Refrigerant recovery machine with improved cam wheel assembly

A refrigerant recovery machine comprising a shell and a cam wheel assembly mounted in a rear side of said shell, wherein said cam wheel assembly comprises:

• an open frame member comprising two symmetrical frame parts, each said frame part comprising a base and two arms respectively extending in a parallel manner from two distal ends of said base, and at least a fastening member affixing each respective arm of one said frame part to the corresponding arm of the other said frame part;
• at least a wear strip fixedly mounted to the base of each frame part, each wear strip having a higher rigidity than said open frame member;
• a sliding block movable up and down in said open frame member, said sliding block comprising a center through hole and an axle bearing mounted in said center through hole, a plurality of friction cylinders arranged on opposing sides of said sliding block and disposed in corresponding contact with said wear strips;
• and
• a cam wheel set inserted through said axle bearing of said sliding block, said cam wheel set comprising a first cam wheel and a second cam wheel, said first cam wheel comprising a coupling rod eccentrically extended from one side thereof and inserted into said axle bearing of said sliding block, said second cam wheel comprising a coupling tube eccentrically extended from one side thereof and coupled to said coupling rod of said first cam wheel in said axle bearing of said sliding block.