with the engine flywheel, the torque converter 9 transmits power to the input shaft 2 of the gearbox through the turbine, after the forward clutch device is combined, the power is transmitted to the forward clutch gear 41, the forward clutch gear is meshed with the output gear 62, and the power is transmitted to the output shaft 61 to be output.

2, the reversing power output process of the hydraulic transmission comprises the following steps: the elastic plate 91 of the torque converter 9 is coupled to the engine flywheel, the torque converter 9 transmits power to the transmission input shaft 2 through the turbine, the first gear 42 is meshed with the second gear 53 to transmit power to the reverse shaft 51, the reverse clutch gear is meshed with the output gear 62 to transmit power to the output shaft 61 to be output.

The forward clutch device and the reverse clutch device of the hydraulic transmission are different from the existing clutch devices;

on one hand, the clutch hub 32 of the forward clutch device and the reverse clutch device is fixedly connected with the forward clutch gear 41/the reverse clutch gear 52, and the clutch hub 32 is fixedly welded with the central rotating shaft 10 in the prior art. Therefore, in comparison, the installation mode of the clutch hub 32 in the scheme is simplified, the clutch hub 32 does not need to be integrally welded and is carburized, and the width of the sliding groove in the clutch hub 32 can be accurately controlled, so that the width of the sliding groove is matched with that of the outer friction plate 33, the axial movement can be realized, and the shaking in the use process caused by circumferential looseness can be avoided.

On the other hand, in the conventional clutch device described in the background art, a region for mounting the piston 35 is formed between the clutch hub 32 and the intermediate rotating shaft main body, the radially extending portion, and the piston 35 is required to form the hydraulic pressure chamber 37 with the clutch hub 32 and the radially extending portion of the intermediate rotating shaft. In the forward clutch device of the scheme, a region for mounting a hydraulic drive assembly is formed by the gearbox input shaft 2 and the first gear 42 integrally connected with the gearbox input shaft. In the reverse clutch device, a region for mounting a hydraulic drive unit is formed by a reverse shaft 51 and a second gear 53 integrally connected thereto. Due to the adoption of the integrated forming process, the problems of welding seams and gaps can be avoided, the strength and the sealing requirements required by the hydraulic cavity 37 are ensured, and the potential safety hazard is eliminated.

Further, the hydraulic transmission of the present embodiment further includes a parking brake device including a brake shaft 71 positioned inside the transmission case 1 through a bearing, and a brake cover 72 attached to the transmission case 1. The gear on the brake shaft 71 is meshed with the output gear 62 on the gearbox output shaft 61, and the outer end part of the brake shaft 71 is positioned in a bearing cavity in the middle of the inner end surface of the brake cover 72 through a bearing. The transmission case 1 is connected with the brake shaft 71 through inner and outer friction plate pairs, a hydraulic driving assembly is connected to the inner end of the brake cover 72, and the output end of the hydraulic driving assembly can axially move along the brake shaft 71 and act on the inner and outer friction plate pairs. The parking brake device comprises a brake shaft 71 and a brake cover 72, wherein the brake shaft 71 is positioned inside the gearbox housing 1 by means of bearings and engages with the output shaft 61 of the gearbox. The brake cover 72 is detachably attached to the transmission housing 1 to facilitate installation and maintenance of the brake clutch portion inside the transmission housing 1. On the basis, the gearbox shell 1 in the scheme is directly connected with the brake shaft 71 through the inner and outer friction plate pairs, and the inner and outer friction plate pairs are controlled through the hydraulic driving assembly. When the hydraulic drive assembly compresses the inner and outer friction plate pairs, the transmission housing 1 provides a braking torque to the brake shaft 71 to further brake the output shaft 61 of the transmission to achieve the purpose of parking braking. Compared with the existing parking brake device, the parking brake device has the advantages that on one hand, the gearbox shell 1 is directly connected with the brake shaft 71 through the inner and outer friction plate pairs, and a connection structure of a plurality of shells is replaced, so that the self strength and the connection strength of the shells and the end covers do not need to be worried. On the other hand, the brake clutch portion of the parking brake device is entirely in the transmission case 1, so that the lubrication system in the transmission case 1 can be shared, and there is no concern about the problem of the sealing property at the connection portion of the plurality of cases and the end cover. The scheme only needs to ensure the sealing performance of the connecting part of the gearbox shell 1 and the brake cover 72.

