Patent Application
20240200655
The present disclosure relates to a J-shaped press-in-place (PIP) seal, such as for an interface between components from dissimilar materials.
A gasket or seal is a mechanical component that fills the space between mating surfaces, generally to prevent leakage of a fluid from or into the joined objects while the seal is under compression. Seals permit “less-than-perfect” mating surfaces on machine parts to be joined without allowing leakage by using the gasket to fill surface irregularities. Seals also keep external contaminants out of the resultant assembly. Seals are commonly produced from sheet or molded materials such as paper, natural rubber, synthetic rubber, metal, or a plastic polymer.
In situations where a joint between two mating components is pressurized, or the mating components are constructed from dissimilar materials, sealing of such a joint becomes even more challenging. Additionally, in such joints, unintended fluid leakage may lead to functional failure of a system thus being sealed. Typically, such leakage may cause additional inconvenience by creating a fluid spill that necessitates a clean-up. Design and selection of a seal for a particular application may thus prove critical to the reliability of a subject system and to the satisfaction of the system's user.
A press-in-place (PIP) seal for an interface between adjacent components, with the PIP seal including a cylindrical structure arranged along a longitudinal axis and characterized by a J-shape in a cross-sectional view. The cylindrical structure is configured to be arranged inside a first component and be compressed by a second component against the first component when the PIP seal is installed within the interface. The J-shape includes a first stem section having a first length arranged orthogonal to and extending toward the longitudinal axis. The first stem is configured to be compressed by the second component to generate sealing pressure between the first and second components when the PIP seal is installed within the interface. The J-shape also includes a second stem section having a second length longer than the first length, arranged orthogonal to and extending toward the longitudinal axis. The second stem is configured to stabilize the cylindrical structure when the PIP seal is installed within the interface. The J-shape further includes a base third section arranged parallel to the longitudinal axis and connecting the first stem section to the second stem section. The third section also defines a concavity between the first and second sections.
The first stem section may include a tip configured to come into contact with the second component when the PIP seal is installed within the interface. The tip may be beveled in the cross-sectional view.
The cylindrical structure may be formed or constructed from an elastic material.
The elastic material may be Ethylene Propylene Diene Monomer (EPDM) rubber.
The material may have Shore A-40 hardness.
The cylindrical structure may be configured to come into contact with a fluid. The PIP seal material may be selected based on its chemical resistance to the fluid.
The fluid may be at least one of moist air, Hydrogen gas, and glycol-based coolant.
Respective transitions between the first stem section, the second stem section, and the base third section may include bends defined by curved profiles.
The cylindrical structure may have a circular or oval contour in a plane orthogonal to the longitudinal axis.
The cylindrical structure may have an irregular contour in a plane orthogonal to the longitudinal axis.
A fluid-pressure joint assembly including first and second components and the press-in-place (PIP) seal for an interface therebetween.
The above features and advantages, and other features and advantages of the present disclosure, will be readily apparent from the following detailed description of the embodiment(s) and best mode(s) for carrying out the described disclosure when taken in connection with the accompanying drawings and appended claims.
Those having ordinary skill in the art will recognize that terms such as “above”, “below”, “upward”, “downward”, “top”, “bottom”, “left”, “right”, etc., are used descriptively for the figures, and do not represent limitations on the scope of the disclosure, as defined by the appended claims. Referring to the drawings, wherein like reference numbers refer to like components,
As shown in
The first and second components 12, 14 may be constructed from different materials having dissimilar coefficients of thermal expansion, such as one of the two components being from metal and the other from plastic. During its operational life, the interface 10A may experience a considerable temperature gradient and gap variation. However, with the PIP seal 18 in place, the interface 10A is intended to withstand and seal considerable fluid pressure. In the assemblies employing the interface 10A with the intent of sealing pressurized fluid, the subject interface may be identified as a “fluid-pressure joint” and with the PIP seal 18 in place, the entire assembly may be identified as a “fluid-pressure joint assembly”.
