阅读说明：本技术 一种适用于大马力拖拉机的液力机械式动力换挡变速器 (Hydraulic mechanical power gear shifting transmission suitable for high-horsepower tractor ) 是由 徐立友 李贤哲 刘孟楠 胡晨明 闫祥海 于 2020-07-22 设计创作，主要内容包括：本发明提供一种适用于大马力拖拉机的液力机械式动力换挡变速器,包括发动机输出轴、独立式动力输出轴PTO、四元件综合式液力变矩器和多挡双离合器自动变速器,所述发动机输出轴上安装有一个由PTO主离合器和PTO副离合器组成并布置在一起的双联离合器,本发明自动变速器采用的是湿式多挡双离合器自动变速器,所述双离合器自动变速器使用了湿式多片离合器和单中间轴传递动力,并安装了八对对应的选换挡齿轮组和四套同步器,不仅较好的解决了动力中断的问题,而且解决了大马力拖拉机负载作业工况复杂、挡位要求数量较多、驾驶员操作繁琐等问题。(The invention provides a hydraulic mechanical power gear shifting transmission suitable for a high horsepower tractor, which comprises an engine output shaft, an independent power output shaft PTO, a four-element comprehensive hydraulic torque converter and a multi-gear double clutch automatic transmission, wherein a duplex clutch which consists of a PTO main clutch and a PTO auxiliary clutch and is arranged together is arranged on the engine output shaft.)

1. The utility model provides a hydromechanical type power transmission of shifting suitable for high horsepower tractor, includes engine output shaft, independent power take off PTO, four-component integrated hydraulic torque converter and multi-gear double clutch automatic gearbox, its characterized in that:

the dual clutch which consists of a PTO main clutch and a PTO auxiliary clutch and is arranged together is arranged on the output shaft of the engine, two pairs of driven gear pairs for the operation of agricultural implements with different rotating speeds are fixedly connected on the output shaft of the engine behind the PTO auxiliary clutch, and the two pairs of driven gear pairs are coaxially connected with a PTO of a load power output shaft for outputting torque to a load;

the input end of the four-element comprehensive hydraulic torque converter is in coaxial transmission connection with the output shaft of the engine, and the output end of the four-element comprehensive hydraulic torque converter is in coaxial transmission connection with the shell of the multi-gear double-clutch automatic transmission; the multi-gear double-clutch automatic transmission comprises two clutches and a plurality of transmission gears, wherein the two clutches are respectively connected with a solid input shaft and a hollow input shaft, the hollow input shaft is of a hollow shaft sleeve structure, the solid input shaft is arranged on the inner side of the hollow shaft sleeve structure, and the plurality of transmission gears are respectively and correspondingly connected to the solid input shaft and the hollow input shaft and used for meeting different working condition load operations of a tractor.

2. The hydromechanical powershift transmission suitable for use with a high horsepower tractor according to claim 1, wherein: the four-element comprehensive hydraulic torque converter comprises a locking clutch, a pump impeller connected with an output shaft of an engine, a turbine connected with the output shaft of the hydraulic torque converter and two guide wheels respectively arranged on the one-way clutches; when the tractor starts and is in a load operation gear, the locking clutch is separated, and the torque converter changes the torque according to the magnitude of the operation load of the tractor; when the tractor is in a transportation gear, the locking clutch is engaged, and the input shaft and the output shaft of the hydraulic torque converter are converted into a hydraulic coupler working condition from rigid connection, namely direct mechanical transmission connection.

3. The hydromechanical powershift transmission suitable for use with a high horsepower tractor according to claim 2, wherein: the lockup clutch is also provided with two sensors and an electromagnetic valve in order to ensure automatic engagement and disengagement, and the two sensors respectively monitor the rotating speed of the pump impeller and the rotating speed of the output shaft of the hydraulic torque converter.

4. The hydromechanical powershift transmission suitable for use with a high horsepower tractor according to claim 3, wherein: a plurality of transmissions keep off the position including the heavy load one keep off, the well load one keeps off, the light load one keeps off, the transportation keeps off, the heavy load keeps off, the well load keeps off, the light load keeps off and the transportation keeps off, wherein, the heavy load keeps off, the well load keeps off, the light load keeps off and the transportation keeps off and all is connected to solid input shaft, the heavy load keeps off, the well load keeps off, the light load keeps off and the transportation keeps off and all is connected to hollow input shaft, the clutch that links to each other with solid input shaft is used for the fender position joint and the separation of control connection on solid input shaft, the clutch that links to each other with hollow input shaft is used for the fender position joint and the separation of control.

