JP2016114061A - Vacuum pump - Google Patents

Abstract

A vacuum that can overcome low pump housing temperatures and high gas loads during vacuum pump operation, can be used at high ambient temperatures, has low consumption in electrical output, and provides at least one of these advantages Provide a pump. A vacuum pump, particularly a turbomolecular pump, having at least one pumping mechanism for pumping gas along a pump channel 10 from an inlet 70 to an outlet of the vacuum pump, wherein the pump channel comprises at least one pump channel. It moves through the first gaps 83a, 83b, 83c, in which the pump function is exhibited during operation of the vacuum pump, and at least one second gap 85a is provided, In the vacuum pump in which the pump function is not exerted during the operation of the vacuum pump, and preferably the pump channel is moved through the second gap, the first gap is at least a factor of the first gap. It is larger than the gap. [Selection] Figure 1

Description

  The present invention is a vacuum pump, in particular a turbo-molecular pump, having at least one pump mechanism, which pumps gas along a pump channel that transitions from the inlet to the outlet of the vacuum pump. Wherein the pump channel has at least one first gap, in which the pump function is exerted during operation of the vacuum pump, and in which case at least one second gap The vacuum pump is characterized in that the pump function is not exhibited during operation of the vacuum pump in the gap, and preferably the pump channel transitions through the second gap. About.

  Vacuum pumps of the type described at the beginning usually provide high compression, high permissible pre-vacuum and / or short run-up times for minimizing process cycle times. However, for some applications (fields), the vacuum pump can only reach a low pump housing temperature during operation, can overcome high gas loads, can be used at high ambient temperatures, and / or Alternatively, it is advantageous to have a low consumption in electrical output, in particular at a pre-vacuum pressure of 1 to 10 mbar.

US Patent Application Publication No. 2013 / 0224001A1

  It is an object of the present invention to provide an improved vacuum pump that provides at least one of the advantages described above.

  This object is achieved by a vacuum pump having the features of claim 1, in particular a vacuum pump of the type described at the outset, in which the second gap is at least a factor of the first gap, in particular. Solved by being developed by being 2x, 3x, 4x, 5x, 6x, 7x, 8x, 9x, 10x larger.

  Within the second gap, the pump function is not realized or does not occur during the operation of the pump, so the second gap is the first gap (in which the pump function occurs during operation). Compared to the above, in the vacuum pump according to the present invention, it is formed larger as a ratio. This allows gas friction to be kept low, especially in the region of the second gap. Compared to the small formed second gap, the pump according to the invention can thus achieve a predetermined final pressure with lower consumption of electrical output. Due to the reduced power consumption, the vacuum pump does not heat as strongly during operation. This allows the temperature of the pump housing to be kept low during the operation of the vacuum pump, which is advantageous in many applications. In addition, the first gap (in which the pump function is exerted during operation of the vacuum pump, and thus the pump effect is generated) has a defined pump function, in particular a sufficiently high compressibility or a sufficiently high suction. The performance is made small so that it can be built up by the member forming the first gap.

  The second gap is preferably a gap through which the pump channel transitions. However, in that case, no pump function occurs in the second gap during operation of the vacuum pump. The ratio of the second gap is larger than that of the first gap (the pump function is generated during operation of the vacuum pump). The resistance to the gas to be transported can be kept low.

  The second gap can also be located outside the pump channel. The second gap can be, for example, a gap in the seal gas labyrinth. By forming the second gap as a ratio larger than the first gap, the gas friction generated in the second gap can be kept low. In this case, the second gap provided outside the pump channel can in particular be provided between the rotating member and the static member. Alternatively, the second gap can be formed between two static members, particularly when it is located outside the pump channel. Even if it is impossible for the second gap to be provided in the pump channel, there is a connection between the second gap and the pump channel for guiding the gas, for example a seal gas labyrinth. Is possible as in The second gap can be connected to the pump channel, in the form of a shunt, or can be connected to the pump channel and the gas.

  Preferably, the factor described above (which indicates the size ratio between the first gap and the second gap) relates to the width of the first gap or the second gap. The second gap thus has a width where the width of the first gap is greater than the width multiplied by the factor. The gap width is then measured through the gap, preferably perpendicular to the direction of transport of the gas to be pumped.

  Preferably, the concept of “gap” does not mean any short free space in the direction of the pump of the gas to be conveyed, or any short gap between two members of the vacuum pump, for example a part of the pump channel And / or a portion between two members, in particular having at least essentially the same width and extending over at least a predetermined length, for example over a length of at least 5 mm or at least 10 mm or at least 15 mm It means the part that is.

