Method and system for supplying a bearing arrangement

Abstract

Method for supplying at least one bearing arrangement (84) serving to guide components that can move relative to one another with an operating medium (18), in particular a lubricant, in which the operating medium (18) is guided from an operating medium reservoir (20) via a first valve arrangement (I) into at least one closed container (22) arranged underneath, the closed container (22) is connected to the bearing arrangement (84) via a conveying channel (24), and externally pressurised gas and / or ambient air is supplied to the closed container (22) via a second valve arrangement (II), in order to convey operating medium (18) from the closed container (22) via the conveying channel (24) with the aid of the differential pressure between the gas supplied to the container (22) and the ambient air.Ambient air and a bearing-side mouth region (26) of the conveying channel (24), which is in particular under negative pressure, to the bearing arrangement (84); characterized in that the operating medium (18) and the gas or ambient air are separated from one another within the closed container (22) by means of a membrane (108).

Description

The present invention relates to a method and a system for supplying at least one bearing arrangement serving for guiding mutually movable components with a working medium, in particular a lubricant, according to the preamble of claim 1 or claim 6, as is known in the art substantially from AT 504 155 A2, for example. A system substantially comparable in type is also disclosed in U.S. Pat. No. 4,157,132 A.Bearings for, for example, rotors of pumps, such as, in particular, vacuum pumps, must be lubricated with the exception of contactless active magnetic bearings. It has been found that active lubrication with operating means is advantageous compared to passive continuous lubrication of grease.Previously, the delivery of the operating or lubricant to such bearings has been effected by means of active pumps, such as a worm shaft or a rotating lubricant pump, which is relatively complicated.The object of the invention is thus to specify a method and a system of the type mentioned at the beginning, with which the outlay for the most optimum possible supply of operating medium to the bearing arrangement is reduced to a minimum. This method and this system should be usable in particular in apparatuses under reduced pressure, in particular in vacuum apparatuses.This object is achieved according to the invention by a method having the features of claim 1 and a system having the features of claim 6.According to the method according to the invention for supplying at least one bearing arrangement serving for guiding mutually movable components with a working medium, in particular a lubricant, the working medium is conducted from a working medium reservoir via a first valve arrangement into at least one closed container arranged beneath it, the closed container is connected via a conveying channel to the bearing arrangement and externally applied gas and / or ambient air is supplied to the closed container via a second valve arrangement in order to convey working medium from the closed container via the conveying channel supported by the differential pressure between the gas or ambient air supplied to the container and a bearing-side opening region of the conveying channel, which opening region is in particular under reduced pressure, to the bearing arrangement. According to the invention, it is provided that the operating medium and the gas or ambient air are separated from one another within the sealed container by means of a membrane. Such a membrane prevents the operating medium and the gas or ambient air from coming into direct contact with one another. For example, a corrugated or flat membrane can be used.In this case, it is possible in particular to act upon the membrane in the manner of a membrane pump with nonreturn valves provided between the operating medium reservoir and the closed container and also in the delivery duct. For the supply of externally supplied gas or ambient air into the sealed container, a valve is sufficient in the simplest case. The region of the closed container which receives gas or ambient air can preferably be supplied with reduced pressure via an in particular adjustable throttle valve. In this case, this throttle valve can be adjusted in particular such that a defined gas volume flow which is smaller than the volume flow entering the container always exits from the closed container. The pressure on the gas side of the diaphragm thus increases, as a result of which the operating medium is pumped into the delivery channel counter to the retaining pressure of the nonreturn valve assigned to the delivery channel. As soon as the valve of the second valve arrangement is closed, the remaining pressure is reduced via the throttle valve connecting the closed container to the negative pressure. In this case, the diaphragm