Turbomolecular vacuum pump, assembly and pumping system

Abstract

A turbomolecular vacuum pump (1) comprising a stator (2) having a mounting flange (6) surrounding a suction port (4) and having a plurality of through holes (20) for the insertion of screws (300), the through holes (20) having a distal section (21) formed in a distal annular portion (22) of the mounting flange (6). The through holes (20) are open on their outer periphery in a proximal annular portion (23) of the mounting flange (6) adjacent to the distal annular portion (22) and located on the side of the suction port (4) of the turbomolecular vacuum pump (1) so as to allow at least partial visualization of a bonding zone (Z) between the turbomolecular vacuum pump (1) (2) and the fixed structure wall (101). Figure 1

Description

Title of the invention: Turbomolecular vacuum pump, assembly and pumping installation Technical field of the invention

[0001] The present invention relates to a turbomolecular vacuum pump. The present invention also relates to a pumping assembly comprising the turbomolecular vacuum pump and a pumping installation comprising the pumping assembly. Technical background

[0002] The generation of a high vacuum in an enclosure requires the use of turbomolecular vacuum pumps composed of a stator in which a rotor is driven in rapid rotation on magnetic bearings, for example at a rotation of more than twenty thousand revolutions per minute.

[0003] The stator includes a fixing flange surrounding a vacuum pump suction port, which is connected to an outlet port provided in a wall of a fixed structure, such as that of a chamber whose pressure one wishes to lower or that of a flange of a valve or a pipe.

[0004] The vacuum pump is generally supported by the mounting flange alone. Tapped holes are provided in the fixed structural wall around the outlet port, through holes are provided in the mounting flange, and screws are adapted so that their shanks pass through the through holes and screw into the associated tapped holes in the fixed structural wall to secure the vacuum pump against the fixed structural wall.

[0005] However, if the rotor is destroyed, the rapidly rotating rotor can suddenly come into contact with the stator and explode inside it. All the accumulated rotational kinetic energy is then transmitted to the stator. The stator transmits this torque to the mounting flange, subjecting the screws to violent shear forces that can lead to their complete breakage. It is essential, however, for the safety of persons and property that, even if the rotor is destroyed while spinning at full speed, the stator remains attached to the fixed structural wall and contains the rotor debris so that this debris, or even the vacuum pump itself, does not become a projectile.

[0006] To avoid shearing of the screws, several solutions propose to promote their deformation in the area of ​​connection of the vacuum pump with the fixed structure wall, in particular by means of through holes in the fixing flange having an adapted geometry.

[0007] In particular, an annular vacuum pump flange is known from document EP1537336B1 in which the through holes comprise a cylindrical distal section followed by a coaxial enlarged proximal section, allowing, under shear forces in any lateral direction in the area of ​​connection between the vacuum pump and the fixed structure, a bending of the screw shank and a corresponding lateral offset between the through hole and the associated tapped hole. This bending of the screw shank increases the screw's holding power without breakage and thus, the vacuum pump's attachment to the wall of the fixed structure.

[0008] There is also a growing trend towards increasing the pumping capacity of vacuum pumps, resulting in increasingly larger pumps. This increased volume necessitates more rigid stators to prevent ovalization. To achieve this, the stators feature thicker mounting flanges and, consequently, longer screws capable of passing through these flanges.

[0009] The lengthening of the mounting flanges complicates the installation of the vacuum pump on the fixed structure. It is indeed more difficult for installers to correctly orient the vacuum pump towards the threaded holes in the wall of the fixed structure without being able to see the locations of the threaded holes, because the length of the flange prevents them from being seen through the through holes, which have become too deep.

[0010] To facilitate the positioning of the long flange-mounted vacuum pump, one solution is to use studs instead of screws. The studs, threaded at both ends, allow the threaded rods to be screwed first into the tapped holes, then the vacuum pump to be slid onto the threaded rods, and finally nuts to be tightened onto the threaded heads protruding from the flange. A first problem is that there may not be sufficient axial clearance under the fixed structural wall to pass the vacuum pump under the assembled threaded rods. Another problem is that the pre-tightening of the threaded rods in the tapped holes may be too deep or too shallow, leading to misalignment of the deformable portions of the studs with the enlarged proximal sections of the through holes in the flange. Summary of the invention

[0011] An object of the present invention is to provide a turbomolecular vacuum pump whose mounting on the walls of fixed structure of enclosure, valve or pipeline is facilitated.

[0012] Another object of the present invention is to provide a turbomolecular vacuum pump whose mounting on the walls of fixed structure of enclosure, valve or pipeline is secure.

