GB2587366A

GB2587366A - Vibration damping connector systems

Info

Publication number: GB2587366A
Application number: GB1913771.0A
Authority: GB
Inventors: David Smith Paul; Packer Simon; Olsen Ian
Original assignee: Edwards Ltd
Current assignee: Edwards Ltd
Priority date: 2019-09-24
Filing date: 2019-09-24
Publication date: 2021-03-31
Also published as: GB201913771D0

Abstract

A vibration damping connector system (110) to connect a vacuum chamber with a vacuum pump has a first end member (112) defining a first end of the flow path, a second end member (116) defining a second end of the flow path, a bellows (120) disposed intermediate the first and second end members to define an intermediate portion of the flow path that is disposed intermediate the first and second ends and a bellows support (126) disposed externally of the bellows. The bellows support has a chamber (128) extending about the bellows (120) and a sealable inlet port (130) to permit pressurisation of the chamber to provide support for the bellows.

Description

VIBRATION DAMPING CONNECTOR SYSTEMS

Field of the Invention

The invention relates to vibration damping connector systems to connect between an inlet, 5 or suction, port of a vacuum pump and a port of a vacuum chamber.

Background to the Invention

Vacuum pumps may be used to establish vacuum conditions in chambers or spaces within, or associated with, many types of equipment. Examples of such equipment include equipment used in electron microscopy, spectrometry or the manufacture, repair or testing of integrated circuits. The vacuum pump may be directly connected with the piece of equipment by a connector system that puts the chamber in flow communication with the suction port of the vacuum pump. When the vacuum pump is running, vibrations induced by rotating or other moving parts of the pump may be transmitted to the attached equipment via the connector system. For example, the vacuum pump may be a turbomolecular pump having a rotor that rotates at high speeds setting up high frequency vibrations. The rotor of a turbomolecular vacuum pump may, for example, rotate at speeds in the region of 60,000 rpm. A turbomolecular vacuum pump may include two sources of significant vibration that establish vibrations at different frequencies. One vibration source is the pump rotor and the other is the cage of the rolling bearings that support the pump rotor. It may be necessary to eliminate, or at least substantially reduce, the vibrations transmitted from the vacuum pump to the attached equipment.

Vibration damping connector systems that use an 0-ring or similar elastomer elements as both a gas seal and a vibration isolation element are known. With this approach, when the system is under vacuum the external gas load applies a compressive force to the elastomer element. This can result in compression set and an associated increase in the stiffness of the elastomer element. In addition, regardless of the load applied the elastomer element will suffer from aging which can also cause an increase in its stiffness. This increase in stiffness will result in reduced vibration isolation performance. The occurrence of compression set also has the potential to cause leakage of the seal when the compressive force is removed causing a failure to seal when the vacuum pump is stopped and then -2 -restarted. Other disadvantages associated with elastomer elements include the inherent relatively high damping and a frequency dependence of the stiffness of the material. For a vibration damping connector system, the stiffness and damping should be as low as possible for optimum performance so both of these effects can result in reduced performance of the isolator.

1JS2018/0363825 discloses a vibration damping connector system that uses a piston arrangement to provide a fluid filled element to act as a vibration isolator. This addresses many of the disadvantages associated with the use of elastomer elements, in particular compression set, aging and relatively high damping. However, this kind of piston arrangement results in a connector system that has high radial stiffness. In the majority of applications, low radial stiffness is required to minimise the transmission of radial vibration from the pump to the vacuum chamber. Furthermore, the vibration damping connector system disclosed by US2018/0363825 has a relatively complex structure employing numerous components and will be both relatively expensive to produce and relatively bulky.

Summary of the Invention

The invention provides a vibration damping connector system as specified in claim 1 The invention also includes a method of supporting a bellows in a vibration damping connector system as specified in claim 15.

Brief Description of the Drawings

In the disclosure that follows, reference will be made to the drawings in which: Figure 1 is a schematic view of a vacuum pump, a vacuum chamber and a vibration damping connector system connecting the vacuum pump with the vacuum chamber, Figure 2 is a cross-section view of the vibration damping connector system of Figure 1; Figure 3 is an enlargement of the circled portion of Figure 2; Figure 4 is a cross-section view corresponding generally to Figure 2 showing another vibration damping connector system; and Figure 5 is a cross-section view of yet another vibration damping connector system.

