Transmission for hydraulically driven wheel excavators

Abstract

The invention discloses a transmission for a hydraulically driven wheeled excavator, comprising a housing, an input shaft rotatably arranged on the housing and a high-speed driving gear and a low-speed driving gear thereon, front and rear axle output shafts rotatably arranged on the housing and a high-speed driven gear and a low-speed driven gear thereon, and also comprising a normally closed wet hydraulic clutch mechanism, a planetary gear set and a synchronizer assembly; the invention controls the clutch of the driving shaft and the input shaft by hydraulic pressure, and after separation, the transmission force transmitted by the input shaft to the front and rear axle output shafts can be cut off, so that the transmission can shift gears during driving, and the gear shift shock is prevented, and the gear damage is effectively prevented, so that the cost and the maintenance rate are reduced, and the planetary gear set is added, and the coordination of multiple shafts and gears is reduced, so that the product structure is more compact, the volume is small, and the space occupied is small, and the overdrive output and the low-speed large transmission ratio output can be realized, so as to improve the low-speed driving at work and the high-speed driving at transition, and has a variety of transmission output ratios.

Description

Technical Field

[0001] The invention relates to a transmission, in particular to a transmission of a hydraulically driven wheel excavator. Background Art

[0002] Wheeled excavators, as multi-purpose engineering machinery, have been widely used. Wheeled excavators are also divided into mechanically driven wheeled excavators and hydraulically driven wheeled excavators. Hydraulically driven wheeled excavators are becoming more and more popular among users due to their strong maneuverability, small impact during operation, and no need for special transportation tools. However, the transmission of hydraulically driven wheeled excavators currently has the following shortcomings:

[0003] 1. The existing transmission structure of hydraulically driven wheeled excavators cannot achieve gear shifting during driving, especially when high and low speed gear shifting is required under different working conditions; if gear shifting is not done during driving, the gears will be damaged and deformed, causing the excavator to not work properly, reducing work efficiency, and it is difficult to disassemble and repair, with high maintenance costs;

[0004] 2. Since the hydraulically driven wheeled excavator needs to travel at a low speed when working and at a high speed when transferring to improve the working efficiency, the transmission structure of the existing hydraulically driven wheeled excavator mainly adopts a multi-axis gear structure. This structure not only cannot simultaneously meet the low-speed driving during working and high-speed driving during transfer, but also has a complex structure, large size, and occupies a large space. Summary of the invention

[0005] In order to overcome the above-mentioned deficiencies in the prior art, an object of the present invention is to provide a transmission for a hydraulically driven wheeled excavator, which has a compact structure and a small size, and can simultaneously meet the requirements of low-speed driving during operation and high-speed driving during transfer.

[0006] The present invention is realized by the following technical scheme: a transmission of a hydraulically driven wheeled excavator comprises a housing and an input shaft rotatably arranged on the housing, and front and rear axle output shafts, the input shaft is provided with a high-speed driving gear and a low-speed driving gear matched with a needle bearing, the front and rear axle output shafts are provided with a high-speed driven gear and a low-speed driven gear matched with a needle bearing, and also comprises a normally closed wet hydraulic clutch mechanism for hydraulically controlling the clutch of the driving shaft and the input shaft, a planetary gear set for outputting a low-speed ratio, and a synchronizer assembly for high-speed and low-speed shifting;

[0007] The normally closed wet hydraulic clutch mechanism comprises a clutch housing, a driving shaft, a clutch driven plate, a friction plate assembly, a friction plate pressure plate, a hydraulic cylinder, a piston, a return disc spring, and a disc spring assembly. The clutch housing is connected to the housing, the driving shaft is connected to the input shaft through a deep groove ball bearing, the clutch driven plate is mounted on the input shaft, the friction plate assembly is mounted on the driving shaft and is pressed and fixed by the friction plate pressure plate, the friction plate pressure plate and the piston are fixed to the driving shaft through a thrust bearing, the hydraulic cylinder is sealed with the piston and then fixed to the clutch housing through a flange, a disc spring assembly mounted on the driving shaft is provided between the piston and the flange, and a variable piston motor is connected to the input end of the driving shaft;

[0008] The planetary gear set includes a sun gear, a ring gear, a planet carrier, and a plurality of planetary gears. The sun gear is fixed on the input shaft, and the sun gear and the input shaft are integrally formed. The ring gear is locked and fixed to the clutch housing by bolts. Each of the planetary gears is installed on the planet carrier and meshes with the sun gear and the ring gear at the same time. The planet carrier is sleeved on the input shaft and rotates around the input shaft. The low-speed gear driving gear and the planet carrier are connected and fixed by bolts.

[0009] The synchronizer assembly is installed on the front and rear axle output shafts and is connected to the piston shaft of the hydraulic cylinder through a shift fork. The shift hydraulic cylinder is installed on the box body.

