DE102015113821B4 - Vacuum pump - Google Patents

Abstract

A vacuum pump comprises at least one side channel pump stage, which comprises ring channels concentric to a rotor axis and rotor elements, in particular blade-like rotor elements, which dip into the ring channels. In this case, the side channel pump stage has at least two first ring channels, each with a separate inlet, which are arranged in different planes perpendicular to the rotor axis or in a same plane perpendicular to the rotor axis and are provided with a common outlet.

Description

The invention relates to a vacuum pump, in particular a turbomolecular pump, with at least one side channel pump stage, which comprises ring channels concentric to a rotor axis and, in particular, blade-like rotor elements immersed in the ring channels.

Vacuum pumps are used in different technical processes in order to create a vacuum necessary for the respective process. Side channel pump stages serve in particular to improve the pump behavior in work areas of the vacuum pump, in which particularly high backing pressures, high inlet pressures or high gas loads occur, and to reduce the power consumption of vacuum pumps in these work areas.

A side channel pump stage, which is also referred to as a regenerative pump stage, implements a pump principle which is optimized for use with higher gas pressures and, in particular, also enables energy-efficient pump operation in the laminar flow range, that is to say in the pressure range above the molecular flow range. Accordingly, the achievable discharge pressure and the achievable suction power of the vacuum pump are increased with a side channel pumping stage arranged downstream, for example, of a molecular pump stage, and at the same time the power consumption of the vacuum pump is kept low.

From the EP 1 520 107 B1 a parallel-pumping side-channel pump stage with ring channels concentric to the rotor axis is already known, the outermost ring channel of which is provided with two inlets. The suction can be improved by the parallel suction in this known side channel pump stage. However, there is a problem that the increase in the pumping speed has a negative effect on the compression.

The invention is based on the object of specifying a vacuum pump of the type mentioned at the outset with which the aforementioned problem is eliminated, that is to say a higher pumping speed is achieved at least essentially without impairing the compression.

This object is achieved according to a first aspect of the invention by a vacuum pump with the features of claim 1 and according to a further aspect of the invention by a vacuum pump with the features of claim 6. Preferred embodiments of the vacuum pumps according to the invention are specified in the subclaims.

According to the first aspect of the invention, the vacuum pump comprises at least one side channel pump, which comprises ring channels concentric to a rotor axis and, in particular, blade-like rotor elements immersed in the ring channels, the side channel pump stage having at least two first ring channels, each with a separate inlet, which are different from the rotor axis vertical levels are arranged and provided with a common outlet.

Due to this design, a higher pumping speed is achieved in a simple manner while maintaining a compact structure without significantly affecting the compression. This is achieved in that the side channel pumping stage conveys a gas to be pumped in parallel at least in sections in the functional sense, i.e. the ring channels run side by side, so to speak. On the other hand, the prior art provides for continuous, i.e. series-connected conveying, i.e. the ring channels are arranged one after the other, so to speak. This also applies to the further aspect of the invention.

In order to enable parallel pumping, the side channel pump stage or regenerative pump stage comprises at least two ring channels (side channels), each of which has only a separate inlet, so that the two inlets are separated from one another and the gas to be pumped is partly in one and partly in the other ring channel is promoted. The blade-like rotor elements circulating within the ring channels cause a pump effect in these ring channels. The two ring channels pumping in parallel have only one common outlet. A correspondingly designed side channel stage is particularly suitable for integration into a turbomolecular pump. The vacuum pump according to the invention can therefore in particular be a turbomolecular pump.

The first ring channels are preferably assigned separate rotor elements, each immersed only in one of the two first ring channels.

According to an alternative advantageous embodiment of the vacuum pump according to the invention, however, common rotor elements can also be assigned to the first ring channels, each of which is immersed both in one and in the other first ring channel.

The first ring channels can be arranged at the same radial distance from the rotor axis or can have a different radial distance from the rotor axis.

According to the further aspect of the invention, the vacuum pump comprises at least one Side channel pump stage, which comprises rings concentric to a rotor axis and, in particular, vane-like rotor elements immersed in the ring channels, in which case the side channel pump stage has at least two ring channels each provided with a separate inlet, which are arranged in a same plane perpendicular to the rotor axis and with a common outlet are provided.

The first two ring channels are preferably arranged at a radial distance from one another.

Different embodiments of the vacuum pumps according to the invention are conceivable according to the first and the second aspect.

For example, the common outlet of the first ring channels can expel the gas to be conveyed, in particular against the atmosphere, or transfer it to a backing pump. An alternative expedient embodiment of the vacuum pumps according to the invention is characterized in that the common outlet of the first ring channels transfers the gas to be pumped into at least one further ring channel of the side channel pump stage. The gas to be pumped can be further compressed in this further ring channel and then in particular expelled to the atmosphere or transferred to a backing pump.

The further ring channel can in particular have a smaller radial distance from the rotor axis than the first ring channels.

The further ring channel is preferably arranged in the same plane perpendicular to the rotor axis as at least the first ring channel immediately preceding in the gas flow direction.

According to an alternative expedient embodiment, the further ring channel is arranged in a different plane perpendicular to the rotor axis than the first ring channels, wherein the first ring channels can be arranged in the same or in different planes perpendicular to the rotor axis.

As already mentioned, the further ring channel can in particular expel the gas to be delivered against the atmosphere or transfer it to a backing pump.

