Vacuum pump

Abstract

Vacuum pump, in particular turbomolecular vacuum pump, with a housing in which a rotor rotatable about an axis of rotation and a drive motor for driving the rotor are arranged and which has an outer surface forming at least part of the pump exterior, wherein at least one cooling arrangement is provided on the outer surface of the housing, comprising a plurality of rod-shaped, outwardly projecting cooling elements and / or comprising a plurality of curved, outwardly projecting cooling fins.

Description

[0001] The invention relates to a vacuum pump, in particular a turbomolecular vacuum pump, with a housing in which a rotor rotatable about an axis of rotation and a drive motor for driving the rotor are arranged and which has an outer surface forming at least part of the pump exterior.

[0002] Such a vacuum pump is generally known and is used, for example, in a vacuum system to evacuate a recipient.

[0003] Heat can be generated during the operation of a vacuum pump, for example, by eddy currents induced in the rotor, but also by the drive motor, electrical components, or friction in a bearing used to support the rotor, such as a rolling bearing. This heat can negatively affect not only the operational capability of the vacuum pump, but also the vacuum system encompassing the pump or any work process carried out with that system.

[0004] One well-known method for dissipating heat is to provide cooling fins or louvers on the outside of the housing. The heat can be dissipated passively through convection or radiative cooling, or actively by using a fan to generate an airflow from the cooling fins.

[0005] For particularly efficient heat dissipation, the airflow must be aligned as parallel as possible to the longitudinal axis of the straight cooling fins. However, this requires special measures – either design-related or concerning the installation situation, such as the mounting position of the vacuum pump – to prevent the airflow from being oriented perpendicular to the cooling fins. An airflow oriented perpendicular to the cooling fins would be blocked or at least weakened by them. Consequently, the airflow would no longer reach all areas of the cooling fins, thus reducing overall heat dissipation.

[0006] One object of the invention is therefore to create a vacuum pump which overcomes the aforementioned disadvantages and which in particular enables simpler and better heat dissipation.

[0007] The problem is solved by a vacuum pump with the features of claim 1 and in particular by providing at least one cooling arrangement on the outside of the housing, comprising a plurality of rod-shaped, outwardly projecting cooling elements and / or comprising a plurality of curved, outwardly projecting cooling fins.

[0008] The invention is based on the idea of ​​using a plurality of rod-shaped, outwardly projecting cooling elements and / or a plurality of curved, outwardly projecting cooling fins instead of the previously used straight cooling fins or similar structures to dissipate the heat generated during the operation of the vacuum pump.

[0009] The curved shape allows the cooling fins to be better adapted to the surface design of the vacuum pump housing. This improves airflow along the housing surface, thus facilitating better heat dissipation from the vacuum pump.

[0010] The rod-shaped cooling elements have a larger surface area to volume ratio compared to cooling fins, primarily due to their rod shape.

[0011] This increases the total heat-emitting surface area of ​​the cooling arrangement, so that the heat can be dissipated more effectively overall.

[0012] The rod-shaped design of the cooling elements, also known as cooling rods, creates open, interconnected spaces between the individual rods, which serve as passageways for airflow. This allows air to flow past the cooling rods almost unimpeded and in all directions. The cooling rods thus ensure that the airflow is divided and distributed essentially evenly across the cooling arrangement. The cooling rods therefore increase the total surface area of ​​the cooling arrangement exposed to airflow, allowing more heat to be dissipated.

[0013] By directing the airflow both past the cooling rods and being deflected in different directions by them, the airflow can escape from the cooling arrangement in a direction-independent manner, i.e., in various directions. The cooling arrangement equipped with the cooling rods thus enables practically isotropic heat dissipation.

[0014] It is possible that, in addition to the cooling rods, the cooling arrangement may also include one or more guide elements, for example in the form of conventional cooling fins, for the targeted guidance of the airflow. Furthermore, it is possible that several cooling rods are connected to each other at their free ends, thus forming a wall with openings, which also allows airflow through the cooling arrangement in multiple directions.

