# Peritrochoid Formulae - how to implement these formulae in Solidworks so they are smart models?

Question asked by Sher Shishe on Jun 25, 2020
Latest reply on Aug 11, 2020 by Sher Shishe
Branched to a new discussion

Peritrochoid Formulae How to implement these formulae in Solidworks so they are smart models?

1. Rotor Housing

Inner Surface

X = e cos α + R cos (α/3) + a cos ((α/3)+φ)

Y = e sin α + R sin (α/3) + a sin ((α/3)+φ)

e = 19

R = 130

a = 3

φ = 26.2

2. Rotor

X = R cos 2v + (3/2)(e^2/R)(cos 8v - cos 4v)

+/- e(cos 5v + cos v)(1-(9e^2/R^2)sin^2 3v)^(1/2)

+/- (3/2)(ea’/R)(cos 5v - cos v)

+ a’ cos 2v (1-(9e^2/R^2)sin^2 3v)^(1/2)

Y = R sin 2v + (3/2)(e^2/R)(sin 8v + sin 4v)

+/- e(sin 5v + sin v)(1-(9e^2/R^2)sin^2 3v)^(1/2)

+/- (3/2)(ea’/R)(sin 5v + sin v)

+ a’ sin 2v (1-(9e^2/R^2)sin^2 3v)^(1/2)

These functions are cyclic functions with the period of 2π.

The inner envelope corresponds to:

v = (1/6)π ~ (1/2)π, (5/6)π ~ (7/6)π, (3/2)π ~ (11/6)π

Generally a’ can be determined as follows:

a’ = a - Sp

where

a: amount of parallel transfer of trochoid

Sp: minimum clearance between rotor and rotor housing