US20010022943A1 - Screw rotors and screw machine - Google Patents
Screw rotors and screw machine Download PDFInfo
- Publication number
- US20010022943A1 US20010022943A1 US09/808,904 US80890401A US2001022943A1 US 20010022943 A1 US20010022943 A1 US 20010022943A1 US 80890401 A US80890401 A US 80890401A US 2001022943 A1 US2001022943 A1 US 2001022943A1
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- United States
- Prior art keywords
- screw
- rotors
- surface portion
- pitch circumference
- portions
- Prior art date
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- Granted
Links
- 230000003247 decreasing effect Effects 0.000 claims description 3
- 230000013011 mating Effects 0.000 claims 2
- 239000012530 fluid Substances 0.000 claims 1
- 239000011295 pitch Substances 0.000 description 33
- 230000005484 gravity Effects 0.000 description 13
- 238000007789 sealing Methods 0.000 description 4
- 238000005096 rolling process Methods 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 230000004323 axial length Effects 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 230000001360 synchronised effect Effects 0.000 description 1
Images
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
- F04C25/00—Adaptations of pumps for special use of pumps for elastic fluids
- F04C25/02—Adaptations of pumps for special use of pumps for elastic fluids for producing high vacuum
-
- 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
- F04C18/00—Rotary-piston pumps specially adapted for elastic fluids
- F04C18/08—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
- F04C18/082—Details specially related to intermeshing engagement type pumps
- F04C18/084—Toothed wheels
-
- 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
- F04C18/00—Rotary-piston pumps specially adapted for elastic fluids
- F04C18/08—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
- F04C18/12—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type
- F04C18/14—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type with toothed rotary pistons
- F04C18/16—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type with toothed rotary pistons with helical teeth, e.g. chevron-shaped, screw type
-
- 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
- F04C2220/00—Application
- F04C2220/10—Vacuum
- F04C2220/12—Dry running
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Applications Or Details Of Rotary Compressors (AREA)
- Rotary Pumps (AREA)
- Extrusion Moulding Of Plastics Or The Like (AREA)
Abstract
In screw rotors (21, 22) which are each provided with a screw tooth (211, 221) having a spiral addendum surface portion (211 a, 221a) and a deddendum surface portion (211 c, 221c), and are used as a pair of male and female, between the addendum surface portion (211 a, 221a) and deddendum surface portion (211 c, 221c) of the screw tooth (211, 221), there is provided the pitch circumference portion (211 p, 221p) which forms a predetermined angle range of circular arc having a definite radius rp on an optional transverse cross section, and the radius of the pitch circumference portion (211 p, 221p) is set such that, when the opposing rotors are meshed with each other, out of the meshing clearances between the male and female screw teeth (211, 221), the clearance g1 between the pitch circumference portions (211 p, 221p) becomes smaller than the clearances g2, g3, g4 between the other portions.
Description
- The present invention relates to the screw rotors applied to a screw machine, and to the screw machine such as a dry vacuum pump etc. using the screw rotors.
- Conventionally, as a pump or a compressor which can afford a high-speed, long-time continuous operation, there is known a positive-displacement screw machine having a pair of screw rotors within its housing.
- In such a kind of screw machine, e.g., the screw machine used as a dry vacuum pump, the male and female screw rotors in reverse screw relation with each other are arranged in parallel and meshed with each other so as to be spaced an infinitesimally small clearance apart, and, between the both rotors and the housing surrounding the rotors, there are formed the operation chambers comparted by the meshing portions of the rotors. Also, the screw machine is arranged such that the male and female screw rotors are rotated in synchronism, with the male and female screw rotors intermeshed in substantially a noncontact state, thus causing the volume of the operation chambers to increase on a suction side and to decrease on an exhaust side.
- Also, in the vacuum pump, generally, the two phases of essential performance, i.e., the ultimate pressure and exhaust velocity thereof, are highly required. In the screw machine such as a dry vacuum pump, the meshing engagement of the male and female screw rotors arranged in parallel, as well as the clearance between the both rotors and the housing, exerts a great influence on any phases of the performance. Therefore, in such a screw machine, the clearance between the male and female screw rotors and the clearance between the both rotors and the housing are made small to the utmost, thereby seeking to improve the performance.