[0015] Due to the uniform distribution of incoming air by means of the cooling arrangement, it is irrelevant from which direction the cooling arrangement is approached.

[0016] An airflow can be generated, for example, by means of a blower, with the cooling arrangement being located on the suction or pressure side.

[0017] To direct the airflow precisely, a supply air duct directed towards the cooling arrangement can be provided. Additionally or alternatively, to remove the air heated by the cooling arrangement, an exhaust air duct leading away from the cooling arrangement can be provided. As described below in connection with Fig. 7 As explained in more detail, the exhaust duct can be used in particular to generate an airflow by utilizing a chimney effect.

[0018] By using rod-shaped cooling elements, in combination with at least one appropriately positioned supply and / or exhaust air duct and at least one fan, the cooling effect can be optimized, the inlet and outlet positions of the air can be specified, and the air volumes can be controlled, directed and distributed.

[0019] Furthermore, the uniform distribution of air along the cooling arrangement allows for a largely free choice of the cooling arrangement's shape. The shape of the cooling arrangement can therefore be optimally adapted to the contour of the vacuum pump's outer surface, so that free areas on the outside of the vacuum pump can be better utilized for cooling purposes.

[0020] Based on the advantages described above, it becomes clear that the use of a cooling arrangement equipped with a large number of rod-shaped cooling elements provides better cooling of the vacuum pump than would be possible with purely finned structures.

[0021] Further advantageous embodiments of the invention can be found in the dependent claims, the description and the drawings.

[0022] According to a particularly simple design, the rod-shaped cooling elements can have a constant cross-section. However, it is also possible for the cross-section of the rod-shaped cooling elements to taper or widen towards the outside. In principle, designs are also possible in which the cross-section of the rod-shaped cooling elements changes continuously or discontinuously.

[0023] The rod-shaped cooling elements can, in principle, have any base shape. For example, the rod-shaped cooling elements can have any polygonal base shape. This can be, for example, oval, triangular, or rectangular. Particularly preferably, the rod-shaped cooling elements have a round, especially an oval or circular, base.

[0024] Preferably, all cooling elements are designed identically with respect to their cross-section and base area. However, it is also possible that the rod-shaped cooling elements are at least partially different in design.

[0025] Preferably, the rod-shaped cooling elements are arranged regularly, forming a regular grid pattern. The rod-shaped cooling elements can be arranged in rows and columns. Alternatively, they can be arranged in rows offset from one another. The rod-shaped cooling elements can also be arranged, at least partially, along at least one circular path. Advantageously, several rod-shaped cooling elements can be arranged along different circular paths, each with a different radii. Furthermore, the rod-shaped cooling elements can be arranged in rows or, more generally, in patterns that extend radially or spirally outwards from a point, or are generally arranged concentrically around a point. A regular arrangement of the rod-shaped cooling elements ensures a particularly uniform distribution of the airflow.

[0026] In principle, the rod-shaped cooling elements can also be arranged irregularly, for example according to a random distribution.

[0027] The cooling arrangement can consist at least partially of materials with a thermal conductivity of at least 100 W / (m·K), preferably at least 200 W / (m·K), and particularly preferably at least 300 W / (m·K). Thermally conductive plastics, metals, or metal alloys are preferred materials. Among the metals, aluminum and copper are particularly suitable due to their high thermal conductivity. Aluminum and / or copper alloys are therefore particularly appropriate as examples.

[0028] The cooling arrangement can also have a surface that increases heat radiation, at least in sections, for example by having a suitable structure on the surface of the cooling arrangement. Additionally or alternatively, the cooling arrangement can also have a surface coating that increases heat radiation. In particular, the cooling arrangement can have a surface or surface coating that is at least partially blackened and / or anodized.

[0029] Preferably, the cooling arrangement is provided on a section of the housing that accommodates a heat-generating component of the vacuum pump. In particular, the heat-generating component can be the rotor, the drive motor, and / or a bearing, especially a rolling bearing or a magnetic bearing, for supporting the rotor. According to a preferred embodiment, the section accommodating the heat-generating component can form a lower part of the housing, which accommodates an end section of the rotor facing away from an inlet of the pump. Preferably, the lower part has an outlet of the pump.

