Hydraulic gear shift mechanism of a power shift transmission

Abstract

The application discloses a hydraulic gear shifting mechanism of a power gear shifting gearbox, and belongs to the technical field of gearboxes.The hydraulic gear shifting mechanism comprises a gear selecting cylinder, wherein a gear selecting shaft is arranged in the gear selecting cylinder, the gear selecting cylinder is provided with a first channel allowing the gear selecting shaft to move, a gear shifting knob is connected to the gear selecting shaft, a gear selecting oil pipe joint is arranged on the first channel of one end of the gear selecting shaft, the gear selecting oil pipe joint is provided with a first through hole allowing fluid to pass, and a first screw plug is connected to the other end of the gear selecting shaft through a gear selecting spring.The gear shifting device has simple mechanical structure, is convenient to install and maintain, adopts a hydraulic control mode for gear shifting, does not need manual operation, and is smooth and accurate in gear shifting.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gearbox, in particular to a hydraulic gear shifting mechanism of power shift gearbox. BACKGROUND

[0002] Tractors mainly undertake the main work of traction and transportation in agricultural operations, and have irreplaceable role in agricultural production. At present, the tractors gearbox is mainly manual, but the manual gearbox shifting operation is cumbersome, requires high shifting timing, and has power interruption phenomenon. The traditional manual gearbox shifting system needs to pull the shifting lever by manpower to control the shift fork shifting, which makes the farm hand driving labor intensity, and the shifting operation is time-consuming and laborious. Therefore, the prior art proposes many solutions, such as using hydraulic control mode for shifting operation. The existing patent DE102021123388A1 provides a switching device and a gear box. The switching device includes: a switching fork shaft designed to be movable in its own axial direction under the action of hydraulic driving force; and different gear positions are switched by the switching device, wherein the switching device further includes a first hydraulic driving assembly and a second hydraulic driving assembly arranged at the end of the shift fork shaft, a first assembly groove and a second assembly groove are respectively arranged on the first hydraulic driving assembly and the second hydraulic driving assembly, and a radial seal is installed in the first assembly groove and the second assembly groove, so that the hydraulic driving force directly acts on the first hydraulic driving assembly and the second hydraulic driving assembly, and the shift fork shaft moves in its own axial direction. However, the above-mentioned technology still has room for improvement in terms of smooth and accurate shifting. SUMMARY

[0003] The purpose of the present application is to provide a hydraulic gear shifting mechanism of power shift gearbox, which has simple mechanical structure, is convenient to install and maintain, adopts hydraulic control mode for shifting, does not need human operation, and has smooth and accurate shifting.

[0004] To solve the above technical problems, the present application specifically provides the following technical scheme: a hydraulic gear shifting mechanism of power shift gearbox. The hydraulic gear shifting mechanism of power shift gearbox includes a gear selection cylinder, a gear selection shaft is arranged in the gear selection cylinder, the gear selection cylinder has a first channel allowing the gear selection shaft to move, a gear shifting knob is connected to the gear selection shaft, a gear selection oil pipe joint is arranged on the first channel at one end of the gear selection shaft, the gear selection oil pipe joint has a first through hole allowing fluid to pass through, and a first screw plug is connected to the other end of the gear selection shaft through a gear selection spring. The gear selection shaft is connected to the gear shifting knob through a cylindrical pin, specifically, the gear selection shaft and the gear shifting knob are both provided with through holes for the cylindrical pin to pass through, the cylindrical pin passes through the gear selection shaft and the gear shifting knob to form a connection relationship therebetween, and the assembly relationship between the cylindrical pin and the gear selection shaft and the gear shifting knob can be interference assembly or transition assembly.

[0005] The end of the selection shaft adjacent to the selection spring is provided with a cylindrical protruding column arranged in the selection spring, so that the selection spring abuts against the end face of the selection shaft and cannot be loosened, and more importantly, the cylindrical protruding column has the effect of guiding and installing the selection spring during the installation of the selection spring and the selection shaft, and the length of the cylindrical protruding column can control the displacement distance of the selection shaft, thereby playing a limiting role.

[0006] The present application controls the movement of the selection shaft by inputting fluid through the selection oil pipe joint and controlling the oil pressure input into the left oil cavity of the selection shaft to drive the gear shifting handle to switch to other fork shafts, and the selection spring at the end of the selection shaft provides elastic support to help the selection shaft switch back to the initial fork shaft position, so that the selection and gear shifting process is completed by the electro-hydraulic system and manual operation of the operator is not required, thereby greatly reducing the operation steps of the operator.

[0007] The present application controls the movement of the selection shaft by inputting fluid through the selection oil pipe joint and controlling the oil pressure input into the left oil cavity of the selection shaft to drive the gear shifting handle to switch to other fork shafts, and the selection spring at the end of the selection shaft provides elastic support to help the selection shaft switch back to the initial fork shaft position, so that the selection and gear shifting process is completed by the electro-hydraulic system and manual operation of the operator is not required, thereby greatly reducing the operation steps of the operator.

