DE102020200642B3 - Piston accumulator system and monitoring module and monitoring method for a piston accumulator system - Google Patents

Abstract

The invention relates to a piston accumulator system (10) with an accumulator housing (12) and a flying piston (14) which separates a gas space (16) and a liquid space (18) in the accumulator housing (12), with a monitoring module (20) connected to it the piston (14) is arranged, which by means of the piston (14) drivable energy generation unit (24) for generating electrical energy, an energy storage unit (26) for storing the electrical energy, a sensor arrangement (28) for determining operating data of the piston storage system (10 ) and a radio unit (32) for transmitting the operating data. The invention also relates to a monitoring module (20) to be arranged on a piston (14) of a piston accumulator system (10) having an energy generation unit (24) which can be driven by means of the piston (14) and has a housing part and a housing part along a longitudinal axis (15). movable moving part, wherein the energy generation unit (24) is set up to generate electrical energy from a movement of the moving part relative to the housing part, an energy storage unit (26), a sensor arrangement (28) and a radio unit (32). Finally, the invention relates to a method for monitoring a piston accumulator system (10) with a flying piston (14), with the steps of a) driving an energy generation unit (24) by means of the piston (14) and generating electrical energy, b) operating a piston ( 14) arranged sensor arrangement (28) with the electrical energy and determination of operating data of the piston accumulator system (10) by means of the sensor arrangement, c) wireless transmission of the operating data.

Description

The invention relates to a piston accumulator system with an accumulator housing and a flying piston which separates a gas space and a liquid space in the accumulator housing from one another. The invention also relates to a method for monitoring a piston accumulator system.

Piston accumulator systems are used for cyclical intermediate storage and delivery of mechanical energy, especially when there is a short-term need for high mechanical power. To store the mechanical energy, liquid, typically oil, is pumped into the liquid space, so that gas, typically nitrogen, is compressed in the gas space by means of the piston. This increases the pressure in the gas space. In order to ensure the charged state of the piston accumulator system, liquid is prevented from flowing out of the liquid space, typically by closing a valve. To discharge the piston storage system, liquid is allowed to flow out of the liquid space, typically by opening the valve, so that the gas pressure drives liquid out of the liquid space via the piston.

Out EP 2 647 849 A2 a device for determining the position of a movable piston which is arranged within a piston accumulator as a partition between a gas space and a fluid space is known. The determination device comprises at least one pressure sensor for capturing pressure data, at least one ultrasonic sensor for capturing ultrasonic data and at least one computer unit for evaluating the data. The position of the piston can be determined with the computer unit. The sensors and the computer unit are arranged on a housing or outside the housing of the piston accumulator. A thermal capacity can be introduced into the piston in order to cool the gas when the piston accumulator is being charged, so that more energy can be absorbed.

DE 10 2005 015 948 A1 describes a fluidic component with at least one sensor device and with a wireless data transmission device for transmitting sensor and / or control signals between the fluidic component and an external control device. In this case, at least one solar cell arrangement or a thermoelectric converter or a converter which converts the kinetic energy of a moving part of the fluidic component into electrical energy is electrically connected as an energy supply device for providing the operating voltage for the data transmission device. For example, a permanent magnet arranged on a piston can generate energy when passing at least one coil arranged along the movement path or another magnetically sensitive element in this coil or in this magnetically sensitive element, which energy can be used as supply energy. Electrical buffers can be provided for buffering electrical energy.

Out DE 199 42 509 A1 a method and a device for supplying electrical consumers in or on a pneumatic device with electrical supply energy are known. The pneumatic device is connected to a pressure source via a pneumatic line. The energy transfer to the pneumatic device takes place via the pneumatic line by means of sound waves, microwaves, pressure changes or a gas flow in the pneumatic line. A conversion of this transmitted energy into the electrical supply energy takes place in or on the pneumatic device.

DE 10 2004 055 054 A1 discloses a method and a hydraulic circuit for supplying electrical consumers, in particular electrical actuators, a hydraulic circuit with electrical energy, the electrical energy required to actuate and control the electrical consumers by at least partially converting the hydraulic energy of the pressure medium conveyed by a hydraulic pump , is produced.

In many cases, the functionality of a piston accumulator system is of crucial importance for the safety of a system with the piston accumulator system. Piston accumulator systems are used, for example, to turn the blades of wind turbines out of the wind when there is a threat of overload, for example due to gusts of wind. A dangerous failure mechanism in piston accumulator systems is leakage past the piston, in which case gas can enter the liquid space from the gas space or, conversely, liquid can enter the gas space from the liquid space.

Object of the invention

It is an object of the invention to improve the operational safety of piston accumulator systems.

Description of the invention

This object is achieved according to the invention by a piston accumulator system according to claim 1, a monitoring module according to claim 15 and a monitoring method according to claim 25. The respective subclaims and the Description indicate advantageous embodiments and variants.

Piston accumulator system according to the invention

According to the invention, a piston accumulator system is provided. The piston accumulator system has an accumulator housing. The piston accumulator system also has a flying piston. The flying piston separates a gas space and a liquid space in the storage housing from one another. The flying piston has no mechanical connection from the accumulator housing. In particular, there is no piston rod extending out of the storage housing. The gas space is typically filled with nitrogen. The liquid space is typically filled with oil. The piston accumulator system can have a pump in order to pump liquid into the liquid space.

• - eine mittels des Kolbens antreibbare Energiegewinnungseinheit zum Erzeugen elektrischer Energie,
• - eine Energiespeichereinheit zum Speichern der elektrischen Energie,
• - eine Sensoranordnung zum Ermitteln von Betriebsdaten des Kolbenspeichersystems und
• - eine Funkeinheit zum Übermitteln der Betriebsdaten.

According to the invention, a monitoring module is arranged on the piston. The monitoring module has the following:

• - an energy generation unit that can be driven by means of the piston to generate electrical energy,
• - an energy storage unit for storing electrical energy,
• - A sensor arrangement for determining operating data of the piston accumulator system and
• - a radio unit for transmitting the operating data.

The monitoring module is preferably a monitoring module according to the invention as described below. The piston accumulator system can advantageously be monitored using a monitoring method according to the invention described below.

The energy generation unit can generate electrical energy that can be used for the monitoring module from mechanical, in particular kinetic, and / or thermal energy of the piston. The mechanical energy can in particular be kinetic energy of a rigid body movement of the piston. To generate the electrical energy, the energy generation unit can have a magnet that can be moved relative to a coil and / or a piece of mass supported on a piezo element. A change in the acceleration of the piston leads to a deflection of the magnet or piece of mass that can be used to generate electrical energy. To convert thermal energy into electrical energy, the energy generation unit can have a thermoelectric and / or pyroelectric generator, in particular a Peltier element. A temperature gradient that can be used for this purpose can be applied to the piston, since the gas in the gas space is heated or cooled when the piston storage system is being charged or discharged.

As an alternative or in addition to generating energy by means of the drive through the piston, the energy generation unit can have a photodiode for converting electromagnetic waves, in particular light, into electrical energy. To provide the electromagnetic waves, a light source can be provided on the storage housing, in particular facing the piston on an end face of the gas space.

The electrical energy obtained can be held in the energy storage unit until it is required to operate the sensor arrangement and / or the radio unit. The sensor arrangement and the radio unit can therefore be operated independently of the current generation of electrical energy by the energy generation unit. The energy generation unit, the sensor arrangement and the radio unit are fundamentally electrically connected to the energy storage unit. The aforementioned components can thereby be supplied with electrical energy from the energy storage unit.

The sensor arrangement has at least one sensor. The operating data can include the measured values of the sensor or sensors. Alternatively or additionally, the operating data can be derived from the measured values. The sensor arrangement can have an evaluation unit for processing measured values of the sensor arrangement.

The piston typically has a seal arrangement. The operating data determined can be used in particular to monitor the sealing arrangement, preferably in the context of a method according to the invention described below. The sealing arrangement can have one or more sealing devices, each with one or more sealing elements, each with one or more dynamic and / or static sealing sections.

The radio unit is basically set up for wireless transmission of the operating data. The radio unit can have a radio transmitter for this purpose. The radio unit is preferably also set up to receive radio signals, for example containing control information for the monitoring module. The radio unit can then have a combined radio transmitter / receiver. The radio unit can in particular have a radio frequency radio transmitter or radio frequency radio transmitter / receiver or a lightwave radio transmitter or lightwave radio transmitter / receiver. The radio unit can be a Bluetooth module exhibit. The radio unit can comprise a microcontroller.

