Electro-hydraulic control front power output structure of tractor

Abstract

An electro-hydraulic control front power output structure of a tractor is arranged in a shell. Comprising an input shaft, an output shaft parallel to the input shaft, a driven gear meshed with the input shaft and rotatably arranged on the output shaft in a sleeving mode, a friction plate type clutch assembled between the driven gear and the output shaft, a brake plate matched with the friction plate type clutch and fixed to a shell, and a PTO control valve arranged on the lower side of the output shaft. The shell and the output shaft are provided with an oil guide channel communicated with the PTO control valve and the friction plate type clutch, and the power transmission device is characterized in that the PTO control valve comprises a PTO valve body communicated with the oil guide channel, a double-speed motor arranged in the PTO valve body, a gear pump connected with the output end of the double-speed motor and arranged in the PTO valve body, and a pressure relay for detecting the oil pressure in the PTO valve body. Abrasion of the gear pump is reduced, stability of the gear pump is improved, service life of the gear pump is prolonged, failure rate is effectively reduced, and structural reliability is improved.

Description

Technical Field

[0001] The utility model relates to an electro-hydraulic controlled front power output structure for a tractor, belonging to the technical field of tractor power output. Background Art

[0002] The tractor equipped with front agricultural implements requires that the tractor must be equipped with a front power output device, so that the tractor has a front power output and a rear power output. The front power output may not work when the tractor is running. The existing tractor electro-hydraulic controlled front power output device has the following defects:

[0003] 1. Most of the existing tractor electro-hydraulic controlled front power output devices add a constant mesh gear pump inside the box. After the tractor is started, the constant mesh gear pump keeps working. When power output is required, the electromagnetic proportional control pressure reducing valve controls the engagement of the internal clutch. This working mode causes the gear pump to be in working state after the tractor is started, which not only shortens the life of the gear pump and reduces its stability, but also causes energy waste;

[0004] 2. The electromagnetic proportional control pressure reducing valve is a precision hydraulic component. During use, it is easy for the electromagnetic proportional control pressure reducing valve to get stuck due to poor cleanliness, and the failure rate remains high.

[0005] 3. The sealing ring on the power output shaft at the clutch oil inlet is in direct contact with the housing. The housing needs to ensure high processing accuracy. The power output shaft rotates at high speed during operation. If the processing accuracy is poor, it will cause abnormal wear of the sealing ring and cause seal failure. Utility Model Content

[0006] The utility model provides an electro-hydraulic controlled front power output structure for a tractor, in which the gear pump does not start when the front power output structure does not work, thereby preventing the gear pump from being in a working state all the time, reducing wear of the gear pump, improving the stability of the gear pump, extending its service life, reducing energy consumption while maintaining power output, effectively reducing the failure rate, and improving structural reliability.

[0007] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0008] The tractor electro-hydraulic controlled front power output structure is installed in a housing, comprising an input shaft, an output shaft parallel to the input shaft, a driven gear meshing with the input shaft and rotatably sleeved on the output shaft, a friction plate clutch assembled between the driven gear and the output shaft, a brake plate matched with the friction plate clutch and fixed to the housing, and a PTO control valve arranged on the lower side of the output shaft. An oil guide channel connecting the PTO control valve and the friction plate clutch is provided on the housing and the output shaft. The PTO control valve is characterized in that: the PTO control valve comprises a PTO valve body connected to the oil guide channel, a two-speed motor installed in the PTO valve body, a gear pump connected to the output end of the two-speed motor and installed in the PTO valve body, and a pressure relay for detecting the oil pressure in the PTO valve body, and the pressure relay and the two-speed motor are both controlled by a controller in the tractor cab.

[0009] Preferably, a pumping oil passage for conveying the pumped oil of the gear pump is provided on the PTO valve body, the pumping oil passage is connected with the oil guide passage, the pressure relay is mounted on the PTO valve body and the detection end extends into the pumping oil passage.

[0010] Preferably, a friction reducing sleeve matching the output shaft is pressed onto the housing, a sealing ring groove is provided at the rear end of the output shaft, a sealing ring is clamped in the sealing ring groove, and the friction reducing sleeve is loosely fitted over the rear end of the input shaft and contacts the sealing ring.

[0011] Preferably, the friction reducing sleeve is provided with an oil hole for the oil guide passage to pass through.

