JP2021139361A - Turbo molecular pump, and method for manufacturing stator disk for turbo molecular pump - Google Patents

Abstract

To reduce an axial mounting space of a stator disk manufactured from sheet metal without particularly limiting the vacuum performance.SOLUTION: The present invention resides in a turbo molecular pump (111) having a rotor with a plurality of rotor blades distributedly arranged around periphery, and at least one stator disk with a plurality of stator blades distributedly arranged around periphery, in which the rotor can be driven to rotate about a rotation axis to generate pumping action, the rotor cooperates with the stator disk to generate the pumping action, and the stator blades of the stator disk oriented obliquely with respect to a disk plane extending perpendicular to the rotation axis of the rotor. The stator disk is manufactured from sheet metal, and at least one stator blade has a flattened portion at an end in the axial direction.SELECTED DRAWING: Figure 9

Description

The present invention comprises one rotor with a plurality of rotor blades distributed and arranged around the periphery and at least one stator disk with a plurality of stator blades distributed and arranged around the periphery. It can be driven to rotate around a rotating shaft to generate pumping action, the rotor cooperates with the stator disk to generate pumping action, and the stator blades of the stator disk are relative to the rotating shaft of the rotor. With respect to a turbomolecular pump oriented diagonally with respect to a vertically extending disk plane.

The present invention also relates to a method for manufacturing a stator disk with a plurality of stator blades distributed and arranged around a turbo molecular pump.

Stator discs for turbo molecular pumps are typically made by cutting from solid materials, such as milling or sawing, or from sheet metal. In the case of manufacturing from sheet metal, the stator blades are typically punched and then bent to align diagonally with respect to the disk plane. In the case of an assembled pump, the disk plane extends perpendicular to the axis of rotation of the rotor and is defined, for example, by at least one collar of the stator disk.

Manufacture of stator discs from sheet metal is particularly cost-effective, but for comparable performance, the stator discs made from sheet metal have more axial orientations than the stator discs made by cutting. It has the disadvantage of requiring mounting space. The reason is that different manufacturing methods give rise to different shapes of the stator blades.

An object of the present invention is to reduce the axial mounting space of a stator disk manufactured from sheet metal without particularly limiting the vacuum performance.

A clear approach in this regard is to simply form the stator blades "with less tilt", i.e. reduce their angle with respect to the disk plane. However, this has a significant effect on the pumping action of the stator disc and thus on the vacuum performance.

Rather, the problem is solved by a turbomolecular pump having the characteristics of claim 1, in particular by having at least one stator blade provided with a flattening portion at at least one axial end.

Thereby, the material of the stator blades, particularly accurately, on the one hand defines the axial mounting space of the stator blades and, on the other hand, plays a relatively small role in pump performance, especially at least substantially without pumping activity. However, it is flattened. In addition, since such flattening can occur by simple means, the present invention allows optimization of mounting space by structurally particularly simple means, at least with substantially constant pump performance. do.

Flattening can be caused by removal of material or removal of material. We'll go into more detail about this elsewhere.

The term "axial" generally refers to the axis of rotation of the rotor or a direction parallel to it. Thus, the axial end is axially located at the highest or lowest point of the stator blades in the upright pump. Since the pump direction is typically at least substantially parallel to the axis of rotation, the axial end of the stator disc constitutes, in particular, an upstream end and a downstream end.

At least one stator blade may be provided with, for example, only one axial end with a flattening portion, or, for example, one flattening portion at each of two opposing axial ends.

According to one embodiment, it is intended that the flattening portion comprises at least a substantially flat surface. Such surfaces can be created by simple means, thus allowing relatively large mounting space in a simple way.

The surface can preferably extend at least substantially parallel to the disk plane. This allows for a particularly large mounting space.

More preferably, the flattening portion can extend over the entire length of the stator blade. The length of the stator blades at least substantially coincides with its spread in the radial direction, and the description "radial" refers to the axis of rotation of the rotor.

In general, the axial end can be the upstream end or the downstream end of the stator blades. However, it is also possible that both the upstream and downstream ends of the stator blades are provided with flattening portions. In this case, it is possible to achieve twice the mounting space.

Preferably, the plurality or all stator blades of the stator disc are provided with one flattening portion, particularly at the corresponding axial end, i.e., all at the upstream end and / or downstream end. Can be done. Turbo molecular pumps often include multiple stator discs. Here, it is particularly advantageous that a plurality or all of the stator discs include a stator blade having a flattened portion.

The problem of the present invention is also solved by the method for manufacturing a stator disk described in the independent claim pursuing it. It is used to make a stator disk with multiple stator blades distributed and arranged around it, for turbo molecular pumps, especially for turbo molecular pumps of the type described above, where the stator disk is made from sheet metal. The stator blades of the stator disk are oriented diagonally with respect to the extending plane of the sheet metal, and at least one stator blade is at least one end with respect to the normal to the extending plane of the sheet metal. Including being flattened. In general, the present invention also includes a suitable manufacturing method for turbo molecular pumps with a stator disc thus manufactured.

