Overload protection device for rotary cultivator

Abstract

An overload protection device of a rotary cultivator is simple in structure, an overflow valve is mounted on an oil supply pipeline of a hydraulic motor, and when a rotary blade or a rotary blade shaft touches an obstacle which cannot be cut off, hydraulic pressure at an oil inlet of the hydraulic motor is increased suddenly, so that the overflow valve is opened to quickly release pressure, and the rotating speed and torque of the hydraulic motor are quickly reduced; therefore, impact is buffered, overload protection is achieved, and the rotary blade and the blade shaft can be protected. Meanwhile, after the rotary blade can rotate at a low speed to bypass an obstacle, the oil supply management hydraulic pressure is lowered, the overflow valve is closed, so that normal oil supply to the hydraulic motor is recovered, the working state of the rotary blade can be automatically recovered, manual operation is not needed, use is very convenient, and efficiency is high. In addition, a buffering assembly can be additionally arranged, the transmission tile is driven to be far away from the cutter shaft through hydraulic force generated when the oil pressure of the oil supply pipeline is increased suddenly, and therefore power between the rotary blade or the cutter shaft and the hydraulic motor is rapidly disconnected, impact force is rapidly buffered, and overload protection performance is further improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to a rotary cultivator, in particular to a rotary cultivator overload protection device. BACKGROUND

[0002] If the rotary cultivator encounters sundries such as stones and roots that cannot be cut off when plowing, it will produce a very large impact on the rotary cultivator knife, which may directly damage the rotary cultivator knife and knife shaft, or even cause the gear box and the entire rotary cultivator part to deform. In particular, in the current high-standard farmland reconstruction project, there are many stones in the soil, which makes the existing rotary cultivator almost unable to adapt, and it is particularly prone to damage.

[0003] Therefore, how to solve the impact of sundries on the knife and even the entire rotary cultivator during the rotary cultivation process is a technical problem that needs to be solved at present. The applicant in the Chinese utility model with publication number CN218244300U uses a probe rotary cultivation part oil pressure, and actively lifts when the oil pressure reaches the threshold to achieve overload protection. However, this method is difficult to achieve continuous plowing, that is, it needs to be operated again to lower it after lifting, so it is only suitable for scenes with less sundries, and when there are more sundries, it will cause frequent lifting, which seriously affects the plowing efficiency.

[0004] In this regard, the applicant believes that it is necessary to ensure efficiency while protecting against impact overload. UTILITY MODEL CONTENTS

[0005] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the utility model is to provide a rotary cultivator overload protection device, which has the functions of impact overload protection and can continue plowing after passing over the impact object.

[0006] To achieve the above-mentioned purpose, the utility model provides a rotary cultivator overload protection device, which comprises a hydraulic motor, a rotary cultivator knife or knife shaft, and an overflow valve. The hydraulic motor directly or indirectly drives the rotary cultivator knife or knife shaft to rotate. The oil supply pipeline of the hydraulic motor is in communication with the inlet of the overflow valve. When the oil pressure in the oil supply pipeline reaches the opening pressure of the overflow valve, the overflow valve opens to release pressure.

[0007] As a further improvement of the utility model, it further comprises a hydraulic pump, the oil supply pipeline is an oil supply pipe, the inlet of the hydraulic pump is in communication with the hydraulic oil, the outlet of the hydraulic pump is in direct or indirect communication with the first oil port of the hydraulic motor through the oil supply pipe, and the second oil port of the hydraulic motor is in direct or indirect communication with the oil return pipe; the inlet of the overflow valve is in communication with the oil supply pipe.

[0008] As a further improvement of the utility model, it further comprises a reversing valve and an oil tank, two oil inlets of the hydraulic motor are communicated with one end of a first oil pipe and a second oil pipe respectively, the other end of the first oil pipe and the second oil pipe is communicated with two interfaces of the reversing valve respectively, the other two interfaces of the reversing valve are communicated with one end of an oil supply pipe and an oil return pipe respectively, the oil supply pipe is communicated with the outlet of a hydraulic pump, the inlet of the hydraulic pump is communicated with hydraulic oil in the oil tank, and the other end of the oil return pipe is connected into the oil tank; the first oil pipe and the second oil pipe are further communicated with two ends of a third oil pipe respectively, and an overflow valve is connected in series on the third oil pipe, and the overflow direction of the overflow valve is from the first oil pipe to the second oil pipe.

