JP2023552328A - dry vacuum pump - Google Patents

Abstract

Dry vacuum pumps require the ability to absorb large gas flows, at least intermittently, for certain pump applications. The cumulative effects of thermal expansion and shaft flexing motion caused during these transient steps can result in radial contact between a pair of rotors or between a rotor and a stator. The vacuum pump includes at least one pump stage (3a-3e) and a pair of rotors (7) configured to rotate within the at least one pump stage. A dry vacuum pump (1) configured to be rotated by at least one motor (9) of said vacuum pump (1) having at least one pair of double bearings (13a, 13b), Each of the heavy bearings (13a, 13b) has at least one permanent magnet magnetic bearing (14a, 14b) and at least one sliding bearing (15a, 15b) for supporting the rotor, respectively. [Selection diagram] Figure 1

Description

The present invention relates to dry vacuum pumps.

Dry vacuum pumps include one or more pump stages in series between which the pumped gas circulates between an inlet and an outlet. Among the known vacuum pumps, a distinction is made between pumps with rotating lobes, also known by the name "roots", and pumps with claws, also known by the name "claws". These vacuum pumps are called "dry". This is because the pair of rotors rotates within the stator during operation, and the rotors do not come into mechanical contact with each other or the rotor with the stator. This eliminates the need for oil in the pump stage.
A pair of rotors is supported by lubricated bearings at the shaft ends. To facilitate installation and removal, certain rotors are mounted in a cantilevered manner, with the shaft supported only by bearings located on the motor.

Certain pump applications require the ability to absorb large gas flows, at least intermittently. These transients occur most often when the vacuum pump chamber is empty at atmospheric pressure or when gas suddenly enters the vacuum pump chamber. Pumping these powerful gas streams heats up the vacuum pump significantly and places heavy loads on the rotor.
The accumulation of the phenomena of thermal expansion and flexural movement of the shaft caused during these various transient stages can result in radial contact between a pair of rotors or between a rotor and a stator. Although they occur very infrequently, these transient stages can cause significant damage to the vacuum pump.

One aim of the invention is to at least partially solve one of the above-mentioned drawbacks.

To achieve this objective, the subject of the invention relates to a dry vacuum pump with the following characteristics.
- at least one pump stage;
- a pair of rotors configured to rotate within at least one of the pump stages, the pair of rotors configured to rotate by at least one motor of the vacuum pump,
The vacuum pump is characterized in that it has at least one pair of double bearings, including at least one permanent magnet magnetic bearing and at least one sliding bearing, for supporting each of the pair of rotors.

The permanent magnet magnetic bearing centers the rotor on the stator in a steady state regime by centering. This ensures that only slight loads are generated on the shaft for pumping weak or medium gas flows. The permanent magnet magnetic bearing limits deflection phenomena of the rotor during normal operation. Also, vibrations of the rotor caused by resonance phenomena or imbalance during normal operation are also limited.
The plain bearing forms a stop for the rotor in transient mode. That is, a large gas flow is intermittently pumped by providing rotational guidance by sliding only when centering by the permanent magnet magnetic bearing is insufficient. Therefore, plain bearings serve as a backup for permanent magnet magnetic bearings. The advantage of this device is that these bearings are non-contact, so no friction or wear occurs. It does not restrict the flow of the pumped gas and does not require lubrication or diluent gas to protect the gas, so pump performance is not affected. Additionally, these bearings can withstand corrosive environments.
This solution also facilitates the arrangement of vacuum pumps installed "vertically", ie in the direction of the vertical axis. This means that the absence of lubricant means there is no risk of oil or grease migrating from the bearing towards the dry pump stage by gravity.

The vacuum pump may also include one or more of the features described below alone or in combination.
The permanent magnet magnetic bearing may include a stator portion that is fixed to the stator and a rotor portion that rotates integrally with the rotor.
The at least one pair of double-bearing plain bearings is configured to provide a respective clearance between the rotor and the stator between the rotor portion and the stator portion of the at least one double-bearing permanent magnet magnetic bearing. It can be installed with less clearance. This ensures that the contact between rotor and stator occurs first within the plain bearing and not between the stator and rotor parts of the permanent magnet magnetic bearing.