The piston accumulator system according to the invention allows autonomous monitoring of its operating state by recording and transmitting operating data. An external energy source or an external energy supply is not required for this. Due to the continuous or repeated generation of energy at the piston, the energy required for monitoring is available even after very long operating times. The operating data can be recorded directly on the piston (which is not accessible from the outside) and, in particular, relate to the piston itself. Undesired, in particular dangerous, operating states can be recognized in the piston accumulator system according to the invention, so that suitable countermeasures can be initiated in good time, if necessary.

• - einen Gasdrucksensor zur Messung eines Gasdrucks im Gasraum und/oder
• - einen Flüssigkeitsdrucksensor zur Messung eines Flüssigkeitsdrucks im Flüssigkeitsraum und/oder
• - einen Temperatursensor, insbesondere zur Messung einer Temperatur im Gasraum und/oder
• - einen Beschleunigungssensor und/oder
• - einen Distanzsensor, insbesondere zur Messung eines Abstands des Kolbens von einer Wandung, vorzugsweise einer den Gasraum begrenzenden Stirnseite, des Speichergehäuses und/oder
• - einen Impedanzsensor zur Messung einer Impedanz in dem Gasraum aufweisen. Es kann ein weiterer Temperatursensor zur Messung einer Temperatur im Flüssigkeitsraum vorgesehen sein. Der Distanzsensor ist vorzugsweise ein Infrarot-Distanzsensor. Mittels der vorgenannten Sensoren können Betriebsdaten des Kolbenspeichersystems ermittelt werden. Aus der Kombination verschiedener Messwerte der Sensoren bzw. aus der Veränderung der Messwerte kann auf einen Betriebszustand des Kolbenspeichersystems geschlossen werden.

The sensor arrangement can

• - A gas pressure sensor for measuring a gas pressure in the gas space and / or
• - A liquid pressure sensor for measuring a liquid pressure in the liquid space and / or
• - A temperature sensor, in particular for measuring a temperature in the gas space and / or
• - an acceleration sensor and / or
• a distance sensor, in particular for measuring a distance between the piston and a wall, preferably an end face delimiting the gas space, of the storage housing and / or
• - Have an impedance sensor for measuring an impedance in the gas space. Another temperature sensor can be provided for measuring a temperature in the liquid space. The distance sensor is preferably an infrared distance sensor. Operating data of the piston accumulator system can be determined by means of the aforementioned sensors. An operating state of the piston accumulator system can be inferred from the combination of different measured values from the sensors or from the change in the measured values.

The piston advantageously has a sealing device with a first and a second dynamic sealing section. The two dynamic sealing sections seal the piston against the accumulator housing. When the piston moves, the dynamic sealing sections slide along the accumulator housing. A particularly effective separation of the liquid space from the gas space can be achieved by means of two dynamic sealing sections. In particular, one of the sealing sections can primarily seal the gas space and the other sealing section primarily the liquid space. The two dynamic sealing sections can be formed on a common sealing element. This can simplify production, in particular assembly on the piston.

The sensor system can have an inner seal pressure sensor for measuring an inner seal pressure between the first and the second dynamic sealing section. The measurement of the inner seal pressure opens up expanded diagnostic options, in particular with regard to a leak at one or the other dynamic sealing section.

The sealing device can have a first sealing element with a retaining groove in which a second sealing element is arranged. One of the two dynamic sealing sections can be formed on the first or the second sealing element. Alternatively, the two dynamic sealing sections can be formed on the first sealing element. The first sealing element can in turn be arranged in a receiving groove of the piston. The first sealing element can consist of a tough elastic or elastic plastic material, in particular a thermoplastic, for example PTFE. The second sealing element can consist of a rubber-elastic or hyper-elastic material, in particular an elastomer.

At least one pressure channel can extend through the first sealing element. The pressure channel is used to transmit the inner seal pressure to the inner seal pressure sensor. A plurality of pressure channels are preferably formed and in particular are arranged distributed uniformly over the circumference of the first sealing element.

In a first development, the pressure channel can extend from the retaining groove, in particular a groove base of the retaining groove, through the first sealing element. In this embodiment, the two dynamic sealing sections are typically formed on the first sealing element. The second sealing element can have one or two further dynamic sealing sections for sealing on the storage housing. The second sealing element can have two static sealing sections for sealing on the first sealing element. The second sealing element can have a V-shaped cross section. The two static sealing sections are then formed on the legs of the V-shaped cross section and the further dynamic sealing section is formed at the tip. Alternatively, the second sealing element can have an X-shaped cross-section (with two further dynamic and two static sealing sections) exhibit. The pressure channel can open into the retaining groove between the two static sealing sections of the second sealing element. The inner seal pressure sensor then enables the diagnosis of a twisting of the second sealing element

In an alternative development, the sealing device can have two retaining grooves, in each of which a second sealing element is arranged. One of the two dynamic sealing sections can each be formed on the two second sealing elements. If the two dynamic sealing sections are formed on the first sealing element, a further dynamic sealing section can be formed on each of the two second sealing elements. The pressure channel can extend between the two retaining grooves. This enables the two second sealing elements to be monitored.

The first sealing element can have an extension through which the pressure channel runs. The first sealing element can be prestressed on both sides of the extension via a prestressing element of the sealing device. The prestressing of the first sealing element against the storage housing by means of the prestressing elements allows the use of materials for the first sealing element which themselves do not have sufficient elasticity, but have advantages with regard to their sealing properties, such as tough elastic materials. The pretensioning elements can be spaced apart from one another by the extension. The prestressing elements can statically seal the first sealing element with respect to the piston. The prestressing elements can be designed as O-rings, preferably made of rubber-elastic material. A recess for engaging the extension can be formed in the receiving groove of the piston.

The piston accumulator system can have a single-stage sealing arrangement on the piston, in particular with a previously described sealing device with a first and a second dynamic sealing section.

Alternatively, the piston can have a two-stage sealing arrangement with a liquid-side sealing device and a gas-side sealing device. This allows a specific design or layout of the sealing device which is respectively arranged on the gas side or on the liquid side. The gas-side and / or the liquid-side sealing device can each be a previously described sealing device with two dynamic sealing sections.

The sensor system can have an intermediate seal pressure sensor for measuring an intermediate seal pressure between the liquid-side and the gas-side sealing device. The measurement of the intermediate seal pressure opens up expanded diagnostic options, in particular with regard to a leak at the liquid-side and / or the gas-side sealing device.

A further radio unit can be arranged on the storage housing, in particular on an end face of the storage housing that delimits the gas space. The further radio unit can receive operating data transmitted by the radio unit of the monitoring module and preferably forward and / or temporarily store them for further processing. Radio signals are only slightly attenuated by the gas in the gas space, so that the radio unit of the monitoring module can be operated with particularly low power. The further radio unit on the storage housing has a radio receiver, preferably a combined radio receiver / transmitter. In the latter case, the further radio unit on the storage housing can transmit control information for the monitoring module to the radio unit of the monitoring module which is set up to receive radio signals.

It can be provided that the piston has a depression on the gas space side, and that at least the energy generation unit, the energy storage unit and the radio unit of the monitoring module are arranged in the depression. Preferably, some or all of the sensors of the sensor arrangement are also arranged in the trough. Arranged in the trough means that the components mentioned at least extend into the trough and preferably do not protrude from the trough. This arrangement allows a stable and protected attachment of the aforementioned components.

The energy storage unit can have an accumulator and / or a capacitor. An accumulator allows the storage of larger amounts of electrical energy. A capacitor can be charged or discharged particularly quickly.

The energy generation unit can have an energy converter for converting thermal or mechanical energy stored in a thermal and / or mechanical energy store into electrical energy. The energy content of the thermal or mechanical energy store can be increased by means of the piston. The mechanical energy store can be a flywheel, for example.

The piston accumulator system can have an actuator for influencing the piston. The actuator is basically arranged on the piston itself and can be part of the monitoring module. The actuator can be an actively controllable valve. Of the The actuator can have an electrically influenceable material, for example a piezoelectric material. The actuator can open or close a bypass for bypassing a sealing section, a sealing element or a sealing device of a sealing arrangement of the piston. As a result, the lubrication of the sealing arrangement can be influenced, in particular increased. The actuator is basically electrically connected to the energy storage unit of the monitoring module. The actuator can therefore be supplied with electrical energy from the energy storage unit.

The monitoring module can furthermore have a voltage converter, preferably a DC voltage converter, which is set up to increase an output voltage of the energy generation unit to a maximum input voltage of the energy storage unit. By increasing the voltage made available to the energy storage unit, a larger amount of electrical energy can be stored. Furthermore, the energy storage unit can deliver greater electrical power at higher voltages.

