PISTON, COMPRESSOR, COMPRESSED AIR SUPPLY SYSTEM, VEHICLE AND METHOD FOR OPERATING A COMPRESSED AIR SUPPLY SYSTEM

Description

[0001] The invention relates to a compressor according to the preamble of claim 1. The invention also relates to a compressed air supply system, a vehicle and a method for operating a compressed air supply system.

[0002] Compressors, especially piston compressors in vehicles of all kinds, are well known. They are used to provide compressed air and cover a wide range of applications, including braking systems, air suspension systems (especially for level control), clutch boosters, and many more. Important target criteria in the design of compressors include the highest possible flow rate, the lowest possible noise level, the smallest possible dimensions, low manufacturing costs, and high robustness.

[0003] DE 10 2012 019 618 A1 discloses a manufacturing method for a piston with a circumferential seal in the form of a circular cup seal, in particular for use in a pendulum piston compressor.

[0004] In DE 10 2011 121 750 A1, for example, a compressor is disclosed, comprising a piston, the piston head of which is rigidly connected to a connecting rod, wherein a connecting rod bearing eye of the connecting rod is rotatably mounted on an eccentric pin of a drive shaft of a drive motor.

[0005] Nevertheless, the approach of the rigid connection between connecting rod and piston leads to leaks between piston and cylinder due to the design-related wobbling movement, which should be counteracted by appropriate design measures, e.g. seals.

[0006] DE 10 2013 101 110 A1 discloses a reciprocating piston compressor with a piston driven by a slider crank drive and a piston which can be moved back and forth in a cylinder and is sealed against the cylinder wall and which is arranged fixedly to the connecting rod axis, wherein the piston and / or the cylinder are designed such that the sickle-shaped gaps between the piston edge and the cylinder wall which arise during the compression stroke due to the relative inclination or tilting between the piston and the cylinder can be sealed and leaks are thereby compensated.

[0007] The concept of a two-stage compressor has proven successful, in which the supplied air is first compressed to a low-pressure level in a low-pressure stage and then to a high-pressure level in a high-pressure stage connected to the low-pressure stage.

[0008] To increase compactness, a two-stage compressor can be designed in such a way that both compressor stages are formed by only one piston, for example by means of a piston that can be acted upon from both sides.

[0009] For example, GB 241,907 discloses a multi-stage compressor which can realize any number of compressor stages by means of a piston having any number of stage sections and a cylinder designed to match.

[0010] Furthermore, DE 10 2010 054 710 A1 discloses a compressor for a compressed air supply of a compressed air supply system, which has at least one two-stage compressor unit with a single cylinder with a single piston that can be acted upon from two sides in a compression chamber of the cylinder.

[0011] DE 10 2012 223 114 A1 further describes a dual-piston compressor unit. A drive shaft of the compressor unit's motor interacts with the unit's dual piston via a guide slot in the unit's dual piston, allowing the dual piston to alternately perform a compression process in the unit's two cylinders. The axis of the drive shaft is positioned eccentrically to the center axis of the two cylinders, resulting in fewer piston position changes and thus lower noise.

[0012] The concept still requires improvement with regard to the aforementioned disadvantages and target criteria. Therefore, it is desirable to implement the function of a powerful, especially two-stage, compressor in the most compact and robust design possible.

[0013] The one already mentioned in this application with reference to Fig.1 and Fig.2A, Fig.2B The compressor 100 described in WO 2018 / 197182 A2 for a compressed air supply 10 of a compressed air supply system 200, for operating a pneumatic system 500, has a piston of the type mentioned above.

[0014] The compressor 100 of WO 2018 / 197182 A2 has: a first compression chamber 104, a second compression chamber 106, an air supply connection 120 and a compressed air outlet 124, a piston 1112 with a first pressurizable end face 113 which is directed towards the first compression chamber 104 and a second pressurizable end face 115 opposite the first end face 113, which is directed towards the second compression chamber 106, wherein the first compression chamber 104 is delimited by the first end face 113 and the second compression chamber 106 is delimited by the second end face 115 of the piston 1112, wherein the first end face 113 is a solid side 114 and the second end face 115 is a stepped side 116, and the piston 1112 is connected to a drive 102 via a connecting rod 128, wherein the first compression chamber 104 and the second compression chamber 106 are connected to each other via a connecting line 122.In the compressor 100 of WO 2018 / 197182 A2, it is provided that the connecting rod 128 is rigidly, in particular rigidly and without joints, connected to the piston 1112 on a piston side 128.1 and is rotatably connected to a rotating part 131 of the drive 102 on a drive side 128.2, and the piston 1112 carries at least one seal 138 on the stage side 116, which seals the first compression chamber 104 and / or the second compression chamber 106.

[0015] The information already provided in this application with reference to Fig.3A, Fig.3B The seal 138 on the piston 1112 described above still needs to be improved with regard to the disadvantages and target criteria mentioned above.

[0016] This is where the invention comes in, the object of which is to provide an improved device, in particular a piston and a compressor, as well as a method, which at least partially fulfill the goals and target criteria formulated above, in particular through an improved structural design. In particular, it is an object of the invention to design the device and the method in such a way that, within the framework of the improved structural design, on the one hand, an improved sealing effect and, on the other hand, an improved retention of the seal is achieved, which is also held pressure-tight on the step side, so that the first compression chamber and the second compression chamber are sealed even under long-term and high stress as part of the wobbling movement of a piston.

[0017] The object with regard to the device is achieved with a compressor according to claim 1.

[0018] Such a compressor has proven particularly useful for supplying compressed air to a compressed air supply system, for operating a pneumatic system, wherein the piston is designed to be movably guided in a cylinder of the compressor during operation of the compressor and can be connected to a drive via a connecting rod, wherein the connecting rod can be connected to the piston on one piston side and can be rotatably connected to a rotating part of the drive on one drive side.

[0019] Such a piston of the compressor according to the invention comprises: a first pressurizable end face, which is provided to be directed toward a first compression chamber of the compressor during operation, and a pressurizable second end face, opposite the first end face, which is provided to be directed toward a second compression chamber of the compressor during operation. In particular, the first compression chamber can advantageously be delimited by the first end face and the second compression chamber can be delimited by the second end face of the piston.

[0020] In such a compressor, the invention also provides that the first compression chamber and the second compression chamber are connected to one another via a pressurizable connecting line.

[0021] According to the invention, to achieve the object, it is further provided that the annular sealing body is held as a sealing sleeve of the sealing arrangement with its profile base between a step-side piston ring arranged on the second end face and a compression chamber-side retaining ring in a pressure-tight manner on the step side.

[0022] The object relating to the device is also achieved by a compressor using the piston according to the invention, namely a compressor, in particular a compressor, for a compressed air supply of a compressed air supply system, for operating a pneumatic system, comprising a first compression chamber, a second compression chamber, an air supply connection and a compressed air outlet, and the piston.

[0023] According to the invention, the compressor is provided with: a cylinder having a first compression chamber and a second compression chamber, an air supply connection and a compressed air outlet, and the piston.

[0024] The invention is based on the consideration that the basic approach of a piston, as described in the context of the compressor of WO 2018 / 197182 A2 with an already advantageous seal, fundamentally provides the right approach for the implementation of a compressor with a first and second compression chamber. That is, the approach consists in providing a seal that seals the first compression chamber from the second compression chamber, wherein the piston has a first end face as a solid side and a second end face as a stepped side.

[0025] The seal is advantageously designed to seal the second compression chamber from the crankcase interior and / or from the environment and / or to seal the first compression chamber from the second compression chamber. The at least one seal advantageously provides a pressure-tight seal acting in the radial direction on both an outer and an inner side of the step side of the piston and is particularly advantageously formed by a single sealing body.

[0026] As described by way of example in WO 2018 / 197182 A2 (full page 114), a full side is to be understood as a flat formation of a first end face of the piston that extends essentially continuously across the cylinder cross-section.

[0027] As in WO 2018 / 197182 A2 (step side 116), a step side is to be understood as a substantially annular configuration of the present second end face, i.e., which does not make the piston on the second end face pressurizable over the entire cylinder cross-section, but instead provides an annular space that can only be pressurized, in particular an annular space in the peripheral circumference of the second end face.

[0028] The content of WO 2018 / 197182 A2 and its disclosure are hereby incorporated by reference in their entirety into the present application and are thus also available as disclosure content in this application. By way of example, reference is made to the embodiments with respect to Fig.1 , Fig.2 as well as Fig.5 WO 2018 / 197182 A2, which is described in this application as Fig.1 , Fig.2 and Fig.3 are shown.

[0029] There, it is shown by way of example within the scope of an embodiment, merely for explanatory purposes and in a non-limiting manner, that --following the concept of the invention-- the first end face is formed as a solid side, there substantially dome-shaped, while the second end face is formed as an annular surface, there substantially annularly arranged in the outer circumference to form a step side.

[0030] Other embodiments are possible; for example, the stepped side could also be only partially annular or have an inner annular space. The stepped side could also have a full inner space, which is therefore not limited to a merely pressurizable peripheral annular surface, as is described in the exemplary embodiments of the present application. In this respect, a stepped side can refer to any smaller stepped configuration of a pressurizable surface on the second end face of the piston that is smaller than a full side of the first end face of the piston. Realistically, however, the essentially circular full side, or the annular step side, has proven to be pressurizable and sealable with an annular seal, which is conceptually in the foreground here, as described in this application in Fig.1 , Fig.2 and as well as Fig.4 bis Fig.8 shown in the preferred embodiments.

[0031] Following the above-mentioned fundamental considerations regarding the piston shape and seal, the seal is advantageously formed as such by means of a profiled annular sealing body having a circumferentially extending first annular lip on an outer side of the seal and a circumferentially extending second annular lip on an inner side of the seal. The sealing body therefore advantageously has a first and a second annular sealing lip on the outer and inner sides, respectively, for sealing on the outside and on the inside of the annular peripheral annular space on the step side of the piston, i.e., for sealing the second compression chamber from the first compression chamber.

[0032] Based on this consideration, the invention further recognized that it is advantageous to achieve the object in an improved manner if the annular sealing body is formed as a sealing sleeve with a profile that is open in circumferential cross-section and has a profile base, the profile wall of which is formed by means of the first annular lip and the second annular lip. Again advantageously, the profile wall of the profile is formed by means of the first annular lip and the second annular lip; however, the profile according to the invention is open in its circumferential cross-section and therefore has a free profile base. Here, the invention, in contrast to the previously known forms of the aforementioned prior art, recognized that the circumferential cross-section of the profile should fundamentally be open. The prior art, on the other hand, follows the approach that the circumferential cross-section should also be provided with a sealing profile filling.The present invention follows a different finding; namely, by means of a free-standing profile base, it is possible to fulfil the task not only with regard to a good seal, but also to use the open profile for an advantageous holding of the sealing sleeve.

[0033] According to the invention, in contrast to the prior art, it is further provided that the sealing sleeve with its profile base is held pressure-tight on the step side between a piston ring arranged on the second end face and a retaining ring on the compression chamber side.

[0034] This feature utilizes the freestanding profile base of the open profile to hold the sealing collar at its profile base between a step-side piston ring and a compression-chamber-side retaining ring.

[0035] Furthermore, the sealing sleeve mount, with its profile base between the piston ring on the step side located on the second end face and the retaining ring on the compression chamber side, is designed to be pressure-tight, thus ensuring a pressure-tight design of the entire sealing assembly, including the sealing sleeve, piston ring, and retaining ring. It is similar to a previously known solid-profile sealing body, but now with improved structure and stability, and supports the entire sealing assembly. This significantly supports the longevity and pressure-tightness of the sealing assembly.

[0036] The mounting of the sealing sleeve at its profile base between the step-side piston ring on the one hand and the compression chamber-side retaining ring on the other hand ensures a secure structural mounting and also a pressure-tight mounting, which avoids pressure loss along the contact surface between the profile base, piston ring and retaining ring and, on the other hand, also supports the sealing effect of the sealing lips due to the shape of the profile base.

[0037] Furthermore, the invention also leads to the solution of the problem relating to the device, a compressed air supply system of claim 24 and a vehicle with the compressed air supply system according to claim 25.

[0038] The compressed air supply system according to the invention is designed to operate a pneumatic system with a compressor according to one of claims 1 to 23 and comprises: an air supply and the compressor connected to it via an air supply connection, a pneumatic main line having an air dryer and pneumatically connected to the compressor via a compressed air outlet to a compressed air connection of a gallery, a pressure medium storage tank pneumatically connected to the compressor via a charging connection.

[0039] The object relating to the method is also achieved by a method using the piston according to the invention as claimed in claim 26. The method for operating a compressed air supply system comprises the steps: Compressing air from a crankcase interior and / or the environment in a first compression chamber of the compressor to a low pressure level, further compressing the compressed air compressed to a low pressure level in the first compression chamber in a second compression chamber of the compressor to a high pressure level, feeding the compressed air compressed to a high pressure level in the second compression chamber from the compressed air outlet via a

[0040] Pneumatic main line to a gallery's compressed air connection, especially via an air dryer.

[0041] Advantageous further developments of the invention can be found in the subclaims, which define the concept of the invention within the framework of further developments with advantages.

[0042] Even though the developments described here provide for a series connection of a first compression chamber and a second compression chamber—generally in the sense of a series connection of two compressor stages of a multi-stage compressor—it should nevertheless be understood that the concept of the invention is not limited thereto. Alternatively, in another development, the concept of the invention can also be implemented in a multi-stage compressor whose two or more compressor stages are implemented in the sense of a parallel connection—generally in the sense of a parallel connection of two compressor stages of a multi-cylinder compressor.

