DE102013203577A1 - vacuum pump - Google Patents

Abstract

The invention relates to a vacuum pump with at least one side channel pump stage, which comprises a side channel delimited by at least one stator element, and with a coolant circuit for cooling the vacuum pump with a coolant, the coolant circuit having at least one coolant channel for the side channel pump stage, which is delimited at least in regions by the stator element is.

Description

The invention relates to a vacuum pump with at least one side channel pumping stage, which comprises a side channel delimited by at least one stator element.

Vacuum pumps are used in various technical processes, for example in semiconductor production, in order to remove gaseous media from a volume to be evacuated and to produce a vacuum necessary for the respective process. In addition to high-vacuum pumping stages such as Holweck or turbomolecular pumping stages side channel pumping stages are used, which are both suitable for generating a pure vacuum with a low final pressure and at the same time, the delivered media to a high outlet pressure and in some cases even directly up to atmospheric pressure compacted. A vacuum pump with a side channel pumping stage typically additionally includes a motor for rotationally driving a rotor element of the side channel pumping stage, and drive electronics for driving the motor.

A disadvantage of known vacuum pumps of the aforementioned type is that their actual performance data generally remain well behind the theoretically expected performance data and the performance of the vacuum pumps deteriorates over time. The vacuum pumps require relatively frequent maintenance and, overall, have a limited service life, which reduces the economics of known vacuum pumps. The maintenance and failure susceptibility of the vacuum pumps can be attributed to the high temperatures occurring during the operation of the vacuum pumps, which due to the associated thermal load in the medium and long term lead to an impairment of the functioning of the temperature-sensitive pump components.

The object of the invention is therefore to provide a vacuum pump, which has a high performance and at the same time a reduced maintenance and failure susceptibility, which can be operated permanently and reliably without restriction of their functionality and which has a long service life.

This object is achieved by a vacuum pump with the features of claim 1.

The vacuum pump includes at least one side channel pumping stage having a side channel defined by at least one stator element. The vacuum pump further comprises a coolant circuit for cooling the vacuum pump with a coolant, wherein the coolant circuit has at least one coolant channel for the side channel pumping stage, which is delimited at least in regions by the stator element.

According to the invention, it has been recognized that the heat generation in the area of the side channel pumping stage caused by its pumping effect in known vacuum pumps to deterioration of the operating characteristics of the vacuum pump, which on the one hand affects the performance characteristics of the pump and on the other hand, a significant load on the pump components occurs during their operation, which increases the maintenance and failure susceptibility of the vacuum pump and reduces their expected service life.

Through the coolant passage having the coolant passage defined by the at least one stator element of the side passage pumping stage, the thermal energy caused by the pumping mechanism of the side passage pumping step is effectively dissipated, so that excessive heating and thermal stress of the vacuum pump thereby deteriorating the performance and the flow rate expected life of the pump is avoided.

Thus, a vacuum pump is provided whose performance at least approximately corresponds to the theoretically expected performance and which achieves high reliability in operation and a long service life.

Advantageous embodiments are described in the subclaims, the description and the figures.

According to an advantageous embodiment, the coolant circuit is designed to cool at least one further component of the vacuum pump. As a result, the performance of the vacuum pump can be further improved and its service life can be further increased. In particular, the further component may be a motor, which in particular serves for rotationally driving a rotor element of the side channel pumping stage, or a drive electronics, which is designed in particular for driving the motor, which is preferably designed as an electric motor. The drive electronics can also be used to evaluate signals that are supplied by sensors of the vacuum pump, for example, from a temperature sensor explained below. These components also generate considerable amounts of heat during the operation of the vacuum pump, through the controlled discharge of which the operating characteristics of the vacuum pump can be improved. Furthermore, it may be at the another component to a high vacuum pumping stage such as a Holweckpumpstufe, a turbomolecular pumping stage, a Gaedepumpstufe, a Siegbahnpumpstufe or Kreuzgewindepumpstufe act, which can be provided in addition to the side channel pumping stage and their performance can also be improved by the cooling. By using a common coolant circuit for cooling the side channel pumping stage and the at least one further component, a considerable improvement in the operating behavior of the pump as a whole is achieved with little effort. The further component may also be a housing of the vacuum pump.

The further component may also include a bearing plate of the vacuum pump. Such a bearing plate can be arranged for example in the region of a rolling bearing of the vacuum pump, with which a rotor shaft of the vacuum pump, on which the rotor element of the side channel pumping stage is arranged, is rotatably mounted on the pump housing. The bearing plate can be designed to fix an outer ring of the rolling bearing in the direction of the axis of rotation so as to be displaceable on the housing of the vacuum pump. The bearing plate can be screwed in particular firmly with the stator of the Seitenkanalpumpstufe. In this embodiment, there is a strong thermal coupling of the bearing plate with the stator, so that by cooling the bearing plate, the cooling of the Seitenkanalpumpstufe supported and thus the cooling can be improved overall. Two bearing plates of the vacuum pump, e.g. associated with different rolling bearings of the vacuum pump to be cooled by the coolant circuit.

