1
闄?/p>
褰?/p>
澶栨枃鏂囩尞鍘熸枃锛?/p>
The
commonly
used
sources
of
power
in
hydraulic
systems
are
pumps and accumulators .
Similarly,accumulator
connected
to
atmosphere
will
dischange
oil
at atmosphere pressure until it empty. only when connected to a system
having
resistance to flow can pressure be developed.
Three
types
of
pumps
find
use
in
fluid-power
systems:rotary,reciprocating or piston-type,
and 3,centrifugal pumps.
Simple hydraulic system may use but one type of pump . The trend
is to use pumps with the most satisfactory characteristics for the specific
tasks
involved
.
In
matching
the
characteristics
of
the
pump
to
the
requirements of the hydraulic system , it is not unusual to find two types
of
pumps
in
series
.
For
example
,
a
centrifugal
pump
may
be
to
supercharge
a
reciprocating
pump
,
or
a
rotary
pump
may
be
used
to
supply
pressurized
oil
for
the
contronls
associated
with
a
reversing
variabledisplacement
pumps
.
Most
power
systems
require
positive
displacement pumps . At high pressure , reciprocating pumps are often
preferred to rotary pumps .
1
銆?/p>
Rotary pumps