[0009] As a further improvement of the utility model, it further comprises a rotary tillage frame and a gear box, the cutter shaft, the hydraulic motor and the gear box are all installed on the rotary tillage frame, a rotary tiller is installed on the cutter shaft, the hydraulic motor is driven to rotate by hydraulic oil, the power of the output shaft is input into the gear box, and finally the gear box is driven to rotate, and the gear sleeve directly or indirectly drives the cutter shaft to rotate.

[0010] As a further improvement of the utility model, a transmission part is arranged on the cutter shaft, the gear sleeve and the end cover are assembled, and the gear sleeve and the end cover are both sleeved on the cutter shaft; the transmission part is assembled with the transmission tile;

[0011] A tile shaft is arranged on the transmission tile, the tile shaft is arranged in a piston hole and assembled with a piston, and the piston is sealingly and slidingly installed in the piston hole; one end of the piston hole on the two sides of the piston is communicated with one end of a connecting liquid supply hole and one end of a disconnecting liquid supply hole, the disconnecting liquid supply hole and the piston hole are arranged on a switching sleeve, one end of the switching sleeve is assembled and fixed with the end cover, the other end is arranged in a sealing sleeve and assembled and fixed with the sealing sleeve in a sealing mode, the sealing sleeve is arranged in a liquid supply sleeve, and the sealing sleeve is assembled with the liquid supply sleeve in a sealing mode, an inner side of the switching sleeve is further provided with a tile groove, and the transmission tile is assembled and slidingly installed in the tile groove;

[0012] The other end of the disconnecting liquid supply hole is communicated with one end of a disconnecting through hole, a disconnecting liquid supply ring groove is arranged on the disconnecting through hole, the disconnecting through hole is communicated with one end of a second pipe head, and the second pipe head is communicated with a liquid supply pipe;

[0013] The connecting liquid supply hole is arranged on the sealing sleeve, the other end of the connecting liquid supply hole is communicated with a connecting liquid supply ring groove, the connecting liquid supply ring groove is communicated with one end of a connecting channel, the other end of the connecting channel is communicated with one end of a first pipe head, and the first pipe head is connected into hydraulic oil;

[0014] The disconnected liquid supply ring groove, the connecting channel, the connected liquid supply ring groove and the disconnected through hole are arranged on the liquid supply sleeve, the liquid supply sleeve is installed on the gear box shell or the rotary tillage frame, and the liquid supply sleeve and the switching sleeve are relatively circumferentially rotatable; the spring is installed between the inner wall of the connecting liquid supply hole of the piston and the sealing sleeve, and the spring applies the elastic force to the piston to extrude the transmission tile.

[0015] As a further improvement of the utility model, the transmission tile and the transmission part are provided with the spline and the spline groove which are assembled with each other.

[0016] As a further improvement of the utility model, the first pipe head is communicated with the oil return pipe.

[0017] As a further improvement of the utility model, the first pipe head is communicated with the hydraulic oil of the pressure maintaining oil way.

[0018] As a further improvement of the utility model, the second pipe head is communicated with the interface of the energy accumulator.

[0019] As a further improvement of the utility model, the gear box comprises a gear box shell, the gear box shell is internally provided with a gear shifting tooth and a transmission sleeve, the transmission sleeve is sleeved outside the output shaft of the hydraulic motor, the transmission sleeve is respectively provided with a driving large tooth and a driving small tooth, the gear shifting tooth is sleeved outside a gear shifting shaft, and the gear shifting shaft is installed on the rotary tillage blade frame.

[0020] The gear shifting tooth is respectively provided with a gear shifting large tooth and a gear shifting small tooth, and is assembled with a gear shifting fork and a gear shifting rod.

