JP7177113B2 - flange element - Google Patents

Description

The present invention relates to a flange element that is arranged between two vacuum devices, in particular between two flanges that are each associated with a vacuum device. The flange element has an annulus portion defining a penetration in which at least one group for a plurality of fixing elements, arranged circumferentially distributed, in particular on a circle. is formed. The receptacle can be a through opening or a blind hole.

In short, the present invention does not relate to a separate flange element, ie to an integrated component or a flange portion forming a one-piece component of a vacuum device, eg a pump housing or a chamber housing. Such independent flange elements are known in principle and are used, for example, as so-called transition flanges for connecting a vacuum container, also called a vacuum chamber, and a vacuum pump. For example, the pump can have a larger flange than the vacuum vessel, or vice versa. In such an arrangement the transition flange is also referred to as a reducer flange or reducer piece. This is because the gas inlet of the pump and the gas outlet of the vacuum vessel have different sized cross-sections, in particular diameters of different sizes, so that the flow cross-section for the gas to be discharged is different between the vacuum vessel and the pump. because it decreases during the transition between The pump and vacuum vessel can also have the same diameter at the transition. A transition flange which in this case is arranged between the pump and the vacuum vessel is not referred to as a reducer flange or reducer piece, but for example an adapter flange or adapter piece or simply an adapter.

Depends on whether both vacuum devices to be vacuum-technically connected to each other have the same diameter, or different diameters, or, generally speaking, any cross-sections that are the same or different in the transition section. not only when using vacuum devices that are operated at high speeds (especially turbomolecular pumps), but in principle also when using other vacuum pumps, in so-called crash cases It should be ensured that the connections between are not broken.

In a crash case, the rotational movement of the rotating unit of the vacuum pump is abruptly interrupted. Rotational energy must therefore be absorbed by the connection between the pump and the vacuum vessel. This means that the connection between the pump flange and the chamber flange must be able to absorb the crash torque that occurs in the event of a crash, without the pump being pulled out of the chamber.

Numerous measures are known in the prior art to ensure crash safety. One known measure consists in providing, in at least one of the flanges involved (typically the pump flange), through openings for fixing screws, each with a so-called screw release. Here, the through-openings each have an enlarged diameter over part of their axial length, i.e. the screw is freed from the surrounding material of the flange in this axial region of the through-openings. . This has the consequence that in the event of a crash the fixing screw can move, thus reducing the maximum load. The crash torque is thereby reduced or, in other words, elongated in time.

US2009/081056A1

SUMMARY OF THE INVENTION It is an object of the present invention to further increase the crash safety of the connection between two vacuum devices, in particular a turbomolecular vacuum pump and a vacuum vessel.

This task is solved by the features of claim 1 .

According to the invention, at least some groups, in particular all groups of receptacles, are each formed as a safety receptacle.

In short, according to the invention the flange element is not only used as an adapter or reducer piece between both vacuum devices, the flange element according to the invention additionally has a safety function. The receptacle, which is anyway required for fixing in the vacuum system, is used according to the invention to increase crash safety. By means of the configuration of the receptacle it can be achieved that in particular in the event of a crash the fixing element can move and thus the maximum load is reduced. This reduces crush torque.

In particular, the receptacle is formed in such a way that it deviates in one or more dimensions from the configuration normally required for each fastening element. For example, in receptacles formed as through-openings, these are, according to the invention, of a purely cylindrical shape (for example, a shape originally required for the penetration of common fixing elements such as fixing screws). may differ from Thus, for example, over part of the axial length of the through-opening it is possible to provide a so-called release for the fixing element. This will be described later in detail. A reduction in crush torque can also be achieved in other ways by a special configuration of the housing. Thus, the screw release is not the only possibility to provide a safety feature in the receptacle that is required anyway. Thus, for example, the receptacle can be formed as a circumferential slot. Its radial dimension is aligned with the diameter of each anchoring element and its dimension is greater than the radial dimension in the circumferential direction. The space created by this expansion can be filled with a material different from that of the ring portion. Thus for example a metal foam filling this space can be used. Seen in the circumferential direction, this material is arranged on the side of the area provided for the insertion of the fixation element. On the other hand, in the event of a crash, the securing element is moved so that it can cooperate with the material in the circumferentially expanded receptacle in the event of a crash, thus reducing the crash torque. Decrease.

The flange element according to the invention is particularly advantageously used in vacuum systems in which one of the other participating flanges, in particular the pump flange, is likewise provided with a safety receptacle, in particular a through opening, for the fixing element. is. In such a system, axially successive safety features, i.e. flange elements according to the invention and pump flanges which likewise have safety receptacles, are connected in series, as it were. Due to the safety receptacle according to the invention in the receptacle of the flange element, the vacuum system as a whole is able to absorb higher crash torques, so that overall crash safety is increased.