It is also possible for two or more different and in particular all of the abovementioned various further components to be cooled by the coolant circuit.

According to an advantageous embodiment, the coolant circuit comprises a further coolant channel for the further component. By such a further coolant channel direct cooling of the other component can be effected. The respective coolant channel can be limited to at least partially by the respective component. By "at least partially limited" is understood in the present disclosure in principle that the coolant channel is limited over at least part of its preferably closed flow cross-section through the respective component. In principle, the respective coolant channel can also be delimited over its entire flow cross-section by the respective component.

In the case of the drive electronics, it is preferred if the coolant channel for the drive electronics is delimited at least in regions by a particularly heat-conducting and / or metallic plate or cooling plate on which the drive electronics are fastened by a preferably thermally conductive connection.

The further coolant channel may be connected to the coolant channel for the side channel pumping stage in series or in parallel with coolant. As a result, the coolant flow and the cooling effect caused thereby can be specifically adapted to the requirements of the side channel pumping stage and the respective further component or components. In this case, the pump components to be cooled can be arranged along the various coolant channels in such a way that overall a cooling effect corresponding to the respective requirements is achieved.

For cooling a bearing plate, a coolant channel may be provided which is at least partially bounded by the bearing plate and which is preferably connected coolant-conducting with a coolant channel for the side channel pumping stage. By providing a bounded by a bearing plate or through this coolant channel, which is connected to a coolant channel for the Seitenkanalpumpstufe, it is possible to realize a structurally simple way a coolant channel for the side channel pumping stage, which extends over substantially the entire length of Side channels of the pumping stage extends and is located in close proximity to the side channel and at the same time accessible via the bearing plate from the outside and thus can be integrated in a structurally simple manner in the coolant circuit.

Preferably, both the motor and the drive electronics are each cooled by a coolant channel which is limited at least partially by the motor or a cooling plate for the drive electronics, wherein the channel for the motor and the channel for the drive electronics are preferably connected in series with each other coolant ,

According to one embodiment, a coolant-conducting series connection is provided between a first coolant channel for the side channel pumping stage and for the high-vacuum pumping stage and a second coolant channel for the drive electronics and for the motor. The second coolant channel preferably comprises a coolant channel, which is delimited at least in regions by a cooling plate for the drive electronics, and a coolant channel following it in the coolant flow direction, which is delimited at least partially by the engine. The first coolant channel follows Preferably, in the direction of coolant flow to the second channel and is at least partially limited by the Seitenkanalpumpstufe. The high vacuum pumping stage can either have its own coolant channel and delimit it at least in regions, or it can be cooled indirectly via the coolant channel for the side channel pumping stage in the manner described below. A modification of the above embodiment provides that the coolant channel for the engine is arranged in the flow direction of the coolant in front of the coolant channel for the drive electronics.

A further embodiment provides that a coolant channel for the motor and for the drive electronics on the one hand and a coolant channel for the side channel pumping stage and for the high vacuum pumping stage on the other hand are connected in parallel with each other.

The further component, in particular the high vacuum pumping stage, can also be indirectly cooled by being thermally conductively connected to the at least one stator element of the side channel pumping stage or to another, third pumping component, which in turn is directly cooled by the coolant circuit, i. which at least partially limits a coolant channel of the coolant circuit, or which is also indirectly cooled by the coolant circuit.

In particular, in the case of a series connection of two coolant channels, the flow cross sections of the two channels and thus their hydraulic conductance are preferably adapted so that there is a desired distribution of the coolant to the two channels.

According to one embodiment, at least one, in particular adjustable, orifice is provided in the coolant circuit, which limits a flow cross section for the coolant. The aperture can be arranged in particular in one of at least two parallel-connected coolant channels. The hydraulic conductivity of the respective channel can then be flexibly adapted to the respective conditions.

A further embodiment provides that at least one temperature sensor is provided for measuring the temperature of the side channel pumping stage. This makes it possible to monitor the temperature of the side channel pumping stage during operation and e.g. to control the operation of the side channel pumping stage and / or the coolant circuit depending on the measured temperature of the vacuum pump so that the side channel pump is always operated in a favorable temperature range. The at least one temperature sensor is preferably arranged between the coolant channel and the side channel of the side channel pumping stage and / or in the vicinity of a gas outlet of the side channel pumping stage. As a result, a particularly direct and therefore meaningful measurement of the temperature of the side channel pumping stage is achieved. The temperature sensor can also be arranged on a bearing holder or on a bearing plate of a rotary bearing of the vacuum pump and can measure the temperature of the bearing holder or the bearing plate, wherein the bearing holder and / or the bearing plate can be cooled by the coolant circuit.

