GB2111126A - Rotary positive-displacement fluid-machines - Google Patents
Rotary positive-displacement fluid-machines Download PDFInfo
- Publication number
- GB2111126A GB2111126A GB08137164A GB8137164A GB2111126A GB 2111126 A GB2111126 A GB 2111126A GB 08137164 A GB08137164 A GB 08137164A GB 8137164 A GB8137164 A GB 8137164A GB 2111126 A GB2111126 A GB 2111126A
- Authority
- GB
- United Kingdom
- Prior art keywords
- rotors
- location
- pumping chamber
- mechanical pump
- outlet
- 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- Withdrawn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
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C23/00—Combinations of two or more pumps, each being of rotary-piston or oscillating-piston type, specially adapted for elastic fluids; Pumping installations specially adapted for elastic fluids; Multi-stage pumps specially adapted for elastic fluids
- F04C23/001—Combinations of two or more pumps, each being of rotary-piston or oscillating-piston type, specially adapted for elastic fluids; Pumping installations specially adapted for elastic fluids; Multi-stage pumps specially adapted for elastic fluids of similar working principle
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Applications Or Details Of Rotary Compressors (AREA)
- Rotary-Type Compressors (AREA)
Abstract
A pump e.g. a multi-stage vacuum pump, includes a pumping chamber through which extends a pair of parallel shafts 3. Each shaft 3 carries in tandem rotors 4, 5 and 6 at least two of which are of the Northey, or "claw", type, Figs. 4 and 6 (not shown). The rotors are arranged on the shafts in co-operating matching pairs, and each pair occupies an individual location in the pumping chamber and is separated from the adjacent pair(s) of rotors by a fixed partition(s) 8, 9. Each "claw" type rotor of one pair is mounted on its shaft in reverse orientation to the corresponding "claw" type rotor(s) of the adjacent pair(s). The rotors 4 may be of the two-lobed Roots type, Fig. 2 (not shown). <IMAGE>
Description
SPECIFICATION
Mechanical pumps
The present invention relates to mechanical pumps, and in particular, to large, oil free, high vacuum mechanical pumps.
In a number of industries, for example, the food processing industry, it is essential that air and other gases delivered by mechanical pumps or compressors are oil and particle free.
In order to improve the efficiency of such pumps, it is known for multistage pumps to include at the output stage and the stage immediately adjacent the output stage, rotors of the intermeshing "claw" type. Such multistage pumps have considerable gas transfer volumes and re-expansion into the swept volume of the preceeding stage can occur unless prevented from doing so by an interstage non return valve. However, such valves are disadvantageous in that they tend to complicate the pump design.
It is an aim of the present invention to provide a mechanical pump which is efficient in that it can attain a high vacuum commensurate with low power input and is of relatively simple design in that it requires no interstage non return valves.
According to the present invention, a mechanical pump comprises a pumping chamber having an inlet and an outlet for the passage therethrough of fluid to be pumped, a pair of shafts extending through the pumping chamber, each shaft supporting for rotary movement therewith in tandem at least two rotors of the intermeshing "claw" type, each rotor forming one of a complementary pair, each complementary pair occupying an individual location in the pumping chamber, adjacent locations being separated by a partition, each rotor of the complementary pair in one location being mounted on its shaft in reverse orientation to the rotors of this complementary pair in the adjacent location.
An advantage of the mechanical pump as defined above, is that by arranging the pairs of rotors in adjacent stages or locations in a reverse orientation, this allows a direct transfer of gas from one stage to the next through a transfer port in the partition wall separating the adjacent locations or stages with minimal interstage volume. The outlet of one stage on one side of the interstage partition becomes the inlet of the next stage on the other side of the partition.
An embodiment of the invention will now be described, by way of example, reference being made to the Figs. of the accompanying diagrammatic drawings in which:
Figure 1 is a longitudinal cross-section through a mechanical pump;
Figure 2 is a transverse cross-section through the first or inlet stage of the mechanical pump of Fig. 1;
Figure 3 is a section on the line A-A in Fig.
