turbomolecular vacuum pump

Abstract

To provide a turbo molecular vacuum pump that includes a stator, a rotor, and a stator blade and has an exhaust speed improved for respective states in a region of a pump intake port.SOLUTION: A stator blade 20 includes a fitting part 28 with an end part 30 for being fitted to a stator 12. The stator blade is fitted to the stator by the end part. The end part defines a fitting plane 32. A blade plane 26 and the fitting plane extend while being perpendicular to a rotation axis 18 and are separated from each other along the rotation axis.SELECTED DRAWING: Figure 9A

Description

[Technical Field]

[0001] The present invention relates to a turbomolecular vacuum pump comprising a stator, at least one rotor having a plurality of rotor blades distributed in the circumferential direction, the rotor being rotatably drivable about a rotation axis to provide pumping action, and at least one stator vane attached to the stator and interacting with the rotor to provide pumping action, the stator vane having a plurality of stator blades distributed in the circumferential direction, the stator blades defining blade planes. [Background technology]

[0002] By blade plane is meant the plane in which the stator blades lie, extending perpendicular to the axis of rotation. That is, the blade plane may be defined by any part of the stator blade, as long as it intersects or touches the stator blade. Thus, the blade plane may extend through the stator blade centrally, for example, in an axial direction extending parallel to the axis of rotation, or may be defined by the upper or lower blade edge.

[0003] Turbomolecular vacuum pumps should have, among other things, the highest possible pumping speed. In this context, the design of the inlet area, i.e., the area around the pump inlet, which defines the inlet plane, is of particular importance. Here, optimal utilization of the structural space available in the pump housing for accommodating the pumping components, in particular the rotor-stator set located closest to the pump inlet, is particularly important. In this context, a rotor-stator set is understood to mean a set of rotor blades and stator vanes arranged one above the other in the axial direction.

[0004] Typically, the stator vanes are attached to the stator by clamping their radially outer regions, specifically in a plane axially at the height of the blade plane, via a spacer ring fitted into the pump housing. The spacer ring and the pump housing are components of the stator of the vacuum pump; that is, within the scope of this disclosure, the pump housing is considered a component of the stator. In this case, the stator vanes are clamped between two spacer rings that are directly adjacent to each other in the axial direction. In sheet-metal stator vanes, for example, the collar region that runs radially outward of the stator vane is axially clamped via the spacer ring. In contrast, in milled or sawn stator vanes, the blades can be axially clamped by their radially outer blade tips, i.e., by their free end portions. Axial clamping of the stator vanes to the stator requires radial structural space within the pump housing.

[0005] When designing the intake area of ​​a turbomolecular vacuum pump, i.e., the area of ​​the pumping components that is located closest to the pump inlet, it is attempted to arrange the rotor-stator set as close as possible to the pump inlet in the axial direction in order to obtain the highest possible pumping speed, i.e., the first rotor blade on the intake side should be located as close as possible to the pump inlet in the axial direction in order to minimize flow losses. At the same time, the rotor-stator set, and thus even the first stator blade, should have an outer diameter that is as large as possible relative to the inner diameter of the respective pump housing where it is located.

[0006] Here too, it must be noted that in the region of the pump inlet, the construction space is limited by the pump flange and the means used to connect the pump flange to the recipient flange. These means may in particular be screws, and in this case it must also be taken into account that sufficient space must be provided in the flange for handling the screws and for the tools that drive them. Furthermore, the pump flange must meet certain criteria, such as ISO standards, in particular with regard to its diameter.

[0007] The aforementioned peripheral conditions limit the structural space provided for the rotor blades and stator vanes in the region of the pump inlet, so the rotor-stator set cannot be arbitrarily positioned near the pump inlet while at the same time the outer diameter of the first stator vane must also be as large as possible. Summary of the Invention [Problem to be solved by the invention]

[0008] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a turbomolecular vacuum pump which has an improved pumping speed in the region of the pump inlet for the respective situation. [Means for solving the problem]

[0009] This object is achieved according to the invention by a turbomolecular vacuum pump as defined in claim 1, in particular in that the stator vanes have mounting parts with end portions for mounting on the stator, by means of which the stator vanes are mounted on the stator, the end portions defining a mounting plane, the blade plane and the mounting plane extending perpendicular to the axis of rotation and spaced apart from each other along the axis of rotation.

[0010] The end portion is the part of the mounting portion that directly interacts with the stator (eg, a spacer ring and a shoulder portion of the pump housing or two spacer rings) to mount the vane to the stator.

[0011] The attachment plane is a plane in which at least a portion of the end portion lies that is axially further away from the blade plane than other areas of the attachment portion.

[0012] The axial separation of the mounting plane and the blade plane allows the blade plane to be positioned closer to the pump inlet, assuming the same axial mounting position. This reduces flow losses in the inlet area and improves pumping speed. Calculations based on the parameters of existing turbomolecular vacuum pumps have shown that pumping speed improvements of more than 3% can actually be achieved for the primary gas, i.e., nitrogen. In one example, the calculations assumed that the rotor-stator set closest to the pump inlet was positioned 10 mm closer to the pump inlet than without the inventive configuration. For nitrogen, an increase of 240 liters / second was achieved with the conventional configuration to 249 liters / second with the inventive configuration.

[0013] The geometry of the inlet area, in particular of the pump housing and flange area, does not have to be modified for the purposes of the invention, so that the pump according to the invention here meets the respective standards, such as ISO standards.

[0014] Advantageous embodiments of the invention are set forth in the dependent claims, the description and the drawings.

[0015] According to one embodiment, the blade plane is located axially closer to the pump inlet than the mounting plane, so that the structural conditions of existing turbomolecular vacuum pumps, in particular the shoulders of the pump housing present in or near the inlet region, can still be used for mounting the stator vanes, in particular the first stator vanes.

