EP3327293A1 - Vacuum pump having multiple inlets - Google Patents

Abstract

A vacuum pump, in particular a turbomolecular pump, comprising a housing with at least two separate inlets for connecting at least one recipient, and at least one pumping stage arranged in the housing for conveying fluid, in particular aspirated fluid from the at least one recipient, in the direction of an outlet provided on the housing Vacuum pump, wherein the pumping stage has at least one with respect to a stator rotatable about a rotation axis rotor, wherein the stator and the rotor are designed such that they cause a pumping action with rotating rotor, by which the fluid is conveyed in the direction of the outlet is characterized in that the at least two inlets in the circumferential direction of the rotor seen offset from each other on the housing are arranged and at least one plane extending perpendicular to the axis of rotation extends through the at least two inlets.

Description

The present invention relates to a vacuum pump, in particular turbomolecular pump, comprising a housing having at least two separate inlets for connecting at least one recipient, at least one pumping stage arranged in the housing for conveying fluid, in particular from the at least one recipient aspirated fluid, in the direction of a housing provided outlet of the vacuum pump, wherein the pumping stage has at least one with respect to a stator rotatable about a rotation axis rotor, wherein the stator and the rotor are configured such that they cause a pumping action with rotating rotor through which the fluid promotes in the direction of the outlet becomes.

Such vacuum pumps are known from the prior art. They are also referred to as split-flow vacuum pumps or as multi-inlet vacuum pumps.

In such, multiple inlets having vacuum pumps, the problem arises that they can not be realized in a simple manner in a compact form, since the multiple inlets require a correspondingly large space on the housing of the vacuum pump.

The present invention has for its object to provide an improved vacuum pump with at least two separate inlets, the vacuum pump can be realized in a compact design.

The object is achieved by a vacuum pump with the features of claim 1. Preferred embodiments and further developments of the invention are specified in the dependent claims.

A vacuum pump according to the invention, in particular turbomolecular pump, preferably split-flow pump, comprises a housing with at least two separate inlets for connecting at least one recipient, at least one pumping stage arranged in the housing for conveying fluid, in particular from the at least one recipient aspirated fluid, in the direction of housing provided on the housing of the vacuum pump, wherein the pumping stage has at least one relative to a stator rotatable about a rotation axis rotor, wherein the stator and the rotor are configured such that they cause a pumping action with rotating rotor, through which the fluid in the direction of Outlet is promoted, and wherein the at least two inlets in the circumferential direction of the rotor seen offset from each other on the housing are arranged and at least one plane extending perpendicular to the axis of rotation extends through the at least two inlets.

Since in the vacuum pump according to the invention, the plane perpendicular to the axis of rotation and also passes through the two inlets and cuts the two inlets, the inlets are at least substantially at the same axial height on the housing of the vacuum pump. In contrast to an offset along the axial direction arrangement of the inlets, thus the axial length of the vacuum pump according to the invention can be kept short. The vacuum pump according to the invention can therefore be made compact and thus realize in a compact design.

With the terms "axial" and "axial direction" is turned off in a direction extending along the axis of rotation, while with the term "circulation direction" on a parked in the circumferential direction about the axis of rotation around direction is turned off.

In the vacuum pump according to the invention, a main inlet may be provided in addition to the at least two inlets on the housing. Preferably, the main inlet is located at an axial end of the housing, in particular at the end face of the housing lying at the axial end, wherein, preferably, the at least two inlets are not provided on this housing front side.

The main inlet and also the other inlets may in particular be ports of the vacuum pump, to which containers or receptacles to be evacuated can be connected.

The plane passing through the at least two inlets preferably does not pass through the main inlet. The at least two inlets are thus seen in the axial direction offset from the main inlet. The inlets are, in particular, secondary inlets at which the at least one pumping stage develops a lower pumping action than at the main inlet.

