WO2020099834A1 - Moteur en tant qu'étage d'entraînement moléculaire - Google Patents

Moteur en tant qu'étage d'entraînement moléculaire Download PDF

Info

Publication number
WO2020099834A1
WO2020099834A1 PCT/GB2019/053149 GB2019053149W WO2020099834A1 WO 2020099834 A1 WO2020099834 A1 WO 2020099834A1 GB 2019053149 W GB2019053149 W GB 2019053149W WO 2020099834 A1 WO2020099834 A1 WO 2020099834A1
Authority
WO
WIPO (PCT)
Prior art keywords
stage
molecular drag
gap
accordance
rotor shaft
Prior art date
Application number
PCT/GB2019/053149
Other languages
English (en)
Inventor
Alexander James PATEY
Richard Glyn Horler
Original Assignee
Edwards Limited
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Edwards Limited filed Critical Edwards Limited
Priority to EP19804785.4A priority Critical patent/EP3880969A1/fr
Publication of WO2020099834A1 publication Critical patent/WO2020099834A1/fr

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
    • F04D19/044—Holweck-type 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
    • F04D19/00—Axial-flow 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
    • 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
    • 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
    • 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
    • F04D19/046—Combinations of two or more different types of 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
    • F04D25/00—Pumping installations or systems
    • F04D25/02—Units comprising pumps and their driving means
    • F04D25/06—Units comprising pumps and their driving means the pump being electrically driven
    • F04D25/0606—Units comprising pumps and their driving means the pump being electrically driven the electric motor being specially adapted for integration in the pump
    • 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
    • F04D29/58—Cooling; Heating; Diminishing heat transfer
    • F04D29/5806—Cooling the drive system