[0013] To this end, the invention relates to a turbomolecular vacuum pump comprising a stator and a rotor configured to rotate in the stator, the stator comprising a mounting flange surrounding a suction orifice of the turbomolecular vacuum pump and in which are provided a plurality of through holes for the insertion of screws or studs intended to be screwed into tapped holes in a fixed structural wall for the securing of said vacuum pump to said wall, the through holes having a distal section provided in a distal annular portion of the mounting flange,characterized in that the through holes are perforated on the outer periphery in a proximal annular portion of the fixing flange adjacent to the distal annular portion and located on the side of the suction port of the turbomolecular vacuum pump so as to allow at least partial visualization of a bonding zone between the turbomolecular vacuum pump and the wall of the fixed structure.

[0014] It is thus possible to visualize, at least partially, on the one hand, the threaded ends of the screws or studs passing through the proximal annular portion of the mounting flange at the moment of their insertion into the tapped holes, and on the other hand, the tapped holes in the fixed structural wall into which the screws or studs are intended to be inserted and against which the mounting flange is intended to be secured. This visualization of the connection area makes it possible to accurately align the threaded ends of the screws or studs with the tapped holes in order to match their respective axes and thus correctly position the vacuum pump. Mounting the turbomolecular vacuum pump on the fixed structural wall can therefore be facilitated.Furthermore, it is possible to check simply by visual inspection through the openings whether the threaded end of a screw or stud is damaged by simply loosening the screw or stud, even when the vacuum pump is secured against the fixed structural wall.

[0015] The vacuum pump may further include one or more of the features described below, taken alone or in combination.

[0016] The opening of the through holes extends over an axial length, for example, between 5% and 30%, or between 10% and 20%, of the axial length of the fixing flange.

[0017] The axial length of the mounting flange is for example between 20% and 60%, as between 30% and 50% of the axial length of a stator housing receiving rotor stages with fins of the rotor.

[0018] According to one embodiment, the through holes respectively have a proximal section formed in the proximal annular part of the fixing flange, the proximal section having a cross-section enlarged compared to the cross-section of the distal section and opening out on the side of the suction port of the turbomolecular vacuum pump.

[0019] According to one embodiment, the through holes are made by lateral openings provided in the proximal sections.

[0020] The opening of the through holes formed by the lateral openings extends for example over the entire axial length of the proximal sections of enlarged cross-section.

[0021] The cross-sections of the proximal segments may be oblong.

[0022] The lateral openings can be formed by external sides of the cross sections of the proximal segments flush with the periphery of the fixing flange.

[0023] The centers of the cross sections and the axes of the distal sections can be aligned in a radial direction, the axes of the distal sections being offset on the inner side of the fixing flange relative to the centers of the cross sections.

[0024] According to one embodiment, the through holes are made on the outer periphery in the proximal annular part of the fixing flange because the distal sections are made at least partially at a radial distance greater than that of a radial end of the proximal annular part so that the screws or studs intended to be inserted into the through holes are located at least partly outside the proximal annular part.

[0025] The distal sections can be entirely provided at a radial distance greater than that of the radial end of the proximal annular part so that the screws or studs intended to be inserted into the through holes are entirely located outside the proximal annular part.

[0026] The proximal annular part has, for example, an externally polygonal section having as many sides as through holes, such as dodecagonal.

[0027] The invention also relates to a pumping assembly characterized in that it comprises a turbomolecular vacuum pump as described above and screws or studs inserted into the through holes of the fixing flange.

[0028] In the case of screws, each screw has a shank surmounted by a screw head.

[0029] According to one embodiment of the screws, the shank has a distal portion located on the side of the screw head having a cross-section wider than a cross-section of an adjacent proximal portion of the shank located on the side of a threaded end of the screw, the distal portion being intended to be inserted into the distal section of the distal annular part of the fixing flange, the proximal portion being intended to be inserted into the openwork proximal annular part of the fixing flange.

[0030] In the case of studs, each stud has a shank having a threaded end, the shank being surmounted by a threaded head, each stud having a screw nut on the threaded head.

[0031] According to one embodiment of the studs, the shank has a distal portion located on the side of the threaded head having a cross-section wider than a cross-section of an adjacent proximal portion of the shank located on the side of a threaded end of the stem, the distal portion being intended to be inserted into the distal section of the distal annular part of the fixing flange, the proximal portion being intended to be inserted into the openwork proximal annular part of the fixing flange.

[0032] The invention further relates to a pumping installation having a fixed structural wall in which tapped holes are provided around an outlet orifice, characterized in that the pumping installation comprises a pumping assembly as described above, attached to the fixed structural wall.

