EP1636496A1 - Rotary impeller for a turbomolecular pump - Google Patents
Rotary impeller for a turbomolecular pumpInfo
- Publication number
- EP1636496A1 EP1636496A1 EP04736844A EP04736844A EP1636496A1 EP 1636496 A1 EP1636496 A1 EP 1636496A1 EP 04736844 A EP04736844 A EP 04736844A EP 04736844 A EP04736844 A EP 04736844A EP 1636496 A1 EP1636496 A1 EP 1636496A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- impeller according
- blade
- impeller
- blades
- strip
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D19/00—Axial-flow pumps
- F04D19/02—Multi-stage pumps
- F04D19/04—Multi-stage pumps specially adapted to the production of a high vacuum, e.g. molecular pumps
- F04D19/042—Turbomolecular vacuum pumps
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/02—Selection of particular materials
- F04D29/023—Selection of particular materials especially adapted for elastic fluid pumps
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
- F05D2300/00—Materials; Properties thereof
- F05D2300/10—Metals, alloys or intermetallic compounds
- F05D2300/17—Alloys
- F05D2300/173—Aluminium alloys, e.g. AlCuMgPb
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
- F05D2300/00—Materials; Properties thereof
- F05D2300/40—Organic materials
- F05D2300/43—Synthetic polymers, e.g. plastics; Rubber
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
- F05D2300/00—Materials; Properties thereof
- F05D2300/40—Organic materials
- F05D2300/43—Synthetic polymers, e.g. plastics; Rubber
- F05D2300/436—Polyetherketones, e.g. PEEK
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
- F05D2300/00—Materials; Properties thereof
- F05D2300/60—Properties or characteristics given to material by treatment or manufacturing
- F05D2300/603—Composites; e.g. fibre-reinforced
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
- F05D2300/00—Materials; Properties thereof
- F05D2300/60—Properties or characteristics given to material by treatment or manufacturing
- F05D2300/611—Coating
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
- F05D2300/00—Materials; Properties thereof
- F05D2300/70—Treatment or modification of materials
- F05D2300/702—Reinforcement
Definitions
- This invention relates to a rotary impeller for a turbomolecular pump, such pumps being typically used to create vacuum environments for semiconductor processing.
- a standard turbomolecular pump includes a rotary impeller comprising arrays of (normally) angled blades arranged for rotation at high speed, for example up to sixty thousand revolutions per minute, between alternately arranged arrays of stationary blades of a stator.
- the blades of the stator are inclined in the opposite direction to those of the rotor.
- turbomolecular pumps gas is typically received from a high vacuum chamber, compressed and delivered to a backing pump, for example a multi-stage rotary pump.
- the backing pump is required as turbomolecular pumps normally operates with an exhaust pressure up to about 10 "1 mbar and so the use of the backing pump can provide backing pressures in this region and deliver pumped gas to the atmosphere.
- the pumping capacity of a turbomolecular pump is heavily dependent on the absolute speed that the blades are able to travel. This speed is limited by allowable stresses within the material of the impeller blades.
- the hub and blades of a rotary impeller of a turbomolecular pump are machined from a solid piece of lightweight metal, for example aluminium or one of its alloys.
- the present invention proposes alternative materials and methods of manufacture for rotary impellers for turbomolecular pumps.
- the present invention provides a rotary impeller for a turbomolecular pump, the impeller comprising a hub, a plurality of blades formed from a reinforced polymeric material, and means for attaching the blades to the hub.
- a number of advantages can be obtained from the use of reinforced polymeric materials in place of the metal materials conventionally used for the impeller blades.
- a first advantage is due to the lighter weight of the blades and superior strength to weight ratios in comparison to blades formed from metal. In view of this, a higher rotation speed can be achieved, and this can result in improved pump performance.
- a second advantage is that the impeller has a reduced rotational inertia in comparison to an impeller having metal blades. This can improve safety within the environment surrounding the pump during use, as in the event of an impeller seizure less energy is imparted to the pump stator.
- the polymeric material is reinforced by one of fibres and particles.
- these fibres or particles are preferably directionally aligned to provide greatest strength in the region and/or direction of the highest load acting on the blade during use of the impeller.
- a substantial proportion, for example 75 to 85%, of the fibres or particles are preferably aligned in a direction extending from the root to the tip of the blade.
- the polymeric material may be reinforced by carbon fibres, fibres or particles formed from glass or a ceramic material, or synthetic fibres, for example para- aramid, or KevlarTM, fibres.