- Further, the screw machine has some types such as a Lysholm type, a square threaded type (with a Quinby-shaped (square-shaped) tooth profile), and a spiraxial type (with a spiraxial screw tooth profile formed by combining an epitrochoid with an Archimedean spiral curve). In the Lysholm type, the one whose rotors have four threads or more each with the female rotor increased by one thread relative to the male rotor is in frequent use. In the square threaded type and the spiraxial type, the one in which the male and female rotors have one thread each is in frequent use.
- In the case of the square threaded type or the spiraxial type, in the transverse cross section perpendicular to the rotation axis, the position of center of gravity thereof is heavily displaced from the rotation center. Hence, in order to strike a couple balance, it is necessary to form large cavities by means of as cast, etc., for opening cavities on the end faces of each of the screw rotors, thus causing the manufacturing process to be complex.
- Further, the screw machine takes such a rotor form that, at the meshing portions of the male and female screw rotors, there occurs a difference of relative circumferential speed between the both rotors. Hence, it happens in some cases that the both screw rotors having a small clearance at the meshing portions undergo thermal expansion due to the high-speed, long-time continuous operation under a heavy load, etc., so that the both rotors are slidingly contacted, thereby causing seizure between the male and female screw rotors. Consequently, there is a problem that the meshing clearance between the rotors must be ensured even at the sacrifice of the pump performance to some extent so that such seizure between the rotors due to the thermal expansion may not occur.
- Accordingly, the invention aims at reducing the meshing clearance between the screw rotors to improve the performance, and additionally an object thereof is to provide the screw machine capable of effectively preventing the seizure between the rotors even under a long-time high-speed continuous operation.
- In order to solve the aforesaid problem, the invention is characterized in that, in the screw rotors which are each provided, around the rotation axis, with the screw tooth having a spiral addendum surface portion and the deddendum surface portion forming a spiral groove between the addendum surface portions, and are used as a pair of male and female in reverse screw relation with each other, between the addendum surface portion and the deddendum surface portion of the screw tooth, there is provided the pitch circumference portion which forms a predetermined angle range of circular arc having a definite radius on the optional transverse cross section perpendicular to the rotation axis.
- Since the pitch circumference portion is provided, on the cross section perpendicular to the rotation axis, the position of center of gravity is never heavily displaced from the rotation center, and there is no need to form complex cavities by means of as cast, etc., thereby enabling reduction in the manufacturing costs.
- In each of the screw rotors, the offset of the position of center of gravity from the rotation center becomes smaller as compared with the spiraxial type of screw rotor and the square threaded type of screw rotor both having the equivalent exhaust sectional area and rotor diameter. Hence, since the lead number is made integral to position the position of center of gravity on the rotation center axis, there is no need to form the complex cavities by means of as cast etc. for striking a couple balance.
- By arranging such that the pitch circumference portion is formed in a band shape in the radial location substantially at the midpoint between the addendum surface portion and the deddendum surface portion, the tooth profiles of the respective rotors can be formed in common so as to facilitate the processing, and also the required sealing performance at the meshing portions of the screw rotors can be exerted by the pitch circumference portion having a definite width.
- In the invention, it is preferable that the radius of the pitch circumference portion is set such that, when one of the pair of male and female rotors is meshed with the opposing rotor, of the meshing clearances between the male and female screw teeth, the clearance between the pitch circumference portions is smaller than the clearances between the other portions. In this case, when the male and female screw rotors are meshed with each other, of the meshing clearances between the male and female screw teeth, the clearance between the pitch circumference portions is smaller than the clearances between the other portions. Hence, the meshing clearance between the rotors becomes the smallest between the pitch circumference portions. Thereby, however, when the screw rotors undergo thermal expansion, the pitch circumference portions with a definite radius are initially abutted against each other into a rolling contact, and thus seizure is difficult to occur as compared with the conventional machine in which the tooth portions of the both rotors are most apt to be slidingly contacted.
- Further, since the meshing clearance per se between the rotors can be maintained the smallest between the pitch circumference portions, the efficiency can be increased.
