Piston compressor

Abstract

Piston compressor (1) for compressing gases, comprising at least one cylinder (6), at least one piston (5) mounted in each cylinder (6) of each cylinder housing (8), so that each piston (5) and each cylinder (6) define a compression chamber (29) for compressing the gas, an inlet valve (19) for each compression chamber (29), an outlet valve (20) for each compression chamber (29), at least one mechanism (40) with which the at least one piston (5) is in mechanical operative connection for an oscillating movement of the at least one piston (5), at least one lubricating chamber (44) in which the at least one mechanism (40) is at least partially arranged and the at least one mechanism (40) can be lubricated with a lubricant in the at least one lubricating chamber (44), a housing (45) for defining the lubricating chamber (44),at least one membrane (34) and with the at least one membrane (34) each lubrication chamber (44) is separated from each compression chamber (29), wherein an end region of each membrane (34) facing away from the compression chamber (29) is indirectly fastened to the remaining piston compressor (1) by means of a fastening element (49).

Description

[0001] The present invention relates to a piston compressor according to the preamble of claim 1 and a piston compressor system according to the preamble of claim 14. State of the art

[0002] Piston compressors are used for a wide variety of technical applications to compress gases. In a piston compressor, a piston performs an oscillating motion. The piston is mounted on a cylinder. An inlet valve serves to introduce the gas into the compression chamber, and an outlet valve serves to discharge the gas from the compression chamber. The compression chamber is defined at an end opposite the piston by a surface of a cylinder head. The inlet valve and the outlet valve are generally integrated into the cylinder head. The oscillating motion of the piston is achieved by means of a mechanism. The mechanism is designed, for example, as a crank drive with a crankshaft and a connecting rod, or as a roller shoe with a roller and a drive shaft with at least one cam. The mechanism is arranged in a lubrication chamber.The lubrication chamber is filled with a lubricant, such as lubricating oil, to lubricate the moving components of the mechanism. The mechanism is driven, for example, by an electric motor. The piston performs the oscillating movement between a certain dead center and a certain bottom dead center, and the differential volume of the compression chamber between the top and bottom dead centers of the piston defines the stroke volume. The dead volume of the compression chamber is the volume of the compression chamber at the top dead center of the piston.

[0003] For certain technical applications involving the compression of gases, it is necessary to supply compressed gases with a high degree of purity. The hermetic separation between the cylinder on the one hand and the piston with the piston rings as a gap seal on the other is not complete, meaning that lubricant from the lubrication chamber can enter the compression chamber of the piston compressor and the compressed gas would thus be contaminated with lubricant. To prevent this undesirable and avoidable contamination of the compressed gas, it is already known to create an additional chamber between the compression chamber and / or the chamber containing the piston on the one hand and the lubrication chamber on the other, and to provide this with an extraction system, for example. However, this is disadvantageously very complex, so that the piston compressor is expensive to manufacture and requires a large installation space.Diaphragm compressors are also known, but they have a small displacement volume per unit volume of the installation space.

[0004] EP 0 541 482 B1 discloses a piston compressor for oil-free compression of gases, comprising at least one cylinder and a piston guided therein, which is provided with at least one slotted, so-called captured piston ring accommodated in an annular groove on the piston, which, with its peripheral surface facing away from the inner surface of the cylinder, defines a space of the annular groove acted upon by the pressure of the gas in the compression chamber of the cylinder, and which, starting from this peripheral surface, has two radial, mutually parallel boundary surfaces, of which the surface facing the compression chamber extends over part of the radial ring width, wherein the piston ring is guided in a sliding manner with its two parallel boundary surfaces on corresponding surfaces of the annular groove, wherein the remaining surface of the piston ring facing the compression chamber, starting from the peripheral surface facing the inner surface of the cylinder, is designed as a wedge surface.which extends at an angle of 5 to 15° to a parallel to the boundary surface facing the compression chamber up to this boundary surface.

[0005] DE 2020699 A1 discloses a plunger piston compressor with single- or multi-stage piston and / or cylinder designs, wherein at least one bellows, generally referred to as at least one diaphragm, is arranged between each piston and the crankcase. Attaching the bellows to the rest of the plunger piston compressor with an intermediate piece disadvantageously does not ensure complete hermetic separation of the crankcase from the compression chamber, nor does it allow for easy assembly and disassembly of the bellows. Disclosure of the inventionAdvantages of the invention

[0006] A piston compressor according to the invention for compressing gases, comprising at least one cylinder, at least one piston, which is mounted in each cylinder of a cylinder housing, so that each piston and each cylinder define a compression chamber for compressing the gas, an inlet valve for each compression chamber, an outlet valve for each compression chamber, at least one mechanism with which the at least one piston is in mechanical operative connection for an oscillating movement of the at least one piston, at least one lubrication chamber in which the at least one mechanism is at least partially arranged and the at least one mechanism in which at least one lubrication chamber can be lubricated with a lubricant, a housing for delimiting the lubrication chamber, at least one diaphragm, and with the at least one diaphragm, each lubrication chamber is separated from each compression chamber,wherein an end region of each diaphragm facing away from the compression chamber is indirectly attached to the rest of the piston compressor by means of a fastening element.

[0007] In a further embodiment, the fastening element is designed as a sealing ring and / or fastening ring.

[0008] In a supplementary embodiment, the sealing ring and / or fastening ring comprises a first ring with an extension substantially in the axial direction and a second ring with an extension substantially in the radial direction.

[0009] In an additional variant, the end region facing away from the compression chamber, in particular the end of each membrane, is fastened to the fastening element with a material connection and / or force-locking connection and / or form-locking connection, in particular to a second ring of the fastening element.

[0010] Preferably, the end region facing away from the compression chamber, in particular the end of each membrane, is fastened in a fluid-tight manner to the fastening element, in particular to a second ring of the fastening element.

[0011] In a further embodiment, the fastening element, in particular a first ring of the fastening element, is fastened to the rest of the piston compressor with a positive connection and / or non-positive connection.

[0012] In an additional embodiment, the fastening element, in particular a first ring of the fastening element, is fastened to the rest of the piston compressor with a clamp connection between two fastening components. The at least one diaphragm can thus be easily removed from the rest of the piston compressor simply by loosening the clamp connection. The one clamp connection with the two fastening components thus forms a fastening means for the indirect fixation and fastening of the at least one diaphragm. Fastening components are components or parts of the piston compressor between which the clamp connection for the fastening element is formed. The clamp connection is thus formed by prestressing the fastening element with a compressive force between two fastening components. The clamp connection is a force-locking connection and preferably a form-locking connection.

[0013] In a supplementary variant, the two fastening components are the cylinder housing and a flange plate.

[0014] In particular, the connection between each membrane and the fastening element is designed to be completely circumferential.