In principle, it is possible in a vacuum system for a plurality of flange elements according to the invention to be connected axially one behind the other, so to speak in series. It is thus possible for two or more safety flange pieces according to the invention to be arranged axially one behind the other between two vacuum devices which are to be connected to one another in terms of vacuum technology.

Another advantage of the present invention is that the additional safety feature of the flange element does not require additional axial structural length. This is because the means according to the invention, ie the configuration of the receptacle as a safety receptacle, do not require such an axial expansion of the flange element.

Preferably, the safety accommodation can be a through opening. Basically, it can also be designed as a blind hole. In principle, mixed groups of security receptacles with through openings and blind holes are also possible.

According to one possible embodiment, the safety receptacles each have one basic portion with a basic diameter and an enlarged portion with an enlarged diameter with respect to the basic diameter. The base part and the extension part lie directly one behind the other in the axial direction of the housing. In principle, however, it is also possible for one or more differently shaped transition portions to be provided therebetween.

In any case, the receiving parts necessary for fixing in the vacuum system are in this embodiment crush-safe, in that at least some of the receiving parts are each provided with a so-called release part of the fixing element. Used to enhance. This safety feature can be realized without extending the axial structural length and with minimal additional effort during the manufacture of the flange element. In other words, the receiving portion to be produced anyway for the fastening element in the ring portion is only radially expanded over part of its axial length. For this reason, only one additional work step is required per receptacle.

The invention further relates to a system comprising at least one flange element according to the invention and a plurality of identical fixing elements. The safety receptacles then each have, at least in part, a shape or dimensions that differ from the corresponding shape or dimensions of the fastening element. Independent protection is required for such systems. In particular, in at least one direction and in at least one section, the dimensions of the receptacle are greater than the dimensions of the corresponding fastening element. In the release portions mentioned above, for example, the diameter at the extension portion is respectively greater than the diameter of the fixation element. In each of the slots mentioned above, the dimension in the circumferential direction is greater than the diameter of the fixing element.

The invention further relates to a vacuum system comprising at least one flange element according to the invention, at least one vacuum device, in particular a vacuum pump or vacuum vessel, and a plurality of fixing elements. The flange elements are then fixable or fixed to the vacuum device by means of fixing elements each cooperating with one of the receptacles of the flange element.

Preferably, the number of receptacles, in particular the number of safety receptacles, of at least one group is greater than the minimum number of receptacles required for the vacuum device. In particular, the number of receptacles is an integer multiple of the minimum number. In practice, for example, a vacuum pump, or its flange, has a so-called ISO size, whereby this ISO size in the corresponding flange, ie the flange element according to the invention, corresponds to the predetermined size of the accommodation for the fastening element. require, or at least suggest, the number and arrangement of (also referred to as hole patterns). According to this development of the invention, the flange element has more holes than required or suggested. This is for example (but not necessarily) an integer multiple of this quantity. For example, when the applicable standard for the so-called DN250 diameter requires 12 fixing screws and the flange element according to the invention has a hole pattern with 24 or 36 holes, during assembly the vacuum The pump can be adjusted or aligned correspondingly finer in the circumferential direction. Thus, for example, radially projecting members, such as seal gas valves or pre-vacuum flanges, can be positioned more accurately.

In particular, the vacuum system according to the invention has two vacuum devices. Between them an inventive flange is or can be arranged. In particular, one vacuum device is a vacuum pump, preferably a turbomolecular pump, and the other vacuum device is a vacuum container (hereinafter also referred to as vacuum chamber) to be evacuated by the vacuum pump.

The flange element can then have two groups of receptacles arranged distributed in the circumferential direction, one group for one vacuum device and the other group for the other. vacuum device. One or both groups of receptacles can be released according to the invention, i.e. each receptacle has, according to the invention, a base portion with a basic diameter and a base portion enlarged with respect to the basic diameter. It is possible to have an enlarged portion with a sized diameter.

In a possible embodiment, the receptacles for fixing in the vacuum pump are blind holes with an internal thread without openings, whereas the receptacles for fixing in the vacuum vessel each pass through It is formed as an opening and released according to the invention. In doing so, the extension with the enlarged diameter is preferably directed towards the vacuum vessel or towards the flange of the vacuum vessel.

Further advantageous embodiments of the flange element according to the invention and of the vacuum system according to the invention are described in the dependent claims, the following description and the drawings.

Preferably, the safety receptacles formed in the annular portion of the flange element are each formed as a through opening. Through this the fixing element can be passed. The fixing element is in particular a screw with a threaded part and a screw head. The thread is provided with an external thread at least in its end region. In connection with the vacuum device or with the flange of the vacuum device, the arrangement of the flange elements is preferably such that the base part of each safety housing is on the screw head and the extension part is on the vacuum device or on the vacuum device. is directed to the flange of the

In another preferred embodiment, two groups of receptacles for a plurality of fastening elements are provided, each arranged in a circumferentially distributed manner , one group for one vacuum device and the other for a plurality of fastening elements. group is associated with the other vacuum device. Both groups of receptacles can each be designed as through openings or as blind holes. A preferred embodiment, however, contemplates that one group of receptacles is formed as through openings and the other group of receptacles as blind holes. The inventive release of the receptacle is then preferably provided in the through-opening. Additionally, however, it is also possible for each blind hole to be provided with an opening.