[0016] According to one embodiment, the vanes are of one piece.

[0017] The vanes may be stamped and / or bent parts made of sheet metal, i.e., so-called sheet metal vanes, or may be produced by machining the starting material. These possibilities for producing vanes are basically known and are suitable for the invention insofar as they also allow the production of vanes configured according to the invention with blade and mounting planes spaced apart in the axial direction.

[0018] Sheet metal vanes often actually consist of two semicircular or semi-annular halves to facilitate or even allow assembly. Therefore, when referring to the "vane" in this case, it means both halves taken together. In short, when referring in this disclosure to a unitary or one-piece construction in the context of such sheet metal vanes, it is understood that the two halves of the vane are each integral.

[0019] In a sheet metal vane, the attachment portion may be formed by a collar on the radially outer side of the vane, which has an end portion at the radially outer side and is connected to the stator blade at the radially inner side. Thus, while known sheet metal vanes are disc-shaped over their entire diameter, i.e., including the radially outer collar, the sheet metal vane according to the invention has an attachment portion at the radially outer side, which leads from the blade plane to an attachment plane defined by its end portion.

[0020] In principle, it is also possible, in particular depending on the respective design of the turbomolecular vacuum pump, to design the radially inner collar of the stator blade as a mounting part, so that the stator blade can be fastened radially inner to the stator.

[0021] In this case, the attachment portion may have a radially outer or radially inner collar portion that is in the blade plane and is connected to the vane.

[0022] According to another embodiment, the attachment portion is formed by a free end portion of the stator blade. In particular, sawn or milled stator blades may be configured in this way. In this case, at least some, preferably all, of the stator blades have a radial, in particular radially outer, end portion that leads from the blade plane to the attachment plane, and these end portions together form the attachment portion of the stator blade.

[0023] According to one embodiment, the mounting part has a transition part leading from the blade plane to the end part of the mounting part. The size and / or shape of the transition part can be selected in principle as desired, in particular to adjust the axial distance between the blade plane and the mounting plane. The transition part is not directly attached to the stator, but rather the attachment of the vane to the stator, for example by clamping, takes place via the end part.

[0024] According to one embodiment, the transition portion has at least partly the shape of a cylinder or a cone with the axis of rotation as the central axis.

[0025] According to one embodiment, the end portion of the mounting part has a toroidal or conical shape with the axis of rotation as the central axis or has a curved course in a cross section including the axis of rotation. The shape of the end portion can basically be selected freely, in particular depending on the respective desired clamping shape in the stator.

[0026] According to one embodiment, the mounting portion has or includes an L-shape in cross section containing the axis of rotation, i.e. diagrammatically the vane may be configured in a pot or hat shape.

[0027] According to one embodiment, the L-shape is formed by the transition portion and the end portion of the mounting portion, where the transition portion extends parallel to the axis of rotation, while the end portion extends perpendicular to the axis of rotation and therefore extends in the mounting plane, i.e. the end portion defining the mounting plane lies entirely in the mounting plane.

[0028] According to one embodiment, the stator vane is part of a turbomolecular pump stage comprising a plurality of stator vanes and a plurality of rotor blades, each having a plurality of rotor blades, which interact to provide a pumping action. The turbomolecular pump stage may have one or more rotor stator sets. The stator vane is particularly part of the first rotor stator set, i.e., the rotor stator set closest to the pump inlet. In particular, the first stator vane of the rotor stator set, i.e., the rotor stator set closest to the pump inlet, is configured in accordance with the present invention.

[0029] According to one embodiment, the stator vane is the vane located axially closest to the pump inlet among a plurality of stator vanes spaced apart in the axial direction of the stator. Additionally or alternatively, in addition to this vane, one or more stator vanes of the same design may be provided, in which the blade plane is located axially closer to the pump inlet than the mounting plane. In this case, the axial distance between the blade plane and the mounting plane may be the same for all stator vanes configured according to the invention or may vary, for example, increasing or decreasing toward the pump inlet. Identical stator vanes are understood in this context to be vanes whose blade planes and mounting planes are spaced apart from each other in the axial direction, i.e., along the rotation axis. In this sense, identical stator vanes may be identical, but this is not required; they may differ from each other in other respects. For example, identical stator vanes may have different diameters. The axial distance between the blade plane and the mounting plane may also differ for identical stator vanes.

[0030] According to one embodiment, the stator blades are clamped axially to the stator with the end portions of the mounting parts. Such possibilities for mounting the stator blades to the stator are basically known and therefore compatible with the present invention, i.e. the invention does not necessarily require new mounting methods.

[0031] According to one embodiment, exactly one stator vane is sandwiched between two spacer rings, each configured as a separate component. Alternatively, two or more stator vanes may each be sandwiched between two identical spacer rings. Only one, several, or all of the two or more stator vanes may be configured according to the invention, i.e., may have a gap between the blade plane and the mounting plane.

[0032] According to one embodiment, exactly one stator vane is sandwiched between a spacer ring configured as a separate component and a shoulder portion of the stator, in particular a shoulder portion of the pump housing forming part of the stator. Alternatively, two or more stator vanes may be sandwiched between the spacer ring and the shoulder portion. Only one, several, or all of the two or more stator vanes may be configured according to the invention, i.e., may have a gap between the blade plane and the mounting plane. Therefore, the invention is also suitable for these commonly known mounting methods.

[0033] According to one embodiment, the stator, in particular the pump housing forming part of the stator, has in the region of the pump inlet a flange portion for establishing a mechanical connection with the recipient and a shoulder portion axially spaced from the pump inlet, the shoulder portion providing together with the flange portion an assembly area for at least one connection element, in particular at least one screw, which is attached to the flange portion. area Provided that exactly one stator vane is sandwiched between the spacer ring and the shoulder portion, which are configured as separate components, or two or more stator vanes are sandwiched between the spacer ring and the shoulder portion, where again only one, several or all of the two or more stator vanes may be configured according to the invention, i.e. may have a spacing between the blade plane and the mounting plane.

