Tag: #FluidDynamics

Oil Trapping in Double-Acting Vane Pumps

A hidden issue in vane pump design — oil trapping (hydraulic lock) — can lead to noise, pressure spikes, and component damage. 🔎 What Is Oil Trapping? Oil trapping occurs when: 👉 A sealed chamber of oil is trapped between two vanes 👉 The chamber volume decreases during rotation 👉 But the oil cannot escape […]

Working Principle of a Double-Acting Vane Pump

Working Principle of a Double-Acting Vane Pump What Is a Double-Acting Vane Pump? A double-acting vane pump is a positive displacement pump in which: • The rotor rotates inside an elliptical cam ring • Multiple sliding vanes divide the space into sealed chambers • Two suction zones and two discharge zones are formed during each […]

Why Is the Single-Acting Vane Pump Called a Non-Unloading Pump

Core Reason: Permanent Eccentricity In a standard single-acting vane pump: The cam ring and rotor maintain fixed eccentricity Pump displacement remains constant Flow is continuously delivered during rotation There is no built-in pressure unloading path Therefore, the pump does not automatically unload under pressure, so it is called a non-unloading vane pump.   Hydraulic Behavior […]

Working Principle of a Single-Acting Vane Pump

Single-acting vane pumps are widely used in medium-pressure hydraulic systems due to their smooth flow output and stable operation. Understanding their working principle helps optimize system design and maintenance. 1.What Is a Single-Acting Vane Pump? A single-acting vane pump is a type of positive displacement pump that: • Uses a rotor mounted eccentrically inside a […]

Repairing a Gear Pump：What Are the Component Replacement Principles?

In practical hydraulic system maintenance, repairing a gear pump is not simply about replacing damaged parts. A scientific repair strategy ensures performance recovery, safety, and long service life. Below are the professional principles followed in industrial maintenance. 1. Replace as a Matched Pair Principle Gears, bearings, and wear plates must be evaluated as matched components. […]

Common Gear Pump Failures

Most gear pump failures are system-related rather than pump-related. Proper oil cleanliness, correct suction design, and routine inspection are key to long-term reliability. 1.Insufficient Pressure or Flow One of the most common gear pump problems in daily operation: Internal wear of gears and housing Excessive internal leakage Incorrect pump speed or oil viscosity Result: Reduced […]

How to Eliminate Oil Trapping in Hydraulic Pumps

Method 1: Add Pressure Relief Grooves Relief grooves are machined on side plates or valve plates to connect trapped chambers to low-pressure zones. This allows oil to escape gradually and prevents sudden pressure build-up. Method 2: Optimize Port Timing & Geometry Proper inlet and outlet port timing ensures trapped oil chambers are released at the […]

Oil Trapping in Gear Pumps： Causes & Effects in Hydraulic Systems

1.What Is Oil Trapping? Oil trapping occurs when a small volume of hydraulic fluid becomes sealed between meshing gear teeth during rotation. As the gears continue to rotate, this trapped oil has no direct flow path to the inlet or outlet. 2.How Does Oil Trapping Occur in Gear Pumps? Two gear teeth come into full […]