Automobile hub motor compositely driven by symmetrically arranged disc type motor differential gear train
Technical Field
The invention relates to a driving transmission system of an electric automobile, in particular to an automobile hub motor compositely driven by a symmetrically-arranged disc type motor differential gear train.
Background
With the increasing environmental problems and energy consumption problems, the electric vehicle technology is becoming more important and the development thereof is accelerating. The technical advantages of the electric vehicle driven by the hub motor in the aspects of vehicle general arrangement structure, chassis active control and control convenience are generally concerned by the industry and academia, and many well-known automobile enterprises and research institutions successively promote concept automobiles driven by the hub motor.
The driving motor technology is one of the most important core technologies of an electric vehicle, and the hub motor is an important one of the core technologies. The hub motor technology is a technology for integrating a driving motor and a hub, and the main characteristic of the technology is the high integration of a power system, a transmission system and a braking device with the hub and the driving motor, so that the mechanical transmission part of the pure electric automobile can be simplified to the maximum extent, and the space in the automobile is greatly increased. The hub motor can directly obtain electric energy, so that energy loss is reduced to the minimum, the efficiency of the whole vehicle is improved, driving force can be immediately generated, and the acceleration time is shortened.
At present, a hub motor on a passenger vehicle mostly adopts a structure mode of directly driving a radial magnetic field inner rotor motor acceleration and deceleration device or a radial magnetic field outer rotor motor, and generally adopts four-wheel drive or two-wheel drive. Because each driving wheel is driven by an independent hub motor, each wheel can be independently controlled, and a plurality of wheels can also be controlled, so that the control freedom degree is improved, the dynamic control of controlling the stability of the vehicle body and the like can be easily achieved, and meanwhile, the electric braking and the braking energy recovery of the whole vehicle are also easily realized.
Although the in-wheel motor has many advantages, the current in-wheel motor driving technology still has some problems to be solved:
(1) in order to meet the requirements of the automobile power system under different running conditions, the driving system is required to have large torque at low speed and high power output performance at high speed, and has a large speed regulation range and a large torque variation range. Meanwhile, in order to improve the endurance mileage of the whole vehicle, the motors are required to operate efficiently in a wider speed regulation range, and the requirements are difficult to be met by a single motor at the same time;
(2) due to the limitation of the space size of the wheel hub and the requirements of the electric vehicle on the power and the torque of the wheel hub motor, the design and the manufacturing difficulty of the wheel hub motor are increased, and the wheel hub motor is not suitable for adopting a new driving mode of dispersing multi-power according to different road conditions;
(3) the hub motor is integrated in the hub, unsprung mass can be increased, driving comfort is affected, the hub motor is required to have high power and torque density to reduce mass, and the currently commonly adopted radial magnetic field motor has the defects of large axial size, heavy mass, poor low-speed performance, difficulty in improving the space utilization rate in the wheel and the like.
Disclosure of Invention
In order to solve the problems in the prior art, the invention provides an automobile hub motor compositely driven by a symmetrically-arranged disc type motor differential gear train, which can provide large torque when a driving system is started at a low speed and can realize high-efficiency operation in a wider speed range, so that the automobile hub motor adapts to variable driving conditions of a vehicle, the driving efficiency of the system is effectively improved, and the driving mileage is prolonged.
The technical scheme for realizing the functions is as follows: the utility model provides a composite drive's of differential gear train of symmetric arrangement disk motor automobile wheel hub motor which characterized in that:
the planetary differential gear train comprises a central shaft, a first disc type motor, a second disc type motor and a planetary differential gear train;
one end of the central shaft is rotatably supported with a wheel hub through a first bearing, the other end of the central shaft is fixedly connected with a steering knuckle, a tire is fixedly arranged on the wheel hub, and a brake is fixedly arranged on the steering knuckle; the first disc type motor is arranged on the central shaft and close to the hub, and the second disc type motor is arranged on the central shaft and close to the steering knuckle; the planetary differential gear train is arranged on the central shaft and is positioned between the hub and the first disc type motor;
the first disc motor comprises a first disc motor stator and a first disc motor rotor, the second disc motor comprises a second disc motor stator and a second disc motor rotor, the first disc motor stator and the second disc motor stator are fixedly connected with the central shaft, the first disc motor rotor is rotatably supported on the central shaft through a second bearing, the second disc motor rotor is rotatably supported on the central shaft through a third bearing, a gap exists between the first disc motor rotor and the first disc motor stator, a gap exists between the second disc motor rotor and the second disc motor stator, and a gap exists between the first disc motor stator and the second disc motor stator;
the planetary differential gear train comprises a sun gear, a planet carrier and a gear ring; the sun gear is fixedly connected with the first disc type motor rotor and can rotate around the central shaft through the second bearing, the planet gear is meshed with the sun gear and can be rotatably supported on the planet carrier through a fourth bearing, the planet carrier is fixedly connected with the hub and can be rotatably supported on the central shaft through the first bearing, and the gear ring is fixedly connected with the second disc type motor rotor through the rotating shell and can rotate around the central shaft through the third bearing and the second disc type motor rotor; and the brake disc is fixedly connected with the rotor of the second disc type motor and is matched with the brake.
