Gear shifting device of tractor

Abstract

The utility model relates to the technical field of tractors, in particular to a tractor gear shifting device. Comprising a control box body, two gear shifting shafts are installed on the control box body, a speed change shifting fork is fixedly installed at the end, close to an upper cover, of each gear shifting shaft, the end, away from the speed change shifting fork, of each gear shifting shaft is slidably installed in a guide cylinder, the outer side of the guide cylinder is fixedly connected with a gear shifting rocker arm, and the guide cylinder is fixedly connected with the control box body in the axial direction; a gear selecting mechanism used for driving the gear shifting shaft to move in the axial direction is installed on the control box body and comprises a gear selecting rocker arm located on the outer side of the control box body. And the gear selecting rocker arm and the gear shifting rocker arm are respectively in transmission connection with the corresponding control handles through flexible shaft transmission mechanisms. By means of the structure, the control handle can be in transmission connection with the gear shifting rocker arm and the gear selecting rocker arm through the flexible shaft transmission mechanism during transmission connection, other devices in a tractor can be avoided during installation, limitation of installation space is avoided, and installation is convenient.

Description

Technical Field

[0001] This utility model relates to the field of tractor technology, specifically to a tractor shifting device. Background Technology

[0002] The tractor shifting device is the core component of the tractor transmission system. It is used to switch between different gears during operation to adjust speed and traction to meet different working conditions.

[0003] Currently, most tractor gear shifting devices use a multi-link control method, where a multi-link mechanism is hinged between the control handle and the rocker arm. This type of multi-link gear shifting device is easily limited by installation space and is relatively inconvenient to install. Utility Model Content

[0004] To address the aforementioned problems, this utility model provides a tractor shifting device to solve the problem that the installation of existing multi-link shifting devices is easily limited by installation space, resulting in inconvenience during installation.

[0005] This utility model is achieved using the following technical solution: a tractor gear shifting device, including a control box, on which two shift shafts are mounted. A shift fork is fixedly mounted at the end of the shift shaft away from the control box, and a guide cylinder is slidably mounted at the end of the shift shaft away from the shift fork. A shift rocker arm is fixedly connected at the end of the guide cylinder away from the shift fork, and the guide cylinder is rotatably engaged with the control box. A gear selection mechanism for driving the shift shafts to move axially is mounted on the control box. The gear selection mechanism includes a gear selection rocker arm located outside the control box and rotatably engaged with the control box. The gear selection rocker arm and the shift rocker arm are respectively driven by a flexible shaft transmission mechanism to their corresponding control handles.

[0006] With the above structure, the control handle can be connected to the shift rocker arm and the gear selector rocker arm via a flexible shaft transmission mechanism. During installation, it can avoid other internal devices of the tractor and is not limited by the installation space, making it relatively convenient to install.

[0007] Preferably, the guide cylinder has a limiting hole on its side wall, and a limiting pin is fixedly installed at the end of the shift shaft away from the shift fork. The limiting pin is located in the limiting hole and slides in cooperation with the limiting hole. Through the cooperation between the limiting hole and the limiting pin, the shift shaft and the guide cylinder can only slide relative to each other, and cannot rotate.

[0008] Preferably, two symmetrical limiting holes are provided. A limiting pin passes through the shift shaft, and both ends of the limiting pin extend outward to the outside of the shift shaft. The two ends of the limiting pin are respectively located in the two limiting holes and slide in cooperation with the limiting holes. The arrangement of two symmetrical limiting holes makes the shift shaft more stable when sliding.

[0009] Preferably, the limiting hole is an oblong hole, and the limiting pin is cylindrical, with the diameter of the limiting pin being equal to the width of the limiting hole. By setting the diameter and width of the limiting hole to be equal, the shift shaft can be prevented from shaking, further increasing the stability during the shifting process.

[0010] Preferably, the guide cylinder has an annular mounting groove on its side wall near the shift rocker arm, and a sealing ring is installed in the mounting groove, with the sealing ring located between the guide cylinder and the control box. The sealing ring prevents dust and other contaminants from entering the control box through the gap between the guide cylinder and the control box, and subsequently into the gearbox, thus affecting the service life of the device.