2;
Figure 4 is a transverse cross-section through the intermediate stage of the mechanical pump of Fig. 1;
Figure 5 is a cross-section on the line A-A of Fig. 4;
Figure 6 is a transverse cross-section through the final or outlet stage of the mechanical pump of Fig. 1;
Figure 7 is a cross section on the line C-C of Fig. 6; and
Figure 8 is a perspective view illustrating the relationship between the rotors forming part of the inlet, intermediate and output stages of the mechanical pump of Fig. 1.
As shown in Fig. 1, a mechanical pump 1 includes a pumping chamber 2 through which pass a pair of parallel shafts 3. Each shaft 3 supports for rotation therewith, three rotors 4, 5 and 6. The rotors 4, 5 and 6 are arranged in complementary pairs and the pairs are arranged in tandem on their respective shafts 3. The pumping chamber 2 is divided by partitions 8, 9 into three spaced locations, 10, 11, and 12, each occupied by a pair of rotors.
At its right hand end (as shown), each shaft 3 carries a timing gear 13, and at its left hand end (as shown) one shaft 3 is drivable by a motor via a fluid coupling, (not shown) in a manner known in the art.
Referring also to Figs. 2 and 3, the rotors 4 at location 10 are of the figure-of-8 or Rootstype, and form part of the first or inlet stage of the multistage pump 1.
The profile of the rotors 4 ensure that they have "minimal carry over" volume. By this is meant that the profiles of the co-operating rotors 4 are such that during their inter action the volume of gas trapped on the exhaust side of the rotors which is carried back to the inlet side of the rotors is kept to a practical minimum. This is important since if pockets of gas are carried over from the exhaust to the inlet side of the rotors, said pockets of gas will tend to expand and reduce the volumetric efficiency of the pump.
An inlet 1 5 to the pumping chamber 2 is provided, which as shown communicates with location 10, and an outlet 1 6 from the location 10 or inlet stage is provided in partition 9.
A bypass valve 50 is provided at the input stage for a reason which will be explained later.
Referring also to Figs. 4 to 8, the rotors 5 and 6 at locations 11 and 1 2 respectively are of the intermeshing "claw" type. Rotors 5 at the location 11 form the second or intermediate stage of the multistage pump 1, whilst the rotors 6 at location 1 2 form the third or outlet stage of pump 1.
It will be observed that the orientation of rotors 5 is such that the tip 20 of each rotor claw points towards the right as shown in Fig.
4, whilst the orientation of rotors 6 is such that the tip 21 of each rotor claw points to the left as shown in Fig. 6. In other words the orientation of rotors 6 is reversed as compared to the orientation of rotors 5.
The partition 8 dividing the intermediate and output stages is formed with an arcuate slot 22 which forms, in part, the outlet from the intermediate stage and, in part, the inlet to the output stage. The through slot 22 is stepped at 23 to form a channel 24 on the right hand surface of the partition (as shown in Fig. 5). Similarly the slot 22 is stepped at 25 to form a channel 26 on the left hand side of partition 8. The channel 26 and slot 22 form the inlet to the outlet stage.
An outlet 30 is provided from the outlet stage and is in the form of an arcuate slot in an end wall 31 defining with the partition 8, the location 1 2. The outlet 30 communicates via a one-way valve 33, with an outlet 32 from the pump 1.
Also, in partition 8, there is a conduit 40 which leads from an inlet 42 to the output stage. The inlet 42 is a connection for the admission of air ballast.
In operation, when a motor drives one shaft 3, by means of the timing gears 13, both shafts 3 will be driven in synchronisation thereby driving the various pairs of rotors synchronously.
Fluid to be pumped will enter the inlet 1 5 into the inlet stage where it will be pumped and exit via outlet 1 6 to the intermediate stage. At the intermediate stage it will be further pumped and will exit via slot 22 into the final outlet stage where it will exit via outlet 30 non-return valve 33 and outlet 32.
When the pump 1 is used in a high vacuum application, the swept volume of the rotors 6 is mainly at low pressure, and gases which exit from the outlet 32 will tend to reenter the swept volume unless prevented from doing so by the non return valve 33.
The connection 42 permits the introduction of air ballast into the swept volume of the outlet stage when it is isolated from its inlet.
When pumping vapour, the air ballast is compressed with the vapour and so permits delivery of the air/vapour mixture to atmosphere before the vapour is liquified. Furthermore, air ballast can also be used to displace hot gases from the outlet side of the swept volume of the outlet stage.
