Compressor piston, compressor, and piston disassembly method and disassembly tool

Abstract

The invention relates to a piston (1) for a compressor. The piston comprises a piston rod (2) defining a longitudinal axis (L) and a piston ring package (11). The piston ring package comprises a carrier sleeve (9) and a plurality of piston ring arrangements (34). The carrier sleeve extends along the longitudinal axis. The carrier sleeve is disposed on a circumferential surface (2a) of the piston rod. The carrier sleeve is releasably fastened to the piston rod. The plurality of piston ring arrangements are disposed adjacent to one another along the longitudinal axis. The plurality of piston ring arrangements are disposed on an outer circumferential surface of the carrier sleeve. The plurality of piston ring arrangements are fastened to the carrier sleeve. The carrier sleeve preferably has a mechanical interface (9g) for mounting an extraction tool (20). The extraction tool exerts a force (F) directed along the longitudinal axis.

Description

[Technical field]

[0001] The invention does not only relate to a piston for a compressor, but also to a compressor, in particular a high-pressure compressor equipped with such a piston, as well as to an extraction tool and a method for dismantling the piston. [Background technology]

[0002] High pressure reciprocating compressors are often used to compress gases such as methane or hydrogen to pressures between 100 bar (10 MPa) and 1000 bar (100 MPa). Piston compressors typically have a piston guided in a cylinder between top and bottom dead centre. The piston typically comprises a piston rod and a number of piston rings attached to the outer circumference of the piston rod. The piston rings may comprise, for example, carrier rings. Sealing elements are attached to the carrier rings. The sealing elements are used to seal a compression chamber defined by the piston and the cylinder and, optionally, to meter the amount of lubricating oil between the cylinder and the piston.

[0003] Piston rings are wear parts that need to be replaced after a certain period of time. Depending on the piston design, replacing the piston rings requires a complete disassembly of the piston, which is often time consuming. Furthermore, the space in which the compressor operates can be tight, making replacement even more difficult.

[0004] Patent Document 1 describes a piston compressor for compressing a gas. The compressor includes a piston rod and a piston with a plurality of piston ring devices attached to the piston rod. Each of the plurality of piston ring devices includes a carrier ring with an L-shaped cross section and a sealing element fixed to the carrier ring. To facilitate replacement of the sealing elements, the sealing elements are circumferentially divided so that the sealing elements can be removed from the carrier ring without removing the carrier ring from the piston rod. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2003-206860 A Summary of the Invention [Problem to be solved by the invention]

[0006] The object of the present invention is to find a solution that facilitates replacement of seals on compressor pistons. This problem is solved by the subject matter of the respective independent claims. Advantageous embodiments and further developments are the subject matter of the dependent claims which refer to the independent claims and of the following description and figures. [Means for solving the problem]

[0007] According to a first aspect of the present invention, there is provided a piston for a compressor. The piston according to the present invention comprises a piston rod defining a longitudinal axis and a piston ring package. The piston ring package comprises a carrier sleeve extending along the longitudinal axis, the carrier sleeve being disposed on a circumferential surface of the piston rod and releasably fastened to the piston rod, and a plurality of piston ring arrangements disposed adjacent to one another along the longitudinal axis, the plurality of piston ring arrangements being disposed on an outer circumferential surface of the carrier sleeve and fastened to the carrier sleeve. The carrier sleeve preferably has a mechanical interface for mounting a withdrawal tool for applying a force directed along the longitudinal axis.

[0008] According to a second aspect of the invention, a compressor, in particular a high pressure compressor for compressing a gas such as natural gas, methane or hydrogen, comprises a piston according to the first aspect of the invention. The compressor can for example be set to compress the gas to a pressure in the range between 100 bar (10 MPa) and 1000 bar (100 MPa), in particular to a pressure in the range between 100 bar (10 MPa) and 300 bar (30 MPa). For example, the piston can be mounted in a cylinder such that it can move linearly between two dead centres.

[0009] According to a third aspect of the invention there is provided an extraction tool for dismantling a piston according to the first aspect of the invention, the extraction tool comprising a coupling device for attachment to a preferred mechanical interface of the carrier sleeve and a tensioning device for applying a force along the longitudinal axis to the coupling device.

[0010] According to a fourth aspect of the invention, there is provided a method for dismantling a piston according to the first aspect of the invention, in which an extraction tool is coupled to a preferred mechanical interface of a carrier sleeve of a piston ring package. By applying a force along the longitudinal axis of the carrier sleeve by the extraction tool, the entire piston ring package is extracted from the piston rod. For example, the extraction tool according to the third aspect of the invention may be used to carry out the method.

