Sealing system for an internal-combustion engine

A sealing system for an internal-combustion engine is provided in which a lubricating-oil-carrying space particularly an oil catching space, is separated by wall elements from adjoining space sections, which wall elements have elastic sealing elements for sealing off the spaces. For the compensation of sealing gap tolerances, a sealing element is provided which has at least two sealing arms which come to rest on the space wall to be sealed off. Despite larger sealing gap tolerances, a secure oil-tight separation of spaces is thereby provided.

BACKGROUND AND SUMMARY OF THE INVENTION

The invention relates to a sealing system for an internal-combustion engine. Preferred embodiments of the invention relate to a sealing system for an internal-combustion engine, in which a lubricating oil catching space is separated by wall elements from adjoining space sections, which wall elements have elastic sealing elements for sealing off the spaces.

It is generally customary to separate oil-carrying space sections in an internal-combustion engine by means of corresponding sealing elements in order to thereby prevent an undesirable transfer of lubricating oil. In U.S. Pat. No. 5,467,843, for example, an intermediate shaft disposed below the crankshaft is separated by means of wall cross-struts. At the edges of these cross-struts, sealing elements are inserted in a groove, by means of which sealing elements, the two spaces are sealed off. However, it is a problem when major sealing gap tolerances are to be compensated, particularly as a result of the mounting or assembly of the engine structure. When conventional sealing elements are used which have, for example, a circular cross-section, in the case of sealing gap tolerances, either the two components are no longer reliably sealed off or a sealing pressure takes place which, for example, when plastic parts are used, generates sealing forces in the main force closure which may damage the plastic part.

It is therefore an object of the invention to further develop a sealing device which can be used for shutting-of or sealing-off oil-guiding space sections and which, despite existing sealing gap tolerances of, for example, +/−2 to 3 mm, ensures a reliable sealing off of the oil space or spaces.

This object of the invention is achieved by providing a sealing system for an internal-combustion, in which a lubricating oil catching space is separated by wall elements from adjoining space sections, which wall elements have elastic sealing elements for sealing off the spaces, wherein a sealing element is provided for compensation of sealing gap tolerances which has at least two sealing arms which in use abuttingly engage a space wall to be sealed off.

By means of a sealing device equipped with at least two sealing arms, sealing gap tolerances can be compensated so that, despite existing sealing gaps, the oil-carrying space or spaces are securely sealed off. As a result of the fact that the two sealing arms rest elastically or flexibly in the secondary force closure against the space wall to be sealed off, no excessive sealing forces are generated so that the sealing element according to the invention is suitable particularly for sealing off plastic components or similar devices.

This specification and the following claims describe additional advantageous further developments and improvements of the sealing system according to preferred embodiments of the invention for an internal-combustion engine.

A particularly advantageous embodiment of a sealing profile is obtained when the cross-section of the sealing elements is Y-shaped.

Sealing elements according to the preferred embodiments of the invention are particularly suitable for separating two oil suction spaces from one another in an internal-combustion engine. In this case, the oil shut-off wall provided with the sealing element is arranged between an oil suction pipe and an oil barrier insertion part which separates the two oil suction spaces from one another.

For packaging reasons, the oil suction pipe is constructed in two parts according to certain preferred embodiments of the invention, that is, of a base part and of a flat cover part closing an opening of the base part. As a result, the oil pan can be flanged directly to the crankcase without having to change, for example, the space of the oil pan because of the oil suction pipe.

For optimizing the flow of the suctioned-off lubricating oil, two spillway-type projections are provided on the interior side of the cover part according to certain preferred embodiments of the invention.

Two embodiments of the invention will be explained in detail in the following description and drawing.

DETAILED DESCRIPTION OF THE DRAWINGS

An oil catching housing2has a space section4which, in the following, will be called a first oil collecting space and in which the oil collects which is required for the lubricating oil supply of the internal-combustion engine. In the first oil collecting space4, a snorkel6is placed at its lowest point, which snorkel6leads by way of a first oil suction pipe8to the suction side of an oil pump10. In the oil catching housing2, a second space12is situated which in the following is called a second oil collecting space and which has a flatter construction than the first collecting space4. In the second oil collecting space12, an oil snorkel14is also arranged at its lowest point, which oil snorkel14is connected by way of a second oil suction pipe16with a second suction side of the oil pump10constructed as a double pump.

