MOUNTING A FLANGED VACUUM PUMP TO A VACUUM SYSTEM

Abstract

A vacuum pump comprises an inlet flange for connecting to a vacuum chamber, where the inlet flange comprises a plurality of apertures for receiving a plurality of protruding fixing elements extending from the vacuum chamber. The protruding fixing elements comprise an enlarged retaining portion at an end remote from the vacuum chamber and a fastener receiving portion having at least one radial dimension that is smaller than a corresponding dimension of the enlarged retaining portion. A fastening mechanism is provided that comprises a plurality of slots each extending from a same side of a plurality of apertures. The fastening mechanism is configured to be rotatable between a mounting position in which the apertures are aligned with the protruding fixing elements and a sealing position in which the slots are aligned with the protruding fixing elements.

Claims

1. A vacuum pump comprising: an inlet flange for connecting to a vacuum chamber, said inlet flange comprising a plurality of apertures for receiving a plurality of protruding fixing elements extending from said vacuum chamber, said protruding fixing elements comprising an enlarged retaining portion at an end remote from said vacuum chamber and a fastener receiving portion having at least one radial dimension that is smaller than a corresponding dimension of said enlarged retaining portion; a fastening mechanism comprising a plurality of slots each extending from a same side of a plurality of apertures; wherein said fastening mechanism is configured to be rotatable between a mounting position in which said apertures are aligned with said protruding fixing elements and a sealing position in which said slots are aligned with said protruding fixing elements.

2. The vacuum pump according to claim 1, wherein at least a portion of a surface of said fastening mechanism surrounding each of said slots is sloped, such that said at least a portion of said fastening mechanism is thinner closer to said aperture and thicker further from said aperture.

3. The vacuum pump according to claim 2, wherein a surface of said retaining portion of said protruding fixing elements extending radially beyond said fastener receiving portion is sloped, an angle of said slope corresponding to an angle of said sloped surface surrounding said slots.

4. The vacuum pump according to claim 1, said plurality of apertures being sized such that at least one dimension of said apertures is larger than a width of said slots.

5. The vacuum pump according to claim 1, wherein said fastening mechanism comprises said inlet flange, said inlet flange comprising said plurality of slots each extending from said plurality of apertures, said pump being rotatable between said mounting position and said sealing position when mounting said pump to a vacuum system.

6. The vacuum pump according to claim 1, wherein said fastening mechanism comprises a fastener mounted around an outer surface of said vacuum pump adjacent to said inlet flange, said fastener comprising: a plurality of apertures and said plurality of slots, said plurality of slots each extending from a same side of said plurality of apertures; wherein said fastener is mounted to be rotatable about said outer surface of said pump between a mounting position in which said plurality of apertures on said fastener are aligned with said plurality of flange apertures on said flange and a sealing position in which a portion of said plurality of slots are aligned with said plurality of apertures on said flange.

7. The vacuum pump according to claim 6, wherein said fastener comprises a ring and said slots extend in a circumferential direction parallel to a circumference of said ring, so that protruding fixing elements passing through said apertures move from said plurality of apertures along said plurality of slots on rotation of said fastener from said mounting position to said sealing position.

8. The vacuum pump according to claim 1, wherein said fastening mechanism comprises a plurality of retainers corresponding to said plurality of protruding fixing elements, said plurality of retainers being formed of a material that is softer than a material forming a portion of said fastening mechanism comprising said slots and being configured to be mounted between said enlarged portion of said protruding fixing elements and said portion of said fastening mechanism comprising said slots.

9. The vacuum pump according to claim 8, wherein said plurality of retainers each comprise a side wall partially surrounding an aperture, said side wall comprising an opening configured such that said corresponding protruding fixing element can be pushed through said opening on mounting of said retaining element to said protruding fixing element, at least one dimension of said aperture being smaller than a corresponding dimension of said enlarged retaining portion of said protruding fixing element.