The inlets are preferably located at the other axial end of the housing, which faces the axial end with the main inlet. The inlets may be arranged or formed on the peripheral surface of the housing. They are therefore preferably not on the housing front side at the other axial end of the housing. Preferably, the main inlet is located at an upper axial end of the housing, in particular at the upper end side, while the inlets are located at a lower axial end of the housing.

Each of the inlets may have an inlet opening with a center. The inlet opening may be at least approximately circular, square or rectangular. Preferably, the plane passes through the midpoints the inlets. The inlets can therefore be exactly at the same height, whereby a particularly compact design can be realized.

Also, the plane can not pass through the center of at least one of the inlets. The centers and thus the at least two inlets can therefore have an at least slight offset in the axial direction. The axial offset of two inlets is preferably smaller than the sum of the radii of the two inlets. The inlets are thus, although not exactly, still at least substantially at the same axial height, so that a compact, short design of the vacuum pump can be realized.

Preferably, each inlet opening has a certain area, wherein at least 25%, preferably at least 30%, more preferably at least 40% and even more preferably at least 50% of the areas of the inlet openings are located at the same axial height when viewed in the axial direction. With reference to the axial direction, this results in a partial overlap of the inlet openings. It can thus be achieved that the inlet openings are at least substantially at the same axial height, and the vacuum pump can be realized in a compact design.

The inlets may be so connected to the pumping stage or be in fluid communication that at the inlets different pressure levels are generated. The pumping stage therefore develops different pumping effects at the inlets.

Alternatively, the inlets may be connected to the pumping stage or in fluid communication with the pumping stage such that at least approximately the same pressure levels are created at the inlets.

The plane which intersects the inlets may also pass through the outlet of the vacuum pump. The inlets can thus be at least substantially at the same axial height as the outlet. This allows a particularly compact, axially short design of the vacuum pump can be realized.

The outlet is seen in the direction of rotation to the inlets offset from the housing arranged or formed. Preferably, the outlet is seen in the direction of rotation between the at least two inlets. The outlet may have a circular, square or rectangular outlet opening.

In particular, the outlet opening may have a center point. The plane may pass through the centers of the openings of the inlets and through the center of the outlet opening. This can be achieved that the outlet and the inlets are exactly at the same axial height. The compactness can be further improved. However, it may also be provided an at least slight axial offset between the mentioned centers.

The vacuum pump may have at least one Holweckpumpstufe, wherein the at least two inlets open into the Holweckpumpstufe. The inlets can thus be fluidly connected or coupled to the Holweckpumpstufe.

The arrangement of the inlets on the at least substantially the same axial height of the vacuum pump can be realized particularly easily using a Holweckpumpstufe, since the coupling between an inlet and Holweckpumpstufe can be particularly easily realized, for example by a channel which extends from the outside of the housing extends radially inward to the Holweckspalt the Holweckpumpstufe. In addition, different pressure levels at the inlets can be realized in a simple manner.

Preferably, the Holweckpumpstufe to the radially outer Holweckpumpstufe of at least two nested Holweckpumpstufen.

The vacuum pump may comprise at least one turbomolecular pump stage, wherein the at least two inlets may open into the turbomolecular pump stage. The inlets may thus be fluidly connected or coupled directly to the turbomolecular pumping stage. As a result, lower pressure levels in the inlets can be realized in particular in comparison to a coupling of the inlets to a Holweckpumpstufe.

The at least one turbomolecular pumping stage is preferably connected upstream of the at least one Holweckpumpstufe in the vacuum pump. That a fluid conveyed via the main inlet into the vacuum pump first flows through the turbomolecular pumping stage and then first through the holweck pumping stage. A pumping channel extending between the main inlet and the outlet thus runs first through the turbomolecular pumping stage and then through the Holweck pumping stage. The secondary inlets may be, e.g. in the area of the turbomolecular pumping stage or Holweckpumpstufe, lead into the pumping channel.