- the polymeric material may be a matrix or epoxy, such as a polyetheretherketone.
- the blades are preferably in the form of lengths or strips of reinforced polymeric material attached to the hub of the impeller, using, for example, pins. These strips may be attached to the hub using a number of different techniques.
- each strip is bent to provide a pair of impeller blades, with the bend in the strip being located around a retaining pin fastened to the hub.
- the strip (prior to bending) may be shaped to have two substantially equally sized and parallel aligned end portions bridged by a central portion, the central portion being angled to the parallel line of the two end portions providing a dog-leg bend in the strip. In such an arrangement, the strip is bent along the central portion to provide the pair of impeller blades.
- each blade is formed from a respective strip, with the attachment means being located at or towards one end of the strip.
- the attachment means being located at or towards one end of the strip.
- a pin passes through a hole in one end of the strip.
- This end of the strip may be thickened or otherwise reinforced in the region surrounding the hole.
- each blade may comprise a pair of strengthening plates sandwiching one end of the strip, with the pin passing through holes formed in these plates. These holes may be machined at an angle, for example at an acute angle to a normal to the surface of the blade, corresponding to the angle of tilt the blade is desired to have to the plane of rotation of the impeller.
- the blade is secured in a position at an angle to the plane.
- the pin may attach a plurality of blades in different rows to the hub.
- an end of each blade may be fashioned to have a dovetail or similar shape.
- the dovetail is desirably configured to fit snugly into a similarly shaped slot provided in the hub.
- the dovetail may be provided from built up layers of the blade material.
- a dovetail of different material may be bonded to the blade. Where the dovetail portion is provided from a separate material, the separate material may be bonded or fastened to the end of the blade.
- generally flat blades may be bonded or otherwise fastened into pre-machined slots in the hub.
- Any of the blades previously described may further comprise a coating (for example a metal) selected to be non-reactive with chemicals passing through the pump in use.
- Figure 1 (a) illustrates a plan view of a first embodiment of a strip for forming blades for a rotary impeller for a turbomolecular pump, and Figure 1 (b) shows the strip of Figure 1 (a) bent to form the blades;
- Figure 2 illustrates a plan view of a second embodiment of a strip for forming blades for a rotary impeller
- Figure 3 illustrates a technique for attaching the blades of Figure 1 (b) to the hub of the impeller
- Figure 4 illustrates a perspective view of a third embodiment of a blade for a rotary impeller
- Figure 5 illustrates a perspective view of a fourth embodiment of a blade for a rotary impeller
- Figure 6 illustrates a technique for securing a fifth blade embodiment to the hub of the impeller.
- Figure 7 illustrates an embodiment a wherein individual pins are each used to secure more than one blade to the hub of the impeller.
- FIGS 1 to 7 illustrate various techniques for providing an impeller having blades formed from fibre or particle reinforced polymeric material attached to a hub of the impeller.
- each of the blades is formed from a strip of reinforced polymeric material attached to the hub.
- Figure 1 illustrates a strip 10 of fibre or particle reinforced polymeric material used for forming adjacent blades 12, 14 of a rotary impeller of a turbomolecular pump.
- the rectangular strip 10 is folded about the dashed line 16 shown in Figure 1 (a) to provide a substantially U-shaped, blade pair arrangement 18 shown in Figure 1 (b).
- Figure 2 shows a broadly similar embodiment to Figure 1.
- the strip 20 is not rectangular, but includes a dog-leg bend 22 in its centre portion. Similar to the first embodiment, the strip 20 is folded about the dashed line 24 across the dog-leg bend 22 to provide the substantially U-shaped, blade pair arrangement. This arrangement is advantageous over that shown in Figure 1 (b) in that the blade pair arrangement formed from the strip 20 has a reduced height compared to the arrangement of Figure 1 (b) formed from the rectangular strip 10.
- FIG 3 shows in section an example of how the previously discussed blade pair arrangements are attached to an impeller hub 26.
- the hub 26 is provided with a circumferential recess 28. Passing through the walls 30 bounding the recess 28 are holes or apertures 32 configured to receive a securing pin 34, about which the bend 36 in the blade pair arrangement 18 extends.
- the apertures 32 and pin 34 are so arranged in relation to the recess 28 and blade pair arrangement 18 that the blade pair arrangement 18 is securely pinned against an inner circumferential surface 38 of the hub 26.
- Figures 4 to 6 illustrate embodiments in which a blade 40, 50, 60 is formed from a single strip of material.
