Patent Description:
Premature failure in valve seal assemblies used in engine valves, especially engines used in aerospace applications, can be particularly problematic. For example, conventional valve seal assemblies, commonly used in many jet engines, are subjected to significant forces and other stresses when air flow impinges on the seal. Butterfly seals, for example, are routinely used in these applications. Butterfly seals, however, include a carbon seal ring that deforms under the pressure of significant air flow forces occurring during operation. This deformation can cause the valve to fail.

More specifically, conventional valves can be more prone to failure because of the configuration of their constituent parts. For example, a conventional butterfly valve includes a disk member, a retainer, and a seal disposed between a surface of the retainer and a surface of the disk member. The seal, however, is not supported by a substrate, or not strongly supported on a base structure. Consequently, when subjected to a significant air flow, the absence of a strong substrate attachment causes the seal to move excessively.

Further, when the seal is constructed of carbon it can bend when exposed to these air flow forces. Bending can also cause the seal to deform or rupture, resulting in failure. When the seal fails, the retainer extends into the valve's bore, causing the conventional valve to jam in the open position. Accordingly, conventional valves can have a short lifespan, resulting in increased service frequency for jet engines that use them. <CIT> discloses a butterfly shutoff valve including a sealing arrangement providing minimal internal leakage.

Given the aforementioned deficiencies, a need exists for improved seal retention configurations that minimize the effect of air flow forces and other stresses. Also needed is an improved substrate that adequately supports seals included in valve assemblies. Furthermore, there exists a need to extend the life of carbon seals to minimize part servicing and/or replacement, which in turn saves costs. The embodiments featured herein help solve the above-noted deficiencies.

In accordance with claim <NUM>, the invention provides a valve assembly including a seal and a retainer. The valve assembly also includes a retaining ring providing a force securing the seal between the retainer and a disk member. The retaining ring is disposed at a slant in a cavity formed by adjoining the retainer to the disk member.

Additional features, advantages, and other aspects of various embodiments are described below with reference to the accompanying drawings. It is noted that the present disclosure is not limited to the specific embodiments described herein. These embodiments are presented for illustrative purposes. Additional embodiments, or modifications of the embodiments disclosed, will be readily apparent to persons skilled in the relevant art(s) based on the teachings provided.

Illustrative embodiments may take form in various components and arrangements of components. Illustrative embodiments are shown in the accompanying drawings, throughout which like reference numerals may indicate corresponding or similar parts in the various drawings. The drawings are for purposes of illustrating the embodiments and are not to be construed as limiting the disclosure. Given the following enabling description of the drawings, the novel aspects of the present disclosure should become evident to a person of ordinary skill in the relevant art(s).

While the illustrative embodiments are described herein for particular applications, it should be understood that the present disclosure is not limited thereto. Those skilled in the art and with access to the teachings provided herein will recognize additional applications, modifications, and embodiments within the scope thereof and additional fields in which the present disclosure would be of significant utility.

<FIG> is a cross-sectional view of a conventional valve assembly <NUM>. The conventional valve assembly <NUM> includes a disk member <NUM>, a retainer <NUM>, and a seal <NUM> secured by retainer <NUM> onto a surface of disk member <NUM>. In the conventional valve assembly <NUM>, the seal <NUM> can move excessively into an air flow, or stream, because of the lack of a strong substrate attachment. This substrate deficiency is inherently present in the design, and limits the seal's lifespan as explained above.

More specifically, excessive bending forces exerted on seal <NUM> during operation can lead to premature failure, especially when seal <NUM> is made of carbon. These forces also cause the retainer <NUM> to fail by causing the retainer <NUM> to extend into the valve's bore (not shown). This extending causes the conventional valve assembly <NUM> to jam in the open position. The exemplary embodiments described herein resolve these issues.

<FIG> illustrates a cross-sectional view of a valve assembly <NUM> in accordance with various aspects described herein. The valve assembly <NUM> can be a butterfly seal assembly, and can include a disk member <NUM> and a retainer <NUM> with a seal <NUM> secured therebetween. At least one of the disk member <NUM> and the retainer <NUM> can be made of either steel, stainless steel, or generally speaking, of a corrosion-resistant material (e.g. corrosion-resistant steel).

