CN115107508A - Double-motor multi-mode driving system of electric automobile - Google Patents

Double-motor multi-mode driving system of electric automobile Download PDF

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Publication number
CN115107508A
CN115107508A CN202210647911.8A CN202210647911A CN115107508A CN 115107508 A CN115107508 A CN 115107508A CN 202210647911 A CN202210647911 A CN 202210647911A CN 115107508 A CN115107508 A CN 115107508A
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gear
motor
ring
row
synchronizer
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Chinese (zh)
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吴景铼
张云清
洪先乾
郜文豪
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Huazhong University of Science and Technology
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Huazhong University of Science and Technology
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
    • B60K17/00—Arrangement or mounting of transmissions in vehicles
    • B60K17/04—Arrangement or mounting of transmissions in vehicles characterised by arrangement, location, or kind of gearing
    • B60K17/043—Transmission unit disposed in on near the vehicle wheel, or between the differential gear unit and the wheel
    • B60K17/046—Transmission unit disposed in on near the vehicle wheel, or between the differential gear unit and the wheel with planetary gearing having orbital motion
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
    • B60K1/00—Arrangement or mounting of electrical propulsion units
    • B60K1/02—Arrangement or mounting of electrical propulsion units comprising more than one electric motor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
    • B60K17/00—Arrangement or mounting of transmissions in vehicles
    • B60K17/04—Arrangement or mounting of transmissions in vehicles characterised by arrangement, location, or kind of gearing
    • B60K17/16—Arrangement or mounting of transmissions in vehicles characterised by arrangement, location, or kind of gearing of differential gearing
    • B60K17/165—Arrangement or mounting of transmissions in vehicles characterised by arrangement, location, or kind of gearing of differential gearing provided between independent half axles
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/80—Technologies aiming to reduce greenhouse gasses emissions common to all road transportation technologies
    • Y02T10/84—Data processing systems or methods, management, administration

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Structure Of Transmissions (AREA)

Abstract

The invention discloses a dual-motor multi-mode driving system of an electric automobile, belonging to the technical field of pure electric automobile driving, comprising: the system comprises a first motor, a second motor, a first synchronizer, a second synchronizer, a Simpson planetary gear row, a power output unit and a main controller; an output shaft of the first motor is connected with a first synchronizer, and an output shaft of the second motor is connected with a second synchronizer; the first synchronizer and the second synchronizer are both connected with the Simpson planetary gear row; the Simpson planetary gear row is also connected with an output shaft of the first motor, an output shaft of the second motor and the power output unit respectively; the first motor, the second motor, the first synchronizer, the second synchronizer and the power output unit are all connected with the main controller. The driving system can reduce the energy consumption of the electric automobile, reduce the volume of the driving system and improve the driving efficiency.

Description

Double-motor multi-mode driving system of electric automobile
Technical Field
The invention belongs to the technical field of pure electric vehicle driving, and particularly relates to a double-motor multi-mode driving system of an electric vehicle.
Background
With the development of automobiles, people have more and more requirements on performances such as economy, riding comfort and the like on the premise of meeting the dynamic property. Electric vehicles have been greatly developed for their excellent economic performance. The efficiency of the driving system of the electric automobile is a main factor influencing the economy of the electric automobile, and nowadays, the driving system of the commercial electric automobile mostly adopts a driving form of a single motor and a fixed reduction ratio or a driving form of a single motor and a multi-gear transmission. The single-motor reinforced constant-speed-ratio driving system cannot give consideration to economic performance on the premise of meeting the power performance, and cannot fully exert the advantages of a pure electric vehicle. The driving mode of the single motor and the multi-gear gearbox can improve the economy of the automobile under the condition of ensuring that the power performance of the whole automobile is unchanged, but inevitable power interruption can be caused in the gear shifting process, and the driving experience of a user is influenced.
In order to improve the economy of the electric vehicle and improve the smoothness of the mode switching, more and more dual-motor transmission systems are proposed. The reason for the improved economy of a dual motor drive system is that it can be driven with a single motor with a low power requirement, thereby reducing the power losses of the motor. As a solution, chinese patent application No. 201910817933.2 discloses a hybrid drive device, in which a power system adopts a double-planet-row structure, including a sun gear, a planet carrier, a ring gear, a brake, and a clutch. This power drive arrangement can realize that compound power shunts and output power shunts, can realize multiple pure electric and hybrid drive mode, but its structure is bigger than normal on pure electric vehicles, and mainly used hybrid drive, the conversion of drive mode need rely on stopper and clutch in addition, and both all need the hydraulic system energy supply, if directly used for pure electric vehicles, will increase whole car energy consumption.
Disclosure of Invention
Aiming at the defects and the improvement requirements of the prior art, the invention provides a dual-motor multi-mode driving system of an electric automobile, which aims to reduce the energy consumption of the electric automobile.
In order to achieve the above object, the present invention provides a dual-motor multi-mode driving system for an electric vehicle, comprising: the system comprises a first motor, a second motor, a first synchronizer, a second synchronizer, a Simpson planetary gear row, a power output unit and a main controller;
an output shaft of the first motor is connected with a first synchronizer, and an output shaft of the second motor is connected with a second synchronizer; the first synchronizer and the second synchronizer are both connected with the Simpson planetary gear row; the Simpson planetary gear row is also connected with an output shaft of the first motor, an output shaft of the second motor and the power output unit respectively; the first motor, the second motor, the first synchronizer, the second synchronizer and the power output unit are all connected with the main controller.