- The screw machine according to the invention is characterized in that, with the screw rotors arranged as the male and female rotors meshed with each other, the both rotors are housed in parallel within the housing forming a suction port and an exhaust port, so as to be meshed with each other in a noncontact meshing engagement, and that, between the housing and the both rotors, there are formed a plurality of operation chambers which are transferred in the axial direction of the rotation axis by rotation of the screw rotors, and have volume increased in the transfer section communicating with the suction port, while decreased in the transfer section communicating with the exhaust port.
- The present disclosure relates to the subject matter contained in Japanese patent application No. 2000-72893 (filed on Mar. 15, 2000), which is expressly incorporated herein by reference in its entirety.
- FIG. 1 is a front sectional view of main portions showing the schematic internal structure of the screw machine according to an embodiment of the invention.
- FIG. 2 is a transverse sectional view of the vicinity of the screw rotors of the screw machine according to an embodiment of the invention.
- FIG. 3 is a front view showing the meshing relation between the male and female screw rotors according to an embodiment of the invention.
- FIG. 4 is a section view taken on line A-A of FIG. 3.
- FIG. 5 is a type section view of the meshing portions showing the setting state of the meshing clearances between the male and female screw rotors according to an embodiment of the invention.
- FIGS.6(a) to 6(c) are views each illustrating the position of center of gravity on the transverse section of each of the screw rotors according to an embodiment of the invention. FIG. 6(a) is a transverse sectional view of the screw rotor of an embodiment thereof, FIG. 6(b) a transverse sectional view of a spiraxial type of rotor as a comparative example, and FIG. 6(c) a transverse sectional view of a square threaded type of rotor as another comparative example.
- FIG. 7 is a front view showing the meshing relation between the male and female screw rotors according to another embodiment of the invention.
- FIGS.8(a) and 8(b) are views showing the shapes of the opposite ends of the male and female screw rotors according to another embodiment of the invention. FIG. 8(a) is a left side view thereof, and FIG. 8(b) a right side view thereof.
- A preferred embodiment of the invention will be explained below based on the drawings.
- FIGS.1 to 6 are the views illustrating the screw rotors and screw machine according to an embodiment of the invention.
- The screw machine of the embodiment, an application of the invention to a dry vacuum pump, includes the
housing 11 forming asuction port 11 a and anexhaust port 11 b, the male andfemale screw rotors housing 11 in parallel so as to be meshed with each other in a noncontact meshing engagement with a predetermined clearance (an infinitesimally small clearance), thebearings members housing 11 and thescrew rotors synchronous gears 25 a, 25 b integrally mounted on thescrew rotors respective rotors motor 26 coupled to one end of therotor 22. - The female
side screw rotor 21 and the maleside screw rotor 22 are of external diameter and axial length such as to be spaced a predetermined clearance, e.g., a clearance of 50 μm with respect to the inner wall surface 11 i of thehousing 11. Between thehousing 11 and the both screw rotors, there are formed a plurality ofspiral operation chambers 31, which are comparted one from another at the meshing portions of thescrew rotors screw rotors - As the
screw rotors operation chambers 31 have the volume increased in the transfer section on the left end side as seen in FIG. 1. While the volume is increased, as shown in FIG. 2, the operation chambers communicate with thesuction port 11 a of thehousing 11, and are transferred to the right side as seen in FIG. 1 after the completion of suction. Thereafter, the operation chambers have the volume decreased in the transfer section on the right end side as seen in FIG. 1. In the area of the completion of compression where the volume of theoperation chambers 31 falls below a predetermined value, theoperation chambers 31 on the right end side as seen in FIG. 1 communicate with theexhaust port 11 b so as to be exhausted. - Specifically, as shown in FIGS. 3 and 4, the
screw rotor 21 is provided with thespiral screw tooth 211 around the rotation axis C1. Thescrew tooth 211 has the spiral band-shapedaddendum surface portion 211 a and thededdendum surface portion 211 c forming the spiral groove with apredetermined groove width 211 b between theaddendum surface portions 211 a. Also, between theaddendum surface portion 211 a anddeddendum surface portion 211 c of thescrew tooth 211, there are provided thepitch circumference portion 221 p, the addendum-sideinclined face 211 d toward theaddendum surface portion 211 a relative to thepitch circumference portion 211 p, and the deddendum-sideinclined face 211 e toward thededdendum surface portion 211 c relative to thepitch circumference portion 211 p. - On the other hand, the
