I am designing a machine consisting of gears , four bar mechanisms and rollers but I need the reference of a software where I can draw or construct the instruments and components and execute the motion of all the components together for the machine to operate , kindly suggest me something .
OnShape is a full featured cloud / browser based 3D CAD software that is free to use if you don't mind your work being publicly accessible. It supports animation. The product quality is excellent. (I have no connection with the company.)
Here's a sample linkage animation from YouTube.