Further, the simpson planetary gear row includes: the planetary gear set comprises a front planetary gear row gear ring, a front planetary gear row sun gear, a front planetary gear row planet carrier, a rear planetary gear row gear ring, a rear planetary gear row sun gear, a rear planetary gear and a rear planetary gear row planet carrier;
the front planetary gear row gear ring and the front planetary gear row sun gear are meshed with the front planetary gear, and the front planetary gear is arranged on the front planetary gear carrier;
the rear planet gear row ring gear and the rear planet gear row sun gear are both meshed with the rear planet gear, and the rear planet gear is arranged on the rear planet row planet carrier;
the front planetary gear row planet carrier and the rear planetary gear row gear ring are connected to form an integrated component, and the front planetary gear row gear ring is respectively connected with the first synchronizer and the output shaft of the first motor; the rear planet row planet carrier is connected with the second synchronizer, and the rear planet gear row sun gear and the front planet gear row sun gear are connected with an output shaft of the second motor.
Furthermore, the first synchronizer comprises a first joint gear ring, a first synchronizing ring, a first joint sleeve and a first shifting fork which are coaxially arranged;
the first joint gear ring is connected with an output shaft of a first motor, the first synchronizing ring and the first joint gear ring rotate synchronously, and the first shifting fork and the first joint sleeve are connected in a separable mode;
when the first shifting fork is separated from the first joint sleeve, the first joint sleeve is not jointed with the first synchronizing ring, and when the first shifting fork is connected with the first joint sleeve, the first shifting fork pushes the first joint sleeve to be jointed with the first synchronizing ring, so that the first synchronizing ring is jointed with the first joint gear ring and is connected with the first joint gear ring to lock the first motor.
Further, the second synchronizer includes: the second joint gear ring, the second synchronizing ring, the second joint sleeve, the second shifting fork, the third synchronizing ring and the third joint gear ring are coaxially arranged;
the second joint gear ring is connected with the rear planet row planet carrier, the third joint gear ring is connected with an output shaft of a second motor, the second synchronizing ring and the second joint gear ring rotate synchronously, the third synchronizing ring and the third joint gear ring rotate synchronously, and the second shifting fork and a second joint sleeve are in separable connection;
when the second shifting fork is separated from the second joint sleeve, the second joint sleeve is not jointed with the second synchronizing ring and the third synchronizing ring; when the second shifting fork is connected with the second joint sleeve, the second shifting fork pushes the second joint sleeve to be jointed with the second synchronizing ring, so that the second synchronizing ring is jointed with the second joint gear ring, the rear planet carrier connected with the second joint gear ring is locked, the second shifting fork pushes the second joint sleeve to be jointed with the third synchronizing ring, so that the third synchronizing ring is jointed with the third joint gear ring, and the second motor connected with the third joint gear ring is locked.
Further, the power output unit comprises a main speed reducer gear set and a differential mechanism;
the main speed reducer gear set comprises an input gear and an output gear, the input gear and the output gear are meshed, and the output gear is connected with the differential; the front planet carrier and the rear planet gear row and gear ring integrated component are connected with the input gear.
Further, the driving system comprises six driving modes, wherein the six driving modes comprise a first single-motor driving mode, a second single-motor driving mode, a third single-motor driving mode, a fourth single-motor driving mode, a dual-motor torque coupling driving mode and a dual-motor rotating speed coupling driving mode;
the first single motor drive mode is that the first motor is locked and the second motor passes through a first fixed transmission ratio i 1 Driving the electric vehicle;
the second single motor driving mode is that the rear planet row planet carrier is locked, and the second motor passes through a second fixed transmission ratio i 2 Driving the electric vehicle;
the third single motor driving mode is that the second motor is locked and the first motor passes through a third fixed transmission ratio i 3 Driving the electric vehicle;
the fourth single motor driving mode is that the planet carrier of the rear planet row is locked, and the first motor passes through a fourth fixed transmission ratio i 4 Driving the electric vehicle;
the double-motor torque coupling driving mode is that the planet carrier of the rear planet row is locked, and the first motor passes through a fourth fixed transmission ratio i 4 Driving the electric vehicle with the second motor at a second fixed gear ratio i 2 Driving the electric vehicle;
the dual-motor rotating speed coupling driving mode is that the first motor and the second motor drive the electric automobile in a variable transmission ratio in a rotating speed coupling mode;
and selecting fixed transmission ratios in different driving modes according to the number of teeth of an input gear and an output gear of the main speed reducer gear set and the Simpson planetary gear row.
Further, the first fixed gear ratio i 1 A second fixed gear ratio i 2 A third fixed gear ratio i 3 And a fourth fixed gear ratio i 4 Respectively satisfy:
i 1 ＝i f (1+i p1 )
i 2 ＝i f i p2
i 3 ＝i f (1+i p1 )/i p1
i 4 ＝i f (1+i p1 +i p2 )/i p1
wherein i f Representing the ratio of the input gear of the final drive gearset to the output gear of the final drive gearset, i p1 Representing the gear ratio, i, of the ring gear of the front planetary gear row to the sun gear of the front planetary gear row p2 The gear ratio of the rear planetary gear row ring gear to the rear planetary gear row sun gear is shown.
Further, in the dual-motor rotating speed coupling driving mode, the speed of the first motor, the speed of the second motor and the speed of the electric automobile satisfy the following conditions:
Figure BDA0003684712420000041
wherein, ω is 1 、ω 2 Respectively representing the rotation speed of the first motor and the rotation speed of the second motor, v representing the vehicle speed, R ω Representing the rolling radius of the tire of the electric vehicle.