[0011] The idea of ​​the present invention is to preassemble piston rings (also referred to herein as piston ring devices) onto a carrier sleeve to form a piston ring package or cartridge, which is then fixed to a piston rod as a preassembled unit, i.e., a number of piston rings are preassembled onto the outer periphery of the carrier sleeve, which is then pressed against the outer periphery of the piston rod or the piston rod is threaded through the carrier sleeve. The carrier sleeve preferably also has a mechanical interface or coupling structure that allows a extraction tool to be secured thereto for applying an axial force to the carrier sleeve to disassemble the piston ring package. This facilitates the extraction of the piston rings together with the carrier sleeve from the piston rod.

[0012] One advantage of the present invention is that the piston rings are attached to a carrier sleeve rather than directly to the piston rod circumference, meaning that the carrier sleeve and the piston rings can be pulled off the piston rod together as a whole. A favorable mechanical interface further simplifies the withdrawal of the carrier sleeve from the piston rod. This not only simplifies disassembly of the piston rings, but also facilitates the installation of new piston rings, making it possible to replace all of the piston rings at the same time.

[0013] A further advantage of preassembled piston ring packages is that they can be manufactured with high precision, configured at the production site, and tested as needed, thereby reducing the labor required to assemble the piston ring package, center and fit the piston rings, when replacing the piston ring package at the compressor site, e.g., on a transport ship, drilling platform, etc.

[0014] According to some embodiments, it may be provided that the carrier sleeve is frictionally attached to the rod circumferential surface of the piston rod. Thus, the inner circumferential surface of the carrier sleeve is frictionally connected to the rod circumferential surface of the piston rod at least in some areas or is allowed to rest against the rod circumferential surface. Thus, a reliable axial fixation of the carrier sleeve is achieved. Optionally, the carrier sleeve can also be axially fixed by a fixing element screwed into the piston rod.

[0015] According to some embodiments, the preferred mechanical interface may be formed by a screw thread, which has the advantage of facilitating the coupling between the extraction tool and the carrier sleeve.

[0016] According to an exemplary embodiment, the sleeve inner circumferential surface of the carrier sleeve can rest on a first rod axial section of the rod circumferential surface of the piston rod in a first sleeve end region of the carrier sleeve. The thread can be formed as an internal thread on the sleeve inner circumferential surface in a second sleeve end region of the carrier sleeve, which is located opposite the first sleeve end region with respect to the longitudinal axis, where the sleeve inner circumferential surface in the second sleeve end region of the carrier sleeve is spaced apart from the second rod axial section of the rod circumferential surface of the piston rod in a radial direction perpendicular to the longitudinal axis. Thus, the piston rod can be tapered from the first sleeve end region of the carrier sleeve towards the second sleeve end region of the carrier sleeve, for example in a step or transition cone. An annular gap is formed between the internal thread in the second sleeve end region of the carrier sleeve and the outer circumferential surface of the piston rod. A removal tool can be inserted into this gap. This further facilitates the removal of the piston ring package. Additionally, internal threads have the advantage that they minimize the space required for a suitable mechanical interface.

[0017] According to some embodiments, the carrier sleeve has a sleeve body and a sleeve collar as a collar projecting radially from the axial end of the sleeve body. It can be provided that the piston ring arrangement located last with respect to the longitudinal axis is stationary with respect to the sleeve collar. In this way, it is made possible to fix the individual piston rings in the axial direction very simply. At the axial end of the sleeve body, from which the sleeve collar projects radially, it is made possible, for example, to form the end of the first sleeve end region of the carrier body, which optionally rests on the rod circumferential surface of the piston rod. In other words, since the sleeve collar is preferably arranged opposite the preferred mechanical interface, this mechanical interface is advantageously arranged also in the end region of the carrier sleeve.

[0018] Optionally, the sleeve collar is allowed to rest against a shoulder on the piston rod, which is a simple way of axially fixing the piston ring package to the piston rod.

[0019] According to some embodiments, the piston ring arrangements are enabled to be connected to one another along the longitudinal axis, and are therefore advantageously axially fixed to the carrier sleeve.

[0020] According to an exemplary embodiment, it may be provided that the piston ring package has a first end piece and a second end piece, and the piston ring arrangement is clamped between the first end piece and the second end piece, thereby providing a simple way of axially fixing all the piston rings relative to one another.

[0021] According to some embodiments, each of the piston ring arrangements clamped between the first and second end pieces may have a through hole. A connecting threaded rod connecting the first and second end pieces may extend through the through hole. For example, the connecting threaded rod may be screwed into a thread provided on the second end piece. The first end piece may be fixed to the connecting threaded rod via a nut. The connecting threaded rod offers the advantage that the clamping force can be precisely adjusted in the axial direction. Furthermore, in this way, centering of the piston ring is simplified.

[0022] Optionally, the first end piece can be formed by a ring element and the second end piece can be formed by another piston ring device, whereby the second end piece performs both the function of a piston ring and the function of fixing another piston ring, thereby advantageously reducing the number of components in the piston ring package.

