TWI825313B - Dry primary vacuum pump - Google Patents

Abstract

The invention relates to a dry primary vacuum pump (1) comprising - a stator (2) comprising at least one end piece (14, 15) and at least two stator elements (10, 11, 12), and - two shafts (7) of rotors (6) configured to revolve synchronously in reverse directions in the pumping stages (3a-3f). Each stator element (10, 11, 12) is assembled axially with another stator element (10, 11, 12) or with an end piece (14, 15) to form at least two pumping stages (3a-3f) mounted in series between a suction (4) and a discharge (5) of the vacuum pump (1). At least one stator element (10, 11, 12) is produced by the assembly of two complementary half-shells (100a, 100b, 110a, 110b, 120a, 120b) which meet along an assembling surface (8).

Description

Dry main vacuum pump

The present invention relates to dry main vacuum pumps, in particular to multi-stage dry main vacuum pumps such as Lu type, claw type and/or screws.

Dry main vacuum pumps consist of several pumping stages in series, in which the gas to be pumped is circulated between suction and discharge. Vacuum pumps known to be distinguished include those with rotating vanes (also known as "roots vacuum pumps"), those with claws (also known as "claw vacuum pumps") or even Those with screws. These vacuum pumps are said to be "dry" because during operation, the rotor rotates within the stator and there is no mechanical contact between the rotors or between the rotor and the stator. This makes it possible to use no oil in the pumping stage.

When mating the various components of a vacuum pump together, it is not possible to axially mat the entire rotor into the stator by simple axial displacement. It is also not possible to consider machining a one-piece stator to create the cavities forming the compression chambers.

In order to allow both mechanisms and placement together and to ensure good sealing, the stator of a dry vacuum pump consists, for example, of the axial assembly of several stator elements, which are assembled along their individual transverse walls and inserted An individual annular seal is provided, which is axially compressed and isolates each compression chamber from the outside atmosphere.

This type of dry pump structure requires separate mechanical components of each stator, and then performs a lengthy and difficult assembly operation consisting of: adapting the two rotor shafts to the support frame, setting the positioning of the blades of the final compression chamber, and setting the final compression chamber. The last stator element of the annular seal is positioned, the vanes of the penultimate compression chamber are adjusted, the penultimate stator element is brought together with the annular seal, and so on up to the first stator element. Bearing in mind that the gaps between the rotor blades and stator walls are extremely small to ensure sealing of each compression stage of the vacuum pump, understand that this assembly is particularly lengthy and difficult, and is estimated to take on a dry vacuum pump with five or six stages. Several manpower hours.

Another problem with these known multistage dry vacuum pumps is the difficulty in aligning the stator elements one after the other; the risk of errors has been observed between the first and last stator elements, making it difficult to control the rotor and rotor in series manufacturing. gap between stators.

For example, a vacuum pump structure is also known from US Patent No. 6,572,351 B2, which has a stator in the form of two half-shells, and the two half-shells are assembled radially along a longitudinal assembly surface that is generally parallel to the rotor axis. , the stator is tightly closed at its ends by two axially mated, added end pieces. Mating such pumps together makes it much faster.

However, especially when they are applied to methods using corrosive gases or abrasive powders, especially in the surface treatment or semiconductor industries, it can prove necessary to frequently replace all or some of the stator parts, more particularly those at the highest gas pressure Stator piece on the side. Dry vacuum pumps with a half-shell construction are disadvantageous since the entire vacuum pump must be replaced, even if only one part may be damaged.

It is an object of the present invention to at least partially solve at least one of the aforementioned deficiencies.

To this end, the subject of the invention is a dry main vacuum pump, which consists of: A stator comprising at least one end piece and at least two stator elements, each stator element being axially assembled with another stator element or with the end piece to form at least two pumping stages installed in series between the suction and discharge of the vacuum pump , The two shafts of the rotor are constructed to rotate synchronously in opposite directions in the pumping stage to drive the pumping of gas between suction and discharge; The vacuum pump is characterized in that at least one stator element is produced by the assembly of two complementary half-shells meeting along an assembly surface.

