Specifications

MAYCO C30HDZ PUMP — OPERATION AND PARTS MANUAL — REV. #12 (04/03/12) — PAGE 27
HOW IT WORKS
The C30HDZ concrete pump has one main pumping piston which
is valved by means of two ball checks. (A inlet, and B outlet.)
The secondary piston is used as a compensator piston to smooth
out the pulsations of a single piston action. Note: The compensator
will not start operating until material is pumped into the line and
back pressure develops.
The
compensator spring , which is installed on the compensator
piston rod, deflects with each piston stroke. This “
spring cushion ”,
in conjunction with the cam profile, produces and uninterrupted
smooth flow of material under average pumping conditions.
The pumping cylinder (Figure 10) retracts drawing the material
past the ball (A) and filling the cylinder. The compensator piston
is pumping the material out to the nozzle and causing ball (B) to
seat preventing the material from returning to the pumping cylinder
intake.
An automatic, centrifugal clutch is installed to engage and
disengage the pumping action without stopping or starting the
engine. The
centrifugal clutch is set at 1100 R.P.M. The engine
idle speed is approximately 875 R.P.M.; therefore, the clutch is
completely disengaged at idle. The throttle settings while pumping
should always maintain an engine R.P.M. high enough to prevent
the clutch from slipping and burning the clutch lining.
The return spring which is installed on the rocker arm, is installed
to eliminate shock and stress between the cam roller and the
cam weldment when the pump is in operation. If the return spring
is removed or replaced for any reason, maintain the backing
plate dimension of 3” as shown on Figure 3, to produce the
proper pre-loading of the spring for a smooth performance.
Figure 10. Pumping Cylinder