screw rotor 22 is provided with thespiral screw tooth 221 around the rotation axis C2 so as to be in reverse screw relation with thescrew rotor 21. Thescrew tooth 221 has the spiral band-shaped addendum surface portion 221 a and thededdendum surface portion 221 c forming the spiral groove with apredetermined groove width 221 b between the addendum surface portions 221 a. Also, between the addendum surface portion 221 a anddeddendum surface portion 221 c of thescrew tooth 221, there are provided thepitch circumference portion 221 p, the addendum-sideinclined face 221 d toward the addendum surface portion 221 a relative to thepitch circumference portion 221 p, and the deddendum-sideinclined face 221 e toward thededdendum surface portion 221 c relative to thepitch circumference portion 221 p. - The
pitch circumference portions screw rotors pitch circumference portions respective screw rotors deddendum surface portion 221 c, and form a stepped tooth profile along with the addendum-sideinclined face 221 d and the deddendum-sideinclined face 221 e. Further, similarly to the angle range of thepitch circumference portions rotor 22 in FIG. 4 is identical to the angle range θ1 of theaddendum surface portion 211 a on the transverse cross section of therotor 21, and the angle range of thededdendum surface portion 221 c of therotor 22 is identical to the angle range θ2 of thededdendum surface portion 211 c on the transverse cross section of therotor 21. The angle ranges θ1, θ2, θ3 may be set to any value, and the angle range θ3 of thepitch circumference portions - Also, the respective connecting shapes are set in a manner that the connecting portions between the
addendum surface portions 211 a, 221 a and thepitch circumference portions respective screw rotors respective rotors pitch circumference portions deddendum surface portions respective screw rotors respective rotors addendum surface portions 211 a, 221 a and thededdendum surface portions respective screw rotors addendum surface portions 221 a, 211 a) of the respectiveopposing screw rotors - Further, as shown in FIG. 5, in the
screw rotors pitch circumference portions female screw teeth pitch circumference portions - Furthermore, as shown in FIG. 6(a), in each of the
screw rotors rotors 21, 22) in a spiraxial type of screw rotor R10 as shown in FIG. 6(b), or as compared with the offset S3 (e.g., 6.032 mm in the case of having the exhaust sectional area and rotor radius equivalent to that of each of therotors 21, 22) in a square threaded type of screw rotor R20 as shown in FIG. 6(c). (The larger the angle range θ3 of thepitch circumference portion screw rotors - The operation will now be explained.
- In the screw machine of the embodiment arranged as described above, at the start time of or during normal operation, the male and
female screw rotors female screw teeth pitch circumference portions rotors pitch circumference portions screw rotors pitch circumference portions tooth portions rotors - Also, in each of the
screw rotors - Further, the
pitch circumference portion addendum surface portion 211 a, 221 a and thededdendum surface portion rotors screw rotors 21, 22 (between the adjacent operation chambers 31) can be exerted by thepitch circumference portions - FIGS. 7 and 8 are the views showing the screw rotors according to another embodiment of the invention, and any other arrangement than that of the rotors of the screw machine is entirely similar to that of the aforesaid embodiment.
- In each of the
screw rotors screw rotors h 1, 211 h 2, 221h 1, 221 h 2 opened on the axially opposite ends are formed with at least one arranged in a predetermined radial location, e.g., at a substantially constant depth. As a matter of course, the number, position, depth, etc. of the concave portion for adjusting the couple balance can be set accordingly. Any other arrangement than this is similar to that of the aforesaid embodiment. - Also in this embodiment, the similar advantage to the aforesaid embodiment can be attained. In addition, since the concave portions211
h 1, 211 h 2, 221h 1, 221 h 2 for the couple balance are each shaped as a concavity in a circular hole form with an identical diameter, the adjustment of the couple balance can be performed through a simple processing. - Further, in the aforesaid embodiment, the respective screw rotors are explained such that the flight leads thereof are equal from the suction side to the exhaust side. Alternatively, for example, a plurality of screw portions with different leads from each other may be provided so that the lead on the compressor side is smaller than that on the suction side, or the pitches between the screw teeth may become steplessly gradually smaller the nearer to the exhaust side. That is, it is possible to form the screw rotors with variable leads.