Further, the main controller selects the driving mode with the highest efficiency from the six driving modes to drive the electric vehicle on the principle of optimal efficiency.
Further, the efficiency η of the drive system satisfies:
Figure BDA0003684712420000051
Figure BDA0003684712420000052
wherein, T 1 、T 2 Output torques, ω, of the first and second electric machines in each mode, respectively 1 、ω 2 Output rotation speed, T, of the first and second motors in each mode, respectively c2 、ω c2 The torque and the rotating speed of the rear planet row planet carrier are respectively.
Generally, by the above technical solution conceived by the present invention, the following beneficial effects can be obtained:
(1) according to the invention, the output shafts of the two motors are respectively connected with the first synchronizer and the second synchronizer, the first synchronizer and the second synchronizer are both connected with the Simpson planetary gear row, and when the electric automobile needs to be braked, the corresponding synchronizers lock the corresponding motors to realize braking; in the field of automobiles, a person skilled in the art conventionally recognizes that the synchronizer is mainly used for shifting gears, and the first synchronizer and the second synchronizer are innovatively used as braking mechanisms to replace a traditional brake, so that braking is realized, hydraulic energy supply is avoided, and energy consumption of the whole automobile is reduced.
(2) Furthermore, the invention also designs the structure of the synchronizer, when the electric automobile needs to be braked, the shifting fork is pushed to realize braking, the structure is simple and the braking mode is simple, similar to a dog clutch.
(3) Preferably, the front planet carrier and the rear planet gear row and gear ring integrated component are connected with the power output unit, and compared with the prior art that the rear planet carrier is connected with the power output unit, the power output connection mode can compress the transverse space of the whole system, the structure is more compact, and the volume of the driving system is reduced.
(4) Based on the connection relationship among the two motors, the Simpson planetary gear row and the power output unit, the two motors transmit power in different driving modes according to different fixed transmission ratios and different power flow transmission routes through different gear states of the two synchronizers, and the main controller selects different driving modes according to an efficiency optimization principle to enable the motors to work at the highest efficiency.
Drawings
FIG. 1 is a schematic structural diagram of a dual-motor electric vehicle driving system according to the present invention;
FIG. 2 is a schematic three-dimensional structure diagram of a first synchronizer according to the present invention;
FIG. 3 is a schematic diagram of a three-dimensional structure of a second synchronizer according to the present invention;
FIG. 4 is a power transmission path diagram for a first single motor drive mode provided by the present invention;
FIG. 5 is a power transmission path diagram for a second single motor drive mode provided by the present invention;
FIG. 6 is a power transmission path diagram for a third single motor drive mode provided by the present invention;
FIG. 7 is a power transmission path diagram for a fourth single motor drive mode provided by the present invention;
FIG. 8 is a power transmission path diagram of the dual motor torque coupling drive mode provided by the present invention;
fig. 9 is a power transmission path diagram of the dual-motor rotational speed coupling driving mode provided by the invention. The same reference numbers will be used throughout the drawings to refer to the same or like elements or structures, wherein:
1-first electric machine, 2-second electric machine, 3-first synchronizer, 4-second synchronizer, 5-Simpson planetary gear train, 6-input gear, 7-output gear, 8-differential, 31-first synchronizer holder, 32-first engaging ring gear, 33-first synchronizing ring, 34-first engaging sleeve, 35-first shift fork, 41-second synchronizer holder, 42-second engaging ring gear, 43-second synchronizing ring, 44-second engaging sleeve, 45-second shift fork, 46-third synchronizing ring, 47-third engaging ring gear, 51-front planetary gear train ring gear, 52-front planetary gear train sun gear, 53-front planetary gear train, 54-rear planetary gear train, 55-rear planetary gear train carrier, 56-rear planet gear row sun gear, 57-front planet carrier and rear planet gear row ring gear integrated component.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.
In the present invention, the terms "first", "second", and the like in the description and the drawings are used for distinguishing similar objects, and are not necessarily used for describing a particular order or sequence. The terms "left", "right", "middle", and the like are used in an orientation based on the orientation shown in the drawings or the orientation that the product is usually placed in when used, and are used only for convenience of describing the invention and simplifying the description, but do not indicate or imply that the device or element referred to must have a specific orientation, construction and operation, and therefore should not be construed as limiting the invention.
As shown in fig. 1, the dual-motor multi-mode driving system for an electric vehicle provided by the present invention comprises: the system comprises a first motor 1, a second motor 2, a first synchronizer 3, a second synchronizer 4, a Simpson planetary gear row 5, a power output unit and a main controller; an output shaft of the first motor is connected with the first synchronizer, and an output shaft of the second motor is connected with the second synchronizer; the first synchronizer 3 and the second synchronizer 4 are both connected with the Simpson planetary gear row 5; the Simpson planetary gear row 5 is also connected with an output shaft of the first motor 1, an output shaft of the second motor 2 and a power output unit respectively; the first motor 1, the second motor 2, the first synchronizer 3, the second synchronizer 4 and the power output unit are all connected with the main controller.
As shown in fig. 2 and 3, the first synchronizer and the second synchronizer are configured to brake the first motor or the second motor according to different gears, so that a power transmission path of the motor is changed. The first synchronizer 3 acts on the output shaft of the first electric machine 1, the second synchronizer 2 acts on the rear planet carrier 55 of the simpson planetary gear train 5 in a leftward locking manner, and the second synchronizer 2 acts on the output shaft of the second electric machine 2 in a rightward locking manner.