The extending plane of the sheet metal preferably coincides with the disc plane perpendicular to the axis of rotation, especially when the pump is assembled. In particular, when the stator blades are oriented, the collar supporting the stator blades remains in the extending plane of the sheet metal. In this case, the extension plane of the color can be referred to. The normals are oriented parallel to the axis of rotation of the rotor, especially when the pump is assembled.

According to the evolution, flattening is intended to include molding, especially cold molding and / or pressing. In this case, in particular, the stator blades are not bent at the surface, but are substantially compressed within the cross section of the stator disk. In general, in particular, the material is fluidly and / or deformed by extrusion. Generally preferably, the material of the stator blades is pressed so that the region adjacent to the axial end in particular is raised. Basically, for flattening, for example, forming and / or pressing forces can be applied to the stator blades or ends at least substantially parallel to the normal or the axis of rotation of the rotor. During flattening, the stator blades can preferably be supported on a flat side opposite to the flattened portion, preferably on a surface.

It is also possible to selectively or additionally produce, for example, the flattened portion by machining or, for example, grinding.

In general, flattening can be done especially at the corners of the cross section of the stator blades. In general, it is preferred that the material portion be removed from its position at the corner, i.e., either moved by molding or separated from the stator blade by, for example, cutting. The material portion to be removed is preferably at least substantially triangular in cross section. The surface of the flattening portion defines, in particular, one side of this triangle, that is, a side that faces the center of gravity of the surface of the stator blade, particularly with respect to the cross section of the stator blade.

In general, the stator blades particularly include a first flat side that points in the same direction as the flattened end with respect to the normal and / or a second flat side that faces in the opposite direction. With respect to the pump direction, in particular, the upper or first side portion in the pump direction and the lower or second side portion in the pump direction. It can be seen that the flat side is generally oriented diagonally, but is oriented in one of the opposite directions along the normal, that is, the flat side is oriented in the corresponding direction.

According to one embodiment, flattening is intended to include moving the material of the stator blades, especially primarily in the direction of the first flat side, so as to flow. With respect to the turbo molecular pump described above, this means that, in particular, the stator blades, on the first flat side, feature a material storage section in the same direction as the flattened end with respect to the rotor axis of rotation. This can specifically constitute a protrusion and / or a bead and / or be placed in the immediate vicinity of the flattening portion. The first flat side is, in particular, the upper and / or upstream flat side of the blade in an upright pump, and in particular, the end is the upstream end. However, it is also possible, for example, to flatten the downstream end, and in particular the material storage portion is generated on the downstream flat side.

For example, in general, the stator blades can be formed by punching and / or oriented obliquely by bending. The flattening can be, for example, an additional method step or part of an additional method step, or can be provided within a method step that is essentially molded and / or oriented. Basically, flattening can be done, in particular, before, during and / or after punching and / or mage.

Another aspect of the present invention proposes the turbo molecular pump according to claim 11. For example, one rotor with a plurality of rotor blades that can be formed and / or can be manufactured or can be manufactured according to the above type and are distributed and arranged around the periphery and distributed and arranged around the periphery. It has at least one stator disk with a plurality of stator blades, the rotor can be driven to rotate about a rotation axis to generate pumping action, and the rotor is driven to generate pumping action. Collaborate with. The stator blades of the stator discs are oriented obliquely with respect to the disc plane extending perpendicular to the rotor axis of rotation, and the stator blades are supported by at least one collar, particularly the inner and / or outer collars. The collars are arranged axially eccentrically with respect to at least one stator blade. In particular, the collar can be arranged axially eccentrically with respect to all the stator blades of the stator disc.

That is, the collar is arranged so as to be displaced in the axial direction with respect to the height of the center of the blade in the axial direction. The eccentric arrangement allows simplification of assembly, especially pump disassembly. The stator disc can be easily removed from the pump due to the eccentric arrangement of the collars.

Especially in the case of such an arrangement in which the stator discs are radially derived from between the two rotor discs for disassembly or introduced between the two rotor discs for assembly-in this case, the stator discs are In particular, the-with at least two separable ring segments reduces the risk of collision with other stator elements, especially spacer rings, on the axial side where the collar is misaligned. This is because, in that case, the stator blades are axially short. Indeed, this may theoretically increase the risk of collision on the other axial side, but most often when the stator disc is intended to be removed "in order", this other axial. The absence of such elements, especially spacer rings, on the side of the allows for a given assembly sequence.

Preferably, it is intended that the coupling point between the collar, collar and each stator blade and / or the axial center of the collar is located before or after the axial center of the stator blade with respect to the pump direction. be able to. For upright pumps, this is especially consistent with the axially centered top or bottom placement of the stator blades.