The assembly surface is, for example, a flat assembly surface, which passes, for example, through the central plane of the dry main vacuum pump. The flat assembly surface contains, for example, the axis of the rotor shaft. This flat assembly surface may be extremely flat, or may for example have complementary relief forms or grooves to seal at the stator element level.

The axial assembly of the stator elements of a vacuum pump has the advantage of allowing the replacement of parts that damage the pump without having to replace the entire stator half. Furthermore, the half-shell architecture has the potential to reduce assembly time because there are fewer interfaces to align, retaining this advantage of the half-shell architecture. This architecture also has the potential to reduce the risk of cumulative alignment defects. This can reduce the cost of the vacuum pump and make it easier to mate together.

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

The stator elements may be assembled together or with at least one end piece by axially assembling their transverse faces with complementary mating elements. Complementary mating elements facilitate mating the pumps together by guiding the assembly of the stator elements and pre-holding the stator elements together.

According to exemplary embodiments, complementary mating components include: axial recesses formed in the transverse facets of at least one sub-element, and An axial nose formed in the transverse face of the end piece or an axial collar formed in the transverse face of the stator element is adapted to fit into the axial recess.

According to exemplary embodiments, at least one sub-element may include at least one transverse separation wall to at least partially form at least two pumping stages. At least one sub-element includes, for example, two transverse separating walls parallel to each other to at least partially form two or three pumping stages. At least one stator element includes, for example, three transverse separating walls parallel to each other to at least partially form three or four pumping stages. The number of stator elements is then smaller than the number of pumping stages.

According to an exemplary embodiment, all stator elements are produced by the assembly of two separate half-shells.

According to another exemplary embodiment, at least some of the sub-elements are unitary. For example, the one-piece stator element forms at least partially a first pumping stage connected to suction and/or a last pumping stage connected to discharge. In fact, the stator element located at the end of the vacuum pump can be more difficult to machine into a half-shell form.

According to an exemplary embodiment, at least one transverse face of the stator element includes at least two thermal decoupling spacers. The exchange surface between stator elements can therefore be reduced to just the spacers. The air or padding between the spacers creates a thermal resistance that may limit heating of the stator by conduction. Thermal decoupling between stator elements makes it possible to facilitate temperature control of each stator element, which control can, for example, be more easily provided to each stator element independently.

According to an exemplary embodiment, the half shells are glued together and the stator elements are glued together. This embodiment is particularly suitable for neutral gas pumping applications, such as transfer gas lock pumping, which allows the substrate to be placed in a vacuum before being introduced into a processing chamber attached to the gas lock. The tightness of the vacuum pump created by the adhesive makes it possible to obtain a compact pump at a controlled cost.

According to an exemplary embodiment, the vacuum pump also includes a one-piece seal including first and second end annular portions, at least one intermediate annular portion, and two side rails connecting the end annular portion and the intermediate annular portion, the The end annular portion is inserted between the end piece or one-piece stator element on the one hand and the stator element on the other hand, the intermediate annular portion is inserted between the two stator elements, and the side rails are inserted between at least two half-shells .

According to exemplary embodiments, the axial nose of at least one end piece and/or the axial collar of at least one stator element includes a peripheral annular groove that receives a sealed end annular portion or an intermediate annular portion. It is thus possible to obtain a good seal by radially compressing the end annular portion and the intermediate annular portion by the end pieces and by the succession of the stator elements mating with each other.

According to an exemplary embodiment, at least one side rail of the seal includes at least a portion having a rectangular section received within a longitudinal channel having complementary rectangular sections.

According to an exemplary embodiment, the seal includes at least one coupler connecting the central annular portion to the side rails, the coupler including a straight connecting strap and a curved connecting strap paired with the straight connecting strap. Curved connecting strips make it possible to ensure a seal between the half-shells. Straight connecting straps may strengthen the coupler.

At least straight connecting strips, for example having a cross-section at least partially inscribed in a rectangle, are accommodated in grooves having a complementary rectangular cross-section. The part of the seal with the rectangular section makes it possible to create a barrier to the gas along the longitudinal groove in order to reduce the risk of leakage between the low-pressure pumping stage connected to the suction and the high-pressure pumping stage connected to the discharge.