[0034] Such configurations of the inlet region of turbomolecular vacuum pumps, i.e. with a shoulder axially spaced apart from the flange, are basically known, which means that the invention is also suitable for such configurations. The stator vane according to the invention can therefore be configured in particular so that it can be fastened to a shoulder of the stator, in particular the pump housing.

[0035] According to one preferred development, the stator vane sandwiched between the spacer ring and the shoulder portion is the stator vane located axially nearest to the pump intake, the mounting plane of this stator vane being located in the area of ​​the shoulder portion and the blade plane of this stator vane being located between the pump intake and the shoulder portion.

[0036] The present invention further Please request 11 According to the patent application, there is provided a stator vane for a turbomolecular vacuum pump, the stator vane comprising a plurality of circumferentially distributed stator blades, the stator blades defining blade planes, and a mounting portion having end portions by which the stator vane can be mounted to a stator of a turbomolecular vacuum pump, the end portions defining mounting planes, the stator vane defining a central axis, the blade planes and the mounting plane extending perpendicular to the central axis and spaced apart from each other along the central axis, when the stator vane is used as specified in the turbomolecular vacuum pump according to the invention, the central axis of the stator vane coincides with the axis of rotation of the rotor.

[0037] The stator vanes may be configured like the stator vanes of the turbomolecular vacuum pump according to the invention described above, i.e. a development of the stator vanes disclosed in connection with the turbomolecular vacuum pump is , request This also applies to the vanes claimed in claim 11.

[0038] The invention will now be described, by way of example only, with reference to the drawings, in which: [Brief explanation of the drawings]

[0039] [Figure 1] 1 shows a perspective view of a turbomolecular pump according to the prior art; [Figure 2] FIG. 2 shows a bottom view of the turbomolecular pump of FIG. [Figure 3] 3 shows a cross-sectional view of a turbomolecular pump taken along the section line AA shown in FIG. 2. [Figure 4] 3 shows a cross-sectional view of the turbomolecular pump taken along the section line BB shown in FIG. 2. [Figure 5] 3 shows a cross-sectional view of the turbomolecular pump taken along the section line CC shown in FIG. 2. [Figure 6A] 1 shows a simplified side view of a prior art stator vane; [Figure 6B] 1 shows a simplified side view of a prior art stator vane; [Figure 7] 1 shows a simplified side view of a stator vane according to the present invention; [Figure 8] 1 shows in a simplified plan view one half of a vane according to the invention, which consists of two halves; [Figure 9A] 1 shows in simplified cross-sectional view a portion of a turbomolecular vacuum pump according to the present invention; [Figure 9B] 1 shows in simplified cross-sectional view a portion of a turbomolecular vacuum pump according to the present invention; [Figure 9C] 1 shows in simplified cross-sectional view a portion of a turbomolecular vacuum pump according to the present invention; [Figure 10A] 9B is a view corresponding to FIG. 9A illustrating an alternative option for mounting the vanes to the stator. [Figure 10B] 9B is a view corresponding to FIG. 9A illustrating an alternative option for mounting the vanes to the stator. [Figure 10C] 9B is a view corresponding to FIG. 9A illustrating an alternative option for mounting the vanes to the stator. [Figure 10D] 9B is a view corresponding to FIG. 9A illustrating an alternative option for mounting the vanes to the stator. [Figure 10E] 9B is a view corresponding to FIG. 9A illustrating an alternative option for mounting the vanes to the stator. DETAILED DESCRIPTION OF THE INVENTION

[0040] The prior art turbomolecular pump 111 shown in Figure 1 has a pump inlet 115 surrounded by an inlet flange 113. In a manner known per se, a recipient (not shown) may be connected to the pump inlet 115. Gas coming from the recipient can be drawn in from the recipient via the pump inlet 115 and pumped through the pump to a pump outlet 117. An auxiliary vacuum pump, for example a rotary vane pump, may be connected to the pump outlet 117.

[0041] The inlet flange 113 forms the upper end of a housing 119 of the vacuum pump 111 in the orientation of the vacuum pump according to Fig. 1. The housing 119 has a lower part 121. Arranged laterally on the lower part 121 is an electronics housing 123. The electronics housing 123 accommodates electrical and / or electronic components of the vacuum pump 111, for example for operating an electric motor 125 (see also Fig. 3) arranged in the vacuum pump. The electronics housing 123 is provided with a number of connections 127 for accessories. Furthermore, a data interface 129 (for example according to the RS485 standard) and a current supply connection 131 are arranged on the electronics housing 123.

[0042] There are also turbomolecular pumps that do not have this type of attached electronics housing, but are connected to external drive electronics.

[0043] The housing 119 of the turbomolecular pump 111 is provided with a ventilation inlet 133, particularly in the form of a ventilation valve. The vacuum pump 111 can be vented via the ventilation inlet 133. A seal gas connection 135 (also called a purge gas connection) is also arranged in the region of the lower part 121. A purge gas can be introduced into a motor chamber 137 via the seal gas connection 135 to protect the electric motor 125 (see, for example, FIG. 3 ) from the gas pumped by the pump. The electric motor 125 is accommodated in the motor chamber 137 of the vacuum pump 111. Two coolant connections 139 are also arranged in the lower part 121. One coolant connection serves as a coolant inlet and the other as an outlet. A coolant can be introduced into the vacuum pump for cooling purposes. The other turbomolecular vacuum pump present (not shown) is operated exclusively air-cooled.