[0008] According to an embodiment of the present application, the selection cylinder is connected with the gear shifting cylinder at the upper end, the selection cylinder and the gear shifting cylinder are in internal communication, and the first screw plug is connected with the selection cylinder. The selection cylinder cooperates with the first screw plug and the selection spring to form elastic support for the selection shaft. When maintenance and replacement are required, the selection shaft can be quickly taken out by disassembling the selection cylinder, and when the selection shaft is reassembled, the first screw plug and the selection spring can be used to correct the coaxiality of the selection shaft. The first screw plug and the selection spring are coaxial with the first channel, and can correct the coaxiality of the disassembled selection shaft, thereby eliminating the need for correction of the selection shaft.

[0009] According to an embodiment of the present application, the first sealing ring is arranged at the connection position of the first screw plug and the selection cylinder to prevent leakage or entry of external medium. The selection oil pipe joint is in communication with the first channel of the selection cylinder, and the selection oil pipe joint and the selection cylinder form a connection relationship and the connection contact surface is provided with the first sealing ring. The connection relationship between the selection oil pipe joint and the selection cylinder can be threaded connection, specifically, a threaded hole is arranged at the end of the first channel of the selection cylinder, and the selection oil pipe joint is externally provided with threads matched with the threaded hole, so that the threaded connection is formed between the selection oil pipe joint and the selection cylinder, thereby preventing leakage of medium or entry of external dirt.

[0010] According to an embodiment of the present application, a magnet bolt is connected to the end of the shift shaft adjacent to the shift oil pipe joint, and a first magnet seat and a first magnet are arranged between the magnet bolt and the shift shaft.

[0011] A displacement sensor is arranged on the shift cylinder outside the end of the shift shaft adjacent to the shift oil pipe joint, the position of the shift shaft is determined by detecting the first magnet fixed to the end of the shift shaft by the magnet bolt, and the moving speed and distance of the shift knob are accurately controlled in combination with the oil pressure sensor arranged on the gearbox shell, so that the shift process is fast and accurate, and the magnet bolt and the first magnet can clean the inside of the first channel. In the long-term use of the shift shaft and the first channel, friction debris may occur, the first magnet can collect magnetic debris, and the shift oil pipe joint continuously inputs and outputs fluid to realize the discharge of the debris existing in the first channel, so as to avoid the influence of the debris on the sealing effect and the smoothness of the shift shaft.

[0012] According to an embodiment of the present application, one side surface of the first magnet is in contact with the surface of the shift shaft, and a ring groove is arranged on the contact surface of the shift shaft and the first magnet, and a second sealing ring is arranged in the ring groove. The other side surface of the first magnet is connected with the magnet bolt, and a first magnet seat is arranged between the magnet bolt and the first magnet, that is, the first magnet is arranged in the first magnet seat, and the first magnet and the first magnet seat are both provided with an installation through hole capable of allowing the magnet bolt to pass through. The magnet bolt is screwed to the end of the shift shaft through the installation through hole to limit the first magnet and the first magnet seat. The first magnet arranged in the first magnet seat can avoid being cracked under stress, and the second sealing ring of O-ring structure installed at the contact position of the first magnet and the shift shaft plays a buffering role for coping with the input fluid pressure, avoids the first magnet from being cracked under excessive pressure, and enables the first magnet and the shift shaft to form a gap to accommodate the wear debris in the channel, so as to facilitate subsequent cleaning effect of discharging fluid.

[0013] According to an embodiment of the present application, the shift cylinder has a second channel, the axis of the second channel is staggered with the axis of the first channel, a shift shaft is arranged in the second channel, the two ends of the shift shaft are in contact with the inner wall of the second channel and the shift shaft can move relative to the second channel, one side surface of the shift shaft has a first groove, and one end of the shift knob is arranged in the first groove. The contact part of the two ends of the shift shaft and the inner wall of the second channel can be provided with a sealing structure. The axial movement of the shift shaft is controlled by controlling the input oil pressure on both sides to drive the shift knob to rotate, so as to push the shift fork into the gear position to be switched.

[0014] According to an embodiment of the present application, shift oil pipe joints are arranged at the second channel ports of the two ends of the shift shaft, and a third sealing ring is arranged on the contact end surface of the shift oil pipe joint and the second channel of the shift cylinder to seal the oil cavity. The shift oil pipe joint has a second through hole allowing fluid to pass through.

[0015] According to an embodiment of the present application, a magnet bolt is threadedly connected to one end of the shift shaft, a second magnet is arranged between the magnet bolt and the shift shaft, and the second magnet is externally covered by a second magnet seat. A second sealing ring in the form of an O-ring is arranged at the position where the shift shaft contacts the second magnet seat, and the second sealing ring functions as a buffer to cope with the input fluid pressure, to prevent the second magnet from being excessively pressed and broken, and to allow the second magnet to accommodate wear debris in a certain gap formed between the second magnet and the shift shaft, thereby facilitating subsequent cooperation with the in-out fluid discharge to achieve a cleaning effect.

