JP6153579B2 - Method of manufacturing rotor disk or stator disk for vacuum pump and rotor disk or stator disk for vacuum pump - Google Patents

Description

  The present invention relates to a method for the production of a rotor disk or stator disk for a vacuum pump and to a rotor disk or stator disk for a vacuum pump.

  Many successful types of molecular pumps are based on a disk in which a plurality of vanes are attached to a carrier ring that sits on a high-speed rotating shaft. For example, a so-called turbo molecular pump in which a rotor disk and a stator disk exist alternately is an example. The shape of the blade has a great influence on the performance data and durability of the pump.

  Many types of rotor disks or stator disks are known from the prior art. The flowing structure consists of a thin plate that is pressed to produce a circular disk with a plurality of radial slits during manufacture. The radial slit is provided only over the outer part. The portions existing between the slits are bent, that is, protruded out of the disk surface, resulting in a plurality of blades. This solution is shown in Patent Document 1.

  Patent Document 2 belongs to a friction vacuum pump in which stator blades and rotor blades are formed. The stator blade is formed from a thin plate. During manufacture, the blades are suitably twisted to have an increasing height from the inside to the outside (German: geschraenkt). The rotor blades are adapted accordingly. Thereby, the gap between the vanes is constant and as small as possible.

  The twisting of the blades (German: Schraenken) has the disadvantage that a material change is caused. This significantly limits the stability of the blade.

  This often causes problems, especially in vacuum pumps, for example turbomolecular pumps with very high rotational speeds. This is because the thin plate is formed extremely thin. This prevents the disk from being exposed to high speed rotation. This is because the material load is too high at the foundation of the blade.

  From practice, in the rotor disk or stator disk, the blade angle is changed in order to adjust the degree of overlap between the individual blades and the so-called optical density (German: Dichtheit). Is also known. The disk surfaces are then oriented parallel to each other. Such technical possibilities for manufacturing often limit the change of the vane angle so that the vane overlaps once more at its inner diameter and no longer optically at its outer diameter. It is not dense (German: dict). The disadvantage here is that in order to achieve optical density at the outer diameter of the disc, the vane angle needs to be chosen very flat on the outside, which is open. The structure is made smaller and the suction capacity is limited accordingly.

  Disseminated solutions known from practice (solutions in which the disc is manufactured from sawing a channel formed from a solid material and tilted with respect to the disc surface) have a manufacturable shape Has the disadvantage of being limited by For example, it is difficult to create a steep angle of attack (German: Anstelwinkel) on a blade foundation. This is because the saw contacts the outer member of the blade.

German Patent Application Publication No. 100 52 637 German utility model 297 15 035 specification

  The technical problem on which the present invention is based is a method for the production of a rotor disk or a stator disk, which makes it possible to optimize the overlap of the blades and, accordingly, to improve the compressibility and the suction capacity It is to provide a method of being. Furthermore, a rotor disk or stator disk having a very good suction capacity and a very good compressibility should be provided.

  This technical problem is solved by a method having the features of claim 1 and a rotor disk or stator disk having the features of claim 7.

  A method according to the invention for the manufacture of a rotor disk or stator disk for a vacuum pump, wherein the rotor disk or stator disk is formed from a blank made of solid material and inclined with respect to the disk surface The method produced by the channel sawing is distinguished in that at least one disk surface of the blank is formed in radial symmetry before channel sawing.

  According to this embodiment, it is possible to implement, for example, a rotor disk or a stator disk in a convex spherical shape. It is possible to optimize the overlap of the blades by the curvature, which is a radial synonym. The overlap can be positive, “zero” (that is, the disc is barely optically dense in the axial direction), or negative (ie, in the axial direction, the predetermined It is also possible that a gap exists between the vanes).

  In accordance with an advantageous embodiment of the invention, both disc surfaces are bent in radial symmetry. In this embodiment, the blade shape of the stator disk or rotor disk is formed according to the required requirements, i.e. with a positive overlap, with a negative overlap or "zero". It has the merit that it can be formed with an overlap.