[0044] The underside 141 of the vacuum pump can be used as a base, so that the vacuum pump 111 can be operated in a vertical position relative to the underside 141. Moreover, the vacuum pump 111 can be fixed to the recipient via the inlet flange 113 and thus operated in a suspended state, so to speak. Furthermore, the vacuum pump 111 can be configured so that it can be operated even when oriented in a different direction than that shown in FIG. 1. Vacuum pump configurations are also possible in which the underside 141 can be arranged not only facing downwards, but also facing sideways or upwards. In this case, any angle is conceivable in principle.

[0045] In particular, other turbomolecular vacuum pumps (not shown) that exist, which are larger than the pump shown, cannot be operated in a vertical position.

[0046] 2 further comprises various screws 143. These screws 143 secure components of the vacuum pump, not specifically identified here, to one another. For example, a bearing cover 145 is secured to the lower surface 141.

[0047] Further fastening holes 147 are arranged in the underside 141. Via the fastening holes 147, the pump 111 can be fixed, for example, to a mounting surface. This is not possible with other existing turbomolecular vacuum pumps (not shown), in particular those larger than the pump shown.

[0048] 2 to 5 show a coolant line 148 in which a coolant can be circulated, the coolant being introduced and withdrawn via the coolant connection 139.

[0049] As shown in the cross-sectional views of Figures 3-5, the vacuum pump has multiple process gas pumping stages for pumping process gas acting on a pump inlet 115 to a pump outlet 117.

[0050] A rotor 149 is disposed within the housing 119. The rotor 149 has a rotor shaft 153 that is rotatable about a rotation axis 151.

[0051] The turbomolecular pump 111 has multiple turbomolecular pump stages connected in series to provide a pumping action. Each turbomolecular pump stage has multiple radially extending rotor blades 155 fixed to the rotor shaft 153 and multiple stator vanes 157 arranged between the rotor blades 155 and fixed within the housing 119. In this case, each rotor blade 155 and its adjacent stator vane 157 form one turbomolecular pump stage. The stator vanes 157 are held at a desired axial distance from each other by spacer rings 159.

[0052] The vacuum pump further comprises Holweck pump stages arranged radially inside and outside one another and connected in series to provide a pumping action. There are alternative turbomolecular vacuum pumps (not shown) that do not have Holweck pump stages.

[0053] The rotor of the Holweck pump stage includes a rotor hub 161 disposed on the rotor shaft 153 and two cylindrically sided Holweck rotor sleeves 163, 165 fixed to and supported by the rotor hub 161. The Holweck rotor sleeves 163, 165 are oriented coaxially with respect to the rotation axis 151 and engage radially with one another. Two cylindrically sided Holweck stator sleeves 167, 169 are also provided. The Holweck stator sleeves 167, 169 are likewise oriented coaxially with respect to the rotation axis 151 and engage radially with one another.

[0054] The pumping surfaces of the Holweck pump stages are formed by the side surfaces, i.e., the radially inner and / or outer surfaces of 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, forming a radial Holweck gap 171, and together with this outer surface forms the first Holweck pump stage following the turbomolecular pump. 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 together with this outer surface forms the second Holweck pump stage. The radially inner surface of the inner Holweck stator sleeve 169 opposes the radially outer surface of the inner Holweck rotor sleeve 165, forming a radial Holweck gap 175, and together with this outer surface forms the third Holweck pump stage.

[0055] A radially extending channel may be provided at the lower end of the Holweck rotor sleeve 163. The radially outer Holweck gap 171 is connected to the central Holweck gap 173 via the channel. A further radially extending channel may be provided at the upper end of the inner Holweck stator sleeve 169. The central Holweck gap 173 is connected to the radially inner Holweck gap 175 via the channel. This allows multiple Holweck pump stages that engage with each other in series. A connecting channel 179 that leads to the exhaust port 117 may be provided at the lower end of the radially inner Holweck rotor sleeve 165.

[0056] The pumping surfaces of the Holweck stator sleeves 167, 169 each have a plurality of Holweck grooves that extend axially and spirally around the rotation axis 151. On the other hand, the opposing sides of the Holweck rotor sleeves 163, 165 are smoothly formed and pump gas for operating the vacuum pump 111 forward in the Holweck grooves.

[0057] For the rotatable support of the rotor shaft 153, a rolling bearing 181 is provided in the region of the pump outlet 117 and a permanent magnetic bearing 183 is provided in the region of the pump inlet 115.

[0058] In the region of the rolling bearing 181, the rotor shaft 153 is provided with a conical splash nut 185. The splash nut 185 has an outer diameter that increases towards the rolling bearing 181. The splash nut 185 is in sliding contact with at least one scraping element of the working medium reservoir. In other existing turbomolecular vacuum pumps (not shown), a splash screw may be provided instead of a splash nut. This allows for various configurations to be realised, so that the term "splash tip" is also used in this context.

[0059] The working medium reservoir comprises a number of absorbent discs 187 stacked one above the other, which are impregnated with a working medium, e.g., a lubricant, for the rolling bearings 181.

[0060] During operation of the vacuum pump 111, the working medium is transferred by capillary action from the working medium reservoir via the scraping element to the rotating splash nut 185 and is then forced by centrifugal force along the splash nut 185 towards the increasing outer diameter of the splash nut 185 towards the rolling bearing 181, where it performs, for example, a lubrication function. The rolling bearing 181 and the working medium reservoir are enclosed in the vacuum pump by a trough-like insert 189 and a bearing cover 145.