The first synchronizer mainly comprises: the first synchronizer fixing seat 31, the first joint gear ring 32, the first synchronizing ring 33, the first joint sleeve 34 and the first shifting fork 35 are coaxially arranged, and the first joint gear ring 32, the first synchronizing ring 33, the first joint sleeve 34 and the first shifting fork 35 are positioned inside the first synchronizer fixing seat 31 and are coaxially arranged with the first synchronizer fixing seat 31; the first synchronizer fixing seat 31 is connected with the gearbox shell and used for fixing the whole synchronizer; the first engaging gear ring 32 is connected with an output shaft of the first motor, the first synchronizing ring 33 rotates synchronously with the first engaging gear ring 32, and the first shift fork 35 is detachably connected with the first engaging sleeve 34; when the first shift fork 35 is in the middle position, that is, when the first shift fork 35 is separated from the first engaging sleeve 34, the first engaging sleeve 34 is not engaged (not contacted) with the first synchronizing ring 33, so as to define that the first synchronizer is in the middle gear, and at this time, the first synchronizer does not work, and the first motor is in a free state; when the first shifting fork 35 is connected with the first engaging sleeve 34, the first shifting fork 35 pushes the first engaging sleeve 34 to move leftward and is engaged with the first synchronizer fixing seat 31 and the first synchronizing ring, the first synchronizing ring is engaged with the first engaging gear ring, and a part connected with the first engaging gear ring is locked, namely the first motor is locked, so that the first synchronizer is defined to be in a left gear at the moment;
the second synchronizer mainly comprises: a second synchronizer fixing seat 41, a second joint gear ring 42, a second synchronizing ring 43, a second joint sleeve 44, a second shifting fork 45, a third synchronizing ring 46 and a third joint gear ring 47 which are coaxially arranged, wherein the second joint gear ring 42, the second synchronizing ring 43, the second joint sleeve 44, the second shifting fork 45, the third synchronizing ring 46 and the third joint gear ring 47 are positioned inside the second synchronizer fixing seat 41 and are coaxially arranged with the second synchronizer fixing seat 41;
wherein, the second synchronizer fixing base 41 is connected with the gearbox shell, the second joint ring gear 42 is connected with the rear planet carrier 55 of the Simpson planetary gear row 5, the third joint ring gear 47 is connected with the output shaft of the second motor, the second synchronizing ring 43 rotates synchronously with the second joint ring gear 42, the third synchronizing ring 46 rotates synchronously with the third joint ring gear 47, and the second shifting fork 45 is detachably connected with the second joint sleeve 44; when the second fork 45 is in the middle position, that is, the second fork 45 is separated from the second engaging sleeve 44, the second engaging sleeve 44 is not engaged with the second synchronizing ring 43, and the second engaging sleeve 44 is not engaged with the third synchronizing ring 46, which defines that the second synchronizer is in the middle gear, and the second synchronizer is in the non-operating state or the non-locking state; when the second shift fork 45 pushes the second engaging sleeve 44 to move leftward and engage with the second synchronizer fixing seat 41 and the second synchronizing ring 43, so that the second synchronizing ring 43 engages with the second engaging gear ring 42, the part connected with the second engaging gear ring 42 is locked, i.e., the rear planet carrier is locked, the power transmission path of the motor is changed, and the second synchronizer is defined to be in a left gear at this time; the second shift fork 45 pushes the second coupling sleeve 44 to the right and engages the second synchronizer holder 41 and the third synchronizer ring 46, the third synchronizer ring 46 engages the third engaging ring 47, and the portion connected to the third engaging ring 47, i.e., the second electric motor, is locked, defining that the second synchronizer is in the right gear at this time.
The power output unit is used for outputting the power of the first motor and the power of the second motor to drive the electric automobile.
Specifically, the simpson planetary gear row includes: a front planetary gear row ring gear 51, a front planetary gear row sun gear 52, a front planetary gear 53, a front planetary gear row planet carrier, a rear planetary gear row ring gear, a rear planetary gear row sun gear 56, a rear planetary gear 54, and a rear planetary gear row planet carrier 55; wherein, the front planet gear row ring gear 51 and the front planet gear row sun gear 52 are all meshed with the front row planet gear 53, the front planet gear row planet carrier is connected with the rear planet gear row ring gear to form a front planet gear row planet carrier and rear planet gear row ring gear integrated component 57, the rear planet gear row ring gear and the rear planet gear row sun gear 56 are all meshed with the rear row planet gear 54, the front row planet gear is arranged on the front planet gear row planet carrier, and the rear row planet gear is arranged on the rear planet gear row planet carrier; the rear carrier 55 is connected to the second ring gear 42 of the second synchronizer; the front planetary gear row ring gear 51 is connected with the first conjoined ring gear 32 of the first synchronizer.
The output shaft of the first motor 1 is connected with a first synchronizer and a front planetary gear row ring gear 51 in sequence; the output shaft of the second electric machine 2 is connected in sequence with the second synchronizer, the rear planetary gear row sun gear 56 and the front planetary gear row sun gear 52; the front planet carrier and the rear planet gear row and gear ring integrated component are connected with the power output unit;
the double-motor driving system designed by the invention can have 6 driving modes, the conversion of the six driving modes is completed by a first synchronizer and a second synchronizer, the first synchronizer has a middle gear and a left gear, and the second synchronizer has a middle gear, a left gear and a right gear; when the first synchronizer is located at the middle gear, the second synchronizer can be located at the middle gear, the left gear and the right gear, and when the first synchronizer is located at the left gear, the second synchronizer can be located at the middle gear, the left gear and the right gear, so that six driving modes are formed.