The hydraulic drive assembly and the inner and outer friction plate pairs of the parking brake device are the same as the hydraulic drive assembly and the inner and outer friction plate pairs in the forward clutch device and the reverse clutch device, but the installation positions of the hydraulic drive assembly and the inner and outer friction plate pairs are different, and the parking brake device is specifically as follows:

the hydraulic drive assembly includes a piston 35, and a hold-down spring 36 that drives the piston 35 back. A hydraulic chamber 37 is formed between the piston 35 and the transmission housing 1 or the brake cover 72, and one end of the hold-down spring 36 abuts against the piston 35 and the other end abuts against the brake cover 72 or the transmission housing 1. In the above technical solution, the hydraulic driving assembly includes a piston 35 and a hold-down spring 36, wherein the piston 35 is driven by hydraulic pressure to approach the inner and outer friction plate pairs, so as to hold down the outer friction plate 33 and the inner friction plate 34, and increase the friction force between the outer friction plate 33 and the inner friction plate 34. The clutch is now in the closed state. The hold-down spring 36 pushes the piston 35 away from the inner and outer friction plate pairs after the hydraulic pressure is removed, so as to reduce the friction force between the outer friction plate 33 and the inner friction plate 34, and the clutch device is in a disconnected state. The transmission housing 1 is provided with a radial extension part arranged along the radial direction of the brake shaft 71, a hydraulic cavity 37 is formed between the piston 35 and the radial extension part of the transmission housing 1, and at least two side walls of the piston 35 are respectively and hermetically abutted against the inner wall of the transmission housing 1 and the inner wall of the radial extension part. One end of the hold-down spring 36 abuts against the piston 35 and the other end abuts against the brake cover 72. In this solution, a hydraulic chamber 37 is formed between the piston 35 and the radially extending portion of the transmission housing 1, and the strength of the transmission housing 1 can fully meet the pressure-resistant requirement of the hydraulic chamber 37. And the radial extension part and the gearbox shell 1 are integrally formed (the gearbox shell 1 is mostly integrally formed), and the problem of pore oil leakage caused by other connecting structures can not exist. Spring mounting grooves 39 are formed in the inner end surface of the brake cover 72 and the end surface of the piston 35 close to the brake cover 72, and two ends of the compression spring 36 are respectively embedded in the spring mounting grooves 39 of the brake cover 72 and the piston 35. The brake cover 72 in this embodiment acts directly as the spring seat 38, thereby facilitating installation of the hold-down spring 36 and eliminating the spring seat 38.

The inner friction plate pair and the outer friction plate pair comprise a plurality of outer friction plates 33 and inner friction plates 34 which are arranged at intervals, the outer friction plates 33 and the transmission shell 1 are circumferentially positioned and can axially move relatively, and the inner friction plates 34 and the brake shaft 71 are circumferentially positioned and can axially move relatively. A baffle plate 73 is fixedly connected to the inner end part of the gearbox shell 1, and the hydraulic drive assembly and the inner and outer friction plate pairs are arranged in an area enclosed by the baffle plate 73, the brake shaft 71, the gearbox shell 1 and the brake cover 72. A guide pin 74 is fixed between the baffle plate 73 above the inner and outer friction plate pairs and the gearbox shell 1, the guide pin 74 is axially parallel to the brake shaft 71, and the outer friction plate 33 and the guide pin 74 are circumferentially positioned and can axially move relatively.

In a further scheme, a transmission input shaft 2 in the hydraulic transmission is a hollow shaft, a PTO shaft 8 penetrates through the transmission input shaft 2, and the PTO shaft 8 and the transmission input shaft 2 are arranged concentrically. The outer end of the PTO shaft 8 is connected with a worm gear in the torque converter 9, and the inner end of the PTO shaft 8 is connected with an oil pump coupling. Specifically, the outer end of the transmission input shaft 2 is connected to a worm wheel in the torque converter 9 through a turbine, and the outer end of the PTO shaft 8 is connected to the worm wheel of the torque converter 9. The technical scheme relates to a PTO shaft arrangement structure. In the structure, the transmission input shaft 2 is a hollow shaft rod, and the PTO shaft 8 is arranged inside the transmission input shaft 2 in a penetrating way. So configured, the PTO shaft 8 can extend out of the transmission along the shaft hole inside the transmission input shaft 2 and be directly connected with the torque converter 9, and its inner end can also drive the oil pump to run. Compared with the prior art, the PTO shaft 8 and the input shaft assembly are in a gear transmission mode. According to the scheme, the torque converter 9 can directly drive the oil pump through the PTO shaft 8, so that the transmission mode of the PTO shaft 8 is optimized. In addition, in the installation mode, the transmission case input shaft 2 is not required to be connected with a gear, so that the installation structure is simplified, the transmission case can be more compact, and the space optimization of the transmission structure on the whole machine is facilitated. Further, the PTO shaft 8 in the scheme is arranged in the transmission input shaft 2 in a penetrating mode, even the PTO shaft 8 is arranged without occupying other space in the transmission, and the space occupied by the PTO shaft 8 device in the traditional transmission is saved.

