Method for assembling a vacuum pump

Abstract

The invention relates to a method for assembling a vacuum pump, in particular a turbomolecular pump, wherein the vacuum pump comprises a pumping system, a housing for receiving the pumping system and a cooling device, and wherein the housing comprises a housing section composed of a receiving part and a cover part, wherein the method comprises the following steps: positioning a cooling component of the cooling device in a recess of the receiving part or the cover part, and assembling the housing section by pressing the cover part and the receiving part together by means of one or more connecting means, wherein during the pressing together the cooling component is pressed into the recess, in particular in a form-fitting manner.

Description

[0001] The invention relates to a method for assembling a vacuum pump, in particular a turbomolecular pump, and to a vacuum pump, in particular a turbomolecular pump.

[0002] Vacuum pumps, and in particular turbomolecular pumps, are fundamentally well-known devices in terms of their construction and function, and are versatile and used in various applications and environments in industry and science.

[0003] Vacuum pumps can be used to create a vacuum in a vacuum chamber, for which purpose the vacuum chamber is connected to an inlet of the vacuum pump. Depending on the design of the vacuum pump, the target pressure generated in the vacuum chamber can be many orders of magnitude below the prevailing atmospheric pressure.

[0004] To generate a vacuum, the pumping components of a vacuum pump typically move at high speed, which can lead to a significant temperature increase in at least parts of the pump. Vacuum pumps therefore usually include a cooling system, which comprises cooling components arranged within a section of the pump housing. These cooling components can be, for example, coolant lines that can be pressurized with a coolant. For improved cooling, these coolant lines can be curved and / or meandering. In this case, they are also referred to as "cooling coils."

[0005] For efficient cooling, it is known in the art to press cooling coils into a lower housing part of the vacuum pump. However, a disadvantage is that such installation of cooling coils in vacuum pumps requires special tools and additional assembly steps, such as presses with a pressing force of several tons, and that subsequent replacement of an installed cooling coil is usually not possible without causing damage. The assembly of such vacuum pumps is therefore difficult.

[0006] The purpose of the invention is to simplify the assembly of vacuum pumps.

[0007] This problem is solved by a method having the features of claim 1.

[0008] The method according to the invention relates to the assembly of a vacuum pump, in particular a turbomolecular pump. This pump comprises a pumping system, a housing for receiving the pumping system, and a cooling device. The housing comprises a housing section composed of a receiving part and a cover part. The method according to the invention comprises the following steps: First, a cooling component of the cooling device is positioned in a recess of the receiving part or the cover part. The housing section is then assembled by pressing the cover part and the receiving part together using one or more connecting elements. During this pressing action, the cooling component is pressed into the recess, in particular by positive locking.

[0009] The term "pressing in" in the present disclosure is to be understood as occurring against resistance. The cooling component pressed into the recess is therefore fixed in a defined position and does not lie "loosely" in the receiving part or cover part.

[0010] In this disclosure, the terms "pressing in" and "compressing" refer to relative actions of the respective components on each other. The process can thus be carried out by pressing the receiving part onto the covering part, the covering part onto the receiving part, or by pressing both parts against each other simultaneously.

[0011] The method according to the invention is characterized in that a force, required on the one hand to fix the cooling component and on the other hand for good thermal coupling between the cooling component and the housing section, is exerted on the cooling component by means of the connecting means during the assembly of the housing section. An additional step for pressing in the cooling component, in particular by means of a device separate from the vacuum pump, for example a press, is therefore eliminated.

[0012] According to a further embodiment, the connecting element(s) is arranged and fastened in such a way that it remains part of the vacuum pump even in the assembled state and continues to press the cover and the receiving part together. In particular, none of the connecting elements are removed in a subsequent assembly step; rather, the connecting element(s) is an integral part of the vacuum pump and, in particular, is integrated into the housing. By means of the connecting element(s), the force acting on the cover and the receiving part, and especially the force acting on the cooling component, is maintained even when the vacuum pump is installed, thus ensuring particularly good thermal coupling between the cooling component and the recess on a permanent basis.

[0013] In some embodiments, the force applied during compression can be selectively adjusted. This improves the reproducibility of the process.

[0014] In particular, the force can be adjusted so that it is above a lower threshold value, from which sufficiently good thermal coupling between the cooling component and the recess is ensured, and / or below an upper threshold value, from which an undesired deformation of the or at least one connecting element and / or the cooling component and / or the cover part and / or the receiving part occurs.

[0015] For example, the or at least one of the connecting means can comprise a fastener that can be attached by means of a rotary motion, whereby the force on the fastener can be determined and adjusted during fastening using a suitable measuring device. In particular, the or at least one of the connecting means can be a bolted connection comprising a bolt element, where the tightening torque is measured during tightening, for example, using a suitable torque wrench. This allows the force exerted by the bolt element to be determined and adjusted.