The main controller selects the gear position of the first synchronizer or the second synchronizer according to the efficiency optimization principle, so that the most efficient driving mode is selected from the 6 driving modes to drive the electric automobile. The 6 driving modes include a first single-motor driving mode, a second single-motor driving mode, a third single-motor driving mode, a fourth single-motor driving mode, a dual-motor torque coupling driving mode, and a dual-motor rotational speed coupling driving mode.
The power output unit is used for outputting the power provided by the first motor or/and the second motor to wheels according to the driving mode selected by the main controller so as to drive the electric automobile.
Specifically, the power output unit comprises a main speed reducer gear set and a differential mechanism 8, wherein the main speed reducer gear set comprises an input gear 6 and an output gear 7, the input gear 6 is meshed with the output gear 7, and the output gear 7 is connected with the differential mechanism 8; the front planet carrier and the rear planet gear row and gear ring integrated component are connected with the input gear 6 through gears, the input gear 6 is in meshed transmission with the output gear 7, and power is output to wheels through the differential mechanism 8.
When the first synchronizer is in a middle gear, the first motor drives a front planetary gear row gear ring of the Simpson planetary gear row, the first motor is in a working state (namely a free state), and the state of the second motor is determined according to the gear state of the second synchronizer; when the first synchronizer is in a left gear, a first motor connected with the first joint gear ring is locked; when the second synchronizer is in a middle gear, the second motor drives a rear planetary gear row sun gear and a front planetary gear row sun gear of the Simpson planetary gear row, and the second motor is in a working state; when the second synchronizer is in a left gear, the second motor is in a working state, the second motor drives the sun gear of the rear planetary gear row and the sun gear of the front planetary gear row of the Simpson planetary gear row, and the planet carrier of the rear planetary gear row connected with the second joint gear ring 42 is locked; the second electrical machine connected to the third, engaging ring gear 47 is locked when the second synchronizer is in the right gear, the different states corresponding to different power transmission paths of the electrical machines.
The first single motor driving mode is that the first synchronizer is locked leftwards, namely a first shifting fork 35 of the first synchronizer pushes a first engaging sleeve 34 to enable a first synchronizing ring 33 to be engaged with a first engaging gear ring 32, the first motor is locked, the second motor drives the electric automobile through a first fixed transmission ratio, at the moment, the second synchronizer is in a middle gear, namely a second shifting fork 45 of the second synchronizer is separated from a second engaging sleeve 44; as shown in fig. 4, the power transmission path is such that the power of the second electric machine 2 is output to the input gear 6 of the final drive gear set through the rear planetary gear row sun gear 56, the front planetary gear row sun gear 52, the front planetary gear 53, the front planetary gear row carrier, and the rear planetary gear row-ring integrated member 57 in this order;
the second single motor driving mode is that the second synchronizer is locked leftwards, namely a second shifting fork 45 of the second synchronizer pushes a second engaging sleeve 44 to enable a second synchronizing ring 43 to be engaged with a second engaging gear ring 42, the planet carrier of the rear planet row is locked, the second motor drives the electric automobile through a second fixed transmission ratio, and at the moment, the first synchronizer is in a middle gear; as shown in fig. 5, the power transmission path is such that the power of the second electric machine 2 is output to the final drive gear set input gear 6 via the rear planetary gear row sun gear 56, the rear planetary gear 54, and the front planetary gear row carrier and rear planetary gear row ring gear integrated member 57 in this order.
The third single motor driving mode is that the second synchronizer is locked to the right, namely a second shifting fork 45 of the second synchronizer pushes a second joint sleeve 44 to enable a third synchronizing ring 46 to be jointed with a third joint gear ring 47, the second motor is locked, and the first motor drives the electric automobile through a third fixed transmission ratio; at the moment, the first synchronizer is in a middle gear; as shown in fig. 6, the power transmission path is such that the power of the first electric motor 1 is output to the final drive gear set input gear 6 via the front planetary gear row ring gear 51, the front planetary gear 53, the front planetary gear row carrier, and the rear planetary gear row ring gear integrated member 57 in this order.
The fourth single motor driving mode is that the second synchronizer is locked leftwards, namely a second shifting fork 45 of the second synchronizer pushes a second joint sleeve 44 to enable a second synchronizing ring 43 to be jointed with a second joint gear ring 42, the planet carrier of the rear planet row is locked, and the first motor drives the electric automobile through a fourth fixed transmission ratio; at the moment, the first synchronizer is in a middle gear; as shown in fig. 7, the power transmission path of the first motor 1 is that the power is output to the input gear 6 of the main speed reducer gear set through the front planetary gear row ring gear 51, the front planetary gear 53, the front planetary carrier, and the rear planetary gear row ring gear integrated member 57 in sequence; the other path is output to the final drive gear set input gear 6 via a front planetary gear row ring gear 51, a front row planetary gear 53, a front planetary gear row sun gear 52, a rear planetary gear row sun gear 56, a rear planetary gear 54, a front planetary gear row carrier, and a rear planetary gear row ring gear integrated member 57 in this order.