A plastic insertion part18is inserted in the oil catching housing2, which plastic insertion part18, in the installed condition, separates the two oil collecting spaces4,12from one another. The insertion part18has a rearward side wall20which engages in a holding groove22arranged on the bottom of the oil catching housing2and extends transversely to the longitudinal course of the oil catching housing2. This groove and tongue connection is additionally sealed off by silicone or flexible foam because it is to be prevented that, during an inclined position of the motor vehicle, lubricating oil from the first oil collecting space4flows into the second oil collecting space12. In contrast, in an inclined position of the engine, the lubricating oil situated in the first oil collecting space4can flow under the insertion part18. As a result, this space section is also utilized for receiving the oil volume required for a reliable lubricating oil supply.

The oil suction pipe16extends above the insertion part18, which operates as an oil-tight shut-off wall between the two oil suction spaces4,12. So that the oil suction pipe16does not protrude beyond the flange surface24of the oil catching housing2, a duct26with a circular-arc-shaped cross-section, in which the oil suction pipe16is accommodated, is provided on the top side of the insertion part18. On the face of the insertion part18facing the oil pump10, the receiving duct26changes into an also circular-arc-shaped recess28. A plastic separating element30fastened to the oil suction pipe16engages in this recess28. The corresponding face of the separating element30adapted to the contour of the recess28has a receiving groove32in which an elastomer sealing element34is received as an oil-tight separation between the oil suction pipe16and the plastic insertion part18. The omega-shaped sealing element34has a sealing web36which is clampingly received in the groove32of the separating element30. Furthermore, the sealing element34has two sealing arms38and40which, in the installed condition, rest sealingly against the surface of the recess28of the plastic insertion part18. Because of the omega-shaped cross-sectional profile of the sealing element34, sealing gap tolerances of approximately +/−2.5 mm can be absorbed or compensated. For the sealing-off with respect to the plastic insertion part18, the two sealing arms38and40operate in the secondary force closure, so that the forces which are introduced by way of the sealing element34into the plastic insertion part18are low and do not damage the plastic insertion part18.

In the present embodiment, the sealing gap tolerances are a result of the assembly sequence: The oil pump10together with the oil suction pipe16is mounted on a crankcase bottom half, which is not shown, while the plastic insertion part18is screwed into the oil guiding housing2. As a result of the ψ or Y-shaped sealing element34, such tolerances can be securely and reliably compensated. Thus, despite the oil suction pipe16traversing the plastic insertion part18, it is ensured that, when the internal-engine is in an inclined position, the lubricating oil situated in the first oil collecting space4cannot flow into the rearward second oil collecting space12.

A second embodiment of an elastomer sealing element34ais illustrated in FIG.5. The Y-shaped sealing element34a, in turn, has a sealing web36awhich is received in the groove32of the separating element30. The two sealing arms38aand40a, in turn, in the installed condition, rest sealingly against the surface of the recess28of the plastic insertion part18.

The oil suction pipe16illustrated in detail inFIGS. 6to8is constructed in two parts and consists of a base part44having an opening42, the opening42being closed off by a flatly constructed cover46. The cover46is frictionally welded to the base part44and securely seals off the opening42. For optimizing the flow of the lubricating oil suctioned off from the second oil collection space12, one spillway-type projection48and50respectively is arranged on the interior side of the cover46at the start and at the end. Because of the flow direction of the lubricating oil illustrated inFIG. 7, a breakaway edge AK is formed when the lubricating oil enters the opening42forming a chamber. As a result of the projection48engaging in the opening42(in the mounted condition), this breakaway edge is eliminated and, without being swirled or dammed up, the lubricating oil can be transmitted to the outlet52of the oil suction pipe16. Analogously, a retaining edge SK is formed at the outlet of the opening42forming the chamber. By means of the projection50engaging in the opening42, the oil flow is directed by way of the projection50into the center of the flow cross-section, whereby the retaining edge is eliminated.