can be moved back solely by its intrinsic tension and / or can be reset again by a spring device. During this return movement or the corresponding return stroke of the membrane, operating medium is again sucked from the operating medium reservoir into the sealed container, which is then available for the next pumping phase.Such a method is suitable in particular for supplying bearings for devices under reduced pressure, such as pumps, in particular vacuum pumps. In this case, in order to assist the delivery of the operating medium to the bearing arrangement, the differential pressure between the externally charged gas or ambient air supplied to the sealed container and the reduced pressure in the interior of the relevant device can be used. By using pneumatic effects in this way, the corresponding delivery of the operating medium is ensured even without an active pump, as a result of which the outlay for supplying the bearing arrangement is correspondingly reduced.According to a preferred embodiment of the method according to the invention, a bearing arrangement of a device under reduced pressure, such as in particular a pump, in particular a vacuum pump, is supplied with the operating medium. In this case, the differential pressure between the gas or ambient air supplied to the sealed container and the reduced pressure within the housing of the relevant device is advantageously used to support the delivery of operating medium.The operating medium flow supplied to the bearing arrangement is preferably controlled and / or regulated via the gas and / or ambient air supply into the sealed container. In this case, the gas and / or ambient air supply into the sealed container can be adjusted in particular by means of a throttle valve.The valve arrangements can be actuated or controlled in particular such that operating medium is alternately conducted from the operating medium reservoir into the sealed container arranged underneath via the first and the second valve arrangement and externally applied gas and / or ambient air is supplied to the sealed container in order to convey operating medium from the sealed container to the bearing arrangement.Thus, the first and the second valve arrangement can be alternately opened and closed again, whereby a regular supply of operating medium to the relevant bearing arrangement is ensured.In particular in the case that the externally supplied gas comes into contact with the operating medium within the sealed container, an inert gas can be used as the gas.It is also advantageous in particular if the channel volume to the bearing arrangement to be supplied is selected to be smaller than the volume of the sealed container. This ensures in particular that an empty channel can also be completely flowed through.The conveying channel can be, in particular, an ascending channel. The closed container is expediently connected to the conveying channel in a lower region. As already mentioned, a check valve can be assigned to the delivery channel. Such a non-return valve can be arranged at any desired point in the conveying channel, but it is expediently provided in its inlet region.The closed container can also be connected to different bearing arrangements via a plurality of separate conveying channels in order to supply a plurality of bearing arrangements. In this case, the different delivery channels can each be assigned their own, in particular adjustable, throttle valve, with the result that the volume flows can be kept as equal as possible or in a desired ratio relative to one another, independently of different channel geometries. The operating medium flow to the bearing arrangements can in particular also be adjusted again via the second valve arrangement or the gas and / or ambient air supply. The settings can also be changed later in particular.Via the second valve arrangement, in particular, an intermittent supply of operating medium to the bearing arrangement can be effected at any desired intervals, whereby an over-lubrication can be effectively prevented.The respective bearing arrangement can advantageously also be supplied with operating medium alternately via a plurality of sealed containers. Such an use of a plurality of sealed containers enables a continuous supply of operating medium without interruption, in that the sealed containers are clocked in opposite directions, so that the bearing arrangement can always be actively supplied via at least one container.It is also advantageous in particular if the fill level of the sealed container is monitored via at least one fill level sensor. Such a fill level sensor can be used in particular for the active control and / or regulation of the fill level of the sealed container.It is also advantageous if the operating medium throughput in a respective conveying channel is monitored by means of at least one flow sensor. Such a flow sensor can be used for controlling and / or regulating the quantity of operating medium supplied to the relevant bearing