  By the description that the pump function is performed or caused within the first gap, it is meant that a pumping effect or pumping action occurs, particularly in the gap during pump operation. The gas to be pumped is thus actively transported through the gap and flows from the gap inlet to the gap outlet as well as along the pump channel.

  Preferably, the first gap is provided between the rotating member and the static member of the vacuum pump. In doing so, both members cooperate to cause pump function during the first gap during pump operation. The interaction between the rotating member and the static member provides a pumping action in the first gap.

  The second gap can be provided between two members of the vacuum pump. They do not cooperate to perform the pump function during pump operation. Preferably, both members with the second gap between them are a rotating member and a static member. However, both members then perform the pump function in the region of the second gap. Alternatively, both members can be static members.

  According to one embodiment of the present invention, all gaps (in which the pump function is not exerted) are at least more than the gap in which the pump channel travels and the pump function is exerted therein. Large by a factor. This effectively reduces gas friction along the pump channel and reduces the power consumption of the vacuum pump to achieve a predetermined final pressure. This is especially the case when a gap in which the pumping effect does not occur is provided in the pump channel or when the pump channel passes through this gap.

  The first gap is, for example, a Holbeck gap. The Holbeck gap is formed between the surface of the Holbeck rotor that generates the pumping effect and the surface of the Holbeck stator that generates the pumping effect.

  The second gap is, for example, the gap between the smooth surface of the Holbeck rotor (which forms, for example, the back side against the pumping surface of the Holbeck rotor) and the opposite smooth surface of the static member. As such, in a rotating Holbeck rotor, there is no pumping effect between the smooth back surface of the Holbeck rotor and the smooth surface of the static member, or in any case only a low pumping effect.

  In accordance with another aspect of the invention (as claimed in the independent invention), vacuum pumps, particularly turbomolecular pumps, have at least one pump mechanism. This is for pumping gas along a pump channel that transitions from the inlet to the outlet of the vacuum pump. In doing so, the pump channel moves through at least one first gap in which the pump function is exerted during operation of the vacuum pump. In that case, the pump mechanism has a Holbeck pump mechanism having a Holbeck rotor and a Holbeck stator. In this case, the first gap is a Holbeck gap, which is provided between the side surface of the Holbeck stator and the side surface of the Holbeck rotor. At that time, the Holbeck gap has a width narrower than 0.5 mm, preferably smaller than 0.3 mm, particularly at the rated rotational speed of the Holbeck pump mechanism.

  In particular, based on the narrow Holbeck gap, an early seal of the Holbeck pump mechanism is achieved at high pre-vacuum pressures (which can occur in the outlet area). Moreover, it is possible to achieve a lower excess current loss in the region of the Holbeck gap. This can improve the compression performance of the Holbeck pump mechanism.

  Preferably, a narrow Holbeck gap is used in a vacuum pump whose inlet has an inlet flange having a diameter of DN100 or DN160.

  In accordance with a preferred development of the invention, the pump mechanism has a Holbeck pump mechanism with only one Holbeck stage or a maximum of two Holbeck stages.

  In doing so, the vacuum pump is configured for more than two, especially nested, Holbeck stages, especially in terms of structural space, but in practice only one Holbeck stage or a maximum of two While a Holbeck stage has been realized, it can be intended that no other Holbeck stage has been realized, for example, due to a missing Holbeck stage or by omitting one of the two Holbeck rotors.

  Preferably, the pump mechanism has a Holbeck pump mechanism. The pumping surface has a total length shorter than 120 mm, preferably shorter than 95 mm, especially when viewed along the axial direction of the pump. This allows gas friction in the Holbeck pump mechanism to be minimized, thereby requiring less electrical power consumption of the vacuum pump.

  In accordance with a development of the invention, the Holbeck pump mechanism has at least one, preferably just one Holbeck rotor. The length is 60 mm at maximum in the axial direction of the pump, preferably 55 mm at maximum, and more preferably 48 mm at maximum. The Holbeck pump mechanism can thus be formed short in proportion in the axial direction. This causes lower gas friction in the Holbeck pump mechanism. This has an advantageous effect on the required electrical power consumption of the vacuum pump to achieve a predetermined final pressure.