The monitoring module can be releasably attached to the piston. The monitoring module can then simply be removed from the piston when the monitoring module or the piston are to be replaced. The monitoring module is preferably held magnetically on the piston. The monitoring module can then be attached or removed particularly quickly and easily, in particular without tools.

• - einen Kolben mit einer Aufnahmenut,
• - ein in der Aufnahmenut angeordnetes erstes Dichtelement mit zwei dynamischen Dichtabschnitten und mit wenigstens einer Haltenut, wobei sich ein Druckkanal durch das Halteelement hindurch erstreckt,
• - zwei Vorspannelemente, die beidseits eines Fortsatzes des ersten Dichtelements, durch welchen der Druckkanal verläuft, das erste Dichtelement vorspannen, und
• - wenigstens ein zweites Dichtelement, das in der Aufnahmenut angeordnet ist, wird ein eigener erfinderischer Gehalt zugeschrieben. In die Aufnahmenut kann ein Anschlusskanal für einen (Innerdichtungs-) Drucksensor münden.

Having a piston arrangement, in particular for a piston accumulator system according to the invention as described above

• - a piston with a receiving groove,
• - A first sealing element arranged in the receiving groove with two dynamic sealing sections and with at least one holding groove, with a pressure channel extending through the holding element,
• two prestressing elements which prestress the first sealing element on both sides of an extension of the first sealing element through which the pressure channel runs, and
• - At least one second sealing element, which is arranged in the receiving groove, is assigned an inventive content of its own. A connection channel for an (inner seal) pressure sensor can open into the receiving groove.

• - ein erstes Dichtelement mit einer Haltenut, wobei sich ein Druckkanal von der Haltenut, insbesondere einem Nutgrund der Haltenut, ausgehend durch das erste Dichtelement hindurch erstreckt,
• - zwei Vorspannelemente, die beidseits eines Fortsatzes des ersten Dichtelements, durch welchen der Druckkanal verläuft, angeordnet sind,
• - ein zweites Dichtelement mit einem ersten und einem zweiten statischen Dichtabschnitt, das in der Aufnahmenut angeordnet ist, wobei der Druckkanal zwischen dem ersten und dem zweiten statischen Dichtabschnitt mündet.

A sealing device, in particular for such a piston arrangement, is also regarded as inventive, which has the following:

• a first sealing element with a retaining groove, a pressure channel extending from the retaining groove, in particular a groove base of the retaining groove, through the first sealing element,
• - two prestressing elements, which are arranged on both sides of an extension of the first sealing element through which the pressure channel runs,
• - A second sealing element with a first and a second static sealing section, which is arranged in the receiving groove, wherein the pressure channel opens between the first and the second static sealing section.

Monitoring module according to the invention

• - eine mittels des Kolbens antreibbare Energiegewinnungseinheit mit einem, vorzugsweise ringförmigen, Gehäuseteil und einem relativ zu dem Gehäuseteil entlang einer Längsachse beweglichen Bewegungsteil, wobei die Energiegewinnungseinheit dazu eingerichtet ist, aus einer Bewegung des Bewegungsteils relativ zu dem Gehäuseteil elektrische Energie zu erzeugen,
• - eine Energiespeichereinheit zum Speichern der elektrischen Energie,
• - eine Sensoranordnung zum Ermitteln von Betriebsdaten des Kolbenspeichersystems und
• - eine Funkeinheit, insbesondere mit einem Bluetooth-Modul, zum Übermitteln der Betriebsdaten.

A monitoring module to be arranged on a piston of a piston accumulator system, in particular a piston accumulator system according to the invention described above, also falls within the scope of the present invention. The monitoring module has the following:

• - An energy generation unit that can be driven by means of the piston and has a, preferably ring-shaped, housing part and a moving part that is movable relative to the housing part along a longitudinal axis, the energy generation unit being set up to generate electrical energy from a movement of the moving part relative to the housing part,
• - an energy storage unit for storing electrical energy,
• - A sensor arrangement for determining operating data of the piston accumulator system and
• - A radio unit, in particular with a Bluetooth module, for transmitting the operating data.

The monitoring module according to the invention can have further features of the monitoring module of the piston accumulator system according to the invention.

The energy generation unit can generate usable electrical energy from mechanical energy of the piston for the monitoring module.

For this purpose, a relative movement of the moving part and the housing part is used. The housing part can typically be attached to the piston. The moving part can be received in the housing part. A relative movement of the housing part and the moving part can take place when the acceleration of the piston, and thus of the housing part typically attached to the piston, changes. The piston is also typical movable along the longitudinal axis in an accumulator housing of the piston accumulator system. To generate the electrical energy, the energy generation unit can have a piece of mass supported on a piezo element. A change in the acceleration of the piston and therefore of the monitoring module leads to a deflection of the mass piece that can be used to generate electrical energy. By deflecting the mass, the piezo element can be deformed so that it generates electrical energy.

The electrical energy obtained can be held in the energy storage unit until it is required to operate the sensor arrangement and / or the radio unit. The sensor arrangement and the radio unit can therefore be operated independently of the current generation of electrical energy by the energy generation unit. The energy generation unit, the sensor arrangement and the radio unit are fundamentally electrically connected to the energy storage unit. The aforementioned components can thereby be supplied with electrical energy from the energy storage unit.

The sensor arrangement has at least one sensor. The operating data can include the measured values of the sensor or sensors. Alternatively or additionally, the operating data can be derived from the measured values. The sensor arrangement can have an evaluation unit for processing measured values of the sensor arrangement. The operating data determined can be used in particular to monitor the sealing arrangement, preferably in the context of a method according to the invention described below.

The radio unit is basically set up for wireless transmission of the operating data. The radio unit can have a radio transmitter for this purpose. The radio unit is preferably also set up to receive radio signals, for example containing control information for the monitoring module. The radio unit can then have a combined radio transmitter / receiver. The radio unit can in particular have a radio frequency radio transmitter or radio frequency radio transmitter / receiver or a lightwave radio transmitter or lightwave radio transmitter / receiver. The radio unit can have a Bluetooth module. The radio unit can comprise a microcontroller.

The monitoring module according to the invention allows the operating state of a piston accumulator system to be monitored independently by recording and transmitting operating data. An external energy source or an external energy supply is not required for this. Due to the continuous or repeated energy generation in the monitoring module itself, the energy required for monitoring is available even after very long operating times. The operating data can be recorded directly on the monitoring module and relate in particular to the piston. Undesired, in particular dangerous, operating states of a piston accumulator system can be detected with the monitoring module according to the invention, so that, if necessary, suitable countermeasures can be initiated in good time.

The energy generation unit can have at least one magnet arranged on the moving part and at least one coil arranged on the housing part, preferably have a plurality of magnets and / or coils arranged symmetrically to the longitudinal axis. By induction due to a relative movement of magnet (s) and coil (s), a relatively large amount of electrical energy can be obtained easily and reliably. The at least one magnet is preferably arranged on a rim of the moving part that is located radially outside with respect to the longitudinal axis. The at least one magnet can be a (single) ring magnet. If there are several magnets, a separate coil can be provided for each magnet.

The moving part can preferably be moved from a neutral position in both directions along the longitudinal axis against the action of a spring device relative to the housing part. As a result, electrical energy can be generated regardless of the direction of a change in movement. A resonance frequency of the moving part preferably corresponds to a clock frequency of a pump for charging a piston accumulator system with the monitoring module. This allows a particularly large amount of electrical energy to be generated.

It can be provided that at least one first support magnet and at least one second support magnet of the spring device are arranged on the housing part, between which the at least one magnet of the energy generation unit is arranged. The at least one magnet thus serves on the one hand for inductive energy generation and on the other hand at the same time for resilient mounting of the moving part by magnetic levitation. The support magnets are preferably aligned in such a way that they each repel the magnet of the power generation unit from themselves. The support magnet or the support magnets can also be used to hold the monitoring module on the piston.

Alternatively or additionally, it can be provided that the spring device has at least one spring element, preferably two spring elements acting against one another. The usage of (Linear) spring elements make it possible to set up a resonance frequency that is independent of the movement amplitude of the moving part. The spring element or the spring elements can be coil springs. The spring element or the spring elements can be supported on the one hand on the moving part and on the other hand on the housing part. The spring element or the spring elements can encompass a guide rod of the housing part on which the moving part is displaceably guided.

The moving part can have extensions which are guided in grooves in the housing part. The extensions can prevent a rotation of the moving part about a movement axis. The extensions can be arranged on a rim of the moving part.

The housing part can have a guide rod on which the moving part is guided with a sleeve section. The guide rod can define a direction of movement of the moving part with respect to the housing part. The guide rod is preferably arranged on a housing cover of the housing part.

