Nortrac BE-SBS72G Operator's Manual - page 4
INSTALLATION INSTRUCTIONS FOR SNOWBLOWER-cont’d
P.T.O. SHAFT ANGLES
Previous examples clearly demonstrate that universal joint angle is directly related with life of P.T.O.In order to
reduce angle, it is necessary to increase the distance between snowblower and tractor
H.P.
P.T.O. angles
Estimated
life
in
hours
60@540
RPM
Using
#50
PTO
5°
°
10°
°
15°
°
20°
°
25°
°
450
hours
195
hours
90
hours
40
hours
20
hours
HOW TO DETERMINE P.T.O. ANGLE
A=P.T.O height at tractor
B=P.T.O height at blower
L=Cross center distance
in working position
C=A-B
A
A
L
L
B
B
C
1) Lower blower on ground.
2) Take measures A,B and L
3) Subtract B of A (A-B
=
C)
4) Divide L by C (L/C
=
F)
5) Compare F Factor in table to
find P.T.O.angle(interpolate,
if necessary).
F
FACTOR
ANGLE
20°
°
10°
°
15°
°
25°
°
30°
°
6
2.75
3.75
2.15
1.75
P.T.O. Shafts are made to transmit power with angles
at universal joints. However, these angles should be kept
to a minimum. Larger the angle, shorter the life of P.T.O.
Take for example a snowblower sold for a tractor capacity
of 60-70 H.P., Which would be attached to a 60 H.P.
Tractor, operating at maximum capacity (60 H.P.
Continuous).
Too Large Angles at P.T.O. Joints
AVOID
ACCEPTABLE
Reasonable Angles at P.T.O. Joints
Transmission
size
H.P.
540 R.P.M.
Joint
Angle
Life expectency
(in hours)
10
20
30
40
50
60
70
80
90
10
20
30
40
50
60
70
80
90
100
110
120
540
35°
35°
15°
15°
30°
30°
25°
25°
20°
20°
10°
10°
5°
5°
10
20
30
40
50
60
80
100
150
200
250
400
500
700
1000
1500
2000
2500
3000
3500
4000
5000
300
EX:Transmissionn size 60 for 60 H.P. @ 540 R.P.M. with joint angle of 10”
will have an expected life of 670 hours.
This table is valid only for 540 R
.
P
.
M
.
3