EPICYCLIC GEARING
The
epicyclic gearing consists of:
- a sun gear,
- three or more planet gears,
- an internally toothed ring.
If the group of gears is free to rotate, the
planetary differential is obtained.
In this case, its function is to transfer the motion from a
crankshaft to two
shafts, so that they can
rotate at different speeds from each other, but with a constant torque ratio transmitted to them.
In the event that even only one of the components of the gearing is fixed, the
planetary reduction gear is obtained in three different configurations.
The function of this reducer is to alter the speed ratios between the input shaft and the output shaft and specifically this occurs thanks to the reduced speed rotation of the
satellite carrier with respect to the sun gear.
INTERNAL AND EXTERNAL TOOTH RING GEAR
The ring gears are mechanical parts that are normally used in planetary gearboxes and are obtained using
hardening and tempering steel such as 39NiCrMO3 and 42CrMo4 with
nitriding heat treatment.
They can also be constructed with
case hardening material such as 20MnCR5 and case hardening heat treatment.
It is often applied a
toothing process, which can take place both on the inside and on the outside of the piece.
SATELLITE GEAR
Satellite gears are generally used in planetary gearboxes.
They find their final use field in:
- industrial applications,
- agricultural machinery,
- earthmoving.
Their function is to transport the movement from the solar gears towards the ring gear by reducing the number of revolutions and increasing the transmission torque.
These objects are generally made from carburising material such as 20MnCr5, or with
quenched and tempered steel such as 39NiCrMo3.
The
finishes can be simply of toothing,
shaving or
grinding on the profile.
SUN GEAR
Sun gear is used:
- in tractors,
- in earth-moving machines,
- in reduction gears to supply a high torque to the driving wheels, or to the gearmotor.
It is a highly stressed
transmission system, generally it is built with
high-strength materials such as 17NiCrMo6 or 18CrNiMo7-6.
To improve its hardness, it is common tu use heat treatments such as
case hardening, while a toothing, shaving or grinding finish is applied to the tooth depending on the field of application and the specific stresses to which the
kinematic mechanism is subjected.