The sleeve section is preferably connected to a rim of the moving part via spokes. Extensions for guidance in grooves of the housing part can be formed on the rim. Components of the energy generation unit, for example accumulators, and / or or of the sensor system can be arranged in a space-saving manner between the spokes.

It can be provided that a housing cover of the housing part has printed conductor tracks, and that at least one sensor of the sensor arrangement is arranged on the housing cover, preferably all sensors of the sensor arrangement are arranged on the housing cover. The energy storage unit is preferably also arranged on the housing cover. This enables a particularly compact and integrated design of the monitoring module.

The housing part and the moving part are preferably designed to be rotationally symmetrical with respect to the longitudinal axis. This can simplify the assembly of the monitoring module. Furthermore, a rotational symmetry can counteract a tilting of the moving part with respect to the housing part in the event of an axial relative movement. The rotational symmetry can be established with respect to rotations by 90 ° or 120 ° or multiples thereof.

Monitoring method according to the invention

The scope of the present invention also includes a method for monitoring a piston accumulator system with an accumulator housing and a flying piston which separates a gas space and a liquid space in the accumulator housing from one another. The flying piston has no mechanical connection from the accumulator housing. In particular, there is no piston rod extending out of the storage housing. The piston accumulator system is preferably a piston accumulator system according to the invention, particularly preferably with a monitoring module according to the invention.

1. a) Antreiben einer Energiegewinnungseinheit mittels des Kolbens und Erzeugen elektrischer Energie,
2. b) Betreiben einer an dem Kolben angeordneten Sensoranordnung mit der elektrischen Energie und Ermitteln von Betriebsdaten des Kolbenspeichersystems mittels der Sensoranordnung,
3. c) Drahtloses Übermitteln der Betriebsdaten.

The procedure consists of the following steps:

1. a) Driving an energy generation unit by means of the piston and generating electrical energy,
2. b) operating a sensor arrangement arranged on the piston with the electrical energy and determining operating data of the piston storage system by means of the sensor arrangement,
3. c) Wireless transmission of the operating data.

The energy generation unit is basically arranged on the piston. The sensor arrangement has at least one sensor. The operating data can include the measured values of the sensor or sensors. Alternatively or additionally, the operating data can be derived from the measured values. The sensor arrangement can have an evaluation unit for processing measured values of the sensor arrangement. The transmitted operating data are typically further processed outside of the memory housing.

This method allows a piston accumulator system, in particular its piston, to be monitored, preferably with regard to a sealing arrangement of the piston, without an external energy supply. With the method according to the invention, operating data can be recorded and transmitted on the flying piston that were previously inaccessible. In particular, the recorded and transmitted operating data can allow conclusions to be drawn about a possible leakage of the sealing arrangement on the piston. Undesired, in particular dangerous, operating states of the piston accumulator system can therefore be recognized and eliminated before consequential damage occurs.

The electrical energy is preferably temporarily stored between steps a) and b). The energy generation and the determination and transmission of the operating data can thus be separated from one another in terms of time. In particular, operating data can also be determined when no electrical energy can be generated, for example when the piston storage system is in an idle state.

A functional efficiency parameter of the piston accumulator system is preferably determined from the operating data. The functional capability parameter can indicate a current performance, in particular a maximum amount of energy that can be called up, in relation to a nominal performance of the piston accumulator system that is new, in particular not deteriorated by wear. The functional capability parameter can alternatively or additionally describe a state of wear of a sealing arrangement of the piston. The functionality parameter can indicate when maintenance of the piston accumulator system is required. As an alternative or in addition, the functionality characteristic value can indicate whether a security-relevant problem has occurred. In this case, the health characteristic typically comprises a binary value.

A leak via a sealing arrangement of the piston can be determined from the operating data. The leakage can be a leakage of gas from the gas space into the liquid space. Alternatively or additionally, leakage of liquid from the liquid space into the gas space can be determined. In particular, a leakage rate and / or a leakage volume can be determined in each case. A failure of the sealing arrangement endangers the functionality of the piston accumulator system. If an (impermissible) leakage is detected via the sealing arrangement, the piston accumulator system can be put out of operation and repaired before it fails.

It can be provided that a monitoring module of the piston accumulator system, which has the energy generation unit, the sensor arrangement and a radio unit for transmitting the operating data, is switched from a sleep mode to a monitoring mode when a predefined wake-up event takes place. In the idle mode, the monitoring module consumes particularly little energy. By switching the monitoring module from the sleep mode to the monitoring mode only when required, it can be achieved that sufficient electrical energy is still stored in an energy storage unit of the monitoring module for the acquisition of operating data of the piston storage system. The wake-up event can be a predefined acceleration of the piston or a predefined travel path of the piston relative to the accumulator housing being exceeded. The wake-up event can be the generation of a predefined electrical voltage or a predefined amount of electrical energy by the energy generation unit. The wake-up event can be triggered by an operator, for example by pressing a button or selecting a button. This means that the monitoring module can be kept in (energy-saving) sleep mode for a particularly long time; Monitoring only takes place on special request by the operator.

A lubrication state of the piston can be inferred from a movement profile of the piston. The lubrication state can in particular relate to a sealing arrangement of the piston. If a predetermined number of movements of the piston which do not reach a minimum travel distance of the piston are exceeded, a condition of insufficient lubrication can be recognized. Insufficient lubrication can increase the wear and tear on the sealing arrangement and, in the worst case, lead to its failure. By recognizing insufficient lubrication conditions, maintenance measures can be planned and taken before damage occurs.

The electrical energy obtained in step a) can be used to actively influence the piston, in particular to increase the lubrication of a sealing arrangement of the piston. This can reduce wear on the sealing arrangement. For this purpose, for example, a bypass can be opened to bypass a seal of the sealing arrangement.

Further features and advantages of the invention emerge from the description and the drawing. According to the invention, the features mentioned above and those detailed below can be used individually or collectively in any desired, expedient combinations. The embodiments shown and described are not to be understood as an exhaustive list, but rather have an exemplary character for describing the invention.

Figure list

• 1 ein erfindungsgemäßes Kolbenspeichersystem mit einem fliegenden Kolben, der in einem Speichergehäuse einen Gasraum von einem Flüssigkeitsraum trennt und an dem ein erfindungsgemäßes Überwachungsmodul angeordnet ist, in einer schematischen Schnittansicht;
• 2 einen gehäuseseitigen Bereich des Kolbens aus 1 mit Aufnahmenuten für Dichtungseinrichtungen zur Abdichtung des Kolbens gegenüber dem Speichergehäuse, in einer schematischen Schnittansicht;
• 3 eine Aufnahmenut des Kolbens aus 1 mit einer darin angeordneten Dichtungseinrichtung mit einem ersten Dichtelement, das eine Haltenut für ein zweites Dichtelement aufweist, wobei sich ein Druckkanal von einem Nutgrund der Haltenut durch das erste Dichtelement erstreckt, und wobei an dem ersten und dem zweiten Dichtelement jeweils zwei dynamische Dichtabschnitte zur Abdichtung an dem Speichergehäuse ausgebildet sind, in einer schematischen Schnittansicht;
• 4 eine weitere Dichtungseinrichtung mit einem ersten Dichtelement, das zwei Haltenuten für zweite Dichtelemente aufweist, wobei die zweiten Dichtelemente jeweils einen dynamischen Dichtabschnitt zur Abdichtung an dem Speichergehäuse aufweisen, und wobei sich zwischen den Haltenuten ein Druckkanal durch das erste Dichtelement erstreckt, in einer schematischen Schnittansicht;
• 5 eine weitere Dichtungseinrichtung mit einem ersten Dichtelement, an dem ein erster dynamischer Dichtabschnitt ausgebildet ist und das eine Haltenut für ein zweites Dichtelement mit einem zweiten dynamischen Dichtabschnitt aufweist, wobei sich zwischen dem ersten dynamischen Dichtabschnitt und der Haltenut ein Druckkanal durch das erste Dichtelement erstreckt, in einer schematischen Schnittansicht;
• 6 einen Kolben für ein erfindungsgemäßes Kolbenspeichersystem mit einem erfindungsgemäßen Überwachungsmodul, welches eine Energiegewinnungseinrichtung mit einem Gehäuseteil und einem Bewegungsteil, eine Energiespeichereinheit, eine Sensoranordnung und eine Funkeinheit aufweist, in einer schematischen Schnittansicht;
• 7 das Bewegungsteil und zwei ringförmige Elemente des Gehäuseteils des Überwachungsmoduls aus 6, wobei zwischen den beiden ringförmigen Elementen eine Spule zur induktiven Erzeugung elektrischer Energie bei Bewegung des Bewegungsteils angeordnet ist, in einer schematischen Perspektivansicht;
• 8 die Spule und eines der ringförmigen Elemente des Gehäuseteils sowie das Bewegungsteil des Überwachungsmoduls aus 6, in einer schematischen Perspektivansicht;
• 9 eines der ringförmigen Elemente des Gehäuseteils des Überwachungsmoduls aus 7, wobei das ringförmige Element Stützmagnete zur Befestigung des Gehäuseteils an dem Kolben und zur magnetischen Levitation des Bewegungsteils aufweist, in einer schematischen Perspektivansicht;
• 10 einen Gehäusedeckel des Gehäuseteils des Überwachungsmoduls aus 6, wobei an dem Gehäusedeckel eine Führungsstange zur Führung des Bewegungsteils und Speicherelemente der Energiespeichereinheit angeordnet sind, in einer schematischen Perspektivansicht;
• 11 ein schematisches Ablaufdiagramm eines erfindungsgemäßen Überwachungsverfahren für ein Kolbenspeichersystem.