[0016] The force adjustment need not be quantitative; a purely qualitative adjustment is also possible. For example, each fastener can be designed to exert only a specific force, particularly a force above the aforementioned lower threshold and / or below the aforementioned upper threshold. This can be achieved, for instance, by including an element in each fastener that prevents a further increase in force when the upper threshold is exceeded. This could be, for example, if the element's maximum mechanical strength corresponds to the upper threshold. The element could be the fastener itself, such that perceptible plastic deformation occurs when the upper threshold is reached or exceeded.Such designs allow for basic control of the force exerted by the or each connecting element without having to determine and adjust it quantitatively.

[0017] In a further embodiment, the compression and pressing are carried out in such a way that the cooling component, the cover part and the receiving part retain their shape at least to an extent which, after loosening the or each connecting means, allows the cover part and receiving part to be separated and the cooling component to be removed from the recess directly, in particular without tools.

[0018] The method according to the invention is therefore particularly repeatable in that at least the cover part and the receiving part, preferably also the cooling component, and especially preferably also the connecting element(s), are not damaged during the compression and pressing process. The pressing process is thus not carried out in such a way that removal of the cooling component would only be possible by destroying or damaging the cooling component, the cover part, or the receiving part.

[0019] For example, the receiving part and the cover part can each have a pressure surface that can be pressed against each other by means of the connecting element(s). This prevents damage to the cooling component during assembly, as pressing the surfaces against each other limits the insertion of the cooling component; that is, the pressure surfaces act as a stop. This can be done as an alternative or in addition to the adjustment of the force exerted during compression as described above. In particular, a maximum tolerable force on the cooling component, the cover part, and / or the receiving part can be determined in advance by means of suitable tests. In some embodiments, a heat-coupling medium can be applied to the receiving part and / or the cooling component and / or the cover part before the housing section is assembled.The heat coupling medium can be applied at least section by section; in particular, it can be applied to the entire cooling component and / or to each section of the receiving part and / or cover part that contacts the cooling component when assembled. The heat coupling medium further enhances the thermal coupling between the cooling component and the housing section, for example, by filling gaps between the cooling component and the housing section that may exist in the assembled state due to design limitations and / or manufacturing tolerances.

[0020] In particular, the heat coupling medium has a particularly high thermal conductivity and / or possesses a sufficiently low stiffness or viscosity so that the heat coupling medium adapts to different types of structures.

[0021] For example, the heat coupling medium can be a fluid, a gel, or a paste.

[0022] The problem is also solved by a vacuum pump according to the invention, in particular a turbomolecular pump, with the features of claim 6.

[0023] This assembly comprises a pump system, a housing for the pump system, and a cooling device. The housing includes a housing section composed of a receiving part and a cover part, the assembly being achieved by pressing the receiving part and cover part together using at least one connecting element. The receiving part has a recess in which a cooling component of the cooling device is arranged. The cooling component is pressed into the recess by pressing the receiving part and cover part together.

[0024] The vacuum pump is characterized by the fact that it comprises at least one connecting element, and in particular several connecting elements, by which the receiving part and the cover part are pressed together to assemble the housing section, and at the same time the cooling component is pressed into the recess. This secures the cooling component in the recess and ensures particularly good thermal coupling between the cooling component and the housing section.

[0025] In particular, the vacuum pump according to the invention is a vacuum pump that can be mounted using at least one embodiment, in particular several or all embodiments, of the method described above and has the necessary features for this purpose.

[0026] According to a further embodiment, a cross-section of the recess corresponds to a cross-section of the cooling component in such a way that a contact surface of the recess is at least partially in a form-fitting manner against the cooling component.

[0027] In particular, the positive locking formed by the contact surface of the recess with the cooling component acts in the direction of the receiving part and in directions transverse to the receiving part, so that the cooling component lies defined in the contact surface of the recess, but is not surrounded by the receiving part in the direction of the cover part.

[0028] According to a further embodiment, a cross-section of the cover part corresponds to a cross-section of the cooling component such that a contact surface of the cover part rests against the cooling component in a form-fitting manner, at least partially. For example, a corresponding recess, in particular a groove, can be provided in the cover part, which corresponds to the cross-section of the cooling component such that the latter is at least partially received in the recess and an inner surface of the recess forms the contact surface.

[0029] With a suitable design of the recess, embodiments are also conceivable in which the contact surface of the cover part is flat, i.e., it has no depressions or protrusions. In particular, the cooling component can lie almost completely within the recess and protrude only slightly from the receiving part, so that it is pressed into the recess by the flat contact surface of the cover part. Such a cover part is particularly advantageous and simple to manufacture, and especially beneficial for cooling components with at least partially rectangular and / or D-shaped and / or U-shaped cross-sections, wherein the cooling component can be arranged such that a flat side of the rectangular and / or D-shaped and / or U-shaped cross-section faces the flat contact surface of the cover part.