10. The vacuum pump according to claim 1, wherein said fastening mechanism comprises a retaining element comprising a plurality of apertures for receiving said plurality of protruding fixing elements, each of said plurality of apertures in said retaining element comprise a receiving portion and a reduced sized retaining portion, said retaining element being rotatable between a mounting position where said receiving portions of said apertures are aligned with said protruding fixing elements and a retaining position where said retaining portions of said apertures are aligned with said protruding fixing elements, at least one dimension of said retaining portion being smaller than a corresponding dimension of said enlarged retaining portion of said protruding fixing element.

11. The vacuum pump according to claim 1, wherein said fastening mechanism comprises a biasing element comprising a plurality of apertures for receiving said plurality of protruding fixing elements, at least a portion of at least one surface of said biasing element being sloped, such that portions of said biasing element are thicker around said apertures and are thinner away from said apertures.

12. The vacuum pump according to claim 10, wherein said retaining element and said biasing element are a same element.

13. The vacuum pump according to claim 11, wherein said fastening mechanism comprises a fastener mounted around an outer surface of said vacuum pump adjacent to said inlet flange, said fastener comprising: a plurality of apertures and said plurality of slots, said plurality of slots each extending from a same side of said plurality of apertures; wherein said fastener is mounted to be rotatable about said outer surface of said pump between a mounting position in which said plurality of apertures on said fastener are aligned with said plurality of flange apertures on said flange and a sealing position in which a portion of said plurality of slots are aligned with said plurality of apertures on said flange, and wherein said fastener is configured to be mounted between said biasing element and said flange of said pump.

14. The vacuum pump according to claim 11, wherein at least a portion of a surface of said fastening mechanism surrounding each of said slots is sloped, such that said at least a portion of said fastening mechanism is thinner closer to said aperture and thicker further from said aperture and wherein said sloped surface of said biasing element is configured to face said surface of said fastening mechanism comprising said sloped portions surrounding each of said slots.

15. The vacuum pump according to claim 13, wherein said fastener and said biasing element are configured such that when said apertures are aligned a combined thickness of said fastener and said biasing element is reduced and on rotation of at least one of said fastener and biasing element to a retaining position said combined thickness is increased.

16. The vacuum pump according to claim 14, wherein said sloped surface of said biasing element and said surface of said fastening mechanism which it faces are coated with a low friction coating.

17. The vacuum pump according to claim 10, further comprising an intermediate element comprising axial protrusions extending from at least one surface, said fastening mechanism being configured such that on rotation of said intermediate element relative to other elements of said fastening mechanism said axial protrusions travel along one of said sloped surfaces of said fastening mechanism, such that a width of said fastening mechanism changes on said relative rotation.

18. The vacuum pump according to claim 17, said intermediate element comprising said slots and being configured to rotate between a mounting position where a combined thickness of said fastening mechanism is reduced to a retaining position where said combined thickness is increased.

19. The vacuum pump according to claim 17, wherein said axial protrusion comprises rolling elements.

20. The vacuum pump according to claim 6, wherein at least one of said fastener, biasing, intermediate and retaining elements comprises a plurality of articulated sections.

21. The vacuum pump according to claim 20, wherein each articulated section comprises at least one aperture and at least one slot.

22. The vacuum pump according to claim 20, wherein each articulated section is curved.

23. The vacuum pump according to claim 1, wherein said vacuum pump comprises a turbomolecular pump.

24. A vacuum system comprising a vacuum chamber comprising an outlet comprising a plurality of protruding fixing elements extending around said outlet towards an exterior of said chamber and a vacuum pump according to claim 1, said vacuum pump being mounted to said vacuum chamber by said plurality of protruding fixing elements extending through said apertures on said inlet flange of said vacuum pump and said slots of said fastening mechanism.