[0033] In the case where the screws or studs intended to be inserted into the through holes are located at least partly outside the proximal annular portion, the pumping installation may include vibration sensors and / or actuators and / or elastic compression elements and / or thermal and / or mechanical insulating blocks and / or deformable members, between the screws or studs, arranged on the end wall of the distal annular portion of the fixing flange or between the end wall of the distal annular portion of the fixing flange and the wall of the fixed structure. Brief description of the figures

[0034] Other advantages and features will become apparent upon reading the description of the invention, as well as the accompanying drawings in which:

[0035] [Fig-1] Fig. 1 shows a schematic axial cross-sectional view of an example of a pumping installation comprising a pumping assembly secured to a fixed structural wall by means of screws.

[0036] [Fig.2] The [Fig.2] shows a partial schematic axial cross-sectional view of a housing and a screw of the pumping assembly attached to a fixed structural wall of the [Fig.1].

[0037] [Fig.3] The [Fig.3] shows a perspective view of a housing of the pumping assembly of the [Fig.1].

[0038] [Fig.4] The [Fig.4] shows a perspective view of a screw of the pumping assembly of the [Fig.1].

[0039] [Fig.5] The [Fig.5] shows a partial top view of the housing of the [Fig.3].

[0040] [Fig. 6] Fig. 6 shows a perspective view of a stator housing for another example of a project.

[0041] [Fig.7] [Fig.7] shows a view similar to [Fig.5] for another embodiment.

[0042] [Fig.8] Fig.8 shows a view similar to Fig.2 for a pumping assembly attached to a fixed structural wall by means of studs.

[0043] In these figures, identical elements bear the same reference numbers. Detailed description

[0044] The following embodiments are examples. Although the description refers to one or more embodiments, this does not necessarily mean that each reference relates to the same embodiment, or that the features apply only to a single embodiment. Simple features of different embodiments can also be combined or interchanged to provide other embodiments, without departing from the scope of the invention as defined by the claims.

[0045] The axial direction is defined as the direction parallel to the axis of rotation II of the vacuum pump rotor and the radial or transverse directions are defined as those perpendicular to the axial direction.

[0046] Fig. 1 illustrates an example of an embodiment of a pumping installation 100 having a fixed structural wall 101 in which tapped holes 102 are provided around an outlet orifice 103. The fixed structural wall 101 is for example that of a container whose pressure is to be lowered or that of a flange of a valve or a pipeline.

[0047] The pumping installation 100 comprises a pumping unit 200 attached to the fixed structure wall 101.

[0048] The pumping assembly 200 includes a turbomolecular vacuum pump 1 and screws 300 (Figures 1, 2 and 4) or studs 400 ([Fig.8]) for securing the vacuum pump 1 to the fixed structure wall 101.

[0049] The turbomolecular vacuum pump 1 comprises a stator 2 in which a rotor 3 is configured to rotate at high speed in axial rotation, for example, at more than twenty thousand revolutions per minute. The pumped gases enter through a suction port 4 and are discharged through a discharge port (not visible) of the turbomolecular vacuum pump 1. In operation, the discharge port is connected to a primary pump.

[0050] According to one embodiment, the stator 2 comprises a housing 2a in which a recess 8 is provided and has at least two annular stator stages 9 received in the recess 8. The recess 8 is, for example, cylindrical. The stator 2 also comprises a high-pressure sleeve 2b in which the discharge port of the vacuum pump 1 is provided.

[0051] The annular stator stages 9 are respectively arranged between two successive bladed rotor stages 10 of the rotor 3. The annular stator stages 9 and the bladed rotor stages 10 follow one another axially along the axis of rotation II of the rotor 3 in the turbomolecular stage. Each bladed rotor stage 10 has inclined blades that extend in a substantially radial direction from a hub 11 of the rotor 3. The blades are regularly distributed around the periphery of the hub 11. The rotor 3 has by example more than four stages rotor with blades 10, as between seven and sixteen stages rotor with blades 10 (seven in the example illustrated in [Fig.1]).

[0052] According to one embodiment, the rotor 3 has at least one skirt 5, called a Holweck skirt, downstream of the bladed rotor stages 10 in the direction of flow of the pumped gases, formed by a smooth cylinder, which rotates opposite helical grooves 7 of the stator 2, for example formed in the high-pressure sleeve 2b. The helical grooves 7 of the stator 2 allow the pumped gases to be compressed and guided towards the discharge port.

[0053] According to one embodiment, the rotor 3 further comprises an internal bowl 15, coaxial with the axis of rotation II, arranged opposite a dome 17 of the stator 2, projecting below the rotor 3 and whose base is connected to the high-pressure bushing 2b. In operation, the rotor 3 rotates in the stator 2 without contact between the internal bowl 15 and the dome 17.