Correspondingly, in one embodiment of the invention, one group of receptacles is each formed as a through opening through which the fastening element can be passed, and the other group of receptacles is , respectively, is formed as a blind hole, in particular a blind hole with an internal thread, into which a fixing element can be inserted, in particular screwed.

Furthermore, in the region of one of the two groups, in particular in the region of the group of receptacles each formed as a blind hole, the annular portion of the flange element has a greater axial thickness in the region of the other group. is intended to have This ensures that sufficiently long fixing elements can be used. Advantageously, in particular standard screws with a given axial length, which are already present at the user, can then advantageously continue to be used despite the use of the flange element according to the invention. is.

According to another embodiment of the invention, the two groups comprise an inner group and an outer group. The inner group is then located on the curve, in particular on the circle. It is generally located radially inside the curve, in particular the circle, on which the outer group is located. In this case, it is advantageous if the receptacles of the inner group are each designed as a blind bore, in particular a blind bore with an internal thread, and the receptacles of the outer group are each designed as a through opening. .

Flanges used in vacuum technology are typically circular. Preferably, therefore, the ring portion of the flange element according to the invention is a torus portion. This portion defines planes in which the central axes extending through the penetration defined by the torus portion are orthogonal. Both groups of receptacles are located on coaxial circles centered on this central axis in such a preferred embodiment.

Apart from this particular embodiment, one embodiment of the invention provides that the inner group of receptacles is associated with a vacuum device formed as a vacuum pump, in particular a turbomolecular pump, and the other group of receptacles is intended to be associated with a vacuum device formed as a vacuum vessel to be evacuated by a vacuum pump.

Both groups of receptacles can have the same number of receptacles, for example 12, 14 or 36 receptacles respectively. However, this is not required. The number of receptacles of the other group can differ from the number of receptacles of the inner group.

In a preferred embodiment, the two groups are offset from each other in the circumferential direction, whereby in particular one receptacle of one group is in each case circumferentially between two receptacles of the other group. located in the center , especially in the center.

The offset between the two groups makes it possible to simplify the access of the fixing elements provided for the receptacles at the assembly site.

According to another embodiment, in the safety housing, the safety housings of the basic part and of the extension part are each cylindrically shaped.

Preferably, a particularly conical transition section is provided in each safety receptacle between the base section and the extension section. Its inner diameter increases from a basic diameter at the base portion to an enlarged diameter at the enlarged portion.

With respect to the production of the safety housings, these are preferably each first made by a first tool in the ring part with a through-hole having a basic diameter and subsequently this through-hole starting from the side of the ring part. is expanded over part of its length to an enlarged diameter by a second tool different from the first tool, wherein at the same time during the expansion of the through-hole, in particular by the second tool, A conical transition is formed between the base portion formed by the remaining portion of the throughbore and the enlarged portion having the enlarged diameter.

Such manufacturing methods also require independent protection.

Furthermore, according to the invention at least one end face of the ring part, in particular both end faces, is formed completely by a flat sealing surface for the abutment of the seal, in particular by a flat ground sealing surface. ing. This requires more care in handling the flange element, but simplifies its manufacture. This is because there need not be a protective surface projecting with respect to the sealing surface, ie the sealing surface need not be formed as a recessed surface.

The maximum thickness of the ring portion is preferably in the range between 15 mm and 35 mm.

As mentioned above, it is advantageous to provide, in the region of the group of receptacles each formed as a blind hole, an annular portion of the flange element with a greater axial thickness so that sufficiently long fixing screws can be used. can be In this case, the greatest axial thickness of the ring portion is present in the area of the blind hole. However, it is not essential that the annular portions have different axial thicknesses. The annular portion of the flange element according to the invention can have a constant axial thickness. This means at the same time a maximum axial thickness.

When regions of different axial thickness are present, for example the axial thickness of the region of the receptacle formed as an open through opening is about 20 mm, whereas the unopened bag It is contemplated that the axial thickness in the area of the hole can be approximately 26 mm.

The invention is explained below by way of example in connection with the drawings. The figure shows:

Perspective view of a turbomolecular pump Bottom view of the turbomolecular pump in FIG. FIG. 2 is a cross-sectional view of the turbomolecular pump along line AA shown in FIG. FIG. 2 is a cross-sectional view of the turbomolecular pump along line BB shown in FIG. Cross-sectional view of the turbomolecular pump along line CC shown in FIG. Figures 4a and 4b show various views of an inventive flange element according to embodiments of the invention; Figures 4A and 4B are different views of another embodiment of a flange element according to the invention; Figures 4A and 4B are different views of another embodiment of a flange element according to the invention; Figures 4A and 4B are different views of another embodiment of a flange element according to the invention; Fig. 3 shows a vacuum device according to the invention in an adapter variant with a flange element between two vacuum devices of the same effective diameter; Fig. 3 shows an inventive vacuum device with a reducer variation with an inventive flange element between two vacuum devices of different effective diameters;

The turbomolecular pump 111 shown in FIG. 1 has a pump inlet 115 surrounded by an inlet flange 113 . A vacuum vessel, not shown, can be connected to this pump inlet in a known manner. Gases from the vacuum vessel can be drawn from the vacuum vessel via pump inlet 115 and conveyed through the pump to pump outlet 117 . A pre-vacuum pump (eg a rotary vane pump) can be connected to the pump outlet.

