PIN-DRIVE 1626709 - Caterpillar

Illustration 1 g02221913
Return accumulator (below the return filters)
Illustration 2 g02221914
Partial schematic of return hydraulic system (1) Main control valve (2) Bypass check valve (3) Slow return check valve (4) Return accumulator (5) Line (bypass tube) (6) Line (to hydraulic oil filters) (7) Line (to hydraulic oil cooler) (8) Hydraulic oil cooler (9) Return filters (10) Hydraulic tankReturn accumulator (4) is connected to the return circuit before bypass check valve (2) and slow return check valve (3).
Illustration 3 g02221933
(11) Chamber (nitrogen gas) (12) Bladder (13) PortDuring some operations, excessive pressure is momentarily created in the return circuit. The accumulator absorbs pressure spikes in the return hydraulic circuit.In the accumulator, gas chamber (11) is surrounded by bladder (12). The gas chamber is filled with nitrogen gas. The accumulator is connected to the return circuit through port (13) .When a pressure spike occurs, the pressure in the return system at port (13) rises. The nitrogen gas pressure in chamber (11) is lower than the pressure in port (13). Bladder (12) compresses inside chamber (11). The pressure spike is absorbed by bladder (12) .Once the pressure spike has been dissipated, the pressure in port (13) reduces. The nitrogen gas pressure in chamber (11) is greater than the pressure in port (13). Bladder (12) expands.