Preferably, the coolant channel extends over at least approximately the entire length of the side channel. This ensures a particularly effective removal of the heat generated in the side channel, since the heat is dissipated directly everywhere. The coolant channel may be delimited at least approximately along its entire length by the at least one stator element at least in regions.

The coolant channel may extend over at least 60%, preferably at least 75% and most preferably at least 90% of the angular range defined with respect to a rotational axis of the side channel pumping stage which is covered by the side channel and which may include a full 360 ° turn. The side channel and / or the coolant channel in this case preferably extend at least in regions in a circle around the axis of rotation.

A particularly effective cooling of the side channel pumping stage is achieved if the coolant channel, relative to the axis of rotation of the side channel pumping stage, is spaced from the side channel in the radial direction at least over part of its length.

A particularly preferred embodiment provides that the coolant channel is arranged over at least approximately its entire length in the immediate vicinity of the side channel. As a result, the effectiveness of the cooling of the side channel pumping stage is further increased. Preferably, the coolant channel has a shortest distance from the side channel over its length, which is at most 50%, preferably at most 25% and particularly preferably at most 15% of the maximum distance of the side channel from the axis of rotation.

A particularly simple construction of the vacuum pump results when the side channel and / or the coolant channel is delimited by at least two stator elements over at least part of its length, which preferably abut one another and are connected to one another, in particular by screwing. In the stator can then a Be provided groove, which corresponds to the side channel, and / or a groove which corresponds to the coolant channel, and which forms the boundary for the side channel and for the coolant channel together with another groove or a flat surface of the other stator.

In a region adjoining the respective side channel or coolant channel, the two stator elements can lie substantially flat against each other, whereby a connection sealing the coolant channel between the two stator elements can be created. A stator element may in each case be configured essentially disk-shaped, wherein the disk plane is preferably oriented substantially perpendicular to the rotational axis of the side channel pumping stage and wherein the surface of the disk delimiting the respective side or coolant channel is preferably formed by a flat side of the disk and the two disks especially abut each other on their flat sides and are connected to each other.

For even better sealing, in particular of the coolant channel, a particularly elastic sealing element between the at least two stator elements may be provided, on which the two stator elements can bear sealingly. The sealing element may e.g. may be formed as an O-ring, which preferably sealingly connects a closed annular surface of the one stator with a closed annular surface of the other stator to seal the coolant channel and the side channel, which may be disposed on different sides of the annular surfaces against each other. The O-ring may be disposed between the coolant passage and the side passage in the radial direction related to the rotational axis. There may also be at least one further O-ring which seals the coolant channel and / or the side channel with respect to the region outside the stator elements delimiting the two channels.

According to an advantageous embodiment, the coolant inlet of the coolant channel is arranged in the vicinity of a gas outlet of the side channel pumping stage and / or the coolant outlet of the coolant channel is arranged in the vicinity of a gas inlet of the side channel pumping stage. As a result, the cooling effect is adapted to the heat development in the side channel pumping stage such that, during operation of the pump, an essentially homogeneous temperature distribution occurs everywhere and locally greatly increased temperatures are avoided.

In the vicinity of the gas outlet of the side channel pumping stage, due to the high gas pressure and the increased friction, a particularly pronounced evolution of heat occurs, which can be compensated by the arrangement of the coolant inlet in this area and the associated greater cooling effect. The area of the coolant outlet, which provides a lower cooling effect, is accordingly used to cool the area of the gas inlet in which less heat is generated due to the lower gas pressures. In principle, however, the coolant inlet and / or the coolant outlet can also be arranged at a location other than that specified above.

The direction in which the coolant in the coolant channel flows around the rotational axis of the side channel pumping stage during operation of the pump may be opposed to the direction in which the gas flows through the side channel of the associated side channel pumping stage. This achieves a cooling effect which effectively compensates for the gradient of heat generation along the side channel caused by the increased heat generation in the region of the gas outlet and the lower heat generation in the region of the gas inlet. In principle, however, the coolant and the gas can also flow in the same direction around the axis of rotation of the side channel pumping stage.

According to an advantageous embodiment, the vacuum pump comprises a plurality of side channel pumping stages, each of which comprises a side channel defined by at least one stator element. Several and in particular all side channel pumping stages may be designed according to at least one of the advantageous embodiments described above with regard to the at least one side channel pumping stage. By providing several side channel pumping stages, the achievable pumping power and the achievable minimum ultimate pressure of the vacuum and the maximum output pressure of the pump can be improved. The side channel pumping stages can be connected to one another in series and / or in parallel with gas. A high performance pump may, in principle, comprise one or two or more than two interconnected side channel pumping stages.

The coolant circuit preferably comprises in each case at least one coolant channel for each side channel pumping stage, the coolant channels each being delimited by the stator element which delimits the side channel of the respective side channel pumping stage. This ensures effective cooling of the stator elements of all side channel pump stages.