The seal <NUM> can be secured partly between a first surface <NUM> of the disk member <NUM> and a second surface <NUM> of the retainer <NUM>. A part of the seal <NUM> can protrude outwardly, away from the disk member <NUM> and the retainer <NUM>. The part of seal <NUM> protruding outwardly performs the sealing operation of the valve when the valve assembly <NUM> is actuated. The seal <NUM> can be an L-shaped seal. That is, its cross-section can have a form shaped substantially like an L. The seal <NUM> can also have other cross-section shapes, known to one of skill in the relevant art(s). For example, a T-shaped seal could also be used.

A cavity <NUM> is formed by adjoining the disk member <NUM> and the retainer <NUM>. Specifically, the retainer <NUM> includes a first groove <NUM> and the disk member <NUM> includes a second groove <NUM>, which, when the two parts are joined, form the cavity <NUM>.

A retaining ring <NUM> is disposed at a slant <NUM> with respect to a bottom surface of cavity <NUM>. Generally speaking, the retaining ring <NUM> is angled (i.e., slanted) with respect to an inner surface of cavity <NUM>. The retaining ring <NUM> can have a rectangular cross-section. Furthermore, the retaining ring <NUM> can be made of an age-hardened iron super alloy, or generally speaking, from an iron-based alloy.

When disposed (i.e., with the slanted orientation with respect to the bottom surface of the cavity <NUM>), the retaining ring <NUM> provides a radial force. That is, the retaining ring <NUM> provides a force from right to left in <FIG>, which keeps the seal <NUM> secured in place. This configuration provides stronger seal retention in comparison with the seal retention in the conventional valve assembly <NUM>.

The retaining ring <NUM> provides an additional retaining force that helps keep the seal <NUM> in place during typical operation where an air stream is incident on the valve assembly <NUM>. The retaining force is, in addition to the forces being generated by the retainer <NUM>, pressing or biasing the seal <NUM> on the disk member <NUM>. As such, the seal <NUM> is securely held in place and does not excessively protrude into the air stream. Thus, the stresses exerted on the seal <NUM> by the air stream are prevented (or reduced to a minimum) because the retaining ring <NUM> provides the additional retaining for securing the seal <NUM> during operation. In this manner, the embodiments provide highly durable seals. For valve assemblies that utilize carbon seals, increased durability can be obtained as carbon seals are more susceptible to failure, than other types of seals, from being overly stressed.

<FIG> illustrates a cross-sectional view of a valve assembly <NUM> in accordance with various aspects described herein. The valve assembly <NUM> includes a support <NUM> disposed at a bottom end of the seal <NUM>. In some embodiments, the support <NUM> can be a metal support. In other embodiments, the support <NUM> can be made of steel.

The support <NUM> confers several advantages to the valve assembly <NUM>. For example, the support <NUM> acts as a substrate for the seal <NUM>, thus providing increased physical support when the valve assembly <NUM> is operated. In addition, the support <NUM> biases the seal <NUM> against the valve body wall (not shown). This additional biasing reduces leakage when the valve assembly is operated.

<FIG> illustrates an example of a top view <NUM> of the valve assembly <NUM> (or of the valve assembly <NUM>). The retainer <NUM> is disposed at the circumference of the disk member <NUM>. The seal <NUM> (not shown) can be secured between the disk member <NUM> and the retainer <NUM>. The force securing the seal <NUM> therebetween is provided by the retaining ring <NUM>. The valve assembly <NUM> can also include a port <NUM> structurally configured to receive a portion of an actuator (not shown). The actuator can be used to switch the valve in open and closed positions, or in any intermediate positions.

In aerospace applications, the valve assembly <NUM> can be a butterfly valve. More precisely, the valve assembly <NUM> can be a pressure-regulating butterfly valve assembly. Such a valve could be the lead pressure regulating valve in a jet engine. As such, the valve assembly <NUM> can provide a robust pressure regulating system in which the carbon seal used (i.e., the seal <NUM>) has an increased lifespan because stresses resulting from the air stream it is subjected to are reduced. These reduced stresses result from the seal <NUM> being tightly secured between disk member <NUM> and retainer <NUM>.

<FIG> illustrates an example exploded view <NUM> of the valve assembly <NUM>. Specifically, <FIG> shows a more detailed view of the retaining ring <NUM>. While the retaining ring <NUM> has a rectangular cross-section, it is sloped inwardly. This configuration provides the slant <NUM> (as shown in <FIG>) when all the components are assembled to make the valve assembly <NUM>.

