(1)液压泵在结构上需保证具有自吸能力，而液压马达就没有这一要求。

(1) The structure of the hydraulic pump needs to ensure that it has self-priming capacity, but the hydraulic motor does not have this requirement.

(2)叶片泵依靠叶片跟转子一起高速旋转而产生的离心力使叶片始终贴紧定子的内表面，起封油作用，形成工作容积。若将其当马达用，必须在液压马达的叶片根部装上弹簧，以保证叶片始终贴紧定子内表面，以便马达能正常起动。

(2) The vane pump relies on the centrifugal force generated by the high-speed rotation of the vane and the rotor, which makes the vane always close to the inner surface of the stator, plays the role of sealing oil, and forms the working volume. If it is used as a motor, a spring must be installed at the root of the blade of thehydraulic motor to ensure that the blade is always close to the inner surface of the stator, so that the motor can start normally.

(3)液压马达要求能在很宽的转速范围内正常工作，因此，应采用液动轴承或静压轴承。因为当马达速度很低时，若采用动压轴承，就不易形成润滑滑膜。

(3) Hydraulic motor is required to work normally in a wide speed range, so hydraulic bearing or hydrostatic bearing should be used. Because when the motor speed is very low, if the use of dynamic bearing, it is not easy to form lubricating film.

(4)为了减小吸油阻力，减小径向力，一般液压泵的吸油口比出油口的尺寸大。而液压马达低压腔的压力稍高于大气压力，所以没有上述要求。

(4) In order to reduce the suction resistance and radial force, the suction port of hydraulic pump is larger than the outlet port. The pressure of the low pressure chamber of the hydraulic motor is slightly higher than the atmospheric pressure, so there is no such requirement.

(5)液压马达一般需要正反转，所以在内部结构上应具有对称性，而液压泵一般是单方向旋转的

没有这一要求。
(5) The hydraulic motor generally needs forward and reverse rotation, so it should have symmetry in the internal structure, while the hydraulic pump generally rotates in one direction, so there is no such requirement.

(6)液压马达必须具有较大的起动扭矩。由于液压马达与液压泵具有上述不同的特点，使得很多类型的液压马达和液压泵不能互逆使用。

(6) The hydraulic motor must have a large starting torque. Due to the above different characteristics of hydraulic motor and hydraulic pump, many types of hydraulic motor and hydraulic pump can not be used in reverse.