WO2019074620A1

WO2019074620A1 - Piston with groove pressure equalization channels to prevent radial collapse of compression rings

Info

Publication number: WO2019074620A1
Application number: PCT/US2018/051277
Authority: WO
Inventors: William R. Sorensen; Callen James SCHMALZ; William D. Mcnulty; Aditya A. SHARMA
Original assignee: Cummins Inc.
Priority date: 2017-10-13
Filing date: 2018-09-17
Publication date: 2019-04-18

Abstract

An apparatus and a method include a piston in a cylinder bore for an internal combustion engine. The piston has an outer cylindrical surface with a first annular groove adjacent a second annular groove. The first annular groove is adjacent to the crown end of the piston, and the second annular groove is offset a distance away from the first annular groove. Each of the first and second annular grooves has a base extending between upper and lower walls sized to receive a compression ring. A channel extends from the outer cylindrical surface towards the base of the second annular groove to pressurize a cavity between the second compression ring and the base with blow-by gas from the cylinder bore to energize or push the compression ring radially outward to contact the cylinder bore.

Description

PISTON WITH GROOVE PRESSURE EQUALIZATION CHANNELS TO PREVENT RADIAL COLLAPSE OF COMPRESSION RINGS

Cross -Reference to Related Application:

[00001] This application claims the benefit of the filing date of U.S. Provisional

Application Ser. No. 62/572,060 filed on October 13, 2017, which is incorporated herein by reference.

TECHNICAL FIELD

[00002] The present application relates generally to a piston of an internal combustion engine, and more particularly to feature on the piston that channels combustion gas to energize a compression ring radially outwardly against a cylinder bore.

BACKGROUND

[00003] Various pistons have been developed that include an oil control ring in a cylinder bore that further includes a passageway from an enclosed space above the oil control ring to a cavity behind the oil control ring. When the piston is moving in a downward direction, a blowby gas pressure above the oil control ring is relieved through the passageways. As a result, oil pressure is reduced above the oil control ring and the oil control ring can quickly move into sealing contact with the upper surface of an annular groove. Movement of the oil control ring toward the lower radial wall of the groove also provides a seal between the two members when the piston is moving upwardly at the beginning of the compression and exhaust strokes, thus providing a seal against reverse oil flow from the cylinder wall into the cavity behind the oil control ring. As a result, the amount of oil transported to the compression ring is decreased, and total oil consumption as well as variability are substantially reduced. Gas pressure above the oil control ring is reduced by venting the blowby gas through the passageways to the chamber behind the oil control ring.

[00004] However, further contributions in this area of technology are need to reduce the rate of oil consumption of the engine. Therefore, there remains a significant need for the apparatuses, methods and systems disclosed herein. SUMMARY

[00005] One embodiment is a unique system, method, and apparatus that includes a piston for an internal combustion engine that is configured to energize a compression ring radially outwardly with a blow-by gas from a cylinder bore. The piston has an outer cylindrical surface with first, second, and third annular grooves therein. The first annular groove is adjacent to the crown end of the piston, and the second annular groove is offset a distance away from the first annular groove. Between the first and the second annular grooves is a first land, and between the second and the third annular grooves is a second land. The first and the second annular grooves each have a base that extends between an upper wall and a lower wall. The first and the second annular grooves are configured for each to receive a compression ring therein.

[00006] In one form, the channels extend from the outer cylindrical surface of the second land to the base of the second annular groove without any channels extending from the outer cylindrical surface to the first land. In another form, one or more channels extend from the outer cylindrical surface of both of the first and second lands towards the base of the first and second annular grooves, respectively. A cavity is correspondingly formed between the upper wall, base, and lower wall of each of the first and the second annular grooves and inside face of the compression ring. The channels are fluidly connected to the cavities and the channels are configured to pressurize the cavities between the compression rings and the base of the first and second annular grooves with a blow-by gas from a cylinder bore to push the compression rings radially outward toward the cylinder bore. The channels can have a circular or semi-circular cross-sectional shape or the channels are slots having a rectangular or square cross-sectional shape. The blow-by gas travels from the cylindrical bore through the channels and into the cavities wherein the air pressure builds up behind the compression ring to energize the compression ring radially outwardly and against the cylinder bore to avoid collapse of the compression ring. If only channels that extend to the base of the first annular groove are present, without channels also extending to the second annular groove, then sealing the blow-by gas in the cavity of the first groove, achieves a power savings. However, ifthe channels that to the second annular groove are present, without channels also extending to the first annular groove, then sealing the blow-by gas in the cavity of the second groove, helps to reduce oil consumption by providing better sealing between the compression ring and the cylinder bore because the compression ring is energized radially outwardly and against the cylinder bore. The third annular groove has a base that extends between an upper wall and a lower wall wherein the third annular groove is configured to receive an oil control ring therein.

