CN210101297U

CN210101297U - Series double-motor differential power split stepless speed change transmission system

Info

Publication number: CN210101297U
Application number: CN201921079041.9U
Authority: CN
Inventors: 杨振忠
Original assignee: Guangxi Yuchai Machinery Co Ltd
Current assignee: Guangxi Yuchai Machinery Co Ltd
Priority date: 2019-07-11
Filing date: 2019-07-11
Publication date: 2020-02-21
Anticipated expiration: 2029-07-11

Abstract

The utility model discloses a series double-motor differential power split stepless speed change transmission system, which comprises an engine output/differential input shaft, a first motor, a second motor, a motor controller, a power split device, a clutch, a gearbox, an engine power output shaft and a storage battery; the first motor and the second motor are arranged in series, the power of the engine is transmitted to the first motor by the input shaft of the engine output/differential mechanism to generate power, and meanwhile, the input shaft of the engine output/differential mechanism outputs power outwards through the power dividing device, the clutch and the gearbox to form a first power path; the first motor supplies power to the second motor and the storage battery through the motor controller, and the second motor outputs power outwards through the power dividing device, the clutch and the gearbox to form a second power path. The utility model discloses a continuously variable transmission system has two power paths of mechanical power and electric power.

Description

Series double-motor differential power split stepless speed change transmission system

Technical Field

The present invention relates to a continuously variable transmission system, and more particularly to a series double-motor differential power split continuously variable transmission system (EMCVT).

Background

The existing transmission systems (using a tractor as an example) are divided into a manual gear shifting transmission system, a power uninterrupted automatic gear shifting transmission system and a hydraulic mechanical stepless speed change transmission system (HMCVT) according to a gear shifting mode.

1. Manual transmission system that shifts:

when the tractor works in the field, the change of land resistance is large, the load change of the whole tractor is large, the tractor adopting a manual gear shifting transmission system needs frequent stopping and gear shifting so as to meet the requirements of traction force and speed of farm tool operation, the working intensity of workers is large, the working efficiency is low, and the working quality is unstable; meanwhile, the rotating speed of the engine is directly related to the speed of the vehicle, the change range of the rotating speed of the engine is large due to the change of the speed of the whole vehicle, and the engine cannot work in a stable and economical rotating speed range, so that the oil consumption is high, the emission is poor, and the vibration and abrasion are large. The transmission system has simple structure and low manufacturing and maintenance cost, and is suitable for the current purchase level of farmers. In advanced countries of the world, manual gear shifting transmission systems are mostly applied to tractor products with horsepower below 80 Hp.

2. The continuous automatic gear shifting transmission system of tractor power:

a gear shifting process performed under a vehicle running condition in which power from an engine to a transmission is not interrupted; the wet-type multi-plate clutch is used as a gear shifting executing mechanism, when gears need to be changed, two clutches for gear shifting are sequentially separated and combined according to the change of control oil pressure, and gear shifting without stopping is achieved during vehicle load running, so that the problem of stopping and gear shifting during manual gear shifting transmission system operation is solved, the operation intensity of workers is reduced, and the operation comfort and the operation efficiency are improved. However, the engine speed of the uninterrupted automatic gear shifting transmission system is directly related to the vehicle speed, the change range of the engine speed is large due to the change of the vehicle speed, the engine cannot work in a stable and economical rotating speed range, and the engine has high oil consumption, poor emission and large vibration abrasion. Meanwhile, due to the fact that the tractor has a large operation requirement and a large number of gears, the transmission structure needs a large number of clutches and proportional valves, and a 160-horsepower 16-gear gearbox is taken as an example: the full-domain automatic gearbox needs 8 clutches and 8 hydraulic proportional valves; due to the consistency, the gear shifting performance of the transmission system needs to be debugged and calibrated on a special delivery test bed, the abrasion of a clutch is increased along with the increase of the service time, the gear shifting control time is changed, the smoothness is poor, and gear shifting impact is generated. At present, the technology of the systems is basically mastered by foreign companies and mainly depends on import, and the transmission system has the disadvantages of complex structure, high price, difficult price reduction and high maintenance cost. For reasons of price, in advanced countries of the world, powershift transmissions are mostly applied to 80-200Hp tractor products.

3. Hydro-mechanical continuously variable transmission (HMCVT):

the transmission system consists of a hydraulic plunger variable pump/motor/multi-row differential mechanism/wet clutch and a brake, and has the main advantages that: the power of the engine is divided into two power routes through a differential mechanism, one power route is a mechanical power route, and the power is directly transmitted to an input shaft of a gearbox; one is a hydraulic power route, and after the machine-liquid-machine power conversion process, the hydraulic power route and the input shaft of the gearbox realize the confluence of all power; by the power splitting and converging principle, the torque and the rotating speed of the transmission system can be automatically and continuously changed according to the speed and the traction requirement of the vehicle, and the traction and the speed requirement of the vehicle during speed change can be ensured.

The transmission system (HMCVT) realizes stepless automatic change of the vehicle transmission system, and has the advantages of low operation intensity of workers, good operation comfort, high operation efficiency and high quality; because the rotating speed and the torque of the engine are completely decoupled (irrelevant) with the speed and the traction of the whole vehicle, the engine can stably work in a low oil consumption area, and has small vibration and good emission.

The high-pressure variable plunger pump/motor, the proportional valve and the like adopted by the transmission system (HMCVT) belong to precise hydraulic coupling parts, have very high requirements on clean and clean assembly, use cleanliness and maintenance cleanliness, need special hydraulic oil and have high use and maintenance cost; the transmission gear box of the system adopts a multi-row differential mechanism and a wet clutch or a brake to realize the regional change of 4-6 gears, the system has a large number of parts and a complex structure, the key technology of the system is basically mastered by foreign companies, products mainly depend on import, and the transmission system has high cost and difficult price reduction. Due to the price and the use and maintenance, the system is used in a very small amount in the Chinese market. For cost reasons, the Hydraulic Mechanical Continuously Variable Transmission (HMCVT) is mostly applied to 200-400 Hp tractor products in advanced countries of the world.

