Piston ring for a piston compressor

Abstract

Piston ring (1) comprising a first ring body (10) and a second ring body (20), which ring bodies (10, 20) are arranged adjacent and concentric to each other in axial direction (A), the first ring body (10) having a radially outward outer side (11), an upper side (12) and a lower side (13) and a radially inward inner side (14), the second ring body (20) being designed as a segmented sealing ring (20) comprising a plurality of sealing ring segments (20a, 20b, 20c), which sealing ring segments (20a, 20b, 20c) each have a radially outward sealing face (21a, 21b, 21c), an upper sealing ring segment end side (22a, 22b, 22c) and a lower sealing ring segment side (23a, 23b, 23c) and a radially inward inner side (24a, 24b, 24c), the sealing ring segments (20a, 20b, 20c) each being guided on the first ring body (10) by at least one guide (4a, 4b, 4c, 5a, 5b, 5c), which guide (4a, 4b, 4c, 5a, 5b, 5c) substantially prevents a twisting of the sealing ring segments (20a, 20b, 20c) relative to the first ring body (10, 20) in circumferential direction (U) and allows a displacement of the sealing ring segments (20a, 20b, 20c) transversely to the axial direction (A).

Description

Technical Field

[0001] The present invention relates to a piston ring for a reciprocating compressor and a reciprocating compressor having such a piston ring. Background Technology

[0002] In a reciprocating compressor, the working medium is compressed by a piston that reciprocates within a cylinder. The seal that seals the annular gap between the piston and the cylinder wall is called a piston ring.

[0003] The piston ring described in EP 3555502A1 comprises a sealing ring designed as a friction seal that slides along the inner wall of the cylinder and has support rings, namely a base ring and a top ring, arranged on both sides axially. The sealing ring has three tangential cuts on its inner side, dividing it into three sealing ring segments. A clamping ring placed along the inner side of the sealing ring generates a preload, pressing each sealing ring segment against the inner wall of the cylinder. Wear caused by material abrasion is compensated by the pressure of each sealing ring segment in the direction of the cylinder wall. Therefore, the sealing ring exhibits good radial adaptability, thus forming a good seal against the cylinder wall, preventing or reducing any possible leakage. Such piston rings are suitable for use with reciprocating compressors with compression chambers subjected to high pressure loads and / or high temperature loads exceeding 500 bar.

[0004] The disadvantage of this type of piston ring is that the sealing ring or sealing ring section may be damaged when it is pushed back, so in some cases, the sealing effect of the sealing ring may be reduced. Summary of the Invention

[0005] Based on the above-mentioned prior art, the object of the present invention is to eliminate such and additional disadvantages of the prior art, and in particular to specify a piston ring mentioned at the beginning, wherein the seal has safe and good sealing contact with the cylinder wall of the reciprocating compressor without the risk of damage.

[0006] The present invention is further based on the objective of providing a reciprocating compressor comprising at least one piston ring as described below, which has more favorable operating characteristics, and in particular, a longer service life.

[0007] The objective of this invention is achieved through piston rings and a piston compressor having the features described in the invention. Further protection is intended for the invention by relating to further advantageous embodiments of the invention.

[0008] The objective of this invention is achieved through a piston ring for a reciprocating compressor, comprising a first annular body and a second annular body arranged axially adjacent to each other and coaxially. The first annular body has a radially outward outer surface, an upper side surface, a lower side surface, and a radially inward inner surface. The second annular body is designed as a segmented sealing ring comprising multiple sealing ring segments, each sealing ring segment having a radially outward sealing surface, an upper sealing ring segment side surface, a lower sealing ring segment side surface, and a radially inward sealing ring inner surface. In the assembled state, the segmented sealing ring thus has a radially outward sealing ring surface, upper and lower sealing ring side surfaces, and a radially inward sealing ring inner surface. The sealing ring segments are guided on the first annular body by at least one guide that substantially prevents the sealing ring segments from twisting relative to the first annular body in the circumferential direction and allows the sealing ring segments to move laterally to the axial direction, i.e., outwardly.

[0009] For the purposes of this invention, the term "axial" refers to the direction extending along the rotation axis of each annulus (perpendicular to the diameter of the annulus).

[0010] For the purposes of this invention, "lateral to axial" displacement refers to the displacement of the sealing section substantially within the annular plane formed by the second annular body and generally perpendicular to an imaginary plane that is perpendicular to the annular plane and extends through the axis of rotation.

