Hydrostatic power take-off (PTO) system of tractor

Abstract

The utility model discloses a tractor hydrostatic power take-off (PTO) system which comprises a PTO box arranged on a chassis of a vehicle. The gear shifting mechanism is arranged in the PTO box; the hydraulic motor is arranged at the upper part of the PTO box; the power output of the gear shifting mechanism is connected with the power output shaft; the gear shifting mechanism comprises a first shaft, a second shaft and a third shaft which are sequentially arranged in parallel from top to bottom, the first shaft is connected with an output shaft of the hydraulic motor, and the third shaft is connected with the power output shaft. According to the utility model, the arrangement is simple and compact, an independent hydraulic motor is adopted to drive a PTO system, intelligent control of PTO rated output and follow-up output of PTO following the running speed of a tractor can be realized, and the requirement of power loss is reduced.

Description

Technical Field

[0001] This utility model belongs to the field of tractor technology, specifically a tractor hydrostatic PTO system. Background Technology

[0002] The existing tractor power take-off system, namely PTO, lacks flexibility in layout. The PTO housing is set in the chassis in an integral layout, which is very complex in structure.

[0003] Regarding the structure of PTO transmissions, PTO assemblies using mechanical transmission structures have very complex machining and assembly processes. PTO assemblies typically employ a long shaft structure, which involves complex machining processes that affect transmission efficiency and also results in a very long PTO housing. The large volume of the PTO housing is not conducive to the overall vehicle layout.

[0004] Regarding the operation of the PTO system, in the traditional mechanical transmission mechanism, the gears inside the PTO keep rotating continuously when the tractor is working, which results in high energy consumption of the engine and poor economy.

[0005] To address the problems of the aforementioned mechanical transmission PTO systems, Chinese patent CN221049488U discloses an electric PTO system for tractors. This system uses an electric motor as the driving force for the PTO, including a PTO housing independently mounted on the vehicle chassis, and at least one motor that provides power entirely to the PTO housing via a driveshaft. A gear shifting device for changing speeds is also installed within the PTO housing. While this structure solves the problems to some extent, the presence of a driveshaft and universal joint between the motor and the PTO results in an excessively long overall length. Separating the motor and PTO housing leads to an excessively large assembly size. Furthermore, the electric motor-driven PTO experiences significant mechanical vibration and impact, and the relatively low torque of the electric motor makes it unsuitable for applications with high loads and high torque. Utility Model Content

[0006] This utility model provides a tractor hydrostatic PTO system with a simple and compact layout. It uses a separate hydraulic motor to drive the PTO system and can achieve intelligent control of the PTO rated output and the PTO output following the tractor's driving speed, thereby reducing the need for power loss.

[0007] A tractor hydrostatic PTO system includes: a PTO housing mounted on the vehicle chassis; a shifting mechanism housed inside the PTO housing; a hydraulic motor mounted on the upper part of the PTO housing; and a power output shaft connected to the shifting mechanism. In this invention, the hydraulic motor and PTO housing are tightly integrated, with the hydraulic motor's output shaft directly connected to the shifting mechanism's input shaft. This eliminates intermediate transmission mechanisms and universal joints, resulting in a simple structure, low cost, and significantly reduced longitudinal length of the PTO housing, leading to a simple and compact layout. The use of hydraulic motor technology is mature, suitable for high-load and high-torque applications, and offers low vibration and impact, longer lifespan, and high reliability. Operationally, the hydraulic motor drive enables stepless speed change and reverse rotation, meeting various working conditions and providing ease of operation.

[0008] Preferably, the shifting mechanism includes a first shaft, a second shaft, and a third shaft arranged in parallel from top to bottom. The first shaft is connected to the output shaft of the hydraulic motor, and the third shaft is connected to the power output shaft. In this invention, the first shaft serves as the power input shaft of the PTO and is directly connected to the hydraulic motor, reducing the shaft length and shortening the overall PTO housing. The three shafts are arranged in a parallel vertical configuration, facilitating the design of the PTO housing as a flat structure with a height dimension greater than its longitudinal dimension, significantly shortening the longitudinal length of the PTO system and resulting in a compact structure.

