Determine the degree of freedom for following planar linkage

Determine the degree of freedom for following planar linkage: Find the planar degree of freedom, If you add By link and remove BF and DH from figure shown in above.

Solution

[c]...........

As given in figure

No of links l = 20

No of joints j = 12 [ 11 pin and 1 slider

No of lower pair h = 0

So if n = no of degree of freedom

then as per Gruebler’s equation

n = 3 [l-1] -2*j -h

n = 3 [20-1] -2*12 - 0

= 57 - 24 = 33

[d] ...............................

If we remove link BF and DH then

No of links l = 15

No of joints j = 12 [ 11 pin and 1 slider

No of lower pair h = 0

So if n = no of degree of freedom

then as per Gruebler’s equation

n = 3 [l-1] -2*j -h

   = 3 [15-1] - 2* 12

= 42 - 24 = 18