The invention is shown in the drawing and is explained in more detail using exemplary embodiments. Show it:

• 1 a piston storage system according to the invention with a flying piston which separates a gas space from a liquid space in a storage housing and on which a monitoring module according to the invention is arranged, in a schematic sectional view;
• 2 a housing-side area of the piston 1 with receiving grooves for sealing devices for sealing the piston against the accumulator housing, in a schematic sectional view;
• 3 a receiving groove of the piston 1 with a sealing device arranged therein with a first sealing element, the one Has retaining groove for a second sealing element, wherein a pressure channel extends from a groove base of the retaining groove through the first sealing element, and wherein two dynamic sealing sections are formed on the first and the second sealing element for sealing on the storage housing, in a schematic sectional view;
• 4th a further sealing device with a first sealing element which has two retaining grooves for second sealing elements, the second sealing elements each having a dynamic sealing section for sealing on the storage housing, and wherein a pressure channel extends through the first sealing element between the retaining grooves, in a schematic sectional view;
• 5 a further sealing device with a first sealing element on which a first dynamic sealing section is formed and which has a retaining groove for a second sealing element with a second dynamic sealing section, a pressure channel extending through the first sealing element between the first dynamic sealing section and the retaining groove, in a schematic sectional view;
• 6th a piston for a piston storage system according to the invention with a monitoring module according to the invention, which has an energy generation device with a housing part and a moving part, an energy storage unit, a sensor arrangement and a radio unit, in a schematic sectional view;
• 7th the moving part and two ring-shaped elements of the housing part of the monitoring module 6th , wherein a coil for the inductive generation of electrical energy when the moving part is moved is arranged between the two ring-shaped elements, in a schematic perspective view;
• 8th the coil and one of the annular elements of the housing part and the moving part of the monitoring module 6th , in a schematic perspective view;
• 9 one of the annular elements of the housing part of the monitoring module 7th , wherein the annular element has support magnets for fastening the housing part to the piston and for magnetic levitation of the moving part, in a schematic perspective view;
• 10 a housing cover of the housing part of the monitoring module 6th , wherein a guide rod for guiding the moving part and storage elements of the energy storage unit are arranged on the housing cover, in a schematic perspective view;
• 11 a schematic flow diagram of a monitoring method according to the invention for a piston accumulator system.

1 shows a piston accumulator system 10 . The piston accumulator system 10 has a storage enclosure 12th on. In the storage enclosure 12th is a flying piston 14th arranged. The flying piston 14th is in the storage enclosure 12th along a longitudinal axis 15th versatile. The flying piston 14th separates a gas space 16 from a liquid space 18th . The gas room 16 is filled with nitrogen. The fluid space 18th is filled with oil, especially hydraulic oil.

On the piston 14th is a monitoring module 20th arranged. The monitoring module 20th is here in a trough on the gas side 22nd of the piston 14th recorded. The hollow 22nd can also be used as a recess in the piston 14th are designated. Components of the monitoring module 20th are in 1 shown in a highly abstracted manner.

The monitoring module 20th has an energy generation unit 24 and an energy storage unit 26th on. The energy generation unit 24 is from the piston 14th driven and used to generate electrical energy. The energy generation unit 24 can for this purpose convert energy, in particular mechanical energy, into electrical energy. The energy storage unit 26th serves for the intermediate storage of the energy generation unit 24 generated electrical energy. To the energy storage unit 26th to be able to provide an input voltage which is greater than an output voltage of the energy generation unit 24 , the monitoring module can 20th one in 1 have voltage converters not shown in detail. The energy storage unit 26th can have one or more accumulators and / or capacitors.

The monitoring module 20th further comprises a sensor arrangement 28 on. The sensor arrangement 28 is used to determine the operating data of the piston accumulator system 10 . The sensor arrangement 28 can do a variety of in 1 sensors not shown in detail include, for example, a gas pressure sensor for measuring a gas pressure in the gas space 16 , a liquid pressure sensor for measuring a liquid pressure in the liquid space 18th , Temperature sensors for measuring temperatures in the gas space 16 or liquid space 18th , an acceleration sensor, a distance sensor for measuring a distance of the piston 14th of one the gas compartment 16 limiting end face 30th of the storage enclosure 12th and / or an impedance sensor for measuring an impedance in the gas space 16 . The sensor arrangement 28 can also have a Intermediate seal pressure sensor for measuring an intermediate seal pressure between two sealing devices of a sealing arrangement of the piston 14th and / or have an inner seal pressure sensor for measuring an inner seal pressure between two sealing sections of a sealing device. The sensor arrangement 28 can furthermore have an evaluation unit for processing measured values from the individual sensors.

The monitoring module 20th furthermore has a radio unit 32 on. The radio unit 32 is used to transmit the data from the sensor arrangement 28 recorded or determined operating data of the piston accumulator system 10 . The radio unit 32 can be a bluetooth module. To that of the radio unit 32 To receive the transmitted operating data, the gas compartment 16 limiting end face 30th of the storage enclosure 12th another radio unit 34 be arranged. At the front 30th can be an implementation 36 for connecting the additional radio unit 34 be trained. The implementation 36 is basically sealed gas-tight.

The sensor arrangement 28 and the radio unit 32 are included in the energy generation unit 24 generated electrical energy operated. The electrical energy can the sensor arrangement 28 or the radio unit 32 immediately when they are generated in the energy generation unit 24 are fed. Typically the sensor arrangement 28 and the radio unit 32 but from the energy storage unit 26th supplied with electrical energy.

In 2 is a radially outer area of the piston 14th of the piston accumulator system 10 from 1 shown enlarged. The piston 14th adjoins a cylinder wall radially on the outside 38 of the storage enclosure 12th at. The perimeter wall 38 surrounds the longitudinal axis 15th ring-shaped, compare also 1 .

The piston 14th has two grooves 40 for two in the 1 and 2 Sealing devices, not shown, have a two-stage sealing arrangement. One of the sealing devices is designed as a liquid-side sealing device and is closer to the liquid space 18th arranged; the other sealing device is designed as a gas-side sealing device and is closer to the gas space 16 arranged.

The grooves 40 are along the longitudinal axis 15th spaced from each other. Between the two grooves 40 a connecting channel opens 42 . The connection channel 42 transfers one between the two in the grooves 40 held sealing devices prevailing pressure (referred to here as intermediate seal pressure) to the intermediate seal pressure sensor. The connection channel 42 can radially outward into a circumferential groove 43 , which is between the grooves 40 all around the piston 14th extends, open.

In one of the two grooves 40 opens a connection channel 44 . The connection channel 44 transfers one in the receiving groove 40 prevailing pressure (here referred to as inner seal pressure) to the inner seal pressure sensor. The second slot too 40 can have a further connection channel for a further inner seal pressure sensor of the sensor arrangement 28 have (not shown).

The piston 14th also has two guide grooves 46 on. In the guide grooves 46 are in the 1 and 2 Guide bands, not shown in detail, for supporting the piston 14th on the cylinder wall 38 of the storage enclosure 12th arranged. The two grooves 40 for the sealing devices can in the axial direction between the two guide grooves 46 be trained.

3 shows a sealing device 48 a sealing arrangement 50 . The sealing device 48 is in the receiving groove 40 of the piston 14th , compare 1 and 2 , arranged. The sealing device 48 seals the piston 14th opposite the cylinder wall 38 of the storage enclosure 12th from. Also in the second slot 40 can such a sealing device 48 be arranged.

The sealing device 48 has a first sealing element 52 on. The first sealing element 52 has a first and a second dynamic sealing section 54a , 54b on. When the piston moves 14th the dynamic sealing sections slide 54a , 54b of the first sealing element 52 on the cylinder wall 38 along.