  In accordance with another aspect of the invention (claimed as an independent invention), a vacuum pump, particularly a turbomolecular pump, pumps gas along a pump channel that travels from the inlet to the outlet of the vacuum pump. At least one pump mechanism. The pump mechanism then has at least one turbomolecular pump stage. This has a plurality of rotor disks fixed to the rotor shaft and a plurality of stator disks provided so as not to rotate between the rotor disks in the axial direction. The pump channel then extends through the turbomolecular pump stage. In this case, at least one rotor disk and / or at least one stator disk is omitted in the turbomolecular pump stage. As a result, the pump stage has free space at the location of the omitted rotor disk or stator disk.

  The vacuum pump thus provides more free space for the rotor disk and / or stator disk than is actually incorporated in the vacuum pump, and the corresponding free space instead of multiple disks omitted. Have By eliminating the rotor disk and / or the stator disk, gas friction in the turbomolecular pump stage can be reduced. The specified operation of the vacuum pump can thus be performed with lower power consumption. This prevents excessive heating of the vacuum pump and the current consumption of the vacuum pump can be reduced.

  Preferably, at least one disk pair (consisting of a stator disk adjacent to and cooperating with the rotor disk) is omitted. In particular, the omitted disk pair is the outermost disk pair of the turbomolecular pump stage located in the direction of the pre-vacuum. This is because the omission of this disk pair can provide a good compromise between the reduction of gas friction on the one hand and the compression or suction performance of the turbomolecular pump stage on the other hand. .

  Preferably, the rotor disk and / or the stator disk of at least one turbomolecular pump stage has a spherical disk shape. Alternatively, a stepped disk shape can be contemplated.

  According to one development of the invention, the vacuum pump has at least one, preferably exactly one, turbomolecular pump stage. This is provided with up to six rotor disks. In that case, the flange provided in the inlet of the vacuum pump has the flange diameter of DN100.

  According to another development of the invention, the vacuum pump has at least one, preferably just one, turbomolecular pump stage. This is provided with a maximum of four rotor disks, the flange which can be provided at the inlet of the vacuum pump having a flange diameter of DN160.

  In accordance with another aspect of the invention (claimed as an independent invention), a vacuum pump, particularly a turbomolecular pump, pumps gas along a pump channel that travels from the inlet to the outlet of the vacuum pump. And at least one pump mechanism, and an electric motor for driving the pump mechanism. In this case, the electric motor has a stator and a rotor that can rotate about a rotation axis and cooperates with the stator. In that case, the stator has a packet of steel sheet, and the reverse iron core of the rotor has a packet of steel sheet. And in that case, the steel sheets of the stator and / or rotor reverse core steel sheet packets are connected to each other by back lacquers (German: Backack) and are not welded to each other, or are bolstered. Absent.

  Since the stator and / or rotor steel sheet packets are bundled only by the back lacquer, welding or bundling is omitted, so that during the operation of the electric motor, eddy current losses in each steel sheet packet Can be minimized. This can reduce the heating of the electric motor and thus the heating during operation of the vacuum pump. Moreover, the required electrical power consumption of the electric motor to achieve a predetermined final pressure can be reduced.

  The steel sheet is in particular an iron sheet or an electrode sheet.

  According to one embodiment of the invention, each steel sheet of the stator and / or rotor sheet steel packet has a thickness of less than 0.4 mm, preferably less than 0.36 mm. With such a thin plate, the eddy current loss in the steel plate packet of the stator and / or rotor can be kept particularly low.

  Preferably, the electric motor has a maximum motor output located above a predetermined value, in particular at least essentially 10 watts, above the motor output intended for the specified operation of the vacuum pump. The electric motor thus has a relatively low drive output. This is especially so compared to electric motors used in vacuum pumps according to the prior art. They are configured for the shortest possible run-up time, and thus can provide more than 10 watts of power for the motor power required for the primary operating point.

  The reduction of the maximum motor output to a predetermined value, for example 10 watts, on top of a predetermined motor output for the prescribed operation of the vacuum pump, in particular, makes the electric motor compact. And, on the other hand, has the advantage that eddy current losses that occur during operation of the electric motor can be reduced. Moreover, the use of copper used on the side of the rotor, especially for the formation of electrical coils, can be reduced.

  The electric motor can be configured for a drive voltage of at least approximately 48 volts. In the vacuum pumps known from the prior art, the electric motor is usually configured for a drive voltage of 24 volts, so that the drive voltage is different from the normal drive voltage of 24 volts, depending on the variation of the electric motor according to the invention. And at least approximately doubled to 48 volts. In this case, preferably, the maximum drive voltage is the same as a safety small voltage of 50 volts (German: Sicherheitskleinspanung) in rail voltage operation (50 volts DC). The doubling of the drive voltage from 24 volts to 48 volts leads to a halving of the current flowing through the electric motor under the same power consumption, thereby reducing the drive loss.