- According to the invention, between the addendum surface portion and the deddendum surface portion of the screw tooth, there is provided the pitch circumference portion which forms a predetermined angle range of circular arc having a definite radius on an optional transverse cross section perpendicular to the rotation axis. Consequently, since the offset of a gravity center position of the rotor from the rotation center can be made small, there is no need to form the complex cavities by means of as cast etc. for striking a couple balance.
- When the screw rotors undergo thermal expansion due to a continuous, high-speed operation etc., and the like case, the pitch circumference portions with a definite radius are initially abutted against each other into a rolling contact so that the both rotors are slidingly contacted, thereby enabling preventing the occurrence of seizure. Consequently, it is possible to solve the conventional problem that the meshing clearance between the screw rotors must be set to a large value for preventing seizure even at the sacrifice of exhaust performance.
Claims (5)
1. A screw rotor that is provided, around a rotation axis, with a screw tooth having a spiral addendum surface portion and a deddendum surface portion forming a spiral groove between adjacent turns of the addendum surface portion, and that is to be used in combination with a mating screw rotor in reverse screw relation to form male and female pair, the screw rotor comprising:
a pitch circumference portion which is provided between said addendum surface portion and said deddendum surface portion and which forms circular arc extending in a predetermined angle range and having a constant radius on an arbitrary transverse cross section perpendicular to said rotation axis.
2. The screw rotor according to , wherein said pitch circumference portion is formed in a band shape in a radial location substantially at a midpoint between said addendum surface portion and said deddendum surface portion.
claim 1
3. The screw rotor according to or (U.S. ), wherein said radius of said pitch circumference portion is set such that, when said screw rotor is meshed with said mating screw rotor, a meshing clearance between said pitch circumference portions of said screw rotors meshed with each other is smaller than other meshing clearances between said screw rotors.
claim 1
2
claim 1
4. A screw machine comprising:
a pair of male and female rotors meshed with each other, each of said rotors being constructed by the screw rotor according to any one of to ;
claims 1
3
a housing forming a suction port and an exhaust port, and accommodating therein said rotors to extend in parallel to each other and to be meshed with each other in a non-contact meshing engagement state;
a plurality of operation chambers that are provided between said housing and said rotors, and that have volume increased in a transfer section communicating with said suction port, while decreased in a transfer section communicating with said exhaust port.
5. The screw machine according to , wherein fluid is transferred in an axial direction of said rotation axis by rotation of said screw rotors.
claim 4
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JPP2000-072893 | 2000-03-15 | ||
JP2000072893A JP4282867B2 (en) | 2000-03-15 | 2000-03-15 | Screw rotor and screw machine |
JP2000-072893 | 2000-03-15 |
Publications (2)
Publication Number | Publication Date |
---|---|
US20010022943A1 true US20010022943A1 (en) | 2001-09-20 |
US6386848B2 US6386848B2 (en) | 2002-05-14 |
Family
ID=18591232
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/808,904 Expired - Fee Related US6386848B2 (en) | 2000-03-15 | 2001-03-15 | Screw rotors and screw machine |
Country Status (7)
Country | Link |
---|---|
US (1) | US6386848B2 (en) |
EP (1) | EP1134357B1 (en) |
JP (1) | JP4282867B2 (en) |
KR (1) | KR100682584B1 (en) |
AT (1) | ATE278099T1 (en) |
DE (1) | DE60105871T2 (en) |