[0015] In a further embodiment, the components of the piston compressor are sealed against one another with at least one seal, and the components are the cylinder housing and / or a cylinder head and / or a flange plate and / or a housing for a lubrication chamber and / or the fastening element. Two components of the piston compressor rest against one another at a contact surface, in particular a flat contact surface, in particular with a compressive force. Due to the fact that the components are made of metal and / or a hard material, it is generally not possible to achieve a seal between this contact surface and the two components of the piston compressor. For this reason, it is necessary to seal the contact surface with the seal in order to ensure that, for example, the compression chamber and the outer space of the diaphragm are sealed off from the environment.

[0016] In a supplementary variant, the at least one membrane is designed as at least one bellows.

[0017] In particular, each diaphragm divides the cylinder sub-chamber defined by a cylinder, a piston, and preferably a flange plate, particularly in the radial direction, into an inner diaphragm chamber and an outer diaphragm chamber. The gas to be compressed, which escapes from the compression chamber at the gap seal between the piston guide and the piston, thus reaches only the outer diaphragm chamber. Lubricating oil on the plain bearing of the piston rod from the lubrication chamber thus reaches only the inner diaphragm chamber. This advantageously prevents lubricating oil from being carried over into the compression chamber, and additionally, the compressed gas in the outer diaphragm chamber can be discharged into the environment or fed back to the inlet valve to reuse the leak at the gap seal between the piston and the piston guide on the cylinder.

[0018] Preferably, the stroke height of each piston between the top and bottom dead center of the piston is less than 30%, 10%, 5%, or 3% of the extension of the at least one diaphragm, in particular of the at least one bellows, relevant for the stroke movement in the direction of a longitudinal axis of the cylinder. The diaphragm thus experiences a small amount of expansion and compression during the stroke movements of the piston, so that the diaphragm has a long service life due to the minimal mechanical stress.

[0019] Piston compressor system according to the invention for compressing gases, comprising a piston compressor with at least one piston and with at least one mechanism with which the at least one piston is in mechanical operative connection for an oscillating movement of the at least one piston, a lubrication system with at least one lubricating oil line, a lubricating oil container and a conveying device for lubricating oil for lubricating the at least one mechanism arranged in a lubrication chamber, a drive motor for the piston compressor, a container with the gas to be compressed, a container with the compressed gas, wherein the piston compressor is designed as a piston compressor described in this patent application.

[0020] In a further variant, a throttle channel is formed from the lubrication chamber into the diaphragm interior for conducting lubricating oil into the diaphragm interior, and a drain channel is formed from the diaphragm interior into the lubricating oil line for conducting lubricating oil from the diaphragm interior into the lubricating oil line and / or into the lubricating oil reservoir. The flow cross-sectional area of ​​the throttle channel is smaller than the flow cross-sectional area of ​​the drain channel; preferably, the flow cross-sectional area of ​​the throttle channel is smaller than 70%, 50%, 30%, or 10% of the flow cross-sectional area of ​​the drain channel. Lubricating oil can thus advantageously be conducted into the diaphragm interior for lubrication and cooling of the diaphragm interior and the plain bearing of the piston rod.

[0021] In a further variant, a lubrication chamber is separated from a compression chamber in a fluid-tight manner by means of at least one membrane.

[0022] In a supplementary embodiment, the membrane interior is sealed fluid-tight from the membrane exterior in each piston compressor.

[0023] The components are preferably made of metal, in particular steel and / or aluminum.

[0024] In an additional embodiment, the at least one seal is designed to be completely circumferential in the circumferential direction.

[0025] In a further embodiment, the at least one sealing ring and / or the at least one fastening ring have any desired shape in a section perpendicular to the longitudinal axis of the cylinder, in particular circular or rectangular, in particular square, or elliptical.

[0026] In an additional embodiment, the at least one seal is made of an elastic material. The modulus of elasticity is preferably in kN / mm 2 the seal is less than 30, 20, 10, 5, 3 or 2.

[0027] Preferably, the at least one seal is prestressed with a compressive force.

[0028] In a supplementary variant, the at least one seal is prestressed with a compressive force substantially, in particular with a deviation of less than 30°, 20° or 10°, in the axial direction.

[0029] In a further embodiment, the at least one seal is arranged at least partially, in particular completely, in a respective groove.

[0030] Advantageously, the at least one groove is designed to be completely circumferential in the circumferential direction.

[0031] In an additional embodiment, one seal is arranged in only one groove.

[0032] In a supplementary embodiment, the two fastening components for each clamping connection are designed to extend completely around a longitudinal axis of the cylinder in a tangential direction. This allows for a secure, force-locking fastening of the at least one fastening element.

[0033] In an additional variant, a seal is formed between two components, in particular between the two fastening components for each clamping connection, completely circumferentially in the tangential direction for fluid-tight sealing of a gap between the two components, in particular two fastening components, with respect to the environment.

[0034] In a supplementary embodiment, a groove is formed in each component, in particular in each fastening component for each clamping connection, completely circumferentially in the tangential direction and the seal is arranged at least partially, in particular completely, in the groove.

[0035] In an additional variant, the at least one fastening component is formed by the cylinder housing and / or a flange plate and / or a housing for the lubrication chamber and / or the piston and / or a part of the piston. The diaphragm is indirectly fixed to the rest of the piston compressor at an upper end or an upper end region and / or at a lower end or lower end region, each with a fastening element.

[0036] In a supplementary embodiment, the at least one fastening element is ring-shaped.

[0037] In a further embodiment, the at least one fastening element is designed to extend completely around a longitudinal axis of the cylinder in the tangential direction. This allows for a hermetic separation of the at least one lubrication chamber from the at least one compression chamber.

[0038] In particular, the axial and / or radial extent of the at least one fastening element is substantially constant, in particular with a deviation of less than 30%, 20% or 10%.

[0039] In a further variant, the at least one membrane is fixed to the at least one fastening element with a material connection, in particular a welded connection and / or adhesive connection, as a sealing means for a hermetic separation of one lubrication chamber from one compression chamber.

[0040] In a supplementary embodiment, the at least one material connection between the at least one membrane and the at least one fastening element is formed in a tangential direction completely circumferentially with respect to a respective longitudinal axis of the cylinder and is preferably produced by means of laser welding.

[0041] In a further variant, the at least one seal is ring-shaped.

[0042] In an additional embodiment, the at least one seal is formed in one component, in particular only one component.

[0043] In a supplementary embodiment, the at least one seal is at least partially, in particular completely, made of HPU and / or PU (polyurethane) and / or NBR (acrylonitrile-butadiene rubber) and / or FPM and / or FKM (fluororubber) and / or EPDM (ethylene-propylene-diene rubber) and / or silicone and / or PTFE (polytetrafluoroethylene) and / or POM (polyoxymethylene).

[0044] In a supplementary variant, the at least one seal between two components is prestressed with a compressive force due to a connection between at least two components with a fixing element, in particular a screw and / or a bayonet connection and / or a locking connection.

[0045] Preferably, a flange plate is formed between each cylinder housing and each housing for the lubrication chamber. The flange plate transfers the forces acting on the cylinder housing, for example due to friction between the piston and the piston guide, indirectly to the housing for the lubrication chamber. The flange plate as an additional component makes it easy to design the axial extension of a guide bore for the plain bearing of the piston rod with a sufficiently large axial extension of this guide bore as a plain bearing by means of a bearing socket without thereby significantly increasing the overall axial extension of the piston compressor. In addition, the flange plate can improve the flexibility during assembly and disassembly of the piston compressor.