Inlet flange 113 forms the upper end of housing 119 of vacuum pump 111 in the vacuum pump orientation of FIG. Housing 119 has a lower portion 121 . An electronics housing 123 is arranged laterally on this. Electronics housing 123 houses the electronic and/or electronic components of vacuum pump 111 . These are for example for actuating an electric motor 125 which is arranged in the vacuum pump. Electronics housing 123 is provided with a plurality of connections 127 for accessories. Furthermore, a data interface 129 (for example according to the RS485 standard) and a current supply connection 131 are arranged in the electronics housing 123 .

The housing 119 of the turbomolecular pump 111 is provided with a vent inlet 133, in particular in the form of a vent valve. Via this it is possible to vent the vacuum pump 111 . In the region of the lower part 121 there is also a sealing gas connection 135 (also called purge gas connection). Via this, purge gas can be drawn into the motor chamber 137 to protect the electric motor 15 (see FIG. 3) against the gases carried by the pump. The electric motor 125 of the vacuum pump 111 can be housed in the motor chamber. Two further coolant connections 139 are provided in the lower part 121 . In this case, one coolant connection is provided as coolant inlet and the other coolant connection as outlet. A coolant can be directed into the vacuum pump for cooling purposes.

The lower side 141 of the vacuum pump can be used as a base so that the vacuum pump 111 can be operated vertically on the lower side 141 . However, the vacuum pump 111 can also be fastened to the vacuum vessel via the inlet flange 113, so that it can be operated in a quasi-suspended manner. Further, the vacuum pump 111 can be configured so that it can be operated when oriented differently than shown in FIG. Embodiments of the vacuum pump in which the lower side 141 is arranged sideways or upwards rather than downwards can also be realized.

Various screws 143 are further arranged on the underside 141 represented in FIG. By means of these structural members of the vacuum pump, which are not specified in detail here, are fixed to each other. For example, a bearing cover 145 is secured to the lower surface 141 .

A fixing hole 147 is further provided on the lower side surface 141 . Via this, the pump 111 can be fixed, for example, to a support surface.

Coolant piping 148 is represented in FIGS. It is possible for a coolant to be circulated therein which is introduced or discharged via a coolant connection 139 .

As shown in the cross-sectional views of FIGS. 3-5, the vacuum pump has multiple process gas pumping stages. This is for conveying the process gas acting on the pump inlet 115 to the pump outlet 117 .

A rotor 149 is disposed within the housing 119 . This rotor has a rotor shaft 153 rotatable about a rotation axis 151 .

The turbomolecular pump 111 has a plurality of pump stages connected in series with each other for pumping action. The pump stages have a plurality of radial rotor discs 155 fixed to the rotor shaft 153 and a stator disc 157 positioned between the rotor discs 155 and fixed within the housing 119 . A rotor disk 155 and a stator disk 157 adjacent thereto each form a turbomolecular pump stage. The stator discs 157 are held at the desired axial spacing from each other by spacer rings 159 .

The vacuum pump further comprises Holweck pump stages arranged radially inward and outward of each other and connected in series with each other for pumping action. The rotor of the Holweck pump stage has a rotor hub 161 arranged on the rotor shaft 153 and two Holweck rotor sleeves 163, 165 of cylindrical profile which are fixed to and carried by the rotor hub 161 . They are oriented coaxially with the axis of rotation 151 and are radially connected to each other inwardly and outwardly. Furthermore, two Holweck stator sleeves 167, 169 of cylindrical profile are provided. They are likewise oriented coaxially with respect to the axis of rotation 151 and are connected to each other inward and outward when viewed in the radial direction.

The surfaces of the Holweck pump stages that exert the pumping action are formed by the lateral surfaces, namely the inner and/or outer surfaces of the Holweck rotor sleeves 163, 165 and the Holweck stator sleeves 167, 169. The radially inner surface of the outer Holweck stator sleeve 167 faces the radially outer surface of the outer Holweck rotor sleeve 163, forming a radial Holweck gap 171, and this and the turbomolecular pump. It forms the following first Holweck pump stage. The radially inner surface of the outer Holweck rotor sleeve 163 faces the radially outer surface of the inner Holweck stator sleeve 169, forming a radial Holweck gap 173, and is aligned with the second holder sleeve 169. Form a Beck pump stage. The radially inner surface of the inner Holweck stator sleeve 169 faces the radially outer surface of the inner Holweck rotor sleeve 165 forming a radial Holweck gap 175 and is aligned with the third holder sleeve 169 . Form a Beck pump stage.

