WORM AND NUT TYPE

in this type

 worm and steering shaft     

      being separated part 

this with the help of coupling Stays connected                        

        Of worm above side  Made of bronze nut remain fit 

and nut  inside  as like u Of size made teeth  

when the worm is rotated  At that time With worm Nut also moving up and down 

and the nut is being  fit with Cross shaft                                                                       when it happens above  and down nut  at the time Cross shaft also moving and steering linkages It happens working