System

Abstract

The invention relates to a system comprising at least two separating devices (10, 12), one separating device (10) having a bellows (14) with a plurality of individual bellows folds (16), which separates two medium spaces (18, 20) from one another, and the other separating device (12) forming a compensator (21), a compensator (21) which communicates in a fluid-conducting manner with one of the two medium spaces (18, 20) of the bellows (14) and which separates a third medium space (22), the displacement volume (VS) being compensated by means of the compensator (21), the coupling side (76) of the two separating devices (10, 12) has a displacement volume corresponding to a displacement volume (V) of the bellows (14) during a movement between a predeterminable minimum bellows length and a predeterminable maximum bellows length of the bellows, characterized in that the respective one of the two separating devices (10, 12) is only subjected to a load up to a predeterminable setpoint pressure from the coupling side (76) thereof, and in that the displacement volume (V) corresponds to the displacement volume (V) of the bellows (14) during a movement between the predeterminable minimum bellows length and the predeterminable maximum bellows length of the bellows. In this case, the other separating device remains at the same time free of pressure on the connection side (48) thereof, or the compensator (21) is subjected to the pressure of an energy store, such as a working gas, received in the third medium space (22).

Description

Technical Field

[0001] The present invention relates to a system comprising at least two separating devices, one of which has a bellows with a plurality of individual bellows pleats separating two media spaces from each other, and the other separating device constituting a compensator fluidly connected to one of the two media spaces of the bellows and separating a third media space, wherein the compensator can compensate for a displacement volume corresponding to the volume displaced by the bellows when it moves between a preset minimum bellows length and a maximum bellows length. Background Technology

[0002] In addition to gas chamber, gravity accumulators, spring accumulators, diaphragm accumulators, bellows accumulators, or piston accumulators, there are embodiments in which a bellows with multiple individual, interconnected bellows folds (e.g., corrugated or folded bellows made of metal or plastic) is used as the separating element of the separating device. Bellows made of special plastics (e.g., polytetrafluoroethylene, PTFE) offer advantages in terms of superior media and temperature resistance compared to conventional elastomer materials. Bellows made of metal typically also offer exceptional media and temperature resistance, and their applications are expanded due to their extremely high sealing performance against media, including gases, achieving absolute sealing when combined with liquids and technical gas sealing. This last advantage makes metal bellows accumulators unique compared to all other accumulator structures and is particularly suitable if it is necessary to virtually eliminate the possibility of gas loss in hydraulic accumulators and / or if the operating medium cannot be contaminated by trace amounts of nitrogen. The excellent sealing properties for both liquids and gases make metal bellows accumulators also well-suited for use as media separators.

[0003] When using corrugated or diaphragm bellows (hereinafter referred to as bellows) made of metal or plastic (each with a separation member formed by bellows pleats between the gas and liquid sides, such as in a gas-liquid accumulator), special consideration must be given to the extended and compressed length of the corrugated or diaphragm bellows, in conjunction with the existing operating pressure and temperature. Additionally, depending on the structural type, a bellows can only withstand a completely specific pressure differential between its inner and outer sides. Exceeding these allowable pressure differentials may lead to bellows failure due to wall failure (e.g., cracking), including in hydraulic supply circuits to which such bellows are typically connected. In the case of nitrogen-filled accumulators, the accumulator loses its pre-fill pressure and thus its accumulating function in the event of bellows rupture. If the system is used as a media separator, the media to be separated may undesirably mix in the event of failure. Even if the bellows is not immediately damaged by an unacceptable pressure differential, but only suffers pre-existing damage (i.e., the separation function is temporarily maintained), the bellows wall will eventually fail, depending on the operating mode. Therefore, when designing bellows accumulators (as one possible separation device), ensuring with the highest priority that no unacceptable bellows length and pressure differential occur on the bellows structure under any possible operating conditions (pressure and temperature) is required. However, if the absence of pressure differential on the bellows is mentioned below, the possibility of pressure differential caused by the elastic properties of the bellows structure combined with the compression or tension of the bellows folds is excluded. This pressure differential characteristic of bellows is usually small enough that it can be withstood by the bellows without problems.