[0054] The rotor 3 is, for example, made of a single piece (monobloc). The rotor 3 is fixed to a drive shaft 12 of the vacuum pump 1, driven in rotation in the stator 2 by an internal motor 16 of the vacuum pump 1. The motor 16 is, for example, arranged in the dome 17 of the stator 2, itself arranged under the internal bowl 15 of the rotor 3, the drive shaft 12 passing through the dome 17 of the stator 2.

[0055] The rotor 3 is guided laterally and axially by magnetic bearings and backup mechanical bearings, supporting the drive shaft 12 of the rotor 3, located in the stator 2. The active magnetic bearings allow the rotor 3 to be kept levitating in the created magnetic field. Other electrical or electronic components, such as position sensors, can be housed in the dome 17 of the stator 2.

[0056] The stator 2 further includes a fixing flange 6 surrounding the suction port 4, for connecting the vacuum pump 1 to the fixed structure wall 101 and for connecting the suction port 4 of the vacuum pump 1 and the outlet port 103 of the fixed structure wall 101.

[0057] The support of the vacuum pump 1 is achieved by the single fixing flange 6 surrounding the suction port 4 at the end of the stator 2.

[0058] The suction port 4 and the outlet port 103 are cylindrical. The mounting flange 6 of the vacuum pump 1 is annular. In the illustrative example, the mounting flange 6 is arranged at the end of the stator housing 2a.

[0059] The mounting flange 6 is relatively "thick," that is, it has a relatively large axial dimension, particularly to prevent ovalization of the stator 2 of a large vacuum pump 1 with a high pumping capacity. The axial length 11 of the mounting flange 6 is, for example, between 20% and 60%, or between 30% and 50% of the axial length. L of the stator housing 2a of the stator 2 receiving the annular stator stages 9 of the stator 2 and the vane rotor stages 10 of the rotor 3 ([Fig.2]). The axial length 11 of the mounting flange 6 is, for example, between 5 cm and 10 cm, such as between 6 cm and 8 cm.

[0060] As more clearly seen in figures 2 and 3, a plurality of through holes 20 is provided in the fixing flange 6.

[0061] The through holes 20 pass through the fixing flange 6 in an axial direction parallel to the axis of rotation II. These through holes 20 allow the insertion of the screws 300 intended to be inserted into the tapped holes 102 of the fixed structure wall 101 to secure the vacuum pump 1 against the fixed structure wall 101 surrounding the outlet port 103.

[0062] The screws 300 have shanks 320 having a threaded end, the shanks 320 being surmounted by screw heads 310 ([Fig. 4]). The length of the shanks 320 is adapted to allow them to pass through the fixing flange 6 along its axial length and to screw into the associated tapped holes 102 in the fixed structural wall 101. The screws 300 are, for example, made of steel, such as stainless steel.

[0063] The through holes 20 are regularly distributed around the perimeter of the fixing flange 6. The number and distribution of the through holes 20 correspond of course to those of the tapped holes 102 of the fixed structure wall 101 and to the number of screws 300. There are for example between eight and sixteen, such as twelve, through holes 20, screws 300 and tapped holes 102.

[0064] The through holes 20 have a cylindrical distal section 21 formed in a distal annular portion 22 of the fixing flange 6 ([Fig.2]). The screw heads 310 are intended to abut against the radial wall of the distal annular portion 22 once the screws 300 are screwed into the wall of the fixed structure 101.

[0065] The fixing flange 6 has a proximal annular portion 23 adjacent and coaxial with the distal annular portion 22, the proximal annular portion 23 being located on the side of the suction port 4. The end wall of the proximal annular portion 23 of the fixing flange 6 is intended to come into contact with the wall of the fixed structure 101. A sealing gasket 27 can be interposed between the wall of the proximal annular portion 23 and the wall of the fixed structure 101, the sealing gasket 27 being partially received in an annular groove 26 formed in the end wall of the fixing flange 6 (Figures 1 and 5).

[0066] The through holes 20 are openworked on the outer periphery in the proximal annular part 23 of the fixing flange 6 located on the side of the suction port 4 of the vacuum pump 1 so as to allow at least partial visualization of a bonding zone Z between the turbomolecular vacuum pump 1 and the fixed structure wall 101.