[0009] Preferably, a first-gear drive gear and a second-gear drive gear with different transmission ratios are loosely fitted on the first shaft; a first-gear driven gear and a second-gear driven gear are fixedly mounted on the second shaft; and an output shaft gear that meshes with the second-gear driven gear is fixedly mounted on the third shaft. A shifting actuator is provided at the position on the first shaft between the first-gear drive gear and the second-gear drive gear. In this invention, the first-gear drive gear and the first-gear driven gear mesh, the second-gear drive gear meshes with the second-gear driven gear, and the second-gear driven gear meshes with the output shaft gear. The shifting actuator can engage or disengage with the first-gear drive gear and the second-gear drive gear, achieving neutral, first-gear, and second-gear selective output. This invention uses a two-gear transmission to achieve PTO output with different speed ratios.

[0010] Preferably, the center line connecting the output shaft, second shaft, and third shaft of the hydraulic motor forms a triangle. This avoids the centers of the three shafts being on the same straight line, shortens the height, and further reduces the height of the PTO housing. Specifically, the center of the hydraulic motor output shaft is located to the left of the line connecting the hydraulic motor output shaft and the third shaft, meaning the hydraulic motor output shaft and the third shaft are located in the middle of the PTO housing, resulting in reasonable stress distribution on the first and third shafts.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] The PTO system is driven by a separate hydraulic motor, which avoids the disadvantage of engine-driven systems that cannot interrupt power. It enables intelligent control of the PTO's rated output and its output following the tractor's speed, reducing the need for power loss.

[0013] The first shaft is directly connected to the hydraulic motor, reducing the shaft length and shortening the overall PTO housing. The three shafts are arranged in a parallel vertical structure, which makes it easy to design the PTO housing as a flat structure with a height dimension greater than the longitudinal dimension, greatly shortening the longitudinal length of the PTO system and making the structure compact.

[0014] Using a hydraulic motor avoids the drawbacks of electric motor drives, making it suitable for applications with high loads and high torque. It also has less vibration and impact, longer lifespan, and higher reliability.

[0015] In terms of operation, the hydraulic motor drive can achieve stepless speed change and reverse operation, meeting the working conditions and is easy to operate. Attached Figure Description

[0016] Figure 1 This is a simplified structural diagram of a tractor hydrostatic PTO system according to the present invention.

[0017] Figure 2 This is a front view of a tractor hydrostatic PTO system as described in this utility model.

[0018] Figure 3 yes Figure 2 Top view.

[0019] Figure 4 This is a schematic diagram of the shifting mechanism described in this utility model.

[0020] Figure 5 This is a structural diagram of a tractor hydrostatic PTO system as described in this utility model, with the hydraulic motor installed.

[0021] In the diagram: 1-PTO housing, 2-hydraulic motor, 3-power output shaft, 4-shifting mechanism, 401-first shaft, 402-second shaft, 403-third shaft, 404-first gear drive gear, 405-second gear drive gear, 406-first gear driven gear, 407-second gear driven gear, 408-output shaft gear, 409-shifting actuator, 5-mounting part. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. The illustrative embodiments and descriptions of the present invention are used to explain the present invention and do not constitute an improper limitation of the present invention.

[0023] In the description of this utility model, it should be understood that the terms "left", "right", "up", "down", "front", "back", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or structure referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0024] Example 1:

[0025] like Figures 1-3 As shown, a tractor hydrostatic PTO system includes: a PTO housing 1, which is mounted on the vehicle chassis; a shift mechanism 4, which is disposed inside the PTO housing 1; a hydraulic motor 2, which is mounted on the upper part of the PTO housing 1; and a power output shaft 3, through which the power output of the shift mechanism 4 is connected. The working principle of this embodiment is that the hydraulic motor 2 is integrated into the PTO housing 1, and the hydraulic motor 2 and the PTO housing 1 are tightly connected without a transmission shaft in between. The output shaft of the hydraulic motor 2 is directly connected to the input shaft of the shift mechanism 4, and after gear shifting, power is output from the power output shaft 3.

[0026] Example 2:

[0027] like Figures 1-3 As shown, a tractor hydrostatic PTO system includes: a PTO housing 1, which is mounted on the chassis of the vehicle; and a shifting mechanism 4, which is disposed inside the PTO housing 1.

[0028] like Figure 5 As shown, this embodiment also includes a hydraulic motor 2. A mounting part 5 is provided on the upper part of the PTO housing 1, and the hydraulic motor 2 is mounted on the mounting part 5. A hydraulic motor mounting part is provided on the upper part of the PTO housing 1, and the hydraulic motor 2 is directly mounted on the upper part of the PTO housing 1; a power output shaft 3, and the power output of the shifting mechanism 4 is connected to the power output shaft 3.