The bypass valve 50 is mounted in the first stage, since the first stage is often of larger displacement than the intermediate and output stage.
The bypass valve 50 is operative to avoid excessive inter stage pressure build up.
The pump as described above is free from non return valves in the partitions dividing the various locations or stages of the pump. By reversing the orientation of the two pairs of intermeshing claw type rotors, this permits transfer of gas from one stage to the next through a transfer port in the interstage partition with minimal interstage volume. In effect, the output of one stage, becomes the inlet of the next adjacent stage.
Claims (7)
1. A mechanical pump comprising a pumping chamber having an inlet and an outlet for the passage therethrough of fluid to be pumped; a pair of parallel shafts extending through the pumping chamber, each shaft supporting for rotary movement therewith in tandem at least two rotors of the intermeshing "claw" type, each rotor forming one of a complementary pair, each complementary pair occupying an individual location in the pumping chamber, adjacent locations being separated by a partition, each rotor of the complementary pair in one location being mounted on its shaft in reverse orientation to the rotors of the complementary pair in the adjacent location.
2. A mechanical pump as claimed in claim 1 in which the partition has an arcuate through slot which permits the passage of fluid from one location to the next adjacent location.
3. A mechanical pump as claimed in claim 1 or 2, in which a one way valve is positioned at the outlet from the pumping chamber to control the passage of fluid through said outlet.
4. A mechanical pump as claimed in any one of claims 1 to 3, in which means is provided for the admission of air ballast to the location in the pump immediately adjacent the outlet from the pumping chamber.
5. A mechanical pump as claimed in any one of claims 1 to 4, in which a further rotor is mounted on each shaft in tandem with said at least two rotors, said further rotor being of the Roots type and forming one of a complementary pair occupying a location immediately adjacent the inlet to the pumping chamber.
6. A mechanical pump as claimed in claim 5, in which a bypass valve is positioned in the location occupied by the pair of Roots type rotors.
7. A mechanical pump constructed and arranged substantially as hereinbefore described with reference to and as illustrated in the Figures of the accompanying drawings.
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB08137164A GB2111126A (en) | 1981-12-09 | 1981-12-09 | Rotary positive-displacement fluid-machines |
DE19823244099 DE3244099A1 (en) | 1981-12-09 | 1982-11-29 | MECHANICAL PUMP |
FR8220574A FR2517755A1 (en) | 1981-12-09 | 1982-12-08 | PERFECTED MECHANICAL PUMP WITH PUSHED VACUUM |
JP21536282A JPS6020595B2 (en) | 1981-12-09 | 1982-12-08 | mechanical pump |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB08137164A GB2111126A (en) | 1981-12-09 | 1981-12-09 | Rotary positive-displacement fluid-machines |
Publications (1)
Publication Number | Publication Date |
---|---|
GB2111126A true GB2111126A (en) | 1983-06-29 |
Family
ID=10526496
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB08137164A Withdrawn GB2111126A (en) | 1981-12-09 | 1981-12-09 | Rotary positive-displacement fluid-machines |
Country Status (4)
Country | Link |
---|---|
JP (1) | JPS6020595B2 (en) |
DE (1) | DE3244099A1 (en) |
FR (1) | FR2517755A1 (en) |
GB (1) | GB2111126A (en) |