The plain bearings may each have a ring that is clamped and mounted in a bore of the stator or rotor and/or a ring that is clamped and mounted on the shaft of the stator and/or rotor. Each plain bearing thus comprises, for example, a single ring clamped and mounted in a bore, or a single ring clamped and mounted on a shaft, or two rings. In the latter case, one is clamped and mounted in the hole and the other is clamped and mounted on the shaft.
Plain bearings may be surface-treated in the bore of the stator or rotor, and/or on the shaft of the stator or rotor, and/or in the bore and/or on the shaft, and may be clamped and mounted on the bore and/or shaft. The ring may have a coating or surface treatment. For example, each plain bearing may be coated or surface treated in the bore only, or coated or surface treated in the shaft only, or coated or surface treated in the bore and the shaft, or in the bore and/or the shaft. A coating or surface treatment is applied to the ring which is clamped and attached to the ring.

The vacuum pump may have at least two pump stages arranged in series, with a pair of double bearing permanent magnet magnetic bearings disposed in the axial passage between two successive pump stages.
The vacuum pump may have at least two pump stages arranged in series, and a pair of double bearing plain bearings may be arranged in the axial passage between two successive pump stages.
A pair of dual bearing permanent magnet magnetic bearings may be disposed at the shaft end, and the pump stage may be interposed between the motor and the shaft end. A pair of double-bearing plain bearings may be arranged at the shaft end, and at least one pump stage may be interposed between the motor and the shaft end.

The dual-bearing permanent magnet magnetic bearings may be spaced apart from the plain bearings along the rotor, or may be located adjacent to them. For example, a permanent magnet magnetic bearing may be provided at the shaft end, and a sliding bearing may be provided between the shaft passage such as the first shaft passage, that is, the first pump stage and the second pump stage. Thereby, the vacuum pump can be made more compact.

According to an embodiment of the invention, a pair of double-bearing permanent magnet magnetic bearing stator parts and/or a pair of double-bearing sliding bearings surround the rotor.
According to an embodiment of the invention, a pair of double-bearing permanent magnet magnetic bearings and/or a pair of double-bearing sliding bearings are arranged inside the respective rotor.
Each plain bearing may have a silicon carbide coating or a nickel/PTFE coating.
The permanent magnet magnetic bearings may each have a nickel/PTFE coating.
The vacuum pump may also include at least two roller bearing arrangements configured to support respective rotors in the drive part of the vacuum pump.

1 is a schematic diagram of a first embodiment of a dry vacuum pump of the present invention; FIG. FIG. 2 is a cross-sectional view showing details of the shaft end of the dry vacuum pump of FIG. 1; FIG. 6 is a sectional view showing details of the shaft end of another modified example of the dry vacuum pump of the present invention. 3 is a schematic diagram showing details of another variant of the dry vacuum pump at the shaft end of the invention; FIG. 2 is a view similar to FIG. 1 for a second embodiment of the dry vacuum pump of the invention; FIG. 2 is a view similar to FIG. 1 for a third embodiment of the dry vacuum pump of the invention; FIG.

Other features and advantages of the invention will become apparent from the following description, given by way of example and not limitation, with reference to the accompanying drawings, in which: FIG.
Identical elements are provided with the same reference numerals in these figures. The following embodiment is an example. The following description may refer to one or more embodiments, but this does not necessarily mean that each reference is to the same embodiment or that the features apply only to a single embodiment. It's not a thing. Individual features of the various embodiments may also be combined or exchanged to provide other embodiments.
"Upstream" is understood to mean an element located before another element with respect to the direction of circulation of the pumped gas. Conversely, "downstream" is understood to mean an element located after another element with respect to the direction of circulation of the pumped gas. Axial direction is defined as the longitudinal direction of the vacuum pump along which the axis of rotation of the rotor extends.

The invention applies to any type of dry vacuum pump 1 having at least one pump stage 3a to 3e, which vacuum pump has from 1 to 10 pump stages, such as for example 5 pump stages 3a to 3e. It's good to be prepared. The vacuum pump 1 may be a roughing vacuum pump configured to discharge pumped gas at atmospheric pressure. Alternatively, it may be a dry vacuum pump that has one to three pump stages, is connected upstream of the roughing vacuum pump during use, and the discharge pressure during operation is the pressure obtained by the roughing vacuum pump.
The vacuum pump 1 has a pair of rotors 7 configured to rotate within a compression chamber of at least one pump stage 3a to 3e, and directs gas from an intake orifice 4 to a discharge orifice 5 as shown in FIG. The gas is pumped in the direction of circulation indicated schematically by the arrow.