[0021] The gear shifting shaft is further provided with a first transmission tooth, the first transmission tooth is meshed with a second transmission tooth, the second transmission tooth is meshed with a third transmission tooth, the third transmission tooth is meshed with a fourth transmission tooth, the second transmission tooth, the third transmission tooth and the fourth transmission tooth are installed in the gear box through corresponding gear shafts, the fourth transmission tooth is sleeved outside a gear sleeve, and the gear sleeve is directly or indirectly assembled with the blade shaft.

[0022] The utility model discloses the beneficial effects are:

[0023] The utility model discloses simple structure installs overflow valve on the oil supply pipeline of hydraulic motor, utilizes rotary blade or rotary blade axle to meet the obstacle that cannot cut off, and the hydraulic pressure of hydraulic motor oil inlet place increases suddenly, thereby opens overflow valve and rapidly releases pressure, this makes the rotating speed of hydraulic motor, torque rapidly drop, thereby buffering impact to realize overload protection, can protect rotary blade, blade axle. Meanwhile, after rotary blade can slowly rotate and bypass the obstacle, oil supply management hydraulic pressure drops, and overflow valve closes to restore normal oil supply to hydraulic motor, can automatically restore the working condition of rotary blade, need not manual operation again, it is very convenient to use, and the efficiency is high. In addition, the utility model discloses can increase buffer assembly, and the hydraulic pressure of oil supply pipeline oil pressure increases suddenly and drives transmission tile to be far away from blade axle, thereby rapidly disconnects the power between rotary blade or blade axle and hydraulic motor, thereby rapidly buffers impact, further improves overload protection performance. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is the structure diagram of the utility model Figure 1 ;

[0025] Figure 2 It is the structure diagram of the utility model Figure 2 ;

[0026] Figure 3 It is the structure diagram of the utility model

[0027] Figure 4 It is the structure diagram of the utility model

[0028] Figure 5 It is the hydraulic principle diagram of overload protection hydraulic system

[0029] Figure 6 It is the structure diagram after increasing buffer assembly

[0030] Figure 7 It is the structure diagram after increasing buffer assembly Figure 6 ; DETAILED DESCRIPTION

[0031] The technical scheme in the utility model embodiment will be clearly and completely described below with reference to the drawings in the utility model embodiment.

[0032] Refer to Figures 1-5The rotary cultivator overload protection device of the embodiment includes a rotary cultivator frame 310, a cutter shaft 320, a hydraulic motor 120, a gear box 400, a hydraulic pump 110, and an overflow valve 140. The cutter shaft 320, the hydraulic motor 120, and the gear box 400 are all mounted on the rotary cultivator frame 310. The cutter shaft 320 is provided with a rotary cultivator blade 330. The hydraulic motor 120 is driven to rotate by hydraulic oil. The power of the output shaft is input into the gear box 400, and finally drives the cutter shaft 320 to rotate, thereby driving the rotary cultivator blade 330 to rotate to achieve cultivation.

[0033] The gear box 400 includes a gear box shell 410, a shift gear 430, and a transmission sleeve 420. The transmission sleeve 420 is mounted on the output shaft of the hydraulic motor 120 and cannot rotate relative to the circumference. The transmission sleeve 420 is provided with a driving large gear 421 and a driving small gear 422. The shift gear 430 is mounted on the shift shaft 401 and cannot rotate relative to the circumference but can move relative to the axis. The shift shaft 401 is mounted on the rotary cultivator frame 310 and can rotate relative to the circumference.

[0034] The shift gear 430 is provided with a shift large gear 431 and a shift small gear 432. The shift gear 430 is assembled with a shift fork 460, and the shift fork 460 is assembled with a shift lever 461. The shift lever 461 drives the shift fork 460 to move, thereby driving the shift gear 430 to move axially on the shift shaft 401 to achieve gear shifting. The gear positions include:

[0035] The neutral gear, the shift large gear 431 and the shift small gear 432 do not mesh with the driving small gear 422 and the driving large gear 421, so that the transmission sleeve 420 cannot drive the shift gear 430 to rotate.