According to an expedient practical embodiment of the vacuum pumps according to the invention, the rotor elements are carried by a rotor hub of a rotor shaft rotating about the rotor axis or by a rotor element carrier rotating with the rotor hub or rotor shaft or are formed on the rotor hub or the rotor element carrier. The carrier or the hub can be disc-shaped and form a rotor disc extending in a plane perpendicular to the rotor axis. The rotor elements can protrude from the carrier or from the hub and in particular axially, i.e. extend parallel to the rotor axis.

In this case, a gap seal is preferably provided between the rotor hub or the rotor element carrier and the boundary of a respective ring channel.

The vacuum pumps according to the invention are preferably each designed as a turbomolecular pump which comprises at least one turbomolecular pump stage upstream of the side channel pump stage.

The vacuum pump or turbomolecular pump can in particular also comprise at least one molecular pump stage connected between the at least one turbomolecular pump stage and the side channel pump stage.

The molecular pump stage can in particular comprise a Holweck or Siegbahn stage.

The blade-like rotor elements can optionally be arranged on rotor organs of a molecular pump stage or can be integrally formed on them.

In general, the rotor elements can be provided in the form of separate components or can be formed in one piece with a common, however configured carrier. Such a carrier can be combined with another component of the vacuum pump, e.g. a rotor member, connected or formed by this component.

For example, one or more blade-like rotor elements can be arranged or formed on the free end of a Holweck sleeve, in particular with respect to the vacuum pump on the outlet side. As a result, the side channel pump stage can be easily arranged behind the Holweck pump stage in the pumping direction, because an additional complicated guidance of the gas is avoided. This simplifies the design of the vacuum pump.

In the case of first ring channels arranged in the same planes, the rotor elements can, for example, be arranged or formed on the inside and outside of the Holweck sleeve opposite one another and the first ring channels can run opposite one another with respect to the Holweck sleeve. In the case of ring channels arranged in different planes, the rotor elements can, for example, be jointly on the outside, jointly on the inside, or alternatively for the first two ring channels on the outside and on be arranged or molded on the inside. Correspondingly, the first ring channels can be arranged on the inside, outside or in each case on the inside or outside in relation to the Holweck sleeve.

Alternatively or additionally, it can be provided that the rotor elements arranged or molded on the end of the Holweck sleeve have a common radial width that is smaller than a radial gap for the rotor elements. As a result, the rotor elements can be easily inserted axially into the gap and into ring channels arranged behind them, which considerably simplifies the assembly of the vacuum pump. In general, it can alternatively or additionally be provided that the rotor elements do not protrude in the radial direction beyond the Holweck sleeve or beyond an area of the Holweck sleeve axially adjacent to the area of the rotor elements or beyond an imaginary axial extension of the Holweck sleeve.

In one embodiment, the rotor elements can be formed from material that has stopped after the material has been removed at the free end of the Holweck sleeve or in the region of the free end of the Holweck sleeve.

The blade-like rotor elements can, for example, also be provided on ring-shaped elevations of a rotor hub, the corresponding ring channels, in which the blade-like rotor elements circulate, being provided around the blade-like rotor elements.

The ring channels can at least partially have two side walls and a channel bottom, at least one side wall of the ring channel being curved. The curvature of the at least one side wall can be concave, for example. In particular, an axially symmetrical configuration of the ring channel to a central plane of the rotor is also conceivable. The curvature of the at least one side wall can each be semicircular in cross section. In particular, such constructions are also conceivable in which the blade-like rotor elements are V-shaped in cross section.

It is also advantageous if a blade height of the blade-like rotor elements is 60% to 100% of the width of an assigned rotor disk.

The side channel radius can be in particular in the range of 80% and 120% of the rotor disk width.

According to a further expedient embodiment of the vacuum pump according to the invention, the channel base has a width in a range between 20% and 120% of the rotor disk width.

The blade spacing of the rotor blades can advantageously be in a range between 50% to 100% of the rotor disk width. The blade spacing is preferably less than 55% of the rotor disk width with a side channel area that is less than 2.5 times the blade area.

Alternatively, the blade spacing can, for example, also be greater than 85% of the rotor disk width, specifically with a side channel area that is greater than 5 times the blade area.

It is also particularly advantageous if the blade-like rotor elements have first and second partial blades, as is shown in FIG DE 10 2009 021 620 A1 is described. The angle between at least one partial blade and the direction of movement of the blade can in particular be less than 90 °.

A respective impeller can, for example, also have a second blade, wherein, for example, a central web is arranged between the blades in the direction of the circumference of the impeller, the height of which is at least partially less than the height of the blades. In this case, at least one partial blade can have a rear side lagging in relation to the direction of rotation, which extends over the center of the edge of the impeller. At least one blade can also have a bevel on its rear side. It is also particularly advantageous if the first and second partial blades are arranged offset to one another in the circumferential direction.

The blade-like rotor elements can in particular also comprise blades, each of which has a rear side lagging in the direction of movement with an outer edge which is provided with a bevel, as is shown in FIG DE 10 2009 021 642 A1 is described.

The back and the chamfer can each include a flat surface. The blade can comprise two blade sections, each with a rear section, and at least one blade section can form, for example, an angle of less than 90 ° with the direction of movement. The impeller can also comprise a second blade, a central web being provided between the blade and the second blade. For example, designs are also conceivable in which the blade comprises two blade sections which are arranged offset to one another in the direction of movement. The section backs of the blade sections can extend over a center of the impeller. The middle web between two successive blades can at least sectionally have a central web height that is less than a blade height. The blade can be arranged in the radial direction, in particular on the edge of the impeller.