arrangement.The system according to the invention for supplying at least one bearing arrangement serving for guiding mutually movable components with a working medium, in particular a lubricant, correspondingly comprises a working medium reservoir and at least one closed container arranged beneath it, to which working medium can be supplied from the working medium reservoir via a first valve arrangement, wherein the closed container is connected to the bearing arrangement via a conveying channel and externally applied gas and / or ambient air can be supplied to the closed container via a second valve arrangement, in order to convey working medium from the closed container to the bearing arrangement via the conveying channel supported by the differential pressure between the gas or ambient air supplied to the container and a bearing-side opening region of the conveying channel, which opening region is in particular under reduced pressure. According to the invention, a membrane is provided within the sealed container, by means of which membrane the operating medium and the gas or ambient air are separated from one another. In this case, the region of the closed container which can be supplied with gas or ambient air can preferably be supplied with reduced pressure via an in particular adjustable throttle valve. The membrane can be designed, for example, as a corrugated or flat membrane.It is in particular conceivable to act upon the membrane in the manner of a membrane pump with check valves provided between the operating medium reservoir and the closed container and in the delivery channel. The region of the closed container which receives gas or ambient air can preferably be supplied with reduced pressure via an in particular adjustable throttle valve. Following a respective pumping phase, the diaphragm can be moved back solely by its intrinsic tension and / or can be reset again by a spring device.The bearing arrangement is preferably contained in a device under reduced pressure, such as in particular a pump, in particular a vacuum pump.The operating medium flow supplied to the bearing arrangement can advantageously be controlled and / or regulated by the supply of gas and / or ambient air into the sealed container.Preferably, the gas and / or ambient air supply into the sealed container is adjustable via a throttle valve.Preferably, the first and the second valve arrangement can be controlled via a control device in such a way that operating medium is alternately transferred from the operating medium reservoir into the sealed container arranged beneath it and externally supplied gas and / or ambient air is supplied to the sealed container in order to convey operating medium from the sealed container to the bearing arrangement.The conveying channel can be designed in particular as an ascending channel. The closed container is expediently connected to the conveying channel in a lower region. As already mentioned, a non-return valve can be associated in particular with the delivery channel.The channel volume to the bearing arrangement to be supplied is preferably smaller than the volume of the sealed container.To supply a plurality of bearing arrangements, the sealed container can also be connected to different bearing arrangements via a plurality of separate conveying channels.The valve arrangements can be controlled via a control device in particular such that operating medium is supplied to a respective bearing arrangement alternately via separate closed containers.A respective delivery channel is expediently assigned an in particular adjustable throttle valve. Alternatively or additionally, a respective delivery channel can also be assigned in particular a check valve.At least one fill level sensor is preferably assigned to the operating medium reservoir. A respective delivery channel can in particular also be provided with at least one flow sensor.The first and second valve arrangements can each be designed, for example, as poppet valves which can be actuated, for example, via a common actuator in particular such that, with a spring- or play-guided hysteresis, with a respective actuation of the actuator, first one of the valve arrangements closes and then the other valve arrangement opens. The structure of the supply system is thus further simplified. It is sufficient to simply switch the actuator between two states in order to ensure the desired delivery of operating medium.The invention is explained in more detail below with reference to exemplary embodiments with reference to the drawing, in which: FIG. 1 shows a schematic illustration of an exemplary embodiment of a system according to the invention for supplying a working medium to a bearing arrangement serving for guiding mutually movable components, FIG. 2 shows a schematic illustration of a further exemplary embodiment of the system according to the invention with a membrane arranged within the sealed container, and FIG. 3 shows a schematic illustration of an