WO2000075538A1

WO2000075538A1 - A fluid passage seal

Info

Publication number: WO2000075538A1
Application number: PCT/US2000/013857
Authority: WO
Inventors: David G. Baltz; Allyn P. Bock; Frederick R. Brotherson; Deborah K. Light; Lynette M. Lipski; Joseph T. Phillips
Original assignee: Caterpillar Inc.
Priority date: 1999-06-03
Filing date: 2000-05-19
Publication date: 2000-12-14

Abstract

A fluid passage seal (10) includes a resilient member (20, 20') made from an elastomeric material and a rigid tubular member made from a plastic material. The rigid tubular member (30) defines a first end (33) and a second end (34). The resilient member (20, 20') defines a flat end portion (204, 214, 204') being attached to the respective first and second end (33, 34).

Description

A FLUID PASSAGE SEAL

Technical Field

The present invention relates generally to a fluid passage seal, and more particularly to a ferrule seal for an engine to provide a leak- free seal between respective coolant and oil passages in an engine block and an engine head in order to prevent any leakage of engine coolant into engine oil and vice-versa.

Background Art

A typical engine assembly includes an engine block, a first gasket with a fire ring positioned on top of the engine block, a spacer deck positioned on top of the first gasket, a second gasket positioned on top of the spacer deck, and lastly, an engine head positioned on top of the second gasket, the head being bolted to the engine block. The fire ring provides a leak- free seal between the head and the block, thus preventing combustible fuel and resultant combustion products from blowing into an engine jacket. A liquid coolant is generally circulated in the engine jacket to maintain the engine operating temperature at a desired level .

Liquid coolant passages within the engine block and the head facilitate the flow of the liquid coolant between the engine block and head. In order to provide a leak- free seal between the coolant passages in the block and the head, ferrule seals are located within the spacer deck. These ferrule seals prevent the coolant from leaking between the engine block and head as the coolant flows through the passages under the pressure generated by a coolant flow pump.

If the coolant leaks past the ferrule seal, it can corrode the spacer deck and the mounting bolts that fasten the head to the block. Continued coolant leakage can cause loss of cooling capacity and even a catastrophic failure of the engine.

Ferrule seals are also used m the oil lubrication passages m the engine head and block in a similar manner. Any oil leakage past the ferrule seal can cause loss of lubricating capacity and a catastrophic failure of the engine.

Most currently used ferrule seals have the shape of a tall narrow column, or a cylinder, formed from an elastomeric material such as a fluoroelastomer . Such seal designs have limited load bearing capacity and can fail under pressure because the elastomeric material is displaced radically, thereby causing the seal to leak. One of the designs currently being used by the assignee of the present invention includes a metal cylinder inserted within the tall narrow column. While the sealing ability of this tall narrow column of elastomeric material is increased due to the stiff metal cylinder present as a backing, this poses an additional problem. The nonbacked-up portion of the elastomeric material is displaced radially. Also, when the engine block and head are bolted together and the bolts are torqued, the elastomeric material is displaced radially, and m some instances, radially outward away from the stiff metal cylinder leaving the extremities, top and bottom of the metal cylinder exposed, which can gouge the head and/or the block. When the engine is overhauled or rebuilt, the head and the block have to be ground or honed m the places where the metal cylinder has gouged the material . Additionally, since the metal cylinder inserted within the tall narrow elastomeric column was not bonded to the elastomeric seal. As stated above, when clamped m place, the column of elastomeric material displaced outwardly from the sealing surface. This outward displacement prevented adequate sealing of the elastomeric material at the sealing surface.

It is been desirable to have a ferrule seal having a rigid insert that does not gouge the head and/or the block. It is desirable to have a seal which does not buckle or radially displace resulting m a leak path when compressed. It is also desirable to have a ferrule seal formed from an elastomer and having a shape that mimics the dynamic deformation and compression of an O-ring seal rather than a cylindrical column of an elastomer.

The present invention is directed to overcome one or more problems of heretofore utilized ferrule seals for sealing respective coolant and oil passages between the block and head.

Disclosure of the Invention

In one aspect of the present invention, a fluid passage seal includes (a) a resilient member made from elastomeric materials and (b) a rigid tubular member made from plastic materials and located between each end of the resilient members a resilient member made from elastomeric materials. The resilient member includes a first end having a cylindrical outer surface, a curved end surface, and a cylindrical inner surface. The resilient member further includes a second end having a cylindrical outer surface, a curved end surface, and a cylindrical inner surface. The resilient member also includes a middle portion connected to the first end and the second end. The middle portion has a cylindrical outer surface and a cylindrical inner surface. The cylindrical outer surface of the middle portion is connected to the cylindrical outer surfaces of the first end and the second end to respectively form an uninterrupted surface with the respective cylindrical outer surfaces of the first and second ends. The cylindrical inner surface of the middle portion is connected to the cylindrical inner surfaces of the first end and the second end to respectively form a first end radically directed inner surface and a second end radically directed inner surface. The first end, second end and middle portions are of a unitary construction. It is contemplated that for ease of manufacture, a unitary construction including a first end, second end, and middle portion may be used. It is contemplated that the unitary construction could be achieved by molding the resilient member over the rigid tubular member.