The inlets are preferably not inlets of intermediate aspirations of a vacuum pump, which serve to evacuate a volume between an inner and an outer seal.

The invention also relates to a recipient for connection to a vacuum pump according to the invention, wherein the recipient has at least two outlets, which are designed for connection to the at least two inlets of the vacuum pump and arranged on the housing of the recipient. The outlets are - as the inlets of the vacuum pump - in the circumferential direction of the recipient spaced apart and are at least substantially on the same axial height. The recipient can also be made compact.

The invention further relates to a vacuum system with at least one vacuum pump according to the invention and at least one recipient, which is connected to the vacuum pump, wherein vacuum seals, in particular O-rings, are provided for sealing the vacuum connections between the outlets of the recipient and the inlets of the vacuum pump become. The seals may have different thicknesses to provide tolerance compensation.

Fig. 1

eine perspektivische Ansicht einer Turbomolekularpumpe,

Fig. 2

eine Ansicht der Unterseite der Turbomolekularpumpe von Fig. 1,

Fig. 3

einen Querschnitt der Turbomolekularpumpe längs der in Fig. 2 gezeigten Schnittlinie A-A,

Fig. 4

eine Querschnittsansicht der Turbomolekularpumpe längs der in Fig. 2 gezeigten Schnittlinie B-B,

Fig. 5

eine Querschnittsansicht der Turbomolekularpumpe längs der in Fig. 2 gezeigten Schnittlinie C-C,

Fig. 6

eine Querschnittsdarstellung einer erfindungsgemäßen Vakuumpumpe,

Fig. 7

eine seitliche Ansicht einer weiteren erfindungsgemäßen Vakuumpumpe,

Fig. 8

eine seitliche Ansicht von noch einer erfindungsgemäßen Vakuumpumpe, und

Fig. 9

eine Querschnittsdarstellung eines erfindungsgemäßen Vakuumsystems.

The invention will be described by way of example with reference to advantageous embodiments with reference to the accompanying figures. It show, each schematically:

Fig. 1

a perspective view of a turbomolecular pump,

Fig. 2

a view of the bottom of the turbomolecular pump from Fig. 1 .

Fig. 3

a cross section of the turbomolecular pump along in Fig. 2 shown section line AA,

Fig. 4

a cross-sectional view of the turbomolecular pump along in Fig. 2 shown section line BB,

Fig. 5

a cross-sectional view of the turbomolecular pump along in Fig. 2 shown section line CC,

Fig. 6

a cross-sectional view of a vacuum pump according to the invention,

Fig. 7

a side view of another vacuum pump according to the invention,

Fig. 8

a side view of still a vacuum pump according to the invention, and

Fig. 9

a cross-sectional view of a vacuum system according to the invention.

In the Fig. 1 shown turbomolecular pump 111 comprises a pump inlet 115 surrounded by an inlet flange 113, to which in a conventional manner, a non-illustrated recipient can be connected. The gas from the recipient may be drawn from the recipient via the pump inlet 115 and conveyed through the pump to a pump outlet 117 to which a backing pump, such as a rotary vane pump, may be connected.

The inlet flange 113 forms according to the orientation of the vacuum pump Fig. 1 the upper end of the housing 119 of the vacuum pump 111. The housing 119 comprises a lower part 121, on which an electronics housing 123 is arranged laterally. Housed in the electronics housing 123 are electrical and / or electronic components of the vacuum pump 111, eg for operating an electric motor 125 arranged in the vacuum pump. A plurality of connections 127 for accessories are provided on the electronics housing 123. In addition, a data interface 129, for example, according to the RS485 standard, and a power supply terminal 131 on the electronics housing 123 are arranged.

On the housing 119 of the turbomolecular pump 111, 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 region of the lower part 121 is still a sealing gas connection 135, which is also referred to as purge gas, arranged, via which purge gas for the protection of the electric motor 125 (see, eg Fig. 3 ) can be brought before the pumped by the pump gas in the engine compartment 137, in which the electric motor 125 is housed in the vacuum pump 111. In the lower part 121 two coolant connections 139 are further 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 for cooling purposes in the vacuum pump.