25. A method of mounting a flanged vacuum pump according to claim 1, to a vacuum chamber comprising a plurality of protruding fixing elements extending around an outlet, said method comprising: aligning apertures in the fastening mechanism with the protruding fixing elements; sliding the aligned apertures over the protruding fixing elements; and rotating a portion of the fastening mechanism comprising the slots so that the protruding fixing elements slide within the slots in the fastening mechanism.

26. A kit for mounting a flanged pump to a vacuum chamber, said kit comprising: a plurality of bolts configured for mounting in a plurality of bolt receiving holes located around a fluid opening in said vacuum chamber, said bolts comprising an attaching end portion for mounting in and attaching to said bolt receiving holes, a fastener receiving portion and an enlarged retaining portion remote from said attaching end portion, said fastener receiving portion having at least one dimension that is smaller than a corresponding dimension of said retaining portion; and a fastening mechanism for mounting to said flanged pump, said fastening mechanism comprising: a plurality of apertures said plurality of apertures being sized such that said retaining portion can pass through said apertures; and a plurality of slots each extending from a same side of said plurality of apertures; wherein said fastening mechanism is configured to be mounted to said flanged pump by wrapping said fastening mechanism around an outer surface of said flanged pump adjacent to said flange such that said fastening mechanism is rotatable about said outer surface between a mounting position in which said plurality of apertures are aligned with said plurality of bolt receiving holes and a sealing position in which a portion of said plurality of slots are aligned with said plurality of bolt receiving holes.

27. The kit according to claim 26, wherein at least a portion of a surface of said fastening mechanism surrounding each of said slots is sloped, such that said at least a portion of said fastening mechanism is thinner closer to said aperture and thicker further from said aperture, movement of said bolts along said slots from said aperture at said mounting position to said sealing position pushing said pump towards said vacuum chamber.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0076] Embodiments of the present invention will now be described further, with reference to the accompanying drawings, in which:

[0077] FIG. 1 shows a portion of a pump according to an embodiment attached to a chamber with a fastener;

[0078] FIG. 2 schematically shows a portion of a fastener ring;

[0079] FIG. 3 shows a drive interface on a fastener according to an embodiment;

[0080] FIG. 4 shows a transverse view of a portion of a fastener with a bolt head and sloped surface;

[0081] FIG. 5 schematically shows the mounting of a pump to a vacuum chamber outlet;

[0082] FIG. 6 shows a fastener being wrapped around a pump adjacent to a flange;

[0083] FIG. 7 shows a pump attached to a chamber using a fastener according to an embodiment;

[0084] FIG. 8 schematically shows an anti-rotation device according to an embodiment;

[0085] FIG. 9 shows the anti-rotation device according to an embodiment in more detail;

[0086] FIG. 10 shows a flow diagram illustrating steps in a method of mounting a pump according to an embodiment;

[0087] FIGS. 11A-C show a fastening mechanism according to an embodiment;

[0088] FIGS. 12A and 12B shows a fastening mechanism with an intermediate element;

[0089] FIG. 13 shows a pump with a fastening mechanism attached; and

[0090] FIG. 14A shows a fastening mechanism with retainers; and

[0091] FIGS. 14B and C shows the retainers.

DETAILED DESCRIPTION

[0092] Before discussing the embodiments in any more detail, first an overview will be provided.

[0093] Installing pumps such as vacuum pumps to a vacuum system can be challenging. Other related equipment and the tool location creates a challenging environment for installing and swapping the pumps where the pumps are installed directly to the tool. During installation, the pump must be lifted to the mating face and up to twelve bolts installed while holding the pump against the mating face. This creates a dangerous and difficult ergonomic environment for the installers. Furthermore, the bolts are often difficult to reach in some areas depending on the tool.