The dual-motor torque coupling driving mode is that the second synchronizer is locked leftwards, the first motor drives the electric automobile through a fourth fixed transmission ratio, and the second motor drives the electric automobile through a second fixed transmission ratio; at the moment, the first synchronizer is in a middle gear; as shown in fig. 8, the power transmission path is that the power of the second electric machine 2 is output to the input gear 6 of the main speed reducer gear set through the sun gear 56 of the rear planetary gear set, the planet gears 54 of the rear planetary gear set, and the planet carrier and ring gear integrated member 57 of the front planetary gear set and the rear planetary gear set in sequence; the power of the first motor 1 is output to the main reduction gear set input gear 6 through the front planetary gear row ring gear 51, the front planetary gear 53, the front planetary gear row planetary carrier and the rear planetary gear row ring gear integrated member 57 in sequence on the one hand, and is output to the main reduction gear set input gear 6 through the front planetary gear row ring gear 51, the front planetary gear 53, the front planetary gear row sun gear 52, the rear planetary gear row sun gear 56, the rear planetary gear 54, the front planetary gear row planetary carrier and the rear planetary gear row ring gear integrated member 57 in sequence on the other hand.
The double-motor rotating speed coupling driving mode is that the first synchronizer and the second synchronizer are not locked (namely the first synchronizer and the second synchronizer are both positioned at a middle gear), and the first motor and the second motor drive the electric automobile in a variable transmission ratio in a rotating speed coupling mode. As shown in fig. 9, the power transmission path is such that the power of the first electric machine 1 is output to the input gear 6 of the main reducer gear set via the front planetary gear row ring gear 51, the front planetary gear 53, the front planetary carrier, and the rear planetary gear row ring gear integrated member 57 in this order; the power of the second motor 2 is output to the main reduction gear set input gear 6 through the rear planetary gear row sun gear 56, the front planetary gear row sun gear 52, the front planetary gear 53, and the front planetary gear row carrier and rear planetary gear row ring integrated member 57 in this order.
Different fixed transmission ratios are selected according to the number of teeth of an input gear and an output gear of a main speed reducer gear set of the power output unit and the Simpson planetary gear row.
Specifically, the specific formula for calculating the first fixed gear ratio is:
i 1 ＝i f (1+i p1 )
wherein i 1 Representing a first fixed gear ratio, i f Representing the ratio of the input gear of the final drive gearset to the output gear of the final drive gearset, i p1 The gear ratio of the front planetary gear row ring gear to the front planetary gear row sun gear is shown.
The specific formula for calculating the second fixed gear ratio is:
i 2 ＝i f i p2
wherein i 2 Representing a second fixed gear ratio, i f Representing the ratio of the teeth of the input gear of the main reducer gearset to the teeth of the output gear of the main reducer gearset, i p2 The gear ratio of the rear planetary gear row ring gear to the rear planetary gear row sun gear is shown.
The specific formula for calculating the third fixed gear ratio is:
i 3 ＝i f (1+i p1 )/i p1
wherein i 3 Representing a third fixed gear ratio, i f Representing the ratio of the teeth of the input gear of the main reducer gearset to the teeth of the output gear of the main reducer gearset, i p1 The gear ratio of the front planetary gear row ring gear to the front planetary gear row sun gear is shown.
The specific formula for calculating the fourth fixed gear ratio is:
i 4 ＝i f (1+i p1 +i p2 )/i p1
wherein i 4 Representing a fourth fixed gear ratio, i f Representing the ratio of the input gear of the final drive gearset to the output gear of the final drive gearset, i p1 Representing the gear ratio, i, of the ring gear of the front planetary gear row to the sun gear of the front planetary gear row p2 The gear ratio of the rear planetary gear row ring gear to the rear planetary gear row sun gear is shown.
Under the rotating speed driving mode, the relation among the speeds of the first motor, the second motor and the electric automobile is as follows:
Figure BDA0003684712420000131
wherein, ω is 1 Representing the speed of rotation, ω, of the first motor 2 Representing the rotational speed of the second motor, v representing the vehicle speed, R ω Indicating the rolling radius of a tyre of a motor vehicle, i f Representing the ratio of the input gear of the final drive gearset to the output gear of the final drive gearset, i p1 Representing the gear ratio, i, of the ring gear of the front planetary gear row to the sun gear of the front planetary gear row p2 The gear ratio of the rear planetary gear row ring gear to the rear planetary gear row sun gear is shown.
The main controller determines the states of the brake and the motor according to a mode switching control strategy in the energy management strategy, namely, a comprehensive efficiency optimal principle of the power system, so that the six modes are selected, one driving mode is selected from the 6 driving modes to drive the electric automobile, and the efficiency of the transmission system is further improved.
Wherein, the driving efficiency corresponding to different driving modes is related to the output torque and the output rotating speed of the first motor and the second motor and the torque and the rotating speed of the rear planet row planet carrier, and the output torque and the output rotating speed of the first motor and the second motor, the torque and the rotating speed of the rear planet row planet carrier and the gear ratio i of the front planet row gear ring and the front planet row sun gear p1 The gear ratio i of the gear ring of the rear planetary gear row to the sun gear of the rear planetary gear row p2 Correlation of i p1 、i p2 And to a fixed transmission ratio in different drive modes; the efficiency of the dual-motor driving system designed by the invention is related to the fixed transmission ratio under different driving modes, based on the special connection relation among the two motors, the Simpson planetary gear row and the power output unit, the motors transmit power in different power flow transmission routes under different fixed transmission ratios through different gear states of the two synchronizers, and the main controller selects different driving modes according to the principle of optimal efficiency to enable the motors to work under the highest efficiency.