exemplary embodiment of a vacuum pump, the rotor mounting of which comprises a rotary bearing, for the supply of which the system according to the invention can be used.FIG. 1 shows a schematic representation of an exemplary embodiment of a system 10 suitable for carrying out the method according to the invention for supplying a bearing arrangement 84 serving for guiding mutually movable components with a working medium 18, in particular a lubricant.The system 10 comprises an operating medium reservoir 20 and at least one sealed container 22 arranged underneath, to which operating medium 18 can be supplied from the operating medium reservoir 20 via a first valve arrangement I.The closed container 22 is connected in a lower region via an in particular ascending conveying channel 24 to the bearing arrangement 84. Externally supplied gas and / or ambient air can be supplied to the sealed container 22 via a second valve arrangement II in order to convey operating medium 18 from the sealed container 22 via the conveying channel 24 to the bearing arrangement 84 supported by the differential pressure between the gas or ambient air supplied to the container 22 and a bearing-side opening region 26 of the conveying channel 24, which opening region is in particular under reduced pressure.The bearing arrangement is contained in a device 28 which is under reduced pressure and which, as will be described in more detail below, can be, for example, a pump, in particular a vacuum pump.The device 28 comprises a housing 72, in which in particular the bearing arrangement 84 is also contained, In addition, the operating medium reservoir 20 and the sealed container 22 can also be arranged within this housing 72.The externally supplied gas or the ambient air that can be supplied to the sealed container 22 via the second valve arrangement II has a pressure p a, while a negative pressure p v that is lower than the pressure p a. prevails within the housing 72. The pressure difference, by which the delivery of operating medium to the bearing arrangement 84 is assisted, thus results from the difference between the two pressures p a and p v.The operating medium flow supplied to the bearing arrangement 84 can be controlled and / or regulated by the supply of gas and / or ambient air into the sealed container 22. For this purpose, the system 10 can comprise a control device 30, by means of which the valve arrangements I, II can be controlled accordingly. This control device 30 can be integrated in a control unit 106 (see also FIG. 3 ) assigned to the device 28 or can also be provided separately therefrom.The gas and / or ambient air supply into the sealed container 22 can be adjusted in the desired manner, in particular via a throttle valve 32. In the present exemplary embodiment, this throttle valve 32 is arranged behind the second valve arrangement II, as viewed in the direction of flow of the gas or of the ambient air.The first and the second valve arrangement I, II can in particular be controlled again via the control device 30 in such a way that operating medium 18 is alternately transferred from the operating medium reservoir 20 into the sealed container 22 arranged beneath it and externally supplied gas and / or ambient air is supplied to the sealed container in order to convey operating medium 18 from the sealed container 22 to the bearing arrangement 84.The channel volume to the bearing arrangement 84 to be supplied can be smaller than the volume of the sealed container 22, in particular, in order to ensure that an empty channel 24 can also be completely flowed through.Alternatively or additionally, the channel 24 can have a check valve at any point in order to prevent an undesired return flow of operating medium 18.If a plurality of bearing arrangements 84 are to be supplied via the system 10, the sealed container 22 can also be connected to the various bearing arrangements 84 via a plurality of separate conveying channels 24.An in particular adjustable throttle valve can be assigned to a respective delivery channel 24, so that the volume flows can be kept as equal as possible or in a desired ratio relative to one another, independently of the different channel geometries.Operating medium 18 can also be supplied to the storage arrangement 84 alternately via separate sealed containers 22. Such a supply via a plurality of closed containers 22 enables a continuous supply of operating medium without interruption by the containers 22 being clocked in opposite directions. This ensures that the supply always takes place via at least one container 22.At least one fill level sensor can also be assigned to a respective sealed container 22 in order to monitor the respective fill level. Such a fill level sensor can in particular be connected again to the control device 30 in order to control and / or regulate the fill level in the desired manner.At least one flow sensor can also be assigned to a respective feed channel 24. Such a flow sensor can also be connected in