Compressor and method for compressing a working medium

Abstract

Compressor (1) and method for compressing a working medium, comprising the steps: - moving of a drive piston (2) which is driven by way of a driving medium within a first cylinder (3) between a first end position and a second end position; - moving of a high pressure piston (7) which compresses the working medium within a second cylinder (8) between a first end position and a second end position, - arranging of a high pressure seal (11) for sealing the high pressure piston (7); - arranging of a magazine (10) with a receptacle (IIa) for the high pressure seal (11) and with at least one replacement high pressure seal (12) in a first operating position, in which the high pressure piston (7) is sealed by way of the high pressure seal (11); - transferring of the magazine (10) from the first operating position into a second operating position, in which the high pressure piston (7) is sealed by way of the replacement high pressure seal (12).

Description

[0001] Compressors and methods for compressing a working medium

[0002] The invention relates to a method according to the preamble of claim 1 and a compressor according to the preamble of claim 9.

[0003] Compressors of this type are known in the prior art in a wide variety of designs (see, for example, US 4,104,008 A).

[0004] US Patent 4,104,008 A discloses a pneumatically operated hydraulic pump comprising a working chamber and a pneumatic piston, the pneumatic piston being connected to a hydraulic piston. Compressed air is supplied to the pneumatic piston by means of an auxiliary slide valve, which is sealed against the working chamber, and a control slide valve, to move the pneumatic piston against the spring force of a helical compression spring. The movement of the pneumatic piston moves the hydraulic piston in a hydraulic cylinder onto which a valve body is mounted, serving to connect hydraulic lines.

[0005] US Patent 2015 / 101679 A1 discloses a high-pressure fluid system with improved safety, maintenance, and service features, comprising a housing, a valve seat assembly, a lubrication flow path, and an adjustable valve. The adjustable valve is designed to control the flow of pump fluid from the valve seat assembly to the sealing assembly.

[0006] DE 197 10 717 A1 discloses a high-pressure device comprising drive means and pressure-generating means that can be actuated by the drive means for pressure generation in a pressure fluid. The drive means and the pressure-generating means are detachably connected to each other by a frame arrangement.

[0007] In a reciprocating compressor, the volume to be compressed must be sealed against the cylinder tube. Ideally, the seals have negligible leakage. However, should a leakage occur due to wear or damage, it is detected according to current best practices, and the seals are replaced. For this purpose, the compressor is stopped, and if necessary, a redundant compressor is used. A service technician is then called in to replace the seals on-site.

[0008] This service call is usually unpredictable and results in additional travel time and therefore high costs. Furthermore, the operator must expect downtime or provide a backup system. The latter, however, leads to higher acquisition costs.

[0009] Replacing the seals currently usually involves the following steps:

[0010] - Relieve pressure on the compressor and its attachments.

[0011] - With highly flammable gases, such as molecular hydrogen, the compressor must be purged with an inert gas (e.g., nitrogen) before opening. This process can take a considerable amount of time, depending on the volume.

[0012] - Removal of all attachments in order to remove the seal.

[0013] - Removal of the old seal, installation of the new seal (depending on the installation method and diameter, seals may need to be calibrated or heated before installation).

[0014] - Assembly of all attachments.

[0015] - When dealing with highly flammable gases, the system must be purged with an inert gas (e.g., nitrogen) before introducing the working medium. This process can take a considerable amount of time, depending on the volume.

[0016] - Apply pressure and perform leak tests.

[0017] Accordingly, the object of the invention is to alleviate or eliminate at least some disadvantages of the prior art. In particular, the invention aims to make the replacement of the high-pressure seal simpler, faster, and more cost-effective.

[0018] This problem is solved by a method having the features of claim 1 and a compressor having the features of claim 9. Preferred embodiments are specified in the dependent claims.

[0019] The inventive method for compressing a preferably gaseous working medium therefore comprises at least the following steps:

[0020] - Moving an object driven by a drive medium

[0021] drive piston within a first cylinder between a first end position and a second end position;

[0022] - Moving a high-pressure piston that compresses the working medium within a second cylinder between a first end position and a second end position,

[0023] - Arranging a high-pressure seal to seal the high

[0024] pressure piston;

[0025] - Arranging a magazine with a recording for the high

[0026] pressure seal and with at least one spare high-pressure seal in a first operating position in which the high-pressure piston is sealed by the high-pressure seal;

[0027] - Transferring the magazine from the first operating position to a second operating position, in which the high-pressure piston is sealed by the replacement high-pressure seal.

[0028] The compressor according to the invention has at least the following characteristics:

[0029] - a drive piston within a first cylinder that can be actuated by a drive medium, wherein the drive piston is movable between a first end position and a second end position;

[0030] - a high-pressure piston within a second cylinder for compressing the working medium, wherein the high-pressure piston is movable between a first end position and a second end position; a high-pressure seal for sealing the high-pressure piston;

[0031] - a magazine with a holder for the high-pressure seal and with at least one spare high-pressure seal;

[0032] - a changing device with a drive for transferring the magazine between a first operating position for sealing the high-pressure piston by the high-pressure seal and a second operating position for sealing the high-pressure piston by the replacement high-pressure seal.