If the vacuum pump comprises at least one turbomolecular pump stage, at least one molecular pump stage and at least one side channel pump stage or regenerative pump stage, a common drive can be assigned to the turbomolecular pump stage, the molecular pump stage and the side channel pump stage or regenerative pump stage. In this case, the vacuum pump or turbomolecular pump in question can be designed with only one drive and only one drive shaft.

• 1 eine perspektivische Ansicht einer Turbomolekularpumpe des Standes der Technik,
• 2 eine Ansicht der Unterseite der Turbomolekularpumpe von 1,
• 3 einen Querschnitt der Turbomolekularpumpe längs der in 2 gezeigten Schnittlinie A-A,
• 4 eine Querschnittsansicht der Turbomolekularpumpe längs der in 2 gezeigten Schnittlinie B-B,
• 5 eine Querschnittsansicht der Turbomolekularpumpe längs der in 2 gezeigten Schnittlinie C-C,
• 6 eine Schnittansicht einer erfindungsgemäßen Turbomolekularpumpe.
• 7 eine Schnittansicht einer alternativen Ausführungsform einer erfindungsgemäßen Turbomolekularpumpe.
• 8 eine schematische Draufsicht einer beispielhaften Ausführungsform einer erfindungsgemäßen Vakuumpumpe, wobei die beiden ersten Ringkanäle einen unterschiedlichen radialen Abstand zur Rotorachse aufweisen,
• 9 eine schematische Darstellung einer weiteren beispielhaften Ausführungsform der erfindungsgemäßen Vakuumpumpe mit in unterschiedlichen zur Rotorachse senkrechten Ebenen angeordneten ersten Ringkanälen,
• 10 eine schematische Teildarstellung einer weiteren beispielhaften Ausführungsform der erfindungsgemäßen Vakuumpumpe mit in unterschiedlichen zur Rotorachse senkrechten Ebenen angeordneten ersten Ringkanälen,
• 11 eine schematische Teildarstellung einer weiteren beispielhaften Ausführungsform der erfindungsgemäßen Vakuumpumpe mit in der gleichen zur Rotorachse senkrechten Ebene angeordneten ersten Ringkanälen,
• 12 einen Teilquerschnitt durch einen beispielhaften ersten Ringkanal der erfindungsgemäßen Vakuumpumpe,
• 13 einen beispielhaften Querschnitt eines ersten Ringkanals der erfindungsgemäßen Vakuumpumpe,
• 14 einen weiteren beispielhaften Querschnitt eines ersten Ringkanals der erfindungsgemäßen Vakuumpumpe, und
• 15 einen weiteren beispielhaften Querschnitt eines ersten Ringkanals der erfindungsgemäßen Vakuumpumpe.

The invention is explained in more detail below on the basis of exemplary embodiments with reference to the drawing; in this show:

• 1 1 shows a perspective view of a turbomolecular pump of the prior art,
• 2nd a bottom view of the turbomolecular pump of FIG 1 ,
• 3rd a cross section of the turbomolecular pump along the in 2nd shown cutting line AA ,
• 4th a cross-sectional view of the turbomolecular pump along the in 2nd shown cutting line BB ,
• 5 a cross-sectional view of the turbomolecular pump along the in 2nd shown cutting line CC ,
• 6 a sectional view of a turbomolecular pump according to the invention.
• 7 a sectional view of an alternative embodiment of a turbomolecular pump according to the invention.
• 8th 2 shows a schematic top view of an exemplary embodiment of a vacuum pump according to the invention, the two first ring channels being at a different radial distance from the rotor axis,
• 9 1 shows a schematic representation of a further exemplary embodiment of the vacuum pump according to the invention with first ring channels arranged in different planes perpendicular to the rotor axis,
• 10th 2 shows a schematic partial illustration of a further exemplary embodiment of the vacuum pump according to the invention with first ring channels arranged in different planes perpendicular to the rotor axis,
• 11 2 shows a schematic partial illustration of a further exemplary embodiment of the vacuum pump according to the invention with first ring channels arranged in the same plane perpendicular to the rotor axis,
• 12 2 shows a partial cross section through an exemplary first ring channel of the vacuum pump according to the invention,
• 13 an exemplary cross section of a first ring channel of the vacuum pump according to the invention,
• 14 another exemplary cross section of a first ring channel of the vacuum pump according to the invention, and
• 15 another exemplary cross section of a first ring channel of the vacuum pump according to the invention.

In the 1 shown turbomolecular pump 111 includes one of an inlet flange 113 surrounding pump inlet 115 , to which a recipient, not shown, can be connected in a manner known per se. The gas from the recipient can pass through the pump inlet 115 sucked out of the recipient and through the pump to a pump outlet 117 are promoted to which a backing pump, such as a rotary vane pump, can be connected.

The inlet flange 113 forms according to the alignment of the vacuum pump 1 the top of the case 119 the vacuum pump 111 . The housing 119 includes a lower part 121 on which there is an electronics housing on the side 123 is arranged. In the electronics housing 123 are electrical and / or electronic components of the vacuum pump 111 housed, for example to operate an electric motor arranged in the vacuum pump 125 . On the electronics housing 123 are multiple connections 127 intended for accessories. There is also a data interface 129 , eg according to the RS485 standard, and a power supply connection 131 on the electronics housing 123 arranged.

