Variable displacement mechanism, plunger pump and plunger motor

The utility model provides a variable displacement mechanism, which is used for driving a swash plate (6) of a plunger pump or a plunger motor to swing around a swing axis (O2) along a first swing direction (R1) and a second swing direction (R2) which are opposite to each other, and is characterized in that the variable displacement mechanism comprises two motors (9) which are respectively arranged on two sides of the swash plate; the speed reduction transmission mechanisms are arranged between the motors and the swash plate, and each motor drives the swash plate to swing through the corresponding speed reduction transmission mechanism. The utility model further provides a plunger pump and a plunger motor. 本申请提供了一种变量机构，用于驱动柱塞泵或柱塞马达的斜盘(6)绕摆动轴线(O2)沿彼此相反的第一摆动方向(R1)和第二摆动方向(R2)摆动，其特征在于，所述变量机构包括：两个电机(9)，所述两个电机分别设置于斜盘两侧；以及设置在每个电机与斜盘之间的减速传动机构，每个电机通过相应的减速传动机构驱动斜盘摆动。本申请还提供了一种柱塞泵和柱塞马达。