油泵是一个使机械能变为液体压力能的能量转换装置。液压马达是一个使液体压力能变为机械能的能量转换装置。本章讨论容积式油泵及液压马达。这种油泵的特点是其流量取决于工作空间的可变容积的大小,与压力无关。压力仅通过泄漏影响其流量,而其额定工作压力则主要取决于工作空间的密封性能及有关另部件承受载荷的能力;油泵的功率则取决于压力和流量的乘积。 The pump is an energy converter that turns mechanical energy into liquid pressure energy. A hydraulic motor is an energy converter that turns liquid pressure into mechanical energy. This chapter discusses displacement pumps and hydraulic motors. The characteristic of this pump is that its flow rate depends on the size of the variable volume of the working space, independent of pressure. Pressure only affects the flow through the leak, and its rated working pressure depends mainly on the sealing performance of the work space and on the ability of the other components to withstand the load; the power of the pump depends on the product of pressure and flow.