  According to a preferred development of the invention, the vacuum pump has a sealing gas labyrinth with a maximum of three labyrinth stages. The vacuum pump can then be configured for more than three labyrinth stages, in which case a reduction to a maximum of three labyrinth stages is omitted for another labyrinth stage, and this (Notwithstanding the structural space intended for this purpose). In order to minimize gas friction, the labyrinth stage having the largest diameter is preferably omitted. This is because in this the relative speed between the rotor and the stator of the seal gas labyrinth is the highest and thus the friction loss is also highest.

  The reduction of the labyrinth stage is particularly caused when the sealing gas labyrinth is formed from a rotating surface, e.g. the surface of a radially extending member of the Holbeck rotor hub, and a static surface, e.g. a surface facing the rotor hub. And that both surfaces have a plurality of ring-shaped ridges that interpenetrate each other, where one surface has more ridges than the other surface. Is possible.

  In accordance with another aspect of the invention, it is contemplated that during operation of the vacuum pump, a lower seal gas flow (especially below a predetermined threshold, in particular 15 sccm) will flow through the seal gas labyrinth. Thereby, a reduction in rotor temperature can be achieved and the heat generated during operation of the pump is reduced.

  According to another aspect of the present invention, instead of a seal gas labyrinth, a Gode stage or a Ziegburn stage (German: Gaedestuffe, Siegbahnstuffe) can be used.

  The pump according to the invention can be a side channel pump or a side channel high vacuum pump. In that case, the side channel vacuum pump operates from the atmosphere to the high vacuum region and is usually a vacuum pump having a combination of a side channel pump and a Holbeck stage. The pump system of the side channel pump includes a rotor disk having a plurality of blades provided on the outer periphery, a ring-shaped working chamber, and a side channel. This side channel extends between the vane and the housing wall located outside the vane. The lateral channel is narrowed to the disc profile at one point by an interrupting element. The interrupting element separates the inlet provided in the side channel into the side channel from the outlet also provided in the housing. The pump effect is caused through a thread-shaped flow from the inlet to the outlet by the rotating rotor blades. This creates a pressure difference between the inlet and outlet. The lower final pressure can be achieved by the continuous connection of multiple pump stages.

  In the vacuum pump according to the invention, in particular, its maximum power consumption is reduced compared to the vacuum pumps known from the prior art, in particular this reduces the eddy current loss in the electric motor and reduces the vacuum pump. This is done by measures that lead to a reduction in the gas friction of the gas conveyed through. Since excessive heating of the vacuum pump during operation can be prevented thereby, the embodiment of the vacuum pump according to the invention is obviously used in combination with air cooling instead of complicated water cooling Is possible. Moreover, it is possible to use air-cooled at higher ambient temperatures (for example, temperatures higher than 40 degrees). Furthermore, higher gas loads can be overcome under the same power consumption.

  The present invention will now be described by way of example with reference to the accompanying drawings. The figure simplifies the following.

Cross-sectional view of variations related to the invention of the vacuum pump Sectional drawing of another variation which concerns on invention of a vacuum pump.

  The vacuum pump shown in FIG. 1 has a pump inlet 70 surrounded by an inlet flange 68 and a plurality of pump stages for conveying gas spanning the pump inlet through a pump channel 10 to a pump outlet 10 (not shown). . An outlet region 71 shown in FIG. 1 is opened in the pump outlet. In the illustrated example, the outlet region 71 is a portion of the pump channel 10 that is located at the end of the inner Holbeck stage downstream of the flow. The vacuum pump has a stator having a static housing 72 and a rotor provided in the housing 72. The rotor has a rotor shaft 12 that is rotatably supported about a rotation shaft 14.

  The vacuum pump is formed as a turbomolecular pump and has a pumping mechanism formed of a plurality of turbomolecular pump stages connected in series with each other and performing pumping. The turbomolecular pump stage includes a plurality of turbomolecular rotor disks 16 connected to the rotor shaft 12, and a turbomolecular plurality of stator disks 26 provided between the rotor disks 16 and fixed in the housing 72. Have. The stator disk 26 is held at a desired axial interval by a spacer ring 36. The rotor disk 16 and the stator disk 26 provide an axial pumping action in the direction of the arrow 58, i.e. the pumping direction, in the suction area 50 (German: Schöpferberich). The pump channel 10 extends through the turbomolecular pump stage and further through the Holbeck pump mechanism that follows the turbomolecular pump stage.

  The Holbeck pump mechanism has a plurality of Holbeck pump stages that are nested in each other in the radial direction (in German) and are serially connected to each other to perform pumping. The member on the rotor side of the Holbeck pump stage has a rotor hub 72 connected to the rotor shaft 12, a cylinder side-shaped Holbeck rotor sleeve 76, 78 fixed to and supported by the rotor hub 74. ing. These rotor sleeves are oriented coaxially with respect to the rotary shaft 14 and are telescopically connected. Further, two holbek stator sleeves 80 and 82 having a cylinder side surface shape are provided. They are likewise oriented coaxially with respect to the axis of rotation 14 and are nested in the radial direction.

  The pumping surface of the Holbeck pump stage is formed by the radial sides of the Holbeck rotor sleeves 76 and 78 and the Holbeck stator sleeves 80 and 82 facing each other forming a narrow radial Holbeck gap. Yes. In this case, the surface that produces one of the pumping effects (in this case, that of the Holbeck rotor sleeve 76 or 78) is formed smoothly and produces the opposing pumping effect of the Holbeck stator sleeves 80, 82. The surface has a Holbeck thread. The Holbeck thread portion has a plurality of grooves that transition in the axial direction about the rotation shaft 14 in a thread line shape. In these grooves, the gas is conveyed by the rotation of the rotor sleeves 76 and 78, and pumping is thereby performed.

  As shown in FIG. 1, the Holbeck gap 83 a transitions between the outer Holbeck stator sleeve 80 and the outer Holbeck rotor sleeve 76. The second Holbeck gap 83b transitions between the Holbeck rotor sleeve 76 and the inner Holbeck stator sleeve 82. The third Holbeck gap 83c transitions between the inner Holbeck stator sleeve 82 and the inner Holbeck rotor sleeve 78. At the downstream end of the Holbeck gap 83c, the pump channel 10 opens into the outlet region 71, through which the gas conveyed from the inlet 70 is pumped to the outlet (not shown). . On the radially inner side of the inner n Holbaek rotor sleeve 78, another gap 85a is provided. This gap opens to a shunt in the outlet region 71 and connects the outlet region 71 with the labyrinth seal 130. The gap 85a is thus not a member of the pump channel 10.

  In the represented variation, the gap 85a (in which at least essentially the pump function occurs during operation of the vacuum pump) is at least a predetermined factor, for example, 2, 3, 4, 5 It is larger than the Holbaek gaps 83a, 83b and 83c by double, six times, seven times, eight times, nine times or ten times.

  In the region of each Holbeck pump stage, basically a plurality of grooves form a pump channel for the gas to be pumped. The Holbeck pump stage then provides a pumping action, in particular based on the Holbeck thread, and carries the gas carried by the turbomolecular pump stage along the pump channel further through the Holbeck pump stage to the outlet. To do.

  The rotor shaft 12 is rotatably supported by a roller bearing 84 in the area of the pump outlet and a permanent magnet bearing 86 in the area of the pump inlet 70.

  The permanent magnet bearing 86 includes a rotor-side bearing half 88 and a stator-side bearing half 90. Each of these has one ring stack. The ring laminated portion is composed of a plurality of rings 92 and 94 of permanent magnets laminated together in the axial direction. In this case, the magnet rings 92 and 94 face each other while forming a radial bearing gap. The stator-side magnet ring 94 is carried by a stator-side carrying portion. This extends through the magnet ring 94 and is suspended by the column 108 of the housing 72. The magnet ring 94 on the stator side is fixed to the end of the magnet ring laminated portion facing the inside of the pump by a balance element 114 and a fixing ring 116.

  An emergency or safety support 98 is provided in the magnet support 86. This is formed as a non-lubricated roller bearing. During normal operation of the vacuum pump, the safety bearing 98 (German: Fanglager) stands up. This only intervenes when the rotor is excessively deflected radially with respect to the stator, forming a radial stop for the rotor. This stopper prevents the rotor-side structure from colliding with the stator-side structure.

  A conical splash nut 100 is provided on the roller shaft 12 in the region of the roller support 84. This has an outer diameter that increases towards the roller bearing 84. The splash nut 100 is in sliding contact with a skimmer (German: Abstriefer) of the working medium storage unit. It has a plurality of absorbent disks 102 that contain a working medium, such as a lubricant. During operation, the working medium is transmitted from the working medium reservoir through the skimmer to the rotating splash nut 100 by the capillary effect, and by centrifugal force, the roller bearing in the direction of the increasing outer diameter along the splash nut 100. 84. Therefore, for example, it exhibits a lubricating function. The roller bearing 84 and the working medium reservoir are surrounded by a tank-shaped insert 124 and a vacuum pump cover element 126.

  However, bearings for the rotor shaft 12 formed in other ways are also possible. For example, a 5-stage active magnet bearing could be provided for the rotor shaft 12.

  The vacuum pump has a drive motor 104 formed as an electric motor for rotationally driving the rotor. The rotor is formed by the rotor shaft 12. The control unit 106 drives the motor 104.

  A plurality of seals are provided between the individual components of the vacuum pump. Some of these seals are labeled 107 for illustration purposes.

  The vacuum pump further has a seal gas inlet 122 closed by a sealing element 120. This can connect a bearing part chamber for the roller bearing part 84 provided in the vacuum pump to the outside of the pump, and supply seal gas to the bearing part chamber via this.

  In the region between the rotor hub 74 and the separation wall 128 (the rotor shaft 12 extends through the separation wall while forming a radial gap), a rabbling seal 130 is formed. Such a labyrinth seal 130 is also referred to as a seal gas labyrinth. The seal gas labyrinth 130 is formed by a rotating surface 132 (which is formed on the rotor hub 74) and a static surface 134 (which is formed on the separating wall 128) that is complementary thereto. ing.

  The surfaces 132 and 134 have a plurality of ridges that are in the shape of a ring that interpenetrate each other. This is illustrated in FIG. In the vacuum pump of FIG. 1, since five ring-shaped ridges are provided on the surfaces 132 and 134, it can be said that this is a five-stage seal gas labyrinth.

  The basic structure of the vacuum pump in FIG. 2 corresponds to the structure of the vacuum pump in FIG. However, the vacuum pump of FIG. 2 is further optimized in terms of reduced power consumption. This keeps the pump heating (temperature rise) low, especially during operation during air cooling, keeps the current consumption of the vacuum pump low, and allows higher gas loads for the same power consumption It is to do.

  This is particularly true in the vacuum pump of FIG. 2 where the pair of rotor disk 16 and stator disk 26 located farthest from the pump inlet 70 in the turbomolecular pump stage on the opposite side of the pump inlet 70 is omitted. As a result, this is achieved by forming the free space 136 at the omitted location of the disk. Omission of the disk pair eliminates gas friction (gas friction along the pump channel 10 that travels through the pump stage) due to the transport of gas generated in this disk pair, thereby reducing the power consumption of the electric motor 104. Is required.

  In the vacuum pump of FIG. 2, the inner Holbeck rotor sleeve (see reference numeral 78 in FIG. 1) is omitted, so the vacuum pump of FIG. 2 has two telescopically connected Holbeck rotor sleeves 76. Has only one Holbeck pump stage. By reducing the Holbeck stage to, for example, two stages, gas friction can be reduced.

  As further shown in FIG. 2, the seal gas labyrinth 130 is reduced in three stages in the vacuum pump of FIG. This is because, in the surface 134 that produces the pump effect, on the side of the separation wall 128, instead of five ring-shaped ridges (see FIG. 1), only three ring-shaped ridges are provided. Done by being. Thus, both outer labyrinth stages are omitted in order to minimize gas friction within the seal gas labyrinth 130. This is because in these, the relative speed between the stationary separating wall 128 and the rotor hub 74 rotating during pump operation is the highest, and therefore the gas friction loss is the highest. Thus, gas friction can be reduced by eliminating the seal gas labyrinth stage. In addition, the power consumption required for the electric motor 104 to achieve a predetermined final pressure can be reduced.

  In the vacuum pump of FIG. 2, the electric motor 104 is an electric thin plate (German: Elektroblechen) which is covered by the back lacquer (German: Backack) and bound by the back lacquer. Have a packet. As a result, the steel sheets of each packet of steel sheets are connected to each other only by the back lacquer and are not bound by welding or brazing. The rotating packet of the electric thin plate is, in particular, the reverse iron core (or reverse C-shaped iron core, German: Eisenrueckschlus) of the electric motor 104. By coating the electrical sheet with the back lacquer, the electrical sheets are insulated from each other, which can reduce eddy current losses in the packet. A further reduction in eddy current loss is that each steel sheet of the rotor and stator reverse core steel sheet packet has a thickness of less than 0.4 mm, preferably less than 0.36 mm, and particularly preferably at least This is achieved by having a thickness of approximately 0.35 mm.