[0030] In principle, the cooling arrangement can also be provided on a section of the housing which is heated by an external heat source separate from the vacuum pump, for example by heat generated by the vacuum system or a bake-out element.

[0031] The cooling arrangement preferably comprises a base body from which the cooling elements protrude. The cooling elements can be formed integrally with the base body. However, it is also possible for the cooling elements to be provided as separate parts, attached to the base body individually or in groups. This allows the cooling elements to be specifically adapted to the characteristics of the vacuum pump. For example, materials with particularly high thermal conductivity can be used where a particularly high heat generation is expected.

[0032] According to an advantageous embodiment, the base body can be formed by a section of the housing. In other words, the cooling arrangement is an integral part of the housing; in particular, the cooling arrangement can form a wall of the housing. This offers the advantage that the heat can be dissipated directly and therefore particularly efficiently from the heat-generating components via the cooling arrangement. Furthermore, this allows the cooling arrangement to be integrated during the manufacturing of the housing.

[0033] According to an alternative embodiment, the base body can also be designed as a separate component from the housing. This allows the base body to be made of a different material than the housing. In particular, the base body can be made of a material with higher thermal conductivity, thus enabling particularly efficient heat dissipation.

[0034] Preferably, the base body, which is formed separately from the housing, is attached to the housing by means of a fastening element. For example, the base body can be connected to the housing using a thermally conductive joining material, such as a thermally conductive adhesive. However, it is also possible to connect the base body to the housing mechanically, for example, by means of a screw, rivet, clip, or clamp connection. To increase heat transfer between the base body and the pump housing, a thermal paste or another intermediate material suitable for thermal coupling can also be provided.

[0035] Preferably, the cooling arrangement has a base surface on a side facing away from the cooling elements, which is at least partially complementary to the surface design of the outside of the housing. This allows the cooling arrangement to conform to the outside of the housing via its base surface.

[0036] An advantageous further development provides that a base surface of the cooling arrangement has a recess that is at least partially complementary to a raised or recessed area on the outside of the housing. In particular, a rim that laterally delimits the cooling arrangement can be complementary to the raised or recessed area. Alternatively, the rim of the cooling arrangement can be at least partially complementary to a base surface of the raised or recessed area.

[0037] In this way, the cooling arrangement can be optimally adapted to the geometric conditions of the housing exterior.

[0038] Furthermore, the base body can have at least one through-opening. For example, the through-opening can be designed to complement a raised or recessed area on the outer surface of the housing, so that the base body of the cooling arrangement surrounds the raised or recessed area. Additionally, a functional unit of the vacuum pump, e.g., a blower, can be provided in the through-opening. The through-opening can also serve to accommodate a fastening element for attaching the cooling arrangement to the housing of the vacuum pump.