Cited By (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3617889A1 (en) * | 1985-05-30 | 1986-12-04 | The Boc Group Plc, Windlesham, Surrey | MECHANICAL PUMP |
GB2185288A (en) * | 1986-01-11 | 1987-07-15 | Fleming Thermodynamics Ltd | Screw type compression and expansion machine |
US5046934A (en) * | 1988-10-24 | 1991-09-10 | Leybold Aktiengesellschaft | Twin shaft vacuum pump with purge gas inlet |
US5049050A (en) * | 1988-10-24 | 1991-09-17 | Leybold Aktiengesellschaft | Method for operating a twin shaft vacuum pump according to the Northey principle and a twin shaft vacuum pump suitable for the implementation of the method |
EP0594461A1 (en) * | 1992-10-22 | 1994-04-27 | The BOC Group plc | Vacuum pumps |
EP0793021A1 (en) * | 1996-03-01 | 1997-09-03 | The BOC Group plc | Vacuum pumps |
WO2005019653A1 (en) * | 2003-08-18 | 2005-03-03 | The Boc Group Plc | Low pulsation booster pump |
CN103104491A (en) * | 2011-11-11 | 2013-05-15 | 中国科学院沈阳科学仪器研制中心有限公司 | Roots and claw-type rotor combined multi-stage dry vacuum pump |
US9476423B2 (en) | 2011-08-17 | 2016-10-25 | Oerlikon Leybold Vaccum Gmbh | Roots pump connection channels separating adjacent pump stages |
DE102018203992A1 (en) * | 2018-03-15 | 2019-09-19 | Gardner Denver Schopfheim Gmbh | Rotary engine |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6097395U (en) * | 1983-12-12 | 1985-07-03 | 大亜真空技研株式会社 | dry vacuum pump |
DE3405509A1 (en) * | 1983-12-20 | 1985-06-27 | Herold & Co GmbH, 8586 Gefrees | Positive displacement pump |
DE3413892A1 (en) * | 1984-02-24 | 1985-09-05 | Multimatic Maschinen GmbH & Co, 4520 Melle | DEVICE FOR DISTILLING POLLUTED SOLVENTS OR THE LIKE |
JPS6221494U (en) * | 1985-07-23 | 1987-02-09 | ||
JPS63303185A (en) * | 1987-05-30 | 1988-12-09 | Yoshimitsu Saito | Flexibilizing processing and wrinkling processing for artificial leathers and machine device therefor |
US4943215A (en) * | 1988-02-29 | 1990-07-24 | Leybold Aktiengesellschaft | Multistage vacuum pump with bore for fouling removal |
EP0448750B1 (en) | 1990-03-27 | 1996-05-01 | Leybold Aktiengesellschaft | Multistage dry compressing vacuum pump and method for its operation |
Family Cites Families (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB596064A (en) * | 1945-07-17 | 1947-12-24 | Stothert & Pitt Ltd | Improvements in or relating to rotary pumps |
DE538256C (en) * | 1930-02-25 | 1931-11-12 | Griffith Thomas | Multiple rotary lobe pump (compressor) |
GB479199A (en) * | 1936-08-01 | 1938-02-01 | Edward Dodson | Improvements in or connected with rotary pumps |
FR856614A (en) * | 1938-06-20 | 1940-07-29 | Rotary internal combustion engine | |
GB735823A (en) * | 1952-08-23 | 1955-08-31 | Frank Berry | Improvements in or relating to a rotary fluid power device such as a motor or pump |
GB818691A (en) * | 1957-05-20 | 1959-08-19 | Lacy Hulbert & Company | Improvements in rotary air pumps |
DE1287729B (en) * | 1961-10-19 | 1969-01-23 | ||
GB1248032A (en) * | 1967-09-21 | 1971-09-29 | Edwards High Vacuum Int Ltd | Rotary mechanical vacuum pumps of the intermeshing screw type |
GB1284552A (en) * | 1969-08-08 | 1972-08-09 | Arthur E Brown | Improvements in rotary-positive displacement fluid machines |
US3922117A (en) * | 1972-11-10 | 1975-11-25 | Calspan Corp | Two-stage roots type compressor |
GB2088957B (en) * | 1980-12-05 | 1984-12-12 | Boc Ltd | Rotary positive-displacement fluidmachines |
-
1981
- 1981-12-09 GB GB08137164A patent/GB2111126A/en not_active Withdrawn
-
1982
- 1982-11-29 DE DE19823244099 patent/DE3244099A1/en active Granted
- 1982-12-08 FR FR8220574A patent/FR2517755A1/en not_active Withdrawn