Specifically, the efficiency η of the drive system is the relationship between the output torque and the output rotational speed of the first motor and the second motor, and the torque and the rotational speed of the rear carrier:
Figure BDA0003684712420000141
wherein, T 1 、T 2 Output torques, ω, of the first and second electric machines, respectively, for each mode 1 、ω 2 Output speeds, T, of the first and second motors in each mode, respectively c2 Torque of the rear planet carrier, omega c2 The rotating speed of the planet carrier of the rear planet row, v is the current speed, R ω Is the tire radius;
Figure BDA0003684712420000142
wherein, T 1 、T 2 、ω 1 、ω 2 、T c2 Are all equal to i p1 、i p2 Correlation, i.e. T 1 ＝T 1 (i p1 ，i p2 )、T 2 ＝T 2 (i p1 ，i p2 )、ω 1 ＝ω 1 (i p1 ，i p2 )、ω 2 ＝ω 2 (i p1 ，i p2 )、T c2 ＝T c2 (i p1 ，i p2 )；i f Input gear of main speed reducer gear set andgear ratio of the output gear, i p1 Representing the gear ratio, i, of the ring gear of the front planetary gear row to the sun gear of the front planetary gear row p2 The gear ratio of the rear planetary gear row ring gear to the rear planetary gear row sun gear is shown.
The invention has a torque coupling driving mode and a rotating speed coupling driving mode at the same time, and the dynamic property of the vehicle can be improved when the vehicle is suitable for more working conditions; in the mode switching process, at least one motor is in a working state, so the impact degree of mode switching is reduced, and the smoothness is improved.
The double-motor multi-mode driving system gives consideration to the power performance and the economy of the whole vehicle, only uses the single motor for driving when the required power of the vehicle is smaller, and uses the double motors for driving when the required power of the vehicle is larger, thereby improving the economic performance of the vehicle. And under single motor drive mode, two motors have different drive ratios, are suitable for different driving conditions, such as city, cross-country, high-speed, etc. under different operating modes, optimize the economic nature of low power. In the dual motor drive mode, the dual motors have a speed coupling and a torque coupling to optimize economy under high power demand conditions. And the driving system is provided with two motors, and at least one motor is in a working state, so that the problem of power interruption does not exist.
More importantly, the first synchronizer and the second synchronizer are innovatively used as braking mechanisms to replace a traditional brake to realize braking, different driving modes are realized through the synchronizers, a hydraulic system is not required to be added to maintain the state of each driving mode, and additional energy consumption exchange required by the realization of different driving modes by adopting a clutch or a brake depending on the hydraulic system can be effectively avoided.
When the electric automobile needs to be braked, the shifting fork is pushed to realize braking, and the electric automobile is similar to a dog clutch, simple in structure and simple in braking mode. Moreover, the synchronizer can ensure that the gear is not impacted and is convenient to operate when in gear shifting, and the gear shifting time is shortened.
Compared with the prior art that the rear planet row planet carrier is connected with the power output unit, the connection mode of the output power can compress the transverse space of the whole system, the structure is more compact, and the volume of a driving system is reduced.
It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims (10)

1. A dual-motor multi-mode driving system of an electric automobile is characterized by comprising: the system comprises a first motor (1), a second motor (2), a first synchronizer (3), a second synchronizer (4), a Simpson planetary gear row (5), a power output unit and a main controller;
the output shaft of the first motor (1) is connected with a first synchronizer (3), and the output shaft of the second motor (2) is connected with a second synchronizer (4); the first synchronizer (3) and the second synchronizer (4) are connected with the Simpson planetary gear row (5); the Simpson planetary gear row (5) is also connected with an output shaft of the first motor (1), an output shaft of the second motor (2) and a power output unit respectively; the first motor (1), the second motor (2), the first synchronizer (3), the second synchronizer (4) and the power output unit are all connected with the main controller.
2. The drive system according to claim 1, characterized in that the simpson planetary gear row (5) comprises: a front planet gear row gear ring (51), a front planet gear row sun gear (52), a front planet gear (53), a front planet carrier, a rear planet gear row gear ring, a rear planet gear row sun gear (56), a rear planet gear (54) and a rear planet carrier (55);
the front planetary gear row gear ring (51) and the front planetary gear row sun gear (52) are meshed with a front row planetary gear (53), and the front row planetary gear (53) is arranged on a front planetary gear carrier;
the rear planet gear row ring gear and the rear planet gear row sun gear (56) are meshed with the rear planet gear (54), and the rear planet gear (54) is arranged on the rear planet row planet carrier (55);
the front planetary gear row planet carrier and the rear planetary gear row gear ring are connected to form an integrated component, and the front planetary gear row gear ring (51) is respectively connected with a first synchronizer and an output shaft of a first motor; the rear planet row planet carrier (55) is connected with a second synchronizer, and the rear planet gear row sun gear (56) and the front planet gear row sun gear (52) are connected with an output shaft of a second motor.
3. The drive system according to claim 2, characterized in that said first synchronizer comprises a first ring gear (32), a first synchronizer ring (33), a first engaging sleeve (34) and a first fork (35) arranged coaxially;
the first joint gear ring (32) is connected with an output shaft of a first motor, the first synchronous ring (33) and the first joint gear ring (32) rotate synchronously, and the first shifting fork (35) is detachably connected with a first joint sleeve (34);
when the first shifting fork is separated from the first joint sleeve, the first joint sleeve is not jointed with the first synchronizing ring, and when the first shifting fork is connected with the first joint sleeve, the first shifting fork pushes the first joint sleeve to be jointed with the first synchronizing ring, so that the first synchronizing ring is jointed with the first joint gear ring and is connected with the first joint gear ring to lock the first motor.
