Fixed-ring reduction screen

Planetary gear ratio

Inputs

Sun gear teethNsteethDeclared sun tooth count for a fixed-ring, sun-input, carrier-output configuration.

Ring gear teethNrteethDeclared internal ring tooth count for the same standard planetary configuration.

Declared planet countP—User-entered number of evenly spaced planets used only for the spacing-integer check.

Sun input speedninDeclared sun input speed for the fixed-ring ratio screen.

Sun input torqueTinDeclared sun input torque before user-entered efficiency.

Declared planetary efficiencyη%User-entered transmission efficiency; this workspace does not select or validate a design efficiency.

Fixed-ring reduction ratio

Nominal planet teeth

teeth

Planet-spacing tooth quotient

—

Ideal carrier output speed

300

Declared-efficiency carrier torque

i = 1 + Nr/Ns; Np = (Nr − Ns)/2; ncarrier = nsun/i; Tcarrier = Tsun iη

A first-pass number, not a code check, certification, or approval. Read the method and its limits below. What this is and is not.

Calculation snapshot

Formula version 1.0.0

Sun gear teeth	24
Ring gear teeth	96
Declared planet count	3
Sun input speed	1500
Sun input torque	10
Declared planetary efficiency	92

Fixed-ring reduction ratio	5 :1
Nominal planet teeth	36 teeth
Planet-spacing tooth quotient	24 —
Ideal carrier output speed	300 rpm
Declared-efficiency carrier torque	46 N·m

i = 1 + Nr/Ns · Np = (Nr − Ns)/2 · ncarrier = nsun/i · Tcarrier = Tsun iη

SDP/SI planetary gear design guide: https://sdp-si.com/planetary-gear-design/index.php

This printout is a record of displayed inputs and deterministic formula output. It is not an approval, certification, or engineering conclusion.

Method

Calculate the fixed-ring, sun-input/carrier-output planetary ratio, nominal planet teeth, speed, and declared-efficiency torque.

i = 1 + Nr/Ns; Np = (Nr − Ns)/2; ncarrier = nsun/i; Tcarrier = Tsun iη

When

Don’t

This is a fixed-ring, sun-input, carrier-output tooth and ratio screen. It does not verify complete planetary assembly, module/pressure angle compatibility, interference, load sharing, tooth stress, bearing loads, efficiency, heat, backlash, lubrication, durability, service duty, safety, or product selection.