The lower side 141 of the vacuum pump can serve as a base, so that the vacuum pump 111 can be operated standing on the bottom 141. However, the vacuum pump 111 can also be fastened to a recipient via the inlet flange 113 and thus be operated to a certain extent suspended. In addition, the vacuum pump 111 can be designed so that it can also be put into operation, if it is aligned differently than in Fig. 1 is shown. Embodiments of the vacuum pump can also be implemented in which the lower side 141 can not be turned down but can be turned to the side or directed upwards.

At the bottom 141, the in Fig. 2 is shown, various screws 143 are still arranged, by means of which here unspecified components of the vacuum pump are attached to each other. For example, a bearing cap 145 is attached to the bottom 141.

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

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

Like the sectional views of the FIGS. 3 to 5 1, the vacuum pump comprises a plurality of process gas pumping stages for conveying the process gas pending at the pump inlet 115 to the pump outlet 117.

In the housing 119, a rotor 149 is arranged, which has a about a rotation axis 151 rotatable rotor shaft 153.

Turbomolecular pump 111 includes a plurality of turbomolecular pump stages operatively connected in series with a plurality of rotor disks 155 mounted on rotor shaft 153 and stator disks 157 disposed between rotor disks 155 and housed in housing 119. A rotor disk 155 and an adjacent stator disk 157 each form a turbomolecular one pump stage. The stator disks 157 are held by spacer rings 159 at a desired axial distance from each other.

The vacuum pump 111 further comprises Holweck pumping stages which are arranged one inside the other in the radial direction and which are pumpingly connected to one another in series. The rotor of the Holweck pump stages comprises a rotor hub 161 arranged on the rotor shaft 153 and two cylinder shell-shaped Holweck rotor sleeves 163, 165 fastened to the rotor hub 161 and oriented coaxially with the rotation axis 151 and nested in the radial direction. Furthermore, two cylinder jacket-shaped Holweck stator sleeves 167, 169 are provided, which are also oriented coaxially to the rotation axis 151 and, as seen in the radial direction, are nested one inside the other.

The pump-active surfaces of the Holweck pump stages are formed by the lateral surfaces, ie by the radial inner and / or outer surfaces, the Holweck rotor sleeves 163, 165 and the Holweck stator sleeves 167, 169. The radially inner surface of the outer Holweck stator sleeve 167 faces the radially outer surface of the outer Holweck rotor sleeve 163 to form a radial Holweck gap 171 and forms with this the first Holweck pump stage following the turbomolecular pump stages. The radially inner surface of the outer Holweck rotor sleeve 163 faces the radially outer surface of the inner Holweck stator sleeve 169 forming a radial Holweck gap 173 and forms with this a second Holweck pumping stage. The radially inner surface of the inner Holweck stator sleeve 169 faces the radially outer surface of the inner Holweck rotor sleeve 165 to form a radial Holweck gap 175 and forms with this the third Holweck pumping stage.

At the lower end of the Holweck rotor sleeve 163, a radially extending channel may be provided, via which the radially outer Holweck gap 171 is connected to the middle Holweck gap 173. In addition, at the upper end of the inner Holweck stator sleeve 169, a radially extending channel may be provided, via which the middle Holweck gap 173 is connected to the radially inner Holweck gap 175. As a result, the nested Holweck pump stages are connected in series. Furthermore, a connecting channel 179 to the outlet 117 may be provided at the lower end of the radially inner Holweck rotor sleeve 165.

The above-mentioned pump-active surfaces of the Holweck stator sleeves 163, 165 each have a plurality of Holweck grooves running around the axis of rotation 151 in the axial direction, while the opposite lateral surfaces of the Holweck rotor sleeves 163, 165 are smooth and the gas for operating the Drive vacuum pump 111 in the Holweck grooves.