[0023] According to some embodiments, the piston ring arrangements can each include a carrier ring surrounding an outer circumferential surface of a carrier sleeve, and a sealing element attached to the carrier ring.

[0024] According to some embodiments of the extraction tool, the coupling device comprises a coupling sleeve, which receives the end region of the piston rod and can be coupled to a suitable mechanical interface of the carrier sleeve, and an end plate, which has a through hole with an internal thread and is connected to the coupling sleeve. It can be provided that the tensioning device comprises a tensioning screw, which can be screwed into the internal thread of the end plate to be supported against the axial end of the piston rod. The coupling sleeve of the extraction tool can have, for example, an external thread, which can be screwed into the mechanical interface of the carrier sleeve, which is designed as an internal thread. To remove the carrier sleeve, for example in the above-mentioned process, the threaded rod of the extraction tool is screwed into the internal thread of the end plate of the coupling sleeve and pressed against the axial end of the piston rod. The reaction force directed longitudinally away from the piston rod is transmitted via the internal thread of the end plate to the coupling sleeve, which in turn transmits it to the carrier sleeve, facilitating the carrier sleeve to be pulled out of the piston rod.

[0025] Features and advantages disclosed with respect to one aspect of the invention are also disclosed for each other aspect. 1 shows drawings used to explain an embodiment. [Brief description of the drawings]

[0026] [Figure 1] FIG. 2 is a perspective view of a piston according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view of the piston shown in FIG. 1; [Diagram 3] 4 is a cross-sectional view of a piston according to a further embodiment; [Figure 4]3 is a cross-sectional view from FIG. 2 during disassembly of the piston by a method according to an embodiment of the invention, the disassembly being performed using an extraction tool according to an embodiment of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Generally, in the drawings, identical parts are designated by the same reference numbers unless otherwise noted. FIG. 1 is an exemplary perspective view of a piston 1 for a compressor (not shown). In particular, the compressor can be a high-pressure piston compressor, set to compress gases such as natural gas, methane, hydrogen, etc., in particular to pressures ranging between 100 bar (10 MPa) and 500 bar (50 MPa). For example, the compressor can be used on transport ships or drilling platforms. For example, gas accumulated in a storage tank, for example by vaporization from a liquid phase, can be compressed to supply it to an internal combustion engine. As will be explained in more detail below, the piston 1 can be moved alternately horizontally or vertically between two opposite dead centers by a crankshaft. The piston 1 can be guided in a cylinder (not shown). Optionally, the piston 1 can be designed as a double-acting piston, so that it performs a compression work both when moving in a first direction and when moving in the opposite direction.

[0028] 1, the piston 1 may have a piston rod 2 and a piston ring package 11. The piston 1 may further have a piston top 5 and / or an axial lock 8.

[0029] FIG. 2 is a partial cross-sectional view of the piston 1 shown in FIG. 1. As shown in FIGS. 1 and 2, the piston rod 2 can be realized, for example, as a shaft having a circular cross section. In general, the piston rod 2 defines a longitudinal axis L surrounded by a rod circumferential surface 2a as the circumferential surface of the piston rod 2. As shown in FIG. 2, the piston rod 2 can have a first rod axial section 2d designed as a centering section having a first diameter and a rod extension section 2f having a second diameter smaller than the first diameter. The rod extension section 2f is arranged at a position away from the first rod axial section 2d along the longitudinal axis L. As exemplarily shown in FIG. 2, the first rod axial section 2d and the rod extension section 2f can be connected to each other by a first rod cone section 2e. A rod end 2h of the piston rod 2, which ends at a rod end face 2i of the piston rod 2, has a third diameter. The third diameter can be substantially the same as the first diameter, as exemplarily shown in Fig. 2. In this case, the rod extension 2f can be connected to the rod end 2h, for example, by a second rod cone 2g or by a rod shoulder, as exemplarily shown in Fig. 2. However, it is also conceivable that the third diameter is equal to the second diameter or, in general, that the third diameter is smaller than the first diameter.

[0030] Optionally, the rod end 2h of the piston rod 2 may have an outer rod thread 2k, as also illustrated in Fig. 2. For example, the rod shoulder 2b may be disposed directly adjacent to the first rod axial portion 2d with respect to the longitudinal axis L. In particular, as illustrated exemplarily in Fig. 2, the rod shoulder 2b may be disposed such that the first rod axial portion 2d is located between the rod end face 2i and the rod shoulder 2b.