[0016] According to an embodiment of the present application, a displacement sensor corresponding to the position of the second magnet at the end of the shift shaft is arranged outside the shift cylinder. The displacement sensor arranged outside the shift cylinder can accurately control the moving distance and speed of the shift shaft by detecting the position of the second magnet on the shift shaft in combination with the oil pressure sensor arranged on the transmission housing, thereby accurately and rapidly controlling the transmission shift process.

[0017] According to an embodiment of the present application, the shift cylinder has a third channel, the axis of the third channel is arranged in a staggered manner with the axis of the first channel, a four-wheel drive shaft is arranged in the third channel, and the four-wheel drive shaft is movable relative to the third channel. A four-wheel drive knob is arranged on the shift shaft, a linear bearing is arranged at the connection position of the four-wheel drive knob and the shift shaft, one side surface of the four-wheel drive shaft has a second groove, and one end of the four-wheel drive knob is arranged in the second groove. When the four-wheel drive shaft is in the initial position, the transmission is in the front-wheel drive mode. By inputting pressure oil to the right oil cavity of the four-wheel drive shaft, i.e., the right side of the third channel, the axial movement of the four-wheel drive shaft is controlled, the transmission is switched to the four-wheel drive mode, the input pressure is removed, the four-wheel drive shaft is pushed by the four-wheel drive spring, returns to the initial position, and pushes the four-wheel drive knob to rotate, thereby pushing the four-wheel drive knob shaft to make the transmission return to the front-wheel drive position.

[0018] According to an embodiment of the present application, a linear bearing is arranged between the four-wheel drive shaft and the third channel, i.e., the linear bearing is coaxially arranged inside the third channel, and the four-wheel drive shaft passes through the linear bearing.

[0019] The linear bearing is used to reduce the friction between the four-wheel drive shaft and the surrounding objects during the axial movement of the four-wheel drive shaft, to ensure smooth axial movement of the four-wheel drive shaft, and to calibrate the coaxiality of the reciprocating four-wheel drive shaft. For example, if the end of the four-wheel drive shaft is too long, the coaxiality may be deviated due to gravity, and the linear bearing can solve this problem.

[0020] According to an embodiment of the present application, the third channel of the shift cylinder is connected with a shift oil pipe joint at one end, the shift oil pipe joint has a second through hole allowing fluid to pass through, the other end of the third channel is provided with a second screw plug, and the four-wheel drive spring is arranged between the four-wheel drive shaft and the second screw plug. The four-wheel drive shaft is provided with a cylindrical protruding column at one end adjacent to the four-wheel drive spring, and the cylindrical protruding column is arranged in the four-wheel drive spring, so that the four-wheel drive spring abuts against the end face of the four-wheel drive shaft and cannot be loosened, and the cylindrical protruding column of the four-wheel drive shaft can provide installation guide for the four-wheel drive spring and limit the displacement distance of the four-wheel drive shaft by limiting the length of the cylindrical protruding column of the four-wheel drive shaft.

[0021] According to an embodiment of the present application, the second screw plug cooperates with the four-wheel drive spring to elastically support the four-wheel drive shaft, and the coaxiality of the four-wheel drive shaft can be corrected by the second screw plug cooperating with the four-wheel drive spring. The second screw plug is coaxial with the third channel, and the second screw plug and the four-wheel drive spring are also coaxial with the third channel. The four-wheel drive shaft can be corrected in coaxiality after disassembly, and the correction step of the four-wheel drive shaft is omitted.

[0022] The end of the four-wheel drive shaft adjacent to the shift oil pipe joint can be in contact with the inner wall of the third channel, and a sealing structure such as a sealing ring can be arranged at the contact part.

[0023] According to an embodiment of the present application, the second screw plug is provided with a third sealing ring at the connection end of the third channel of the shift cylinder, and the shift oil pipe joint is provided with a third sealing ring at the connection end of the third channel of the shift cylinder.

[0024] According to an embodiment of the present application, a magnet bolt is threadedly connected to the end of the four-wheel drive shaft adjacent to the shift oil pipe joint, a second magnet is arranged between the magnet bolt and the four-wheel drive shaft, and the second magnet is covered with a second magnet seat. A second sealing ring is arranged at the contact surface of the second magnet and the four-wheel drive shaft. The second sealing ring and the second magnet seat can prevent the fluid pressure from damaging the second magnet, and the second sealing ring can form a gap between the second magnet and the end face of the four-wheel drive shaft to facilitate the collection of debris generated during the operation of the equipment, so that the debris can be taken out by the fluid to achieve the cleaning effect in the third channel.

[0025] A displacement sensor corresponding to the position of the second magnet at the end of the four-wheel drive shaft is arranged outside the shift cylinder, which can detect the position of the second magnet on the four-wheel drive shaft and determine the position of the four-wheel drive shaft. Combined with the oil pressure sensor in the gearbox, the four-wheel drive mode or the front-wheel drive mode of the gearbox can be accurately controlled.