For rotatably supporting the rotor shaft 153, a roller bearing 181 in the region of the pump outlet 117 and a permanent magnet bearing 183 in the region of the pump inlet 115 are provided.

In the area of the roller bearing 181, a conical spray nut 185 with an outer diameter increasing toward the rolling bearing 181 is provided on the rotor shaft 153. The spray nut 185 is in sliding contact with at least one scraper of a resource storage. The resource storage comprises a plurality of stackable absorbent discs 187 provided with a rolling bearing bearing means 181, e.g. with a lubricant, soaked.

During operation of the vacuum pump 111, the operating means is transferred by capillary action of the resource storage on the scraper on the rotating sprayer nut 185 and due to the centrifugal force along the sprayer 185 in the direction of increasing outer diameter of the spray nut 185 to the roller bearing 181 out promoted, where eg fulfills a lubricating function. The rolling bearing 181 and the resource storage are enclosed by a trough-shaped insert 189 and the bearing cap 145 in the vacuum pump.

The permanent magnet bearing 183 includes a rotor-side bearing half 191 and a stator-side bearing half 193, each comprising a ring stack of a plurality of stacked in the axial direction of permanent magnetic rings 195, 197 include. The ring magnets 195, 197 are opposed to each other to form a radial bearing gap 199, wherein the rotor-side ring magnets 195 are disposed radially outward and the stator-side ring magnets 197 radially inward. The magnetic field present in the bearing gap 199 causes magnetic repulsive forces between the ring magnets 195, 197, which cause a radial bearing of the rotor shaft 153. The rotor-side ring magnets 195 are supported by a carrier section 201 of the rotor shaft 153, which surrounds the ring magnets 195 radially on the outside. The stator-side ring magnets 197 are supported by a stator-side support portion 203 which extends through the ring magnets 197 and is suspended on radial struts 205 of the housing 119. Parallel to the axis of rotation 151, the rotor-side ring magnets 195 are fixed by a lid element 207 coupled to the carrier section 203. The stator-side ring magnets 197 are fixed parallel to the axis of rotation 151 in one direction by a fastening ring 209 connected to the carrier section 203 and a fastening ring 211 connected to the carrier section 203. Between the fastening ring 211 and the ring magnet 197, a plate spring 213 may also be provided.

Within the magnetic bearing, an emergency bearing 215 is provided, which runs empty in the normal operation of the vacuum pump 111 without contact and engages only with an excessive radial deflection of the rotor 149 relative to the stator to a radial stop for the rotor 149th to form, since a collision of the rotor-side structures with the stator-side structures is prevented. The safety bearing 215 is designed as an unlubricated rolling bearing and forms with the rotor 149 and / or the stator a radial gap, which causes the safety bearing 215 is disengaged in the normal pumping operation. The radial deflection at which the safety bearing 215 engages is dimensioned large enough so that the safety bearing 215 does not engage during normal operation of the vacuum pump, and at the same time small enough so that a collision of the rotor-side structures with the stator-side structures under all circumstances is prevented.

The vacuum pump 111 includes the electric motor 125 for rotationally driving the rotor 149. The armature of the electric motor 125 is formed by the rotor 149 whose rotor shaft 153 extends through the motor stator 217. On the extending through the motor stator 217 through portion of the rotor shaft 153 may radially outside or embedded a permanent magnet assembly be arranged. Between the motor stator 217 and the portion of the rotor 149 extending through the motor stator 217, a gap 219 is arranged, which comprises a radial motor gap, via which the motor stator 217 and the permanent magnet arrangement for the transmission of the drive torque can influence magnetically.

The motor stator 217 is fixed in the housing within the motor space 137 provided for the electric motor 125. About the sealing gas port 135, a sealing gas, which is also referred to as purge gas, and which may be, for example, air or nitrogen, enter the engine compartment 137. Via the blocking gas, the electric motor 125 can be provided with process gas, e.g. against corrosive fractions of the process gas. The engine compartment 137 may also be evacuated via the pump outlet 117, i. In the engine compartment 137, at least approximately, the vacuum pressure caused by the backing pump connected to the pump outlet 117 prevails.