[0039] The present disclosure includes, among other things, the following items and embodiments: 1. Vacuum pump (111), in particular a turbomolecular vacuum pump (111), with a housing (119) in which a rotor (149) rotatable about an axis of rotation (151) and a drive motor (125) for driving the rotor (149) are arranged, and which has an outer surface forming at least part of the pump's exterior, wherein at least one cooling arrangement (225) is provided on the outer surface of the housing (119), comprising a plurality of rod-shaped, outwardly projecting cooling elements (229) and / or comprising a plurality of curved, outwardly projecting cooling fins (243). 2. Vacuum pump (111) according to embodiment 1, wherein the rod-shaped cooling elements (229) have a constant cross-section or taper outwards. 3. Vacuum pump (111) according to embodiment 1 or 2, wherein the cooling elements (229) are arranged regularly, in particular in rows and columns. 4.Vacuum pump (111) according to one of the preceding embodiments, wherein the cooling arrangement (225) has at least a section having a surface and / or surface coating that increases heat radiation, in particular wherein the cooling arrangement (225) has at least a section having a blackened and / or anodized surface or surface coating. 5. Vacuum pump (111) according to one of the preceding embodiments, wherein the cooling arrangement (225) is provided on a section of the housing (119) which accommodates a heat-generating component of the vacuum pump (111). 6. Vacuum pump (111) according to embodiment 5, wherein the section accommodates the rotor (149), the drive motor (125) and / or a bearing (181), in particular a rolling bearing (181) or a magnetic bearing (183), for the rotor (149). 7.Vacuum pump (111) according to embodiment 5 or 6, wherein the section forms a lower part (121) of the housing (119) which accommodates an end section of the rotor (149) facing away from an inlet (115) of the pump (111), in particular wherein the lower part (121) has an outlet (117) of the pump (111). 8. Vacuum pump (111) according to one of the preceding embodiments, wherein the cooling arrangement (225) has a base body (227) from which the cooling elements (229) project, in particular wherein the cooling elements (229) are formed integrally with the base body (227) or are provided as separate parts attached individually or in groups to the base body (227). 9. Vacuum pump (111) according to embodiment 8, wherein the base body (227) is formed by a section of the housing (119). 10.Vacuum pump (111) according to embodiment 8, wherein the base body (227) is designed as a component separate from the housing (119) and is attached to the housing (119) by means of a fastening means. 11. Vacuum pump (111) according to embodiment 10, wherein the base body (119) has a base surface on a side facing away from the cooling elements (229), which is designed to be at least partially complementary to a surface design of the outside of the housing (119). 12. Vacuum pump (111) according to embodiment 10 or 11, wherein a rim laterally delimiting the base body (227) is designed to be at least partially complementary to a raised area (237) or recess formed on the outside of the housing (119). 13. Vacuum pump (111) according to one of embodiments 10 to 12, wherein the base body (227) is penetrated by at least one through-opening.

[0040] The invention is described below by way of example with reference to advantageous embodiments and the accompanying figures. These 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. 6 a perspective view of a turbomolecular vacuum pump according to one embodiment of the invention, Fig. 7 the turbomolecular vacuum pump of Fig. 6In another installation situation, Fig. 8 shows a perspective detail view of a lower part of a turbomolecular vacuum pump according to a further embodiment of the invention, and Fig. 9 shows a perspective detail view of curved cooling fins for use together with the lower part of Fig. 8 .

[0041] The Figs. 1 to 5 show a known vacuum pump in the form of a turbomolecular vacuum pump 111, which, according to the principles associated with Figs. 6 to 8 The vacuum pumps 111 described in the invention can be designed as follows. Conversely, the following statements apply in conjunction with the Figs. 1 to 5 also for the vacuum pumps according to the invention Figs. 6 to 8 .

[0042] The in Fig. 1The 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.

[0043] The inlet flange 113 forms a Fig. 1 The 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 arranged laterally. The electronics housing 123 contains electrical and / or electronic components of the vacuum pump 111, e.g., for operating a drive motor 125 arranged in the vacuum pump, which here is designed as an electric motor 125 (see also Fig. 3The 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.

[0044] There are also turbomolecular pumps that do not have such an attached electronics housing, but are connected to external drive electronics.

[0045] 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 ) before the gas pumped by the pump can be admitted into the engine compartment 137, in which the electric motor 125 is housed in the vacuum pump 111.

[0046] The lower section 121 also has two coolant connections 139, 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. Additionally or alternatively, air cooling can be provided, as described in connection with Figs. 6 to 8 will be explained in more detail.

[0047] The lower side 141 of the vacuum pump 111 can generally serve as a base, so that the vacuum pump 111 can be operated standing upright on its underside 141. As explained below in connection with Figs. 6 to 8As explained, a cooling arrangement 225 can also be provided on the underside 141 of the vacuum pump 111 for at least partial cooling of the vacuum pump 111. The vacuum pump 111 is then preferably attached to a receiver via the inlet flange 113 and can thus be operated in a suspended position. Furthermore, the vacuum pump 111 can be designed so that it can also be put into operation 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.

