RAMMER 255E, Operator'S Manual

Page: 44 / 68

COPYRIGHT © 2020 SANDVIK MINING AND CONSTRUCTION OY Page 44 - Lubrication
Carrier hydraulic oil 255E
A standard carrier, with a proper hammer circuit, meets the requirements of the
necessary cooling capacity. If the oil temperature tends to be too high during the
hammer operation, the following things must be checked:
■
The hammer circuit pressure relief valve is not open when the hammer is
operated.
■
The hammer circuit pressure drops are reasonable. Less than 10 bar (145 psi) in
the pressure line and less than 5 bar (75 psi) in the return line.
■
Hydraulic pumps, valves, cylinders, motors etc. and hammer do not have
internal leakages.
If all of the above mentioned things are in order, and the temperature of the
hydraulic oil still tends to be too high, extra cooling capacity is needed. Consult the
carrier manufacturer or dealer for details.
2.3 OIL FILTER
The purpose of the oil filter is to remove impurities from the hydraulic oil. Air and
water are also impurities in oil. Not all impurities can be seen with the naked eye.
Impurities enter the hydraulic system:
■
During hydraulic oil changes and refilling.
■
When components are repaired or serviced.
■
When the hammer is being installed on the carrier.
■
Because of component wear.
Normally the existing main oil filters of the carrier are used as hammer circuit return
line filters. Consult the carrier manufacturer or your local dealer concerning
instructions for the filter change intervals.
In hydraulic hammer work the carrier oil filter must fulfil the following
specifications:
■
The oil filter must allow maximum particle size of 25 microns (0.025 mm).
■
The oil filter material must be artificial fibre cloth or very fine gauge metallic
mesh to withstand pressure fluctuations.
■
The oil filter must have a nominal flow capacity of at least twice the hammer's
maximum flow.
In general, oil companies guarantee new oils to have a particle count of 40 microns
maximum. Filter the oil when filling the tank.
The damage caused by hydraulic oil impurities in the carrier and hammer circuits:
1. The working life of the pumps and other components is significantly shortened.
■
Rapid wear of parts.
■
Cavitation.
2. Wear of cylinder and gaskets.