The prior art transmission system described above suffers from the following disadvantages:

1. the manual gear shifting transmission system is adopted, so that the structure is simple, the manufacture, the maintenance and the repair are easy, and the cost is low. The disadvantages are as follows:

(1) the tractor adopting the manual gear shifting transmission system needs frequent stopping and gear shifting to meet the requirements of traction force and speed of farm tool operation, and has the advantages of high working strength of workers, low working efficiency and unstable working quality.

(2) The rotating speed of the engine is directly related to the speed of the vehicle, the change range of the rotating speed of the engine is large due to the change of the speed of the whole vehicle, the engine cannot work in a stable and economical rotating speed range, and the engine has high oil consumption, poor emission and large vibration abrasion.

2. The uninterrupted automatic power shifting transmission system realizes non-stop gear shifting during vehicle load running, and improves the operation efficiency and the control comfort of the tractor. The disadvantages are as follows:

(1) the rotating speed of the engine of the transmission system is directly related to the speed of the vehicle, the change range of the rotating speed of the engine is large due to the change of the speed of the vehicle, the engine cannot work in a stable and economical rotating speed range, and the transmission system is high in oil consumption, poor in emission and large in vibration abrasion.

(2) The transmission system needs a large number of clutches and proportional valves, the abrasion of the clutches is increased along with the increase of the service time, the gear shifting control time is changed, the smoothness is poor, and gear shifting impact is generated.

(3) The traditional power gear shifting gearbox is in single-power line stepped transmission, realizes super crawling gears (ultra-low speed), and needs to be added with a plurality of complex reduction gear trains. Furthermore, the stepless transmission during the main operations of rotary tillage and the like cannot be realized, i.e. the optimal running speed of the rotary cultivator cannot be matched theoretically

(4) At present, the technology of the systems is basically mastered by foreign companies and mainly depends on import, and the drive train has high price, difficult price reduction and high maintenance cost.

3. A hydraulic mechanical stepless speed change transmission system (HMCVT) realizes a global stepless speed change system consisting of 4-6 gears, has high working efficiency and good control comfort, decouples the output of an engine from the load and the speed of a vehicle, and enables the engine to stably run in a low-oil consumption and low-emission region. The disadvantages are as follows:

(1) the mechanical speed-changing system composed of 4-6 gears is a speed-changing mechanism composed of multiple rows of differential mechanisms and 4-6 wet clutches or brakes, and has the advantages of complex structure, high requirement on part processing and high cost.

(2) The hydraulic power shunting system composed of the hydraulic precision matching parts has high requirements on clean and clean assembly, use cleanliness and maintenance cleanliness, needs special hydraulic oil and is high in use and maintenance cost.

(3) Since the technology of these systems is basically mastered by foreign companies, the products mainly depend on import, the cost is very high, and the price reduction is difficult.

Therefore, a transmission system is needed to solve the above technical problems of the prior transmission system.

The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information constitutes prior art already known to a person skilled in the art.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a stepless speed change transmission system of two motor differential power shunts of establishing ties, it can effectively overcome the problem that above-mentioned prior art's transmission system exists.

In order to achieve the above object, the present invention provides a series double-motor differential power splitting stepless speed change transmission system, which is arranged at the power output end of an engine, and comprises an engine output/differential input shaft, a first motor, a second motor, a motor controller, a power splitting device, a clutch, a gearbox, an engine power output shaft and a storage battery; the first motor and the second motor are arranged in series, the power of the engine is transmitted to the first motor by the input shaft of the engine output/differential mechanism to generate power, and meanwhile, the input shaft of the engine output/differential mechanism outputs power outwards through the power dividing device, the clutch and the gearbox to form a first power path; the first motor supplies power to the second motor and the storage battery through the motor controller, and the second motor outputs power outwards through the power dividing device, the clutch and the gearbox to form a second power path.

In a preferred embodiment, the power split device comprises a left side gear, a right side gear and a differential carrier; the first motor comprises a first motor hollow input shaft, a first motor rotor and a first motor stator, the first motor rotor is mechanically connected with the first motor hollow shaft, and the first motor hollow shaft is connected with the left half axle gear and used for enabling the first motor rotor to generate electricity through the power of the engine; the second motor comprises a second motor hollow output shaft, a second motor rotor and a second motor stator, the second motor rotor is mechanically connected with the second motor hollow output shaft, and the second motor rotor outputs the second motor power independently through the second motor hollow output shaft; the first motor stator and the second motor stator are arranged in a common motor stator shell; the engine output/differential input shaft passes through the first motor hollow input shaft, the first motor hollow input shaft passes through the second motor hollow output shaft, the engine output/differential input shaft, the first motor hollow input shaft and the second motor hollow output shaft are in a three-shaft coaxial nested structure, the engine output/differential input shaft passes through the first motor hollow input shaft and is connected with a differential planet carrier, and meanwhile, the engine power output shaft is connected with the differential planet carrier and used for outputting engine power.

In a preferred embodiment, the transmission includes a transmission input shaft, a transmission synchronizer and a transmission gear set and a central drive pinion. The input shaft of the gearbox is fixedly connected with the right half-shaft gear and used for inputting power to the gearbox; the gearbox synchronizer, the gearbox gear set and the gearbox input shaft form a fixed shaft type 4-6 gear gearbox; the central transmission driving gear is mechanically connected with a gear set of a gearbox, and the rotating speed of an input shaft of an engine output/differential mechanism is changed by the gearbox, then is transmitted to a central transmission driven gear by the central transmission driving gear, and then is output outwards by a half shaft gear/half shaft of the central transmission differential mechanism.

In a preferred embodiment, the series dual-motor differential power split continuously variable transmission system further comprises a second motor output driving gear, a second motor output driven gear, a power shift driving gear, a power shift driven gear, a power shift transmission gear, a clutch output driving gear and a clutch output driven gear. The second motor output driving gear is fixedly connected with the second motor hollow output shaft; the second motor output driven gear is fixedly connected with an input shaft of a first/power transmission clutch (C1/C2) and is meshed with a second motor output driving gear; the power shifting driving gear is fixedly connected with an output shaft of a power shifting clutch (C1); the power shifting driven gear is fixedly connected with the power shifting transmission shaft and is meshed with the power shifting driving gear; the power shifting transmission gear is fixedly connected with the power shifting transmission shaft and is mechanically connected with a gear set of the gearbox; the clutch output driving gear is fixedly connected with an output shaft of a power transmission clutch (C2); the clutch output driven gear is fixedly connected with the input shaft of the gearbox and is meshed with the clutch output driving gear.

