US20050214139A1 - Liquid delivery pump for liquid chromatograph - Google Patents
Liquid delivery pump for liquid chromatograph Download PDFInfo
- Publication number
- US20050214139A1 US20050214139A1 US11/071,180 US7118005A US2005214139A1 US 20050214139 A1 US20050214139 A1 US 20050214139A1 US 7118005 A US7118005 A US 7118005A US 2005214139 A1 US2005214139 A1 US 2005214139A1
- Authority
- US
- United States
- Prior art keywords
- plunger
- crosshead
- liquid
- pump
- ball
- 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.)
- Abandoned
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Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B53/00—Component parts, details or accessories not provided for in, or of interest apart from, groups F04B1/00 - F04B23/00 or F04B39/00 - F04B47/00
- F04B53/14—Pistons, piston-rods or piston-rod connections
- F04B53/144—Adaptation of piston-rods
- F04B53/147—Mounting or detaching of piston rod
Definitions
- the present invention relates to a liquid delivery pump for a liquid chromatograph, and more specifically, relates to a structure for holding a plunger moving reciprocally within a pump room.
- FIG. 2 is a sectional view of a conventional liquid delivery pump for a liquid chromatograph.
- reference numeral 1 is a pump head
- reference numeral 2 is a plunger
- reference numeral 3 is a sealing material for allowing the plunger 2 to slide while preventing leak
- reference numeral 4 is a pump room formed within the pump head 1
- reference numerals 5 and 6 are inlet and outlet for liquid to be delivered, respectively, and having check valves 5 a and 5 b
- reference numeral 7 is a pump body
- reference numeral 8 is a bearing
- reference numeral 9 is a spring
- reference numeral 10 is a crosshead
- reference numeral 11 is a cam rotationally driven by a motor not shown in the figure
- reference numeral 12 is a cam follower that rolls along the circumference of the cam 11 .
- a tip side (left side in FIG. 2 ) of the plunger 2 is inserted into the pump room 4 through the sealing material 3 , and a base side (right side in FIG. 2 ) thereof is connected to the crosshead 10 .
- the crosshead 10 axially supported by the bearing 8 moves reciprocally within the tubular pump body 7 with force imparted by the rotating cam 11 via the cam follower 12 in a forward direction (toward the left side in FIG. 2 ) and force imparted by the spring 9 in a retreating direction (toward the right side in FIG. 2 ).
- the plunger 2 moves reciprocally within the pump room 4 accompanying with the movement of the crosshead 10 . Accordingly, the pump room 4 is alternately pressurized and depressurized, and associated operations of the check valves 5 a and 6 a cause liquid to flow from the inlet 5 to the outlet 6 , thereby delivering liquid.
- the plunger 2 A is formed of a material with high hardness, and good wear and chemical resistance such as sapphire.
- a metal having a surface coated with a ceramic film may be used (for example, see Patent Reference 1 ).
- FIG. 3 illustrates a connecting structure between the plunger 2 and the crosshead 10 in more detail.
- Reference numeral 15 is a plunger holder.
- One end of the plunger holder 15 is fixed to the base side of the plunger 2 , and the other end thereof is machined to form a spherical end 15 a .
- the plunger holder 15 is fixed to the crosshead 10 with a screw cap 16 , so that the plunger 2 and the crosshead 10 are connected.
- the spherical end 15 a of the plunger 2 abuts against a flat end face 10 a of the crosshead 10 with point contact.
- the plunger 2 freely rotates while moving reciprocally along the crosshead 10 .
- Patent reference 1 Japanese Patent Publication (Kokai) NO.
- an object of the present invention is to provide a liquid delivery pump for a liquid chromatograph with production and maintenance costs lower than those of the conventional device.
- a plunger holder is formed in a ball, and a plunger is connected to the plunger holder with a screw.
- a liquid delivery pump comprises a crosshead moving reciprocally accompanied with a rotational movement of a cam, and a plunger having a tip portion inserted into a pump room via a sealing material and a base portion connected to the crosshead so as to rotate freely.
- the ball abuts against a flat end surface of the crosshead at a connection section between the crosshead and the plunger, and the base portion of the plunger is screwed in the ball.