[0067] It is thus possible to visualize, at least partially, on the one hand, the threaded ends of the screws 300 passing through the proximal annular part 23 of the fixing flange 6 at the time of their insertion into the tapped holes 102 and, on the other hand, the tapped holes 102 of the fixed structural wall 101 into which the screws 300 are intended to be inserted and against which the fixing flange 6 is intended to be secured. This visualization of the connection area Z makes it possible to accurately align the threaded ends of the screws 300 with the tapped holes 102 in order to match their respective axes and thus correctly position the vacuum pump 1. The mounting of the turbomolecular vacuum pump 1 onto the fixed structural wall 101 can therefore be facilitated. It is also possible to easily check by visual inspection through the openings whether the threaded end of a screw 300 is damaged by simply loosening the screw 300 even when the vacuum pump 1 is secured against the fixed structural wall 101.

[0068] Figures 1, 2, 3 and 5 show a first example of an embodiment in which the through holes 20 respectively have a proximal section 24 formed in the proximal annular part 23 of the fixing flange 6, the proximal section 24 being adjacent and coaxial with the distal section 21 with a possible connecting portion between the two, for example conical or similar, the proximal section 24 having a cross-section enlarged compared to the cross-section of the distal section 21. The proximal section 24 opens on the side of the suction port 4 of the vacuum pump 1.

[0069] The rods 320 of the screws 300 can thus deform with the displacement of the stator 2 relative to the fixed structural wall 101 in the event of a rotor 3 crash. The rods 320 of the screws 300 can then stretch in the proximal sections 24 and deform without breaking, following the displacement of the stator 2, allowing for an offset between the through holes 20 and the associated tapped holes 102. Thus, even if the rotor 3 is destroyed while traveling at full speed, the stator 2 remains attached to the fixed structural wall 101 and contains the debris from the rotor 3.

[0070] The through holes 20 are here perforated by lateral openings 25 made in the proximal sections 24, to allow visualization of the connection zone Z.

[0071] The opening of the through holes 20 formed by the lateral openings 25 extends for example over an axial length 12 between 5% and 30%, as between 10% and 20%, of the axial length 11 of the fixing flange 6. The opening of the through holes 20 formed by the lateral openings 25 extends for example over the entire axial length 12 of the proximal sections 24 of enlarged section.

[0072] The axial length 12 of the opening of the through holes 20 formed by the lateral openings 25 is, for example, between 0.5 cm and 2 cm, such as 1 cm. The axial length 12 of the opening represents a small proportion of the axial length 11 of the mounting flange 6, allowing visual inspection of the connection area Z without compromising the mechanical strength of the mounting flange 6.

[0073] As more clearly seen in [Fig.5], the cross-sections of the proximal segments 24 can be oblong, that is to say here be longer than wide and be terminated by two half-cylinders.

[0074] The lateral openings 25 are formed by the external sides of the cross sections flush with the periphery of the mounting flange 6. The through holes 20 are then offset outwards from the flange 6, to the edge of the stator 2 instead of being provided symmetrically.

[0075] According to one embodiment, the centers of the cross sections and the axes of the distal sections 21 are aligned in the radial direction, the axes of the distal sections 21 being offset on the inner side of the fixing flange 6 with respect to the centers of the cross sections.

[0076] It can also be foreseen that the shanks 320 of the screws 300 have a distal portion 321 located on the side of the screw head 310 having a cross-section wider than a cross-section of an adjacent proximal portion 322 of the shank 320 located on the side of a threaded end of the screw 300.

[0077] The distal portion 321 is intended to be inserted into the cylindrical distal section 21 of the distal annular part 22 of the fixing flange 6. The distal portion 321 is smooth to avoid weakening the screw 300 at the level of the distal portion 321.

[0078] The proximal portion 322 has a smooth section and a threaded end. The proximal portion 322 is designed to be inserted into the perforated proximal annular portion 23 of the mounting flange 6. The thicker distal portion 321 will be less deformed in the event of a rotor 3 crash, unlike the thinner proximal portion 322, which will be more easily deformed. This favors deformation of the screws 300 in the proximal portion 322 of the rod 320 located outside the distal section 21, as the proximal portion 322 can deform in the proximal sections 24. Furthermore, the elongation of the screws 300 is limited because the wider distal portion 321 is less susceptible to deformation.

[0079] Once the screw 300 is assembled, only the smooth part of the proximal portion 322 comes out of the tapped hole 102, which prevents the formation of a break initiation of the screw 300 in the threaded end before the deformation of the smooth part of the refined proximal portion 322.

[0080] A leak detection channel 500 can also be provided between the through hole 20 and the annular groove 26 ([Fig. 5]). A tracer gas can then be injected through the lateral opening 25 and a leak detector fluidly connected to the vacuum pump 1 (for example, to the suction port 4 or the discharge port) can be used to monitor whether tracer gas can be found in the vacuum pump 1 in order to check the tightness of the sealing gasket 27.