5. The hydromechanical powershift transmission suitable for use with a high horsepower tractor according to claim 4, wherein: two clutches in the multi-gear double-clutch automatic transmission are two groups of multi-plate clutches which are coaxially arranged together, and the two clutches are arranged in a closed oil cavity filled with hydraulic oil, so that larger torque can be transmitted.

6. The hydromechanical powershift transmission suitable for use with a high horsepower tractor according to claim 5, wherein: the multi-gear double-clutch automatic transmission is also provided with a gear selecting and shifting control mechanism and a clutch control mechanism for controlling the two clutches to act.

7. The hydromechanical powershift transmission suitable for use with a high horsepower tractor according to claim 6, wherein: the multi-gear double-clutch automatic transmission also comprises a rotating speed sensor which is arranged corresponding to the input shaft, the output shaft, each clutch input shaft and each clutch output shaft and is used for detecting the rotating speed of each shaft;

the electronic control unit is used for acquiring the rotating speed information of the rotating speed sensor and controlling the action of the clutch control mechanism and the gear selecting and shifting control mechanism according to the rotating speed information, the signal output end of the rotating speed sensor is connected with the signal input end of the electronic control unit, and the electronic control unit is in control connection with the clutch control mechanism and the gear selecting and shifting control mechanism.

8. The hydromechanical powershift transmission suitable for use with a high horsepower tractor according to claim 7, wherein: the independent power output shaft PTO comprises a high-speed PTO gear pair, a low-speed PTO gear pair, a PTO main clutch, a PTO auxiliary clutch, a load power output shaft PTO and a power output shaft synchronizer arranged on the load power output shaft PTO; the load power output shaft PTO is controlled by a PTO auxiliary clutch;

the independent power output shaft PTO also comprises a sensor for detecting the rotating speed of the load power output shaft PTO and a sensor for detecting the rotating speed of a crankshaft of the engine; and the electronic control unit acquires the rotating speed information of the rotating speed sensor and controls the rotating speed of the load power output shaft PTO according to the rotating speed information, the signal output end of the rotating speed sensor is connected with the signal input end of the electronic control unit, and the electronic control unit is in control connection with the hydraulic control system.

9. The hydromechanical powershift transmission suitable for use with a high horsepower tractor according to claim 8, wherein: the control system of the four-element integrated hydraulic torque converter comprises an ECU (electronic control Unit), a sensor system, a signal processing system and an execution control mechanism, wherein the ECU is used for receiving the driving state information of the engine and the tractor monitored by the sensors and the intervention information given by a driver, then carrying out comparison operation, and sending out a control command according to a set program to enable the corresponding execution mechanism to control the hydraulic torque converter to work;

the sensor system is used for monitoring the tractor load operation state, converting tractor load operation state information into an electric signal and providing a reference basis;

the executing mechanism comprises a lock-up clutch electromagnetic valve and is used for receiving a control command of the ECU and then controlling the hydraulic torque converter.

10. The hydromechanical powershift transmission suitable for use with a high horsepower tractor according to claim 9, wherein: the control system of the double-clutch automatic transmission comprises a TCU, a sensor system, a signal processing system and an executing mechanism, wherein the TCU is used for receiving vehicle running state information detected by the sensor system and intervention information given by a driver, then carrying out comparison operation, sending out a control command according to a set rule, and controlling the transmission to work through the corresponding executing mechanism;

the sensor system is used for testing the running state of the vehicle, converting the mechanical quantity of the vehicle running state information into an electric signal and providing a gear shifting opportunity reference basis;

the actuating mechanism comprises a gear shifting electromagnetic valve and a pressure regulating electromagnetic valve and is used for receiving a control command of the TCU and then carrying out automatic gear shifting and regulation of oil pressure on the double clutches.

Technical Field

The invention belongs to the technical field of transmission equipment, and particularly relates to a hydraulic mechanical power gear shifting transmission suitable for a high-horsepower tractor.

Background

At present, the technology of the automatic transmission is developed very rapidly, particularly, the double-clutch automatic transmission has a very good development trend, the technology of the automatic transmission is mature, the problem of transmission interruption of gear shifting power can be well solved, and the automatic transmission is applied more and more widely in recent years.

