Fan inlet with curved lip and cylindrical member forming labyrinth seal
First Claim
1. A plastic, injection-molded shroud in combination with a fan, said fan comprising blades connected at their outer tips by a band, said shroud being positioned around said fan, said shroud extending axially from an inlet portion to an outlet portion, said outlet portion being formed to guide airflow into a heat exchanger;
- a) said shroud comprising an inlet lip which is curved in cross-section and positioned at the inlet portion of the shroud, said lip extending radially inward and axially downstream from the inlet portion of the shroud to a trailing edge;
b) said fan band comprising an integral flange extending radially outward from the outer tip of said blades, said flange being flared away from the direction of airflow, toward the outlet of said shroud;
c) said shroud further comprising an intermediate cylindrical wall attached to said inlet lip of said shroud, said intermediate cylindrical wall being positioned;
1) radially between the inner surface of said shroud and portions of the outer surface of said fan band so as to form a wall-to-band radially restrictive running clearance;
2) with its inner radius not exceeding that of the flange on the fan band;
3) to extend axially rearward from the inlet lip terminating axially adjacent and upstream of the flange on the fan band, forming a flange-to-wall axially restrictive running clearance therebetween.
3 Assignments
0 Petitions
Accused Products
Abstract
An improved plastic, injection-molded shroud/banded fan combination in which the shroud extends axially from an inlet portion to an outlet portion, and the outlet portion comprises means for connecting a heat exchanger to the shroud, More specifically, the shroud includes an inlet lip which is curved in cross-section and positioned at the inlet portion of the shroud. The lip extends radially inward and axially downstream from the inlet portion of the shroud to a trailing edge. An intermediate cylindrical wall is attached to said inlet lip. The intermediate cylindrical wall is positioned: 1) coaxially with the fan; and 2) radially between the inner surface of the shroud and portions of the outer surface of the fan band so as to form a wall-to-band radially restrictive running clearance.
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Citations
18 Claims
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1. A plastic, injection-molded shroud in combination with a fan, said fan comprising blades connected at their outer tips by a band, said shroud being positioned around said fan, said shroud extending axially from an inlet portion to an outlet portion, said outlet portion being formed to guide airflow into a heat exchanger;
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a) said shroud comprising an inlet lip which is curved in cross-section and positioned at the inlet portion of the shroud, said lip extending radially inward and axially downstream from the inlet portion of the shroud to a trailing edge; b) said fan band comprising an integral flange extending radially outward from the outer tip of said blades, said flange being flared away from the direction of airflow, toward the outlet of said shroud; c) said shroud further comprising an intermediate cylindrical wall attached to said inlet lip of said shroud, said intermediate cylindrical wall being positioned;
1) radially between the inner surface of said shroud and portions of the outer surface of said fan band so as to form a wall-to-band radially restrictive running clearance;
2) with its inner radius not exceeding that of the flange on the fan band;
3) to extend axially rearward from the inlet lip terminating axially adjacent and upstream of the flange on the fan band, forming a flange-to-wall axially restrictive running clearance therebetween. - View Dependent Claims (4, 5, 12, 13, 14, 15, 16, 17, 18)
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2. A plastic, injection-molded shroud in combination with a fan, said fan comprising blades connected at their outer tips by a band, said shroud being positioned around said fan, said shroud extending axially from an inlet portion to an outlet portion, said outlet portion being formed to guide airflow into a heat exchanger;
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a) said shroud comprising an inlet lip which is curved in cross-section and positioned at the inlet portion of the shroud, said lip extending radially inward and axially downstream from the inlet portion of the shroud to a trailing edge;
said lip comprises openings for guiding recirculating airflow away from said fan inlet;b) said shroud further comprising an intermediate cylindrical wall attached to said inlet lip, said intermediate cylindrical wall being positioned radially between the inner surface of said shroud and portions of the outer surface of said fan band so as to form a wall-to-band radially restrictive running clearance. - View Dependent Claims (6, 7, 8, 9, 10, 11)
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3. A plastic, injection-molded shroud in combination with a fan, said fan comprising blades connected at their outer tips by a band, said shroud being positioned around said fan, said shroud extending axially from an inlet portion to an outlet portion, said outlet portion being formed to guide airflow into a heat exchanger;
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a) said shroud comprising an inlet lip which is curved in cross-section and positioned at the inlet portion of the shroud, said lip extending radially inward and axially downstream from the inlet portion of the shroud to a trailing edge; b) said shroud further comprising an intermediate cylindrical wall attached to said inlet lip, said intermediate cylindrical wall being positioned radially between the inner surface of said shroud and portions of the outer surface of said fan band so as to form a wall-to-band radially restrictive running clearance, said trailing edge of said shroud inlet lip being offset axially from the upstream edge of said fan blades so as to establish a lip-to-blade axially restrictive running clearance therebetween, said inlet portion of said shroud comprising an outer shroud wall having at least one opening connecting a space radially outward of said intermediate cylindrical wall with space outside the shroud, whereby recirculating airflow is directed away from said lip-to-blade axially restrictive running clearance.
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Specification