The stator disc can include, for example, an outer collar and / or an inner collar. Basically, the outer and inner collars of the stator disc can be placed at the same or different axial heights. The terms "outside" and "inside" here mean with respect to the axis of rotation of the rotor, i.e., radially outside and radially inside.

In some embodiments, the collars are arranged axially eccentrically with respect to a plurality of, especially all stator blades. This is preferably true for the entire collar and / or the outer and / or inner collar. In general, the stator blades can be arranged at the same height, especially in the axial direction.

Basically, the collar can be formed, for example, in a ring shape, especially in a continuous ring shape or by a plurality of ring segments. For example, the inner collar can be formed in a continuous ring shape and the outer collar can be formed by a plurality of ring segments. In this case, it should be considered that the stator disc itself can preferably be manufactured from the ring segment, i.e., "continuous" in that case relates to the ring segment of the stator disc.

Stator discs can generally be manufactured from sheet metal, especially by punching and / or bending. In general, the stator disc can consist of, for example, at least two partial rings, particularly halflings.

It can be seen that the turbomolecular pumps and manufacturing methods described herein can be advantageously developed individually and in combination depending on the embodiments and individual characteristics of the other turbomolecular pumps or manufacturing methods described herein.

Hereinafter, the present invention will be described with reference to the accompanying drawings in an exemplary advantageous embodiment.

Perspective view of turbo molecular pump Lower view of the turbo molecular pump of FIG. Cross-sectional view of the turbo molecular pump along the cutting line AA shown in FIG. Cross-sectional view of the turbo molecular pump along the cutting line BB shown in FIG. Cross-sectional view of the turbo molecular pump along the cutting line CC shown in FIG. A cross-sectional view of a prior art stator blade manufactured from a solid material by cutting in a cutting plane lateral to the extending direction of the stator blade. Cross-sectional view of a prior art stator blade manufactured from sheet metal Cross-sectional view showing excess material of stator blades made from sheet metal Stator blade of FIG. 8 after flattening Significantly simplified side view of prior art stator discs The figure corresponding to that of FIG. 10 of a stator disk with collars arranged eccentrically with respect to the stator blades.

The turbo molecular pump 111 shown in FIG. 1 has a pump inlet 115 surrounded by an inlet flange 113, to which, as is well known per se, a recipient (not shown) can be connected. Gas from the recipient is drawn from the recipient via the pump inlet 115 and can be transferred through the pump to the pump outlet 117, to which a preliminary vacuum pump, such as a rotary vane pump, is connected. be able to.

The inlet flange 113 constitutes the upper end of the housing 119 of the vacuum pump 111 when the vacuum pump is oriented according to FIG. The housing 119 has a lower portion 121, and an electronic device housing 123 is arranged next to the lower portion. The electrical and / or electronic components of the vacuum pump 111 are housed in the electronic equipment housing 123, for example, to operate the electric motor 125 arranged in the vacuum pump (see also FIG. 3). The electronic device housing 123 is provided with a plurality of ports 127 for accessories. In addition, for example, a data interface 129 and a power supply port 131 according to the RS485 standard are arranged in the electronic device housing 123.

There are also turbo molecular pumps that are connected to external drive electronics rather than having such an attached electronics housing.

The housing 119 of the turbo molecular pump 111 is provided with a filling inlet 133 in the form of a filling valve, and the vacuum pump 111 can fill the filling through the filling inlet. Furthermore, in the region of the lower portion 121, a seal gas port 135, which is also called a scavenging gas port, is arranged, and the scavenging gas is transferred from the gas transferred by the pump through the scavenging gas port to the electric motor 125 (see, for example, FIG. 3). The electric motor 125 can be introduced into the motor space 137-in which the electric motor 125 is housed in the vacuum pump 111-to protect. Furthermore, two coolant ports 139 are arranged in the lower portion 121, one of these coolant ports is provided as an inlet for the coolant, and the other coolant port is provided as an outlet for the coolant. This coolant can be introduced into the vacuum pump for cooling. Other existing turbomolecular vacuum pumps (not shown) can be operated solely by air cooling.

Since the lower side 141 of the vacuum pump can be used as a stand surface, the vacuum pump 111 can be operated while standing on the lower side 141. However, the vacuum pump 111 may be fixed to the recipient via the inlet flange 113 so that it may be operated in a suspended state to some extent. In addition, the vacuum pump 111 can be configured to operate even when oriented differently than that shown in FIG. It is also possible to realize an embodiment of a vacuum pump in which the lower side 141 can be arranged so that it faces sideways or upwards instead of facing downwards. In this case, basically any angle is possible.

In particular, other existing turbomolecular vacuum pumps (not shown) that are larger than the pumps shown here cannot be operated in an upright position.