The lower end of the Holweck rotor sleeve 163 may be provided with radially extending channels. Via this, the radially outer Holweck gap 171 is connected with the central Holweck gap 173 . In addition, the upper end of the inner Holweck stator sleeve 169 can be provided with radially extending channels. Via this, the central Holweck gap 173 is connected with the radially inner Holweck gap 175 . A plurality of Holweck pump stages, which are connected in and out of each other, are thereby connected in series with each other. The lower end of the radially inner Holweck rotor sleeve 165 can additionally be provided with a connecting channel 179 to the outlet 117 .

The surfaces of the Holweck sleeves 163 and 165 that exert the above-described pumping action each have a plurality of Holweck grooves that extend in the axial direction while spiraling around the rotation axis 151 . On the other hand, the opposite sides of the Holweck rotor sleeves 163, 165 are smooth and deliver gas for operation of the vacuum pump 111 into the Holweck grooves.

A rolling bearing 181 in the region of the pump outlet 117 and a permanent magnet bearing 183 in the region of the pump outlet 115 are provided for the rotatable bearing of the rotor shaft 153 .

A conical splash nut 185 is provided on the rotor shaft 153 in the region of the rolling bearing 181 . It has an outer diameter that increases towards the rolling bearing 181 . The splash nut 185 is in sliding contact with at least one scraping member (German: Abstreifer) of the working medium reservoir. The working medium reservoir has a plurality of absorbent discs 187 stacked one above the other. These discs are impregnated with a working medium for the rolling bearing 181, eg a lubricant.

During operation of the vacuum pump 111, the working medium is transferred from the working medium reservoir through the scraping member by capillary action to the rotating splash nut 185, and along the splash nut 185 by centrifugal force. It is transported towards rolling bearing 181 in the direction of the increasing outer diameter of 185 . There, for example, a lubricating function is exhibited. The rolling bearing 181 and the working medium reservoir are enclosed in the vacuum pump by a trough-shaped insert 189 and a bearing cover 145 .

The permanent magnet bearing 183 has a rotor-side bearing half 191 and a stator-side bearing half 193 . These have one ring stack each. The ring stack consists of a plurality of rings 195, 197 of permanent magnets axially stacked one above the other. The ring magnets 195, 197 face each other forming a radial bearing gap 199, with the rotor-side ring magnet 195 radially outward and the stator-side ring magnet 197 radially inward. are placed in A magnetic field present in the bearing gap 199 causes a magnetic repulsion between the ring magnets 195,197. This provides radial support for the rotor shaft 153 . The rotor-side ring magnet 195 is carried by a support portion 201 of the rotor shaft 153 . It surrounds the ring magnet 195 radially outwards. The stator-side ring magnet 197 is carried by the stator-side support portion 203 . It extends through ring magnet 197 and is suspended from struts 205 of housing 119 . Parallel to the axis of rotation 151 , a rotor-side ring magnet 195 is fixed by means of a cover element 207 which is connected with the support part 203 . The stator-side ring magnet 197 is fixed in one direction parallel to the rotation axis 151 by a fixed ring 209 connected with the support portion 203 and by a fixed ring 211 connected with the support portion 203 . Moreover, between the fixing ring 211 and the ring magnet 197 a disc spring 213 can be provided.

An emergency or safety bearing 215 is provided inside the magnetic bearing. During normal operation of the vacuum pump, it idles without contact and only comes into effect when the rotor 149 is excessively deviated radially with respect to the stator. A radial stop for the rotor 149 is formed as the rotor side structure is prevented from colliding with the stator side structure. Safety bearing 215 is formed as a non-lubricated rolling bearing and forms a radial clearance with rotor 149 and/or stator. This clearance provides for the safety bearing 215 not to act during normal pump operation. The radial excursion through which the safety bearing acts is dimensioned sufficiently large that the safety bearing 215 does not act during normal operation of the vacuum pump, and at the same time it is sufficiently small that the structure on the rotor side is prevented under all circumstances from colliding with the structure on the stator side.

The vacuum pump 111 has an electric motor 125 that drives the rotor 149 to rotate. The armature of electric motor 125 is formed by rotor 149 . Its rotor shaft 153 extends through the motor stator 217 . The portion of the rotor shaft 153 that extends through the motor stator 217 can have a permanent magnet arrangement arranged radially outwardly or embedded therein. An intermediate space 219 is arranged between the portion of rotor 149 that extends through motor stator 217 and motor stator 217 . It has a radial motor clearance. Via this, the motor stator 217 and the permanent magnet arrangement can magnetically influence each other for driving torque transmission.

