Air tube disc clutches and brakes, High torque clutches – Wichita Clutch Low Inertia (LI) High Torque Clutch User Manual
Page 3

Air Tube Disc Clutches and Brakes
46
Wichita Clutch 800-964-3262
P-1100-WC 1/12
Estimated time to start
=
Start Angle
60
360° Crankshaft RPM
=
90˚ 60 = 0.5 sec.
360˚ 30
P
1
= Line pressure to clutch
P
2
= Required pressure to clutch
LN = Natural log
k = Inflation coefficient
(ATD-224 H.T. @ 100 PSI)
= 2,600
u = For ATD-224 H.T. Clutch @ 100 PSI
= 2.5
Time to 26% of line pressure.
= 0.027 seconds
Clutch will be fully inflated at 90˚ of crank shaft
rotation.
Clutch exhaust time @ 100 PSI = E = .078
(page 52).
Note:
This application example is for preliminary
sizing only. Contact a Wichita Sales Engineer
or the factory for final selection.
High Torque Clutches
Clutch Selection
Per the application factors on page 23 a “Back
Geared Press is ‘Group C’.”
HP Torque 124,081
100 RPM
=
630
=
630
= 197
The preliminary clutch selection based on
124,081 lb.in. and 197 HP/100 RPM is an
ATD-224 Low Inertia High Torque Clutch.
(page 48)
A Low Inertia High Torque Clutch was chosen
because of the continuous duty (non-cyclic)
operation having a rel a tive ly low heat HP
requirement.
ATD-224 Low Inertia High Torque Clutch =
280 HP/100 RPM
Rated Torque = 480,000 lb.in @ 100 PSI
Required clutch air pressure is:
PSI =
Clutch required torque x (100 PSI)
Catalog rated torque @ 100 PSI
Actual required clutch PSI
PSI =
124,081
x (100 PSI)
480,000
= 26 PSI minimum is required.
This application has 100 PSI available.
Contact velocity of rotating disc is:
V
c
=
(Diameter of Center Plate) (π) (RPM)
12 in.ft.
=
24 ft.
12
(π) (204) = 1,282
min.
(Ductile iron is not required, see page 23).
Maximum bore for ATD-224 High Torque Low
Inertia Clutch = 7 in.
Check clutch inflation time for 90˚ start angle (see
page 52, PSI pressure curves)
t =
t =
LN
2,600
LN
k
P
1
P
1
- P
2
1
u
[ ]
[ ]
[ ]
100
100 - 26
1
2.5