The sealing device 48 also has two biasing elements 56 on. The prestressing elements 56 press the first sealing element 52 , especially its dynamic sealing sections 54a , 54b in to the longitudinal axis 15th radial direction against the cylinder wall 38 . The prestressing elements 56 are each designed as O-rings here. The prestressing elements 56 can use the first sealing element 52 static with respect to the piston 14th seal. Between the two prestressing elements 56 extends an appendix 58 of the first sealing element 52 radially inwards. Through the appendix 58 are the two prestressing elements 56 spaced from one another in the axial direction.

The first sealing element 52 has a retaining groove 60 on. The retaining groove 60 is in the axial direction between the two dynamic sealing sections 54a , 54b arranged. Starting from a groove base 62 the retaining groove 60 extends a pressure channel 64 through the first sealing element 52 . The pressure channel 64 runs here through the appendix 58 . Of the Pressure channel 64 connects the retaining groove 60 fluidically with the circumferential groove 43 or the connection channel 42 of the piston 14th .

In the holding groove 60 is a second sealing element 66 the sealing device 48 arranged. The second sealing element 66 can be formed with an X-shaped cross section. The second sealing element 66 has two more dynamic sealing sections here 68a , 68b on. When the piston moves 14th the other dynamic sealing sections slide 68a , 68b of the second sealing element 66 on the cylinder wall 38 along. The second sealing element 66 also has two static sealing sections 70a , 70b on. The pressure channel 64 opens between the two static sealing sections 70a , 70b in the holding groove 60 . When the second sealing element 66 in the holding groove 60 should twist, transmit the pressure channel 64 and the connection channel 42 between the two dynamic sealing sections 54a , 54b of the first sealing element 52 prevailing inner seal pressure to the inner seal pressure sensor of the sensor arrangement 28 . The inner seal pressure sensor therefore enables the correct arrangement and alignment of the second sealing element to be monitored 66 .

The two dynamic sealing sections 54a , 54b of the first sealing element 52 act primarily as a liquid seal, in particular when the piston 14th emotional. The two dynamic sealing sections 68a , 68b of the second sealing element 66 act primarily as a gas seal. With the piston at a standstill 14th the two dynamic sealing sections act 68a , 68b of the second sealing element 66 also as a static liquid seal for leakage of liquid via the sealing device 48 opposite.

4th shows a further sealing device 72 for the piston 14th a piston accumulator system 10, compare 1 . The sealing device 72 has a first sealing element 74 and two second sealing elements 76 on. The sealing arrangement 72 can via preload elements 56 pre-tensioned in a receiving groove 40 of the piston 14th be arranged, compare 3 . The first sealing element 74 and the second sealing elements 76 the sealing device 72 replace the first and the second sealing element 52 , 66 the sealing device 48 .

The first sealing element 74 has two retaining grooves 78 on. In each of the two holding grooves 78 is one of the second sealing elements 76 arranged. On the two second sealing elements 76 is a dynamic sealing section 80 for sealing on the storage housing 12th educated. The second sealing elements 76 furthermore each have two static sealing sections 82 for sealing against the first sealing element 74 on. The second sealing elements 76 can each have a V-shaped cross-section. On the first sealing element 74 can have additional dynamic sealing sections 84 be trained.

Between the two holding grooves 78 or between the two second sealing elements 76 extends a pressure channel 86 through the first sealing element 74 . The pressure channel 86 transmits one between the two second sealing elements 76 or between the axially inner further sealing sections 84 prevailing inner seal pressure to an inner seal pressure sensor of the sensor arrangement 28 .

5 shows a further sealing device 88 for the piston 14th a piston accumulator system 10 , compare 1 . The sealing device 88 has a first sealing element 90 and a second sealing element 92 on. The sealing arrangement 88 can have prestressing elements 56 pre-tensioned in a receiving groove 40 of the piston 14th be arranged, compare 3 . The first sealing element 90 and the second sealing element 92 the sealing device 88 replace the first and the second sealing element 52 , 66 the sealing device 48 .

The first sealing element 90 has a retaining groove 94 on. In the holding groove 94 is the second sealing element 92 arranged. On the first sealing element 90 is a first dynamic sealing section 96 educated. On the second sealing element 92 is a second dynamic sealing section 98 educated. The first dynamic sealing section 96 is typically the liquid space 18th assigning to the piston 14th arranged; the second dynamic sealing section 98 is typically the gas space 16 assigning to the piston 14th arranged. On both sides of the second sealing element 92 or the retaining groove 94 can have additional dynamic sealing sections 100 on the first sealing element 90 be trained.

The second sealing element 92 also has two static sealing sections 82 for sealing against the first sealing element 90 on. The second sealing element 92 may have a V-shaped cross-section.

Between the first dynamic sealing section 96 of the first sealing element 90 and the second sealing element 92 or the retaining groove 94 extends a pressure channel 102 through the first sealing element 90 . The pressure channel 102 transmits one between the two dynamic sealing sections 96 , 98 prevailing inner seal pressure to an inner seal pressure sensor of the sensor arrangement 28 .

6th shows a piston 14th for a piston accumulator system 10 , compare 1 . The piston 14th has two in guide grooves 46 held Guide bands 103 on. The guide bands 103 grip the piston 14th ring-shaped. In the axial direction with respect to a longitudinal axis 15th between the two guide bands 103 points the piston 14th a, here single-stage, sealing arrangement 50 on. A sealing device of the sealing arrangement 50 is in a receiving groove 40 of the piston 14th held. The sealing device can be one of the sealing devices described above 48 , 72 or 88 be, compare 3 , 4th or 5 .

On the piston 14th is a monitoring module 20th held detachable. The monitoring module 20th can be magnetically attached to the piston 14th be attached. The monitoring module 20th is here mostly in a hollow 22nd of the piston 14th sunk.

The monitoring module has an energy generation unit 24 , an energy storage unit 26th , a sensor array 28 and a radio unit 32 on. With regard to their functions and in particular the sensor equipment of the sensor arrangement 28 reference is made to the above description.

The energy generation unit 24 has a housing part 104 and a moving part 106 on. The moving part 106 is along a longitudinal axis 15th opposite the housing part 104 movable. I'm in the storage enclosure 12th inserted condition of the piston 14th is the piston 14th in turn along the longitudinal axis 15th in the storage enclosure 12th movable, compare 1 . The housing part 104 has two annular elements 108a , 108b , compare also 7th , 8th and 9 , and a housing cover 110 , compare also 10 , on. The two ring-shaped elements 108a , 108b can be constructed identically. Between the two annular elements 108a , 108b is a coil 112 arranged. The sink 112 is used for the inductive generation of electrical energy when the moving part moves 106 . The moving part 106 has several magnets 114 on. The magnets 114 are on a rim 116 of the moving part 106 held. The magnets 114 are here symmetrical with respect to the longitudinal axis 15th arranged, compare 8th .

The two ring-shaped elements 108a , 108b of the moving part 104 each have several, here six, supporting magnets 118a , 118b on. The magnets 114 of the moving part 106 are (in the axial direction with respect to the longitudinal axis 15th ) between the support magnets 118a , 118b of the two annular elements 108a , 108b arranged. The support magnets 118a , 118b are oriented in such a way that they hold the magnets 114 of the moving part 106 repel each. The moving part 106 is thereby between the two annular elements 108a , 108b held in suspension so that there is an acceleration of the piston 14th or the housing part 104 in both directions along the longitudinal axis 15th relative to the housing part 104 can move. The magnets 114 and the support magnets 118a , 118b in this respect form a spring device of the energy generation unit 24 . The support magnets 118a des (in 6th lower) annular element 108a can also be used to attach the monitoring module 20th on the piston 14th magnetically on a piston crown 119 of the piston 14th be held.

The rim 116 of the moving part 106 can have spokes 120 with a sleeve section 122 be connected, compare in particular 7th and 8th . About the sleeve section 122 can the moving part 106 on a guide rod 124 of the housing part 104 be led, compare 6th . The guide bar 124 is here on the housing cover 110 held, compare 10 .

To prevent the moving part 106 around the longitudinal axis 15th opposite the housing part 104 rotates or tilts about a transverse axis, a further guidance of the moving part 106 on the housing part 104 be set up. Here the moving part points 106 Appendages 126 on, compare 8th . The two ring-shaped elements 108a , 108b each have grooves 128 on, compare 8th and 9 . In the assembled state of the annular elements 108a , 108b complement the respective grooves 128 each other and extend parallel to the longitudinal axis 15th . The appendages 126 grip into the grooves 128 a, compare 7th and 8th .