The straight connecting strap of the coupler is inserted, for example, between the end ring located on the suction side of the vacuum pump and the curved connecting strap of the coupler.

The following specific aspects are examples. Although a statement refers to one or more concrete aspects, this does not necessarily mean that each frame of reference is with respect to the same concrete aspect, or that the characteristic applies only to a single concrete aspect. Simple features of different embodiments may also be combined or interchanged to provide other embodiments.

The main vacuum pump is defined as a volumetric vacuum pump that uses a two-rotor shaft and is built to draw, transfer, and then discharge the gas to be pumped at atmospheric pressure. The rotor shaft is driven into rotation by the motor of the main vacuum pump.

"Upstream" is understood to mean that an element is placed in front of another element with respect to the direction of circulation of the gas to be pumped. On the other hand, "downstream" is understood to mean that an element is placed behind another element with respect to the circulation direction of the gas to be pumped; the element located upstream in the direction of the pumped gas is at a pressure lower than that of the element. components downstream.

The axial direction is defined as the longitudinal direction of the pump, where the axis of the rotor shaft extends.

The dry main vacuum pump 1 of Figure 1 includes a stator 2 forming at least two pumping stages 3a to 3f mounted in series between suction 4 and discharge 5 (not visible in the figure).

The vacuum pump 1 also includes two shafts 7 of the rotor 6 , which are configured to rotate synchronously in opposite directions in the pumping stages 3 a to 3 f , so that the rotor 6 drives gas to pump between suction 4 and discharge 5 .

The shaft 7 carries a rotor 6, which for example has blades of the same profile, such as a "Rubber" (Fig. 2), a "claw", a screw, or based on another similar volumetric vacuum pump principle. The shaft 7 is driven by a motor located at one end of the vacuum pump 1, for example.

The vacuum pump 1 includes, for example, six pumping stages 3a, 3b, 3c, 3d, 3e, 3f, in which the gas to be pumped can circulate. Each pumping stage 3a, 3b, 3c, 3d, 3e, 3f is formed by a compression chamber receiving the rotor 6, the compression chamber including individual inlets and outlets. During rotation, the gas sucked in from the inlet is trapped between the volume created by the rotor 6 and the stator 2 and is then driven by the rotor 6 to the next stage.

As will be seen later, successive pumping stages 3a - 3f are coupled in series one after another by individual interstage channels coupling the outlet of the previous pumping stage 3a - 3e to the next pump The entrance to level 3b~3f will be sent. The inlet of the first pumping stage 3 a is connected to the suction 4 of the vacuum pump 1 . The outlet of the final pumping stage 3f is connected to the discharge 5 . The axial dimensions of the rotor 6 are, for example, equal or decrease with the pumping stage, the pumping stage 3a located on the side of the suction 4 receiving the rotor 6 with the largest axial dimension.

Vacuum pump 1 is the main vacuum pump, which can be started at atmospheric pressure. It is constructed to discharge pumped gases at atmospheric pressure. These vacuum pumps are said to be "dry" because during operation, the rotor 6 rotates within the stator 2 without mechanical contact between the rotors or between the rotor and the stator 2. This makes it possible to use no oil in the pumping stages 3a to 3f. .

The stator 2 includes at least two stator elements 10, 11, 12 and at least one end piece (here first and second end pieces 13, 14). The end pieces 13 , 14 form, for example, supports for bearings, in particular rolling bearings, of the shaft 7 of the rotor 6 .

Each stator element 10 , 11 , 12 is axially connected to another stator element 10 , 11 , 12 or to one of the two end pieces 13 , 14 of the stator 2 (that is, in a direction parallel to the axis of the shaft 7 ) are assembled to form a compression chamber that receives the pumping stages 3a~3f of the rotor 6.

The stator 2 includes for example two to five axially assembled stator elements 10 , 11 , 12 , for example three as exemplified in FIG. 1 .