[0026] According to an embodiment of the present application, a linear bearing is arranged at the connection between the selection cylinder and the selection shaft, that is, the selection cylinder is internally provided with the linear bearing, and the selection shaft can pass through the linear bearing. The linear bearing does not move with the selection shaft, thereby reducing the resistance of the selection shaft when moving axially, and the linear bearing can calibrate the coaxiality of the reciprocating selection shaft. For example, when the selection shaft is too long, the end part thereof can deviate from the coaxiality due to gravity, and the linear bearing can solve this problem.

[0027] Compared with the prior art, the present application has the following advantages. The selection oil pipe joint of the present application inputs fluid and controls the oil pressure input into the left oil cavity of the selection shaft to control the movement of the selection shaft, thereby driving the shift knob to switch to other shift fork shafts. The selection spring at the end of the selection shaft provides elastic support and helps the selection shaft switch back to the initial shift fork shaft position. The selection and shift process is controlled by the electro-hydraulic system throughout the process, which can realize sensitive shift response and rapid shift action, and is especially suitable for complex operations that require frequent shifting. Compared with the manual control method of the prior art, the present application can reduce the power interruption time, does not require manual operation, and greatly reduces the operation steps of the operator. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only exemplary, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the provided drawings.

[0029] Figure 1 A hydraulic shift mechanism scheme of a power shift gearbox according to the present application;

[0030] Figure 2 A hydraulic shift mechanism scheme of a power shift gearbox according to the present application;

[0031] Figure 3 A Figure 2 A-A direction sectional view of a hydraulic shift mechanism of a power shift gearbox;

[0032] Figure 4 A magnet bolt and selection shaft connection scheme according to the present application;

[0033] Figure 5 A Figure 2 B-B direction sectional view of a hydraulic shift mechanism of a power shift gearbox;

[0034] Figure 6 A Figure 2 C-C direction sectional view of a hydraulic shift mechanism of a power shift gearbox;

[0035] Figure 7 This is a schematic diagram of the connection scheme between the self-locking pin and the shift lever in this case.

[0036] Explanation of reference numerals in the attached diagram: 1. Shift cylinder; 2. Selector cylinder; 3. Selector oil pipe connector; 4. First sealing ring; 5. Magnetic bolt; 6. First magnet; 7. First magnet seat; 8. Second sealing ring; 9. Selector shaft; 10. Cylindrical pin; 11. Shift lever; 12. Four-wheel drive lever; 13. Linear bearing; 14. Selector spring; 15. First plug; 16. Displacement sensor; 17. Second plug; 18. Third sealing ring; 19. Four-wheel drive spring; 20. Four-wheel drive shaft; 21. Second magnet; 22. Second magnet seat; 23. Shift oil pipe connector; 24. Shift shaft; 25. Self-locking pin. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] The concepts involved in this application will first be described with reference to the accompanying drawings. It should be noted that the following descriptions of various concepts are only for the purpose of making the content of this application easier to understand and do not constitute a limitation on the scope of protection of this application; furthermore, the embodiments and features in the embodiments of this application can be combined with each other unless otherwise specified. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0039] Example 1:

[0040] like Figures 1-4 As shown, this invention provides a hydraulic shifting mechanism for a power shift transmission. It includes a shift cylinder 2, which houses a shift shaft 9. The shift cylinder 2 has a first channel allowing the shift shaft 9 to move. A shift lever 11 is connected to the shift shaft 9. A shift oil pipe connector 3 is provided on the first channel at one end of the shift shaft 9. The shift oil pipe connector 3 has a first through hole allowing fluid to pass through. A first plug 15 is connected to the other end of the shift shaft 9 via a shift spring 14. The shift shaft 9 is connected to the shift lever 11 via a cylindrical pin 10. Specifically, both the shift shaft 9 and the shift lever 11 have through holes for the cylindrical pin 10 to pass through. The cylindrical pin 10 passes through the shift shaft 9 and the shift lever 11 to form a connection. The assembly relationship between the cylindrical pin 10 and the shift shaft 9 and shift lever 11 can be an interference fit or a transition fit.

[0041] The end of the selection shaft 9 is provided with a cylindrical protruding column which is arranged in the selection spring 14, so that the selection spring 14 is in abutment with the end face of the selection shaft 9 and cannot be loosened, and more importantly, the cylindrical protruding column has the effect of guiding and installing the selection spring 14 during the installation of the selection spring 14 and the selection shaft 9, and the length of the cylindrical protruding column can control the displacement distance of the selection shaft 9, thereby playing a limiting role, and when the cylindrical protruding column of the selection shaft 9 abuts against the first screw plug 15, the gear shifting handle 11 is just located on the other yoke shaft, thereby preventing the selection shaft 9 from being pushed through and unable to shift gears.

