EP3611381B1 - Method for producing a vacuum pump - Google Patents

Description

The present invention relates to a method for producing a vacuum pump, in particular a turbomolecular pump, in which a first element is connected to a second element by means of an adhesive, the first and second elements each having a first and second adhesive area intended for the adhesive.

The invention also relates to a vacuum pump, in particular a turbomolecular pump, comprising a first element and a second element, which are connected by means of an adhesive, the first and second elements each having a first and second adhesive area provided for the adhesive.

An exemplary prior art vacuum pump includes a Holweck stage which has a cylindrical rotor sleeve. The rotor sleeve rotates during operation of the pump in order to convey a gas to be conveyed along a screw path, which is usually formed in a standing cylinder body which encloses the rotor sleeve and/or is enclosed by it. The rotor sleeve is attached to a rotor hub using an adhesive. Turbomolecular pumps in particular are known to rotate at high speeds, which is why there is generally high stress on all the elements involved and their connections.

Methods or vacuum pumps known from the prior art are in the documents DE 10 2013 209614 A1 and JP 2013 160118 A refer to.

It is an object of the invention to improve the resilience of an adhesive connection in a vacuum pump.

This object is achieved by a manufacturing method for a vacuum pump according to claim 1, and in particular in that at least one of the adhesive areas is at least partially, in particular completely, treated by means of plasma before joining. The adhesive area is understood to be a surface that does not necessarily have to be flat and which is intended to be wetted with the adhesive.

The plasma treatment activates the adhesive area so that the adhesive can bond better to the element in question. This significantly increases the adhesive strength of the adhesive on the treated adhesive area, so that an overall firm and resilient connection is achieved.

Such a treatment can be carried out and handled simply and inexpensively. A particular advantage of plasma treatment is that it not only activates the adhesive area, but also degreases and cleans it and causes a roughening and enlargement of the surface. All of these effects also improve the bonding of the adhesive to the adhesive area. This means that conventional treatments to improve adhesion can preferably be dispensed with. For example, manual degreasing is no longer necessary, which saves personnel costs. Alternatively or additionally, for example, a grinding process can be dispensed with, which also simplifies the process. This applies in particular in the case that the adhesive area to be treated is formed on an inner surface of the, for example, cylindrical element, since grinding treatment is often particularly complex or even impossible here. Nevertheless, to further improve the adhesive connection, these effects can also be brought about individually or in combination in a conventional manner during production, for example by providing additional process steps comprising degreasing, cleaning, roughening and/or enlarging the surface of the adhesive area. For example, a washing process, in particular a mechanical one, can be provided before the plasma treatment.

Furthermore, the plasma treatment also brings about the effects mentioned particularly uniformly and reproducibly in relation to the treated surface. This significantly increases process reliability and significantly reduces production waste. No cleaning products are necessary in the workplace. Eliminating manual cleaning also reduces the risk of injury and chemical exposure for production personnel. Decontamination of the element to be bonded by cleaning tools that may be dirty is also avoided. And even if a conventional pretreatment, such as washing, in particular to remove dust particles, is also provided and contamination should occur, for example due to residual contamination in a washing machine, this is reduced or removed by the plasma treatment.

Another advantage of plasma treatment is that its effects, especially the activation of the surface, last for a relatively long time. Intermediate storage of the elements is therefore possible, which makes the manufacturing process additionally flexible.

The invention makes it possible to reduce the likelihood of adhesion or adhesion breaks between the element in question and the adhesive. This strengthens the connection overall.

Another advantage relates to the development of the vacuum pump. The vacuum pump is designed, for example, using previous calculations, for example using the finite element method. Material parameters of the adhesive regarding, among other things, its strength are required. These are usually provided by the adhesive supplier. However, before knowledge of the invention, the strengths calculated from this deviated from those that were determined in tests on vacuum pump parts, in particular because the parameters are specified for standardized test conditions, which cannot easily be met in the production of vacuum pumps. This made development difficult. In the manufacturing process according to the invention, on the other hand, almost or actually the strengths specified by the supplier are achieved in a particularly reliable but simple manner. This enables a more precise design and thus improved development of the vacuum pump.

Last but not least, means for generating plasma, such as plasma ovens or chambers, also have particularly low acquisition costs, are easy to operate, require few safety measures and rarely require maintenance.

