HLDA
– Double acting - Doubled thrust hydraulic linear actuator
Use and maintenance manual
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Pag. 32
Contents may change without notice
3) Unscrew the stop screw (19) by turning it anticlockwise with an
Allen wrench until the screw is complete with drawn inside the end
flange threaded hole.
4) Unscrew the nuts (20) from the tie rods (18): they must be
gradually unscrewed all at the same time.
5) Slide off the end flange (13) and the tube (16).
6) If the actuator control unit requires the cylinder chamber head
flange side to be also filled with oil, and the piston rod seal ring (3)
to be replaced, remove the screw (2) and the flange (1). Unscrew
the piston rod (15) threaded end from the adaptor bush. Slide off
the piston rod (15) from the head flange (1).
7) Disassemble the head flange.
Seals replacement
Prior to reassembly check that the actuator components are in good
conditions and clean. Lubricate all the surfaces of the parts, which
move in contact with other components, by a recommended grease.
If the O-ring must be replaced, remove the existing one from its
groove, clean the groove carefully and lubricate it with a protective oil
or grease film. Assemble the new O-ring into its groove and lubricate
it with a protective oil or grease film.
1) Replace the O-ring (5) of the head flange (1).
2) Replace the back-up-ring (4) of the end flange (13).
3) Replace the scraper-ring (33) into the flange (32) placed under the
head flange
To replace the piston rod seal rings (3) proceed as follows :
1) Remove the existing seal ring (3) with its O-ring from their groove.
2) Clean the groove carefully and lubricate it with a protective oil or
grease film.
3) Assemble the new O-ring into its groove and lubricate it with a
protective oil or grease film.
4) Assemble the new seal ring (3) into the flange groove, inside its
rubber O-ring, by bending it : take care that the bending radius is
as large as possible to avoid damaged the seal. Then enlarge the
seal ring with your fingers so as to restore its round shape: pay
attention not to utilise any tools which can damage the seal ring.
To replace the piston seal ring (7) proceed as follows :
1) Remove the existing seal ring (7) with its O-ring from their groove.
2) Clean the groove carefully and lubricate it with a protective oil or
grease film.
