Rock Drill Accumulator: Function, Maintenance, and Replacement

The accumulator is a critical component in hydraulic rock drills that stores hydraulic energy and smooths pressure fluctuations. A failed accumulator significantly reduces drill performance and can damage other components.

How the Accumulator Works

The accumulator consists of a pressure vessel divided by a membrane or bladder into a gas chamber (pre-charged with nitrogen) and a hydraulic oil chamber. It absorbs pressure spikes and releases stored energy during the percussion cycle.

Signs of Accumulator Failure

A failed accumulator causes: reduced impact energy, irregular percussion, increased hydraulic system pressure fluctuations, and in severe cases, complete loss of percussion. The membrane or bladder failure is the most common failure mode.

Nitrogen Pre-Charge

The nitrogen pre-charge pressure must be maintained at the manufacturer's specified level. Check the pre-charge pressure at every major service interval using a nitrogen charging kit. Never use oxygen or compressed air — only dry nitrogen.

Membrane/Bladder Replacement

When the membrane or bladder fails, the accumulator must be disassembled and the internal element replaced. This requires specialized tools and must be done carefully to avoid damage to the pressure vessel.

Accumulator Supply

Nova Rock Drill supplies complete accumulators and replacement membranes for all major rock drill brands. Contact us for fast delivery.