Hello Aditya,

In SpaceClaim, on the Design tab is the Equation button.  Here you can make a Helicoid shaped surface.

Then use the Pull tool to add thickness to the surface.

The shape of this part is circular. If you are good at math, you can modify the equation and type in the formula for an ellipse, but I will make a sketch, draw an inner and outer ellipse and extrude those to cut this solid.

This shows how to make the shape you first asked about which has edges that are spirals.  The last image you show has a ramp feature and can be constructed without starting with a helicoid.