The side channels of different side channel pumping stages can be based on the axis of rotation of the at least one side channel pumping stage in the radial direction and / or axial direction be arranged consecutively. As described above, a side channel may be delimited by at least two, in particular disc-shaped, stator elements.

A stator element may also define a plurality of different side channels and thus constitute a common stator element for more than one side channel pumping stage. Accordingly, a coolant channel delimited by the stator element may also constitute a common coolant channel for more than one side channel pumping stage. A stator element may also define a plurality of different coolant channels each associated with one of a plurality of side channels defined by the respective stator element.

For example, at least one disk-shaped stator element on its two opposite flat sides each have a groove bounding a side channel and / or the stator element may each have on both sides a groove delimiting a coolant channel for a side channel pumping stage. This represents a particularly simple constructional variant with which, in particular, a plurality of side channel pumping stages succeeding one another in the direction of the rotation axis can be realized. The two side channels and / or coolant channels bounded by the stator element can be connected to one another in a gas-conducting or coolant-conducting manner by a corresponding connecting channel formed in the stator element.

Preferably, at least two coolant channels of different side channel pumping stages are connected to each other with coolant. The coolant channels can be connected in series with each other, so that they are traversed by the coolant in sequence. The coolant channels can also be connected to one another in parallel and through which the coolant flows in parallel. In a parallel connection of the coolant channels, the flow in the two coolant channels can be independently regulated, for example by appropriate adjustment of the flow cross-section and / or the arrangement of a diaphragm in a respective coolant channel, so that the cooling of the individual side channel pumping stages can be flexibly adapted to the thermal load For example, to adapt the cooling to different load cases, in particular to the final pressure to be generated or the resulting gas load.

According to an advantageous embodiment, at least two coolant channels of different, in particular in the axial or radial direction immediately consecutive, Seitenkanalpumpstufen extend from their respective coolant inlet in opposite directions about an axis of rotation of the Seitenkanalpumpstufen around to their respective coolant outlet. This makes it possible to arrange the different coolant channels so that they overlap with respect to the angle ranges covered by them and relate to the rotational axis of the side channel pumping stage and an angular offset between the inlets and outlets of successive coolant channels is avoided. As a result, a structurally particularly simple arrangement is achieved, since the different coolant channels or the stator elements bounding them can be constructed substantially identically and arranged congruently to each other.

For example, each of the coolant channels may have a course oriented around the rotational axis of the side channel pumping stage, covering approximately the entire angular range related to the rotational axis of the side channel pumping stage, with a relatively small angular range between the coolant inlet and the coolant outlet not being covered by the channel and thus free can stay. In particular, in this case can be achieved by the above-described embodiment with alternating flow directions of the coolant, that the remaining free between the inlets and the outlets of different coolant channels angle ranges overlap at least partially. The overlapping angle ranges can then be used for other components of the pump or the coolant circuit.

For example, a return passage of the coolant circuit may be provided, which passes through a plurality of stator elements which define the side channels of the side channel pumping stages. Specifically, the return passage for the coolant may be disposed in the above-described overlapping angle range remaining free between the inlets and the outlets of the various side channel pumping stages.

In the context of the present description, a coolant circuit is understood to mean both a closed circuit for the coolant and a section for the coolant between a coolant inlet and a coolant outlet, which can be completed by connecting the inlet and the outlet to one another in a closed circuit. The coolant circuit may comprise, especially in the case of a closed coolant circuit, a coolant pump with which the coolant can be driven in the circuit, and / or a cooling unit or a heat exchanger with which the coolant can be cooled. The coolant pump and / or the heat exchanger may be formed as part of the vacuum pump or externally a corresponding coolant inlet and coolant outlet of the vacuum pump can be connected.

According to an advantageous embodiment, the coolant circuit is coupled heat-exchanging via at least one heat-conducting element with a further coolant circuit. The cooling of the coolant circuit, which comprises the limited by the stator of the Seitenkanalpumpstufe coolant channel and which is also referred to as a primary circuit, takes place through the further coolant circuit, which is also referred to as a secondary circuit, via the heat-conducting element. The further coolant circuit may e.g. be connected via a coolant inlet and a coolant outlet of the vacuum pump with an external coolant pump and / or an external coolant aggregate or heat exchanger. The heat exchanging element may in particular be formed by a plate on which the drive electronics are arranged and which exchanges the heat between the two coolant circuits and for this purpose preferably at least partially delimits a coolant channel of both circuits. This cooling plate can have a relatively large surface and thus ensure effective heat exchange. In principle, a liquid-gas heat exchanger, e.g. a water-air heat exchanger may be provided which, for cooling a liquid refrigerant in the primary circuit or a liquid refrigerant in an existing secondary circuit, exchanges heat between the liquid refrigerant and a gas present outside the primary circuit and especially outside the vacuum pump, e.g. the ambient air, causes.