[0033] Advantageously, this significantly simplifies seal replacement. In many cases, a service technician is not required for seal replacement. The compressor can remain operational or ready for use during the seal replacement. According to the invention, at least one spare high-pressure seal is arranged on the magazine. If the high-pressure seal can no longer guarantee a seal against the high-pressure piston due to wear or damage, the replacement device is activated such that the magazine is moved from the first operating position to the second operating position. In doing so, the high-pressure seal is moved from a functional position sealing the high-pressure piston to a standby position away from the high-pressure piston.Conversely, the replacement high-pressure seal is moved from a standby position away from the high-pressure piston to a functional position adjacent to the high-pressure piston, in which the high-pressure piston is sealed in the second cylinder via the replacement high-pressure seal. In the first and second operating positions, the high-pressure piston is fixedly or detachably connected to the drive piston, so that the high-pressure piston is driven by the drive piston. Preferably, the drive piston and the high-pressure piston are designed as pressure intensifiers (pressure converters), whereby a lower pressure of the drive medium is converted into a higher pressure of the working medium. When all (replacement) high-pressure seals are worn, the magazine can either be replaced entirely with a corresponding magazine containing unused (replacement) high-pressure seals, or new (replacement) high-pressure seals can simply be inserted into the magazine.The magazine can have a corresponding access opening for this purpose. Replacing the magazines on-site is quick and easy. Calibration and the installation of the (replacement) high-pressure seals advantageously do not need to be done on-site, but can be prepared in advance. Service calls for seal replacement can therefore be planned.

[0034] For the purposes of this disclosure, directional terms such as "axial", "radial" refer to the central axis of the high-pressure piston.

[0035] Various design options are provided for transferring the magazine from the first operating position to the second operating position.

[0036] In one version of the design, the following steps are performed to transfer the magazine from the first operating position to the second operating position:

[0037] - Shifting the magazine, including the high-pressure seal arranged in the receiver, relative to the second cylinder, essentially in the direction of the central axis of the high-pressure piston, from the first operating position to a first intermediate position that releases the high-pressure seal from the high-pressure piston;

[0038] - Transferring the magazine from the first intermediate position to a second intermediate position in which the replacement high-pressure seal is essentially coaxial with the high-pressure piston; and

[0039] - Moving the magazine, including the replacement high-pressure seal, essentially in the direction of the central axis of the high-pressure piston from the second intermediate position to the second operating position.

[0040] In this embodiment, the magazine is axially displaceable to allow the high-pressure seal to be removed from the high-pressure piston. The second cylinder, however, can be fixed axially. In the first operating position, the high-pressure seal rests against the outer circumference of the high-pressure piston to seal its reciprocating movement. By actuating the changeover device, the magazine can be moved axially in one direction to the first intermediate position, in which the high-pressure seal, viewed along the central axis of the high-pressure piston, is located outside the piston. The magazine is then moved to the second intermediate position, in which the central axes of the replacement high-pressure seal and the high-pressure piston are essentially collinear. Finally, the magazine is moved axially in the other direction to position the replacement high-pressure seal sealingly on the high-pressure piston.

[0041] In this design variant, moving the magazine from the first operating position to the first intermediate position preferably comprises the following steps:

[0042] - Detaching the high-pressure piston from the drive piston,

[0043] - Arranging the drive piston and the high-pressure piston at a distance from each other and

[0044] - Moving the magazine from the first operating position essentially in the direction of the central axis of the high-pressure piston, so that the high-pressure seal is positioned between the high-pressure piston and the drive piston in the first intermediate position, viewed in the direction of the central axis of the drive piston.

[0045] After reaching the second operating position of the magazine, the high-pressure piston can again be coupled with the drive piston to continue the compression of the working medium.

[0046] In this design variant, it is advantageous if the high-pressure piston is immobilized by a magnetic element in the direction of the central axis when the drive piston and the high-pressure piston are moved away from each other.

[0047] In a second design variant, the following steps are performed to transfer the magazine from the first operating position to the second operating position:

[0048] - Moving the magazine together with the high-pressure seal arranged in the receiver, along with the second cylinder, essentially in the direction of the central axis of the high-pressure piston away from the drive piston from the first operating position to a first intermediate position that releases the high-pressure seal from the high-pressure piston;

[0049] - Transferring the magazine from the first intermediate position to a second intermediate position in which the replacement high-pressure seal is essentially coaxial with the high-pressure piston; and

[0050] - Moving the magazine together with the replacement high-pressure seal, along with the second cylinder, essentially in the direction of the central axis of the high-pressure piston towards the drive piston, from the second intermediate position to the second operating position.

[0051] In the first operating position, the high-pressure seal sits tightly on the high-pressure piston. To release the high-pressure seal from the high-pressure piston, the magazine, together with the second cylinder, can be moved axially in one direction to the first intermediate position, in which the sealing contact between the high-pressure piston and the high-pressure seal is released. Preferably, in the first intermediate position, the high-pressure seal on the magazine is pushed axially beyond one end of the high-pressure piston, so that the high-pressure seal is located axially outside the high-pressure piston. The magazine can then be moved to the second intermediate position, which prepares the arrangement of the replacement high-pressure seal. Finally, the magazine, together with the second cylinder, can be moved axially in the other direction to seat the replacement high-pressure seal on the magazine, sealing it tightly on the piston.

[0052] to arrange high-pressure pistons.

[0053] In a third design variant, the following steps are performed to transfer the magazine from the first operating position to the second operating position:

[0054] - Moving the high-pressure piston essentially in the direction of the central axis of the high-pressure piston away from the magazine together with the high-pressure seal arranged in the receptacle, until the high-pressure seal is released from the high-pressure piston, so that the magazine is arranged in a first intermediate position;

[0055] - Transferring the magazine from the first intermediate position to a second intermediate position in which the replacement high-pressure seal is essentially coaxial with the high-pressure piston; and

[0056] - Moving the high-pressure piston essentially in the direction of the central axis of the high-pressure piston towards the magazine until the replacement high-pressure seal is positioned on the high-pressure piston.

[0057] In this design variant, the magazine and the second cylinder for the high-pressure piston can be fixed in place when replacing the high-pressure seal. Instead, the high-pressure piston can be pushed out of the high-pressure seal on the magazine, thus releasing the magazine's movement into the second intermediate position. For this purpose, the high-pressure piston can be shifted beyond the first or second end position. Advantageously, this is achieved by reducing the pressure in a pressure chamber on the side of the drive piston opposite the high-pressure piston, compared to the first operating position. After replacing the high-pressure seal, the pressure in the pressure chamber can be increased again to the level of the first operating position, so that the drive piston's movement in the second operating position is limited to the first and second end positions.