  In the vacuum pump of FIG. 2, the remaining holbeck rotor sleeve 76 is further shortened to 46 mm, for example, with respect to the axial direction of the vacuum pump, so that the pump is based on the two remaining holbeck pump stages. The effective length is 92 mm. The shortened pumping length of the Holbeck pump stage achieves a further reduction in gas friction and, consequently, a reduction in the power consumption of the electric motor 104 necessary to achieve a predetermined final pressure. The

  Furthermore, the electric motor 104 is configured so that its maximum motor output is at a maximum, 10 watts above the required motor output for its operating point, and / or it accepts a drive voltage of 48 volts. ing.

  In the vacuum pump of FIG. 2, the pump channel passes therethrough and also exists between the rotating and static members of the vacuum pump, both members being pumped. The gaps that cooperate to provide such are configured such that such gaps are at least a factor, e.g., five times smaller than gaps where the pumping effect of the vacuum pump does not occur. All gaps where the pumping effect does not occur are in particular gaps through which the pump channel travels and / or gaps between the movable and static members. However, it can also be a gap provided between two static members.

  For example, the Holbeck gap 83 a that moves between the outer Holbeck stator sleeve 80 and the outer Holbeck rotor sleeve 76 is also the same as the Holbeck gap 83 b that moves between the inner Holbeck stator sleeve 82 and the outer Holbeck rotor sleeve 76. However, the gap 85 extending radially inward of the Holbeck stator sleeve 82 is configured to be larger than the gap 83a and the gap 83b by, for example, a factor of five.

  In particular, it is particularly advantageous if the Holbeck gaps 83a and 83b are configured to have a width of less than 0.3 mm at the rated rotational speed of the Holbeck hub 74. This leads to low overcurrent losses in the Holbeck pump stage and in particular also to higher compression. As a result, the output performance of the vacuum pump can be improved.

10 Pump channel 12 Rotor shaft 14 Rotating shaft 16 Rotor disc 26 Stator disc 36 Spacer ring 50 Suction area (German: Schöpferberich)
58 Arrow 68 Inlet flange 70 Pump inlet 71 Outlet area 72 Housing 74 Rotor hub 76, 78 Holbeck rotor sleeve 80, 82 Holbeck stator sleeve 83a, 83b, 83c Holbeck gap 84 Roller bearing part 85 Gap 85a Gap 86 Permanent magnet bearing part 88 Rotor-side bearing half 90 Stator-side bearing half 92, 94 Permanent magnet ring 98 Safety bearing 100 Splash nut 102 Absorbent disc 104 Drive motor 106 Control unit 107 Seal 108 Strut 114 Balance element 116 Fixing ring 120 Sealing element 122 Seal gas inlet 124 Insert 126 Cover element 128 Separation wall 130 [Labyrinth seals 132, 134 Pumping surface 136 Space

Claims (15)