The above configuration has the advantage that the primary circuit can be designed as a closed circuit formed as part of the vacuum pump, for example with a corresponding coolant pump, without having to simultaneously integrate a coolant aggregate or an excessively large heat exchanger into the vacuum pump. In the primary circuit, e.g. a corrosion-resistant coolant can be used, which is particularly well suited for the direct cooling of the affected components, without e.g. due to an external connection of the coolant circuit there is the risk of leakage losses or the accidental use of an unsuitable coolant. The secondary circuit, however, can be operated with water as the coolant, which can be supplied from outside the vacuum pump, so that coolant losses in the connection area of this circuit are unproblematic.

According to one embodiment, the at least one stator element is made of a material which is a metal material which can be produced by casting or cast and / or an aluminum or an aluminum alloy, at least regionally and in particular in the region of a surface defining the coolant channel. Thereby, the manufacturing cost of the stator element can be reduced. Alternatively or additionally, a bearing plate or a coolant channel of the coolant circuit defining surface of the bearing plate may be formed of such a material.

The coolant of the coolant circuit for the side channel pumping stage, which may be formed by a primary circuit as described above, is preferably liquid. The coolant is preferably a corrosion-resistant coolant over the material of the stator element, which may be one of the aforementioned materials. For example, the refrigerant may be glycol or a glycol mixture, an oil, in particular a polychlorinated biphenyl (PCB), a liquid sodium, e.g. NaK-78 or contain or consist of an ethanol. Depending on the material of the components to be cooled and in particular of the stator element, the coolant may also contain or consist of water.

If a secondary circuit as described above is provided, it preferably also contains a liquid coolant which in particular contains or consists of water. The secondary circuit may in principle also be a gaseous coolant, such as e.g. Contain air.

The vacuum pump may comprise one or more high vacuum pumping stages, with a high vacuum pumping stage e.g. may be formed by a Holweckpumpstufe, a turbomolecular pumping stage, a Gaedepumpstufe, a Siegbahnpumpstufe or a Kreuzgewindepumpstufe. The one or more high-vacuum pumping stages are preferably arranged upstream of the side-channel pumping stage and upstream of the latter.

Another object of the invention is a vacuum pump with at least one side channel pumping stage, which comprises a limited by at least one stator side channel, with a motor, with a drive electronics for the engine and with a coolant circuit for cooling the vacuum pump with a coolant, wherein the coolant circuit at least a first Coolant channel for the side channel pumping stage and at least a second coolant channel for the engine and / or for the drive electronics comprises.

This allows a pumping behavior or the operating life of the vacuum pump worsening excessive heating of the side channel pumping stage and the motor and / or the drive electronics effectively avoid and ensure a high pumping capacity and a long service life of the vacuum pump. In addition to controlling the motor, the drive electronics can also be set up to evaluate signals supplied by sensors of the vacuum pump, such as a temperature sensor as described above.

The first coolant channel and the second coolant channel may be connected in a coolant-conducting manner in series or in parallel with one another. As a result, a coherent coolant circuit for the mentioned components can be achieved, which can be realized with little effort, wherein the cooling effect exerted on the respective components can be specifically adapted to the respective requirements by the corresponding serial or parallel coolant-conducting connection.

Hereinafter, the present invention will be described by way of example with reference to advantageous embodiments with reference to the accompanying drawings. Show it:

1 a vacuum pump according to an embodiment of the invention in a schematic representation,

2 a vacuum pump according to another embodiment of the invention in a schematic representation,

3 a vacuum pump according to another embodiment of the invention in a schematic representation,

4 a stator of a side channel pumping stage of a vacuum pump according to an embodiment of the invention in plan view, and

5 a schematic representation of the coolant flow direction through a plurality of side channel pumping stages in a vacuum pump according to an embodiment of the invention.

1 shows a vacuum pump 10 according to an embodiment of the invention in a schematic representation. The vacuum pump 10 includes a side channel pumping stage 12 which at least one stator element 14 comprising an electric motor 22 for rotationally driving a rotor element of the side channel pumping stage 12 , a cooling plate with a drive electronics arranged thereon 20 for the engine 22 and a high vacuum pumping stage 24 ,

The pump 10 further includes a coolant circuit 25 which one from outside the pump 10 accessible coolant inlet 44 and one from outside the pump 10 accessible coolant outlet 46 the vacuum pump 10 includes, wherein inlet 44 and outlet 46 via coolant channels 18 . 26 of the coolant circuit 25 Kühlmitteleleitend interconnected. The arrowheads in 1 indicate the direction of coolant flow from the inlet 44 to the outlet 46 ,

The coolant channel 18 serves to cool the side channel pumping stage 12 and is at least partially through the stator 14 the side channel pumping stage 12 limited. The high vacuum pumping stage 24 is indirectly via the side channel pumping stage 12 coolable, with which it is connected thermally conductive. The cooling of the high vacuum pump stage 24 can in principle also take place via a bearing plate of the vacuum pump and / or via the housing of the vacuum pump. The coolant channel 26 serves to cool the engine 22 and the cooling plate with the drive electronics 20 and for this purpose has two longitudinal sections connected in series with coolant, one of which is at least partially provided by the electric motor 22 and the other at least partially through the cooling plate 20 is limited. The coolant channel 18 and the coolant channel 26 are each in the area of the inlet 44 and the outlet 46 merged and are thus connected in parallel with each other coolant.

