JP6138897B2 - Vacuum pump - Google Patents

Description

  The present invention relates to a vacuum pump, particularly a turbo molecular pump.

  Illustratively, a turbomolecular vacuum pump has a rotor with a rotor shaft. On the rotor shaft, a plurality of rotor disks are provided offset in the axial direction. Each rotor disk has a plurality of rotor blades distributed in the circumferential direction. Moreover, the exemplary turbomolecular vacuum pump has a stator having a plurality of stator disks. Each of these has a plurality of stator blades distributed in the circumferential direction. In this exemplary turbomolecular vacuum pump, a plurality of rotor disks and stator disks are alternately provided in the axial direction.

  Exemplary turbomolecular pumps have predetermined vacuum technical performance values. This is for example the suction performance and the compression ratio. These occur at the target rotational speed of the rotor. The customer requirements for vacuum technical performance values, however, vary greatly. In practice, various vacuum pump models are maintained for different requirements, or vacuum pumps are structurally complex and adapted to special requirements, or even intentionally developed.

German Patent Application Publication No. 10201313215A1

  The object of the present invention is to simply satisfy the different requirements of vacuum pumps.

  This problem is solved by a vacuum pump according to the features of claim 1. In particular, at least one pure rotor region is provided in the axial region of the rotor (in the region in which the side connection is not open), in which at least two of the rotor regions are provided. The rotor part is continuous without having a stator part located between it and / or provided with at least one pure stator region, in which at least two stator parts are in between It is solved by being continuous without having a rotor part located.

  In other words, unlike the usual structure of a vacuum pump in which rotor portions and stator portions are alternately provided in the axial direction, there is no individual or multiple rotor portions and / or stator portions.

  In other words, according to the invention, for example, for each pump structure according to the invention, one or more stator parts or rotor parts can be intentionally omitted.

  The rotor part and the stator part are in particular so-called rotor disks or stator disks. They each have a plurality of rotor blades or stator blades distributed in the circumferential direction, and these are measured in the axial direction and have a height smaller than their diameter, in particular an essentially smaller height. Therefore, it has a disk shape. The rotor part and the stator part are provided in particular stacked on top of each other, and in the prior art are provided alternately, i.e. one stator disk followed by one rotor disk and vice versa. In the embodiment according to the invention, on the contrary, at least two rotor disks are continuous in the pure rotor area without having a stator disk located between them, while in the pure stator area at least two It can be intended that the stator disks are continuous without having a rotor disk located between them.

  For further clarification, we start with an exemplary turbomolecular pump having alternating rotor and stator portions, as is known in the prior art. This turbomolecular pump has a predetermined vacuum technical performance value. Unlike the vacuum technical performance values of the pump, for example when individual turbocharger pumps are required, only the individual or multiple rotor parts and / or stator parts are removed or omitted in the assembly. This alters or reduces the possible performance value of the pump within the framework of the turbomolecular pump structure. However, while this meets the requirements in a very simple manner, the pump does not need to be structurally changed. This allows not only one predetermined performance characteristic to be provided by a single pump model, but also multiple different performance characteristics to be realized by the same pump model. As a result, fewer different pump models need to be maintained and less structural adaptations of the pump to customer requirements need to be implemented, while different customer requirements can be accommodated It is.

  As long as the stator part fulfills structural challenges in addition to its vacuum technical function within the vacuum pump, the stator part can be a pure rotor area by means of alternative pieces for structural challenges, e.g. spacer pieces. Can be replaced. In general, it is possible to provide an axial distance between two rotor parts in a pure rotor region, in particular without depending on the presence or absence of alternative pieces.

  Both the developments described above and the subsequent developments are described only for one or more pure rotor regions, but are applicable to correspondingly pure stator regions. This further improves the variety of variations.