[0010] Furthermore, the output shafts of the front and rear axles of the present invention are provided at both ends with tapered roller bearings I and flanges respectively mounted in cooperation with the housing, and a bearing cover I and an oil seal for sealing the tapered roller bearing I are provided between the flange and the housing.

[0011] Furthermore, the input shaft of the present invention has a tapered roller bearing II at one end mounted in cooperation with the housing, and the tapered roller bearing II at this end is sealed and connected to the housing through a bearing cover II, and the other end of the input shaft has a tapered roller bearing III mounted in cooperation with the clutch housing.

[0012] Furthermore, the clutch housing of the present invention is provided with an oil inlet hole connected to the interior of the hydraulic cylinder.

[0013] Furthermore, a spacer sleeve installed on the input shaft is provided between the high-speed gear driving gear and the low-speed gear driving gear of the present invention.

[0014] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0015] 1. The present invention adds a normally closed wet hydraulic clutch mechanism and a shift synchronizer assembly to hydraulically control the clutch of the driving shaft and the input shaft. After separation, the transmission force transmitted by the input shaft to the front and rear axle output shafts can be cut off, so that the transmission can shift gears while driving, preventing shift shock, effectively preventing gear damage, reducing costs, and lowering maintenance rates.

[0016] 2. The present invention adds a planetary gear set and reduces the coordination of multiple shafts and gears, making the transmission more compact, small in size, and taking up less space. It can also achieve overdrive output and low-speed and high-speed ratio output to improve low-speed driving during work and high-speed driving during transition, and can have a variety of transmission output ratios. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments with reference to the following drawings:

[0018] Figure 1 It is a schematic diagram of the structure of the present invention. DETAILED DESCRIPTION

[0019] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0020] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0021] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0022] Refer to Figure 1As shown, the transmission of the hydraulically driven wheeled excavator of this embodiment includes a housing 1 and an input shaft 2 rotatably arranged on the housing 1, and front and rear axle output shafts 3. The input shaft 2 is provided with a high-speed driving gear 11 and a low-speed driving gear 12 which are mounted in cooperation with a needle bearing 10. A spacer sleeve 4 mounted on the input shaft 2 is provided between the high-speed driving gear 11 and the low-speed driving gear 12. The front and rear axle output shafts 3 are provided with a high-speed driven gear 31 and a low-speed driven gear 32 which are mounted in cooperation with a needle bearing 30. The transmission also includes a normally closed wet hydraulic clutch mechanism for hydraulically controlling the clutch of the driving shaft and the input shaft, a planetary gear set for outputting a low gear ratio, and a synchronizer assembly 5 mounted on the front and rear axle output shafts 3. The synchronizer assembly 5 is mounted on the front and rear axle output shafts 3 and is connected to the piston shaft 70 of the shift hydraulic cylinder 7 through a shift fork 6. The shift hydraulic cylinder 7 is mounted on the housing 1.

[0023] Among them, the normally closed wet hydraulic clutch mechanism includes a clutch housing 80, a driving shaft 81, a clutch driven plate 82, a friction plate assembly 83, a friction plate pressure plate 84, a hydraulic cylinder 85, a piston 86, a return disc spring 87, and a disc spring assembly 801. The clutch housing 80 is connected to the housing 1, the driving shaft 81 is connected to the input shaft 2 through a deep groove ball bearing 87, the clutch driven plate 82 is mounted on the input shaft 2, the friction plate assembly 83 is mounted on the driving shaft 81 and is pressed and fixed by the friction plate pressure plate 84, the friction plate pressure plate 84 and the piston 86 are fixed to the driving shaft 81 through a thrust bearing 88, the hydraulic cylinder 85 is sealed with the piston 86 and then fixed to the clutch housing 80 through a flange 89, a disc spring assembly 801 installed on the driving shaft 81 is provided between the piston 86 and the flange 89, and a variable piston motor 8 is connected to the input end of the driving shaft 81.

[0024] The planetary gear set includes a sun gear 20, a ring gear 21, a planet carrier 22, and multiple planetary gears 23. The sun gear 20 is fixed on the input shaft 2. The sun gear 20 and the input shaft 2 are integrally formed. The ring gear 21 is locked and fixed to the clutch housing 80 by bolts. Each of the planetary gears 23 is installed on the planet carrier 22 and meshes with the sun gear 20 and the ring gear 21 at the same time. The planet carrier 22 is sleeved on the input shaft 2 and rotates around the input shaft. The low-speed driving gear 12 and the planet carrier 22 are fixed by bolt connection. The bolt connection can more conveniently output different speed ratios by replacing the low-speed driving gear 12 with different speed ratios.

[0025] Preferably, both ends of the front and rear axle output shafts 3 are respectively provided with tapered roller bearings Ⅰ33 and flanges 34 mounted in cooperation with the housing 1, and a bearing cover Ⅰ35 and an oil seal 36 for sealing the tapered roller bearings Ⅰ33 are provided between the flange 34 and the housing 1.

