For those uses where the operation speed range
can hardly be adapted to a fixed displacement
engine, Equipos Cid Hnos offers a double displacement
engine range.
By using an external pressure signal, similar
to the external pressure, similar to the working
pressure by means of a directional valve,
through one of the holes in the intermediate
band, between the distribution valve and the
engine crankcase. The position of the cam
that mobilizes the shaft is modified. The
displacement is swiftly changed between two
preset values, thus varying the shaft output
speed, even at full load and speed conditions.
The distribution valve is designed with broad
sleeves for the oil inlet (high pressure)
and outlet (low pressure), to and from the
cylinders, enabling a swift flow.
It is internally fitted with cavities for
oil passage, which are hydraulically balanced
to reduce lateral loads. This effect keeps
the valve centered within its location, thus
reducing friction.
B 10 running life (see references below) –
It is the number of devices where it can be
expected that a 10% of the rollers show an
evidence that they are about to reach the
end of their useful life, while a 90% can
still be satisfactory. Average life is four
times B 10 life. A more exact data can be
calculated by means of the following formula:
The
monogram (the following graphic) shows the
B 10 rolling life of conical rollers used
in the engine to be considered. Application
example (see references below): Lateral load (W) = 408 Kg
working at a Distance (A) = 50 mm from
the assembly face. Pressure (P) = 210 Kg/cm²
at the engine inlet. Shaft speed (N) = 25 Rpm.
B10 estimated life = 5000
hours.
The following spotted-chain example begins
with the W lateral face in the vertical axis,
intercepts A distance, searches the P pressure
and cuts the corresponding N curve until the
horizontal line B10 is cut.
The monogram can also be used to estimate
the rolling life with zero lateral load, beginning
in the cycle, at the appropriate pressure
on the vertical axis, for example: Pressure (P) = 210 Kg/cm². Shaft speed (N) = 200 Rpm.
Estimated B10 life will be
= 2200 hours.
Monogram
to determine the working life of rollers
DBV
MONOGRAM
REFERENCES
W
=
Lateral load
A = Distance from
the load center to the assembly load
P = Pressure