[0031] In particular, the piston rod 2 can be made of a metallic material such as a high-strength structural steel. As shown in FIG. 1 and in detail in FIG. 2, the piston ring package 11 can be configured with a carrier sleeve 9 and a number of piston ring arrangements 34. Each of the piston ring arrangements 34 consists of a piston ring 3 and a chamber ring 4. Optionally, the piston ring package 11 can also be configured with a first end piece 4a, for example designed as a last chamber ring, and a second end piece 7, for example designed as a cover ring, as shown by way of example in FIG. 2. Optionally, the piston ring package 11 further comprises one or more connecting threaded rods 10a, as shown by way of example in FIG. 2. The connecting threaded rods 10a hold together the piston ring arrangement 34 consisting of the piston ring 3 and the chamber ring 4, and the first end piece 4a and the second end piece 7. As shown in FIG. 2, in a possible embodiment, the piston ring 3 can be configured not only from a single part, but also from a number of ring parts (3a, 3b). FIG. 2 shows that the piston ring arrangements 34 arranged towards the first sleeve end region 9e of the carrier sleeve 9 are configured with a chamber ring 4 and in each case a single piston ring 3. In contrast, FIG. 2 further shows that the piston ring arrangements 34 arranged towards the second sleeve end region 9f are configured with a chamber ring 4 and a piston ring 3. The piston ring 3 in each case consists of a first piston ring part 3a and a second piston ring part 3b. In a further embodiment not shown, it is also possible that all piston rings 3 consist of a single part. Or it is also possible that all piston rings 3 consist of at least two piston ring parts, i.e. a first piston ring part 3a and a second piston ring part 3b.

[0032] The carrier sleeve (support sleeve) 9 functions as a holder (holding part) or a carrier (support part, carrying part) of the piston ring device 34. As shown exemplarily in FIG. 2, the carrier sleeve 9 can have a cylindrical sleeve body 9a. In general, the carrier sleeve 9 is realized as an elongated sleeve-shaped part extending between a first sleeve end region 9e and a second sleeve end region 9f arranged opposite to it. The carrier sleeve 9, in particular the sleeve body 9a, has a sleeve inner peripheral surface 9d as an inner peripheral surface and a sleeve outer peripheral surface 9c as an outer peripheral surface facing the sleeve inner peripheral surface 9d. The sleeve outer peripheral surface 9c can form, for example, a side surface of a cylinder. The sleeve inner peripheral surface 9d can also form a cylindrical region. Furthermore, the sleeve inner peripheral surface 9d can be formed, for example, to have a step that defines the cylindrical region with respect to the longitudinal axis L, as shown exemplarily in FIG. 2.

[0033] Optionally, the carrier sleeve 9 can have a sleeve collar 9b as a collar at one axial end, for example at the end of the sleeve body 9a, for example at the end to which the first sleeve end region 9e is connected. As shown exemplarily in FIG. 2, the sleeve collar 9b projects perpendicularly from the sleeve outer peripheral surface 9c of the sleeve body 9a and thus extends in the radial direction R.

[0034] In this preferred embodiment, the carrier sleeve 9 also has a mechanical interface 9g for connecting or attaching an extraction tool 20 (FIG. 4). The mechanical interface 9g can be realized by a thread formed on the carrier sleeve 9, for example at the end of the sleeve body 9a, as shown for example in FIGS. 2 and 4. FIG. 2 shows an example in which the mechanical interface 9g is realized as an internal thread (9g) formed on the sleeve inner circumference 9d of the carrier sleeve 9. As shown exemplarily in FIG. 2, the mechanical interface 9g can be arranged in the second sleeve end region 9f of the carrier sleeve 9, regardless of the specific design. Thus, in the example shown in FIG. 2, the internal thread (9g) is formed in the second sleeve end region 9f of the sleeve body 9a facing away from the optional sleeve collar 9b. Instead of a thread, the mechanical interface 9g can also be designed differently. A different design of mechanical interface 9g forms a connection between the carrier sleeve 9 and the extraction tool 20 which allows the carrier sleeve 9 to be extracted, for example by a mechanical interface 9g having a slot extending (running) perpendicular to the carrier sleeve 9 which forms part of a bayonet lock with the extraction tool 20.

[0035] As shown in FIG. 2, each piston ring arrangement 34 preferably consists of a chamber ring 4 and a piston ring 3. The chamber ring 4 can have an L-shaped cross section, as exemplarily shown in FIG. 2. The piston ring 3 is held by the chamber ring 4, in particular by its outer periphery. As shown in FIG. 2, the piston ring 3 can be held in a receiving space of the chamber ring 4, which is formed, for example, by an L-shaped cross section. In general, the piston ring 3 protrudes beyond the outer periphery of the chamber ring 4. FIG. 2 shows, by way of example, that a first subset of the piston rings 3 is designed as a sealing element having a rectangular cross section, while a second subset of the piston rings 3 is designed as a sealing element having a trapezoidal cross section. However, it is also conceivable that all the piston rings 3 have the same design. Furthermore, other cross-sectional shapes of the piston rings 3 are conceivable. And / or that all the piston rings 3 have the same cross section. It is also conceivable that several ring parts (3a, 3b) of the piston ring 3 are held on the chamber ring 4. As shown in Fig. 1, the piston ring arrangements 34, and in particular the chamber ring 4, can each have at least one ring through hole 4d. The ring through holes 4d can be provided in a number, for example two, three or four, along the circumferential direction for each piston ring arrangement 34. Fig. 2 is a purely exemplary cross-sectional view in which two ring through holes 4d per piston ring arrangement 34 are visible.