particular again to the control device 30 in order to control and / or regulate the quantity of operating medium supplied to the bearing arrangement 84 via said control device.The two valve arrangements I, II can each comprise a poppet valve. In this case, these poppet valves can be assigned, for example, a common actuator, by means of which the valve arrangements can be controlled in particular such that, with a spring- or play-guided hysteresis during a movement of the actuator, first one of the two valve arrangements I, III closes and then the other valve arrangement opens, which brings about a further simplification of the system 10. Thus, the actuator in question only has to be switched back and forth between two states in order to achieve the desired delivery.In particular, in the case that the externally supplied gas comes into contact with the operating medium 18 within the sealed container 22, an inert gas can be used as the gas.While in the embodiment shown in FIG. 1 the throttle valve 32 is arranged behind the second valve arrangement II in the flow direction of the gas or ambient air supplied to the sealed container 22, embodiments are also conceivable in principle in which this throttle valve 32 is arranged in front of the second valve arrangement II.FIG. 2 shows a schematic representation of a further exemplary embodiment of the system 10 according to the invention, in which a membrane 108 is provided within the sealed container 22, by means of which membrane the operating medium 18 and the gas or ambient air are separated from one another.The region of the sealed container 22 to which gas or ambient air can be applied is connected in the present case via a throttle valve 110, which can be adjusted in particular, to the interior of the housing 72, in which vacuum p v prevails which is lower than the pressure p a outside the housing 72.In addition, a check valve 112 is provided in the delivery channel 24. In the present case, the first valve arrangement I also comprises a check valve 114.The diaphragm 108 can accordingly be actuated in the manner of a diaphragm pump with check valves 112, 114 provided in the delivery channel 24 and between the operating medium reservoir 20 and the sealed container 22. For the supply of externally supplied gas or ambient air into the sealed container 22, a valve is sufficient in the simplest case. The throttle valve 110 can be adjusted such that a defined gas volume flow which is smaller than the volume flow entering the container 22 always exits from the closed container 22. The pressure on the gas side of the diaphragm 108 thus increases, as a result of which the operating medium 18 is pumped counter to the retaining pressure of the nonreturn valve 112 assigned to the conveying channel 24 into the conveying channel 24 and via the latter to the bearing arrangement 84. A return flow of operating medium 18 into the operating medium reservoir 20 is prevented by the check valve 114. As soon as the valve of the second valve arrangement II is closed, the remaining pressure is reduced via the throttle valve 110 connecting the closed container 22 to the negative pressure p v.The diaphragm 108 can be moved back solely by its intrinsic tension and / or reset again by a spring device. During the corresponding return stroke of the membrane 108, operating medium 18 is sucked again from the operating medium reservoir 20 into the sealed container 22, which is then available for the next pumping phase.Moreover, this system shown in FIG. 2 can in particular again be embodied in the same way as the system described with reference to FIG. 1. Corresponding parts are assigned the same reference numerals.As already mentioned, the system 10 according to the invention can be provided in particular for supplying operating medium to a bearing arrangement 84 which is part of a rotor bearing arrangement of a device 28, such as a vacuum pump, for example.FIG. 3 shows a schematic illustration of an exemplary embodiment of such a vacuum pump, the rotor mounting of which comprises a bearing arrangement 84 designed as a rotary bearing, for the supply of which the system 10 according to the invention can be used.The vacuum pump shown in FIG. 3 comprises a pump inlet 70 surrounded by an inlet flange 68 and a plurality of pump stages for conveying the gas present at the pump inlet 70 to a pump outlet not shown in FIG. 3. The vacuum pump comprises a stator with a static housing 72 and a rotor arranged in the housing 72 with a rotor shaft 12 mounted rotatably about an axis of rotation 14.The vacuum pump is designed as a turbomolecular pump and comprises a plurality of turbomolecular pump stages connected in series with one another in a pump-effective manner, having a plurality of turbomolecular rotor disks 16 connected to the rotor shaft 12 and a plurality of turbomolecular stator disks 26 arranged in the axial direction between the rotor disks 16 and fixed in the housing 72, which are held at a desired axial distance