US2156227A - Engine packing - Google Patents

Description

April 25, 1939. R c. PAYNE ENGINE PACKING Original Filed July 16, 1934 Patented Apr. 25, 1939 UNITED STATES ATENT OFFICE ENGINE PACKING Rufus C. Payne, Chicago, Ill.

Claims.

In a reciprocating engine, compressor or the like, the usual form of piston fits into the cylinder with a small amount of clearance, and has thereon certain circumferential grooves. Seated 5 in these grooves are the conventional elements which we term piston rings, said rings being transversely out having more or less inherent resiliency to stop the passage of gas, thereby conserving compression, and thus more power is made available. These rings must quite accurately fit the contour of the cylinder walls as well as the side walls of the circumferential grooves. In new pistons this is more or less simple. But after a certain amount of use the cylinders become worn out of round by the unequal pressure exerted by the reciprocating piston, due mostly to the side thrust of the connecting rod. Under these conditions the parts become worn, and we have What is termed piston slap and loss of compression. A ring to conform to the out of round cylinder must have incorporated in its makeup a quality of resiliency. By seating underneath the ring in the ring groove a thin spring, termed an expander or inner spring, this difiiculty is overcome, since the expander supplements the natural thrust of the ring, thus causing it to conform to the out of round cylinder. The unequal side thrust of the piston occurring in certain predetermined directions causes unequal wear on the piston. In order to compensate for this Wear,

I have cam ground or reduced the thickness of my ring in diametrically opposite points to allow the intermediate portions of the ring to be thrust outwardly by my expander to take the place of such wear, this arrangement also reducing the piston slap. In addition to the passage of gas past the ring during the operation of the engine, oil from the lubricating system passes into the combustion space where it produces smoke, deposits carbon, etc., and is thus a nuisance and an added expense. Various efforts have been made to return this oil to the crank case after lubricating the cylinder walls.

It is the object of this invention to produce a 45 one piece circumferentially slotted ring that shall to the utmost extent possible, correct the unfavorable conditions found in a worn cylinder in which the engine loses compression and is pumping oil. By pumping oil is meant lubricating oil is pumped into the combustion chamber and partially burned.

These objects and others will appear as I proceed with the description wherein reference is made to the accompanying drawing, where like n e a s ef to l P s n t e d fierent views. It is to be understood that the illustrative drawing used is for the purpose of showing the preferred form of my invention, and that I do not wish the interpretation of my invention to be limited to these exact details, but shall include all modifications embraced in the intent and purpose of my invention as disclosed in my specifications, and as further defined in the claims.

The structure described is illustrated by the accompanyingdrawing in which Fig. 1 is a horizontal section through a piston, showing the invention in position thereon.

Fig. 2 is a section on line 2-2 of Fig. 3.

Fig. 3 is a vertical section through a cylinder and a piston, with parts broken away showing the invention in position thereon.

Fig. 4 is an enlarged section of the oil ring, piston and cylinder with parts broken away.

Fig. 5 is an enlarged section of the compression ring, cyinder and piston with parts broken away.

Fig. 6 is an enlarged sectional view of my ring taken on a median line, showing the solid sections of said ring.

Numeral l indicates a piston of the conventionalv sort, 2 the circumferential grooves for holding the rings, 3 my one piece circumferentially slotted oil ring having the slot 4 midway of the body and continuing around to within a short space of the transverse cut as at 5, and terminating diametrically opposite this cut as at 6. These rings are seated in the slots 2 of the piston l in the usual manner.

The circumferential slot 4 divides the ring into, what may be termed, an upper and a lower section. These sections are connected together only, at their ends and at their central portions. The ring 3 is provided with a circumferential groove, part of which is in one section and part in the other, Figsr i and 5. The sides of the roove, being curved in cross-section, constitute cam surfaces which are adapted to be engaged by a sinuous expander ring 9.

By thus slotting the ring circumferentially we are enabled through the action of my expander I to not only give the ring an outward or radial thrust, but at the same time a thrust of each piece sideways by reason of the fact that the edges 8 of expander I tend to travel along the curved surface 9. This outward thrust is continued around to the two oppositesidesofthering up to the solid portions 5 and 6, which are points where pivotal action of the piston takes place, and along the line of the piston pin (not shown). As the portions 5 and 6 of my ring are thinner than the major or intermediate portions, they are weaker and are flexed at these points, while the intermediate portions l0 and l l are caused to be pushed outwardly against the cylinder walls where the main amount of wear occurs. This action is brought about largely by the humps in my expander and the manner in which they are disposed.

As shown in Fig. 1 there are more complete humps of the expander engaging the piston on each side of the median line I2 as at H) or II Where the greatest pressure is required than there are on either side of the median line l3. These humps are equally distributed about each median line. So in Fig. 2 as shown, I may vary the number of humps in the expander but keeping a similar relation to the flexing points of my ring and the teetering points of the piston.

