US20220145894A1 - Vacuum pump and vacuum pump constituent component - Google Patents
Vacuum pump and vacuum pump constituent component Download PDFInfo
- Publication number
- US20220145894A1 US20220145894A1 US17/440,563 US202017440563A US2022145894A1 US 20220145894 A1 US20220145894 A1 US 20220145894A1 US 202017440563 A US202017440563 A US 202017440563A US 2022145894 A1 US2022145894 A1 US 2022145894A1
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- Prior art keywords
- cooling
- heating
- water
- spacer portion
- spacer
- Prior art date
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- 239000000470 constituent Substances 0.000 title claims description 17
- 238000001816 cooling Methods 0.000 claims abstract description 97
- 238000010438 heat treatment Methods 0.000 claims abstract description 87
- 230000007246 mechanism Effects 0.000 claims abstract description 27
- 125000006850 spacer group Chemical group 0.000 abstract description 133
- 239000000498 cooling water Substances 0.000 description 12
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 10
- 229910052782 aluminium Inorganic materials 0.000 description 10
- 238000003754 machining Methods 0.000 description 9
- 239000000463 material Substances 0.000 description 9
- 238000013459 approach Methods 0.000 description 6
- 229910001220 stainless steel Inorganic materials 0.000 description 6
- 239000010935 stainless steel Substances 0.000 description 6
- 238000007789 sealing Methods 0.000 description 5
- 230000002093 peripheral effect Effects 0.000 description 4
- 230000007423 decrease Effects 0.000 description 3
- 238000012423 maintenance Methods 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 238000012546 transfer Methods 0.000 description 3
- 239000002245 particle Substances 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 230000001681 protective effect Effects 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 239000004065 semiconductor Substances 0.000 description 2
- 244000261422 Lysimachia clethroides Species 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 230000012447 hatching Effects 0.000 description 1
- 230000020169 heat generation Effects 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 238000005339 levitation Methods 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
Images
Classifications
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- 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
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- 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
- F04D29/40—Casings; Connections of working fluid
- F04D29/52—Casings; Connections of working fluid for axial pumps
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- 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
-
- 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
- F04D29/582—Cooling; Heating; Diminishing heat transfer specially adapted for elastic fluid pumps
- F04D29/584—Cooling; Heating; Diminishing heat transfer specially adapted for elastic fluid pumps cooling or heating the machine
Abstract
The present disclosure provides a vacuum pump of which a thermal resistance between a heater and a water-cooling tube is high and which has a small number of components. The vacuum pump includes: a main body casing having an intake portion and an exhaust portion of gas; a turbo-molecular pump mechanism portion in which stator blades and rotor blades are formed; and a motor for rotating the rotor blades, wherein the main body casing has a base spacer capable of thermal conduction between a heating spacer portion and a water-cooling spacer portion having been integrally molded, and the base spacer is provided with a boundary portion having been molded such that a cross section thereof assumes a narrow neck shape between the heating spacer portion and the water-cooling spacer portion.
Description
- This application is a U.S. national phase application under 35 U.S.C. § 371 of international application number PCT/JP2020/011072 filed on Mar. 13, 2020, which claims the benefit of priority to JP application number 2019-058859 filed on Mar. 26, 2019. The entire contents of each of international application number PCT/JP2020/011072 and JP application number 2019-058859 are incorporated herein by reference.
- The present disclosure relates to a vacuum pump such as a turbo-molecular pump and to a constituent component of the vacuum pump.
- Generally, a turbo-molecular pump is known as one type of a vacuum pump. The turbo-molecular pump is configured to rotate a rotor blade by energizing a motor inside a pump main body and exhaust gas (process gas) having been sucked into the pump main body by blowing away a particle of the gas. In addition, some types of turbo-molecular pumps are provided with a heater and a cooling tube to appropriately control a temperature of each area inside the pump.
- Since the heater and the cooling tube of a turbo-molecular pump such as that described above are provided in order to realize conflicting functions of heating and cooling, positional relationships and peripheral components must be carefully designed. For example, while a temperature of rotor blades plays a dominant role in a temperature inside a pump, unless a cooling function is designed appropriately, it is difficult to maintain the temperature of the rotor blades and a vicinity thereof at a desired temperature (for example, around 70° C.). In addition, when respective installation locations of the heater and the cooling tube are too close to each other, their respective functions cancel each other out due to heat exchange and makes it difficult to perform temperature control in an efficient manner.
- Furthermore, a component for holding the heater and a component for holding the cooling tube (holding components) are usually molded as separate fixtures from the perspectives of a difference in functions, ease of machining, and the like. Therefore, performing temperature control using a heater and a cooling tube increases the number of components and also increases costs required for machining and management of components, assembly of the components, and the like.
- An object of the present disclosure is to provide a vacuum pump of which a thermal resistance between a heater and a water-cooling tube (cooling tube) is high and which has a small number of components and to provide a vacuum pump constituent component.
