Does the space between the vanes increase or decrease at the inlet?

In hydraulic pumps, particularly those using vanes, the behavior of the space between the vanes is critical to the pump's function. At the inlet of the pump, the vanes experience centrifugal force, which tends to push them outward. As the pump operates and the liquid enters, the space between the vanes increases due to the design of the rotor and the movement of the vanes. The increasing space allows for a smoother and more efficient flow of the hydraulic fluid into the pump, minimizing the risk of cavitation and ensuring that the pump can maintain effective suction.

The design is such that as the fluid enters, it has more room to fill up the volume between the vanes. This characteristic aids significantly in the overall performance of the pump, as the increasing space helps prevent pressure build-up that could hinder efficient fluid movement. Understanding this dynamic is key for diagnosing pump behavior and ensuring optimal operating conditions.