[0058] Preferably, the pressure chamber is formed between a first piston element of the drive piston and a second piston element of the drive piston. The first and second piston elements can be connected to each other via a connecting element, in particular a connecting rod, which provides a maximum distance between the first and second piston elements in the first and second operating positions, respectively, and a minimum distance between the first and second piston elements in the first intermediate position.

[0059] In a fourth design variant, the following steps are performed to transfer the magazine from the first operating position to the second operating position:

[0060] - Displacing the high-pressure seal from a position arranged outside the receptacle, as seen in the direction of the central axis of the high-pressure piston, to a position arranged in the receptacle, wherein the replacement high-pressure seal is arranged in a further receptacle of the magazine, so that the magazine is arranged in a first intermediate position;

[0061] - Transferring the magazine from the first intermediate position to a second intermediate position in which the replacement high-pressure seal is essentially coaxial with the high-pressure piston; and

[0062] - Moving the replacement high-pressure seal from the position located in the further recess of the magazine to a position located outside the further recess of the magazine, as seen in the direction of the central axis of the high-pressure piston.

[0063] In the first, second, and third embodiments described above, the high-pressure seal is located within the magazine's receptacle in the first and second operating positions when the working medium is compressed. In the fourth embodiment, the magazine's receptacle is free of the high-pressure seal in the first operating position. In the second operating position, the receptacle is free of the substitute high-pressure seal. Therefore, in the first operating position, the high-pressure seal is located outside the magazine's receptacle when viewed axially. In the second operating position, the substitute high-pressure seal is located outside the magazine's receptacle when viewed axially.When replacing the high-pressure seal, the new seal can first be inserted into the receptacle on the magazine before the magazine, along with the replacement seal, is moved to the second intermediate position for inserting the new seal. Finally, the replacement seal is pushed out of the receptacle to position it in the second operating position. During compressor operation, one of the receptacles on the magazine is therefore always empty to accommodate a worn high-pressure seal during the replacement process.

[0064] In the fourth embodiment, the high-pressure seal and the backup high-pressure seal are preferably moved together with the second cylinder. In this embodiment, it is particularly advantageous if the high-pressure seal and the backup high-pressure seal each have essentially the same inner and outer diameter as the second cylinder. Preferably, in the first operating position, the high-pressure seal is arranged adjacent to an axial end region of the second cylinder. In the second operating position, the backup high-pressure seal is arranged adjacent to the axial end region of the second cylinder. Furthermore, it is preferred if the high-pressure seal, viewed axially, is arranged between the second cylinder and a pressure element. The pressure element is mounted so as to be axially displaceable by means of the exchange device.To move the high-pressure seal from outside the receptacle into the receptacle, the pressure element is axially shifted in one direction via the changeover device, so that the high-pressure seal is moved together with the second cylinder. Correspondingly, the second cylinder is moved in the other direction to push the replacement high-pressure seal out of the receptacle. The pressure element is carried along with it. The movement of the pressure element in one direction and the movement of the second cylinder in the other direction is effected by the drive, for example, a pneumatic drive, of the changeover device.

[0065] In each of the previously described design variants, the magazine can be pivoted, on the one hand, about a pivot axis running essentially parallel to the central axis of the high-pressure piston, or on the other hand, it can be moved essentially in a direction perpendicular to the central axis of the high-pressure piston, to transfer it from the first intermediate position to the second intermediate position.

[0066] According to a preferred embodiment, a sensor device is provided for detecting a leakage of the working medium. The sensor device can be designed according to the prior art. For example, a pressure increase in a normally unpressurized leakage line can be detected in conjunction with the high-pressure seal. Furthermore, a gas measurement can be performed in the leakage line.

[0067] Preferably, a control device is connected on the one hand to the sensor device and on the other hand to the changing device in order to transfer the magazine from the first operating position to the second operating position when a leakage of the working medium is detected.

[0068] In a first preferred embodiment, the changeover device for transferring the magazine from the first operating position to a first intermediate position is designed to move the magazine, together with the high-pressure seal arranged in the receptacle, essentially in the direction of the central axis of the high-pressure piston relative to the second cylinder.

[0069] In the first embodiment, a clamping device is preferably provided for the detachable coupling of the high-pressure piston to the drive piston. In the coupled state, the high-pressure piston moves together with the drive piston. In the released state, the high-pressure piston is decoupled from the movement of the drive piston. In other embodiments, the drive piston and the high-pressure piston can be permanently connected.

[0070] To create space for replacing the high-pressure seal in this variant, it is advantageous if the high-pressure piston is arranged in the first intermediate position of the magazine in a state detached from and spaced apart from the drive piston. It is particularly preferred if, in the first intermediate position of the magazine, the high-pressure piston is in its first end position and the drive piston is in its second end position, which is further away from it. In this embodiment, the high-pressure piston and the drive piston are maximally separated in the first intermediate position, so that sufficient space is available to remove the high-pressure seal. To allow the high-pressure piston to be positioned at a distance from the drive piston in preparation for seal replacement, a magnetic element is preferably provided to fix the high-pressure piston in the first end position, detached from the drive piston.

[0071] In a second preferred embodiment, the changeover device for transferring the magazine from the first operating position to a first intermediate position is designed to move the magazine together with the second cylinder essentially in the direction of the central axis of the high-pressure piston.

[0072] In a third preferred embodiment, the changeover device for transferring the magazine from the first operating position to a first intermediate position is configured to move the high-pressure piston essentially in the direction of the central axis of the high-pressure piston beyond the first or second end position.