[0036] As exemplarily shown in FIG. 2, the piston ring arrangements 34 are arranged on the sleeve outer circumferential surface 9c of the carrier sleeve 9. In particular, the carrier sleeve 9 passes through the central ring openings of all the chamber rings 4. The piston ring arrangements 34 or the chamber rings 4 are arranged next to each other or on top of each other such that the chamber rings 4 butt against each other. Optionally, the last chamber ring 4 (4a) relative to the longitudinal axis L is stationary relative to an optional sleeve collar 9b of the carrier sleeve 9, as exemplarily shown in FIG. 2. As also shown in FIG. 2, the piston ring arrangements 34 can be aligned such that the through openings of the chamber rings 4 are aligned. The piston ring arrangements 34 and in particular the chamber rings 4 can be frictionally fixed (frictionally engaged) to the sleeve outer circumferential surface 9c of the carrier sleeve 9, for example by forming an interference fit between the central ring openings of the chamber rings 4 and the sleeve outer circumferential surface 9c of the carrier sleeve 9.

[0037] As shown exemplarily in FIG. 2, the piston ring arrangement 34 can be clamped between an optional first end piece 4a and an optional second end piece 7. As shown in FIG. 2, the second end piece 7 can in particular be arranged in a second sleeve end region 9f of the carrier sleeve 9. The first end piece 4a can be arranged in a first sleeve end region 9e of the carrier sleeve 9, for example so as to rest against an optional sleeve collar 9b of the carrier sleeve 9. The second end piece 7 can be formed, for example, by a cover ring surrounding the sleeve outer circumferential surface 9c of the carrier sleeve 9. The first end piece 4a can be formed, for example, by the last or outermost chamber ring 4, as shown by way of example in FIG. 2. However, it is also conceivable that the first end piece 4a is formed by an optional sleeve collar 9b of the carrier sleeve 9 or by a ring element as described for the second end piece 7.

[0038] As exemplarily shown in FIG. 2, the first end piece 4a can have an end recess 4b with an internal thread. A plurality of end recesses 4b per first end piece 4a is also conceivable, the end recesses 4b being aligned with the ring through-holes 4d of the chamber ring 4. As part of this, the second end piece 7 can have one or more connection recesses 7a, which are aligned with the ring through-holes 4d of the chamber ring 4. As exemplarily shown in FIG. 2, a connection threaded rod 10a can be provided. This connection threaded rod 10a extends through the connection recesses 7a of the second end piece 7 and through the ring through-holes 4d of the chamber ring 4, and is screwed into the internal thread of each end recess 4b of the first end piece 4a. To axially fix the chamber ring 4 along the connection threaded rod 10a or to generate a clamping force between the second end piece 7 and the first end piece 4a, a connection nut 10b can be screwed onto the end of the connection threaded rod 10a that protrudes beyond the second end piece 7, as exemplarily shown in FIG. 2. In general, each piston ring arrangement 34 can thus have a ring through-hole 4d and a connecting threaded rod 10a extending through the ring through-hole 4d. The connecting threaded rod 10a connects the second end piece 7 to the first end piece 4a. In this way, all piston ring arrangements 34 can be connected to one another along the longitudinal axis L.

[0039] The piston ring package 11 is arranged on the rod circumferential surface 2a of the piston rod 2. As exemplarily shown in FIG. 2, the piston rod 2 can be threaded into a recess defined by a sleeve inner circumferential surface 9d of the carrier sleeve 9. The piston ring package 11 is thus arranged on the piston rod 2 such that the carrier sleeve 9 extends along the longitudinal axis L. Optionally, it can be provided, for example, that the carrier sleeve 9 is frictionally attached to the rod circumferential surface 2a of the piston rod 2. For example, the sleeve inner circumferential surface 9d of the carrier sleeve 9 in a first sleeve end region 9e of the carrier sleeve 9 can bear against a first rod axial portion 2d of the rod circumferential surface 2a on the piston rod 2, as exemplarily shown in FIG. 2. In general, the sleeve inner circumferential surface 9d of the carrier sleeve 9 is allowed to at least partially come into contact with the rod circumferential surface 2a of the piston rod 2. In general, the carrier sleeve 9 is thus releasably attached to the piston rod 2. 2, the sleeve inner circumferential surface 9d in the second sleeve end region 9f of the carrier sleeve 9 can be arranged at a distance in the radial direction R from the second rod axial portion (shaft portion) of the rod circumferential surface 2a of the piston rod 2. Thus, an annular gap can be formed between the sleeve inner circumferential surface 9d of the carrier sleeve 9 and the rod circumferential surface 2a of the piston rod 2 in the second sleeve end region 9f of the carrier sleeve 9. This facilitates access to a mechanical interface 9g, for example in the form of an internal thread.