- (1) In order to achieve the object described above, a vacuum pump according to the present disclosure includes: a pump mechanism portion in which a stator blade and a rotor blade are formed;
- a casing which encloses the pump mechanism portion;
- a motor for rotating the rotor blade; and
- a vacuum pump constituent component which is capable of thermal conduction between a heating portion and a cooling portion having been integrally molded, wherein
- the vacuum pump constituent component is provided with a boundary portion formed so that a cross section thereof assumes a narrow neck shape between the heating portion and the cooling portion.
- (2) In addition, in order to achieve the object described above, another vacuum pump according to the present disclosure is the vacuum pump according to (1), wherein the boundary portion is formed between a notched portion on an outer side and a tapered portion on an inner side of the vacuum pump constituent component.
- (3) In addition, in order to achieve the object described above, a vacuum pump constituent component according to the present disclosure is capable of thermal conduction between a heating portion and a cooling portion having been integrally molded, wherein the vacuum pump constituent component is provided with a boundary portion molded so that a cross section thereof assumes a narrow neck shape between the heating portion and the cooling portion.
- (4) In addition, in order to achieve the object described above, another vacuum pump constituent component according to the present disclosure is the vacuum pump constituent component according to (3), wherein the boundary portion is formed between a notched portion on an outer side and a tapered portion on an inner side.
- According to the present disclosure described above, a vacuum pump of which a thermal resistance between a heater and a water-cooling tube is high and which has a small number of components and a vacuum pump constituent component can be provided.
-
FIG. 1 represents a vertical cross section of a turbo-molecular pump according to a first embodiment of the present disclosure. -
FIG. 2A is an enlarged view showing a part of the turbo-molecular pump according to the first embodiment, andFIG. 2B is an enlarged view showing another area by changing phases. -
FIGS. 3A to 3C are explanatory views showing, side by side from right to left, a heating and cooling structure according to the first embodiment of the present disclosure, a heating and cooling structure according to a second embodiment of the present disclosure, and a conventional structure. -
FIG. 4 is an explanatory view showing an outline of temperature control. - Hereinafter, vacuum pumps according to respective embodiments of the present disclosure will be described with reference to the drawings.
FIG. 1 schematically shows a vertical section of a turbo-molecular pump 10 as a vacuum pump according to a first embodiment of the present disclosure. The turbo-molecular pump 10 is configured to be connected to a vacuum chamber (not illustrated) of an object device such as a semiconductor manufacturing apparatus, an electron microscope, or a mass spectrometer. - The turbo-
molecular pump 10 integrally includes a cylindrical pumpmain body 11 and a box-shaped electric case (not illustrated). In the pumpmain body 11 among these components, an upper side inFIG. 1 constitutes anintake portion 12 to be connected to a side of the object device and a lower side constitutes anexhaust portion 13 to be connected to an auxiliary pump or the like. - In addition, besides an upright posture in a vertical direction such as that shown in
FIG. 1 , the turbo-molecular pump 10 can also be used in an upside-down posture, a horizontal posture, and an inclined posture. - While the electric case (not illustrated) houses a power supply circuit portion for supplying power to the pump
main body 11 and a control circuit portion for controlling the pumpmain body 11, detailed descriptions of these components will be omitted here. - The pump
main body 11 includes amain body casing 14 which constitutes an approximately cylindrical chassis. Themain body casing 14 is constructed by connecting, in series in an axial direction, an intake-side casing 14 a as an intake-side component that is positioned in an upper part inFIG. 1 and an exhaust-side casing 14 b as an exhaust-side component that is positioned on the lower side inFIG. 1 . In this case, the intake-side casing 14 a can also be referred to as a casing or the like and the exhaust-side casing 14 b can also be referred to as a base or the like. - The intake-
side casing 14 a and the exhaust-side casing 14 b are stacked in a radial direction (a left-right direction inFIG. 1 ). In addition, in the intake-side casing 14 a, an inner circumferential surface in one end portion (a lower end portion inFIG. 1 ) in the axial direction opposes an outer circumferential surface in an upper end portion 29 b of the exhaust-side casing 14 b. Furthermore, the intake-side casing 14 a and the exhaust-side casing 14 b are airtightly coupled to each other by a plurality of hexagon socket screws (not illustrated) so as to sandwich an O ring (a sealing member 41) that is housed inside a groove portion. - Roughly speaking, the exhaust-
side casing 14 b has a bisected structure made up of a tubular base spacer 42 (a vacuum pump constituent component) and abase body 43 which blocks one end portion (a lower end portion inFIG. 1 ) in the axial direction of thebase spacer 42. In this case, thebase spacer 42 and thebase body 43 can also be respectively called an upper base and a lower base or the like. While thebase spacer 42 has aheating spacer portion 46 and a water-cooling spacer portion 47 which support aheater 48 and a water-cooling tube 49 for a TMS (Temperature Management System), details of thebase spacer 42 will be provided later. - The pump