[0029] like Figure 4 As shown in the figure, in this embodiment, the shifting mechanism 4 includes a first shaft 401, a second shaft 402 and a third shaft 403 arranged in parallel from top to bottom. The first shaft 401 is connected to the output shaft of the hydraulic motor 2, and the third shaft 403 is connected to the power output shaft 3.

[0030] like Figure 4As shown, in this embodiment, a first-gear drive gear 404 and a second-gear drive gear 405 with different transmission ratios are loosely fitted on the first shaft 401. A first-gear driven gear 406 and a second-gear driven gear 407 are fixed on the second shaft 402. An output shaft gear 408 that meshes with the second-gear driven gear 407 is fixed on the third shaft 403. A gear shifting actuator 409 is provided at the position of the first shaft 401 between the first-gear drive gear 404 and the second-gear drive gear 405.

[0031] In this embodiment, as Figure 2 As shown, the center lines connecting the output shaft of the hydraulic motor 2, the second shaft 402, and the third shaft 403 form a triangle. The center of the output shaft of the hydraulic motor 2, the center of the second shaft 402, and the center of the third shaft 403 also form a triangle. The center of the output shaft of the hydraulic motor 2 coincides with the center of the first shaft 401. Specifically, the center of the output shaft of the hydraulic motor 2 is located to the left of the line connecting the output shaft of the hydraulic motor 2 and the third shaft 403, meaning the output shaft of the hydraulic motor 2 and the third shaft 403 are located in the middle of the PTO housing 1. The first shaft 401 and the third shaft 403 experience reasonable stress. Because the second shaft 402, as an intermediate shaft, experiences less stress, it can be positioned at the edge.

[0032] like Figure 4 As shown, the power transmission principle in this embodiment is as follows: the first gear drive gear 404 meshes with the first gear driven gear 406, the second gear drive gear 405 meshes with the second gear driven gear 407, and the second gear driven gear 407 meshes with the output shaft gear 408; the shifting actuator 409 can engage or disengage with the first gear drive gear 404 and the second gear drive gear 405 to achieve neutral, first gear, and second gear selective output.

[0033] The transmission path in this embodiment is as follows:

[0034] When the shift actuator 409 is in the left position, the power passes sequentially through the hydraulic motor 2, the first shaft 401, the first gear drive gear 404, the first gear driven gear 406, the intermediate shaft, the output shaft gear 408, the third shaft 403, and the power output shaft 3.

[0035] The two transmission paths in this embodiment are as follows:

[0036] When the shift actuator 409 is in the left position, the power passes sequentially through the hydraulic motor 2, the first shaft 401, the second gear drive gear 405, the second gear driven gear 407, the output shaft gear 408, the third shaft 403, and the power output shaft 3.

Claims

1. A tractor hydrostatic PTO system, characterized in that... include: PTO housing (1), the PTO housing (1) is mounted on the chassis of the vehicle; shift mechanism (4), the shift mechanism (4) is located inside the PTO housing (1); hydraulic motor (2), the hydraulic motor (2) is mounted on the upper part of the PTO housing (1); power output shaft (3), the shift mechanism (4) is connected to the power output shaft (3); the shift mechanism (4) includes a first shaft (401), a second shaft (402) and a third shaft (403) arranged in parallel from top to bottom, the first shaft (401) is connected to the output shaft of the hydraulic motor (2), and the third shaft (403) is connected to the power output shaft (3).

2. The tractor hydrostatic PTO system according to claim 1, characterized in that: A first-gear drive gear (404) and a second-gear drive gear (405) with different transmission ratios are loosely fitted on the first shaft (401). A first-gear driven gear (406) and a second-gear driven gear (407) are fixed on the second shaft (402). An output shaft gear (408) that meshes with the second-gear driven gear (407) is fixed on the third shaft (403). A gear shifting actuator (409) is provided at the position of the first shaft (401) between the first-gear drive gear (404) and the second-gear drive gear (405).

3. A tractor hydrostatic PTO system according to claim 1, characterized in that: The line connecting the centers of the output shaft, the second shaft (402), and the third shaft (403) of the hydraulic motor (2) forms a triangle.

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