Definitions

  • the present invention relates to a molecular drag stage, preferably for a turbo- molecular pum p.
  • the present invention further relates to a turbomolecular pum p with such a m olecular drag stage.
  • turbom olecular vacuum pum ps com prise a housing form ing an inlet and an outlet. I n the housing a m otor is arranged in order to rotate a rotor shaft.
  • the turbomolecular vacuum pum p comprises a turbom olecular stage where veins are interacting with a stator in order to convey a gaseous medium from the inlet towards the outlet.
  • the turbomolecular stage is followed by a m olecular drag stage such as a Holweck stage.
  • Known m olecular drag stages com prise a rotating cylinder close to a stator with a narrow gap in between wherein either the stator or the cylinder has a threaded groove or a thread.
  • the present technical problem is solved by a m olecular drag stage in accordance to claim 1 as well as a turbomolecular pump in accordance to claim 1 1 .
  • a m olecular drag stage in accordance with the present invention comprises a housing with an inlet and an outlet.
  • a rotor shaft is rotatably supported within the housing.
  • the m olecular drag stage further com prises an electric motor within the housing, wherein the m otor is built by a m otor stator surrounding the rotor shaft in order to rotate the rotor shaft.
  • a small gap is defined between the outer side of the rotor shaft and the inner side of the m otor stator, such that the rotor shaft and the motor stator are contact-free and the rotor shaft is rotatable within the motor stator.
  • the outer side of the rotor shaft or the inner side of the m otor stator com prises a thread or a threaded groove in order to convey a gaseous m edium from the inlet to the outlet.
  • one of the outer side of the rotor shaft or the inner side of the m otor stator com prises a thread or a threaded groove while the opposite surface is sm ooth.
  • the motor itself of the molecular drag stage is adapted to actively convey the gaseous m edium towards the outlet.
  • a heat build-up in the m otor is pre vented and the efficiency of the molecular drag stage is enhanced by utilizing the motor itself as active elem ent for conveying the gaseous medium .
  • the in nerm ost side of the motor stator together with the outer side of the rotor shaft thus is building an additional molecular drag stage.
  • m olecules of the gaseous medium are conveyed by a molecular drag process.
  • At least one further pum p stage built as m olecular drag stage is im plem ented wherein the pum p stage comprises a rotor elem ent connected to the rotor shaft to interact with a non-rotating pump stator elem ent to convey the gaseous m edium from the inlet to the outlet.
  • the rotor elem ent m ay be built as cylindrical elem ent surrounded by or surrounding the pum p stator element.
  • either the rotor element or the pump stator element comprise a thread or threaded groove to build a m olecular drag stage.
  • a sm all gap is defined between the rotor element and the pum p stator for a contact-less rota tion of the rotor element, in order to convey a gaseous m edium from the inlet towards the outlet.
  • At least two and preferably four further pum p stages are imple mented wherein m ore preferably neighboring pum p stages share a com mon rotor element and convey the gaseous medium in opposite directions.
  • the outer surface of the rotor element may belong to a first pum p stage wherein the inner surface of the sam e rotor elem ent m ay belong to the neighboring pum p stage, in order to achieve a compact design of the molecular drag stage.
  • the gap between the outer side of the rotor shaft and the inner side of the m otor stator defines an entrance through which the gaseous medium enters into the gap and an exit through which the gaseous medium leaves the gap, wherein the entrance is in fluid com m unication with an exit of the last pum p stage and the exit of the gap is preferably in direct fluid com m unication with the outlet.
  • the gaseous m edium is first flowing to one or further pum p stages built by respective rotor elem ents and pum p stator elem ents, and after this the gaseous medium is conveyed through the gap formed by the electric motor towards the outlet.
  • the active gap of the electric m otor is utilized for conveying the gaseous m edium through the outlet.
  • a pressure is below 30m bar and more preferably below 10 2 m bar .
  • a pressure is equal to the pressure of the environment or below. More preferably the pressure at the exit is between l OOm bar and 0.02m bar.
  • the main flow of the gaseous m edium is directed through the gap.
  • the gap of the electric m otor is not utilized as bypass or the like.
  • no purge gas is conveyed through the gap.
  • the exit of the last pum p stage is connected with the outlet only via the gap.
  • gas leaving the last pum p stage can only reach the outlet if flowing through the active gap of the electric m otor.
  • the pump stages are built as Holweck stages.
  • the m otor stator is built as a lam inated stator core com prising a plurality of sheet elements.
  • the plurality of sheet elements is arranged within the m otor stator, or in other words, the m otor stator surrounds the plu rality of sheet elem ents connected to the rotor shaft.
  • the sheet elements of the motor stator are m ade of steel.
  • directly adjacent sheet elements of the m otor stator differ at their inner side from each other in at least one structural feature, such as a protrusion or indentation that is displaced from one sheet elem ent to the next, wherein along the length of the gap the thread or threaded groove is form ed by the sum of the individual displaced structural features.
  • the thread or threaded groove of the gap is built in a step-wise m anner.
  • the present invention relates to a vacuum pump com prising a m olecular drag stage as described above.
  • the m olecular pump is a turbomo- lecular pum p com prising a turbom olecular pum p stage.
  • the turbom olecular pump stage com prises veins connected to the rotor shaft interacting with stator veins in order to convey a gaseous m edium from the inlet towards the outlet.
  • the turbom olecular pump stage is arranged upstream of the molecular drag stage in accordance with the general flow of the gaseous m e dium within the vacuum pum p.
  • the vacuum pum p is able to produce a vacuum of 1 0 2 to 10 12 m bar.
  • Fig. 1 shows a schem atic drawing of a vacuum pum p in accordance with the present invention
  • Fig. 2 shows a detailed view of the m otor stator in accordance to the present invention.
  • the vacuum pump 10 of Fig. 1 is built as turbom olecular vacuum pum p com prising a turbomolecular pump stage 1 2 and a m olecular drag stage 14.
  • the vacuum pum p 10 comprises a housing 16, wherein in the housing 16 a rotor shaft 18 is rotatably supported by, for example, ball bearings 20. The rotor shaft 18 is rotated by an electric motor 22.
  • the rotor shaft 18 is connected with rotor elements built as veins 24, interacting with stator veins 26 in order to convey a gaseous m edium from an inlet 28 towards an outlet 30.
  • the gaseous m edium is conveyed through the turbom olecular pum p stage 12 and enters the molecular drag stage 14.
  • the rotor shaft 1 8 is connected to a rotor element 32 with a first cylinder 34 and a second cylinder 36.
  • a threaded first stator 38 is implem ented, wherein the thread of the first stator 38 faces the outer surface of the first cylinder 34 such that the gaseous medium is pum ped through the first pum p stage 40 from an entrance 42 of the m olecular drag stage 14 to a first turning point 44.
  • the inner surface of the first cylinder 34 is facing a second threaded pum p stator 46 form ing a second pum p stage 48, pum ping the gaseous m edium from the first turning point 44 to a second turning point 50.
  • the gaseous medium is pum ped through a third pum p stage 52 and a fourth pump stage 54, which are equal or sim ilarly built as the first pum p stage 40 or the second pum p stage 48.
  • the gas reaches a last turning point 56 which lies within the vacuum pum p 1 0.
  • the electric m otor 22 com prises a motor stator 58, wherein a gap 60 is defined between the motor stator 58 and the outer surface 62 of the rotor shaft 18.
  • the inner surface 64 of the m otor stator 58 comprises a thread 66, thereby actively pumping the gaseous m edium from the last turning point 56 form ing the entrance of the gap 60 towards the outlet 30.
  • the gaseous medium entering the m olecular drag stage 14 through the entrance 42 can only reach the outlet 30 through the gap 60.
  • the gaseous medium is actively pum ped in the gap 60 by the thread 66 in order to enhance the efficiency of the molecular drag stage 14, and to avoid frictional losses as well as heat-up within the electric motor 22.
  • the outer surface 62 of the rotor shaft 18 may com prise a thread or threaded groove.
  • the inner surface 64 of the motor stator 58 may be built as planar surface.
  • the motor stator 58 is built by a plurality of sheet elements 68 preferably m ade of steel.
  • the sheet elem ents 68 may comprise a structural feature 70 which can be built as protrusion or indentation.
  • Fig. 2 shows the structural fea ture 70 as protrusion .
  • the structural feature 70 is displaced from one sheet elem ent 68 to the next or neighboring by a small angular amount, thereby form ing the thread 66 in a step-wise m anner by the structural features 70.
  • the thread or threaded groove in the active gap 60 of the electric motor 22 is easy to m anufacture such that m anufacturing costs of the m otor stator 58 of the electric motor 22 can be reduced.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Non-Positive Displacement Air Blowers (AREA)