Furthermore, one end of the central shaft close to the steering knuckle is provided with a wire routing hole for supplying power to the first disc type motor and the second disc type motor.
The invention has the advantages that:
(1) the hub motor device provided by the invention has multiple driving working modes, can be more suitable for variable driving working conditions of urban vehicles, and effectively improves the driving efficiency of the system, thereby prolonging the driving mileage of the electric automobile;
(2) the invention adopts two disc type motors as power sources, converts a high-power motor with high demand performance index into two medium-power and low-power motors with relatively low demand performance index, and can effectively reduce the design and manufacture difficulty of the motor especially under the condition that the space of a wheel hub limits the size of the motor;
(3) the two axial flux disc type motors adopt a symmetrical arrangement structure, so that the axial magnetic pull force of the axial flux disc type motors is effectively counteracted; in addition, the rated power, the rated rotating speed and the rated torque of the two axial flux disc type motors are different, the rated power, the rated rotating speed and the rated torque of the first disc type motor are low, and the first disc type motor is responsible for providing high-torque power when the vehicle runs at low speed or climbs; the second disc type motor has higher rated rotating speed and high power, and can provide high-power output when a vehicle runs at high speed, so that the performance and the working efficiency of the hub motor are further improved.
Drawings
FIG. 1 is a longitudinal cross-sectional view of the present invention;
FIG. 2 is a view of the present invention from the inside;
FIG. 3 is an isometric cut-away perspective view of a structure of the present invention;
FIG. 4 is a diagram of the high efficiency operation area of a conventional single motor or single motor and reducer in-wheel motor system;
FIG. 5 is a schematic diagram of the high-efficiency working area of the automobile hub motor driven by the symmetrically arranged novel disc type motor differential gear train in a composite mode.
The reference numbers in the figures illustrate: 1. a central shaft; 2. a first bearing; 3. a hub; 4. a knuckle; 5. a tire; 6. a brake; 7. a first disc motor; 71. a first disc motor stator; 72. a first disc motor rotor; 8. a second disc motor; 81. a second disc motor stator; 82. a second disc motor rotor; 9. a planetary differential gear train; 91. a sun gear; 92. a planet wheel; 93. a planet carrier; 94. a ring gear; 10. a wiring hole; 11. a second bearing; 12. a third bearing; 13. a fourth bearing; 14. rotating the housing; 15. a brake disk.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings of the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention. Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.
Referring to fig. 1 to 3, a novel compound driven automobile wheel hub motor of disc motor differential gear train of symmetrical arrangement, including motor center shaft 1, 1 one end of center shaft has wheel hub 3 through the rotatable support of first bearing 2, and the center shaft 1 other end is connected with knuckle 4 admittedly, and fixed mounting has tire 5 on wheel hub 3, and fixed mounting has stopper 6 on the knuckle 4, installs first disc motor 7, second disc motor 8 and planet differential gear train 9 in the middle of the center shaft 1 respectively.
And a wiring hole 10 is formed at one end of the central shaft 1 close to the steering knuckle 4 and used for supplying power to windings of the first disc type motor 7 and the second disc type motor 8.
The first disc motor 7 includes a first disc motor stator 71 and a first disc motor rotor 72, the second disc motor 8 includes a second disc motor stator 81 and a second disc motor rotor 82, both the first disc motor stator 71 and the second disc motor stator 81 are fixedly connected to the central shaft 1, the first disc motor rotor 72 is rotatably supported on the central shaft 1 through a second bearing 11, the second disc motor rotor 82 is rotatably supported on the central shaft 1 through a third bearing 12, an air gap is formed between the first disc motor rotor 72 and the first disc motor stator 71, an air gap is formed between the second disc motor rotor 82 and the second disc motor stator 81, and the first disc motor stator 71 and the second disc motor stator 81 are separated by air to prevent magnetic fields thereof from affecting each other.