In a preferred embodiment, the mechanical power of the engine is input to the power split device via the engine output/differential input shaft, and the differential carrier splits the mechanical power into two parts: one part is distributed to the right half shaft gear through the differential planet carrier and is directly output to the input shaft of the gearbox; the other part is distributed to a left side gear through a differential planet carrier and is transmitted to a first motor rotor through a first motor hollow input shaft to generate electricity and convert the electricity into electric power, the electric power is directly transmitted to a second motor to convert the electricity into mechanical energy after being subjected to pressure regulation and frequency modulation by a motor controller, and the mechanical energy is output to a second motor output driving gear and a second motor output driven gear through a second motor hollow output shaft and is transmitted to an input shaft of a first/power transmission clutch (C1/C2); thereby achieving a split mode of mechanical power of the engine of the continuously variable transmission system.

In a preferred embodiment, in the continuously variable transmission mode, the clutch C2 is engaged, the C1 is disengaged, the second motor is used for transmitting electric power to the transmission input shaft through the first/power transmission clutch (C1/C2) input shaft, the power transmission clutch (C2) output shaft, the clutch output driving gear and the clutch output driven gear, and part of mechanical power of the engine which is divided by the right axle gear is combined at the transmission input shaft; thereby realizing a confluence mode of the mechanical power of the engine and the electric power of the second motor of the continuously variable transmission system.

In a preferred embodiment, under a certain gear, the rotating speed of the right half-shaft gear and the central transmission driven gear form a fixed linear proportional relationship through a transmission system of the clutch and the gearbox, namely form a fixed linear proportional relationship with the speed of the whole vehicle;

the rotating speed of the right half shaft gear is in a linear inverse proportion relation with the rotating speed of the left half shaft gear in the power dividing device, namely when the whole vehicle speed is reduced and the traction force is increased, the speed and the torque of the right half shaft gear are reduced and increased according to a fixed proportion, at the moment, the rotating speed of the left half shaft gear is opposite to the increasing and decreasing direction of the rotating speed of the right half shaft gear, namely the rotating speed of the right half shaft gear is increased, the rotating speed of the left half shaft gear is reduced, otherwise, the rotating speed of the right half shaft gear is reduced, and the rotating speed of the left half shaft;

when the rotating speed of the engine is unchanged, namely the rotating speed of a differential planet carrier connected with an output/differential input shaft of the engine is unchanged, the power change of the first motor can be realized through the rotating speed change of the left half axle gear because the hollow input shaft of the first motor is connected with the left half axle gear, and the electric energy is output to the second motor after the current, the voltage and the frequency are converted/controlled by the motor controller, so that the speed of the second motor is matched with the rotating speed of the input shaft of the gearbox, and the stepless speed change mode of the stepless speed change transmission system in a certain gear is realized.

In a preferred embodiment, in the continuously variable transmission driving mode, the first motor is always in a power generation state, and the speed and the traction of the whole vehicle are decoupled (unrelated) with the rotating speed and the torque of the engine through the characteristics of a differential mechanism of the power splitting device.

In a preferred embodiment, in the shifting mode, when the clutch C2 is disengaged, the clutch C1 is engaged, the rotor of the second motor is adjusted by the controller to match the rotation speed of the central transmission driving gear under the corresponding gear at the shifting time, and the power of the second motor is transmitted to the end through the hollow output shaft of the second motor, the output driving gear of the second motor, the output driven gear of the second motor, the input shaft of the first/power transmission clutch (C1/C2), the output shaft of the clutch C1, the power shifting driving gear, the power shifting driven gear, the power shifting transmission shaft, the power shifting transmission gear, the corresponding gear in the gear set, the central transmission driving gear and the central transmission driven gear, and finally reaches the driving wheel, thereby realizing the global stepless speed changing shifting mode of the stepless speed changing transmission system.

In a preferred embodiment, when low speed driving is required, the power required by walking output by the rotor of the second motor reaches the input shaft of the gearbox, and the engine output/differential input shaft provides the most of the required engine power for the rear end part through the power output shaft of the engine; meanwhile, the right half shaft gear is connected with an input shaft of the gearbox, the running speed of the vehicle is controlled by the rotating speed of the right half shaft gear, and the rotating speed of the right half shaft gear is reduced by adjusting the rotor of the first motor to a higher rotating speed, so that the running speed of the vehicle controlled by the stepless speed change transmission system is in a crawling and slow running speed mode.

In a preferred embodiment, when a reverse gear is required, the motor controller inputs reverse voltage and current to control the second motor rotor to rotate reversely, the reverse power of the second motor rotor is transmitted to the input shaft of the first/power transmission clutch (C1/C2), the output shaft of the power transmission clutch (C2), the clutch output driving gear and the clutch output driven gear through the second motor hollow output shaft, the second motor output driving gear, the second motor output driven gear, the first/power transmission clutch (C1/C2) and the transmission gear set, and the reverse power is transmitted to the central transmission driven gear through the transmission gear set, and at the moment, the generated rotation speed of the first motor rotor reaches the highest range, so that the reverse gear mode of the continuously variable transmission system is realized.

In a preferred embodiment, when the vehicle needs heavy load starting, the continuously variable transmission system is in a hybrid power state for a short time, and mechanical power split by the engine is output to the input shaft of the gearbox through the right half-shaft gear; the power of the second motor during power assistance is between a rated power state and a peak power state, the power of the second motor during power assistance depends on the accelerator opening interval of an operator, at the moment, the motor controller controls the storage battery to supply power to the second motor through a route, electric energy is converted into mechanical energy through a second motor rotor, and the mechanical energy is transmitted to the transmission input shaft through a second motor hollow output shaft, a second motor output driving gear, a second motor output driven gear, a first/power transmission clutch (C1/C2) input shaft, a power transmission clutch (C2) output shaft, a clutch output driving gear and a clutch output driven gear; at the moment, the power of the second motor and the power of the engine are converged at the input shaft of the gearbox, and the sum of the two powers is larger than the required power during starting and accelerating, so that the starting assistance mode of the stepless speed change transmission system is realized.

