RU2535599C1 - Ice piston seal oil scraper - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: upper oil scraper is fitted in piston groove as well as mid oil scraper and lower oil scraper while expansion rings are arranged there between. Working surface of oil scrapers feature flat cylindrical part and skew towards piston stroke to TDC and has expansion rings arranged there between. Oil scrapers feature rectangular profile. Note here that said flat cylindrical surface of every underlying ring is larger than that of overlying ring. Minimum depth of hydrodynamic lubing ply is formed on cylinder wall.

EFFECT: minimised mechanical losses and motor oil wastes.

3 cl, 1 dwg

Description

The invention relates to mechanical engineering, and specifically to the design, manufacture and operation of internal combustion engines.

Known oil scraper piston devices of internal combustion engines containing oil scraper rings and expanders of various designs (Application No. 53-22204, Japan, 1978; Application No. 59-20859, Japan, 1984; copyright certificate No. 1312217, USSR, 1985, patent RU No. 2458239, IPC F02F 5/00, published on 08/10/2012).

Known oil scraper ring of an internal combustion engine containing scraper elements and an expansion ring located between them, made in the form of a truncated cone (patent RU No. 2447307, RU IPC F02F 5/00, published on 04/10/2012).

The prototype has a significant drawback, which is that the presence of only two scraper elements located in one piston groove of the oil scraper piston device limits the possibility of forming the minimum necessary lubricant layer for a wide range of ICEs, leaving an excessive amount of oil on the cylinder wall, as with small so, especially at high speeds of the crankshaft of the engine, which is reflected in increased oil consumption and environmental degradation of the engine. In addition, the expander is quite metal-intensive, has a significant mass and dimensions exceeding the dimensions of the scraper elements, not technologically advanced for small engines with small cylinder diameters.

The technical result, the achievement of which the present invention is directed, is to increase the efficiency of the oil scraper piston device, increase its life, reduce the consumption of motor oil, and improve the environmental performance of the engine.

The technical result is achieved in that in the oil scraper piston device of an internal combustion engine containing oil scraper rings, the working surface of which has a flat cylindrical part and a bevel in the direction of movement of the piston in the upper position, and expansion rings located between them are new, that the oil scraper rings are made a rectangular profile, while the flat cylindrical part of the working surface of each underlying ring is larger than the flat cylindrical part of the working surface in overlying ring.

The expansion rings are made in the form of axial wave-like extenders of the membrane type and are installed with a gap relative to the cylinder wall.

The depth of the piston groove is equal to the radial thickness of the oil scraper rings.

The drawing shows a partial section of an internal combustion engine.

The internal combustion engine contains a cylinder 1, a piston 2, a piston groove 3, in which an upper oil scraper ring 4, a middle oil scraper ring 5 and a lower oil scraper ring 6, expansion rings 7, conical drain holes 8 are installed.

Oil scraper piston device operates as follows.

When the piston 2 moves to the lower position, the lower oil scraper ring 6, having a maximum contact area of the working surface with the cylinder wall 1, determined by the maximum value of h ₁ (the height of the flat cylindrical part of the working surface of the oil scraper ring) and, accordingly, the minimum specific pressure on the cylinder wall 1, with its lower end protruding from the piston groove 3 within the guaranteed clearance between the cylinder wall 1 and the piston 2, removes the main part of the oil from the cylinder wall 1. Removable from the cylinder wall 1 and oil through the gap between the wall of the cylinder 1 and the piston 2 is discharged into the crankcase. Following it, the oil scraper ring 5 with an increased specific pressure on the wall of the cylinder 1, due to the lower value of h _2, removes a smaller part of the oil from the wall of the cylinder 1, leaving a thickness of the oil layer on the wall of the cylinder 1, approaching the minimum required value, finally formed by the oil scraper ring 4 s even lower h ₃ and even greater specific pressure. The oil removed from the cylinder wall 1 by the oil scraper rings 5 and 4 is removed through the radial channels of the expansion rings 7 and the drain conical openings 8 into the internal piston cavity 2. The conical drain openings 8 improve the removal of oil from the piston groove 3 and counteract the suction of oil from the internal cavity of the piston 2 by working intake stroke, when a vacuum is generated above the piston 2 and in the gaps of the piston groove 3. Expansion rings 7, made in the form of axial wave-like extenders of the membrane type and installed with a gap relative to the cylinder wall 1, compensate for changes in the width of the piston groove 3 due to thermal deformation of the piston 2 and wear of the shelves of the groove 3, eliminating the gap between the shelves of the piston groove 3 and the lower end of the lower oil scraper ring 6 and the upper end of the upper oil scraper ring 4. Expansion rings 7 eliminate axial clearances in the oil scraper piston device, thereby eliminating the "pumping" effect, accompanied by giving the job of piston rings.

Thus, each subsequent ring, overlapping the permissible technological gaps between the wall of the cylinder 1 and the working surface of the previous ring, as well as the gap in the lock of the previous ring, reduces the amount of oil left on the wall of the cylinder 1, bringing it closer to the calculated value. The more oil scraper rings in the oil scraper piston, the less hydraulic resistance the oil exerts when the piston moves to the lower position, thereby increasing engine efficiency. Considering that engine oil is a fluid that is practically incompressible, and the piston speed is huge, measured in meters per second, translating the dynamics of the process of removing oil from the engine cylinder wall with one or even two oil scraper rings into a static process n the number of oil scraper rings will favorably affect the whole work engine. When the piston 2 moves to the upper position, the bevels made on the working surfaces of the oil scraper rings ensure the safety of the formed oil layer thickness on the cylinder wall 1, preventing it from scraping in the direction of the compression rings and entering the combustion chamber.

Claims (3)

1. Oil scraper piston device of an internal combustion engine containing oil scraper rings located in the piston groove, the working surface of which has a flat cylindrical part and beveled in the direction of piston movement to the upper position, and expansion rings located between them, characterized in that the scraper rings are made of a rectangular profile moreover, the flat cylindrical part of the working surface of each underlying ring is larger than the flat cylindrical part of the working surface th rings. 2. Oil scraper piston device of an internal combustion engine according to claim 1, characterized in that the expansion rings are made in the form of axial wave-like extenders of the membrane type and are installed with a gap relative to the cylinder wall. 3. Oil scraper piston device of an internal combustion engine according to claim 1, characterized in that the depth of the piston groove is equal to the radial thickness of the scraper rings.