[0081] Fig. 6 illustrates an alternative embodiment of the housing 2a of the vacuum pump 1.

[0082] In this variant, the cross-sections of the proximal sections 24 have an oblong “D” shape. The lateral openings 25 are formed by the flat external sides of the “D” shapes of the cross-sections flush with the periphery of the fixing flange 6.

[0083] Figure 7 illustrates another embodiment in which the through holes 20 are openwork on the outer periphery in the proximal annular part 23 of the fixing flange 6 because the distal sections 21 are provided at least partially at a radial distance greater than that of a radial end of the proximal annular part 23 so that the screws 300 intended to be inserted into the through holes 20 are located at least partly outside the proximal annular part 23.

[0084] The distal sections 21 can be entirely provided at a radial distance greater than that of the radial end of the proximal annular part 23 so that the screws 300 intended to be inserted into the through holes 20 are entirely located outside the proximal annular part 23. In other words, the through holes 20 are devoid of proximal sections.

[0085] The proximal annular portion 23 then has, for example, a polygonal external cross-section, such as dodecagonal, with as many sides as there are through holes 20 provided in the mounting flange 6. The proximal annular portion 23 has a cylindrical internal shape. A proximal annular portion 23 with a polygonal external cross-section facilitates machining. Also, this polygonal external shape can allow the passage of a tool for handling the vacuum pump 1, such as a lifting fork (for example, in the case of a vacuum pump whose orientation is reversed with respect to [Fig. 1]).

[0086] The through holes 20 allow the screws 300 to deform with the displacement of the stator 2 relative to the fixed structural wall 101 in the event of a rotor 3 crash. The screws 300 can stretch and deform without breaking at the proximal annular portion 23, following the displacement of the stator 2, thus allowing an offset between the through holes 20 and the associated threaded holes 102. Therefore, even if the rotor 3 is destroyed while traveling at full speed, the stator 2 remains attached to the fixed structural wall 101 and contains the debris from the rotor 3.

[0087] As in the previously described embodiments, the opening of the through holes 20 extends for example over an axial length 12 of between 5% and 30%, as between 10% and 20%, of the axial length 11 of the fixing flange 6. The axial length 12 of the opening of the through holes 20 is for example between 0.5 cm and 2 cm, such that 1 cm.

[0088] As in the previous examples, it can be foreseen that the shanks 320 of the screws 300 have a distal portion 321 located on the side of the screw head 301 having a section wider than a section of an adjacent proximal portion 322 of the rod 320 located on the side of a threaded end of the screw 300. This favors the deformation of the screws 300 in the proximal portion 322 of the rod 320 located outside the distal section 21.

[0089] In this embodiment, due to the clearance provided in the stator 2 by the openings, the pumping installation 100 may also include auxiliary devices 600 or 700 such as vibration sensors and / or actuators and / or elastic compression elements and / or thermal and / or mechanical insulating blocks and / or deformable members, arranged between the screws 300 on the circumference of the end wall of the distal annular portion 22 or between the end wall of the distal annular portion 22 of the fixing flange 6 and the fixed structure wall 101.

[0090] Vibration sensors 700 can be arranged on the circumference of the end wall of the distal annular portion 22 of the mounting flange 6, between the screws 300. These vibration sensors can be dynamic force sensors such as axial strain gauges or mechanical or thermal sensors such as accelerometers or strain gauges. These sensors can be used to measure the vibrations created by the vacuum pump 1 on the fixed structural wall 101.

[0091] Actuators 700 can be arranged on the circumference of the end wall of the distal annular portion 22 of the fixing flange 6, between the screws 300. The actuators, in particular those of high force and very low displacement, such as piezoelectric actuators, can allow the vibrations created by the vacuum pump 1 to be attenuated by compensation.

[0092] It is also possible to arrange elastic compression elements 600, such as springs, between the screws 300, so as to connect the end wall of the distal annular portion 22 of the fixing flange 6 to the fixed structure wall 101. The elastic compression elements can allow the vacuum pump 1 to be detached from the fixed structure wall 101 as soon as the screws 300 are loosened to facilitate the dismantling of the vacuum pump 1.

[0093] Thermal and / or mechanical insulating blocks 600 can also be arranged between the screws 300 to connect the end wall of the distal annular portion 22 of the mounting flange 6 to the fixed structural wall 101. The height of the insulating blocks in the axial direction is greater, for example by 1 / 100 mm, than the length of the proximal annular portion 23 to form thermal and / or mechanical insulation between the fixed structural wall 101 and the mounting flange 6. Contact between the stator 2 and the fixed structural wall 101 is thus entirely achieved via the insulating blocks. The thermal insulating blocks can be made of fiberglass. Mechanical insulating blocks, to reduce vibrations, can be made of plastic material, such as polymer material.

[0094] Deformable members 600 can also be arranged between the screws 300, so as to connect the end wall of the distal annular portion 22 of the fixing flange 6 and the fixed structure wall 101. The deformation of these members makes it possible to reduce and control the torque transmitted to the fixed structure wall and to the screws 300 in the event of a crash of the vacuum pump 1. The deformable members are for example made in the form of bars, and are for example made of steel, such as stainless steel, which has good elongation properties.

[0095] The other features of this embodiment example are similar to the embodiment examples previously described.

[0096] Figure 8 shows a pumping assembly 200 comprising 400 studs for secure the turbomolecular vacuum pump 1 to the wall of fixed structure 101.

[0097] The studs 400 have shanks 420 having a threaded end, the shanks 420 being surmounted by threaded heads 410. The length of the shanks 420 is adapted to be able to pass through the fixing flange 6 along its axial length and to screw into the associated tapped holes 102 of the fixed structural wall 101. The studs 400 further have a respective nut 430, such as a cap nut, which is screwed onto the threaded head 410. The studs 400 are, for example, made of steel, such as stainless steel.

[0098] Like the screws 300, the studs 400 are inserted into the through holes 20 through the fixing flange 6 to be screwed into the tapped holes 102 of the fixed structure wall 101.

[0099] The nuts 430 of the studs 400 are intended to come into buttress against the radial wall of the distal annular part 22 once the studs 400 are screwed into the fixed structure wall 101.

[0100] During assembly, the studs whose threaded heads 410 are provided with respective nuts 430 can be pre-assembled on the vacuum pump 1 to be assembled to the fixed structure wall 101 in the same way as the screws 300.

[0101] As with the screws, it is thus possible to visualize, at least partially, on the one hand, the threaded ends of the shanks 420 of the studs 400 passing through the proximal annular portion 23 of the mounting flange 6 at the moment of their insertion into the tapped holes 102 and, on the other hand, the tapped holes 102 of the fixed structural wall 101 into which the studs 400 are intended to be inserted and against which the mounting flange 6 is intended to be secured. This visualization of the connection area Z makes it possible to accurately align the tapped holes 102 with the threaded ends of the studs 400 in order to match their respective axes and thus correctly position the vacuum pump 1. Mounting the turbomolecular vacuum pump 1 on the fixed structural wall 101 can thus be facilitated. It is also possible to verify simply by visual inspection through the openings if the threaded end of a 420 rod of stud 400 is damaged by simple loosening of the stud 400 even when the vacuum pump 1 is secured against the fixed structure wall 101.

[0102] In addition, as in the previous examples, the shanks 420 of the studs 400 behave like the shanks 320 of the screws 300 and can deform in the proximal sections 24 or in the openings of the through holes 20 with the displacement of the stator 2 relative to the fixed structure wall 101 in the event of a crash of the rotor 3.

[0103] Furthermore, according to one embodiment of the studs 400, the stem 420 may have a distal portion 421 located on the side of the threaded head 410 having a cross-section wider than a cross-section of an adjacent proximal portion 422 of the stem 420 located on the side of a threaded end of the stud 400. The distal portion 421 is smooth to prevent weakening of the stud 400 at the distal portion 421. The distal portion 421 is intended to be inserted into the distal section 21 of the distal annular portion 22 of the fixing flange 6. The proximal portion 422 has a smooth portion and a threaded end. The proximal portion 422 is intended to be inserted into the perforated proximal annular portion 23 of the fixing flange 6.Once the stud is assembled, only the smooth part of the proximal portion 422 protrudes from the tapped hole 102, which prevents the formation of a break initiation point in the stud 400 at the threaded end before the deformation of the smooth part of the refined proximal portion 422.

[0104] The other features of this embodiment example are similar to the embodiment examples previously described.

Claims

Demands

1. Turbomolecular vacuum pump (1) comprising a stator (2) and a rotor (3) configured to rotate in the stator (2), the stator (2) comprising a mounting flange (6) surrounding a suction port (4) of the turbomolecular vacuum pump (1) and in which are provided a plurality of through holes (20) for the insertion of screws (300) or studs (400) intended to be screwed into tapped holes (102) of a fixed structural wall (101) for securing said vacuum pump (1) to said wall (101), the through holes (20) having a distal section (21) formed in a distal annular portion (22) of the mounting flange (6),characterized in that the through holes (20) are openworked on the outer periphery in a proximal annular portion (23) of the fixing flange (6) adjacent to the distal annular portion (22) and located on the side of the suction port (4) of the turbomolecular vacuum pump (1) so as to allow at least partial visualization of a bonding zone (Z) between the turbomolecular vacuum pump (1) (2) and the fixed structure wall (101).

2. Vacuum pump (1) according to the preceding claim, characterized in that the opening of the through holes (20) extends over an axial length (12) between 5% and 30%, as between 10% and 20%, of the axial length (11) of the fixing flange (6).

3. Vacuum pump (1) according to any one of the preceding claims, characterized in that the axial length (11) of the mounting flange (6) is between 20% and 60%, as between 30% and 50% of the axial length (L) of a housing (2a) of the stator (2) receiving the vane rotor stages (10) of the rotor (3).

4. Vacuum pump (1) according to any one of the preceding claims, characterized in that the through holes (20) respectively have a proximal section (24) formed in the proximal annular part (23) of the fixing flange (6), the proximal section (14) having a cross-section enlarged compared to the cross-section of the distal section (21) and opening out on the side of the suction port (4) of the turbomolecular vacuum pump (1), the through holes (20) being perforated by lateral openings (25) formed in the proximal sections (24).

5. Vacuum pump (1) according to claim 4, characterized in that the opening of the through holes (20) formed by the lateral openings (25) extends over the entire axial length (12) of the proximal sections (24) of enlarged cross-section.

6. Vacuum pump (1) according to any one of claims 4 or 5, characterized in that the lateral openings (25) are formed by external sides of the cross sections of the proximal sections (24) flush with the periphery of the fixing flange (6).

7. Vacuum pump (1) according to any one of claims 5 or 6, characterized in that the cross sections of the proximal segments (24) are oblong.

8. Vacuum pump (1) according to any one of claims 1 to 3, characterized in that the through holes (20) are openworked on the outer periphery in the proximal annular part (23) of the fixing flange (6) because the distal sections (21) are provided at least partially at a radial distance greater than that of a radial end of the proximal annular part (23) so that the screws (300) or studs (400) intended to be inserted into the through holes (20) are located at least partly outside the proximal annular part (23).

9. Vacuum pump (1) according to the preceding claim, characterized in that the distal sections (21) are entirely provided at a radial distance greater than that of the radial end of the proximal annular part (23) so that the screws (300) or studs (400) intended to be inserted into the through holes (20) are entirely located outside the proximal annular part (23).

10. Vacuum pump (1) according to the preceding claim, characterized in that the proximal annular part (23) has an externally polygonal cross-section having as many sides as through holes (20), such as dodecagonal.

11. Pumping assembly (200) characterized in that it comprises a turbomolecular vacuum pump (1) according to any one of the preceding claims and screws (300) or studs (400) inserted into the through holes (20) of the mounting flange (6).

12. Pumping assembly (200) according to the preceding claim, characterized in that each screw (300) has a shank (320) surmounted by a screw head (310), the shank (320) having a distal portion (321) located on the side of the screw head (310) having a section wider than a section of an adjacent proximal portion (322) of the stem (320) located on the side of a threaded end of the screw (300), the distal portion (321) being intended to be inserted into the distal section (21) of the distal annular part (22) of the fixing flange (6), the proximal portion (322) being intended to be inserted into the openwork proximal annular part (23) of the fixing flange (6).

13. Pumping assembly (200) according to claim 11, characterized in that each stud (400) has a shank (420) surmounted by a threaded head (410), the shank (420) having a distal portion (421) located on the side of the threaded head (410) having a cross-section wider than a cross-section of an adjacent proximal portion (422) of the shank (420) located on the side of a threaded end of the shank (420), the distal portion (421) being intended to be inserted into the distal section (21) of the distal annular portion (22) of the fixing flange (6), the proximal portion (322) being intended to be inserted into the openwork proximal annular portion (23) of the fixing flange (6).

14. Pumping installation (100) having a fixed structural wall (101) in which tapped holes (102) are provided around an outlet orifice (103), characterized in that the pumping installation (100) comprises a pumping assembly (200) according to any one of claims 11 to 13 attached to the fixed structural wall (101).

15. Pumping installation (100) according to the preceding claim, comprising a turbomolecular vacuum pump (1) according to any one of claims 8 to 10 characterized in that the pumping installation (100) comprises vibration sensors and / or actuators and / or elastic compression elements and / or thermal and / or mechanical insulating blocks and / or deformable members, between the screws (300) or studs (400), arranged on the end wall of the distal annular portion (22) of the fixing flange (6) or between the end wall of the distal annular portion (22) of the fixing flange (6) and the fixed structure wall (101).

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