It is also contemplated that a pair of resilient members may be utilized at a first end and a second end of the rigid tubular member. The pair of resilient members include a first end having a cylindrical outer surface, a curved end surface, and a cylindrical inner surface. It is contemplated that this construction could be achieved by forming the pair of resilient members on the rigid tubular member. Alternatively, this construction could be achieved by bonding or fastening the resilient member to the rigid tubular member. The rigid tubular member includes a cylindrical outer surface, a cylindrical inner surface, the first end surface and the second end surface. The rigid tubular member has a length substantially equal to the length of the middle portion inner surface of the resilient member. The cylindrical outer surface, first end surface and second end surface of the rigid member are respectively encapsulated by the cylindrical inner surface of the middle portion, the radically directed inner surface of the first end and the radically directed inner surface of the second end.

Brief Description of the Drawings

FIG. 1 is a sectional side view of an embodiment of the fluid passage seal of the present invention; [and]

FIG. 2 is a sectional side view of another embodiment of the fluid passage seal of the present invention; and FIG. 3 is a sectional side view of another embodiment of the fluid passage seal of the present invention.

Best Mode for Carrying Out the Invention Fig. 1 shows a preferred embodiment of the present invention. A seal 10 includes a resilient member 20 made from elastomeric materials and a rigid tubular member 30 made from plastic materials. In this embodiment, the resilient member 20 has a tubular configuration. The rigid member 30 is located within the resilient member 20. As shown m Fig. 1, the rigid member 30 is located concentrically within the resilient member 20.

The resilient member 20, with the tubular configuration, includes a first end portion 200, a second end portion 210 and a middle portion 220. The first end portion 200 has a cylindrical outer surface 201, a curved end surface 202, a cylindrical inner surface 203, and a flat end surface 204 extending at least partially between the cylindrical outer surface 201 and the cylindrical inner surface 203. A pre- established spacing or distance is defined between the cylindrical outer surface 201 and the cylindrical inner surface 203. The flat end surface 204 extends at least half the distance between the cylindrical outer surface 201 and the cylindrical inner surface 203. The flat end surface 204 supports the resilient member 20. Any loads placed on the resilient member 20 are transferred to the rigid member 30 by the flat end surface 204. The second end portion 210 of the tubular configuration has a cylindrical outer surface 211, a curved end surface end 212 and a cylindrical inner surface 213. The middle or connecting portion 220 has a cylindrical outer surface 221 and a cylindrical inner surface 222. The middle portion is connected to the first end portion 200 and the second end portion 210 as shown m Fig. 1. And, preferably, m this embodiment, the first end portion, the middle portion and the second end portion are of one unitary construction, made, for example, by injection molding an elastomeric material . As further shown m this embodiment, the cylindrical outer surface 221 of middle portion 220 is connected to the cylindrical outer surfaces 201,211 of the first and second end portions 200,210 respectively, to form an uninterrupted smooth surface therewith. The cylindrical inner surface 222 of middle portion 220 is connected to each of the flat end surface 204 of first end portion 200 and the flat end surface 214 of second end portion 210 to respectively define an outer extremity of flat end surface 204 and the flat end surface 214

The rigid tubular member 30 includes a cylindrical outer surface 31 and a cylindrical inner surface 32, a first end surface 33 and a second end surface 34 as shown m Fig. 1. The rigid tubular member 30 has a length desirably substantially equal to the length of the middle portion 220 of resilient member 20, and preferably marginally less than the length of the middle portion. In the preferred embodiment, the cylindrical outer surface 31, the first end surface 33 and the second end surface 34 of member 30 are respectively encapsulated or are covered by the cylindrical inner surface 222, flat end surface 204 and flat end surface 214 of resilient member 20, respectively. In the preferred embodiment, the cylindrical outer surface 31, the first end surface 33, and the second end surface 34 are bonded to the cylindrical inner surface 222, the flat end surface 204 and the flat end surface 214 respectively. Alternatively, the resilient member 20 and the rigid member 30 can be attached or formed together forming a unitary construction. In another embodiment, as shown m Fig. 2, the cylindrical outer surface 31 of rigid member 30 has one or more grooves 41 formed therein for meeting with respective one or more ridges 42 formed on the cylindrical inner surface 222 of resilient member 20.

In the preferred embodiment, the resilient member 20 is made from tough resilient elastomeric materials such as fluoroelastomers or silicone polymers. These materials are well known to those skilled m the art and need not be discussed m any further detail. The rigid member 30 is made preferably from plastic material such as polycarbonate or polycarbonate reinforced with reinforcing fibers such as aramid fibers, glass fibers and the like. Such materials are also well known to those skilled m the art and need not be discussed m any further detail .

Referring Fig. 3, in this embodiment, additional elements of a like feature have been added and are designated by a prime (' ) number.