[0036] The high-speed gear, the driving large gear 421 meshes with the shift small gear 432, and the shift large gear 431 does not mesh with the driving small gear 422.

[0037] The low-speed gear, the driving large gear 421 does not mesh with the shift small gear 432, and the shift large gear 431 meshes with the driving small gear 422.

[0038] The shift shaft 401 is further provided with a first transmission gear 441. The first transmission gear 441 meshes with a second transmission gear 442, the second transmission gear 442 meshes with a third transmission gear 443, and the third transmission gear 443 meshes with a fourth transmission gear 444. The second transmission gear 442, the third transmission gear 443, and the fourth transmission gear 444 are all mounted in the gear box through corresponding gear shafts. The fourth transmission gear 444 is mounted on the gear sleeve 450, and the gear sleeve 450 is directly or indirectly assembled with the cutter shaft 320, so that the fourth transmission gear 444 can drive the cutter shaft 320 to rotate.

[0039] In combination Figure 5The two oil inlets of the hydraulic motor 120 are respectively communicated with one end of the first oil pipe 221 and the second oil pipe 222, the other end of the first oil pipe 221 and the second oil pipe 222 is respectively communicated with two interfaces of the reversing valve 130, the other two interfaces of the reversing valve 130 are respectively communicated with one end of the oil supply pipe 211 and the oil return pipe 212, the oil supply pipe 211 is communicated with the outlet of the hydraulic pump 110, the inlet of the hydraulic pump 110 is communicated with the hydraulic oil in the oil tank 150, the other end of the oil return pipe 212 is connected into the oil tank 150; the first oil pipe 221 and the second oil pipe 222 are also respectively communicated with two ends of the third oil pipe 312, and the overflow valve 140 is connected in series on the third oil pipe 213, and the overflow direction of the overflow valve 140 is from the first oil pipe 221 to the second oil pipe 222.

[0040] In use (forward rotation of the rotary tiller), the hydraulic pump 110 is started, the hydraulic oil is pressurized and pumped into the oil supply pipe 211, then into the first oil pipe 221, and then into the hydraulic motor 120 to drive the hydraulic motor 120 to run, then from the second oil pipe 222 into the oil return pipe 212, and finally back to the oil tank. During the overflow process, the pressure of the oil return pipe is maintained, so there is still some pressure entering the hydraulic motor. In this way, on the one hand, it can ensure that the hydraulic motor rotates, so that the rotary tiller can pass around obstacles, and on the other hand, it can prevent the hydraulic motor from stopping quickly and causing a large impact, and also prevent the rotary tiller shaft from being stuck.

[0041] Once the rotary tiller or rotary tiller shaft is impacted and overloaded, the rotational speed of one side of the rotary tiller shaft will be lower than the rotational speed of the hydraulic motor, so that the hydraulic pressure at one end of the hydraulic motor inlet is significantly higher than the hydraulic pressure at one end of the outlet, that is, the hydraulic pressure of the oil supply pipe 211 is significantly higher than the hydraulic pressure of the oil return pipe 212, when the opening pressure of the overflow valve is reached, the overflow valve is opened, so that part of the hydraulic oil in the oil supply pipe 211 is input into the oil return pipe 212 through the third oil pipe 213 and then back to the oil tank, which greatly reduces the supply of the hydraulic motor 120, and the hydraulic oil pressure is greatly reduced, so the rotational speed of the hydraulic motor 120 is rapidly reduced, and even reverses under the impact, thereby greatly buffering the impact force. In actual use, once the rotary tiller 330 is stuck, the rotational speed of the hydraulic motor will be reduced, so that the rotary tiller 330 rotates slowly to pass around the obstacle, which on the one hand can buffer the impact and realize overload protection, thereby avoiding direct damage to the rotary tiller, the tiller shaft, the rotary tiller frame and the like; on the other hand, the rotary tiller 330 is used to rotate around the obstacle, and after passing around the obstacle, the hydraulic pressure is restored and the hydraulic motor resumes work to continue plowing, that is, the working state is automatically restored, thereby greatly improving the efficiency and facilitating use.

