| 主权项 |
1. A ventilation device for an apparatus for a heating, ventilation and/or air-conditioning of a motor vehicle passenger space, comprising a turbine having blades mounted turning about an axis of rotation (A1) 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 the peripheral wall of the casing, the peripheral wall of the casing moving progressively away from the periphery of the turbine from a volute tongue to a distal end (E2) of the volute, the radial expansion of the volute being defined by an angle of expansion (ai), characterised by the fact that the initial angle of expansion (a1) in the vicinity of the volute tongue is 1.5 times to 3 times greater than the final angle of expansion (a2) in the vicinity of the distal end (E2) 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 the turbulences generated at the volute tongue, and by the fact that the radial expansion of the volute is defined by the equation:Rvi=(Rt+dtv)×(θi×tan(a1-(a1-a2θmax)×θi))(1)in which:
Rvi is the radius of the volute at a determined point (Ei) of the volute, Rt is the outer radius of the turbine, dtv is the minimum radial distance between the outer edge of the blades of the turbine and the volute tongue, θ1 is the angle defined by the initial end (E1) of the volute and the determined point (E1) of the volute about the axis of rotation (A1), a1 is the initial angle of expansion of the volute, a2 is the final angle of expansion of the volute, θmax is the volute angle which corresponds to the angle defined by the initial end (E1) of the volute and the distal end (E2) of the volute about the axis of rotation (A1) and by the fact that the volute angle (θmax) is between 290 and 315 degrees. |