Further, various bolts 143 are arranged on the lower side 141 illustrated in FIG. 2, and these bolts fix the parts of the vacuum pump, which are not further specified here, to each other. For example, the bearing cover 145 is fixed to the lower side 141.

In addition, fixing holes 147 are arranged on the lower side 141, and the pump 111 can be fixed to, for example, a mounting surface through these fixing holes. This is not possible, especially for other existing turbomolecular vacuum pumps that are larger than the individually illustrated pumps.

A coolant line 148 is shown in FIGS. 2 to 5, and a coolant introduced and derived can be circulated in the cooling line through the coolant port 139.

As the cross-sectional views of FIGS. 3-5 show, the vacuum pump has a plurality of process gas pump stages for transferring the process gas present at the pump inlet 115 to the pump outlet 117.

A rotor 149 is arranged in the housing 119, and the rotor includes a rotor shaft 153 that can rotate about a rotation shaft 151.

The turbo molecular pump 111 has a plurality of radial rotor disks 155 fixed to the rotor shaft 153 and a stator disk 157 disposed between the rotor disks 155 and fixed to the housing 119, effectively in series with the pump. It has multiple turbo molecular pump stages interposed in it. In this case, the rotor disk 155 and the adjacent stator disk 157 each form one turbo molecular pump stage. The stator discs 157 are held by spacer rings 159 at desired axial spacing from each other.

In addition, the vacuum pumps have Holbeck pump stages that are radially spaced apart from each other and effectively interleaved with each other in the pump. There are other existing turbomolecular vacuum pumps that do not have a Holbeck pump stage.

The rotor of the Holbeck pump stage has one rotor hub 161 arranged on the rotor shaft 153 and two cylinder shell shaped Holbeck rotor sleeves 163,165 fixed to and supported by the rotor hub 161. These Holbeck rotor sleeves are coaxially oriented with respect to the rotating shaft 151 and are nested in each other in the radial direction. Further, two cylinder shell-shaped Holbeck stator sleeves 167 and 169 are provided, and these Holbeck stator sleeves are also coaxially oriented with respect to the rotating shaft 151 and are nested with each other when viewed in the radial direction. Has been done.

The pump active surface of the Holbeck pump stage is composed of shell surfaces, i.e., radial inner and / or outer surfaces, Holbeck rotor sleeves 163,165 and Holbeck stator sleeves 167,169. The radial inner surface of the outer Holbeck stator sleeve 167 faces the radial outer surface of the outer Holbeck rotor sleeve 163 while forming a radial Holbeck gap 171 and, together with this radial outer surface, a turbo molecule. It constitutes a first Holbeck pump stage following the pump. The radial inner surface of the outer Holbeck rotor sleeve 163 faces the radial outer surface of the inner Holbeck stator sleeve 169, forming a radial Holbeck gap 173, and together with this radial outer surface a second. It constitutes the Holbeck pump stage. The radial inner surface of the inner Holbeck stator sleeve 169 faces the radial outer surface of the inner Holbeck rotor sleeve 165 while forming a radial Holbeck gap 175, and together with this radial outer surface a third. It constitutes the Holbeck pump stage.

At the lower end of the Holbeck rotor sleeve 163, a radially extending passage can be provided that connects the Holbeck gap 171 located on the outer side in the radial direction with the central Holbeck gap 173 by the intervention thereof. In addition, a radially extending passage can be provided at the upper end of the inner Holbeck stator sleeve 169 to connect the central Holbeck gap 173 to the radial inner Holbeck gap 175 by its intervention. .. As a result, the Holbeck pump stages nested in each other are interposed in series with each other. Further, a connecting passage 179 to the outlet 117 can be provided at the lower end of the Holbeck rotor sleeve 165 located inward in the radial direction.

The pump-active surfaces of the Holbeck stator sleeves 167 and 169 each include a plurality of Holbeck grooves spirally extending axially about the rotation shaft 151, with opposing shells of the Holbeck rotor sleeves 163 and 165. The surface is formed to be smooth and propels the gas for operating the vacuum pump 111 in the Holbeck groove.

In order to rotatably bearing the rotor shaft 153, a rolling bearing 181 is provided in the region of the pump outlet 117 and a permanent magnet bearing 183 is provided in the region of the pump inlet 115.

In the area of rolling bearing 181 the rotor shaft 153 is provided with a conical spray nut 185 having an outer diameter that increases towards rolling bearing 181. The spray nut 185 is in sliding contact with at least one wiper of the working medium accumulator. For other existing turbomolecular vacuum pumps (not shown), spray bolts can be provided instead of spray nuts. Therefore, the term "spray tip" is also used in this context as different configurations are possible.

The working medium accumulator has a plurality of hygroscopic discs 187 stacked one above the other, and these discs absorb a working medium for the rolling bearing 181 such as a lubricant.