On the housing 119 the turbomolecular pump 111 is a flood inlet 133 , in particular in the form of a flood valve, is provided, via which the vacuum pump 111 can be flooded. In the area of the lower part 121 is also a sealing gas connection 135 , which is also referred to as a purge gas connection, via which purge gas is used to protect the electric motor 125 (see e.g. 3rd ) in front of the gas pumped into the engine compartment 137 in which the electric motor 125 in the vacuum pump 111 is housed, can be brought. In the lower part 121 are also two coolant connections 139 arranged, wherein one of the coolant connections is provided as an inlet and the other coolant connection as an outlet for coolant, which can be passed into the vacuum pump for cooling purposes.

The bottom side 141 The vacuum pump can serve as a stand, so that the vacuum pump 111 on the bottom 141 can be operated standing. The vacuum pump 111 but can also via the inlet flange 113 attached to a recipient and thus operated to some extent hanging. In addition, the vacuum pump 111 be designed so that it can also be put into operation if it is aligned in a different way than in 1 is shown. Embodiments of the vacuum pump can also be realized in which the underside 141 can not be arranged downwards, but turned to the side or upwards.

On the bottom 141 , in the 2nd is shown, there are still various screws 143 arranged, by means of which components of the vacuum pump, which are not further specified here, are fastened to one another. For example, a bearing cap 145 on the bottom 141 attached.

On the bottom 141 are also mounting holes 147 arranged over which the pump 111 can be attached to a support surface, for example.

In the 2nd to 5 is a coolant line 148 shown, in which the coolant connections 139 coolant introduced and discharged can circulate.

Like the sectional views of the 3rd to 5 show, the vacuum pump comprises several process gas pumping stages to promote at the pump inlet 115 process gas to the pump outlet 117 .

In the case 119 is a rotor 149 arranged one around a rotor axis 151 rotatable rotor shaft 153 having.

The turbomolecular pump 111 comprises several turbomolecular pump stages with several pumps connected in series with each other on the rotor shaft 153 attached radial rotor disks 155 and between the rotor disks 155 arranged and in the housing 119 stator washers 157 . Thereby form a rotor disk 155 and an adjacent stator disc 157 one turbomolecular pump stage each. The stator disks 157 are by spacer rings 159 held at a desired axial distance from each other.

The vacuum pump also comprises Holweck pump stages which are arranged one inside the other in the radial direction and have a pumping effect and are connected in series. The rotor of the Holweck pump stages includes one on the rotor shaft 153 arranged rotor hub 161 and two on the rotor hub 161 attached and supported by this cylindrical jacket-shaped Holweck rotor sleeves 163 , 165 that are coaxial to the rotor axis 151 oriented and nested in the radial direction. There are also two cylindrical Holweck stator sleeves 167 , 169 provided, which is also coaxial to the rotor axis 151 oriented and nested one inside the other in the radial direction.

The pump-active surfaces of the Holweck pump stages are due to the lateral surfaces, that is to say the radial inner and / or outer surfaces, of the Holweck rotor sleeves 163 , 165 and the Holweck stator sleeves 167 , 169 educated. The radial inner surface of the outer Holweck stator sleeve 167 is the radial outer surface of the outer Holweck rotor sleeve 163 forming a radial Holweck gap 171 opposite and forms with this the first Holweck pump stage following the turbomolecular pumps. The radial inner surface of the outer Holweck rotor sleeve 163 stands for the radial outer surface of the inner Holweck stator sleeve 169 forming a radial Holweck gap 173 opposite and forms a second Holweck pump stage. The radial inner surface of the inner Holweck stator sleeve 169 is the radial outer surface of the inner Holweck rotor sleeve 165 forming a radial Holweck gap 175 opposite and forms the third Holweck pump stage.

At the lower end of the Holweck rotor sleeve 163 can be provided a radially extending channel through which the radially outer Holweck gap 171 with the middle Holweck gap 173 connected is. In addition, the upper end of the inner Holweck stator sleeve 169 a radially extending channel can be provided, through which the central Holweck gap 173 with the radially inner Holweck gap 175 connected is. This means that the nested Holweck pump stages are connected in series. At the lower end of the radially inner Holweck rotor sleeve 165 can also be a connecting channel 179 to the outlet 117 be provided.

The aforementioned pump-active surfaces of the Holweck stator sleeves 163 , 165 each have several spirals around the rotor axis 151 Holweck grooves running in the axial direction, while the opposite lateral surfaces of the Holweck rotor sleeves 163 , 165 are smooth and the gas to operate the vacuum pump 111 drive in the Holweck grooves.

For rotatable mounting of the rotor shaft 153 are a roller bearing 181 in the area of the pump outlet 117 and a permanent magnet bearing 183 in the area of the pump inlet 115 intended.

In the area of the rolling bearing 181 is on the rotor shaft 153 a conical spray nut 185 with one to the rolling bearing 181 increasing outside diameter provided. The spray nut 185 is in sliding contact with at least one scraper of an equipment storage. The operating fluid storage comprises several stacked absorbent disks 187 with a resource for the rolling bearing 181 , for example soaked with a lubricant.

In operation of the vacuum pump 111 the equipment is transferred by capillary action from the equipment storage via the wiper to the rotating spray nut 185 transmitted and as a result of the centrifugal force along the spray nut 185 in the direction of the increasing outside diameter of the injection nut 185 to the rolling bearing 181 promoted where, for example, it has a lubricating function. The roller bearing 181 and the resource storage are through a trough-shaped insert 189 and the bearing cap 145 enclosed in the vacuum pump.