Compared with the prior art, the utility model discloses a stepless speed change transmission system of series connection bi-motor differential power split has following beneficial effect: the power of the engine is divided into two power routes through a differential mechanism, one power route is a mechanical power route, the other power route is an electric power route, and the mechanical power route is directly transmitted to an input shaft of a 4-gear or 6-gear gearbox; the electric power route transmits electric power to the second motor through a power conversion mode of the motor-motor, and transmits the electric power to the input shaft of the gearbox, and the electric power is converged with the mechanical power route; through the power splitting and converging principle of the differential, the output torque and the rotating speed of a transmission system (EMCVT) are automatically and continuously changed according to the change of the vehicle speed and the traction force, and the non-stop speed change of the tractor under the load state is realized. The scheme (EMCVT) designs a second motor power independent transmission line which is not superposed with a gearbox power transmission line, and realizes automatic gear shifting of a 4-6-gear gearbox, so that the motor can work in a high-efficiency area, and further the global stepless speed change of the whole machine from zero to the maximum designed speed range is realized. The automation of field operation driving is realized, the labor intensity of workers is greatly reduced, and the operation efficiency and quality are improved; meanwhile, the motor has high response speed, excellent gear shifting smoothness and short gear shifting time, so that the friction work of the gear shifting clutch is reduced, and the service life and the reliability of the clutch are improved. The differential power splitting structure realizes complete decoupling (independent and irrelevant) of the torque and the rotating speed of the engine and the traction force and the speed of a vehicle, the engine can stably run in an optimized low-oil-consumption area, the oil consumption of the engine is reduced by more than 10%, the requirement of emission policy and regulation is easily met, and the vibration and the abrasion of the engine are reduced. The speed of the tractor running system is independent of the rotating speed of the power output shaft of the engine, so that the best matching point of the running speed and the theoretical rotating speed of the farm tool can be found, the working efficiency is improved, and the oil consumption and the emission are reduced. Due to the low-speed and high-torque characteristics of the permanent magnet alternating current motor, the scheme can realize the function of ultra-low-speed crawling gear, stably work within the driving speed range of 0-0.1km/h, output most of engine power through the power output shaft and be used for special operations such as ditching and the like. Reverse gear is not needed to be arranged in the gearbox, and any reverse speed of 0-Vmax km/h can be realized by means of the reverse rotation of the second motor, so that various operation requirements of the tractor are met. By means of the rated power or instantaneous high power function of the second motor, the power-assisted vehicle starts at low speed and heavy load, the ground acceleration time and the land blocks which are not operated are reduced, and the crop sowing area is increased. The gearbox can be designed into a 4-6-gear fixed shaft type gearbox according to the power of the tractor, a synchronizer gear shifting structure is adopted, the gearbox is simple and reliable in structure, parts are greatly reduced, the transmission efficiency is high, and the cost is low. The main key parts, the high-power permanent magnet synchronous motor and the motor controller, the high-power discharge battery and other technologies and products are completely mastered by local manufacturers and produced in a large scale, and the local purchasing channel is wide. Due to the high reliability and low cost of the motor and the controller, the manufacturing, using and maintaining cost of the transmission system is greatly reduced.

Drawings

Fig. 1 is a schematic structural view of a continuously variable transmission system according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of an electrical power conversion module of a motor controller of a continuously variable transmission system according to an embodiment of the present invention.

Description of the main reference numerals:

1-engine, 2-engine output/differential input shaft, 3-torsional vibration damper, 4-first motor bearing cap, 5-motor stator common housing, 6-first motor stator, 7-first motor rotor, 8-second motor stator, 9-second motor rotor, 10-first motor hollow input shaft, 11-second motor hollow output shaft, 12-left side gear, 13-differential planet carrier, 14-right side gear, 15-gearbox input shaft, 16-power shift transmission shaft, 17-power shift transmission gear (Z5), 18-engine power output shaft, 19-rear axle housing, 20-center transmission differential side gear/half shaft, 21-center transmission driven gear, 22-central transmission driving gear, 23-gearbox gear set (Z6/Z7/Z8/Z9), 24-clutch output driven gear (Zn), 25-clutch output driving gear (Zm), 26-power transmission clutch (C2) output shaft, 27-power shifting clutch (C1) output shaft, 28-power shifting driving gear (Z3), 29-power shifting driven gear (Z4), 30-second motor output driven gear (Z2), 31-clutch input shaft and 32-second motor output driving gear (Z1).

Detailed Description

The following detailed description of the present invention is provided in conjunction with the accompanying drawings, but it should be understood that the scope of the present invention is not limited by the following detailed description.

Throughout the specification and claims, unless explicitly stated otherwise, the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element or component but not the exclusion of any other element or component.

As shown in fig. 1, fig. 1 is a schematic structural diagram of a continuously variable transmission system according to an embodiment of the present invention. According to the utility model discloses two motor differential power split's of preferred embodiment in series connection continuously variable transmission system (EMCVT), engine output/differential input shaft 2 passes through in first motor hollow input shaft 10, and the hollow input shaft 10 of MG1 first motor passes through in the hollow output shaft 11 of MG2 second motor, and three axles are coaxial nested structure, and the first motor stator 6 of MG1 and MG2 second motor stator 8 are installed in stator common casing 5. The MG1 first motor rotor 7 is mechanically connected with the MG1 first motor hollow input shaft 10, the MG1 first motor hollow input shaft 10 is connected with the left side gear 12; the engine 1 is mechanically connected with an engine output/differential input shaft 2 through a torsional damper 3, and the engine output/differential input shaft 2 passes through a first motor hollow input shaft 10 and is connected with a differential planet carrier 13 for outputting engine power; the MG2 second motor rotor 9 is mechanically connected with the MG2 second motor hollow output shaft 11, and outputs the second motor power separately through the MG2 second motor hollow output shaft 11; the right half shaft gear 14 is fixedly connected with a gearbox input shaft 15 and is used for inputting power to the gearbox; the transmission input shaft 15, the transmission synchronizer and the transmission gear set 23(Z6/Z7/Z8/Z9) form a fixed shaft type 4-6 gear transmission, gears Z6/Z7/Z8/Z9 and the like in the transmission gear set 23(Z6/Z7/Z8/Z9) are mechanically connected with the central transmission driving gear 22, and power after speed change is transmitted to the central transmission driven gear 21 through the central transmission driving gear 22 and then transmitted to a tractor driving wheel through a tail end speed reduction transmission (not shown).