The moving part 106 and the annular elements 108a , 108b of the housing part 104 can be rotationally symmetrical with respect to the longitudinal axis 15th be trained. The moving part 106 is here rotationally symmetrical with regard to rotations of 120 ° or multiples thereof. The annular elements 108a , 108b are rotationally symmetrical here with regard to rotations of 60 ° or multiples thereof.

On the housing cover 110 can not be shown in detail conductor tracks for the electrical connection of the power generation unit 24 the energy storage unit 26th , the sensors of the sensor array 28 as well as the radio unit 32 be trained. The conductor tracks can be printed on the housing cover, in particular on both sides. Some or all of the sensors in the sensor array 28 and the radio unit 32 can be attached to the housing cover 110 be held. The radio unit 32 and, for example, a gas pressure sensor for measuring a gas pressure in the gas space 16 or a distance sensor for measuring a distance of the piston 14th from one end face 30th a storage enclosure 12th can on the outside of the housing cover 110 be arranged, compare 6th . Other sensors of the sensor arrangement 28 , for example an acceleration sensor, can be attached to the inside of the housing cover 110 be arranged. Also components of the energy storage unit 26th , for example capacitors 130 , can be found on the inside of the housing cover 110 be arranged, compare 10 .

11 shows a flow chart of a monitoring method for a piston accumulator system. The method is exemplified below using the piston accumulator system described above 10 , compare 1 , or the monitoring module 20th , compare 6th described.

Before the procedure is carried out, the monitoring module 20th are in an energy-saving sleep mode. The monitoring module 20th is then in one step 202 initially switched to a monitoring mode. The sensor system is in the monitoring mode 28 activated. This can be triggered by a user. Alternatively, it can be provided that the monitoring module 20th a movement of the piston 14th detects and automatically activates the monitoring mode.

Then in one step 204 the energy generation unit 24 from the piston 14th driven so that electrical energy is generated. Oscillations or vibrations of the piston can be used for this purpose 14th be used, since this is a relative movement between the moving part 106 and the housing part 104 cause. The electrical energy generated is in one step 206 at least predominantly in the energy storage unit 26th cached.

The ones in the energy storage unit 26th stored electrical energy is created in one step 208 used the sensor assembly 28 to operate and in one step 210 Operating data of the piston accumulator system 10 to determine. The operating data can be measured values from sensors in the sensor arrangement 28 correspond and / or by means of an evaluation unit of the sensor arrangement 28 be derived from the measured values. The steps 208 and 210 are typically carried out at the same time. The operating data determined are finally in one step 212 from the radio unit 32 of the monitoring module 20th to the other radio unit 34 transmitted by radio. Also the radio unit 32 is powered by electrical energy from the energy storage unit 26th operated. The other radio unit 34 is typically connected via cables to a power supply and an analysis unit, for example a PC. In the analysis unit, the operating data can be processed in one step 214 further analyzed. Alternatively or additionally, the operating data and / or information derived from the operating data can be further transmitted by the analysis unit via a radio link, for example to one of the storage housing 12th remotely located (possibly additional) PC.

When analyzing the operating data, a functional efficiency parameter of the piston accumulator system can in particular 10 to be determined. The functional efficiency parameter can indicate how high the efficiency of the piston accumulator system is 10 compared to a new piston accumulator system 10 is.

It can also be determined whether there is a leak through the sealing arrangement 50 of the piston has taken place. In particular, a leakage volume and / or a leakage rate (volume flow) can be determined. If a leak has occurred, it is preferably also determined whether there is gas from the gas space 16 into the liquid space 18th has reached or, conversely, whether liquid is from the liquid space 18th in the gas compartment 16 has arrived. Particularly preferably, it can also be recognized whether a leak has occurred in both directions.

Furthermore, a lubrication state of the piston 14th be estimated. A movement profile of the piston can be used for this purpose 14th be evaluated. In particular, it can be determined that there is a lack of lubrication if the piston has moved a predetermined number of times 14th has not reached a minimum travel distance.

The aforementioned analyzes can alternatively already be carried out in the evaluation unit of the sensor arrangement 28 be performed. The operating data then contain the corresponding analysis results.

If necessary, it can be done in one step 216 The piston 14th actively influenced. An influencing order can be sent from the further radio unit 34 to the radio unit 32 of the monitoring module 20th be transmitted. The other radio unit 34 can also be used to send radio signals and the radio unit 32 can also be designed to receive radio signals. To influence the piston 14th is from the power generation unit 24 generated electrical energy is used, typically this in the energy storage unit 26th was cached. The active influencing can aim, for example, at a lubrication state of the sealing arrangement 50 of the piston 14th to increase. To do this, a valve can be opened or an active material on the piston 14th are electrically deformed, so that oil from the liquid space 18th in the area of dynamic sealing sections 54a , 54b , 68a , 68b or. 80 or. 96 , 98 , compare 3 , 4th or 5 , got.

In a final step 218 can the monitoring module 20th again in the Can be switched to sleep mode. Most of the sensors in the sensor arrangement are inactive in the idle mode. In particular, an acceleration sensor can also remain active in the idle mode in order to switch over automatically 202 to enable monitoring mode. By switching 218 In the idle mode, it can be achieved that in a renewed process run immediately after switching on the monitoring mode in a new step 202 enough electrical energy in the energy storage unit 26th is stored to the sensor assembly 28 to be able to operate to determine operational data.

The steps 204 to 216 can be carried out consecutively without a temporal overlap. Typically the steps 204 to 216 but carried out at least partially overlapping in time (simultaneously). In particular, the steps 204 to 214 and possibly also step 216 all take place at the same time.

1. a) Antreiben (204) einer Energiegewinnungseinheit (24) mittels des Kolbens (14) und Erzeugen elektrischer Energie,
2. b) Betreiben (208) einer an dem Kolben (14) angeordneten Sensoranordnung (28) mit der elektrischen Energie und Ermitteln (210) von Betriebsdaten des Kolbenspeichersystems (10) mittels der Sensoranordnung (28),
3. c) Drahtloses Übermitteln (212) der Betriebsdaten.

In summary, the invention relates to a piston accumulator system ( 10 ) with a storage enclosure ( 12th ) and a flying piston ( 14th ), which has a gas space ( 16 ) and a liquid space ( 18th ) in the storage enclosure ( 12th ) separates from each other, whereby a monitoring module ( 20th ) on the piston ( 14th ) is arranged, which one by means of the piston ( 14th ) drivable energy generation unit ( 24 ) for generating electrical energy, an energy storage unit ( 26th ) to store the electrical energy, a sensor arrangement ( 28 ) to determine the operating data of the piston accumulator system ( 10 ) and a radio unit ( 32 ) for transmitting the operating data. The invention also relates to a monitoring module ( 20th ) to be arranged on a piston ( 14th ) a piston accumulator system ( 10 ) having a means of the piston ( 14th ) drivable energy generation unit ( 24 ) with a housing part ( 104 ) and one relative to the housing part ( 104 ) along a longitudinal axis ( 15th ) moving moving part ( 106 ), whereby the energy generation unit ( 24 ) is set up, from a movement of the moving part ( 106 ) relative to the housing part ( 104 ) to generate electrical energy, an energy storage unit ( 26th ), a sensor arrangement ( 28 ) and a radio unit ( 32 ). Finally, the invention relates to a method for monitoring a piston accumulator system ( 10 ) with a flying piston ( 14th ), with the steps

1. a) driving ( 204 ) an energy generation unit ( 24 ) by means of the piston ( 14th ) and generating electrical energy,
2. b) operate ( 208 ) one on the piston ( 14th ) arranged sensor arrangement ( 28 ) with the electrical energy and determining ( 210 ) of operating data of the piston accumulator system ( 10 ) by means of the sensor arrangement ( 28 ),
3. c) Wireless transmission ( 212 ) the operating data.

