Patent Grant
11821440
This application is a Section 371 National Stage Application of International Application No. PCT/JP2019/004745, filed Feb. 2, 2019, which is incorporated by reference in its entirety and published as WO 2019/159855 A1 on Aug. 22, 2019 and which claims priority of Japanese Application No. 2018-025854, filed Feb. 16, 2018.
The present invention relates to a vacuum pump such as a turbomolecular pump, and a control device of the vacuum pump.
The turbomolecular pump device disclosed in, for example, WO 2011/111209, has conventionally been known. The turbomolecular pump device of WO 2011/111209 is provided with cooling devices 13 as described in paragraph 0010 and shown in FIGS. 1, 2, and the like. The cooling devices 13 are interposed side by side in the axial direction between a pump main body 11 and a power supply apparatus 14, and cool mainly electronic components of a motor drive circuit in the power supply apparatus 14. The cooling devices 13 each have a jacket main body 13a in which a cooling water passage is formed, and a cooling water inlet 13b and a cooling water outlet 13c for circulating cooling water in the cooling water passage by means of a water-feeding pump.
The discussion above is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter. The claimed subject matter is not limited to implementations that solve any or all disadvantages noted in the background.
Incidentally, vacuum pumps such as turbomolecular pumps need to be downsized for reasons such as the surrounding space of the vacuum equipment to be connected. In some cases, electrical equipment such as motor drive circuits and control circuits need to be downsized as well, and in such a case, the mounting density of the electrical equipment increases easily, thereby raising the temperatures of the electrical equipment. The mounting density of the electrical equipment is increased also by improved performance of the vacuum pump, thereby easily increasing the temperatures of the electrical equipment. For this reason, even when the cooling devices disclosed in, for example, WO 2011/111209 are used, cooling needs to be performed as efficient as possible. Efficient cooling can extend the life of the electrical equipment.
In order to enhance the cooling effect, air cooling using, for example, a cooling fan in place of the water cooling described in WO 2011/111209 is considered. However, the external dimensions of the vacuum pump increase by providing the cooling fan, making downsizing of the vacuum pump difficult. Moreover, use of the cooling fan causes the generated air flow to raise dust in the clean room, making it difficult to maintain the clean environment. In addition, when the cooling fan is used, intensive use of an air conditioner to eliminate the raised dust may result in an increase of the total energy consumption. For these reasons, it is difficult to employ air cooling to achieve efficient cooling in a vacuum pump such as a turbomolecular pump; thus, it is desired that water cooling be employed.
The present invention was contrived in order to solve the foregoing problems, and an object thereof is to provide a vacuum pump capable of efficiently cooling electrical equipment, and a control device of the vacuum pump.
In order to achieve the object described above, the present invention provides a vacuum pump comprising a pump main body, and a control device disposed outside the pump main body, wherein the control device includes a cooling portion in which a cooling medium flow passage is formed, and an electrical component portion that has a heat generating component and can be cooled by the cooling portion, the electrical component portion is attached to the cooling portion so that heat from the electrical component portion can be transferred, the electrical component portion is provided with a circuit board that has the heat generating component mounted thereon and is fixed to the cooling portion, and a mold portion that at least partially covers the circuit board and the heat generating component, and the heat can be transferred toward the cooling portion via the mold portion.
In order to achieve the object described above, the present invention according to another aspect is a vacuum pump in which a penetrating portion that penetrates the circuit board and into which the mold portion enters is formed in the circuit board, and the heat can be transferred toward the cooling portion via the mold portion and the penetrating portion.
In order to achieve the object described above, the present invention according to another aspect is a vacuum pump in which the cooling portion faces the mold portion entering the penetrating portion, at a position opposite to a side of the circuit board on which the heat generating component is mounted.
In order to achieve the object described above, the present invention according to another aspect is a vacuum pump in which the cooling portion partially exposes the cooling medium flow passage toward the electrical component portion.
In order to achieve the object described above, the present invention according to another aspect is a control device of a vacuum pump, comprising a cooling portion in which a cooling medium flow passage is formed, and an electrical component portion that has a heat generating component and can be cooled by the cooling portion, wherein the electrical component portion is attached to the cooling portion so that heat from the electrical component portion can be transferred, the electrical component portion is provided with a circuit board that has the heat generating component mounted thereon and is fixed to the cooling portion, and a mold portion that at least partially covers the circuit board and the heat generating component, and the heat can be transferred toward the cooling portion via the mold portion.