- FIG. 1 is a schematic view showing a liquid delivery pump according to an embodiment of the present invention
- FIG. 2 is a schematic view showing a conventional liquid delivery pump
- FIG. 3 is a detailed view showing the conventional liquid delivery pump.
- FIG. 1 is a schematic view showing a liquid delivery pump according to an embodiment of the present invention.
- FIG. 1 corresponds to FIG. 3 , and an overall structure of the liquid delivery pump is substantially the same as that shown in FIG. 2 .
- the same reference numerals are used for elements functionally same as those in FIG. 3 , and descriptions thereof are omitted.
- a difference from the conventional pump is that a plunger holder 15 is formed in a ball.
- Manufacturing technology for a ball with a high degree of sphericity has been established in the field of bearings, and it is possible to produce balls at relatively low cost and high-quality.
- Such a ball thus manufactured or obtained is provided with a screw hole 15 b for screwing a female screw to form the plunger holder 15 .
- the plunger 2 is provided with a male screw 2 a at a base portion thereof, so that the male screw 2 a is screwed into the screw hole 15 b .
- the plunger 2 and the plunger holder 15 are connected.
- an operation of the pump constructed as described above is basically the same as the conventional pump shown in FIG. 3 .
- a surface (spherical surface) of the plunger holder 15 abuts against a flat end surface 10 a of the crosshead 10 , so that the plunger 2 rotates freely.
- the spherical body with a high degree of sphericity for example, a ball bearing
- the plunger holder 15 is used as the plunger holder 15 , so that the plunger 2 moves smoothly and slides without grinding against the sealing material 3 shown in FIG. 2 , even when the sealing material 3 is slightly off-centered or deformed. As a result, it is possible to reduce wear of the plunger 2 and the sealing material 3 .
- the plunger 2 is screwed in the plunger holder 15 , so that it is easy to replace the plunger 2 when it is worn out. It is necessary to replace only the plunger 2 , thereby reducing replacement cost as compared with the conventional pump.
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Reciprocating Pumps (AREA)
- Details Of Reciprocating Pumps (AREA)
Abstract
A liquid delivery pump includes a pump room for transferring liquid, a plunger having one end located in the pump room for moving reciprocally therein for delivering the liquid in the pump room, and a base end, and a crosshead for reciprocal movement situated adjacent to the pump room and having a flat end surface. A ball is attached to the crosshead to contact the flat end surface thereof. The base end is attached to the crosshead so that the plunger rotates freely relative to the flat end surface through the ball.
Description
- The present invention relates to a liquid delivery pump for a liquid chromatograph, and more specifically, relates to a structure for holding a plunger moving reciprocally within a pump room.
-
FIG. 2 is a sectional view of a conventional liquid delivery pump for a liquid chromatograph. In the figure,reference numeral 1 is a pump head;reference numeral 2 is a plunger;reference numeral 3 is a sealing material for allowing theplunger 2 to slide while preventing leak;reference numeral 4 is a pump room formed within thepump head 1;reference numerals check valves 5 a and 5 b;reference numeral 7 is a pump body;reference numeral 8 is a bearing; reference numeral 9 is a spring;reference numeral 10 is a crosshead;reference numeral 11 is a cam rotationally driven by a motor not shown in the figure; andreference numeral 12 is a cam follower that rolls along the circumference of thecam 11. - A tip side (left side in
FIG. 2 ) of theplunger 2 is inserted into thepump room 4 through the sealingmaterial 3, and a base side (right side inFIG. 2 ) thereof is connected to thecrosshead 10. Thecrosshead 10 axially supported by the bearing 8 moves reciprocally within thetubular pump body 7 with force imparted by the rotatingcam 11 via thecam follower 12 in a forward direction (toward the left side inFIG. 2 ) and force imparted by the spring 9 in a retreating direction (toward the right side inFIG. 2 ). Theplunger 2 moves reciprocally within thepump room 4 accompanying with the movement of thecrosshead 10. Accordingly, thepump room 4 is alternately pressurized and depressurized, and associated operations of thecheck valves inlet 5 to theoutlet 6, thereby delivering liquid. - The plunger 2A is formed of a material with high hardness, and good wear and chemical resistance such as sapphire. A metal having a surface coated with a ceramic film may be used (for example, see Patent Reference 1).
-
FIG. 3 illustrates a connecting structure between theplunger 2 and thecrosshead 10 in more detail. InFIG. 3 , the elements same as those shown inFIG. 2 are given the same reference numerals, and their descriptions are omitted.Reference numeral 15 is a plunger holder. One end of theplunger holder 15 is fixed to the base side of theplunger 2, and the other end thereof is machined to form aspherical end 15 a. Theplunger holder 15 is fixed to thecrosshead 10 with ascrew cap 16, so that theplunger 2 and thecrosshead 10 are connected. Thespherical end 15 a of theplunger 2 abuts against aflat end face 10 a of thecrosshead 10 with point contact. Accordingly, theplunger 2 freely rotates while moving reciprocally along thecrosshead 10. With such a structure, it is possible to prevent grinding or shifting off center between theplunger 2 and the sealingmaterial 3 shown inFIG. 2 when theplunger 2 moves and slides reciprocally against the sealingmaterial 3, thereby minimizing wear of theplunger 2 and the sealingmaterial 3. - Patent reference 1: Japanese Patent Publication (Kokai) NO.
- In the connecting structure between the plunger and the crosshead described above, it is necessary to machine the spherical end of the plunger holder with a high degree of sphericity to ensure smooth rotation of the plunger, thereby increasing production cost. Moreover, when the plunger is worn out, it is necessary to replace the plunger holder fixed to the plunger together with the plunger, thereby increasing maintenance cost as well.
- In view of the problems described above, an object of the present invention is to provide a liquid delivery pump for a liquid chromatograph with production and maintenance costs lower than those of the conventional device.
- Further objects and advantages of the invention will be apparent from the following description of the invention.
- In order to attain the objects described above, according to the present invention, a plunger holder is formed in a ball, and a plunger is connected to the plunger holder with a screw. In other words, according to the present invention, a liquid delivery pump comprises a crosshead moving reciprocally accompanied with a rotational movement of a cam, and a plunger having a tip portion inserted into a pump room via a sealing material and a base portion connected to the crosshead so as to rotate freely. The ball abuts against a flat end surface of the crosshead at a connection section between the crosshead and the plunger, and the base portion of the plunger is screwed in the ball.
- In the field of bearings or the like, manufacturing technology has been established to produce a ball with a high degree of sphericity. Accordingly, it is possible to manufacture or obtain a high-quality ball at low cost. According to the present invention, such a ball can be used as the plunger holder, thereby reducing production cost. In terms of performance, the plunger can move freely and follow deformation of the sealing material, thereby reducing wear of the sealing material. As a result, it is possible to provide a highly durable liquid delivery pump for a liquid chromatograph. When the plunger is worn, it is possible to replace only the plunger, thereby reducing maintenance cost.
-
FIG. 1 is a schematic view showing a liquid delivery pump according to an embodiment of the present invention; -
FIG. 2 is a schematic view showing a conventional liquid delivery pump; and -
FIG. 3 is a detailed view showing the conventional liquid delivery pump. - Hereunder, embodiments of the present invention will be explained with reference to the accompanying drawings.
FIG. 1 is a schematic view showing a liquid delivery pump according to an embodiment of the present invention.FIG. 1 corresponds toFIG. 3 , and an overall structure of the liquid delivery pump is substantially the same as that shown inFIG. 2 . InFIG. 1 , the same reference numerals are used for elements functionally same as those inFIG. 3 , and descriptions thereof are omitted. - As shown in
FIG. 1 , in the embodiment, a difference from the conventional pump is that aplunger holder 15 is formed in a ball. Manufacturing technology for a ball with a high degree of sphericity has been established in the field of bearings, and it is possible to produce balls at relatively low cost and high-quality. Such a ball thus manufactured or obtained is provided with ascrew hole 15 b for screwing a female screw to form theplunger holder 15. - The
plunger 2 is provided with amale screw 2 a at a base portion thereof, so that themale screw 2 a is screwed into thescrew hole 15 b. When themale screw 2 a is screwed into thescrew hole 15 b as indicated by the arrow, theplunger 2 and theplunger holder 15 are connected. - In the embodiment, an operation of the pump constructed as described above is basically the same as the conventional pump shown in
FIG. 3 . A surface (spherical surface) of the plunger holder 15 abuts against aflat end surface 10 a of thecrosshead 10, so that theplunger 2 rotates freely. Different from the conventional pump, the spherical body with a high degree of sphericity (for example, a ball bearing) is used as theplunger holder 15, so that theplunger 2 moves smoothly and slides without grinding against the sealingmaterial 3 shown inFIG. 2 , even when thesealing material 3 is slightly off-centered or deformed. As a result, it is possible to reduce wear of theplunger 2 and the sealingmaterial 3. - Moreover, the
plunger 2 is screwed in theplunger holder 15, so that it is easy to replace theplunger 2 when it is worn out. It is necessary to replace only theplunger 2, thereby reducing replacement cost as compared with the conventional pump. - The disclosure of Japanese Patent Application No. 2004-088924, filed on Mar. 25, 2004, is incorporated in the application.