[0042] The present application controls the movement of the selection shaft 9 by inputting fluid through the selection oil pipe joint 3 and controlling the oil pressure input into the oil cavity on the left side of the selection shaft 9, thereby driving the gear shifting handle 11 to switch to other yoke shafts, the selection spring 14 at the end of the selection shaft 9 provides elastic support, helps the selection shaft 9 to switch back to the initial yoke shaft position, the selection spring 14 can balance the oil pressure at the front end, ensures the accurate movement position of the selection shaft 9, and after the oil pressure at the front end is removed, the selection shaft 9 returns quickly, the whole selection and gear shifting process is completed by the electro-hydraulic system control, without the need for manual operation of the operator, and the operation steps of the agricultural operator are greatly reduced.

[0043] The present application controls the movement of the selection shaft 9 by inputting fluid through the selection oil pipe joint 3 and controlling the oil pressure input into the oil cavity on the left side of the selection shaft 9, thereby driving the gear shifting handle 11 to switch to other yoke shafts, the selection spring 14 at the end of the selection shaft 9 provides elastic support, helps the selection shaft 9 to switch back to the initial yoke shaft position, the selection spring 14 can balance the oil pressure at the front end, ensures the accurate movement position of the selection shaft 9, and after the oil pressure at the front end is removed, the selection shaft 9 returns quickly, the whole selection and gear shifting process is completed by the electro-hydraulic system control, without the need for manual operation of the operator, and the operation steps of the agricultural operator are greatly reduced.

[0044] The selection cylinder 2 is connected with the gear shifting cylinder 1 at the upper end, the selection cylinder 2 is in communication with the gear shifting cylinder 1 inside, and the first screw plug 15 is connected with the selection cylinder 2. The selection cylinder 2 cooperates with the first screw plug 15 and the selection spring 14 to form elastic support for the selection shaft 9, when maintenance and replacement are needed, the selection shaft 9 can be quickly taken out by disassembling the selection cylinder 2, and when the selection shaft 9 is installed back, the coaxiality of the selection shaft 9 can be corrected through the first screw plug 15 and the selection spring 14, the first screw plug 15 and the selection spring 14 are coaxial with the first channel, and the disassembled selection shaft 9 can be corrected in coaxiality, thereby eliminating the correction steps of the selection shaft 9.

[0045] The first sealing ring 4 is arranged at the connection between the first screw block 15 and the gear selection cylinder 2 to avoid leakage or external medium entering. The gear selection oil pipe joint 3 is in communication with the first channel of the gear selection cylinder 2, and the gear selection oil pipe joint 3 is in connection with the gear selection cylinder 2 and the connection surface is provided with the first sealing ring 4. The connection relationship between the gear selection oil pipe joint 3 and the gear selection cylinder 2 can be threaded connection, specifically, a threaded hole is arranged at the end of the first channel of the gear selection cylinder 2, and the gear selection oil pipe joint 3 is externally provided with threads matched with the threaded hole, so that the threaded connection is formed, thereby avoiding leakage of medium or entry of external dirt.

[0046] The magnet bolt 5 is connected to the end of the gear selection shaft 9 adjacent to the gear selection oil pipe joint 3, and the first magnet seat 7 and the first magnet 6 are arranged between the magnet bolt 5 and the gear selection shaft 9.

[0047] The displacement sensor 16 is arranged on the gear selection cylinder 1 outside the end of the gear selection shaft 9 adjacent to the gear selection oil pipe joint 3, the position of the gear selection shaft 9 is judged by detecting the first magnet 6 fixed to the end of the gear selection shaft 9 by the magnet bolt 5, and the moving speed and distance of the gear selection handle 11 are accurately controlled in combination with the oil pressure sensor installed on the gearbox shell, so as to ensure that the gear selection process is fast and accurate, and the magnet bolt 5 and the first magnet 6 arranged can clean the inside of the first channel. In the long-term use of the gear selection shaft 9 and the first channel, friction debris may occur, the first magnet 6 can collect magnetic debris, cooperate with the continuous input and output of fluid of the gear selection oil pipe joint 3 to realize the discharge of the debris existing in the first channel, and avoid the influence of the debris on the sealing effect and the smoothness of the gear selection shaft 9.

[0048] One side surface of the first magnet 6 is in contact with the surface of the gear selection shaft 9, and a ring groove is arranged on the contact surface of the gear selection shaft 9 and the first magnet 6, and the second sealing ring 8 is arranged in the ring groove. The other side surface of the first magnet 6 is connected with the magnet bolt 5, and the first magnet seat 7 is arranged between the magnet bolt 5 and the first magnet 6, that is, the first magnet 6 is arranged in the first magnet seat 7, and the first magnet 6 and the first magnet seat 7 are both provided with mounting through holes capable of allowing the magnet bolt 5 to pass through, and the magnet bolt 5 passes through the mounting through holes and is threadedly connected with the end of the gear selection shaft 9 to limit the first magnet 6 and the first magnet seat 7. The first magnet 6 is arranged in the first magnet seat 7 to avoid stress cracking of the first magnet 6, and the second sealing ring 8 of O-ring structure is arranged at the contact position of the first magnet 6 and the gear selection shaft 9 to play a buffering role for resisting the input fluid pressure, avoid the first magnet 6 from being broken due to excessive pressure, and enable the first magnet 6 and the gear selection shaft 9 to form a gap to accommodate wear debris in the channel, so as to facilitate subsequent cooperation with the in-out fluid to discharge and play a cleaning effect.

