Fan frame with noise muffling structure

A fan frame with noise muffling structure, comprising:

• an axial fan frame having a top and a bottom, and defining a centered air flow passage that extends from the top to the bottom and has a passage inner wall, an air inlet formed on the top and an air outlet formed on the bottom;
• the axial fan frame further having a noise muffling zone in at least one area of the axial fan frame located between the passage inner wall of the air flow passage and a frame outer periphery of the axial fan frame;
• the noise muffling zone having at least one noise muffling unit provided therein;
• the at least one noise muffling unit located between the top and the bottom and being isolated from, and not communicating with, the air flow passage;
• the at least one noise muffling unit internally defining a hollow cavity, which is closed in between but not extended through the top and the bottom;
• and the hollow cavity being horizontally aligned with a plurality of blades of a fan wheel in the air flow passage, so that the hollow cavity can absorb vibration of the frame and noise produced by the frame vibration.