226 Index
Continuous rotation hydraulic motors
(Continued)
gear motors, 72-3
piston motors, 75-6
radial piston motors, 76
vane motors, 73-4
Control valves, 94-123
direction control, 94-105
flow control, 94, 114-23
pressure control, 95, 106-7
Counterbalance valve, 106, 113-14
Darcy'
s
equation, 31
Density, 5-6
relative see Specific gravity
Diaphragm pressure switch, 127
Direction control valves, 94-105
direct acting and pilot-operated, 95-7
normally open and normally closed, 95
open and closed center hydraulic circuits, 97-100
shuttle valves, 104-5
spool-type, 101-4
Discharge, 27-9
Displacement volume, 38
Double-acting hydraulic cylinders, 85-8
Drive shaft, 41
Duplex-type filters, 141-2
Eccentricity, 51
Edge-type filters, 142
Electro-hydraulic servo valves, 125-6
Electro-hydraulic stepping motors, 82
Elevation (potential) head, 31
Energy, 9
Energy head, 31
Eulerian method, 25
Excessive heat, 198, 201
Excessive noise, 198, 200
Expansion joints, 162
External gear pump, 41-5
internal leakage of oil, 44-5
theoretical flow rate, 44
volumetric displacement, 43
principle of working, 143-5
tell-tale, 142-3
Fire-resistant fluids, 171-2
Fixed flow valves, 115
Flexible hoses, 165-6
see also Pipes and hoses
Flow, 24-33
incorrect, 198, 202-3
laminar, 26, 32
mass,
25
meaning of, 25
non-rotational, 27
non-uniform, 26
rate,
27-9
rotational, 27
steady, 26
turbulent, 27, 32
uniform, 26
unsteady, 26
velocity, 25
volumetric, 25
Flow control valves, 94, 114-23
adjustable flow, 115
ball valve, 117-18
butterfly valve, 116-17
fixed flow, 115
globe valve, 116
meter-in/meter-out functions, 120-3
pressure-compensated, 116, 118-20
throttling valve, 115, 118
valve characteristics, 122-3
Flow measurement, 33-6
orifice plate-type flowmeter, 35-6
rotameter, 33-4
turbine-type flowmeter, 34-5
Flowmeters, 130
Fluids, 4-5, 36
pressure in, 17
Foam-resistant fluids, 172-3
Force, 7
Forced balanced pressure transducer, 21
Foreign particles in hydraulic pumps, 65
Filters, 136-45
absorbent, 141
beta ratio, 138
duplex-type, 141-2
edge-type, 142
filter location, 140
fluid cleanliness level, 138-40
mechanical, 140
micron, 137
number particles/ml, 139-40
Gage pressure, 18
Gas-loaded accumulators, 148
Gases, 5
Gaskets, 68
Gear motors, 72-3
Gear pumps, 40-7
external, 41-5
gerotor pump, 46
inspection of
gears,
67
internal, 45-6