A parallel range-extended tractor power system

Abstract

The present application relates to a parallel range-extended tractor power system, including an engine, a transmission mechanism, a first motor, a second motor, a power coupler, a power battery pack, a driving force output shaft and a PTO output shaft, the engine is respectively connected to a first clutch and a second clutch through a transmission mechanism, the first clutch is connected to a first motor rotor, the second clutch is connected to a second motor rotor, the second motor is connected to a power coupler through a third clutch, the power coupler connects the driving force output shaft and the PTO output shaft, the first motor and the second motor are connected through a first inverter, and the first motor and the second motor are respectively connected to a power battery pack through a second inverter and a third inverter. The present application can fully improve the efficiency of the drive system of a hybrid tractor under various operating conditions, thereby reducing the cost of agricultural production.

Description

Technical Field

[0001] The invention relates to the field of hybrid tractors, and in particular to a parallel-range extended-range tractor power system. Background Art

[0002] At present, hybrid tractors mainly include series hybrid tractors and parallel hybrid tractors. The mainstream series hybrid tractors have one and only one drive motor. Due to the complexity of agricultural production, tractors have a variety of operating conditions including transportation, rotary tillage and plowing. The torque selection for these operating conditions varies greatly. The use of a single motor solution will inevitably make the tractor less efficient when the required torque is large and the required torque is small, and the motor's high efficiency range cannot be fully utilized, which reduces the efficiency of the hybrid tractor and increases the cost of agricultural production. The extended-range hybrid tractor adopts a series hybrid configuration, and the engine cannot directly drive the tractor, which increases the number of energy conversions, reduces the efficiency of the hybrid tractor, and increases the cost of agricultural production. The parallel hybrid tractor drive wheel and the engine are mechanically connected, so it is difficult for the engine's operating point to always be in the optimal area, which reduces agricultural production efficiency and increases agricultural production costs. Summary of the invention

[0003] In view of the problems existing in the prior art, the present invention provides a parallel extended-range tractor power system, which can flexibly select the driving mode according to the actual operating conditions, and can fully improve the driving system efficiency of the hybrid tractor under various operating conditions, thereby reducing the cost of agricultural production.

[0004] The technical solution adopted by the invention to solve the above technical problems is: a hybrid power system, including an engine, a transmission mechanism, a first motor, a second motor, a power coupler, a power battery pack, a driving force output shaft and a PTO output shaft, the engine is respectively connected to a first clutch and a second clutch through a transmission mechanism, the first clutch is connected to the first motor rotor, the second clutch is connected to the second motor rotor, the second motor is connected to the power coupler through a third clutch, the power coupler connects the driving force output shaft and the PTO output shaft, the first motor and the second motor are connected through a first inverter, and the first motor and the second motor are respectively connected to the power battery pack through a second inverter and a third inverter.

[0005] In an optional implementation, the transmission mechanism includes a first gear, a second gear and a third gear, the third gear is arranged on the output shaft of the engine and is meshed with the first gear and the second gear respectively, the input end of the first clutch is connected to the first gear, and the output end is connected to the first motor rotor, the input end of the second clutch is connected to the second gear, and the output end is connected to the second motor rotor.

[0006] In an optional implementation, the power coupler includes a planetary gear mechanism, a selection gear, a speed regulating gear and an intermediate gear. The first motor is connected to the selection gear, and the selection gear is meshed with the speed regulating gear and the intermediate gear respectively. The speed regulating gear is meshed with the ring gear of the planetary gear mechanism. The input end of the third clutch is connected to the second motor, and the output end is connected to the sun gear of the planetary gear mechanism. The driving force output shaft is arranged on the planetary carrier of the planetary gear mechanism, and the intermediate gear is connected to the PTO output shaft.

[0007] In an optional implementation, a fourth clutch is further included, which is installed between the intermediate gear and the PTO output shaft. The fourth clutch controls the engagement or separation of the intermediate gear and the PTO output shaft to control the transmission or interruption of power between the two.

[0008] In an optional implementation, the power coupling further includes a sun gear locking mechanism, and when the first motor is driven independently, the sun gear is locked by the sun gear locking mechanism.