The pair of rotors 7 has a mating profile that can be assembled on the shafts 6a, 6b or made integrally with the shafts 6a, 6b of the rotor 7 (referred to as integral rotors). The rotor 7 is, for example, of the "roots" type with two or more lobes, or of the "claw" type, or another similar, based on a positive displacement vacuum pump principle.

The vacuum pump 1 has, for example, at least two pump stages 3a to 3e arranged in series. Each pump stage 3a-3e of the stator 2 is formed by a compression chamber receiving two mating rotors 7, which compression chambers are provided with a respective inlet and a respective outlet. During rotation, gas drawn in from the suction port is trapped in the volume created between the rotor 7 and the stator 2, and is transported by the rotor 7 toward the next stage. Successive pump stages 3a-3e are connected in series one after the other, with respective interstage channels connecting the outlet of the previous pump stage to the inlet of the next pump stage.

The suction port of the first pump stage 3a communicates with the suction orifice 4 of the vacuum pump 1. The outlet of the final pump stage 3e communicates with the discharge orifice 5. The axial dimensions of each pump stage are, for example, the same or decrease according to the order of arrangement of the pump stages 3a to 3e, with the pump stage 3a located close to the intake orifice 4 having the largest axial dimension.
These vacuum pumps are called "dry". The reason is that during operation, the rotors 7 rotate within the stator 2 without mechanical contact with each other or with the stator 2, which makes it possible to use no oil in the pump stages 3a-3e. This is to become.

The rotor 7 is configured to be rotated by at least one motor 9 in the drive 8 of the vacuum pump 1 . The vacuum pump 1 has a single motor 9 attached to one of the rotors 7 at one end of the vacuum pump 1, for example the last pump stage 3e of this vacuum pump 1.
In addition to the motor 9, the drive 8 may have a synchronous gear 10 and at least two rolling bearing arrangements 11a, 11b for supporting a respective rotor 7 in the drive 8.

The drive unit 8 has, for example, a plurality of pairs, for example, three pairs of rolling bearing devices 11a, which can be arranged on both sides of the motor 9 as the rolling bearing devices 11a of the drive shaft 6a. For example, there is one rolling bearing device 11a at the shaft end of the drive section 8, and there are two rolling bearing devices 11a interposed between the motor 9 and the pump stages 3a to 3e. The rolling bearing device 11b of the driven shaft 6b may be arranged symmetrically with the rolling bearing device 11a of the drive shaft 6a. The rolling bearing devices 11a and 11b include, for example, ball bearings.

The rolling bearing devices 11a, 11b may be lubricated by a lubricant in an oil sump 12 of the drive section 8 of the vacuum pump 1, and this oil sump 12 is provided between the motor 9 and the pump stages 3a to 3e. There is. The lubricant lubricates the rolling bearings of the rolling bearing devices 11a and 11b and the synchronous gear 10 of the rotor 7.
The vacuum pump 1 also includes a lubricant sealing device (not shown) interposed between the drive section 8 and the dry pump section through which the gas of the pump stages 3a to 3e circulates. This sealing device allows the dry pump section to rotate the shafts 6a and 6b while restricting movement of the lubricant.

The vacuum pump 1 also includes at least one pair of double bearings 13a, 13b, with at least one permanent magnet magnetic bearing 14a, 14b and at least one sliding bearing 15a, 15b, for supporting each of the pair of rotors 7. have The rotor can rotate contact-free during "normal" operation in these double bearings 13a, 13b arranged in the dry pump part, ie popump stages 3a-3e.

These permanent magnet magnetic bearings 14a and 14b are bearings that support the rotating rotor 7 by magnetic levitation without contacting the rotor 7. Each of these bearings has, for example, a rotor part 17a configured to rotate within a stator part 17b. This rotor part 17a rotates with the rotor 7 and supports magnets, whose rotation generates a magnetic field that ensures the centering of the stator part 17b (see FIG. 2).
Each of the permanent magnet magnetic bearings 14a, 14b may have a nickel/PTFE coating, in particular a coating heat treated at a temperature below the Curie point. This coating covers the rotor part 17a and/or the stator part 17b.
The sliding bearings 15a and 15b are each mounted with a clearance d between them and the rotor 7. This clearance is smaller than the operating clearance between rotor 7 and smaller than the operating clearance between rotor 7 and stator 2. The clearance d at this radius is, for example, greater than 0.1 mm and/or less than 0.5 mm. The clearance between the rotor portion 17a and the stator portion 17b of the permanent magnet magnetic bearings 14a, 14b is, for example, larger than the clearance d.