  The vacuum pump has at least one lateral connection in one embodiment. The side connection is different from the inlet and outlet of the vacuum pump. The present invention can be intentionally used in this embodiment to adjust the vacuum technical performance value of the pump area before and after the connection. In particular, this will intentionally adjust the achievable pressure in the chamber connected to the side connection (for example in a chamber where more residual gas is allowed or desired). Is possible. A complicated structural change of the vacuum pump is then not necessary.

  The lateral connection can be provided in at least one region of the rotor. Alternatively or additionally, a side connection can be provided between the inlet and outlet of the vacuum pump. As an alternative or in addition, the pure rotor region can be provided in the axial direction immediately before or immediately after the side connection, or in the vicinity of the side connection. is there. Alternatively, the vacuum pump can have no lateral connections.

  In one embodiment, in the axial direction, one stator part is provided between the first rotor part in the pump direction and the second rotor part in the pump direction. This achieves better vacuum technical performance values, while the pump can be adapted to different requirements.

  In another embodiment, the rotor portions are each formed by a rotor disk that is manufactured independently of the rotor shaft and secured to the rotor shaft. In other words, this can be a disk rotor. Alternatively, a full rotor can be provided. In this full rotor, the rotor portion can be integrally connected to the rotor shaft.

  Further embodiments are described in the dependent claims, the description and the drawings.

The invention will now be described by way of example only with reference to the drawings.

Turbo molecular pump with pure rotor region and pure stator region Turbomolecular pump with lateral connections and pure rotor area. Another turbomolecular pump with lateral connections and pure rotor area.

  FIG. 1 shows a vacuum pump formed as a turbomolecular pump 10. This vacuum pump has an inlet 30 surrounded by an inlet flange 31 and a plurality of pump stages for transporting gas extending to the inlet 30 to the outlet. The outlet is not represented in FIG. 1 (see, for example, pump outlet 32 depicted in FIG. 2). The turbo molecular pump 10 does not have a side connection. The turbo-molecular pump 10 includes a stator having a static housing 36 and a rotor 12 provided in the housing 36. The rotor has a rotor shaft 14 that is rotatably supported about the rotor shaft R.

  The turbo-molecular pump 10 includes a plurality of turbo-molecular pump stages that are serially connected to each other and perform a pumping action. These pump stages are connected to the rotor shaft 14, have a plurality of rotor parts formed as turbomolecular rotor disks 16, and are arranged between the rotor disks 16 in the axial direction and fixed to the housing 36. In addition, it has a plurality of stator portions formed as a turbomolecular stator disk 32. These are held together at a desired axial spacing by a spacer ring 40. The rotor disk 16 and the stator disk 22 provide an axial pumping action directed in the pump direction P in the suction area.

  In addition, the turbomolecular pump 10 has three holbeck pump stages that are arranged in a radial manner (German) and are connected in series and perform the pumping action. The member on the rotor side of the Holbeck pump stage has two holbeck rotor sleeves 46 and 48 which are fixed to the rotor shaft 14 and carried by the cylinder shaft. They are oriented coaxially with respect to the rotation axis R and are connected in a nested manner. Further, cylinder side-shaped Holbeck stator sleeves 50 and 52 are provided. They are likewise oriented coaxially with respect to the axis of rotation R and are connected in a nested manner. The pumping surfaces of the Holbeck pump stage are each formed by radial side surfaces facing each other forming a narrow radial Holbeck gap, that is, the Holbeck rotor sleeves 46, 48 and the Holbeck stator sleeve 50, 52 is formed by each side surface. In this case, one of the pumping surfaces, in this case for example that of the Holbeck rotor sleeve 46 or 48, is formed smoothly, with the opposing pumping surface of each Holbeck stator sleeve 50, 52 being And a structured portion having a plurality of grooves that change in the axial direction around the rotation axis R in a screw line shape. The gas is conveyed in these grooves by the rotation of the rotor 12, and pumping is performed thereby.

  The support of the rotatable rotor shaft 14 is effected by a roller bearing 54 in the outlet area and by a permanent magnet bearing 56 in the inlet 30 area.