According to one embodiment of the invention, it is provided that the plasma treatment is carried out at a pressure below atmospheric pressure. In this way, good activation of the surface can be achieved in particular. Alternatively, treatment at atmospheric or higher pressure is also possible.

It is also advantageous if, according to one exemplary embodiment, the plasma is generated from air as a plasma process gas. This enables a particularly simple manufacturing process, as special plasma process gases do not have to be kept available. Alternatively, another gas or gas mixture can also be used as the plasma process gas.

In a further development of the method according to the invention, the first and/or second element is treated as a whole with plasma. This means that essentially the entire surface of the element is treated. This happens, for example, in a chamber that is filled with plasma. This means the entire surface is exposed to the plasma. This has the advantage that the element can be easily inserted into the chamber without the need for precise alignment of the element. The manufacturing process is thus further simplified.

Any reference made herein to the first or second element is for illustrative purposes only. It goes without saying that the embodiments described in each case can also be transferred to the other element. In principle, more than two elements can be glued together.

In a further exemplary embodiment, the plasma treatment is carried out for at least 1 minute, in particular at least 3 minutes, and/or at most 10 minutes, in particular at most 7 minutes. About 5 minutes is particularly advantageous.

The plasma can be generated, for example, using direct current, alternating current, which is particularly low or high frequency, and/or microwaves.

According to a further development, the first and/or the second element are provided or produced with a macroscopically defined surface roughness, in particular in addition to a microscopic roughness achieved by the plasma treatment. The average roughness depth Rz in µm, at least in the adhesive area, can advantageously be, for example, at least 0.8, in particular at least 1.6, in particular at least 3.2, in particular at least 6.3, and / or at most 50, in particular at most 25, in particular at most 20, in particular at most 17.5.

The first and second elements are intended for rotation during operation of the vacuum pump. So these are rotor parts. The process is particularly advantageous here because of the high forces during rotation.

According to the invention, the vacuum pump has a Holweck stage, wherein the first element comprises a pump-active element of the Holweck stage, namely a Holweck rotor sleeve.

In an unclaimed embodiment, the vacuum pump can, for example, have a permanent magnet electric motor, wherein one or the first element can in particular comprise an electromagnetically drivable rotor motor magnet, a permanent magnet, a load-bearing sleeve and/or a return ring.

In one embodiment, only one of the elements is treated with plasma, in particular one which comprises a plastic at the adhesive area. In this way, a good connection can still be achieved while saving costs. However, both elements can also be treated with plasma. In particular, the first element can be a plastic and/or composite material, in particular carbon fiber composite material, aramid fiber composite material, glass fiber composite material, basalt fiber composite material, hybrid fabric composite material with thread or fiber components of several of the aforementioned composite materials and/or a layered combination of the aforementioned fabric types in multi-layer composite. These offer high strength with low weight.

In a further development it is provided that the first element comprises an at least essentially cylindrical section and in this section a fiber composite material, the fibers of which at least a significant proportion run at least essentially in the circumferential direction. This can also be referred to as a radial winding of the fibers, since they run in the radial plane. This causes temperature and/or centrifugal force expansion minimized in the radial direction, so that the pump can be designed with narrow gaps and therefore particularly effective, for example with regard to a high compression ratio. Contact between the elements, which could lead to pump failure, is effectively prevented.

The second element can advantageously comprise a metal material, for example aluminum, in particular at least one of the alloys EN AW-6082, EN AW-7075, EN AW-7475, EN AW-2618, EN AW-2618A, titanium, in particular the alloy TiAl6V4 , cast steel, in particular at least one of the alloys EN-GJL-150, -200, -250, -300, -350, EN-GJS-400-15, EN-GJS-500-7, EN-GJS-600-3, Steel, in particular at least one of the alloys 1.0711, 1.0715, 1.0721, 1.0736, E235, H320B, and / or stainless steel, in particular at least one of the alloys 1.4301, 1.4305, 1.4401, 1.4429, 1.4435.

According to a further development, it is provided that a recess is provided on the first and/or the second element and an area in the recess at least partially forms the adhesive area. This allows the adhesive to be applied particularly precisely and held in the adhesive area. In addition, the plasma treatment enables a relatively free design of this recess, since no conventional pretreatments, in particular no grinding or the like, are necessary. The recess can in particular be formed circumferentially, in particular as a groove and/or undercut, and/or as a circumferential set of individual recesses.