[0073] In a fourth preferred embodiment, the changeover device for transferring the magazine from the first operating position to a first intermediate position is configured to move the second cylinder substantially in the direction of the central axis of the high-pressure piston in order to move the high-pressure seal from a position axially outside the receptacle to a position within the receptacle. Furthermore, the changeover device is preferably configured to transfer the magazine from the first intermediate position to a second intermediate position in which the substitute high-pressure seal is arranged substantially coaxially with the high-pressure piston. Accordingly, the central axes of the substitute high-pressure seal and the high-pressure piston are substantially co-linearly aligned in the second intermediate position. In the second intermediate position, the substitute high-pressure seal is located, viewed axially, outside the high-pressure piston.By means of an axial relative movement between the replacement high-pressure seal and the high-pressure piston, the second operating position can be reached, in which the high-pressure piston is sealed by the replacement high-pressure seal.

[0074] In the first preferred embodiment described above, the changing device for transferring the magazine from the second intermediate position to the second operating position is preferably designed to move the magazine, including the replacement high-pressure seal arranged in the receptacle, essentially in the direction of the central axis of the high-pressure piston relative to the second cylinder.

[0075] In the second preferred embodiment described above, the changing device for transferring the magazine from the second intermediate position to the second operating position is preferably designed to move the magazine together with the second cylinder essentially in the direction of the central axis of the high-pressure piston.

[0076] In the third preferred embodiment described above, the changing device for transferring the magazine from the second intermediate position to the second operating position is preferably designed to move the high-pressure piston essentially in the direction of the central axis of the high-pressure piston back into the first or second end position.

[0077] In the fourth preferred embodiment described above, the changing device for transferring the magazine from the second intermediate position to the second operating position is preferably configured to move the second cylinder essentially in the direction of the central axis of the high-pressure piston in order to move the replacement high-pressure seal from a position arranged in a further receptacle of the magazine to a position arranged axially outside the receptacle.

[0078] According to a preferred embodiment, a gaseous working medium, in particular molecular hydrogen, is compressed.

[0079] According to a preferred embodiment, the drive piston is operated with a drive medium different from the working medium, preferably gaseous, in particular air.

[0080] To move the high-pressure seal away from the high-pressure piston and instead position the replacement high-pressure seal adjacent to the high-pressure piston, the exchange device in a preferred embodiment is configured to pivot the magazine about a pivot axis running essentially parallel to the central axis of the high-pressure piston between the first intermediate position and the second intermediate position. In this embodiment, the magazine can be pivoted such that the replacement high-pressure seal is moved from a waiting position away from the high-pressure piston to a position collinear with the high-pressure piston.

[0081] In another preferred embodiment, the changing device for moving the magazine is arranged essentially in a direction perpendicular to the central axis of the high-pressure piston between the first intermediate position and the second intermediate position. In this embodiment, the magazine is essentially displaceable in a radial direction in order to move the replacement high-pressure seal from the waiting position away from the high-pressure piston to the position arranged coaxially with the high-pressure piston.

[0082] According to a preferred embodiment, the high-pressure seal and the spare high-pressure seal each have a housing in which at least one sealing element, preferably detachably, is arranged. This design facilitates the arrangement of unused sealing elements in the magazine once the sealing elements of the high-pressure seal and spare high-pressure seal have worn out. The sealing element is preferably circumferential and extends over the entire circumference of the high-pressure piston.

[0083] According to a preferred embodiment, the high-pressure seal and the substitute high-pressure seal each have a first sealing element for sealing a high-pressure side and a second sealing element for sealing a low-pressure side. The first sealing element is located on the side of the high-pressure piston, and the second sealing element is located on the side of the drive or low-pressure piston.

[0084] Furthermore, it is advantageous if the high-pressure seal and the replacement high-pressure seal each have a bearing element, in particular a guide band, a radial plain bearing or a recirculating ball bearing, for supporting the high-pressure piston. The bearing element preferably extends over the entire circumference of the high-pressure piston.

[0085] To enable long operating times of the compressor without maintenance intervals, the magazine preferably has several spare high-pressure seals, with preferably between 2 and 7 spare high-pressure seals being provided.

[0086] Depending on the design, the drive for transferring the magazine between the first operating position and the second operating position preferably has at least one linear and / or rotary drive, in particular an electric, hydraulic or pneumatic drive.

[0087] The previously described magazine with the interchangeable device can be used with different compressor types.

[0088] In a preferred embodiment, a single-acting drive piston is provided.

[0089] Another preferred embodiment is characterized by

[0090] - another high-pressure piston on the side of the drive piston facing away from the high-pressure piston;

[0091] - another magazine with a receiving element for a further high-pressure seal for sealing the further high-pressure piston in a first operating state of the further magazine and with at least one further replacement high-pressure seal for sealing the further high-pressure piston in a second operating state of the further magazine;

[0092] - another changing device for transferring the additional magazine between the first operating position and the second operating position.

[0093] This design therefore incorporates a double-acting drive piston. The high-pressure piston and the second high-pressure piston can be operated in parallel or in stages.

[0094] Replacing the other high-pressure seal and inserting the other replacement high-pressure seal can be done as with the above-described design variants, so that repetitions can be avoided.

[0095] The invention is further explained below with reference to exemplary embodiments shown in the drawings.

[0096] Fig. 1 shows a first embodiment of a compressor according to the invention with a drive piston and a high-pressure piston in a central position, wherein a magazine with a high-pressure seal and a substitute high-pressure seal is arranged in a first operating position.

[0097] Fig. 2 shows the compressor according to Fig. 1, with the drive piston and high-pressure piston arranged in the other end position.

[0098] Fig. 3 shows the compressor according to Fig. 1, 2, wherein the drive piston is moved away from the high-pressure piston after releasing a clamping device, so that a free space is formed between the drive piston and the high-pressure piston.

[0099] Fig. 4 shows the compressor according to Figs. 1 to 3 in a first intermediate position of the magazine, in which the high-pressure seal is shifted into the free space between the drive piston and the high-pressure piston.

[0100] Fig. 5 shows the compressor according to Figs. 1 to 4 in a changeover position after pivoting the magazine from the first intermediate position, with the replacement high-pressure seal arranged next to the high-pressure piston.