The hydraulic torque converter applied to the light loader and integrated with three elements comprises a pump impeller, a turbine, a guide wheel, a locking clutch and a sliding one-way clutch. The hydraulic torque converter is a continuously variable transmission which can automatically change the torque conversion coefficient along with the difference of the running resistance of the loader. When the loader starts or runs on a bad road, the locking clutch is separated, and the torque converter acts, so that the characteristics of hydraulic transmission, automatic adaptation to resistance change and reduction of gear shifting times are fully exerted. In addition, the hydraulic torque converter also has the functions of ensuring smooth starting of the loading machine, attenuating torsional vibration in a transmission system, preventing overload of the transmission system and the like.

The five-gear double-clutch automatic transmission applied to the light transport tractor comprises a main input shaft used for being connected with a power source, a double clutch in transmission connection with the main input shaft, an intermediate shaft and a main output shaft, wherein the double clutch comprises an input end in coaxial transmission connection with the main input shaft, an odd-numbered gear transmission shaft, an even-numbered gear transmission shaft and a clutch mechanism used for selecting the input end to be in transmission connection with the odd-numbered gear transmission shaft or the even-numbered gear transmission shaft. Odd-even gear transmission shafts and even-even gear transmission shafts are arranged between the corresponding sections of the intermediate shafts, and corresponding odd-even gear sets and corresponding odd-even gear synchronizers are arranged between the odd-even gear transmission shafts and the even-even gear transmission shafts. Because one clutch in the double clutches corresponds to an odd gear and the other clutch corresponds to an even gear, when the vehicle is shifted into one gear, the other clutch and the corresponding next gear are already in a preparation state through the corresponding synchronizer, and the next gear can be immediately engaged as long as the current gear is separated, so that the gear selecting and shifting speed of the double-clutch transmission is very high, and the problem of power transmission interruption can be well solved.

However, although the dual clutch automatic transmission in the prior art can better solve the problem of power transmission interruption, when the dual clutch automatic transmission is used on a high-horsepower tractor, the high-horsepower tractor is complex in use condition, more in gear requirement, larger in traction load and the like. Therefore, the existing dual clutch automatic transmission has not been able to satisfy the above-described needs.

Disclosure of Invention

In view of this, the present invention provides a hydromechanical power shift transmission suitable for a high horsepower tractor.

The technical scheme adopted by the invention is as follows: a hydromechanical power gear shifting transmission suitable for a high-horsepower tractor comprises an engine output shaft, an independent power output shaft PTO, a four-element comprehensive hydraulic torque converter and a multi-gear double-clutch automatic transmission,

the dual clutch which consists of a PTO main clutch and a PTO auxiliary clutch and is arranged together is arranged on the output shaft of the engine, two pairs of driven gear pairs for the operation of agricultural implements with different rotating speeds are fixedly connected on the output shaft of the engine behind the PTO auxiliary clutch, and the two pairs of driven gear pairs are coaxially connected with a PTO of a load power output shaft for outputting torque to a load;

the input end of the four-element comprehensive hydraulic torque converter is in coaxial transmission connection with the output shaft of the engine, and the output end of the four-element comprehensive hydraulic torque converter is in coaxial transmission connection with the shell of the multi-gear double-clutch automatic transmission; the multi-gear double-clutch automatic transmission comprises two clutches and a plurality of transmission gears, wherein the two clutches are respectively connected with a solid input shaft and a hollow input shaft, the hollow input shaft is of a hollow shaft sleeve structure, the solid input shaft is arranged on the inner side of the hollow shaft sleeve structure, and the plurality of transmission gears are respectively and correspondingly connected to the solid input shaft and the hollow input shaft and used for meeting different working condition load operations of a tractor.

Furthermore, the four-element comprehensive type hydraulic torque converter comprises a locking clutch, a pump impeller connected with an output shaft of the engine, a turbine connected with the output shaft of the hydraulic torque converter and two guide wheels respectively arranged on the one-way clutches; when the tractor starts and is in a load operation gear, the locking clutch is separated, and the torque converter changes the torque according to the magnitude of the operation load of the tractor; when the tractor is in a transportation gear, the locking clutch is engaged, and the input shaft and the output shaft of the hydraulic torque converter are converted into a hydraulic coupler working condition from rigid connection, namely direct mechanical transmission connection.

Furthermore, in order to ensure automatic engagement and disengagement of the lockup clutch, the lockup clutch is further provided with two sensors and an electromagnetic valve, wherein the two sensors respectively monitor the rotating speed of the pump impeller and the rotating speed of the output shaft of the torque converter.