[0009] In an optional implementation, the second motor is an integrated motor for electric and electric generation, and the power battery pack can be charged by an external power source.

[0010] In an optional implementation, the second motor can charge the power battery pack and also serve as a driving source;

[0011] When the first motor and the second motor are used as driving sources, the first motor and the second motor are both in an electric state, and the power battery pack supplies power to the first motor through the second inverter and supplies power to the second motor through the third inverter;

[0012] When the second motor generates electricity and the first motor serves as a driving source, the second motor charges the power battery pack through the third inverter and supplies power to the first motor through the first inverter.

[0013] In an optional implementation, there are at least one or more of the following driving modes: a pure electric mode, in which the engine is not started and the first motor and the second motor are driven simultaneously;

[0014] In the extended-range mode, the engine is started, the engine drives the second motor, the second motor acts as a generator to supply energy to the first motor and the power battery pack, and the first motor outputs power through the power coupler;

[0015] In hybrid mode, the engine is started, the second motor is started, the power of the engine is input to the power coupler, and the power of the second motor is also input to the power coupler, realizing parallel hybrid power;

[0016] Among them, the pure electric mode, extended-range mode and hybrid mode can choose to engage or disengage the fourth clutch to achieve PTO power output or interrupt PTO power output.

[0017] The beneficial effects of the present application are as follows: 1. When the present application is in pure electric mode, a dual-motor drive mode is started, that is, both the first motor and the second motor are used as drive motors, and the power of the first motor and the second motor is coupled through a power coupler to realize power output. Compared with the existing single-motor solution, the torque of the first motor and the second single machine is matched to improve the range of the motor's high-efficiency zone, thereby improving the efficiency of the hybrid tractor.

[0018] 2. In the extended-range mode of the present application, the engine drives the second motor, and the second motor acts as a generator to provide electrical energy to the power battery pack and the first motor. Because there is no mechanical connection between the engine and the first motor at this time, the engine can always be in the most efficient range.

[0019] 3. In the hybrid mode of the present application, the engine drives the rotor of the first motor, and then transmits power to the power coupler through the rotor of the first motor. At the same time, the second motor also outputs power to the power coupler. The hybrid mode is a parallel hybrid power. Compared with the existing extended-range hybrid tractor that adopts a series hybrid power configuration, the engine can directly drive the vehicle, reducing the number of energy conversions and significantly improving efficiency.

[0020] 4. In the pure electric mode, extended-range mode and hybrid mode of this application, the fourth clutch can be selected to engage or disengage to achieve PTO power output or interrupt PTO power output, which has strong applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the structure of the invention.

[0022] Markings in the figure: 1. engine, 2. first motor, 3. second motor, 4. first gear, 5. second gear, 6. third gear, 7. first clutch, 8. second clutch, 9. third clutch, 10. fourth clutch, 11. power battery pack, 12. selection gear, 13. speed regulating gear, 14. planetary gear mechanism, 1401. ring gear, 1402. planetary gear, 1403. sun gear, 1404. planetary carrier, 15. PTO output shaft, 16. intermediate gear, 17. driving force output shaft. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the invention clearer, the invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that in the description of the invention, unless otherwise specified, the meaning of "multiple" is two or more; the orientation or position relationship indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0024] See also Figure 1 The invention provides a parallel extended-range tractor power system, including an engine 1, a transmission mechanism, a first motor 2, a second motor 3, a power coupler, a power battery pack 11, a driving force output shaft 17 and a PTO output shaft 15, the engine 1 is respectively connected to a first clutch 7 and a second clutch 8 through a transmission mechanism, the first clutch 7 is connected to the rotor of the first motor 2, the second clutch 8 is connected to the rotor of the second motor 3, the second motor 3 is connected to the power coupler through a third clutch 9, the power coupler connects the driving force output shaft 17 and the PTO output shaft 15, the first motor 2 and the second motor 3 are connected through a first inverter, the first motor 2 and the second motor 3 are respectively connected to the power battery pack 11 through a second inverter and a third inverter, the second motor 3 is an electric and generator integrated motor, and the power battery pack 11 can be charged by an external power supply.