main body 11 includes an approximately cylindricalmain body casing 14. Anexhaust mechanism portion 15 and a rotation driving portion (hereinafter, referred to as a “motor”) 16 are provided inside themain body casing 14. Among these components, theexhaust mechanism portion 15 is a composite-type component made up of a turbo-molecularpump mechanism portion 17 as a pump mechanism portion and a thread groovepump mechanism portion 18 as a thread groove exhaust mechanism portion. - The turbo-molecular
pump mechanism portion 17 and the thread groovepump mechanism portion 18 are consecutively arranged in the axial direction of the pumpmain body 11 and, inFIG. 1 , the turbo-molecularpump mechanism portion 17 is arranged on the upper side inFIG. 1 and the thread groovepump mechanism portion 18 is arranged on the lower side inFIG. 1 . Hereinafter, basic structures of the turbo-molecularpump mechanism portion 17 and the thread groovepump mechanism portion 18 will be schematically described. - The turbo-molecular
pump mechanism portion 17 arranged on the upper side inFIG. 1 transfers gas using a large number of turbine blades and includesstator blades 19 androtor blades 20 having predetermined inclined or curved surfaces and being formed in a radial pattern. In the turbo-molecularpump mechanism portion 17, thestator blades 19 and therotor blades 20 are arranged so as to be alternately lined up across approximately ten steps. - The
stator blades 19 are integrally provided on themain body casing 14 androtor blades 20 penetrate between upper andlower stator blades 19. Therotor blades 20 are integrated with acylindrical rotor 28, and therotor 28 is concentrically fixed to arotor shaft 21 so as to cover an outside of therotor shaft 21. With a rotation of therotor shaft 21, therotor blades 20 rotate in a same direction as therotor shaft 21 and therotor 28. - In this case, aluminum is adopted as a material of main components of the pump
main body 11, and materials of the exhaust-side casing 14 b, thestator blades 19, therotor 28, and the like to be described later are also aluminum. In addition, inFIG. 1 , in order to prevent the drawing from appearing excessively complicated, hatchings that indicate a cross section of components in the pumpmain body 11 have been omitted. - The
rotor shaft 21 is machined into a stepped columnar shape and extends from the turbo-molecularpump mechanism portion 17 to the thread groovepump mechanism portion 18 on the lower side. In addition, themotor 16 is arranged in a center part in an axial direction of therotor shaft 21. Themotor 16 will be described later. - The thread groove
pump mechanism portion 18 includes a rotorcylindrical portion 23 and athread stator 24. Thethread stator 24 is also called an “external thread” and the like and aluminum is adopted as the material of thethread stator 24. Anoutlet port 25 to be connected to an exhaust pipe is arranged in a stage subsequent to the thread groovepump mechanism portion 18, and an inside of theoutlet port 25 and the thread groovepump mechanism portion 18 are spatially connected to each other. - The
motor 16 described earlier includes rotors (reference sign omitted) fixed to an outer circumference of therotor shaft 21 and stators (reference sign omitted) arranged so as to surround the rotors. Power for operating themotor 16 is supplied by the power supply circuit portion or the control circuit portion housed in the electric case (not illustrated) described earlier. - Although a detailed illustration and reference signs will be omitted, a contactless bearing (a magnetic bearing) that utilizes magnetic levitation is used to support the
rotor shaft 21. Therefore, in the pumpmain body 11, high-speed rotation is performed in an abrasion-free manner and a long-life environment which eliminates the need for a lubricant is realized. It should be noted that a combination of a radial magnetic bearing and a thrust bearing can be adopted as the magnetic bearing. - Furthermore, protective bearings (also referred to as “touchdown (T/D) bearings”, “backup bearings”, and the like) 32 and 33 in a radial direction are arranged at predetermined intervals around upper and lower parts of the
rotor shaft 21. For example, even when problems such as an electrical failure or an atmospheric entry occur, theprotective bearings rotor shaft 21 from changing significantly and protect therotor blades 20 and peripheral portions thereof from damage. - During an operation of the turbo-
molecular pump 10 structured as described above, themotor 16 described earlier is driven and therotor blades 20 rotate. In addition, with the rotation of therotor blades 20, gas is sucked in from theintake portion 12 shown on the upper side inFIG. 1 and the gas is transferred to a side of the thread groovepump mechanism portion 18 while causing a gas particle to collide with thestator blades 19 and therotor blades 20. Furthermore, the gas is compressed in the thread groovepump mechanism portion 18, the compressed gas enters theoutlet port 25 from theexhaust portion 13, and the gas is exhausted from the pumpmain body 11 via theoutlet port 25. - It should be noted that the