[0048] Other existing turbomolecular vacuum pumps (not shown), which are particularly larger than the pump shown here, cannot be operated in a standing position.

[0049] 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.

[0050] Mounting holes 147 are also arranged on the underside 141, through 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.

[0051] 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.

[0052] 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.

[0053] A rotor 149 is arranged in the housing 119, which has a rotor shaft 153 rotatable about a rotation axis 151.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] During operation of the vacuum pump 111, the operating medium is transferred by capillary action from the operating medium reservoir 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 towards the rolling bearing 181, where it fulfills, for example, a lubricating function.

[0064] The rolling bearing 181 and the operating fluid reservoir are enclosed in the vacuum pump by a trough-shaped insert 189 and the bearing cover 145.

[0065] The permanent magnet bearing 183 comprises a rotor-side bearing half 191 and a stator-side bearing half 193, each containing a ring stack of several axially stacked permanent magnet rings 195, 197. The ring magnets 195, 197 face 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 radially inside. The magnetic field present in the bearing gap 199 induces magnetic repulsion forces between the ring magnets 195, 197, which result in the radial support of the rotor shaft 153. 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 on the 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 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 in one direction, parallel to the axis of rotation 151, by a retaining ring 209 connected to the support section 203 and a retaining ring 211 also connected to the support section 203. A disc spring 213 may also be provided between the retaining ring 211 and the ring magnets 197.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] Based on Figs. 6 to 8 The concept underlying the invention will below be explained by way of example only.

[0071] All in Figs. 6 to 8 The vacuum pumps 111 shown have in common that they each have at least one cooling arrangement 225 on an outer side of their housing 119 for cooling the vacuum pump 111. The cooling arrangements 225 each comprise a base body 227 and a plurality of rod-shaped cooling elements 229 projecting outwards from the base body 227, which are also referred to as cooling rods 229 and whose design will be explained in more detail elsewhere.

[0072] In the Figs. 6 to 8 In the illustrated embodiments, the cooling arrangements 225 are each provided on a section of the housing 119, which accommodates a heat-generating component. More precisely, the cooling arrangements shown in the Figs. 6 to 8The cooling arrangements 225 shown are each arranged on the lower part 121, which accommodates the rolling bearing 181 and the drive motor 125 as heat-generating components (see also Fig. 3 ). The lower part 121 is accordingly Fig. 3 Furthermore, an end section of the rotor 149 facing away from the pump inlet 115 is included, which, in the presence of a magnetic field, can also represent a heat-generating component due to the eddy currents induced by the magnetic field in the rotating rotor 149.

[0073] The respective cooling arrangements 225 can also be attached to other locations on the housing 119. For example, at least one cooling arrangement 225 can be provided on the electronics housing 123.

[0074] The in the Figs. 6 to 8The illustrated cooling arrangements 225 are each designed as a separately configured component and are attached to the respective base part 121 by means of fasteners, for example by screws. In principle, however, the cooling arrangements 225 can also be attached to the base parts 121 in other ways, for example by means of a thermally conductive adhesive.

[0075] As shown by the Figs. 6 to 8 As can be seen, the cooling rods 229, with the exception of some peripheral cooling rods 229, exhibit the following characteristics: Fig. 8 The cooling arrangement 225 shown each has a circular cross-section and extends outwards along its length from the base body 227 with a constant cross-section.

[0076] In the illustrated embodiments, the cooling rods 229 are formed integrally with the base body 227. However, the cooling rods 229 can also be formed as separate parts attached to the base body 227, either individually or in groups.

[0077] The in Fig. 6 The vacuum pump 111 shown has two cooling arrangements 225 on its lower part 121. A first cooling arrangement 225 is located on the underside 141 of the lower part 121 and a second cooling arrangement 225 is located on a side surface 231 of the lower part 121.

[0078] Heat is actively dissipated from the lower cooling arrangement 225 by means of an airflow (arrow K) generated by a fan (not shown), which hits the base body 227 and is deflected in all directions (indicated by arrows W) via the spaces formed between the cooling rods 229.