During operation of the vacuum pump 111, the working medium is transmitted from the working medium accumulator to the rotating spray nut 185 via the wiper by capillary action, and due to centrifugal force, the outer diameter of the spray nut 185 is transmitted along the spray nut 185. Is transferred towards the rolling bearing 181 in the increasing direction, where the working medium satisfies, for example, the lubrication function. The rolling bearing 181 and the working medium accumulator are surrounded by a tub-shaped insert 189 and a bearing cover 145 in a vacuum pump.

The permanent magnet bearing 183 has a bearing half body 191 on the rotor side and a bearing half body 193 on the stator side, and these bearing halves consist of a plurality of permanent magnet rings 195 and 197 stacked vertically in the vertical direction, respectively. It has one ring stack. The ring magnets 195 and 197 face each other while forming a radial bearing gap 199, the ring magnet 195 on the rotor side is arranged on the outer side in the radial direction, and the ring magnet 197 on the stator side is arranged on the inner side in the radial direction. ing. The magnetic field present in the bearing gap 199 provokes a magnetic repulsive force between the ring magnets 195 and 197 that produces a radial bearing of the rotor shaft 153. The ring magnet 195 on the rotor side is supported by a carrier portion 201 of the rotor shaft 153, which surrounds the ring magnet 195 from the outside in the radial direction. The ring magnet 197 on the stator side is supported by the carrier portion 203 on the stator side, and this carrier portion extends through the ring magnet 197 and is suspended on the radial brace 205 of the housing 119. Parallel to the rotating shaft 151, the ring magnet 195 on the rotor side is fixed by a cover element 207 connected to the carrier portion 201. The ring magnet 197 on the stator side is fixed in one direction in parallel with the rotation shaft 151 by a fixing ring 209 coupled to the carrier portion 203 and a fixing ring 211 coupled to the carrier portion 203. In addition, a countersunk spring 213 can be provided between the fixing ring 211 and the ring magnet 197.

An emergency or safety bearing 215 is provided within the magnetic bearing, which idles without contact during standard operation of the vacuum pump 111, with the rotor 149 being excessive relative to the stator. Only when radially displaced to the rotor engages to form a radial stopper for the rotor 149, which is done to prevent collisions between the stator-side and rotor-side structures. .. The safety bearing 215 is formed as a non-lubricated rolling bearing and, together with the rotor 149 and / or the stator, constitutes a radial gap that causes the safety bearing 215 to be released during standard pump operation. The radial displacement with which the safety bearing 215 engages is large enough so that the safety bearing 215 does not engage during the standard operation of the vacuum pump, and at the same time, the collision between the stator side structure and the rotor side structure. Is set small enough to prevent under all circumstances.

The vacuum pump 111 includes an electric motor 125 for rotationally driving the rotor 149. The anchor of the electric motor 125 is composed of a rotor 149, and the rotor shaft 153 of the rotor extends through the motor stator 217. A permanent magnet device can be arranged in the portion of the rotor shaft 153 extending through the motor stator 217 on the outer side in the radial direction or embedded. An intermediate space 219 is arranged between the motor stator 217 and the portion of the rotor 149 extending through the motor stator 217, the intermediate space having a radial motor gap, through which the motor The stator 217 and the permanent magnet device can be magnetically affected to transmit drive torque.

The motor stator 217 is fixed in the housing in the motor space 137 provided for the electric motor 125. Through the seal gas port 135, a seal gas, also called scavenging gas, which can be, for example, air or nitrogen, can reach into the motor space 137. Through the seal gas, the electric motor 125 can be protected from the process gas, for example, the corrosive components of the process gas. The motor space 137 can also be evacuated through the pump outlet 117, i.e., within the motor space 137 is at least largely dominated by the vacuum pressure generated by the preliminary vacuum pump connected to the pump outlet 117.

In addition, the rotor hub 161 and the wall 221 defining the motor space 137 are well known in their own right to achieve good sealing of the motor space 217, especially for the Holbeck pump stage located radially outward. The so-called labyrinth seal 223 can be provided.

6-11 show the stator blades or stator discs in a remarkably schematic view. The stator disk 157 of the turbo molecular pump 111 of FIGS. 1-5 can be formed according to the present invention, that is, the present invention can be used in a turbo molecular pump as described with reference to FIGS. 1-5.

6 and 7 are used to illustrate the prior art. In both cases, the stator blade 20 is shown in a cross section, that is, in a cutting plane lateral to the extending direction of the stator blade. This extending direction extends radially with respect to the rotational magnetism of the rotor in the pump. The rotation axis of the rotor is indicated by the broken line 21 in FIGS. 6 to 11. That is, the cut plane of the cross section shown here extends parallel to the rotating shaft 21 of the rotor (not shown here) that extends vertically here and in another figure. Therefore, the blade 20 extends perpendicularly to the rotation axis 21 and is inclined with respect to a plane (not shown) extending horizontally in the illustrated cross section. That is, in FIGS. 6 and 7 (and also in FIGS. 8 and 9), in particular, the cut surface of the blade 20 inclined with respect to the horizontal, which faces outward in the radial direction, is seen. In other words, this applies to all FIGS. 6-11, so to speak, looking radially along the flat side of each blade 20, with FIGS. 10 and 11 in particular the axis of rotation of the rotor. It has been simplified to show the development of.