Detailed Description

Referring to Figure 1, a vacuum pump 10 is shown connected with a vacuum chamber 12 by means of a vibration damping connector system 110. The vacuum pump 10 may be a turbomolecular pump having a primary pumping mechanism that comprises a plurality of rotor blades 14 mounted on a rotor shaft 16 and a plurality of stator blades 18 disposed in interleaving relationship with the rotor blades. The rotor shaft 16 may be supported by a bearing system 20 and driven by a motor 22. The bearing system 20 may comprise a lower bearing in the form of a rolling bearing and an upper bearing in the form of a magnetic bearing that may be coupled with a backup in the form of a second rolling bearing. It is to be understood that the references to upper and lower bearings are not intended to be limiting and are simply references to the vacuum pump 10 in the orientation shown in Figure 1. The vacuum pump 10 may additionally comprise a secondary pumping mechanism 24. The secondary pumping mechanism 24 may be a molecular drag pumping mechanism such as a Gaede mechanism, a Holweck mechanism or a Siegbahn mechanism. The pumping mechanism or mechanisms are operable to pump gases and vapours from an inlet or suction port 26 of the vacuum pump 10 to an outlet, or exhaust port 28. The vibration damping connector system 110 places the suction port 26 in flow communication with a port, or opening, 30 of the vacuum chamber 12 so that the vacuum pump 10 can be used to establish vacuum conditions in the vacuum chamber. The vacuum chamber 12 is a chamber (or space) in, or associated with, a piece of equipment 32 in which vacuum conditions are to be established. Such equipment 32 may, for example, be equipment used in electron microscopy, spectrometry or the manufacture, repair or testing of integrated circuits. The piece of equipment 32 may support the weight of the vacuum pump 10 via the vibration damping connector system 110. Thus, for example, the vacuum pump 10 may be suspended from the piece of equipment 32 via the vibration damping connector system 110. -4 -

Referring to Figures 2 and 3 the vibration damping connector system 110 comprises a first end member 112 having a through-passage 114, a second end member 116 having a through-passage 118 and a first bellows 120 disposed intermediate the first and second end members 112, 116. The first and second end members 112, 116 may be generally circular section tubular bodies. The first bellows 120 is a generally cylindrical corrugated member defining a through-passage 122. When connected to the vacuum pump 10 and the piece of equipment 32, the vibration damping connector system 110 provides a sealed flow path between the port 30 of the vacuum chamber 12 and the suction port 26 of the vacuum pump 10. The through-passage 114 defines a first end of the flow path, the through-passage 118 defines a second end of the flow path and the through-passage 122 defines an intermediate portion of the flow path that extends from the first end to the second end so that there is a continuous sealed flow path extending through the vibration damping connector system 110. The through-passages 114, 118, 122 may be disposed in line so as to have a common axis 124, which may coincide with the longitudinal axis of the vibration damping connector system 110.

The vibration damping connector system 110 further comprises a bellows support 126 that is disposed externally of the first bellows 120 to provide support for the bellows 120 to resist the gas load in the vibration damping connector system that occurs whenever a connected vacuum pump is in use. The bellows support 126 comprises a chamber 128 that extends about the bellows 120 and has a sealable inlet port 130 configured to permit pressurisation of the chamber. In this example, the bellows support 126 comprises a second bellows 132 surrounding the bellows 120 so that the chamber 128 is defined between the first and second bellows 120, 132, which define respective sidewalls of the chamber. The pressurised chamber 128 and second bellows 132 provide support for the bellows 120 by resisting axial loads that would tend to compress the bellows 120 and cause relative movement of the first and second end members 112, 116 towards one another. The first and second bellows 120, 132 may be arranged so as to be coaxial. The bellows 120, 132 may be arranged such that the inwardly extending corrugations of one bellows are disposed opposite the outwardly extending corrugations of the other bellows. Thus, in the illustrated example, the inwardly extending corrugations of the first bellows 120 are disposed opposite -5 -the outwardly extending corrugations of the second bellows 132. The first and second bellows 120, 132 may be metal bellows made, for example, of stainless steel.