At least one of the stator elements 10 , 11 , 12 includes, for example, at least one transverse separating wall 15 . A hole is formed in the transverse separation wall 15 to allow the shaft 7 of the rotor 6 to pass through. Therefore, the assembly of the stator element 10, 11, 12 with another stator element 10, 11, 12 or with one of the two end pieces 13, 14 at least partially forms at least two pumping stages 3a to 3f.

By way of example, the stator element 10 connected to the suction 4 includes a single transverse dividing wall 15 which together with the first end piece 13 at least partially forms two front pumping stages 3a, 3b. The second two stator elements 11 , 12 comprise two transverse separating walls 15 parallel to each other, which close the second pumping stage 3b and form with the second end piece 14 the last four pumping stages 3c, 3d, 3e, 3f. The number of stator elements 10, 11, 12 is then less than the number of pumping stages 3a to 3f.

At least the stator elements 10 , 11 , 12 are produced by the assembly of two complementary half-shells 100 a , 100 b , 110 a , 110 b , 120 a , 120 b that meet along the assembly surface 8 .

The assembly surface 8 is, for example, a flat assembly surface, which passes, for example, through the central plane of the dry main vacuum pump 1 . The flat assembly surface 8 contains, for example, the axis of the shaft 7 of the rotor 6 . This flat assembly surface 8 may be extremely flat, or may for example have complementary relief forms or grooves to seal at the stator element level.

Axial assembly of the stator elements 10, 11, 12 of the vacuum pump 1 has the advantage of allowing replacement of parts that damage the pump without having to replace the entire stator half. Furthermore, the half-shell architecture has the potential to reduce assembly time because there are fewer interfaces to align, retaining this advantage of the half-shell architecture. This architecture also has the potential to reduce the risk of cumulative alignment defects. Therefore, the cost of the vacuum pump 1 can be reduced, and it is easy to connect them together.

The stator elements 10, 11, 12 are assembled together or with the end pieces 13, 14 by axially assembling their transverse faces 10a, 10b, 11a, 11b, 12a, 12b, 13a, 14a (Fig. 3).

The transverse faces 10a, 10b, 11a, 11b, 12a, 12b of the stator elements 10, 11, 12 are opposite faces of the stator elements 10, 11, 12 and extend substantially transversely with respect to the axial direction. Figure 4 shows an example of a half shell 110b, and the arrangement of the two opposite transverse half surfaces 11a, 11b can be better seen.

These transverse faces 10a, 10b, 11a, 11b, 12a, 12b, 13a, 14b may have complementary mating elements.

According to an exemplary embodiment, the complementary mating element is formed by an axial recess 16 and a complementary axial nose 17 .

The axial recess 16 is formed in the transverse faces 10a, 11a, 12a, 12b of at least one of the stator elements 10, 11, 12. The axial recesses 16 are adapted to receive corresponding axial noses 17 formed in the transverse faces 13a, 14a of the end pieces 13, 14, or corresponding axial noses 17 formed in the transverse faces 10b, 11b of the stator elements 10, 11. Collar 18.

The axial noses 17 of the end pieces 13 , 14 and the axial collars 18 of the stator elements 10 , 11 project in the axial direction and have, for example, an oblong form, which essentially corresponds to the compression chamber of the pumping stages 3 a to 3 f cross-sectional form. The axial nasal process 17 has, for example, a solid form.

Therefore, according to the exemplary embodiment seen in Figure 1, at least some of the sub-elements 10, 11 (here the first two) include an axial recess 16 formed in the first transverse face 10a, 11b and a second opposite axial recess 16 formed in the second opposite face. Axial collar 18 of transverse faces 10b, 11b. Furthermore, at least one stator element (here the last 12 ) includes an axial recess 16 formed in the first transverse face 12 a and an axial recess 16 formed in the second opposite transverse face 12 b.

These complementary mating elements facilitate mating the pumps 1 together by guiding the axial assembly of the stator elements 10, 11, 12 and pre-fixing the stator elements 10, 11, 12 together.

Specific aspects of the variation of the stator elements will now be described with reference to Figures 5A and 5B.

In this example, at least one transverse surface 11b of the stator element 11 includes at least two thermal decoupling spacers 19 (Fig. 5A). For example, there are four thermal decoupling spacers 19 on at least one of the two lateral half-faces of the half-shells 100a, 100b, 110a, 110b, 120a, 120b.