[0042] In some embodiments, Figures 1-5The design has achieved good results, but if the rotating speed of the hydraulic motor is large, and suddenly encounters an obstacle, the rotating speed of the rotary blade is greatly reduced, at this time the overflow valve may not be able to depressurize in time, and there is also a risk of damaging the rotary blade, the blade shaft and other parts. To this end, the embodiment is improved as follows:

[0043] Referring to Figures 6-7 , a buffer assembly is added, and the buffer assembly includes a transmission part 321, a liquid supply sleeve 510 end cover 520, a switching sleeve 530, a transmission shoe 540, and a sealing sleeve 570.

[0044] The blade shaft 320 is provided with a transmission part 321, the gear sleeve 450 is assembled with the end cover 520, and the gear sleeve 450 and the end cover 520 are both circumferentially rotatable and sleeved on the blade shaft 320; the transmission part 321 is assembled with the transmission shoe 540. Specifically, the transmission shoe 540 is provided with a structure that is engaged with the transmission part 321 spline and spline groove, so that the transmission shoe 540 cannot rotate relative to the blade shaft 320.

[0045] The transmission shoe 540 is provided with a shoe shaft 541, the shoe shaft 541 is inserted into the piston hole 532 and assembled with the piston 542, the piston 542 is sealingly and slidingly installed in the piston hole 532; the piston hole 532 is in communication with one end of the connecting liquid supply hole 571 and one end of the disconnecting liquid supply hole 531 on both sides of the piston, the disconnecting liquid supply hole 531 and the piston hole 532 are arranged on the switching sleeve 530, one end of the switching sleeve 530 is assembled and fixed with the end cover 520, the other end is inserted into the sealing sleeve 570 and assembled and fixed with it, the sealing sleeve 570 is inserted into the liquid supply sleeve 510, and the sealing sleeve 570 is sealingly and circumferentially rotatably assembled with the liquid supply sleeve 510, the inner side of the switching sleeve 530 is further provided with a shoe groove 533, and the transmission shoe 540 is engaged and slidingly installed in the shoe groove 533.

[0046] The other end of the disconnecting liquid supply hole 531 is in communication with one end of the disconnecting through hole 514, the disconnecting through hole 514 is provided with a disconnecting liquid supply ring groove 511, the disconnecting through hole 514 is in communication with one end of the second pipe head 561, and the second pipe head 561 is in communication with the liquid supply pipe 211.

[0047] The connecting liquid supply hole 571 is arranged on the sealing sleeve 570, the other end of the connecting liquid supply hole 571 is in communication with the connecting liquid supply ring groove 513, the connecting liquid supply ring groove 513 is in communication with one end of the connecting channel 512, the other end of the connecting channel 512 is in communication with one end of the first pipe head 562, and the other end of the first pipe head 562 is in communication with the oil return pipe 212. The first pipe head 562 can also be in communication with the hydraulic oil of the pressure maintaining oil way, thereby providing a stable hydraulic pressure.

[0048] The disconnect liquid supply ring groove 511, the connecting channel 512, the connecting liquid supply ring groove 513, and the disconnect through hole 514 are all arranged on the liquid supply sleeve 510, which is installed on the gear box shell 410 or the rotary tillage frame 310, and can rotate relative to the switching sleeve 530. The spring 550 is installed between the piston 542 and the inner wall of the sealing sleeve 570 at the connecting liquid supply hole 571, and the spring 550 exerts a spring force on the piston 420 to press the transmission shoe 540, so that the transmission shoe 540 is kept in pressure contact with the transmission part 321 in the initial state.

[0049] In normal use, the pressure difference between the oil inlet and the oil outlet of the hydraulic motor is small, so it can be ensured that the hydraulic pressure of the disconnect liquid supply hole 531 is not enough to push the piston to overcome the spring force and the hydraulic pressure in the connecting channel 512 to move away from the knife shaft 320, so that the transmission shoe 540 is kept in pressure contact with the transmission part 321.

