Are there any gearbox and drive electric cars electric reducer
Are there any gearbox and drive electric cars electric reducer. With the growing popularity of the electric car, gearbox subject gradually decreases. In our previous impression, engine and transmission are two of the most important part of the car, they are closely related and necessary. For electric vehicles, because the motor itself has very high rotation speed and torque output range, so it is no longer need a gearbox. However, the electric car really not without a gearbox shift? Of course not, reducer to replace the gearbox, become a indispensable important part of electric cars. Electric cars - are there any transmission and gear reducer motor speed Demand, driven torque characteristics are very suitable for pure electric mode, the motor drive system is no longer need more gear transmission, drive system structure was greatly simplified. Because the car need to increase the motor torque, so you need to set up a fixed speed reduction gear, slow down the speed of the motor and increase torque, to adapt to the working condition of a variety of car. The electric car is single speed transmission with fixed ratio cut motor speed and increase torque device, different models transmission ratio. Between the drive motor and drive axle shaft speed reducer, power output shaft of the drive motor through the spline directly connected to the input shaft gear speed reducer. Reducer on the one hand will drive motor power to drive the half shaft, have the effect of lower speed increasing torque, on the other hand for automotive and when driving on rough road surface of turning, left and right driving wheels in different rotate speed, guarantee the smooth running of the vehicle. Dynamic route is shown in figure 1. Geely emgrand EV300 single speed transmission structure is shown in figure 2. The main reduction ratio is 8. O, tachometer maximum output torque of 2500 n · m, deceleration efficiency is more than 90%. The role of the electric speed reducer motor + reducer scheme can reduce the overall weight of the drive system and the manufacturing cost, two solutions exist at present, but the motor + reducer plan more. For example, motor + reducer + rear axle solutions used instead of the motor + rear axle, the overall weight of the package with gear box scheme of whole light weight than without a reducer for at least 100 kg, reducing costs by more than 10000 yuan. If electric cars no reducer, output to the wheel torque is too small, especially climbing and so on need big torque is difficult to satisfy. And everyday use, most of the time are on the road, if choose high torque motor, the price will be high, the vehicle performance is down. The wheel rotational speed range is 0 RPM (commonly used Start) To 1000 RPM ( Speed of 100 km/h) , especially in the city of 50 km/h speed, ( Corresponding wheel speed 500 RPM) Now most of the civilian motor, in the speed range is not very high efficiency, can choose is to use a higher power motor, usually means that several times the cost of the increase. Gear box twisting the main effect is to slow down, is a low-cost solution. In addition, the car in the corner, there are differences between the two wheel rotation speed is around, the current use of mature differential solution, differential speed can be regulated automatically according to the driving resistance change wheels. If the motor direct driving, not only need complex algorithm matching turning radius and the wheel speed difference, more difficult is to keep the wheel speed and dynamic theory ( Two wheels, at the same time, according to the theory of design) Otherwise can't avoid the wheels skid, cause unnecessary risks. From the cost and technology maturity, or motor + gearbox of the world now.