The permanent magnet bearing 183 includes a rotor half of the bearing 191 and a stator side bearing half 193 , each of which is a ring stack of a plurality of permanent magnetic rings stacked on one another in the axial direction 195 , 197 include. The ring magnets 195 , 197 lie with each other forming a radial bearing gap 199 opposite, the rotor-side ring magnets 195 radially outside and the stator-side ring magnets 197 are arranged radially inside. That in the storage gap 199 existing magnetic field causes magnetic repulsive forces between the ring magnets 195 , 197 which shows a radial bearing of the rotor shaft 153 cause. The ring magnets on the rotor side 195 are from a beam section 201 the rotor shaft 153 worn which is the ring magnet 195 radially surrounds outside. The ring magnets on the stator side 197 are from a stator-side support section 203 worn, which is through the ring magnets 197 extends through and on radial struts 205 of the housing 119 is hung. Parallel to the rotor axis 151 are the ring magnets on the rotor side 195 through one with the beam section 203 coupled cover element 207 fixed. The ring magnets on the stator side 197 are parallel to the rotor axis 151 in one direction by one with the support section 203 connected mounting ring 209 as well as one with the support section 203 connected mounting ring 211 fixed. Between the mounting ring 211 and the ring magnet 197 can also have a disc spring 213 be provided.

There is an emergency or catch bearing inside the magnetic bearing 215 provided, which is in normal operation of the vacuum pump 111 runs idle without touching and only with excessive radial deflection of the rotor 149 engages relative to the stator to a radial stop for the rotor 149 to form, since a collision of the rotor-side structures with the stator-side structures is prevented. The catch camp 215 is designed as an unlubricated rolling bearing and forms with the rotor 149 and / or the stator a radial gap, which causes the backup bearing 215 is disengaged in normal pump operation. The radial deflection at which the catch bearing 215 engages is large enough so that the catch bearing 215 does not come into engagement during normal operation of the vacuum pump, and at the same time is small enough so that a collision of the rotor-side structures with the stator-side structures is prevented under all circumstances.

The vacuum pump 111 includes the electric motor 125 for rotatingly driving the rotor 149 . The anchor of the electric motor 125 is through the rotor 149 formed, the rotor shaft 153 through the motor stator 217 extends through. On the through the motor stator 217 extending portion of the rotor shaft 153 A permanent magnet arrangement can be arranged radially on the outside or embedded. Between the motor stator 217 and that through the motor stator 217 extending portion of the rotor 149 is a space 219 arranged, which comprises a radial motor gap over which the motor stator 217 and can magnetically influence the permanent magnet arrangement for transmitting the drive torque.

The motor stator 217 is in the housing inside for the electric motor 125 provided engine compartment 137 fixed. Via the sealing gas connection 135 A sealing gas, which is also referred to as purge gas and which can be, for example, air or nitrogen, can enter the engine compartment 137 reach. The electric motor can use the sealing gas 125 be protected from process gas, for example from corrosive components of the process gas. The engine compartment 137 can also be through the pump outlet 117 be evacuated, ie in the engine compartment 137 there is at least approximately that of the pump outlet 117 connected forevacuum pump caused vacuum pressure.

Between the rotor hub 161 and one the engine compartment 137 limiting wall 221 can also be a so-called labyrinth seal known per se 223 be provided, in particular to better seal the engine compartment 217 compared to the radially outside Holweck pump stages.

In the 6 shown turbomolecular pump according to the invention 10th also includes several series-connected Holweck pump stages with two Holweck sleeves 163 , 165 . On the inner Holweck sleeve 165 are rotor elements at their outlet end 22 arranged in first ring channels 18th and 20th immerse and in it around the rotor axis 16 rotate. The rotor elements 22 are opposite on an outside and an inside of the inner Holweck sleeve 165 arranged. The first ring channel runs accordingly 18th concentrically around the outside of the Holweck sleeve and the first ring channel 20th - in the same horizontal plane - inside concentric to the Holweck sleeve 165 . The rotor elements extend 22 from the Holweck sleeve 165 in the corresponding first ring channel 18th respectively. 20th inside, i.e. radially outwards or inwards.

The first ring channels 18th and 20th have a common outlet 26 on that near a pump outlet 117 is arranged. The pump outlet 117 can be open to the atmosphere or connected to a backing pump. The first ring channels 18th and 20th have separate inlets, which, however, in the view of 6 are not visible. At the common outlet 26 the parallel gas flows of the first ring channels unite 18th and 20th .

7 also shows a turbomolecular pump 10th with Holweck pump stages, with an inner Holweck sleeve 165 two sets of rotor elements 22 are arranged in two corresponding first ring channels 18th and 20th immerse and in it around the rotor axis 16 rotate. The ring channels 18th , 20th are arranged in different horizontal levels and run around the outside of the Holweck sleeve. The ring channels 18th , 20th are concentric to the rotor axis 16 aligned. The rotor elements 22 extend from the Holweck sleeve 165 radially outwards into the corresponding ring channels 18th , 20th . Alternatively or additionally, rotor elements or ring channels on the inside of the Holweck sleeve 165 be arranged.