- 1982-12-08 JP JP21536282A patent/JPS6020595B2/en not_active Expired
Cited By (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3617889A1 (en) * | 1985-05-30 | 1986-12-04 | The Boc Group Plc, Windlesham, Surrey | MECHANICAL PUMP |
FR2582741A1 (en) * | 1985-05-30 | 1986-12-05 | Boc Group Plc | MULTI-STAGE MECHANICAL PUMP COMPRISING CENTRAL CONDUITS TO PREVENT GAS LEAKAGE |
GB2185288A (en) * | 1986-01-11 | 1987-07-15 | Fleming Thermodynamics Ltd | Screw type compression and expansion machine |
US5046934A (en) * | 1988-10-24 | 1991-09-10 | Leybold Aktiengesellschaft | Twin shaft vacuum pump with purge gas inlet |
US5049050A (en) * | 1988-10-24 | 1991-09-17 | Leybold Aktiengesellschaft | Method for operating a twin shaft vacuum pump according to the Northey principle and a twin shaft vacuum pump suitable for the implementation of the method |
EP0594461A1 (en) * | 1992-10-22 | 1994-04-27 | The BOC Group plc | Vacuum pumps |
EP0793021A1 (en) * | 1996-03-01 | 1997-09-03 | The BOC Group plc | Vacuum pumps |
WO2005019653A1 (en) * | 2003-08-18 | 2005-03-03 | The Boc Group Plc | Low pulsation booster pump |
US9476423B2 (en) | 2011-08-17 | 2016-10-25 | Oerlikon Leybold Vaccum Gmbh | Roots pump connection channels separating adjacent pump stages |
CN103104491A (en) * | 2011-11-11 | 2013-05-15 | 中国科学院沈阳科学仪器研制中心有限公司 | Roots and claw-type rotor combined multi-stage dry vacuum pump |
DE102018203992A1 (en) * | 2018-03-15 | 2019-09-19 | Gardner Denver Schopfheim Gmbh | Rotary engine |
WO2019175267A1 (en) * | 2018-03-15 | 2019-09-19 | Gardner Denver Schopfheim Gmbh | Rotary piston engine |
US11441563B2 (en) | 2018-03-15 | 2022-09-13 | Gardner Denver Schopfheim Gmbh | Rotary piston compressor/pump/blower with a ventilation channel |
DE202019005982U1 (en) | 2018-03-15 | 2023-11-06 | Gardner Denver Schopfheim Gmbh | Rotary piston engine |
US11879458B2 (en) | 2018-03-15 | 2024-01-23 | Gardner Denver Schopfheim Gmbh | Rotary piston compressor/pump/blower with a ventilation channel |
Also Published As
Publication number | Publication date |
---|---|
JPS58106191A (en) | 1983-06-24 |
DE3244099C2 (en) | 1987-11-05 |
DE3244099A1 (en) | 1983-06-23 |
FR2517755A1 (en) | 1983-06-10 |
JPS6020595B2 (en) | 1985-05-22 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US4504201A (en) | Mechanical pumps | |
GB2111126A (en) | Rotary positive-displacement fluid-machines | |
GB2088957A (en) | Rotary positive-displacement Fluid-machines | |
KR0133154B1 (en) | Screw pump | |
US2804260A (en) | Engines of screw rotor type | |
US3844695A (en) | Rotary compressor | |
US6312240B1 (en) | Reflux gas compressor | |
US3756753A (en) | Two stage screw rotor machines | |
KR20030076257A (en) | Vacuum pump | |
EP1479913A2 (en) | Roots pump | |
US7537440B2 (en) | Scroll compressor with multiple isolated inlet ports | |
JPH0368237B2 (en) | ||
US5846066A (en) | Vacuum pumps with claw-type rotor and roots-type rotor near the outlet | |
US2956735A (en) | Rotary compressor | |
RU207017U1 (en) | COMPRESSOR | |
GB2065776A (en) | Rotary-piston Fluid-machines | |
CN209818301U (en) | Multi-stage vacuum pump sharing drive shaft | |
CN209621604U (en) | A kind of multi-stage roots vacuum pump | |
JPS6336086A (en) | Multi-stage screw type vacuum pump | |
USRE29627E (en) | Rotary compressor | |
CN109854501A (en) | A kind of multi-stage roots vacuum pump | |
JP2933352B2 (en) | Multi-stage roots type vacuum pump | |
US4033708A (en) | Rotary compressor | |
CN111720328A (en) | Multi-stage vacuum pump sharing drive shaft | |
RU2022175C1 (en) | Two-rotor vacuum pump |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |