Schwing SP 500 - Page 129

129
Appendix
SP 500 / 750-15 / 750-18 / 1000 / 1250 Operation Manual
Example 1—Checking ow at a given pressure
Your unit is congured on the rod side (standard from
the factory). You notice that your machine is not getting
as many strokes per minute as you are used to seeing.
You count the strokes and see that you are getting
about 21-1/2 per minute. You check your pressure
gauge and see that the hydraulic oil pressure is at 220
bar. To determine whether your unit is acting normally:
Locate the 220 bar oil pressure marking on the rod side
scale (Item A in the example below). Draw a line straight
across the page until you intersect with the horsepower
curve (Item B). Next, draw a straight line down from the
intersection point until you pass through the rod side
number of strokes scale, and read the strokes per min-
ute. At 220 bar you should be getting a little more than
21 strokes per minute. Your unit is ne.
13
CONCRETE OUTPUT (cu yd / h)
NUMBER OF STROKES
(stroke / min.)
OIL VOLUME
(liter / min.)
NUMBER OF STROKES
(stroke / min.)
OIL VOLUME
(liter / min.)
26 39 52 65 78 92 105 118 131 1440
103
157 170 183
ROD SIDE
HYDRAULIC RELIEF VALVE IS SET AT
300 BAR MAX. PRESSURE (4350 PSI).
PUMP SPEED
2100 RPM
PERFORMANCE CHARACTERISTICS OF
THE AXIAL PISTON HYDRAULIC PUMP
PISTON SIDE
PISTON
SIDE
ROD
SIDE
100 200 300 400
350
100 200 300 40050 150 250
500
5 10 15 20 25
5 10 15 20 25 30
15.5
PISTON SIDE
(bar)
ROD SIDE
(bar)
CONCRETE
PRESSURE
(BAR)
7
14
21
28
34
41
48
55
62
70
76
83
90
97
103
110
117
124
131
138
CONCRETE
PRESSURE
(PSI)
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
1500
1600
1700
1800
1900
2000
1285 88.6
52758
350
50
100
150
200
250
300
50
100
150
200
250
300
350
OIL PRESSURE (BAR)
30
196
170.5
26
EXAMPLE 1
C. Where the line leaves the
graph tells you how many
yards/hour you can expect
(in this case, about 138).
Where the line crosses the
number of strokes scale tells
you how many strokes per
minute you can expect (in
this case, a little over 21).
B. Draw a line STRAIGHT
across the page until you
contact the horsepower
curve of the rodside. Then
draw a line straight down
from the intersection point.
A. Find 220 bar
on the rod side oil
pressure scale.
breakpoint
178 bar
output chart use.eps