rotor shaft 21 as well as therotor blades 20, the rotorcylindrical portion 23, rotors (reference signs omitted) of themotor 16 that integrally rotate with therotor shaft 21, and the like can be collectively referred to as, for example, a “rotor portion”, a “rotating portion”, or the like. - Next, a heating and cooling structure that is constituted by the
base spacer 42 described earlier and peripheral components thereof will be described. As shown inFIGS. 1, 2A, and 2B , thebase spacer 42 is concentrically combined with thebase body 43 described earlier and constitutes an exhaust-side area of themain body casing 14. Thebase body 43 has astator column 44 which is responsible for supporting themotor 16, therotor shaft 21, and the like, and thebase spacer 42 encloses a proximal end-side circumference of thestator column 44 at a predetermined interval in the radial direction. - As shown partially enlarged in
FIG. 2A , thebase spacer 42 has aheating spacer portion 46 and a water-coolingspacer portion 47. Thebase spacer 42 is an integrally molded article formed by subjecting a cast aluminum piece to predetermined machining and processing, and theheating spacer portion 46 and the water-coolingspacer portion 47 are integrated with each other. In addition, thebase spacer 42 is combined with thebase body 43 so as to face a side of theheating spacer portion 46 and coupled to thebase body 43 via a hexagon socket screw (not illustrated) so as to sandwich an O ring (a sealing member 45). - In this case, the
base spacer 42 and thebase body 43 can also be integrally molded using cast aluminum or stainless steel. However, since adopting separate components as in the present embodiment reduces dimensions of external shapes, easiness increases in various aspects including machining, management, transportation, and handling during assembly of the components. - Next, the
heating spacer portion 46 is annularly formed as a whole and has a rectangular cross section. In addition, thethread stator 24 described earlier is combined with and fixed to theheating spacer portion 46 in a state that enables heat transfer. - A
heater 48 for heating and atemperature sensor 51 such as that shown inFIG. 2B are mounted to theheating spacer portion 46. Among these components, theheater 48 is inserted to theheating spacer portion 46 from outside and fixed to theheating spacer portion 46 via aheater mounting tool 50 having aplate material 50 a, ahexagon socket screw 50 b, and the like. Theheater 48 varies an amount of heat generation by energization control. In addition, theheater 48 transfers generated heat to theheating spacer portion 46 and raises the temperature of theheating spacer portion 46. In this case, an arrangement of theheater 48 is given due consideration so that theheater 48 can approach thethread stator 24 and heat thethread stator 24 in an efficient manner. - In addition, in the present embodiment, there are two
heaters 48 which are arranged at approximately 180-degree intervals in theheating spacer portion 46. However, the present disclosure is not limited to this configuration and the number of theheaters 48 can be increased or reduced. Nevertheless, heating can be performed more efficiently when, for example, the number of theheaters 48 is increased to four and theheaters 48 are arranged at 90-degree intervals. - The
temperature sensor 51 described earlier is inserted to theheating spacer portion 46 from outside and fixed via a temperaturesensor mounting tool 53. In other words, thetemperature sensor 51 is attached to a same component (a single component) as theheater 48. In addition, thesensor mounting tool 53 has a similar structure to theheater mounting tool 50 described earlier and has aplate material 53 a, ahexagon socket screw 53 b, and the like. - In the present embodiment, there are two
temperature sensors 51 which are arranged at approximately 180-degree intervals in theheating spacer portion 46. In addition, thetemperature sensors 51 are arranged at approximately center of a phase related to the arrangement of the heater 48 (approximately center of the two heaters 48) and are lined up in a single row in a circumferential direction at 90-degree intervals together with theheaters 48. Furthermore, thetemperature sensors 51 are arranged so as to approach thethread stator 24 as much as possible and is configured to detect the temperature of theheating spacer portion 46 having been heated by theheater 48 at a position close to thethread stator 24. In this case, as thetemperature sensors 51, for example, various general sensors such as a thermistor can be adopted. - The water-cooling
spacer portion 47 described earlier is molded in an annular shape as a whole and is positioned in an upper part in the drawing (in an area on the intake side) with respect to theheating spacer portion 46 that constitutes a base. In addition, the water-coolingspacer portion 47 has a larger outer diameter and a larger inner diameter than theheating spacer portion 46 and protrudes in a flange shape toward an outer side in the radial direction. - Furthermore, the upper end portion 29 b of the water-cooling
spacer portion 47 is machined so as to be thinner than other portions of the water-coolingspacer portion 47 and protrudes upward in an erected-wall shape. In addition, the upper end portion 29 b of the water-coolingspacer portion 47 is configured to penetrate to an inner side of the intake-side casing 14 a and fit with the intake-side casing 14 a via the sealingmember 41. - When compared with the