[0046] In a further embodiment, the flange plate is fastened in a form-fitting and / or force-fitting manner to the respective cylinder housing and / or to the respective housing for the lubrication chamber. The flange plate is preferably fastened to the cylinder housing and / or to the housing for the lubrication chamber by means of at least one fixing element, in particular at least one screw. For this purpose, corresponding bores with and / or without an internal thread are formed on the cylinder housing and / or on the housing for the lubrication chamber. The internal thread serves to screw in an external thread on the screw. In addition, at least one bore for the screw to pass through is also formed in the flange plate.The screw with a screw head is subjected to a tensile force, so that the cylinder housing rests on the flange plate with a compressive force and / or the flange plate rests on the housing for the lubrication chamber with a compressive force, creating a force-fitting connection. In addition, there is preferably essentially no radial play and / or no radial distance between the at least one bore in which the screw is arranged and the screw, so that a form-fitting connection is additionally provided between the cylinder housing and the flange plate and / or between the flange plate and the housing for the lubrication chamber. The fixing element is preferably designed as a bayonet connection or a rivet.Preferably, the positive connection between the cylinder housing and the flange plate and / or between the flange plate and the housing for the lubrication chamber is designed with a positive locking geometry and a counter-positive locking geometry.

[0047] In an additional variant, the maximum radial extension of the flange plate is greater than the maximum axial extension of the flange plate, preferably greater than 70%, 50% or 30% of the maximum axial extension of the flange plate.

[0048] In a supplementary embodiment, the axial extension of the flange plate as the thickness of the flange plate is essentially constant, in particular with a deviation of less than 30%, 20%, 10%, 5% or 1%, preferably without taking the bearing support into account.

[0049] In a further variant, a connecting channel is formed from the membrane interior into the environment, in particular in the flange plate, for an ambient pressure in the membrane interior and preferably the piston compressor and / or the piston compressor system does not have a throttle channel and / or a drain channel for passing lubricating oil from a lubricating oil circuit through the membrane interior.

[0050] In another variant, the flange plate is disc-shaped.

[0051] In a supplementary embodiment, the cylinder housing and / or the cylinder head and / or the flange plate and / or the housing for the lubrication chamber are formed at least partially, in particular completely, from metal, in particular steel and / or aluminum, and / or from plastic, in particular fiber-reinforced plastic.

[0052] The lubrication chamber is conveniently closed.

[0053] In a further embodiment, the number of folds of the bellows is greater than 5, 10, 30, 50, 100 or 200.

[0054] In an additional variant, the dead volume of each compression chamber is less than 10%, 5%, 3%, or 2% of the displacement volume of each compression chamber. Advantageously, the piston compressor can thus achieve a high pressure of the gas to be compressed with a short piston stroke using the mechanism with a shaft having at least one cam and one roller.

[0055] In a supplementary embodiment, the at least one membrane, in particular the at least one bellows, is arranged at least partially, in particular completely, between the piston and the mechanism in the direction of a longitudinal axis of the cylinder.

[0056] In a further embodiment, the at least one membrane, in particular the at least one bellows, is substantially cylindrical in shape, in particular in the region within the at least one cylinder.

[0057] In a supplementary variant, at least one piston with a piston rod is in mechanical connection with the mechanism.

[0058] Advantageously, the at least one cylinder comprises at least one cylinder head.

[0059] In an additional embodiment, the roller comprises a cylindrical roller with a central bore, and a bearing pin is arranged in the central bore. An annular gap is formed between the cylindrical roller and the bearing pin, and this annular gap is lubricated with the lubricant. The axial ends of the bearing pin are mounted on the roller shoe, for example, with a plain bearing.

[0060] In an additional embodiment, the axial extent of the at least one membrane is greater than 5 times, 10 times, 20 times, or 30 times the thickness of the at least one membrane. The axial extent of the at least one membrane is thus substantially greater than the thickness of the membrane.

[0061] In an additional embodiment, the membrane is made of metal and / or plastic. Preferably, the plastic of the membrane is an elastomer. The membrane is flexible to accommodate the piston's stroke movements. Preferably, the membrane is made of several layers, in particular layers of different materials such as metal and / or plastic. One layer, for example a thin layer of a metal, e.g., aluminum foil, reduces the permeation of substances through the membrane. The membrane has a very small permeation coefficient, particularly for lubricants. Q = P * F * t * Δp / d. Q is the amount of gas or vapor that permeates through a layer of area F with thickness d in time t, when the pressure difference of the permeant in front of and behind the layer is Δp. The gas permeability for oxygen in cm 3 / m 2*d*bar of the membrane is preferably less than 30, 10, 1 or 0.1. The gas permeability for hydrogen in cm 3 / m 2 *d*bar of the membrane is preferably less than 50, 10, 1 or 0.2.

[0062] In a further embodiment, the cylinder has a longitudinal axis. The longitudinal axis of the cylinder corresponds to the direction of movement of the piston mounted in the cylinder.

[0063] The mechanism is conveniently formed by a roller shoe with a roller and a drive shaft with cams.

[0064] In a further embodiment, the mechanism is formed by a crankshaft and a connecting rod as a piston rod.

[0065] In an additional variant, the piston compressor includes an electric motor to drive the piston compressor. For example, the electric motor drives the drive shaft with cams and / or the crankshaft.

[0066] The pressure that can be generated by the piston compressor is in the range of 100 bar to 1000 bar. Short description of the drawings

[0067] In the following, exemplary embodiments of the invention are described in more detail with reference to the accompanying drawings. They show: Fig. 1 a cross-section of a piston compressor for compressing a gas, Fig. 2 a section AA according to Fig. 1 a roller with roller shoe and a drive shaft, Fig. 3 an enlarged partial cross-section of the piston compressor according to Fig. 1, Fig. 4 shows a further enlarged partial cross-section of the piston compressor according to Fig. 1, Fig. 5 a cross-section of two piston compressors for compressing a gas with two cylinder housings and Fig. 6 a highly simplified representation of a compressor system. Embodiments of the invention

[0068] In Fig. Figure 1 shows a cross-section of a piston compressor 1 for compressing gases in a first exemplary embodiment. The piston compressor 1 is used to compress gases, e.g., hydrogen or air, under high pressure. The pressure that can be generated by the piston compressor 1 is, for example, in a range between 100 and 1000 bar.