[0079] Unlike the above based on Fig. 6 The installation situation described applies to the vacuum pump 111 from Fig. 7 Additional air ducts 233, 235 are provided, the boundaries of which are in Fig. 7 are represented schematically by lines and can be formed, for example, by air guide plates.

[0080] Specifically, an air supply duct 233, directed towards the lower cooling assembly 225 and opening laterally onto the cooling assembly 225, is provided below the electronics housing 123. An airflow can reach the lower cooling assembly 225 via the air supply duct 233 in the direction of arrow K. The airflow is oriented transversely to the longitudinal extent of the individual cooling rods 229 of the lower cooling assembly 225.

[0081] Furthermore, an exhaust air duct 235 is provided, extending from one of the other sides of the lower cooling arrangement 225 and initially laterally away from the cooling arrangement 225 and then upwards. Air can therefore flow in in one direction and flow out in a direction perpendicular to it, which would not be possible with elongated cooling elements in the form of fins.

[0082] The in Fig. 7 The vacuum pump 111 shown can be cooled both passively by utilizing the chimney effect and actively by using a blower.

[0083] If the vacuum pump 111 is oriented in the respective installation situation such that the lower part 141 is at the bottom and the pump inlet 115 is at the top, then the exhaust air duct 235, which is aligned parallel to the longitudinal extension of the vacuum pump 111, is also directed upwards.

[0084] During operation of the vacuum pump 111, the cooling arrangement 225 heats up, and consequently, so does the air in the spaces between the cooling rods 229. This air rises in the direction of arrows W via the exhaust air duct 235, allowing cooler air to flow into the cooling arrangement 225 via the supply air duct 233. In this way, the heat generated by the vacuum pump 111 is dissipated via the cooling arrangement 225 using the chimney effect. This effect can be enhanced by a fan that supplies air to the cooling arrangement 225 via the supply air duct 233.

[0085] Fig. 8 Figure 1 shows another embodiment of a lower part 121 of a vacuum pump according to the invention. The underside 141 of the lower part 121 is not flat, but has a raised area 237 in the area of ​​the bearing cover 145 or is provided with a recessed area around the bearing cover 145.

[0086] In this area, a crescent-shaped cooling arrangement 225 is provided around the bearing cover 145, which is thus adapted to the shape of the underside 141 of the lower part 121.

[0087] An airflow (arrow K) supplied to the cooling arrangement 225 from the side can be deflected in all directions by the cooling rods 229 and thus guided partly, but not exclusively, in a circular path (arrow W) around the raised area 237 formed by the bearing cover 145. This would not be possible with a purely ribbed structure.

[0088] Fig. 8This illustrates, by way of example, that the cooling arrangement 225, through the use of cooling rods 229, can also assume complex shapes and simultaneously enable efficient cooling. Due to the free choice of shape, the cooling arrangement 225 can be better adapted to the shape of the vacuum pump 111 than, for example, a ribbed structure, so that a comparatively large portion of the free surface area on the outside of the vacuum pump 111 can be used for cooling.

[0089] It should be noted that a vacuum pump 111 may have conventional cooling elements in addition to the cooling rods 225. In Fig. 8 As conventional cooling elements, cooling sections 239 with straight cooling fins 241 machined in one piece from the lower part 121 are shown purely as examples, namely two cooling sections 239 formed on the side surface 231 of the lower part 121 and one cooling section 239 formed on the underside 141 of the lower part 121.