2 shows a vacuum pump 10 according to a further embodiment of the invention in a schematic representation. In the 2 shown vacuum pump 10 corresponds to the in 1 shown vacuum pump 10 , where at in 2 shown embodiment of the outlet of the coolant channel 26 for the engine 22 and the cooling plate with the drive electronics 20 with the inlet of the coolant channel 18 for the side channel pumping stage 12 Kühlmittelitend is connected, so that the channels 26 . 18 connected in series.

3 shows a vacuum pump 10 according to a further embodiment of the invention in a schematic representation. In the 3 shown vacuum pump 10 is essentially the same as in 2 shown vacuum pump 10 , where at in 3 shown embodiment of the coolant circuit 25 not between a coolant inlet and a coolant outlet of the pump 10 is arranged. Instead, the coolant circuit 25 designed as a closed circuit and includes a coolant pump 54 with which the coolant in the in 3 characterized by the arrowheads sense of rotation can be driven.

The pump 10 also includes a secondary coolant circuit 42 coming from outside the vacuum pump 10 via a corresponding coolant inlet 44 and coolant outlet 46 accessible is. The secondary coolant circuit 42 includes one through the cooling plate 20 for the drive electronics at least partially limited coolant channel 58 , The coolant circuits 25 and 42 are thus on the cooling plate 20 thermally conductive interconnected, so that the cooling plate 20 as a heat exchanger between the two coolant circuits 25 . 42 serves. When to the inlet 44 and the outlet 46 a coolant source is connected, the coolant in the coolant circuit 25 over that of the coolant circuit 42 cooled cooling plate 20 cooled so that the coolant circuit 25 can fulfill its cooling function. Alternatively or additionally, it would also be possible to provide a liquid-gas heat exchanger, for example a water-air heat exchanger, for cooling one in one of the coolant circuits 25 . 42 existing liquid coolant heat exchange between the liquid coolant and one outside the circuits 25 . 42 existing gas causes or the cooling plate 20 could be designed as such a heat exchanger.

4 shows a stator element 14 a side channel pumping stage of a vacuum pump according to an embodiment of the invention in plan view. The stator element 14 is designed disc-shaped, with in 4 the view of a flat side of the disk-shaped stator 14 is shown. The stator element 14 comprises a circular axis about an axis of rotation oriented perpendicular to the disk plane 38 the Seitenkanalpumpstufe running around, formed in the flat side and in the axial direction in the flat side reentrant groove whose conversion is a side channel 16 limited. The one longitudinal end of the groove delimits a gas inlet 34 of the side channel 16 and the other longitudinal end defines a gas outlet 36 of the side channel 16 ,

The stator element 14 further comprises a likewise formed in the flat side and in the axial direction in the flat side reentrant groove whose conversion is a coolant channel 18 for cooling the stator element 14 limited. The coolant channel 18 runs parallel to the side channel 16 and accordingly also runs essentially in a circle around the axis of rotation 38 around. The groove and thus the coolant channel 18 are at a slight distance radially outward from the side channel 16 spaced. The groove and the limited by their conversion coolant channel 18 extend over almost the entire on the axis of rotation 38 related angular range of 360 °. One end of the groove defines an inlet 30 of the coolant channel 16 for the coolant and the other end of the groove defines an outlet 32 of the coolant channel 16 for the coolant. The coolant inlet 30 is near the gas outlet 36 arranged and the coolant outlet 32 is near the gas inlet 34 arranged. The coolant in the coolant channel 18 on the one hand and the gas in the side channel 16 On the other hand, therefore, flow in different directions or in a different direction of rotation about the axis of rotation 38 around from their respective inlet to their respective outlet. Alternatively, the coolant could be in the coolant channel 18 also in the same direction, ie in the same direction of rotation as the gas flow in the side channel 16 around the axis of rotation 38 flow around, ie the coolant can generally flow against the gas flow or with the gas flow. When a plurality of coolant channels are connected in series for a plurality of consecutive side channel pump stages, as described below with respect to FIG 5 1, the direction of rotation of the coolant flow in the coolant channels can alternate from the coolant channel to the coolant channel or from the side channel pumping stage to the side channel pumping stage.

In the not of the coolant channel 18 covered angle range φ between the coolant inlet 30 and the coolant outlet 32 is a return channel 40 provided, which in the axial direction through the stator 14 passes through and serves to return the coolant.

