Manual 26727
VariStroke-I (VS-I) Electro-hydraulic Actuator
Woodward
21
Chapter 2.
Specifications
Physical and Performance Specifications
Table 2-1. Bore and Rod Diameter by Valve Size
Bore Diameter (OD)
Rod Diameter (ID)
4 inches (101.6 mm)
1.75 inches (44.5 mm)
5 inches (127.0 mm)
1.75 inches (44.5 mm)
6 inches (152.4 mm)
2.5 inches (63.5 mm)
8 inches (203.2 mm)
3.5 inches (88.9 mm)
10 inches (254.0 mm)
4.5 inches (114.3 mm)
Table 2-2. Available Springs for Spring Assist Cylinders
Average spring force ± 10% [lbf]
(Reference Spring Rate [lbf/in])
Spring
VS Bore
[in]
VS Stroke
[in]
S
T
U
V
4
4
84
170
351
-
(14)
(28)
(63.5)
-
6
3
162
353
780
-
(36)
(78.7)
(173.3)
-
4
162
353
780
-
(27)
(59)
(130)
-
8
3
393
793
1578
2996
(87.3)
(176.3) (350.7)
(700)
4
393
793
1578
3035
(75.5)
(132.3)
(263)
(505.8)
6
393
793
1554
3035
(43.7)
(88.2)
(183.3) (337.2)
10
4
531
964
1968
4116
(88.5)
(160.8) (327.8)
(686)
6
531
954
1968
4116
(59.0)
(107.3) (218.5) (457.3)
Note
: Average spring force was calculated for cylinder @ 50% of mechanical stroke.
Stall Force (extending):
Extend Stall force can be obtained from following equation:
Extend Stall =
π
OD
²
4
p (p -
supply pressure
)
[in
²
psi = lbf] or [mm
²
MPa = N]
Stall Force (retracting):
Retract Stall force can be obtained from following equation:
Retract Stall =
π
(OD
²
– ID
²
)
4
p (p -
supply pressure
)
[in
²
psi = lbf] or [mm
²
MPa = N]
Released