[0004] To address the aforementioned problems, in accordance with the teachings of DE10009865B4, a gas-hydraulic pressure accumulator (especially a gas-hydraulic pressure accumulator in the form of a pulsation damper) has been proposed to include an accumulator housing comprising a gas space for receiving a gas filling material that generates pre-tightening pressure and an oil space. A bellows or metal bellows is provided to separate the gas space and the oil space from each other. This bellows or metal bellows is closed at one end by an end plate and connected to the accumulator housing at its other end, thus forming an oil space within its interior. Furthermore, an oil passage constructed in the wall of the accumulator housing is introduced as a connecting side, and this oil passage leads into the oil space. By using a stop device that restricts the movement of the bellows end plate (the stop device having a first stop portion consisting of a tubular body extending from the oil passage inlet to near the inner side of the end plate along the inner side of the metal bellows; and a second stop portion consisting of a second tubular body extending concentrically with the first stop portion, extending from the wall of the accumulator housing in the gas space to near the outer side of the metal bellows end plate), mechanical travel restrictions are provided for the bellows on both sides, thus ensuring that neither the compression nor the extension of the bellows exceeds a preset minimum and maximum bellows length. Because the free movement is restricted during bellows stretching and compression, unacceptable high pressure differentials are also avoided, and bellows failure is prevented within the aforementioned range. Nevertheless, mechanical collisions occurring at the corresponding travel restriction structures still impose additional mechanical stress on the bellows-designed separation device, which may reduce the bellows' service life.

[0005] Furthermore, a tensioning cylinder device is known from DE102016008882A1, comprising a housing and a piston-rod unit (as another separating device) arranged at least partially longitudinally movable within the housing, and a compensating element in the form of a bellows body with bellows pleats, which is variable in length and in medium-guided communication with a compressible working gas received in one of the medium spaces within the housing. Thus, the bellows separates two medium spaces (gas / liquid) from each other, while the other separating device in the form of the piston-rod unit forms a compensator for the movement of the bellows, which is in fluid communication with the liquid space of the bellows and separates a third medium space containing a control fluid for driving the piston-rod unit, wherein the compensator can compensate for a displacement volume corresponding to the volume displaced by the bellows between its preset minimum and maximum bellows length. Because the bellows separates the gas side from the liquid side, and the gas side experiences pressure fluctuations in its volume (i.e., the amount of gas encapsulated within the device housing) within the range of the opening and compression processes of the bellows' pleats, this ultimately causes the bellows to also experience this pressure differential during operation, which, at least in the long term, can lead to the loss of bellows function. The amount of gas encapsulated on the gas side of the bellows is also affected by temperature fluctuations, which can similarly lead to high pressure differentials that are unacceptable for the bellows. Summary of the Invention

[0006] Based on the prior art, the present invention is based on the following objective: to improve a known system in such a way that unacceptable high compressive and tensile stresses and pressure differentials involving the bellows as a separating device are avoided during operation.

[0007] The system with the features of claim 1 solves this task in its entirety. According to the feature portion of claim 1, one of the two separating devices bears a load from its connecting side up to a preset rated pressure (also known in technical terms as the design pressure), while the corresponding other separating device remains pressure-free on its connecting side. This allows the system consisting of the two separating devices (designed in a particular design as a bellows accumulator and a piston accumulator) to bear a load from either side up to the rated or design pressure, while the opposite side is pressure-free, thus preventing the bellows from experiencing a significant pressure differential. The application of the rated pressure and the establishment of the pressure-free state are alternated as needed. Under all other operating conditions (where the piston of the piston accumulator is positioned between mutually opposing possible stop positions within the mating accumulator housing), the same pressure exists in all three media spaces or chambers throughout the system, and therefore, there is no significant pressure differential on the bellows in this respect.

[0008] The maximum possible pressure differential across the bellows can be approximately 1 bar, roughly equivalent to ambient pressure, and is generated by a vacuum on the connecting side of the bellows accumulator when the piston of the plug accumulator reaches one of its stop positions adjacent to the bellows due to an operating pressure greater than vacuum. In this respect, the system functions as a media separator. Alternatively, the compensator can also withstand the pressure of an energy accumulator (e.g., working gas or at least one pressure spring) enclosed in a third media space, thereby enabling gas-liquid accumulator applications while reducing the bellows load.