[0012] The beneficial effects of the utility model are:

[0013] The utility model discloses a tractor electro-hydraulic controlled front power output structure, in which a two-speed motor and a pressure relay in a PTO control valve are controlled by a controller in the tractor cab. When power is input to the input shaft, the two-speed motor is started by the controller, which drives the gear pump to rotate to generate high-pressure oil to be pumped into the oil guide channel. The oil is introduced into the friction plate clutch from the oil guide channel, so that the movement of the friction plate clutch combines the driven gear with the output shaft, so that the power of the input shaft is transmitted to the output shaft through the driven gear and the friction plate clutch, thereby realizing power output. When the controller controls the two-speed motor to be turned off, the gear pump stops rotating, stops pumping oil into the oil guide channel, and the friction plate clutch automatically moves back, canceling the connection between the driven gear and the output shaft. When the gear pump is closed, the power output is stopped. The gear pump is driven by the two-speed motor and does not rotate synchronously with the input shaft and the driven gear. When the front power output structure is not working, the gear pump will not start, so as to avoid the gear pump being in a working state all the time, reduce the wear of the gear pump, improve the stability of the gear pump, and extend its service life; a pressure relay is used to detect the oil pressure in the PTO valve body. When the oil pressure reaches the preset value, a signal is fed back to the controller, so that the controller controls the two-speed motor to switch to the low-speed operation mode, thereby reducing energy consumption while maintaining power output; the gear pump power is adjusted by switching the two-speed motor operation mode, replacing the electromagnetic proportional control pressure reducing valve in the prior art, effectively reducing the failure rate and improving the structural reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the electro-hydraulic controlled front power output structure of the tractor in a specific implementation manner.

[0015] Figure 2 for Figure 1 A partial enlarged schematic diagram of .

[0016] Figure 3 for Figure 1 Another partial enlarged schematic diagram of . DETAILED DESCRIPTION

[0017] Combine the following Figures 1 to 3 The embodiments of the present utility model are described in detail.

[0018] The tractor electro-hydraulic controlled front power output structure is installed in a housing 100, comprising an input shaft 1, an output shaft 2 parallel to the input shaft 1, a driven gear 3 meshing with the input shaft 1 and rotatably sleeved on the output shaft 2, a friction plate clutch 4 assembled between the driven gear 3 and the output shaft 2, a brake plate 5 matched with the friction plate clutch 4 and fixed to the housing, and a PTO control valve 6 arranged on the lower side of the output shaft 2, an oil guide channel 7 connecting the PTO control valve 6 and the friction plate clutch 4 is provided on the housing and the output shaft 2, and the characteristic is that the PTO control valve 6 comprises a PTO valve body 8 connected to the oil guide channel, a two-speed motor 9 installed in the PTO valve body 8, a gear pump 10 connected to the output end of the two-speed motor 9 and installed in the PTO valve body 8, and a pressure relay 11 for detecting the oil pressure in the PTO valve body 8, and the pressure relay 11 and the two-speed motor 9 are both controlled by a controller in the tractor cab.

[0019] In the above-mentioned tractor electro-hydraulic controlled front power output structure, the two-speed motor 9 and the pressure relay 11 in the PTO control valve 6 are controlled by the controller in the tractor cab. When the input shaft 1 inputs power, the two-speed motor 9 is started by the controller, driving the gear pump 10 to rotate to generate high-pressure oil to be pumped into the oil guide channel 7. The oil is introduced from the oil guide channel 7 into the friction plate clutch 4, so that the friction plate clutch 4 moves to combine the driven gear 3 with the output shaft 2, so that the power of the input shaft 1 is transmitted to the output shaft 2 through the driven gear 3 and the friction plate clutch 4, so as to realize power output. When the controller controls the two-speed motor 9 to be turned off, the gear pump 10 stops rotating, stops pumping oil to the oil guide channel 7, and the friction plate clutch automatically moves back, canceling the driven gear 3 and the output shaft 2, stop power output, the gear pump 10 is driven by the two-speed motor 9, and does not rotate synchronously with the input shaft 1 and the driven gear 3. When the front power output structure is not working, the gear pump 10 does not start, so as to avoid the gear pump 10 being in a working state all the time, reduce the wear of the gear pump 10, improve the stability of the gear pump 10, and extend its service life; use the pressure relay 11 to detect the oil pressure in the PTO valve body 8, and when the oil pressure reaches the preset value, feedback the signal to the controller, so that the controller controls the two-speed motor to switch to the low-speed operation mode, and reduces energy consumption while maintaining power output; the gear pump power is adjusted by switching the two-speed motor operation mode, replacing the electromagnetic proportional control pressure reducing valve in the prior art, effectively reducing the failure rate and improving the structural reliability.

[0020] The PTO valve body 8 is provided with a pumping oil passage 81 for conveying the pumped oil of the gear pump, and the pumping oil passage 81 is connected with the oil guide passage 7. The pressure relay 11 is installed on the PTO valve body 8 and the detection end extends into the pumping oil passage 81. The gear pump 10 rotates with the dual-speed motor 9 to pump the oil in the housing into the pumping oil passage 81, and the high-pressure oil enters the oil guide passage 7 from the pumping oil passage 81. The pressure relay 11 detects the oil pressure in the pumping oil passage 81. When the pressure reaches a predetermined value, a signal is fed back to the controller, so that the controller controls the dual-speed motor 1 to switch to the low-speed mode, ensuring that the oil continues to enter the friction plate clutch 4 through the oil guide passage 7 to keep the driven gear 3 and the output shaft 2 connected, while reducing energy consumption, which can effectively save energy and improve practicality during the front power output process of the tractor.