[0043] Advantageously, the first end face can be formed as a solid side and the second end face as a stepped side, wherein the piston carries a sealing arrangement, at least one seal, on the second end face, which seals the first compression chamber against the second compression chamber.

[0044] In particular, it may be provided that the seal is formed by means of a profiled annular sealing body with a circumferentially extending sealing first annular lip on an outer side of the seal and a circumferentially extending sealing second annular lip on an inner side of the seal.

[0045] It is advantageously provided that the annular sealing body is formed as a sealing sleeve with a profile which is open in the circumferential cross-section and has a profile base, the profile wall of which is formed by means of the first annular lip and the second annular lip.

[0046] A pressure-tight design of the profile base support between the piston ring and the retaining ring can be advantageously implemented, as is preferably explained in the context of the further developments. In principle, a preferred design specifically for the anchoring or notching or similar reinforced connection between the profile base, piston ring, and retaining ring is suitable for this purpose.

[0047] A reinforced attachment of the profile base between the piston ring and the retaining ring preferably includes a flat contact of the profile base against a surface of the piston ring and a surface of the retaining ring, for example, within a mount or embedding. In addition, notch or guide elements can be provided that engage with an indentation or the like.

[0048] The profile base or corresponding surfaces of the profile against the corresponding piston surface or retaining ring surface can be slightly curved and thus leading and, in addition, still offer free space for a sealing lip movement.

[0049] In particular, the outer side of the seal, in particular of the sealing body, is in circumferential contact with an inner cylinder wall and the inner side of the seal, in particular of the sealing body, is in circumferential contact with an inner side of the cylinder web wall.

[0050] In particular, the seal is provided with an annular sealing body with the first annular lip radially outside the sealing body and a second annular lip radially inside the sealing body. Advantageously, the seal is provided with an annular sealing body with: the first annular lip, which is arranged in the radial direction on the outside of the sealing body, directed in the axial direction towards the second compression chamber, and / or with the second annular lip, which is arranged in the radial direction on the inside of the sealing body, directed in the axial direction towards the second compression chamber.

[0051] In a particularly preferred embodiment, the retaining ring is located in the open profile of the sealing sleeve. This has the advantage that the retaining ring can be fitted into the circumferential cross-section of the open profile; in other words, the retaining ring essentially follows the open profile in its configuration, corresponding to the circumferential cross-section.

[0052] For this purpose, the retaining ring can be rounded in the manner described above on its base surface adjacent to the profile base in order, on the one hand, to enable the sealing lips to pivot and, on the other hand -- like the base surface of the piston ring -- to have further structural elements which implement the sealing of the base surface of the retaining ring and the sealing of the piston ring to the profile base.

[0053] Likewise, the piston ring can have a correspondingly curved or arched base surface. For example, the piston ring can have a substantially convex curvature at its base surface, and the retaining ring can have a correspondingly concave curvature at its base surface, or vice versa, so that the profile base of the sealing sleeve profile is held between these convex or concave curved, possibly spaced, and mating base surfaces.

[0054] In particular, the sealing sleeve, which is profiled in its circumferential cross-section, can be formed with a substantially U-shaped free cross-section along its circumference, forming an open annular groove whose groove wall is formed by the first annular lip and the second annular lip. A U-shaped groove in this respect has proven particularly advantageous for accommodating the retaining ring. In particular, the first annular lip and the second annular lip can be formed in a preferred manner by means of the groove wall in order to create a pressure-tight radial sealing effect against a radial cylinder wall.

[0055] Advantageously, the sealing sleeve can be formed in one piece. The sealing sleeve can have the profile base between a first annular lip and a second annular lip, and at least one access opening can be formed in the profile base. However, the sealing sleeve can also be formed in multiple pieces. Thus, within the scope of a particularly preferred development, it can be provided that the sealing sleeve forms the profile base between a separate part with a first annular lip and a separate part with a second annular lip, leaving a gap for forming a access opening in the profile base. A corresponding further exemplary embodiment is shown in Fig.7A , Fig.7B shown.

[0056] Within the scope of a particularly preferred development, it is further provided that the sealing sleeve has spaced-apart access openings in the profile base, and the retaining ring is connected to the piston ring by means of the fixing elements. The fixing elements can in principle be advantageously designed, as required, to connect the retaining ring to the piston ring by means of the fixing elements in such a way that the profile base is held pressure-tight on the step side between the piston ring arranged on the second end face on the step side and the retaining ring on the compression chamber side. The fixing elements can, for example, be made of metal or plastic or another suitable synthetic material. It can be particularly advantageous for the fixing elements to generally engage through the access openings in the sealing sleeve.In particular, it has proven advantageous that the sealing sleeve has a number of through-openings in the profile base which correspond to the number of fixing elements, with one fixing element in each case reaching through a through-opening.

[0057] In principle, one or more fixing elements can be formed on the piston ring or one or more fixing elements on the retaining ring or, in a further modification, one or more fixing elements can be formed on the piston ring and the retaining ring, e.g., integrally formed on one of these or both.

[0058] Thus, it has proven advantageous in a first modification that the piston ring has a first number of fixing elements and the retaining ring has a second number of fixing grooves, for realizing a connection, in particular a positive or non-positive connection, between the piston ring and the retaining ring; the first and second numbers are preferably the same, but do not necessarily have to be the same. For example, a first number of fixing elements can be held in a common single ring groove or in a second number of fixing grooves, wherein each of the fixing grooves accommodates exactly one fixing element. A corresponding exemplary embodiment is shown in Fig.4A, Fig.4B which allows both modifications. A corresponding further exemplary embodiment is shown in Fig.6A, Fig.6B or Fig.7A , Fig.7B shown. There, the sealing sleeve clearly has a corresponding number of openings for the number of fixing elements, and the piston ring has a number of fixing elements, and the retaining ring has the same number of fixing grooves for establishing a connection between the piston ring and the retaining ring. These embodiments enable comparatively simple installation of the sealing system formed by the piston ring, sealing sleeve, and retaining ring, which is also designed to be particularly resistant to rotation.

[0059] In addition, it has proven advantageous in a second modification that the retaining ring has a first number of fixing elements and the piston ring has a second number of fixing grooves, in order to realize a connection, in particular a positive or non-positive connection, between the piston ring and the retaining ring. Here, too, the first and second numbers are preferably the same, but do not necessarily have to be the same. For example, a first number of fixing elements can be held in a common single ring groove or in a second number of fixing grooves, wherein each of the fixing grooves accommodates exactly one fixing element. A corresponding exemplary embodiment is shown in Fig.5A, Fig.5B There, it is shown that the sealing sleeve has a corresponding number of openings for the number of fixing elements, the retaining ring has a number of fixing elements, and the piston ring has a number of fixing grooves for establishing a connection between the piston ring and the retaining ring. This embodiment enables a comparatively simple installation of the sealing system formed by the piston ring, sealing sleeve, and retaining ring.

[0060] These and other variants have the particular advantage that -- in addition to the axial holding of the piston ring and the retaining ring -- namely, because the fixing elements grip through the openings of the sealing sleeve, the sealing sleeve is held between the piston ring and the retaining ring in a rotationally secure manner.

[0061] For this purpose, a fixing element can in principle be designed in a variety of ways; for example, a comparatively secure design of a fixing element can be achieved by the fixing element being formed as a clamping screw, wherein the clamping screw is screwed into a screw hole.

[0062] In particular, it may also be advantageous for a fixing element to be formed as a clamping tooth. The clamping tooth is advantageously designed to be held on a clamping stop or in a clamping fit. For this purpose, a clamping tooth can have a web-like design and have a clamping element or clamping grid on a web flank. The number of clamping teeth and / or the number of clamping grooves and / or the number of access openings are advantageously arranged along the circumference of the piston ring and / or retaining ring and / or sealing element. These are particularly advantageously evenly spaced.

[0063] In particular, in a first modification, a clamping tooth is advantageously clamped in a clamping groove or fixed by means of a press fit. A corresponding exemplary embodiment is shown in Fig.4A, Fig.4B and Fig.5A, Fig.5B shown. In these aforementioned or similar embodiments, a radially outer surface and / or radially inner surface of a web flank of the clamping tooth can frictionally engage with an opposite, radially outer surface and / or radially inner surface of a wall of a clamping groove via the radially inner and / or radially outer surfaces to create an interference fit of the clamping tooth in the clamping groove.

[0064] In a second modification, a clamping tooth can pass through a clamping groove and be fixed by means of a clinch or rivet connection. A corresponding exemplary embodiment is shown in Fig.6A und Fig.6B shown. In these aforementioned or similar embodiments, a clamping tooth can have a locking element at a distal end, which has a clamping groove with a corresponding undercut on a side facing away from the distal end, for implementing a connection in the manner of a clinch or rivet connection. Special rivets, such as small spiral rivets, can also be advantageously used.

[0065] Within the scope of a preferred development, the piston ring can be arranged in that, in a first modification, it is fastened to the second end face or, in a second modification, it is formed integrally therewith. In particular, according to the first modification, it can be formed integrally with the step side. In particular, according to the second modification, it can be formed separately and connected to the step side in a suitable manner; e.g., glued, welded, or connected in a materially bonded manner in this way. In simple terms, according to the first modification, the piston ring is advantageously formed as part of the piston directly on the piston and, according to the second modification, is advantageously firmly connected to the piston.

[0066] Within the scope of a further preferred development, at least one, in particular a number of one or more sealing ridges, preferably at least one circumferential sealing ridge, are advantageously formed on the piston ring and / or on the retaining ring. In particular, a sealing ridge can be arranged on the side of the piston ring facing the sealing sleeve and / or a sealing ridge can be arranged on the side of the retaining ring facing the sealing sleeve.

[0067] This allows the sealing sleeve with its profile base to be connected to the piston ring and / or retaining ring in a particularly advantageous manner in a pressure-tight manner.

[0068] The sealing sleeve is also advantageously secured against accidental displacement by means of a sealing ridge, i.e., it is securely held in a position reliably defined by the sealing ridge. Overall, the sealing sleeve, with its profile base on the step side, can be held pressure-tight and securely in a particularly advantageous manner.

[0069] For example, a first sealing ridge can be arranged radially inward relative to the fixing element, and a second sealing ridge can be arranged radially outward relative to the fixing element. A number of sealing ridges can generally be arranged on the piston ring and the retaining ring, preferably offset from one another in the radial direction. Preferably, at least two sealing ridges, preferably circumferential, of the piston ring and / or the retaining ring are each arranged on the side facing the sealing sleeve.

[0070] In this regard, it has proven particularly advantageous that a sealing ridge on the retaining ring is a radially inner sealing ridge which is offset closer to the through-opening than a sealing ridge on the piston ring which, as a radially outer sealing ridge, is offset further away from the through-opening.

[0071] In this regard, with the same proviso, in a particularly preferred variant, a sealing ridge on the retaining ring can also be a radially outer sealing ridge that is offset closer to the through-opening than a sealing ridge on the piston ring, which, as a radially inner sealing ridge, is offset further away from the through-opening in comparison. In other words, in this particularly preferred variant, the sealing ridges offset further away from the through-opening can be arranged on the piston ring, and the sealing ridges offset closer to the through-opening in comparison can be arranged on the retaining ring.

[0072] Additionally or alternatively, it can also be provided that a sealing ridge on the retaining ring is a radially outer sealing ridge which is offset further away from the through-opening than a sealing ridge on the piston ring which, as a radially inner sealing ridge, is offset closer to the through-opening.

[0073] In this regard, with the same proviso, a particularly preferred variant of this alternative can also provide that, in combination therewith, a sealing ridge on the retaining ring is a radially inner sealing ridge that is offset further toward the through-opening than a sealing ridge on the piston ring, which, as a radially outer sealing ridge, is offset closer to the through-opening. In other words, in this particularly preferred variant, the sealing ridges offset further away from the through-opening can be arranged on the retaining ring, and the sealing ridges offset closer to the through-opening can be arranged on the piston ring.

[0074] Advantageously, the piston ring and the retaining ring are each made of plastic; in particular, they are made of plastic. Advantageously, the piston ring and the retaining ring can also be connected to each other and / or to the sealing sleeve by means of an adhesive bond and / or ultrasonic welding connection.

[0075] In particular, it has proven advantageous within the scope of a further preferred modified development that the retaining ring - alternatively to a ring formed as a separate part - is formed by filling a preferably U-shaped annular space of the sealing sleeve with plastic. This has the aforementioned advantage that a preferably U-shaped groove can accommodate the retaining ring. In particular, the first annular lip and the second annular lip can be formed in a preferred manner by means of the groove wall in order to create a pressure-tight radial sealing effect against a radial cylinder wall. Furthermore, in this modified development, a retaining connection can advantageously be formed between the piston ring and the sealing sleeve and the retaining ring.

[0076] Regardless of the previously explained arrangement or positioning of a sealing ridge and regardless of the material of the piston ring and / or the retaining ring, it has proven advantageous for a sealing ridge to be designed such that it can be fully or partially pressed into the profile base of the sealing sleeve or can otherwise penetrate into the profile base of the sealing sleeve or its volume area when fixing the profile base between the base of the piston ring and the base of the retaining ring. A sealing ridge is therefore designed with an appropriately pointed penetration side, i.e. advantageously a formed ridge edge towards the profile base of the sealing sleeve - for example, best in the form of a burr. The hardness of the material, in particular the plastic, of the sealing ridge is advantageously greater than the hardness of the material, in particular the plastic, of the sealing sleeve or its profile base.In this respect, the sealing web is generally and advantageously designed in such a way that it can deform the sealing sleeve in order to connect the sealing sleeve with its profile base in a pressure-tight manner to the piston ring and / or retaining ring; but advantageously does not cut or incise it in order to maintain its consistency.

