US5064345A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multi-sweep blade with abrupt sweep transition
Assignee: Bosch Automotive Motor Systems Corp
•
Filing: 1989-11-16
•
Granted: 1991-11-12
•
Expires: 2009-11-16
Abstract
Abstract A blade for a fan or blower which has an abrupt transition region between an inner blade region which has a negative leading edge sweep angle, and an outer blade region which is highly forwardly swept. The outer blade region is further characterized by a blade chord that increases with increasing radius. The fan provides a low pitch width and superior noise and efficiency trade-offs.
Inventors
- 👤 Richard Kimball
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 11:11
CPC Classifications
F; F04; F04D; F04D29/00; F04D29/26; F04D29/32; F04D29/38; F04D29/384; F04D29/386; F04D29/325; F04D29/326; F05; F05D; F05D2240/00; F05D2240/20; F05D2240/30; F05D2240/307; Y; Y10; Y10S; Y10S416/00; Y10S416/05
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
173 words
A fan comprising an inner hub designed to rotate in a predetermined rotation direction, the hub being attached to blades extending outwardly from the hub to blade tips, the blades being characterized by: (a) an outer forwardly swept blade region having a leading edge sweep angle θ that is swept in the predetermined rotational direction at an angle of at least 20°; (b) a rearwardly swept inner blade region in which the leading edge sweep angle θ is swept away from the predetermined rotational direction; (c) a transition blade region extending from the outer blade region to the inner blade region, the length of the transition blade region is no greater than 0.01 R, where the transition blade region is measured from an outer blade region where θ is at least 20° to an inner blade region that is rearwardly swept so that the leading edge sweep angle θ is -10° or less, and where R=the fan radius; and (d) a blade chord which increases with increasing radius in the outer blade region.
Claim 2
Dependent Claim
173 words
A fan comprising an inner hub designed to rotate in a predetermined rotation direction, the hub being attached to blades extending outwardly from the hub to blade tips, the blades being characterized by: (a) an outer forwardly swept blade region having a leading edge sweep angle θ that is swept in the predetermined rotational direction at an angle of at least 20°; (b) a rearwardly swept inner blade region in which the leading edge sweep angle θ is swept away from the predetermined rotational direction; (c) a transition blade region extending from the outer blade region to the inner blade region, the length of the transition blade region is no greater than 0.01 R, where the transition blade region is measured from an outer blade region where θ is at least 20° to an inner blade region that is rearwardly swept so that the leading edge sweep angle θ is -10° or less, and where R=the fan radius; and (d) a blade chord which increases with increasing radius in the outer blade region.
Claim 3
Dependent Claim
22 words
The fan of claim 1 in which θ changes at least 40° over a radial distance of less than 4% of R.
Claim 4
Dependent Claim
25 words
The fan of claim 1 in which θ is at least 30° over a distance of at least 0.05 R in the outer blade region.
Claim 5
Dependent Claim
44 words
The fan of claim 3 in which θ is -20° or less at a point in the inner blade region which is positioned a distance less than 0.10 R from a point in the outer blade region at which θ is greater than 25°.
Claim 6
Dependent Claim
44 words
The fan of claim 1 in which θ is -20° or less at a point in the inner blade region which is positioned a distance less than 0.10 R from a point in the outer blade region at which θ is greater than 25°.
Claim 7
Dependent Claim
35 words
The fan of claim 1 in which the blade chord increases at least 20% over the range r/R 0.70 to r/R=0.98, where R=the radius to a radial position along the blade and R=the fan radius.
Claim 8
Dependent Claim
23 words
The fan of claim 1 in which θ becomes positive at a point in the transition region where r/R is greater than 0.7.
Claim 9
Dependent Claim
32 words
The fan of claim 1 in which θ is greater than 40° at a point between r/R=0.94 and r/R=0.98, and θ is less than -30° at a point between r/R=0.60 and 0.70.
Claim 10
Dependent Claim
17 words
The fan of any one of claim 1, 8 or 4 further comprising a rotating tip band.
Claim 11
Dependent Claim
21 words
The fan of any one of claims 7 or 4 further comprising means to mount said fan adjacent a heat exchanger.
References Cited (Backward Citations)
US1146121A
Cited
GB228072A
Cited
US1825114A
Cited
US2212041A
Cited
US3826591A
Cited
US3972646A
Cited
US4505641A
Cited
US4358245A
Cited
US4685513A
Cited
US4459087A
Cited
US4569632A
Cited
EP0168594A1
Cited
US4569631A
Cited
US4729714A
Cited
US4684324A
Cited
US4840541A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-11-11 | 1995-05-13 | 1995-11-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-11-11 | 1999-05-13 | 1999-11-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-11-11 | 2003-05-13 | 2003-11-12 | $7700.00 | Window Closed / Lapsed |