The sliding bearings 15a, 15b each have, for example, a ring that is clamped and installed in a bore of the stator 2 or the rotor 7 and/or a ring that is clamped and installed on the shaft 23 of the stator 2 and/or the rotor 7. . The plain bearings 15a, 15b may also be provided with a coating in the bore of the stator 2 or rotor 7 and/or in the shaft 23, 18 of the stator 2 or rotor and/or in the bore and/or in a ring clamped and mounted on the shaft. Or it may be surface treated.
The plain bearings 15a, 15b each have a silicon carbide (SiC) coating or a nickel/PTFE coating, and can in particular have a heat-treated coating. These coatings cover rings, holes or axes such as the axle 6a of the rotor 7 or the axes 18, 23 of the plug seal 19, as shown below.

Permanent magnet magnetic bearings 14a, 14b center the rotor 7 in steady state regime. This creates a negligible load on the rotor 7 for pumping a weak and medium gas flow. These permanent magnet magnetic bearings 14a, 14b can limit the deflection phenomenon of the rotor 7 during normal operation. They also limit vibrations of the rotor 7 during normal operation caused by resonance phenomena or balance defects.
The sliding bearings 15a, 15b form a stationary state of the rotor 7 in the transient mode. That is, a large flow of gas is intermittently pumped by providing rotational guidance by sliding only when centering by the permanent magnet magnetic bearings 14a, 14b is insufficient. The sliding bearings 15a, 15b thus provide backup for the permanent magnet magnetic bearings 14a, 14b.
The advantage of this device is that these bearings 13a, 13b are non-contact, so there is no friction or wear. They do not restrict the flow of the pumped gas and do not require lubrication or diluent gas to protect the gas, so pump performance is not affected. Furthermore, these bearings 13a, 13b can also be adapted to corrosive environments.
This solution also allows for an arrangement of the vacuum pump 1 that is installed "vertically", ie in the direction of a vertical axis. This is because the absence of lubricant means that there is no risk of oil or grease migrating by gravity from the bearings 13a, 13b towards the pump stages 3a-3e.

According to the first embodiment shown in FIG. 1, the sliding bearings of the permanent magnet magnetic bearings 14a, 14b and the pair of double bearings 13a, 13b are located at the shaft ends 16a, 16b, and the pump stages 3a-3e are It is arranged between the motor 9 of the drive unit 8 and the shaft ends 16a, 16b. This structure is called a cantilever structure because there is no contact between the pair of rotors 7 and the bearings 13a, 13b.

As can be seen from the non-limiting example of FIG. Has a ring. The stator portion 17b has, for example, one annular portion fixed to the stator 2.
The plug seal 19 has, for example, a body 20 with a base having a complementary shape, for example cylindrical, to the central housing 22 of the rotor 7, on which is mounted a shaft 18 coaxial with the axis of rotation of the rotor. There is. This main body 20 is made of steel, for example. Further, the plug seal 19 has a toric seal 21 made of fluorine elastomer or the like interposed between the main body 20 and the rotor 7. This plug seal 19 is fixed to the rotor 7 by screwing, for example.

The plug seal 19 hermetically closes the central housing 22 of the rotor 7 to prevent corrosive gases, powders, or other substances from entering the central housing 22 that could cause corrosion or damage to the rotor 7. ing.
The sliding bearings 15a, 15b are here mounted in the stator 2 with a clearance d relative to the shaft 18 of the plug seal 19.
The sliding bearings 15a, 15b each have a ring that is mounted, for example, by being clamped into a hole in the stator 2.
The shaft 18 protruding at the axial end of the rotor 7 may be made integral with the main body of the rotor 7 . This variant applies in particular in the case of integral rotors 7 without plug seals.

FIG. 3 shows a variant embodiment of the vacuum pump 1, in which a pair of double bearings 13a, 13b, a permanent magnet magnetic bearing 14a, 14b and/or a plain bearing 15a, 15b are located inside the respective rotor 7. It is located.
More specifically, here, the vacuum pump 1 has permanent magnet magnetic bearings 14a, 14b arranged inside each rotor 7, and sliding bearings 15a, 15b arranged inside each rotor 7.
In the example of FIG. 3, a pair of double bearings 13a, 13b are arranged at the shaft ends 16a, 16b, and the rotor part 17a of the permanent magnet magnetic bearings 14a, 14b has, for example, a plug seal 19 facing the stator part 17b. has a ring fixed within the housing. This ring is attached to a shaft 23 protruding from the stator 2 and inserted into the housing of the plug seal 19. In this example, the plug seal 19 does not have a shaft 18, but has a housing coaxial with the axis of rotation of the rotor.

The sliding bearings 15a, 15b are here mounted in the housing of the respective plug seal 19 via a clearance d with respect to the shaft 23 of the stator 2.
It is also conceivable to arrange the rotor part 17a and the plain bearings 15a, 15b of the permanent magnet magnetic bearings 14a, 14b directly in the axial cavity of the rotor 7 facing the shaft 23 projecting from the stator 2. This is particularly true in the case of integral rotors 7 without plug seals.

FIG. 4 shows another embodiment in which the vacuum pump 1 has a pair of double bearings 13a, 13b located at the shaft ends 16a, 16b and a pair of double bearings 13a, 13b surrounding the rotor 7.
In this example, the rotor portion 17a of the permanent magnet magnetic bearings 14a, 14b is formed on the rotor 7, for example. A stator section 17b of permanent magnet magnetic bearings 14a, 14b and a ring of plain bearings 15a, 15b are formed on the stator 2, which each surround a rotor section 17a of the rotor 7.
The vacuum pump 1 may have only a pair of double bearings 13a, 13b surrounding each rotor 7. These may be located at the shaft ends 16a, 16b as in FIG. 4 or at other locations along the rotor 7.

5 and 6 thus show that the permanent magnet magnetic bearings 14a, 14b of the pair of double bearings 13a, 13b are arranged in the axial passage between two successive pump stages 3a-3e, and/or The sliding bearings 15a, 15b of the pair of double bearings 13a, 13b show two examples in which they are arranged in the axial passage between two successive pump stages 3a to 3e.
The permanent magnet magnetic bearings 14a, 14b of the pair of double bearings 13a, 13b may be arranged apart from the sliding bearings 15a, 15b, or may be arranged adjacent to the sliding bearings 15a, 15b.
For example, permanent magnet magnetic bearings 14a, 14b are provided at the shaft ends, and sliding bearings 15a, 15b are provided in the first shaft passage, that is, between the first and second pump stages 3a, 3b. Thereby, the compactness of the vacuum pump 1 can be improved.

In the illustrative example of Figures 5 and 6, the permanent magnet magnetic bearings 14a, 14b and the sliding bearings 15a, 15b of the pair of double bearings 13a, 13b are arranged in the axial passage between the two respective pump stages 3a-3e. In particular, the first axial passage (Fig. 5) between the first and second pump stages 3a and 3b, and the second axial passage between the second and third pump stages 3b and 3c. It is located in the shaft passage (Fig. 6).
If the bearings 13a, 13b are arranged between any two of each pump stage 3a-3e, the shaft ends 16a, 16b are free, without any guiding means by the cantilevered intake orifice 4 (FIG. 5). You can leave it as is. Alternatively, the vacuum pump 1 may be equipped with conventional bearings such as ball bearings 24a, 24b (FIG. 6) at the rotor shaft ends 16a, 16b. The ball bearings 24a, 24b are lubricated with, for example, grease.

1 Vacuum pump 2 Stator 3a to 3e Pump stage 4 Intake orifice 5 Discharge orifice 6a, 6b Shaft 7 Rotor 8 Drive unit 9 Motor 10 Synchronous gears 11a, 11b Rolling bearing device 12 Oil sump 13a, 13b Double bearings 14a, 14b Permanent magnet Magnetic bearings 15a, 15b Slide bearings 16a, 16b Rotor shaft ends 17a, 17b Rotor portion 18 Shaft 19 Plug seal 20 Main body 22 Central housing d Clearance

Claims (12)

A dry vacuum pump (1),
- at least one pump stage (3a to 3e);
- a pair of rotors (7) configured to rotate within at least one said pump stage (3a-3e);
- comprising at least one pair of double bearings (13a, 13b),
The pair of rotors are configured to be rotated by at least one motor (9) of the vacuum pump (1),
At least one pair of said double bearings (13a, 13b) includes at least one permanent magnet magnetic bearing (14a, 14b) and at least one sliding bearing (15a, 15b), respectively.
The permanent magnet magnetic bearings (14a, 14b) include a stator portion (17b) fixed to the stator (2) and a rotor portion (17a) that rotates integrally with the rotor (7),
The sliding bearings (15a, 15b) of at least one pair of the double bearings (13a, 13b) are formed such that there is a respective clearance (d) between the rotor (7) and the stator (2). The clearance (d) is between the rotor portion (17a) and the stator portion (17b) of the permanent magnet magnetic bearings (14a, 14b) of at least one pair of the double bearings (13a, 13b). A dry vacuum pump characterized by a gap smaller than that of the The dry vacuum pump of claim 1,
Each of the sliding bearings (15a, 15b) is a ring that is clamped and attached to a hole in the stator (2) or the rotor (7), or a shaft (23) of the stator (2) or the rotor (7). ) Dry vacuum pump characterized in that it has a ring which is clamped and mounted on the shaft (18) of the device. The dry vacuum pump according to claim 1 or 2,
The slide bearings (15a, 15b) are arranged in holes in the stator (2) or the rotor (7), and/or shafts (23, 18) in the stator (2) or the rotor (7), and/or in the holes. Dry vacuum pump characterized by a coating or surface treatment on the ring which is clamped to and/or mounted on the shaft. The dry vacuum pump according to any one of claims 1 to 3,
The permanent magnet magnetic bearings (14a, 14b) of the pair of double bearings (13a, 13b) have at least two pump stages (3a to 3e) arranged in series, and the permanent magnet magnetic bearings (14a, 14b) of the pair of double bearings (13a, 13b) A dry vacuum pump characterized in that it is disposed in an axial passage between stages (3a to 3e). The dry vacuum pump according to any one of claims 1 to 3,
It has at least two of the pump stages (3a to 3e) arranged in series, and the sliding bearings (15a, 15b) of the pair of double bearings (13a, 13b) are arranged in series, and the sliding bearings (15a, 15b) of the pair of double bearings (13a, 13b) are arranged in series. ~3e) A dry vacuum pump characterized in that it is disposed in an axial passageway between 3e and 3e. The dry vacuum pump according to any one of claims 1 to 5,
The permanent magnet magnetic bearings (14a, 14b) of the pair of double bearings (13a, 13b) are located at the shaft ends (16a, 16b), and at least one of the pump stages (3a to 3e) is connected to the motor ( 9) and the shaft ends (16a, 16b). The dry vacuum pump according to any one of claims 1 to 5,
The sliding bearings (15a, 15b) of the pair of double bearings (13a, 13b) are located at the shaft ends (16a, 16b), and at least one of the pump stages (3a to 3e) is connected to the motor (9). A dry vacuum pump, characterized in that it is interposed between the shaft ends (16a, 16b). The dry vacuum pump according to any one of claims 1 to 7,
The stator portion (17b) of the permanent magnet magnetic bearings (14a, 14b) of the pair of double bearings (13a, 13b) and/or the sliding bearing (15a, 15b) surrounds said rotor (7). The dry vacuum pump according to any one of claims 1 to 7,
The permanent magnet magnetic bearings (14a, 14b) of the pair of double bearings (13a, 13b) and/or the sliding bearings (15a, 15b) of the pair of double bearings (13a, 13b) are A dry vacuum pump characterized in that it is arranged inside a rotor (7). The dry vacuum pump according to any one of claims 1 to 9,
Dry vacuum pump, characterized in that each of said plain bearings (15a, 15b) has a silicon carbide coating or a nickel/PTFE coating. The dry vacuum pump according to any one of claims 1 to 10,
Dry vacuum pump (1), characterized in that said permanent magnet magnetic bearings (14a, 14b) each have a nickel/PTFE coating. The dry vacuum pump according to any one of claims 1 to 11,
Dry vacuum pump, characterized in that it has at least two rolling bearing devices (11a) configured to support the rotor (7) in the drive part (8) of the vacuum pump (1).

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