[0030] The cooling component can have an axially symmetric cross-section. In particular, the cooling component can be arranged symmetrically with respect to a plane of symmetry running between the cover part and the receiving part. In particular, the cross-section of the cover part is then also a mirror image of the cross-section of the recess with respect to the plane of symmetry.

[0031] Regardless of whether the cooling component has an axially symmetric cross-section or not, embodiments are also conceivable in which the cross-section of the cover part and the recess are not symmetrical with respect to the plane of symmetry. For example, a maximum recess provided for the cooling component in the cover part can be larger or smaller than a maximum recess depth. Depending on the other structural characteristics of the vacuum pump, such an arrangement can be advantageous compared to a symmetrical design, particularly if a portion of the housing section is to be better cooled by the cooling component.

[0032] In particular, the cooling component is positively surrounded on one side by the contact surface of the recess and on the other side by the contact surface of the cover part, so that the cooling component is, at least in part, completely positively surrounded by the contact surface of the cover part and the contact surface of the recess. This results in particularly good thermal coupling between the cooling component and the housing section.

[0033] In some embodiments, the cooling component comprises a coolant line, wherein in particular the coolant line comprises one or more rigid pipe sections and / or wherein the coolant line comprises at least one, preferably several, curved, in particular meandering, sections and is in particular designed as a cooling coil.

[0034] For example, the cooling component may extend exclusively in a plane. Such a cooling component may, at least in sections, have a curved, circular, rectangular, and / or meandering shape within that plane.

[0035] In particular, the cooling component can have a circular cross-section, and the contact surface of the recess and / or the cover part can each have a semicircular cross-section, at least partially, especially in opposing sections, in order to surround the cooling component with the contact surfaces in a form-fitting manner, at least partially. Such embodiments are particularly advantageous in manufacturing. However, a cross-section of the cooling component and / or the contact surfaces that is at least partially rectangular, D-shaped, or U-shaped is also conceivable.

[0036] With a sufficiently complex design of the mounting and cover parts, the cooling component can have a three-dimensional structure, meaning it can extend not only within a single plane, but also, for example, orthogonally to that plane. This has the advantage that the cooling effect of the component can cover a larger area of ​​the housing section.

[0037] According to a further embodiment, the cover part comprises a counterpart that engages in the recess. Such a counterpart can, for example, be shaped like a stamp and engage in the recess at least partially, in particular over its entire length.

[0038] In particular, any contact surface of the cover part is formed on the counterpart. A cover part with such a counterpart allows the cooling component to be pressed into the recess in a defined manner, with simultaneous positive locking for particularly good thermal coupling. For example, the counterpart allows the cooling component to be positioned completely within the recess, which enables particularly good cooling of the receiving part.

[0039] In particular, the cover part and the receiving part each have a pressure surface, the pressure surface of the cover part being pressed against the pressure surface of the receiving part by means of the connecting element(s). This allows the compression of the cover part and receiving part to be limited, and thus, in particular, the pressing of the cooling component into the recess is prevented, thereby avoiding damage to the cooling component. However, it is also conceivable that the pressure surface of the cover part and / or the receiving part has at least one raised and / or recessed element, so that the pressure surface of the cover part is only pressed against the pressure surface of the receiving part in sections and / or at specific points.

[0040] In some embodiments, at least one connecting element is detachable. Such embodiments allow for non-destructive replacement of the cooling component, since the connecting element(s) are detachable and the cover part is removable when the connecting elements are detached, thereby allowing the cooling component to be removed from the recess when the cover part is removed.

[0041] In particular, at least one of the connecting means comprises a screw connection. Such a screw connection can, for example, be formed by a threaded bolt and a threaded hole, wherein the threaded hole is formed either in the cover part or the receiving part, and a through-hole for the threaded bolt is provided in the other part of the housing section. This offers the advantage of a connection that is easy to manufacture and has an adjustable force between the receiving part and the cover part. This is particularly advantageous because the threaded bolt only needs to be accessible from one side of the housing section with a suitable tool, such as a wrench, for mounting the vacuum pump.In principle, it is also conceivable that both the cover part and the receiving part have a through hole for the threaded bolt and that the screw connection is made by means of the threaded bolt and a nut.

[0042] In each of the above-described embodiments of the screw connection, at least one of the through holes can have a countersunk hole that can accommodate the head of the threaded bolt or a nut that may be present. This means that such screw connections do not produce any potentially disruptive protruding parts.

[0043] According to another embodiment, a lower part of the housing comprises the receiving part or the cover part.

[0044] According to another embodiment, the housing comprises a lower part, an upper part and an intermediate part in between, and the intermediate part comprises the cover part or the receiving part.

[0045] In particular, the housing section is formed by the lower part and the intermediate piece. This has the advantage that, especially in embodiments with detachable connecting means, the housing section can be easily assembled and disassembled.