Thermal decoupling spacers 19 are formed, for example, on the transverse faces of the axial collar 18 carrying the complementary mating elements.

When the stator elements 10, 11, 12 are mated to each other, the thermal decoupling spacer 19 of the stator element 11 contacts the transverse face 12a of the other stator element 12 (Fig. 5B). A gap is formed between the end of the axial collar 18 and the bottom of the axial recess 16 of the adjacent stator element.

The exchange surface between the stator elements can thus be reduced to just these spacers 19 . The air or lining between the spacers 19 creates a thermal resistance which may limit the heating of the stator 2 due to conduction between the stator elements 10, 11, 12. Thermal decoupling between the stator elements 10 , 11 , 12 makes it possible to facilitate temperature control of each stator element, which control can for example be easily provided to each stator element 10 , 11 , 12 independently.

In the vacuum pump 1 according to the invention, the interstage channels coupling the pumping stages 3a to 3f of the pump 1 can be produced in different ways.

The inlet to each chamber of the pumping stage generally occurs on one and the same side of the vacuum pump 1 (generally on its top surface), and the outlet on the other side.

According to a first exemplary embodiment, the interstage channels are located outside the stator elements 10 , 11 , 12 . They are produced, for example, by flexible or non-flexible lines.

According to another exemplary embodiment, the interstage channels are formed at least partially inside the stator elements 10 , 11 , 12 .

In this case, they can pass through the transverse separation wall 15 . Alternatively, they extend on at least one side of the compression chamber of the pumping stages 3a to 3f.

The interstage channels can be produced in the stator elements 10 , 11 , 12 , which are axially assembled together or with the end pieces 13 , 14 , and open in the transverse faces 10 a , 11 a , 12 a The inter-stage channel will be closed.

For the sake of illustration, FIG. 10 has shown an example in which the interstage channel 9 is on the first pumping stage 3 a of the vacuum pump 1 . The pumping stage 3a includes an interstage channel 9 extending between the inlet and outlet of the compression chamber by surrounding it. The interstage channel 9 opens on the transverse face 34 a of the stator element 34 .

The interstage channels 9 are easily accessible via the transverse faces 10b, 11b, 12b (not shown), 34a of the stator elements 10, 11, 12, 34. They are simple to machine, rework, line or clean.

According to another exemplary embodiment, the interstage channel passes through the stator element and opens on the outer surface of the stator element. They can then be closed by one or more plates of the stator 2 assembled on the outer surface of the stator elements. For example, there are two plates closing opposite outer surfaces of the stator element. Because of the accessibility of interstage channels, this configuration makes it possible to create or easily rework interstage channels. This easy accessibility also makes it possible to clean or line the interior of the channel.

Furthermore, in the vacuum pump 1 according to the present invention, the sealing performance of the assembled vacuum pump 1 can be produced by different means.

According to the first exemplary embodiment, for example by solidifying the adhesive, the half-shells 100a, 100b, 110a, 110b, 120a, 120b are glued together, and the stator elements 10, 11, 12 are glued together, and Glue to end pieces 13, 14.

This aspect is particularly suitable for neutral gas pumping applications, such as transfer airlock pumping, which allows the substrate to be placed in a vacuum before being introduced into a processing chamber attached to the airlock. The tightness of the vacuum pump 1 produced by the glue makes it possible to obtain a compact and potentially cost-limiting pump 1 .

According to another exemplary embodiment better seen in Figure 6, the vacuum pump 1 also includes a single-piece seal 20, which includes: first and second end annular portions 21a, 21b; at least one intermediate annular portion 22a , 22b; and two side rails 23a, 23b, which couple the end annular portion and the intermediate annular portion 21a, 21b, 22a, 22b.

The terminal annular portions 21a, 21b and the at least one intermediate annular portion 22a, 22b are parallel to each other. The side rails 23a, 23b right-angle couple the end annular portions and the intermediate annular portions 21a, 21b, 22a, 22b. The end annular portions 21a, 21b and at least one intermediate annular portion 22a, 22b and the side rails 23a, 23b have a substantially circular cross-section, for example.