[0077] Embodiments of the invention will now be described below with reference to the drawings. These are not necessarily intended to depict the embodiments to scale; rather, where useful for explanation, the drawings are schematic and / or slightly distorted. With regard to supplements to the teachings immediately apparent from the drawings, reference is made to the relevant prior art. It should be noted that numerous modifications and changes to the form and detail of an embodiment can be made without deviating from the general idea of the invention.

[0078] The features of the invention disclosed in the description, the drawings and the claims can be essential for the further development of the invention both individually and in any combination. Furthermore, all combinations of at least two of the features disclosed in the description, the drawings and / or the claims fall within the scope of the invention. The general idea of the invention is not limited to the exact form or detail of the preferred embodiments shown and described below, or limited to an object that would be limited compared to the object claimed in the claims. In the case of specified dimension ranges, values lying within the stated limits are also intended to be disclosed as limit values and to be used and claimed as desired. For the sake of simplicity, the same reference numerals are used below for identical or similar parts or parts with identical or similar functions.Further advantages, features and details of the invention will become apparent from the following description of the preferred embodiments and from the drawing, which shows in: . Fig. 1 is a pneumatic circuit diagram of a pneumatic system known per se with a particularly preferred embodiment of a compressed air supply system as described in WO 2018 / 197182 A2, wherein a compressor is designed as a double compressor with a single piston in a single cylinder to form two compression chambers, and in which the piston is preferably used according to the concept of the invention; Fig. 2A is a schematic sectional view of the compressor of the Fig.1 in a sectional plane perpendicular to the drive axis; Fig.2B is a schematic sectional view of the compressor of the Fig.1 in a sectional plane parallel to both the drive and the piston axis; Fig. 3A shows a seal for a piston according to the prior art as described in WO 2018 / 197182 A2 in a first version, in a sectional view; Fig. 3B shows a seal for a piston according to the prior art as described in WO 2018 / 197182 A2 in a second version, in a sectional view; Fig. 4A shows a piston according to the concept of the invention in a first embodiment in a sectional view, shown in a schematically shown compressor as a double compressor based on the model of Fig.2A, Fig.2B ; Fig.4B Detail of the piston of the first embodiment according to the Fig.4A in the area of the seal; Fig.5A a piston according to the concept of the invention in a second embodiment in an exploded view; Fig.5B a detail of the piston of the second embodiment according to the Fig.5A in the area of the seal; Fig.6A a piston according to the concept of the invention in a third embodiment in an exploded view; Fig.6B a detail of the piston of the third embodiment according to the Fig.6A in the area of the seal; Fig.7A a piston according to the concept of the invention in a fourth embodiment in a sectional view, shown in a partially shown compressor as a double compressor according to the model of Fig.2A, Fig.2B ; Fig.7Bin view (i) a first part of the seal and a second part of the seal for the seal composed of the first and second parts as a sealing arrangement of the Fig.7A in an exploded view and a retaining ring in view (ii) for insertion into a receptacle of the piston of the Fig.7C ; Fig.7C in a perspective view of the pistons of the Fig.7A according to the concept of the invention in the fourth embodiment with the Fig.7B mentioned receptacle for the retaining ring of view (ii) of the Fig.7B ; Fig.8 a piston according to the concept of the invention in a fifth embodiment in a sectional view, also shown in an exploded view with screws and in an assembled perspective view for a schematically shown compressor as a double compressor according to the model of Fig.2A, Fig.2B ; Fig.9 a piston according to the concept of the invention in a sixth embodiment in a disassembled perspective view for a schematically shown compressor as a double compressor according to the model of Fig.2A, Fig.2B ; Fig.10A, Fig.10B each in a sectional view generally independent of the previously explained embodiments, some variants of a feasible profile base of an annular sealing body of a sealing sleeve with sealing webs; Fig.11A a vehicle of any type, such as a car or a commercial vehicle such as a truck or a trailer (not shown), in a schematic representation with a pneumatic system known per se with a particularly preferred embodiment of a compressed air supply system of the Fig.1 , wherein a compressor is designed as a double compressor with a single compression chamber, and in which a piston according to the concept of the invention is preferably used; the piston can be designed according to the concept of the invention in a first, second or third or fourth embodiment as shown in Fig.4A bis Fig.7C are shown; Fig.11B vehicle in the form of a passenger car in schematic representation with an electronically controlled air suspension system (ECAS), which is provided with a particularly preferred embodiment of a compressed air supply system of the Fig.1 and is shown here in a realistic perspective view.

[0079] Compressors according to the concept of the invention are preferably used in a compressed air supply system - here special requirements have arisen with regard to compression performance and compactness.

[0080] However, a compressor according to the concept of the invention can also be used for other types of compressed air sources. It is also to be understood that the compressor can be used not only preferably in compressed air supply systems or for the passenger car or commercial vehicle sector. Furthermore, applications for vacuum generators, in particular vacuum pumps, have also emerged. A compressed air supply system is shown as an example of a preferred embodiment in Fig.1 shown and described below.

[0081] Fig.1 shows a pneumatic system 300 with a compressed air supply system 200 and a pneumatic system 500, in the present case in the form of an air spring system, of a vehicle 400 (not shown in detail).

[0082] In the present case, the air suspension system is formed with an exemplary number of four air springs 210, each air spring 210 being assigned to a wheel of a vehicle 400 (not shown in detail). Only symbolically shown in the present case is a support 410 formed near the wheel of the vehicle 400, which can be raised when the air spring 210 is filled or lowered when the air spring 210 is deflated. An air spring 210 comprises an air bellows, referred to here as a bellows 211, for receiving compressed air and an air spring valve 212, which holds or releases the amount of compressed air in the bellows 211 or allows the bellows 211 to be filled with compressed air. The air spring valve 212 is designed as a controllable solenoid valve, here as a 2 / 2-way valve. Each of the air spring valves 212 is shown here in a normally closed state by the spring force of a spring not further specified.

[0083] The air suspension valves 212 are connected to a gallery line 220 designed as a collecting line via suitable spring branch lines 221. Directly connected to the gallery line 220 is a tension-pressure sensor 230, which is capable of measuring a pressure in the gallery line 220—and, with appropriate switching of the air suspension valves 212—also a pressure in the air springs 210. The tension-pressure sensor 230 can also measure a storage pressure in conjunction with an accumulator system, namely, in this case, the accumulator 224, the pneumatic line 40, and the accumulator valve 41. Pressure sensor signals can be transmitted to an air suspension control system and / or a vehicle control system (not shown in detail here) to initiate further control measures. The pneumatic system 500 in the form of the air suspension system is supplied with compressed air from the compressed air supply system 200.

[0084] For this purpose, the pneumatic system 500 is connected to the compressed air supply system 200 via a compressed air connection 2. Compressed air from a compressed air supply 10 with a compressor 100 can be supplied to the compressed air connection 2 via a main pneumatic line 30. Compressed air from a pressurized fluid reservoir 224 can also be supplied to the compressed air connection 2 via a further compressed air connection 2' and a further pneumatic line 40. The compressed air supply system 200 has suitable isolating valves for expediently selecting the type of compressed air supply to the pneumatic system 500, namely a first isolating valve 31 in the main pneumatic line 30 and a second isolating valve 41 in the further pneumatic line 40. The first and second isolating valves 31, 41 are each designed as a controllable solenoid valve—here as a 2 / 2-way valve.

[0085] In Fig.1 The first and second isolation valves 31, 41 are each shown in a closed state, so that the pneumatic system 500 is completely separated from the compressed air supply system 200. This advantageously results in an air dryer 222 of the compressed air supply system not being adversely affected (e.g., filled) by compressed air movements in the pneumatic system 500 or the transfer of compressed air from the pressure medium reservoir 224 to the pneumatic system 500 when the first isolation valve 31 is closed.

[0086] Overall, the compressed air supply system 200 comprises a compressed air supply 10, to which the main pneumatic line 30 is connected. In the main pneumatic line 30, the air dryer 222 is pneumatically connected in series on the compressed air supply side, and the first isolating valve 31 is pneumatically connected on the compressed air connection side. A valve arrangement configured as a pneumatic parallel circuit is connected between the air dryer 222 and the first isolating valve 31.

[0087] The valve arrangement has a check valve 32 that automatically opens in the ventilation direction B to the pneumatic system 500 and closes in the exhaust direction E from the pneumatic system 500 to the air dryer 222. A throttle 34 is arranged in a pneumatic line connected as a bypass line 33 parallel to the pneumatic main line 30. It serves as a regeneration throttle and can be flowed through bidirectionally. The throttle 34 has a nominal diameter sufficient to provide a pressure drop when venting the pneumatic system 500 with the first isolation valve 31 open, such that an air dryer 222 is sufficiently regenerated as part of a pressure swing adsorption.

[0088] A compressed air flow guided in the venting direction E can be vented to the environment U via a venting line 35 connected to the main pneumatic line 30 to a venting connection 3. A further isolating valve 36, which can be opened for a venting process, is arranged in the venting line 35. Like the first and second isolating valves 31, 41, the further isolating valve 36 is designed as a controllable solenoid valve, namely here as a 2 / 2-way valve.

[0089] In a modification not shown here, a fundamentally different design of the pneumatic main line 30 and vent line 35 can also be provided, e.g. with a suitable pilot-operated vent solenoid valve arrangement or the like.

[0090] The compressed air supply 10 has in the present case a compressor 1100 designed according to the concept of the invention, which is configured on the basis of the Fig.1 , Fig.2A und Fig.2B The particularly preferred embodiment shown by way of example is described below. The compressor 1100 of the compressed air supply 10 is formed with the compressed air supply 10 as a device that can be connected separately to the compressed air supply system 200.

[0091] The component of the compressed air supply 10, which can be referred to as a compressed air supply device, has a compressed air outlet 124 to which the main pneumatic line 30 of the compressed air supply system 200 can be connected. Furthermore, the compressed air supply 10 has a charging connection 126 to which a pneumatic line 37 leading to the pressure medium reservoir 224 can be connected via a further isolating valve 38.

[0092] The pressure medium reservoir 224 is connected to the pneumatic line 37 via the aforementioned second compressed air connection 2'. The further pneumatic line 40 to the compressed air connection 2 is also connected to the second compressed air connection 2'. When the further isolating valve 38 is open, compressed air can only flow through the pneumatic line 37 unidirectionally, namely in a further venting direction E' as viewed from the pressure medium reservoir 224. For this purpose, the pneumatic line 37 has a further check valve 39, which automatically opens in the further venting direction E' and closes in the opposite direction. The pneumatic line 37 is thus designed to supply compressed air from the pressure medium reservoir 224 to the charging connection 126 of the compressed air supply 10 when the further isolating valve 38 opens.

[0093] Furthermore, the compressed air supply 10 has an air supply connection 0, via which air from an air supply L - filtered in a filter 52 of an intake line 51 - can be supplied.

[0094] As from Fig.1 As can be seen, the compressor 1100 of the compressed air supply 10 is designed with a first compression chamber 104 and a second compression chamber 106. According to the concept of the invention, in the embodiment described here, the compressor 1100 is provided with a single cylinder 118, as in Fig.2A und Fig.2B described in more detail.

[0095] A single piston 1112 of the compressor 1100, which can be pressurized on both sides in the interior of the cylinder 1118, is driven for movement by a motor M via a drive shaft 102. The cylinder 1118 with piston 1112 of the compressor 1100 is arranged here on a single side of the motor M, forming both compression chambers 104 and 106; in particular, on a single side of the drive shaft 102.

[0096] As can be seen from the description of the Fig.2A und Fig.2B As can be seen, this is a particularly compact arrangement of the cylinder 1118 using a single piston 1112.

[0097] The compressed air supply or compressor 1100 has a connecting line 122 between the first compression chamber 104 and the second compression chamber 106. In this case, the connecting line 122 is formed as a passage through a piston body of the piston 1112 and is thus designed to be particularly compact. Due to the comparatively short connecting line 122, the entire compression chamber in the cylinder 1118 is kept small, so that a particularly high compression pressure amplitude can be achieved.

[0098] If necessary, the availability of compressed air, ie in particular a quantity of compressed air, can be increased even further by supplying additional pressure medium to the second compression chamber 106 via the second optionally usable charging connection 126 and - in a so-called boost operation - further compressing it together with the compressed air of the first compression chamber 104, which has been compressed to a high level, in the second compression chamber 106 and making it available in the compressed air outlet 124. For such a compressor 1100, various embodiments following the concept of the invention are shown below, for which, in addition to the Fig.1 other areas of application are conceivable.

[0099] Fig.2A shows a compressor 1100 according to a preferred embodiment in a first sectional view. A piston 1112 is arranged in a cylindrical cavity within a cylinder 1118. The piston 112 is connected via a rigidly connected connecting rod 128, which is rotatably movable about a rotational axis running through point S2 perpendicular to the sectional plane, to an eccentrically arranged shaft section 132 via a rotatable connection 162, which in turn is connected to a drive shaft 102 for transmitting the drive movement. Piston 1112 and connecting rod 128 are designed in one piece, in particular coaxially assembled along a common piston axis A. The piston 1112 is also shown highly schematically, as are other areas of this view. In particular, the design of the piston 1112 can deviate from the design shown here, in particular to realize functionally dependent wobble kinematics.Such different further training courses are available in . Fig.3A, Fig.3B and concerning the concept of the invention in Fig.4A shown.

[0100] In this case, the rotatable connection 162 is realized via a connecting rod bearing 152. The drive shaft 102 and the eccentrically arranged shaft section 132 are part of a rotating part 131 of the drive.

[0101] The connecting rod 128 has a piston side 128.1 facing the piston 1112 and a drive side 128.2 facing the drive shaft 102.

[0102] The drive shaft 102, in turn, performs a rotational movement D about a rotational axis passing through a point S1 perpendicular to the section plane. Due to the rigid connection of the drive shaft 102 to the eccentrically arranged shaft section 132 and the offset of the two points S1 and S2, a rotational movement of the drive shaft 102 leads to a deflection H of the piston in the stroke direction.

[0103] Furthermore, within the cylindrical cavity enclosed by the cylinder 1118, a rotationally symmetrical cylinder inner web 110 with an L-shaped cross-section is arranged, extending radially inward from the cylinder inner wall 119. Due to the L-shaped cross-section, the cylinder inner web 110 has a web wall 111 on its inside that is directed toward the piston 1112. Thus, the inner wall of the cylinder 1118 and the cylinder inner web 110 form an annular space that is open toward the piston 1112 and represents the second compression chamber 106.

[0104] The piston 1112 has, on the side facing away from the connecting rod 128, a first end face 113 designed as a solid side 114, which together with the inner wall of the cylinder 1118 delimits the first compression chamber 104.

[0105] Furthermore, the piston 1112 has, on the side facing the connecting rod 128, an annular piston step which is formed in the form of a hollow cylinder, the outer wall of which is congruent with the outer wall of the piston 1112 at the level of the solid side 114 and which is closed off on the side of the piston 1112 opposite the solid side 114 by a second end face 115 designed as a step side 116.

[0106] Furthermore, the cylinder 1112 is designed such that the piston 112, in particular the side facing the connecting rod 128 with the stepped side 116, can move in an oscillating manner within the annular space formed by the cylinder inner web 110 and the inner wall of the cylinder 1118. The second compression chamber 106 is created by the delimitation of the practically annular space formed by the cylinder inner web 110, the inner wall of the cylinder 1118, and the stepped side 116.

[0107] The piston 1112 further comprises a seal 138 shown schematically here, which in the embodiment shown schematically here as well as in the preferred embodiments of the Fig.4A bis Fig.10B in the sense of a sealing arrangement according to the concept of the invention is basically arranged on the front side on the step side 116 of the piston 1112.

[0108] The seal 1138 in the sense of a sealing arrangement according to the concept of the invention - as it is described in relation to the preferred embodiments of the Fig.4A bis Fig.10B shown-- leads to improved sealing of the second compression chamber 106 with respect to the first compression chamber 104 and of the compression chambers 104, 106 with respect to a crankcase interior 160.

[0109] For this purpose, the seal 1138 basically has an outer side 1138.1 and an inner side 1138.2. The outer side 1138.1 of the seal 1138 is arranged on the outer circumference, i.e. the outer side of the - described in simplified terms - annular seal 1138 as part of a sealing arrangement to be explained below, and thus establishes circumferential, constant contact with an inner cylinder wall 119, which in particular forms a cylindrical cavity. The inner side 1138.2 of the seal 1138 is arranged on the inner side, i.e. on the inner circumference of the - described in simplified terms - annular seal 1138 and thus establishes circumferential, constant contact with an inner side 109 of the web wall. By means of the arrangement and design of the piston 112, the cylinder 1118 and the inner cylinder web 110, it is therefore possible to use a comparatively small number of seals or sealing arrangements, in particular only a single seal orSealing arrangement 1138 to ensure the sealing of both compression chambers 104, 106.

[0110] In Fig.2A Furthermore, the relative inclination of piston 1112 and the connecting rod 128, which is rigidly connected to the piston 1112, to the cylinder 118 is visible. This inclination is caused by the portion of the offset existing perpendicular to the stroke direction between the axis of rotation of the drive shaft passing through point S1 and the axis of rotation of the rotary movement between the connecting rod 128 and the eccentrically arranged shaft section 132 passing through point S2. This portion of the offset existing perpendicular to the stroke direction depends on the angular position of the drive shaft 102 or the eccentrically arranged shaft section 132. At the top or bottom dead center of the piston 112, when the deflection H in the stroke direction is maximum, the portion of the offset existing perpendicular to the stroke direction is zero.At the midpoint of the travel between the two dead centers of piston 1112, when the deflection H in the stroke direction is zero, the portion of the offset existing perpendicular to the stroke direction is accordingly at its maximum. The relative inclination of piston 1112 or connecting rod 128 to cylinder 1118 creates openings, in particular crescent-shaped gaps, between piston 1112 and the inner wall of cylinder 1118 or cylinder inner land 110. Such openings lead to the escape of compressed air from second compression chamber 106 into first compression chamber 104 and / or into the environment U or into a crankcase interior 160. To avoid this, or to compensate for the wobbling motion of piston 1112, seal 138 is designed accordingly.This includes sufficient dimensioning and elastic behavior of the seal 1138, so that even if openings arise between the piston 1112 and the cylinder 1118 due to the wobbling movement, the sealing of the compression chambers 104 and 106 is ensured.

[0111] Fig.2B shows a further sectional view of a preferred embodiment of a compressor in a sectional plane parallel to both the drive and piston axes A. The sectional view shows how air from the environment U or the crankcase interior 160 can reach the first compression chamber 104 via an air supply connection 120 arranged within the piston 1112 and the connecting rod 128. An air supply valve flap 142 arranged on the full side 114 of the piston 112 ensures that air can only flow into the first compression chamber 104 via the air supply connection 120, but not out. This is achieved by the air supply valve flap 142 closing against the pressure increasing in the first compression chamber 104 when the first compression chamber 104 is reduced in size due to the deflection H and the associated compression of the air located therein.Accordingly, when the first compression chamber 104 is enlarged, the air supply valve flap 142 opens due to the negative pressure prevailing in the first compression chamber 104 relative to the environment, so that air flows from the environment or the crankcase interior 160 into the first compression chamber 104.

[0112] Furthermore, a check valve 130 is arranged within the piston 1112 as a further connection between the first compression chamber 104 and the air supply connection 120 or the crankcase interior 160, which is held in the closed state by a spring force F. Thus, air in the first compression chamber 104, the pressure of which exceeds a certain maximum value, which is particularly potentially harmful to the compressor, can escape through the check valve 130 into the environment via the air supply connection 120. Alternatively, the check valve 130 can also be arranged such that the air escapes directly into the crankcase interior 160 or the environment U, i.e., without being guided via the air supply connection 120.

[0113] Furthermore, a connecting line 122 is arranged within the piston 1112 between the first compression chamber 104 and the second compression chamber 106. This connecting line 122 represents a gas-carrying connection between the two compression chambers 104 and 106. In this case, analogous to the air supply valve flap 142, it has a connecting valve flap 144, which ensures that air flows only in one direction through the connecting line 122, namely from the first compression chamber 104 to the second compression chamber 106. Accordingly, the connecting valve flap 144 closes against the increasing pressure when the second compression chamber 106 decreases in size and opens when it increases in size, so that air can flow from the first compression chamber 104 into the second compression chamber 106.The air compressed in the second compression chamber 106 can be made available to consumers of a pneumatic system 500, in particular via a compressed air supply system 200, via a compressed air outlet 124.

[0114] Furthermore, a charging port 126 leading to the second compression chamber 106 is arranged in the cylinder 1118 and has a charging valve flap 146. Air, which was compressed, for example, at a previous time and is stored and maintained in a pressure medium reservoir 224, can be supplied to the second compression chamber 106 via the charging port 126.

[0115] In this way, the power of compressor 1100 can be increased temporarily, particularly to provide compressed air more quickly. The charging valve flap 146 ensures that air flows exclusively into the second compression chamber 106 via the charging port 126 and cannot escape via the charging port 126.

[0116] Furthermore, the piston 1112 does not have a cylindrical shape, but rather a cross-section that varies along a piston axis A. In this embodiment, the piston 1112 has a cross-section with a minor piston diameter KN at the level of the solid side 114. On the stepped side 116, however, the piston 1112 has a major piston diameter KH that is larger than the minor piston diameter KN. Due to these different diameters and the course of the piston diameter between the stepped side 116 and the solid side 114, a variable, essentially non-cylindrical course of both an outer side 1112.1 and an inner side 1112.2 of the piston 112 results, which leads to the piston 1112 being practically dome-shaped. Such a design, in particular, achieves mobility of the piston 1112 within the cylinder 1118, in particular despite the wobbling movement of the piston 1112.

[0117] The piston main diameter KH cannot be larger than the diameter of the cylinder 118, but it is possible and even sensible if the diameter of the outer side 138.1 of the seal 138 is larger than the piston main diameter KH and also than the diameter of the cylinder 118. In this way, it is possible for the piston 1112 together with the seal 138 to create a seal between the first compression chamber 104 and the second compression chamber 106 or between the second compression chamber 106 and the crankcase interior 160, despite the wobbling movement of the piston 1112 and the resulting openings and gaps between the piston 1112 and the cylinder 1118 or the piston 1112 and the web wall 111.

[0118] At the same time, the movement of the piston 1112 is not significantly hindered or blocked despite the larger diameter of the outer side 1138.1 of the seal 1138, since the seal 1138 of the sealing arrangement according to the concept of the invention is preferably formed from an elastic material.

[0119] The shape of the piston 1112 is practically dome-shaped in the present case, so that the piston is designed to fit a dome-shaped section 164 of the cylinder 1118. The piston 1112 has an outer side 1112.1 and an inner side 1112.2. In particular, the piston 1112 is - analogous to the Fig.3 shown embodiment - due to its dome-shaped configuration, it is suitable, despite its wobble kinematics, for moving in a predominantly cylindrical or - as in the present case - dome-shaped interior of a cylinder 1118. Also clearly visible is the seal 138 with an outer side 138.1 and an inner side 138.2. The outer side 138.1 is in contact with an inner cylinder wall 119 over the outer circumference of the seal 138, thus creating a pressure-tight seal with respect to a first compression chamber 104. The inner side 138.2 of the seal 138 is in contact with an inner side 109 of the web wall over the inner circumference of the seal 138, thus creating a pressure-tight seal with respect to a crankcase interior 160. Furthermore, in the present case, the piston 1112, in particular the coupling section 164 of the piston 1112, is fastened to a connecting rod 128 by means of a piston screw 166.In this view, only the piston side 128.1 of the connecting rod 128 is visible.

[0120] In particular, a check valve 130, an air supply connection 120, a connecting line 122, an air supply valve flap 142, a connecting valve flap 144, a charging valve flap 146 as well as a compressed air outlet 124 and a charging connection 126 may also be provided. These features essentially correspond to those in Fig.2B already symbolically represented characteristics.

[0121] In contrast to the Fig.2B illustrated embodiment may consist in that the air supply valve flap 142 and the check valve 130 are not as in Fig.2B shown are connected together to an air supply connection 120 guided by a connecting rod 128, but are arranged separately in the piston 1112 and are connected in a gas-conducting manner to a crankcase interior 160 - or in the case of the check valve 130, can be connected depending on the spring force.

[0122] Even though, in the presently described embodiment, the connecting line 122 provides for a series connection of the first compression chamber 104 and the second compression chamber 106—generally in the sense of a series connection of two compressor stages of a multi-stage compressor—it should nevertheless be understood that the concept of the invention is not limited thereto. Alternatively, in another embodiment, the concept of the invention can also be implemented in a multi-stage compressor whose two or more compressor stages are implemented in the sense of a parallel connection—generally in the sense of a parallel connection of two compressor stages of a multi-cylinder compressor.

[0123] The Fig.3A shows a first version of a seal 138a, known per se from WO 2018 / 197182 A2, which essentially corresponds to a previously described seal 138.

[0124] The seal 138a comprises a sealing body 139a having a first annular lip 139.1a and a second annular lip 139.2a. The first annular lip 139.1a is arranged on the outside of the sealing body 139a in a radial direction RR such that it extends in an axial direction RA toward a second compression chamber 106. The first and / or second annular lip 139.1a, 139.2a has, in particular, a free end arranged in the second compression chamber 106.

[0125] The second annular lip 139.2a is arranged in a radial direction RR on the inside of the sealing body 139a. It also extends in an axial direction RA toward the second compression chamber 106. The sealing body 139a is attached to a step side 116 of a piston 1112.

[0126] The Fig.3B shows another version of a seal 138b, known per se from WO 2018 / 197182 A2. The essential difference between the seal 138b and the seal in Fig.3A The feature of the seal 138a shown is that a sealing body 139b of the seal 138b has—in addition to a first annular lip 139.1b and a second annular lip 139.2b—an additional third annular lip 139.3b, which is arranged on the outside of the sealing body 139b in a radial direction RR and is directed in an axial direction RA toward the first compression chamber 104. The third annular lip 139.3b has, in particular, a free end that is arranged in the first compression chamber 104.

[0127] The now further preferred design of the seal 1138 of the sealing arrangement according to the concept of the invention is described with reference to preferred embodiments of a piston of the Fig.4A bis Fig.10B explained in more detail.

[0128] The seal 1138 of the sealing arrangement according to the concept of the invention proves to be further improved for the realization of a function of a powerful, in particular two-stage, compressor in the most compact and robust design possible. This means that the embodiments of a piston of the Fig.4A bis Fig.10B are preferably designed for a compressor 1112, in particular a compressor, for a compressed air supply 10 of a compressed air supply system 1100 as shown in Fig.1 shown, or for operating a pneumatic system 500 as further shown in Fig.11B in relation to a compressed air supply system of the Fig.11A is shown.

[0129] Here and below, the same reference numerals are used for the same or similar features or features with the same or similar function for the sake of simplicity; nevertheless, a distinction is made between the embodiments of a sealing arrangement 1001, 1002, 1003, 1004, 1005, 1006 according to the further Fig.4A und Fig.4B , Fig.5A und Fig.5B , Fig.6A und Fig.6B , Fig.7A and Fig.7B , Fig.8 , Fig.9 differentiated in detail; the continuing education variants of the Fig.10A, Fig.10B are designed to be equally advantageous for all embodiments. However, all embodiments of the sealing arrangement 1001, 1002, 1003, 1004, 1005, 1006 implement the concept of the invention with the previously explained advantages of the invention as well as the further developments of the invention.

[0130] Fig.4A und Fig.4B show in detail a particularly preferred first embodiment of a sealing arrangement 1001 with an annular sealing body 1139 as a sealing sleeve 1021, a compression chamber-side retaining ring 1031 in the sealing sleeve, and a step-side piston ring 1011; this for attachment to a second end face 115 of the piston 1112, designed as a step side 116.

[0131] The piston 1112 is shown here in a schematically illustrated cylinder 1118 with a schematically illustrated cylinder inner wall 119. In the piston, the first end face 113 is clearly formed as a solid face 114.

[0132] In this respect, schematically in Fig.4A --using the same reference numerals as above-- for identical or similar features or features of identical or similar function, the pistons 1112 are shown in the cylinder 1118, forming a first compression chamber 104 and a second compression chamber 106, which are sealed from one another via the sealing arrangement 1001 according to the first embodiment.

[0133] All preferred embodiments of the sealing arrangement 1001, 1002, 1003, 1004, 1005, 1006 implement the following features, explained by way of example with reference to the first sealing arrangement 1001, in a type of sandwich structure.

[0134] In accordance with the concept of the invention, the sealing arrangement 1001 comprises the sealing sleeve 1021, which is profiled in circumferential cross-section, between the step-side piston ring 1011 and the compression-chamber-side retaining ring 1031. The sealing arrangement 1001 according to the first and further embodiments thus comprises a step-side piston ring 1011 and, for forming the annular sealing body 1139, a sealing sleeve 1021 and retaining ring 1031 according to the first embodiment.

[0135] The sealing arrangement 1001 according to the first preferred embodiment is shown in Fig.4B shown in detail. The annular sealing body 1139 of the sealing sleeve 1021 forms the previously explained first annular lip 1139.1 on an outer side 1138.1 of the seal 1138 and the second annular lip 1139.2 on the inner side 1138.2 of the seal 1138. The sealing sleeve 1021 is thus designed as an annular sealing body 1139, formed with a Fig.4B shown circumferential cross-section, which clearly forms the open profile 1020; the opening 1140 in the profile is essentially rectangular here, with the first and second annular lips 1139.1, 1139.2 merging into the profile base 1139.3 with a rounded portion 1141. The profile wall of the profile 1020 provided with the profile opening 1140 is thus formed by the first and second annular lips 1139.1, 1139.2 and, in a rounded manner, merges into the profile base 1139.3. This is the case over the entire circular ring circumference of the sealing sleeve 1121.

[0136] Also in the present case --as in the further embodiments of a further sealing arrangement 1001, 1002, 1003, 1004-- the profiled sealing sleeve 1121 --i.e., like the further embodiments of the sealing sleeve 1022, 1023, 1024 -- is formed with a circumferentially substantially U-shaped free cross-section of the profile opening 1140, forming an annular groove which is open in this respect, i.e. open to the second compression chamber 106, the groove wall of which is formed by means of the aforementioned first and second annular lips 1139.1, 1139.2 and the base of which is formed with the aforementioned profile base 1139.3.

[0137] At the profile base 1139.3, as in the other embodiments of the sealing arrangement 1001, 1002, 1003, 1004, the sealing sleeve 1021, 1022, 1023, 1024 is held pressure-tight on the step side 116 of the piston between the step-side piston ring 1011, 1012, 1013, 1014 and the compression chamber-side retaining ring 1031, 1032, 1033, 1034; this is also the case in all three embodiments of the sealing arrangement 1001, 1002, 1003, 1004, which is made clear by the same reference numerals.

[0138] Likewise --evident in the Fig.4B , Fig.5B , FiG.6B , Fig.7B as well as Fig.8 and Fig.10A, Fig.10B -- it can be seen for all embodiments of the sealing arrangement 1001, 1002, 1003, 1004, 1005, 1006 with respect to the profile base 1139.3 of the profile 1020 that these are held between a concavely curved adjacent sealing side 1010 of the piston ring, 1011, 1012, 1013 and a matching convexly curved holding side 1030 of the retaining ring.

[0139] The rounding 1141 of the profile opening 1140 thus provides space for the transition of the sealing lips 1139.1, 1139.2 to the profile base 1139.3 in such a way that the curvature of the sealing sleeve 1021, 1022, 1023, 1024 can move between the convex curvature of the sealing side 1010 on the piston ring 1011, 1012, 1013 and the holding side 1030 on the retaining ring 1031, 1032, 1033, or can adjust elastically to maintain the sealing effect. Thus, it can be understood that the curvature of the profile 1020 of the sealing sleeve 1021, 1022, 1023, 1024 is guided between the convex shape of the holding side 1030 of the retaining ring 1031, 1032, 1033 1034 or the sealing side 1010 of the piston ring 1011, 1012, 1013, 1014.

[0140] These, as well as the following features of the profile base 1139.3 are realized in all embodiments and in this respect this is made clear by the use of the same reference numerals.

[0141] The profile base 1139.3 is formed in such a soft or elastic material that it accommodates the sealing ridges 1119, which are designed here as sealing edges. The sealing ridges 1119 are pressed into the profile base 1139.3 when the profile base is fixed between the base side of the piston ring 1011, 1012, 1013 and the base side of the retaining ring 1031, 1032, 1033. The sealing ridges 1119 serve to improve the sealing of the sealing sleeve 1021, 1022, 1023, 1024 at its profile base 1139.3 between the sealing side 1010 of the piston ring 1011, 1012, 1013 and the retaining side 1030 of the retaining ring 1031, 1032, 1033.

[0142] Furthermore, the profile base 1139.3—also in all embodiments of the sealing arrangement 1001, 1002, 1003—has access openings 1116 spaced apart along the annular circumference of the sealing sleeve. Said sealing webs 1119 are formed on the sealing sleeve 1011, 1012, 1013 for forming indentations in the profile base 1139.3 of the profile 1020. That is, Specifically, two small sealing edges (e.g., approximately 0.3 mm high) are formed on the piston ring 1011, 1012, 1013 and the retaining ring 1031, 1032, 1033, recognizable as small triangles. These sealing edges are intended to press into the profile base 1139.3 of profile 1020 of the sealing sleeve 1021, 1022, 1023, 1024, thereby supporting the seal. The piston and retaining rings are made of aluminum and are intended to be sealed via the sealing edges.

[0143] The sealing lands are realized once on the outside as 1119.A and once on the inside as 1119.I to increase the sealing effect; this is done, as previously explained, with said sealing lands 1119.A and 1119.I, respectively, on the sides of the piston ring 1011, 1012, 1013 and the retaining ring 1031, 1032, 1033. This means that a first sealing land 1119.I is provided radially inward and a second sealing land 1119.A is provided radially outward with respect to the aforementioned sealing opening 1116. A first radially inward sealing land 1119.I is provided on each of the piston rings 1011, 1012, 1013 and the retaining ring 1031, 1032, 1033; if necessary, it can also be provided on only one piston ring or only on one retaining ring. Similarly, a second sealing land 1119.A can be provided radially outwardly on the piston ring 1011, 1012, 1013 and retaining ring 1031, 1032, 1033, or only on the piston ring or only on the retaining ring.

[0144] In the present case, the formation of two circumferential sealing webs 1119.A and two circumferential sealing webs 1119.I has proven to be advantageous, so that the piston ring 1011, 1012, 1013 has two circumferential sealing webs 1119.I, 1119.A and the retaining ring 1031, 1032, 1033 also has two circumferential sealing webs 1119.I, 1119.A, wherein one of the circumferential sealing webs 1119.I, 1119.A is arranged radially inside the through-openings 1116 and one radially outside the through-openings 1116.

[0145] In the present case, it has also proven advantageous that the radially inwardly extending sealing ridges 1119.I are arranged offset from one another, with the sealing ridge 1119.I of the retaining ring 1031, 1032, 1033 being radially offset slightly outward, i.e., closer to the through-opening 1116. In contrast, the radially inwardly extending sealing ridge 1119.I of the piston ring is radially offset slightly inward compared to the sealing ridge 1119.I of the retaining ring.

[0146] However, both sealing lands 1119.I are only offset from each other with their crests to the extent that they still overlap; in this case, the crest of one sealing land 1119.I is opposite a flank of the other sealing land 1119.I. Similarly, a sealing land 1119.A of the retaining ring is radially offset somewhat closer to the through-opening 1116, i.e., radially offset more inwardly than the sealing land 1119.A of the piston ring, which is radially offset somewhat outwardly. Both sealing lands 1119.A overlap in that their crests are each arranged opposite a flank of the opposite sealing land 1119.A. This arrangement of the sealing webs 1119.A 1119.I is implemented -- also in the same way in all three embodiments of the sealing arrangement 1001, 1002, 1003, 1004 -- to increase the sealing effect at the profile base 1139.3 of the sealing sleeve between the piston ring and the retaining ring.

[0147] Regardless of the previously explained arrangement or positioning of a sealing web 1119, 1119.A 1119.I and regardless of the material of the piston ring 1011, 1012, 1013 and / or the retaining ring 1031, 1032, 1033, it has proven advantageous that a sealing web 1119.A 1119.I is designed in such a way that it is pressed completely or partially into the profile base 1139.3 of the sealing sleeve 1011, 1012, 1013 or can otherwise penetrate into the profile base 1139.3 of the sealing sleeve 1011, 1012, 1013 or into its volume area when fixing the profile base 1139.3 between the base side of the piston ring 1011, 1012, 1013 and the Base side of the retaining ring 1031, 1032, 1033. A sealing ridge is thus designed with an appropriately pointed penetration side, i.e. advantageously a formed ridge edge towards the profile base of the sealing sleeve - for example, best in the form of a ridge, e.g. the aforementioned apex ridges.The hardness of the material, in particular the plastic, of the sealing rib is advantageously greater than the hardness of the material, in particular the plastic, of the sealing sleeve or its profile base. In this respect, the sealing rib 1119, 1119.A 1119.I is generally and advantageously designed such that it can deform the sealing sleeve in order to connect the sealing sleeve with its profile base 1139.3 in a pressure-tight manner to the piston ring and / or retaining ring; advantageously, however, it does not cut it in order to maintain its consistency.

[0148] The through-openings 1116 are formed in the profile base 1139.3 for the passage of a fixing element, which, like the number of through-openings 1116 in the profile base, is arranged circumferentially on the retaining ring and / or piston ring. A fixing element can, in principle, be formed in any suitable manner as a rounded, oval, or circumferentially extending, more or less wide pin, stud, or even a comparatively wide, partially or fully circumferential web.

[0149] The retaining ring 1031, 1032, 1033, 1034 or piston ring 1011, 1012, 1013, 1014 thus has - in both cases or alternatively only one, or alternately - a fixing element 1113 preferably for each through-opening 1116, so that the retaining ring 1031, 1032, 1033 is connected to the piston ring 1011, 1012, 1013, 1014 by means of the fixing elements 1113 thus extending through; i.e. due to the through-openings in the sealing sleeve, the sealing sleeve 1121, 112, 1123 is also held against rotation on the profile base 1139.3 between the piston ring and retaining ring.

[0150] Specifically, the Fig.5A, Fig.5B and Fig.6A, Fig.6B , Fig.7A , Fig.8 , Fig.9 visible fixing pin as fixing element 1113 due to its circumferentially limited extent and fitting into the through openings 1116 the parts of the sealing arrangement 1001, 1002, 1003, 1004, 1005, 1006; ie the piston ring 1011, 1012, 1013, 1014, 1015, 1016, the sealing sleeve 1021, 1022, 1023, 1024, 1025, 1026 and the retaining ring 1031, 1032, 1033, 1034, 1035, 1036 of the sealing arrangement 1001, 1002, 1003, 1004, 1005, 1006 are held against each other in a rotationally secure manner.

[0151] The additional clamping effect is explained below and results in the sealing arrangement 1001, 1002, 1003, 1004, 1005, 1006 remaining held together even in their sandwich structure. As will be explained in detail with reference to the embodiments of the sealing arrangement 1001, 1002, 1003, 1004, 1005, 1006, it becomes clear that the fixing elements 1113 can be implemented in different ways in terms of their design or attachment to the retaining ring and / or piston ring.

[0152] While in the present case the sealing sleeve 1021, 1022, 1023, 1024, 1025, 1026 has a corresponding number of access openings 1116 for the number of fixing elements 1113, this can also be realized differently. In particular, the piston ring 1011, 1013, 1015 ( Fig.4A / Fig.4B and Fig.6A / Fig.6B ) fixing elements 1113, or the retaining ring 1032, 1034 ( Fig.5A / Fig.5B , Fig.7A , Fig.9 ) fixing elements 1113; the fixing elements 1113 can also be formed separately as in Fig.8 shown.

[0153] Accordingly, in the present case, according to the embodiment of the Fig.4A, Fig.4B and Fig.6A, Fig.6B the retaining ring 1031, 1033 has a receptacle --such as a groove in the retaining ring 1031 or a passage as in the retaining ring 1033-- for a fixing element 1113. In a variant, according to the embodiment of the Fig.5A, Fig.5B , Fig.7A , Fig.8 the piston ring 1012, 1014, 1015 may have a receptacle—such as a groove for a fixing element 1113. Corresponding receptacles, such as a groove or a passage, are marked with the reference numeral 1114.

[0154] Furthermore, in this case, the fixing elements 1113 are arranged along the circumference of the piston and retaining ring and / or the piston ring or retaining ring, evenly spaced along the ring circumference. The fixing elements 1113 are illustrated and designed as clamping teeth or short webs or pins. However, the fixing elements can also be formed as a number of clamping screws.

[0155] The receptacles 1114 are shown and designed here as clamping grooves or similar receptacles for the fixing elements 1113. However, in the case that the fixing elements are formed as a number of clamping screws, the receptacles 1114 can also be designed as screw holes - this will be explained with reference to Fig.8 described.

[0156] However, the design of the fixing elements shown here as clamping teeth has proven to be advantageous compared to the use of clamping screws for the fixing elements, since a locking of the clamping teeth 1113 in a clamping groove or bore or similar receptacle 1114, as explained below, can be realized particularly advantageously.

[0157] Referring now to the first embodiment of a sealing arrangement 1001 according to Fig.4B It can be seen that the fixing element 1113 is formed as a clamping tooth that engages in a receptacle 1114 in the form of a clamping groove on the retaining ring 1031. This means that the clamping tooth as a fixing element 1113 is formed integrally on the piston ring 1011. The fixing element 1113 passes through the through-opening 1116 on the profile base 1139.3 of the sealing sleeve 1021 and is clamped laterally—i.e., on its sides 1117.A, 1117.I—with the flanks 1114.A, 1114.I of the receptacle 1114.

[0158] Referring to the second embodiment of the sealing arrangement 1002 according to Fig.5B a fixing element 1113 is formed integrally on the retaining ring 1032 and extends through the through-opening 1116 in the profile base 1139.3 of the sealing sleeve 1022 and thus projects into the receptacle 1114 on the piston ring 1012. Without again describing the previously explained clamping principle in detail, it is also provided here that the fixing element 1113, designed as a clamping tooth, is held in a clamping manner on its sides 1117.A, 1117.I by flanks 1114.I, 1114.A of the receptacle 1114.

[0159] Referring to the third embodiment of a sealing arrangement 1003, according to Fig.6B As can be seen, the fixing element 1113 is essentially designed as a rivet or clinch element, so that it can engage behind an undercut 1117.H on the retaining ring 1033 on the other side of the receptacle 1114, which is formed here as a passage, in the sense of a flange 1117 with an edge 1117.R.

[0160] Fig.7A shows in a perspective sectional view a piston 1112 for a compressor 1100 according to the concept of the invention in a fourth embodiment; shown in a partially shown compressor 1100 as a double compressor according to the model of the embodiment of Fig.2A, Fig.2B .

[0161] Here, too, the illustrated sealing arrangement 1004 according to the concept of the invention has a sealing sleeve 1024 profiled in circumferential cross-section between the step-side piston ring 1014 and the compression chamber-side retaining ring 1034. The sealing arrangement 1004 according to this fourth embodiment thus has a step-side piston ring 1014, and for forming the annular sealing body 1139, a sealing sleeve 1024, and a retaining ring 1034 according to the fourth embodiment.

[0162] The annular sealing body 1139 of the sealing sleeve 1024 forms the previously explained first annular lip 1139.1 on an outer side 1138.1 of the seal 1138 and the second annular lip 1139.2 on the inner side 1138.2 of the seal 1138. Also in the present case, the sealing sleeve 1024 is designed as an annular sealing body 1139, formed with a Fig.7B shown circumferential cross-section, which clearly forms the open profile 1020.

[0163] The opening 1140 in the profile is also recognizable here as being essentially rectangular, with the first and second annular lips 1139.1, 1139.2 each merging into the profile base 1139.3 with a rounded portion 1141. The profile wall of the profile 1020 provided with the profile opening 1140 is thus formed by the first and second annular lips 1139.1, 1139.2 and merges into the profile base 1139.3 in a rounded manner. This is also the case with the sealing sleeve 1024 over the entire circular ring circumference.

[0164] Also present in the sealing arrangement 1004 --as in the previously explained embodiments of a further sealing arrangement 1001, 1002, 1003-- the profiled sealing sleeve 1141 --i.e. like the further embodiments of the sealing sleeve 1021, 1022, 1023-- is formed with a circumferentially substantially U-shaped free cross-section of the profile opening 1140; i.e. forming an annular groove which is open in this respect, i.e. open to the second compression chamber 106, the groove wall of which is formed by means of the aforementioned first and second annular lips 1139.1, 1139.2 and the base of which is formed with the aforementioned profile base 1139.3.

[0165] At the profile base 1139.3, in the sealing arrangement 1004—as in the previously explained embodiments of the sealing arrangement 1001, 1002, 1003—the sealing sleeve 1024 is held pressure-tight on the step side 116 of the piston between a step-side piston ring 1014 and a compression-chamber-side retaining ring 1034; this is also the case in all four embodiments of the sealing arrangement 1001, 1002, 1003, 1004, which is made clear by the same reference numerals.

[0166] In the present case, a through-opening 1116 is formed in the profile base 1139.3 for the passage of a fixing element, which, like the number of through-openings 1116 in the profile base, is arranged circumferentially on the retaining ring and / or piston ring. As previously explained, a fixing element can generally be formed in any suitable manner as a rounded, oval, or circumferentially extending, more or less wide pin, stud, or even a comparatively wide, partially or fully circumferential web.

[0167] The retaining ring 1034 or the piston ring 1014 thus preferably has a fixing element 1113 for each through-opening 1116 - in both cases or alternatively only one of the two, or both alternately - so that the retaining ring 1034 is connected to the piston ring 1014 by the fixing elements 1113 passing through it; ie due to the through-openings in the sealing sleeve, the sealing sleeve 1124 is also held against rotation on the profile base 1139.3 between the piston ring and the retaining ring.

[0168] Specifically, the Fig.7A , Fig.7B The visible fixing web acts as a fixing element 1113 due to its completely circumferential extension and fitting into the through-openings 1116, the parts of the sealing arrangement 1004; ie the piston ring 1014, the sealing sleeve 1124 and the retaining ring 1034 of the sealing arrangement 1004 are held against each other in a rotationally secure manner.

[0169] The sealing arrangement 1004 according to the fourth preferred embodiment is shown in Fig.7B View (i) shown in detail. Fig.7B shows in view (i) a first sealing body part 1139A of the sealing arrangement 1004 and a second sealing body part 1139I of the seal 1004 for the seal composed of the first and second part as the sealing arrangement 1004 of the Fig.7A in an exploded view and a retaining ring 1034 in view (ii) for insertion into a receptacle 1114 of the piston 1112 of the Fig.7C. Fig.7C shows in a perspective view the piston 1112 of the Fig.7A according to the concept of the invention in the fourth embodiment with the Fig.7B mentioned receptacle 1114 for the retaining ring 1034 of view (ii) of the Fig.7B .

[0170] In contrast to the previously explained embodiments of a sealing sleeve 1021, 1022, 1023, the sealing sleeve 1024 described and shown here, as already described in the Fig.7A Identified by hatching, the sealing sleeve 1024 according to the present embodiment comprises a first separate part 1139A located outside the annular space for forming the first annular lip 1139.1 of the sealing body 1139, and a second separate part located inside the annular space for forming the second annular lip 1139.2 of the sealing body 1139.

[0171] In this respect, the sealing body parts referred to here are the first part 1139A as the sealing body part located outside the annular space and the second part 1139I as the sealing body part located inside the annular space in view (i) of the Fig.7B shown in an exploded view.

[0172] The first and second sealing body parts 1139A, 1139I therefore do not come into contact with each other, even if they together form the sealing sleeve 1124 of the sealing arrangement 1138 with the sealing sleeve 1124 shown in view (i) of the Fig.7B outer side 1138.1 of the seal and inner side 1138.2 of the seal.

[0173] Rather, the first and second sealing body parts 1139A, 1139I are actually --as in Fig.7A shown—held at a distance by the fixing element 1113 in the form of an annular web, which extends around the entire circumference of the ring. The fixing element 1113 of the sealing arrangement 1004 according to the fourth embodiment, formed in the form of the annular web, thus forms the previously described access opening in the sealing arrangement 1004; in other words, the fourth embodiment of the sealing sleeve 1024 is formed in two parts with the first and second sealing body parts 1139A, 1139I, leaving a distance to form the access opening 1116 of the sealing sleeve 1024.

[0174] The first and second outer and inner sealing body parts 1139A, 1139I can thus be placed separately into one another while maintaining the distance --which is established here in the form of the through-opening 1116-- thus forming a concentric ring arrangement with a distance of the through-opening 1116 maintained therebetween.

[0175] In this annular space of the distance --that is, the through-opening 1116-- the annular web of the fixing element 1113 engages, as shown in view (ii) of the Fig.7B is shown.

[0176] The retaining ring 1034 has the annular web forming the fixing element 1113 and can—at the moment the annular web of the fixing element 1113 engages the through-opening 1116, i.e., reaches through the remaining distance between the first and second sealing body parts 1139A, 1139I—engage in the receptacle 1114 of the piston ring 1014. While the fixing web of the fixing element 1113 engages in the receptacle 1114 of the piston ring 1014 and is clamped there, the retaining ring, with its collar 1034B, secures the spaced-apart sealing body parts 1139A, 1139I, thus fixing them relative to one another on the piston ring 1014.

[0177] The previously explained convexly curved holding side 1030 of the in view (ii) of the Fig.7B The retaining ring 1034 shown is designed as a collar 1034B in order to be pressed against the sealing side 1010 of the piston ring 1014, which in this case is concave. This is designed so that the profile base 1139.3 of the sealing sleeve 1024 - that is, precisely that profile base 1139.3 into which the first and second ring lips 1139.1, 1139.2 each merge - can be clamped between the collar 1034B and the groove 1014N of the retaining side 1030.

[0178] Nevertheless, the present fourth embodiment of a sealing sleeve 1024 - --that is, the sealing arrangement 1004 formed from the actually separate first and second sealing body parts 1139A, 1139I and the retaining ring 1034 -- offers the advantage that the retaining ring 1034 with its fixing element 1113 (as a ring with a fully circumferential web) can be introduced into the through-opening 1116 or pushed into the receptacle 1114 of the piston ring 1014 and secured there, much more easily than in the previously explained embodiments of the sealing arrangement 1001, 1002, 1003. In other words, the ring-inner and ring-outer sealing body parts 1139I and 1139A can be introduced separately into a gap between the previously mentioned collar 1034B of the retaining ring 1034 and the groove 1014N of the piston ring 1014, i.e. between the sealing side 1030 of the piston ring 1034 and the holding side 1030 of the retaining ring 1034.

[0179] Put very simply, it has proven advantageous to insert the sealing body parts 1139A, 1139I separately between the piston ring 1014 and the retaining ring 1034 to form the sealing arrangement 1004, rather than, conversely, to insert the retaining ring 1034 into a sealing arrangement 1004 that is already assembled - that is to say with an integrally formed annular sealing body 1139 with first and second annular lips 1139.1, 1139.2.

[0180] An adjustment of the fixing element 1113 into the through-opening 1116 of the sealing sleeve 1024 is therefore not necessary in the present case, and an angularly precise adjustment of the fixing web of the fixing element 1113 into the receptacle 1114 is also not necessary, since these are to be locked to one another independently of the angle of rotation.

[0181] Fig.8 shows a piston according to the concept of the invention in a fifth embodiment in view (i) in an exploded view with screws; these are also shown in the sectional view (ii) and in an assembled perspective view (iii) for a compressor as a double compressor according to the model of Fig.2A, Fig.2B ;

[0182] Also in the fifth embodiment according to the Fig.8 In the present case, the fixing elements 1113 are arranged along the circumference of the piston and retaining ring and / or the piston ring or retaining ring at equal distances along the ring circumference. The fixing elements 1113 are - previously according to embodiments according to the Fig.4A, Fig.4B , Fig.5A, Fig.5B and Fig.6A, Fig.6B represented as clamping teeth or short bars or pins-- in the fifth embodiment according to the Fig.8 formed as a number of clamping screws and thus as fixing elements 1113 recognizable in the exploded view (i).

[0183] The receptacles 1114 are -previously according to embodiments according to Fig.4A, Fig.4B , Fig.5A, Fig.5B and Fig.6A, Fig.6B as clamping grooves or similar receptacles for the fixing elements 1113-- in the case of the fifth embodiment according to the Fig.8 designed as screw holes; this applies to the receptacles 1114 in the piston 1112 and in this case also to receptacles in the retaining ring 1035 and / or sealing sleeve 1025, as can also be seen in the exploded view (i).

[0184] The sealing sleeve 1025 also has a corresponding number of through-openings 1116 for the number of fixing elements 1113; in the simplest case, these can be holes or threaded screw holes. Accordingly, in the present case, the retaining ring 1035 has a receptacle 1114 for a fixing element 1113 in the form of a screw; in the simplest case, this can therefore be a hole or a threaded screw hole for the screw. In the present case, the hole or screw hole has a Fig.8 visible chamfer for fitting and countersinking the screw.

[0185] In principle, in another embodiment, another type of receptacle 1114 is also conceivable, such as a groove in the retaining ring 1035 or a passage as in the retaining ring 1035. In addition, the piston ring 1015 or the bottom of the piston 1112 has a receptacle 1114 for a fixing element 1113 in the form of a screw; here too, in the simplest case, this can be a hole or a screw hole with a thread for the screw. Here too, in another embodiment, a groove for a fixing element 1113 is suitable. Corresponding receptacles 1114, such as a groove or a passage, are identified by the reference numeral 1114 in Fig.8 .

