Patent ID: 9228594
Filing Date: 2016-01-05
CPC Classification: F01D,F04D,F05D

Claim Text:
1. An airflow passage structure for use with a fan, wherein said fan has a blade and a frame having an airflow inlet, said airflow passage structure comprising: a sidewall having an uneven thickness; and an airflow channel defined by an inner surface of said sidewall, and comprising a channel entrance and a channel exit, wherein said sidewall is in connection with said frame of said fan, a continuous and integrated passage is formed by said inner surface of said sidewall and an inner surface of said frame of said fan, said blade is disposed in said continuous and integrated passage, said channel exit is in communication with said airflow inlet of said fan, and the diameter of said airflow channel is non-uniformly distributed, wherein the thickness of each portion of said inner surface of said sidewall is greater than the thickness of said inner surface of said frame, the thickness of said inner surface of said frame is a constant, said airflow channel has a narrowest portion located at a thickest portion of said sidewall, said channel entrance is closer to said narrowest portion of said airflow channel than said channel exit, each of the diameter of said channel entrance and the diameter of said channel exit is greater than the diameter of said narrowest portion of said airflow channel, and a radius of said airflow channel at said narrowest portion is less than a radius defined from a center of said fan to an edge of said blade along a radial direction.