3
WORKING OF PUMP
UPSTROKE
DOWNSTROKE
A
B
C
D
G
H
J
I
F
A
B
C
D
G
E
H
J
I
F
E
UPSTROKE -
When Grease Control Valve is opened, compressed air enters
at arrow A and passes through passage B to the underside of
the Piston C, driving the Piston C and Piston Rod D upwards.
The air above the Piston is evacuated through passage E, past
the Slider Valve F and out at arrow G.
The Piston approaches top dead centre and Piston Rod D
makes contact with the Slider Rod H. Now the Slider Rod H
starts moving up with the Piston Rod D.
DOWNSTROKE -
The incoming air is now led via passage E to the upper side
of Piston C, driving it and the Piston Rod D downwards. The
air under the Piston C is evacuated through passage B, past
the Slider Valve F and out at arrow G.
The Piston approaches bottom dead centre and Piston rod
D makes contact with the Slider Rod H. When Slider Rod H
passes its centre position, the Pusher Spring I and Pusher
Button J snap it over to its lower position.
The air motor repeats Upstroke & Downstroke in continuous cycle to produce a reciprocating motion, driven by compressed air. This
motion is transferred via a connecting rod to the piston in the Pumping Section. During every upstroke, non return valves (with spring
& ball check) get opened & the piston lifts the grease. During every downstroke, non return valves get closed & the piston discharges
grease from the outlet valve.
Closing the Grease Control Valve shuts off the air motor & pump stops dispensing grease.