For example, an at least substantially cylindrical connection region can be defined between the first and second elements. This makes it possible, for example, to achieve good joining accuracy.

The cylindrical connection region can, for example, be arranged coaxially to a rotation axis of a rotor of the vacuum pump.

Furthermore, the connection region can, for example, be arranged axially in a ring shape relative to an axis of rotation of a rotor of the vacuum pump. The alignment of the connection area is not limited to purely radial or axially extended areas coaxial to a rotation axis of a rotor of the vacuum pump, but can also represent a diagonal or freely shaped area, which is advantageously arranged in a ring shape coaxial to a rotation axis of a rotor of the vacuum pump.

A combination of several connection areas with the same or different orientation between two elements is also possible. Furthermore, several connection areas of the same and/or different orientation, in particular radially and axially, can merge into one another and define a common, multi-axial, complex connection area.

Each connection area can comprise one, in particular two, three or many advantageously ring-shaped recesses for adhesive; these can each be designed with a predominantly rectangular or complex cross-section.

The object of the invention is also achieved by a vacuum pump with the features of the independent device claim, and in particular in that at least one of the adhesive areas has been at least partially treated by means of plasma before joining.

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

einen Teilbereich T der Fig. 3 in vergrößerter Darstellung.

Fig. 7

einen Teilbereich U der Fig. 3 in vergrößerter Darstellung.

The invention is described below by way of example using advantageous embodiments with reference to the attached figures. Show it schematically:

Fig. 1

a perspective view of a turbomolecular pump,

Fig. 2

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

Fig. 3

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

Fig. 4

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

Fig. 5

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

Fig. 6

a subarea T the Fig. 3 in an enlarged view.

Fig. 7

a subarea U the Fig. 3 in an enlarged view.

In the Fig. 1 Turbomolecular pump 111 shown comprises a pump inlet 115 surrounded by an inlet flange 113, to which a recipient, not shown, can be connected in a manner known per se. The gas from the recipient can be sucked out of 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, can be connected.

The inlet flange 113 forms the alignment of the vacuum pump according to 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. Electrical and/or electronic components of the vacuum pump 111 are accommodated in the electronics housing 123, for example for operating an electric motor 125 arranged in the vacuum pump. On the electronics housing 123 several connections 127 are provided for accessories. In addition, a data interface 129, for example according to the RS485 standard, and a power supply connection 131 are arranged on the electronics housing 123.

A flood inlet 133, in particular in the form of a flood valve, is provided on the housing 119 of the turbomolecular pump 111, via which the vacuum pump 111 can be flooded. In the area of the lower part 121 there is also a sealing gas connection 135, which is also referred to as a flushing gas connection, via which flushing gas to protect the electric motor 125 from the gas delivered by the pump into the engine compartment 137, in which the electric motor 125 in the vacuum pump 111 is accommodated, can be brought. Two coolant connections 139 are also arranged in the lower part 121, one of the coolant connections being provided as an inlet and the other coolant connection being provided as an outlet for coolant, which can be directed into the vacuum pump for cooling purposes.

The lower side 141 of the vacuum pump can serve as a standing surface, so that the vacuum pump 111 can be operated standing on the underside 141. The vacuum pump 111 can also be attached to a recipient via the inlet flange 113 and can therefore be operated hanging, so to speak. In addition, the vacuum pump 111 can be designed so that it can be put into operation even if it is oriented in a different way than in Fig. 1 is shown. Embodiments of the vacuum pump can also be implemented in which the underside 141 can be arranged not facing downwards, but facing to the side or facing upwards.

At the bottom 141, the in Fig. 2 is shown, various screws 143 are arranged, by means of which components of the vacuum pump that are not specified here are fastened to one another. For example, a bearing cover 145 is attached to the underside 141.

Fastening holes 147 are also arranged on the underside 141, via which the pump 111 can be fastened to a support surface, for example.

In the Figures 2 to 5 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 Figures 3 to 5 show, the vacuum pump comprises several process gas pumping stages for conveying the process gas present at the pump inlet 115 to the pump outlet 117.

A rotor 149 is arranged in the housing 119 and has a rotor shaft 153 which can be rotated about a rotation axis 151.

