sun-and-planet gear

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July 14, 2026

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The sun-and-planet gear system is a type of epicyclic gear train. It consists of two wheels. One wheel is positioned on a central axis, and the other wheel rotates around it. The wheel on the central axis is typically driven by the other wheel. The "sun gear" is the name given to the gear wheel that is located on the central axis. This mechanism is used to create a specific type of motion where one gear orbits another.12

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William Murdock
…credited with devising the so-called Sun-and-planet motion, a means of making a steam engine give continuous revolving motion to a shaft provided with a flywheel. Watt, however, patented this motion in 1781. Murdock also experimented with compressed air and in 1803 constructed a steam gun. He retired from business in…
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…credited with devising the so-called Sun-and-planet motion, a means of making a steam engine give continuous revolving motion to a shaft provided with a flywheel. Watt, however, patented this motion in 1781. Murdock also experimented with compressed air and in 1803 constructed a steam gun. He retired from business in…
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James Watt
The Watt engine
…in 1781 with his so-called sun-and-planet gear, by means of which a shaft produced two revolutions for each cycle of the engine. In 1782, at the height of his inventive powers, he patented the double-acting engine, in which the piston pushed as well as pulled. The engine required a new…
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…in 1781 with his so-called sun-and-planet gear, by means of which a shaft produced two revolutions for each cycle of the engine. In 1782, at the height of his inventive powers, he patented the double-acting engine, in which the piston pushed as well as pulled. The engine required a new…
Read More