[0061] The permanent magnet magnetic bearing 183 has a rotor-side bearing half 191 and a stator-side bearing half 193. Each half has a ring stack, which consists of multiple rings 195, 197 of permanent magnets stacked axially one above the other. The ring magnets 195, 197 face each other, forming a radial bearing gap 199, with the rotor-side ring magnet 195 positioned radially outward and the stator-side ring magnet 197 positioned radially inward. The magnetic field present in the bearing gap 199 generates a magnetic repulsion force between the ring magnets 195, 197. This repulsion force provides radial support for the rotor shaft 153. The rotor-side ring magnet 195 is supported by a support portion 201 of the rotor shaft 153. The support portion 201 surrounds the ring magnet 195 radially outward. The stator-side ring magnet 197 is supported by a support portion 203 of the stator shaft 153. The support part 203 extends through the ring magnet 197 and is suspended on radial struts 205 of the housing 119. The rotor-side ring magnet 195 is fixed parallel to the rotation axis 151 by a cover element 207 connected to the support part 203. The stator-side ring magnet 197 is fixed in one direction parallel to the rotation axis 151 by a fixing ring 209 connected to the support part 203 and a fixing ring 211 connected to the support part 203. A disc spring 213 may further be provided between the fixing ring 211 and the ring magnet 197.

[0062] An emergency or safety bearing 215 is provided within the magnetic bearing. During normal operation of the vacuum pump, the emergency or safety bearing 215 runs free and only engages if the rotor 149 is displaced excessively radially relative to the stator, thereby forming a radial stop for the rotor 149 so that collisions between rotor-side and stator-side structures are prevented. The safety bearing 215 is configured as a non-lubricated rolling bearing and forms a radial gap with the rotor 149 and / or the stator. This gap prevents the safety bearing 215 from engaging during normal pump operation. The radial displacement that the safety bearing 215 engages is dimensioned to be sufficiently large so that the safety bearing 215 does not engage during normal operation of the vacuum pump, and at the same time is sufficiently small so that collisions between rotor-side and stator-side structures are prevented under all circumstances.

[0063] The vacuum pump 111 includes an electric motor 125 that rotates a rotor 149. The armature of the electric motor 125 is formed by the rotor 149. A rotor shaft 153 of the rotor 149 extends through a motor stator 217. A permanent magnet assembly may be disposed radially outward or embedded on the portion of the rotor shaft 153 that extends through the motor stator 217. An intermediate chamber 219 is disposed between the motor stator 217 and the portion of the rotor 149 that extends through the motor stator 217. The intermediate chamber 219 defines a radial motor gap. Through the motor gap, the motor stator 217 and the permanent magnet assembly may magnetically interact to transmit a driving torque.

[0064] The motor stator 217 is fixed in the housing in a motor chamber 137 provided for the electric motor 125. A seal gas connection 135 allows a seal gas (also called purge gas, which may be, for example, air or nitrogen) to reach the motor chamber 137. The seal gas protects the electric motor 125 against process gases, for example corrosive parts of the process gas. The motor chamber 137 may be evacuated via the pump outlet 117, i.e., a vacuum pressure is applied to the motor chamber 137 at least approximately, which is achieved by an auxiliary vacuum pump connected to the pump outlet 117.

[0065] A so-called labyrinth seal 223, known per se, may further be provided between the rotor hub 161 and the wall 221 that defines the motor chamber 137. This achieves better sealing of the motor chamber 217, in particular with respect to the radially outer Holweck pump stages.

[0066] As will be described below with reference to Figures 7 and subsequent figures, in the turbomolecular vacuum pump according to the present invention, features not shown in Figures 7 and subsequent figures may be configured as described above with reference to Figures 1 to 5.

[0067] 6A and 6B illustrate, in highly simplified side view, prior art metal plate vanes 20 and how they are used in the conventional intake region of a turbomolecular vacuum pump.

[0068] The stator vane 20, which is manufactured by stamping and bending and thus has a single structure, includes a radially outer collar 24 (hereinafter also referred to as the outer collar), a radially inner collar (not shown) (hereinafter also referred to as the inner collar), and a plurality of stator blades 22 positioned therebetween. The stator blades 22 are bent and inclined relative to a blade plane 26 defined by the collar. In FIG. 6A, the stator blades 22 protrude from both sides of the blade plane 26, while in FIG. 6B, they protrude only from one side. The outer collar 24 is used to mount the stator vane 20 to a stator (not shown), for example, by sandwiching the outer collar 24 between two spacer rings. The outer collar 24 thereby also defines a mounting plane 32; in other words, in known stator vanes 20, the blade plane 26 and the mounting plane 32 coincide with each other.

[0069] The sheet-metal vane 20 according to the invention, shown in FIG. 7 (see also FIGS. 8 and 9A ), has stator blades 22 inclined to one side between an inner collar (not shown) and a radially outer collar portion 24 a (hereinafter, outer collar 24 a), corresponding to known sheet-metal vanes (e.g., as shown in FIG. 6B ). The outer collar 24 a, located in a blade plane 26, is a component of a specially configured mounting portion 28. In addition to the outer collar 24 a, the mounting portion 28 has an end portion 30 and a transition portion 34. The end portion 30 defines a mounting plane 32 extending from the blade plane 26 at an axial distance 52, and the transition portion 34 extends axially (i.e., parallel to the axial direction Z) from the outer collar 24 a, i.e., from the blade plane 26 to the mounting plane 32. This sheet-metal vane 20 according to the invention can be produced by stamping and bending, similar to known sheet-metal vanes. The distance 52 between the blade plane 26 and the mounting plane 32 is, for example, 10 mm.

[0070] The end portions 30 are used to attach the vanes 20 to the stator of a turbomolecular vacuum pump, as will be explained in more detail in connection with Figure 9A.