In some embodiments, the present invention provides a series dual motor differential power split continuously variable transmission system having a continuously variable power output mode:

referring to fig. 1, a differential mechanism composed of a left side gear 12, a right side gear 14, and a differential carrier 13 is used as a power splitting device for engine output power; mechanical power generated by the engine 1 is input to a differential planet carrier 13 through an engine output/differential input shaft 2, the differential planet carrier 13 serves as a power input component of a differential to output the input power to two directions, part of the power is distributed to a right half shaft gear 14 through the differential planet carrier 13 and is directly output to a transmission input shaft 15, and part of the mechanical power is distributed to a left half shaft gear 12 through the differential planet carrier 13 and is transmitted to a first motor rotor 7 through a first motor hollow input shaft 10 to generate electricity and convert the electricity into electric power; electric power is directly transmitted to the second motor rotor 9 to be converted into mechanical function after being subjected to pressure and frequency regulation through a motor controller (as shown in fig. 2, fig. 2 is a schematic diagram of an electric power conversion module of a motor controller of a continuously variable transmission system according to an embodiment of the present invention), and is output to the second motor output driving gear 32(Z1) and the second motor output driven gear 30(Z2) through the second motor hollow output shaft 11, and is transmitted to the input shaft 31 of the first/power transmission clutch (C1/C2), and the output shaft 26 of the power transmission clutch (C2) is combined in an automatic shift (CVT) mode, the output shaft 27 of the power shift clutch (C1) is separated, and the power of the second motor MG2 is transmitted to the transmission input shaft 24(Zn) → through the first/power transmission clutch (C1/C2) input shaft 31 → the power transmission clutch (C2) output shaft 26 → the clutch output driving gear 25(Zm) → clutch output driven gear 24(Zn) → the transmission input shaft 15 and the engine power split with the right half shaft gear 14 is merged at the transmission input shaft 15, realizing the confluence mode of the engine power.

In some embodiments, the present invention provides a continuously variable transmission system with series dual motor differential power splitting having a continuously variable speed mode:

referring to fig. 1, in a certain gear, the rotation speed of the right half-axle gear 14 is in a fixed linear proportional relationship with the central transmission driven gear 21 through a transmission system such as a gearbox, i.e. a fixed linear proportional relationship with the vehicle speed V. Since the right side gear 14 is in a linear inverse relationship with the rotation speed of the left side gear 12 in the differential mechanism (power split device), when the speed of the whole vehicle is reduced and the traction force is increased under a certain engine rotation speed and power, the speed and torque of the right side gear 14 are reduced and increased according to a fixed proportion, and at this time, the rotation speed of the left side gear 12 is opposite to the increase and decrease direction of the rotation speed of the right side gear 14, that is: the rotation speed of the right side gear 14 is increased and the rotation speed of the left side gear 12 is decreased, whereas the rotation speed of the right side gear 14 is decreased and the rotation speed of the left side gear 12 is increased. Theoretically, the rotation speed of the engine 1 is unchanged, namely the rotation speed of the differential planet carrier 13 connected with the engine output/differential input shaft 2 of the engine 1 is unchanged, because the first motor MG1 is connected with the left side gear 12 through the first motor hollow input shaft 10, the change of the power of the first motor rotor 7 of the MG1 is realized through the rotation speed change of the left side gear 12, the current, the voltage and the frequency are converted/controlled through a motor controller, and the power of the second motor rotor 9 of the MG2 is output; the speed of the second motor rotor 9 is matched with the rotating speed of the input shaft 15 of the gearbox, and the stepless speed change mode under a certain gear is completed.

In an automatic shift (CVT) running mode, the MG1 first motor rotor 7 is always in the first motor state; meanwhile, the decoupling (irrelevant) relation between the speed and traction force of the whole vehicle and the rotating speed and torque of the engine is realized through the structural characteristics of the differential (power dividing device), and the working stability of the engine is ensured.

In some embodiments, the utility model discloses a stepless speed change transmission system of two motor differential power shunts of establishing ties has universe stepless speed change mode of shifting:

referring to fig. 1, generally, the speed range of the whole tractor is 0-50km/h, and the fixed-axis transmission with 4-6 gears is required according to the power of the tractor, so that the first motor MG 1/the second motor MG2 can work in a high-efficiency area within the full speed range of the tractor, and the total efficiency of the transmission system is improved.

In the shift mode: the MG2 motor controller receives a speed state signal of the tractor sent by a VCU (not shown) of the vehicle controller, and generates a rotating speed control signal of the MG2 second motor, the power at the moment comes from a storage battery with high discharge rate, the clutch C2 is separated and the clutch C1 is combined according to the logic control requirement of the clutch when shifting gears, and the rotating speed of the rotor 9 of the second motor is adjusted to be matched with the rotating speed of the central transmission driving gear 22 at a certain gear at the shifting time; the MG2 second motor power passes through the second motor hollow output shaft 11 → the second motor output driving gear 32(Z1) → the second motor output driven gear 30(Z2) → the first/power transmission clutch (C1/C2) input shaft 31 → the power shift clutch (C1) output shaft 27 is engaged → the power shift driving gear 28(Z3) → the power shift driven gear 29(Z4) → the power shift transmission shaft 16 → the power shift transmission gear 17(Z5) → one of the gears Z6/Z7/Z8/Z9 determined in structural design → the center transmission driving gear 22 → the center transmission driven gear 21 → a final transmission (not shown) → to finally reach the driving wheels (not shown).

At this moment, the MG2 second electric machine rotor 9 passes through the above-mentioned gear shifting transmission route, crosses the power route of the transmission input shaft 15, and directly provides load power to the central transmission driving gear 22 of the tractor; according to the force principle of the differential mechanism, the right half-shaft gear 14 still has the torque which is proportional to the first motor MG 1; the MG1 first motor enters an unloading state → a second motor state → a speed tracking and speed regulating mode according to a real-time speed signal and a target gear signal of the central transmission driving gear 22 and a command sent by a VCU (vehicle control unit not shown), the rotating speed of the input shaft 15 of the gearbox is regulated to reach a synchronous gear-disengaging speed range by regulating the rotating speed of the left half axle gear 12, a TCU (transmission control unit not shown) sends a command signal to a gear-shifting executing mechanism, and a gear-shifting executor is in gear-disengaging, the gear-disengaging process of the structure needs the first motor MG1 to actively regulate the speed and disengage the gear, and the reason is that the rotational inertia of the first motor is large and the synchronizer is difficult to disengage the gear.