[0009] In this regard, it is preferably specified that one of the separating devices is designed as a bellows accumulator, while the other separating device, as a compensator, has an accumulator, preferably in the form of a piston accumulator. If possible, other accumulators may also be used as compensators if these accumulators allow their separating members to withstand overpressure up to the rated or design pressure of the accumulator system on both sides, while the other side remains pressure-free. If this is not the case (as is often the case in diaphragm accumulators and airbag accumulators), then the accumulator system can only withstand maximum load from one side depending on its installation orientation, and can only be used to a limited extent for the working pressure on the opposite side. Regarding the number of bellows accumulators and piston accumulators in the accumulator system, variations are also conceivable in which multiple bellows accumulators and piston accumulators, more than one in number, are coupled to each other via medium exchange.

[0010] In another preferred embodiment of the system according to the invention, the piston accumulator is connected to the medium space of the bellows accumulator via a connecting pipe that guides a coupling medium that can be received by one of the two piston spaces of the piston accumulator adjacent to the piston space of the bellows accumulator. By using a liquid coupling medium (which completely fills one side of the bellows accumulator and the side of the piston accumulator connected downstream as a compensator), the maximum and minimum bellows lengths during bellows stretching and compression can be limited, while reliably preventing unacceptable pressure differentials. On the other side of the accumulator piston, a working gas (preferably nitrogen) or a mechanical spring is provided as an energy accumulator for applications where the system is used as a gas-liquid accumulator or a hydraulic accumulator. When functioning as a medium separator, a medium is present there that needs to be separated from the medium on the connecting side of the bellows accumulator.

[0011] Alternatively, the coupling medium can be contained within a common accumulator housing and bounded by the outer side of the bellows and the adjacent piston walls of the accumulator piston, thus obtaining a bellows-piston accumulator system without additional connecting lines, wherein the bellows and piston are located within a common accumulator housing. In another preferred embodiment of the system according to the invention, when using connecting lines, at least one additional hydraulic system component is connected in the connecting lines between the two separating devices. For example, the system component may be part of a hydraulic block in which filling and testing blocks, valves, and sensors (pressure, temperature, etc.) may be integrated.

[0012] Preferably, it is further specified that the length of the connecting pipe is selected such that different system states, particularly different system states at different temperatures, are formed in the two separating devices. In this way, the two storage devices or separating devices can also be actively heated or cooled to different temperatures, or only the connection between the storage devices can be heated, cooled, or temperature-regulated. In such applications, for example, by maintaining a constant temperature on the gas side of the piston storage device, its size can be designed to be as small as possible, since the required gas volume of the storage device typically increases with increasing operating temperature bandwidth.

[0013] In another preferred embodiment of the system according to the invention, the bellows accumulator can be connected to a pressure source with its other medium space, and similarly, another piston space can also be connected to the pressure source, said other piston space being separated by the accumulator piston and arranged on the side of the other separating device opposite to the bellows. Thus, in addition to functioning as a medium separator, the system can also be used to compensate for pressure differentials that may occur during operation and arise on the opposite connecting sides of the two separating devices.

[0014] In another preferred embodiment of the system according to the invention, a corresponding separating device is housed within the common accumulator housing, and a stop is provided within the accumulator housing in the direction toward the bellows accumulator, the stop restricting the movement of the accumulator piston toward the bellows. Thus, the movement of the accumulator piston is restricted in the direction toward the bellows, thereby avoiding unacceptable high pressure differentials.

[0015] Furthermore, it is preferably specified that the piston accumulator has a piston position indicator for the accumulator piston. This allows any possible piston position to be detected and displayed during system operation. In this respect, the system is monitored, and any potential sources of failure can be detected immediately. Appendix picture illustrate

[0016] The following text is based on the appendix pictureThe invention will be described in detail with reference to one embodiment. Here, a highly simplified and non-proportional version is used. picture Show, the only

[0017] Appendix picture The schematic structure of a system comprising two separate partitions is shown. Detailed Implementation