  As already explained, the disk surface can be formed in a convex spherical shape. However, there is also the possibility of implementing the disk surface in a concave spherical shape. The choice of this embodiment also depends on how the final disk shape or overlap should be formed.

  Another embodiment of the present invention contemplates that at least one disk surface has a curvature with a radius or a curvature with multiple radii. This also makes it possible to obtain a desired disk shape. For example, the degree of overlap of the disks can be adjusted by the sphericity. Here, the sphericity is selected here so that the disc has the desired overlap of the positive areas, the overlap of the negative areas, or the “zero” overlap.

  According to another advantageous embodiment of the invention, a step is provided on the outer diameter part of the stator disk. This step serves to allow the disk to be placed between the spacer rings inside the vacuum pump, regardless of its thickness at the outer diameter.

  Another advantageous embodiment of the invention contemplates that the disk portion at the outer diameter of the stator disk has a thickness that is thinner or thicker than the convex spherical or concave spherical disk portion. This also allows the vanes to be made optically dense only at the inner diameter, but optically transparent at the outer diameter, or vice versa.

  In accordance with another embodiment of the invention, the thickness of the rotor or stator disk is configured to decrease from the inside to the outside in the blank. In accordance with another embodiment of the invention, the thickness of the rotor disk or stator disk is configured to increase from the inside to the outside in the blank. When formed so as to increase from the inside toward the outside, a structure that is open toward the outside due to optical density in the axial direction occurs without considering the blade angle.

  In addition to the thickness of the blank inside, i.e. near the axis, and outside, i.e. in the direction of the spacer ring, the radius, e.g. convex or concave spherical radius, is also a factor affecting the overlap of the blades. .

  According to another advantageous embodiment of the invention, the blank is processed by high-speed cutting (high-speed-cutting). In high speed cutting, material is removed, i.e., channels are formed in the blank, while no pressure is exerted on the blank. This has the advantage that the strength of the stator blades or rotor blades that are finally produced is not reduced.

  A rotor disk or stator disk according to the invention for a vacuum pump, wherein the rotor disk or stator disk is a plurality of channel saws formed from a blank made of solid material and inclined with respect to the disk plane What is produced by grinding stands out in that the at least one disk surface of the blank is formed in radial symmetry before the sawing of the channels.

  This aspect of the rotor disk or stator disk optimizes the blade overlap regardless of the blade angle. The overlap can be positive, “zero”, or negative.

  According to another advantageous embodiment of the invention, both disk surfaces are formed in radial symmetry. This means that both sides of the disk are bent when viewed in the axial direction of the disk. The disk surface can have a mirror-symmetric curvature. However, it is also possible to form the bends on both disc surfaces differently. For example, one surface can be formed in a convex spherical shape, and the other surface can be formed in a concave spherical shape.

  According to another advantageous embodiment of the invention, it is possible for at least one disk surface to be formed in a convex spherical or concave spherical shape. With this implementation, the blade overlap can be selected according to the requirements of the finished disc.

  According to another advantageous embodiment of the invention, it is possible for at least one disk surface to have a radius of curvature or a radius of curvature. This also allows the degree of overlap to be selected and the suction capacity to be optimized with respect to the disk requirements.

  According to a particularly advantageous embodiment of the invention, a stepped portion is provided on the outer diameter of the stator disk. This step ensures that the stator disk is accommodated between the pump spacer rings regardless of thickness.

  According to another embodiment of the invention, the disk portion in the outer diameter portion of the stator disk has a thickness that is thinner or thicker than the convex spherical or concave spherical disk portion. This also makes it possible, for example, to make the blades optically dense only on the outside but optically transparent on the inside, or the blades are optically dense only on the inside, and It can be formed to be optically transmissive on the outside.

  “Inside” means the direction of the inner diameter portion of the disc, and “outside” means the direction of the outer diameter portion of the disc.

