Patent Application
20170226958
The present disclosure relates generally to spring energized seals. More specifically, the present disclosure relates to spring energized seals for use with sealing the cylinder liners or sleeves of a combustion engine and the like.
Internal combustion engines typically use seals to prevent the leaking of liquids and gases from the various components of the engine. One application includes the use of a seal that prevents the leaking of coolant that circulates around the cylinder liner of a cylinder in the engine. This seal is often disposed in a groove located between the cylinder liner and the cylinder block of the engine.
One skilled in the art can appreciate that this environment may be particularly harsh due to the temperature extremes (including hot and cold) such seals may experience as well as the corrosive agents such as exhaust and coolants that the seals are exposed to over time. This may lead to the failure of the seal and require the seal to be replaced, leading to downtime for the engine and unwanted costs.
Moreover, large bore heavy duty engines are requiring a longer life between engine rebuilds and overhauls, which is the best time to replace such seals without incurring the unwanted costs just mentioned. Current elastomer liner seals may not always meet the desired life and temperature requirements of such applications. Likewise, the current materials used in such seals may not resist the chemical attack of all the fluids to which they may become exposed. Consequently, the seals may fail and be unable to maintain the necessary sealing force before scheduled maintenance, which is undesirable.
Therefore, it is desirable to develop a seal for such applications that is more robust than has yet been devised.
A seal assembly is provided that defines an aperture, that the aperture defines defining a longitudinal axis and a radial direction that is perpendicular to the longitudinal axis. The seal assembly comprises a spring member, and a sealing member that at least partially encapsulates the spring member and that includes: a perimeter that runs in a plane that is parallel to both the longitudinal axis and the radial direction perpendicular to the longitudinal axis, and thatthat the perimeter defines defining a first axial extremity and a second axial extremity, a first sealing surface that runs paralleloriented parallel to the longitudinal axis, and a sealing feature that is positioned axially between the first and second axial extremities, and that faces in athe sealing feature positioned diametrically opposite direction than the direction the and facing away from the first sealing surface faces along the direction that is perpendicular to the longitudinal axis in the radial direction.
A seal assembly that includes a substantially annular cylindrical configuration that defines an aperture that defines a cylindrical axis and a radial direction is provided. The seal assembly comprises a spring member that includes two arm portions that extend substantially in a direction that is parallel to the cylindrical axis and that meet forming a flex point, and a sealing member that at least partially encapsulates the spring member and that includes: a first sealing feature, and a second sealing feature that is positioned axially and radially adjacent the flex point of the spring member and that faces in a direction that is diametrically opposite the direction that the first sealing feature faces along the radial direction, and an elastomeric material that includes a base resistant type 5 fluoroleastomer made from a copolymer of propylene and tetrafluoroethylene.
An engine assembly is provided that comprises an engine block that includes a bore, a cylinder liner disposed in the bore and that defines an annular groove, and a seal assembly disposed in the annular groove that defines a cylindrical axis and a radial direction, the seal assembly including a spring member that includes two arm portions that extend substantially in a direction that is parallel to the cylindrical axis and that meet forming a flex point, and a sealing member that at least partially encapsulates the spring member and that includes: a first sealing feature, and a second sealing feature that is positioned axially and radially adjacent the flex point of the spring member and that faces in a direction that is diametrically opposite the direction that the first sealing feature faces along the radial direction, and an elastomeric material that includes a base resistant type 5 fluoroleastomer made from a copolymer of propylene and tetrafluoroethylene.
In some embodiments as will be discussed, a new cylinder sleeve seal assembly is provided that uses a metal spring to help recover loses in sealing force due to elastic relaxation. As a result, the seal assembly will typically seal well at the most severe cold temperatures. Furthermore, a material is selected for the sealing member that includes a base resistant type 5 fluoroleastomer made from a copolymer of propylene and tetrafluoroethylene. This material may be able to resist the chemical attack associated with basic engine coolants of all types.
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While this embodiment has an annular cylindrical configuration, other embodiments may have other configurations. For example, the annular configuration may be polygonal, etc. In such embodiments, the cylindrical axis A would be replaced by a longitudinal axis A′ and the radial direction R would be replaced by another direction R′ that is perpendicular to the longitudinal axis A′.