Further, a plurality of transmission keep off the position including heavy load first fender, well load first fender, light load first fender, the transportation keeps off, heavy load keeps off, well load keeps off, light load keeps off and the transportation keeps off, wherein, heavy load first keeps off, well load first keeps off, light load keeps off and the transportation keeps off and all is connected to solid input shaft, heavy load keeps off, well load keeps off, light load keeps off and the transportation keeps off and all is connected to hollow input shaft, the clutch that links to each other with solid input shaft is used for the fender position joint and the separation of control connection on solid input shaft, the clutch that links to each other with hollow input shaft is used for the fender position joint and the separation of control connection on hollow input shaft.

Furthermore, two clutches in the multi-gear double-clutch automatic transmission are two groups of multi-plate clutches which are coaxially arranged together, and the two clutches are arranged in a closed oil cavity filled with hydraulic oil, so that larger torque can be transmitted.

Furthermore, the multi-gear double-clutch automatic transmission is also provided with a gear selecting and shifting control mechanism and a clutch control mechanism for controlling the two clutches to act.

Furthermore, the multi-gear double-clutch automatic transmission also comprises a rotating speed sensor which is arranged corresponding to the input shaft, the output shaft, each clutch input shaft and each clutch output shaft and is used for detecting the rotating speed of each shaft;

the electronic control unit is used for acquiring the rotating speed information of the rotating speed sensor and controlling the action of the clutch control mechanism and the gear selecting and shifting control mechanism according to the rotating speed information, the signal output end of the rotating speed sensor is connected with the signal input end of the electronic control unit, and the electronic control unit is in control connection with the clutch control mechanism and the gear selecting and shifting control mechanism.

Furthermore, the independent power output shaft PTO comprises a high-speed PTO gear pair, a low-speed PTO gear pair, a PTO main clutch, a PTO auxiliary clutch, a load power output shaft PTO and a power output shaft synchronizer arranged on the load power output shaft PTO; the load power output shaft PTO is controlled by a PTO auxiliary clutch;

the independent power output shaft PTO also comprises a sensor for detecting the rotating speed of the load power output shaft PTO and a sensor for detecting the rotating speed of a crankshaft of the engine; and the electronic control unit acquires the rotating speed information of the rotating speed sensor and controls the rotating speed of the load power output shaft PTO according to the rotating speed information, the signal output end of the rotating speed sensor is connected with the signal input end of the electronic control unit, and the electronic control unit is in control connection with the hydraulic control system.

Furthermore, the control system of the four-element integrated hydraulic torque converter comprises an ECU, a sensor system, a signal processing system and an execution control mechanism, wherein the ECU is used for receiving the driving state information of the engine and the tractor monitored by the sensors and the intervention information given by a driver, then carrying out comparison operation, and sending out a control command according to a set program to enable the corresponding execution mechanism to control the hydraulic torque converter to work.

The sensor system is used for monitoring the tractor load operation state, converting tractor load operation state information into an electric signal and providing a reference basis;

the executing mechanism comprises a lock-up clutch electromagnetic valve and is used for receiving a control command of the ECU and then controlling the hydraulic torque converter.

Furthermore, the control system of the double-clutch automatic transmission comprises a TCU, a sensor system, a signal processing system and an executing mechanism, wherein the TCU is used for receiving vehicle running state information detected by the sensor system and intervention information given by a driver, then carrying out comparison operation, sending out a control command according to a set rule, and controlling the transmission to work through the corresponding executing mechanism;

the sensor system is used for testing the running state of the vehicle, converting the mechanical quantity of the vehicle running state information into an electric signal and providing a gear shifting opportunity reference basis;

the actuating mechanism comprises a gear shifting electromagnetic valve and a pressure regulating electromagnetic valve and is used for receiving a control command of the TCU and then carrying out automatic gear shifting and regulation of oil pressure on the double clutches.

Compared with the prior art, the invention has the beneficial effects that: the automatic transmission adopts a wet multi-gear double-clutch automatic transmission, the double-clutch automatic transmission uses a wet multi-plate clutch and a single intermediate shaft to transmit power, and eight pairs of corresponding gear selecting and shifting gear sets and four sets of synchronizers are installed, so that the problem of power interruption is well solved, and the problems of complex load operation working condition, more gear required quantity, complex driver operation and the like of a high-horsepower tractor are solved.