[0025] Among them, the transmission mechanism includes a first gear 4, a second gear 5 and a third gear 6. The third gear 6 is arranged on the output shaft of the engine 1 and is meshed with the first gear 4 and the second gear 5 respectively. The input end of the first clutch 7 is connected to the first gear 4, and the output end is connected to the rotor of the first motor 2. The first gear 4, the first clutch 7 and the first motor 2 are coaxially arranged. The input end of the second clutch 8 is connected to the second gear 5, and the output end is connected to the rotor of the second motor 3. The second clutch 8, the second gear 5 and the second motor 3 are coaxially arranged. The first clutch 7 controls the combination or separation of the first gear 4 and the rotor of the first motor 2 to control the transmission or interruption of power between the two. The second clutch 8 controls the combination or separation of the second gear 5 and the rotor of the second motor 3 to control the transmission or interruption of power between the two.

[0026] Specifically, the power coupler includes a planetary gear mechanism 14, a selection gear 12, a speed regulating gear 13 and an intermediate gear 16. The planetary gear mechanism 14 includes a ring gear 1401, a planetary gear 1402, a sun gear 1403 and a planet carrier 1404. The first motor 2 is connected to the selection gear 12, and the selection gear 12 is meshed with the speed regulating gear 13 and the intermediate gear 16 respectively. The speed regulating gear 13 is meshed with the ring gear of the planetary gear mechanism 14. The input end of the third clutch 9 is connected to the second motor 3, and the output end is connected to the sun gear 1403 of the planetary gear mechanism 14. The third clutch 9 controls the second motor 3 and the sun gear 14 03 is engaged or separated to control the transmission or interruption of power between the two. The driving force output shaft 17 is arranged on the planetary carrier of the planetary gear mechanism 14. The power coupler also includes a sun gear locking mechanism. When the first motor 2 is driven independently, the sun gear 1403 is locked by the sun gear locking mechanism. The intermediate gear 16 is connected to the PTO output shaft 15. The fourth clutch 10 is installed between the intermediate gear 16 and the PTO output shaft 15. The fourth clutch 10 controls the engagement or separation of the intermediate gear 16 and the PTO output shaft 15 to control the transmission or interruption of power between the two.

[0027] In addition, the second motor 3 can both charge the power battery pack 11 and serve as a driving source. When the first motor 2 and the second motor 3 are used as driving sources, the first motor 2 and the second motor 3 are both in an electric state, and the power battery pack 11 supplies power to the first motor 2 through the second inverter and supplies power to the second motor 3 through the third inverter. When the second motor 3 generates electricity and the first motor 2 serves as a driving source, the second motor 3 charges the power battery pack 11 through the third inverter and supplies power to the first motor 2 through the first inverter. It should be noted that the parts not described in detail in this application are all prior art.

[0028] The present application includes multiple driving modes, which are pure electric mode, extended-range mode and hybrid mode. The state of charge SOC of the power battery pack 11 can be divided into three states: large, medium and small. The SOC small is < (0.2~0.3), the SOC large is > (0.7~0.8), and the SOC medium is between the two.

[0029] When the SOC of the power battery pack is medium or large, the pure electric mode can be started. When in the pure electric mode, the first motor 2 is a high-power drive motor and the second motor 3 is a low-power drive motor. The torque is flexibly distributed according to the optimal working points of the first motor 2 and the second motor 3. The torque of the first motor 2 and the second motor 3 is coupled through the power coupler to achieve power output. Compared with the existing solution using a single motor, the torque of the first motor 2 and the second single machine 3 is matched to increase the range of the motor's high-efficiency zone, thereby improving the efficiency of the hybrid tractor.

[0030] The extended-range mode can be started when the SOC of the power battery pack is small or medium. When in the extended-range mode, the engine 1 is started, the second clutch 8 is engaged, and the second motor 3 acts as a generator to supply power to the first motor 2 and the power battery pack 11 at the same time. The first motor 2 outputs power through the power coupler. Because there is no mechanical connection between the engine 1 and the first motor 2 at this time, the engine 1 can always be in the most efficient range.

