Application example of energy recovery of accumulator Ⅰ

The vehicle hydrostatic energy storage drive system is shown in the figure.

In this system, due to the existence of the accumulator, there is no direct connection between the flow rate q1 of the hydraulic pump and the variable motor q2 in the system. The flow rate difference (q3=q1-q2) will directly flow into or out of the hydraulic accumulator, namely The hydraulic pump and the variable motor have independent rotational speeds. The quantitative variable motor adopts a symmetrical structure. Through the zero-point axial plunger swash plate structure, the quantitative variable motor can work completely reversibly, that is, the size and direction of the displacement V2 can be changed. The variable motor can work in four quadrants. When the variable motor works in one quadrant, it drives the vehicle forward; when the variable motor works in the first quadrant, it drives the vehicle backward, that is, the reverse gear condition of the vehicle is realized by changing the rotation direction of the variable motor; when the variable motor works in the second quadrant and the fourth quadrant, it drives the vehicle forward. The quadrants are respectively forward and backward braking conditions. The hydrostatic transmission system adapts to changes in external load and changes in motor operating conditions by adjusting the inclination angle and direction of the variable motor swash plate.
After the energy storage element accumulator is added to the vehicle transmission system, the working mode of the transmission system has undergone great changes. Mainly manifested in:
① When the vehicle starts, the engine or the accumulator or both provide energy to drive the vehicle to start;
②Only the engine provides energy to drive the vehicle to start and charge the accumulator at the same time. When the system reaches the specified pressure, the engine stops or is in an idling state. At this time, the accumulator provides the energy required for the vehicle to travel until it cannot be satisfied. When the vehicle is required to drive, the engine will resume normal work and be kept near the corresponding economic working area. When peak power is required, it will be supplemented by the accumulator; ③When the vehicle is decelerating or braking, the engine is stopped or idling, and the hydraulic motor is pumped. Working in working mode, the inertial energy of the vehicle is converted into hydraulic energy and stored in the accumulator, which is released to drive the vehicle as needed, so that the braking energy can be recovered (usually dissipated in the form of heat energy at the brake).
Therefore, the main features of the vehicle hydrostatic energy storage drive system are:
① The engine can work intermittently to reduce fuel consumption and emissions;
②Using secondary adjustment technology to completely separate the engine load from the working load;
③The accumulator can provide scored power and reduce the installed capacity of the engine;
④ It can reduce braking frequency and realize partial braking energy recovery;
⑤It is easy to realize the direct drive/all-wheel drive of the vehicle, and the structure of the test vehicle is correspondingly simple, which reduces the vibration and noise caused by the mechanical transmission;
⑥Improve the maneuverability and driving stability of the vehicle, and improve its riding comfort.