Drawings

FIG. 1 is a schematic diagram of the overall transmission configuration of the hydromechanical powershift transmission of a high horsepower tractor according to the present invention;

FIG. 2 is a diagram of a drive route for a heavy load first gear in an embodiment of the present invention;

FIG. 3 is a diagram of a drive route for a second level of transportation in an embodiment of the present invention;

FIG. 4 is a functional block diagram of a control system for a four-element integrated torque converter of the present invention;

FIG. 5 is a block diagram of the hydraulic control system of the multi-speed dual clutch automatic transmission of the present invention;

FIG. 6 is a functional block diagram of an automatic shift control system for a multi-speed dual clutch automatic transmission according to the present invention;

the labels in the figure are: 1. engine output shaft, 2, PTO master clutch, 3, PTO secondary clutch, 4, slipping one-way clutch, 5, lock-up clutch, 6, turbine, 7, pump impeller, 8, solid shaft clutch C1, 9, hollow shaft clutch C2, 10, transport secondary gear pair, 11, light duty secondary synchronizer, 12, light duty secondary gear pair, 13, medium duty secondary gear pair, 14, hollow input shaft, 15, heavy duty secondary gear pair, 16, light duty primary gear, transport primary synchronizer, 17, solid input shaft, 18, output shaft, 19, transport primary gear pair, 20, light duty primary gear pair, 21, medium duty primary gear pair, 22, heavy duty primary gear, medium duty primary synchronizer, 23, heavy duty primary gear pair, 24, output shaft gear pair, 25, heavy duty secondary synchronizer, 26, main reducer bevel gear pair, 27, half shaft, 28, 6, turbine, 7, pump impeller, 9, heavy duty primary gear pair, 15, heavy duty primary gear pair, 14, heavy duty primary gear pair, and output shaft, Inter-axle differential 29, one-way clutch 30, idler pulley 31, load power take-off PTO 32, high speed PTO gear pair 33, power take-off synchronizer 34, low speed PTO gear pair.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the present invention, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments, and all other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the protection scope of the present invention.

A hydraulic mechanical power gear shifting transmission suitable for a high-horsepower tractor comprises an engine output shaft, an independent power output shaft PTO, a four-element comprehensive hydraulic torque converter and a multi-gear double-clutch automatic transmission, wherein a duplex clutch which consists of a PTO main clutch and a PTO auxiliary clutch and is arranged together is installed on the engine output shaft;

the input end of the four-element comprehensive hydraulic torque converter is in coaxial transmission connection with the output shaft of the engine, and the output end of the four-element comprehensive hydraulic torque converter is in coaxial transmission connection with the shell of the multi-gear double-clutch automatic transmission; the multi-gear double-clutch automatic transmission comprises two clutches and a plurality of transmission gears, wherein the two clutches are respectively connected with a solid input shaft and a hollow input shaft, the hollow input shaft is of a hollow shaft sleeve structure, the solid input shaft is arranged on the inner side of the hollow shaft sleeve structure, and the plurality of transmission gears are respectively and correspondingly connected to the solid input shaft and the hollow input shaft and used for meeting different working condition load operations of a tractor.

In the multi-gear double-clutch automatic transmission, the reverse gear mode is selected by additionally arranging a reverse mechanism, the direction of all forward gears is changed, and the reverse gears with the same torque and the same number as those of the forward gears can be obtained.

Furthermore, the four-element comprehensive type hydraulic torque converter comprises a locking clutch, a pump impeller connected with an output shaft of the engine, a turbine connected with the output shaft of the hydraulic torque converter and two guide wheels respectively arranged on the one-way clutches; when the tractor starts and is in a load operation gear, the locking clutch is separated, and the torque converter changes the torque according to the magnitude of the operation load of the tractor; when the tractor is in a transportation gear, the locking clutch is engaged, and the input shaft and the output shaft of the hydraulic torque converter are converted into a hydraulic coupler working condition from rigid connection, namely direct mechanical transmission connection.

Furthermore, in order to ensure automatic engagement and disengagement of the lockup clutch, the lockup clutch is further provided with two sensors and an electromagnetic valve, wherein the two sensors respectively monitor the rotating speed of the pump impeller and the rotating speed of the output shaft of the hydraulic torque converter and send corresponding electric signals to the electronic controller.

Further, a plurality of transmission keep off the position including heavy load first fender, well load first fender, light load first fender, the transportation keeps off, heavy load keeps off, well load keeps off, light load keeps off and the transportation keeps off, wherein, heavy load first keeps off, well load first keeps off, light load keeps off and the transportation keeps off and all is connected to solid input shaft, heavy load keeps off, well load keeps off, light load keeps off and the transportation keeps off and all is connected to hollow input shaft, the clutch that links to each other with solid input shaft is used for the fender position joint and the separation of control connection on solid input shaft, the clutch that links to each other with hollow input shaft is used for the fender position joint and the separation of control connection on hollow input shaft.