[00007] This summary is provided to introduce a selection of concepts that are further described below in the illustrative embodiments. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter. Further embodiments, forms, objects, features, advantages, aspects, and benefits shall become apparent from the following description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[00008] Fig. 1 is a partial cross-sectional view of a piston of the present disclosure.

[00009] Fig. 2 is a partial cross-sectional view of a piston of the present disclosure.

[00010] Fig. 3 is a front view of the embodiment of the piston illustrated in Fig. 1 without channels in the top or first groove.

[00011] Fig. 4 is a top view of another embodiment of a piston before a channel is added to the piston.

[00012] Fig. 5 is a partial cross-sectional view of the embodiment of the piston illustrated in Fig. 4.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[00013] For the purposes of clearly, concisely and exactly describing exemplary embodiments of the invention, the manner and process of making and using the same, and to enable the practice, making and use of the same, reference will now be made to certain exemplary embodiments, including those illustrated in the figures, and specific language will be used to describe the same. It shall nevertheless be understood that no limitation of the scope of the invention is thereby created, and that the invention includes and protects such alterations, modifications, and further applications of the exemplary embodiments as would occur to one skilled in the art.

[00014] With reference to Figs. 1 and 3, there is illustrated a schematic view of an exemplary embodiment of a piston 10. The piston 10 is a type that is used in an internal combustion engine wherein the piston 10 is disposed in a bore 12 of a cylinder. The piston 10 is substantially similar to the piston 100 illustrated in Fig. 2, therefore for the sake of brevity similar features will not be described unless noted otherwise. The piston 10 has a crown end 14 which is in contact with the bore 12 and a cylinder head of the engine (not shown) to define a combustion chamber.

[00015] The piston 10 includes a first annular groove 20 and a second annular groove 22 in an outer cylindrical surface 24 wherein the first annular groove 20 is positioned near the crown end 14 and the second annular groove 22 is positioned adjacent to the first annular groove 20. Throughout the application "near" the crown end 14 is defined as close, proximate, adjacent, or next to the crown end 14. In the illustrated embodiment, the piston 10 includes a third annular groove 26 wherein the third annular groove 26 is positioned adjacent to the second annular groove 22. In the illustrated embodiment, the second annular groove 22 is located between the first annular groove 20 and the third annular groove 26. In alternative embodiments, it is contemplated that the piston 10 includes any of the first, second, and third grooves 20, 22, and 26.

[00016] The piston 10 includes a first land 27 disposed between the first annular groove 20 and the second annular groove 22 wherein the first land 27 includes the outer cylindrical surface 24. The first land 27 has a diameter that is larger than a diameter of either first annular groove 20 or a diameter of the second annular groove 22. The piston 10 also includes a second land 29 disposed between the second annular groove 22 and the third annular groove 26 wherein the second land 29 includes the outer cylindrical surface 24. The second land 29 has a diameter that is larger than a diameter of either second annular groove 22 or a diameter of the third annular groove 26. The piston 10 also includes a piston skirt 31 that extends from the third annular groove 26 towards an end opposite the crown end 14.

[00017] Since both of the first annular groove 20 and the second annular groove 22 are similar in construction, for the sake of brevity only second annular groove 22 will be described with similar corresponding features for first annular groove 20. It is contemplated that in other embodiments the first annular groove 20 may be configured differently than the second annular groove 22. The second annular groove 22 includes a radially inwardly disposed base 28 that spans between an upper wall 30 and a lower wall 32. The radially inwardly disposed base 28 is a cylindrical wall having a diameter that is less than the diameter of the outer cylindrical surface 24 of the piston 10. The upper wall 30 extends from the outer cylindrical surface 24 to the radially inwardly disposed base 20. The lower wall 32 extends from the outer cylindrical surface 24 to the radially inwardly disposed base 20. In the illustrated embodiment, the upper wall 30 and the lower wall 32, respectively, form an obtuse angle A and an obtuse angle B with the outer cylindrical surface 24. In other embodiments, the upper wall 30 and/or the lower wall 32 can form a right or acute angle with the outer cylindrical surface 24.