To form the side channel pumping stage, the in 4 shown stator disc 14 with another, in 4 Stator disc not shown connected in such a way that the stator discs abut each other with their flat sides. The other stator is so complementary to the in 4 formed stator, that the two stator discs together a coolant channel 18 with a closed cross section and a side channel 16 form, except for a circumferential opening, through which the rotor element of the side channel pumping stage in the side channel 16 engages, has a closed cross-section. The two stator elements 14 are about screw holes 52 firmly connected.

A temperature sensor 28 is between the side channel 16 and the coolant channel 18 arranged and used to measure the temperature of the side channel pumping stage. The temperature sensor 28 can in principle at any point between the side channel 16 and the coolant channel 18 be arranged and in particular in the vicinity of the gas outlet 36 because there the highest temperatures can be measured and measured directly due to the high gas pressure.

During operation of the pump, an in 4 not shown rotor element of the Seitenkanalpumpstufe in the direction of the arrow 48 driven in rotation. The rotor element can be arranged on a rotor shaft which extends through the in the region of the axis of rotation 38 provided opening 60 of the stator element 14 can extend through. The rotor element preferably has a ring of blades extending into the side channel 16 extend into it. The side channel 16 points in the area between the gas inlet 34 and the gas outlet 36 Preferably, an enlarged cross-section with respect to the rotor blades and the gas is in the side channel 16 preferably around the circular main orientation of the side channel 16 spiraling around in the direction of the arrow 48 driven and compressed. In the area of the gas outlet 36 has the side channel 16 Preferably, compared to the rotor blades not or at most slightly enlarged cross-section on, which in 4 based on the non-recessed area 50 of the stator element 14 it can be seen that the extracted gas is in the area of the outlet 36 stripped off and through the outlet 36 from the side channel 16 is encouraged.

The pump with the in 4 shown stator element 14 can be several in the direction of the axis of rotation 38 comprise side-channel pumping stages arranged one behind the other, which are formed as described above. The coolant channel 18 can be connected in series with the coolant channels of the other side channel pumping stages, ie that the coolant inlet 30 Kühlmitteleitend with the coolant outlet of a preceding, eg in the axial direction in front of the plane of 4 arranged, pumping stage is connected and the coolant outlet 32 Kühlmittelitend with the coolant inlet a subsequent, for example, in the axial direction behind the plane of 4 arranged, pumping stage is connected. The compounds can thereby by in the axial direction through the respective stator 14 be formed extending therethrough coolant-conducting connection channels.

The side channel 16 may be connected in series with the side channels of the further side channel pumping stages by the inlet 34 is gas-conductively connected to the outlet of the preceding pumping stage and the outlet 36 is connected to the inlet of the subsequent pump stage gas-conducting. For this purpose, one can in each case in the axial direction through a respective stator disc 14 be provided extending therethrough gas-conducting connection channel.

Preferably, all in the axial direction one behind the other arranged stator discs 14 the vacuum pump one each as in 4 shown coolant return passage 40 on, wherein the coolant return passages 40 in the axial direction are arranged substantially congruent one above the other and together form an oriented in the axial direction through all side channel pumping stages extending coolant return passage.

5 shows a schematic representation of the coolant flow direction through a plurality of side channel pumping stages in a vacuum pump according to an embodiment of the invention in the direction of the axis of rotation 38 seen. The vacuum pump may be as described above with respect to 4 be described described.

5 shows a plurality of interconnected coolant channels 18 , each associated with a side channel pumping stage and as described above 4 are formed. The coolant channels 18 are in 5 shown spaced apart in the radial direction and can be assigned accordingly in the radial direction successive Seitenkanalpumpstufen. The coolant channels 18 but can also according to the above description to 4 follow each other in the axial direction and be assigned in the axial direction successive Seitenkanalpumpstufen.

The coolant passes through a supply channel 56 which can lead through or be delimited by a bearing plate, for example, into the first coolant channel 18 , This coolant channel 18 flows through the coolant in a first on the axis of rotation 38 referred direction of rotation and then passes through a connecting channel 62 in the next coolant channel 18 , which flows through the coolant in the opposite direction of rotation. In this way, the coolant flows through all the coolant channels 18 , wherein the flow direction of the coolant from channel 18 to channel 18 alternates until the coolant finally leaves the last coolant channel 18 in the coolant return passage 40 flows. The coolant return channel 40 runs in the of the coolant channels 18 uncovered angular range φ through all the stator disks back to a coolant outlet of the vacuum pump. The coolant channel 40 can also pass through a bearing plate of the vacuum pump or be limited by the end plate.