Furthermore, two clutches in the multi-gear double-clutch automatic transmission are two groups of multi-plate clutches which are coaxially arranged together, and the two clutches are arranged in a closed oil cavity filled with hydraulic oil, so that larger torque can be transmitted.

Furthermore, the multi-gear double-clutch automatic transmission is also provided with a gear selecting and shifting control mechanism and a clutch control mechanism for controlling the two clutches to act.

Furthermore, the multi-gear double-clutch automatic transmission also comprises a rotating speed sensor which is arranged corresponding to the input shaft, the output shaft, each clutch input shaft and each clutch output shaft and is used for detecting the rotating speed of each shaft;

the electronic control unit is used for acquiring the rotating speed information of the rotating speed sensor and controlling the action of the clutch control mechanism and the gear selecting and shifting control mechanism according to the rotating speed information, the signal output end of the rotating speed sensor is connected with the signal input end of the electronic control unit, and the electronic control unit is in control connection with the clutch control mechanism and the gear selecting and shifting control mechanism.

Furthermore, the independent power output shaft PTO comprises a high-speed PTO gear pair, a low-speed PTO gear pair, a PTO main clutch, a PTO auxiliary clutch, a load power output shaft PTO and a power output shaft synchronizer arranged on the load power output shaft PTO; the load power output shaft PTO is controlled by a PTO auxiliary clutch;

the independent power output shaft PTO also comprises a sensor for detecting the rotating speed of the load power output shaft PTO and a sensor for detecting the rotating speed of a crankshaft of the engine; and the electronic control unit acquires the rotating speed information of the rotating speed sensor and controls the rotating speed of the load power output shaft PTO according to the rotating speed information, the signal output end of the rotating speed sensor is connected with the signal input end of the electronic control unit, and the electronic control unit is in control connection with the hydraulic control system.

Furthermore, the control system of the four-element integrated hydraulic torque converter comprises an ECU, a sensor system, a signal processing system and an execution control mechanism, wherein the ECU is used for receiving the driving state information of the engine and the tractor monitored by the sensors and the intervention information given by a driver, then carrying out comparison operation, and sending out a control command according to a set program to enable the corresponding execution mechanism to control the hydraulic torque converter to work. The ECU of the present invention includes an engine electronic control unit and a tractor drive system electronic control unit.

The sensor system is used for monitoring the tractor load operation state, converting tractor load operation state information into an electric signal and providing a reference basis;

the executing mechanism comprises a lock-up clutch electromagnetic valve and is used for receiving a control command of the ECU and then controlling the hydraulic torque converter.

Furthermore, the control system of the double-clutch automatic transmission comprises a TCU, a sensor system, a signal processing system and an executing mechanism, wherein the TCU is used for receiving vehicle running state information detected by the sensor system and intervention information given by a driver, then carrying out comparison operation, sending out a control command according to a set rule, and controlling the transmission to work through the corresponding executing mechanism;

the sensor system is used for testing the running state of the vehicle, converting the mechanical quantity of the vehicle running state information into an electric signal and providing a gear shifting opportunity reference basis;

the actuating mechanism comprises a gear shifting electromagnetic valve and a pressure regulating electromagnetic valve and is used for receiving a control command of the TCU and then carrying out automatic gear shifting and regulation of oil pressure on the double clutches.

The invention is described in detail below with reference to the accompanying drawings:

one embodiment of the present invention is a hydromechanical powershift transmission suitable for a high horsepower tractor, including a housing, a main input shaft for power input drivingly connected to a crankshaft of an engine 1 as a power source, a main output shaft for power output to a center, a load power output shaft PTO 31 for power output from a load, a torque converter, a multi-speed dual clutch automatic transmission, an axial differential 28, a half shaft 27, and the like.

When the load power output shaft PTO 31 of the tractor works, the main clutch 2 in the independent power output shaft PTO is firstly engaged, the electronic control unit ECU immediately engages the PTO auxiliary clutch 3 by receiving an engine speed signal and a speed signal of the load power output shaft PTO, and controls the power output shaft synchronizer 33 to select a proper speed gear, so that the load power output shaft PTO keeps a constant speed and outputs stable power. The power transmission route is as follows: the engine 1 transmits power to the PTO high-speed gear pair 32 or the PTO low-speed gear pair 34 through the main input shaft, selects a desired rotation speed gear through the power output shaft synchronizer 33, and transmits torque to the load power output shaft PTO 31. Thus, the load power output shaft PTO 31 can maintain a constant rotation speed and output a stable power to the outside.

