Double-motor pure-electric multi-mode power system and driving method thereof

Abstract

The invention discloses a double-motor pure-electric multi-mode power system and a driving method thereof. The system includes a primary motor and a secondary motor, the main motor and the auxiliary motor drive the differential assembly to rotate. A differential assembly outputs power. A planetary assembly is connected between each of the main motor and a secondary motor and a differential. When the double motors are started, the main driving gear and the auxiliary driving gear are driven to rotate, the rotational speed of the main motor is gradually increased, the main driving gear drives theinput gear to drive the sun gear, thereby driving the auxiliary driving gear to drive the ring gear, and the sun gear and the ring gear generate power to superimpose the transmission planetary row, the planetary row drives a rotary arm, and the rotary arm outputs a high-speed power mode. Through combination control of the brake and the release and switch among different shifts in cooperation withthe two motors, a plurality of driving modes, such as low-speed, medium-speed, high-speed and ultra-high-speed driving modes, the economic requirements of low speed and experience of high-speed driving fun can be met, and the system and the method are widely adapted to pure electric power system of new energy vehicles.

Description

technical field [0001] The invention belongs to a vehicle power system, and in particular relates to a pure electric power system applied to a vehicle and a driving method thereof. Background technique [0002] With the continuous development of society and vehicle engineering technology, the number of cars is increasing, which puts a lot of pressure on the environment and energy. It is urgent to carry out major innovations in vehicle engineering drive technology. One is hybrid technology, and the other is pure power. electric technology. The above two technologies mainly involve the innovation of vehicle transmission system, one is the introduction of energy storage devices, and the other is the introduction of electric drive devices, such as motors. As far as the current pure electric drive is concerned, most vehicles use motors and single-speed ratio gearboxes to drive vehicles, which can meet the requirements of medium and low-speed electric vehicles in some areas to a ...

AI Technical Summary

Problems solved by technology

However, the main problems faced by the research and development of automatic transmission technology for electric vehicles are as follows: 1. The input speed is nearly three times higher than that of traditional fuel vehicles (the input speed of traditional fuel vehicles is mostly within 3000rpm, while the speed of electric vehicles is mostly above 12000rpm), As a result, the gearbox efficiency, shifting method, and lubrication method have undergone qualitative changes, and traditional gearbox technology has been difficult to adapt to; 2. Traditional fuel vehicles all have an idling working state, so the shifting hydraulic pump can provide the lowest shifting pressure

However, the motor of an electric vehicle is gradually increased from 0 speed to the specified speed, and the traditional hydraulic shift technology is no longer applicable; 3. The motor overload torque is large and the acceleration is large, and the input torque of the gearbox is much greater than that of traditional fuel vehicles, resulting in shifting and clutching. Components are difficult to match; 4. Traditional vehicles use mechanical brakes, and there is no requirement for energy recovery; however, electric vehicles need to maximize the recovery of braking energy as much as possible, which makes it difficult to control the braking and shifting of gearboxes; 5. Compared with traditional As far as automobiles are concerned, electric vehicles have extremely high requirements on the transmission efficiency of automatic transmissions, which makes the structural design of automatic transmissions difficult; 6. High-frequency vibration, self-excited vibration, noise, impact, fatigue damage, fretting It is difficult to deal with a series of problems such as wear and tear; 7. The equivalent axial width is small, that is, the automatic gearbox needs to be designed thinner to leave a better space for the axial size of the motor, resulting in a huge equivalent load of the tooth width and difficult design Big; Eighth, the automatic transmission is required to shift quickly without power interruption; Ninth, with the development of ultra-high technology and low cost of vehicles, the automatic transmission is required to be low in cost

Therefore, so far, there is no real two-speed or multi-speed automatic transmission system adapted to the use of electric vehicles, especially the use of high-end electric vehicles with ultra-high speed requirements.

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