  The permanent magnet bearing 56 has a rotor-side bearing half 60 and a stator-side bearing half 58. Each of these has a ring stack. The ring lamination part is composed of a plurality of rings of permanent magnets laminated together in the axial direction. In this case, the magnet rings face each other while forming a radial bearing gap.

  An emergency or safety support 62 is provided inside the permanent magnet support 56. This is formed as a non-lubricated roller bearing and runs idle in a non-contact manner in normal vacuum pump operation. Then, when the rotor 12 is excessively deflected in the radial direction with respect to the stator, the rotor 12 is engaged for the first time, and a radial stopper for the rotor 12 is formed. This stopper prevents the rotor-side structure from colliding with the stator-side structure.

  In the region of the roller support portion 54, a conical splash nut (German: Spritzmutter) 64 is provided on the rotor shaft 14. The splash nut has an outer diameter that increases toward the roller bearing 54. This is in sliding contact with a working medium storage skimmer (German) having a plurality of absorbent disks 66 immersed in a working medium, for example a lubricating medium. During operation, the working medium is transmitted from the working medium reservoir to the rotating splash nut 64 via the skimmer by the capillary effect. Then, it is conveyed along the splash nut 64 by the centrifugal force in the direction of the outer diameter of the splash nut 64 that becomes larger, to the roller support portion 54, where, for example, a lubricating function is satisfied.

  The turbo molecular pump 10 has a plurality of drive motors 68. This is for rotationally driving the rotor, and the rotor is formed by the rotor shaft 14. A control unit (not shown) drives the drive motor 68.

  The turbomolecular group 10 in FIG. 1 has a pure rotor region 28 and a pure stator region 29. Within the pure rotor region 28, the two rotor disks 16 are continuous without having a stator disk 22 between them. There is no stator disk 22 between the rotor disks 16. In the pure stator region 29, two stator disks 22 are continuous without having a rotor disk 16 between them. Here, accordingly, there is no rotor disk 16 between the stator disks 22. Both rotor disks 16 in the pure rotor area 28 and both stator disks 22 in the pure stator area 29 are spaced apart from each other in the axial direction.

  Each stator disk 22 is formed in the form of two half rings. They can be placed between the rotor disks 16 from the side, ie in the radial direction. In so doing, the stator disk 22 is placed on and supported by the spacer ring 40. The stator disk 22 is thereby particularly easily pulled away or removed, making the turbomolecular pump 10 meet certain requirements in vacuum technical performance values.

  FIG. 2 shows another turbomolecular pump 10. However, it has a side connection 26. A side connection 26 is provided for connection of an additional vacuum chamber not shown. Inside this, a different quality of vacuum needs to be achieved in the chamber connected to the inlet 30. The side connection 26 defines a connection area 34 of the rotor 12. In this, the side connection part 26 is opened. The stator disk 22 is not provided in the connection area 34. A large axial distance is provided between the rotor disks 16 that delimit the connection area. This interval basically corresponds to the axial extension of the connection region 34. In other words, the connection region 34 is in a state of being left open by an element that generates a pump effect.

  The gas that enters the pump via the side connection 26 is pumped in the pump direction P (ie downward in FIG. 2) and finally to the outlet 32.

  Outside the connection area 34, rotor areas 28 are provided at intervals in the axial direction of the rotor 12. There is no opening in the connection. The pure rotor area 28 has three successive rotor disks 16. There is no stator disk 22 between them. The pure rotor region 28 is provided immediately before the connection region 34 in the pump direction P. In addition, a stator disk 22 is provided between the first rotor disk 16 and the second rotor disk 16 in the pump direction P. Immediately after the connection region 34 in the pump direction P, the turbo molecular pump 10 has the rotor disks 16 and the stator disks 22 provided alternately in the axial direction.