Typically, a joint is said to have a large gap variation when design and/or manufacturing tolerances of the mating components become a significant percentage of the thickness of the employed seal. In such a situation, under maximum material condition of the mating components, i.e., when such components are to their maximum allowable size, the actual compression of the seal in the assembled joint may exceed approximately 20-35% of its thickness, and lead to additional stress on those components. On the other hand, in such a situation under a minimum material condition of the mating components, i.e., when such components are at their minimum allowable size, compression of the seal may be less than ideally required to retain pressurized fluid without leakage.
As shown in
As shown in
The cylindrical structure 20 may be formed or otherwise constructed from an elastic or compliant material. More specifically, the material of the cylindrical structure 20 may be selected to have Shore A-40 hardness. The Shore A Hardness scale generally measures the hardness of flexible molded rubbers that range in hardness from very soft and flexible, to medium and somewhat flexible, to hard with almost no flexibility at all. Semi-rigid plastics may also be measured on the high end of the Shore A scale. The compliant material of the PIP seal 18 may be especially useful in an embodiment of the interface 10A required to withstand significant fluid pressure and retain its structural and sealing integrity. For example, in such an embodiment, the cylindrical structure 20 may be compressed to 25-47% of its thickness when the second component 14 is fastened to the first component 12.
In an embodiment where the cylindrical structure 20 is intended to come into contact with and seal off a particular fluid, the specific material of the PIP seal 18 may be selected based on its compatibility with the working fluid conveyed through the interface 10A. Additionally, material of the cylindrical structure 20 may be selected to reliably withstand projected temperature range and pressure at the interface 10A. Specifically, at the interface between the first and second components 12, 14 of a motor vehicle powertrain subassembly, the temperature range may be −30 to +110 degrees Celsius. Also, such a vehicle powertrain embodiment of the interface 10A may be required to seal fluid pressure in the 350 KPa range. Furthermore, the material of the PIP seal 18 may be selected based on its resistance to fluid diffusivity and chemical resistance to the subject fluid. Such a fluid may, for example, be moist air, Hydrogen gas, or glycol-based (˜50% by volume) coolant. An exemplary material for the cylindrical structure 20 which would satisfy the above requirements is Ethylene Propylene Diene Monomer (EPDM) rubber.
The cylindrical structure 20 is further characterized by a J-shape 22 in a cross-sectional view taken along section 3-3 in
The J-shape 22 additionally includes a base third section 28 arranged parallel to the longitudinal axis X. The base third section 28 connects the first stem section 24 to the second stem section 26, thereby defining a concavity or a depression 30 between the first and second sections 24, 26. The depression 30 is configured to facilitate orderly contact between the second component 14 and the first section 24 as well as of the second section 26 with the planar surface 26A. The depression 30 is also configured to minimize the likelihood of contact and/or interference of the second component 14 with the base third section 28. As may be seen in
The first stem section 24 may include a tip 24-1 configured to come into contact with the second component 14 when the PIP seal 18 is being installed within the interface 10A. The tip 24-1 may be beveled or tapered as shown in the cross-sectional view 2-2 to facilitate insertion of the second component 14 into the open inner region 20A surrounded by the cylindrical structure 20. Tapering of the tip 24-1 may be provided by undercuts 34 shown in
The detailed description and the drawings or figures are supportive and descriptive of the disclosure, but the scope of the disclosure is defined solely by the claims. While some of the best modes and other embodiments for carrying out the claimed disclosure have been described in detail, various alternative designs and embodiments exist for practicing the disclosure defined in the appended claims. Furthermore, the embodiments shown in the drawings or the characteristics of various embodiments mentioned in the present description are not necessarily to be understood as embodiments independent of each other. Rather, it is possible that each of the characteristics described in one of the examples of an embodiment may be combined with one or a plurality of other desired characteristics from other embodiments, resulting in other embodiments not described in words or by reference to the drawings. Accordingly, such other embodiments fall within the framework of the scope of the appended claims.