[0049] Embodiment 2:

[0050] Referring to the accompanying drawings Figure 1 - the accompanying drawings Figure 2 , and the accompanying drawings Figure 5As shown, the embodiment is further optimized on the basis of the scheme of Embodiment 1, and the scheme is as follows: the shift cylinder 1 has a second channel, the axis of the second channel is staggered with the axis of the first channel, a shift shaft 24 is arranged in the second channel, the two end portions of the shift shaft 24 are in contact with the inner wall of the second channel, and the shift shaft 24 can move relative to the second channel, one side surface of the shift shaft 24 has a first groove, and one end portion of the shift fork 11 is arranged in the first groove. The two end portions of the shift shaft 24 in contact with the inner wall of the second channel can be provided with a sealing structure. The axial movement of the shift shaft 24 is controlled by controlling the oil pressure input on both sides, the shift fork 11 is rotated, and the shift fork is pushed into the gear position to be switched.

[0051] The second channel ports at the two ends of the shift shaft 24 are provided with shift oil pipe joints 23, the contact end surface of the shift oil pipe joint 23 with the second channel of the shift cylinder 1 is provided with a third sealing ring 18 for sealing the oil cavity, and the shift oil pipe joint 23 has a second through hole allowing fluid to pass through.

[0052] One end portion of the shift shaft 24 is threadedly connected with a magnet bolt 5, a second magnet 21 is arranged between the shift shaft 24 and the magnet bolt 5, and the second magnet 21 is externally covered with a second magnet seat 22. The second sealing ring 8 of the O-ring structure is installed at the contact position of the shift shaft 24 and the second magnet seat 22 to play a buffering role, so as to cope with the input fluid pressure, avoid excessive pressure of the second magnet 21, and enable the second magnet 21 to form a certain gap with the shift shaft 24 to accommodate the wear debris in the channel, so as to facilitate subsequent cooperation of the in-out fluid to discharge and play a cleaning effect.

[0053] The shift cylinder 1 is externally provided with a displacement sensor 16 corresponding to the position of the second magnet 21 at the end portion of the shift shaft 24. The displacement sensor 16 is arranged on the outside of the shift cylinder 1, the position of the second magnet 21 on the shift shaft 24 is detected, and the oil pressure sensor installed on the gearbox shell is combined to accurately control the moving distance and moving speed of the shift shaft 24, so as to accurately and rapidly control the gearbox shifting process.

[0054] Embodiment 3:

[0055] Referring to the accompanying drawings Figure 1 - the accompanying drawings Figure 2 and the accompanying drawings Figure 6As shown, the embodiment is further optimized on the basis of the scheme of embodiment 1. The shift cylinder 1 has a third channel, the axis of the third channel is staggered with the axis of the first channel, the four-wheel drive shaft 20 is arranged in the third channel, and the four-wheel drive shaft 20 can move relative to the third channel. The four-wheel drive shift head 12 is arranged on the shift shaft 9, and the four-wheel drive shift head 12 is connected with the straight line bearing 13 at the connection position of the four-wheel drive shift head 12 and the shift shaft 9. One side of the four-wheel drive shaft 20 has a second groove, and one end of the four-wheel drive shift head 12 is arranged in the second groove. When the four-wheel drive shaft 20 is in the initial position, the gearbox is in the front-wheel drive mode. By inputting pressure oil to the right side of the four-wheel drive shaft 20, that is, the right side of the third channel, the four-wheel drive shaft 20 is controlled to move axially, the gearbox is switched to the four-wheel drive mode, the input pressure is removed, the four-wheel drive shaft 20 is pushed by the four-wheel drive spring 19, and returns to the initial position, and pushes the four-wheel drive shift head 12 to rotate, thereby pushing the four-wheel drive shift head 12 to move axially to make the gearbox return to the front-wheel drive position.

[0056] The four-wheel drive shaft 20 and the third channel are provided with the straight line bearing 13, that is, the straight line bearing 13 is coaxially arranged in the third channel, and the four-wheel drive shaft 20 passes through the straight line bearing 13.

[0057] The straight line bearing 13 reduces the friction between the four-wheel drive shaft 20 and the surrounding objects during axial movement of the four-wheel drive shaft 20, so as to ensure smooth axial movement of the four-wheel drive shaft 20, and the straight line bearing 13 can calibrate the coaxiality of the reciprocating four-wheel drive shaft 20. For example, if the end of the four-wheel drive shaft 20 is too long, the end may deviate from the coaxiality due to gravity, and the straight line bearing 13 can solve this problem.