In the scheme, two groups of bearings are arranged between the side wall of the inner outer end part of the PTO shaft 8 and the inner wall of the shaft hole of the transmission input shaft 2 at least, so that the relative circumferential rotation of the PTO shaft 8 and the transmission input shaft 2 is realized. Further, a seal member is provided between the outer end side wall of the PTO shaft 8 and the shaft hole inner wall of the transmission input shaft 2. Or a bearing between the side wall of the outer end part of the PTO shaft 8 and the inner wall of the shaft hole of the transmission input shaft 2 is a sealing bearing assembly so as to realize the sealing between the PTO shaft 8 and the transmission input shaft 2. In the technical scheme, the PTO shaft 8 is arranged in the transmission input shaft 2 in a penetrating mode and can rotate relative to the transmission input shaft in the circumferential direction, and the PTO shaft can rotate by adopting two groups of bearings at the inner end and the outer end of the PTO shaft 8. In addition, in order to prevent the oil in the torque converter 9 from flowing between the PTO shaft 8 and the transmission input shaft 2, it is necessary to seal the outer end side wall of the PTO shaft 8 and the shaft hole inner wall of the transmission input shaft 2. There are two sealing schemes, one is to directly arrange a sealing component (such as a sealing ring) for sealing. Alternatively, the bearing is selected as a sealed bearing assembly, such as a bi-metallic plain bearing 81 (shown) for sealing purposes.

Based on above-mentioned structure, hydraulic transmission's in this scheme lubricating structure as follows:

1, a first lubricating oil channel 104 is arranged inside the side wall of the input shaft 2 of the gearbox, the outer end of the first lubricating oil channel 104 is communicated with the shaft end of the input shaft 2 of the gearbox, and the inner end of the first lubricating oil channel 104 is provided with a first radial oil hole 105 formed in the inner wall surface of the input shaft 2 of the gearbox and at least two second radial oil holes 106 formed in the outer wall surface of the input shaft 2 of the gearbox. The first radial oil hole 105 is communicated with the transmission input shaft 2 and the PTO shaft 8 in a clearance mode, and the two second radial oil holes 106 respectively face the inner friction plate pair and the outer friction plate pair and a bearing between the on-vehicle clutch gear 41 and the transmission input shaft 2; the inner end of the second radial oil hole 106 may communicate directly with the first lubricating oil passage 104 or with a gap between the transmission input shaft 2 and the PTO shaft 8. On the basis of the scheme, the scheme also needs to solve the problems of bearing lubrication arranged between the side wall of the inner outer end part of the PTO shaft 8 and the inner wall of the shaft hole of the transmission input shaft 2 and lubrication in the forward clutch device. Therefore, further, in the scheme, the first lubricating oil channel 104 is arranged inside the side wall of the input shaft 2 of the gearbox, and the outer end of the first lubricating oil channel 104 is arranged at the shaft end of the central rotating shaft 10 and can be used for connecting an oil circuit. The inner end of the first lubricating oil channel 104 is arranged on the inner wall surface of the transmission input shaft 2, and the lubricating oil can enter a gap between the PTO shaft 8 and the transmission input shaft 2 from the inner wall surface and flows to the two axial ends to lubricate the bearings on the two sides respectively. Meanwhile, in consideration of lubrication of the on-vehicle clutch device outside the transmission input shaft 2, a plurality of second radial oil holes 106 are further provided at the inner end of the first lubricating oil passage 104 for delivering lubricating oil to the outside of the transmission input shaft 2. Through the structure, the scheme can realize the targeted lubrication of the inner and outer friction plate pairs and the bearing in the clutch device. The lubrication efficiency is higher, i.e. the lubrication is achieved by a smaller amount of lubricating oil.

2, a second lubricating oil channel 102 is arranged inside a shaft rod of the reversing shaft 51, the outer end of the second lubricating oil channel 102 is communicated with the shaft end of the reversing shaft 51, and the inner end of the second lubricating oil channel 102 is provided with at least two third radial oil holes 103 which are respectively communicated with the inner and outer friction plate pairs and a bearing between the reversing clutch gear 52 and the reversing shaft 51. This technical scheme is for lubricating to the spare part among the clutch device that backs a car, and similar with above-mentioned clutch device that follows a car, its effect also can realize carrying out the pertinence lubrication to inside and outside friction disc pair, bearing in the clutch device, and lubrication efficiency is higher, realizes lubricating through a less amount of lubricating oil promptly.

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.

Claims

1. A lubrication structure on a hydraulic transmission comprises a transmission shell (1), and a transmission input shaft (2), a forward clutch device, a reverse clutch device and an output shaft (61) device which are arranged in the transmission shell (1); the forward clutch device comprises a forward clutch gear (41) which is sleeved on the input shaft (2) of the gearbox through a bearing, and a first gear (42) which is integrated with the input shaft of the gearbox; the forward clutch gear (41) is connected with the input shaft (2) of the gearbox through an inner friction plate pair and an outer friction plate pair; the method is characterized in that: the gear box is characterized in that a first lubricating oil channel (104) is arranged inside the side wall of the gear box input shaft (2), the outer end of the first lubricating oil channel (104) is communicated with the shaft end of the central rotating shaft (10), at least two second radial oil holes (106) formed in the outer wall surface of the gear box input shaft (2) are formed in the inner end of the first lubricating oil channel (104), the two second radial oil holes (106) face the inner friction plate pair and the outer friction plate pair respectively, and a bearing between the forward clutch gear (41) and the gear box input shaft (2) is arranged.

2. The lubrication structure on a hydraulic transmission case according to claim 1, wherein: the transmission input shaft (2) is a hollow shaft, a PTO shaft (8) penetrates through the transmission input shaft (2), and the PTO shaft is positioned in the transmission input shaft (2) through bearings at two end parts of the PTO shaft and is arranged concentrically with the transmission input shaft (2); the outer end of the PTO shaft (8) is connected with the torque converter (9), and the inner end of the PTO shaft (8) is connected with an oil pump coupling.

3. The lubrication structure on a hydraulic transmission case according to claim 2, wherein: a first lubricating oil channel (104) is arranged inside the side wall of the gearbox input shaft (2), the outer end of the first lubricating oil channel (104) is communicated with the shaft end of the central rotating shaft (10), a first radial oil hole (105) is formed in the inner end of the first lubricating oil channel (104) and communicated with a gap between the gearbox input shaft (2) and the PTO shaft (8), and the first radial oil hole (105) is formed in the inner wall surface of the gearbox input shaft (2) between the two groups of bearings.

4. The lubrication structure on a hydraulic transmission case according to claim 2, wherein: the outer end of the PTO shaft (8) is connected with the torque converter (9), and the inner end of the PTO shaft (8) is connected with the oil pump.

5. The lubrication structure on a hydraulic transmission case according to claim 2, wherein: a sealing component is arranged between the side wall of the outer end part of the PTO shaft (8) and the inner wall of the shaft hole of the transmission input shaft (2); or a bearing between the side wall of the outer end part of the PTO shaft (8) and the inner wall of the shaft hole of the transmission input shaft (2) is a sealing bearing assembly so as to realize the sealing between the PTO shaft (8) and the transmission input shaft (2).

6. The lubrication structure on a hydraulic transmission case according to any one of claims 1 to 5, wherein: the forward clutch gear (41) is fixedly connected with a clutch hub (32), and the clutch hub (32) is connected with the input shaft (2) of the gearbox through an inner friction plate pair and an outer friction plate pair; the inner friction plate pair and the outer friction plate pair comprise a plurality of outer friction plates (33) and inner friction plates (34) which are arranged at intervals, the outer friction plates (33) and the clutch hub (32) are circumferentially positioned and can axially move relatively, and the inner friction plates (34) and the transmission input shaft (2) are circumferentially positioned and can axially move relatively.

7. The lubrication structure on a hydraulic transmission case according to claim 1, wherein: the reversing clutch device comprises a reversing shaft (51), a reversing clutch gear (52) sleeved on the reversing shaft (51) through a bearing, and a reversing shaft integrated second gear (53) meshed with the input shaft integrated first gear (42); the reverse clutch gear (52) is connected with the reverse shaft (51) through an inner friction plate pair and an outer friction plate pair; a second lubricating oil channel (102) is arranged in the axle of the reversing axle (51), the outer end of the second lubricating oil channel (102) is communicated with the axle end of the reversing axle (51), and the inner end of the second lubricating oil channel (102) is provided with at least two third radial oil holes (103) which are respectively communicated with the inner friction plate pair, the outer friction plate pair and a bearing between the reversing clutch gear (52) and the reversing axle (51).

8. The lubrication structure on a hydraulic transmission case according to claim 7, wherein: the reversing clutch gear (52) is fixedly connected with a clutch hub (32), and the clutch hub (32) is connected with the reversing shaft (51) through an inner friction plate pair and an outer friction plate pair; the inner friction plate pair and the outer friction plate pair comprise a plurality of outer friction plates (33) and inner friction plates (34) which are arranged at intervals, the outer friction plates (33) and the clutch hub (32) are circumferentially positioned and can axially move relatively, and the inner friction plates (34) and the reverse shaft (51) are circumferentially positioned and can axially move relatively.