[0186] As shown in the sectional view (ii) of the Fig.8 As can be seen, the fixing elements 1113 in the manner of fixing pins also lock the parts of the sealing arrangement 1005 due to their circumferentially limited extension and fitting into the through-openings 1116 - as previously explained with reference to the sealing arrangement 1001, 1002, 1003, 1004. This means that - just as the piston ring 1011, 1012, 1013, the sealing sleeve and the retaining ring 1031, 1032, 1033 of the sealing arrangement 1001, 1002, 1003, 1004 are held against each other in a rotationally secure manner - this is also the case in the fifth embodiment according to the Fig.8 Particularly evident in the sectional view (ii) is that the piston ring 1015, the retaining ring 1035, and the sealing sleeve 1025 of the sealing arrangement 1005 are held against one another in a rotationally secure manner. The sealing sleeve 1025 is clamped between the retaining ring 1035 and the piston ring 1015 with a suitable tightening torque of the screws as fixing elements 1113, with a corresponding clamping effect due to the tightening torque. In this case, the piston ring 1015 is formed integrally with the piston 1112.

[0187] The additional clamping effect causes the sealing arrangement 1005 to hold itself together in its sandwich structure, as shown in view (iii) of the Fig.8 can be seen; this has also been explained above with regard to the embodiments of the sealing arrangement 1001, 1002, 1003, 1004.

[0188] Fig.9 shows a piston according to the concept of the invention in a sixth embodiment in a disassembled perspective view for a schematically shown compressor as a double compressor according to the model of Fig.2A, Fig.2B . Also in the sixth embodiment of the sealing arrangement 1006 according to the Fig.9 In the present case, fixing elements 1113 are evenly spaced along the circumference of the piston 1112 and retaining ring 1036 and / or the piston ring 1016 or retaining ring 1036 and arranged along the ring circumference; a fixing element 1113 is similar to the embodiment of the Fig.5B as a fixing pin and here part of the retaining ring 1036 - the fixing pin thus passes through the number of through-openings 1116 in the sealing sleeve 1026 for the number of fixing elements 1113 in the direction of the piston ring 1016.

[0189] The fixing elements 1113 not shown here are -previously according to embodiments according to the Fig.4A, Fig.4B , Fig.5A, Fig.5B and Fig.6A, Fig.6B shown as clamping teeth or short bars or pins-- in the sixth embodiment according to the Fig.9 as a number of molded-on fixing pins on the retaining ring 1036. For this purpose, in the sixth embodiment, the retaining ring 1036 is cast into the sealing sleeve 1026; the cast-in mass can serve to form the retaining ring 1036 with fixing pins. The cast-in mass can flow as a self-fixing plastic mass into the through-openings 1116 in the sealing sleeve 1026, in particular further into receptacles 1114 (not shown here) in the bottom of the piston 1112 or in the piston ring 1016. The fixing pins, as a fixing element 1113, can be held in place in the through-opening 1116 due to their circumferentially limited expansion and fit. The cast-in mass can be adhesive.

[0190] However, a retaining ring 1036 with a fixing pin can also be glued or welded into the sealing sleeve 1026 as a single piece, e.g., by ultrasonic welding. This creates a permanent, integral connection between the retaining ring 1036 and the piston ring 1016 on the piston 1112, which holds the sealing sleeve 1026 in place.

[0191] Referring to Fig.10A und Fig.10B These represent a situation that can generally be realized independently of the previously explained embodiments at the profile base 1139.3 of an annular sealing body 1139 of a sealing sleeve, through which a fixing element extends. By way of example, reference is made here to a sealing arrangement 1001, 1002, 1003, 1004, 1005, 1006. However, the profile base 1139.3 of an annular sealing body 1139 of a sealing sleeve can be realized not only with one of the previously explained sealing sleeves 1021, 1022, 1023, 1024, 1025, and 1026, but also generally with another suitable sealing sleeve not explained in detail here.

[0192] The profile base 1139.3 of such a sealing sleeve is in any case generally designed to be so soft or elastic in the material as to accommodate the sealing webs 1119 which penetrate here as sealing edges or in another way into the profile base 1139.3 of such a sealing sleeve and are designed accordingly.

[0193] The ones here in Fig.10A and also Fig.10B The sealing webs 1119 shown are each pressed into the profile base 1139.3 or penetrate into it or its volume area in another way when fixing the profile base between the base side of the piston ring 1011, 1012, 1013 ... 1016 and the base side of the retaining ring 1031, 1032, 1033 ... 1036.

[0194] Each of the sealing webs 1119 serves to improve the sealing of the sealing sleeve 1021, 1022, 1023, 1024, 1025, 1026 at its profile base 1139.3 between the sealing side 1010 of the piston ring 1011, 1012, 1013, ...1016 and the holding side 1030 of the retaining ring 1031, 1032, 1033. Fig.10A und Fig.10B show different arrangements which can be realized differently or in variation of the arrangement in the sealing arrangement 1001, 1002, 1003, 1004, 1005, 1006.

[0195] As from Fig.10A It can be seen that the sealing bars 1119 can also be set differently than, for example, in Fig.5B visible; ie each of the sealing webs 1119 can be arranged with a different radial distance to the fixing element 1113 than in Fig.5B . This shows Fig.5B specifically an arrangement of sealing ridges 1119, in which the radially inwardly extending sealing ridges 1119.I are arranged offset from one another, wherein the sealing ridge 1119.I of the retaining ring 1031 is radially offset slightly outwards, i.e. closer to the through-opening 1116. Analogously, in Fig.5B the radially outwardly extending sealing webs 1119.A are arranged offset from one another, wherein the sealing web 1119.A of the retaining ring 1031 is radially offset slightly inwards, i.e. also closer to the through-opening 1116.

[0196] In the design of the Fig.10A this is different; with a slightly different designation are the sealing ridges 1119.H on the retaining ring - this can therefore be according to the modification of the Fig.10A different from the retaining ring 1031, 1032, 1033, 1034, 1035, 1036 - both further spaced from the through-opening 1116, while the sealing webs 1119.K on the piston ring - this can be done in a modification of the Fig.10A unlike the piston ring 1011, 1012, 1013, 1014, 1015, 1016 -- both are spaced closer to the through opening 1116 and are offset inwards.

[0197] As from Fig.10B It can be seen that the sealing bars 1119 can also be set differently than in Fig.5B is evident; ie, for example, the sealing webs 1119 can be arranged only on one side but diagonally - so to speak point-symmetrically - to the fixing element 1113. In a solid line, a single sealing web 1119.K on the piston ring is a radially outer sealing web and this is offset further outwards from the through-opening 1116 than the single sealing web 1119.K on the retaining ring, which is a radially inner sealing web and this is offset further closer to the through-opening 1116.

[0198] Conversely, the single sealing land 1119.K on the piston ring, shown in broken lines, is a radially inner sealing land and is offset further inward from the through-opening 1116. The single sealing land 1119.H on the retaining ring, shown in broken lines, is, in contrast, a radially outer sealing land and is offset further closer to the through-opening 1116.

[0199] In all embodiments and variants of their arrangements, the sealing ridges 1119 are formed as elements on the piston ring 1011, 1012, 1013, 1014, 1015, 1016 and / or retaining ring 1031, 1032, 1033, 1034, 1035, 1036 by pressing into the profile base 1139.3 of a sealing sleeve and are thus designed to hold it in a rotationally secure manner and, in particular, also to seal it. In this respect, the sealing ridge 1119, 1119.K, 1119.H—as already explained above—is generally and advantageously designed such that it can deform the profile base 1139.3 of the sealing sleeve in order to connect the sealing sleeve with its profile base 1139.3 in a pressure-tight manner to the piston ring and / or retaining ring. advantageous but not cut to maintain its consistency.

[0200] Regardless of the previously explained arrangement or positioning of a sealing ridge 1119, 1119.K, 1119.H and regardless of the material of the piston ring 1011, 1012, 1013, 1014, 1015, 1016 and / or the retaining ring 1031, 1032, 1033, 1034, 1035, 1036, it has proven advantageous that a sealing ridge 1119, 1119.K, 1119.H is designed in such a way that it can be fully or partially pressed into the profile base 1139.3 of the sealing sleeve or can otherwise penetrate into the profile base 1139.3 of the sealing sleeve or into its volume area when fixing the profile base 1139.3 between the base side of the piston ring 1011, 1012, 1013, 1014, 1015, 1016 and the base side of the retaining ring 1031, 1032, 1033, 1034, 1035, 1036. A sealing web is thus designed with an appropriately pointed penetration side, i.e. advantageously a formed web edge towards the profile base of the sealing sleeve - for example, best in the form of a ridge, e.g. the aforementioned apex ridges -- .A hardness of the material, in particular the plastic, of the sealing web is advantageously greater than a hardness of the material, in particular the plastic, of the sealing sleeve or its profile base.

[0201] Fig.11A shows a vehicle 400 with a compressed air supply system 200 of the Fig.1 in schematic form, where the cylinder 1100 with piston 1112 of the compressor 1100 is also shown schematically. Analogous to that in relation to Fig.2A und Fig.2B As described, the compressor 1100 has: a first compression chamber 104, a second compression chamber 106, an air supply connection 120 and a compressed air outlet 124, a piston 1112 with a first pressurizable end face 113 which is directed towards the first compression chamber 104 and a second pressurizable end face 115 opposite the first end face 113, which is directed towards the second compression chamber 106, wherein the first compression chamber 104 is delimited by the first end face 113 and the second compression chamber 106 is delimited by the second end face 115 of the piston 1112, and the piston 1112 is connected to a drive 102 via a connecting rod 128, wherein the first compression chamber 104 and the second compression chamber 106 are connected to one another via a connecting line 122, wherein the connecting rod 128, in particular rigid, in particular rigid and joint-free, is connected to the piston 1112 on one piston side 128.1 and on one drive side 128.2 is rotatably connected to a rotating part 131 of the drive 102, and the first end face 113 is a solid side 114 and the second end face 115 is a stepped side 116, wherein the piston 112 carries at least one seal 1138 on the stepped side 116, which seals the first compression chamber 104 and / or the second compression chamber 106, wherein the seal 1138 is formed by means of a profiled annular sealing body 1139 with a circumferentially extending first annular lip on an outer side 1138.1 of the seal and a circumferentially extending second annular lip on an inner side 1138.2 of the seal.

[0202] According to the concept of the invention, the seal 1138 is part of a sealing arrangement 1001, 1002, 1003, 1004 in which it is provided that the annular sealing body 1139 is formed as a sealing sleeve 1021, 1022, 1023, 1024 with a profile 1020 which is open in the circumferential cross-section and has a profile base, the profile wall of which is formed by means of the first annular lip 1139.1 and the second annular lip 1139.2, wherein the sealing sleeve 1021, 1022, 1023, 1024 is held with its profile base between a step-side piston ring 1011, 1012, 1013 and a compression chamber-side retaining ring 1031, 1032, 1033 in a pressure-tight manner on the step side 116.

[0203] As also with regard to Fig.2A und Fig.2B As described above, in the preferred embodiment, the connecting rod 128 in the compressor 1100 is also formed integrally with the piston 1112 and is free of joints relative to the piston 1112. In the compressor 1100, the first compression chamber 104 is cylindrical or cylindrical with a dome-shaped section 164 and / or the second compression chamber 106 is annularly cylindrical. Even if, in the embodiment described here, a connecting line 122 is provided for a series connection of the first compression chamber 104 and the second compression chamber 106 - generally in the sense of a series connection of two compressor stages of a multi-stage compressor - it should nevertheless be understood that the concept of the invention is not limited thereto.Alternatively, in another embodiment, the concept of the invention can also be implemented in a multi-stage compressor whose two or more compressor stages are implemented in the sense of a parallel connection - generally in the sense of a parallel connection of two compressor stages of a multi-cylinder compressor.

[0204] In detail, a vehicle 400 with a pneumatic system 500 in Fig.11B shown, which is implemented as part of an ECAS system (Electronically Controlled Air Suspension) for level control of the air-sprung vehicle 400 with an ECU and air springs 210 on supports 410.

[0205] The electronic lines to the ECU and the pneumatic lines to the air springs 210 and the compressed air supply system 200 are also shown; these include corresponding compression springs 300 on the wheel suspensions and the aforementioned compressed air supply system 200, which is shown here in detail with the motor compressor and air dryer 222 in perspective as an exploded view.