from one another by spacer rings 36. The rotor disks 16 and stator disks 26 provide an axial pumping action in the scoop region 50 directed in the direction of the arrow 58.The vacuum pump also comprises three Holweck pump stages arranged one inside the other in the radial direction and connected in series with one another in a pumping manner. The rotor-side part of the Holweck pump stages comprises a rotor hub 74 connected to the rotor shaft 12 and two cylinder-jacket-shaped Holweck rotor sleeves 76, 78, which are fastened to the rotor hub 74 and supported by the latter and are oriented coaxially with respect to the rotational axis 14 and are nested one inside the other in the radial direction. Furthermore, two cylindrical jacket-shaped Holweck stator sleeves 80, 82 are provided, which are likewise oriented coaxially with respect to the axis of rotation 14 and are nested one inside the other in the radial direction. The pump-active surfaces of the Holweck pump stages are each formed by the radial lateral surfaces of a Holweck rotor sleeve 76, 78 and a Holweck stator sleeve 80, 82, which are situated opposite one another to form a narrow radial Holweck gap. In this case, one of the pump-active surfaces is configured to be smooth-in the present case that of the Holweck rotor sleeve 76 or 78-and the opposite pump-active surface of the Holweck stator sleeve 80, 82 has a structuring with grooves which run helically around the axis of rotation 14 in the axial direction and in which the gas is driven forward by the rotation of the rotor and is thereby pumped.The vacuum pump comprises a drive motor 104 for rotationally driving the rotor, the rotor of which is formed by the rotor shaft 12. A control unit 106 controls the motor 104.The rotatable mounting of the rotor shaft 12 is effected by a rotary bearing 84 designed as a rolling bearing in the region of the pump outlet and a permanent magnet bearing 86 in the region of the pump inlet 70.The permanent magnet bearing 86 comprises a rotor-side bearing half 88 and a stator-side bearing half 90, which each comprise a ring stack of a plurality of permanent magnetic rings 92, 94 stacked one on top of the other in the axial direction, wherein the magnetic rings 92, 94 are opposite one another to form a radial bearing gap 96.Inside the magnetic bearing 86 an emergency or backup bearing 98 is provided, which is designed as an unmated roller bearing and runs empty without contact during normal operation of the vacuum pump and only engages with an excessive radial deflection of the rotor with respect to the stator in order to form a radial stop for the rotor, which prevents a collision of the rotor-side structures with the stator-side structures.The rotary bearing 84 is supplied with an operating medium such as a lubricant. As FIG. 3 shows, a conical spray nut 100 with an outer diameter increasing toward the rotary bearing 84 can be provided on the rotor shaft 12 in the region of the rotary bearing 84, said nut being in sliding contact with at least one scraper of an operating medium reservoir comprising a plurality of absorbent disks 102 impregnated with an operating medium, such as a lubricant. In operation, the operating medium is transferred by capillary action from the operating medium reservoir via the scraper to the rotating injection nut 100 and, as a result of the centrifugal force, is conveyed along the injection nut 100 in the direction of the increasing outer diameter of the injection nut 100 towards the pivot bearing 84, where it performs a lubricating function, for example.The control device 30 of the system 10 according to the invention can be integrated in the control unit 106 of this vacuum pump or can also be provided separately therefrom. The bearing arrangement 84 supplied with operating medium 18 via the system 2 according to the invention is arranged within the housing 72 of the vacuum pump in which a negative pressure prevails. Within this housing 72 of the vacuum pump, in particular the operating medium reservoir 20 and the sealed container 22 of the system 10 according to the invention can also be provided.List of reference characters10 System 12 Rotor shaft 14 Rotational axis 16 Rotor disk 18 Operating medium 20 Operating medium reservoir 22 Sealed container 24 Delivery channel 26 Bearing-side mouth region 28 Device 30 Control device 32 Throttle valve 36 Spacer ring 50 Scoop region 58 Arrow 68 Inlet flange 70 Pump inlet 72 Housing 74 Rotor hub 76, 78 Holweck rotor sleeve 80, 82 Holweck stator sleeve 84 Bearing arrangement, Rotary bearing 86 Permanent magnet bearing 88 Rotor-side bearing half 90 Stator-side bearing half 92, 94 Permanent magnetic ring 96 Radial bearing gap 98 Catching bearing 100 Injection nut 102 Absorbent disk 104 Drive motor 106 Control unit 108 Membrane 110 Throttle valve 112 Nonreturn valve 114 Nonreturn valve I First valve arrangement II Second valve arrangement p a Pressure of the inert gas / ambient air P supplied v Pressure within the housing

Claims