[0026] Preferably, one end of the input shaft 2 is provided with a tapered roller bearing II13 which is mounted in cooperation with the housing 1, and the tapered roller bearing II13 at this end is sealed and connected to the housing 1 through a bearing cover II14, and the other end of the input shaft 2 is provided with a tapered roller bearing III15 which is mounted in cooperation with the clutch housing 80, and the clutch housing 80 is provided with an oil inlet hole 802 which is connected to the interior of the shift hydraulic cylinder 7.

[0027] The working principle of the present invention is as follows: when there is no hydraulic oil, the disc spring assembly 801 rebounds the piston 86 to press the friction plate pressure plate 84 so that the friction plate pressure plate 84 presses the friction plate assembly 83, and the transmission force input by the driving shaft 81 can transmit torque to the friction plate pressure plate 84 through the friction plate assembly 83, and the friction plate pressure plate 84 is fixed on the input shaft 2, and the input shaft 2 has a transmission force (that is, the input shaft 2 is combined with the driving shaft 81). When separation is required, hydraulic oil is passed from the oil inlet 802 to the hydraulic cylinder 85, and the piston 86 moves outward to press the disc spring When the assembly 801 is pressurized, the return disc spring 87 drives the friction plate pressure plate 84 to drive the friction plate assembly 83 to bounce open, so that the friction plate assembly 83 does not transmit torque to the friction plate pressure plate 84 (that is, the driving shaft 81 is separated from the input shaft 2). After separation, the transmission force from the input shaft 2 to the front and rear axle output shafts 3 can be cut off, making it easier for the front and rear axle output shafts 3 to allow the synchronizer assembly to shift the high and low speed driven gears under the transmission without transmission force, thereby preventing gear shifting shock, preventing gear damage, reducing costs, reducing maintenance rates, and extending the service life of the transmission.

[0028] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A transmission for a hydraulically driven wheeled excavator, comprising a housing and an input shaft rotatably arranged on the housing, and front and rear axle output shafts, wherein a high-speed driving gear and a low-speed driving gear are mounted in cooperation with needle bearings on the input shaft, and a high-speed driven gear and a low-speed driven gear are mounted in cooperation with needle bearings on the front and rear axle output shafts, characterized in that: It also includes a normally closed wet hydraulic clutch mechanism for hydraulically controlling the clutch of the driving shaft and the input shaft, a planetary gear set for outputting a low gear ratio, and a synchronizer assembly for high and low speed shifting; The normally closed wet hydraulic clutch mechanism comprises a clutch housing, a driving shaft, a clutch driven plate, a friction plate assembly, a friction plate pressure plate, a hydraulic cylinder, a piston, a return disc spring, and a disc spring assembly. The clutch housing is connected to the housing, the driving shaft is connected to the input shaft through a deep groove ball bearing, the clutch driven plate is mounted on the input shaft, the friction plate assembly is mounted on the driving shaft and is pressed and fixed by the friction plate pressure plate, the friction plate pressure plate and the piston are fixed to the driving shaft through a thrust bearing, the hydraulic cylinder is sealed with the piston and then fixed to the clutch housing through a flange, a disc spring assembly mounted on the driving shaft is provided between the piston and the flange, and a variable piston motor is connected to the input end of the driving shaft; The planetary gear set includes a sun gear, a ring gear, a planet carrier, and multiple planetary gears. The sun gear is fixed on the input shaft, and the sun gear and the input shaft are integrally formed. The ring gear is locked and fixed to the clutch housing by bolts. Each planetary gear is installed on the planet carrier and meshes with the sun gear and the ring gear at the same time. The planet carrier is sleeved on the input shaft and rotates around the input shaft. The low-speed gear driving gear and the planet carrier are fixed by bolts. The synchronizer assembly is installed on the front and rear axle output shafts and is connected to the piston shaft of the shift hydraulic cylinder through a shift fork. The shift hydraulic cylinder is installed on the box body.

2. The transmission of the hydraulically driven wheel excavator according to claim 1, characterized in that: The two ends of the front and rear axle output shafts are respectively provided with tapered roller bearings I and flanges which are mounted in cooperation with the housing, and a bearing cover I and an oil seal for sealing the tapered roller bearings are provided between the flange and the housing.

3. The transmission of the hydraulically driven wheel excavator according to claim 1, characterized in that: One end of the input shaft is provided with a tapered roller bearing II which is mounted in cooperation with the housing, and the tapered roller bearing II is sealed and connected to the housing through a bearing cover II, and the other end of the input shaft is provided with a tapered roller bearing III which is mounted in cooperation with the clutch housing.

4. The transmission of the hydraulically driven wheel excavator according to claim 1 or 3, characterized in that: The clutch housing is provided with an oil inlet hole which is communicated with the interior of the hydraulic cylinder.

5. The transmission of the hydraulically driven wheel excavator according to claim 1, characterized in that: A spacer sleeve installed on the input shaft is arranged between the high-speed gear driving gear and the low-speed gear driving gear.

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