1–1
NEMA Size Gearhead Selection
How to choose the type of gearhead depends primarily on the application.
Some of the factors to be considered to make proper trade-offs between cost
and performance are shown below. The hybrid design of planetary and spur
gears are not offered by us but are available on the market, and are included
for comparison purposes.
Planetary
Low Cost
Planetary
Spur
Hybrid
Torque
Capacity
Load Sharing
Power to
Weight Ratio
Power to
Size Ratio
Torsional
Stiffness
Backlash
Cost
Available
Number of
Gear Ratios
High
Yes
High
High
High
Low
6-10 minutes
High
Low
Medium
Low
Yes
Medium
Medium
Medium
Medium
7-14 minutes
Meduim
Low
No
Low
Low
Low
High
30 min. max.
Low
High
Planetary
Section Only
Medium
Medium
Medium
Medium
Medium
GEARHEAD TYPE
DESIGN
FACTORS
Medium
Medium
limited by spur gear
pair strength
TRUE PLANETARY
SPUR GEAR
+
HYBRID
