Proving a 2D slider crank mechanism fits the Gruebler's Equation

[bortonj88]

Homework Statement

Need to prove that a slider crank mechanism fits the Grueblers eqaution, already done for a four bar mechanism no problem, however having some serious problems with the slider crank. If l is the number of links and j is the number of joints

Homework Equations

Grueblers equation is
3l-2j-4=0

The Attempt at a Solution

Looking at a slider crank mechanism, i deduced that l=4 and j=3, however it does not fit the grueblers equation

 

[TaiwanCountry]

Slide crank is also a kind of four bar.(You need 4 vector to describe that,if it has offset.)

The block count one. i=4 , j=4 .