[0101] Fig. 6 shows the compressor according to Figs. 1 to 5, with the replacement high-pressure seal pushed onto the high-pressure piston.

[0102] Fig. 7 shows the compressor according to Figs. 1 to 6 in the second operating position, with the high-pressure piston again coupled to the drive piston.

[0103] Figures 8 to 12 each show a second embodiment of the compressor according to the invention with a magazine that is displaceable in the axial and radial direction, wherein Figure 8 represents the first operating position, Figure 9 the first intermediate position, Figure 10 a state between the first and second intermediate positions, Figure 11 the second intermediate position and Figure 12 the transition to the second operating position.

[0104] Figs. 13 and 14 each show a third embodiment of the compressor according to the invention, in which the release of the high-pressure seal from the high-pressure piston is effected by moving the high-pressure piston between the first operating position (see Fig. 13) and a first intermediate position (see Fig. 14).

[0105] Figs. 15 and 16 each show a fourth embodiment of the compressor according to the invention, in which the high-pressure seal is arranged outside a receptacle of the magazine in the first operating position (see Fig. 15) and is pushed into the receptacle by means of the second cylinder (see Fig. 16).

[0106] Figures 1 to 7 show a first embodiment of a compressor 1 for compressing a gaseous working medium, for example, molecular hydrogen. The compressor 1 has a pressure intensifier with a drive piston 2, which is moved back and forth within a first cylinder 3 between a first end position (see Fig. 2) and a second end position (not shown). A gaseous driving medium, in particular compressed air, is used to drive the drive piston 2. The drive piston 2 seals a first volume 4 of the first cylinder 3 against a second volume 6 of the first cylinder 3 by means of a seal 5. Furthermore, a high-pressure piston 7, which compresses the working medium, is provided and is moved back and forth within a second cylinder 8 between a first end position (see Fig. 2) and a second end position (not shown). The high-pressure piston 7 has a smaller piston area than the drive piston 2.The low-pressure piston 2 opens, thus achieving a pressure increase from the low-pressure to the high-pressure side. In the first embodiment, a detachable clamping device 9 is provided to couple the high-pressure piston 7 to the drive piston 2. This clamping device 9 is known per se, so further details are unnecessary. In other embodiments, see Figures 8 to 16, the high-pressure piston 7 can be fixedly connected to the drive piston 2 in order to transmit the movement of the drive piston 2 to the high-pressure piston 7.

[0107] The compressor 1 also has a magazine 10, which is equipped with a receptacle 11a for a high-pressure seal 11 and with at least one further receptacle 12a for a spare high-pressure seal 12. The high-pressure seal 11 seals the high-pressure piston 7 in a first operating position during compression of the working medium. The spare high-pressure seal 12 seals the high-pressure piston 7 in a second, different operating position of the magazine 10 during compression of the working medium. Furthermore, a changeover device 13 is provided for the automatic replacement of the high-pressure seal 11 with the spare high-pressure seal 12. The changeover device 13 has a drive 14 (shown schematically only in Fig. 1) with which – as will be explained in detail below – the magazine 10 can be moved from the first operating position to the second operating position (and vice versa).

[0108] As can be seen schematically in Fig. 1, a sensor device 15 is provided for detecting a leakage of the working fluid. The sensor device 15 is connected to a leakage line 16, in which escaping working fluid (and possibly also escaping drive fluid) can be detected. The sensor device 15 can – as is known in the prior art – include a pressure measuring element for detecting the gas pressure in the leakage line 16. Additionally or alternatively, the sensor device 15 can be configured for qualitative or quantitative gas measurement. Numerous possibilities for this, based on electrical, physical, and / or chemical measurement principles, are known in the prior art, so they will not be discussed in detail here. Furthermore, the compressor 1 has an electronic control device 17, which is connected on one side to the sensor device 15 and on the other side to the changeover device 13.If a leakage of the working medium is detected at the sensor device 15, the drive 14 of the changing device 13 is controlled by the control device 17 in such a way that the magazine 10 is moved from the first operating position to the second operating position in order to arrange the replacement high-pressure seal 12 on the high-pressure piston 7.

[0109] In the embodiment shown, the high-pressure seal 11 and the replacement high-pressure seal 12 each have a housing 18 in which at least one annularly circumferential sealing element 19 is reversibly detachable. In the embodiment shown, the high-pressure seal 11 and the replacement high-pressure seal 12 each have a first annularly circumferential sealing element 19a for sealing a high-pressure side and a second annularly circumferential sealing element 19b for sealing a low-pressure side of the compressor 1. Furthermore, in the embodiment shown, the high-pressure seal 11 and the replacement high-pressure seal 12 each have an annularly circumferential bearing element 20, in the embodiment shown a guide band, for supporting the high-pressure piston 7.

[0110] Depending on the design, the magazine 10 can have several spare high-pressure seals 12. It is often advantageous if the magazine 10 is provided with between 2 and 7 spare high-pressure seals 12.

[0111] The drawing only shows the components of the compressor that are essential for understanding the invention.

[0112] It is clear to those skilled in the art that the compressor typically comprises numerous other components, which are, however, well known in the prior art. In the first embodiment shown in Figures 1 to 7, the magazine 10 is displaceable along a central axis 21 of the high-pressure piston and pivotable about a pivot axis running parallel to and at a distance from it. For this purpose, the drive 14 of the changeover device 13 according to Figures 1 to 7 has a drive rod 14a, which can be displaced longitudinally and pivoted about its own longitudinal axis 14b.

[0113] Figures 1 to 7 illustrate the individual steps involved in changing from the first operating position using the high-pressure seal 11 to the second operating position using the replacement high-pressure seal 12.

