© 2019, Gast Manufacturing
We reserve the right to make any alterations which may be due to any technical improvements
Printed in the USA
5
Estimated Ball Bearing Life of Air Motors
Air Model Model
Shaft Speed in RP
Ball Bearing Life Hours L
10
1AM
10,000
28,000
1UP
6,000
14,000
2AM
3,000
30,000
4AM
3,000
14,000
6AM
3,000
6,500
8AM
2,000
8,000
16AM
2,000
15,000
Based on running pressure of 60 PSI and coupling connection to motor load. The direction, magnitude and location of applied loads to the
motor shaft will change expected bearing life. Driving the motor with wet dirty compressed air can reduce expected bearing life. The above
are life estimates not warrantied minimum values.
SPUR AND WORM REDUCERS - OPERATING AND MAINTENANCE INSTRUCTIONS
General Information:
The product nameplate specifies all information required when
ordering parts or requests for information. The type of lubricant
required for unit is also specified on the nameplate.
Product Use Criteria
• All worm gear reducers require that the air motor be mounted
so that the inlet and exhaust ports are at a 90º angle to the
centerline of the reducer output shaft.
• Gear reducers are NOT self-locking. If a brake is required for
safety, as in the case of air pressure failure, etc., contact your
Gast Distributor/Representative.
• Some worm gear reducers may be shipped with a plug in the
top pipe plug. The plug must be removed and the breather plug
installed for proper operation.
Spur Gear Reducer Specifications
Model
GR11
GR20
GR25
Speed Range (Reducer Output
Shaft)
33.3 to 400 RPM
30 to 300 RPM
20 to 200 RPM
Gear Reduction
15:1
10:1
15:1
Maximum Allowable End Thrust
With Zero Overhung Load. (Re-
ducer Output Shaft)
100 lbs/45,4 kg
200 lbs/90,8 kg @300 RPM to
800 lbs/363,2 kg at 30 RPM
250 lbs/113,5 kg @200 RPM to
800 lbs/363,2 kg at 20 RPM
Maximum Allowable Overhung
Load With Zero End Thrust.
(Reducer Output Shaft)
100 lbs/45,4 kg @ 333 RPM to
200 lbs/90,8 kg at 33.3 RPM
200 lbs/90,8 kg @ 300 RPM to
600 lbs/272,4 kg at 30 RPM
200 lbs/90,8 kg @ 200 RPM to
600 lbs/272,4 kg at 20 RPM
Lubrication
Use a 300 ssu at 100°F/38°C turbine quality lubricant – Gast #AG292A, Gulf Harmony 53, Shell Tellus
33, Socony DTE heavy medium or Humble Nuto 53.
For horizontal operation,
remove both plugs and add oil to top hole until other hole overflows.
For vertical operation,
fill to overflow point of upper most hole.
• Check the oil level in spur gear reducers which have been
stored or not operated for a period of time.
• Gear motors require proper lubrication. Insufficient oil level
can cause loss of performance, damage or failure of the gear
reducer.