[0069] The piston compressor 1 has a drive shaft 2 with two cams 3, which rotate about a rotational axis 26. The drive shaft 2 is driven by an electric motor (not shown). The rotational axis 26 lies in the plane of the drawing of Fig. 1 and is perpendicular to the plane of Fig. 2. A piston 5 is mounted in a cylinder 6, i.e. a piston guide 7 of the cylinder 6, which is formed by a cylinder housing 8. Fully circumferential annular grooves 15 are formed on a radial outer side of the piston 5. A piston ring 16 is arranged in each of the annular grooves 15. The piston 5 is formed in two parts with a first piston part 5a and a second piston part 5b. A compression chamber 29 is delimited exclusively by the first piston part 5a. The maximum axial extension of the second piston part 5b is significantly greater than the maximum extension of the first piston part 5a, for example the maximum axial extension of the second piston part 5b is greater than 2, 3 or 5 times the maximum extension of the first piston part 5a. The ring grooves 15 with the piston rings 16 are formed in the second piston part 5b and between the first piston part 5a and the second piston part 5b.Optionally, at least one annular groove 15 and at least one piston ring 16 can also be formed in the first piston part 5a (not shown). The first piston part 5a is fastened to the second piston part 5 in a form-fitting and / or force-fitting manner, in particular by a bolt 86 or connecting piece 86 formed on the first piston part 5a with an external thread being screwed into a bore 87 with an internal thread on the second piston part 5b as a screw connection 88. Instead of the screw connection 88 (. Fig. 3) A bayonet connection or snap-in connection or a material connection, for example a welded connection or an adhesive connection (not shown) may also be provided for the connection between the first and second piston parts 5a, 5b. The compression chamber 29 is delimited by the cylinder housing 8 with the cylinder head 17 and the piston 5, i.e., the first piston part 5a. The end 18 of the cylinder head 17 is the part of the surface of the cylinder head 17 that delimits the compression chamber 29 and is not designed and / or functions as a cylinder 6. An inlet channel 22 with an inlet valve 19 and an outlet channel 24 with an outlet valve 20 open into the compression chamber 29. The gas flows into the compression chamber 29 through the inlet channel 22 with an inlet opening 21, and the gas flows out of the compression chamber 29 again under high pressure through the outlet channel 24 with an outlet opening 23. The inlet valve 19, e.g.a check valve, is designed such that only gas can flow into the compression chamber 29 and the outlet valve 20, e.g. a check valve, is designed such that only gas can flow out of the compression chamber 29. The volume of the compression chamber 29 is changed due to an oscillating stroke movement of the piston 5. The piston 5 is supported indirectly by a piston rod 14 on the drive shaft 2. The piston 5 and the piston rod 14 are aligned coaxially and / or concentrically to one another. A roller shoe 9 with a roller 10 is attached to the end of the piston rod 14. The roller 10 can execute a rotational movement, the axis of rotation 25 of which is in the plane of the drawing according to. Fig. 1 and perpendicular to the plane of Fig. 2. The drive shaft 2 with the at least one cam 3 has a shaft rolling surface 4 and the roller 10 has a roller rolling surface 11.

[0070] The roller running surface 11 of the track roller 10 rolls on the shaft rolling surface 4 of the drive shaft 2 at a contact surface 12 with the two cams 3. The roller shoe 9 is mounted as a plain bearing in a roller shoe bearing formed by the cylinder housing 8. A spring 27, i.e. spiral spring 27, as an elastic element 28, which is clamped between a flange plate 43 and the roller shoe 9, applies a compressive force to the roller shoe 9 so that the roller rolling surface 11 of the track roller 10 is in constant contact with the shaft rolling surface 4 of the drive shaft 2. The spring 27 as the elastic element 28 rests on the roller shoe 9 and the flange plate 43 so that the flange plate 43 acts to support the elastic element 28. The roller shoe 9, the piston rod 14 and the piston 5 thus jointly perform an oscillating stroke movement. The roller 10 is mounted in the roller shoe 9 with a plain bearing 13.The roller shoe 9 with roller 10 and the drive shaft 2 with cam 3 thus function as a mechanism 40 for generating the oscillating movement of the piston 5.

[0071] The intake valve 19 and the exhaust valve 20 are installed or integrated in the cylinder head 17. The cylinder head 17 is a component of the cylinder 6 or the cylinder housing 8. The cylinder head 17 is fastened to the cylinder 6 and thus also to the cylinder housing 8 by means of fixing elements 38 in the form of screws 39. A part of the surface 18 of the cylinder head 17 forms a surface 18 or end 18 which delimits the compression chamber 29. The intake valve 19 comprises a valve piston 30, an elastic element 35 as a spring 36 and a support element 37 for the spring 36. In a closed position of the valve piston 30, the valve piston 30 rests in a fluid-tight manner on a valve sealing seat 32 which extends completely in the tangential direction ( Fig. 1). The outlet valve 20 comprises, in an analogous manner, a valve piston 31 for the outlet valve 20, the elastic element 35 as the spring 36 and the support element 37 for the spring 36 ( Fig. 1). The spring 36 of the exhaust valve 20 rests on a valve sealing seat 33 in the closed position of the exhaust valve 20. The valve sealing seat 32 for the intake valve 19 and the valve sealing seat 33 for the exhaust valve 20 are formed as correspondingly shaped geometries on the cylinder head 17. The intake valve 19 and the exhaust valve 20 with the valve pistons 30, 31 are pneumatically actuated. Due to the pressure change in the compression chamber 29 during the stroke movement of the piston 5, the intake valve 19 is opened and the exhaust valve 20 is closed during the increase in the volume of the compression chamber 29, and vice versa during the stroke movement of the piston 5 during the reduction in the volume of the compression chamber 29.

[0072] The piston 5 is mounted on the piston guide 7 of the cylinder 6 and performs an oscillating translational movement in the direction of a longitudinal axis 41 of the cylinder 6. The mechanism 40 is arranged in a lubrication chamber 44, and the lubrication chamber 44 is delimited by a closed housing 45 for the mechanism 40 and the lubrication chamber 44. The closed housing 45 is in Fig. 1 only partially provided. In the lubrication chamber 44, the mechanism 40 is lubricated with a lubricant, for example lubricating oil or fuel. The lubricant is necessary due to the design of the bearings of the moving components as a plain bearing. The piston compressor 1 compresses, for example, hydrogen for a fuel cell or air or oxygen for breathing in the compression chamber 29. The gas to be compressed must therefore not be contaminated with the lubricant from the lubrication chamber 44, even not in very small quantities. The bearing of the radial outer side of the piston 5 on the piston guide 7 of the cylinder 6 with the piston rings 16 as a gap seal does not allow for complete hermetic separation of the lubrication chamber 44 from the compression chamber 29 containing the gas to be compressed.

[0073] For this reason, the lubrication chamber 44 is hermetically separated and sealed from the compression chamber 29 by a diaphragm 34 acting as a bellows 34. The bellows 34 acting as the diaphragm 34 is made of metal and / or plastic. The plastic is, in particular, an elastomer. The axial extension of the diaphragm 34 is substantially greater than the thickness of the diaphragm 34. The annular and disc-shaped flange plate 43 is arranged between the cylinder housing 8 and a housing 45 for the mechanism 40, in the direction of the longitudinal axis 41 of the cylinder 6. The flange plate 43 serves to transmit forces acting on the cylinder housing 8 to the housing 45 for the lubrication chamber 44 and the mechanism 40.