[0071] As can be seen in FIG. 8 , each half of the two-piece sheet-metal stator vane 20 according to the present invention (only one half is shown in FIG. 8 , but the halves are formed corresponding to FIGS. 7 and 9A ) has a circular shape, i.e., both the outer collar 24 a and the collar portion 24 b (hereinafter referred to as the inner collar 24 b) located inside in the radial direction R each have a semicircular shape. The diagonally arranged stator blades 22 are located between the inner collar 24 b and the outer collar 24 a. In the assembled state, the two inner collars 24 b of the two halves of the stator vane 20 define a circular opening through which extends the rotor (not shown) of a turbomolecular pump, the rotation axis of which coincides with the central axis of the stator vane 20 formed by the two halves. Also visible in FIG. 8 are a transition portion 34 extending in the axial direction Z and an end portion 30 extending perpendicularly to the transition portion 34 and projecting radially outward from the transition portion 34.

[0072] 9A, the end portion 30 of the mounting portion 28 of the stator vane 20 closest to the pump inlet 36 is sandwiched between a spacer ring 50 and a shoulder portion 40 of the pump housing 38. This positions the blade plane 26 closer to an inlet plane 54 defined by the flange portion 42 and the pump inlet 36 than to the mounting plane 32. This allows the spacing 56 between the inlet plane 54 and the blade plane 26 to be reduced compared to known pumps, which is beneficial to the performance of the turbomolecular pump 10 because flow losses are reduced.

[0073] An assembly area 44 is located between the shoulder portion 40 and the flange portion 42, through which heads 48 of circumferentially distributed mounting screws 46 are accessible, and by means of the mounting screws 46 the flange portion 42 can be screwed onto a recipient not shown.

[0074] The blade plane 26 then contacts the pump housing 38 1. The rotor is located at the height of the assembly area 44, which has remained unused up to now for the arrangement of the stator blades due to the reduced inner diameter of the rotor.

[0075] The stator vane 20 shown in Figure 9A is the first, i.e., the vane 20 closest to the pump inlet 36, and forms part of a turbomolecular pump stage having a plurality of stator vanes 20 and a plurality of rotor blades 58 comprising rotor blades 16 of the rotor 14. Only the first rotor blade 58 is shown in Figure 9A. The other stator vanes, not shown, are each sandwiched between two spacer rings 50 and may be formed as a continuous disk, as in the prior art, or similarly in accordance with the present invention, with the mounting plane axially spaced from the blade plane.

[0076] The transition portion 34 has a cylindrical shape, and in this case, the outer collar 24a and the transition portion 34, and the transition portion 34 and the end portion 30 each form an angle of at least approximately 90°, so that the mounting portion 28 has an L-shape in a cross section including the rotation axis 18, and the stator vane 20 has an overall hat or pot shape.

[0077] 9B and 9C show that two or more stator vanes 20 may be sandwiched between the spacer ring 50 and the shoulder portion 40. Another moving vane 58 having a rotor blade 16 is provided between the stator vane 20 located closest to the pump intake 36 and another or subsequent stator vane 20. In the configuration according to the present invention, the other stator vane 20 sandwiched between the spacer ring 50 and the shoulder portion 40 may be configured with a mounting plane 32 axially spaced from the blade plane 26 (see FIG. 9B). Moreover, the other stator vane 20 may be configured as a continuous disk as in the prior art (see FIG. 9C).

[0078] FIG. 10A shows that the vane 20 may be sandwiched with the end portions 30 of its mounting portion 28 between two spacer rings 50 of the stator 12 .

[0079] 10B to 10E differ from the embodiment of Fig. 9A in the shape of the mounting portion 28 including the end portion 30 and in the shape of the clamping surface of the spacer ring 50. These embodiments exemplarily demonstrate that the configuration of the stator vane 20 according to the invention is not limited to the hat or pot shape according to Fig. 9A, but that the mounting portion 28 can in principle have any shape.

[0080] 10B to 10E, the spacer rings 50 can conform to the shape of the end portions 30 with their respective clamping surfaces. In this case, the clamping surfaces of the spacer rings 50 do not have to strictly conform to the shape of the respective end portions 30. In each specific case, it may be acceptable or desirable for the end portions 30 of the vanes 20 to deform as they are clamped, thus automatically conforming to the interacting clamping surfaces of the spacer rings 50.

[0081] According to FIG. 10B, the transition portion 34 is conical and merges into an end portion 30 which is also conical and has the same cone angle, the free end of which defines a mounting plane 32 therein.

[0082] In the embodiment of FIG. 10C, unlike the embodiment of FIG. 10B, there is no outer collar located in the blade plane 26; that is, the transition portion 34 runs directly from the radially outer end of the blade 22 to the end portion 30.

[0083] 10D, both the transition 34 and the end portion 30 are curved. The curved course can in principle be chosen arbitrarily. Here, the mounting plane 32 is defined by the apex of the end portion 30.

