VACUUM CLEANER CYCLONE WITH HELICAL CYCLONE EXPANSION REGION

A vacuum cleaner dirt collection assembly having a housing, an air inlet and air outlet connected to the housing and a cyclone chamber inside the housing. The cyclone chamber has top and bottom walls, and an outer wall joining the top and bottom walls to form a generally enclosed space. The outer wall has a helical guide channel extending radially outward from the adjacent portion of the outer wall. An inner wall, located inside the enclosed space, has a generally cylindrical or frustroconical surface having one or more openings fluidly connecting the enclosed space to the air outlet. A separator plate is located inside the enclosed space at a location between the top and bottom walls. The separator plate extends towards the outer wall and is spaced from the outer wall by a gap.