Abstract

L'invention concerne un étage d'entraînement moléculaire (14), de préférence destiné à une pompe turbomoléculaire (10), comprenant un boîtier (16) comprenant une entrée (28) et une sortie (30), un arbre de rotor (18) supporté rotatif à l'intérieur du boîtier (16), un moteur électrique (22) dans lequel le moteur (22) est construit par un stator de moteur (58) entourant l'arbre de rotor (18) afin de faire tourner l'arbre de rotor (18). Ainsi, un petit espace (60) est délimité entre le côté extérieur (62) de l'arbre de rotor (18) et le côté intérieur (64) du stator de moteur (58). Le côté extérieur (62) de l'arbre de rotor (18) ou le côté intérieur (64) du stator de moteur (58) comprend un filetage (66) ou une rainure filetée afin de transporter un milieu gazeux de l'entrée (28) à la sortie (30).
PCT/GB2019/053149 2018-11-14 2019-11-07 Moteur en tant qu'étage d'entraînement moléculaire WO2020099834A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP19804785.4A EP3880969A1 (fr) 2018-11-14 2019-11-07 Moteur en tant qu'étage d'entraînement moléculaire

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB1818600.7 2018-11-14
GB1818600.7A GB2579028A (en) 2018-11-14 2018-11-14 Molecular drag stage

Publications (1)

Publication Number Publication Date
WO2020099834A1 true WO2020099834A1 (fr) 2020-05-22

Family

ID=64739600

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB2019/053149 WO2020099834A1 (fr) 2018-11-14 2019-11-07 Moteur en tant qu'étage d'entraînement moléculaire

