Planetary Gearbox: Here Comes the Sun
The precise rotation of the planets around our sun is the perfect metaphor for how planetary gearboxes are able to make automatic transmissions function so well. A step up from the basic transmission, which is also known as a gear reducer or gear boxes, a planetary gearbox functions on the rotational concept evident in how planets rotate around the sun. It is a well oiled system that enables an automatic transmission to adjust speed and a plethora of other factors without direct commands, a system that would not exist without the example in the sky that led to the creation of the planetary gearbox.
Not only is the overall name for this speed reducer a nod to the heavens but the individual gears and how they are oriented also refer to planetary arrangements. There is always a center gear, known as the sun gear, around which all the other gears, known as planet gears, revolve. Because of the use of multiple gears and the way they are arranged around the central sun gear, a planetary gearbox is able to reduce or increase torque to a greater extent then a basic gear reducer and is even more impressive with its range when two or more planetary gearboxes are combined. This is the case with automatic transmissions.
The size and number of the teeth attached to each gear, whether they are planet gears or the sun gear, also make a difference. Because they must put up with a lot of physical strain these gears must be strong and steady like planets in the atmosphere. That is why they are often made of heavy duty steel alloys. Such a material also ensures that they will not be affected by environmental or chemical corrosion and therefore increase the operating longevity of not just themselves but the machine they are working within.