velocity ratio
N3
N4
5
22
22
22/22=1:1
24/24= 1:1
7
32
32
32/32=1:1
24/24= 1:1
9
40
40
40/40=1:1
24/24=1:1
Speed
Gear pair 1
Actual velocity
ratio
Theoretical
velocity ratio
N5
N6
5
24
12
24/12=2:1
32/16=2:1
7
44
34
34/16= 17/8
32/16=2:1
9
60
42
42/22= 21/11
32/16=2:1
Overall speed ratio:
¿
N
1
N
6
=
42.22
B.
Use the Morse PT-93 Catalog to select a Speed Reducer
Select a worm gear speed reducer for a bark conveyor at a paper mill. The speed reducer will be
driven by a 1750-RPM electric motor directly connected by a coupling. The conveyor will
operate six hours per day and the head shaft speed will be 47 RPM. Calculations indicate that 2000-inch pounds of torque are needed at the conveyor head shaft.1.What is the service factor for the given application?
2.What is the overall drive ratio?
3.If a belt drive is used for the secondary reduction, what should be the ratio of the worm gear reducer? Belt drive ratio is 1.24.
