The planetary gearbox is a special type of the circulating gearbox
family and is normally used as a reduction gearbox, meaning it reduces
the revolutions per minute. In general, this type of gearbox consists
of the following main parts:
1. pinion gear, also called sunwheel or sun gear
2. hollow wheel with internal gearing, often used as casing
3. planet wheels, typically 3 per stage but special arrangements
possible
4. planet carrier, guiding the planet wheels and keeping them in
place
5. output shaft, also called planet shaft
Normally, a planetary gearbox has 3 planet wheels. According to
the technical requirements and stresses of the gearbox, the number
of planet wheels may be increased. If a planetary gearbox consists
of two or more planet carriers, so called stages, it is called a
two- or multi-staged gearbox. The more stages are used in this type
of gearbox, the higher is the possible reduction or transmission.
There are special types of planetary gearboxes that use the so called
Simpson-Set or Ravigneaux-Set of stages and planet gears.
Planetary gearboxes offer a wide range of possibilites
for input and output. The standard configuration is the input via
the pinion gear and the output via the planet shaft. In this case,
the hollow wheel ist fixed in its position. This configuration is
also the best example to explain the name “planetary”
gearbox, because the planet wheels are circling around the turning
pinion wheel the same way that the planets in our solar system are
turning around the sun. All in all, 6 different combinations of
input and output can be apllied.
Hollow wheel fixed
Pinion gear fixed
Planet shaft fixed
Input pinion wheel
Output planet shaft
Input hollow wheel
Output planet shaft
Input pinion wheel
Output hollow wheel
Input planet shaft
Output pinion wheel
Input planet shaft
Output hollow wheel
Input hollow wheel
Output pinion wheel
That way, several reduction and transmission ratios
may be generated with only one planetary gearbox. This makes them
the first choice for automatic transmissions used in the automotive
sector.
The planetary gearbox has the following
advantages compared to a common spur gearbox:
• load distribution on 3 planet wheels
• compact design, minimal installation space requirements
• transmission of high torques
• long lifetime
• coaxial input and output
Interested? We would be pleased to counsel you concerning your custom
made drive solution. Take charge and get in touch with GSC!
Vertrieb@gsc-schwoerer.de