The turbomolecular pump 111 comprises a plurality of turbomolecular pump stages connected in series with one another and having a plurality of radial rotor disks 155 attached to the rotor shaft 153 and stator disks 157 arranged between the rotor disks 155 and fixed in the housing 119. A rotor disk 155 and an adjacent stator disk 157 each form a turbomolecular pump pump stage. The stator disks 157 are held at a desired axial distance from one another by spacer rings 159.

The vacuum pump also includes Holweck pump stages that are arranged one inside the other in the radial direction and are effectively connected in series. The rotor of the Holweck pump stages includes a rotor hub 161 arranged on the rotor shaft 153 and two cylindrical jacket-shaped Holweck rotor sleeves 163, 165 which are fastened to the rotor hub 161 and supported by it, which are oriented coaxially to the axis of rotation 151 and nested in one another in the radial direction.

Furthermore, two cylindrical jacket-shaped Holweck stator sleeves 167, 169 are provided, which are also oriented coaxially to the axis of rotation 151 and are nested within one another when viewed in the radial direction.

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

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

The above-mentioned pump-active surfaces of the Holweck stator sleeves 167, 169 each have several spirals around the axis of rotation 151 Holweck grooves running in the axial direction, while the opposite lateral surfaces of the Holweck rotor sleeves 163, 165 are smooth and drive the gas to operate the vacuum pump 111 in the Holweck grooves.

To rotatably support the rotor shaft 153, a rolling bearing 181 is provided in the area of the pump outlet 117 and a permanent magnet bearing 183 in the area of the pump inlet 115.

In the area of the rolling bearing 181, a conical injection nut 185 with an outer diameter increasing towards the rolling bearing 181 is provided on the rotor shaft 153. The injection nut 185 is in sliding contact with at least one wiper of an operating medium storage. The operating medium storage comprises a plurality of absorbent disks 187 stacked on top of each other, which are soaked with an operating medium for the rolling bearing 181, for example with a lubricant.

During operation of the vacuum pump 111, the operating fluid is transferred by capillary action from the operating fluid storage via the wiper to the rotating injection nut 185 and, as a result of the centrifugal force, is conveyed along the injection nut 185 in the direction of the increasing outer diameter of the injection nut 185 to the rolling bearing 181, where it e.g. fulfills a lubricating function. The rolling bearing 181 and the operating fluid storage are enclosed in the vacuum pump by a trough-shaped insert 189 and the bearing cover 145.

The permanent magnet bearing 183 comprises a rotor-side bearing half 191 and a stator-side bearing half 193, each of which comprises a ring stack made up of a plurality of permanent magnetic rings 195, 197 stacked on top of one another in the axial direction. The ring magnets 195, 197 lie opposite one another to form a radial bearing gap 199, with the rotor-side ring magnets 195 being arranged radially on the outside and the stator-side ring magnets 197 being arranged radially on the inside. The magnetic field present in the bearing gap 199 calls magnetic Repulsion forces between the ring magnets 195, 197, which cause the rotor shaft 153 to be supported radially. The rotor-side ring magnets 195 are carried by a carrier section 201 of the rotor shaft 153, which surrounds the ring magnets 195 on the radial outside. The stator-side ring magnets 197 are supported by a stator-side support section 203, which extends through the ring magnets 197 and is suspended on radial struts 205 of the housing 119. The rotor-side ring magnets 195 are fixed parallel to the rotation axis 151 by a cover element 207 coupled to the carrier section 203. The stator-side ring magnets 197 are fixed parallel to the rotation axis 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. A disc spring 213 can also be provided between the fastening ring 211 and the ring magnets 197.

An emergency or safety bearing 215 is provided within the magnetic bearing, which runs empty without contact during normal operation of the vacuum pump 111 and only comes into engagement when there is an excessive radial deflection of the rotor 149 relative to the stator to form 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 backup bearing 215 is designed as an unlubricated rolling bearing and forms a radial gap with the rotor 149 and/or the stator, which causes the backup bearing 215 to be disengaged during normal pumping operation. The radial deflection at which the backup bearing 215 comes into engagement is large enough so that the backup bearing 215 does not come into engagement 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 occurs under all circumstances is prevented.