Between the rotor hub 161 and a motor space 137 delimiting wall 221 may also be a so-called. And per se known labyrinth seal 223 may be provided, in particular to achieve a better seal of the engine compartment 217 against the Holweck pump stages located radially outside.

The above-described vacuum pump 111 may be configured as a split-flow vacuum pump to provide two or more auxiliary inlets serving as secondary inlets, in addition to the main intake pump inlet 115 formed on the upper end side of the pump 111 Fig. 1 to 5 not shown). These sub-inlets may be arranged on the peripheral surface of the vacuum pump 111 and the housing 119, including the lower part 121, respectively.

According to the invention, the at least two secondary inlets in the direction of rotation of the rotor shaft 153 offset from each other on the housing 119, which also includes the lower part 121, arranged and at least one perpendicular to the rotation or rotation axis 151 extending plane (not shown in FIG Fig. 1 to 5 ) runs through the side inlets. The secondary inlets are therefore at least substantially, with respect to the longitudinal direction of the axis of rotation 151, at the same axial height. As a result, despite the secondary inlets, the vacuum pump 111 can be designed to be compact or relatively short, in particular in comparison to an arrangement in which the secondary inlets are arranged or formed offset relative to one another in the longitudinal direction of the rotation axis 151. The secondary inlets can open into the radially outer Holweck gap 171, in such a way that at each secondary inlet a different pressure level or alternatively the same pressure level can be effected. Alternatively, the secondary inlets may open into one of the turbomolecular pumping stages or at another location in the pumping channel.

In the Fig. 6 Vacuum pump 33 shown in a purely schematic cross-sectional illustration comprises a housing 11, which in the manner of the housing 119 with the lower part 121, can be configured, and in addition to the main inlet 13 at least two inlets 15, of which in Fig. 6 only one inlet 15 can be seen. The inlets 15 serve as secondary inlets. To each of the inlets 13, 15, an outlet of a recipient (not shown) may be connected to evacuate the recipient via the pump 33.

Furthermore, at least one pumping stage 17 is formed in the housing 11, which may be, for example, at least one turbomolecular pumping stage, a Holweck pumping stage or a combination of turbomolecular pumping stages and downstream Holweck pumping stages. The pumping stage 17 has a rotor 19, cf. the above-mentioned rotor 149, which is rotatable about a rotation axis 21 with respect to a stator (not shown) about a Pumping effect to produce. The pumping action allows fluid, such as process gas or air, to be pumped from the recipient or recipients through the inlets 13, 15 into the pump and through the pump to its outlet (not shown, see the pump outlet 117 in FIG Fig. 1 ) are pumped. From there it can be pumped on, for example by means of a backing pump.

In the vacuum pump 33 of Fig. 6 the at least two inlets 15 are remote from the main inlet 13 and offset in particular in the direction of rotation U of the rotor 19 to each other on the housing 11. At least one plane E1 extends perpendicular to the axis of rotation 21 and through the at least two inlets 15. With respect to the axis of rotation 21 seen The two inlets 15 are thus at the same axial height of the vacuum pump 33, whereby a compact and short design of the vacuum pump 33 is possible.

As further in Fig. 6 At least one other plane E2, which is perpendicular to the axis of rotation 21 and is offset in the axial direction to the plane E1, cuts the main inlet 13th

The vacuum pump shown in a side view Fig. 7 comprises a housing 11 having an upper housing part 23 and a lower housing part 25. In the housing interior, the vacuum pump is the Fig. 7 like the pump according to Fig. 6 built up. Furthermore, an unillustrated main inlet may be provided on the upper housing part 23, for example on the upper end side of the housing part 23, in a manner similar to that of the vacuum pump of FIG Fig. 1 to 5 ,

The vacuum pump the Fig. 7 comprises two inlets 15a, 15b, which in the direction of rotation U of a rotor 19 (see. Fig. 6 ) Seen offset from one another on the lower housing part 25 are arranged, wherein the plane perpendicular to the axis of rotation 21 extending plane E1 through the two inlets 15a, 15b.