8th shows a schematic plan view of an exemplary embodiment of a vacuum pump according to the invention 10th with a side channel pump stage 12 leading to a rotor axis 16 concentric ring channels 18th , 20th and immersed in this. especially blade-like rotor elements 22 (cf. the 6 to 15 ), which is also simply called blades 22 be designated. Here is the rotor axis 16 through the axis a rotor shaft 14 the vacuum pump 10th Are defined.

The side channel pump stage 12 has two with only one separate inlet 24th provided first ring channels 18th , 20th on, either in different to the rotor axis 16 vertical planes (see also 7 , 9 and 10th ) or in the same to the rotor axis 16 vertical plane (see also 6 and 11 ) arranged and with a common outlet 26 are provided. In the direction of flow, the direction of rotation of the rotor shaft (indicated by the arrow) 14 corresponds behind the common outlet 26 is a scraper 28 intended.

In the embodiment according to 8th point the first two ring channels 18th , 20th for example a different radial distance from the rotor axis 16 on. These first ring channels can 18th , 20th in different or in the same to the rotor axis 16 vertical plane.

9 shows a schematic partial representation of an exemplary embodiment of the vacuum pump according to the invention 10th with in different to the rotor axis 16 vertical ring-shaped first ring channels 18th , 20th . These have ring channels 18th , 20th in the present case an equal radial distance from the rotor axis 16 on. In addition, the ring channels 18th , 20th separate, each only in one of the two ring channels 18th , 20th immersing blade-like rotor elements 22 assigned.

The blade-like rotor elements 22 can in particular from a rotor hub 30th one around the rotor axis 16 rotating rotor shaft 14 or one with the rotor hub 30th or rotor shaft 14 rotating rotor element carrier or worn on the rotor hub 30th or the rotor element carrier.

10th shows a schematic partial representation of another exemplary embodiment of the vacuum pump according to the invention with in different to the rotor axis 16 vertical ring-shaped first ring channels 18th , 20th . In the present case, the first two ring channels 18th , 20th however, common blade-like rotor elements 22 assigned, each immersing both in one and in the other first ring channel. The first ring channels 18th , 20th again have the same radial distance from the rotor axis 16 .

11 shows a schematic partial representation of a further exemplary embodiment of the vacuum pump according to the invention 10th with in the same to the rotor axis 16 vertical plane arranged first ring channels 18th , 20th . Here are the first two ring channels 18th , 20th arranged at a radial distance from each other. The ring channels 18th , 20th are separate again, for example, only in one of the two ring channels 18th , 20th immersing blade-like rotor elements 22 assigned. The rotor elements 22 can in particular from a rotor hub 30th the one around the rotor axis 16 rotating rotor shaft 14 or one with the rotor hub 30th or rotor shaft 14 rotating Rotor element carrier worn or on the rotor hub 30th or the rotor element carrier.

The common outlet 26 of the first ring channels 18th , 20th can, for example, expel the gas to be pumped against the atmosphere or transfer it to a backing pump. However, versions are also conceivable, for example, in which the common outlet 26 of the first ring channels 18th , 20th the gas to be pumped into at least one further ring channel (not shown) of the side channel pump stage 12 passes. The further ring channel can be in the same to the rotor axis 16 vertical plane such as at least the first ring channel immediately preceding in the gas flow direction or in another to the rotor axis 16 vertical plane can be arranged than the first ring channels 18th , 20th . The further ring channel can in particular expel the gas to be delivered against the atmosphere or transfer it to a backing pump.

Between the rotor hub 30th or a respective rotor element carrier and the limitation of a respective ring channel 18th , 20th a gap seal can be provided in each case.

The vacuum pump 10th can at least one of the side channel pump stage 12 include upstream turbomolecular pump stage. At least one molecular pump stage can be connected between the at least one turbomolecular pump stage and the side channel pump stage. The vacuum pump can thus be designed in particular as a turbomolecular pump.

The molecular pump stage preferably comprises at least one Holweck or Siegbahn stage.

The arrangement of rotor elements 22 and ring channels 18th , 20th according to 9 can also as one 6 corresponding, but rotated by 90 ° arrangement can be understood. In other words, in 9 the rotor axis 16 as shown vertically, but also parallel to the direction of extension of the rotor hub 30th or to one through the rotor hub 30th run defined level. Accordingly, the arrangement of the 11 as one 7 corresponding, but rotated by 90 ° arrangement can be understood.

Accordingly, it is possible to arrange rotor elements 22 and ring channels 18th , 20th the 10th aligned by 90 °. In this case, for example, on the inner Holweck sleeve 165 the 6 or 7 alternatively or additionally, blade-like rotor elements 22 be arranged, which are formed by recesses, that is, by remaining material after removal of material at the free end of the Holweck sleeve 165 . You can do this accordingly 10th two concentric ring channels arranged in the same horizontal plane 18th , 20th be provided partially outside the axial region of the Holweck sleeve 165 are arranged. The rotor elements 22 have a common radial width that is smaller than a radial gap for the rotor elements 22 . The rotor elements 22 are not in a radial direction over the Holweck sleeve 165 or via an axially to the area of the rotor elements 22 adjacent area of the Holweck sleeve 165 or via an imaginary axial extension of the Holweck sleeve 165 out ahead. An advantage here is the particularly simple assembly, since such a Holweck sleeve simply axially into the gap for the rotor elements 22 can be inserted without there being an undercut with a ring channel boundary.

12 shows a partial cross section through an exemplary first ring channel 18th , 20th the vacuum pump according to the invention 10th .