[0074] A lower axial end portion of the bellows 34 as the membrane 34 is fixed to an annular fastening element 49 as a sealing ring 46 made of metal with a material connection 52 as a welded connection 53 ( Fig. 1 and Fig. 4). The fastening element 49 as the sealing ring 46 is L-shaped in cross-section, with a first leg 59 in cross-section extending substantially in the radial direction 57 and a second leg 60 in cross-section extending substantially in the axial direction 56. The first leg 59 in cross-section forms a first ring 59, and the second leg 60 forms a second ring 60. The welded joint 53 is preferably produced by laser welding. The welded joint 53 is formed in the tangential direction 58 completely circumferentially between the bellows 34 and the annular fastening element 49 as the sealing ring 46 at an axial end of the second ring 60 facing the compression chamber 29. Thus, the welded joint 53, as the material-to-material connection 52, is fluid-tight for the hermetic separation of the lubrication chamber 44 from the compression chamber 29.The material connection 52 thus also forms a sealing means 42 and a fastening means 47. An axial direction 56 is aligned in the direction of the longitudinal axis 41 of the cylinder 6. A radial direction 57 is aligned perpendicular to the longitudinal axis 41. The extension of the annular fastening element 49 is significantly larger in diameter in the radial direction 57 than in the axial direction 56. The annular fastening element 49 on the first ring 59 is fastened between the cylinder housing 8 and the flange plate 43 with a compressive force in a clamped connection. The cylinder housing 8 and the flange plate 43 thus form a fastening component 50 for the force-fitting fastening of the fastening element 49 by means of a compressive force in the clamped connection.In addition, due to the geometry of the fastening element 49, the cylinder housing 8 and the flange plate 43, the fastening element 49 is positively fastened to the cylinder housing 8 and the flange plate 43, in particular in the radial direction 57 and in the axial direction 56.

[0075] The flange plate 43 is screwed to the housing 45 for the mechanism 40 with fixing elements 38 as screws 39. Due to the structural geometry of the piston compressor 1, a lubricant and / or gas would also flow outward along gaps 51 and / or contact surfaces 51 in the radial direction 57 from the space inside and outside the bellows 34 as the diaphragm interior 61 and diaphragm exterior 62, the compression chamber 29, and the lubrication chamber 44. The gap 51 is formed between the fastening element 49 and the flange plate 43, between the fastening element 49 and the cylinder housing 8, between the flange plate 43 and the housing 45 for the mechanism 40 and for the lubrication chamber 44, and between the cylinder head 17 and the cylinder housing 8 ( Fig. 1 and Fig. 4). For this reason, a groove 55 is formed in each of the cylinder housing 8, the flange plate 43, and the housing 45. Two grooves 55 are formed in the cylinder housing 8. A seal 54 is arranged in each groove 55 ( Fig. 1 and Fig. 4). The seals 54 and the grooves 55 are formed to extend completely around the circumference in the tangential direction 58 and the circumferential direction 58. The size of the seals 54 and grooves 55 is designed such that they are preloaded in the axial direction 56 with a compressive force, on the one hand between the cylinder housing 8 and the sealing ring 46 and, on the other hand, between the sealing ring 46 and the flange plate 43. The axial expansion of the seals 54 without preload is thus greater than with preload and compression. The seal 54 between the flange plate 43 and the housing 45 and the seal 54 between the cylinder head 17 and the cylinder housing 8 are also preloaded with a compressive force in the axial direction 56. The components 8, 17, 42, 45, 46, 47, 49 of the piston compressor 1 are thus sealed against one another by the elastic seals 54.The compression chamber 29, the diaphragm interior 61, the diaphragm exterior 62, and the lubrication chamber 44 are thus sealed from the environment at the contact surfaces 51 between the components 8, 17, 42, 45, 46, 47, 49. The seals 54 are made of EPDM or silicone, for example. Each seal 54 is arranged in only one groove 55. At least one connecting channel 102, preferably two connecting channels 102, is provided in the flange plate 43. Fig. 5, from the membrane interior 61 into the environment, so that in the membrane interior 61 essentially the ambient pressure is present to reduce the stress on the membrane 34 in deviation from the Fig. 6 illustrated compressor system 65 with a throttle channel 84 and a drain channel 85 in the flange plate 43. The flange plate 43 thus has not only a mechanical function, but also hydraulic and / or pneumatic functions.

[0076] The bellows 34 is attached in a fluid-tight manner at an upper axial end facing the compression chamber 29 by means of a sealing ring 46 as a fastening means 47 at the lower end of the piston 5, ie the second piston part 5b ( Fig. 1 and Fig. 3). The diaphragm 34 is fluid-tightly connected at an upper axial end to a lower end of the sealing ring 46 by the sealing means 42 as the fastening means 47. The sealing means 42 and the fastening means 47 between the sealing ring 46 as the fastening means 47 and the diaphragm 34 are formed by a material-to-material connection 52, in particular a welded connection 53 and / or an adhesive connection. The welded connection 53 is produced, for example, by laser welding. In a similar manner, an upper end of the sealing ring 46 is fixed to the lower end of the piston 5, i.e., the second piston part 5b. The sealing means 42 and the fastening means 47 between the sealing ring 46 and the piston 5 are formed by a material-to-material connection 52, in particular a welded connection 53 and / or an adhesive connection.The sealing ring 46 acts as a fastening means 47 for sealing and additionally for indirectly fastening the membrane 34 to the piston 5.

[0077] The material connection 52 between the diaphragm 34 and the sealing ring 46 as fastening means 47 and between the sealing ring 46 as fastening means 47 and the second piston part 5b is designed to be completely continuous in the circumferential direction 58 for a fluid-tight, hermetic separation between a diaphragm interior 61 and a diaphragm exterior 62. The diaphragm 34 divides the cylinder sub-space delimited by the cylinder 6, the piston 5 and the flange plate 43 into the diaphragm interior 61 and the diaphragm exterior 62. A mixture of lubricating oil and air is located in the diaphragm interior 61 due to an incomplete seal between the lubricating chamber 44 and the diaphragm interior 61. The gas to be compressed is located in the diaphragm exterior 62 due to the incomplete seal at the gap seal between piston 5 and cylinder 6.The membrane interior 61 is fluid-tight and hermetically separated from the membrane exterior 62 in order to avoid contamination of the gas to be compressed, in particular with lubricating oil, by means of a carryover of the lubricating oil at the gap seal between the piston 5 with piston rings 16 and the cylinder 6 with piston guide 7.