In installing rings in a cylinder it is quite necessary that in wearing them in or getting a permanent seat, the ring be prevented from turning in its groove in the piston. To take care of this I insert a pin inthe expander as at [4; this in turn may enter a hole in the piston by a loose fit. This pin is located on the pivoting line of the cylinder and diametrically opposite the transverse cut in said ring. By taking advantage of the cam formation (gradual reduction of the depth) of my ring, I create a condition so that one or more of the humps on my expander which are located in the gradually decreasing thickness of said ring tend permanently to locate themselves therein. If I construct my expander such that two humps come within the limits of the reduced thickness, they are placed symmetrical with respect to such reduced portion, as at l5, Fig. 1, and any tendency to rotate circumferentially in either direction would be the equivalent of climbing a hill, thus the point of least resistance is to remain symmetrical relative to a line evenly dividing the limits of such reduced portion, or cam ground section. -As the expander is pinned to the piston and the humps on the expander are located in thevalley between two elevated portions, it follows that the ring is prevented from rotating circumferentially.

In reducing the depth of my ring I preferably make the reduction gradual, say like a cam, commencing about 45 as at I6, from a median'line and continuing the reduction to the median line as at H, and from this gradually increasing for another 45 as at 18, where the normal depth is reached. This process is repeated on the opposite side as at I9, 20, 2! and I have a cam formation at diametrically opposite points on my ring. By this method I get a smooth even resiliency.

The bearing face of one of the rings is adapted to be formed to prevent passage of oil.

As shown in Fig. 4, this is accomplished by bevelling the upper outer corners of the two sections of the ring as at 22, respectively. This construction will permit the ring to override the oil, on the upward stroke, while on the downward stroke the sharp corner 24 will scrape the oil from the cylinder wall and cause it to flow back to the crank case through the passages 25 drilled in a slanting direction through the piston I. 'These passages are spaced from each other around the periphery of the piston and at the very edge of the oil ring groove. By means of this slot 4 along the middle line of the ring I form another scraping edge 26 on the lower corner of the upper section, whereby I get the effect of two rings in one. The oil from this source scraped from the cylinder wall passes inwardly through said slot 4 and around the edges'of my expander as at 21, thence back to the crank case through openings 28, provided in the piston wall. I am able through the means just described to keep up a continual circulation of fresh lubricating oil around my expander thereby keeping it in a cool and live condition. Unless provision is made for circulating the oil, the same will become overheated and disintegrated by the heat of combustion in the cylinders. As a result a gummy substance as a residue is formed, and soon the sides of the rings will become glued to the walls of the circumferential slots thereby impeding their free movement. Freedom of movement is necessary for the perfect performance of any piston ring as otherwise they will become overheated and lose their resiliency. This condition applies equally well to the expander because if this element is not relieved of the excessive heat as it accumulates, it loses its elasticity, thereby depriving the ring of the necessary resiliency for it to assume the out of round of a worn. cylinder.

By varying the contour of the bearing face of my ring, I am able to use it as a compression, or, I might term it, a compensator ring. When used for this purpose a portion of the bearing face of the ring is provided with a slight inward circumferential curve as at 29. The desirable feature of this contour is such that as the narrow faces 39 and 3| wear down from use the contact surface increases as the wear continues.

It is not necessary to repeat the explanation of the action of the expander between the inside of the ring and the bottom of the groove, as the slot on the median line and curve on the inner surface is the same as my oil ring just described. This ring stops any gas that may get past the fire ring 32.

What I claim and wish to secure by Letters Patent is:

1. A split piston ring having a pair of circumferential slots extending through the ring at each side of the diameter passing through the split in the piston ring and extending on opposite sides from points adjacent to the split to points adjacent to the portion of the ring diametrically opposite said split, said ring tapering from points angularly spaced from the ends thereof toward the diameter passing through said split and having a circumferential groove provided with inclined side walls for receiving a light sinuous spring.

2. A split piston ring having a circumferential slot therethrough at each side of the split and extending around the ring a distance slightly less than the semi-circumference of the ring, said ring having a circumferential groove on its periphery, said groove being curved in cross-section, said ring gradually increasing in thickness from the ends to points 90 spaced therefrom and then gradually decreasing in diameter to a point diametrically opposite said ends.

3. A split piston ring for a circumferential groove on a piston for an engine, said ring having two circumferential slots extending radially therethrough, said slots extending from points adjacent the ends of said ring to points opposite said ends on said ring for dividing said ring into two sections, the inner peripheral surface of said ring being concave, a sinuous spring member engaging the concave surface of said ring for radially expanding said ring and for spreading the ringsections apart, and means for preventing rotation of said spring member, said ring being of varying thickness to provide two portions only of maximum thickness arranged opposite each other at substantially 90 from the ends of said ring, said thickened portions gradually tapering into two thinner portions arranged opposite each other.

4. In combination, a piston having a circumferential groove therein, a split piston ring therein, said ring being thinner at two diametrically opposite sides only than at the remaining portion thereof, a sinuous ring spring element between the bottom of said groove and said ring and engaging said ring, the curves of said element being symmetrically arranged at each side of a diameter passing through the thin portions of said ring, and means for preventing circumferential movement of said element.

5. In combination, a cylinder, a piston for said cylinder, said piston having a circumferenthe ring to points opposite said split to provide 5 spaced ring sections, the upper edges of the ring sections each being beveled, the inner peripheral surface of said ring being concave, and a sinuous resilient ring interposed between the concave surface of said ring and the piston Wall for radially 10 expanding said ring and for spreading said sections, said ring being of varying thickness to provide two thin portions arranged 180 apart and only two portions of maximum thickness also arranged 180 apart and 90 from the split in said 15 ring.

RUFUS C. PAYNE.

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