[0018] Based on the principle in Figure 1 picture The system as a whole is shown in a highly simplified manner. The system includes two separating devices 10 and 12. One separating device 10 has a bellows 14 with multiple individual bellows pleats 16, depicted only stylizedly, that separates two variable-volume media spaces 18 and 20, wherein media space 20 is presented to move to a volume of almost zero. The other separating device 12 is configured as a compensator 21, which is in fluid-guided communication with the media space 18 of the bellows and therein separates a third media space 22, which is determined according to… picture In picture It indicates that it occupies its maximum possible volume. With the aid of the compensator 21, the displacement volume VS can be compensated, the displacement volume corresponding to the volume V displaced by the bellows 14 as it moves between its preset minimum and maximum bellows lengths, wherein according to... picture As shown, the displacement volume VS occupies its minimum value. picture In the diagram, the bellows 14 is shown in its retracted or withdrawn position, and thus occupies its minimum bellows length. The bellows pleats 16 are closed from their inner side toward the first medium space 18 by a plate-like end body 24, which, in the maximum extended position of the bellows 14, abuts its free end face against a flat, extending terminating wall 26 on the inner side of a mating bellows accumulator housing 28. This bellows accumulator housing, as shown, can also be constructed in multiple parts, and in particular consists of a body portion 30 and a bottom portion 32, which are preferably securely connected to each other along a threaded section 34, especially by a secure threaded connection. However, during operation of the separating device 10, the bellows 14 does not necessarily need to impact the end stop, such as the terminating wall 26, within its maximum possible range of extension and retraction; instead, it can, by design, occupy an intermediate moving position.

[0019] One of the separating devices 10 is constructed as a bellows accumulator 36, while the other separating device 12 is constructed as a hydraulic piston device and / or accumulator in the form of a piston accumulator 38. Such piston accumulators 38 or working cylinders are conventional and will not be discussed in further detail here. In the following, the cylinder arrangement is described according to the appendix. pictureThis is further described as a piston accumulator in detail. The piston accumulator 38 has a cylinder tube serving as the accumulator housing 40, which is closed at its free end by screw-in cylinder heads 42 and 44. The cylinder head 42 facing the bellows accumulator 36 has a fluid passage 46 arranged on its edge side. Furthermore, the other cylinder head 44 also has a channel-like fluid passage 48 arranged on its edge side, which can be hermetically sealed by a threaded fitting or a plug if necessary.

[0020] Piston accumulator 38 has an accumulator piston 50, which is movably guided along the inner wall of the accumulator housing 40. The accumulator piston 50 also has a piston rod 52, which is concentrically arranged with the longitudinal axis 54 of the separating device 12 and guided in the cylinder head 44 at the piston end facing the third medium space 22. In the illustrated position, the piston rod 52 passes through the medium space 22. Furthermore, the piston rod 52 is guided at its other free end face within a hollow cylindrical receiving portion 56 in the accumulator piston 50. In particular, the piston rod 52 is threaded to the receiving portion 56 of the accumulator piston 50 along another threaded section 58 at its free end region in this respect. When facing the attached... picture In the direction of observation, the accumulator piston 50, together with the hinged piston rod 52, moves to the right, and as the bellows 14 is pulled upward, the volume V in the bellows accumulator 36 and the volume of the third medium space 22 both decrease, and according to picture The almost zero displacement volume VS increases to the maximum preset volume. The same applies in the reverse case: when the volume V and the volume in space 22 increase, the displacement volume VS between the accumulator piston 50 and the adjacent termination cover or cylinder head 42 arranged in the accumulator housing 40 decreases.

[0021] Furthermore, concentric with the longitudinal axis 54, the cylinder head 42 is partially penetrated by a piston position indicator 57, which is received by its measuring rod portion 59, fixedly arranged on the cylinder head 42, within a hollow cylindrical central recess 61 in the piston rod 52. When the piston-rod units 50 and 52 move, a magnet unit or sensor unit 63 moves simultaneously, introduced from the free end face into the bottom of the accumulator piston 50, more precisely along the fixed measuring rod portion 59. Thus, by means of a measurement evaluation device (not shown but conventional in the art), the position of the piston-rod units 50 and 52 within the accumulator housing 40 can be determined, which in turn provides a measurable inference about two opposing accumulator volumes, which are thus separated from each other by the piston-rod units 50 and 52. Such a sensor device for determining component position is also known in technical terms as an LVDT.