[0078] The upper sealing ring 46 as fastening means 47 also forms a fastening ring 47 for fastening the membrane 34 to the piston 5. The sealing ring 46 has a sleeve-shaped or cylinder-shaped extension 63 which extends into a recess on the second piston part 5b ( Fig. 3). At the upper end of the piston rod 14 facing the piston 5, the piston rod 14 is formed with a small axial extension and a larger radial diameter, so that a stop ring 64 is formed on the piston rod 14. The stop ring 64 is preferably formed integrally with the rest of the piston rod 14. The axial end of the sleeve-shaped extension 63 of the fastening element 63 facing the compression chamber 29 rests on this stop ring 64, which is completely formed in the circumferential direction 58. This allows tensile forces in the piston rod 14 to be transmitted from the piston rod 14 indirectly to the piston 5 in a form-fitting manner via the fastening element 49 as the sealing ring 46 and the fastening means 47, and vice versa, in that the axial end of the sleeve-shaped extension 63 rests with a compressive force on the underside and the axial end of the stop ring 64 facing the lubrication chamber 44.Furthermore, the axial end of the piston rod 14 rests on the piston 5, i.e. the second piston part 5b, so that compressive forces in the piston rod 14 can also be transmitted from the piston rod 14 to the piston 5 and vice versa by transmitting a compressive force between the axial end of the piston rod 14 and the piston 5. The geometry of the piston rod 14 with stop ring 64 and of the piston 5, i.e. the recess in the second piston part 5b, are designed such that in the radial direction 57 there is play or a radial distance between the piston rod 14, in particular the stop ring 64, on the one hand, and the piston 5 and the sealing ring 46, on the other hand. The piston 5 and the piston rod 14 are separate components. In the radial direction 57, a relative movement between the piston rod 14 and the piston 5 is therefore possible.Thus, within this radial clearance or radial distance, no forces can be positively transmitted between the piston 5 and the piston rod 14, thereby reducing the stress on the piston 5 caused by radial forces. This advantageously reduces the mechanical wear between the piston guide 7 on the cylinder 6 and the piston 5 with the piston rings 16.

[0079] In the radial direction 57, an optional guide ring 89 is formed between the second ring 60 of the lower sealing ring 46 and the piston rod 14. A guide bore 90 is formed in the flange plate 43, so that the flange plate 43 is annular. The piston rod 14 is mounted in the guide bore 90 as a plain bearing. In addition, a cylinder jacket-shaped bearing socket 105 ( Fig. 1) designed to increase the axial extent of the guide bore 90. The radial inner side of the bearing socket 105 also forms the plain bearing for the piston rod 14. The bearing socket 105 is arranged within the elastic element 28; preferably, at least 50% or 90% of the axial extent of the bearing socket 105 is arranged within the elastic element 28. Analogously, a guide bore 90 is formed in the guide ring 89 as a plain bearing for the piston rod 14. A friction-reducing and / or locally harder coating, e.g., a DLC coating as a diamond-like carbon coating, can be applied to the outside of the piston rod 14 and / or on the plain bearing at one of the guide bores 90 to reduce friction and mechanical wear.

[0080] The axial extension of the piston rod 14 is substantially greater than the sum of the axial extension of the at least one guide bore 90; preferably, the axial extension of the piston rod 14 is greater than 2 times, 3 times, or 5 times the sum of the axial extension of the at least one guide bore 90, whereby the sum can also have only one summand. The cylinder jacket-shaped guide bores 90 in the flange plate 43 and the guide ring 89 have only a small clearance or a radial distance of a few µm, for example 0 to 50 µm, between the radial outer side of the piston rod 14 and the radial inner sides of the guide bores 90 in the radial direction 57. The guide ring 89 can additionally be designed and function as a piston rod seal 89, for example, by being made of plastic rather than metal.This plain bearing of the piston rod 14 on the guide bores 90 is lubricated with lubricating oil carried over from the lubrication chamber 44 due to the clearance or radial clearance. The axial end regions of the guide bores 90 are conical to prevent increased mechanical wear on a sharp edge. Furthermore, the guide bores 90 are essentially aligned at a right angle to the disc-shaped flange plate 43, i.e., a fictitious plane spanned by the disc-shaped flange plate 43, for example, with a deviation of less than 5°, 3°, or 1°. The guide bore 90 in the flange plate 43 serves to guide the piston rod 14.Due to the small clearance or radial distance between the piston rod 14 and the guide bore 90 in the flange plate 43, only a small leakage occurs from the lubrication chamber 44 into the diaphragm interior 61 and vice versa, so that the flange plate 43 also assumes a sealing function between the diaphragm interior 61 and the lubrication chamber 44.

[0081] The cylinder head 17 is designed with a centering geometry 91 as a centering projection 93 for alignment in the radial direction 57. The cylinder housing 8 is designed with a counter-centering geometry 92 as a centering recess 94. A radial outer side 91 of the centering projection 93 thus forms the convexly curved centering geometry 91. A radial inner side 92 at the centering recess 94 forms the concavely curved counter-centering geometry 92. The centering geometry 91 and the counter-centering geometry 92 are essentially aligned parallel to one another and parallel to the longitudinal axis 41 of the cylinder 6 and the piston rod 14, in particular with a deviation of less than 5°, 3°, or 1°. The centering geometry 91 and the counter-centering geometry 92 are formed completely circumferentially in the tangential direction 58 or circumferential direction 58. The centering geometry 91 and the counter-centering geometry 92 have a contact with each other completely circumferentially, ieThe centering geometry 91 rests on a contact surface on the counter-centering geometry 92. This centers the cylinder head 17 with respect to the cylinder 6 and the cylinder housing 8, and vice versa.

[0082] The cylinder housing 8 is centered with respect to the flange plate 43 using a centering geometry 91 and a counter-centering geometry 92, and vice versa, as described above. For this purpose, an axial end region on the cylinder housing 8 forms a centering projection 93. A radial outer side 92 of the centering projection 93 forms a counter-centering geometry 92. A large centering recess 94 is formed on the flange plate 43, so that a remaining circumferential ring delimiting the centering recess 94 forms a centering geometry 91 on a radial inner side 91.

[0083] The housing 45 is centered with a centering geometry 91 and a counter-centering geometry 92 relative to the flange plate 43, and vice versa, analogously as described above. For this purpose, an axial end region of the housing 45 forms a centering projection 93. A radial inner side 91 of the centering projection 93 forms a centering geometry 91. A large centering recess 94 is formed on the flange plate 43, so that a remaining ring, which borders the centering recess 94 and completely surrounds it in the circumferential direction 58 or tangential direction 58, forms a counter-centering geometry 92 on a radial outer side 92. The flange plate 43 thus indirectly functions to center the cylinder housing 8 relative to the housing 45 for the lubrication chamber 44 and the mechanism 40.

[0084] In addition, a centering geometry 91 is formed on the cylinder housing 8 as a radial inner side on a centering recess 93 ( Fig. 4). A radial outer side of the sealing ring 46 and the fastening ring 47 as fastening element 49 forms a counter-centering geometry 92 for aligning in the radial direction 57 of the fastening element 49 with respect to the cylinder housing 8.

[0085] Thus, centering geometries 91 and counter-centering geometries 92 are formed on the components 8, 17, 42, 45, 46, 47, 49 for positive centering as a radial alignment of the components 8, 17, 42, 45, 46, 47, 49 to one another. The term "centering" thus means a, in particular radial, alignment of the components 8, 17, 42, 45, 46, 47, 49 to one another. The centering geometry 91 and the counter-centering geometry 92 can also be formed by at least one centering pin and at least one counter-centering bore, in which at least one centering pin is arranged in at least one counter-centering bore (not shown).