  In accordance with a possible embodiment of the invention, the thickness of the rotor or stator disk is designed to decrease from the inside to the outside in the blank. There is also the possibility that the thickness of the roller disk or stator disk is formed so as to increase from the inside to the outside in the blank. As a result, for example, the structure opened outwards without taking into account the blade angle results in optical density in the axial direction.

  According to a particularly advantageous embodiment of the invention, the stator disk or rotor disk is formed as a stator disk or rotor disk processed by high-speed cutting. High speed cutting removes the material for channel formation in the absence of pressure so that the workpiece is never exposed to stress or the like. The stator disk or rotor disk thus completed has a particularly high stability.

  In accordance with a preferred embodiment of the invention, the stator disk or rotor disk has an index between 0 and -0.2 (German: Kennzahl) after channel sawing (German: Einsagen). In this case, the disc is optically dense. These discs have very good compressibility.

  According to another advantageous embodiment of the invention, the disc is formed completely optically dense. This also ensures a very good compression condition for the disc.

  According to another advantageous embodiment, the disc is optically densely formed at the outer or inner diameter. As a result, a very good suction capability is achieved according to the application type.

  When the rotor disk has a thicker thickness at the outer diameter than the inner diameter and the thickness of the outer diameter is significantly different from the thickness of the inner diameter, It leads to strength problems based on high centrifugal force due to weight concentration. When the stator disk has the described spherical shape and the rotor disk is correspondingly concavely formed, a structure is formed that is optically open outwards in the rotor disk. Since the rotor blades are thinner towards the outside and thus lighter, the centrifugal force on the rotor disk decreases at the same rotational speed. Alternatively, the rotor disk can rotate at a higher speed. In doing so, the disk material is not subjected to a load beyond its original extent. This improves the compressibility and suction capacity, so that in some cases the reduction in these values caused by the open rotor disk structure is offset or even reduced.

  Additional features and advantages of the present invention will occur based on the accompanying drawings. In the drawings, several embodiments of a stator disk or rotor disk are shown only by way of example. The figure shows:

The top view of the disc blank which concerns on invention. 1b is a cross-sectional view taken along line I-I of FIG. The top view of a stator disk. FIG. 2b is a cross-sectional view taken along line II-II in FIG. 2a. Modified example. The top view of a rotor disk. FIG. 5 is a sectional view taken along line AA in FIG. 4. The side view of a rotor disk. The top view of a rotor disk. Sectional drawing according to line BB of FIG. Sectional drawing according to line CC of FIG. FIG. 8 is a sectional view taken along line DD in FIG. 7. The figure for derivation | leading-out for determining the opening property of a turbo shape. FIG. 6 is a top view of a modified embodiment of a stator disk. FIG. 12b is a cross-sectional view taken along line XII-XII of FIG.

  1a and 1b show a blank 11 (German: Rohling) for the stator disk 1. FIG. This is formed in a convex spherical shape. The thickest disc thickness is located at the outer diameter portion 3. In the inner diameter portion 2, the blank 11 has a thickness h1. In the outer diameter part 3, the blank 11 has a thickness h2.

  The blank 11 has a convex spherical shape. Prior to forming the channels for the stator blades or rotor blades, the blank 11 is formed into a final convex spherical shape. That is, the blank 11 has the outer contour of the final finished stator or rotor disk prior to the formation of channels for the stator or rotor blades.

  The blank 11 is formed from a convex spherical blank that is formed into a final convex spherical shape prior to the formation of channels for the stator blades or rotor blades. That is, the blank 11 has the outer contour that the final finished stator or rotor disk has before the formation of the channels for the stator or rotor blades.

  Depending on the implementation of the thicknesses h1 and h2 and the convex spherical radius R, the overlap of the blades can be optimized irrespective of the blade angle. The overlap can be positive, can be "zero" (the disc is barely optically dense in the axial direction), or it can be negative (axial) (Predetermined gap between the blades during direction observation).

  d1 determines the diameter of the inner diameter portion of the disk. Up to the diameter d2, the disk is formed parallel to the surface. Between the diameters d2 and d3, the disk 1 has a radius of curvature R, which is a radial synonym. Between the diameters d3 and d4, the disc is again formed plane-parallel. This is because, for example, it is accommodated between spacer pieces (not shown) of the turbo molecular pump.