Method for supplying at least one bearing arrangement (84) serving for guiding mutually movable components with a working medium (18), in particular a lubricant, in which the working medium (18) is guided from a working medium reservoir (20) via a first valve arrangement (I) into at least one closed container (22) arranged beneath it, the closed container (22) is connected via a conveying channel (24) to the bearing arrangement (84), and externally applied gas and / or ambient air is supplied to the closed container (22) via a second valve arrangement (II) in order to convey working medium (18) from the closed container (22) via the conveying channel (24), supported by the differential pressure between the gas or ambient air supplied to the container (22) and a bearing-side opening region (26) of the conveying channel (24), which is in particular under reduced pressure, to the bearing arrangement (84); characterized in that, separating the operating medium (18) and the gas or ambient air inside the sealed container (22) from one another by means of a membrane (108).Method according to Claim 1, characterized in that the operating medium (18) is supplied to a bearing arrangement (84) of a device (28) which is under reduced pressure, such as in particular a pump, in particular a vacuum pump.Method according to claim 1 or 2, characterised in that the operating medium flow supplied to the bearing arrangement (84) is controlled and / or regulated via the gas and / or ambient air supply into the sealed container (22).Method according to claim 3, characterised in that the gas and / or ambient air supply into the sealed container (22) is adjusted by means of a throttle valve (32).Method according to at least one of the preceding claims, characterized in that operating medium (18) is alternately conducted from the operating medium reservoir (20) into the sealed container (22) arranged beneath it via the first and the second valve arrangement (I, II) and externally supplied gas and / or ambient air is supplied to the sealed container (22) in order to convey operating medium (18) from the sealed container (22) to the storage arrangement (84).System (10) for supplying at least one bearing arrangement (84) serving for guiding mutually movable components with an operating medium (18), in particular a lubricant, with an operating medium reservoir (20) and at least one closed container (22) arranged beneath it, to which operating medium (18) can be supplied from the operating medium reservoir (20) via a first valve arrangement (I), wherein the closed container (22) is connected to the bearing arrangement (84) via a conveying channel (24) and externally charged gas and / or ambient air can be supplied to the closed container (22) via a second valve arrangement (II), In order to convey operating medium (18) from the sealed container (22) via the conveying channel (24), supported by the differential pressure between the gas or ambient air supplied to the container (22) and a bearing-side opening region (26) of the conveying channel (24), which opening region is in particular under reduced pressure, to the bearing arrangement (84); characterized in that a membrane (108) is provided within the sealed container (22), by means of which membrane the operating medium (18) and the gas or ambient air are separated from one another.System according to claim 6, characterised in that the bearing arrangement (84) is contained in a device (28) under reduced pressure, such as in particular a pump, in particular a vacuum pump.System according to claim 6 or 7, characterised in that the operating medium flow supplied to the bearing arrangement (84) can be controlled and / or regulated by the supply of gas and / or ambient air into the sealed container (22).System according to claim 8, characterised in that the supply of gas and / or ambient air into the sealed container (22) is adjustable via a throttle valve (32).System according to one of Claims 6 to 9, characterized in that the first and the second valve arrangement (I, II) can be controlled via a control device (30) in such a way that operating medium (18) is transferred alternately from the operating medium reservoir (20) into the sealed container (22) arranged beneath it and externally acted upon gas and / or ambient air is fed to the sealed container (22) in order to convey operating medium (18) from the sealed container (22) to the bearing arrangement (84).System according to one of Claims 6 to 10, characterized in that the region of the closed container (22) which can be supplied with gas or ambient air can be supplied with reduced pressure via an in particular adjustable throttle valve (110).System according to one of Claims 6 to 11, characterized in thatthe conveying duct (24) is assigned a nonreturn valve (112).System according to one of Claims 6 to 12, characterized in that at least one fill level sensor is assigned to the sealed container (22).

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