The vacuum pump 111 includes the electric motor 125 for rotating the rotor 149. The armature of the electric motor 125 is formed by the rotor 149, the rotor shaft 153 of which extends through the motor stator 217. A permanent magnet arrangement can be arranged radially on the outside or embedded on the section of the rotor shaft 153 that extends through the motor stator 217. Between the motor stator 217 and the section of the rotor 149 that extends 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 can magnetically influence each other for transmitting the drive torque.

The motor stator 217 is fixed in the housing within the engine compartment 137 provided for the electric motor 125. A sealing gas, which is also referred to as purging gas and which can be, for example, air or nitrogen, can reach the engine compartment 137 via the sealing gas connection 135. The barrier gas can be used to protect the electric motor 125 from process gas, for example from corrosive components of the process gas. The engine compartment 137 can also be evacuated via the pump outlet 117, i.e. in the engine compartment 137 there is at least approximately the vacuum pressure caused by the backing vacuum pump connected to the pump outlet 117.

A so-called and known labyrinth seal 223 can also be provided between the rotor hub 161 and a wall 221 delimiting the engine compartment 137, in particular in order to achieve a better sealing of the engine compartment 217 compared to the Holweck pump stages located radially outside.

In Fig. 6 is an enlarged section T of Fig. 3 shown, in which the connections between the rotor hub 161 and the Holweck rotor sleeves 163 and 165 are better visible. There are five pairs of corresponding adhesive areas 231 and 232, 233 and 234, 235 and 236, 237 and 238 and 239 and 240 visible, each filled with an adhesive. They are formed by their respective surfaces at respective connection areas between the Holweck rotor sleeves 163 and 165 on the one hand and the rotor hub 161 on the other hand. At least one of the adhesive areas 231 to 240 is at least partially pretreated with plasma.

Here, a material pairing of carbon fiber composite material is glued on the side of the Holweck rotor sleeves 163, 165 and metal on the side of the rotor hub 161. The fibers of the rotor sleeves 163 and 165 are advantageously wound radially, i.e. they run in the circumferential direction and perpendicular to the image plane Fig. 6 .

In one or both of the glued elements, a recess, in particular a circumferential recess, in particular a groove, can be provided for the adhesive. For example, the adhesive area 232 is formed by a circumferential recess, namely an undercut. The adhesive areas 234, 236, 238 and 240 are also circumferential, but are designed as grooves. The adhesive areas 233, 235, 237, 239, on the other hand, are flat, while the adhesive area 231 is designed as an edge. The adhesive area pairings 233 and 234, 235 and 236, 237 and 238 and 239 and 240 together with the adhesive therein form radial connections. The adhesive areas 231 and 232, on the other hand, form a connection with the adhesive that is aligned both radially and axially. Of course, other numbers, arrangements and combinations of adhesive areas are possible.

In Fig. 7 is a section U of Fig. 3 shown enlarged and essentially shows the structure and attachment of the electric motor 125. A permanent magnet arrangement on the rotor shaft 153 in the area of the electric motor 125 for the magnetic transmission of the drive torque comprises at least one or more, in particular regularly coaxially arranged and / or magnetized permanent magnets 241, which are different, in particular hard magnetic materials may include, in particular samarium cobalt (Sm-Co), neodymium iron boron (Nd-Fe-B) and/or ferrites (strontium ferrites Sr-Fe-O, barium ferrites Ba-Fe-O or cobalt- Ferrites Co-Fe-O). These powdery materials can be formed into permanent magnets in particular by tool-bound or hot isostatic pressing and a subsequent and/or integrated sintering process and/or in a plastic bond as an injection molding compound and then used to drive the rotor 149 (see. Fig. 3 ) be used.

The arrangement of the permanent magnet(s) 241 on the rotor shaft 153 can in particular be carried out coaxially in a ring shape. Permanent magnets typically have only low mechanical strengths and/or low elongation values. The multi-axial, largely radial tensile stresses in the permanent magnets resulting from the operation of the pump and rotation of the rotor 149 due to temperature and/or centrifugal force expansion can be minimized by a load-receiving sleeve 242 which is at least partially, advantageously annular, in particular completely radially enclosing or covering the permanent magnet arrangement.

The load-bearing sleeve 242 is advantageously connected to the internal permanent magnet(s) in a non-positive manner using a radial press or shrink connection and/or in particular an adhesive connection. That's how it is Fig. 7 an adhesive area 243 is provided, which is bonded to an adhesive area 244 of the permanent magnet 241, at least one of the adhesive areas 243 and 244 having been previously treated by plasma.