[0094] Embodiments provide a fastener kit for mounting pumps to vacuum systems and in particular, for mounting vacuum pumps to semiconductor tools. The fastener may be built in some embodiments in several detachable parts that can be installed on the pump adjacent to the inlet flange prior to moving the pump into the installation location. Specialised bolts that are pre-installed on the tool can be used, these bolts having heads that fit through holes in the fastener and intermediate portions that slide through a slot on the fastener which slot has a smaller width than the diameter of the head, but a larger width than the diameter of the intermediate portion. The slot edges on the fastener have a raised feature that is angled such that as the fastener is turned the bolt head slides through the slot and up the angled raised surface creating an upward force on the flange of the pump by the fastener as it turns and in this way tensions the bolts. These upward forces provided on turning the ring generate a sealing force for the pump against any seal potentially an O ring on the tool.

[0095] In some embodiments there is provided a locking mechanism that may be used to inhibit the ring from backing up once fully turned and becoming detached during operation. This way installation of a pump, perhaps a pump to a system such as a tool can be made faster and safer.

[0096] FIG. 1 shows a portion of a pump 10 for mounting to a vacuum system 15. Pump 10 comprises flange 12 comprising a plurality of apertures (not shown) through which bolts 20 extend. Fastener 30 comprises a ring having apertures 32 which are dimensioned such that the retaining ends 22 of bolt 20 can pass through the apertures and slots 34 which are narrower than the apertures 32 and along which the bolts can slide but through which the retaining ends 22 cannot pass. Thus, once the pump and fastener 30 are mounted on bolts 20, rotation of the fastener 30 from a mounting position where the apertures 32 are aligned with the bolts and the apertures in the flange 12, to a sealing position where the bolts are now aligned with slots 34 is all that is required to install the pump 10 to the vacuum system 15. In effect, the slots 34 have a smaller dimension than the retaining heads 22 and thus, hold the fastener 30 and therefore the pump 10 in place against the vacuum system 15.

[0097] FIG. 2 shows fastener 30 in more detail. Fastener 30 is in this embodiment made up of a plurality of articulated components which are held together by bolts and each of which comprise at least one aperture 32 with a slot extended therefrom 34. Each of the components are curved such that when they are mounted around the pump they form a ring which matches the outer surface of the flange component. The bolts holding the components together allow for some rotational movement of the components allowing the fastener 30 to be wrapped around the outer surface of the pump 10 and then fastened thereto by fastening the two ends of the fastener 30 together to form a ring.

[0098] FIG. 3 shows a portion of fastener 30 having a drive interface 36 for receiving a drive tool for rotating the fastener and moving it from the mounting to the sealing position during installation and form the sealing to the mounting position during swapping of a pump. In this embodiment, the drive interface extends from the surface of the fastener 30. In other embodiments, it may comprise a recess within the fastener.

[0099] FIG. 4 shows a side view of a portion of fastener 30 with the bolt head 32 extending through the slot and being held by it. The slot is shown in side view and one can see a sloped surface 37 extending along the side edges of the slot from the aperture end on the left of the diagram to the other end of the slot on the right of the diagram. This slope means that on rotation of the fastening means the bolt head 32 slides along the slope and thus, there is a vertical component to its movement and this pushes the pump towards the vacuum system. Although not shown, the bolt head 22 has a surface that mates with the slope and which is also angled in a corresponding manner allowing for improved support of the bolt head across a greater surface area.

[0100] FIG. 5 schematically shows the mounting of a pump which in this embodiment comprises turbomolecular pump 40 to a vacuum system which in this embodiment comprises the outlet of a vacuum chamber 60. In this embodiment, a plurality of bolts 20 are mounted around the vacuum chamber outlet and these bolts have a contoured surface such that the retaining end 22 has a larger diameter than the intermediate fastener receiving portion 24. The apertures 42 in the flange of the turbo pump are aligned with the bolts such that on mounting the turbo pump the bolts pass through the apertures 42 and the flange of the turbo pump mates with the surface around the vacuum chamber outlet 60.

[0101] FIG. 6 schematically shows how fastener 30 is wrapped around turbo pump 40 of FIG. 5 to provide a means of holding the turbo pump against the vacuum chamber outlet 60. Although the fastener is shown being wrapped around the turbo pump when it is mounted adjacent to the vacuum chamber, this is purely illustrative and generally the fastener will wrapped around and attached to the pump before it is mounted to the vacuum chamber.

