Smith, Gambrell & Russell, LLP
Double screw rotor assembly
 A power-saving, low-noise double screw rotor assembly, which includes a casing and a pair of screw rotors, wherein the casing has an inside wall defining a compression chamber, an inlet port and an outlet port communicating with the compression chamber. The screw rotors are mounted in the compression chamber and meshed together, each having a spiral thread around the periphery. The thread defines an equidistant pitch. The addendum of the thread defines an outside diameter and is abutted against the inside wall of the casing, the dedendum defines a root diameter. A thread height is defined between the addendum of thread and the dedendum of thread, the thread height gradually reduces in direction from the inlet port toward the outlet port. The dedendum of thread and side walls of the thread of each screw rotor define with the inside wall of the casing at least one transfer chamber having a volume gradually reducing in direction from the inlet port toward the outlet port. 
Industrial Technology Research Institute
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F04C F04C F04C
inventional inventional inventional
Cheng-Chan Jiun-Hung Hong-Sheng Zhang-Hua Hann-Tsong Ming-Fong
Tsai Chen Fang Fong Wang Chen