[00018] The first annular groove 20 and the second annular groove 22 are configured and adapted to receive a first compression ring 34 and a second compression ring 36, respectively. The first compression ring 34 is similar to the second compression ring 36, therefore for the sake of brevity only the second compression ring 36 will be described. The second compression ring 36 has an inner diameter 38 that is larger than a diameter of the radially inwardly disposed base 28 of the second annular groove 22. As a result of the difference in sizes of the inner diameter 38 of the second compression ring 36 and the diameter of the radially inwardly disposed base 28, there is a substantially enclosed cavity 40 that is formed between the second compression ring 36, the upper wall 30, the radially inwardly disposed base 28, and the lower wall 32.

[00019] The piston 10 includes a first plurality of channels 42 that are fluidly connected to the first annular groove 20 and are arranged circumferentially around the piston 10. The piston 10 includes a second plurality of channels 44 that are fluidly connected to the second annular groove 20 and are arranged circumferentially around the piston 10. In other embodiments, the piston 10 may only include one of either the first plurality of channels 42 or the second plurality of channels 44. For the sake of brevity, only the second plurality of channels 44 will be described with the first plurality of channels 42 being substantially similar. In other forms, the first plurality of channels 42 may be different from the second plurality of channels 44. The second plurality of channels 44 can include any number of channels 44, for example, between 4 and 16. The second plurality of channels 44 can be arranged with an equal or unequal spacing between the channels 44 or any variation of spacing as desired.

[00020] The second plurality of channels 44 extend from the outer cylindrical surface 24 at a position above the upper wall 30 of the second annular groove 20 to intersect the upper wall 30 near the radially inwardly disposed base 28 such that the channels 44 fluidly connect bore 12 with the cavity 40. Alternatively, the second plurality of channels 44 extend from the outer cylindrical surface 24 at a position above the upper wall 30 of the second annular groove 20 towards the radially inwardly disposed base 28 wherein the second plurality of channels 44 engage a portion of the radially inwardly disposed base 28 and a portion of the upper wall 30. In any configuration, the plurality of channels 44 are configured and arranged such that the channels 44 pressurize the cavity 40 between the second compression ring 36 and the radially inwardly disposed base 28 with a blow-by gas pressure from the cylinder bore 12 such that the second compression ring 36 is pushed radially outward toward the cylinder bore 12 by the gas pressure. As such, the second compression ring 36 contacts and seats against the cylinder bore 12. The plurality of channels 44 have a substantially circular cross sectional shape with a diameter between about 2 millimeters to about 20 millimeters and the size of the channels 44 will vary depending on the size of the piston 10. In one embodiment, the channels 44 have a 4 millimeter diameter. In other embodiments, the plurality of channels 44 have a semi-circular cross sectional shape.

[00021] Illustrated in Fig. 2, piston 100 includes a plurality of channels 144 that are similar to the plurality of channels 44, except the plurality of channels 144 have a slot-like configuration. In this configuration, the plurality of channels 144 are slots with a rectangular or triangular cross-sectional shape.

[00022] The third annular groove 26 is similar to the second annular groove 22 however the third annular groove 26 is sized and configured to receive an oil control ring 50 therein. The third annular groove 26 has a radially inwardly disposed base 52 that extends between an upper wall 54 and a lower wall 56. The third annular groove 26 is configured to receive the oil control ring 50 therein. The radially inwardly disposed base 52 is a cylindrical wall having a diameter that is less than the diameter of the outer cylindrical surface 24 of the piston 10. The upper wall 54 extends from the outer cylindrical surface 24 to the radially inwardly disposed base 52. The lower wall 56 extends from the outer cylindrical surface 24 to the radially inwardly disposed base 52. In the illustrated embodiment, the upper wall 54 and the lower wall 56, respectively, form substantially right angles with the outer cylindrical surface 24. In other embodiments, the upper wall 54 and/or the lower wall 56 can form an obtuse or acute angle with the outer cylindrical surface 24.

[00023] With reference to Figs. 4 and 5, there is illustrated a schematic view of an exemplary embodiment of a piston 200. Piston 200 can include any number of channels that can be configured in which the lands and annular grooves are structurally intact after formation of the channels. There is illustrated in Fig. 4 an arrangement of channel locations 202 for a plurality of channels. The channel locations 202 are located in first land 204 with an

approximate spacing of 45 degrees between the channel locations 202. One technique of manufacturing channels similar to channels 44 and 144 includes machining or drilling into the first land 204 to a base 206 or an upper wall 207 of a second annular groove 208. In other forms, piston 200 can include a different number of channels, and piston 200 can include channels associated with a first annular groove 210.