List of reference symbols

Piston accumulator system

10

Storage enclosure

12th

piston

14th

Longitudinal axis

15th

Gas compartment

16

Fluid space

18th

Monitoring module

20th

trough

22nd

Energy generation unit

24

Energy storage unit

26th

Sensor arrangement

28

Front side

30th

Radio unit

32

further radio unit

34

execution

36

Cylinder wall

38

Grooves

40

Connection channel

42

Circumferential groove

43

Connection duct

44

Guide grooves

46

Sealing device

48

Sealing arrangement

50

first sealing element

52

first, second dynamic sealing section

54a, 54b

Prestressing elements

56

Appendix

58

Holding groove

60

Groove base

62

Pressure channel

64

second sealing element

66

further dynamic sealing sections

68a, 68b

static sealing sections

70a, 70b

Sealing device

72

first sealing element

74

second sealing elements

76

Holding grooves

78

dynamic sealing section

80

static sealing sections

82

further dynamic sealing sections

84

Pressure channel

86

Sealing device

88

first sealing element

90

second sealing element

92

Holding groove

94

first dynamic sealing section

96

second dynamic sealing section

98

further dynamic sealing sections

100

Pressure channel

102

Guide bands

103

Housing part

104

Moving part

106

annular elements

108a, 108b

Housing cover

110

Kitchen sink

112

Magnets

114

rim

116

Support magnets

118a, 118b

Piston crown

119

Spokes

120

Sleeve section

122

Guide rod

124

Appendages

126

Grooves

128

Capacitors

130

Activate monitoring mode

202

Driving the power generation unit 24

204

Caching

206

Operating the sensor assembly 28

208

Determination of operational data

210

Transmission of the operating data

212

Analyze the operational data

214

Influencing the piston 14

216

Activate sleep mode

218

Claims (31)

Piston storage system (10) with a storage housing (12) and a flying piston (14) which separates a gas space (16) and a liquid space (18) in the storage housing (12) from one another, characterized in that a monitoring module (20) on the Piston (14) is arranged, which has: - an energy generation unit (24) that can be driven by means of the piston (14) for generating electrical energy, - an energy storage unit (26) for storing the electrical energy, - a sensor arrangement (28) for determining Operating data of the piston storage system (10) and - a radio unit (32) for transmitting the operating data. Piston accumulator system (10) Claim 1 , characterized in that the sensor arrangement (28) - a gas pressure sensor for measuring a gas pressure in the gas space (16) and / or - a liquid pressure sensor for measuring a liquid pressure in the liquid space (18) and / or - a temperature sensor and / or - an acceleration sensor and / or - has a distance sensor and / or - an impedance sensor for measuring an impedance in the gas space (16). Piston accumulator system (10) according to one of the preceding claims, characterized in that the piston (14) has a sealing device (48; 72; 88) with a first and a second dynamic sealing section (54a, 54b; 80; 96, 98), and that the sensor system (28) has an inner seal pressure sensor for measuring an inner seal pressure between the first and the second dynamic sealing section (54a, 54b; 80; 96, 98). Piston accumulator system (10) Claim 3 , characterized in that the Sealing device (48; 72; 88) has a first sealing element (52; 74; 90) with a retaining groove (60; 78; 94) in which a second sealing element (66; 76; 92) is arranged, with at least one pressure channel (64; 86; 102) extends through the first sealing element (52; 74; 90). Piston accumulator system (10) Claim 4 , characterized in that the pressure channel (64) extends from the retaining groove (60), in particular a groove base (62) of the retaining groove (60), through the first sealing element (52). Piston accumulator system (10) Claim 4 , characterized in that the sealing device (72) has two retaining grooves (78), in each of which a second sealing element (76) is arranged, and that the pressure channel (86) extends between the two retaining grooves (78). Piston accumulator system (10) according to one of the Claims 4 to 6th , characterized in that the first sealing element (52; 74; 90) has an extension (58) through which the pressure channel (64; 86; 102) runs, and that the first sealing element (52; 74; 90) on both sides of the extension (58) is prestressed via a respective prestressing element (56) of the sealing device (48; 72; 88). Piston accumulator system (10) according to one of the preceding claims, characterized in that the piston (14) has a two-stage sealing arrangement with a liquid-side sealing device (48; 72; 88) and a gas-side sealing device (48; 72; 88), and that the sensor system (28) has an intermediate seal pressure sensor for measuring an intermediate seal pressure between the liquid-side and the gas-side sealing device (48; 72; 88). Piston accumulator system (10) according to one of the preceding claims, characterized in that a further radio unit (34) is arranged on the accumulator housing (12), in particular on an end face (30) of the accumulator housing (12) delimiting the gas space (16). Piston storage system (10) according to one of the preceding claims, characterized in that the piston (14) has a depression (22) on the gas chamber side, and that at least the energy generation unit (24), the energy storage unit (26) and the radio unit (32) of the monitoring module ( 20) are arranged in the trough (22). Piston storage system (10) according to one of the preceding claims, characterized in that the energy storage unit (26) has an accumulator and / or a capacitor (130). Piston accumulator system (10) according to one of the preceding claims, further comprising an actuator for influencing the piston (14). Piston storage system (10) according to one of the preceding claims, characterized in that the monitoring module (20) furthermore has a voltage converter, preferably a DC voltage converter, which is set up to convert an output voltage of the energy generation unit (24) to a maximum input voltage of the energy storage unit (26) to increase. Piston accumulator system (10) according to one of the preceding claims, characterized in that the monitoring module (20) is detachably attached to the piston (14), preferably held magnetically on the piston (14). Monitoring module (20) to be arranged on a piston (14) of a piston accumulator system (10) comprising: - An energy generation unit (24) which can be driven by means of the piston (14) and has a preferably ring-shaped housing part (104) and a moving part (106) that is movable relative to the housing part (104) along a longitudinal axis (15), the energy generation unit (24) is set up to generate electrical energy from a movement of the moving part (106) relative to the housing part (104), - an energy storage unit (26) for storing the electrical energy, - A sensor arrangement (28) for determining operating data of the piston accumulator system (10) and - A radio unit (32), in particular with a Bluetooth module, for transmitting the operating data. Monitoring module (20) after Claim 15 , characterized in that the energy generation unit (24) has at least one magnet (114) arranged on the moving part (106) and at least one coil (112) arranged on the housing part (104), preferably several each arranged symmetrically to the longitudinal axis (15) Has magnets (114) and coils (112). Monitoring module (20) after Claim 15 or 16 , characterized in that the moving part (106) can be moved from a neutral position in both directions along the longitudinal axis (15) against the action of a spring device relative to the housing part (104). Monitoring module (20) after Claim 16 and Claim 17 , characterized in that at least one first support magnet (118a) and at least one second support magnet (118b) of the spring device are arranged on the housing part (104), between which the at least one Magnet (114) of the energy generation unit (24) is arranged. Monitoring module (20) after Claim 17 , characterized in that the spring device has at least one spring element, preferably two spring elements acting against one another, in particular in the form of a helical spring. Monitoring module (20) according to one of the Claims 15 to 19th , characterized in that the moving part (106) has extensions (126) which are guided in grooves (128) of the housing part (104). Monitoring module (20) according to one of the Claims 15 to 20th , characterized in that the housing part (104) has a guide rod (124) on which the moving part (106) is guided with a sleeve section (122), preferably the guide rod (124) on a housing cover (110) of the housing part (104 ) is arranged. Monitoring module (20) after Claim 21 , characterized in that the sleeve section (122) is connected to a rim (116) of the moving part (106) via spokes (120). Monitoring module (20) according to one of the Claims 15 to 22nd , characterized in that a housing cover (110) of the housing part (104) has printed conductors, and that at least one sensor of the sensor arrangement (28) is arranged on the housing cover (110), preferably all sensors of the sensor arrangement (28) on the housing cover ( 110) are arranged. Monitoring module (20) according to one of the Claims 15 to 23 , characterized in that the housing part (104) and the moving part (106) are designed to be rotationally symmetrical with respect to the longitudinal axis (15). Method for monitoring a piston accumulator system (10) with an accumulator housing (12) and a flying piston (14) which separates a gas space (16) and a liquid space (18) in the accumulator housing (12) from one another, comprising the steps a) driving (204) an energy generation unit (24) by means of the piston (14) and generating electrical energy, b) operating (208) a sensor arrangement (28) arranged on the piston (14) with the electrical energy and determining (210) operating data of the piston storage system (10) by means of the sensor arrangement (28), c) wirelessly transmitting (212) the operating data. Procedure according to Claim 25 , characterized in that the electrical energy is temporarily stored between steps a) and b). Procedure according to Claim 25 or 26th , characterized in that a functional efficiency value of the piston accumulator system (10) is determined from the operating data. Method according to one of the Claims 25 to 27 , characterized in that a leak via a sealing arrangement (50) of the piston (14) is determined from the operating data. Method according to one of the Claims 25 to 28 , characterized in that a monitoring module (20) of the piston accumulator system (10), which has the energy generation unit (24), the sensor arrangement (28) and a radio unit (32) for transmitting the operating data, is switched from a sleep mode to a monitoring mode when a predefined wake-up event takes place. Method according to one of the Claims 25 to 29 , characterized in that a movement profile of the piston (14) is used to deduce a lubrication state of the piston (14), in particular wherein when a predetermined number of movements of the piston (14) which do not reach a minimum travel distance of the piston (14) are exceeded, a lack of lubrication is recognized. Method according to one of the Claims 25 to 30th , characterized in that the electrical energy obtained in step a) is used to actively influence the piston (14), in particular to increase the lubrication of a sealing arrangement (50) of the piston (14).

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