Country Status (4)

Country Link
EP (1) EP3880969A1 (fr)
GB (1) GB2579028A (fr)
TW (1) TW202106979A (fr)
WO (1) WO2020099834A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114076106A (zh) * 2020-08-18 2022-02-22 佛山市顺德区美的洗涤电器制造有限公司 电机组件、风机和吸油烟机
GB2607339A (en) * 2021-06-04 2022-12-07 Edwards Ltd Holweck drag pump

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL135263C (fr) * 1900-01-01
US6179573B1 (en) * 1999-03-24 2001-01-30 Varian, Inc. Vacuum pump with inverted motor
US20040265152A1 (en) * 2003-06-05 2004-12-30 Gotta Romina Silvia Compact vacuum pump
US20150030475A1 (en) * 2013-07-26 2015-01-29 Pfeiffer Vacuum Gmbh Vacuum pump

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102014118083A1 (de) * 2014-12-08 2016-06-09 Pfeiffer Vacuum Gmbh Turbomolekularpumpe
DE102014118881A1 (de) * 2014-12-17 2016-06-23 Pfeiffer Vacuum Gmbh Vakuumpumpe

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL135263C (fr) * 1900-01-01
US6179573B1 (en) * 1999-03-24 2001-01-30 Varian, Inc. Vacuum pump with inverted motor
US20040265152A1 (en) * 2003-06-05 2004-12-30 Gotta Romina Silvia Compact vacuum pump
US20150030475A1 (en) * 2013-07-26 2015-01-29 Pfeiffer Vacuum Gmbh Vacuum pump

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114076106A (zh) * 2020-08-18 2022-02-22 佛山市顺德区美的洗涤电器制造有限公司 电机组件、风机和吸油烟机
CN114076106B (zh) * 2020-08-18 2024-03-12 佛山市顺德区美的洗涤电器制造有限公司 电机组件、风机和吸油烟机
GB2607339A (en) * 2021-06-04 2022-12-07 Edwards Ltd Holweck drag pump

Also Published As

Publication number Publication date
TW202106979A (zh) 2021-02-16
GB201818600D0 (en) 2018-12-26
EP3880969A1 (fr) 2021-09-22
GB2579028A (en) 2020-06-10

Similar Documents

Publication Publication Date Title
US8235678B2 (en) Multi-stage vacuum pumping arrangement
WO2020099834A1 (fr) Moteur en tant qu'étage d'entraînement moléculaire
EP2491249B1 (fr) Pompe à vide
EP2064449B1 (fr) Mécanisme de pompage moléculaire
EP2481077B1 (fr) Système de spectromètre de masse
US8740588B2 (en) Multiple inlet vacuum pumps
CN102016323B (zh) 具有电动机和泵的布局结构
US9624938B2 (en) Integrated motor bearing and rotor
JPS62255597A (ja) 真空ポンプ
WO1991004417A1 (fr) Unite de pompe ou de compresseur
EP3524822A1 (fr) Pompe à vide, plaque hélicoïdale pour pompe à vide, élément d'espacement et corps cylindrique rotatif
EP2757266B1 (fr) Pompe à vide rotative
JPH01138397A (ja) 分子ポンプ
EP1851439B1 (fr) Pompe a vide
CN105324578B (zh) 真空泵
US8393854B2 (en) Vacuum pump
JP7015106B2 (ja) 真空ポンプ、および真空ポンプに備わる回転円筒体
JP2019023469A (ja) 真空ポンプ
WO2021105656A1 (fr) Étage de pompage d'une pompe à vide
JP2011027049A (ja) ターボ分子ポンプ
US20100322799A1 (en) Turbomolecular pump
EP3497337A1 (fr) Pompe à vide
CN110177950B (zh) 带有级间入口的多级涡轮分子泵
JP2021017810A (ja) 真空ポンプ
CN114593074A (zh) 带弹性间隔件的真空泵

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 19804785

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

ENP Entry into the national phase

Ref document number: 2019804785

Country of ref document: EP

Effective date: 20210614