[0058] One end of the third channel of the shift cylinder 1 is connected with the shift oil pipe joint 23, the shift oil pipe joint 23 has a second through hole allowing fluid to pass through, the other end of the third channel is provided with the second screw plug 17, and the four-wheel drive spring 19 is arranged between the second screw plug 17 and the four-wheel drive shaft 20. The four-wheel drive shaft 20 has a cylindrical protruding column adjacent to the four-wheel drive spring 19, the cylindrical protruding column is arranged in the four-wheel drive spring 19, so that the four-wheel drive spring 19 abuts against the end surface of the four-wheel drive shaft 20 and cannot be loosened, and the cylindrical protruding column of the four-wheel drive shaft 20 can provide installation guide for the four-wheel drive spring 19, and limit the displacement distance of the four-wheel drive shaft 20 by limiting the length of the cylindrical protruding column of the four-wheel drive shaft 20.

[0059] The second screw plug 17 cooperates with the four-wheel drive spring 19 to elastically support the four-wheel drive shaft 20, and can also correct the coaxiality of the four-wheel drive shaft 20 by the cooperation of the second screw plug 17 and the four-wheel drive spring 19. The second screw plug 17 is coaxial with the third channel, and the second screw plug 17 and the four-wheel drive spring 19 are also coaxial with the third channel. The four-wheel drive shaft 20 can be corrected in coaxiality after disassembly, and the correction step of the four-wheel drive shaft 20 is omitted.

[0060] The end of the four-wheel drive shaft 20 adjacent to the gear shift oil pipe joint 23 can be in contact with the inner wall of the third channel, and a sealing structure, such as a sealing ring, can be arranged at the contact part.

[0061] The second screw block 17 is provided with a third sealing ring 18 at the third channel connecting end of the gear shift cylinder 1, and the gear shift oil pipe joint 23 is provided with a third sealing ring 18 at the third channel connecting end of the gear shift cylinder 1.

[0062] The four-wheel drive shaft 20 is threadedly connected with a magnet bolt 5 at the end adjacent to the gear shift oil pipe joint 23. A second magnet 21 is arranged between the magnet bolt 5 and the four-wheel drive shaft 20, and the second magnet 21 is externally covered by a second magnet seat 22. A second sealing ring 8 is arranged at the contact surface between the second magnet 21 and the four-wheel drive shaft 20. The arrangement of the second sealing ring 8 and the second magnet seat 22 can prevent the fluid pressure from damaging the second magnet 21, and the second sealing ring 8 can form a certain gap between the second magnet 21 and the end surface of the four-wheel drive shaft 20, so as to collect the debris that may be generated during the operation of the equipment, so that the debris can be taken out by the continuously incoming fluid to achieve the cleaning effect in the third channel.

[0063] The gear shift cylinder 1 is externally provided with a displacement sensor 16 corresponding to the position of the second magnet 21 at the end of the four-wheel drive shaft 20, which can detect the position of the second magnet 21 on the four-wheel drive shaft 20 and determine the position of the four-wheel drive shaft 20. In combination with the oil pressure sensor in the gearbox, the four-wheel drive mode or the front-wheel drive mode of the gearbox can be accurately controlled.

[0064] Embodiment 4:

[0065] Referring to the drawings Figure 3 The present embodiment provides a further optimization scheme based on the embodiment 2. A linear bearing 13 is arranged at the connection between the gear selection cylinder 2 and the gear selection shaft 9, that is, the gear selection cylinder 2 is internally provided with the linear bearing 13, and the gear selection shaft 9 can pass through the linear bearing 13. The linear bearing 13 does not move with the gear selection shaft 9, thereby reducing the resistance of the gear selection shaft 9 when moving axially, and the linear bearing 13 can calibrate the coaxiality of the reciprocating gear selection shaft 9. For example, if the end of the gear selection shaft 9 is too long, the end may deviate from the coaxiality due to gravity, and the linear bearing 13 can solve this problem.

[0066] Embodiment 5:

[0067] Referring to the drawings Figure 7As shown, the embodiment provides further optimization scheme on the basis of embodiment 2, the gear selection cylinder 2 is provided with assembly through hole corresponding to the position of the gear shift knob 11 on one side, the assembly through hole is provided with self-locking pin 25, the end of the self-locking pin 25 has telescopic structure, such as the end is provided with telescopic ball, the spring is arranged between the ball and the end of the self-locking pin 25, that is, the end of the self-locking pin 25 has hole body and limits the ball in the hole body to expose part of the ball, the spring is arranged between the ball and the self-locking pin 25, the side of the gear shift knob 11 has at least two arc-shaped grooves, and the arc-shaped grooves can cooperate with the telescopic structure of the end of the self-locking pin 25 to form gear shift self-locking. During vehicle driving or use, gear shift knob 11 may be disengaged due to shaking, and the self-locking pin 25 provided solves the disengagement problem.

[0068] It should be noted that the terms used in the present application are only for the purpose of describing specific embodiments, and are not intended to limit the scope of the present application. As shown in the specification of the present application, unless the context clearly indicates otherwise, "one", "a", "an" and / or "the" do not refer to a single number, but also include plural. The terms "include", "contain" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or includes elements inherent to such process, method or device. Without more limitations, the element defined by the statement "including one" does not exclude the presence of other identical elements in the process, method or device including the element.