- While the present invention has been explained with reference to the specific embodiments, the explanation is illustrative and the invention is limited only by the appended claims.
Claims (3)
1. A liquid delivery pump for a liquid chromatograph, comprising:
a pump room for transferring liquid,
a plunger having one end located in the pump room for moving reciprocally therein for delivering the liquid in the pump room, and a base end,
a crosshead for reciprocal movement situated adjacent to the pump room and having a flat end surface, and
a ball attached to the crosshead to contact the flat end surface thereof, said base end being attached to the crosshead so that the plunger rotates freely relative to the flat end surface through the ball.
2. A liquid delivery pump according to claim 1 , further comprising sealing means attached to the pump room, through which the plunger passes, and a cam for reciprocally moving the crosshead.
3. A liquid delivery pump according to claim 2 , wherein said base portion of the plunger is screwed into the ball.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2004-088924 | 2004-03-25 | ||
JP2004088924A JP4086001B2 (en) | 2004-03-25 | 2004-03-25 | Liquid chromatograph pump |
Publications (1)
Publication Number | Publication Date |
---|---|
US20050214139A1 true US20050214139A1 (en) | 2005-09-29 |
Family
ID=34990054
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/071,180 Abandoned US20050214139A1 (en) | 2004-03-25 | 2005-03-04 | Liquid delivery pump for liquid chromatograph |
Country Status (3)
Country | Link |
---|---|
US (1) | US20050214139A1 (en) |
JP (1) | JP4086001B2 (en) |
CN (1) | CN1317558C (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20090104083A1 (en) * | 2007-10-23 | 2009-04-23 | Shimadzu Corporation | Check valve, infusion device using the same, and method of manufacturing the same |
US20110192277A1 (en) * | 2010-02-08 | 2011-08-11 | Masanori Fujiwara | Cam mechanism and liquid sending pump having same |
WO2015150908A1 (en) * | 2014-04-02 | 2015-10-08 | Agilent Technologies, Inc. | Fluid pump with a bearing with a laterally compact imparting body with two convex coupling caps which lie opposite one another |
US10955431B2 (en) * | 2017-08-30 | 2021-03-23 | Hitachi High-Tech Corporation | Automatic analysis device with syringe pump |
US11920582B2 (en) | 2019-12-27 | 2024-03-05 | Kyocera Corporation | Plunger, pump, and liquid analysis device |
Families Citing this family (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2007292011A (en) * | 2006-04-27 | 2007-11-08 | Shimadzu Corp | Liquid feed pump and liquid chromatograph using liquid feed pump |
JP4972613B2 (en) * | 2008-07-02 | 2012-07-11 | 株式会社日立ハイテクノロジーズ | Liquid feeding device and liquid chromatograph |
KR101000853B1 (en) | 2008-10-24 | 2010-12-14 | 홍도의 | A high-pressuer plunger pump |
CN102052275B (en) * | 2009-10-30 | 2012-10-10 | 北京普析通用仪器有限责任公司 | Parallel liquid phase chromatographic pump |
CN102312812A (en) * | 2010-06-29 | 2012-01-11 | 株式会社岛津制作所 | Solution feed pump |
JP5370310B2 (en) * | 2010-08-03 | 2013-12-18 | 株式会社島津製作所 | Feed pump |
CN102155378B (en) * | 2011-03-17 | 2012-12-05 | 芜湖天乐分析仪器有限公司 | High-pressure constant current pump of liquid chromatograph |
JP6227308B2 (en) * | 2013-07-12 | 2017-11-08 | 三菱重工業株式会社 | Rotating machine |
CN105223298B (en) * | 2014-06-20 | 2019-01-08 | 苏州普源精电科技有限公司 | A kind of liquid chromatograph with piston structure |
KR101887550B1 (en) * | 2017-03-13 | 2018-09-06 | 비씨태창산업(유) | High pressure plunger pump |
CN107387400B (en) * | 2017-08-08 | 2020-08-21 | 江苏同济分析仪器有限公司 | Method for assembling plunger mechanism of high-pressure infusion pump of liquid chromatograph |
RU178551U1 (en) * | 2017-12-04 | 2018-04-06 | Акционерное общество "Научно-исследовательский институт Приборостроения имени В.В. Тихомирова" | WAVE WAVE LOAD |
JP6993303B2 (en) * | 2018-07-26 | 2022-01-13 | 京セラ株式会社 | Plunger, pump, and liquid analyzer |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
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US6736049B2 (en) * | 2000-12-11 | 2004-05-18 | Gilson, Inc. | High pressure low volume pump |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
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CN2178285Y (en) * | 1993-12-11 | 1994-09-28 | 江汉大学 | Reciprocating helical double plunger pump |
JPH09292381A (en) * | 1996-04-26 | 1997-11-11 | Shimadzu Corp | Liquid feeding pump |
JPH09318611A (en) * | 1996-05-28 | 1997-12-12 | Shimadzu Corp | Liquid feed pump for liquid chromatograph |
JP3988275B2 (en) * | 1998-09-29 | 2007-10-10 | 株式会社島津製作所 | Feed pump |
CN1152256C (en) * | 2001-04-06 | 2004-06-02 | 中国科学院大连化学物理研究所 | Electroosmotic current driven high-pressure perfusion pump |
CN1207568C (en) * | 2002-06-03 | 2005-06-22 | 复旦大学 | Thermal expanding microstream high-pressure gradient pump and its application method |
-
2004
- 2004-03-25 JP JP2004088924A patent/JP4086001B2/en not_active Expired - Lifetime
-
2005
- 2005-03-04 US US11/071,180 patent/US20050214139A1/en not_active Abandoned
- 2005-03-22 CN CNB2005100590739A patent/CN1317558C/en active Active
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6736049B2 (en) * | 2000-12-11 | 2004-05-18 | Gilson, Inc. | High pressure low volume pump |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20090104083A1 (en) * | 2007-10-23 | 2009-04-23 | Shimadzu Corporation | Check valve, infusion device using the same, and method of manufacturing the same |
US8382454B2 (en) * | 2007-10-23 | 2013-02-26 | Shimadzu Corporation | Check valve, infusion device using the same, and method of manufacturing the same |
US20110192277A1 (en) * | 2010-02-08 | 2011-08-11 | Masanori Fujiwara | Cam mechanism and liquid sending pump having same |
US8863644B2 (en) | 2010-02-08 | 2014-10-21 | Shimadzu Corporation | Cam mechanism and liquid sending pump having same |
WO2015150908A1 (en) * | 2014-04-02 | 2015-10-08 | Agilent Technologies, Inc. | Fluid pump with a bearing with a laterally compact imparting body with two convex coupling caps which lie opposite one another |
US10955431B2 (en) * | 2017-08-30 | 2021-03-23 | Hitachi High-Tech Corporation | Automatic analysis device with syringe pump |
US11920582B2 (en) | 2019-12-27 | 2024-03-05 | Kyocera Corporation | Plunger, pump, and liquid analysis device |
Also Published As
Publication number | Publication date |
---|---|
CN1317558C (en) | 2007-05-23 |
CN1673735A (en) | 2005-09-28 |
JP4086001B2 (en) | 2008-05-14 |
JP2005274391A (en) | 2005-10-06 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: SHIMAZDU CORPORATION, JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:ASO, YOSHIAKI;REEL/FRAME:016348/0994 Effective date: 20050303 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |