Case 21E, 121E, 221E, 321E Series 3 Wheel Loaders Repair Manual

Manuals: Service Manual
Introduction
Engine
Front Axle
Rear Axle
Brake System
Hydrostatic Drive
Frame
Steering
Heating and Airconditioning
Electrical System
Working Equipment
Manual Extract: BRAKE ACCUMULATOR
As regards their operation, the accumulators are identical, they are membrane-type and ensure a certain number of activations of the connected users in case of hydraulic pressure lack.
The membrane accumulator consists of a pressure resistant steel container, inside which a membrane made of elastic material is assembled as separating element.

The membrane is locked with a ring nut between the body lower and upper part. In the membrane central lower section is dived a metallic disc preventing its slipping out from fluid inlet port.

Without hydraulic pressure, the membrane, loaded on the gas side to pre charge pressure (P0), leans against the inner surface of the accumulator and the poppet stops the liquid flow.

With hydraulic pressure applied, the pre charge pressure is exceeded by compressing nitrogen, the poppet is lifted and liquid flows into the accumulator. The useful quantity of liquid results from the difference between gas volume and minimum and maximum service pressure.