As shown, the two inlets 15a, 15b may have a circular cross-section with a respective center M1 or M2, respectively. The plane E1 passes through the two midpoints M1 and M2. As a result, the center points M1, M2 lie with respect to the axis of rotation 21 at the same axial height.

Alternatively, the midpoints M1 and M2 can have a slight axial offset seen in the axial direction, which is preferably smaller than the sum of the radii of the cross-sectional areas. In such an axial offset, the plane E1 can not run through both centers M1 and M2 simultaneously, but very well cut both inlets 15a, 15b. The inlets 15a, 15b then have slightly different axial heights.

The vacuum pump the Fig. 8 is like the vacuum pump the Fig. 7 built up. However, the vacuum pump is the Fig. 8 the outlet 27 seen in the circumferential direction U between the two inlets 15a, 15b. The outlet 27 has a circular outlet opening through whose center M3 the plane E1 extends. The same applies to the centers M1, M2 of the inlet openings of the inlets 15a, 15b. The outlet 27 is thus exactly at the same axial height as the two inlets 15a, 15b.

The vacuum system 31 of the Fig. 9 comprises a vacuum pump 33 as described above and a recipient 35 with chambers 37, 39. The one chamber 37 is vacuum-tightly connected to the main inlet 13 of the vacuum pump 33, while the other chamber 39 is vacuum-tightly connected to the one auxiliary inlet 15a. To the in Fig. 9 not shown, other secondary inlet 15b is a further, not shown chamber of the recipient 35 vacuum-tight connected.

As in Fig. 9 is shown, the chamber 37 jumps in the radial direction, relative to the axis of rotation 21, relative to the chamber 39 something out. To get this lead To compensate or to compensate for other tolerances, a thick seal 41, in particular O-ring seal, between the outlet of the chamber 39 and the inlet 15 a to be inserted, while a thin seal 43, in particular O-ring seal, between the outlet the chamber 37 and the main inlet 13 is arranged.

The vacuum pumps described allow a compact design, since the secondary inlets 15, 15a, 15b are arranged at least substantially at the same axial height. In this case, the secondary inlets 15, 15a, 15b can be connected to the pumping stages such that different pressure levels are effected in the inlets during pump operation.

LIST OF REFERENCE NUMBERS

11

casing

13

main inlet

15

Inlet, secondary inlet

15a

Inlet, secondary inlet

15b

Inlet, secondary inlet

17

pump stage

19

rotor

21

axis of rotation

23

Upper housing part

25

lower housing part

27

outlet

31

vacuum system

33

vacuum pump

35

recipient

37

chamber

39

chamber

41

poetry

43

poetry

111

Turbo molecular pump

113

inlet flange

115

pump inlet

117

pump outlet

119

casing

121

lower part

123

electronics housing

125

electric motor

127

accessory port

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

axis of rotation

153

rotor shaft

155

rotor disc

157

stator

159

spacer ring

161

rotor hub

163

Holweck rotor sleeve

165

Holweck rotor sleeve

167

Holweck stator

169

Holweck stator

171

Holweck gap

173

Holweck gap

175

Holweck gap

179

connecting channel

181

Rolling

183

Permanent magnetic bearings

185

spray mother

187

disc

189

commitment

191

Rotor-side bearing half

193

stator side half

195

ring magnet

197

ring magnet

199

bearing gap

201

support section

203

support section

205

radial strut

207

cover element

209

support ring

211

fixing ring

213

Belleville spring

215

Emergency or catch camp

217

motor stator

219

gap

221

wall

223

labyrinth seal

U

circumferentially

E1

level

E2

level

M1

Focus

M2

Focus

M3

Focus

Claims (11)