TW (1) | TW505738B (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN105952641A (en) * | 2016-07-11 | 2016-09-21 | 中国石油大学(华东) | Three-section type screw rotor and twin-screw vacuum pump comprising same |
CN108437401A (en) * | 2018-05-28 | 2018-08-24 | 中国石油大学(华东) | A kind of full smooth taper screw rotor of double screw extruder |
EP3608592A1 (en) | 2018-08-06 | 2020-02-12 | Polyflam | Heating device comprising at least one air injection rail |
CN113586449A (en) * | 2021-08-25 | 2021-11-02 | 西安交通大学 | Rotor of variable-rotor type linear double-screw compressor and design method |
CN113953934A (en) * | 2021-11-11 | 2022-01-21 | 格力电器(武汉)有限公司 | Rotor coating pre-grinding device and pre-grinding method |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP3906806B2 (en) * | 2003-01-15 | 2007-04-18 | 株式会社日立プラントテクノロジー | Screw compressor and method and apparatus for manufacturing the rotor |
CN1961153A (en) * | 2004-05-24 | 2007-05-09 | 纳博特斯克株式会社 | Screw rotor and screw type fluid machine |
CN100392249C (en) * | 2005-01-31 | 2008-06-04 | 浙江大学 | Arc screw tooth shape of large flow double screw pump |
ITPR20090054A1 (en) * | 2009-07-10 | 2011-01-11 | Robuschi S P A | DRY SCREW COMPRESSOR |
EP3368771B1 (en) | 2015-10-30 | 2021-03-31 | Gardner Denver Inc. | Complex screw rotors |
CN110966265B (en) * | 2018-09-28 | 2022-03-22 | 党祎贤 | Vacuum pump for collection and injection |
TW202040004A (en) * | 2019-04-19 | 2020-11-01 | 亞台富士精機股份有限公司 | Rotor and screw pump |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2931308A (en) * | 1957-03-29 | 1960-04-05 | Improved Machinery Inc | Plural intermeshing screw structures |
NL162721C (en) * | 1969-02-12 | 1980-06-16 | Cerpelli Orazio | SCREW PUMP. |
SU1000598A1 (en) * | 1979-01-25 | 1983-02-28 | Предприятие П/Я А-1125 | Screw pump |
JPH01267384A (en) * | 1988-04-15 | 1989-10-25 | Hitachi Ltd | Screw rotor having beveled tooth |
ATE229127T1 (en) * | 1995-12-11 | 2002-12-15 | Busch Sa Atel | TWIN SCREW SET |
DE59604068D1 (en) * | 1995-12-11 | 2000-02-03 | Busch Sa Atel | TWIN CONVEYOR SCREWS |
US6093009A (en) * | 1999-02-17 | 2000-07-25 | Jacks, Jr.; Morris G. | Apparatus and method for controlling angular relation between two rotating shafts |
-
2000
- 2000-03-15 JP JP2000072893A patent/JP4282867B2/en not_active Expired - Fee Related
-
2001
- 2001-03-14 DE DE60105871T patent/DE60105871T2/en not_active Expired - Fee Related
- 2001-03-14 AT AT01106252T patent/ATE278099T1/en not_active IP Right Cessation
- 2001-03-14 TW TW090105950A patent/TW505738B/en not_active IP Right Cessation
- 2001-03-14 EP EP01106252A patent/EP1134357B1/en not_active Expired - Lifetime
- 2001-03-15 KR KR1020010013386A patent/KR100682584B1/en not_active IP Right Cessation
- 2001-03-15 US US09/808,904 patent/US6386848B2/en not_active Expired - Fee Related
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN105952641A (en) * | 2016-07-11 | 2016-09-21 | 中国石油大学(华东) | Three-section type screw rotor and twin-screw vacuum pump comprising same |
CN108437401A (en) * | 2018-05-28 | 2018-08-24 | 中国石油大学(华东) | A kind of full smooth taper screw rotor of double screw extruder |
EP3608592A1 (en) | 2018-08-06 | 2020-02-12 | Polyflam | Heating device comprising at least one air injection rail |
CN113586449A (en) * | 2021-08-25 | 2021-11-02 | 西安交通大学 | Rotor of variable-rotor type linear double-screw compressor and design method |
CN113953934A (en) * | 2021-11-11 | 2022-01-21 | 格力电器(武汉)有限公司 | Rotor coating pre-grinding device and pre-grinding method |
Also Published As
Publication number | Publication date |
---|---|
KR100682584B1 (en) | 2007-02-15 |
US6386848B2 (en) | 2002-05-14 |
ATE278099T1 (en) | 2004-10-15 |
JP2001263276A (en) | 2001-09-26 |
DE60105871D1 (en) | 2004-11-04 |
EP1134357A3 (en) | 2003-01-02 |
JP4282867B2 (en) | 2009-06-24 |
EP1134357A2 (en) | 2001-09-19 |
KR20010092368A (en) | 2001-10-24 |
TW505738B (en) | 2002-10-11 |
EP1134357B1 (en) | 2004-09-29 |
DE60105871T2 (en) | 2005-02-03 |
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