In a gear engaging state, at the moment, the MG2 second motor rotor 9 still works in a primary power state, the MG1 first motor rotor 7 adjusts the rotation speed of the transmission input shaft 15 by adjusting the rotation speed of the MG1 first motor according to the rotation speed requirement of the target gear, so as to reach the synchronous rotation speed requirement of the target gear synchronizer, and the gear shifting execution mechanism executes the gear engaging action from the neutral position. After the gear is put into operation, the MG1 first electric machine rotor 7 is unloaded to enter a power generation state, the power shift clutch (C1) output shaft 27 is disengaged, the power transfer clutch (C2) output shaft 26 is engaged, and the second electric machine rotor 9 is switched to a normal driving power route, transmits power to the transmission input shaft 15 through relevant gears, and outputs the power in confluence with the mechanical split power of the transmission input shaft 15.

All gear shifting processes are the same. In the process of driving gear shifting, the opening degree of an engine accelerator is unchanged, and the rotating speed of the input shaft 15 of the gearbox is adjusted by utilizing the quick response rotating speed change of the MG1 first motor, so that the gear shifting requirement of the synchronizer is met. Due to the characteristic that the differential is decoupled (irrelevant) with the rotating speed and the torque of the engine, the transmission system can be used for eliminating a clutch at the output end of the engine.

In some embodiments, the utility model discloses a stepless speed change transmission system of series connection bi-motor differential power split still has crawl and crawl speed acquisition mode:

continuing to refer to FIG. 1, when very low travel speeds are required, MG2 second electric machine rotor 9 outputs the power required for travel to transmission input shaft 15, and engine output/differential input shaft 2 provides most of the engine power to the rear end agricultural implement through engine power output shaft 18 under this condition. The right half shaft gear 14 is connected with the transmission input shaft 15, the vehicle running speed is controlled by the rotating speed of the right half shaft gear 14, the rotating speed of the right half shaft gear 14 can be reduced by adjusting the MG1 first motor rotor 7 to a higher rotating speed, and the vehicle running speed is controlled to be in a stable state close to 0-0.1km/h, so that a crawling and slow running speed obtaining mode is realized.

In some embodiments, the series dual-motor differential power-split continuously variable transmission system of the present invention further has a reverse mode:

with reference to fig. 1, in the reverse mode, the motor controller inputs reverse voltage and current to control the MG2 to rotate the second motor rotor 9 in reverse direction, and the reverse power of the MG2 second motor is transmitted to the transmission input shaft 15 through the second motor hollow output shaft 11 → the second motor output driving gear 32(Z1) → the second motor output driven gear 30(Z2) → the first/power transfer clutch (C1/C2) input shaft 31 → the power transfer clutch (C2) output shaft 26 → the clutch output driving gear 25(Zm) → the clutch output driven gear 24(Zn), and is transmitted to the transmission reverse central driven gear 21 through the transmission to output power. In the reverse mode, the MG1 first electric machine rotor 7 generates electricity in a rotation speed range up to the highest range, thereby realizing the reverse mode.

In some embodiments, the present invention provides a series dual motor differential power split continuously variable transmission system further having a start boost mode:

with reference to fig. 1, when the tractor needs to start under heavy load, the transmission system is in a hybrid state for a short time, and the mechanical power split by the engine 1 is output to the transmission input shaft 15 through the right half-shaft gear 14; the second motor MG2 is between the rated power and the peak power when assisting power, and the assisting power depends on the accelerator opening interval of the operator; at this time, the power of the second electric motor MG2 is transmitted from the battery of the vehicle to the transmission input shaft 15 via the route MG2, the second electric motor rotor 9 → the second electric motor hollow output shaft 11 → the second electric motor output driving gear 32(Z1) → the second electric motor output driven gear 30(Z2) → the first/power transmission clutch (C1/C2) input shaft 31 → the power transmission clutch (C2) output shaft 26 → the clutch output driving gear 25(Zm) → the clutch output driven gear 24 (Zn); at the moment, the input shaft 15 of the gearbox is merged into two power flows, one power flow is rated power of the MG2 second motor mainly powered by a storage battery, the other power flow is rated power of almost all the engine 1, wherein the design value of the peak power of the MG2 of the second motor is basically equal to the rated power value of the engine 1, the sum of the two power flows is larger than the power required by starting and accelerating, and the starting and accelerating power is generally 1.5-1.8 times of the rated power of the engine 1, so that the requirement on the low-speed starting capacity of the engine can be greatly reduced, the acceleration starting distance of the whole vehicle is reduced, and the area of the land which is not operated is reduced.

As shown in fig. 2, fig. 2 is a schematic diagram of an electric power conversion module of a motor controller of a continuously variable transmission system according to an embodiment of the present invention. In some embodiments, engine (ICE) power of the present invention is split by a differential mechanism to generate a proportion of engine power that is directly transferred to a variable speed drive train; the other part of the engine power passes through the first motor → AC/DC rectification → DC/AC inversion → the second motor → a speed change transmission system → a load; under the normal operation condition, the electric energy of the first motor is completely transmitted to the second motor to be converted into mechanical energy, and the mechanical energy and the direct engine power are transmitted to a load in a combined flow mode; the energy of the energy storage device is only used for providing instantaneous power required by the second motor during gear shifting and acceleration of the whole machine; the power conversion module system sends an instant instruction for charging the energy storage device according to the SOC charge value (electric quantity level) of the energy storage device, and maintains the SOC charge value of the energy storage device to meet the energy storage quantity of gear shifting and starting acceleration.

The above embodiment is only an example of a tractor, but the present invention is not limited thereto, and both road and off-road vehicles are applicable.