[0084] The embodiment of FIG. 10E corresponds to the embodiment of FIG. 10B, except that in this case there is no transition section; instead, the end portion 30 sandwiched between the spacer rings 50 connects directly to the outer collar 24a. The present application relates to the invention described in the claims, but also includes the following as other aspects. 1. In a turbomolecular vacuum pump (10), a stator (12); at least one rotor (14) having a plurality of rotor blades (16) distributed circumferentially, the rotor (14) being rotatably drivable about a rotational axis (18) to provide a pumping action; at least one stator vane (20), the stator vane (20) being attached to the stator (12) and interacting with the rotor (14) to provide a pumping action, the stator vane (20) having a plurality of circumferentially distributed stator blades (22), the stator blades (22) defining a blade plane (26); Equipped with The vane (20) has a mounting portion (28) having an end portion (30) for mounting to the stator (12), the end portion (30) by which the vane (20) is mounted to the stator (12), the end portion (30) defining a mounting plane (32); The blade plane (26) and the mounting plane (32) extend perpendicular to the rotation axis (18) and are spaced apart from each other along the rotation axis (18). Turbomolecular vacuum pump (10). 2. The vacuum pump (10) according to claim 1, wherein the blade plane (26) is located axially closer to the pump intake port (36) than the mounting plane (32). 3. the vanes (20) are integrally constructed; and / or the vane (20) is a stamped and / or bent part made of sheet metal or is produced by cutting a blank, in particular by sawing and / or milling a blank part; The vacuum pump (10) according to 1 or 2 above. 4. the mounting portion (28) is formed by a collar (24) of the stator vane (20), the collar (24) having an end portion (30) radially outward and being coupled to the stator blade (22) radially inward, or vice versa; and / or the mounting portion (28) has a radially outer collar portion (24a) or a radially inner collar portion (24b), the radially outer collar portion (24a) or the radially inner collar portion (24b) being located in the blade plane (26) and coupled to the stator blade (22); At least one vacuum pump (10) according to 1 to 3 above. 5. 4. The vacuum pump (10) according to at least one of 1 to 3 above, wherein the mounting portion (28) is formed by a free end portion of the stator blade (20). 6. The mounting portion (28) has a transition portion (34) that leads from the blade plane (26) to the end portion (30) of the mounting portion (28); In particular, the transition portion (34) has at least partly a cylindrical or conical shape with the axis of rotation (18) as its central axis. At least one vacuum pump (10) according to 1 to 5 above. 7. 7. The vacuum pump (10) of at least one of claims 1 to 6, wherein the end portion (30) of the mounting portion (28) has a cylindrical or conical shape with the rotation axis (18) as a central axis, or has a curved course in a cross section including the rotation axis (18). 8. 8. The vacuum pump (10) of at least one of 1 to 7 above, wherein the mounting portion (28) has or includes an L-shape in a cross section including the rotation axis (18), and in particular the L-shape is formed by a transition portion (34) leading from the blade plane (26) to the end portion (30) of the mounting portion (28) and the end portion (30) of the mounting portion (28). 9. 9. The vacuum pump (10) of at least one of 1 to 8 above, wherein the stator vane (20) is part of a turbomolecular pump stage comprising a plurality of stator vanes (20) and a plurality of rotor blades (58) of the rotor (14), each having a plurality of rotor blades (16), and the stator vane (20) and the rotor blades (58) interact to provide a pumping action. 10. The stator vane (20) is the stator vane (20) located axially closest to a pump intake port (36) among a plurality of stator vanes (20) spaced apart from one another in the axial direction of the stator (12); and / or In addition to the stator vane (20), one or more stator vanes (20) having the same structure as the stator vane (20) are provided, and in each of the one or more stator vanes (20), a blade plane (26) is located axially closer to a pump intake port (36) than an attachment plane (32). At least one vacuum pump (10) according to 1 to 9 above. 11. 11. The vacuum pump (10) according to at least one of 1 to 10, wherein the stationary vane (20) is axially sandwiched between the stator (12) at the end portion (30) of the mounting portion (28). 12. Exactly one stator vane (20) is sandwiched between two spacer rings (50), each constructed as a separate component, or two or more stator vanes (20) are sandwiched between two spacer rings (50), each constructed as a separate component, and / or exactly one stator vane (20) is sandwiched between a spacer ring (50) constructed as a separate component and a shoulder (40) of the stator (12), in particular a shoulder (40) of a pump housing (38) forming part of the stator (12); or Two or more stator vanes (20) are sandwiched between a spacer ring (50) configured as a separate component and a shoulder portion (40) of the stator (12), in particular a shoulder portion (40) of a pump housing (38) forming part of the stator (12). At least one vacuum pump (10) according to 1 to 11 above. 13. the stator (12), in particular the pump housing (38) forming part of the stator (12), has, in the region of the pump inlet (36), a flange portion (42) for establishing a mechanical connection with a recipient, and a shoulder portion (40) axially spaced from the pump inlet (36), the shoulder portion (40) defining, together with the flange portion (42), an assembly region (44) for at least one connecting element, in particular at least one screw (46), which is attached to the flange portion (42); Exactly one stator vane (20) is sandwiched between a spacer ring (50) and a shoulder portion (40) configured as separate components, or two or more stator vanes (20) are sandwiched between a spacer ring (50) and a shoulder portion (40) configured as separate components. At least one vacuum pump (10) according to 1 to 12 above. 14. The vacuum pump (10) of claim 13, wherein the stator vane (20) is the stator vane (20) located axially closest to the pump intake (36), the mounting plane (32) of the stator vane (20) is located in the region of the shoulder portion (40), and the blade plane (26) of the stator vane (20) is located between the pump intake (36) and the shoulder portion (40). 15. A stator vane (20) for a turbomolecular vacuum pump (10), comprising: a plurality of circumferentially distributed stator blades (22) defining a blade plane (26); a mounting portion (28) having an end portion (30) by which the vane (20) is mountable to a stator (12) of the turbomolecular vacuum pump (10), the end portion (30) defining a mounting plane (32); The vane (20) defines a central axis, and the blade plane (26) and the mounting plane (32) extend perpendicular to and are spaced apart from each other along the central axis. Stator blades (20). [Explanation of symbols]