Referring to Figure 2, the first end member 112 may comprise a first (or inboard) end in the form of an upstanding annular rim, or protruding lip, 134, a second (or outer) end in the form of a flange 136 and a tubular body 138 extending between the annular rim and flange. Similarly, the second end member 116 may comprise a first (or inboard) end in the form of an upstanding annular rim, or protruding lip, 140, a second (outer) end in the form of a second flange 142 and a tubular body 144 extending between the rim and flange. Thus, the first and second end members 112, 116 are generally tubular members. The flanges 136, 142 may be industry standard vacuum flanges for securing to respective fittings on the vacuum pump 10 and piece of equipment 32 using standard ISO clamps 34 (Figure 1). The first and second end members 112, 116 may be made of a metal, for example, an aluminium alloy.

The first and second bellows 120, 132 are secured to the first and second end members 112, 116 such as to provide a gas tight seal between the parts. Figure 3 shows one way in which the respective ends of the first and second bellows 120, 122 may be secured to the first and second end members 112, 116, Figure 3 shows the first end member 112. However, as shown in Figure 2, the connection between each of the first and second bellows 120, 132 and the first and second end members 112, 116 may be identical and so in the description that follows, the connection to both end members is described. Referring to Figure 3, the respective ends of the first bellows 120 may be secured to the radially inner sides, or faces 148, of the annular rims 134, 140 by, for example welding. Similarly, the respective ends of the second bellows 132 may be secured to the radially outer sides, or faces, 150 of the annular rims 134, 140 by, for example, welding. Thus, in this example, the annular rims 134, 140 are sandwiched between the respective ends of the bellows 120, 132. The sides 148, 150 of the annular rims 134, 140 may be disposed in parallel spaced apart relationship and extend parallel to the common axis 124. The bellows 120, 132 cooperate with the annular rims 134, 140 to define the chamber 128, which is sealed by the jointing between the ends of the bellows and the annular rims. Thus, in this example, the chamber 128 -6 -extends from the inboard end of the first end member 112 to the inboard end of the second end member 116 Still referring to Figure 3, the sealable inlet port 130 comprises a passage having an upstream end portion 152 that extends from the outer periphery of the tubular body 138 to a downstream end portion 154 that extends from the upstream end portion through the annular rim 134 to an end face 156 of the annular rim. The downstream end portion 154 may extend parallel to the side faces 148,150 of the annular rim 134 and the upstream end portion 152 may be inclined with respect to the downstream end portion 154. The upstream end portion 152 may be threaded over at least a part of its length. A screw 158 may be screwed into the upstream end portion 152 to seal, or at least close, the sealable inlet port 130. In some examples, a suitable sealing compound or tape may be used between the screw 158 and the threading in the upstream end portion 152 to ensure sealing of the sealable inlet port 130. In other examples, other suitable forms of plugs or stoppers may be used to seal the sealable inlet port or a suitable valve may be fitted in the sealable inlet port.

Referring to Figure 2, the vibration damping connector system 110 may be provided with a known axial preloading device 160. The axial preloading device 160 is configured to provide an axial preload to support the mass of the vacuum pump 10 and allow the stiffness of the bellows 120 and bellows support 126 to be optimised for vibration isolation, whilst minimising the contraction of the bellows when vacuum is applied. The axial preloading device may comprise a known strap 160. The strap 160 may comprise a plurality of arms 162 that engage a flange 164 disposed adjacent the annular rim 140 of the second end member 1 1 6 and a screw 166 that extends from a centre portion at which the arms 162 meet to a threaded member supported by arms (not shown), which extend radially inwardly from a flange 168 that projects inwardly from an inner side of the tubular body 138. The flange 168 may be disposed adjacent the annular rim 134 of the first end member 112. The flanges 164, 166 are disposed in the respective through-passages 114, 118 and may be disposed at the ends of the annular lips 134, 140 that adjoin the respective tubular bodies 138, 144. -7 -

As illustrated in Figure 2, the first and second bellows UO, 132 have the same length. It is to be understood that this is not essential. For example, one or both of the first and second end members 112, 116 may be configured to connect with first and second bellows 120, 132 of having different lengths. Thus, for example, one or both of the first and second end members 112, 116 may be configured to connect with a first bellows 120 having a first length and a second bellows 132 having a second length that is less than said first length. Having different length bellows may advantageously assist in tuning the natural frequency of the bellows away from specific vibration frequencies that may be encountered in an operating environment.

As illustrated in Figure 2, there is one sealable inlet port 130. In other examples, there may be multiple sealable inlet ports. For example, there may be a first sealable inlet port provided in the first end member 112 as shown in Figure 2 and a second sealable inlet port provided in the second end member 116. This may be advantageous in that, for example, the first and second end members may then be of identical construction, saving on the need to manufacture stock different parts Figure 4 shows another vibration damping connector system 210, which is similar to the vibration damping connector system 110 of Figures 2 and 3. The vibration damping connector system 210 differs from the vibration damping connector system 110 in that it has two bellows in series, at least one of which has a bellows support, and an isolator mass disposed intermediate the two bellows. Thus, the vibration damping connector system 210 comprises a first end member 212, a second end member 216, a first bellows 220 having a bellows support 226 that comprises a second bellows 232, an isolator mass 312 and a third bellows 320 disposed in series with the first bellows 220. The first and second end members 212, 216 may be generally circular section tubular bodies and have the same or a similar structure to the first and second end members 112, 116 show in Figures 2 and 3.

The bellows support 226 is configured to provide support for the first bellows 220 by resisting the gas load in the vibration damping connector system 210 that occurs whenever a connected vacuum pump is in use. When connected between the vacuum pump 10 and a piece of equipment 32, the vibration damping connector system 210 provides a sealed flow -8 -path between the port 30 of the vacuum chamber 12 and the suction port 26 of the vacuum port 10. The first end member 212 has a through-passage 214 that defines a first end of the flow path, the second end member 216 has a through-passage 318 that defines a second end of the flow path and the first bellows 220, isolator mass 312 and third bellows 320 in series define an intermediate portion of the flow path that extends from the first end to the second end. The various connections between the first end member 212, second end member 216, first and third bellows 220, 320 and isolator mass 312 are such that the flow path defined by the vibration damping connector system 210 is gas tight. The first and second end members 212, 216, first and second bellows 220, 320 and isolator mass 312 may be arranged such that the respective through-passages they define are disposed in line so as to have a common axis 224 that may coincide with the longitudinal axis of the vibration damping connector system 210.

The bellows support 226 comprises a chamber 228 at least partially defined by the first bellows 220 and the second bellows 232 and has at least one sealable inlet port 230 configured to permit pressurisation of the chamber. In this example, the chamber 228 extends from the inboard end of the first end member 212 to the isolator mass 312. The pressurised chamber 228 and second bellows provide support for the first bellows 220 by resisting axial loads that would tend to compress the first bellows 220 and cause relative movement of the first end member 212 and isolator mass 312 towards one another. Although not essential, the vibration damping connector system 210 may comprise a second bellows support 326 to provide support for the third bellows 320 by resisting the gas load in the vibration damping connector system that occurs when a connected vacuum pump is in use. The second bellows support 326 comprises a chamber 328 extending about the third bellows 320 and a sealable inlet port 330 to permit pressurisation of the chamber.

The second bellows support 326 may comprise a fourth bellows 332 that is cooperable with the third bellows 320 to define the chamber 328 in the same way as the first and second bellows 120, 132 and the chamber 128 of the vibration damping connection system 110. In this example, the chamber 328 extends from the inboard end of the second end member 216 to the isolator mass 312. The pressurised chamber 328 and fourth bellows 332 provide support for the third bellows 320 by resisting axial loads that would tend to compress the -9 -third bellows and cause relative movement of the second end member 212 and isolator mass 312 towards one another.

In analogous fashion to the vibration damping connector system 110 the vibration damping connector system 210 may be provided with an axial preloading system. The axial preloading device system is configured to provide an axial preload to support the mass of the vacuum pump 10 and allow the stiffness of the bellows 220, 320 and the respective bellows supports 226, 326 to be optimised for vibration isolation, whilst minimising the contraction of the bellows when vacuum is applied. The axial preloading system may comprise any suitable known bellows preloading devices. For example, the axial preloading system may comprise respective straps 260, 360 fitted within the first and third bellows 220, 320 in similar fashion to the strap 160 described above with reference to Figure 2.

In this example, the first and second bellows 220, 232 are connected to a first side 372 of the isolator mass 312 and the third and fourth bellows 320, 332 are connected to a second side 374 of the isolator mass. The first and second sides 372, 374 are oppositely facing major sides of the isolator mass 312 that face the first and second end members 212, 216 respectively. In analogous fashion to the first and second end members 212, 216, the first and second sides 372, 374 may be provided with respective upstanding annular rims, or lips, 376, 378. The inboard ends of the first and second bellows 220, 232 may be secured to the annular rim 376 in analogous fashion to the bellows 120, 132 and annular rim 134 described above with reference to Figure 3. Similarly, the inboard ends third and fourth bellows 320, 332 may be welded to the annular rim 378.

The isolator mass 312 is configured to provide a desired mass to cooperate with the bellows to provide improved vibration isolation for the connector system. The isolator mass 312 comprises a relatively thinner inner annular portion 379 to which the inboard ends of the bellows 220, 232, 320, 332 are connected and a relatively thicker outer annular portion 380 disposed radially outwardly of the respective outer peripheries of the bellows. Positioning at least a portion, or part, of the isolator mass 312 radially outwardly of the first and second end members 212, 216 provides the potential advantage of enabling the provision of a -10 -relatively large mass to provide a desired vibration isolating function without significantly increasing the length of the vibration damping connector system 210 as a consequence of the series connection of the mass with the first and second end members. In this context the length L of the vibration damping connector system 210 and thicknesses of the inner and outer annular portions 379, 380 of the isolator mass 312 are measured dimensions in the axial, or lengthways, direction of the vibration damping connector system/throughpassages It is to be understood that other forms of isolator mass may be used in the vibration damping connector system 210 and the disclosure relating to the isolator mass is not to be taken as limiting.

Figure 5 shows another vibration damping connector system 410. The vibration damping connector system 410 comprises a first end member 412, a second end member 416 and a bellows 420 having a bellows support 426. When connected between the vacuum pump 10 and a piece of equipment 32, the vibration damping connector system 410 provides a sealed flow path between the port 30 of the vacuum chamber 12 and the suction port 26 of the vacuum port 10. The first end member 412 has a through-passage 414 that defines a first end of the flow path, the second end member 416 has a through-passage 418 that defines a second end of the flow path and the bellows 420 defines a through-passage 422 that defines an intermediate portion of the flow path that extends from the first end to the second end. The connections between the first end member 412, second end member 416 and bellows 420 are such that the flow path is gas tight. The first and second end members 412, 416 and the bellows 420 may be arranged such that the respective through-passages 414, 418, 422 they define are disposed in line so as to have a common axis 424 that may coincide with the longitudinal axis of the vibration damping connector system 410.

The first and second end members 412,416 may be generally circular section tubular bodies and have the same or a similar structure to the first and second end members 112, 116 show in Figures 2 and 3. The first end member 412 may comprise a first (or inboard) end in the form of an upstanding annular rim, or protruding lip, 434, a second (or outer) end in the form of a flange 436 and a tubular body 438 extending between the rim and flange. Similarly, the second end member 416 may comprise a first (or inboard) end in the form of an annular rim, or protruding lip, 440, a second (outer) end in the form of a second flange 442 and a tubular body 444 extending between the rim and flange The flanges 436, 442 may be industry standard vacuum flanges for securing to respective fittings on the vacuum pump 10 and the piece of equipment 32 using standard ISO clamps 34 (Figure 1). The first and second end members 412, 416 may be made of a metal, for example, an aluminium alloy.

The first end member 412 has an annular face 482 defined between the annular lip 434 and the tubular body 438. The second end member 416 has an annular face 484 defined between the annular lip 440 and the tubular body 444. The annular faces 482, 484 are disposed opposed spaced apart relationship. The annular faces 482, 484 may be parallel to one another. The annular faces 482, 484 may be disposed perpendicular to the common axis 424.

In this example, the bellows support 426 comprises a resiliently deformable hollow body 486 that defines a chamber 428 and a sealable inlet port 430 to permit pressurisation of the chamber. The pressurised chamber 428 provides support for the bellows 420 by resisting axial loads that would tend to compress the bellows 420 and cause relative movement of the first and second end members 412, 416 towards one another. The hollow body 486 is configured to be received between the annular faces 482, 484 and engage those faces, at least when the chamber 428 has been inflated. The deformable hollow body 486 may be an annular member and may be made of a plastics or elastomeric material. The hollow body 486 may, for example, be made of a fluoroelastomer such as FKM. The hollow body 484 may have fibre-reinforced walls for added strength, or robustness. The sealable inlet port 430 of the bellows support 426 comprises a filling tube 488 that extends from the deformable hollow body 486. The filling tube 488 may be integral with the hollow body 486 and may extend from the outer periphery of the hollow body. The filling tube 488 may be closed by a plug, stopper or screw 490 that is permanently secured in the filling tube so that the chamber 428 is sealed for life following inflation of the hollow body 486 to a required pressure. Alternatively, the filling tube 488 may be provided with a valve.

Optionally, the valve may be permanently closed following inflation of the hollow body 486 to a required pressure.

-12 -Although not shown in Figure 5, the vibration damping connector system 410 may be provided with an isolator mass and an additional bellows in series with the bellows 420 in analogous fashion to the arrangement shown in Figure 4. In such an arrangement, the additional bellows may also be provided with a bellows support, which may be an additional inflatable sealing member or a further bellows disposed externally of the additional bellows and cooperable with the additional bellows to define a chamber that can be pressurised.

By using a bellows to provide a sealed connection between the first and second end members of the a vibration damping connector system, it is possible to overcome one or more of the disadvantages associated with the use of elastomers in conventional vibration damping connector systems, including compression set, aging and stiffening of the elastomer material, the high damping associated with elastomers and the frequency dependence of the stiffness on the excitation frequency associated with elastomer materials.

Also, with a bellows it is possible to provide a hermetic gas seal whereas an elastomer seal will always leak to some extent due to diffusion of gas through the seal walls. The or each pressurised chamber of the bellows support or bellows supports functions as a gas-filled spring element or elements to provide the spring force required to resist the gas load in a vibration damping connector system and provides the advantage of a lower radial stiffness than is found in connector systems that rely on conventional solid elastomer sealing elements or a piston arrangement as disclosed by US2018/0363825. Thus, vibration damping connector systems comprising one or more bellows with an associated bellows support comprising a pressurised gas-filled chamber may have a relatively low axial and radial stiffness, providing improved vibration isolation when compared with conventional vibration damping connector systems Although an isolator mass in the vibration damping connector system is not essential, including an isolator mass may provide improved isolation performance, effectively using a spring-mass-spring arrangement to give a lower cut-off frequency and a lower force transfer between the vacuum pump and the piece of equipment to which it is connected. Also, in examples in which an isolator mass is provided between two bellows in series as -13 -shown in Figure 4, there is the possibility of tuning to provide different spring rates to address different frequencies.

Although not a preferred option, in examples in which an isolator mass is provided, a conventional elastomer or an inflatable seal may be used on one side of the isolator mass in the absence of a bellows rather than bellows in series in the way illustrated by Figure 4. This would still provide some advantages in terms of providing a lower radial stiffness than conventional arrangements. However, such an arrangement would have the disadvantages associated with relying on elastomer sealing elements rather than a bellows. Those disadvantages may include the loss of the robustness and hermetic seal of a bellows and the high damping and compression set and aging problems associated with elastomer sealing elements, although this would be offset to some extent by the lower damping obtained by having a supported bellows in series with it.

In the example, illustrated in Figure 1, the vibration damping connector system 110 is shown in use supporting a turbomolecular vacuum pump 10 that is suspended from a piece of equipment 32 by the vibration damping connector system. It is to be understood that this is just one example of the ways in which the vibration damping connector system may be used and that it is not essential the vibration damping connector system supports the pump to which it is connected.

In the illustrated examples, the bellows supports comprise a chamber pressurised by gas-filling and the chamber extends around the entire circumference of the bellows that is to be supported. This in not essential as in some examples the bellows support may comprise a plurality of discrete chambers that are pressurised by gas-filling disposed about the bellows they support. Thus, in one example, there may be a plurality of deformable hollow bodies disposed at spaced apart intervals about the bellows they support, each extending around a part of the circumference of the supported bellows.

The or each chamber of the bellows support or supports is pressurised by filling with a gas.

The gas used is preferably air. The currently preferred option is to pressurise the chamber or chambers when the vibration damping connector system is assembled in the factory or -14 -the like. However, pressurisation may be done on site. There may be some advantages to pressurising the chamber or chambers on site. For example, this would make it possible to tune the vibration damping connector system to some degree by adjusting the fill to adjust the spring rate provided by the pressurised chamber or chambers.

It will be understood that although the vibration damping connector system has been described above as being used to connect a turbomolecular vacuum pump with a vacuum chamber, it is to be understood this is not to be taken as limiting. In principle, the vibration damping connector system may be used to connect any form of vacuum pump with a vacuum chamber.

Claims

-15 -Claims A vibration damping connector system to provide a sealed flow path between a port of a vacuum chamber and a suction port of a vacuum pump, said connector system comprising: a first end member defining a first end of said flow path; a second end member defining a second end of said flow path; a first bellows disposed intermediate said first and second end members to define an intermediate portion of said flow path that is disposed intermediate said first and second ends, and a bellows support disposed externally of said first bellows, said bellows support having a chamber extending about said first bellows and a sealable inlet port to permit pressurisation of said chamber to provide support for said first bellows.
2. A vibration damping connector system as claimed in claim 1, wherein, in use, when pressurised, said chamber provides a biasing force that opposes relative movement of said first end member towards said second member.A vibration damping connector system as claimed in claim 1 or 2, wherein a first end of said chamber is at least partially defined by said first end member and a second end of said chamber is at least partially defined by said second end member.A vibration damping connector system as claimed in claim 1, 2 or 3, wherein said sealable inlet port is provided with an inlet valve A vibration damping connector system as claimed in any one of the preceding claims, wherein said bellows support comprises a second bellows extending about said first bellows and said chamber is defined between said first bellows and said second bellows.A vibration damping connector system as claimed in claim 5, further comprising a third bellows and an isolator mass, wherein said first and second bellows are -16 -connected with a first side of said connector body and said first end member and said third bellows is connected with a second side of said connector body and said second end member and is in series with said first bellows to define a second intermediate portion of said flow path.A vibration damping connector system as claimed in claim 6, further comprising a second bellows support disposed externally of said third bellows to provide radial support for said third bellows, said second bellows support having a chamber extending about said third bellows and a sealable inlet port to permit pressurisation of said chamber.A vibration damping connector system as claimed in claim 7, wherein said second bellows support comprises a fourth bellows extending about said third bellows and said chamber is defined between said third bellows and said fourth bellows.A vibration damping connector system as claimed in any one of claims 1 to 4, wherein said bellows support comprises a resiliently deformable hollow body that defines said chamber.10. A vibration damping connector system as claimed in claim 9, wherein said deformable hollow body is made of a plastics or elastomer material.11. A vibration damping connector system as claimed in claim 10, wherein said deformable hollow body comprises reinforcing fibres.12. A vibration damping connector system as claimed in claim 9, 10 or 11, wherein said sealable inlet port comprises a filling tube extending from an outer periphery of said deformable hollow body.13. A vibration damping connector system as claimed in any one of claims 9 to 12, wherein a first end of said hollow body engages said first end member and a second end of said hollow body engages said second end member.14. A system comprising a vacuum pump having a suction port, a piece of equipment defining a vacuum chamber having a port and a vibration damping connector system as claimed in any one of the preceding claims connected with said vacuum pump and piece of equipment to provide a sealed flow path between said vacuum chamber port and said suction port.15. A system as claimed in claim 14, wherein said vacuum pump is suspended from said piece of equipment by said vibration damping connector system. 10 16. A method of supporting a bellows in a vibration damping connector system configured to connect a vacuum pump to a vacuum chamber, said vibration damping connector system comprising a first end member to be connected to a vacuum pump, a second end member to be connected to a piece of equipment that defines said vacuum chamber and bellows, said bellows connected with said first and second end members such that a sealed flow path is defined between said first and second end members, and said method comprising providing a chamber disposed externally of said bellows and having a sealable inlet port, pumping a gas into said chamber to pressurise said chamber and sealing said inflatable inlet port, wherein said pressurised chamber provides support for said bellows.