[0040] As further shown in Fig. 2, an optional sleeve collar 9b of the carrier sleeve 9 can be arranged to bear against a rod shoulder 2b of the piston rod 2. A second sleeve end region 9f of the carrier sleeve 9, on which a mechanical interface 9g is preferably arranged, can for example be arranged facing a rod extension 2f of the piston rod 2.

[0041] The guide ring 6 of the piston 1 is used to contact the inner surface of the compressor cylinder (not shown). As shown in Figs. 1 and 2, the piston 1 comprises a piston top 5. On the piston top 5, the guide ring 6 and the optional piston ring 3 are arranged. The piston top 5 has a cylindrical outer peripheral surface 5b and an inner peripheral surface 5c facing in the opposite direction to the piston outer peripheral surface 5b. The piston outer peripheral surface 5b can be provided with a guide recess in which the guide element or guide ring 6 is arranged. As can be seen in Fig. 1, the guide ring 6 can have, for example, a trapezoidal outer circumference. The piston inner peripheral surface 5c defines a central passage between two opposite end faces of the piston top 5, extending in the longitudinal axis L. As exemplarily shown in Fig. 2, a first piston end face can be provided with a piston centering collar 5a surrounding the passage. As exemplarily shown in FIG. 2, a piston recess 5e laterally surrounding the passage can be formed in the opposing second piston end face.

[0042] The piston rod 2 can be passed through a passage in the piston top (upper end) 5 defined by the piston inner circumferential surface 5c, as shown in Fig. 2. The piston centering collar 5a can be optionally inserted into the carrier sleeve 9 and abut against the sleeve inner circumferential surface 9d of the carrier sleeve 9. Advantageously, as shown in Fig. 2, a first end face of the piston top 5 can be made to rest against the piston ring package 11, e.g. against the carrier sleeve 9 and / or the second end piece 7. The end of the optional connecting threaded rod 10a and the connecting nut 10b protruding from the piston ring package 11 can be accommodated in a corresponding accommodation recess 5d in the first end face of the piston top 5, if provided.

[0043] The optional axial lock 8 can, for example, have a lock ring 8a with a lock inner thread 8b (internal thread) and a number of lock through holes 8c. With the lock inner thread 8b, the lock ring 8a can be screwed onto any rod thread (2h) that can be provided in the end region of the piston rod 2. The lock ring 8a is also fixed by means of a lock fastening means 8d arranged in the lock through holes 8c, preferably by means of a lock spacer disk (spacer washer) 8e, which can be clamped to the piston top 5. In this way, the axial lock 8 exerts an axial force on the carrier sleeve 9 via the piston top 5 or the piston ring package 11 is clamped between the axial lock 8 and the rod collar (2b). In principle, it is also conceivable that the axial lock 8 directly presses against one end of the carrier sleeve 9.

[0044] As exemplarily shown in Fig. 2, the lock ring 8a can be arranged in the piston recess 5e of the piston top 5. Optionally, as exemplarily shown in Fig. 2, a lock spacer disk 8e can be arranged between the bottom of the piston recess 5e and the lock ring 8a with respect to the longitudinal axis L. Furthermore, the lock through hole 8c of the lock ring 8a can be provided with an internal thread into which a lock fastening means (lock screw) 8d is screwed in such a way that it presses against the lock spacer disk 8e or directly against the bottom surface of the piston recess 5e.

[0045] FIG. 3 exemplarily shows another piston 1 in a cross-sectional view. The piston 1 shown in FIG. 3 differs from the piston shown in FIGS. 1 and 2 in that the piston ring arrangements 34 are not connected to one another by a connecting threaded rod 10a, but are clamped between the second end piece 7 and the first end piece 4a by the force exerted by the piston top 5 and the axial lock 8. In particular, the first end face of the piston top 5 is in contact with the second end piece 7, so that the piston ring arrangements 34 are clamped between the piston top 5 and the sleeve collar 9b of the carrier sleeve 9. In this way, the piston ring arrangements 34 can be connected to one another or held securely relative to one another along the longitudinal axis L.

[0046] Fig. 4 shows an example of a withdrawal tool 20 for removing the piston 1. As exemplarily shown in Fig. 4, the withdrawal tool 20 may comprise a connection (connection, connection, coupling) device 21 for attachment to a suitable mechanical interface 9g of the carrier sleeve 9 and a pulling device 22 for applying a force F directed along a longitudinal axis L to the connection device 21.