Having set forth various embodiments and their structure, specific details regarding the assembly of various constitutive elements of valve assembly <NUM> are now described with respect to <FIG> and <FIG>.

<FIG> illustrates a method <NUM> for assembling the retaining ring <NUM> onto a butterfly seal <NUM>. The method <NUM> includes a step <NUM> in which the seal <NUM> is installed on the disk member <NUM>, i.e. on the butterfly portion of the valve. The method <NUM> further includes a step <NUM> for inserting the retaining ring <NUM> in the retainer <NUM>. The step <NUM> includes sliding the retainer <NUM>, including the retaining ring <NUM>, towards the seal <NUM>. The step <NUM> includes securing the retainer <NUM> on the retaining ring <NUM>. The step <NUM> is passively performed when the two parts come together, as a result of the force generated by the retaining ring <NUM>. Furthermore, in some embodiments, a weld can be made at the interface between the disk member <NUM> and the retainer <NUM> to further strengthen the assembly.

<FIG> illustrates various possible positions <NUM> of the retaining ring <NUM> during the assembly of the valve assembly <NUM> and in accordance with various aspects described herein. As mentioned above with respect to <FIG>, the seal <NUM> is desirably installed on the butterfly portion first, and the subsequent steps of the assembly are then carried out. During the assembly, the position <NUM> indicates the position of the retaining ring <NUM> in its free state. More precisely, in its free state, the retaining ring <NUM> is in the position it would assume if it were placed in the groove of the disk member <NUM>.

Upon assembly, the retaining ring <NUM> will expand into the groove of the retainer <NUM>, indicated by the position <NUM>. During expansion, the retaining ring <NUM> will develop an axial pre-load resulting from being compressed axially as it expands radially.

With the retaining ring <NUM> still expanded inside the retainer <NUM>, the two are slipped over the butterfly (i.e. over the disk member <NUM>). Once the retainer <NUM> and the retaining ring <NUM> are mated with the disk member <NUM>, as shown in <FIG>, the retaining ring <NUM> pulls inwardly and radially, thus securing the parts together.

Generally, the embodiments provide a retention method for a seal in a valve assembly. The seal is retained in the valve using a retainer. The retainer includes a retaining ring that expands therein and retracts radially when placed in a proper position. A weld can be provided at interface between the retainer and the disk member of the valve, thereby providing a strong retention force and an adequate supporting substrate for the seal. This configuration extends the lifetime of the seal by reducing the amount of stresses exerted on the seal during valve operation.

While the embodiments have been described in the context of valves, butterfly valves, and valve assemblies, one of ordinary skill in the art will readily recognize that the techniques and configurations disclosed herein can be used in applications where any part is to be secured. For example, the techniques disclosed herein can be used to secure a bearing by using a retainer fitted with the retaining ring, as disclosed above.

Moreover, the embodiments provide a method for creating tamper-proof assemblies. Specifically, because once the seal (or a bearing) is secured, the seal cannot be removed from the assembly without releasing the retaining ring, which can only happen by breaking open the cavity in which the retaining ring is located. As such, for some applications, the embodiments provides advantages where means for providing passive tamper-proof mechanisms for securing parts and components are needed.

Claim 1:
A valve assembly (<NUM>), comprising:
a disk member (<NUM>);
a retainer (<NUM>) having a first groove (<NUM>);
a seal (<NUM>) that can be secured partly between a first surface (<NUM>) of the disk member (<NUM>) and a second surface (<NUM>) of the retainer (<NUM>), a part of the seal (<NUM>) protruding outwardly, away from the disk member (<NUM>) and the retainer (<NUM>), the part of the seal (<NUM>) protruding outwardly performing the sealing operation of the valve assembly (<NUM>) when the valve assembly (<NUM>) is actuated;
a retaining ring (<NUM>);
wherein the disk member (<NUM> has a second groove (<NUM>), and wherein the first groove (<NUM>) and the second groove (<NUM>) form a cavity (<NUM>) in which the retaining ring (<NUM>) is disposed, the retaining ring (<NUM>) being disposed at a slant (<NUM>) with respect to an inner surface of the cavity (<NUM>); and
wherein the retaining ring (<NUM>) urges the retainer (<NUM>) towards the seal (<NUM>).