GWSP oil free scroll vacuum pump is constructed with pump head assembly, crank pin assembly, bracket assembly, air flush assembly, and exhaust valve assembly. Two spiral cylinders, one offset and orbiting against the other fixed with an offset of 180° to form several crescent-shaped pockets of differing sizes. By means of an eccentric drive, the orbiting scroll is made to orbit about the fixed scroll, reducing the volume of the pockets and compressing gas from outside towards the inside thereby pumping the gas from vacuum chamber.