LIST OF REFERENCE NUMBERS

10

vacuum pump

12

Side channel pump stage

14

stator

16

side channel

18

Coolant channel

20

Cooling plate with attached drive electronics

22

engine

24

High vacuum pump stage

25

Coolant circuit

26

Coolant channel

28

temperature sensor

30

Coolant inlet

32

coolant outlet

34

gas inlet

36

gas outlet

38

axis of rotation

40

Coolant return duct

42

another coolant circuit

44

Coolant inlet

46

coolant outlet

48

direction of rotation

50

Wiper area

52

screw

54

Coolant pump

56

supply channel

58

Coolant channel

60

opening

62

connecting channel

φ

angle range

Claims (14)

Vacuum pump ( 10 ) with at least one side channel pumping stage ( 12 ), one by at least one stator ( 14 ) limited side channel ( 16 ), and with a coolant circuit ( 25 ) for cooling the vacuum pump ( 10 ) with a coolant, wherein the coolant circuit ( 25 ) at least one coolant channel ( 18 ) for the side channel pumping stage ( 12 ), which at least partially by the stator ( 14 ) is limited. Vacuum pump according to claim 1, characterized in that the coolant circuit ( 25 ) for cooling at least one further component ( 20 . 22 . 24 ) of the vacuum pump ( 10 ) is formed, which is selected in particular from the group, the drive electronics ( 20 ), a motor ( 22 ), a high vacuum pump stage ( 24 ), a housing and a bearing plate of the vacuum pump ( 10 ). Vacuum pump according to claim 1 or 2, characterized in that the coolant circuit ( 25 ) a further coolant channel ( 26 ) for the further component ( 20 . 22 . 24 ) connected to the coolant channel ( 18 ) for the side channel pumping stage ( 12 ) is preferably connected in series or parallel coolant. Vacuum pump according to one of the preceding claims, characterized in that in the coolant circuit ( 25 ) is provided at least one, in particular adjustable, aperture, which limits a flow cross-section for the coolant. Vacuum pump according to one of the preceding claims, characterized in that a temperature sensor ( 28 ) for measuring the temperature of the side channel pumping stage ( 12 ) is provided, which preferably between the coolant channel ( 18 ) and the side channel ( 16 ) and / or near a gas outlet ( 36 ) of the side channel pumping stage ( 12 ) is arranged. Vacuum pump according to one of the preceding claims, characterized in that the coolant channel ( 18 ) over at least approximately the entire length of the side channel ( 12 ). Vacuum pump according to one of the preceding claims, characterized in that the coolant inlet ( 30 ) of the coolant channel near a gas outlet ( 36 ) of the side channel pumping stage ( 12 ) is arranged and / or the coolant outlet ( 32 ) of the coolant channel near a gas inlet ( 34 ) of the side channel pumping stage ( 12 ) is arranged. Vacuum pump according to one of the preceding claims, characterized in that the vacuum pump ( 10 ) several side channel pump stages ( 12 ), each one by at least one stator ( 14 ) limited side channel ( 16 ), wherein the coolant circuit ( 25 ) for the side channel pumping stages ( 12 ) each have at least one coolant channel ( 18 ) and wherein the coolant channels ( 18 ) in each case by the stator element ( 14 ), which is the side channel ( 16 ) of the respective side channel pumping stage ( 12 ) limited. Vacuum pump according to claim 8, characterized in that at least two coolant channels ( 18 ) various side channel pumping stages ( 12 ) are connected in series or parallel with each other coolant. Vacuum pump according to claim 8 or 9, characterized in that at least two coolant channels ( 18 ), in particular in the axial or radial direction immediately following, side channel pumping stages ( 12 ) from their respective coolant inlet ( 30 ) in opposite directions about a rotation axis ( 38 ) of the side channel pumping stages ( 12 ) around to their respective coolant outlet ( 32 ). Vacuum pump according to one of claims 8 to 10, characterized in that a return duct ( 40 ) of the coolant circuit ( 25 ) by a plurality of stator elements ( 14 ) passing through the side channels ( 16 ) of the side channel pumping stages ( 12 ) limit. Vacuum pump according to one of the preceding claims, characterized in that the coolant circuit ( 25 ) via at least one heat-conducting element ( 20 ) with a further coolant circuit ( 42 ) is coupled heat-exchanging. Vacuum pump ( 10 ) with at least one side channel pumping stage ( 12 ), which one by at least a stator element ( 14 ) limited side channel ( 16 ), with an engine ( 22 ), with a drive electronics ( 20 ) for the engine ( 22 ) and with a coolant circuit ( 25 ) for cooling the vacuum pump ( 10 ) with a coolant, wherein the coolant circuit ( 25 ) at least a first coolant channel ( 18 ) for the side channel pumping stage ( 12 ) and at least one second coolant channel ( 26 ) for the engine ( 22 ) and / or for the drive electronics ( 20 ). Vacuum pump according to claim 13, characterized in that the first coolant channel ( 18 ) and the second coolant channel ( 26 ) are connected in series or parallel with each other coolant.

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