The present invention can provide a vacuum pump capable of efficiently cooling electrical equipment, and a control device of the vacuum pump.
The Summary is provided to introduce a selection of concepts in a simplified form that are further described in the Detail Description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.
A vacuum pump according to one embodiment of the present invention is now described hereinafter with reference to the drawings.
The turbomolecular pump 10 integrally has a cylindrical pump main body 11 and a box-shaped electrical equipment case 31 as an electrical equipment storage (control device). The pump main body 11 has an inlet portion 12 on the upper side in the drawing which is connected to a side of the target device, and an exhaust portion 13 on the lower side which is connected to an auxiliary pump or the like. The turbomolecular pump 10 can be used not only in a vertical posture in the vertical direction as shown in
The electrical equipment case 31 is attached to an outer peripheral surface, which is a side portion of the pump main body 11, in such a manner as to protrude in a radial direction. Thus, the turbomolecular pump 10 of the present embodiment is downsized in the axial direction as compared to the type disclosed in, for example, WO 2011/111209 in which the pump main body and the electrical equipment (electrical component) are arranged in the axial direction (gas transfer direction). Furthermore, the turbomolecular pump 10 of the present embodiment can be installed even if an axial space is relatively narrow.
The pump main body 11 has a cylindrical main body casing 14 with steps. In the present embodiment, the main body casing 14 has a diameter of approximately 350 mm and a height of approximately 400 mm. The inside of the main body casing 14 is provided with an exhaust mechanism portion 15 and a rotary drive portion 16. The exhaust mechanism portion 15 is of a composite type composed of a turbomolecular pump mechanism portion 17 and a thread groove pump mechanism portion 18.
The turbomolecular pump mechanism portion 17 and the thread groove pump mechanism portion 18 are disposed in a continuous fashion in the axial direction of the pump main body 11; in
The turbomolecular pump mechanism portion 17 disposed on the upper side in
The stator blade portion 19 is provided integrally on the main body casing 14, and the rotor blades provided in the rotor blade portion 20 are each sandwiched between upper and lower stator blades provided in the stator blade portion 19. The rotor blade portion 20 is integrated with a rotating shaft (rotor shaft) 21, only an upper end of which is schematically shown in
The rotating shaft 21 passes through the thread groove pump mechanism portion 18 on the lower side and is coupled to the abovementioned rotary drive portion 16, only the outline of which is schematically shown in the drawing. The thread groove pump mechanism portion 18 includes a rotor cylindrical portion 23 and a thread stator 24, wherein a thread groove portion 25, which is a predetermined gap, is formed between the rotor cylindrical portion 23 and the thread stator 24. The rotor cylindrical portion 23 is coupled to the rotating shaft 21 so as to be able to rotate integrally with the rotating shaft 21. An outlet port 26 to be connected to an exhaust pipe is disposed below the thread groove pump mechanism portion 18, whereby the inside of the outlet port 26 and the thread groove portion 25 are spatially connected.
The rotary drive portion 16 is a motor and includes, although not shown, a rotor formed on an outer periphery of the rotating shaft 21 and a stator disposed so as to surround the rotor. The power for activating the rotary drive portion 16 is supplied by power supply equipment or control equipment stored in the electrical equipment case 31 described above.
Although not shown, a non-contact type bearing by magnetic levitation (magnetic bearing) is used to support the rotating shaft 21. Therefore, the pump body 11 can realize an environment in which the pump is not worn when rotated at high speed, has a long life, and does not require lubricating oil. A combination of a radial magnetic bearing and a thrust bearing can be employed as the magnetic bearing. Further, the magnetic bearing can be used in combination with a touchdown bearing to prevent possible damage.
Driving the rotary drive portion 16 rotates the rotor blade portion 20 and the rotor cylindrical portion 23 of the turbomolecular pump mechanism portion 17 that are integrated with the rotating shaft 21. When the rotor blade portion 20 is rotated, the gas is drawn from the inlet portion 12 shown on the upper side of FIG. A, and transferred toward the thread groove pump mechanism portion 18 while causing gas molecules to collide with the stator blades of the stator blade portion 19 and the rotor blades of the rotor blade portion 20. In the thread groove pump mechanism portion 18, the gas transferred from the turbomolecular pump mechanism portion 17 is introduced to the gap between the rotor cylindrical portion 23 and the thread stator 24 and compressed in the thread groove portion 25. The gas compressed inside the thread groove portion 25 enters the outlet port 26 from the exhaust portion 13 and is then exhausted from the pump main body 11 via the outlet port 26.