[00024] Various aspects of the present disclosure are contemplated. According to one aspect, a piston for an internal combustion engine, the piston comprising: a crown end; a first annular groove in an outer cylindrical surface of the piston adjacent to the crown end, the first annular groove having a base that extends between an upper wall and a lower wall, the first annular groove configured to receive a first compression ring therein; a second annular groove in the outer cylindrical surface of the piston, the second annular groove offset a distance from the first annular groove, the second annular groove having a base that extends between an upper wall and a lower wall, the second annular groove configured to receive a second compression ring therein; and a channel extending from the outer cylindrical surface of the piston to the upper wall of the second annular groove, the channel is configured to pressurize a cavity between the second compression ring and the base with a blow-by gas from a cylinder bore such that the second compression ring is pushed radially outward to seat against the cylinder bore. [00025] In certain forms of the foregoing aspect, the channel includes a plurality of channels positioned circumferentially around the second annular groove. In certain forms of the foregoing aspect, a second channel extending from the outer cylindrical surface of the piston towards the upper wall of the first annular groove, the second channel is configured to pressurize a cavity between the first compression ring and the base with a blow-by gas from the cylinder bore such that the first compression ring is energized radially outward to seat against the cylinder bore. In certain forms of the foregoing aspect, the second channel includes a plurality of second channels that are fluidly connected to the first annular groove and are arranged circumferentially around the outer cylindrical surface.

[00026] In certain forms, the piston further comprises a third annular groove in the outer cylindrical surface of the piston, the third annular groove offset a distance from the first and the second annular grooves, the third annular groove having a base that extends between an upper wall and a lower wall, the third annular groove configured to receive an oil control ring therein.

[00027] In certain forms, the first annular groove is configured differently than the second annular groove.

[00028] In certain forms, the channel has a circular cross-section. In certain forms, a diameter of the channel is between 2 millimeters to 10 millimeters.

[00029] In certain forms, the channel is a slot. In certain forms, the slot has a rectangular cross-section.

[00030] In certain forms, the upper wall of the second annular groove is arranged to form an upper obtuse angle with the outer cylindrical surface, and the lower wall of the second annular groove is arranged to form a lower obtuse angle with the outer cylindrical surface.

[00031] In certain forms, the cavity is formed between the second compression ring, the upper wall, the base, and the lower wall of the second annular groove.

[00032] According to another aspect, a piston for an internal combustion engine, the piston comprising: a crown end; a first annular groove in an outer cylindrical surface of the piston, the first annular groove positioned near the crown end, the first annular groove having a base that extends between an upper wall and a lower wall, the first annular groove configured to receive a first compression ring therein; a second annular groove in the outer cylindrical surface of the piston, the second annular groove offset a distance from the first annular groove, the second annular groove having a base that extends between an upper wall and a lower wall, the second annular groove configured to receive a second compression ring therein; and a channel extending from the outer cylindrical surface of the piston towards the base of the second annular groove, the channel is configured to pressurize a cavity between the second compression ring and the base with a blow-by gas from a cylinder bore such that the second compression ring is pushed radially outward toward the cylinder bore.

[00033] In certain forms of this aspect, the channel has a circular cross-section. In certain forms, a diameter of the channel is between 2 millimeters to 10 millimeters.

[00034] In certain forms, the channel is a slot. In certain forms, the slot has a rectangular cross-section.

[00035] In certain forms, the channel includes a plurality of channels positioned circumferentially around the second annular groove.

[00036] In certain forms, the channel extends from the outer cylindrical surface to the upper wall to fluidly connect the cylinder bore with the cavity.

[00037] In certain forms, the piston further comprises a second channel extending from the outer cylindrical surface of the piston towards the base of the first annular groove, the second channel is configured to pressurize a cavity between the first compression ring and the base with a blow-by gas from the cylinder bore such that the first compression ring is energized radially outward toward the cylinder bore. In certain forms, the second channel includes a plurality of second channels that are fluidly connected to the first annular groove and are arranged circumferentially around the outer cylindrical surface.

[00038] In certain forms, the piston further comprises a third annular groove in the outer cylindrical surface of the piston, the third annular groove offset a distance from the first and the second annular grooves, the third annular groove having a base that extends between an upper wall and a lower wall, the third annular groove configured to receive an oil control ring therein.

[00039] In certain forms, the piston further comprises a land disposed between the first annular groove and the second annular groove, the land including the outer cylindrical surface.