[0085] 10. Turbomolecular vacuum pump 12 Stator 14 rotors 16 rotor blades 18 Rotation axis 20 Stator blade 22 stator blades 24 colors 24a, 24b color parts 26 Blade Plane 28 Mounting part 30 End section 32 Mounting plane 34 Transition 36 Pump intake 38 Pump housing 40 Shoulder 42 Flange part 44 Assembly area 46 screws 48 screw head 50 Spacer ring 52 Distance between blade plane and mounting plane 54 Inlet plane at pump inlet 56 Clearance between the inlet plane and the blade plane 58 Moving blade 111 Turbomolecular pump 113 Intake flange 115 Pump intake 117 Pump exhaust port 119 Housing 121 Lower part 123 Electronics Housing 125 electric motor 127 Accessory Connection 129 Data Interface 131 Current supply connection 133 Ventilation intake 135 Seal gas connection 137 Motor Room 139 Coolant Connection 141 Bottom surface 143 Screw 145 Bearing cover 147 Fixed hole 148 Coolant line 149 Rotor 151 Rotation axis 153 rotor shaft 155 Moving blade 157 Stator blade 159 Spacer ring 161 rotor hub 163 Holbeck Rotor Sleeve 165 Holbeck Rotor Sleeve 167 Holbeck Sterling Sleeve 169 Holbeck Sterling Sleeve 171 Holbeck Gap 173 Holbeck Gap 175 Holbeck Gap 179 Connection Channels 181 Rolling bearings 183 Permanent magnet type magnetic bearing 185 Splash Nut 187 discs 189 Insert 191 Rotor side bearing half 193 Stator side bearing half 195 Ring Magnet 197 Ring Magnet 199 Bearing clearance 201 Support part 203 Support part 205 Radial Struts 207 Cover Elements 209 Support Ring 211 Fixing ring 213 Disc spring 215 Emergency bearings or safety bearings 217 Motor Stator 219 Intermediate Room 221 Wall section 223 Labyrinth Seal

Claims

1. In a turbomolecular vacuum pump (10), a stator (12); at least one rotor (14) having a plurality of rotor blades (16) distributed circumferentially, the rotor (14) being rotatably drivable about a rotational axis (18) to provide a pumping action; at least one stator vane (20), the stator vane (20) being attached to the stator (12) and interacting with the rotor (14) to provide a pumping action, the stator vane (20) having a plurality of circumferentially distributed stator blades (22), the stator blades (22) defining a blade plane (26); Equipped with The vane (20) has a mounting portion (28) having an end portion (30) for mounting to the stator (12), with which the vane (20) is mounted to the stator (12), the end portion (30) defining a mounting plane (32); The blade plane (26) and the mounting plane (32) extend perpendicular to the rotation axis (18) and are spaced apart from each other along the rotation axis (18); the stator (12) has a flange portion (42) for establishing a mechanical connection with a recipient in the region of the pump inlet (36) and a shoulder portion (40) axially spaced from the pump inlet (36), the shoulder portion (40) defining, together with the flange portion (42), an assembly region (44) for at least one connection element mounted on the flange portion (42); exactly one stator vane (20) or two or more stator vanes (20) axially closest to the pump intake (36) are sandwiched between a spacer ring (50) and a shoulder portion (40) configured as separate components, the mounting plane (32) of the stator vane (20) is located in the region of the shoulder portion (40), and the blade plane (26) of the stator vane (20) is located between the pump inlet (36) and the shoulder portion (40); Turbomolecular vacuum pump (10).

2. the vanes (20) are of one piece; and / or the vane (20) is a stamped and / or bent part made of sheet metal or is produced by cutting a blank, in particular by sawing and / or milling a blank; A vacuum pump (10) according to claim 1.

3. the attachment portion (28) is formed by a collar (24) of the stator vane (20), the collar (24) having an end portion (30) radially outward and being coupled to the stator blade (22) radially inward, or vice versa; and / or The mounting portion (28) has a radially outer collar portion (24a) or a radially inner collar portion (24b), the radially outer collar portion (24a) or the radially inner collar portion (24b) being located in the blade plane (26) and coupled to the stator blade (22). A vacuum pump (10) according to claim 1 or 2.

4. 3. A vacuum pump (10) according to claim 1 or 2, wherein the attachment portion (28) is formed by a free end portion of the stator blade (22).

5. the mounting portion (28) has a transition portion (34) leading from the blade plane (26) to the end portion (30) of the mounting portion (28); In particular, said transition portion (34) has at least partly a cylindrical or conical shape with said axis of rotation (18) as its central axis. A vacuum pump (10) according to claim 1 or 2.

6. 3. A vacuum pump (10) according to claim 1 or 2, wherein the end portion (30) of the mounting portion (28) has a cylindrical or conical shape with the axis of rotation (18) as a central axis, or has a curved course in a cross section including the axis of rotation (18).

7. 3. A vacuum pump (10) according to claim 1 or 2, wherein the mounting portion (28) has or includes an L-shape in a cross section including the rotation axis (18), in particular the L-shape being formed by a transition portion (34) leading from the blade plane (26) to the end portion (30) of the mounting portion (28) and the end portion (30) of the mounting portion (28).

8. 3. The vacuum pump (10) of claim 1 or 2, wherein the stator vane (20) is part of a turbomolecular pump stage comprising a plurality of stator vanes (20) and a plurality of rotor blades (58) of the rotor (14), each having a plurality of rotor blades (16), and the stator vane (20) and the rotor blades (58) interact to provide a pumping action.

9. 3. The vacuum pump (10) of claim 1 or 2, wherein the stator vanes (20) are axially sandwiched in the stator (12) at the end portions (30) of the mounting portions (28).

10. A vacuum pump (10) as described in claim 1 or 2, wherein the pump housing (38) forming part of the stator (12) has a flange portion (42) in the area of ​​the pump inlet (36) for establishing a mechanical connection with a recipient and a shoulder portion (40) axially spaced from the pump inlet (36), and the connecting element is a screw (46).

11. A stator vane (20) for a turbomolecular vacuum pump (10) according to claim 1 or 2, a plurality of circumferentially distributed stator blades (22) defining a blade plane (26); a mounting portion (28) having an end portion (30) by which the vane (20) can be mounted to a stator (12) of the turbomolecular vacuum pump (10), the end portion (30) defining a mounting plane (32); The vane (20) defines a central axis, and the blade plane (26) and the attachment plane (32) extend perpendicular to and are spaced apart from each other along the central axis. Stator blade (20).

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