[0050] Once the rotary tillage knife encounters an obstacle, the hydraulic pressure in the liquid supply pipe 211 rises rapidly, so that the hydraulic pressure of the disconnect liquid supply hole 531 rises until the spring force is overcome, the hydraulic pressure in the connecting channel 512 pushes the piston away from the knife shaft to move away from the knife shaft to make the transmission shoe 540 separate from the transmission part, so that the power between the hydraulic motor and the knife shaft is cut off, at this time the rotary tillage knife will rotate around the obstacle under the action of inertia until the hydraulic pressure in the liquid supply pipe decreases to restore to the working state. The most important feature of this design is that the power can be quickly disconnected, compared with the scheme, the speed is faster, so the effect of overload protection for some larger impact is better, at the same time it has the function of automatic recovery to working state, and it is also convenient to use and high in efficiency. Figures 1-5

[0051] In some embodiments, an accumulator can be connected to the oil line communicating with the second pipe head 562 to buffer the hydraulic pressure at the connecting channel 512, so as to maintain the hydraulic pressure in the connecting channel 512, so that the piston can be reset under the action of the hydraulic pressure in the connecting channel 512 and the spring force after overload movement to restore to work. Specifically, the other end of the second pipe head 562 directly communicates with the interface of the accumulator, so as to maintain the hydraulic pressure in the connecting channel 512 by using the accumulator.

[0052] In some embodiments, the transmission shoe 540 and the transmission part 321 cannot be arranged with splines and spline grooves, but adopt the mode of pressure contact and friction transmission, so that the shell between the transmission shoe 540 and the transmission part 321 can rotate relative to each other to buffer in time when encountering an overload impact force. This design is similar to the brake structure of the motor, and the power is transmitted to the knife shaft in the "brake state", and the power cannot be transmitted to the knife shaft in the "non-brake state".

[0053] ​The liquid supply ring groove 511 and the connecting liquid supply ring groove 513 are coaxial with the cutter shaft, which makes the piston hole 532 continuously supplied with liquid on both sides of the piston when the cutter shaft rotates relative to the liquid supply sleeve 510, and the liquid supply sleeve 510 rotates relative to the sealing sleeve 570, so as to maintain the corresponding hydraulic pressure.

[0054] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in the present application should be understood as the general meaning understood by the skilled person in the field to which the present application belongs.

[0055] The above is only the preferred specific implementation of the present application, but the protection scope of the present application is not limited to this. Any changes or replacements that can be easily thought of by those skilled in the art within the technical scope disclosed in the present application should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An overload protection device for a rotary cultivator, characterized in that: The hydraulic motor, the rotary tiller or the blade shaft, the overflow valve, the hydraulic motor directly or indirectly drives the rotary tiller or the blade shaft to rotate, the oil supply pipeline of the hydraulic motor is communicated with the inlet of the overflow valve; when the oil pressure in the oil supply pipeline reaches the opening pressure of the overflow valve, the overflow valve opens to release pressure.

2. The PTO shield of claim 1 wherein: The hydraulic pump, the oil supply pipeline is the oil supply pipe, the inlet of the hydraulic pump is communicated with the hydraulic oil, the outlet of the hydraulic pump is directly or indirectly communicated with the first oil port of the hydraulic motor through the oil supply pipe, the second oil port of the hydraulic motor is directly or indirectly communicated with the oil return pipe; the inlet of the overflow valve is communicated with the oil supply pipe.

3. The PTO shield of claim 2 wherein: The reversing valve, the oil tank, the two oil inlets of the hydraulic motor are respectively communicated with one end of the first oil pipe and the second oil pipe, the other end of the first oil pipe and the second oil pipe is respectively communicated with two interfaces of the reversing valve, the other two interfaces of the reversing valve are respectively communicated with one end of the oil supply pipe and the oil return pipe, the oil supply pipe is communicated with the outlet of the hydraulic pump, the inlet of the hydraulic pump is communicated with the hydraulic oil in the oil tank, the other end of the oil return pipe is connected into the oil tank; the first oil pipe and the second oil pipe are also respectively communicated with two ends of the third oil pipe, the overflow valve is connected in series on the third oil pipe, the overflow direction of the overflow valve is from the first oil pipe to the second oil pipe.

