Helical Gearboxes RD - Varvel SpA

Helical Gearboxes RD
SERVICE FACTORS
SERVICE FACTOR of the gearbox
Service factor SF1.0 is meant as typical of 8 hours/day operation, with uniform load, starts/ stops lower than 60 per hour and ambient
temperature between 60 and 95 °F.
The ratio between gearbox maximum output torque M2 of each reduction ratio - listed in gearbox RD ratings, pages 10 to 16 - and
application torque M(app) states the service factor to be bigger than the Application factors listed below.
Application
Agitators (mixers)
Pure liquids
Liquids and solids
Liquids - variable density
Blowers
Centrifugal
Lobe
Vane
Brewing and distilling
Bottling machinery
Brew kettles - continuous duty
Cookers - continuous duty
Mash tubs - continuous duty
Scale hopper - frequent starts
Can filling machine
Car dumpers
Car pullers
Clarifiers
Classifiers
Clay working machinery
Brick press
Briquette machine
Pug mill
Compactors
Compressors
Centrifugal
Lobe
Reciprocating, multi-cylinder
Reciprocating, single-cylinder
Conveyors
- General purpose
Uniformly loaded or fed
- Heavy duty
Not uniformly fed
- Reciprocating or shaker
Crusher
Stone or ore
Dredges
Cable reels .
Conveyors
Cutter head drives
Pumps
Screen drives
Stackers
Winches
Load duration (hrs/day)
Load duration (hrs/day)
Application
< 3 3 - 10 > 10 < 3 3 - 10 > 10
1.00 1.00 1.25
Elevators
Bucket
1.00 1.25 1.50
1.00 1.00 1.50 Centrifugal discharge
1.00 1.00 1.25
1.00 1.25 1.50 Escalators
1.00 1.00 1.25
Freight
1.00 1.25 1.50
1.00 1.00 1.25 Gravity discharge
1.00 1.00 1.25
1.00 1.25 1.50 Extruders
1.00 1.25 1.50 General
Plastics
1.50 1.50 1.50
1.00
1.25
1.25
1.25
1.25
1.00
1.25
1.25
1.25
1.25
1.25
1.00
1.25
1.25
1.25
1.25
1.25
1.25
Variable speed drive
Fixed speed drive
Rubber
Continuous screw operation
Intermittent screw operation
Fans
Centrifugal
1.50
1.75
1.75
1.75
1.00
1.50
1.75
1.75
1.75
1.00
1.50
1.75
1.75
1.75
1.25
1.50 1.75 2.00 Cooling towers
2.00 2.00 2.00
1.00
1.00
1.25
1.00
1.50
1.25
Forced draft
Induced draft
Industrial and mine
1.25
1.50
1.50
1.25
1.50
1.50
1.25
1.50
1.50
1.00 1.25 1.50
Feeders
Apron
1.00 1.25 1.50
1.50 1.75 2.00 Belt
1.00 1.25 1.50
1.50 1.75 2.00 Disc
1.00 1.00 1.25
1.00 1.25 1.50 Reciprocating
1.50 1.75 2.00
2.00 2.00 2.00 Screw
Food industry
1.00 1.25 1.50
1.00
1.00
1.50
1.75
1.00
1.25
1.50
1.75
1.25
1.50
1.75
2.00
Cereal cooker
Dough mixer
Meat grinders
Slicers
1.00
1.25
1.25
1.25
1.00
1.25
1.25
1.25
1.25
1.50
1.50
1.50
Generators and exciters
1.00 1.00 1.25
Hammer mills
1.75 1.75 2.00
1.00 1.00 1.25
Hoists
1.00
1.50
1.25
1.75
1.50
2.00
Heavy duty
Medium duty
Skip hoist
1.25
1.25
1.25
1.75
1.25
1.25
2.00
1.50
1.50
1.75 1.75 2.00
Laundry
Tumblers
1.25 1.25 1.50
Washers
1.50 1.50 2.00
1.25
1.25
2.00
2.00
1.75
1.25
1.25
1.25
1.25
2.00
2.00
1.75
1.25
1.25
1.50
1.50
2.00
2.00
2.00
1.50
1.50
Lumber industry
Barkers
Spindle feed
Main drive
Conveyors
Burner
Main or heavy duty
1.25
1.75
1.25
1.50
1.25
1.75
1.25
1.50
1.50
1.75
1.50
1.50
Main log
1.75 1.75 2.00
Re-saw, merry-go-round 1.25 1.25 1.50
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