This application relates to flyweights for ram air turbines utilized on aircraft as a source of supplemental power generation.
Ram air turbines are known, and are movable between a stowed and a deployed position, typically beneath an aircraft. A ram air turbine may be deployed when the main aircraft engine has failed and a source of power is necessary. When deployed, the ram air turbine has blades which are rotatable, and are driven by air rushing past the aircraft. The blades are driven to rotate, and in turn drive a shaft associated with a generator and/or a pump, which generates electricity and/or hydraulic power for various uses on the aircraft, such as providing hydraulic control, or other control to the pilot.
The angle of incidence of the airstream on the turbine blades is desirably changed as the speed of the turbine changes. In the prior art, a governor is associated with a turbine hub, and includes flyweights which shift the governor components during the initial acceleration of the turbine. The flyweights move under centrifugal force to shift the governor components and change the angle of incidence of the airstream on the blades. The prior art flyweights are typically relatively complex, and include a stainless steel component having a pair of spaced blades, and which are riveted through openings in the stainless steel component to a tungsten component.
A flyweight for use in a ram air turbine has a body with a circumferentially enlarged portion extending between flat sides spaced by an angle of between 45 degrees and 150 degrees. A pivot point is defined by a bore at a circumferentially intermediate point in the body, and is in a relatively thin inner portion. The relatively thin inner portion extends beyond the pivot point to an end that will be radially inward when the flyweight is mounted in a ram air turbine. A governor, a ram air turbine and a method are also disclosed.
These and other features of this invention would be better understood from the following specification and drawings, the following of which is a brief description.
In the prior art, the flyweight had a relatively complex shape and construction as illustrated in
A plan view of flyweight 136 is shown in
As further shown in this Figure, the enlarged portion 138 has its outermost ends formed with generally linear edges 139. Notably, the edges are also tapered. A circumferential extent between the opposed edges 139 is at angle A. In an embodiment, the angle A is 110 degrees. But, in other embodiment, the angle A may range between about 45 degrees and about 150 degrees.
Also shown in
Closer to the pivot point 140, a curve surface 166 merges flat surface 164 into another flat surface 151. Flat surface 151 merges into a curve surface 153 which leads to another flat surface 168. Flat surface 168 is at an angle C relative to a bottom flat surface 170. In one embodiment, angle C was 80 degrees. Angle C may range between about 45 degrees and 135 degrees. A curve surface 172 merges from flat surface 170 into a notch 174, also formed on a curve. From notch 174, the profile extends outwardly to a point 175, and then into a second notch 176. Notch 176 curves into a flat surface 178, and flat surface 178 merges into a curve surface 180 which leads into another flat surface 182 leading back into curve surface 160.
A flyweight made according to the teachings of this application is relatively simplified compared to the prior art.
Although an embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention.
Number | Name | Date | Kind |
---|---|---|---|
3013613 | Blackburn | Dec 1961 | A |
4411596 | Chilman | Oct 1983 | A |
5820074 | Trommer et al. | Oct 1998 | A |
6127758 | Murry et al. | Oct 2000 | A |
7077631 | Eccles et al. | Jul 2006 | B2 |
7197870 | Bannon | Apr 2007 | B2 |
7296970 | Bannon et al. | Nov 2007 | B2 |
7410344 | Seidel et al. | Aug 2008 | B2 |
7416392 | Russ | Aug 2008 | B2 |
7419357 | Nohr et al. | Sep 2008 | B2 |
7982328 | Huntemann | Jul 2011 | B2 |
8066481 | Bannon | Nov 2011 | B2 |
20120107119 | Bannon | May 2012 | A1 |
Number | Date | Country | |
---|---|---|---|
20130230401 A1 | Sep 2013 | US |