As in 12 shown, the ring channel 18th , 20th a channel floor 32 and two side walls 34 , 36 on. The sidewalls 34 , 36 are curved. They have a concave shape. The blade-like rotor elements 22 of the impeller or rotor 38 protrude completely into the ring channel 18th , 20th inside. A radius R _S1 of a blade base 40 is the same size as the radius R _S1 a boundary surface arranged radially in the direction of the shaft 42 of the ring channel 18th , 20th . That means the scoops 22 completely into the side channel 18th , 20th immerse.

Through the curved side walls 34 , 36 the pump performance of the side channel pump stage is significantly improved. The web between the blades is advantageously made as small as possible (not shown). The bucket volume filled with gas should be as large as possible.

These measures significantly improve the vacuum properties of the pump.

$${\text{d}}_{\text{S2}}={\text{d}}_{\text{R1}}+2\cdot \mathrm{\Delta }$$

$${\text{R}}_{\text{S1}}={\text{R}}_{\text{R1}}-\text{h}$$

Improvements in the vacuum technology data are also made possible in particular by an optimized setting of the side channel radius R _S3 (80% to 120% of the rotor width) and the distance between two centers of the side channel semicircles d _S1 (20% to 120% of the rotor width) reached. The optimal radius R _S3 and the optimal distance d _S1 depend on the circumferential speed of the rotor disc and on the blade size. The dimensions R _R1 , R _R3 , d _R1 , Bucket height h and bucket angle α are given. The measure R _S2 can be calculated using the following three equations: $${\text{R}}_{\text{S2}}={\text{R}}_{\text{S1}}+\overline{{\text{R}}^{\text{2nd}}{}_{\text{S3}}-\raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$\mathrm{4th}$}\right.{\text{d}}_{\text{S2}}-{\text{d}}_{\text{S1}}{}^{\text{2nd}}}$$

$${\text{d}}_{\text{S2}}={\text{d}}_{\text{R1}}+\mathrm{2nd}\cdot \mathrm{\Delta }$$

$${\text{R}}_{\text{S1}}={\text{R}}_{\text{R1}}-\text{H}$$

The measure R _S1 is determined by the lower blade edge of the rotor disc.

Δ denotes the axial gap between the rotor and the stator disk. The axial gap Δ can be in particular in a range from 0.01 mm to 0.5 mm. Small axial gaps on the exhaust side and large axial gaps on the intake side make sense. If a labyrinth seal is used on the axial surface between the rotor and stator disks, the axial gap can in particular be more than 0.5 mm.

$$\mathrm{\Delta }\le \text{0}\text{,2 mm für }10{\text{ mbar <p}}_2\le 100\text{ mbar}$$

$$\mathrm{\Delta }\le \text{0}\text{,15 mm für }{\mathrm{\rho }}_2\le 100\text{ mbar}\text{.}$$

The guide values for the axial gaps can be selected as follows (ρ ₂ = outlet pressure): $$\mathrm{\Delta }\le \text{0}\text{, 3 mm for}{\mathrm{\rho }}_{\mathrm{2nd}}\le \mathrm{10th}\text{mbar}$$

$$\mathrm{\Delta }\le \text{0}\text{, 2 mm for}\mathrm{10th}{\text{mbar <p}}_{\mathrm{2nd}}\le 100\text{mbar}$$

$$\mathrm{\Delta }\le \text{0}\text{, 15 mm for}{\mathrm{\rho }}_{\mathrm{2nd}}\le 100\text{mbar}\text{.}$$

The 6 to 8th show exemplary cross sections of a respective first ring channel 18th , 20th the vacuum pump according to the invention 10th .

Here is in 13 the ring channel 18th , 20th overall circular. The ring channel 18th , 20th does not have a flat side channel bottom, but rather a circular cross section.

According to 14 is the ring channel 18th , 20th also circular. The radius of the ring channel 18th , 20th is however smaller than in 13 shown.

According to 15 shows the similar to in 12 trained ring channel 18th , 20th again concave side walls 34 , 36 on, the channel floor 32 is trained plan.

Different from the embodiment of the 12 is in the embodiments of 13 to 15 the blade base is set back in relation to the boundary surface arranged in the direction of the shaft, ie the blades do not completely dip into the annular channel 18th , 20th a.

Reference symbol list

10th

Vacuum pump

12

Side channel pump

14

Rotor shaft

16

Rotor axis

18th

first ring channel

20th

first ring channel

22

blade-like rotor element

24th

inlet

26

Outlet

28

Wipers

30th

Rotor hub

32

Canal floor

34

Side wall

36

Side wall

38

rotor

40

Schaufelgrund

42

Boundary surface

111

Turbomolecular pump

113

Inlet flange

115

Pump inlet

117

Pump outlet

119

casing

121

Lower part

123

Electronics housing

125

Electric motor

127

Accessory connector

129

Data interface

131

Power connector

133

Flood inlet

135

Sealing gas connection

137

Engine compartment

139

Coolant connection

141

bottom

143

screw

145

Bearing cap

147

Mounting hole

148

Coolant line

149

rotor

151

Rotor axis

153

Rotor shaft

155

Rotor disc

157

Stator disc

159

Spacer ring

161

Rotor hub

163

Holweck rotor sleeve

165

Holweck rotor sleeve

167

Holweck stator sleeve

169

Holweck stator sleeve

171

Holweck gap

173

Holweck gap

175

Holweck gap

179

Connecting channel

181

roller bearing

183

Permanent magnet bearings

185

Spray nut

187

disc

189

commitment

191

half of the bearing on the rotor side

193

stator side bearing half

195

Ring magnet

197

Ring magnet

199

Bearing gap

201

Beam section

203

Beam section

205

radial strut

207

Cover element

209

Support ring

211

Mounting ring

213

Belleville spring

215

Emergency or catch camp

217

Motor stator

219

Space

221

Wall

223

Labyrinth seal

Claims (24)