[0114] As shown in Figures 1 and 2, the magazine 1 is arranged in the first operating position, in which the high-pressure piston 7 is sealed by the high-pressure seal 11. The high-pressure piston 7 is coupled to the drive piston 2 via the clamping device 9, so that the high-pressure piston 7 and the drive piston 2 can move back and forth synchronously. Figure 1 shows the drive piston 2 and the high-pressure piston 7 each in a central position between their opposite dead centers. Figure 2 shows the drive piston 2 in the first end position and the high-pressure piston 7 in the first end position.

[0115] As shown in Fig. 3, the clamping device 9 is in the released state, with the high-pressure piston 7 decoupled from the drive piston 2. The high-pressure piston 7 is in the first end position and the drive piston 2 is in the second end position, thus achieving maximum axial distance between the high-pressure piston 7 and the drive piston 2. To achieve this state, a magnetic element can be provided which holds the high-pressure piston 7 in the first end position, released from the drive piston 2. A permanent magnet 22a or a magnetic coil 22b can be provided as the magnetic element. In the embodiment shown, the magnetic coil 22b is arranged concentrically around the high-pressure piston 7 on the second cylinder 8. Furthermore, the rest position of the high-pressure piston 7 can be achieved by a pressure difference between the first volume 4 of the first cylinder 3 and a high-pressure volume 23 of the second cylinder 8.This is achieved by relieving the pressure in the high-pressure volume 23, while the first volume 4 remains pressurized. The resulting force pushes the high-pressure piston 7 into its first end position.

[0116] As shown in Fig. 4, the magazine 10 is arranged in a first intermediate position, shifted axially towards the drive piston 2. Since the high-pressure piston 7 and the drive piston 2 are arranged in opposite end positions, the high-pressure seal 11 on the magazine 10 is located, viewed axially, between the end of the high-pressure piston 7 detached from the drive piston 2 and the drive piston 2. The central axis 11a of the high-pressure seal 11 is arranged collinearly with the central axis 21 of the high-pressure piston 7. The central axis 12a of the replacement high-pressure seal 12 is arranged parallel to and radially spaced from the central axis 21 of the high-pressure piston 7.

[0117] As shown in Fig. 5, the magazine 10 is in a first intermediate position in which the central axis 12a of the replacement high-pressure seal 12 is arranged essentially collinearly with the central axis 21 of the high-pressure piston 7. The central axis 11a of the high-pressure seal 11 is now arranged parallel to and radially spaced from the central axis 21 of the high-pressure piston 7. To reach the changeover position, the magazine 10 is pivoted from the first intermediate position about the pivot axis 14b (see arrow 24 in Fig. 4). The pivot angle depends on the number and arrangement of the replacement high-pressure seals 12 on the magazine 10.

[0118] As shown in Fig. 6, the replacement high-pressure seal 12 is pushed onto the high-pressure piston 7. For this purpose, the magazine 10 is moved axially away from the drive piston 2, starting from the first intermediate position (see Fig. 5), until the replacement high-pressure seal 12 is seated on the high-pressure piston 7.

[0119] As shown in Fig. 7, the drive piston 2 is again coupled to the high-pressure piston 7, so that the operation of the compressor 1 can continue, now with the replaced high-pressure seal 12. Figures 8 to 12 show another embodiment of the compressor 1, and the following discussion will focus solely on the differences compared to the embodiment shown in Figures 1 to 7.

[0120] In this embodiment, the magazine 10, together with the second cylinder 8 for the high-pressure piston 7, is moved from the first operating position (see Fig. 8) away from the first cylinder 3 for the drive piston 2 to the first intermediate position (see Fig. 9). Thus, the clamping device 9 for the releasable coupling between the drive piston 2 and the high-pressure piston 7 can be omitted.

[0121] Furthermore, this embodiment differs from that of Figs. 1 to 7 in that the changing device 13 is designed to move the magazine 10 in a direction perpendicular to the central axis 21 of the high-pressure piston 7, i.e. in a radial direction, from the first intermediate position to the second intermediate position (and vice versa).

[0122] Therefore, the following steps are carried out when changing from the high-pressure seal 11 to the replacement high-pressure seal 12.

[0123] According to Fig. 8, the compressor 1 is arranged in the first operating position, in which the high-pressure seal 11 on the magazine 10 seals the high-pressure piston 7. The central axis 11a of the high-pressure seal 11 coincides with the central axis 21 of the high-pressure piston 21. The backup high-pressure seal 12 is arranged in a standby position radially away from the high-pressure piston 7. The drive piston 2 is in its end position, displaced away from the magazine 10 (see arrow 25a).

[0124] As shown in Fig. 9, the magazine 10 is moved axially together with the second cylinder 8 (see arrows 25b), so that the magazine 10 reaches the first intermediate position. During this movement, the drive piston 2 and the high-pressure piston 7 are in their end positions, moved away from the magazine 10. Thus, as the magazine 10 is moved with the second cylinder 8, the high-pressure seal 11 slides away from the end of the high-pressure piston 7.

[0125] According to Fig. 10, the magazine 10 is displaced in a radial direction relative to the second cylinder 8 (see arrow 26b).

[0126] According to Fig. 11, the magazine 10 is moved further in the direction of arrow 26b into the second intermediate position, in which the replacement high-pressure seal 12 on the magazine 10 is arranged collinearly with the high-pressure piston 7, but outside of it in the axial direction.

[0127] According to Fig. 12, the magazine 10 together with the second cylinder 8 is pushed axially onto the high-pressure piston 7 (see arrow 27) until the second operating position, with sealing arrangement of the replacement high-pressure seal 12 on the high-pressure piston 7, is reached.