[0090] Instead of the in Fig. 8 In addition to the cooling arrangement 225 with cooling rods 229 (or in addition to such cooling rods 229), a cooling arrangement 225 with curved cooling fins 243 can also be provided, as shown by way of example in Fig. 9 The curved cooling fins 243 are curved in such a way that the cooling arrangement 225 surrounds the bearing cap 145 in a crescent shape. This allows an airflow (arrow K) supplied to the cooling arrangement 225 from the side to be guided in a circular path around the bearing cap 145 and to dissipate heat (arrow W). Reference symbol list

[0091] 111 Turbomolecular pump 113 Inlet flange 115 Pump inlet 117 Pump outlet 119 Housing 121 Bottom section 123 Electronics housing 125 Drive motor, electric motor 127 Accessory connection 129 Data interface 131 Power supply connection 133 Flood inlet 135 Barrier gas connection 137 Motor compartment 139 Coolant connection 141 Bottom side 143 Screw 145 Bearing cover 147 Mounting hole 148 Coolant line 149 Rotor 151 Rotation shaft 153 Rotor shaft 155 Rotor disc 157 Stator disc 159 Spacer ring 161 Rotor hub 163 Holweck rotor sleeve 165 Holweck rotor sleeve 167 Holweck stator sleeve 169 Holweck stator sleeve 171 Holweck gap 173 Holweck gap 175 Holweck gap 179 Connecting channel 181 Rolling bearing 183 Permanent magnet bearing 185 Injection nut 187 Washer 189 Insert 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 Cover element 209 Support ring 211 Mounting ring 213 Disc spring 215 Emergency or217 Catching bearing 219 Motor stator 219 Intermediate space 221 Wall 223 Labyrinth seal 225 Cooling arrangement 227 Base body 229 Rod-shaped cooling element, cooling rod 231 Side surface 233 Air duct, supply air duct 235 Air duct, exhaust air duct 237 Raise 239 Cooling section 241 Cooling fin 243 Curved cooling fin . Direction of air intake Direction of air exhaust

Claims

1. Vacuum pump (111), in particular turbomolecular vacuum pump (111), with a housing (119) in which a rotor (149) rotatable about an axis of rotation (151) and a drive motor (125) for driving the rotor (149) are arranged and which has an outer surface forming at least part of the pump exterior, wherein at least one cooling arrangement (225) is provided on the outer surface of the housing (119) comprising a plurality of rod-shaped, outwardly projecting cooling elements (229), wherein the cooling arrangement (225) has a base body (227) which is designed as a component separate from the housing (119) and from which the cooling elements (229) project, wherein the cooling elements (229) are provided as separate parts attached individually or in groups to the base body (227).

2. Vacuum pump (111) according to claim 1, wherein the rod-shaped cooling elements (229) have a constant cross-section or taper outwards.

3. Vacuum pump (111) according to claim 1 or 2, wherein the cooling elements (229) are arranged regularly, in particular in rows and columns.

4. Vacuum pump (111) according to one of the preceding claims, wherein the cooling arrangement (225) has at least partially a surface and / or surface coating that increases heat radiation, in particular wherein the cooling arrangement (225) has at least partially a blackened and / or anodized surface or surface coating.

5. Vacuum pump (111) according to one of the preceding claims, wherein the cooling arrangement (225) is provided on a section of the housing (119) which accommodates a heat-generating component of the vacuum pump (111).

6. Vacuum pump (111) according to claim 5, wherein the section accommodates the rotor (149), the drive motor (125) and / or a bearing (181), in particular a rolling bearing (181) or a magnetic bearing (183), for the rotor (149).

7. Vacuum pump (111) according to claim 5 or 6, wherein the section forms a lower part (121) of the housing (119) which accommodates an end section of the rotor (149) facing away from an inlet (115) of the pump (111), in particular wherein the lower part (121) has an outlet (117) of the pump (111).

8. Vacuum pump (111) according to one of the preceding claims, wherein the base body (227) is attached to the housing (119) by means of a fastening means.

9. Vacuum pump (111) according to one of the preceding claims, wherein the base body (119) has a base surface on a side facing away from the cooling elements (229) which is designed to be at least partially complementary to a surface design of the outside of the housing (119).

10. Vacuum pump (111) according to one of the preceding claims, wherein a rim laterally limiting the base body (227) is formed in a complementary manner, at least in sections, to a raised area (237) or recess formed on the outside of the housing (119).

11. Vacuum pump (111) according to one of the preceding claims, wherein the base body (227) is penetrated by at least one through-opening.

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