[0102] The fastener 30 is an articulated fastener which is wrapped around the outer surface of the turbo pump 40 adjacent to the flange and the ends of which are secured together with bolts. It is mounted so that it can rotate around the outer surface which enables it to lock the turbo pump in place.

[0103] FIG. 7 shows the turbo pump 40 mounted to the vacuum chamber outlet 60 by fastener 30. As can be seen fastener 30 abuts against the flange of the turbo pump 40 and pushes it against vacuum chamber outlet 60. The bolts 20 are at one end of the slot, the fastener 30 having been rotated from the mounting position where the apertures 32 in the fastener are aligned with the bolts, to the position where the bolts are at the other end of the slot and where the retaining end is held vertically by the slot and the fastener is inhibited from rotation by an anti-rotation device 70. In this embodiment the anti-rotation device comprises a pin which goes through holes on the side surfaces of the fastener and resists rotation of the fastener from the sealing position back towards the mounting position. In this embodiment, there is a single pin, in other embodiments there may be more than one pin arranged adjacent to different bolts.

[0104] FIG. 8 shows an alternative anti-rotation device 80 which has the form of an insert which is inserted into the slot and which holds the bolt in position against one end of the slot. Insert 80 has a raised portion 82 which goes under the enlarged retaining end 22 of the bolt and helps to hold it and provides support for the end of the bolt.

[0105] FIG. 9 shows insert 80 in more detail. There are ball bearings 86 which extend out from the side surfaces and help retain the insert in place within the slot. Button 84 can be depressed to release the ball bearings and release the insert 80 from the slot.

[0106] In some embodiments, there may be a single insert 80 for retaining the fastener in the sealing position, while in other embodiments there may be several in different slots.

[0107] FIG. 10 shows a flow diagram illustrating steps in a method of mounting a vacuum pump to a vacuum chamber according to an embodiment. In one step a fastener is wrapped around an outer surface of the vacuum pump and secured in place. In another step contoured bolts are mounted in bolt receiving holes around the vacuum chamber outlet. These two steps may be performed in any order. Once these steps have been performed then the apertures in the vacuum pump flange and the apertures in the fastener are aligned and these aligned apertures are slid over the bolts extending from the vacuum chamber such that the pump is in position adjacent to the vacuum chamber outlet. The fastener is then rotated so that the slots in the fastener are aligned with the bolts and where the slots have a reduced width compared to the end of the bolts, the pump is held in position by the slots. In other embodiments, retainers may be placed between the bolt heads and the slots to retain the pump in position. In some embodiments there are slopes on the surface of the slots and the pump is pushed against a vacuum chamber during rotation of the fastener and this helps provide an effective seal between the vacuum chamber and pump. In some embodiments an anti-rotation device is then inserted such that the bolt is inhibited from moving back along the slot from the sealing to the mounting position which movement would allow the pump to become detached during use.

[0108] FIG. 11 shows several views of a fastening mechanism having a fastener 30 and a retaining element 38 according to an embodiment.

[0109] FIG. 11A shows the fastener 30 that is configured to be mounted adjacent to the flange of the pump and which comprises slots 34 extending from apertures 32. The apertures 32 receive the bolts that extend through the flange of the pump and are attached to the vacuum chamber when the pump is mounted to the vacuum chamber. The slots allow the fastener 30 to rotate with the bolts moving along the slots. The fastening mechanism also comprises a retaining element 38 which is shown in greater detail in FIG. 11B. Retaining element 38 comprises apertures 32 each of which has a reduced sized aperture portion 39 which is the retaining portion of the aperture.