The load-bearing sleeve 242 can comprise a non-magnetic metal, in particular stainless steel or titanium, or in particular a fiber composite material, the fibers of which advantageously extend to at least a significant proportion at least essentially in the circumferential direction in order to accommodate the radial forces that primarily occur when the rotor 149 rotates in the interior of the load-bearing sleeve 242 arranged permanent magnet arrangement to be able to advantageously accommodate it and support it accordingly.

The load-receiving sleeve 242 can have additional functions in addition to supporting the permanent magnet arrangement, for example it can be extended radially on one or both sides beyond the permanent magnet(s) 241 in order to be able to with its radial inner or outer diameter and/or one or both axial End faces form further axial and/or radial centerings and/or connections to the rotor 149 or its elements, in particular the rotor shaft 153.

Advantageously, the overall coaxial alignment of the load-receiving sleeve 240 with the permanent magnet arrangement 241 centered in its interior can be optimized via a radially and/or axially effective centering between the load-receiving sleeve 242 and the rotor shaft 153. The mechanical connection to the rotor shaft 153 takes place in a form-fitting manner as a press or shrink bond and/or advantageously in a cohesive manner, for example with an adhesive bond, for example one with plasma treatment of an adhesive area.

Furthermore, the load-receiving sleeve 242 can have a vacuum technology function analogous to the Holweck sleeves 163, 165, as long as the gap 219 is designed to be advantageous in terms of vacuum technology, analogous to the Holweck columns 171, 173, 175, and the motor stator 217 and/or adjacent stator structures are designed analogously to the Holweck stators 167, 169.

An improvement in the function of the electric motor 125 is possible by a radial arrangement of a ferromagnetic return element 245 in the radial interior of the permanent magnet arrangement or the permanent magnet(s) 241. This return element 245 can be either annular as an independent element that radially encloses the rotor shaft 153 or as a hollow or solid one Rotor shaft 153 can be executed. In both cases, the goal is to advantageously optimize the magnetic circuit of the electric motor by introducing one or more soft magnetic, in particular metallic, elements.

The connections between the return ring 245, permanent magnets 241, rotor shaft 153 and/or load-bearing sleeve 242 are, for example, form-fitting, as a press or shrink bond and/or advantageously cohesive, in particular with at least one adhesive bond. An adhesive bond can, for example, advantageously connect more than two of the aforementioned elements to one another and produce a reliable overall assembly. For all adhesive connections, for example, at least one, in particular several, adhesive areas can be provided per connection partner, of which at least one, in particular several or all of them are pretreated with plasma.

The rotor shaft 153 here has an adhesive area 246, which is formed as a recess which has an additional recesses 247, which also forms the adhesive area 246. The adhesive area 246 is part of an adhesive connection with several other elements, namely the permanent magnet 241, the return element and even a small part of the load-bearing sleeve 242. They have their own adhesive areas 248, 249 and 250, respectively. At least one of the adhesive areas 246, 248, 249 and 250 is pretreated with plasma.

Here, in particular, both on the adhesive areas 243 and 244, a material pairing of carbon fiber composite material on the side of the load-bearing sleeve 242 and plastic on the side of the plastic-bonded compound permanent magnet 241, as well as on the adhesive areas 246 and 248, a material pairing of ferromagnetic steel on the side of the return ring 245 and Aluminum glued on the side of the rotor shaft 153. The materials of the permanent magnet 241 and the load-bearing sleeve 242 also take part in the adhesive areas 246 and 248, namely in an axial end area thereof. This Bonding 246, 248 is designed in a complex form and connects all of the aforementioned parts 153, 241, 242 and 245 across several partial volumes in a multi-axis arrangement.