The four-element comprehensive hydraulic torque converter comprises two pairs of symmetrically arranged one-way clutches 29 arranged on an output shaft in the hydraulic torque converter, a locking clutch 4 for controlling the hydraulic torque converter to work, a pump impeller 7 fixedly connected with a shell of the hydraulic torque converter, a turbine impeller 6 fixedly connected with the output shaft of the hydraulic torque converter and two pairs of symmetrically arranged guide wheels 30 arranged on the respective one-way clutches.

The multi-gear double clutch comprises a solid shaft clutch C1 for controlling heavy load first gear, medium load first gear, light load first gear and transportation first gear, and a hollow shaft clutch C2 for controlling heavy load second gear, medium load second gear, light load second gear and transportation second gear. Also included are solid input shaft 17, hollow input shaft 14. The solid input shaft 17 is in a solid shaft form, and the hollow input shaft 14 is in a hollow shaft sleeve form coaxially sleeved on the solid input shaft 17. And gear selecting and shifting gear sets are arranged between corresponding sections of the input shaft and the output shaft of each clutch. According to the set gear selecting and shifting, the gear selecting and shifting gear set on the solid input shaft 17 comprises a heavy-load one-gear selecting and shifting gear pair 23, a medium-load one-gear selecting and shifting gear pair 21, a light-load one-gear selecting and shifting gear pair 20 and a transport one-gear selecting and shifting gear pair 19. The gear selecting and shifting gear set on the hollow input shaft 14 comprises a heavy-load second-gear selecting and shifting gear pair 15, a medium-load second-gear selecting and shifting gear pair 13, a light-load second-gear selecting and shifting gear pair 12 and a second-gear transporting and shifting gear pair 10. The heavy-duty first-gear pair 23 and the medium-duty first-gear pair 21 are arranged in pairs, and a heavy-duty first-gear synchronizer 22 and a medium-duty first-gear synchronizer 22 for selecting one of the heavy-duty first-gear synchronizer and the medium-duty first-gear synchronizer to be fixedly connected with the output shaft and the other one of the heavy-duty first-gear synchronizer and the medium-duty first-gear synchronizer to be continuously kept empty are arranged between the heavy-duty first. The gear ratio of each group of gear selecting and shifting gear set is set according to the set gear selecting and shifting position.

When the tractor works, the torque transmission routes of all gears of the transmission are similar, and the transmission principle is the same. The states of the components and the power transmission path in the two cases of the heavy load first gear (basic operating gear) and the transportation second gear (highest gear) are specifically described below, and the rest gears are analogized and will not be described in detail.

The heavy-load first gear is a basic working gear, and the transmission route is as follows: the electronic control unit TCU of the gear box detects that the tractor needs to carry heavy load gear operation, the main clutch 2 in the free-standing power take-off shaft PTO is jointed firstly, the auxiliary clutch 3 is jointed secondly, and the synchronizer 33 of the power take-off shaft is jointed according to the left side of the figure; the sensor detects the rotating speed of the hollow transmission shaft, the actuating mechanism controls the solid shaft clutch 8 to be jointed, and the heavy-load first-gear synchronizer 22 and the medium-load first-gear synchronizer 22 are jointed according to the left side of the figure. The power transmission route is as follows: on one hand, the torque transmitted by the engine 1 is transmitted to the power output shaft synchronizer 33 through the PTO low-speed gear pair 34 on the engine output shaft, and finally is taken as the load power output of the tractor through the load power output shaft PTO 31; on the other hand, the torque transmitted by the main input shaft is transmitted to the double-clutch automatic transmission shell through the hydraulic torque converter and the transmission shaft, then transmitted to the solid input shaft 17 through the solid shaft clutch 8, then transmitted to the gear selecting and shifting synchronizer 22 through the heavy-duty first-gear pair 23, then transmitted to the output shaft 18, then transmitted to the drive axle main reducer bevel gear pair 26 through the output gear pair 24, and finally distributed to the left half shaft 27 and the right half shaft 27 through the gear mechanism in the axial differential 28, so that the tractor is driven to operate and run.

