Epicyclic Gear Ratios



Epicylic Gears - Ratio Calculation.
Purpose of Calculation - To calculate the ratios of various epicylic gear arrangements.

Calculation Reference - Roymech.co.uk.

Calculation Validation - On my webpage as identified above I have illustrated three methods of obtaining the required ratios. I have also checked the ratios against Machinery's Handbook 27th edition page 2115.

Introduction - An epicylic gear is a planetary gear arrangement consisting of one or more planet (epicyclic) gears (P) meshed and rotating round a central sun gear (S).   The planet gears are also meshed and rotate within an internal ring gear (A).   The planet gears are fixed to a planet carrier-crank arm ( L ) designed to rotate on the same centre as the sun gear.  Only one planet-carrier /crank arm is used in a single epicyclic gear train.   This complicated arrangement (see below) has a number of modes of operation depending on which members are locked.  Epicyclic gears can be based on spur gears, helical gears, or bevel gears.

Calculation Reference
Machinery's Handbook
Machine Design

Calculation Preview

Submitted On:
28 Mar 2022
File Size:
176.00 Kb
File Version:
File Author:
Roy Beardmore

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Comments: 2
Mtyo 2 years ago
Mtyo 2 years ago