[00040] In certain forms, the first annular groove is configured differently than the second annular groove.

[00041] In certain forms, the upper wall of the first annular groove is arranged to form an upper obtuse angle with the outer cylindrical surface, and the lower wall of the first annular groove is arranged to form a lower obtuse angle with the outer cylindrical surface. [00042] In certain forms, the cavity is formed between the second compression ring, the upper wall, the base, and the lower wall of the second annular groove.

[00043] According to another aspect, a method, comprises providing a piston in a cylinder bore for an internal combustion engine, wherein the piston includes a first annular groove in an outer cylindrical surface of the piston near a crown end, the first annular groove having a base that extends between an upper wall and a lower wall, the first annular groove configured to receive a first compression ring between the upper wall and the lower wall, the piston includes a second annular groove in the outer cylindrical surface positioned a distance from the first annual groove, the second annular groove having a base that extends between an upper wall and a lower wall, the second annular groove configured to receive a second compression ring therein, the piston further includes a second channel extending from the outer cylindrical surface of the piston towards the base of the second annular groove; pressurizing a cavity defined by the upper and lower walls and the base of the second annular groove, and the second compression ring therein with a blow-by gas from the cylinder bore; and energizing the second compression ring radially outward with the blow-by gas in the cavity such that the second compression ring seats against the cylinder bore.

[00044] In certain forms the method further comprises pressurizing a cavity defined by the upper wall, the lower wall, and the base of the first annular groove, and the first compression ring therein with the blow-by gas from the cylinder bore; and energizing the first compression ring radially outward with the blow-by gas in the cavity such that the first compression ring seats against the cylinder bore.

[00045] In certain forms, the second channel includes a plurality of second channels arranged circumferentially around the outer cylindrical surface, and the pressurizing includes pressurizing a plurality of second cavities corresponding to the plurality of second channels.

[00046] In certain forms, the channel extends from the outer cylindrical surface to the upper wall to fluidly connect the cylinder bore with the cavity.

[00047] While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only certain exemplary embodiments have been shown and described. Those skilled in the art will appreciate that many modifications are possible in the example embodiments without materially departing from this invention. Accordingly, all such modifications are intended to be included within the scope of this disclosure as defined in the following claims.

[00048] It should be understood that while the use of words such as preferable, preferably, preferred or more preferred if utilized in the description above indicate that the feature so described may be more desirable, it nonetheless may not be necessary and embodiments lacking the same may be contemplated as within the scope of the invention, the scope being defined by the claims that follow. In reading the claims, it is intended that when words such as "a," "an," "at least one," or "at least one portion" are used there is no intention to limit the claim to only one item unless specifically stated to the contrary in the claim. When the language "at least a portion" and/ or "a portion" is used the item can include a portion and/ or the entire item unless specifically stated to the contrary.

Claims

What is claimed is:

1. A piston for an internal combustion engine, the piston comprising:

a crown end;

a first annular groove in an outer cylindrical surface of the piston adjacent to the crown end, the first annular groove having a base that extends between an upper wall and a lower wall, the first annular groove configured to receive a first compression ring therein;

a second annular groove in the outer cylindrical surface of the piston, the second annular groove offset a distance from the first annular groove, the second annular groove having a base that extends between an upper wall and a lower wall, the second annular groove configured to receive a second compression ring therein; and

a channel extending from the outer cylindrical surface of the piston to the upper wall of the second annular groove, the channel is configured to pressurize a cavity between the second compression ring and the base with a blow-by gas from a cylinder bore such that the second compression ring is pushed radially outward to seat against the cylinder bore.

2. The piston of claim 1 , wherein the channel includes a plurality of channels positioned circumferentially around the second annular groove.

3. The piston of claim 1 , further comprising:

a second channel extending from the outer cylindrical surface of the piston towards the upper wall of the first annular groove, the second channel is configured to pressurize a cavity between the first compression ring and the base with a blow-by gas from the cylinder bore such that the first compression ring is energized radially outward to seat against the cylinder bore.

4. The piston of claim 3, wherein the second channel includes a plurality of second channels that are fluidly connected to the first annular groove and are arranged circumferentially around the outer cylindrical surface.

5. The piston of claim 1, further comprising:

a third annular groove in the outer cylindrical surface of the piston, the third annular groove offset a distance from the first and the second annular grooves, the third annular groove having a base that extends between an upper wall and a lower wall, the third annular groove configured to receive an oil control ring therein.