A seal 10' includes a pair of resilient members 20' made from elastomeric materials and the rigid tubular member 30 made from plastic materials. An individual pair of resilient members 20' are located at each of the first end surface 33 and the second end surface 34 of the rigid member 30. As shown m Fig. 3, the pair of resilient members 20' include an end portion 200' having a configuration equivalent to that of the first end portion 200 and the second end portion 210. The end portions 200' have a cylindrical outer surface 201', defining an equivalent to the cylindrical outer surface 221, and a curved end surface 202', a cylindrical inner surface 203', defining an equivalent to the cylindrical inner surface 222 as shown m Fig. 1., and a flat end surface 204' interposed the entire distance between the cylindrical outer surface 201' and the cylindrical inner surface 203'.

In this application, the pair of resilient members 20' are formed on the rigid tubular member 30. As an alternative, the pair of resilient members 20' could be attached or bonded to the rigid tubular member 30.

Industrial Applicability

The present invention is particularly useful for providing a leak- free union between respective fluid passages in opposing bodies at a connective junction, such as a ferrule seal used for sealing the coolant and/or oil passages m an engine block and head.

Fig. 1 shows a preferred embodiment of the present invention due to the ease of manufacture of a unitary construction of the resilient member. Referring now to Fig. 1, a fluid passage seal 10 is adapted for providing a leak- free union between respective fluid passages m opposing members at a connective junction.

In the preferred embodiment, the sealing surfaces of seal 10 are formed by the first end portion 200 and the second end portion 210 and because of the curved shape of the respective curved end surface 202 and curved end surface 212, the actual seal contact area is increased when the seal is compressed, thereby reducing the chance of a leakage. The seal behaves almost like an 0-rιng. For example, as the block and the head of the engine are bolted together, a force is applied to the first end portion 200 and the second end portion 210. The force acts on each of the curved end surface 202 and curved end surface 212. Thus, the cross-sectional area of a portion of the resilient member 20 is trapped between one of the block and the head, and one of the first end surface 33 and the second end surface 34 of the rigid member 30, respectively. This trapped portion of the resilient member 20 has a compressive load applied thereto resulting m a positive effective seal 10. With the portion of the resilient member 20 trapped between one of the block and the head, and one of the first end surface 33 and the second end surface 34 of the rigid member 30, respectively, the buckling effect and any radially outward tendencies of past seals are eliminated. Because the rigid member 30 is substantially equal to or marginally smaller in length than the middle portion of the resilient member 20, the rigid member can fit inside the resilient member 20 and this helps to transfer the load subjected upon respective first and second end portions 200, 210 of the resilient member 20 to the rigid member 30.

Other aspects, objects and advantages of this invention can be obtained from a study of the drawings, the disclosure and the appended claims.

Claims

1. A seal (10) , comprising: a tubular member (30) being made of a rigid material, said tubular member (30) defining a first end surface (33) and a second end surface (34) being spaced apart a preestablished distance; a resilient member (20,20') being made from an elastomeric material, said resilient member (20,20') defining an end portion (200,210,200'), having a cylindrical outer surface (201,211,201'), a curved end surface (202,212,202') extending from said cylindrical outer surface (201,211,201'), and a cylindrical inner surface (203,213,203') extending from curved end surface (202 , 212 , 202 ' ) , and a flat end surface (204,214,204') being at least partially interposed said cylindrical outer surface (201,211,201') and said cylindrical inner surface (203,213,203' ) ; said first end surface (33) and said second end surface (34) being m contacting relationship with said flat end surface (204,214,204') of said resilient member (20,20'); and said tubular member (30) and said resilient member 20,20') being unitaπly connected.

2. The seal (10) of claim 1, wherein said resilient member (20 , 20 ') further a first end portion

(200), and a second end portion (210) and including a middle portion (220) connecting said first end portion (200) and a second end portion (210) .

3. The seal (10) of claim 2, wherein said tubular member (30) further defines a cylindrical outer surface (31) extending between said first end surface (33) and said second end surface (34) and said middle portion (220) being m contacting relationship with said cylindrical outer surface (31) .

4. The seal (10) of claim 1, wherein said cylindrical outer surface (31) includes a groove (41) .

5. The seal (10) of claim 2 further includes a middle portion (220) connecting each of said pair of resilient members (20) and a portion of said middle portion (220) is m contacting relationship with said groove.

6. The seal (10) of claim 1, wherein said tubular member (30) further defines a cylindrical inner surface (32), said cylindrical inner surface (203,213,203') of said resilient member (20,20') being aligned with said cylindrical inner surface (32) .

7. The seal (10) of claim 1, wherein a distance is defined between said cylindrical outer surface (201,211,201') and said cylindrical inner surface (203,213,203') and said flat end surface (204,214,204'), extending at least one half of the distance defined between said cylindrical outer surface (201,211,201') and said cylindrical inner surface (203,213,203').

8. The seal (10) of claim 7, wherein said flat surface (204,214,204') transfers a load to said first end surface (33) and said second end surface (34) of said rigid tubular member (30) .

9. The seal (10) of claim 1, wherein said pair of resilient members (20,20') are bonded to said tubular member (30) .

10. The seal (10) of claim 1, wherein said pair of resilient members (20,20') are attached to said tubular member (30) .

11. The seal (10) of claim 1, wherein said pair of resilient members (20,20') are formed on said tubular member (30) .