[0011] The piston rings designed according to the present invention are preferably arranged in the piston ring grooves of the piston in a reciprocating compressor. Compared with piston rings known in the prior art, they have the advantage that the individual sealing ring segments do not collide in the circumferential direction during operation. The proposed design therefore prevents damage to the sealing ring segments and increases the service life of the piston rings.

[0012] In the segmented sealing ring region, the piston ring seals mating surfaces (e.g., the inner wall of the cylinder liner in a reciprocating compressor) to prevent gas from escaping from the compression chamber. Each sealing ring segment is designed as a friction seal that slides along the inner wall of the cylinder, thereby allowing the piston ring to run dry or be lubricated. The piston ring according to the invention is preferably suitable for use with reciprocating compressors that have high-pressure loads in the compression chamber, particularly between 500 bar and 1000 bar.

[0013] In its assembled state, the piston ring according to the invention has a radially outward outer surface, a radially inward inner surface, and two piston ring sides arranged therebetween and substantially parallel to each other. When using the piston ring according to the invention, one piston ring side faces the compression chamber, and the other opposing piston ring side faces the crankcase.

[0014] In a preferred embodiment, the guide member, consisting of the contact sides of the first annular body and the sealing ring segment, is designed to extend in a form-fitting manner. For example, the guide member is designed to engage with a guide rib in a guide groove. According to the invention, it is conceivable that the guide rib is arranged on the sealing ring side, while the guide groove is arranged on the first annular body. According to the invention, it is also conceivable that the guide rib is arranged on the first annular body, while the guide groove is arranged on the sealing ring side. In principle, it is also conceivable that both annular bodies have guide ribs and guide grooves, with the guide ribs and guide grooves formed and arranged on the contact sides of the two annular bodies, such that the contact sides are designed to operate in a form-fitting manner.

[0015] By integrating the guide into the contact surface, design work is minimized, and the mechanical load capacity of the piston rings is improved.

[0016] In a preferred embodiment of the piston ring according to the invention, the depth of the guide groove is between 0.5 mm and 4 mm, preferably between 1 mm and 2 mm. Alternatively or additionally, the guide groove has a width between 10 mm and 50 mm, preferably between 20 mm and 40 mm, and particularly preferably between 25 mm and 35 mm.

[0017] This piston ring has the advantage that the sealing ring section is particularly firmly guided on the first annular body.

[0018] In a preferred embodiment of the piston ring according to the invention, the first annular body is integrally formed, preferably continuously. This reduces leakage and increases the mechanical strength of the piston ring.

[0019] In an alternative embodiment of the piston ring according to the invention, the first annular body is formed as a segmented base ring comprising multiple base ring segments. This makes it easier to install the first annular body. Particularly preferably, the number of base ring segments corresponds to the number of sealing ring segments of the segmented sealing ring, as this further facilitates the assembly of the piston ring.

[0020] In another preferred embodiment of the piston ring according to the invention, the first annular body is formed by three base ring segments, and the second annular body is formed by three sealing ring segments. In this case, each of the three base ring segments and the three sealing ring segments extends through a 120° arc, thereby ensuring that each of the base ring or sealing ring segments is subjected to the same mechanical load during the intended use of the piston ring according to the invention.

[0021] Preferably, the axial sealing ring height of the segmented sealing ring is in the range of 1mm to 6mm, so that the second ring body is as compact as possible in the axial direction and occupies very little space.

[0022] In operation, the piston rings according to the invention are arranged in the circumferential piston ring grooves of the piston. The circumferential piston ring grooves are designed such that during operation of the reciprocating compressor, fluid can permeate from the compression chamber into the groove space located behind the sealing ring section, and under sufficient fluid pressure, press the sealing ring section outward against a mating surface, for example, against the inner wall of the cylinder liner of the reciprocating compressor. For this purpose, the axial back clearance of the piston rings in the circumferential piston ring grooves must be sufficiently large.

[0023] This eliminates the need for a clamping ring that presses against the radially inward inner surface of the segmented sealing ring and presses the sealing ring section against the mating surface. The contact pressure between the sealing ring section and the cylinder wall depends on the fluid pressure, which also means that less material detaches from the radially outward sealing surface of the sealing ring section.

[0024] In another preferred embodiment, the piston ring according to the invention further includes at least one additional seal for sealing the annular joint formed in each case by the two opposing ends of adjacent sealing ring segments. By providing one or more such seals, leakage occurring between two adjacent sealing ring segments during use can be significantly reduced according to the invention.

[0025] In a preferred embodiment, the piston ring according to the invention includes an additional seal designed as a single-cut ring. One end of the single-cut ring is designed to have a radially outward protrusion located in its annular plane. This protrusion engages with a groove on the inner side of the sealing ring segment. The single-cut ring is positioned radially inside the sealing ring segment and seals all annular joints between adjacent sealing ring segments in each case. Due to its one-piece design, such a seal is easy to manufacture, quick to assemble, and can withstand mechanical loads.

[0026] Preferably, the groove that the protrusion of the single-cut ring can engage with is arranged in the area of ​​the guide provided on the side of the sealing ring.

[0027] In a preferred embodiment, the piston ring according to the invention optionally includes a third annular body in addition to the first and second annular bodies. The third annular body has a radially outward outer side, an upper side and a lower side, and a radially inward inner side. In this embodiment, a segmented sealing ring is arranged between the first and third annular bodies.

[0028] The first and third annular bodies are support rings arranged on both sides of the segmented sealing ring along its axial direction.

[0029] In operation, the third annular body is preferably arranged on the low-pressure side of the axial direction adjacent to the sealing ring, and its size is designed so that it does not contact the sealing ring during operation, but has the smallest possible gap relative to the mating parts.

[0030] This type of piston ring, also known as a sandwich piston ring, can reduce leakage rate.

[0031] Particularly preferably, the third annular body is a one-piece design, especially a continuous one. This can significantly reduce leakage.

[0032] The sandwich design of the piston ring according to the invention makes it possible to manufacture a second annular body, which is designed as a segmented sealing ring made of plastic material, which is not suitable for sealing high pressure differentials in a "self-supporting" design, i.e., without a support ring.

[0033] In a preferred embodiment, the segmented sealing ring is substantially made of polytetrafluoroethylene (PTFE), although high-temperature polymers such as polyetheretherketone (PEEK), polyimide (PI), polyamide-imide (PAI), polyphenylene sulfide (PPS), or mixtures thereof can also be used for very high pressure differentials. These polymers can withstand high pressure differentials with minimal deformation due to their mechanical properties and also exhibit high thermal resistance. Optionally, the segmented sealing ring can be filled with one or more fillers, particularly carbon, graphite, glass fiber, molybdenum disulfide (MoS2), and / or copper. This makes it possible to particularly improve the dry-running performance of the sealing ring.

[0034] In a preferred embodiment, the first and / or third annular bodies are substantially made of high-temperature polymers, particularly polyetheretherketone (PEEK), polyimide (PI), polyamide-imide (PAI), polyphenylene sulfide (PPS), or epoxy resins; fiber composites, particularly carbon fibers in a PEEK or epoxy resin matrix; metals, particularly copper alloys; or engineering ceramics, particularly alumina, zirconium oxide, silicon carbide, or silicon nitride. These materials possess very high mechanical strength, which can significantly increase the service life of the piston rings. Optionally, the first and / or third annular bodies may be filled with one or more fillers, particularly carbon, graphite, glass fiber, molybdenum disulfide (MoS2), and / or copper. This makes it possible, in particular, to improve their dry-running characteristics.

[0035] In a preferred embodiment of the sandwich piston ring according to the invention, at least one sealing ring segment of the segmented sealing ring is guided on the first and third annular bodies. Preferably, all sealing ring segments of the segmented sealing ring are guided on the first and third annular bodies. This allows for particularly safe guidance of the sealing ring segments and specifies the installation orientation of the three annular bodies, thereby reducing errors when assembling or installing the piston ring according to the invention.

[0036] During the operation of a reciprocating compressor, the return flow of gas temporarily stored in the piston ring grooves—in addition to the axial reverse clearance of the piston rings in the aforementioned circumferential piston ring grooves—can be greatly improved through so-called pressure equalization or return channels. Therefore, the sealing ring section has almost no sealing effect at this stage and thus does not suffer from wear.

[0037] In a preferred embodiment of the piston ring according to the invention, the first or third annular body has at least one radially extending return channel on its side facing away from the sealing ring. When using the piston ring according to the invention, the return channel extends radially across the entire side width and faces the compression chamber. Preferably, the return channel has a triangular chamfer.

[0038] Particularly preferably, in the assembled state of the piston rings, the return channels are respectively arranged in the regions of the segmented ends of the segmented sealing rings, thereby significantly improving the return of fluid temporarily stored in the piston ring grooves.

[0039] It would be advantageous if the first and third annular bodies—if present—were suited to enter the cylinder bore “without clearance” during hot operation. To ensure that the first annular body, if present, and the third annular body, do not jam during operation, in a preferred embodiment of the piston ring or sandwich piston ring according to the invention, the radially outward outer side of the first annular body and / or the radially outward oblique outer side of the third annular body are designed to taper axially, preferably tapered, starting from the segmented sealing ring.

[0040] This ensures that during operation, the radially outward outer surfaces of the first and / or third annular bodies do not need to detach from their entire axial height, but are simply understood as extending beyond the area of ​​the cylinder wall. Therefore, the piston rings or sandwich piston rings according to the invention are arranged without clearance in the cylinder bore at operating temperature.

[0041] In an alternative embodiment of the piston ring according to the invention, the first annular body has a chamfer on its radial outer annular edge that faces away from the sealing ring. The chamfer is preferably between 1° and 10°. Additionally or alternatively, the annular land height of the chamfer is at least 4 mm.

[0042] In an alternative embodiment of the piston ring according to the invention, the third annular body has a chamfer on its radially outer annular edge facing the sealing ring. The chamfer is preferably between 1° and 10°. Additionally or alternatively, the annular land height of the chamfer is at least 4 mm.

[0043] In a preferred embodiment of the piston ring according to the invention, in the assembled state of the sealing ring, two adjacent sealing ring segments contact each other along a cut line that extends radially from the inside of each sealing ring segment to the sealing surface. In other words, in the assembled state of the sealing ring, two adjacent sealing ring segments contact each other along a cut line that is tangent to the radially inward inner surface of the sealing ring, forming an angle substantially equivalent to 90°.

[0044] This sealing ring section is particularly robust and easy to manufacture.

[0045] In a preferred alternative embodiment of the piston ring according to the invention, the ends of each sealing ring segment are axially stepped in the circumferential direction. In this embodiment, the stepped ends of adjacent sealing ring segments are arranged to overlap at least in the axial portion to form an axial seal.

[0046] This design of the sealing ring section provides better axial sealing, especially in the area at the end of the section.

[0047] The objective of this invention is further addressed by a reciprocating compressor, particularly a dry-running reciprocating compressor, which includes at least one piston ring as described above. Attached Figure Description

[0048] Various embodiments of the present invention are described below with reference to the accompanying drawings, wherein the same or corresponding elements are generally provided with the same reference numerals. As shown:

[0049] Figure 1a Perspective view of the first ring-shaped body;

[0050] Figure 1b Figure 1a The top view of the first annular body shown;

[0051] Figure 1c Figure 1a The bottom view of the first annular body shown;

[0052] Figure 2a A perspective view of the second annular body, which is designed as a segmented sealing ring;

[0053] Figure 2b Figure 2a A top view of the segmented sealing ring shown;

[0054] Figure 3 Top view of the third ring-shaped body;

[0055] Figure 4 include Figure 1a The first ring body shown and Figure 2a The piston ring of the second annular body shown;

[0056] Figure 5 Piston rings consisting of three annular bodies;

[0057] Figure 6 A longitudinal section passing through the sealing device arranged on the piston;

[0058] Figure 7 A longitudinal section passing through a second embodiment of the sealing device;

[0059] Figure 8 An exploded view of the piston ring, including the segmented first annular body and the mating cap;

[0060] Figure 9a Figure 8 The bottom view of the first ring-shaped body in the middle;

[0061] Figure 9b The first annular body along Figure 9a Cross-section of the XX line;

[0062] Figure 10 Figure 8 Top view of the second annular body;

[0063] Figure 11a Figure 8 A top view of the third ring-shaped body;

[0064] Figure 11b The third ring body along Figure 11a The cross-section of the YY line in the diagram. Detailed Implementation

[0065] Figure 1a A perspective view of the first annular body 10 is shown. The annular body 10 has a radially outward outer side 11, an upper side 12, a lower side 13, and a radially inward inner side 14. The first annular body 10 is designed as a continuous ring and includes three return channels 2 distributed in the circumferential direction and extending radially along the entire width of the side. Each of these return channels 2 has two triangular chamfers 3 at the transition from the return channel 2 to the side 12. On the side 13 opposite to the return channels 2, the annular body 10 further includes three guides 5a-c distributed in the circumferential direction. In this embodiment example, these guides are designed as grooves, which will be described in detail below.

[0066] Figure 1b yes Figure 1a A top view of the first annular body. It shows three radially extending return channels 2 with chamfers 3, which are arranged on the upper side 12 and offset by 120° relative to the piston ring axis A in the circumferential direction U. The guides 5a-c and the center of the return channels 2 are arranged offset by 60° relative to each other in the circumferential direction U.

[0067] Figure 1c It shows Figure 1a and 1b A bottom view of the first annular body. This shows three groove-shaped recesses 5a-c transverse to the axial direction A on the lower side 13 of the first annular body 10, which are staggered by 120° from each other in the circumferential direction U. In this embodiment, each groove-shaped recess 5a-c has a groove width B of 27.5 mm. N and a groove depth T of 1.6mm N .

[0068] Figure 2a A perspective view of a second annular body 20 is shown, which is a segmented sealing ring 20 comprising three sealing ring segments 20a-c. In the assembled state, the segmented sealing ring 20 has a radially outward sealing ring surface 21, an upper sealing ring side surface 22 and a lower sealing ring side surface 23, and a radially inward sealing ring inner side 24, which are respectively formed by the radially outward sealing surfaces 21a-c, the upper sealing ring segment side surfaces 22a-c and the lower sealing ring segment side surfaces 23a-c, and the radially inward inner sides 24a-c of each sealing ring segment 20a-c (for clarity, ...). Figure 2a (Not shown in the accompanying drawings). Each of the three sealing ring sections 20a-c has a guide 4a-c designed as a guide rib.

[0069] Figure 2b It shows Figure 2a The diagram shows a top view of the segmented sealing ring 20. The sealing ring 20 has three radial portions S, each extending radially from the inner side of the segmented sealing ring 20 to the sealing surface. Each of the three sealing ring segments 20a-c extends through a 120° arc and includes guide ribs 4a-c, which are staggered by 120° from each other in the circumferential direction U. Guide rib B is selected. R The width allows guide ribs 4a-c to engage virtually "without gaps". Figure 1a -c is located in the guide groove 5a-c of the first annular body 10. Therefore, mutual torsion or displacement of the sealing ring segments 20a-c on the first annular body 10 in the circumferential direction U can be prevented. In the illustrated embodiment example, guide rib B... R Its width is approximately 27.5mm, and the guide rib T... R The depth is approximately 1.5 mm.

[0070] Figure 3A top view of a third annular body 30 is shown, which has a radially outward outer side 31, an upper side 32, and a lower side (not shown), and a radially inward inner side 34. The annular body 30 is formed as a continuous ring. The first annular body 10, the segmented sealing ring 20, and the third annular body 30 are arranged sequentially along an axial direction A extending perpendicular to the circumferential direction U, with the segmented sealing ring 20 positioned between the first and third annular bodies (not shown).

[0071] Figure 4 It shows including Figure 1a The first annular body 10 shown and Figure 2a The piston ring 1 of the second annular body 20 shown has a sealing ring segment 20a-c guided on the first annular body 10 by guides 4a-c and 5a-c. In the illustrated embodiment, the guides 4a-c and 5a-c are formed by a locking structure between the contact surfaces of the first annular body 10 and the sealing ring segment 20a-c. In this case, the guide ribs 4a-c arranged on the side of the sealing ring 20 engage with the guide grooves 5a-c arranged on the side of the top ring 10, thereby substantially preventing the sealing ring segment 20a-c from twisting relative to the first annular body 10 in the circumferential direction U, and allowing the sealing ring segment 20a-c to be displaced laterally to the axial direction A.

[0072] Figure 5 A longitudinal section through a piston ring 1 is shown, which includes a first annular body 10, a second annular body 20, and a third annular body 30. The second annular body 20 is designed as a segmented sealing ring with three sealing ring segments 20a-c, arranged between the first annular body 10 and the third annular body 30. On its side 12 facing the compression chamber V, the first annular body 10 has a plurality of return channels 2, which, in the assembled state of the piston ring 1, are axially staggered by A in the regions of the segmented ends of the segmented sealing ring 20. Figure 5In the illustrated embodiment, the sides of the contacting annular bodies 10, 20, and 30 are designed to operate in a shape-fitting manner, such that all sealing ring segments 20a-c are guided by guides 4a-c, 5a-c, and 9a-c (shown only for sealing ring segment 20a) on the first annular body 10 and the third annular body 30. In this context, sealing ring segment 20a has a guide 4a designed as a guide rib on its side 22a facing the first annular body 10, which engages with a guide 5a designed as a guide groove formed on the side 13 of the first annular body 10 facing the segmented sealing ring 20. Sealing ring segment 20a further includes a second guide 4a forming a guide groove on its side 23a facing the third annular body 30, which engages with a guide 9a arranged on the side 32 of the third annular body 30 facing the segmented sealing ring 20. Guide elements 5a, 4a, 4a, and 9a are formed on their respective sides 13, 22a, 23a, and 32, such that the mounting orientation of the annular bodies 10, 20, and 30 including them is predetermined axially. In this embodiment, the height H of the axial sealing ring is... D It is 4.5mm.

[0073] Figure 6 A longitudinal section of a reciprocating compressor 100 is shown, the compressor comprising a cylinder 40 having a cylinder inner wall 41, a piston 50, and at least one piston ring 1 in a retracted state arranged in the piston 50 according to the invention. The piston 50 is designed as a multi-piece piston and includes a plurality of piston bodies 51 arranged sequentially in the axial direction, each piston body 51 having a cavity disc 52 forming a circumferential piston ring groove 7 for receiving the piston ring 1. Figure 6 In this reciprocating compressor 100, the compression chamber V is located at the top, while the low-pressure side crankcase K is located at the bottom. The piston rings 1 include a sealing ring 20, an optional clamping ring 60, a first annular body 10, and a third annular body 30. The clamping ring 60 preferably applies an outward preload to the sealing ring 20 in the radial direction R, causing its straightened ring segments 20a, 20b, 20c to abut against the cylinder inner wall 41 with their outward sealing surfaces 21, particularly even in a depressurized state. In this embodiment, the first annular body 10 is designed as a top ring, while the third annular body 30 is designed as a support ring or base ring. The piston rings 1 are spaced apart in the radial direction R to form an inner gap 8 relative to the chamber disk 52. The inner gap 8 is fluidly connected to a further upward space, not visible in the illustrated view, via a return channel 2 formed on the side of the top ring 10 facing the compression chamber and an outer gap 6 on the side of the compression chamber.

[0074] Figure 7 It shows crossing Figure 6The longitudinal section of the piston compressor 100, however, has a second embodiment of the piston ring 1 according to the invention in a new state, i.e., before the sealing ring 20 is worn. In an advantageous embodiment, the sealing ring 20 or its illustrated sealing ring segment 20a is designed such that its radially outward sealing surface 21 extends radially R beyond the outer side 11 of the top ring 10 and beyond the outer side 31 of the base ring 30 in the new state. Thus, during commissioning, the sealing ring 20 contacts the cylinder inner wall 41, making the gap between the outer sealing surface 21 and the cylinder inner wall 41 extremely small, and the sealing ring segments 20a-c are pressed radially R outward by the pressure applied in the inner gap 8, thereby dislodging the material from the outer sealing surface 21 of the sealing ring 20 until the sealing ring 20 adapts to the shape of the bore of the cylinder 40 at operating temperature. During subsequent operation of the reciprocating compressor 100, the outer sealing surface 21 of the sealing ring sections 20a-c will wear. Consequently, the worn sealing ring sections 20a-c are pressed outward in the radial direction R due to the pressure applied in the inner clearance 8, and pushed outward in the radial direction R as the sealing surface 21 wears accordingly, so that despite the wear, a sealing effect is maintained between the outer sealing surface 21 and the cylinder inner wall 41. Figure 7 In the illustrated embodiment, the top ring 10 and the support ring 30 are designed such that their radially outward outer surfaces 11 and 31, starting from the sealing ring 20, are at least partially tapered in the axial direction A, so that the radially outward outer surfaces 11 and 31 of the top ring 10 and the support ring 30 do not contact the cylinder inner wall 40 over their entire axial height in the retracted and preheated operating states. Figure 6 Compared to the piston rings shown, Figure 7 The piston ring 1 shown does not have a clamping ring for pressing the shown sealing ring section against the cylinder inner wall 41 on the radially inward inner side of the sealing ring 20.

[0075] Figure 8 A further embodiment of the piston ring 1 is shown, wherein a segmented first annular body 10, a single-cut ring 70 with a fastening element 71, a segmented second annular body 20 and a third annular body 30 are arranged adjacent to each other in the axial direction A, and the fastening element 71 is radially convex at one end of the single-cut ring 70, which can engage with a groove 25 on the inner side of the second annular body 20.

[0076] Figure 9a It shows Figure 8 The bottom view of the first annular body 10 is shown. The first annular body 10 is designed as a segmented base ring consisting of three base ring segments 10a-c, each segment extending through an arc of 120°. In the illustrated embodiment, the guides 5a-c arranged on the base ring side are designed to always have a groove width B of 11 mm. NThe guide groove is formed in each case by two opposing, axially stepped mating ends of adjacent base ring segments. In other words, the end of the base ring segment 10a, designated as reference numeral 5a.a, together with the end of the base ring segment 10c, designated as reference numeral 5a.c, forms the guide groove 5a. Therefore, the ends of the base ring segments 10c and 10b, designated by reference numerals 5c.c and 5c.b, respectively, form the guide groove 5c, while the ends of the base ring segments 10b and 10a, designated by reference numerals 5b.b and 5b.a, respectively, form the guide groove 5b.

[0077] Figure 9b Show along Figure 9a The XX line passes through Figure 9a The cross-section of the base ring 10 is shown. It shows a complete base ring segment 10c with annular end portions 5c.c and 5a.c, which are stepped in the axial direction A, and a cut base ring segment 10a with axially stepped annular end portions 5a.a. In this embodiment, the base ring 10 has an axial height H of 3 mm. G Furthermore, the base ring 10 has a chamfer on its radial outer ring edge 15 facing away from the sealing ring (not shown). In this embodiment, the chamfer angle α1 is 4°, and the ring height H... S It is 0.5mm.

[0078] Figure 10 It shows Figure 8 The figure shows a top view of a second annular body 20 with three sealing ring segments 20a-c. Each sealing ring segment extends 120° in the circumferential direction U and, in the assembled state, contacts each other at the radial cutting lines S extending from the inner side of each sealing ring segment to the sealing surface. The two opposite ends of adjacent sealing ring segments 20a-c each form an annular end gap 80. Three guide ribs 4a-c are also shown in the figure, extending laterally to the axial direction A and offset from each other by 120° in the circumferential direction U. In this embodiment, each guide rib 4a-c has a width B of 11 mm. R Therefore, the width B of the guide rib R The choice was made so that guide ribs 4a-c could fit with the guide ribs essentially "without gap". Figure 8 The guide grooves 5a-c of the first annular body 10 shown engage. In the illustrated embodiment, one of the sealing ring segments, namely the sealing ring segment 20c, includes a groove 25 on its inner side 24c, the groove being... Figure 8 The area shown is for receiving the guide rib 4c of the fastening element 71. The groove 25 is designed as a groove extending along the axial direction A over the entire height of the sealing ring.

[0079] Figure 11a It shows Figure 8The top view of the third annular body 30 shown is a continuous design, having a radially outward outer side 31, an upper side 32, and a lower side ( Figure 11b The middle part is 33) and the inner side is radially inward 34. The third annular body 30 also has a chamfer on its radially outer annular edge 35 facing the sealing ring (not shown).

[0080] Figure 11b It shows Figure 11a The third annular body 30 shown is along Figure 11a The cross-section of the YY line is shown. It includes the upper side 32, the lower side 33, and the radial outer ring edge 35. The chamfer on side 32 faces the sealing ring (not shown). As shown in the enlarged view portion Z, the chamfer α3 in this embodiment is 4°, and the ring height H... S It is 0.5mm.

Claims

1. A piston ring (1), comprising: A first annular body (10) and a second annular body, these annular bodies being arranged axially adjacent to each other and coaxially with each other, The first annular body (10) has a radially outward outer side (11), an upper side (12) and a lower side (13), and a radially inward inner side (14). The second annular body is formed as a segmented sealing ring comprising multiple sealing ring segments (20a, 20b, 20c). Each of these sealing ring segments (20a, 20b, 20c) has a radially outward sealing surface (21a, 21b, 21c), an upper sealing ring segment side surface (22a, 22b, 22c), a lower sealing ring segment side surface (23a, 23b, 23c), and a radially inward inner side (24a, 24b, 24c). The sealing ring segments (20a, 20b, 20c) are each guided on the first annular body (10) by at least one guide (4a, 4b, 4c, 5a, 5b, 5c) formed into guide ribs that engage with guide grooves. These guides (4a, 4b, 4c, 5a, 5b, 5c) substantially prevent the sealing ring segments (20a, 20b, 20c) from twisting relative to the first annular body (10) in the circumferential direction (U) and allow these sealing ring segments (20a, 20b, 20c) to shift laterally in the axial direction (A).

2. The piston ring (1) according to claim 1, wherein the guides (4a, 4b, 4c, 5a, 5b, 5c) formed by the contact sides of the first annular body (10) and the sealing ring segments (20a, 20b, 20c) are designed to extend in a shape-fitting manner to each other.

3. The piston ring (1) according to claim 1, wherein the depth of the guide groove (TN) is between 0.5 mm and 4 mm, and / or wherein the guide groove has a width (BN) between 10 mm and 50 mm.

4. The piston ring (1) according to any one of claims 1 to 3, wherein the first annular body (10) is a single piece.

5. The piston ring (1) according to any one of claims 1 to 3, wherein the first annular body (10) is formed as a segmented base ring comprising a plurality of base ring segments (10a, 10b, 10c).

6. The piston ring (1) according to any one of claims 1 to 3, wherein the first annular body (10) is formed of three base ring segments (10a, 10b, 10c), wherein the second annular body is formed of three sealing ring segments (20a, 20b, 20c), and wherein the base ring segments (10a, 10b, 10c) and the sealing ring segments (20a, 20b, 20c) each extend through an arc of 120°.

7. The piston ring (1) according to any one of claims 1 to 3, wherein, The segmented sealing ring has an axial sealing ring height (HD) between 1 mm and 6 mm.

8. The piston ring (1) according to any one of claims 1 to 3, wherein it does not have a clamping ring (60) located on the radially inward inner side of the segmented sealing ring for pressing the sealing ring segments (20a, 20b, 20c) against the mating surface.

9. The piston ring (1) according to any one of claims 1 to 3 further comprises at least one additional seal (70) for sealing the ring end gap (80) formed by two opposing ends of adjacent sealing ring segments (20a, 20b, 20c).

10. The piston ring (1) according to claim 9 includes an additional seal (70) formed as a single-cut ring, wherein one end of the single-cut ring is L-shaped and has a radially outward protrusion (71) located in the annular plane of the single-cut ring, the protrusion (71) being able to engage with a groove (25) on the inner side (24a, 24b, 24c) of the sealing ring section (20a, 20b, 20c).

11. The piston ring (1) according to any one of claims 1 to 3, comprising a third annular body (30) having a radially outward outer side (31), an upper side (32) and a lower side (33) and a radially inward inner side (34), wherein the segmented sealing ring is disposed between the first annular body (10) and the third annular body (30).

12. The piston ring (1) according to claim 11, wherein at least one sealing ring segment of the segmented sealing ring is guided on the first annular body (10) and the third annular body (30).

13. The piston ring (1) according to claim 11, wherein the first annular body (10) or the third annular body (30) has at least one radially extending return channel (2) on its side away from the sealing ring, the return channel (2) extending radially across the entire side width and facing the compression chamber (V) during the intended use of the piston ring (1).

14. The piston ring (1) according to claim 11, wherein, Starting from the segmented sealing ring, the radially outward outer side (11) of the first annular body (10) and / or the radially outward outer side (31) of the third annular body (30) are tapered along the axial direction (A).

15. The piston ring (1) according to claim 11, wherein the first annular body (10) has a chamfer at its radial outer annular edge (15) opposite to the sealing ring.

16. The piston ring (1) according to claim 11, wherein the third annular body (30) has a chamfer at its radial outer annular edge (35) facing the sealing ring.

17. The piston ring (1) according to any one of claims 1 to 3, wherein, In the assembled sealing ring, two adjacent sealing ring segments (20a, 20b, 20c) always contact along a cutting line (S) that extends radially from the inner side (24a, 24b, 24c) of each sealing ring segment (20a, 20b, 20c) toward the sealing surface (21a, 21b, 21c).

18. The piston ring (1) according to any one of claims 1 to 3, wherein the ends of each sealing ring segment (20a, 20b, 20c) are designed to be axially stepped in the circumferential direction (U), and the stepped ends of adjacent sealing ring segments (20a, 20b, 20c) are arranged to be at least partially stacked along the axial direction (A) to form an axial seal.

19. A piston compressor (100) comprising at least one piston ring (1) according to any one of claims 1 to 3.

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