Vacuum pump (10), in particular turbomolecular pump, with at least one side channel pump stage (12) which comprises ring channels (18, 20) concentric to a rotor axis (16) and, in particular, blade-like rotor elements (22) immersed in the ring channels (18, 20), wherein the side channel pump stage (12) has at least two first ring channels (18, 20), each with a separate inlet (24), which are arranged in different planes perpendicular to the rotor axis (16) and are provided with a common outlet (26). Vacuum pump after Claim 1 , characterized in that the first ring channels (18, 20) are assigned separate rotor elements (22), each immersed only in one of the two first ring channels (18, 20). Vacuum pump after Claim 1 , characterized in that the first ring channels 18, 20) are assigned common rotor elements (22), each of which is immersed both in one and in the other first ring channel. Vacuum pump according to one of the preceding claims, characterized in that the first ring channels (18, 20) are arranged at the same radial distance from the rotor axis (16). Vacuum pump according to one of the Claims 1 to 3rd , characterized in that the first ring channels (18, 20) have a different radial distance from the rotor axis (16). Vacuum pump (10), in particular turbomolecular pump, with at least one side channel pump stage (12) which comprises ring channels (18, 20) concentric to a rotor axis (16) and, in particular, blade-like rotor elements (22) immersed in the ring channels (18, 20), wherein the side channel pump stage (12) has at least two first ring channels (18, 20), each with a separate inlet (24), which are arranged in a same plane perpendicular to the rotor axis (16) and are provided with a common outlet (26). Vacuum pump after Claim 6 , characterized in that the two first ring channels (18, 20) are arranged at a radial distance from one another. Vacuum pump according to one of the preceding claims, characterized in that the common outlet (26) of the first ring channels (18, 20) ejects the gas to be pumped against the atmosphere or transfers it to a backing pump. Vacuum pump according to one of the Claims 1 to 7 , characterized in that the common outlet (26) of the first ring channels (18, 20) transfers the gas to be pumped into at least one further ring channel of the side channel pump stage. Vacuum pump after Claim 9 , characterized in that the further ring channel a has a smaller radial distance from the rotor axis (16) than the first ring channels (18, 20). Vacuum pump after Claim 9 or 10th , characterized in that the further ring channel is arranged in the same plane perpendicular to the rotor axis (16) as at least the first ring channel (20) immediately preceding viewed in the gas flow direction. Vacuum pump after Claim 9 or 10th , characterized in that the further ring channel is arranged in a different plane perpendicular to the rotor axis (16) than the first ring channels (18, 20) arranged in the same or different planes perpendicular to the rotor axis (16). Vacuum pump according to one of the Claims 9 to 12 , characterized in that the further ring channel ejects the gas to be conveyed against the atmosphere or transfers it to a backing pump. Vacuum pump according to one of the preceding claims, characterized in that the rotor elements (22) from a rotor hub (30) of a rotor shaft (14) rotating around the rotor axis (16) or from one rotating with the rotor hub (30) or rotor shaft (14) Rotor element carrier (165) carried or formed on the rotor hub (30) or the rotor element carrier (165). Vacuum pump after Claim 14 , characterized in that a gap seal is provided between the rotor hub (30) or the rotor element carrier (165) and the boundary of a respective ring channel (18, 20). Vacuum pump according to one of the preceding claims, characterized in that the vacuum pump comprises at least one turbomolecular pump stage upstream of the side channel pump stage (12). Vacuum pump according to one of the preceding claims, characterized in that the vacuum pump comprises at least one molecular pump stage upstream of the side channel pump stage (12). Vacuum pump after Claim 17 , characterized in that the molecular pump stage is connected between a turbomolecular pump stage and the side channel pump stage. Vacuum pump after Claim 17 or 18th , characterized in that the molecular pump stage comprises at least one Holweck stage or Siegbahn stage. Vacuum pump according to one of the Claims 17 to 19th , characterized in that the rotor elements (22) are arranged on at least one rotor member (165) of the molecular pump stage or are integrally formed thereon. Vacuum pump according to one of the Claims 17 to 20th , characterized in that the molecular pump stage comprises at least one Holweck pump stage and the rotor elements (22) are arranged on at least one Holweck sleeve (165) of the Holweck pump stage or are integrally formed thereon. Vacuum pump after Claim 21 , characterized in that the rotor elements (22) are arranged at the free end of the Holweck sleeve (165) or in the region of the free end of the Holweck sleeve (165) or are integrally formed thereon. Vacuum pump after Claim 22 , characterized in that the rotor elements (22) in the radial direction not over the Holweck sleeve (165) or over an area axially adjacent to the area of the rotor elements (22) of the Holweck sleeve (165) or over an imaginary axial extension of the Protrude the Holweck sleeve (165). Vacuum pump after Claim 22 or 23 , characterized in that the rotor elements (22) of material that has remained after the material has been removed are formed at the free end of the Holweck sleeve (165) or in the region of the free end of the Holweck sleeve (165).

Images