Turbomachine shroud fibrous tip seal

Rotary kinetic fluid motors or pumps – Bearing – seal – or liner between runner portion and static part – Between blade edge and static part

Reexamination Certificate

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Other Related Categories

C415S173300, C415S119000, C415S173600

Type

Reexamination Certificate

Status

active

Patent number

06471472

Description

ABSTRACT:

FIELD OF THE INVENTION
The invention generally relates to fans for use in cooling systems. The invention relates particularly to a seal structure in a gap between the shroud and rotor of the fan to reduce noise by removing the swirling components of air flow at the tip region of fan blades and to minimize air leakage across the gap resulting in fan efficiency gains.
BACKGROUND OF THE INVENTION
Conventionally, in axial flow fans, tip seals of a labyrinth type have been used to reduce tip air leakage or the flow of air in a gap (on the order of 5 mm) between the shroud and rotor. Ribs have also been used in an effort to reduce this air leakage. A disadvantage of the labyrinth seal is that this seal is difficult to manufacture and that often the axial constraints of the vehicle limit the proper design of the seal. Ribs in the tip region only prevent the swirling component of the flow from causing turbulence by reentering the fan. However, the ribs do not seal the air leakage through the tip gap effectively.
Accordingly, there is a need to provide a seal structure to decrease the gap between the rotor and shroud and to remove the swirling components of flow in the tip region of a fan so as to reduce noise with marginal losses in static efficiency.
SUMMARY OF THE INVENTION
An object of the invention is to fulfill the need referred to above. In accordance with the principles of the present invention, this objective is achieved by providing a turbomachine for moving air. The turbomachine includes a shroud disposed about a longitudinal axis and a rotor assembly mounted for rotation about the longitudinal axis. The rotor assembly has a plurality of blades and tips of the blades are coupled to an annular band. The annular band is disposed with respect to the shroud so as to define a gap extending continuously between an outer surface of the annular band and an inner surface of the shroud. A seal structure extends from the inner surface of the shroud and into the gap. The seal structure has a density sufficient to reduce swirl of recirculating airflow and to minimize air leakage across the gap.
In accordance with another aspect of the invention, a method of reducing effects of air flow between a shroud and a rotor assembly is provided. The shroud is disposed about a longitudinal axis and the rotor assembly is mounted for rotation about the longitudinal axis. The rotor assembly has a plurality of blades and tips of the blades are coupled to an annular band. The annular band is disposed with respect to the shroud so as to define a gap extending continuously between an outer surface of the annular band and an inner surface of the shroud. The method includes providing fibers, bristles or filaments extending from the inner surface of the shroud and into the gap to reduce swirl and minimize air leakage across the gap.
Other objects, features and characteristics of the present invention, as well as the methods of operation and the functions of the related elements of the structure, the combination of parts and economics of manufacture will become more apparent upon consideration of the following detailed description and appended claims with reference to the accompanying drawings, all of which form a part of this specification.


REFERENCES:
patent: 3680977 (1972-08-01), Rabouyt et al.
patent: 3719365 (1973-03-01), Emmerson et al.
patent: 3779341 (1973-12-01), Huggins
patent: 3799128 (1974-03-01), Small
patent: 3834001 (1974-09-01), Carroll et al.
patent: 3970319 (1976-07-01), Carroll et al.
patent: 4181172 (1980-01-01), Longhouse
patent: 4213426 (1980-07-01), Longhouse
patent: 4247247 (1981-01-01), Thebert
patent: 4396351 (1983-08-01), Hayashi et al.
patent: 4398508 (1983-08-01), Moon et al.
patent: 4406581 (1983-09-01), Robb et al.
patent: 4728257 (1988-03-01), Handschuh
patent: 4859150 (1989-08-01), Takigawa
patent: 4971336 (1990-11-01), Ferguson
patent: 4989886 (1991-02-01), Rulis
patent: 5024267 (1991-06-01), Yamaguchi et al.
patent: 5106104 (1992-04-01), Atkinson et al.
patent: 5183382 (1993-02-01), Carroll
patent: 5335920 (1994-08-01), Tseng et al.
patent: 5342167 (1994-08-01), Rosseau
patent: 5489186 (1996-02-01), Yapp et al.
patent: 5496045 (1996-03-01), Millener et al.
patent: 5498139 (1996-03-01), Williams
patent: 5518364 (1996-05-01), Neise et al.
patent: 5522698 (1996-06-01), Butler et al.
patent: 5749584 (1998-05-01), Skinner et al.
patent: 5755444 (1998-05-01), Carnis et al.
patent: 5971400 (1999-10-01), Turnquist et al.
patent: 5980203 (1999-11-01), Zatorski et al.
patent: 6010132 (2000-01-01), Bagepalli et al.
patent: 6030175 (2000-02-01), Bagepalli et al.
patent: 6036437 (2000-03-01), Wolfe et al.
patent: 6053699 (2000-04-01), Turnquist et al.
patent: 6079945 (2000-06-01), Wolfe et al.
patent: G8614073.6 (1988-05-01), None
patent: 19803502 (1999-08-01), None
PCT International Search Report, mailed Aug. 17, 2001.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Turbomachine shroud fibrous tip seal does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Turbomachine shroud fibrous tip seal, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Turbomachine shroud fibrous tip seal will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-2929310

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.