[0086] The relevant axial extension 48 of the bellows 34 in the direction of the longitudinal axis 41, ie the area of ​​the diaphragm 34 which absorbs the stroke movements of the piston 5 between the top and bottom dead center, is significantly greater than the stroke height of the piston 5 than the difference between the top and bottom dead center of the piston 5. The extension 48 is, for example, 100 mm to 150 mm and the stroke height of the piston 5 is preferably 10 mm, but a maximum of 50 mm. Fig. In Figure 1, the extension 48 and the stroke height of the piston 5 are not drawn to scale for graphic reasons. Thus, the mechanical stress for the deformation of the diaphragm 34 is low because a slight axial deformation occurs per unit length of the bellows 34 of the extension 48. The diaphragm 34 can therefore be designed not only as a bellows 34 in this relevant area with the extension 48, but also as a simple diaphragm 34 without folding. Due to this slight deformation of the diaphragm 34 in this relevant area with the extension 48, the diaphragm 34 has a service life that corresponds at least to the service life of the rest of the piston compressor 1. Due to the small stroke height of the piston 5 and the large extension 48 of the diaphragm 34, the axial extension of the piston guide 7 is significantly smaller than the axial extension of the cylinder housing 8. The diaphragm 34 is arranged completely in the cylinder housing 8.For example, the axial extension of the piston guide 7 is less than 70%, 50%, 30%, or 10% of the axial extension of the cylinder housing 8. The piston rod 14 must be designed to be kink-resistant, for example, by the axial extension of the piston rod 14 being at least 5 times, 10 times, or 15 times greater than the diameter of the piston rod 14 outside the stop ring 64. The diameter of the piston rod 14 outside the stop ring 64 is, for example, less than 10 mm, e.g., 9 mm or 8 mm. The piston 5 and the piston guide 7 have, for example, a diameter between 10 mm and 50 mm, preferably between 20 mm and 40 mm.

[0087] In Fig. 6 shows a compressor system 65 with the piston compressor 1 described above. The compressor system 66 has in the Fig. 6 illustrated embodiment has only one piston compressor 1, but can also be designed with several piston compressors 1 and / or with one piston compressor 1 with several cylinders 6 and several pistons 5. The piston compressor 1 in Fig. 6 is shown in a highly simplified and schematic manner. The compressor system 66 comprises a container 66 with gas to be compressed, a container 67 with the compressed gas, and a lubricating oil container 81. The gas to be compressed is fed to the piston compressor 1 through a suction line 68, and the compressed gas is fed to the container 67 through a pressure line 69. The membrane outer space 62 is fluidly connected to the suction line 68 by a leakage return line 70 and thus also fluidly connected to the inlet valve 19 and the inlet channel 22 of the piston compressor 1, and also fluidly connected to the container 66. The leakage return line 70 is connected through a leakage bore 103 ( Fig. 5) in the cylinder housing 8 is connected to the diaphragm outer space 62. The gap seal between the piston guide 7 on the cylinder 6 and the piston 5 with the piston rings 16 is not completely tight, so that the gas to be compressed enters the diaphragm outer space 62 and this leakage of the gas to be compressed is fed back to the suction line 68, i.e. is reused and not discharged unused into the environment. A throttle 71 acting as a constriction limits the volume flow of leakage gas passed through the leakage return line 70. A pressure sensor 74 monitors the pressure in the diaphragm outer space 62. A pressure sensor 72 monitors the pressure in the suction line 68. A pressure sensor 73 monitors the pressure in the pressure line 69. A shut-off device 75, in particular a valve 75, can reduce the flow of the gas to be compressed from the container 66 to the piston compressor 1 or can also completely close it off.A shut-off device 76, in particular a valve 76, in the pressure line 69 can reduce or completely close off the flow of the compressing gas from the piston compressor 1 into the container 67.

[0088] The lubrication chamber 44 of the piston compressor 1 is sealed from the environment, and lubricating oil in the lubricating oil reservoir 81 is pumped by a conveying device 79, in particular a gear pump 80, through a lubricating oil line 77 from the lubricating oil reservoir 81 into the lubrication chamber 44. A throttle channel 84 with a small flow cross-sectional area is formed from the lubrication chamber 44 into the diaphragm interior 61. A drain channel 85 with a significantly larger flow cross-sectional area than in the throttle channel 84 is formed from the diaphragm interior 61 to a lubricating oil line 78. The flow cross-sectional area of ​​the drain channel 85 is, for example, at least 2, 3, or 5 times larger than the flow cross-sectional area of ​​the throttle channel 84.The lubricating oil conducted by the throttle channel 84 from the lubrication chamber 44 into the diaphragm interior 61 is conducted through the drain channel 85 and the lubricating oil line 78 back into the lubricating oil reservoir 81. This creates a lubricating oil circuit that not only lubricates the mechanism 40 in the lubrication chamber 44, but also cools it and additionally lubricates the diaphragm interior 61. Due to the conduction of the lubricating oil in the lubricating oil circuit to the outside of the piston compressor 1, additional heat can be released from the lubricating oil to the environment, for example, via the lubricating oil lines 77, 78 and the lubricating oil reservoir 81. Optionally, an additional heat exchanger, preferably with a fan for ambient air, can be installed or integrated into the lubricating oil circuit as an oil cooler (not shown). The pressure in the lubricating oil chamber 44 is higher than in the environment, for example, a pressure between 2 and 5 bar.The lubricating oil tank 81 is essentially at ambient pressure of 1 bar due to a vent valve 83 that connects the lubricating oil tank 81 to the environment. As a safety measure, the pressure in the lubricating oil tank 81 is monitored by a pressure sensor 82. The pressure sensors 72, 73, 74, and 82 are connected to a control and / or regulating unit (not shown) via data lines (not shown). The control and / or regulating unit records the pressures detected by the pressure sensors 72, 73, 74, and / or 82 and, depending on the detected pressures, can trigger an error message and / or shutdown of the compressor system 65. The pressure sensors 72, 73, 74, and / or 82 can additionally and / or exclusively comprise a display device for visually displaying the pressure. The visual pressure display also allows a user of the compressor system 65 to manually monitor the correct pressure.The lubrication chamber 44 and the membrane interior 61 are thus lubricated and cooled by a lubrication system 104 of the compressor system 65.

[0089] The compressor system 65 comprises a base frame 95 or a base element 95, preferably made of metal, for securing the essential components of the compressor system 65. The base frame 95 or the base element 95 rests on the floor or subsurface. The container 66 containing the gas to be compressed, the container 67 containing the high-pressure gas to be compressed, the lubricating oil container 81, and the piston compressor 1 are attached to the base frame 95 or base element 96. The essential components 1, 66, 67, 81 are each secured to the common base frame 95 with separate retaining elements 96. The retaining elements 96 are components of the base frame 95.