The electrical equipment case 31 is described next. As shown in
The cooling jacket 36 includes a jacket main body 37 and a cooling pipe 38. The jacket main body 37 is a casting that integrally includes a horizontal portion 39 oriented substantially horizontally and a vertical portion 40 oriented substantially vertically. Aluminum or the like can be employed as the material (casting material) of the cooling jacket 36. The horizontal portion 39 has a base end side thereof connected to the vertical portion 40 and facing outside the pump main body 11 (so as to be away from the pump main body 11) and has a tip end side facing the pump main body 11.
Furthermore, as shown in
As shown in
However, the arrangement of the power supply circuit portion 33 and the control circuit portion 34 is not limited to the arrangement described above; the power supply circuit portion 33 and the control circuit portion 34 may be arranged vertically, with the control circuit portion 34 disposed below.
As shown in
The cooling pipe 38 is bent into a C-shape in the vertical portion 40 as shown by a broken line, and includes parallel portions 50 extending substantially horizontally and parallel to each other, and a vertical connecting portion 51 connecting the parallel portions 50. Both ends 52, 53 of the cooling pipe 38 slightly protrude approximately several mm from an end surface 54 of the vertical portion 40.
In the present embodiment, of the both ends 52, 53 of the cooling pipe 38, the end 53 on the lower side in
Moreover, the cooling pipe 38 is partially exposed from the inner surface 46 of the vertical portion 40, and a part of the cooling pipe 38 in a circumferential direction thereof is configured as an exposed portion 55 protruding from the inner surface 46. The exposed portion 55 is located behind the power supply circuit portion 33 fixed to the inner surface 46, is in contact with the mold resin 74, and is separated from the power supply circuit portion 33. In the present embodiment, only the parallel portion 50 on the upper side of
The cooling portion is generally cooled by the cooling water flowing through the cooling pipe 38. However, the cooling medium (refrigerant) is not limited to the cooling water; a fluid other than water or other cooling medium such as a cold gas may be used.
In the present embodiment, the exposed portion 55 and the inner surface 46 of the vertical portion 40 are in contact with the mold resin 74, but the configuration is not limited thereto; for example, a gap (space) of a predetermined distance can be interposed partially or entirely between the inner surface 46 of the vertical portion 40 and the mold resin 74.
The configuration is not limited thereto; when casting the jacket main body 37, the cooling pipe 38 may be disposed so as to be fit in the vertical portion 40 over the entire circumference, then the casting may be performed, and thereafter the inner surface 46 may be cut so that the exposed portion 55 appears. However, it is conceivable that, in a case where the vertical portion 40 is relatively thin, and the cooling pipe 38 and the outer surface 47 are not thick enough, the cooling pipe 38 easily separates from the vertical portion 40 due to a load acting on the vertical portion 40 during cutting. In such a case, it is assumed that it is difficult to adjust the level of the load applied during cutting. For this reason, as illustrated in
Next, the power supply circuit portion 33 is described on the basis of
Examples of the circuit components 62 include transformers, coils, capacitors, filters, diodes, field effect transistors (FETs), and the like.
Here, when mounting various circuit components 62 onto the circuit board 61, the directions (or “postures”) of the circuit components 62 are determined in view of the heights thereof. In other words, although the cooling jacket 36 is positioned on the back side of the circuit board 61 (the non-mounting side) as described above, the circuit components 62 become far away from the cooling jacket 36 as the heights of the circuit components 62 increase on the mounting side of the circuit board 61. Mounting the circuit components 62 having large heights (i.e., tall circuit components 62) upright makes it difficult to transfer heat to the cooling jacket 36 by heat conduction or heat transmission, and as a result the power supply circuit portion 33 cannot be cooled easily.
Therefore, in the present embodiment, the circuit components 62 are laid out on the circuit board 61, at sections where a necessary area can be secured. In such a state in which the circuit components 62 are laid out, the heights thereof from the circuit board 61 can be reduced, and this state can be referred to as “tilted state” or the like. By laying the circuit components 62 so that a larger portion of the circuit components 62 comes close to the cooling jacket 36, the circuit components 62 can be cooled efficiently.
Furthermore, a plurality of sheet metal members 71 made of metal are mounted on the circuit board 61. The sheet metal members 71 can be fixed by providing the circuit board 61 with a member for supporting the sheet metal members 71 or by providing the sheet metal members 71 with ribs for screwing the sheet metal members 71. Aluminum or the like, for example, is used as the material of the sheet metal members 71.
The sheet metal members 71 may be in a flat shape or an L-shape and are fixed to the circuit board 61 so as to stand upright substantially perpendicularly from the circuit board 61 (in an upright posture). The sheet metal members 71 have the thickness direction thereof oriented in a direction in which a mounting surface of the circuit board 61 extends (a direction perpendicular to the thickness direction of the circuit board 61). Mounting the sheet metal members 71 in this orientation can minimize the area occupied by the sheet metal members 71 on the mounting surface of the circuit board 61.
In addition, the sheet metal members 71 can be used for mounting the circuit components 62. Of the various circuit components 62, diodes and other semiconductor elements that tend to increase in temperature are fixed to plate surfaces of the sheet metal members 71. Conduction of the semiconductor elements can be ensured by connecting lead portions (not shown) of the semiconductor elements fixed to the sheet metal members 71 to wiring of the circuit board 61. Providing the circuit components 62 on the plate surfaces of the sheet metal members 71 in this manner can increase the area on the circuit board 61 on which the circuit components 62 can be mounted.
As shown in
The mounting surface of the circuit board 61 and the rear surface side of the same which is the non-mounting side are spatially connected via the slits 72, allowing the heat passing through the slits 72 to move between the mounting surface and the rear surface of the circuit board 61. The larger the opening areas of the slits 72, the easier for the heat to move. Moreover, in the present embodiment, the holes penetrating the circuit board 61 are configured as the long-hole slits 72. However, the shape of the slits 72 is not limited thereto; for example, the slits 72 can have various shapes such as a rectangular shape, a square shape, a circular shape, a triangular shape, a diamond shape, and a trapezoidal shape. The locations of the holes penetrating the circuit board 61 are not limited to the vicinity of the circuit components 62 (including the sheet metal members 71); the holes can be arranged, for example, immediately below the circuit components 62 or positions intersecting with the circuit components 62.
Also, the circuit board 61 is sealed with the mold resin 74 as described above. As shown in
The mold resin 74 is configured to fulfill the function of improving the insulation with respect to the circuit board 61, the drip-proof function, the waterproof function, and the like. The mold resin 74 also functions to cool the power supply circuit portion 33 by coming into contact with the various circuit components 62 and the circuit board 61 and entering the slits 72 described above. Specifically, the mold resin 74 not only removes the heat from the various circuit components 62 and the circuit board 61 but also transfers part of the removed heat to the rear surface side of the circuit board 61 via the slits 72.
In addition, in the present embodiment, the gap between the circuit board 61 and the vertical portion 40 of the cooling jacket 36 or the exposed portion 55 of the cooling pipe 38 is filled. Therefore, the heat reaching the rear surface side of the circuit board 61 can further be transferred toward the cooling jacket 36 via the mold resin 74. By sufficient cooling, a space not filled with the mold resin 74 can be formed between the circuit board 61 and the cooling jacket 36, and the heat can be transferred through the space facing the cooling jacket 36.
The control circuit portion 34 is described next. The control circuit portion 34 is for controlling the mechanisms such as the motor provided in the pump main body 11. As shown in
Further, the control circuit portion 34 of the present embodiment has a two-layer laminate structure and includes a metal substrate (aluminum substrate) 86 bolted to the cooling jacket 36, and a resin substrate (glass epoxy substrate or the like) 87 conductively connected to the metal substrate 86. Although not shown, in addition to the circuit components 62, connectors and the like in accordance with various standards are mounted on, for example, the resin substrate 87.
In the present embodiment, since the control circuit portion 34 generates less heat compared with the power supply circuit portion 33, resin sealing as in the power supply circuit portion 33 is not performed on the control circuit portion 34. However, if necessary, the control circuit portion 34 may be resin-sealed except for connection terminals of the connectors.
The heat generated by the control circuit portion 34 is transferred not only from the metal substrate 86 joined to the outer surface 47 of the vertical portion 40, but also from a part that is not in direct contact with the vertical portion 40 (such as the resin substrate 87), to the vertical portion 40 via the metal substrate 86.