[0069] It should also be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. Unless otherwise specified and limited, the terms "mounting", "connection", "connection" and the like should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or the communication between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0070] The above-described embodiments and / or implementations are merely intended to illustrate the preferred embodiments and / or implementations of the present technology, and are not intended to limit the embodiments of the present technology in any form, and any person skilled in the art can make some changes or modifications as other equivalent embodiments without departing from the scope of the technology disclosed in the present disclosure, but should be considered as the same technology or embodiments as the present disclosure.

[0071] The principles and implementations of the present application are described herein using specific examples. The above description of the embodiments is only intended to help understand the method and core idea of the present application. The above description is only the preferred embodiments of the present application. It should be noted that due to the limited nature of the language, there are objectively infinite specific structures. For those skilled in the art, without departing from the principles of the present application, some improvements, refinements or changes can be made, and the above technical features can be combined in an appropriate manner. These improvements, refinements, changes or combinations, or the direct application of the inventive concept and technical solution to other occasions without improvement, shall be considered as the protection scope of the present application.

Claims

1. A hydraulic gear shift mechanism of a power shift gearbox, comprising a gear selection cylinder (2) in which a gear selection shaft (9) is built, the gear selection cylinder (2) having a first passage allowing the gear selection shaft (9) to move, the gear selection shaft (9) having a gear shift knob (11) connected thereto, characterized in that, The first channel of one end of the selecting shaft (9) is provided with a selecting oil pipe joint (3), the selecting oil pipe joint (3) has a first through hole allowing fluid to pass through, the other end of the selecting shaft (9) is connected with a first screw plug (15) through a selecting spring (14); The selecting cylinder (2) is connected with a gear shifting cylinder (1) at the upper end, the selecting cylinder (2) is in communication with the gear shifting cylinder (1) inside, and the first screw plug (15) is connected with the selecting cylinder (2). The selecting shaft (9) is connected with a magnet bolt (5) at the end of the adjacent selecting oil pipe joint (3), and the magnet bolt (5) is provided with a first magnet seat (7) and a first magnet (6) between the selecting shaft (9). The gear shifting cylinder (1) is provided with a displacement sensor (16) on the outside of the gear shifting cylinder (1) at the end of the adjacent selecting oil pipe joint (3) of the selecting shaft (9). One side surface of the first magnet (6) is in contact with the surface of the selecting shaft (9), the other side surface of the first magnet (6) is connected with the magnet bolt (5), and the first magnet seat (7) is arranged between the magnet bolt (5) and the first magnet (6).

2. A hydraulic gear shift mechanism of a power shift gearbox according to claim 1, characterized in that, The gear shifting cylinder (1) has a second channel, the axis of the second channel is staggered with the axis of the first channel, a gear shifting shaft (24) is arranged in the second channel, the two ends of the gear shifting shaft (24) are in contact with the inner wall of the second channel and the gear shifting shaft (24) can move relative to the second channel, one side surface of the gear shifting shaft (24) has a first groove body, and one end of the gear shifting knob (11) is arranged in the first groove body.

3. A hydraulic gear shift mechanism of a power shift gearbox according to claim 2, characterized in that, Gear shifting oil pipe joints (23) are arranged at the second channel ports of the two ends of the gear shifting shaft (24), and the gear shifting oil pipe joints (23) are provided with third sealing rings (18) at the contact end surfaces of the second channel of the gear shifting cylinder (1).

4. The hydraulic gear shift mechanism of a power shift gearbox according to claim 2, wherein A magnet bolt (5) is threadedly connected to one end of the gear shifting shaft (24), a second magnet (21) is arranged between the magnet bolt (5) and the gear shifting shaft (24), and the second magnet (21) is covered by a second magnet seat (22).

5. A hydraulic gear shift mechanism of a power shift gearbox according to claim 4, characterized in that, The gear shifting cylinder (1) is provided with a displacement sensor (16) corresponding to the position of the second magnet (21) at the end of the gear shifting shaft (24).

6. The hydraulic gear shift mechanism of a power shift gearbox according to claim 1, wherein, The gear shifting cylinder (1) has a third channel, the axis of the third channel is staggered with the axis of the first channel, and a four-wheel drive shaft (20) is arranged in the third channel, and the four-wheel drive shaft (20) can move relative to the third channel.

7. A hydraulic gear shift mechanism of a power shift gearbox according to claim 6, characterized in that The selecting shaft (9) is provided with a four-wheel drive knob (12), a linear bearing (13) is arranged at the connection position of the four-wheel drive knob (12) and the selecting shaft (9), one side surface of the four-wheel drive shaft (20) has a second groove body, and one end of the four-wheel drive knob (12) is arranged in the second groove body.

8. A hydraulic gear shift mechanism of a power shift gearbox according to claim 6, wherein The third channel of the gear shifting cylinder (1) is connected with a gear shifting oil pipe joint (23), the gear shifting oil pipe joint (23) has a second through hole allowing fluid to pass through, the other end of the third channel is provided with a second screw plug (17), and the second screw plug (17) is provided with a four-wheel drive spring (19) between the four-wheel drive shaft (20).

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