[0022] Furthermore, the bellows accumulator 36 has two opposing, conventionally type proximity switches 65 that monitor the position of the plate-like end body 24 or the extension of the bellows 14, and transmit sensor data to a suitable measurement evaluation device (not shown). This also allows for monitoring of the size of each individual volume separated from each other by the bellows 14. Due to this sensor monitoring, the functional safety of the entire system is ensured.

[0023] Furthermore, the accumulator piston 50 typically has multiple individual sealing and guiding elements 60 on its outer peripheral side. Such a cylinder or accumulator configuration is conventional in this regard and will not be discussed in detail here.

[0024] When the bellows 14 of the bellows accumulator 36 occupies its fully extended upper position, the volume V in the first medium space 18 is output to the fluid side 66 of the piston accumulator 38 through the accumulator housing opening 62 in this region, the pre-preset length connecting pipe 64, and the lateral fluid connection 46 in the cylinder head 42. The accumulator piston 50 occupies a pushed position within the accumulator housing 40 such that the pushed volume VS on the fluid side 66 substantially corresponds to the volume V displaced by the bellows accumulator 36 during its extended movement. In particular, the connecting pipe 64 can have a very large length. The connecting pipe 64 is sealed at its opposing sides and, for example, screwed into the accumulator housing opening 62 and the fluid connection 46 in the cover member 42.

[0025] When the bellows 14 is in its fully retracted, illustrated position, the accumulator piston 50 preferably moves to its fully left-hand stop position in the viewing direction shown in FIG1, in which the free end face of the accumulator piston 50 abuts against the adjacent end wall of the cylinder head 42. Similarly, it is preferable that when the volume V is fully pushed from the bellows accumulator 36 into the piston accumulator 38, the mating accumulator piston 50 occupies its fully right-hand stop position, abutting against the adjacent end wall of the second cylinder head 44. However, it is also possible to use this intermediate position if necessary.

[0026] The cylindrical bellows 14 can be supported in its lower stop position as shown on a preferably flexible and annular buffer device. Furthermore, the bellows 14 is securely connected at its end side to the bottom portion 32 via a metal receiving ring 70, with its bellows folds 16, and also to the edge region of a plate-like or disc-shaped end body 24. This end body, for supporting the bellows 14, is movable on its outer periphery within the bellows accumulator housing 28 by means of an annular guide 72, wherein such guide 72, not shown in detail, has an interruption to allow fluid exchange to be established between the first medium space 18 and the fluid space 73 bounded by the outer periphery of the bellows 14 and the inner periphery of the bellows accumulator housing 28. In the illustrated position, the bellows 14 is shown in a fully retracted position, in which the bellows pleats 16 are "compacted" while adjacent to each other; however, it is preferably specified that, to reduce the bellows load, the bellows occupy a small pull-out length of the bellows 14, providing an increased second medium space 20, in which the bellows pleats 16 are not directly abutting each other. An additional functional block (not shown) can be inserted into the connecting conduit 64 to guide the medium to receive one or more system components, as described in more detail below.

[0027] Furthermore, the bellows accumulator housing 28 has two eccentrically located fluid inflow or outflow channels 76 in its bottom portion 32, which lead to the second medium space 20. Not only the corresponding channels 76 of the bellows accumulator 36, but also the channel-shaped fluid passages 48 of the piston accumulator 38 constitute the so-called connecting sides of the bellows accumulator 36 and the piston accumulator 38, respectively. Therefore, one channel 76 is used solely for supplying fluid to the second medium space 20 of the bellows accumulator 36, while the other fluid channel 76 is used for discharging fluid from the second medium space 20. A preset fluid flow direction in the delivery line can be maintained by a corresponding, preferably spring-loaded check valve (not shown).

[0028] The following text shall be based on the appendix from now on. picture The function of the overload-safe bellows accumulator 36 is described in detail with reference to the embodiments. pictureThe system solution shown limits the maximum and minimum bellows length during the extension and compression of the bellows 14, while reliably preventing unacceptable pressure differentials. This is achieved by using a liquid coupling medium (e.g., hydraulic oil) that completely fills the first medium space 18 of the bellows accumulator 36 and the fluid side 66 of the downstream piston accumulator 38, thereby establishing the described connection between the two accumulator-type separators 10, 12 via a connecting line 64. On the other side of the accumulator piston 50, a working gas, preferably in the form of nitrogen, should be present in the third medium space 22. For this purpose, the channel-like fluid passage 48 in the cylinder head component 44 is closed by means of a plug or a closed threaded part (neither shown). In this respect, the piston accumulator 38 functions as a hydraulic accumulator. When functioning as a media isolator, a (liquid) medium will be present in the third media space 22, which needs to be separated from another (liquid) medium on the connection side 76 of the bellows accumulator 36, which is connected to a fluid supply unit (not shown). In this regard, a channel-like fluid passage 48 will be opened and connected, for example, to another fluid supply unit (not shown), which is different from the first fluid supply unit.

