What Is a Ring Gear?
A ring gear, as the name suggests, is an annular-shaped gear with teeth either inside or outside the ring. Commonly used as the outer gear in planetary gear systems, a ring gear with internal teeth is also known as an internal gear.
A critical aspect of ring gears is their circular precision and tooth design. The shape and chamfering of the teeth significantly impact the gear’s smooth operation, meshing smoothness, and noise reduction.
Uses of Ring Gears
Ring gears are integral to systems requiring high reduction ratios, like drive plates in automatic transmissions and flywheel clutches in manual transmissions. Segment gears, created by cutting a portion of ring gears, are used in mechanical watches and clocks to transmit reciprocating motion.
Principle of Ring Gears
The functionality of ring gears is best understood within the context of planetary gears, where they are most commonly used. Planetary gear systems consist of sun gears, planetary gears, and ring gears, resembling planets orbiting the sun. These gears are held by a planetary gear carrier.
Planetary gears offer versatile combinations of input and output arrangements between the sun, planetary (carrier), and ring gears, allowing for different gear ratios and rotational directions. The configuration of these gears determines the gear system’s operation: fixing two gears results in a direct input-output connection while leaving one gear free with the other as input produces no output.