Vacuum pump, in particular turbomolecular pump, comprising a housing (11, 119, 121) having at least two separate inlets (15, 15a, 15b) for connecting at least one recipient (35), and at least one pumping stage (17) arranged in the housing (11, 119, 121) for conveying fluid, in particular fluid extracted from the at least one recipient (35), in the direction of an outlet (27, 119, 121) provided on the housing (11, 119, 121) 117) of the vacuum pump, wherein the pumping stage (17) has at least one rotor (19, 149) rotatable relative to a stator about an axis of rotation (21, 151), wherein the stator and the rotor (19, 149) are designed in such a way that they rotate when the rotor rotates ( 19, 149) effect a pumping action by which the fluid is conveyed in the direction of the outlet (27, 117), characterized in that
the at least two inlets (15, 15a, 15b) seen in the direction of rotation (U) of the rotor (19, 149) offset from each other on the housing (11, 119, 121) are arranged and at least one plane perpendicular to the axis of rotation (21, 151) (E1) passes through the at least two inlets (15, 15a, 15b). Vacuum pump according to claim 1,
characterized in that
a main inlet (13, 115) in addition to the at least two inlets (15, 15a, 15b) is provided on the housing (11, 119, 121), in particular on an axial end of the housing (11, 119, 121), wherein the plane (E1) does not extend through the main inlet (13, 115). Vacuum pump according to claim 1 or 2,
characterized in that
each of the inlets (15, 15a, 15b) has an inlet, in particular a circular inlet, with a center (M1, M2), the plane (E1) passing through the centers (M1, M2) of the inlets (15, 15a, 15b) , Vacuum pump according to claim 1 or 2,
characterized in that
each of the inlets (15, 15a, 15b) has an inlet, in particular a circular inlet, with a center (M1, M2), the plane (E1) not being defined by the center (M1, M2) of at least one of the inlets (15, 15a 15b). Vacuum pump according to one of the preceding claims,
characterized in that
each of the inlets (15, 15a, 15b) has an inlet, in particular a circular inlet, each inlet opening (15, 15a, 15b) having a certain area, and wherein at least 25%, preferably 30%, more preferably 40%, still further Preferably, 50% of the surfaces of the inlet openings in the axial direction are at the same axial height. Vacuum pump according to one of the preceding claims,

characterized in that
the inlets (15, 15a, 15b) are connected to the pumping stage (17) in such a way that different pressure levels or at least approximately the same pressure levels can be generated at the inlets (15, 15a, 15b). Vacuum pump according to one of the preceding claims,
characterized in that
the plane (E1) passes through the outlet (27, 117). Vacuum pump according to one of the preceding claims,

characterized in that
said at least one Holweckpumpstufe (163, 165, 167, 169), wherein the at least two inlets (15, 15a, 15b) in the Holweckpumpstufe (163, 165, 167, 169) open. Vacuum pump according to one of the preceding claims,
characterized in that
this at least one turbomolecular pump stage (155, 157), wherein the at least two inlets (15, 15a, 15b) in the turbomolecular pump stage (155, 157) open. A recipient (35) for connection to a vacuum pump (33) according to any one of the preceding claims,
characterized in that
the recipient (35) has at least two outlets which are designed to connect to the at least two inlets (15, 15a, 15b) of the vacuum pump (33) and are arranged on the housing of the recipient (35). A vacuum system (31) comprising at least one vacuum pump (33) according to any one of claims 1 to 9 and at least one recipient (35) connected to the vacuum pump (33) according to claim 10, wherein for sealing the vacuum connections between the outlets of the recipient (33) and the inlets (13, 15, 15a, 15b) of the vacuum pump (33) vacuum seals (41, 43), in particular O-ring seals are provided, which preferably have different thicknesses.

Images