Function - Festo 539733 Notice D'utilisation

Hydraulic power packs with 40 l tank
8.3

Function

• The electric motor (1, 3) drives external gear pump (26). The pump (26) draws oil out of the tank (6) via a
pump suction tube (23). Depending on the variant, the pump's outlet is connected to the pressure-relief
valve's block either directly or via a hose (22).
• The pump delivers oil at a nearly constant volumetric flow rate. The portion of the oil that's not used by
the consuming device must flow back to the tank without resulting in a rise in pressure to a level which
exceeds maximum working pressure. This is the task of the pressure-relief valve (17). This valve is
adjustable so that maximum working pressure can be changed. In the case of pressure limiting, the oil
flows back to the tank (6) via the tube (28). Hydraulic oil pressure is indicated at the pressure gauge
(18).
• Return flow from the consuming device is conducted via the quick connection couplings (12) on the
collecting block. The blue coupling socket (13) is intended for the purpose of relieving pressure from the
diaphragm accumulator and is not a connection for compressed air. The oil flows from the collecting
block back to the tank via the return filter (2).
• There are two further connections (5) directly on the tank. These are provided for connecting the
discharge measurement container.
• The fill-level and hydraulic oil temperature can be read at the sight glass (15).
• The vent filter (4) equalizes air pressure in the reservoir in the event of a fluctuating hydraulic oil level.
Air passing through the filter is filtered at the same time. The air filter is located in the removable cover.
The cover is only removed in order to fill the power unit. A coarse strainer (21) i located underneath this,
which protects against ingress of coarse particles when filling the power unit.
• The hydraulic oil in the tank can be drained via the tank drain plug (16).
24
© Festo Didactic 399636