Abstract
An oil scraper ring (4) includes a ring element (6), having an upper ring edge (8), a lower ring edge, a ring inner side and a ring outer side (14. The ring element (6) is provided with two opposing contact surfaces (20), between which there is a ring gap (18. The ring element (6) is provided with at least one scraper bar (24, 26) on the ring outer side (14. The oil scraper ring (4) is provided with two recesses (28), each arranged on each contact surface (20), and each adjoining at least on the ring outer side (14), the respective contact surface (20) and the upper ring edge (8).
Claims
1-14. (canceled)
15. An oil scraper ring comprising: a ring element, having an upper ring edge, a lower ring edge, a ring inner side and a ring outer side, wherein the ring element is provided with two opposing contact surfaces, between which there is a ring gap, wherein the ring element is provided with at least one scraper bar on the ring outer side, and wherein the oil scraper ring is provided with two recesses, each in the region of the contact surfaces, each adjoining at least on the ring outer side, the respective contact surface and the upper ring edge, and wherein the oil scraper ring is provided with at least one further radial recess in the region spaced apart from the ring gap, which extends at the upper ring edge from the ring outer side in the direction of the ring inner side.
16. The oil scraper ring according to claim 15, wherein the recesses extend symmetrically to a mirror plane of the contact surfaces.
17. The oil scraper ring according to claim 15, wherein in an installed state, a width of the ring gap is defined as a distance of the contact surfaces in the circumferential direction, and wherein a width of a sum of the width of the recesses and the ring gap in the circumferential direction with an installed ring is a factor of 2 to 5 greater than the width of the ring gap.
18. The oil scraper ring according to claim 15, wherein the ring element comprises, an upper scraper bar and a lower scraper bar, wherein the recess extends into a region of an upper scraper bar, and wherein preferably the upper scraper bar is shorter than the lower scraper bar by the width of the recesses.
19. The oil scraper ring according to claim 15, wherein the recess is delimited by a part of a spherical surface, a cylindrical surface, a conical surface or a cuboid surface.
20. The oil scraper ring according to claim 15 wherein the recesses on the contact surface further adjoin the ring inner side.
21. The oil scraper ring according to claim 15, wherein at least one radial recess extends to the ring inner side.
22. The oil scraper ring according to claim 15, wherein at least one radial recess and the two recesses on the ring gap are distributed uniformly over the circumference of the oil scraper ring.
23. The oil scraper ring according to claim 15, wherein the two recesses or radial recess closer to the ring gap are arranged closer to one another than at a ring back, and wherein an even number of radial recesses are used.
24. The oil scraper ring according to claim 15, wherein the two recesses and the at least one radial recess closer to the ring gap each have a depth which decreases in the circumferential direction in the direction of the ring back.
25. The oil scraper ring according to claim 15, wherein the two recesses or the at least one radial recess have a depth which is between 0.1 and 0.3 mm.
26. The oil scraper ring according to claim 15, wherein the two recesses and/or the at least one radial recess do not interrupt the upper scraper ring.
27. A piston ring set with an oil scraper ring according to claim 15, further comprising at least one oil control ring with a control ring element, which comprises an upper control ring edge, a lower control ring edge, a control ring inner side and a control ring outer side, and wherein the control ring element is provided with a control ring gap which is located between two opposite control contact surfaces and wherein the control ring in the region of the control contact surfaces is provided with two recesses which at least on the ring outer side each adjoin the respective contact surface and the lower ring edge.
Description
THE DRAWINGS
[0021] The invention is described hereinafter with reference to schematic prior-art figures and exemplary embodiments of the present invention.
[0022] FIG. 1 shows a partial view in the region of a ring gap of a conventional oil scraper ring.
[0023] FIG. 2 shows a diagram of a partial view of an oil scraper ring according to the invention with sloping recesses at the ring gap.
[0024] FIG. 3 shows a partial view of an oil scraper ring according to the invention with recesses at the ring gap which are delimited by a partial surface of a cone surface.
[0025] FIG. 4 shows a diagram of a partial of an oil scraper ring according to the invention with cuboid recesses at the ring gap.
[0026] FIG. 5 shows a partial view of an oil scraper ring according to the invention with recesses at the ring gap which extend from an outer side to an inner side.
[0027] FIG. 6 shows a partial view at a point spaced apart from the ring gap at which a radial recess is provided which interrupts the upper scraper bar.
[0028] FIGS. 7 and 8 show diagrams of further versions of a radial recess which in each case are not interrupted by an upper scraper bar.
[0029] FIG. 9 shows a diagram of a further version of a radial recess which extends from the ring outer side to the ring inner side.