[0110] When mounting the pump to the vacuum chamber, the apertures 32 in the fastener 30 and retaining element 38 are aligned and the bolts extending from the vacuum chamber pass through these apertures. The fastener 30 and retaining element 38 are then rotated. Rotation of the retaining element 38 causes the reduced sized portion 39 of the apertures to be aligned with the bolts such that the enlarged end of the bolt cannot pass through this smaller aperture and the pump is held in position. Rotation of the fastener 30 causes the bolts to travel along the slots and the sloped surfaces of the fastener 30 and the retaining element 38 move over each other such that rather than the thicker and thinner portions being aligned so that the fastening mechanism has a reduced thickness the thicker portions are aligned giving an increased thickness to the fastening mechanism which provides a biasing force on the pump biasing it against the vacuum chamber and improving the sealing.

[0111] FIG. 11C shows the alignment of the fastener 30 and the retaining elements 38 in the mounting position when the sloped sections fit together and a reduced width of the fastening mechanism is provided. Relative rotation of these two elements allows the increased width portions to be aligned and provides for an increased width of the fastening mechanism. In order to provide ease of rotation, the facing surfaces may be coated with a low friction coating such as Teflon.

[0112] FIG. 12A shows an alternative embodiment of a fastening mechanism with an intermediate element 50 mounted between a biasing element 31 and a retaining element 38. In other embodiments, the intermediate element may be mounted between a fastener 30 and a retaining element 38. In still other embodiments it may be mounted between the flange and a retaining and biasing element.

[0113] Intermediate element 50 has protrusions which in this embodiment are in the form of rolling elements or wheels 52 which are configured to travel over the surfaces of the biasing element 31 and the retaining element 38 on rotation of the intermediate element 50. This allows for low friction rotation of this element. Biasing element 31 has an undulating surface such that rotation of the intermediate element from the lower thickness area to the higher thickness area increases the width of the fastening mechanism and may be used to bias the vacuum pump against the flange.

[0114] FIG. 12B shows the intermediate element 50 and in particular the slots 54 which extend through the intermediate element and allow rotation of this element relative to the vacuum pump, with the bolts that fix the vacuum pump to the vacuum chamber traveling within these slots. In an alternative embodiment, where a fastener 30 is used rather than a biasing element 31 then slots may be within the fastener 30 rather than the intermediate element 50 and the fastener may rotate relative to the intermediate element. In some embodiments, both the biasing element and the retaining element have correspondingly sloped surfaces.

[0115] FIG. 13 shows a pump 10 with a fastening mechanism in place. In this embodiment the fastening mechanism comprises a retaining element 38 and an intermediate element 50.

[0116] FIG. 14A shows an alternative embodiment that is similar to that of FIGS. 1 to 7, but where the slot has a constant cross section that is the same as the aperture for receiving the bolt and thus, does not act to retain the pump in position, rather retainers in the form of washers 88 are used. These are mounted on the bolt heads and provide a surface for the fastener to rotate on. The material of the washers is selected to be softer than the material of the bolts or fastener so that any wear occurs preferentially on these washers. This allows the washers to be replaced and extends the life of the other components. The washers may also be selected to be a material with a low coefficient of friction.

[0117] FIG. 14B shows the retainer 88 mounted in position on the lip of the enlarged retaining end 22 of the fixing element or bolt. The retainer has an elongated thinner portion which extends into the slot on fastener 30 and helps maintain it in position. In some embodiments the retainer 88 does not have this portion. The edge of the slot of fastener 30 rests on the lip of retainer 88 between the thicker and thinner portions, this lip can be seen more clearly in FIG. 14C. FIG. 14C also shows the shape of the retainer, such that the side walls comprise an opening allowing the retainer to be pushed onto the bolts from the side.

[0118] Although illustrative embodiments of the invention have been disclosed in detail herein, with reference to the accompanying drawings, it is understood that the invention is not limited to the precise embodiment and that various changes and modifications can be effected therein by one skilled in the art without departing from the scope of the invention as defined by the appended claims and their equivalents.

[0119] 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.

[0120] 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.