To sum up, the utility model discloses a stepless speed change transmission system of two motor differential power shunts of establishing ties has following advantage:

1. the engine power is divided into two power routes through the independent action of a differential and two motors, one is a mechanical power route, the other is a mechanical-electric-power route, and the continuous stepless change of the transmission ratio of the transmission system, namely the CVT transmission system, is realized through the principles of power division and convergence; because the CVT transmission system can realize the complete decoupling of the torque and the speed of the engine and the traction force and the speed of the whole vehicle, namely the complete decoupling is independent and irrelevant, the transmission system can keep the engine to stably run in an ideal design interval with low oil consumption and low emission under the condition of meeting the power requirement of the vehicle, and the aims of saving oil of the whole vehicle and reducing the emission are fulfilled.

2. This scheme infinitely variable speed system (CVT) adopts the two motor structures of the shared stator casing of establishing ties, and the two motors of shared stator casing can share rotor axial space, and motor MG1/MG2 cooling water course shares power cable space, and the motor integrates the degree height, has reduced the motor total volume under the same power, and furthest has utilized the axial space of transmission.

3. This scheme power split device adopts bi-motor and differential mechanism mode, is different from the plunger pump/motor drive system of hydraulic power split scheme (HMCVT), and the motor performance is last: the response speed of 0 to large rotating speed and large torque is 2-3 times faster than that of a hydraulic pump system, the speed control accuracy is superior to that of a hydraulic pump/motor system, and the use and maintenance cost is high: the motor is simple to maintain and reliable to use, no running pollution is generated, the requirements on the cleanliness of the hydraulic pump and the motor are very high, and the maintenance cost is very high. Cost and purchase: the equivalent power cost of the permanent magnet synchronous motor is about half of that of a hydraulic pump/motor, and local manufacturers completely master the research and development production technology of the motor.

4. According to the scheme, the automatic gear shifting of all gears of the gearbox is realized by using double motors and independent power transmission lines; the fixed-axis gear transmission is combined with an independent gear shifting route, and the hydraulic transmission is different from a traditional hydraulic pressure (HMCVT) multi-row differential mechanism and a wet clutch or a brake which must be adopted, so that the manufacturing and assembling difficulty is greatly reduced, the number of parts under the same gear is greatly reduced, and the manufacturing cost is reduced; the design reliability of the product is improved, and the use and maintenance cost of the product is reduced.

5. The scheme utilizes the double motors and the power shunt transmission route, fully exerts the characteristic that the peak power of the second motor is more than 2 times of the rated power, designs the power battery and the power circuit to ensure the short-term release of the peak power of the MG2, reduces the volume of the MG2 motor, meets the requirement of uninterrupted gear shifting power of vehicle power, adopts a hybrid power mode under a starting acceleration mode, increases the power of the whole machine by 1.5-1.8 times, greatly reduces the starting acceleration distance, shows that the proportion of the area of the operated land is increased under the same farmland area, and increases the crop yield. The hybrid mode may also be applied to short term tractor obstacle detouring and short term drag overcoming, depending on the control program settings. The traditional Hydraulic (HMCVT) and multi-row differential mechanism transmission system cannot generate the function of mixed power of the scheme at present, and the starting acceleration time is long.

6. The scheme (EMCVT) can realize that the speed of the tractor walking system is independent of the rotating speed of the power output shaft of the engine, so that the theoretical optimal speed matching point can be found out with a driven agricultural implement, the operation efficiency is improved, and the oil consumption and the emission are reduced. Due to the low-speed and high-torque characteristics of the permanent magnet alternating current motor, the scheme can realize the function of ultra-low-speed crawling, stably work within the driving speed range of 0-0.1km/h, output most of engine power through the power output shaft (17) and be used for special operations such as ditching and the like.

7. According to the scheme (EMCVT), reverse gear is not required to be arranged in the gearbox, the reverse rotation of the second motors MG2(8) (9) is relied on, the designed reverse speed of 0-Vmax km/h can be realized, and various operation requirements of the tractor are met.

8. The scheme (EMCVT) mainly comprises key parts, technologies and products such as a high-power permanent magnet synchronous motor, a motor controller and a high-power discharge battery, local manufacturers completely master and produce the EMCVT in a large scale, and local purchasing channels are wide. Due to the high reliability and low cost of the motor and the controller, the manufacturing, using and maintaining cost of the transmission system is lower than that of the HMCVT transmission system consisting of the hydraulic components.

9. The scheme (EMCVT) realizes the automation of field operation driving, greatly reduces the labor intensity of workers and improves the operation efficiency and quality.

10. The scheme (EMCVT) is provided with a high-power first motor MG1, and electric power with specified voltage and frequency is output outwards through a standardized output interface to provide electric power for working machines and tools needing electric power, so that the working range of the whole machine provided with the scheme is expanded.

The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. It is not intended to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and its practical application to enable one skilled in the art to make and use various exemplary embodiments of the invention and various alternatives and modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims and their equivalents.

Claims

1. A series connection double-motor differential power split stepless speed change transmission system is arranged at the power output end of an engine and is characterized in that the stepless speed change transmission system comprises an engine output/differential input shaft, a first motor, a second motor, a motor controller, a power split device, a clutch, a gearbox, an engine power output shaft and a storage battery;

the first motor and the second motor are arranged in series, the engine output/differential input shaft transmits the power of the engine to the first motor to generate power, and the engine output/differential input shaft outputs power outwards through the power dividing device, the clutch and the gearbox to form a first power path; the first motor supplies power to the second motor and the storage battery through the motor controller, and the second motor forms a second power path through the power dividing device, the clutch and the gearbox, wherein the power is output outwards.

2. The series two-motor differential power-split continuously variable transmission system of claim 1, wherein said power-splitting device comprises a left side gear, a differential carrier, and a right side gear;

the first motor comprises a first motor hollow input shaft, a first motor rotor and a first motor stator, the first motor rotor is mechanically connected with the first motor hollow input shaft, and the first motor hollow input shaft is connected with the left half axle gear and used for enabling the first motor rotor to generate electricity through the power of the engine;

the second motor comprises a second motor hollow output shaft, a second motor rotor and a second motor stator, the second motor rotor is mechanically connected with the second motor hollow output shaft, and the second motor rotor outputs second motor power independently through the second motor hollow output shaft;

the first motor stator and the second motor stator are mounted in a motor stator common housing;

the engine output/differential mechanism input shaft is followed pass through in the first motor hollow input shaft, first motor hollow input shaft is followed again pass through in the second motor hollow output shaft, engine output/differential mechanism input shaft first motor hollow input shaft second motor hollow output shaft is the coaxial nested structure of triaxial, engine output/differential mechanism input shaft passes first motor hollow input shaft with the differential mechanism planet carrier is connected, simultaneously engine power output shaft with the differential mechanism planet carrier is connected for output engine power.