[0031] In addition, the hybrid mode can be started when the SOC of the power battery pack is medium. When in the hybrid mode, the first motor 2 is an induction asynchronous motor, and the engine 1 drives the rotor of the first motor 2 through the first clutch 7. The power of the engine 1 is output to the power coupler through the rotor of the first motor 2 to achieve power output. The rotor of the first motor 2 is equivalent to the power output shaft of the engine 1. At the same time, the second motor 2 also outputs power to the power coupler. The output torque of the engine 1 and the torque of the motor 2 are coupled through the power of the power coupler to achieve power output. At this time, this embodiment constitutes a parallel hybrid power. Compared with the existing extended-range hybrid tractor adopting a series hybrid power configuration, the engine 1 can directly drive the vehicle, reducing the number of energy conversions and significantly improving efficiency.

[0032] The power flow of the present application is as follows: when in pure electric mode, the engine 1 does not work, the third clutch 9 is engaged, the first motor 2 and the second motor 3 output power to the power coupler, the first motor 2 is meshed and connected with the ring gear 1401 of the planetary gear mechanism 14 through the speed regulating gear 13, the second motor 3 is connected with the sun gear 1403 of the planetary gear mechanism 14, and the power coupler realizes power output through the planetary carrier 1404, wherein the clutch not mentioned in this mode is in a disconnected state.

[0033] When in the extended-range mode, the engine 1 is working, the second clutch 8 is engaged, and the engine drives the second motor 3 through the third gear 6, the second gear 5 and the second clutch 8. The second motor 3 acts as a generator to supply energy to the first motor 2 and the power battery pack 11. The first motor 2 realizes power output through the power coupler. At this time, since the first motor 2 is driven independently, the sun gear 1403 of the planetary gear mechanism 14 is locked, wherein the clutch not mentioned in this mode is in a disconnected state.

[0034] When in hybrid mode, the engine 1 is working, the first clutch 7 and the third clutch 9 are engaged, and the engine 1 drives the rotor of the first motor 2 through the third gear 6, the first gear 4 and the first clutch 7, and then inputs the power of the engine 1 into the power coupler. At this time, the second motor 3 inputs the power into the power coupler through the third clutch 9, thereby realizing parallel hybrid power, wherein the clutch not mentioned in this mode is in a disconnected state.

[0035] PTO power output, pure electric mode, extended-range mode and hybrid mode can choose to engage or disengage the fourth clutch 10 to achieve PTO power output or interrupt PTO power output.

[0036] The working principle of the present application is as follows: the present invention includes three driving modes, namely pure electric mode, extended-range mode and hybrid mode. In pure electric mode, the pure electric mode can be used when the SOC is medium or large. The first motor 2 adopts a high-power induction asynchronous motor, and the second motor 3 adopts a low-power permanent magnet synchronous motor. The torque of the first motor 2 and the second motor 3 is matched to improve the range of the motor's high-efficiency zone, thereby improving the efficiency of the parallel-range extended-range tractor; in extended-range mode, when the SOC is small or medium, the extended-range mode can be used. At this time, the engine 1 drives the second motor 3, and the second motor 3 acts as a generator to provide electrical energy to the power battery pack 11 and the first motor 2. Because the engine 1 has no mechanical connection with the first motor 2 at this time, the engine 1 can always be in the most efficient range; in hybrid mode, because the existing medium-range extended-range hybrid The tractor adopts a series hybrid configuration, and the engine cannot be driven directly. When it is in SOC and driving at high speed, the motor driving efficiency is low. The present application can adopt a hybrid mode at this time. The hybrid mode is a parallel hybrid mode, in which the engine 1 drives the rotor of the first motor 2, and then transmits power to the power coupler through the rotor of the first motor 2. At this time, the rotor of the first motor 2 is equivalent to the power output shaft of the engine. At the same time, the second motor 3 also outputs power to the power coupler. The engine 1 and the second motor 3 distribute torque according to a certain torque distribution strategy. When the SOC is large, only the pure electric mode can be selected. When the SOC is medium, the pure electric mode, the extended-range mode and the hybrid mode can be selected. When the SOC is small, only the extended-range mode and the hybrid mode can be selected. Regardless of the mode, the output of PTO power can be achieved.