[0206] A compressed air supply system 200 is operated within the vehicle 400 with the following steps: Compressing air from a crankcase interior 160 and / or the environment U in a first compression chamber 104 of the compressor 1100 to a low pressure level, further compressing the compressed air compressed to a low pressure level in the first compression chamber 104 in a second compression chamber 106 of the compressor 1100 to a high pressure level, feeding the compressed air compressed to a high pressure level in the second compression chamber 106 from the compressed air outlet 124 via a main pneumatic line 30 to a compressed air connection 2 of a gallery 220, in particular via an air dryer 222. List of reference symbols (part of the description)

[0207] 1Total compressed air supply 2Compressed air connection, first compressed air connection 2Second compressed air connection 3Vent connection 10Compressed air supply 30Main pneumatic line 31First isolation valve 32Check valve 33Bypass line 34Throttle 35Vent line 36Further isolation valve 37Pneumatic line 38Yet further isolation valve 39Further check valve 40Further pneumatic line 41Second isolation valve 51Suction line 52Filter 102Drive, drive shaft 104First compression chamber, first compression chamber 106Second compression chamber, second compression chamber 109Web wall inside 110Cylinder inner web 111Web wall 113First end face of the piston 114Solid side 115Second end face of the piston 116Step side 1118Cylinder 119Cylinder inner wall 119.1Outer wall of the cylinder inner wall 119.2Inner wall of the cylinder inner wall 120Air supply connection 122Connecting line 124Compressed air outlet 126Charging connection 128Connecting rod 128.1Piston side of the connecting rod 128.2Drive side of the connecting rod 130Check valve 131Rotating part of the drive 132Eccentrically arranged shaft section, eccentric 138, 1138Seal 138.1, 1138.1Outside of the seal 138.2, 1138.2Inside of the seal 139, 139a, 139b, 1139Seal body 139.1 a, 139.1 b, 1139.1First ring lip 139.2a, 139.2b, 1139.2Second ring lip 142Air supply valve flap 144Connection valve flap 146Charging valve flap 150Drive shaft bearing 152Connecting rod bearing 154Compressor housing 156Connecting rod receiving section 158Counterweight section 160Crankcase interior 162Rotating connection 164Cylinder coupling section 166Piston screw 200Compressed air supply system 210Air spring 211Air bellows, bellows 212Air spring valve 1 220Gallery, gallery line 221Spring branch line 222Air dryer 224Pressure medium reservoir, accumulator 230Voltage-pressure sensor APiston axis AD1First seal AD2Second seal AD3Third seal BBeneration direction DSharp portion of the offset perpendicular to the stroke direction EVenting direction E'Further venting direction FSpring force of the check valve H Deflection, deflection of the piston in the stroke direction KH Major piston diameter KN Minor piston diameter M Engine P1 First pressure, pressure in the first compression chamber P2 Second pressure, pressure in the second compression chamber PA External pressure, pressure in the crankcase interior RA Axial direction RR Radial direction S1 Rotational axis of the drive, point S1 S2 Rotational axis of the rotatable connection between the connecting rod and the eccentrically arranged shaft section, point U Surroundings 300 Pneumatic system 400 Vehicle 410 Support 500 Pneumatic system 1001, 1002, 1003, 1004 Sealing arrangement 1010Sealing side 1011, 1012, 1013,1014, 1015, 1016Piston ring 1100Compressor 1112Piston, double-sided pressurizable piston 1112.1External cross-section, outside of the piston 1112.2Internal cross-section, inside of the piston 1113Number of fixing elements, clamping teeth, clamping screws 1114Recording 1114.A, 1114.IFlanken 1116Access opening of the sealing sleeve 1117Flanging 1117.A, 1117.ISides 1117.RRand 1117.HHundercut 1118Cylinder 1119, 1119.A 1119.I Sealing ridge, radial inside, outside and inside sealing ridge 1020open profile of the sealing sleeve 1021, 1022, 1023,1024, 1025, 1026 sealing sleeve 1030Retaining side 1031, 1032, 1033, 1034, 1035, 1036Retaining ring 1100 compressors 1138Seal of the sealing arrangement 1138.1Outside of the seal, 1138.2Inside of the seal, 1139Annular sealing body 1139.1First annular lip of the sealing body 1139.2Second annular lip of the sealing body 1139A, 1139ISeal body parts DLCompressed air KCompressor KSPlastic KVBAdhesive joint RRadial direction USVBUltrasonic welding joint 1031, 1032, 1033, 1034, 1035, 1036Retaining ring 1100 compressors 1138Seal of the sealing arrangement 1138.1Outside of the seal, 1138.2Inside of the seal, 1139Annular sealing body 1139.1First annular lip of the sealing body 1139.2Second annular lip of the sealing body 1139A, 1139ISeal body parts DLCompressed air KCompressor KSPlastic KVBAdhesive joint RRadial direction USVBUltrasonic welding joint

Claims

1. Compression machine (1100), in particular a compressor, in particular for a compressed air feed (10) of a compressed air supply system (200), which compression machine comprises a drive (102) and - a cylinder (1118) having a first compression chamber (104), a second compression chamber (106), an air feed connection (120) and a compressed air outlet (124), and - a piston (1112), the piston (1112) being designed to be moveably guided in the cylinder (1118) of the compression machine (1100) during operation of the compression machine and to be connectable to a drive (102) via a connecting rod (128), the connecting rod (128) being connectable to the piston (1112) on a piston side (128.1) and rotatably connectable to a rotating part (131) of the drive (102) on a drive side (128.2), the piston (1112) comprising: - a first pressurizable end face (113) which is provided to be directed towards a first compression chamber (104) of the compression machine (1100) during operation, and, opposite the first end face (113), a pressurizable second end face (115) which is provided to be directed towards a second compression chamber (106) of the compression machine (1100) during operation, the first compression chamber (104) and the second compression chamber (106) being connected to one another via a pressurizable connecting line (122), and - the first end face (113) being formed as a full-surface solid face (114) and the second end face (115) being formed as an annular stepped face (116), the piston (1112) bearing, on the second end face (115), a sealing arrangement (1001, 1002, 1003, 1004, 1005, 1006) at least one seal (1138) which seals the first compression chamber (104) against the second compression chamber (106), characterized in that - an annular sealing body (1139) is held, as a sealing sleeve (1021, 1022, 1023, 1024, 1025, 1026) of the sealing arrangement (1001, 1002, 1003, 1004, 1005, 1006), in a pressure-tight manner on the stepped face (116) by a profile base, namely between a stepped-face piston ring (1011, 1012, 1013, 1014, 1015, 1016) arranged on the second end face (115) and a compression chamber-side retaining ring (1031, 1032, 1033, 1034, 1035, 1036).

2. Compression machine (1100) according to claim 1, characterized in that the seal (1138) is formed by means of a profiled annular sealing body (1139) comprising a circumferentially extending sealing first annular lip on an outer side (1138.1) of the seal and a circumferentially extending sealing second annular lip on an inner side (1138.2) of the seal.

3. Compression machine (1100) according to claim 1 or claim 2, characterized in that the sealing sleeve (1021, 1022, 1023, 1024,1025, 1026) is formed so as to have a profile (1020) which is open in circumferential cross-section and has the profile base, the profile wall of which is formed by means of a first annular lip (1139.1) and a second annular lip (1139.2).

4. Compression machine (1100) according to any of claims 1 to 3, characterized in that the sealing sleeve (1021, 1022, 1023, 1024, 1025, 1026) profiled in circumferential cross-section is formed so as to have a free cross-section which is substantially U-shaped in circumference, forming an open annular groove, the groove wall of which is formed by means of the first annular lip (1139.1) and the second annular lip (1139.2).

5. Compression machine (1100) according to any of claims 1 to 4, characterized in that the retaining ring (1031, 1032, 1033, 1034, 1035, 1036) lies in the open profile (1020) of the sealing sleeve (1021, 1022, 1023, 1024, 1025, 1026) and is held on the piston ring, in particular the profile base of the sealing sleeve (1021, 1022, 1023, 1024, 1025, 1026) is clamped between the retaining ring (1031, 1032, 1033, 1034, 1035, 1036) and the piston ring (1011, 1012, 1013, 1014, 1015, 1016).

6. Compression machine (1100) according to any of the preceding claims, characterized in that the sealing sleeve (1021, 1022, 1023, 1024, 1025, 1026) comprises a pass-through opening or a plurality of spaced-apart pass-through openings in the profile base, and the retaining ring (1031, 1032, 1033, 1034, 1035, 1036) is connected to the piston ring (1011, 1012, 1013, 1014, 1015, 1016) by means of one or more fixing elements, the fixing element(s) passing through the pass-through opening of the sealing sleeve (1021, 1022, 1023, 1024, 1025, 1026).

7. Compression machine (1100) according to any of the preceding claims, characterized in that the sealing sleeve (1021, 1022, 1023, 1024, 1025, 1026) comprises a number of pass-through openings (1116) in the profile base that corresponds to the number of fixing elements, one fixing element (1113) engaging through each pass-through opening.

8. Compression machine (1100) according to any of the preceding claims, characterized in that the sealing sleeve (1021, 1022, 1023, 1024, 1025, 1026) is formed in one piece.

9. Compression machine (1100) according to any of the preceding claims, characterized in that the sealing sleeve (1021, 1022, 1023, 1024, 1025, 1026) comprises the profile base between a first annular lip (1139.1) and a second annular lip (1139.2), and at least one pass-through opening (1116) is formed in the profile base.

10. Compression machine (1100) according to any of the preceding claims, characterized in that the sealing sleeve (1024) is formed in several pieces.

11. Compression machine (1100) according to claim 10, characterized in that the sealing sleeve (1024) forms the profile base between a separate part comprising a first annular lip (1139.1) and a separate part comprising a second annular lip (1139.2), leaving a gap to form a pass-through opening in the profile base.

12. Compression machine (1100) according to any of the preceding claims, characterized in that: - the piston ring (1011, 1012, 1013) comprises a number of fixing elements and the retaining ring (1031, 1032, 1033) comprises a number of fixing grooves (114) for establishing a connection (117) between the piston ring (1011, 1012, 1013, 1014) and the retaining ring (1031, 1032, 1033), and / or - the retaining ring (1034, 1035, 1036) comprises a number of fixing elements and the piston ring (1014, 1015, 1016) comprises a number of fixing grooves or similar receptacles for establishing a connection (117) between the piston ring (1014, 1015, 1016) and the retaining ring (1034, 1035, 1036).

13. Compression machine (1100) according to any of the preceding claims, characterized in that a fixing element (1113) is formed as a clamping screw, the clamping screw being screwed into a screw hole.

14. Compression machine (1100) according to any of the preceding claims, characterized in that a fixing element is formed as a clamping tooth (1113) which is held on a clamping stop or in a clamping fit.

15. Compression machine (1100) according to any of the preceding claims, characterized in that a clamping tooth (1113) is clamped in a clamping groove or fixed by means of a press fit.

16. Compression machine (1100) according to any of the preceding claims, characterized in that a clamping tooth (1113) engages through a clamping groove and is fixed by means of a clinch connection or rivet connection.

17. Compression machine (1100) according to any of the preceding claims, characterized in that the piston ring (1011, 1012, 1013) is arranged by being fastened to the second end face (115) or formed in one piece therewith, in particular formed in one piece together with the stepped face (116) or formed separately and connected to the stepped face (116).

18. Compression machine (1100) according to any of the preceding claims, characterized in that at least one sealing ridge (1119) is formed on the piston ring (1011, 1012, 1013, 1014, 1015, 1016) and / or on the retaining ring (1031, 1032, 1033, 1034, 1035, 1036), in particular a number of one or more, preferably circumferential sealing ridges (1119) are formed on the piston ring (1011, 1012, 1013, 1014, 1015, 1016) and / or on the retaining ring (1031, 1032, 1033, 1034, 1035, 1036), in particular wherein - a sealing ridge (1119.H) on the retaining ring is a radially inner sealing ridge (1119.1) which is offset closer to the pass-through opening (1116) than a sealing ridge (1119.K) on the piston ring, which, as a radially outer sealing ridge (1119.A), is offset further away from the pass-through opening (1116) in comparison, and / or - a sealing ridge (1119.H) on the retaining ring is a radially outer sealing ridge (1119.A) which is offset further away from the pass-through opening (1116) than a sealing ridge (1119.K) on the piston ring, which, as a radially inner sealing ridge (1119.1), is offset closer to the pass-through opening (1116) in comparison.

19. Compression machine (1100) according to any of the preceding claims, characterized in that the piston ring (1016) and the retaining ring (1036) each consist of plastics material (KS), the piston ring (1016) and the retaining ring (1036) being connected to one another by means of an adhesive connection (KVB) and / or ultrasonic welding connection (USVB).

20. Compression machine (1100) according to any of the preceding claims, characterized in that in order to form a connection between the piston ring (1016) and the sealing element (115), a retaining ring (1036) is formed by filling a U-shaped annular space (121) of the sealing element (115) with plastics material (KS).

21. Compression machine (1100) according to claim 1, characterized in that the connecting rod (128) is formed in one piece together with the piston (1112) and is joint-free relative to the piston (1112).

22. Compression machine (1100) according to claim 1, characterized in that the connecting line (122) is for a series connection of the two compression machine stages (multi-stage compression machine) (122) or alternatively is also connected in parallel (multi-cylinder compression machine).

23. Compression machine (1100) according to claim 1 or claim 22, characterized in that - the first compression chamber (104) is delimited by the first end face (113) of the piston (1112) and the second compression chamber (106) is delimited by the second end face (115) of the piston (1112), and / or - the first compression chamber (104) is cylindrical or is cylindrical and has a dome-shaped portion (164), and / or the second compression chamber (106) is annularly cylindrical.

24. Compressed air supply system (200), in particular for operating a pneumatic system (500), having a compression machine (1100) according to any of claims 1 to 23, comprising: - an air feed and the compression machine (1100) connected thereto via an air feed connection (120), - a pneumatic main line (30) to a compressed air connection (2) of a gallery (220), which main line is pneumatically connected to the compression machine (1100) via a compressed air outlet (124) and comprises an air dryer (222), - a pressure medium reservoir (224) pneumatically connected to the compression machine (1100) via a loading connection (126).

25. Vehicle (400) comprising a compressed air supply system (200) according to claim 24.

26. Method for operating a compressed air supply system (200) according to claim 24, comprising the steps: - compressing air from a crankcase interior (160) and / or from the environment (U) in a first compression chamber (104) of the compression machine (1100) to a low pressure level, - further compressing the compressed air, compressed to a low pressure level in the first compression chamber (104), in a second compression chamber (106) of the compression machine (1100) to a high pressure level, - feeding the compressed air, compressed to a high pressure level in the second compression chamber (106), from the compressed air outlet (124) via a pneumatic main line (30) to a compressed air connection (2) of a gallery (220), in particular via an air dryer (222).