[0029] In order to limit the movement of the bellows 14 to a preset minimum compression length and maximum extension length, the piston accumulator 38 has a maximum displacement volume VS between its relative piston stop positions, which corresponds to the displacement volume V of the bellows 14 between its permissible minimum and maximum lengths. picture The system shown, consisting of the bellows accumulator 36 and the piston accumulator 38, is subjected to a load up to the maximum design pressure on the connection side 48 of the piston accumulator 38, while remaining pressureless on the connection side 76 of the bellows accumulator 36. The bellows 14 is then held in one of its permissible limit positions, i.e., in its minimum retracted position, by the coupling medium enclosed in the connecting conduit 64. Therefore, depending on the installation position of the bellows 14, if the coupling medium, in the form of a coupling fluid, is arranged outside the bellows, the bellows 14 is at its minimum compressed length. However, if, in one configuration, the coupling medium is arranged inside the bellows 14, the bellows is at its maximum extended length (not shown).

[0030] However, regardless of the installation position of the bellows 14, if there is no pressure on the connection side 76 of the bellows accumulator 36, then there is also no pressure on the coupling medium. Therefore, there is no pressure difference between the inner and outer sides of the bellows 14. However, when the system consisting of the bellows accumulator 36 and the piston accumulator 38 is subjected to a load up to the maximum rated or design pressure on the connection side 76 of the bellows accumulator 36, and is depressurized on the connection side 48 of the piston accumulator 38, the accumulator piston 50 is directed towards the attached... picture The bellows is pressed to its right stop position in the direction of observation. Depending on the installation position of the bellows 14, it is either at its minimum compressed length or maximum extended length. Here, the pressure in the coupling medium is equal to the pressure on the connecting side 76 of the bellows accumulator 36, and there is no pressure difference between the inner and outer sides of the bellows 14. The maximum possible pressure difference on the bellows (i.e., acting on the bellows internally and externally) is approximately 1 bar, and this pressure difference causes the accumulator piston 50 of the piston accumulator 38 to move towards the attached... picture When the object being viewed is pressed into its left stop position in the accumulator housing 40, a "vacuum" is generated on the connecting side 76 of the bellows accumulator 36.

[0031] The system is characterized in that the combination of the bellows accumulator 36 and the piston accumulator 38 can withstand loads up to the rated or design pressure from each side 22, 48 or 20, 76, while the opposite sides 20, 76 or 22, 48 are pressureless, and the bellows 14 does not experience a pressure difference between its inner and outer sides. Under all other operating conditions (where the accumulator piston 50 of the piston accumulator 38 is located between opposing stop positions within the accumulator housing 40), the same pressure exists in all three medium spaces 18, 20, 22 of the accumulator system, and therefore there is no pressure difference between its inner and outer sides on the bellows 14.

[0032] The hydraulic functional block (not shown) inserted between the bellows accumulator 36 and the piston accumulator 38 may have additional hydraulic system components, such as filling and testing blocks, valves, sensors, etc. Furthermore, according to the attached... picture In this variant, the two accumulators 36 and 38 can be spatially separated from each other by a sufficiently long connecting structure in the form of a connecting pipe 64, allowing different temperatures to be formed in the two accumulators 36 and 38. In particular, the two accumulators 36 and 38 can be actively temperature-controlled to different levels, especially by heating or cooling the liquid coupling medium. In this application, for example, by maintaining a constant temperature on the gas side of the piston accumulator 38 in the form of a third medium space 22, the size of the piston accumulator can be kept as small as possible, since the required gas volume of the accumulator typically increases with increasing operating temperature bandwidth. According to the appendix... picture One possible application of the system is that, through piston movement in the accumulator housing 40, any fluid on the medium side 20 of the accumulator housing 36 is output to a consumer (not shown) via a corresponding fluid passage under increased pressure. Here, one passage 76 can be used to supply fluid to the bellows 14 at essentially no pressure, while an adjacent passage 76 is used to output fluid under increased pressure.