Often, turbomolecular pump stator discs are milled from solid materials. The stator blade 20 of FIG. 6 is manufactured by cutting, for example, by milling and / or sawing. In this case, the flat disc is typically sawed or milled from the solid material so that multiple blades remain. Based on this manufacturing method, the stator blades 20 include axially flat ends 22 and 24 with respect to the rotating shaft 21 that extend perpendicularly and therefore horizontally to the rotating shaft 21. These edges arise, in particular, from the normally flat end faces of the disc prior to the milling or sawing process.

For cost reasons, it may be advantageous to manufacture the stator discs from sheet metal by a punching process. FIG. 7 illustrates a stator blade 20 made from a well-known sheet metal, which is typically first formed by punching from a flat sheet metal and then bent to bring it in the oblique orientation shown herein. Is done. In particular, from this manufacturing method, the axial ends 22 and 24 with respect to the rotating shaft 21 are not flat and are substantially angular, as is the case with the stator blade 20 of FIG. That is, the stator blade 20 of FIG. 7 particularly has a substantially rectangular cross section, with rectangular corners forming axial ends 22 and 24 of the stator blade 20.

Therefore, the cross-sectional shape of the individual blades varies depending on the manufacturing method: the milled or sawed blade 20 of FIG. 6 has a parallel quadrilateral cross-section. The blade 20 of FIG. 7 punched out from the sheet metal has a rectangular cross section.

Based on the different cross-sectional shapes, the blade 20 of FIG. 7 provides a larger mounting space than that of FIG. 6 with the same pumping action. In other words, the effective total height of the pump of the blade 20 or the stator disk in FIG. 7 is small even if the axial gap is the same or the total height in the axial direction is the same.

In particular, if the goal is to replace the stator disc with an existing pump, i.e. to improve the existing pump structure according to the challenges of the present invention, only some space is available in the axial direction. That is, the goal is ultimately to change the contour of the stator blades made from sheet metal to be as close as possible to the milled contour, especially as in FIG.

The blade contour is now parallelogram because, for example, another forming step flattens only the material triangle of the rectangular cross section that protrudes at the axial end (not particularly vacuum technically important), especially during the punching process. Get closer to the shape. This wastes only a small amount of mounting space in the axial direction without reducing the pumping action. This will be described in more detail below.

FIG. 8 shows another stator blade 20 having a rectangular cross section in an enlarged manner as compared with FIG. 7. Preferably, the axial end 22 can be the upstream end of the stator blade 20 and the axial end 24 can be the downstream end.

A substantially triangular region 26 of the illustrated cross section is marked. The material of the stator blade 20 in this region 26 is trivial enough, i.e., unnecessary for the pumping action of the stator blade 20 or the stator disc. For clarity, the pump direction 28 is marked here by an arrow. The pump direction 28 extends parallel to the rotating shaft 21 of the rotor, which is not shown here.

What is decisive for pumping action is rather the lower flat side 30 on the downstream side of the stator blade 20. That is, as can be seen in FIG. 8, for example, the region 26 occupies the mounting space in the axial direction without exerting a pumping action.

Therefore, the stator blade 20 of FIG. 9 is provided with a flattening portion 32 according to the present invention at an axial end portion 22. Due to this flattening portion, the region 26 with excess material is clearly reduced, and in particular, the overall height of the stator blade 20 and the stator disk in the axial direction is reduced.

The flattening portion 32 is formed here as a surface that is at least substantially flat with respect to the three-dimensional spread of the stator blade 20. In particular, the flattening portion 32 or surface extends over the entire radial extent of the stator blade 20, i.e., over the entire radial length. In this embodiment, the surface of the flattening portion 32 extends perpendicular to the rotation shaft 21 of the rotor of the turbomolecular pump. The gain of the axial mounting space, when projected in FIG. 9, corresponds to the axial spacing of the faces relative to the upper tip of the triangle in FIG. This triangle is shown by a dashed line in FIG. 9, and its tip on the upstream side is indicated by 22'.