[0046] For example, the releasable fastener can comprise the screw connection described above, wherein the through-hole is located in the lower part and the threaded hole in the intermediate part. In such embodiments, the intermediate part can comprise the cover part and the lower part the receiving part. However, a reverse arrangement, in which the intermediate part comprises the receiving part and the lower part the cover part, is also conceivable.

[0047] In principle, it is also possible that the housing of the vacuum pump is made up of two parts and therefore has no intermediate piece, whereby the housing section can be formed by the lower part and the upper part.

[0048] In some embodiments, at least one, and in particular each, section of the cooling component arranged between the receiving part and the cover part is completely enclosed by a contact surface of the recess and / or the cover part. This can be achieved either by direct contact of the respective contact surface with the cooling component or indirectly via a heat coupling medium arranged between the contact surface and the cooling component, which is explained in more detail below. Such embodiments have the advantage of particularly good heat coupling.

[0049] In some embodiments, a thermal coupling medium is arranged at least partially around the cooling component. In particular, the thermal coupling medium is provided separately from the receiving and covering parts and preferably covers the contact surfaces. The thermal coupling medium is characterized, in particular, by high thermal conductivity and / or possesses sufficiently low stiffness or viscosity so that it can be adapted to various structures, and / or is designed to fill cavities between the cooling component and the recess and / or between the cooling component and the covering part. For example, the thermal coupling medium can be thermal paste and / or metal wool and / or metal foil.

[0050] The invention is described below by way of example with reference to advantageous embodiments and the accompanying figures. The figures schematically show: Fig. 1 a perspective view of a turbomolecular pump, Fig. 2 a view of the underside of the turbomolecular pump of Fig. 1 , Fig. 3 a cross-section of the turbomolecular pump along the in Fig. 2 Section line AA shown, Fig. 4 a cross-sectional view of the turbomolecular pump along the in Fig. 2 Section line BB, Fig. 5 shows a cross-sectional view of the turbomolecular pump along the line shown in Fig. 2 Section line CC shown, Fig. 6A: a cross-sectional view of a housing section according to the invention, Fig. 6B: an enlarged view of the image section D from the Fig. 6 , Fig. 6C: a top view of the illustration from the Fig. 6A , Fig. 7A: a cross-sectional view of an alternative embodiment of the housing section according to the invention, Fig. 7B: an enlarged view of image section F from the Fig. 7A, Fig. 8A: a further embodiment of the housing section according to the invention, Fig. 8B: an enlarged view of image section E from the Fig. 8A , Fig. 8C: a top view of the illustration from Fig. 8A .

[0051] The in Fig. 1 The turbomolecular pump 111 shown comprises a pump inlet 115 surrounded by an inlet flange 113, to which a receiver (not shown) can be connected in a manner known per se. The gas from the receiver can be drawn out of the receiver 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.

[0052] The inlet flange 113 forms a Fig. 1The upper end of the housing 119 of the vacuum pump 111. The housing 119 comprises a lower part 121, to which an electronics housing 123 is attached laterally. The electronics housing 123 contains electrical and / or electronic components of the vacuum pump 111, e.g., for operating an electric motor 125 located in the vacuum pump (see also Fig. 3 The electronics housing 123 has several connections 127 for accessories. In addition, a data interface 129, e.g. according to the RS485 standard, and a power supply connection 131 are located on the electronics housing 123.

[0053] There are also turbomolecular pumps that do not have such an attached electronics housing, but are connected to external drive electronics.

[0054] The housing 119 of the turbomolecular pump 111 has a flood inlet 133, in particular in the form of a flood valve, through which the vacuum pump 111 can be flooded. In the area of ​​the lower part 121, a purge gas connection 135, also referred to as a purge gas connection, is also arranged, through which purge gas can be supplied to protect the electric motor 125 (see e.g. Fig. 3 The gas pumped by the pump can be introduced into the motor compartment 137, in which the electric motor 125 is housed in the vacuum pump 111. Two coolant connections 139 are also arranged in the lower part 121, one of which serves as an inlet and the other as an outlet for coolant that can be directed into the vacuum pump for cooling purposes. Other existing turbomolecular vacuum pumps (not shown) are operated exclusively with air cooling.

[0055] The lower side 141 of the vacuum pump can serve as a base, allowing the vacuum pump 111 to be operated standing upright on its underside 141. Alternatively, the vacuum pump 111 can be attached to a receiver via the inlet flange 113 and thus operated in a suspended position. Furthermore, the vacuum pump 111 can be designed to operate even when oriented differently than described. Fig. 1 As shown. It is also possible to implement embodiments of the vacuum pump in which the underside 141 can be arranged facing sideways or upwards instead of downwards. In principle, any angle is possible.

[0056] Other existing turbomolecular vacuum pumps (not shown), which are particularly larger than the pump shown here, cannot be operated in a standing position.

