TM 5-3895-374-24-1
GP255FH
4. Maintenance Belt Drive Bearings, Belts & Sheaves
THE FOLLOWING APPLIES TO BELT DRIVE MODELS ONLY:
Periodically check the alignment of the sheaves and shafts. The shafts must be parallel and the faces of the
sheaves must be In the same plane.
Always use matched belts on the drive assembly.
Never use belt dressing. Oil the machine carefully, avoid getting oil on the belts as this can cause swelling and
premature failure.
Periodically check the belt tension. For new belts, check the tension after every 8-hour period during the first 48
hours of running. When checking the tension, follow steps 10A thru 10H under INSTALLATION.
Ball bearings consume a very small amount of lubricant during operation. The length of time a bearing can run without re-
lubrication depends on the lubricant properties, the size of bearing, the speed and the operating conditions.
A.
Oil lubricated bearings are supplied with overflow cups. Keep oil in these cups at all times. After any prolonged
shut-down period, check the oil level before restarting the blower. Do not check the oil level in a bearing while
the machine is running since most of the oil will not be in the sump. When a bearing Is continually supplied with
new oil, cleaning is seldom required. It is usually sufficient to drain off the old lubricant, flush out the bearing and
refill with new lubricating oil.
B. Grease lubricated bearings require periodic additions of grease to function properly. The grease does not
suddenly lose its lubricating ability, rather it is reduced gradually. The following Is a guide to normal re-lubricating
periods’:
a
For shaft speeds of 3600 rpm or less, re-lubricate after every 1800-2000 hours of operation.
b.
For shaft speeds greater than 3600 rpm, re-lubricate after every 1000-1200 hours of operation.
The following are suggested lubricants for various shaft speeds
A.
Oil Lubricated Bearings
All Shaft Speeds - Oil lubricated bearings are supplied from the factory with SAE 10 lubricating oil which has a
viscosity of 200 SSU at 100°F. Normally, this Is the oil which should be kept In these bearings However, in
applications where the bearing temperature approaches 160-170°F, SAE 20 oil can be substituted.
B.
Grease Lubricated Bearings
Shaft Speeds of 3600 RPM - Use a good grade of ball bearing grease such as Alvania No 3 (Shell Oil Co ) or Its
equivalent. Generally, lubricant of animal or vegetable oil should not be used because of the danger of
deterioration or the forming of acid Only those greases having a soda soap base or a lithium soap base are
recommended.
Shaft Speeds Above 3600 RPM - For these applications, Hauck recommends the use of a non-channeling high
speed grease like Chevron SR I. Bearings for these applications are supplied by the factory with this type of
lubrication.
(page 3-548)