DETAILED DESCRIPTION
[0030] In the following both in the figures and in the text of the description, the same or similar reference numerals are used to refer to the same or similar elements and components.
[0031] FIG. 1 shows a perspective partial view of a conventional oil scraper ring 1 in the region of a ring gap 18. The conventional oil scraper ring 2 comprises a ring element 6 having an upper ring edge 8, a concealed lower ring edge, a ring inner side which is also not visible and a ring outer side 14. The ring element 6 is interrupted at a contact wherein two opposite contact surfaces 20 are formed between themselves between a ring gap 18. Here and in the following the ring gap dimensions are always considered in the installed state. The ring element 6 is provided with at least one scraper bar 24, 26 on the ring outer side. The oil scraper ring according to the prior art and/or according to the invention can further be provided with oil passages which extend between the scraper bars from the ring outer side in the direction of the ring inner side which however are not shown for reasons of clarity.
[0032] FIG. 2 shows a diagram of a perspective partial view of an oil scraper ring 4 according to the invention in the region of the ring gap 18 with sloping recesses 28. Here also the oil scraper ring 4 according to the invention comprises a ring element 6. The ring element here comprises an upper ring edge 8, a lower ring edge which cannot be seen, a concealed ring inner side and a ring outer side 14. The ring element 6 has a ring gap 18 which is delimited by two opposite contact surfaces 20. On its ring outer side 14 the ring element 6 is provided with at least one scraper bar 24, 26. In the region of the contact surfaces 20 the oil scraper ring 4 has two recesses 28, one on each contact surface 20. Each of the recesses in this case adjoins the ring outer side 14, the respective contact surface 20 and the upper ring edge 8. In FIG. 2 the recesses each approximately correspond to a triangular prism. Here, blow-by gases which have passed at least two compression or oil control rings located one above the other can flow into an intermediate chamber between the upper and the lower scraper bar (24, 26). From there the blow-by gases can flow in the circumferential direction and flow through oil passages not shown inwards in the direction of the oil scraper ring groove base and thereby entrain oil droplets. This allows more oil to be fed back in the direction of the crankcase, wherein in particular in an overrun mode less oil can enter into the combustion chamber.
[0033] FIG. 3 shows a partial view of an oil scraper ring according to the invention which corresponds to FIG. 3 apart from the shape of the recesses. Instead of recesses having a triangular cross-section, recesses are used here which are delimited by a part of a cone surface. As a result of this shape, the blow-by gases can flow even better in the direction of the intermediate space between the upper and the lower scraper bar 24, 26.
[0034] FIG. 4 shows a further possibility for configuring the shape of the recesses 28. The other parts of FIG. 4 correspond to FIGS. 2 and 3. The recesses 28 of FIG. 4 are delimited by cuboid surfaces.
[0035] FIG. 5 shows a further possible embodiment of the ring gap 18 or the recesses 28. As in FIG. 4, the recesses 28 of FIG. 5 are delimited by cuboid surfaces, wherein the recesses extend in the radial direction completely through the oil scraper ring 4. Here the blow-by gases can also flow directly through the recesses 24, 26 in the direction of the ring groove base.
[0036] FIG. 6 shows an embodiment of an oil scraper ring in which the recesses of FIG. 4 are used at a location spaced apart from the ring gap and the contact surfaces. These are designated as radial recesses 34 in order to be able to distinguish them from the recesses at the ring gap. Here also this is based on the principle of achieving an improved flow from outside to inside through the oil scraper ring by the blow-by gases.
[0037] In FIG. 7 the radial recess 34 of FIG. 6 is designed to be only very flat so that the radial recess 34 does not interrupt the upper scraper bar 24 in the axial direction. The radial recess 34 in FIG. 7 extends in the radial direction only over a part of the upper ring edge 8. The radial recess 37 forms over the entire upper ring edge 8 so that the radial recess only forms a passage to a piston ring groove base with a positively twisted oil scraper ring. If the oil scraper ring is negatively twisted, the continuous edge between the ring inner side and the upper ring edge abuts against an upper oil scraper piston ring groove of a piston and passage of oil in the radial direction is prevented.
[0038] In FIG. 8 the radial recess 34 is only designed to be very flat as in that of FIG. 7 so that here also the radial recess 34 does not interrupt the upper scraper bar in the axial direction. In FIG. 8 the radial recess 37 extends over the entire upper ring edge 8 so that the radial recess forms a passage to a piston ring groove base in each twist position of the oil scraper ring.
[0039] In FIG. 9 the radial recess 34 of FIG. 6 is lengthened as far as the ring inner side.
