Schwing 30100750, Руководство по эксплуатации

Страница: 102 / 164

Maintenance
Operation Manual - All S P Rock Valve Model s 100 revD a te
Maintenance
Maintenance is what you do to the machine to keep it
in good working condition. There are two kinds of
maintenance, preventative and repairs. Preventative
maintenance is important to avoid unnecessary repairs,
but eventually even well maintained machine parts will
wear out and require repair or replacement.
Some maintenance needs to be done daily, some
weekly, some monthly, some quarterly, some
semiannually and some annually. It is a good idea to
make a checklist that will tell you what maintenance is
due, and when it is due. A checklist is included in the
Appendix section of this manual. Keep accurate
records of maintenance performed, and when the work
was completed. In this way, you will know that all
necessary work has been completed on time. Complete
maintenance records could also make the machine
worth more money when it comes time to sell or trade
it.
There are certain things you should know about the
maintenance of your machine that will not come up on
a timetable of things to do.
We begin the section with some general information
regarding some of these items.
Filtration
General Information
Filtration is the single most important method of
keeping your unit’s hydraulic system operational.
Particles that could damage the components are
introduced into the oil by the differential cylinders and
the valves, through the reservoir breather tube, and by
internal wear in the components themselves.
Additionally, when you change hydraulic oil the new
oil is not clean enough to be used in a concrete pump
without being pre-filtered. In fact, new hydraulic oil is
only filtered at the refinery to 40
μ
(40 microns). The oil
in a Schwing needs to be filtered to a MINIMUM of
25
μ
, and preferably finer than that. Filters are rated by:
• the size of particles they trap, and whether that
size is nominal, or absolute
• the dirt holding capacity, in grams
• the clean element pressure drop for a given
flow rate (in PSI and gallons per minute or bar
and liters per minute), and
• the ratio of particles of a given size
encountered versus particles passed (referred
to as the beta ratio). An example of a beta ratio
would be
β
25 = 200 (pronounced beta twenty
five equals two hundred). This means that for
every 200 particles of 25 microns or larger that
hit the filter media, one makes it through. A
finer filter would be, for example,
β
12 = 200.
A courser filter example would be
β
25 = 75.
For concrete pumps, medium to fine filtration
is required.
NOTE!
It is recommen d e d th a t a fter a n initi a l 100
ho u r bre a k in p erio d , both the hy d r au lic oil
a n d filter a n d motor oil a n d filter be
re p l a ce d . Check with Schwin g ser v ice for
the correct l u bric a nts a n d filter to u se in
yo u r clim a te.
S pecific Information
Here are some facts regarding filtration as they relate to
your pump:
As delivered from the factory, each Schwing is
equipped with a return filter that is rated at 12 micron
(shown as 12
μ
) absolute.
The beta ratio is
β
12 = 200. In our case, the beta ratio
means that for every 200 particles of dirt that hit the
filter media that are 12 micron or larger in size, 1 will
make it through. Although we are not happy about the
one particle that is allowed through, we do not use finer
filtration because A) the components don’t require it,
and B) a finer filter would plug up with dirt too often,
resulting in high maintenance costs to you. We have
settled on a compromise that should afford long service
life and minimum maintenance costs. Don’t be fooled
by the one particle that gets through, this is an
extremely high quality element with very good
trapping characteristics.
The clean element pressure drop is about 6 PSI at 200
liters per minute (element only) + 2 PSI for the
housing, for a total of 8 PSI
Δ
P when the element is
clean. The pressure drop varies with the viscosity of
the oil, which is why you can ignore the delta P pop out
indicator until the oil is heated to normal operating
temperatures.
It will hold between 75 and 80 grams of dirt, when
operating at a flow rate of 200 l/m. The flow rate is
important, because the filter would hold more if you
Home TOC TOC Print Print