The planetary differential gear train 9 includes a sun gear 91, a planetary gear 92, a planetary carrier 93, and a ring gear 94, the sun gear 91 is fixedly coupled to the first disc motor rotor 72 and is rotatable about the central shaft 1 via the second bearing 11, the planetary gear 92 is engaged with the sun gear 91 and is rotatably supported on the planetary carrier 93 via a fourth bearing 13, the planetary carrier 93 is fixedly coupled to the hub 3 and is rotatably supported on the central shaft 1 via the first bearing 2, the ring gear 94 is fixedly coupled to the second disc motor rotor 82 via the rotating housing 14 and is rotatable about the central shaft 1 via the third bearing 12 together with the second disc motor rotor 82, and the brake disc 15 is fixedly coupled to the second disc motor rotor 82 and is engaged with the brake 6.
The working principle of the invention is as follows:
(1) the principle that the hub motor device provided by the invention has various driving working modes is as follows:
the sun gear 91 of the planetary differential gear system 9 is fixedly connected with the first disc motor rotor 72 and can rotate around the central shaft 1 through the second bearing 11; the ring gear 94 is fixedly coupled to the second disc motor rotor 82 via the rotary housing 14 so as to be rotatable together with the second disc motor rotor 82 about the central shaft 1 via the third bearing 12; while the brake disc 15 is fixedly coupled to the second disc motor rotor 82 and cooperates with the brake 6.
Firstly, when the brake 6 works and brakes, so that the gear ring 94 is fixed, and the first disc motor 7 works alone, at the moment, the differential gear train of the hub motor is converted into a planetary gear train with single degree of freedom, and power is input from the first disc motor 7 through the sun gear 91 and is output to the hub 3 through the planet carrier 93.
The system speed reduction ratio is as follows:
take uo ═ Zb/Za
Output torque: t isH=i·Ta
Output rotating speed: n isH=na/i
In the formula, na: rotational speed of sun gear 91 (i.e., rotational speed of first disk motor 7)
nH: rotational speed of planetary carrier 93 (i.e. rotational speed of hub 3)
Za: number of teeth of sun gear 91
Zb: number of teeth of ring gear 94
Ta: torque output of the first disc motor 7
Secondly, when the brake 6 is released, the first disc motor 7 and the second disc motor 8 work simultaneously, at the moment, the wheel hub motor device is in a rotating speed coupling working mode, the power of the wheel hub motor is input through the sun gear 91 by the first disc motor 7 and is input through the gear ring 94 by the second disc motor 8 through the rotating shell 14, and the power is output to the wheel hub 3 through the planet carrier 94.
At this time, take uo ═ Zb/ZaThe method comprises the following steps:
output torque: t isH=-(1+uo)·Ta=-(1+uo)·Tb/uo
in the formula, na: rotational speed of sun gear 91 (i.e., rotational speed of first disk motor 7)
nb: the rotational speed of the ring gear 94 (i.e., the rotational speed of the second disk motor 8)
nH: rotational speed of planetary carrier 93 (i.e. rotational speed of hub 3)
Ta: output torque of the first disc motor 7
Tb: output torque of the second disk motor 8
Za: number of teeth of sun gear 91
Zb: number of teeth of ring gear 94
In particular, when the first disc motor 7 rotates at a speed naWhen 0, the system speed reduction ratio is:
in particular, when the first disk motor 7 and the second disk motor 8 are equal in rotation speed, there is
nH=na=nb
The in-wheel motor system reduction ratio can be considered to be equal to 1.
In summary, the hub motor device provided by the invention has multiple driving operation modes.
(2) The principle that the hub motor device provided by the invention can improve the driving efficiency is as follows:
the high-efficiency working area of the motor is determined by the rated rotating speed and the rated torque of the motor, and for the hub motor system of a single motor or a single motor and a speed reducer, the high-efficiency working area is shown in fig. 4:
the wheel hub motor device provided by the invention is the most different from a wheel hub motor system with a single motor or a single motor and a speed reducer in that the wheel hub motor device has multiple driving working modes, so that the high-efficiency area of the whole power transmission system is widened, the wheel hub motor device can be more suitable for variable driving conditions of a vehicle, the driving efficiency of the system is effectively improved, and the driving range is prolonged. The efficient working area of the automobile hub motor compositely driven by the symmetrically-arranged novel disc type motor differential gear train is shown in fig. 5.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and those skilled in the art can still make modifications to the technical solutions described in the above embodiments, or make equivalent substitutions for some technical features. Therefore, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.