[0037] It should be noted that the above embodiments are only used to illustrate the invention, but the invention is not limited to the above embodiments. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the invention fall within the protection scope of the invention.

Claims

1. A parallel range-extended tractor power system, characterized in that: The invention comprises an engine (1), a transmission mechanism, a first motor (2), a second motor (3), a power coupler, a power battery pack (11), a driving force output shaft (17) and a PTO output shaft (15), wherein the engine (1) is respectively connected to a first clutch (7) and a second clutch (8) through the transmission mechanism, the first clutch (7) is connected to the rotor of the first motor (2), the second clutch (8) is connected to the rotor of the second motor (3), the second motor (3) is connected to the power coupler through a third clutch (9), the power coupler is connected to the driving force output shaft (17) and the PTO output shaft (15), the first motor (2) and the second motor (3) are connected through a first inverter, and the first motor (2) and the second motor (3) are respectively connected to the power battery pack (11) through a second inverter and a third inverter; The power coupler comprises a planetary gear mechanism (14), a selection gear (12), a speed regulating gear (13) and an intermediate gear (16); the first motor (2) is connected to the selection gear (12); the selection gear (12) is meshedly connected to the speed regulating gear (13) and the intermediate gear (16) respectively; the speed regulating gear (13) is meshedly connected to the ring gear of the planetary gear mechanism (14); the input end of the third clutch (9) is connected to the second motor (3); the output end is connected to the sun gear (1403) of the planetary gear mechanism (14); the driving force output shaft (17) is arranged on the planet carrier of the planetary gear mechanism (14); and the intermediate gear (16) is connected to the PTO output shaft (15); The invention also comprises a fourth clutch (10), wherein the fourth clutch (10) is installed between the intermediate gear (16) and the PTO output shaft (15), and the fourth clutch (10) controls the engagement or separation of the intermediate gear (16) and the PTO output shaft (15) to control the transmission or interruption of power between the two.

2. A parallel range-extended tractor power system according to claim 1, characterized in that: The transmission mechanism comprises a first gear (4), a second gear (5) and a third gear (6); the third gear (6) is arranged on the output shaft of the engine (1) and is meshed with the first gear (4) and the second gear (5) respectively; the input end of the first clutch (7) is connected to the first gear (4), and the output end is connected to the rotor of the first motor (2); the input end of the second clutch (8) is connected to the second gear (5), and the output end is connected to the rotor of the second motor (3).

3. A parallel range-extended tractor power system according to claim 1, characterized in that: The power coupler also includes a sun gear locking mechanism, and when the first motor (2) is driven independently, the sun gear (1403) is locked by the sun gear locking mechanism.

4. A parallel range-extended tractor power system according to claim 3, characterized in that: The second motor (3) is an integrated motor for electric and electric generation, and the power battery pack (11) can be charged by an external power source.

5. A parallel range-extended tractor power system according to claim 4, characterized in that: The second motor (3) can charge the power battery pack (11) and can also serve as a driving source; When the first motor (2) and the second motor (3) are used as driving sources, the first motor (2) and the second motor (3) are both in an electric state, and the power battery pack (11) supplies power to the first motor (2) through the second inverter, and supplies power to the second motor (3) through the third inverter; When the second motor (3) generates electricity and the first motor (2) serves as a driving source, the second motor (3) charges the power battery pack (11) through the third inverter and supplies power to the first motor (2) through the first inverter.

6. A parallel range-extended tractor power system according to claim 5, characterized in that: At least one or more of the following driving modes: In the pure electric mode, the engine (1) is not started, and the first motor (2) and the second motor (3) are driven simultaneously; In the extended-range mode, the engine (1) is started, the engine (1) drives the second motor (3), the second motor (3) acts as a generator to supply energy to the first motor (2) and the power battery pack (11), and the first motor (2) outputs power through the power coupler; In the hybrid mode, the engine (1) is started, the second motor (3) is started, the power of the engine (1) is input to the power coupler, and the power of the second motor (3) is also input to the power coupler, thereby realizing a parallel hybrid power; In the pure electric mode, the extended-range mode and the hybrid mode, the fourth clutch (10) can be selected to be engaged or disengaged to achieve PTO power output or interrupt PTO power output.

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