The flattening portion 32 can be formed in different forms. Therefore, the axial end 22 can be ground, for example. In FIG. 9, the stator blade 22 is illustrated as flattened by molding, ie extrusion molding, rather than by grinding. In this case, the forming force was applied from top to bottom, especially substantially perpendicular to the disk plane or parallel to the rotor rotation axis 21. The material of the region 26 or the stator blade 20 is such that it rises within the region projecting laterally from the region 26 shown as a triangle in FIG. 8, and the total height of the stator blade 20 in the axial direction results in the bead 34. It is molded so as to bulge beside the flattening portion 32 so that it does not increase despite its occurrence. During the forming process, the stator blade 20 was preferably supported in a plane along the flat side portion 30.

The bead 34 is arranged here on the flat side portion 36 on the upstream side and facing the same axial direction as the end portion 22. In addition, the bead 34 is located directly adjacent to the flattening portion 32.

The bead 34 is arranged so as not to affect the pumping action of the stator blade 20 at least substantially. This is because the pumping action is substantially determined by the flat side portion 30 on the downstream side. However, by comparison, it can be seen that the region 26 with excess material in FIG. 9 is clearly smaller in the axial direction than that in FIG. Therefore, the flattening portion 32 can easily reduce the mounting space of the stator blade 20 or the stator disk in the axial direction, and does not adversely affect the pump performance.

In the case of the stator blade 20 of FIG. 9, finally, another forming step pushes the excess material or region 26 into a region that no longer interferes, i.e., does not interfere with axial mounting space and pumping action. Preferably, the material is pushed to a fluid technical back surface, such as the flat side 36, which no longer interferes here. The greater the gain from flattening, the flatter the blade angle. For a blade angle of about 10 °, for example which can be provided in the pre-vacuum region, the excess or interfering triangles can be up to 1/3 of the total height.

In particular, in FIGS. 8 and 9, the size ratio of the stator blades 20 is not faithful to the scale and is adapted for illustration purposes. In particular, the length of the rectangular cross section of the actual stator blade 20, that is, the width of the flat side portions 30 and 36 is significantly larger than that shown in the flattened portion.

Basically, the downstream end 24 can also be provided with a flattening portion, however, this is not shown. At that point, it is also possible to push away the interfering triangles underneath the disc or blade 20.

FIG. 10 shows a simplified stator disk 38 having one collar 40 and a plurality of stator blades 20 coupled to the collar 40. The color 40 can be, for example, an inner color and / or an outer color.

The collar 40 is arranged at the center in the axial direction with respect to the stator blade 20, as is customary in the prior art.

FIG. 11 illustrates a stator disk 38 according to the invention in which the collar 40 is arranged axially eccentrically with respect to the stator blade 20. In FIG. 11, with respect to the pump direction 28, which typically extends from top to bottom, the collar 40 is located as a whole and its axial center is located behind or downstream of the axial center of the stator blades. .. The joint between the collar 40 and the stator blade 20 is located at the axial height of the collar 40 and is therefore similarly located after the axial center of the stator blade 20.

Thus, the blade plane, the plane of the axial blade center point, is axially moved and therefore asymmetrical rather than centered with respect to the collar 49. As a result, the disc 38 can be easily removed again at the time of disassembly. This is because the probability of collision with other parts of the lower blade portion in FIG. 11 is reduced.

The stator discs 38 of FIGS. 10 and 11 can be manufactured, for example, from sheet metal and are illustrated here with pointed axial ends 22 and 24 as in FIGS. 7 and 8. In FIGS. 10 and 11, the axial or rotating shaft 21 further extends vertically as in FIGS. 6-9. Thus, again, the blade 20 has a disk plane extending perpendicular to the axis of rotation 21 (not shown) -the collar 40 is located within this disk plane and thus this disk plane extends horizontally. It is tilted with respect to-. In FIGS. 10 and 11, unlike FIGS. 6 to 9, when the collar is the outer collar, the side of the collar 40 facing outward in the radial direction is viewed instead of the cut surface of the blade 20.

It can be seen that the axial end 22 and / or 24 may also be provided with a flattening portion, eg, a flattening portion as shown in FIG. 9, in order to save mounting space in the axial direction.

111 Turbo molecular pump 113 Inlet flange 115 Pump inlet 117 Pump outlet 119 Housing 121 Bottom 123 Electronic equipment housing 125 Electric motor 127 Accessory port 129 Data interface 131 Power supply port 133 Filling inlet 135 Seal gas port 137 Motor space 139 Coolant port 141 Lower 143 Bolt 145 Bearing cover 147 Fixing hole 148 Coolant line 149 Rotor 151 Rotating shaft 153 Rotor shaft 155 Rotor disk 157 Stator disk 159 Spacer ring 161 Rotor hub 163 Holbeck rotor sleeve 165 Holbeck rotor sleeve 167 Holbeck stator sleeve 169 Hol Beck stator sleeve 171 Holbeck gap 173 Holbeck gap 175 Holbeck gap 179 Connection passage 181 Rolling bearing 183 Permanent magnet bearing 185 Spray nut 187 Disc 189 Insert 191 Rotor side bearing half body 193 Stator side bearing half body 195 Ring magnet 197 Ring magnet 199 Bearing gap 201 Carrier part 203 Carrier part 205 Radial brace 207 Cover element 209 Support ring 211 Fixing ring 213 Counterbore spring 215 Emergency or safety bearing 217 Motor stator 219 Intermediate space 221 Wall 223 Labyrinth seal 20 Stator blade 21 Rotating shaft 22 Axial end 24 Axial end 26 Region 28 Pump direction 30 Flat side 32 Flattening 34 Bearing 36 Flat side 38 Stator disk 40 Color