[0128] In the embodiment shown in Figures 8 to 12, a double-acting drive piston 2 is provided. In this embodiment, the compressor 1 has a further high-pressure piston 28 on the side of the drive piston 2 facing away from the high-pressure piston 7. The drive piston 2 drives both the high-pressure piston 7 and the further high-pressure piston 28. Furthermore, an additional magazine 29 is provided with a receiving element 30a for a further high-pressure seal 30 for sealing the further high-pressure piston 28 in a first operating state of the further magazine 29, and with at least one further receiving element 31a for a further replacement high-pressure seal 31 for sealing the further high-pressure piston 28 in a second operating state of the further magazine 29. A further changing device 32 is provided for transferring the further magazine 29 between the first operating position and the second operating position.The additional magazine 29 and the additional exchange device 32 can be designed identically to the magazine 10 and the exchange device 13, respectively, so that repetitions are to be avoided.

[0129] Figures 13 and 14 show a third embodiment of the compressor 1, in which—as in the second embodiment—a double-acting drive piston 2 is provided with a further high-pressure piston 28. In this embodiment, a pressure chamber 33 is further formed between a first piston element 2a of the drive piston 2 and a second piston element 2b of the drive piston 2. The first piston element 2a and the second piston element 2b are connected to each other via a connecting rod 37. The pressure chamber 33 is connected to a pressure line 34 (shown only schematically) to adjust the pressure in the pressure chamber 33. In the first operating position (see Figure 14), a higher initial pressure is provided in the pressure chamber 33.To move the magazine 10 into the first intermediate position, a second, lower pressure is set in the pressure chamber 33, thus reducing the axial distance between the first piston element 2a and the second piston element 2b compared to the first operating position. This causes the high-pressure seal 11 to slide off the high-pressure piston 7. The magazine 10 can then be moved into the second intermediate position. By increasing the pressure in the pressure chamber 33 to the first pressure, the second operating position of the magazine 10 is reached, in which the replacement high-pressure seal 12 is positioned sealingly on the high-pressure piston 7.

[0130] Figures 15 and 16 show a fourth embodiment of the compressor 1. In this embodiment, the receptacle 11a on the magazine 10 is in the first operating position (see Figure 15) in the empty state. The high-pressure seal 11 is arranged, viewed axially, outside the receptacle 11a of the magazine 10 in a circumferential recess 35 of a housing of the pressure converter between a free end region of the second cylinder 8 and an annularly circumferential pressure part 36.

[0131] To replace the high-pressure seal 11 with the replacement high-pressure seal 12, the high-pressure seal 11 is first inserted into the receptacle 11a on the magazine 10. For this purpose, the pressure element 36 is moved away from the drive piston 2 by means of the exchange device 13, so that the high-pressure seal 11, which rests against the pressure element 36, is also moved axially together with the second cylinder 8. The pressure element 36 can, for example, be pneumatically actuated. If necessary, the high-pressure piston 7 must then be moved into the appropriate end position so that the high-pressure seal 11 is released from the high-pressure piston 7. Subsequently, the magazine 10, together with the replacement high-pressure seal 12, is moved into the second intermediate position, in which the replacement high-pressure seal 12 is arranged in the recess 35 of the second cylinder 8. In the embodiment shown, this is achieved by pivoting the magazine 10.Finally, the replacement high-pressure seal 12 is axially pushed out of the further receptacle 12a by means of the changing device 13 by shifting the second cylinder 8, thus reaching the second operating position.

[0132] In the fourth embodiment variant, the displacement of the high-pressure seal and the replacement high-pressure seal is preferably effected by a displacement of the second cylinder 8 essentially in the direction of the central axis of the high-pressure piston.

Claims

Patent claims:

1. Method for compressing a working medium, with the Steps: - Moving an object driven by a drive medium drive piston (2) within a first cylinder (3) between a first end position and a second end position; - Moving a high-pressure piston (7) that compresses the working medium within a second cylinder (8) between a first end position and a second end position, - Arranging a high-pressure seal (11) to seal the high-pressure piston (7); characterized by: - Arranging a magazine (10) with a receptacle (11a) for the high-pressure seal (11) and with at least one spare high-pressure seal (12) in a first operating position in which the high-pressure piston (7) is sealed by the high-pressure seal (11); - Transferring the magazine (10) from the first operating position to a second operating position in which the high-pressure piston (7) is sealed by the replacement high-pressure seal (12).

2. Method according to claim 1, characterized in that the transfer of the magazine (10) from the first operating position to the second operating position comprises: - Displacing the magazine (10) together in the receptacle (11a) on the ordered high-pressure seal (11) relative to the second cylinder (8) essentially in the direction of the central axis (21) of the high-pressure piston (7) from the first operating position to a first intermediate position releasing the high-pressure seal (11) from the high-pressure piston (7); - Transferring the magazine (10) from the first intermediate position to a second intermediate position in which the replacement high-pressure seal (12) is arranged essentially coaxially with the high-pressure piston (7); and - Shifting the magazine (10) together with the replacement high-pressure seal (12) essentially in the direction of the central axis (21) of the high-pressure piston (7) from the second intermediate position into the second operating position.

3. Method according to claim 2, characterized in that the movement of the magazine (10) from the first operating position to the first intermediate position comprises: - Detaching the high-pressure piston (7) from the drive piston (2), - Arranging the drive piston (2) and the high-pressure piston (7) at a distance from each other - Displacing the magazine (10) from the first operating position essentially in the direction of the central axis (21) of the high-pressure piston (7), so that the high-pressure seal (11) is arranged in the first intermediate position, viewed in the direction of the central axis (21) of the drive piston (2), between the high-pressure piston (7) and the drive piston (2).

4. Method according to claim 1, characterized in that the transfer of the magazine (10) from the first operating position to the second operating position comprises: - Displacing the magazine (10) together with the high-pressure seal (11) in the receptacle (11a) together with the second cylinder (8) essentially in the direction of the central axis (21) of the high-pressure piston (7) away from the drive piston (2) from the first operating position to a first intermediate position releasing the high-pressure seal (11) from the high-pressure piston (7); - Transferring the magazine (10) from the first intermediate position to a second intermediate position in which the replacement high-pressure seal (12) is arranged essentially coaxially with the high-pressure piston (7); and - Moving the magazine (10) together with the replacement high-pressure seal (12) together with the second cylinder (8) essentially in the direction of the central axis (21) of the high-pressure piston (7) towards the drive piston (2) from the second intermediate position to the second operating position.