[0033] It should also be noted that, depending on the operating conditions and the friction pair between the annular sealing and guiding element 60 and the accumulator wall inside the accumulator housing 40, a certain pressure difference may occur between the coupling medium and the connection sides 22, 48 of the piston accumulator 38. A conventional accumulator piston 50 can withstand this pressure difference without problems. However, there is no pressure difference between the inner and outer sides of the bellows 14 because the pressure inside and outside the bellows 14 can always be balanced by the axial movement of the bellows 14. This can be achieved by installing a conventional piston position indicator (already designed for...). picture One type of piston position indicator 57 is illustrated in part as a measuring rod assembly 59, which is arranged on the piston accumulator 38 and can reliably detect and display the position of the accumulator piston 50. In addition to the above-described rod sensor assembly (LVDT), electrical terminal position switches, piston position switches, magnetic flip indicators (DE10310427A1), draw rope travel measurement systems, laser measurement systems, and other devices (not shown) can also be used in a conventional manner.

Claims

1. A system comprising at least two separating devices (10, 12), wherein one separating device (10) has a bellows (14) with a plurality of individual bellows folds (16), which separates two medium spaces (18, 20) from one another, and the other separating device (12) constitutes a compensator (21), which is in fluid-conducting communication with one of the two medium spaces (18, 20) of the bellows (14) and separates a third medium space (22), wherein The compensator (21) can compensate for the displacement volume (VS), which corresponds to the displacement volume (V) of the bellows (14) when it moves between a preset minimum bellows length and a preset maximum bellows length. The characteristic is that one of the two separating devices (10, 12) is only subjected to a load up to a preset rated pressure from its connection side (76), while the other separating device is simultaneously kept pressure-free on its connection side (48), or the compensator (21) is subjected to the pressure of the energy storage device—e.g., working gas—accepted in the third medium space (22).

2. The system of claim 1, wherein, One of the separating devices (10) is a bellows accumulator (36), while the other separating device (12) is a compensator (21) with a accumulator, such as a piston accumulator (38).

3. The system of claim 1 or 2, wherein, The piston accumulator (38) is connected to the medium space (18) of the bellows accumulator (36) via a connecting pipe (64) that guides the coupling medium, which can be received by one of the two piston spaces (66) of the piston accumulator (38), or the coupling medium can be received in a common accumulator housing (40) and confined by the outer side of the bellows (14) and the adjacent piston walls of the accumulator piston (50).

4. The system of any of the preceding claims, characterized in that, At least one additional hydraulic system component is connected in the connecting pipe (64) between the two separating devices (10, 12).

5. The system of any of the preceding claims, characterized in that, The length of the connecting pipe (64) is selected such that different system states are formed in the two separating devices (10, 12), especially different system states in different temperature forms.

6. The system of any of the preceding claims, characterized by The bellows accumulator (36) can be connected to the pressure source with its other medium space (20), and similarly, another piston space (22) can also be connected to the pressure source, which is separated by the accumulator piston (50) and arranged on the side of the other partition device (12) away from the bellows (14).

7. The system of any of the preceding claims, characterized in that, The corresponding separation devices (10, 12) are received in the common accumulator housing (40), and there is a stop in the accumulator housing (40) in the direction toward the bellows accumulator (36), which restricts the movement of the accumulator piston (50) toward the bellows (14).

8. The system of any of the preceding claims, characterized in that, The corresponding separation devices (10, 12) are used as gas-liquid accumulators and / or media separators.

9. The system of any of the preceding claims, characterized in that, For its function as an accumulator, the piston accumulator (38) has an energy accumulator, such as a compressed working gas, in another piston space (22); or for its function as a medium separator, the piston accumulator is provided with a fluid connection (48), which preferably guides a different medium than the medium guided by the fluid connection (76) inside the bellows (14) of the bellows accumulator (36).

10. The system of any of the preceding claims, characterized in that, The piston accumulator (38) has a piston position indicator (57) for the accumulator piston (50).

Images