Liebherr HS 835 HD Litronic - Manual (Page 5)

5
Hydraulic
Casing Oscillators
VRM
• Upper tube guide
• Inserts
Accessories
• Lower locking device
• Suspension
Short series for the use with rotary boring equipment or light duty types please refer to the special brochure!
Special types
General Remarks
The hydraulic casing oscillators
have been designed in accor-
dance with the latest technical
know-how. Extremely sturdy con-
struction guarantees cost-effec-
tive use on site. By means of ex-
act statical calculations in con-
junction with higher quality mate-
rial, an optimum conformity of
loads, weight and material
strength is achieved. The internal
wielding stresses – difficult to de-
termine for static calculations,
which would affect the construc-
tion considerably – are eliminated
by means of stress relieving prior
to machining. A prominent feature
of the equipment is the clamping collar consisting
of five links operating on the boring implement. The
individual links surround the casing like a chain so
that a consistent surface pressure is exerted on the
casing circumference. In addition, the large height
of the collar (600 to 800 mm) prevents any damage
to the casings. By means of easily exchangeable
reducer pieces the oscillator can be converted,
within a few minutes, to a smaller casing diameter.
The collar opens uniformly and enables unproblem-
atic insertion of the casing with the cutting shoe.
Another advantage of the machine is the low height
on the excavator side. The excavator can be swiv-
eled by 360° in coupled condition.
Attachment at the excavator itself is torque rigid
and guarantees the transmission of the full rotating
movement of 25° to the casing if the excavator is
firmly situated.
The design and construction of the casing oscillator
is based on the experience of many years of co-op-
eration with companies specializing in pile founda-
tions. In view of the high costs which would result
from a breakdown of the equipment on-site, great
emphasis has been put on exeptionally sturdy con-
struction.
• Power pack
• Hose unit
VRM 3000 in operation