SERIES AJ
9
SELECTION PROCEDURE
fOR REDUCER UNITS
NOTE: If any of the following conditions occur then consult application engineering:-
a) Inertia of the Driven Machine (Referred to motor speed) >1.0
Inertia of Gear Unit plus Motor
b) Ambient temperature is above 120
o
F or
c) The unit is required without a fan
7
DETERMINE THERMAL SERVICE FACTOR (Ft)
Refer to table 2, page 3
Ambient temperature = 68
o
F
Ft = 1.0
-20
0
20
40
60
68
Ambient
temperature
o
F
Factor Ft
1.64 1.50 1.36 1.22 1.07 1.0
10
DETERMINE REQUIRED POWER OF ELECTRIC MOTOR
Refer to ratings tables to determine gear unit efficiency
NOMINAL
RATIO
NOMINAL
OUTPUT SPEED
REV/MIN
CAPACITy
SIZE OF UNIT
A0510
A0610
A0730
A0860
70.0
25.00
Input Power HP (mechanical)
Input Power HP (thermal)
Output Power HP (mechanical)
Output Torque lb-in (mech.)
Efficiency %
0.39
0.81
0.20
497
50
0.64
1.08
0.34
848
53
0.94
2.24
0.57
1430
60
1.47
2.69
0.92
2320
63
Efficiency % = 60 Required motor power = Absorbed power of driven machine x 100 =
.375 x 100
= .625 HP
Efficiency
60
The next largest standard motor power available is selected 0.75 HP
9
DETERMINE THERMAL SERVICE FACTOR (Fd)
Refer to table 4, page 3
% running time = 100
Fd = 1.0
Input
shaft
speed
(Rev / min)
1750
280 - 610
730
Unit
Size
1.0
1.0
>60
1.46
1.26
>50 - 60
% Running time per hour
11
DETERMINE ALLOWABLE OUTPUT POWER THERMAL RATING (Ptherm)
Ptherm
=
Pt x Ft x Fp x Fd x efficiency
100
=
2.24 x 1.0 x 1.0 x 1.0 x 60
100
=
1.344 HP
Thermal output power capacity (Ptherm) must be equal or more than absorbed output power to drive machine
Absorbed output power = 0.375 HP Ptherm = 1.344 HP
Therefore unit is acceptable
12
CHECK OVERHUNG LOADS
If sprocket, gear, etc is mounted on the input or output shaft
then refer to Overhung loads procedure, pages 35 and 36
8
DETERMINE THERMAL SERVICE FACTOR (Fp)
Refer to table 3, page 3
Mounting position = D
Nominal output speed (rev/min) = 25
Fp = 1.0
Unit Output Shaft
Speed (Rev / min)
0 to 100
> 100 to 200
> 200 to 300
1.0
1.0
1.0
ABC
1.0
1.0
1.0
DEF
Mounting