[0021] The housing 100 is press-fitted with a friction-reducing sleeve 12 that matches the output shaft, a sealing ring groove is provided at the rear end of the output shaft 2, a sealing ring 13 is clamped in the sealing ring groove, and the friction-reducing sleeve 12 is loosely fitted on the rear end of the input shaft 2 and contacts the sealing ring 13. The friction-reducing sleeve adopts a process of grinding after carburizing and quenching to reduce the roughness of the inner wall, which can effectively reduce the wear of the housing 100 and the sealing ring 13 and reduce the probability of sealing failure.

[0022] The friction-reducing sleeve 12 is provided with an oil hole 121 for the oil channel 7 to pass through. The setting of the oil hole 121 ensures that the addition of the friction-reducing sleeve 12 does not affect the oil guide of the oil channel 7, thereby ensuring the oil guide reliability of the oil channel 7.

[0023] The friction plate clutch 4 is an existing structure, including a pressure plate 41 positioned on the output shaft by a retaining spring, a static friction plate 42 splined on the output shaft 2, a dynamic friction plate 43 splined with the driven gear 3, a piston cylinder 44 fixed on the output shaft 2, a piston 45 movable on the piston cylinder 44, and a spring 46 mounted on the output shaft 2 and in contact with the piston 45. The rear end of the piston 45 is in contact with the brake plate 5. The pressure plate 41, the dynamic friction plate 43 and the static friction plate 42 are spaced apart along the axial direction of the output shaft 2. An oil chamber 47 connected to the oil guide 7 is formed between the piston cylinder 44 and the piston 45. The piston 45 moves forward with the oil entering the oil chamber 47 and separates from the brake plate 5, pressing the dynamic and static friction plates 42, the dynamic friction plates 43 and the pressure plate 41, and compressing the spring 46, so that the driven gear 3 is combined with the output shaft 2, and the output shaft 2 rotates synchronously with the driven gear 3. Figure 3As shown, in the initial state, the rear end of the piston 45 contacts the brake pad 5, and a plurality of alternately spaced dynamic friction plates 43 and static friction plates 42 are arranged on the rear side of the pressure plate 41, with the outermost static friction plate 42 being the pressure plate 41, the dynamic friction plates 43 and the static friction plates 42 being separated and not in contact with each other, and the front end of the piston 45 is separated and not in contact with the outermost static friction plate 42. At this time, the output shaft 2 will not rotate with the driven gear 3, and the high-pressure oil formed when the dual-speed motor 11 drives the gear pump 10 to rotate enters the oil pump 81 and the oil guide channel 7 through the pumping oil passage 81. In the cavity 47, the piston 45 is pushed forward to separate from the brake pad 5 and compress the spring 46, while pressing the static friction plate 42, the dynamic friction plate 43 and the pressure plate 41 to combine the driven gear 3 with the output shaft 2, drive the output shaft 2 to rotate, and form power output. When the dual-speed motor is turned off and the gear pump 10 stops, the oil stops entering the oil cavity 47, and the elastic restoring force of the spring 46 will push the piston 45 back to its original position, so that the piston 45 contacts the brake pad 5 again, forming a friction brake, stopping the output shaft 2 from rotating, and stopping the power output.

[0024] The above is a complete description of the technical solutions of the embodiments of the utility model in combination with the accompanying drawings. It should be noted that the described embodiments are only part of the embodiments of the utility model. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.

Claims

1. The electro-hydraulic controlled front power output structure of the tractor is installed in a housing, and includes an input shaft, an output shaft parallel to the input shaft, a driven gear meshing with the input shaft and rotatably sleeved on the output shaft, a friction plate clutch assembled between the driven gear and the output shaft, a brake plate matched with the friction plate clutch and fixed to the housing, and a PTO control valve arranged on the lower side of the output shaft. An oil guide passage connecting the PTO control valve and the friction plate clutch is provided on the housing and the output shaft, and the characteristics are: The PTO control valve includes a PTO valve body connected to the oil guide channel, a two-speed motor installed in the PTO valve body, a gear pump connected to the output end of the two-speed motor and installed in the PTO valve body, and a pressure relay for detecting the oil pressure in the PTO valve body. The pressure relay and the two-speed motor are both controlled by a controller in the tractor cab.

2. The tractor electro-hydraulic controlled front power output structure according to claim 1, characterized in that: The PTO valve body is provided with a pumping oil passage for conveying the pumped oil of the gear pump, the pumping oil passage is connected with the oil guide passage, the pressure relay is mounted on the PTO valve body and the detection end extends into the pumping oil passage.

3. The tractor electro-hydraulic controlled front power output structure according to claim 1, characterized in that: The housing is press-fitted with a friction reducing sleeve matched with the output shaft, a sealing ring groove is provided at the rear end of the output shaft, a sealing ring is clamped in the sealing ring groove, and the friction reducing sleeve is loosely fitted on the rear end of the input shaft and contacts the sealing ring.

4. The tractor electro-hydraulic controlled front power output structure according to claim 3, characterized in that: The friction reducing sleeve is provided with an oil hole for the oil guide passage to pass through.

Images