Reference symbol list

111

Turbomolecular pump

113

inlet flange

115

Pump inlet

117

Pump outlet

119

Housing

121

Bottom part

123

Electronics housing

125

Electric motor

127

Accessory connection

129

Data interface

131

Power supply connection

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 disk

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

connection channel

181

roller bearing

183

Permanent magnet bearings

185

Injection nut

187

disc

189

Mission

191

rotor side bearing half

193

stator side bearing half

195

Ring magnet

197

Ring magnet

199

Bearing gap

201

Support section

203

Support section

205

radial strut

207

Lid element

209

Support ring

211

Fastening ring

213

Disc spring

215

Emergency or detention camp

217

Motor stator

219

space

221

wall

223

Labyrinth seal

231-240

Adhesive area

241

Permanent magnet

242

Load-bearing sleeve

243

Adhesive area

244

Adhesive area

245

Inference element

246

Adhesive area

247

recess

248-250

Adhesive areas

Claims (14)

1. A method of manufacturing a vacuum pump (111), in particular a turbomolecular pump, in which a first element (163, 165) is connected to a second element (161) by means of an adhesive,

   wherein the first and the second element (163, 165, 161) each have a first or second adhesive region (231, 232, 233, 234) provided for the adhesive, wherein the vacuum pump (111) has a Holweck stage and the first element (163, 165) comprises a pump-active element of the Holweck stage, namely a Holweck rotor sleeve having a smooth pump-active jacket surface which is disposed opposite a pump-active surface of a Holweck stator sleeve, wherein the pump-active surface of the Holweck stator sleeve has a plurality of Holweck grooves extending helically around the rotation axis in the axial direction, and wherein the Holweck rotor sleeve is supported by a rotor hub which is arranged at a rotor shaft of a rotor of the Holweck stage, characterized in that

   at least one of the adhesive regions (231, 232, 233, 234) is at least partly treated by means of plasma before the connection.
2. A method in accordance with claim 1,
   characterized in that
   the plasma treatment is performed at a pressure below the atmospheric pressure or at atmospheric pressure.
3. A method in accordance with claim 1 or 2,
   characterized in that
   the plasma is generated from air as a plasma process gas.
4. A method in accordance with any one of the preceding claims,
   characterized in that
   the first and/or the second element (163, 165, 161) is/are treated with plasma as a whole.
5. A method in accordance with any one of the preceding claims,
   characterized in that
   the plasma treatment is carried out for at least 1 min and/or at most 10 min.
6. A method in accordance with any one of the preceding claims,
   characterized in that
   the plasma is generated by means of direct current, alternating current, which is in particular of low or high frequency, and/or microwaves.
7. A method in accordance with any one of the preceding claims,
   characterized in that
   the first and the second element (163, 165, 161) are provided for rotation during operation of the vacuum pump (111).
8. A method in accordance with any one of the preceding claims,
   characterized in that
   the first element (163, 165) comprises a composite material.
9. A method in accordance with any one of the preceding claims,
   characterized in that
   the first element (163, 165) comprises an at least substantially cylindrical section and a fiber composite material in this section, with in particular at least a considerable proportion of the fibers of the fiber composite material extending at least substantially in the peripheral direction.
10. A method in accordance with any one of the preceding claims,
    characterized in that
    the second element (161) comprises a metal material.
11. A method in accordance with any one of the preceding claims,
    characterized in that
    a recess is provided at the first and/or the second element (163, 165, 161) and a region in the recess at least partly forms the adhesive region.
12. A method in accordance with any one of the preceding claims,
    characterized in that
    an at least substantially cylindrical connection region is defined between the first and the second element.
13. A method in accordance with claim 12,
    characterized in that
    the cylindrical connection region is arranged coaxially to a rotation axis (151) of a rotor (149) of the vacuum pump (111).
14. A vacuum pump (111), in particular a turbomolecular pump, manufactured by a method in accordance with any one of the preceding claims,

    comprising a first element (163, 165) and a second element (161) which are connected by means of an adhesive,

    wherein the first and the second element (163, 165, 161) each have a first or second adhesive region (231, 232, 233, 234) provided for the adhesive, wherein the vacuum pump (111) has a Holweck stage and the first element (163, 165) comprises a pump-active element of the Holweck stage, namely a Holweck rotor sleeve having a smooth pump-active jacket surface which is disposed opposite a pump-active surface of a Holweck stator sleeve, wherein the pump-active surface of the Holweck stator sleeve has a plurality of Holweck grooves extending helically around the rotation axis in the axial direction, and wherein the Holweck rotor sleeve is supported by a rotor hub which is arranged at a rotor shaft of a rotor of the Holweck stage, characterized in that

    at least one of the adhesive regions (231, 232, 233, 234) is at least partly treated by means of plasma before the connection.

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