4. An overload protection device for a rotary cultivator as claimed in any one of claims 1 to 3, characterized in that: The rotary tiller frame, the gear box, the blade shaft, the hydraulic motor and the gear box are all installed on the rotary tiller frame, the rotary tiller is installed on the blade shaft, the hydraulic motor drives its output shaft to rotate through the hydraulic oil, the power of the output shaft is input into the gear box, and finally drives the gear sleeve to rotate, the gear sleeve directly or indirectly drives the blade shaft to rotate.

5. The PTO shield of claim 4 wherein: The blade shaft is provided with a transmission part, the gear sleeve is assembled with the end cover, and the gear sleeve and the end cover are both sleeved on the blade shaft; the transmission part is assembled with the transmission tile; The transmission tile is provided with a tile shaft, the tile shaft is assembled into the piston hole and assembled with the piston, and the piston is sealingly and slidingly installed in the piston hole; the piston hole is located at the two side portions of the piston and is respectively communicated with one end of the connecting liquid supply hole and one end of the disconnecting liquid supply hole; the disconnecting liquid supply hole and the piston hole are arranged on the switching sleeve, one end of the switching sleeve is assembled with the end cover and fixed, the other end is assembled into the sealing sleeve and fixed in sealing assembly, the sealing sleeve is assembled into the liquid supply sleeve, and the sealing sleeve is sealingly assembled with the liquid supply sleeve; the inner side of the switching sleeve is further provided with a tile groove, and the transmission tile is assembled and slidingly installed in the tile groove; The other end of the disconnecting liquid supply hole is communicated with one end of the disconnecting through hole, the disconnecting through hole is provided with a disconnecting liquid supply ring groove, the disconnecting through hole is communicated with one end of the second pipe head, and the second pipe head is communicated with the liquid supply pipe; The connecting liquid supply hole is arranged on the sealing sleeve, the other end of the connecting liquid supply hole is communicated with the connecting liquid supply ring groove, the connecting liquid supply ring groove is communicated with one end of the connecting channel, the other end of the connecting channel is communicated with one end of the first pipe head, and the first pipe head is connected into the hydraulic oil; The disconnecting liquid supply ring groove, the connecting channel, the connecting liquid supply ring groove and the disconnecting through hole are all arranged on the liquid supply sleeve, the liquid supply sleeve is installed on the gear box shell or the rotary tiller frame, and the liquid supply sleeve and the switching sleeve are relatively circumferentially rotatable assembled; the spring is installed between the inner wall of the connecting liquid supply hole of the piston and the sealing sleeve, and the spring applies a spring force to the piston to extrude the transmission tile.

6. The rotating tillage machine overload protection device of claim 5 wherein: The transmission part is provided with a spline and a spline groove which are assembled with each other.

7. The PTO shield of claim 5 wherein: The first pipe head communicates with the oil return pipe.

8. The rotating tiller overload protection device of claim 5 wherein: The first pipe head communicates with the hydraulic oil of the pressure maintaining oil path.

9. The PTO shield of claim 8 wherein: The second pipe head communicates with the interface of the energy accumulator.

10. An overload protection device for a rotary cultivator as claimed in any one of claims 5 to 9, characterised in that: The gear box comprises a gear box shell, shift gears, and a transmission sleeve, the transmission sleeve is sleeved outside the output shaft of the hydraulic motor, and the transmission sleeve is respectively provided with driving large teeth and driving small teeth, the shift gears are sleeved outside the shift shaft, and the shift shaft is installed on the rotary tiller frame; The shift gears are respectively provided with shift large teeth and shift small teeth, and the shift gears are assembled with the shift yoke, and the shift yoke is assembled with the shift rod; The shift shaft is further provided with a first transmission gear, the first transmission gear is in meshing transmission with a second transmission gear, a third transmission gear, and a fourth transmission gear, the second transmission gear, the third transmission gear, and the fourth transmission gear are installed in the gear box through corresponding gear shafts, and the fourth transmission gear is sleeved outside the gear sleeve, and the gear sleeve is directly or indirectly assembled with the cutter shaft.

Images