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 correct moment.

Optimized port geometry reduces abrupt volume changes during meshing.

Method 3: Improve Pump Structural Design

Advanced pump designs reduce oil trapping by:

Modifying gear tooth profiles

Using floating side plates

Adopting pressure-balanced structures

These designs minimize trapped volume and stabilize internal pressure.

Method 4: Control Operating Conditions

Maintaining proper system conditions helps reduce oil trapping effects:

Avoid excessive operating pressure

Maintain correct oil viscosity

Prevent high-speed operation beyond design limits

Method 5: Choose the Right Pump Type

For applications requiring ultra-smooth flow and low noise, vane pumps or piston pumps offer better control of oil trapping compared to traditional gear pumps.