  This results in an open structure with axial optical density, regardless of the blade angle on the outside.

  Depending on the choice of thickness and radius, the vanes can be formed to be optically dense only on the outside, but optically transparent on the inside. Similarly, it is possible to make the vanes optically dense only on the inside, but optically transparent on the outside.

  FIG. 1 a shows a disc blank 11. The disc blank 11 has a hole in the center for accommodating the saw processing portion.

  FIGS. 2 a and 2 b show a top view of a disk 1 having an inner diameter part 2 and an outer diameter part 3 and a blade 4. The stator disk 1 is completely optically dense in the axial line-of-sight direction. That is, the plurality of blades 4 overlap to the outer diameter portion 3 in the line-of-sight direction in the drawing plane of FIG.

  FIG. 3 shows a partial cross-sectional view of the stator disk 5. The stator disk 5 again has a convex spherical cross section with a radius R. The outer diameter portion 3 of the stator disk 5 is provided with a stepped portion. In order to dispose the stator disk 5 between the spacer rings (not shown) of the vacuum pump (not shown), the stepped portions are formed in plane parallel. It is advantageous if the stator disk is formed in the vacuum pump with the spherical shape described in accordance with the formation of the stator disk 5. Since the rotor disk can be correspondingly concavely formed, a structure is formed in the rotor disk that is optically open towards the outside. Since the rotor blades are thinner toward the outside and thus lighter, the centrifugal force on the rotor disk becomes smaller at the same rotational speed. Alternatively, the rotor disk can rotate at higher speeds without loading the disk material beyond its original extent. This enhances compressibility and suction capacity so that in some cases the reduction in these values caused by the rotor disk structure is offset or even reduced open.

  Even in a concave spherical shape, the blank is produced in a concave spherical shape in its complete shape. After this manufacture, only channels for the formation of stator disks or rotor disks are further formed.

  FIG. 4 shows a rotor disk 7 having a plurality of blades 8. In the region of the outer diameter portion 3, the overlap of the plurality of blades 8 is not provided. The blades 8 are not optically dense here. In the direction of the inner diameter 2, the plurality of blades 8 overlap and the rotor disk is optically dense.

  FIG. 5 shows a cross section of the rotor disk 7. In FIG. 5, it can be seen that the rotor disk 7 has a convex spherical shape. This shape was previously provided in the blank for the rotor disk 7 before the channel 9 (FIG. 4) was formed.

  FIG. 6 shows the rotor disk 7. Individually, the convex spherical shape of the rotor disk 7 can also be seen.

  FIG. 7 shows another rotor disk 10 having a plurality of blades 4. The vanes 4 are arranged optically permeable to one another in the region of the outer diameter part, while being optically dense in the direction of the inner diameter part 2.

  8, 9 and 10 show cross sections along lines BB, CC and DD in FIG. The convex spherical shape of the stator disk 10 can be seen.

  FIG. 11 shows two stator blades or rotor blades 4. These have an opening angle α. The length of the blade is given the reference sign b. The blade height h is denoted by h.

  The width of the blade is the length SD.

  The openability of the blade is determined as follows.

  Openness is defined as the ratio of the area / path (of the “transparent” part in the axial direction) d that is not at least single covered by the active rotor structure to the total path / area filled by the rotor structure. As long as the value is negative, the path / area part is covered not only by a single layer but also by two adjacent rotor blades.

  Optical density occurs when the openness at all possible diameters is "zero" or less. However, part and manufacturing tolerances should also be taken into account, so that optical density that can be reliably produced can only occur for a value slightly less than "zero". .