A sealing feature of any embodiment may have any configuration known or that will be devised in the art such as an edge or lip, a flat surface, etc. For this embodiment, the first sealing feature 112 is an inner sealing surface 116 that is substantially flat in an axial direction and that runs parallel to the cylindrical axis A. The first sealing feature 112 may alternatively be provided with other surface features, such as, for example, undulations extending in the axial or circumferential directions. Similarly, the second sealing feature 114 is a second sealing surface, referred to as an outer sealing surface 118 that is substantially flat and that runs parallel to the cylindrical axis A. In other words, the first sealing feature is oriented parallel to the longitudinal axis or cylindrical axis A. It is contemplated that since the outer sealing surface is relatively short in length along the cylindrical axis, that it may be replaced by a lip or edge. The inner sealing surface 116 is so called as it faces toward the cylindrical axis A and the outer sealing surface 118 is so called as it faces away from the cylindrical axis A.
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Alternatively, a material may be poured or injected into the void and hardened, cured, or bonded to the keeper member and/or the spring member. In some embodiments, the void will be not be filled. In such an embodiment, the first sealing feature 112 will be interrupted from one axial extremity 124 of the seal assembly 100 to the other axial extremity 122 and will have a smaller length along the cylindrical axis A, similar to that of the second sealing feature 114. Also, the perimeter 120 of the cross-section will be open instead of closed. Thus, the sealing member would only partially encapsulate the spring member.
For the various embodiments discussed herein, the spring member comprises a metal alloy and the sealing member comprises an elastomer. Other materials may be used for the spring member and the sealing member provided they have the desired characteristics to make the seal assembly perform for an intended application.
An exemplary list of materials that may be used for the spring member includes, but is not limited to, a metal, a metal alloy, a steel alloy, stainless steel, ceramic, cast blade alloy, cold formable super alloys, etc.
An exemplary list of materials that may be used for the sealing member includes, but is not limited to, FEP (fluorinated-ethylene propylene), PFA (perfluoroalkoxy), PTFE (polytetrafluoroethylene), ETFE (ethylenetetrafluoroethylene), PE (polyethylene), ETCFE, polyurethanes, a base resistant type 5 fluoroleastomer made from a copolymer of propylene and tetrafluoroethylene, peroxide cured fluorocarbon, ethylene-propylene copolymer, a hydrogenated butadiene-acrylonitrile copolymer, etc.
The seal assembly 100 of
The seal assembly may be manufactured in any suitable manner including over molding the sealing member onto the spring member using an injection molding process or the like. Alternatively, the sealing member may be split into two pieces and assembled around the spring member such as shown and described previously with reference to
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Removal of the seal assembly by moving it downward (step 302) is hindered by the sloped surface 224 on the ridge 222 that has a steeper angle than that of the lead-in surface 220. This makes it more difficult to remove the seal assembly 100 than to install it, helping to prevent its unintentional removal. Of course, the removal of the seal assembly can be accomplished if enough force is supplied. In many embodiments, the upward movement (step 300) of the seal assembly 100 is continued until it impinges upon the flange 214.
Once the seal assembly 100 is installed into the groove 212, the cylinder liner 206 and the seal assembly 100 form a subassembly. Then, both are moved downward (step 304) into the appropriate bore 218 of the engine block 202. Though not shown in
While most of the embodiments discussed herein are cylinder liner applications, other engine and industrial applications are compatible with the use of the seal assemblies discussed herein and are therefore within the scope of the present disclosure.
It will be appreciated that the foregoing description provides examples of the disclosed design and function. However, it is contemplated that other implementations of the disclosure may differ in detail from the foregoing examples. All references to the disclosure or examples thereof are intended to reference the particular example being discussed at that point and are not intended to imply any limitation as to the scope of the disclosure more generally. All language of distinction and disparagement with respect to certain features is intended to indicate a lack of preference for those features, but not to exclude such from the scope of the disclosure entirely unless otherwise indicated.
Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein.
It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments of the apparatus and methods of assembly as discussed herein without departing from the scope or spirit of the invention(s). Other embodiments of this disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the various embodiments disclosed herein. For example, some of the equipment may be constructed and function differently than what has been described herein and certain steps of any method may be omitted, performed in an order that is different than what has been specifically mentioned or in some cases performed simultaneously or in sub-steps. Furthermore, variations or modifications to certain aspects or features of various embodiments may be made to create further embodiments and features and aspects of various embodiments may be added to or substituted for other features or aspects of other embodiments in order to provide still further embodiments.
Accordingly, this disclosure includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the disclosure unless otherwise indicated herein or otherwise clearly contradicted by context.