heating spacer portion 46, the water-coolingspacer portion 47 is machined so as to be thinner than theheating spacer portion 46 as a whole and protrudes to an area on an outer side in the radial direction of theheating spacer portion 46. In addition, in aboundary portion 52 between theheating spacer portion 46 and the water-coolingspacer portion 47, a right-angle notchedportion 54 on an outer side and an inclined taperedportion 56 on an inner side approach each other so as to retain a suitable thickness. - In other words, on an outer side of the boundary portion 52 (an outer side of the main body casing 14), an outer
circumferential surface 46 a of theheating spacer portion 46 and alower surface 47 a of the water-coolingspacer portion 47 are machined so as to form the notchedportion 54 in a mutually orthogonal relationship in a cross section. In addition, on an inner side of the boundary portion 52 (an inner side of the main body casing 14), machining is obliquely performed so that an inner diameter gradually increases from the side of theheating spacer portion 46 toward the side of the water-coolingspacer portion 47 to form the taperedportion 56. - An
upper surface 46 b of theheating spacer portion 46 which connects to the taperedportion 56 is positioned on approximately the same plane as thelower surface 47 a of the water-coolingspacer portion 47 described above. In addition, a positional relationship regarding the axial direction between the notchedportion 54 and the taperedportion 56 is set such that the notchedportion 54 is relatively positioned on a lower side (an exhaust side) and the taperedportion 56 is relatively positioned on an upper side (an intake side). - Forming the
boundary portion 52 in such a shape enables theheating spacer portion 46 and the water-coolingspacer portion 47 to seamlessly connect to each other via an area (theboundary portion 52 to act as a thermal conduction portion) which is sandwiched in a bottleneck shape. In addition, by providing theboundary portion 52 that realizes such a narrow neck shape, a conduction path of heat can be narrowed while maintaining favorable thermal conduction by integrating a plurality of components into a single component. - In this case, while the water-cooling
spacer portion 47, theheating spacer portion 46, and theboundary portion 52 are integrated into a single component, various interpretations can be made with respect to a subordinate-superior relationship or regions of these components. For example, theboundary portion 52 can be considered to belong to (or constitute a part of) any one of the water-coolingspacer portion 47 and theheating spacer portion 46. - In addition to the above, the
boundary portion 52 can also be considered to partially belong to both the water-coolingspacer portion 47 and theheating spacer portion 46. Furthermore, theboundary portion 52 can be considered to constitute a region that is independent from both the water-coolingspacer portion 47 and theheating spacer portion 46 in thebase spacer 42. Moreover, a continuous form created by theheating spacer portion 46, theboundary portion 52, and the water-coolingspacer portion 47 can also be referred to, for example, a gooseneck shape. - A water-cooling
tube 49 that is a stainless steel tube is embedded (cast-in) in the water-coolingspacer portion 47 so as to extend in a circumferential direction. The water-coolingtube 49 is arranged so as to approach theboundary portion 52. Cooling water is supplied inside the water-coolingtube 49 via a pipe joint (not illustrated), and the cooling water flows inside the water-coolingtube 49 while drawing heat of the water-coolingspacer portion 47 and is guided out from themain body casing 14. The water-coolingspacer portion 47 is cooled as the cooling water is circulated in this manner. In addition, although not illustrated, a flow rate of the cooling water in the water-coolingtube 49 is controlled by opening and closing of a solenoid valve (switching the solenoid valve on and off). - A state of heating by the
heater 48 is detected by thetemperature sensor 51 that is a thermistor or the like attached at a predetermined position and managed via feedback control by the TMS (Temperature Management System). The TMS is a control method for controlling cooling by the cooling water that flows through the water-coolingtube 49 and heating by theheater 48 and maintaining a temperature of thebase spacer 42 and a periphery thereof to a predetermined value (for example, around 70° C.) suitable for exhausting gas. - In other words, gas (process gas) taken into the turbo-
molecular pump 10 may be introduced in a high-temperature state into the turbo-molecular pump 10 in order to enhance reactivity. In addition, in some cases, such a gas may cause a product (deposited material) to be deposited in the exhaust system such as the thread groovepump mechanism portion 18 once the gas is cooled to be exhausted and drops to or below a certain temperature. - Furthermore, the deposited material may narrow a flow path of gas and cause a decline in performance of the turbo-
molecular pump 10. However, performing temperature control by the TMS described earlier maintains the temperature of the exhaust system at a suitable level and prevents deposited material from being created due to an excessive temperature drop of the gas. - A high temperature setting of the TMS discourages products from being deposited. However, an excessively high temperature setting may adversely affect an electric system and peripheral components. When the temperature inside the main body casing 14 excessively rises, a semiconductor memory (not illustrated) in an electronic circuit is affected and may conceivably lead to, for example, loss of data related to maintenance information such as a pump activation time and an error history.
- When data related to maintenance information is lost, a timing of maintenance and inspection, a timing of replacement of the turbo-
molecular pump 10, and the like can no longer be determined and operations of the turbo-molecular pump 10 are hindered. Therefore, when the temperature inside the main body casing 14 (more precisely, the temperature of an area where the temperature sensor is installed) reaches an upper limit of a permissible range, a solenoid valve (a cooling water valve, not illustrated) that connects to the water-coolingtube 49 is switched on and cooling by the cooling water is performed. - Heat of the
heater 48 is conducted inside theheating spacer portion 46 and transferred to the side of the water-coolingspacer portion 47 via theboundary portion 52. In theboundary portion 52, the notchedportion 54 and the taperedportion 56 are provided adjacent to each other as described earlier and a path of thermal conduction has been narrowed down. Therefore, a thermal resistance by theboundary portion 52 is large and an amount of heat that is conducted from theheating spacer portion 46 to the water-coolingspacer portion 47 is kept to a minimum amount. - In addition, the temperature of the
heating spacer portion 46 is unlikely to be transferred to the water-coolingspacer portion 47, and cooling by the cooling water in the water-coolingtube 49 is prevented from being hindered by the temperature of theheating spacer portion 46. As a result, cost reduction by integrating theheating spacer portion 46 and the water-coolingspacer portion 47 into a single component can be realized while maintaining preferable thermal conduction characteristics. - Furthermore, in the present embodiment, on/off states of the
heater 48 and on/off states of the cooling water valve (not illustrated) are controlled relative to a predetermined temperature (for example, around 70° C.). In addition, as described earlier, since thetemperature sensor 51 is arranged so as to approach thethread stator 24 as much as possible, the temperature of thethread stator 24 can be adjusted in an efficient manner. Therefore, thethread stator 24 on which products are readily deposited can be easily managed at a predetermined temperature (for example, around 70° C.) which is a control target. - In addition, since the
temperature sensor 51 is arranged approximately halfway between the twoheaters 48, the distances to bothheaters 48 are the same. Therefore, a bias is less likely to occur in temperature detection and temperatures can be detected in an even and accurate manner. Furthermore, the temperature of theheating spacer portion 46 can be maintained at a predetermined temperature (for example, around 70° C.) or higher in a highly accurate and uniform manner. - In the present embodiment, the
temperature sensor 51 is provided in theheating spacer portion 46. However, thetemperature sensor 51 is not limited to this configuration and can also be provided in the water-coolingspacer portion 47 in addition to theheating spacer portion 46. In addition, the on/off states of the cooling water valve (not illustrated) can be controlled relative to a separately-set predetermined temperature (for example, a temperature that is sufficiently lower than 70° C.). By also providing thetemperature sensor 51 in the water-coolingspacer portion 47, temperature management of theheating spacer portion 46 and the water-coolingspacer portion 47 can be performed with higher accuracy. -
FIGS. 3A to 3C show comparison among three types of heating and cooling structures in which a relationship between theheating spacer portion 46 and the water-coolingspacer portion 47 has been differentiated. Hereinafter, by citing a heating and cooling structure of a different type from the first embodiment of the present disclosure shown inFIGS. 1, 2A, and 2B as an example and comparing the heating and cooling structure with the heating and cooling structure according to the first embodiment, features of the turbo-molecular pump 10 according to the first embodiment and a heating and cooling structure according to a second embodiment will be described. It should be noted that, in heating and cooling structures that differ from the first embodiment of the present disclosure, portions similar to those of the first embodiment will be denoted by same signs and descriptions will be omitted when appropriate. -
FIG. 3A at the left end ofFIG. 3 shows a type with a conventional structure that includes theheating spacer portion 46 and the water-coolingspacer portion 47 as separate components. In addition, in the conventional structure, theheating spacer portion 46 and the water-coolingspacer portion 47 are airtightly coupled to each other via an O-ring (a sealing member). Furthermore, in the conventional structure, theheating spacer portion 46 is integrally molded with thebase body 43. Moreover, the water-coolingspacer portion 47 is machined as a cast aluminum piece, and theheating spacer portion 46 and thebase body 43 are machined by shaving from a wrought aluminum material. - In the case of a turbo-molecular pump provided with a conventional heating and cooling structure such as that shown in
FIG. 3A , since theheating spacer portion 46 and the water-coolingspacer portion 47 are separate components that are placed apart from each other, there is no direct conduction of heat. Therefore, thermal resistance is high and heat insulating properties are excellent. - However, since the
heating spacer portion 46 is integrally molded with thebase body 43, a large component is to be included in the structure, resulting in increased external dimension and weight of the components. In addition, machining cost of the component that integrates theheating spacer portion 46 and the base body 43 (in this case, the component can be referred to as a “base spacer”) increases. Furthermore, difficulty increases in various aspects including management and transportation for storing the large-sized base spacer and handling of the base spacer during assembly. -
FIG. 3B shows a heating and cooling structure according to the second embodiment of the present disclosure which represents a type in which theheating spacer portion 46 and the water-coolingspacer portion 47 have been integrated into a single component. The heating and cooling structure according to the second embodiment has been created as a first enhancement proposal with respect to the conventional structure described above. In addition, whileFIG. 3C shows the heating and cooling structure according to the first embodiment (a heating and cooling structure similar to that shown inFIGS. 1, 2A, and 2B ), the first embodiment related toFIG. 3C has been created as a further enhancement proposal with respect to the second embodiment shown inFIG. 3B . - In the second embodiment shown in
FIG. 3B , a base spacer 62 which includes theheating spacer portion 46 and the water-coolingspacer portion 47 and which is molded as a single component is coupled to thebase body 43 so as to sandwich an O-ring (the sealing member 45) in a similar manner to the first embodiment described earlier. In addition, while the second embodiment includes aboundary portion 72 that constitutes a thermal conduction portion in a similar manner to the first embodiment, theboundary portion 72 has a shape in which right-angle notchedportions - Furthermore, the
upper surface 46 b of theheating spacer portion 46 is positioned above (on an intake side of) thelower surface 47 a of the water-coolingspacer portion 47 in the drawing. In addition, an innercircumferential surface 47 b of the water-coolingspacer portion 47 forms an erected wall that rises approximately vertically from theupper surface 46 b of theheating spacer portion 46. Furthermore, a flat inner circumference-sideupper surface 47 c that extends in the radial direction is formed between the innercircumferential surface 47 b of the water-coolingspacer portion 47 and the upper end portion 29 b of the water-coolingspacer portion 47. - In the second embodiment configured as described above, since the
heating spacer portion 46 and the water-coolingspacer portion 47 are integrated, when compared with a conventional structure illustrated inFIG. 3A , a weight and an external shape of components on a side of thebase body 43 can be distributed more on the side of the water-coolingspacer portion 47. As a result, with respect to the components constituting the exhaust side, external dimensions and a weight balance of the components can be more equalized (optimized) and easiness increases in various aspects including machining, management, and transportation of the components, and handling of the components during assembly. - An analysis of a thermal resistance between the
heating spacer portion 46 and the water-coolingspacer portion 47 according to the second embodiment described above and a comparison with a conventional structure revealed that, while thermal conduction occurs slightly more readily than the conventional structure, costs related to machining of components and the like are reduced. More specifically, assuming that a thermal resistance and cost in the conventional structure shown inFIG. 3A are represented as 100% as a reference, a thermal resistance according to the second embodiment is 60% and cost according to the second embodiment is 70%. In other words, the heating and cooling structure according to the second embodiment turns out to be a type which promotes cost reduction while keeping a decline in characteristics related to thermal resistance to a certain level as compared to the conventional structure. - It should be noted that, as a numerical analysis of thermal resistances related to the conventional structure and the second embodiment, simulations have been performed by replacing a relationship between a capacity of the heater 48 (a heating state) and a state of control of the cooling water that flows through the water-cooling
tube 49 with a relationship between an average temperature of the thread stator 24 (an external thread) and an on-time related to the cooling water (a solenoid valve open time). -
FIG. 4 shows, in a simplified manner, a relationship between a temperature (an average temperature) T of a measurement area in thethread stator 24 and a solenoid valve open time. On/off states of the solenoid valve are shown in a lower half of the drawing, and a variation in the temperature T of thethread stator 24 is shown in an upper half of the drawing. The temperature rises gradually when the solenoid valve is switched off and the temperature drops gradually when the solenoid valve is switched on. - A target temperature with respect to the
thread stator 24 is set to 70° C. In addition, temperature control of theheater 48 is performed so that the temperature of 70° C. is maintained even in a no-load state where there is no gas flow. In other words, this situation may be fitted toFIG. 4 and described as: the solenoid valve being switched on and off so that a waveform of the temperature T is within a range of 70 to 75° C. - Next, with respect to the first embodiment shown in
FIG. 3C , due to the structure described earlier and shown inFIGS. 1, 2A, and 2B , a thermal resistance relative to the conventional structure is 80% and cost relative to the conventional structure is 70%. In other words, the thermal resistance more closely approaches the conventional structure inFIG. 3A than the second embodiment shown inFIG. 3B and the cost is the same as the second embodiment. Therefore, the heating and cooling structure according to the first embodiment can be described as a type which keeps a decline in thermal resistance to an even lower level while realizing equally low cost as compared to the second embodiment. - It should be noted that the present disclosure is not limited to the first embodiment and the second embodiment described above and various modifications can be made without departing from the spirit and scope of the disclosure. For example, with respect to the first embodiment and the second embodiment of the present disclosure, shapes and dimensions of the
boundary portions heating spacer portion 46 and the water-coolingspacer portion 47. In addition, the shapes and the dimensions of theboundary portions - In addition, in the first embodiment and the second embodiment of the present disclosure, a cast aluminum piece is adopted as the
base spacer 42 that includes theheating spacer portion 46 and the water-coolingspacer portion 47. Therefore, compared to forming thebase spacer 42 by, for example, shaving stainless steel, machining is easier and cost is kept low. However, thebase spacer 42 is not necessarily limited to a cast aluminum piece and, depending on the situation, thebase spacer 42 may be made from stainless steel. - Adopting a cast aluminum piece as the
base spacer 42 results in lower rigidity and strength as compared to adopting stainless steel. In addition, the fact that theboundary portions base spacer 42. However, by casting the water-coolingtube 49 made of stainless steel in a vicinity of theboundary portions spacer portion 47 of thebase spacer 42 as in the first embodiment and the second embodiment of the present disclosure, thebase spacer 42 and, particularly, the vicinity of theboundary portion 72 can be reinforced.