[0011] Preferably, a limiting groove is provided on the side wall of the guide cylinder near the shift rocker arm, and a stop block is fixedly installed at the end of the control box away from the shift fork, with the stop block located within the limiting groove. The limiting groove and the stop block prevent the guide cylinder from moving along with the shift shaft when the shift rocker arm moves axially, further increasing the stability of the device.

[0012] Preferably, the gear selection mechanism further includes a connecting column fixedly connected to the gear selection rocker arm. The connecting column is rotatably connected to the control box. A gear selection lever is fixedly connected to the connecting column, and the gear selection lever is located inside the control box. A shifting column is fixedly connected to the end of the gear selection lever away from the connecting column. A gear selection seat is fixedly installed on the shift shaft. A shifting groove is provided on the side of the gear selection seat near the gear selection lever. The end of the shifting column away from the gear selection lever is located in the shifting groove and slides in cooperation with the shifting groove. By setting up the gear selection lever, when the gear selection rocker arm rotates, it drives the gear selection lever to rotate, thereby making it easier to control the axial movement of the shift shaft. Furthermore, through the cooperation of the gear selection seat and the shifting column, when the gear selection lever rotates, it drives the shift shaft to move axially, making the structure simpler.

[0013] Preferably, a baffle is fixedly installed inside the guide cylinder at the end away from the shift fork. The baffle prevents dust and other debris from entering the device from the inside of the guide cylinder, further increasing the device's service life.

[0014] Preferably, the flexible shaft transmission mechanism includes a first hinged arm hinged to the gear selection rocker arm and the gear shift rocker arm. One end of the flexible shaft is fixedly mounted on the first hinged arm, and a second hinged arm is fixedly connected to the other end of the flexible shaft. The second hinged arm is hinged to the operating handle. A mounting sleeve is fitted on the outer side of the flexible shaft, and fixed seats that are fixedly connected to the tractor frame are fixedly mounted at both ends of the mounting sleeve. The mounting sleeve makes the installation of the flexible shaft more stable and reduces wear between the flexible shaft and other internal devices of the tractor, thereby increasing the service life of the device.

[0015] Preferably, the flexible shaft is a steel wire rope.

[0016] In summary, the beneficial effects of this utility model are as follows:

[0017] By changing the transmission connection between the control handle and its corresponding shift rocker arm or selector arm from a multi-link rigid shaft connection to a flexible shaft transmission mechanism, this device can be installed without having to be planned in advance, making installation more convenient. Attached Figure Description

[0018] Figure 1 This is an exploded view of a tractor gear shifting device according to the present invention;

[0019] Figure 2 A schematic diagram of the structure of the gear shift rocker arm and the flexible shaft transmission mechanism;

[0020] Figure 3 This is a bottom view of the gear shifting device;

[0021] Figure 4 This is a cross-sectional view of the gear shifting device;

[0022] Figure 5 for Figure 4 A magnified view of a portion of area "A" in the image.

[0023] In the diagram: 1-Shift rocker arm; 2-Guide cylinder; 3-Limiting hole; 4-Control box; 5-Selection rocker arm; 6-Connecting column; 7-Shift shaft; 8-Selection lever arm; 9-Actuating groove; 10-Selection seat; 11-Actuating column; 12-Shift fork; 13-Top cover; 14-Limiting pin; 15-Guide cover; 16-Mounting groove; 17-Sealing ring; 18-Stop block; 19-Limiting groove; 20-First hinge arm; 21-Flexible shaft; 22-Fixed seat; 23-Mounting sleeve; 24-Second hinge arm. Detailed Implementation

[0024] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit its scope.

[0025] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", 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 application and simplifying the description, and do not indicate or imply that the device or element 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 application.

[0026] The following is a description of preferred embodiments of the present invention in conjunction with the accompanying drawings.

[0027] like Figure 1 , Figure 2 As shown, this utility model provides a tractor gear shifting device, including a control box 4 fixedly mounted on an upper cover 13. Two shift shafts 7 are mounted on the control box 4; the two shift shafts 7 are a main gear shift shaft and a secondary gear shift shaft, respectively. Gear selection is achieved by axial movement of the shift shafts, and gear shifting is achieved by rotation of the shift shafts. Since their structures are similar, those skilled in the art can easily distinguish them through drawings; therefore, in this application, they are both referred to as shift shafts 7. A shift fork 12 is fixedly mounted on the end of the shift shaft 7 near the upper cover 13. The shift fork 12 is located inside the upper cover and is mainly used to switch the meshing of gears in the gearbox. The cooperation between the shift fork 12 and the gearbox is conventional prior art, which those skilled in the art can easily learn about through patent searches and videos; therefore, it will not be described in detail here. A guide cylinder 2 is slidably mounted on the end of the shift shaft 7 away from the shift fork 12. A shift rocker arm 1 is fixedly mounted on the end of the guide cylinder 2 away from the shift fork 12. Specifically, the shift rocker arm 1 and the guide cylinder 2 are fixed by welding. The guide cylinder 2 is rotatably engaged with the control box 4. The control box 4 is equipped with a gear selection mechanism for driving the shift shaft 7 to move axially. The gear selection mechanism includes a gear selection rocker arm 5 located on the outside of the control box 4.

[0028] In this device, both the shift rocker arm 1 and the gear selection rocker arm 5 are connected to their corresponding operating handles via a flexible shaft transmission mechanism. Specifically, taking the shift rocker arm 1 as an example, the flexible shaft transmission mechanism includes a first hinge arm 20 that is hinged to the shift rocker arm 1. One end of a flexible shaft 21 is fixedly mounted on the first hinge arm 20, and the other end of the flexible shaft 21 is fixedly connected to a second hinge arm 24. The second hinge arm 24 is hinged to the operating handle. An installation sleeve 23 is sleeved on the outside of the flexible shaft 21, and fixed seats 22 that are fixedly connected to the tractor frame are fixedly mounted on both ends of the installation sleeve 23.

[0029] Both ends of the flexible shaft 21 extend out of the mounting sleeve 23 to provide space for the movement of the flexible shaft 21. The mounting sleeve 23 is designed to make the installation of the flexible shaft 21 more stable and to reduce wear between the flexible shaft 21 and other internal devices of the tractor, thereby increasing the service life of the flexible shaft transmission mechanism in this device.

[0030] In this embodiment, the flexible shaft 21 is preferably a steel wire rope.

[0031] like Figure 1 , Figure 3 , Figure 4As shown, a guide cylinder 2 is fixedly installed at the end of the shift rocker arm 1 away from the first hinge arm 20. The guide cylinder 2 is sleeved on the outer side of the shift shaft 7 away from the shift fork 12, and the guide cylinder 2 is slidably engaged with the shift shaft 7. Specifically, a limiting hole 3 is provided on the side wall of the guide cylinder 2, and a limiting pin 14 is fixedly installed at the end of the shift shaft 7 away from the shift fork 12. The limiting pin 14 is located in the limiting hole 3 and is slidably engaged with the limiting hole 3.

[0032] The fit between a single limiting hole 3 and a limiting pin 14 is not stable and the force is uneven, making it prone to damage. Therefore, in order to make the sliding fit between the limiting pin 14 and the limiting hole 3 more stable and to further improve the service life of the device, two limiting holes 3 are symmetrically arranged. The limiting pin 14 passes through the shift shaft 7, and both ends of the limiting pin 14 extend outward to the outside of the shift shaft 7. The two ends of the limiting pin 14 are located in the two limiting holes 3 respectively and slide in fit with the limiting holes 3.

[0033] The limiting hole 3 is an oblong hole, and the limiting pin 14 is cylindrical. The diameter of the limiting pin 14 is equal to the width of the limiting hole 3. When the width of the limiting hole 3 is much larger than the diameter of the limiting pin 14, the shift rocker arm 1 needs to rotate a certain angle before it can drive the shift shaft 7 to rotate, resulting in a high delay in the shifting operation. To avoid this delay, the width of the limiting hole 3 is made equal to the diameter of the limiting pin 14, thus eliminating the transmission delay between the two. Of course, when the width of the limiting hole 3 is equal to the diameter of the limiting pin 14, the friction between the limiting hole 3 and the limiting pin 14 is large, leading to faster wear. To reduce the friction between them, the diameter of the limiting pin 14 can be set to be 1mm smaller than the width of the limiting hole 3.

[0034] like Figure 1 , Figure 4 , Figure 5 As shown, an annular mounting groove 16 is provided on the side wall of the guide cylinder 2 near the shift rocker arm 1. A sealing ring 17 is installed in the mounting groove 16, and the sealing ring 17 is located between the guide cylinder 2 and the control box 4. The sealing ring 17 can prevent dust from entering the device and thus prevent it from entering the gearbox, affecting the service life of the gearbox. Secondly, the sealing ring 17 can also reduce the wear between the guide cylinder 2 and the control box 4, further increasing the service life of the device.

[0035] An annular limiting groove 19 is provided on the side wall of the guide cylinder 2 near the shift rocker arm 1. A stop block 18 is fixedly installed at the end of the control box 4 away from the shift fork 12, and the stop block 18 is located in the limiting groove 19. The cooperation between the limiting groove 19 and the stop block 18 can prevent the guide cylinder 2 from moving when the shift shaft 7 moves axially.

[0036] The mounting groove 16 and the sealing ring 17 are also provided on the connecting column 6, which will not be described in detail here.

[0037] The gear selection mechanism also includes a connecting post 6 fixedly connected to the end of the gear selection rocker arm 5 away from the first hinge arm 20. The axis of the connecting post 6 is perpendicular to the axis of the shift shaft 7. The connecting post 6 is rotatably engaged with the control box 4. A gear selection lever 8 is fixedly sleeved on the outside of the connecting post 6. The gear selection lever 8 is located inside the control box 4. A toggle post 11 is fixedly connected to the end of the gear selection lever 8 away from the connecting post 6. A gear selection seat 10 is fixedly installed on the shift shaft 7. The gear selection seat 10 has a toggle groove 9 on the side near the gear selection lever 8. The end of the toggle post 11 away from the gear selection lever 8 is located in the toggle groove 9 and slides in engagement with the toggle groove 9. When the gear selection lever 8 rotates, the toggle post 11 moves up and down in the toggle groove 9. During this process, the toggle post 11 also drives the gear selection seat 10 to move along the axial direction of the shift shaft 7, thereby driving the shift shaft 7 to move axially.

[0038] As a further illustration of this example, a baffle 15 is fixedly installed inside the guide cylinder 2 at the end away from the shift fork 12, thereby preventing dust from entering the interior of the device from the inside of the guide cylinder 2, and further improving the service life of the device.

[0039] The operating principle of this device is as follows: When shifting gears on the tractor, if shifting is required, the shift fork 12 needs to be rotated, and the corresponding operating handle of the shift rocker arm 1 needs to be manipulated, thereby pulling the flexible shaft 21. This achieves the rotation of the shift rocker arm 1, which in turn drives the shift fork 12 to rotate via the shift shaft 7. When the shift shaft 7 rotates, the gear selector seat 10 also rotates accordingly. During this process, the shift pin 11 is always located in the shift groove 9, and the shift pin 11 is stationary relative to the control box 4. When gear selection is required, the shift fork 12 needs to be moved axially, and the corresponding operating handle of the gear selector rocker arm 5 needs to be manipulated, thereby pulling the flexible shaft 21. This achieves the rotation of the gear selector rocker arm 5, which in turn drives the rotation of the gear selector arm 8. Finally, the shift shaft 7 drives the shift fork 12 to move axially along the shift shaft 7. While the shift shaft 7 moves axially, the limiting pin 14 slides within the limiting hole 3, that is, the shift shaft 7 slides relative to the guide cylinder 2. By controlling the coordination between the two shift rocker arms 1 and the two selector rocker arms 5, the switching of multiple gears in the gearbox can be realized to meet the power requirements of the tractor.

