A simple trapezoidal motion was assumed
for the performance analysis, 1/3
acceleration, 1/3 constant velocity and
1/3 deceleration.
Dial Table
Diameter, in
|
B10 Torque
Capacity of the
Indexer @ 50
index's/min
|
50% Reduction in
B10 Torque Capacity
|
24
|
5000
|
2500
|
36
|
10000
|
5000
|
72
|
20000
|
10000
|
To ensure no operational problems arise from the indexer, it is normal
custom and practice to reduce the B10 Torque Capacity to 50% of the
indexer's manufacturers value.
To account for reduction in B10 Torque capacity at higher index rate
performance levels and not violate proprietary indexer manufacturers
B10 life estimations a simple linear relationship was assumed by ACI.
ACI has provided an Indexer performance comparison between
Aluminum and Carbon Dial Tables. The following diameters, 24", 36" and
72" were compared. The Aluminum dial table was 1" thick and the
Carbon Dial Table was 1.152" (CFCD-001-1000A-R02)
Indexer performance was determined from 50 to 300 index's/min.
Indexer performance was based on the B10 Torque Capacity allowable.
While each individual Indexer manufacturer has there own Torque
Capacity requirements, ACI provides a generic B10 Torque Capacity
covering a range from 5,000 in.lb to 20,000 in.lb. This B10 torque
capacity was at indexer performance of 50 index's/min.
ACI linear B10 Torque Capacity
requirements for index rates
higher than 50 index's/min.
A common index was selected that had
a 270 degree indexing period and a 90
degree dwell period
The indexer performance was estimated for a 24", 36" and 72" diameter 1"
thick aluminum dial table and compared with the performance of a
CFCD-001-1000A-R02 (1.152") carbon fiber disc.
The maximum number
of index's-parts per
minute possible from a
36" diameter Aluminum
Dial table was about
175. The maximum
number of index's-parts
possible from a 36"
diameter Carbon Dial
Table was 275.
A six station indexer was used to determine
performance with a tooling inertia of 8
lb.in.s^2. (3,088 lb.in^2)
The maximum number
of index's-parts per
minute possible from a
24" diameter Aluminum
Dial table was about
200. The maximum
number of index's-parts
possible from a 24"
diameter Carbon Dial
Table was 258.
The maximum number
of index's-parts per
minute possible from a
72" diameter Aluminum
Dial table was about
145. The maximum
number of index's-parts
possible from a 72"
diameter Carbon Dial
Table was 260.
ACI define Indexer Performance has the number of
table index's per minute with respect to the life
(B10 torque capacity on the indexer).
A single rotation of the Camshaft
completes a index and dwell.
The tooling inertia relates to total tooling
loads of 33lb (24" Diameter), 15 lb (36"
Diameter) and 4lb (72" Diameter)
Using the B10 Torque Capacity as a Indexer Performance allowable, the
Indexer's performance ceiling can be obtained with respect to the
number of index's per minute.
The B10 Torque Capacity is a
indication of indexer life in hours.
The number of hours is
proprietary to the indexer
manufacturer.