The second transportation gear is the highest gear, and the transmission route is as follows: the electronic control unit TCU of the speed changing box detects that the tractor needs to transport gears for operation, the main clutch 2 is firstly jointed, the sensor detects the rotating speed of the hollow transmission shaft, the actuating mechanism controls the hollow shaft clutch 8 to be jointed, and the heavy-load first-gear synchronizer 22 and the medium-load first-gear synchronizer 22 are jointed according to the left side of the figure. The power transmission route is as follows: the torque transmitted by the engine 1 is transmitted to a double-clutch automatic transmission shell through a transmission shaft through a hydraulic torque converter, then transmitted to a hollow input shaft 14 through a hollow shaft clutch 9, then transmitted to a second-gear transportation gear pair 10 through a second-gear transportation synchronizer 11 and a second-gear light-load synchronizer 11, then transmitted to an output shaft 18, and finally transmitted to a bevel gear pair 26 of a main speed reducer of a drive axle through an output gear pair 24, and finally power is distributed to a left half shaft 27 and a right half shaft 27 through an internal gear mechanism of an axial differential 28, so that the tractor is driven to travel in transportation operation.

The control system of the tractor hydraulic mechanical power shifting transmission comprises the following steps:

the four-element integrated hydraulic torque converter control system comprises an electronic control unit ECU, a sensor system, a signal processing system and an execution mechanism. The control system has the main functions of providing hydraulic oil with certain pressure for the hydraulic torque converter and controlling the locking clutch in the hydraulic torque converter to work. The electronic control unit ECU receives the driving state information of the engine and the tractor monitored by the sensors and the intervention information given by the driver for comparison operation, and then sends out a control command according to a set program to enable a corresponding executing mechanism to control the hydraulic torque converter to work, and the ECU comprises an engine electronic control unit and a tractor driving system electronic control unit; the sensor system monitors the tractor load operation state, the tractor speed and the gear information, converts the information into electric signals and provides reference basis; the execution mechanism comprises a lock-up clutch electromagnetic valve which is used for changing the oil circuit pressure of the hydraulic torque converter clutch after receiving the control command of the ECU and operating the engagement and the disengagement of the hydraulic torque converter lock-up clutch. The hydraulic torque converter control element comprises a hydraulic torque converter valve, a locking signal valve, a locking relay valve, a locking clutch control valve and a corresponding oil way.

The multi-gear double-clutch automatic transmission control system comprises an input shaft rotating speed sensor, an output shaft rotating speed sensor, a parking position sensor, an oil temperature sensor, a TCU, other control units CAN signals, a gear selecting and shifting executing mechanism, a clutch executing mechanism, a wire harness and the like. During the operation of the transmission, the TCU receives input signals from sensors in the transmission and also acquires input signals from other control units through the CAN bus. The input signals include a driver gear request signal obtained from a gear sensor, an engine speed signal, an engine torque and a tractor accelerator pedal position signal obtained from the EMS, and an ABS/ESP status signal and a tractor running speed signal obtained from an ABS/ESP control system, etc. The TCU analyzes and judges the input signal and makes a decision, then sends a control signal to the gear selecting and shifting executing mechanism and the clutch executing mechanism, the executing mechanism finishes the gear selecting and shifting and the engagement and the disengagement of the clutch, the processes of starting, gear shifting and the like of the tractor are realized, and the gear selecting and shifting state and the clutch engagement and disengagement state are fed back to the TCU.

Furthermore, the actuating mechanism of the multi-gear double clutch is a hydraulic system for realizing alternate control and shifting fork control, and comprises a hydraulic pump oil supply module, a main oil pressure adjusting module, a shifting control module, a double clutch control module, a lubricating and cooling module and an auxiliary module.

The principal features, principles and advantages of the invention have been shown and described above. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only for the purpose of illustrating the principles of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the invention.

For example, the output shaft of the torque converter and the main input shaft of the multi-speed dual clutch automatic transmission may be directly connected in transmission by a coupling. For example, the output shaft gear pair 24 may be mounted at the end of the output shaft 18, while the transaxle bevel gear pair 26 may be randomly distributed in three dimensions within the transmission case as long as it meshes with the output gear. For example, the power take-off shaft 31 as a tractor may be disposed on the side of the tractor or extend the shaft to the rear of the tractor; if the power take-off shaft 31 is arranged on the side of the tractor, the original PTO high-speed gear pair 32 and the original PTO low-speed gear pair 34 can be changed to be engaged by a pair of bevel gear pairs respectively to change the direction of torque transmission.