3. The series two-motor differential power-split continuously variable transmission system of claim 2, wherein the transmission comprises:

the gearbox input shaft is fixedly connected with the right half shaft gear and used for inputting power to the gearbox;

the gearbox synchronizer and the gearbox gear set form a fixed shaft type 4-6 gear gearbox together with the gearbox input shaft; and

and the central transmission driving gear is mechanically connected with the gear set of the gearbox, and the rotating speed of the input shaft of the engine output/differential mechanism is changed by the gearbox, then is transmitted to the central transmission driven gear by the central transmission driving gear, and then is output outwards by the half shaft gear/half shaft of the central transmission differential mechanism.

4. The series two-motor differential power-split continuously variable transmission system of claim 3, further comprising:

the second motor output driving gear is fixedly connected with the second motor hollow output shaft;

the second motor output driven gear is fixedly connected with the clutch input shaft and is meshed with the second motor output driving gear;

the power shifting driving gear is fixedly connected with an output shaft of the power shifting clutch;

the power shifting driven gear is fixedly connected with the power shifting transmission shaft and is meshed with the power shifting driving gear;

the power shifting transmission gear is fixedly connected with the power shifting transmission shaft and is mechanically connected with the gear set of the gearbox;

the clutch output driving gear is fixedly connected with the power transmission clutch output shaft; and

and the clutch output driven gear is fixedly connected with the input shaft of the gearbox and is meshed with the clutch output driving gear.

5. The series two-motor differential power-split continuously variable transmission system according to claim 4, wherein the mechanical power of the engine is input to the power split device through the engine output/differential input shaft, and the differential carrier splits the mechanical power; the first power path is distributed to the right half shaft gear through the differential planet carrier and directly output to the transmission input shaft; the second power route is for passing through differential mechanism planet carrier distributes left side axle gear, and the warp the hollow input shaft of first motor passes to first electric motor rotor electricity generation changes the electric power into, the electric power warp after motor controller pressure regulating, frequency modulation, directly pass to the second motor turns into mechanical energy, mechanical energy passes through the hollow output shaft of second motor exports the second motor output driving gear the second motor output driven gear, and transmit on the clutch input shaft.

6. The series two-motor differential power-split continuously variable transmission system of claim 4, further comprising a power-converge mode in which a power-transfer clutch is engaged and a power-shift clutch is disengaged, and electric power of the second motor is transferred to the transmission input shaft through a clutch input shaft, the power-transfer clutch output shaft, the clutch output driving gear, the clutch output driven gear, and is combined with a part of mechanical power of the engine split by the right-half shaft gear at the transmission input shaft.

7. The series two-motor differential power-split continuously variable transmission system of claim 4, further comprising a continuously variable mode, wherein in a certain gear, the rotation speed of the right half-shaft gear is in a fixed linear direct proportion with the central transmission driven gear through the transmission system of the clutch and the gearbox; the rotating speed of the right half shaft gear is in a linear inverse proportion relation with the rotating speed of the left half shaft gear in the power split device; when the rotating speed of the engine is unchanged, the engine output/differential input shaft is connected with the differential planet carrier, the first motor hollow input shaft is connected with the left side axle gear, the power change of the first motor can be realized through the rotating speed change of the left side axle gear, the power change of the first motor is output to the second motor electric energy after the conversion/control current, voltage and frequency of the motor controller, and the speed of the second motor is matched with the rotating speed of the gearbox input shaft.

8. The series two-motor differential power-split continuously variable transmission system of claim 4, wherein the first motor is always in a generating state under a continuously variable driving condition.

9. The series dual-motor differential power-split continuously variable transmission system of claim 4, further comprising a shift mode, wherein when the power transmission clutch is disengaged and the power shift clutch is engaged, the second motor rotor is adjusted by the controller to rotate at a speed matching the speed of the central transmission driving gear at the corresponding gear at the time of shifting, and the power of the second motor is transmitted from the second motor hollow output shaft, the second motor output driving gear, the second motor output driven gear, the clutch input shaft, the power shift clutch output shaft, the power shift driving gear, the power shift driven gear, the power shift transmission shaft, the power shift transmission gear, the corresponding gear in the gear set, the central transmission driving gear, and the central transmission driven gear to an end transmission, eventually reaching the drive wheels.

10. The series two-motor differential power-split continuously variable transmission system of claim 4, further comprising creep and creep modes, wherein when low speed travel is required, the power required for traveling output by the rotor of the second motor reaches the input shaft of the transmission, and the output/differential input shaft of the engine provides the required engine power to the rear end member through the power output shaft of the engine; meanwhile, the right half shaft gear is connected with the input shaft of the gearbox, the running speed of the vehicle is controlled by the rotating speed of the right half shaft gear, and the rotating speed of the right half shaft gear can be reduced by adjusting the first motor rotor to be high.

11. The series dual-motor differential power-split continuously variable transmission system of claim 4, further comprising a reverse mode, wherein when a reverse operation is required, the motor controller inputs a reverse voltage and a reverse current to control the second motor rotor to rotate in a reverse direction, and the reverse power of the second motor rotor is transmitted to the transmission input shaft through the second motor hollow output shaft, the second motor output driving gear, the second motor output driven gear, the clutch input shaft, the power transmission clutch output shaft, the clutch output driving gear and the clutch output driven gear, and is transmitted to the central transmission driven gear through the transmission gear set to output a reverse power.

12. The series double-motor differential power-split continuously variable transmission system of claim 4, further comprising a starting power-assisted mode, wherein when a vehicle needs to be started under a heavy load, the continuously variable transmission system is in a hybrid power state for a short time, and the mechanical power split by the engine is output to the transmission input shaft through the right half-shaft gear; meanwhile, the motor controller controls the storage battery to supply power to the second motor through a circuit, electric energy is converted into mechanical energy through the second motor rotor, and the mechanical energy is transmitted to the transmission input shaft through the second motor hollow output shaft, the second motor output driving gear, the second motor output driven gear, the clutch input shaft, the power transmission clutch output shaft, the clutch output driving gear and the clutch output driven gear.