Patent ID: RE39774

Claim:
A fan guard to be mounted beside a rotor device of a heat-dissipation fan for supporting said rotor device and supercharging said fan, comprising: a main frame; a first set of guard blades radially arranged inside said main frame and , fixed onto an inner surface of said main frame by one ends end thereof , and respectively having a radially curved profile ; a motor holder disposed inside said main frame for receiving and supporting a motor for driving the rotor device and enabling said motor to be received in a shaft ring of said rotor device; and a second frame and a second set of guard blades arranged upstream of said rotor blades to guide air into said rotor device at an angle so as to make an air inflow to said rotor device have an additional tangential velocity, and thus enhance the work of said rotor blades on air; wherein said first set of guard blades are arranged downstream of rotor blades of said rotor device, and have a shape substantially identical to that of said rotor blades, and an arrangement relative to said rotor blades allowing any one of said guard blades and any one of said rotor blades to constitute an approximate C configuration in a cross-sectional view at a moment that a leading point of said guard blade aligned with a trailing point of said rotor blade in an axial direction, and wherein curves of said downstream guard blades guide an overall air outflow from said rotor device to penetrate therethrough and be outputted in said axial direction, thereby transforming a tangential velocity of said air outflow from said rotor device into a static pressure to supercharge said fan.