[0040] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present utility model, and these improvements and substitutions should also be considered within the protection scope of the present utility model.

Claims

1. A tractor gear shifting device, comprising a control housing (4), wherein two shift shafts (7) are mounted on the control housing (4), and a shift fork (12) is fixedly mounted on one end of the shift shaft (7) away from the control housing (4), characterized in that, The shift shaft (7) is slidably mounted with a guide cylinder (2) at one end away from the shift fork (12). The guide cylinder (2) is fixedly connected with a shift rocker arm (1) at one end away from the shift fork (12). The guide cylinder (2) is rotatably engaged with the control box (4). The control box (4) is equipped with a gear selection mechanism for driving the shift shaft (7) to move axially. The gear selection mechanism includes a gear selection rocker arm (5) located outside the control box (4) and rotatably engaged with the control box (4). The gear selection rocker arm (5) and the shift rocker arm (1) are respectively connected to their corresponding control handles through a flexible shaft transmission mechanism.

2. The tractor shifting device according to claim 1, characterized in that, The guide cylinder (2) has a limiting hole (3) on its side wall. A limiting pin (14) is fixedly installed at the end of the shift shaft (7) away from the shift fork (12). The limiting pin (14) is located in the limiting hole (3) and slides with the limiting hole (3).

3. The tractor shifting device according to claim 2, characterized in that, Two symmetrically arranged limiting holes (3) are provided. The limiting pin (14) passes through the shift shaft (7). The two ends of the limiting pin (14) extend outward to the outside of the shift shaft (7). The two ends of the limiting pin (14) are located in the two limiting holes (3) respectively and slide in cooperation with the limiting holes (3).

4. The tractor shifting device according to claim 3, characterized in that, The limiting hole (3) is an oblong hole, and the limiting pin (14) is cylindrical. The diameter of the limiting pin (14) is equal to the width of the limiting hole (3).

5. The tractor shifting device according to claim 1, characterized in that, The guide cylinder (2) has an annular mounting groove (16) on the side wall near the shift rocker arm (1). A sealing ring (17) is installed in the mounting groove (16) and the sealing ring (17) is located between the guide cylinder (2) and the control box (4).

6. The tractor shifting device according to claim 1, characterized in that, The guide cylinder (2) has a limiting groove (19) on the side wall near the shift rocker arm (1), and a stop block (18) is fixedly installed at the end of the control box (4) away from the shift fork (12), and the stop block (18) is located in the limiting groove (19).

7. The tractor shifting device according to claim 1, characterized in that, The gear selection mechanism also includes a connecting column (6) fixedly connected to the gear selection rocker arm (5). The connecting column (6) is rotatably connected to the control box (4). A gear selection lever (8) is fixedly connected to the connecting column (6). The gear selection lever (8) is located inside the control box (4). A toggle column (11) is fixedly connected to the end of the gear selection lever (8) away from the connecting column (6). A gear selection seat (10) is fixedly installed on the shift shaft (7). A toggle groove (9) is provided on the side of the gear selection seat (10) near the gear selection lever (8). The end of the toggle column (11) away from the gear selection lever (8) is located in the toggle groove (9) and slides in cooperation with the toggle groove (9).

8. The tractor shifting device according to claim 1, characterized in that, A baffle (15) is fixedly installed inside the guide cylinder (2) at the end away from the shift fork (12).

9. The tractor shifting device according to claim 1, characterized in that, The flexible shaft transmission mechanism includes a first hinge arm (20) hinged to the gear selection rocker arm (5) and the gear shift rocker arm (1). One end of the flexible shaft (21) is fixedly installed on the first hinge arm (20), and the other end of the flexible shaft (21) is fixedly connected to a second hinge arm (24). The second hinge arm (24) is hinged to the operating handle. An installation sleeve (23) is sleeved on the outside of the flexible shaft (21), and fixed seats (22) that are fixedly connected to the tractor frame are fixedly installed at both ends of the installation sleeve (23).

10. The tractor shifting device according to claim 9, characterized in that, The flexible shaft (21) is a steel wire rope.

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