Wichita Clutch SV - Standard Ventilated Clutch - Manual (Page 4)

E
Standard Vent Clutches
P-1100-WC 1/12 Wichita Clutch 800-964-3262 125
Calculations
Engine torque =
(HP) (63,000)
=
(325) (63,000)
RPM 1800
Engine torque = 11,375 lb.in.
Clutch torque required while slipping:
Clutch torque =
(WR 2 ) (RPM) (π) lb.in.
(g) (t
s
) (2.5)
W = Weight to be accelerated lb.
R = Radius of gyration ft.
2
g = Acceleration of gravity ft./sec. 2
t
s
= Time of slip, in seconds
T
c
= Clutch torque = 11,707 lb.in.
Clutch heat HP is 1/2 of the total
area in the diagram.
Clutch heat HP =
(T c ) (input RPM)
(1/2)
63,000
Clutch heat HP =
(11,375) (1,800)
(1/2)
63,000
= 162.5 HP
From Clutch Heat Horsepower (Chart B)
for a 6 second start:
HP / in. 2 = .4
Area required =
162.5
= 406 in. 2
.4
To properly select a clutch for this rock
crusher application, the following
information is required:
1. Application horsepower
2. Re quired air pressure
3. Required torque
4. Clutch heat horsepower
5. Shaft diameter
The Specification Table on pages 126-127 gives
ap pli ca tion factors ranging from light duty (the A
group) to extra heavy duty (the D group). This
chart will give the initial se lec tion which is then
compared with the selection made using the
Clutch Heat Horsepower Chart and the Clutch
Area Chart.
How to select
1. The area required is 406 inches. Consult the
column head “Lining Area” in Spec i fi ca tion
Table (pages 126-127). Applicable clutch es
chosen are:
ATD-218, 528 in.
2 ; ATD-124H, 574 in. 2 ;
ATD-314H, 504 in. 2
2. Determine the application
horsepower necessary:
HP/100 RPM =
325
(100) HP
1,800
HP/100 = 18 HP/100 RPM
Clutches selected with this application
horsepower are as follows:
ATD-214H 18 HP/100 RPM, ATD-314H
27 HP/100 RPM, ATD-118 21 HP/100 RPM.
The ATD-314 is selected as having both
sufficient area and torque with min i mum
diameter.
Contact velocity =
(clutch size) (π) (1,800)
12
= 6,597 ft./min.
Ductile material required.
Note: This application example is for
pre lim i nary sizing only. Contact a Wichita Sales
Engineer or the factory for final selection.
Use engine torque for calculations.
When selecting the proper clutch, heat must
be considered. When a clutch is slipped under
load, heat is gen er at ed within the clutch. This
heat as shown to the left is equal to the energy
of the mass that was ac cel er at ed to speed by
the clutch.
In applications where thermal re quire ments are
of concern, consult factory for special
ventilated and super ventilated clutch options.
T
or
que
Input
RPM
Clutch torque
energy
rotating
mass
clutch
heat horsepower
RPM
Coupling and Grinding Mill Clutches