Self-cleaning strainer or filter

A self-cleaning strainer comprising a body member having an inner wall defining an axial main flow passage open at both ends and at least one lateral flow passage in communication with said main passage for the removal of strained fluid;

• annular straining means sealingly mounted within said main passage so as to define a chamber between the outer surface of said straining means and said inner wall of the body member;
• agitator means mounted within said main flow passage so as to be spaced from said straining means and freely rotatable about the longitudinally axis thereof, said agitator means progressively increasing in diameter from a first inlet end to a second outlet end of said main flow passage, and being configured with respect to said straining means such that the distance between said agitator means and said straining means progressively decreases from said first end to said second end and such that fluid traveling through said straining means will cause it to rotate thereby creating a turbulent fluid flow which will prevent material adhering to said straining means without creating a shearing of said material between said agitator means and said straining means.