A vacuum pump, in particular a turbomolecular pump, having at least one pumping mechanism for pumping gas along the pump channel (10) from the inlet (70) of the vacuum pump to the outlet, wherein the pump channel (10) comprises: Transitions through at least one first gap (83a, 83b, 83c), in which the pump function is exerted during operation of the vacuum pump, and at least one second gap (85, 85a), in which the pump function is not exerted during operation of the vacuum pump, preferably in the vacuum pump in which the pump channel (10) transitions through the second gap,
The second gap (85, 85a) is at least a factor, in particular by a factor of 2x, 3x, 4x, 5x, 6x, 7x, 8x, 9x, or 10x. A vacuum pump characterized by being larger than (83a, 83b, 83c). A first gap (83a, 83b, 83c) is provided between the rotating member (76) and the static member (80, 82) of the vacuum pump, both members (76, 80, 82). Work together to realize the pump function during the operation of the vacuum pump and / or
A second gap (85, 85b) is provided between the two members (82, 128) of the vacuum pump, and these members do not cooperate to realize the pump function during operation of the vacuum pump. ,
2. The vacuum pump according to claim 1, wherein both members, in which the second gap (85, 85b) is provided, are a rotating member and a static member. All the gaps (85, 85a) where the pump function is not exhibited during the operation of the vacuum pump pass through the pump channel (10), and the pump function is exhibited during the operation of the vacuum pump. Larger than the gaps (83a, 83b) formed, preferably all gaps (85) where the pump function is not performed are gaps through which the pump channel (10) transitions. The vacuum pump according to claim 1 or 2. The vacuum pump according to any one of claims 1 to 3, wherein the first gap (83a, 83b, 83c) is a Holbeck gap. A vacuum pump, in particular a turbomolecular pump, having at least one pumping mechanism for pumping gas along a pump channel (10) transitioning from an inlet (70) to an outlet of the vacuum pump, wherein the pump channel (10) Transits through at least one first gap (83a, 83b, 83c), in which the pump function is exhibited during the operation of the vacuum pump, and the pump mechanism is connected to the Holbeck rotor (76). A Holbeck pump mechanism having a Holbeck stator (80, 82) is provided, and the first gaps (83a, 83b, 83c) are Holbeck gaps. And between the sides of the Holbeck rotor (76), in particular according to any one of the preceding claims. In the vacuum pump,
A vacuum pump characterized in that the Holbeck gap (83a, 83b, 83c) has a width smaller than 0.5 mm, preferably smaller than 0.3 mm, particularly at the rated rotational speed of the Holbeck pump mechanism. 6. A vacuum pump according to any one of claims 1 to 5, characterized in that the pump mechanism comprises a single Holbeck stage or a Holbeck pump mechanism having a maximum of two Holbeck stages. 2. The pump mechanism according to claim 1, wherein the pump mechanism has a Holbeck pump mechanism, and the pumping surface has a total length shorter than 120 mm, preferably shorter than 95 mm, when viewed in the axial direction of the pump. The vacuum pump according to any one of 6. In a vacuum pump, particularly a turbomolecular pump, having at least one pump mechanism for pumping gas along a pump channel that transitions from the vacuum pump inlet (70) to the outlet, the pump mechanism is fixed to the rotor shaft. Having at least one turbomolecular pump stage having a plurality of rotor disks (16) and a stator disk (26) non-rotatably provided between the rotor disks (16) in the axial direction, and a pump In a vacuum pump according to any one of claims 1 to 8, in which the channel (10) extends through a turbomolecular pump stage.
Since at least one rotor disk (16) and / or at least one stator disk (26) is omitted in the turbomolecular pump stage, the pump stage is omitted from the rotor disk or stator disk (16, 26). A vacuum pump characterized by having a free space (126) at the location of 9. A vacuum pump according to any one of the preceding claims, characterized in that the rotor disk (16) and / or the stator disk (26) of at least one turbomolecular pump stage has a spherical disk shape. The vacuum pump has one turbomolecular pump stage, preferably with just one turbomolecular pump stage, with a maximum of 6 rotor disks (16) and is provided in the inlet (70) of the vacuum pump (70) Has a flange diameter of DN100, or the vacuum pump has one turbomolecular pump stage with up to four rotor disks (16), preferably just one turbomolecular pump 10. A vacuum pump according to any one of the preceding claims, characterized in that the flange provided on the vacuum pump inlet (70) has a flange diameter of DN160. A vacuum pump having at least one pump mechanism for pumping gas along a pump channel (10) transitioning from an inlet (70) to an outlet of the vacuum pump and an electric motor (104) for driving the pump mechanism In particular, in a turbomolecular pump, the electric motor (104) has a stator and a rotor that rotates about the axis of rotation in cooperation with the stator, the stator has a packet of steel sheet, and / or Or in the vacuum pump according to any one of claims 1 to 10, wherein the rotor iron core has a steel sheet packet, and / or the rotor steel sheet packet of the rotor iron core and / or The steel sheets of the stator packet of the electric motor (104) are connected to each other by a back lacquer. Beauty not been welded together, or studs wherein the vacuum pump has not been fastened. Each steel sheet of the stator of the electric motor and / or the steel sheet packet of the rotor has a thickness of less than 0.4 mm, preferably less than 0.36 mm. The vacuum pump according to claim 11. The electric motor (104) is characterized in that it has a maximum motor power which is above the motor power intended beforehand for the specified operation of the vacuum pump by a predetermined value, in particular at least essentially 10 watts. The vacuum pump according to claim 11 or 12. 14. A vacuum pump according to any one of claims 11 to 13, characterized in that the electric motor (104) is configured for a drive voltage of at least approximately 48 volts. A sealing gas labyrinth (130) having a maximum number of labyrinth stages, in particular having a maximum of three labyrinth stages, is provided, the sealing gas labyrinth (130) comprising a rotating surface (132) and a static surface ( 134), both surfaces (132, 134) having a plurality of ring-shaped ridges that interpenetrate each other, one of the surfaces (132) having more ridges than the other surface (134). The vacuum pump according to claim 1, wherein the vacuum pump is provided.

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