The motor stator 217 is fixed in the housing inside a motor chamber 137 provided for the electric motor 125 . Via the seal gas connection 135 the seal gas (also called purge gas, which can be air or nitrogen, for example) leads into the motor chamber 137 . Via the sealing gas, the electric motor 125 can be protected against process gases, for example corrosive constituents of process gases. The motor chamber 137 can also be evacuated via the pump outlet 117 , ie the motor chamber 137 is at least approximately pre-vacuum provided by a pre-vacuum pump connected to the pump outlet 117 . It's becoming

Between the wall 221 delimiting the motor chamber 137 and the rotor hub 161, a so-called labyrinth seal 223 can also be provided. This is in particular to achieve a better sealing of the motor chamber 217 with respect to the radially outwardly located Holweck pump stage.

The flange element 11 according to the invention represented in FIG. 6 has an integral annular portion (eg made from stainless steel). This toroidal portion can have an outer diameter of, for example, 425 mm. The circular penetration of flange 11 has a diameter of, for example, 261 mm.

The region 33 defining the penetration 17 has an axial thickness greater than the axial thickness in the radially outer region 35 . Region 35 is directly connected to inner region 33 in the radial direction. The axial thickness of the inner region 33 may be, for example, 26 mm. In contrast, the axial thickness of the outer region 35 may be, for example, 20 mm.

However, the above dimensions and the following dimensions, and the ratio of the dimensions to each other, are not essential. The flange element according to the invention can basically be provided in any size.

In the outer region 35 of the ring portion 19 twelve receptacles 21 are formed which are evenly distributed in the circumferential direction. These are each provided in the form of through openings which are freed as voids. These are explained in detail on the basis of the enlarged sectional view AA below FIG. The central axis of the safety housing 21 lies on a circle about the central axis 45 of the ring portion extending through the penetration 17 . The circle then has a diameter of, for example, 395 mm.

Similarly, the central axis of the housing portion 31 formed in the inner region 33 of the ring portion 19 is positioned on a circle centered on the central axis 45 . The receptacles are each designed as a blind hole. The blind holes 31 each start from the side of the flange which is stepped between an inner region 33 of greater axial thickness and an outer region 35 of lesser axial thickness. there is On the opposite side of flange 11 both regions 33, 35 are flush with each other. This end face 22 of the flange 11 is formed as a flat ground sealing face 22 . On the opposite side of the flange 11 its end face 32 is formed by a region 33 of greater axial thickness. This end face 32 is likewise formed as a flat ground sealing face.

The flange element 11 according to the invention (see in particular the section view AA below FIG. 6) is characterized in that the through opening 21 formed in the outer region 35 does not have a constant inner diameter. Rather, each through-opening 21 has a base portion 23 with a base diameter and an enlarged portion 25 with a larger diameter than the base diameter. The base portion is, for example, 14 mm. The enlarged diameter of the widened portion, on the other hand, is, for example, 25 mm.

A conical transition section 24 is produced between the extension section 25 and the base section 23 by the manufacturing method described at the outset. It has, for example, an opening angle of 118 degrees. This transition part 24 can be produced, for example, by means of a cylindrical milling cutter or a drill with a correspondingly shaped working tip. Manufacture takes place after the through-opening with the basic diameter has been manufactured in a preceding working step. The portion of this initial through-hole remaining after manufacturing the extension 25 then forms the basic portion 23 of each safety housing 21 according to the invention.

In this case, the widened portion 25 is formed on the side of the flange 11 opposite to the flange side from which the blind hole 31 formed in the inner region 33 of greater axial thickness departs. In other words, the opening of the blind hole 31 on the one hand and the extension 25 of the through-opening 21 on the other hand are oriented axially in opposite directions.

A fixing element not represented in FIG. 6, in particular a fixing screw, which can be passed through the base part 23 of each safety housing, is therefore provided in the area of each extension 25 . , is released due to the enlarged inner diameter there. Thereby, the crush strength of the threaded connection between the flange element according to the invention and the vacuum device is increased as described in the opening part, so that the through opening 21 is also referred to as a safety receptacle and according to the invention. Such flange elements are also referred to as safety flange pieces.

The embodiments of FIGS. 7, 8 and 9 differ by the number of safety receptacles 21 and blind holes 31 or the relative positioning of these two groups of receptacles 21, 31, wherein the implementation of FIG. The example corresponds to the embodiment of FIG. 6 described above, and FIG. 8 shows an additional view of this flange element.

In the embodiment of FIG. 7, the inner group of receptacles has twelve blind holes 31 evenly distributed in the circumferential direction, ie each circumferentially spaced apart by 30 degrees. The outer group of receptacles also has twelve receptacles formed as security receptacles in the form of through openings 21 . Each of these has the same angular position as the inner blind hole 31 . In other words, the two groups of receptacles 31, 21 are here not arranged offset from one another in the circumferential direction.

In contrast, in the embodiment of FIG. 8, a staggered positioning of the two groups of receptacles 31, 21 is provided. Each blind hole 31 is then arranged centrally between the two outer safety receptacles 21 in the circumferential direction. As already mentioned above, this makes it possible to facilitate the access of each fixing element at the assembly site.