6. The piston of claim 1, wherein the first annular groove is configured differently than the second annular groove.

7. The piston of claim 1, wherein the channel has a circular cross-section.

8. The piston of claim 7, wherein a diameter of the channel is between 2 millimeters to 10 millimeters.

9. The piston of claim 1 , wherein the channel is a slot.

10. The piston of claim 9, wherein the slot has a rectangular cross-section.

1 1. The piston of claim 1 , wherein the upper wall of the second annular groove is arranged to form an upper obtuse angle with the outer cylindrical surface, and the lower wall of the second annular groove is arranged to form a lower obtuse angle with the outer cylindrical surface.

12. The piston of claim 1 , wherein the cavity is formed between the second compression ring, the upper wall, the base, and the lower wall of the second annular groove.

13. A piston for an internal combustion engine, the piston comprising:

a crown end;

a first annular groove in an outer cylindrical surface of the piston, the first annular groove positioned near the crown end, the first annular groove having a base that extends between an upper wall and a lower wall, the first annular groove configured to receive a first compression ring therein;

a channel extending from the outer cylindrical surface of the piston towards the base of the second annular groove, the channel is configured to pressurize a cavity between the second compression ring and the base with a blow-by gas from a cylinder bore such that the second compression ring is pushed radially outward toward the cylinder bore.

14. The piston of claim 13, wherein the channel has a circular cross-section.

15. The piston of claim 14, wherein a diameter of the channel is between 2 millimeters to 10 millimeters.

16. The piston of claim 13, wherein the channel is a slot.

17. The piston of claim 16, wherein the slot has a rectangular cross-section.

18. The piston of claim 13, wherein the channel includes a plurality of channels positioned circumferentially around the second annular groove.

19. The piston of claim 13, wherein the channel extends from the outer cylindrical surface to the upper wall to fluidly connect the cylinder bore with the cavity.

20. The piston of claim 13, further comprising:

a second channel extending from the outer cylindrical surface of the piston towards the base of the first annular groove, the second channel is configured to pressurize a cavity between the first compression ring and the base with a blow-by gas from the cylinder bore such that the first compression ring is energized radially outward toward the cylinder bore.

21. The piston of claim 20, wherein the second channel includes a plurality of second

channels that are fluidly connected to the first annular groove and are arranged circumferentially around the outer cylindrical surface.

22. The piston of claim 13, further comprising:

23. The piston of claim 13, further comprising:

a land disposed between the first annular groove and the second annular groove, the land including the outer cylindrical surface.

24. The piston of claim 13, wherein the first annular groove is configured differently than the second annular groove.

25. The piston of claim 13, wherein the upper wall of the first annular groove is arranged to form an upper obtuse angle with the outer cylindrical surface, and the lower wall of the first annular groove is arranged to form a lower obtuse angle with the outer cylindrical surface.

26. The piston of claim 13, wherein the cavity is formed between the second compression ring, the upper wall, the base, and the lower wall of the second annular groove.

27. A method, comprising:

providing a piston in a cylinder bore for an internal combustion engine, wherein the piston includes a first annular groove in an outer cylindrical surface of the piston near a crown end, the first annular groove having a base that extends between an upper wall and a lower wall, the first annular groove configured to receive a first compression ring between the upper wall and the lower wall, the piston includes a second annular groove in the outer cylindrical surface positioned a distance from the first annual groove, the second annular groove having a base that extends between an upper wall and a lower wall, the second annular groove configured to receive a second compression ring therein, the piston further includes a second channel extending from the outer cylindrical surface of the piston towards the base of the second annular groove;

pressurizing a cavity defined by the upper and lower walls and the base of the second annular groove, and the second compression ring therein with a blow-by gas from the cylinder bore; and

energizing the second compression ring radially outward with the blow-by gas in the cavity such that the second compression ring seats against the cylinder bore.

28. The method of claim 27, further comprising:

pressurizing a cavity defined by the upper wall, the lower wall, and the base of the first annular groove, and the first compression ring therein with the blow-by gas from the cylinder bore; and

energizing the first compression ring radially outward with the blow-by gas in the cavity such that the first compression ring seats against the cylinder bore.

29. The method of claim 27, wherein the second channel includes a plurality of second

channels arranged circumferentially around the outer cylindrical surface, and

the pressurizing includes pressurizing a plurality of second cavities corresponding to the plurality of second channels.

30. The method of claim 27, wherein the channel extends from the outer cylindrical surface to the upper wall to fluidly connect the cylinder bore with the cavity.