4. The drive system according to claim 3, characterized in that the second synchronizer (4) comprises: a second joint gear ring (42), a second synchronizing ring (43), a second joint sleeve (44), a second shifting fork (45), a third synchronizing ring (46) and a third joint gear ring (47) which are coaxially arranged;
the second engaging gear ring (42) is connected with the rear planet carrier (55), the third engaging gear ring (47) is connected with an output shaft of a second motor, the second synchronizing ring (43) and the second engaging gear ring (42) rotate synchronously, the third synchronizing ring (46) and the third engaging gear ring (47) rotate synchronously, and the second shift fork (45) and the second engaging sleeve (44) are detachably connected;
when the second shifting fork is separated from the second joint sleeve, the second joint sleeve is not jointed with the second synchronizing ring and the third synchronizing ring; when the second shifting fork is connected with the second joint sleeve, the second shifting fork pushes the second joint sleeve to be jointed with the second synchronizing ring, so that the second synchronizing ring is jointed with the second joint gear ring, the rear planet carrier connected with the second joint gear ring is locked, the second shifting fork pushes the second joint sleeve to be jointed with the third synchronizing ring, so that the third synchronizing ring is jointed with the third joint gear ring, and the second motor connected with the third joint gear ring is locked.
5. A drive system according to claim 4, characterised in that the power take-off unit comprises a final drive gear set and a differential (8);
the main speed reducer gear set comprises an input gear (6) and an output gear (7), the input gear (6) is meshed with the output gear (7), and the output gear (7) is connected with a differential (8); the front planet carrier and the rear planet gear row and gear ring integrated component are connected with the input gear (6).
6. The drive system of claim 5, wherein the drive system comprises six drive modes, the six drive modes comprising a first single motor drive mode, a second single motor drive mode, a third single motor drive mode, a fourth single motor drive mode, a dual motor torque coupling drive mode, and a dual motor speed coupling drive mode;
the first single motor drive mode is that the first motor is locked and the second motor passes through a first fixed transmission ratio i 1 Driving the electric vehicle;
the second single motor driving mode is that the rear planet carrier is locked, and the second motor passes through a second fixed transmission ratio i 2 Driving the electric vehicle;
the third single motor driving mode is that the second motor is locked and the first motor passes through a third fixed transmission ratio i 3 Driving the electric vehicle;
the fourth single motor driveIn a mode that the rear planet row planet carrier is locked, and the first motor passes through a fourth fixed transmission ratio i 4 Driving the electric vehicle;
the double-motor torque coupling driving mode is that the planet carrier of the rear planet row is locked, and the first motor passes through a fourth fixed transmission ratio i 4 Driving the electric vehicle with the second motor at a second fixed gear ratio i 2 Driving the electric vehicle;
the dual-motor rotating speed coupling driving mode is that the first motor and the second motor drive the electric automobile in a variable transmission ratio in a rotating speed coupling mode;
and selecting fixed transmission ratios in different driving modes according to the number of teeth of an input gear and an output gear of the main speed reducer gear set and the Simpson planetary gear row.
7. The drive system of claim 6, wherein the first fixed gear ratio i 1 A second fixed transmission ratio i 2 A third fixed gear ratio i 3 And a fourth fixed gear ratio i 4 Respectively satisfy:
i 1 ＝i f (1+i p1 )
i 2 ＝i f i p2
i 3 ＝i f (1+i p1 )/i p1
i 4 ＝i f (1+i p1 +i p2 )/i p1
wherein i f Representing the ratio of the input gear of the final drive gearset to the output gear of the final drive gearset, i p1 Representing the gear ratio, i, of the ring gear of the front planetary gear row to the sun gear of the front planetary gear row p2 The gear ratio of the rear planetary gear row ring gear to the rear planetary gear row sun gear is shown.
8. The drive system of claim 7, wherein in the dual motor speed coupling drive mode, the first motor, the second motor, and the speed of the electric vehicle are such that:
Figure FDA0003684712410000041
wherein, ω is 1 、ω 2 Respectively representing the rotation speed of the first motor and the rotation speed of the second motor, v representing the vehicle speed, R ω Representing the rolling radius of the tire of the electric vehicle.
9. The drive system according to any one of claims 6 to 8, wherein the main controller selects a most efficient driving mode among the six driving modes to drive the electric vehicle on an efficiency optimization basis.
10. The drive system of claim 9, wherein the efficiency η of the drive system satisfies:
Figure FDA0003684712410000042
Figure FDA0003684712410000043
wherein, T 1 、T 2 Output torques, ω, of the first and second electric machines in each mode, respectively 1 、ω 2 Output speeds, T, of the first and second motors in each mode, respectively c2 、ω c2 The torque and the rotating speed of the rear planet row planet carrier are respectively.
CN202210647911.8A 2022-06-08 2022-06-08 Double-motor multi-mode driving system of electric automobile Pending CN115107508A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117698402A (en) * 2024-01-16 2024-03-15 重庆大学 Multi-mode multi-gear hybrid power transmission system

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117698402A (en) * 2024-01-16 2024-03-15 重庆大学 Multi-mode multi-gear hybrid power transmission system

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