The embodiment of FIG. 9 shows a variation in which both the number of inner blind holes 31 and the number of outer safety receptacles 21 are twenty-four. Again, both the inner blind holes 31 and the outer safety receptacles 21 are evenly spaced in the circumferential direction. A circumferential offset between the two groups of receptacles 31, 21 is not intended here. However, variants not represented here are also possible.

By increasing the number of housings 31 and 21, flexibility during assembly is improved. The user can select the receptacles 31, 21 which are easily accessible for him depending on the particular situation at the installation site.

Apart from the differences mentioned above, the flange elements 11 of the individually described embodiments are each formed as described in connection with FIG.

Figures 10 and 11 show two different applications of the flange element according to the invention. In both examples, the flange element 11 according to the invention is arranged between the vacuum chamber 13 with the flange 13a and the turbomolecular pump 15 with the flange 15a. Pump 15 may be formed as described above in connection with FIGS.

The vacuum chamber (vacuum container) 13 and the vacuum pump 15 have the same inner diameter on the inlet side or the outlet side. This corresponds to the inner diameter of the penetration 17 of the flange element 11 according to the invention. The flange element 11 is therefore not used as a so-called reducer, but as an adapter between the pump 15 and the vacuum chamber 13 or between the corresponding flanges 15a, 13a.

The connection between the flange element 11 of the vacuum chamber 13 and the flange 13a is made in the example shown by a hexagonal screw 27 with a washer. Its head rests on the side of the pump flange 13a opposite the flange element 11 via a washer. On the side of the chamber flange 13a facing away from the flange element 11, the screws 27 each engage a nut 39 with a washer.

A centering ring 41 is arranged between the chamber flange 13 a and the flange element 11 . It is provided with a seal 26, for example in the form of an elastically deformable O-ring. It abuts on the sealing surface 22 in the region of smaller axial thickness 22 of the flange element 11 and on the opposing sealing surface on the chamber flange 13a.

The fixing of the pump 15 on the flange element 11 and on the vacuum chamber 13 via the flange element 11 is done by means of so-called expansion screws 37 (German: Dehnschrauben). The expansion screws 37 each abut on the side of the pump flange 15 a facing away from the flange element according to the invention, with a head having a collar, and the expansion screws 37 are located in one of the blind holes 31 of the flange element 11 . screwed inside.

A centering ring 43 is also arranged between the flange element 11 and the pump flange 15a. It is provided with a seal 36, for example in the form of an elastic O-ring. It abuts on the sealing surface 32 of the region 33 of greater axial thickness of the flange element 11 and on the opposite sealing surface on the pump flange 15a.

Not only the safety housing 21 according to the invention in the flange element 11, but also the through-opening in the pump flange 15a for the screw 37 is provided with a respectively screw-free portion.

In a crash case, the generated torque is absorbed both via the connection between the pump 15 and the flange element 11 and via the connection between the flange element 11 and the chamber 13, so that the If two safety devices are provided one behind the other, they jointly ensure that the pump 15 remains connected to the chamber 13 in a crash case.

Figure 11 shows that the flange element 11 according to the invention can also be used as a reducer. This is made possible by being placed between pump 15 and chamber 13 . Its inlet side and outlet side diameters are of different sizes. In the example shown, the diameter of vacuum chamber 13 is larger than the diameter at the gas inlet of pump 15 . This again corresponds to the inner diameter of the penetration 17 of the flange element 11 according to the invention.

Another difference with respect to the embodiment of FIG. 10 is that for the screws 27 for the fixing of the flange element 11 in the chamber 13 it has blind holes into which the fixing screws 27 are screwed. It is in. Moreover, no centering ring is provided between the chamber 13 and the flange element 11, and an O-ring seal 26 is inserted in a groove formed in the end face of the chamber flange 13a.

Accordingly, the present invention provides a safety flange element. This safety flange element can perform both an adapter function (FIG. 10) as well as a reducer function (FIG. 11) and is simple and inexpensive to manufacture, in short axial lengths and especially in threaded openings 21. Excellent in the release part. This increases the crash safety of a vacuum system with at least one safety flange according to the invention.