  In FIG. 3, another turbomolecular pump 10 is shown with a side connection. Lateral connections are not visible in the illustration, however. The side connection defines a connection area 34. In this, the stator disk 22 is not provided. A pure rotor region 28 is provided immediately before the connection region 34 in the pump direction. Similarly, the stator disk 22 is not provided therein. Opposite a stator disk 22 is provided between the first pair of rotor disks 16 in the pump direction. Immediately after the connecting portion region 34, the rotor disk 16 and the stator disk 22 are provided in a known alternating arrangement.

10 Turbo Molecular Pump 12 Rotor 14 Rotor Shaft 16 Rotor Disc 18 Rotor Blade 22 Stator Disc 24 Stator Blade 26 Side Connection 28 Pure Rotor Region 29 Pure Stator Region 30 Inlet 31 Inlet Flange 32 Outlet 34 Connection Region 36 Housing 40 Spacer Ring 46 Holbeck Rotor Sleeve 48 Holbeck Rotor Sleeve 50 Holbeck Stator Sleeve 52 Holbeck Stator Sleeve 54 Roller Bearing 56 Permanent Magnet Bearing 58 Stator Side Permanent Magnet Bearing Half 60 Rotor Side Permanent Magnet Bearing Half 62 Safety support 64 Splash nut 66 Absorbent disc 68 Drive motor P Pump direction R Rotating shaft

Claims (9)

A vacuum pump (10), in particular a turbomolecular pump,
At least one rotor (12), the rotor having a rotor shaft (14) and at least one rotor portion (16) provided on the rotor shaft (14), the rotor portion being circumferentially A plurality of rotor blades (18) distributed in the
Having at least one stator assigned to the rotor (12), the stator having at least one stator part (22) axially following the rotor part (16), the stator part being circumferentially A plurality of stator blades (24) provided in a distributed manner;
In this case, at least one pure rotor region (28) is provided in the axial region of the rotor (12), in which the side connection (26) is not open. In the vacuum pump (10) in which at least two rotor parts (16) are continuous in the rotor area without a stator part (22) located between them , the pure rotor area (28) A vacuum pump characterized in that an axial spacing is provided between the two rotor parts (16) . At least one pure stator region (29) is provided, in which at least two stator parts (22) are continuous without a rotor part (16) located between them, 2. A vacuum pump according to claim 1, characterized in that there is an axial spacing between the two stator parts (22) of the pure stator region (29). 2. The rotor part (16) is formed by a single rotor disk, each manufactured independently of the rotor shaft (14) and fixed to the rotor shaft (14). Or the vacuum pump (10) of 2. The pure rotor region (28) is provided in the axial direction immediately before or after the side connection (26) or in the vicinity of the side connection (26). The vacuum pump (10) according to any one of claims 1 to 3. A vacuum pump (10), in particular a turbomolecular pump,
At least one rotor (12), the rotor having a rotor shaft (14) and at least one rotor portion (16) provided on the rotor shaft (14), the rotor portion being circumferentially A plurality of rotor blades (18) distributed in the
Having at least one stator assigned to the rotor (12), the stator having at least one stator part (22) axially following the rotor part (16), the stator part being circumferentially A plurality of stator blades (24) provided in a distributed manner;
In this case, at least one pure stator region (22) is provided in the axial region of the rotor (12), in which the side connection (26) is not open. In the vacuum pump (10) in which at least two stator parts (22) are continuous without having a rotor part (16) located between them in the stator area, the pure stator area (29) A vacuum pump characterized in that an axial spacing is provided between the two stator parts (22). 6. Vacuum pump (10) according to any one of claims 1 or 5, characterized in that a lateral connection (26) is provided. The side connection (26) is provided between the inlet (30) and the outlet (32) of the vacuum pump (10), according to any one of the preceding claims. Vacuum pump (10). The vacuum pump (10) according to any one of claims 1 to 5, characterized in that the vacuum pump does not have a lateral connection. The stator portion (22) is provided between the first rotor portion (16) in the pump direction (P) and the second rotor portion (16) in the pump direction (P) in the axial direction. The vacuum pump (10) according to any one of claims 8 to 10.

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