5. Method according to claim 1, characterized in that the transfer of the magazine (10) into the second operating position comprises: - Displacement of the high-pressure piston (7) essentially in direction of the central axis (21) of the high-pressure piston (7) away from the magazine (10) together with the high-pressure seal (11) arranged in the receptacle (11a), until the high-pressure seal (11) is released from the high-pressure piston (7), so that the magazine (10) is arranged in a first intermediate position; - Transferring the magazine (10) from the first intermediate position to a second intermediate position in which the replacement high-pressure seal (12) is arranged essentially coaxially with the high-pressure piston (7); and - Displacement of the high-pressure piston (7) essentially in direction of the central axis (21) of the high-pressure piston (7) towards the magazine (10) until the replacement high-pressure seal (12) is positioned on the high-pressure piston (7).

6. Method according to claim 1, characterized in that the transfer of the magazine (10) from the first operating position to the second operating position comprises: - Displacing the high-pressure seal (11) from a position arranged outside the receptacle (11a) in the direction of the central axis (21) of the high-pressure piston (7) to a position arranged in the receptacle (11a), wherein the replacement high-pressure seal (12) is arranged in a further receptacle (12a) of the magazine (10), so that the magazine (10) is arranged in a first intermediate position; - Transferring the magazine (10) from the first intermediate position to a second intermediate position in which the replacement high-pressure seal (12) is arranged essentially coaxially with the high-pressure piston (7); and - Moving the replacement high-pressure seal (12) from the position arranged in the further receptacle (12a) of the magazine (10) to a position arranged outside the further receptacle (12a) of the magazine (10) as seen in the direction of the central axis (21) of the high-pressure piston (7).

7. Method according to claim 6, characterized in that the high-pressure seal (11) and the replacement high-pressure seal (12) are each moved together with the second cylinder (8).

8. Method according to one of claims 2 to 7, characterized in that the magazine (10) for transferring from the first intermediate position to the second intermediate position is extended by a dimension in the direction of pivot axis (14b) running parallel to the central axis (21) of the high-pressure piston (7) or is substantially shifted in a direction perpendicular to the central axis (21) of the high-pressure piston (7).

9. Compressor (1) for compressing a working medium, having: - a drive piston (2) within a first cylinder (3) which can be actuated by a drive medium, wherein the drive piston (2) is movable between a first end position and a second end position; - a high-pressure piston (7) within a second cylinder (8) for compressing the working medium, wherein the high-pressure piston (7) is movable between a first end position and a second end position; a high-pressure seal (11) for sealing the high-pressure piston (7); characterized by: - a magazine (10) with a receptacle (11a) for the high-pressure seal (11) and with at least one spare high-pressure seal (12); - a changing device (13) with a drive (14) for Transferring the magazine (10) between a first operating position for sealing the high-pressure piston (7) by the high-pressure seal (11) and a second operating position for sealing the high-pressure piston (7) by the replacement high-pressure seal (12).

10. Compressor (1) according to claim 9, characterized in that a sensor device (15) is provided for detecting a leakage of the working medium, wherein a control device (17) is connected on the one hand to the sensor device (15) and on the other hand to the changeover device (13) in order to transfer the magazine (10) from the first operating position to the second operating position when a leakage of the working medium is detected.

11. Compressor (1) according to claim 9 or 10, characterized in that the changing device (13) for transferring the magazine (10) from the first operating position to a first intermediate position is configured to a. the magazine (10) together with the items arranged in the compartment (11a) to displace the high-pressure seal (11) substantially in the direction of the central axis (21) of the high-pressure piston (7) relative to the second cylinder (8) and / or b. to move the magazine (10) together with the second cylinder (8) substantially in the direction of the central axis (21) of the high-pressure piston (7) and / or c. to move the high-pressure piston (7) substantially in the direction of the central axis (21) of the high-pressure piston (7) beyond the first or second end position and / or d. to move the second cylinder (8) substantially in the direction of the central axis (21) of the high-pressure piston (7) in order to move the high-pressure seal (11) from a position arranged axially outside the receptacle (11a) to a position arranged in the receptacle (11a).

12. Compressor (1) according to claim 11, characterized in that the changing device (13) is further equipped to transfer the magazine (10) from the first intermediate position to a second intermediate position arranging the replacement high-pressure seal (12) substantially coaxially with the high-pressure piston (7).

13. Compressor (1) according to claim 12, characterized in that the changing device (13) for transferring the magazine (10) from the second intermediate position to the second operating position is configured to a. to displace the magazine (10) together with the replacement high-pressure seal (12) arranged in the receptacle (11a) substantially in the direction of the central axis (21) of the high-pressure piston (7) relative to the second cylinder (8) and / or b. to move the magazine (10) together with the second cylinder (8) substantially in the direction of the central axis (21) of the high-pressure piston (7) and / or c. to move the high-pressure piston (7) substantially in the direction of the central axis (21) of the high-pressure piston (7) back into the first or second end position and / or d. to move the second cylinder (8) substantially in the direction of the central axis (21) of the high-pressure piston (7) in order to move the replacement high-pressure seal (12) from a position arranged in a further receptacle (12a) of the magazine to bring into a position arranged axially outside the further recording (12a).

14. Compressor (1) according to one of claims 9 to 13, characterized in that the high-pressure seal (11) and the replacement high-pressure seal (12) each have a housing (18) in which at least one sealing element (19; 19a, 19b), in particular detachably, is arranged.

15. Compressor (1) according to one of claims 9 to 14, characterized in that the magazine (10) has several spare high-pressure seals (12), wherein preferably between 2 and 7 spare high-pressure seals (12) are provided.

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