Nordson_EFD_Rhino_SD2_XD2_Operating Manual - 第9页
Rhino SD2/XD2 Pumps 5 Part 1073520-12 E 2013 Nordson Corporation PLUNGER SOL VENT CHAMBER P ACKING GLAND BLEED V A L VE PISTON/UPPER CHECK LOWER CHECK FOLLOWER PLA TE SHOVEL UP DOWN STROKE STROKE OUTPUT POR T OUTPUT POR …
Rhino SD2/XD2 Pumps
4
E 2013 Nordson Corporation
Part 1073520-12
Theory of Operation
The following paragraphs provide theory of operation for
a typical pump air motor and hydraulic section.
Air Motor
See Figure 2. The air motor drives the hydraulic section.
A five-way two-position main air control valve controls
the direction of the air motor shaft movement.
When the air motor piston moves up and down, the
piston trip-bar trips the pilot valves. The pilot valves
send momentary signals to an intermediate valve. The
intermediate valve sends a positive continuous signal to
the main air motor control valve for each direction of
travel. The intermediate valve has manual overrides for
air motor directional changes for performing repairs and
assembling.
Hydraulic Section
See Figure 3. The hydraulic section has a shovel
attached to the end of the hydraulic plunger that projects
into the center of the follower plate. The shovel moves
up and down with the plunger, helping to force material
into the hydraulic section. The hydraulic section
pressurizes the material and forces it out of the pump.
When the plunger strokes downward, the piston/upper
check opens and the lower check closes. Material
between the upper and lower checks is forced upward
through the piston. The material above the upper check
pressurizes and flows out of the material output port.
NOTE: The stainless steel version is a single-acting
hydraulic section that only displaces material on the
downward stroke.
During the upward pump stroke, the plunger and shovel
are pulled upward and the piston/upper check closes.
The lower check opens and allows material to pass into
the lower pump chamber below the upper check. As the
plunger and piston move upward, material from the upper
pump chamber is forced out of the material outlet port.
The solvent chamber surrounds the plunger. The
chamber contains solvent chamber fluid that lubricates
the plunger and packing gland seals. This fluid keeps
material from hardening on the plunger and minimizes
wear on the packing gland seals. The bleed valve is
used to bleed air from the pump.
DOWN STROKE
PILOT VALVE
MAIN AIR MOTOR
CONTROL VALVE
AIR MOTOR
PISTON TRIP-BAR
UP STROKE
PILOT VALVE
UP
STROKE
INTERMEDIATE
VALVE
MANUAL
OVERRIDE
DOWN
STROKE
Figure 2 Air Motor
Rhino SD2/XD2 Pumps
5
Part 1073520-12
E 2013 Nordson Corporation
PLUNGER
SOLVENT CHAMBER
PACKING GLAND
BLEED VALVE
PISTON/UPPER CHECK
LOWER CHECK
FOLLOWER PLATE
SHOVEL
UP
DOWN
STROKE
STROKE
OUTPUT PORT
OUTPUT PORT
Figure 3 Standard and Temperature Conditioned Hydraulic Sections
Rhino SD2/XD2 Pumps
6
E 2013 Nordson Corporation
Part 1073520-12
PLUNGER
SOLVENT CHAMBER
PACKING GLAND
BLEED VALVE
LOWER CHECK
FOLLOWER PLATE
SHOVEL
UP
DOWN
STROKE
STROKE
OUTPUT PORT
MATERIAL DOES
NOT FLOW DURING
THE UPSTROKE.
OUTPUT PORT
MATERIAL FLOW
S
DURING THE
DOWN STROKE.
Figure 4 Stainless Steel Single-Acting Hydraulic Section