Patent ID: 9745983
Date: 2017-08-29
CPC Classifications: F04D,F05D

Claim:
1. A ventilation device for an apparatus for a heating, ventilation and/or air-conditioning of a motor vehicle passenger space, comprising a fan wheel having blades mounted turning about an axis of rotation (A 1 ) inside a radially volute-shaped casing, the casing including an axial mouth for aspiration of air and a radial mouth for delivery of air which communicate with the inside of a volute-shaped compartment delimited by a peripheral wall of the casing, the peripheral wall of the casing moving progressively away from a periphery of the fan wheel from a volute tongue to a distal end (E 2 ) of the volute, the radial expansion of the volute being defined by an angle of expansion (a i ), wherein the initial angle of expansion (a 1 ) in a vicinity of the volute tongue is 1.5 times to 3 times greater than the final angle of expansion (a 2 ) in a vicinity of the distal end (E 2 ) of the volute, so that the peripheral wall of the casing moves more rapidly away from the blades at the start of the volute minimising turbulences generated at the volute tongue, and wherein the radial expansion of the volute is defined by the equation: in which: R R d θ a a θ