11 Flange element 13 Vacuum device, vacuum vessel 15 Vacuum device, vacuum pump 17 Penetration 19 Ring section 21 Safety housing, through opening 22 End face, sealing surface 23 Basic section 24 Transition section 25 Extension section 26 Seal 27 Fixing element 31 Reception section , blind hole 32 end face, sealing surface 33 larger axial thickness region 35 smaller axial thickness region 36 seal 37 fixing element 39 nut 41 centering ring 43 centering ring 45 central shaft 111 turbomolecular pump 113 inlet flange 115 pump inlet 117 pump outlet 119 housing 121 lower part 123 electronics housing 125 electric motor 127 accessory connection 129 data interface 131 current supply connection 133 vent inlet 135 seal gas connection 137 motor chamber 139 coolant connection 141 underside 143 Screw 145 Bearing cover 147 Fixing hole 148 Coolant pipe 149 Rotor 151 Rotating 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 Connection channel 181 Rolling bearing 183 Permanent magnet bearing 185 Splash nut 187 Disc 189 Insert 191 Rotor side bearing half 193 Stator side bearing half 195 Ring magnet 197 Ring magnet 199 Bearing gap 201 carrying part 203 carrying part 205 radial strut 207 cover element 209 support ring 211 fixing ring 213 disc spring 215 emergency or safety bearing 217 motor stator 219 intermediate space 221 wall 223 labyrinth seal

Claims (12)

a flange element (11) arranged between two flanges (13a, 15a) respectively associated with vacuum devices (13, 15), the ring portion (19) defining a penetration (17); in which are formed a plurality of receptacles (21) for a plurality of fixing elements ( 27 ) distributed in the circumferential direction or arranged on a circle in at least one group wherein at least some or all of the receptacles (21) of the group are respectively designed as security receptacles,
Two groups of receptacles (21, 31) for a plurality of fastening elements ( 27 , 37 ) are provided, each arranged in a circumferentially distributed manner, one group for one vacuum device. (13) and the other group is associated with the other vacuum device (15),
In the area (33) of one group of the two groups or in the area of the group of receptacles (31) each formed as a blind hole, the ring portion (19) is lower than in the area (35) of the other group. has a large axial thickness,
Flange element, characterized in that the safety accommodation (21) each has a basic part (23) with a basic diameter and an enlarged part (25) with a diameter enlarged with respect to the basic diameter . 2. Flange element according to claim 1 , characterized in that the safety receptacles (21) are each formed as a through opening through which the fixing element (27) can pass. One group of receptacles (21) is each formed as a through-opening through which a fixing element (27) can be passed, and the other group of receptacles (31) is respectively a blind hole or an internal thread. 3. A flange element according to claim 1 or 2 , characterized in that it is formed as a grooved blind hole into which the fixing element (37) can be inserted or screwed. The two groups have an inner group and an outer group, with the inner group lying on a curve or circle and the curve as a whole on which the outer group lies. Situated radially inside the curve or circle, the inner group of receptacles (31) is formed as a blind hole or a blind hole with an internal thread, respectively, and the outer group of receptacles (31) 4. A flange element according to any one of the preceding claims, characterized in that the (21) are each formed as through openings. The inner group is associated with a vacuum device formed as a vacuum pump (15) or as a turbomolecular pump, and the outer group is a vacuum vessel (13) to be evacuated by the vacuum pump (15). 5. A flange element according to claim 4 , associated with a vacuum device formed as a. 6. A flange according to any one of the preceding claims, characterized in that the two groups have the same number of receptacles (21, 31) or 12, 24 or 36 receptacles (21, 31). element. The two groups are circumferentially offset with respect to each other, wherein in each case one receptacle (31) of one group is circumferentially between two receptacles (21) of the other group, 7. A flange element according to any one of claims 1 to 6 , characterized in that it is arranged centrally between the two receptacles (21) of the group or of the other group. 8. A flange element according to any one of the preceding claims, characterized in that the basic part (23) and the extension part (25) of the safety receptacle (21) are each of cylindrical design. In each safety accommodation (21), between the base portion (23) and the extension portion (25), a conical transition portion (24) is provided, the inner diameter of which is equal to the base portion (23) of the base portion (23). 9. A flange element according to any one of claims 1 to 8 , characterized in that it expands from a diameter to a larger diameter in the widening portion (25). The safety housings (21), respectively, are first made by means of a first tool in the ring portion (19) with a through hole having a basic diameter and subsequently this through hole is cut from the side of the ring portion (19). starting and expanded over part of its length to an enlarged diameter by means of a second tool different from the first tool, wherein simultaneously with the expansion of the through-hole by means of the second tool, Manufactured by a method in which a conical transition portion (24) is formed between a base portion (23) formed by the remaining portion of the throughbore and an enlarged portion (25) having an enlarged diameter. 10. A flange element according to any one of claims 1 to 9 , characterized in that: At least one end face (22, 32) or both end faces (22, 32), respectively, of the ring portion (19) are completely flush or flat for the abutment of the seals (26, 36). 11. The seal of claim 1 to 10 , characterized in that it is formed by a polished sealing surface and/or wherein the ring portion (19) has a maximum axial thickness of between 15 mm and 35 mm. A flange element according to any one of the preceding claims. At least one flange element (11), at least one vacuum device (13, 15) or vacuum pump or vacuum vessel according to any one of claims 1 to 11 and a plurality of fixing elements (27, 37) ), wherein the flange element (11) is connected to the vacuum device (13, 15), wherein the number of receptacles or the number of safety receptacles of at least one group is greater than the minimum number of receptacles required for the vacuum device. and vacuum system.

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