Claims (15)

At least one stator disk (38,157) with one rotor (149) with multiple rotor blades distributed and arranged around the perimeter and multiple stator blades (20) distributed and arranged around the perimeter. The rotor can be driven to rotate about a rotation shaft (21, 151) to generate a pumping action, and the rotor (149) cooperates with the stator disk to generate a pumping action. , The turbo molecular pump (20) in which the stator blades (20) of the stator discs (38,157) are oriented obliquely with respect to the disc plane extending perpendicular to the rotation axis (21,151) of the rotor (149). 111)
The stator discs (38,157) are made from sheet metal, and at least one stator blade (20) has a flattening portion (32) at at least one axial end (22,24). A turbo molecular pump (111) characterized by that. The turbo molecular pump (111) according to claim 1, wherein the flattening portion (32) includes at least a substantially flat surface. The turbo molecular pump (111) according to claim 1 or 2, wherein the surface extends at least substantially parallel to the disk plane. The turbo molecular pump (111) according to claim 1, wherein the flattening portion (32) extends over the entire length of the stator blade (20). The axial end is either the upstream end (22) or the downstream end (24) of the stator blade (20), or the upstream end (22) and downstream of the stator blade (20). The turbo molecular pump (111) according to at least one of claims 1 to 4, wherein both of the side end portions (24) are provided with a flattening portion (32). The turbo molecular pump according to claim 1, wherein all the stator blades (20) of the stator disks (38,157) are provided with at least one flattening portion (32). 111). A stator disk having a plurality of stator blades (20) distributed and arranged around the turbo molecular pump (111), particularly for the turbo molecular pump according to any one of claims 1 to 6. 38,157) In the method for manufacturing
The stator disc (38,157) is manufactured from sheet metal, the stator blades (20) of the stator disc (38,157) are oriented diagonally with respect to the extending plane of the sheet metal, and at least one stator. A method characterized in that the blade (20) is flattened at at least one end (22, 24) with respect to the normal to the extending plane of the sheet metal. 7. The method of claim 7, wherein the flattening comprises molding, especially pressing. The stator blade (20) comprises a first flat side portion (36) oriented in the same direction as the flattened end (22) with respect to the normal, and flattening is performed on the stator blade (20). The method of claim 7 or 8, wherein the material comprises moving in the direction of the first flat side portion (36). The stator blade (20) is formed by punching and / or obliquely oriented by bending, and flattening is an additional method step or part of an additional method step. The method according to at least one of claims 7 to 9, wherein the method is characterized by that. At least one stator disk (38,157) with one rotor (149) with multiple rotor blades distributed and arranged around the perimeter and multiple stator blades (20) distributed and arranged around the perimeter. The rotor can be driven to rotate about the rotation shaft (21, 151) to generate a pumping action, and the rotor (149) cooperates with the stator disk to generate a pumping action. , The stator blades (20) of the stator disks (38,157) are oriented obliquely with respect to the disk plane extending perpendicular to the rotation axis (21,151) of the rotor (149), particularly claim. A turbo molecular pump (111) according to any one of 1 to 6 and / or a turbo molecular pump having a stator disk manufactured or can be manufactured by the method according to any one of claims 7 to 10. 111)
The stator blades (20) are supported by at least one collar (40), especially the inner and / or outer collars, and the collar (40) is at least one stator blade (20), especially the stator discs (38,157). The turbo molecular pump (111) is characterized in that it is arranged eccentrically in the axial direction with respect to all the stator blades (20) of the above. The coupling point between the collar (40), collar (40) and each stator blade (20) and / or the axial center of the collar (40) is the axial direction of the stator blade (20) with respect to the pump direction (28). The turbo molecular pump (111) according to claim 11, wherein the turbo molecular pump (111) is arranged before or after the center of the pump. The turbo molecular pump according to claim 11 or 12, wherein the outer collar and the inner collar (40) of the stator discs (38,157) are arranged at the same or different axial heights. 111). At least one of claims 11-13, wherein the collar (40), in particular the entire inner collar and / or outer collar, is eccentrically arranged with respect to a plurality of, particularly all stator blades (20). The turbo molecular pump (111). The turbo molecular pump (111) according to claim 11, wherein the collar (40) is continuously formed in a ring shape or by a plurality of ring segments.

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