  The invention stands out in that the stator disk 5 or the rotor disks 7, 10 are produced by a lathe as a fully closed disk (German: gedreht). Subsequently, when a spherical shape, for example the convex spherical shape or the concave spherical shape of the stator disk 5 or the rotor disk 7, 10, is created, the channel 9 is sawed (German: Saegen), for example by high speed cutting. Formed in the disks 5, 7, 19.

  FIGS. 12 a and 12 b show a stator disk 5 having a plurality of blades 4. The blade | wing 4 does not overlap in an outer diameter part. In the inner diameter part 2, the blades slightly overlap.

  The disc 5 is optically transmissive according to FIGS. 12a and 12b.

DESCRIPTION OF SYMBOLS 1 Stator disc 2 Inner diameter part 3 Outer diameter part 4 Blade 5 Stator disk 6 Step part 7 Rotor disc 8 Blade 9 Channel 10 Rotor disc 11 Blank 12 Disc surface 13 Disc surface h1 Thickness h2 Thickness R Radius d1 Diameter d2 Diameter d3 Diameter d4 Diameter b Blade length h Blade height S Blade spacing SD Blade width

Claims (10)

A method for manufacturing a rotor disc or stator disc for a vacuum pump, the rotor disc or stator disc is made of a solid material by sawing a plurality of channels formed inclined with respect to the disk surface In a method made from a blank, at least one disk surface of the blank (11) is radially directed from the inner diameter part (2) to the outer diameter part (3) prior to sawing of the channel (9). It is formed to have an extended convex spherical or concave spherical curved disk portion, and in this curved disk portion, the thickness increases radially from the inner diameter portion (2) to the outer diameter portion (3). Or a method of reducing . Both disc surfaces (12, 13) are formed with a curved disc portion extending radially from the inner diameter portion (2) to the outer diameter portion (3) , the other disc surface (12 , 13) is formed in a convex spherical shape or a concave spherical shape so that the thickness increases or decreases in the radial direction from the inner diameter portion (2) toward the outer diameter portion (3). The method according to claim 1. Curved disc portion of the at least one disk surface (12, 13) A method according to claim 1 or 2, characterized in that it has a curvature with one radius or multiple radii. The outer diameter of the stator disc (1,5) in (3), the disc portion, claim 1, characterized in that it comprises a thin or thicker than the disk portion curved convexly spherical or concave spherical 3 The method according to any one of the above. A rotor disc or stator disc for a vacuum pump, the rotor disc or stator disc is, in those having a plurality of channels formed inclined with respect to the disk surface, at least one disk surface (12, 13) Is formed to have a convex spherical or concave spherical curved disk portion extending radially from the inner diameter portion (2) to the outer diameter portion (3), and in this curved disk portion, A rotor disk or stator disk characterized in that the thickness increases or decreases in the radial direction from the inner diameter part (2) toward the outer diameter part (3) . Both disc surfaces (12, 13) are formed with a curved disc portion extending radially from the inner diameter portion (2) toward the outer diameter portion (3) , the other disc surface The curved disk portion of (12, 13) is formed in a convex spherical shape or a concave spherical shape so that the thickness increases or decreases in the radial direction from the inner diameter portion (2) toward the outer diameter portion (3). The rotor disk or stator disk for a vacuum pump according to claim 5 . 7. Vacuum according to claim 5 or 6 , characterized in that the curved disk part of at least one disk surface (12, 13) has a curvature with one radius (R) or a curvature with a plurality of radii. Rotor disk or stator disk for the pump. The outer diameter of the stator disc (5) in (3), the disc portion, any one of claims 5, characterized in that it comprises a thin or thicker than the disk portion curved convexly spherical or concave spherical 7 A rotor disk or stator disk for the vacuum pump according to one item. Disk (1,5,7,10) is a rotor disk or stator disc for a vacuum pump according to any one of claims 5 to 8, characterized in that it is completely optically dense form . Disk (1,5,7,10) is an outer diameter portion (3), or that it is optically dense form in the direction of the inner diameter portion (2) from 9 to claim 5, wherein Rotor disk or stator disk for the described vacuum pump.

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