According to the turbomolecular pump 10 of the present embodiment described above, the cooling pipe 38 of the cooling jacket 36 is provided in such a manner that the exposed portion 55 is exposed from the vertical portion 40. Accordingly, the space outside the exposed portion 55 and the part that is in contact with the exposed portion 55 can be cooled directly. In addition, the inner surface 46 of the vertical portion 40 can be cooled efficiently.
Therefore, efficient cooling can be achieved without using a cooling fan. Since a cooling fan is not used, the turbomolecular pump 10 can be downsized. Moreover, not only is it possible to suppress an increase in temperature of the electrical equipment case 31, but also the product life of the turbomolecular pump 10 can be increased. Since efficient cooling can be achieved, the temperature of the cooling water does not need to be lowered much in the preceding stage of the turbomolecular pump 10.
Since the protruding, exposed portion 55 is formed, more direct cooling can be achieved as compared with the case where the cooling pipe 38 is entirely covered with the material (casting material) of the vertical portion 40. Furthermore, since the inner surface 46 of the vertical portion 40 can be brought close to the shaft center C1 of the cooling pipe 38, the temperature of the inner surface 46 can easily be lowered. Moreover, the vertical portion 40 can be made thin, reducing the space and weight of the cooling jacket 36. In addition, the amount of casting material used when manufacturing the cooling jacket 36 can be reduced, thereby lowering the manufacturing cost.
Since the cooling pipe 38 is incorporated in the cooling jacket 36 by means of casting, an outer peripheral surface of the cooling pipe 38 and the jacket main body 37 can be brought into close contact with each other at low cost. Specifically, in a case where, for example, the jacket main body 37 is produced by scraping an aluminum material and then the cooling pipe 38 is fixed to this produced jacket main body 37, a gap is likely to be created between the jacket main body 37 and the cooling pipe 38, increasing the thermal resistance. In order to perform efficient cooling, a sheet or the like made of a material having high thermal conductivity needs to be interposed between the jacket main body 37 and the cooling pipe 38 to fill the gap, which results in a cost increase. However, by incorporating the cooling pipe 38 by means of casting as described in the present embodiment, the outer peripheral surface of the cooling pipe 38 and the jacket main body 37 can be brought into close contact with each other at low cost.
According to the turbomolecular pump 10 of the present embodiment, since the power supply circuit portion 33 is sealed with the mold resin 74, heat transfer through the mold resin 74 can be achieved. Furthermore, since the slits 72 penetrating the circuit board 61 are provided and the mounting surface and the rear surface (non-mounting surface) of the circuit board 61 are connected by the slits 72, the heat can be released toward the rear surface of the circuit board 61 via the slits 72. In addition, since the rear surface of the circuit board 61 faces the vertical portion 40 of the cooling jacket 36, the heat generated on the mounting surface of the circuit board 61 can be transferred toward the cooling jacket 36 via the mold resin 74 or the slits 72.
In the present embodiment, the mold resin 74 is placed between the circuit board 61 and the cooling jacket 36. Therefore, the heat between the circuit board 61 and the cooling jacket 36 can be transferred via the mold resin 74. For this reason, the heat can be transferred easily as compared with the case where space is provided between the circuit board 61 and the cooling jacket 36.
Note that cooling using the mold resin 74, the slits 72 or the like can further enhance the effect of the water cooling by the cooling jacket 36. Also, the cooling described in the present embodiment can be a cooling technique that combines the heat transfer by the mold resin 74 or the slits 72 and the cooling by means of the cooling jacket 36. In addition, the cooling described in the present embodiment can be a cooling technique that combines air cooling and water cooling, since the space inside the electrical equipment case 31 is cooled as well by the cooling jacket 36.
The present invention can be modified in various ways in addition to the modes described above. For example, although the slits 72 are provided in the circuit board 61 in the present embodiment, penetrating portions such as the slits 72 may be provided on the sheet metal members 71 to allow the entry of the mold resin 74, so that the heat can be transferred through the penetrating portions on the front and back of the sheet metal members 71.
Although elements have been shown or described as separate embodiments above, portions of each embodiment may be combined with all or part of other embodiments described above.
Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are described as example forms of implementing the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2018-025854 | Feb 2018 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2019/004745 | 2/8/2019 | WO |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2019/159855 | 8/22/2019 | WO | A |
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| Number | Date | Country | |
|---|---|---|---|
| 20210025407 A1 | Jan 2021 | US |