[0047] The coupling device 21 can have, for example, a coupling sleeve 21b as a sleeve and a coupling end plate 21d as an end plate. As shown exemplarily in Fig. 4, the coupling sleeve 21b can define an open coupling receiving space 21c, which can be, for example, cylindrical. At a first end of the coupling sleeve 21b, a coupling structure 21a, for example in the form of a screw, can be formed. This coupling structure 21a is designed to be connected to a preferred mechanical interface 9g of a carrier sleeve 9 of the piston ring package 11. Fig. 4 shows by way of example that the coupling structure 21a can be designed, for example, as an external screw.

[0048] The connecting end plate 21d is connected to the connecting sleeve 21b. For example, the connecting sleeve 21b and the connecting end plate 21d can be formed integrally or as one piece. In particular, the connecting end plate 21d can be arranged at a second end opposite to the first end of the connecting sleeve 21b, as exemplarily shown in Fig. 4. The connecting end plate 21d can have a connecting through hole 21e as a through hole having an internal thread, as shown in Fig. 4.

[0049] 4, the tensioning device 22 can be realized particularly simply by a tensioning screw 22a which can be screwed into the internal thread of the connecting through hole 21e of the connecting end plate 21d. The tensioning screw 22a is thereby inserted into the connecting receiving space 21c through the connecting through hole 21e of the connecting end plate 21d. In general, the tensioning device 22 can be inserted into the connecting receiving space 21c from the axial end of the connecting sleeve 21b, so that it can be supported relative to the connecting sleeve 21b for applying an axial force.

[0050] A simple procedure for dismantling the piston 1 can be carried out with the described extraction tool 20. However, the procedure described below can also be carried out with extraction tools 20 of different designs.

[0051] If necessary, first the axial lock 8 and, if necessary, the piston top 5 are removed from the piston rod 2. The piston 1 is then in the assembled state shown in FIG. For example, the carrier sleeve 9 is in frictional contact with the rod circumferential surface 2a of the piston rod 2. Thus, in order to remove the piston ring package 11, which is releasably connected to the piston rod 2, from the piston rod 2, a pulling tool 20 is coupled to a preferred mechanical interface 9g of the carrier sleeve 9 of the piston ring package 11. For example, the rod end surface 2i of the piston rod 2 is inserted into the coupling receiving space 21c of the coupling sleeve 21b of the coupling device 21. Thus, the coupling structure 21a of the coupling sleeve 21b is coupled to the preferred mechanical interface 9g of the carrier sleeve 9. For example, as shown in FIG. 4, the coupling structure 21a of the coupling sleeve 21b, which is designed as an external thread, can be screwed into the mechanical interface 9g of the carrier sleeve 9, which is designed as an internal thread.

[0052] In a further step, the piston ring package 11 is removed from the piston rod 2 as a whole by applying a force F along the longitudinal axis L to the carrier sleeve 9 by means of the extraction tool 20, in particular by means of the tensioning device 22. The tensioning device 22 can, for example, be supported by the rod end face 2i of the piston rod 2 and can apply a force F directed away from the piston rod 2 to the connecting device 21 in order to remove the piston ring package 11 from the piston rod 2. As exemplarily shown in FIG. 4, the tensioning screw 22a can, for example, be screwed into the internal thread of the connecting through hole 21e of the connecting end plate 21d. The tensioning screw 22a is thus supported against the axial end or rod end face (end set) 2i of the piston rod 2, which is located in the connecting receiving space 21c. Optionally, a washer 23 can be arranged between the axial end (2i) and the tensioning screw 22a in order to prevent damage to the piston rod 2 by the tensioning screw 22a. A reaction force thus acts on the connecting sleeve 21b, as shown by the arrow "F" in Fig. 4. This reaction force is transferred to the carrier sleeve 9 via the mechanical interface 9g. The carrier sleeve 9 is thus pulled away from the piston rod 2 along the longitudinal axis L.

[0053] Thus, the piston ring package 11 can be removed as a whole from the piston rod 2. In particular, all piston ring arrangements (assemblies) 34 are removed at the same time. Thus, the piston 1 can be removed easily and efficiently. Similarly, the piston ring package 11 can be mounted as a whole on the piston rod 2, preassembled. Thus, it is possible to replace the piston ring arrangements 34 and to mount the chamber rings 4 and the piston rings 3 very quickly, efficiently and safely. Another major advantage is that the piston ring package 11 is advantageously assembled in a factory, so that all necessary tests and safety specifications can be carried out in the factory. Furthermore, since the chamber rings 4 and the piston rings 3 are delivered in a preassembled state in the piston ring package 11, it is guaranteed that there are almost no assembly errors when assembling the piston ring package 11 on site, for example on a ship.

Claims

1. A piston (1) for a compressor, said piston (1) comprising: a piston rod (2) defining a longitudinal axis (L); A piston ring package (11); The piston ring package (11) comprises: a carrier sleeve (9) arranged on a rod circumferential surface (2a) of the piston rod (2), the carrier sleeve (9) being releasably fastened to the piston rod (2) and extending along the longitudinal axis (L); a plurality of piston ring devices (34) arranged adjacent to one another along the longitudinal axis (L), the plurality of piston ring devices (34) being arranged on a sleeve outer peripheral surface (9c) as an outer peripheral surface of the carrier sleeve (9) and fastened to the carrier sleeve (9); It has The carrier sleeve (9) preferably has a mechanical interface (9g) for mounting an extraction tool (20) for applying a force (F) directed along the longitudinal axis (L). Piston (1).

2. The carrier sleeve (9) is frictionally fixed to the rod circumferential surface (2a) of the piston rod (2). A piston (1) according to claim 1.

3. said mechanical interface (9g) being formed by a screw thread; A piston (1) according to claim 1 or 2.

4. a sleeve inner peripheral surface (9d) as an inner peripheral surface of the carrier sleeve (9) in a first sleeve end region (9e) of the carrier sleeve (9) abuts against a first rod axial portion (2d) of the rod circumferential surface (2a) of the piston rod (2); a second sleeve end region (9f) of the carrier sleeve (9) is located on the opposite side of the longitudinal axis (L) to the first sleeve end region (9e), and the mechanical interface (9g) is formed as an internal thread on the sleeve inner circumferential surface (9d) of the second sleeve end region (9f) of the carrier sleeve (9), a radial direction (R) perpendicular to the longitudinal axis (L), and the sleeve inner circumferential surface (9d) of the carrier sleeve (9) in the second sleeve end region (9f) is located at a distance in the radial direction (R) from the extension (2f) of the rod circumferential surface (2a) of the piston rod (2); A piston (1) according to claim 3.

5. The carrier sleeve (9) A sleeve body (9a); a sleeve collar (9b) protruding radially from an axial end of the sleeve body (9a); It has the last piston ring arrangement (34) relative to the longitudinal axis (L) abuts against the sleeve collar (9b); A piston (1) according to any one of the preceding claims.

6. The sleeve collar (9b) abuts against the shoulder (2b) of the piston rod (2). A piston (1) according to claim 5.

7. The piston ring assemblies (34) are connected to each other along the longitudinal axis (L). A piston (1) according to any one of the preceding claims.

8. The piston ring package (3) has a first end piece (4a) and a second end piece (7), a plurality of said piston ring arrangements (34) are clamped between said first end piece (4a) and said second end piece (7); A piston (1) according to claim 7.

9. Each of the plurality of piston ring devices (34) clamped between the first end piece (4a) and the second end piece (7) has a ring through hole (4d) as a through hole, a connecting threaded rod (10a) connecting the first end piece (4a) and the second end piece (7) to each other extends through the ring through hole (4d); A piston (1) according to claim 8.

10. said first end piece (4a) being formed by said piston ring arrangement (34); said second end piece (7) being formed by a further piston ring arrangement (34); A piston (1) according to claim 8 or 9.

11. Each of the plurality of piston ring devices (34) comprises: a chamber ring (4) surrounding the sleeve outer circumferential surface (9c) of the carrier sleeve (9); A piston ring (3) fastened to the chamber ring (4); It has A piston (1) according to any one of the preceding claims.

12. Equipped with a piston (1) according to any one of claims 1 to 11, Compressor.

13. A extraction tool (20) for dismantling a piston (1) according to any one of claims 1 to 11, comprising: a coupling device (21) for attachment to the mechanical interface (9g) of the carrier sleeve (9); a tensioning device (22) for applying a force (F) directed along said longitudinal axis (L) to said connecting device (21); The extraction tool (20) comprises:

14. The connecting device (21) is a connecting sleeve (21b) as a sleeve adapted to receive an end region of the piston rod (2) and adapted to be connected to the mechanical interface (2g) of the carrier sleeve (9); a connecting end plate (21d) as an end plate connected to the connecting sleeve (21b), the connecting end plate (21d) having a connecting through hole (21e) having an internal thread (21f); It has the tensioning device (22) has a tensioning threaded rod (22a) that can be screwed into the internal thread (21f) of the connecting end plate (21d) so as to be supported against an end face (2i) of the piston rod (2); Extraction tool (20) according to claim 13.

15. A method for dismantling a piston (1) according to any one of the preceding claims, said method comprising the steps of: coupling the extraction tool (20) to the mechanical interface (9g) of the carrier sleeve (9) of the piston ring package (11); removing the piston ring package (11) as a whole from the piston rod (2) by applying a force directed along the longitudinal axis (L) to the carrier sleeve (9) by means of the extraction tool (20); The method comprises:

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