Load sensitive valve, variable displacement hydraulic pump and hydraulic system

The invention provides a load-sensitive valve, a variable displacement hydraulic pump and a hydraulic system. The load-sensitive valve comprises a main body part and a valve core, the main body part comprises a first cavity, a valve cavity and a second cavity which are sequentially connected. The valve element is located in the valve cavity and comprises a first end facing the first cavity and a second end facing the second cavity, the first end comprises a first surface used for bearing the pressure intensity of the first cavity, and the second end comprises a second surface used for bearing the pressure intensity of the second cavity. In the axial extending direction of the valve cavity, the pressure bearing area of the first surface is smaller than that of the second surface. By means of the load sensitive valve, it can be guaranteed that the output flow of a hydraulic system is increased along with increase of load pressure, and normal work of an executing mechanism is guaranteed. 本公开提供一种负载敏感阀、变排量液压泵和液压系统