- a pair of reinforcing plates 42 are bonded or otherwise attached to one end of the blade 40.
- Two through holes 44 are drilled through the reinforced portion of the blade 40 at a slight angle to the plane of the widest surface of the blade 40. This angle corresponds to the desired angle of tilt of the blade 40 to the plane of rotation of the impeller.
- the through holes 44 are suitably shaped to receive locating pins 46 which, in use, would pass through apertures in the hub, similar to the pin 34 shown in Figure 3.
- the plates 42 may be metallic, for example high grade aluminium or titanium, but other materials may also be employed for this purpose.
- the plate material is selected to withstand reaction forces of the locating pins 46 on the blade 40 and other tensile and compressive loads congregating in the reinforced portion of the blade 40 when the impeller is run at operational speeds required for a turbomolecular pump.
- the blade 40 may simply be thickened in the region of the through holes 44.
- a plurality of blade rows may be arranged such that a single locating pin 46 can be used to locate a plurality of parallel aligned blades in different rows.
- a pair of keying plates 48 are bonded or otherwise attached to one end of the blade 50.
- the keying plates 48 may be located within a mould tool in which the blade 50 is cured.
- the keying plates 48 serve a dual purpose of reinforcing the blade 50 at its root and providing a keying means for attaching the blade 50 into a hub.
- the keying plates 48 are substantially dovetail-shaped, but these plates 48 may take any other shape that, desirably, includes a widening portion near the end of the blade.
- the material of the keying plates 48 and their dimensions are selected to withstand tensile and compressive loads congregating in the reinforced portion of the blade 50 when the impeller is run at operational speeds required for a turbomolecular pump.
- the keying plates 48 may be formed from a metallic material, for example high grade aluminium or titanium, or from non-metallic material, for example, layers of the same material from which the blade 50 is formed. So that any centrifugal load may be spread evenly across the keying plates 48, these plates 48 are designed to be substantially mirror images of each other.
- the hub is provided with machined key-holes each configured to receive the dovetailed end of a respective blade 50.
- the blades 50 may be friction fitted into these key-holes and/or bonded in position. Bonding may be through chemical means (for example, an adhesive) or physical means (for example, welding).
- the end of the rectangular blade 60 is simply fitted into a slot 62 formed in the hub 64. Adjacent the root of the blade 60 and to either side of the slot 62, the hub 64 is cut away, as indicated at 66, to provide for a reduction in dilation of the slot 62 should the hub 64 thermally expand during operation of the turbomolecular pump at normal operational speeds, and also to reduce the overall weight of the impeller.
- FIG. 7 shows a development of the embodiment of Figure 4.
- a plurality of blades 70 are arranged in parallel alignment about a hub 71 , and such that adjacent blades overlap in a vertical plane.
- a plurality of pins 72 extend vertically through holes 74 in the hub 71 , with each pin passing through two blades.
- each blade is secured at two ends and each pin secures two blades, thereby improving the security of the blades.
Abstract
Description
Claims
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GBGB0314692.5A GB0314692D0 (en) | 2003-06-25 | 2003-06-25 | Improvements in turbomolecular pumps |
PCT/GB2004/002495 WO2005001294A1 (en) | 2003-06-25 | 2004-06-15 | Rotary impeller for a turbomolecular pump |
Publications (1)
Publication Number | Publication Date |
---|---|
EP1636496A1 true EP1636496A1 (en) | 2006-03-22 |
Family
ID=27637232
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP04736844A Withdrawn EP1636496A1 (en) | 2003-06-25 | 2004-06-15 | Rotary impeller for a turbomolecular pump |
Country Status (5)
Country | Link |
---|---|
EP (1) | EP1636496A1 (en) |
JP (1) | JP2007516372A (en) |
GB (1) | GB0314692D0 (en) |
TW (1) | TW200506221A (en) |
WO (1) | WO2005001294A1 (en) |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4865321B2 (en) * | 2005-12-19 | 2012-02-01 | エドワーズ株式会社 | Vacuum pump |
RU2435076C2 (en) * | 2006-04-29 | 2011-11-27 | Ёрликон Лайбольд Вакуум Гмбх | Manufacturing method of rotors and stators of turbomolecular pump |
JP2014031734A (en) * | 2012-08-01 | 2014-02-20 | Edwards Kk | Component for vacuum pump, and vacuum pump |
DE202013002970U1 (en) * | 2013-03-27 | 2014-06-30 | Oerlikon Leybold Vacuum Gmbh | Tool for producing a multiple rotor blades having rotor disk and rotor disk |
DE102014203172A1 (en) * | 2014-02-21 | 2015-08-27 | Oerlikon Leybold Vacuum Gmbh | Coated CFRP surfaces of turbomolecular pumps |
US10393124B2 (en) | 2015-06-08 | 2019-08-27 | Leybold Gmbh | Vacuum-pump rotor |
GB2570925B (en) * | 2018-02-12 | 2021-07-07 | Edwards Ltd | Reinforced vacuum system component |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE4239391C2 (en) * | 1991-11-27 | 1996-11-21 | Electro Chem Eng Gmbh | Objects made of aluminum, magnesium or titanium with an oxide ceramic layer filled with fluoropolymers and process for their production |
DK98393D0 (en) * | 1993-08-31 | 1993-08-31 | Andersen F S As | A FAN ASSEMBLY |
US5938406A (en) * | 1997-04-18 | 1999-08-17 | Varian, Inc. | Rotor for turbomolecular pump |
JP2000220595A (en) * | 1999-01-27 | 2000-08-08 | Seiko Seiki Co Ltd | Vacuum pump device |
GB2367596A (en) * | 2000-10-06 | 2002-04-10 | Nmb | Fan rotor construction |
-
2003
- 2003-06-25 GB GBGB0314692.5A patent/GB0314692D0/en not_active Ceased
-
2004
- 2004-06-15 WO PCT/GB2004/002495 patent/WO2005001294A1/en active Application Filing
- 2004-06-15 JP JP2006516403A patent/JP2007516372A/en not_active Abandoned
- 2004-06-15 EP EP04736844A patent/EP1636496A1/en not_active Withdrawn
- 2004-06-24 TW TW093118324A patent/TW200506221A/en unknown
Non-Patent Citations (1)
Title |
---|
See references of WO2005001294A1 * |
Also Published As
Publication number | Publication date |
---|---|
WO2005001294A1 (en) | 2005-01-06 |
JP2007516372A (en) | 2007-06-21 |
GB0314692D0 (en) | 2003-07-30 |
TW200506221A (en) | 2005-02-16 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US6726443B2 (en) | Micromachines | |
US6290466B1 (en) | Composite blade root attachment | |
US3679324A (en) | Filament reinforced gas turbine blade | |
US6290465B1 (en) | Rotor blade | |
EP1596068B1 (en) | Vacuum pump | |
US3883267A (en) | Blades made of composite fibrous material, for fluid dynamic machines | |
US4722668A (en) | Device for damping blade vibrations in turbo-machines | |
US3720480A (en) | Rotor construction | |
EP2108844A2 (en) | Turbo vacuum pump | |
JP3098139B2 (en) | Compound molecular pump | |
EP1258634A1 (en) | Vacuum pump | |
WO2005001294A1 (en) | Rotary impeller for a turbomolecular pump | |
CN104791303A (en) | Housing with wear-resistant seal member for axial flow turbine compressor | |
CN103299083A (en) | Rotating body of vacuum pump, fixed member placed to be opposed to same, and vacuum pump provided with them | |
EP1998048A1 (en) | Molecular pump and flange | |
CN105008667A (en) | Turbomachine rotor blade, turbomachine rotor disc, turbomachine rotor, and gas turbine engine with different root and slot contact face angles | |
US3713752A (en) | Composite blade for a gas turbine engine | |
EP1085214A2 (en) | Vacuum pumps | |
KR20010053279A (en) | Turbo-molecular pump | |
WO2005121561A1 (en) | Vacuum pump impeller | |
US7645116B2 (en) | Turbo vacuum pump | |
CN107646076B (en) | Vacuum pump rotor | |
EP1167773A3 (en) | Turbo-molecular pump | |
CN107269320B (en) | Blade | |
US10865648B2 (en) | Turbine rotor blade assembly |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
17P | Request for examination filed |
Effective date: 20051028 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PL PT RO SE SI SK TR |
|
RIN1 | Information on inventor provided before grant (corrected) |
Inventor name: OKOROAFOR, EMMANUEL UZOMA Inventor name: SCHOFIELD, NIGEL PAUL Inventor name: LIU, MICHAEL CHUNG KAU Inventor name: HUNTLEY, GRAEME |
|
DAX | Request for extension of the european patent (deleted) | ||
RAP1 | Party data changed (applicant data changed or rights of an application transferred) |
Owner name: EDWARDS LIMITED |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN |
|
18D | Application deemed to be withdrawn |
Effective date: 20101230 |