[0090] In the Fig. 5, two piston compressors 1 with two pistons 5 and two cylinder housings 8, a mounting bracket 97 is fixed to each cylinder housing 8. In the mounting bracket 97, a connecting bore 99 (not shown) is formed at each end region. The two mounting brackets 97 are connected to each other by a connecting bracket 98. At each end region of the connecting bracket 98, a connecting bore 99 (not shown) is formed, and this connecting bore 99 is aligned with the connecting bores 99 on the mounting bracket 97. In each of these aligned connecting bores 99, a connecting means 100 is arranged in the form of a screw 101 or a rivet. The two cylinder housings 8 are thus connected to each other in a form-fitting and preferably force-fitting manner. The housing 45 for the two pistons 5 and two cylinder housings 8 is, as shown in Fig. 5 is fastened to the base frame 95 by means of the holding element 96. In addition, the connecting bore 99 is formed centrally in the connecting piece 98 and a further connecting piece 98 (not shown) is fastened to this connecting bore 99 on the base frame 95 or base element 95. The mechanical stresses and the forces to be transmitted to the cylinder housing 8 and to the flange plate 43 as well as the housing 45 can be reduced because, due to the connecting piece 98, the two cylinder housings 8 are firmly connected to one another and thus the rigidity is increased and, in addition, with the connecting piece 98 (not shown), the Fig. 5 is fixed to the base frame 95 or the base element 95 by the connecting piece 98 shown. Thus, at least one cylinder housing 8 is fastened to the base frame 95 by at least one connecting piece 98.

[0091] Overall, the piston compressor 1 according to the invention and the compressor system 65 according to the invention offer significant advantages. The diaphragm 34, as the bellows 34, enables the complete hermetic separation of the lubrication chamber 44 containing the lubricant from the compression chamber 29. The piston compressor 1 can thus compress gases, such as hydrogen or oxygen, with high purity requirements. The additional costs for the formation of the diaphragm 34 in the piston compressor 1 are low, so that the piston compressor 1 is advantageously inexpensive to manufacture and requires little installation space.

[0092] An end region of the diaphragm 34 facing away from the compression chamber 29 is indirectly fastened to the rest of the piston compressor 1 by means of the fastening element 49, which is the fastening ring 47. The assembly and disassembly of the piston compressor 1 is thus significantly simplified because the diaphragm 34 with fastening element 49 can already be manufactured by a supplier, and during assembly, only the fastening ring 47 needs to be fastened with the clamp connection. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] EP 0 541 482 B1

[0004] DE 2020699 A1

[0005]

Claims

[1] Piston compressor (1) for compressing gases, comprising - at least one cylinder (6), - at least one piston (5) which is mounted in a respective cylinder (6) of a respective cylinder housing (8), so that each piston (5) and each cylinder (6) define a compression chamber (29) for compressing the gas, - one inlet valve (19) for each compression chamber (29), - an outlet valve (20) for each compression chamber (29), - at least one mechanism (40) with which the at least one piston (5) is in mechanical operative connection for an oscillating movement of the at least one piston (5), - at least one lubricating chamber (44) in which the at least one mechanism (40) is at least partially arranged and the at least one mechanism (40) in the at least one lubricating chamber (44) can be lubricated with a lubricant, - a housing (45) for defining the lubrication chamber (44), - at least one membrane (34) and with the at least one membrane (34) each lubrication chamber (44) is separated from each compression chamber (29), characterized by that an end region of each membrane (34) facing away from the compression chamber (29) is indirectly fastened to the rest of the piston compressor (1) by means of a fastening element (49). [2] Piston compressor according to claim 1, characterized by that the fastening element (49) is designed as a sealing ring (46) and / or fastening ring (47). [3] Piston compressor according to claim 2, characterized by that the sealing ring (46) and / or fastening ring (47) comprises a first ring (59) with an extension substantially in the axial direction (56) and a second ring (60) with an extension substantially in the radial direction (60). [4] Piston compressor according to one or more of the preceding claims, characterized bythat the end region facing away from the compression chamber (29), in particular the end of each membrane (34) is fastened to the fastening element (49) by means of a material-locking connection (52, 53) and / or a force-locking connection and / or a form-locking connection. [5] Piston compressor according to one or more of the preceding claims, characterized by that the end region facing away from the compression chamber (29), in particular the end of each membrane (34) is fastened in a fluid-tight manner to the fastening element (49). [6] Piston compressor according to one or more of the preceding claims, characterized by that the fastening element (49) is fastened to the rest of the piston compressor (1) with a positive connection and / or non-positive connection. [7] Piston compressor according to one or more of the preceding claims, characterized bythat the fastening element (49) is fastened to the rest of the piston compressor (1) by means of a clamping connection between two fastening components (8, 43, 50). [8] Piston compressor according to claim 7, characterized by that the two fastening components (50) are the cylinder housing (8) and a flange plate (43). [9] Piston compressor according to one or more of claims 4 to 8, characterized by that the connection between each membrane (34) and the fastening element (49) is designed to be completely circumferential in the circumferential direction. [10] Piston compressor according to one or more of the preceding claims, characterized bythat the components (8, 17, 42, 43, 45, 46, 49) of the piston compressor (1) are sealed against one another with at least one seal (54) and the components (8, 17, 42, 43, 45, 46, 49) are the cylinder housing (8) and / or a cylinder head (17) and / or a flange plate (43) and / or a housing (45) for a lubrication chamber (44) and / or the fastening element (47). [11] Piston compressor according to one or more of the preceding claims, characterized by that the at least one membrane (34) is designed as at least one bellows (34). [12] Piston compressor according to one or more of the preceding claims, characterized by that each membrane (34) divides the cylinder subspace delimited by a cylinder (6), a piston (5) and preferably a flange plate (43), in particular in the radial direction (57), into a membrane interior space (61) and a membrane exterior space (62). [13] Piston compressor according to one or more of the preceding claims, characterized by that the stroke height of each piston (5) between the top and bottom dead center of the piston (5) is less than 30%, 10%, 5% or 3% of the extension (48) of the at least one membrane (34), in particular of the at least one bellows (34), relevant for the stroke movement, in the direction of a longitudinal axis (41) of the cylinder (6). [14] Piston compressor system (65) for compressing gases, comprising - a piston compressor (1) with at least one piston (5) and with at least one mechanism (40) with which the at least one piston (40) is in mechanical operative connection for an oscillating movement of the at least one piston (5), - a lubrication system (104) with at least one lubricating oil line (77, 78), a lubricating oil tank (81) and a conveying device (79, 80) for lubricating oil for lubricating the at least one mechanism (40) arranged in a lubrication chamber (44), - a drive motor for the piston compressor (1), - a container (66) containing the gas to be compressed, - a container (67) containing the compressed gas, characterized by that the piston compressor (1) is designed according to one or more of the preceding claims. [15] Piston compressor system according to claim 14, characterized by that a throttle channel (84) is formed from the lubricating chamber (44) into the membrane interior (61) for conducting lubricating oil into the membrane interior (61) and that a drain channel (85) is formed from the membrane interior (61) into the lubricating oil line (78) for conducting lubricating oil from the membrane interior (61) into the lubricating oil line (78) and / or into the lubricating oil container (81).

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