Claims (4)
1. A vacuum pump, comprising:
a pump mechanism portion in which a stator blade and a rotor blade are formed;
a casing which encloses the pump mechanism portion;
a motor for rotating the rotor blade; and
a vacuum pump constituent component which is capable of thermal conduction between a heating portion and a cooling portion having been integrally molded, wherein
the vacuum pump constituent component is provided with a boundary portion formed so that a cross section thereof assumes a narrow neck shape between the heating portion and the cooling portion.
2. The vacuum pump according to claim 1 , wherein the boundary portion is formed between a notched portion on an outer side and a tapered portion on an inner side of the vacuum pump constituent component.
3. A vacuum pump constituent component which is capable of thermal conduction between a heating portion and a cooling portion having been integrally molded and which is provided with a boundary portion having been molded so that a cross section thereof assumes a narrow neck shape between the heating portion and the cooling portion.
4. The vacuum pump constituent component according to claim 3 , wherein the boundary portion is formed between a notched portion on an outer side and a tapered portion on an inner side.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2019058859A JP7306845B2 (en) | 2019-03-26 | 2019-03-26 | Vacuum pumps and vacuum pump components |
JP2019-058859 | 2019-03-26 | ||
PCT/JP2020/011072 WO2020195943A1 (en) | 2019-03-26 | 2020-03-13 | Vacuum pump and vacuum pump constituent component |
Publications (1)
Publication Number | Publication Date |
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US20220145894A1 true US20220145894A1 (en) | 2022-05-12 |
Family
ID=72611448
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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US17/440,563 Abandoned US20220145894A1 (en) | 2019-03-26 | 2020-03-13 | Vacuum pump and vacuum pump constituent component |
Country Status (4)
Country | Link |
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US (1) | US20220145894A1 (en) |
JP (1) | JP7306845B2 (en) |
CN (1) | CN113508231A (en) |
WO (1) | WO2020195943A1 (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
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JP2022114559A (en) * | 2021-01-27 | 2022-08-08 | エドワーズ株式会社 | vacuum pump and spacer |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6866472B2 (en) * | 2002-03-12 | 2005-03-15 | Boc Edwards Technologies Limited | Vacuum pump |
US7753661B2 (en) * | 2003-08-08 | 2010-07-13 | Boc Edwards Japan Limited | Vacuum pump |
US9618012B2 (en) * | 2014-02-05 | 2017-04-11 | Shimadzu Corporation | Turbo-molecular pump |
US11009028B2 (en) * | 2016-09-27 | 2021-05-18 | Edwards Japan Limited | Vacuum pump and stator disk to be installed in vacuum pump |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005083271A (en) * | 2003-09-09 | 2005-03-31 | Boc Edwards Kk | Vacuum pump |
JP2012017672A (en) * | 2010-07-07 | 2012-01-26 | Shimadzu Corp | Vacuum pump |
JP6484919B2 (en) * | 2013-09-24 | 2019-03-20 | 株式会社島津製作所 | Turbo molecular pump |
JP6287475B2 (en) * | 2014-03-28 | 2018-03-07 | 株式会社島津製作所 | Vacuum pump |
JP6398337B2 (en) * | 2014-06-04 | 2018-10-03 | 株式会社島津製作所 | Turbo molecular pump |
-
2019
- 2019-03-26 JP JP2019058859A patent/JP7306845B2/en active Active
-
2020
- 2020-03-13 WO PCT/JP2020/011072 patent/WO2020195943A1/en active Application Filing
- 2020-03-13 CN CN202080020393.6A patent/CN113508231A/en active Pending
- 2020-03-13 US US17/440,563 patent/US20220145894A1/en not_active Abandoned
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6866472B2 (en) * | 2002-03-12 | 2005-03-15 | Boc Edwards Technologies Limited | Vacuum pump |
US7753661B2 (en) * | 2003-08-08 | 2010-07-13 | Boc Edwards Japan Limited | Vacuum pump |
US9618012B2 (en) * | 2014-02-05 | 2017-04-11 | Shimadzu Corporation | Turbo-molecular pump |
US11009028B2 (en) * | 2016-09-27 | 2021-05-18 | Edwards Japan Limited | Vacuum pump and stator disk to be installed in vacuum pump |
Also Published As
Publication number | Publication date |
---|---|
JP7306845B2 (en) | 2023-07-11 |
WO2020195943A1 (en) | 2020-10-01 |
CN113508231A (en) | 2021-10-15 |
JP2020159267A (en) | 2020-10-01 |
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