[0057] On the underside 141, which is in Fig. 2As shown, various screws 143 are arranged, by means of which components of the vacuum pump, not further specified here, are fastened to one another. For example, a bearing cover 145 is attached to the underside 141.

[0058] Mounting holes 147 are also arranged on the underside 141, via which the pump 111 can be attached to a support surface, for example. This is not possible with other existing turbomolecular vacuum pumps (not shown), which are particularly larger than the pump shown here.

[0059] In the Figures 2 to 5 A coolant line 148 is shown, in which the coolant introduced and removed via the coolant connections 139 can circulate.

[0060] Like the sectional views of the Figures 3 to 5 As shown, 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.

[0061] A rotor 149 is arranged in the housing 119, which has a rotor shaft 153 rotatable about a rotation axis 151.

[0062] The turbomolecular pump 111 comprises several turbomolecular pump stages connected in series to provide pumping action. These stages have several 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. Each rotor disk 155 and an adjacent stator disk 157 form a turbomolecular pump stage. The stator disks 157 are held at a desired axial distance from each other by spacer rings 159.

[0063] The vacuum pump also includes Holweck pump stages arranged radially within one another and connected in series to effectively pump the pump. Other turbomolecular vacuum pumps exist (not shown) that do not have Holweck pump stages.

[0064] The rotor of the Holweck pump stages comprises a rotor hub 161 arranged on the rotor shaft 153 and two cylindrical Holweck rotor sleeves 163, 165 attached to and supported by the rotor hub 161, which are oriented coaxially to the axis of rotation 151 and nested one inside the other in the radial direction. Furthermore, two cylindrical Holweck stator sleeves 167, 169 are provided, which are also oriented coaxially to the axis of rotation 151 and nested one inside the other in the radial direction.

[0065] The pump-active surfaces of the Holweck pump stages are formed by the outer surfaces, i.e., 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 faces the radial outer surface of the outer Holweck rotor sleeve 163, forming a radial Holweck gap 171, and together they form 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, forming a radial Holweck gap 173, and together they form a second Holweck pump stage. 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 together they form the third Holweck pumping stage.

[0066] At the lower end of the Holweck rotor sleeve 163, a radially extending channel can be provided, through which the radially outer Holweck slot 171 is connected to the central Holweck slot 173. Furthermore, a radially extending channel can be provided at the upper end of the inner Holweck stator sleeve 169, through which the central Holweck slot 173 is connected to the radially inner Holweck slot 175. This connects the nested Holweck pump stages in series. A connecting channel 179 to the outlet 117 can also be provided at the lower end of the radially inner Holweck rotor sleeve 165.

[0067] The aforementioned pump-active surfaces of the Holweck stator sleeves 167, 169 each have several Holweck grooves spiraling around the axis of rotation 151 in the axial direction, while the opposite outer surfaces of the Holweck rotor sleeves 163, 165 are smooth and drive the gas forward in the Holweck grooves for the operation of the vacuum pump 111.

[0068] For the rotatable mounting of the rotor shaft 153, a rolling bearing 181 is provided in the area of ​​the pump outlet 117 and a permanent magnet bearing 183 is provided in the area of ​​the pump inlet 115.

[0069] 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 a fluid reservoir. In other existing turbomolecular vacuum pumps (not shown), an injection screw may be provided instead of an injection nut. Since different designs are thus possible, the term "injection tip" is also used in this context.

[0070] The operating fluid reservoir comprises several stacked absorbent discs 187, which are impregnated with an operating fluid for the rolling bearing 181, e.g. with a lubricant.

[0071] During operation of the vacuum pump 111, the operating fluid is transferred by capillary action from the fluid reservoir via the wiper to the rotating injection nut 185 and, as a result of centrifugal force, is conveyed along the injection nut 185 in the direction of the increasing outer diameter of the injection nut 185 towards the rolling bearing 181, where it performs, for example, a lubricating function. The rolling bearing 181 and the fluid reservoir are enclosed in the vacuum pump by a trough-shaped insert 189 and the bearing cover 145.

[0072] The permanent magnet bearing 183 comprises a rotor-side bearing half 191 and a stator-side bearing half 193, each of which includes a ring stack of several permanent magnet rings 195, 197 stacked axially on top of one another. The ring magnets 195, 197 are positioned opposite each other, forming a radial bearing gap 199, with the rotor-side ring magnets 195 arranged radially outside and the stator-side ring magnets 197 arranged radially inside.

[0073] The magnetic field present in the bearing gap 199 induces magnetic repulsive forces between the ring magnets 195 and 197, which cause the rotor shaft 153 to be radially supported. The rotor-side ring magnets 195 are supported by a support section 201 of the rotor shaft 153, which radially surrounds the ring magnets 195. 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 from radial struts 205 of the housing 119. Parallel to the axis of rotation 151, the rotor-side ring magnets 195 are fixed by a cover element 207 coupled to the support section 201. The stator-side ring magnets 197 are fixed parallel to the axis of rotation 151 in one direction by a fastening ring 209 connected to the carrier section 203 and a fastening ring 211 connected to the carrier section 203.A disc spring 213 can also be provided between the fastening ring 211 and the ring magnets 197.

[0074] Within the magnetic bearing, an emergency or catch bearing 215 is provided, which runs freely without contact during normal operation of the vacuum pump 111 and only engages when there is excessive radial deflection of the rotor 149 relative to the stator, in order to form a radial stop for the rotor 149 and thus prevent a collision between the rotor-side and stator-side structures. The catch 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 catch bearing 215 to be disengaged during normal pump operation. The radial deflection at which the catch bearing 215 engages is dimensioned to be large enough so that the catch bearing 215 does not engage during normal operation of the vacuum pump, and simultaneously small enough to prevent a collision between the rotor-side and stator-side structures under all circumstances.

[0075] The vacuum pump 111 comprises the electric motor 125 for rotating the rotor 149. The armature of the electric motor 125 is formed by the rotor 149, whose rotor shaft 153 extends through the motor stator 217. A permanent magnet arrangement can be arranged radially on the outside or embedded in the section of the rotor shaft 153 extending through the motor stator 217. A space 219 is arranged between the motor stator 217 and the section of the rotor 149 extending through the motor stator 217. This space comprises a radial motor gap through which the motor stator 217 and the permanent magnet arrangement can magnetically influence each other to transmit the drive torque.

[0076] The motor stator 217 is fixed in the housing within the motor compartment 137 provided for the electric motor 125. A purge gas, also known as a sealing gas, which can be, for example, air or nitrogen, can enter the motor compartment 137 via the purge gas connection 135. This purge gas protects the electric motor 125 from process gas, e.g., from corrosive components of the process gas. The motor compartment 137 can also be evacuated via the pump outlet 117, meaning that the vacuum pressure in the motor compartment 137 is at least approximately equal to that produced by the backing pump connected to the pump outlet 117.

[0077] Between the rotor hub 161 and a wall 221 bounding the engine compartment 137, a so-called labyrinth seal 223, which is known per se, can also be provided, in particular to achieve a better seal of the engine compartment 217 against the radially outside Holweck pump stages.

[0078] The housing sections described below are each a component of a turbomolecular pump, which is not otherwise shown in detail and which basically has a structure similar to the one shown in the Figs. 1 to 5 described vacuum pump 111 may have.

[0079] A first embodiment of an arrangement according to the invention of a cooling component 17 in a housing section 11 is shown in Figures 6A to 6C. The housing section 11 is formed by a receiving part 13 and a cover part 15, between which a cooling component 17 is arranged. The cooling component 17 can, for example, be a coolant line 17, in principle comparable to the coolant line 148 of the Figs. 1 to 5 , which in the illustrated embodiment has a circular cross-section. The coolant line 17 can, in particular, have several bends and / or a meandering course through the housing section 11.

[0080] The receiving part 13 and the cover part 15 are pressed together by at least two connecting means 21, such that a pressure surface 37 of the receiving part 13 is pressed against a pressure surface 39 of the cover part, so that the pressure surfaces 37, 39 serve as mutual stop surfaces. It is understood that, in addition to the two connecting means 21 shown in the cross-sectional view, further connecting means 21 may be provided distributed over the housing section 11.

[0081] In the illustrated embodiment, the connecting elements 21 are each designed as screw connections. For this purpose, the receiving part 13 has two threaded bores 33 and the cover part 15 has two through bores 31 for threaded bolts 29. However, a reverse arrangement is also possible, in which the receiving part has the through bore 31 and the cover part has the threaded bore 33.

[0082] Each through-hole 31 is provided on the inlet side with a countersunk hole 35 in which the head of the threaded bolts 29 is countersunk. This results in a particularly space-saving arrangement, since the screw connections 21 do not protrude beyond the cover part 15.

[0083] The arrangement of coolant line 17 is shown in the Fig. 6B shown in more detail. In the embodiment shown, the receiving part 13 has a recess 19 with a semicircular cross-section, into which the coolant line 17 is positively fitted.

[0084] A cross-section of the cover part 15 is shown in the Fig. 6BThe section shown is mirrored with respect to an axis of symmetry A running between cover part 15 and receiving part 13, corresponding to a cross-section of the receiving part 13 or the recess 19. The cross-sections of receiving part 13 and cover part 15 are adapted to an outer circumference of the coolant line 17, whereby the coolant line 17 is positively surrounded by corresponding contact surfaces 23, 25 at recess 19 and recess 20.

[0085] In this embodiment, the cover part 15 also has a recess 20 that is mirrored to the recess 19 and forms the contact surface 25 of the cover part 15. It is understood that embodiments are also possible in which the cover part 15 also has a recess 20, but this recess is not symmetrical to the recess 19.

[0086] This arrangement allows for easy assembly of the coolant line 17 by first positioning the coolant line 17 in the recess 19 and then placing the cover part 15 on top, or alternatively by positioning it in the recess 20 and then placing the receiving part 13 on top. The threaded bolts 29 are then inserted into the through holes 31 and screwed into the threaded holes 33 to form the screw connections 21. The force exerted by the screw connections 21 presses the cover part 15 and the receiving part 13 together, thereby also pressing the coolant line 17 into the recesses 19 and 20.The force is adjustable by means of a suitably chosen torque with which the threaded bolts 29 are tightened, so that a tight positive fit and good thermal coupling between the contact surfaces 23, 25 and the coolant line 17 is achieved, while at the same time damage to the coolant line 17 is avoided.

[0087] At the latest when the pressure surfaces 37, 39 touch, the coolant line 17 is no longer pressed further into the recesses 19, 20. This allows for precise positioning of the coolant line 17 and prevents damage to it.

[0088] Because the screw connections 21 are integrated into the housing section 11 and remain there after assembly is complete, the force acting on the coolant line 17 persists after assembly is complete and the thermal coupling between coolant line 17 and housing section 11 is permanently ensured.

[0089] For improved thermal coupling, a thermal coupling medium, for example a thermal paste, can optionally be applied to the contact surfaces 23, 25 and / or the coolant line 17 before the cover part 15 or the receiving part 13 is fitted.

[0090] The vacuum pump according to the invention particularly allows for the repeatability of the assembly method according to the invention. By loosening the screw connections 21 and then removing the cover part 15 from the receiving part 13, the coolant line 17 can be removed again from the recess 19, for example for a replacement of the coolant line 17. The assembly method according to the invention can then be repeated.

[0091] As can be seen from Fig. 6C, the heads of the threaded bolts 29 are accessible from the top of the cover part 15, so that the screw connections 21 can be loosened or tightened from this side using a suitable tool, for example a screwdriver.

[0092] The cover part 15 can, for example, be provided in a lower part of the turbomolecular pump, for example a lower part 121 as in the one shown by the Figs. 1 to 5described vacuum pump 111, so that the view from Fig. 6C shows a bottom side of the turbomolecular pump.

[0093] The concepts described above with reference to Figures 6A to 6C can also be applied to the alternative embodiments of a housing section with coolant line according to the invention described below. This also applies accordingly to the implementation of the method according to the invention.

[0094] The Figs. 7A and 7B show a further embodiment of the arrangement of the coolant line 17 in the housing section 11 according to the invention.

[0095] This embodiment differs from the embodiment shown in Figures 6A to 6C in that a stamp-shaped counterpart 27 is arranged on the cover part 15, which, in the assembled state, engages in the recess 19 of the receiving part 13. In this embodiment, the contact surface 25 of the cover part 15 is arranged on the stamp-shaped counterpart 27 and, as in Figures 6A to 6C, is adapted to the outer circumference of the coolant line 17.

[0096] In this embodiment, the coolant line 17 is located completely inside the receiving part 13 in the assembled state and thus only on one side of the plane defined by the pressure surfaces 37, 39.

[0097] For assembly, the coolant line 17 is positioned in the recess 19 of the receiving part 13 and then pressed in by pressing the receiving part 13 and the cover part 15 together using the counterpart 27. Alternatively, it is also possible in principle to first position the coolant line 17 on the counterpart 27 and then press it in by pressing the receiving part 13 and the cover part 15 together.

[0098] Another embodiment of the arrangement of the coolant line 17 in the housing section 11 according to the invention is shown in Figs. 8 to 8C.

[0099] Here, in contrast to the embodiment from the Figs. 7A and 7BThe receiving part 13 and the cover part 15 are interchanged in that the receiving part 13 has the through holes 31 and the countersunk holes 35, and the cover part 15 has the threaded holes 33. The assembly method described above remains fundamentally unchanged; that is, the screw connections 21 still press the receiving part 13 and the cover part 15 together in this embodiment, so that the coolant line 17 is pressed into the recess 19 by the cover part 15.

[0100] For assembly, before pressing together the receiving part 13 and the cover part 15, the coolant line 17 can again be positioned either in the recess 19 or on the counterpart 27.

[0101] As can be seen in Fig. 8C, in this embodiment the heads of the threaded bolts 29 are accessible from the top of the receiving part 13. For example, in this embodiment a lower part of the turbomolecular pump can comprise the receiving part 13 and an upper part arranged above the lower part or an intermediate part of the housing located between the upper part and the lower part can comprise the cover part 15. Reference symbol list

[0102] 11 Housing section 13 Mounting part 15 Cover part 17 Cooling component / coolant line 19, 20 Recess 21 Fastener 23, 25 Contact surface 27 Counterpart 29 Threaded bolt 31 Through hole 33 Threaded hole 35 Countersunk hole 37, 39 Pressure surface 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 Motor compartment 139 Coolant connection 141 Bottom 143 Screw 145 Bearing cover 147 Mounting hole 148 Coolant line 149 Rotor 151 Rotation shaft 153 Rotor shaft 155 Rotor disk 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 Connecting channel 181 Rolling bearing 183 Permanent magnet bearing 185 Injection nut 187 Washer 189 Insert 191 Rotor-side bearing half 193 Stator-side bearing half195 Ring magnet 197 Ring magnet 199 Bearing gap 201 Support section 203 Support section 205 Radial strut 207 Cover element 209 Support ring 211 Mounting ring 213 Disc spring 215 Emergency or catch bearing 217 Motor stator 219 Gap 221 Wall 223 Labyrinth seal Axis of symmetry D, E, F Image section

Claims

1. A method for assembling a vacuum pump (111), in particular a vacuum pump (111) according to any one of claims 6 to 15, in particular a turbomolecular pump, wherein the vacuum pump (111) comprises a pumping system (153, 155, 157), a housing (119) for receiving the pumping system (153, 155, 157) and a cooling device (139, 148), and wherein the housing (119) comprises a housing section (11) composed of a receiving part (13) and a cover part (15), wherein the method comprises the following steps: positioning a cooling component (17) of the cooling device (139, 148) in a recess (19, 20) of the receiving part (13) or the cover part (15), and assembling the housing section (11) by connecting the cover part (15) and the receiving part (13) by means of one or more connecting means. (21) are compressed, wherein during the compression the cooling component (17) is pressed, in particular in a form-fitting manner, into the recess (19, 20).

2. Method according to claim 1, wherein the or each connecting means (21) is arranged and fastened in such a way that it remains as part of the vacuum pump (111) even in the assembled state and continues to press the cover part (15) and the receiving part (13) together.

3. Method according to claim 1 or 2, wherein the force acting during compression is selectively adjusted.

4. Method according to one of the preceding claims, wherein the compression and pressing is carried out in such a way that the cooling component (17), the cover part (15) and the receiving part (13) retain their shape at least to an extent which, after loosening the or each connecting means (21), allows the cover part (15) and the receiving part (13) to be separated and the cooling component (17) to be removed from the recess (19, 20) directly, in particular without tools.

5. Method according to one of the preceding claims, wherein a heat coupling medium is arranged on the receiving part (13) and / or on the cooling component (17) and / or on the cover part (15) before the housing section (11) is assembled.

6. Vacuum pump (111), in particular turbomolecular pump, with a pumping system (153, 155, 157), a housing (119) for receiving the pumping system (153, 155, 157) and a cooling device (139, 148), wherein the housing (119) comprises a housing section (11) composed of a receiving part (13) and a cover part (15), wherein the assembly is effected by pressing together the receiving part (13) and the cover part (15) by means of at least one connecting means (21), wherein the receiving part (13) has a recess (19) in which a cooling component (17) of the cooling device (139, 148) is arranged, and wherein the cooling component (17) has been pressed into the recess (19) by pressing together the receiving part (13) and the cover part (15).

7. Vacuum pump (111) according to claim 6, wherein a cross-section of the recess (19) corresponds to a cross-section of the cooling component (17) such that a contact surface (23) of the recess (19) is at least partially in a form-fitting manner against the cooling component (17).

8. Vacuum pump (111) according to claim 6 or 7, wherein a cross-section of the cover part (15) corresponds to a cross-section of the cooling component (17) such that a contact surface (25) of the cover part (15) is at least partially positively engaged with the cooling component (17).

9. Vacuum pump (111) according to one of claims 6 to 8, wherein the cooling component (17) comprises a coolant line, in particular wherein the coolant line comprises one or more rigid pipe sections and / or wherein the coolant line comprises at least one, preferably several, curved sections and is in particular designed as a cooling coil.

10. Vacuum pump (111) according to one of claims 6 to 9, wherein the cover part (15) comprises a counterpart (27) that engages in the recess (19).

11. Vacuum pump (111) according to one of claims 6 to 10, wherein the connecting means (21) is detachable and in particular comprises a screw connection.

12. Vacuum pump (111) according to one of claims 6 to 11, wherein a lower part (121) of the housing (119) comprises the receiving part (13) or the cover part (15).

13. Vacuum pump (111) according to one of claims 6 to 12, wherein the housing (119) comprises a lower part (121), an upper part and an intermediate part in between, and the intermediate part comprises the cover part (15) or the receiving part (13).

14. Vacuum pump (111) according to one of claims 6 to 13, wherein at least one, in particular each, section of the cooling component (17) arranged between receiving part (13) and cover part (15) is completely enclosed by a contact surface (23, 25) of the recess (19) and / or the cover part (15).

15. Vacuum pump (111) according to one of claims 6 to 14, wherein a heat coupling medium is arranged at least sectionally around the cooling component (17).

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