The end rings 21a, 21b are inserted between the end pieces 14, 15 and the stator elements 10, 12 located at the axial ends of the stator 2 (Fig. 1). The intermediate annular portions 22a, 22b are inserted between the two stator elements 10, 11, 12. The seal 20 therefore includes two intermediate annulus 22a, 22b for the three stator elements 10, 11, 12.

The side rails 23a, 23b are inserted between the half-shells 100a, 100b, 110a, 110b, 120a, 120b.

The axial nose 17 of at least one end piece 13 , 14 may comprise a peripheral annular groove which receives the end annular portion 21 a , 21 b of the seal 20 .

At least the axial collar 18 of the stator elements 10 , 11 may comprise a peripheral annular groove 24 which receives the intermediate annular portion 22 a , 22 b of the seal 20 .

It is thus possible to obtain a good seal by radially compressing the end rings 21 a , 21 b and the intermediate rings 22 a , 22 b by the end pieces 13 , 14 and by the succession of the stator elements 10 , 11 , 12 mating with each other.

Furthermore, and as can be better seen in Figures 6 and 7, the seal 20 may comprise at least one coupler 28 connecting the intermediate annulus 22a, 22b to the side rails 23a, 23b.

At least one half of the shell 100a, 100b, 110a, 110b, 120a, 120b may comprise on its assembly surface 8 two longitudinal grooves 25 for receiving the side rails 23a, 23b of the seal 20 and a complementary groove for receiving the coupler 28.

The coupler 28 includes a straight connecting strap 29 and may also include a curved connecting strap 30 paired with the straight connecting strap 29 .

The straight connecting strips 29 are at right angles to the side rails 23a, 23b and radial to the intermediate annular portions 22a, 22b. Curved connecting strips 30 also connect the intermediate annular portions 22a, 22b to the side rails 23a, 23b at right angles to the side rails 23a, 23b in the plane of the assembly surface 8. The straight connecting strip 29 of the coupler 28 is inserted, for example, between the end ring 21 a on the suction 4 side of the vacuum pump 1 on the one hand and the curved connecting strip 30 of the coupler 28 on the other hand. (Figure 6).

When the coupler 28 includes a straight connecting strap 29 and a curved connecting strap 30, the curved connecting strap 30 may ensure the sealing between the half-shells 100a, 100b, 110a, 110b, 120a, 120b, and the straight connecting strap 29 may Reinforced coupler 28.

The complementary grooves are adapted to receive the straight straps 29 and curved straps 30 of the coupler 28 of the seal 20 .

Each intermediate ring 22a, 22b is connected to the side rails 23a, 23b, for example by two couplers 28 arranged opposite each other on the same transverse line.

At least one side rail 23a, 23b of the seal 20 may comprise at least a part with a rectangular section 33, that is to say a parallelepiped part, which is accommodated in a longitudinal groove 25 with a complementary rectangular section, which longitudinal groove 25 forms In at least half of the shells 100a, 100b, 110a, 110b, 120a, 120b. The portion with the rectangular section 33 extends, for example, over a short distance, such as the separation distance of the straight connecting strip 29 and the curved connecting strip 30 . The part of the seal 20 with the rectangular section 33 makes it possible to create a gas barrier along the longitudinal groove 25 in order to reduce the low-pressure pumping stage 3a connected to the suction 4 and the high-pressure pumping stage connected to the discharge 5 Risk of leakage between 3f. The part with the rectangular section 33 is for example interposed between two couplers 28 connecting the side rails 23a, 23b to the central annulus 22a, 22b.

Seal 20 may have a substantially circular cross-section, except for the portion with rectangular section 33 .

According to another exemplary embodiment seen in Figures 8 and 9, at least the straight connecting strip 31 has a cross-section at least partially inscribed in a rectangle, which is accommodated in a groove with a complementary rectangular cross-section. Therefore, the sealing performance is strengthened.

According to a third exemplary embodiment (not shown), the vacuum pump 1 includes a seal, which includes two end annular portions parallel to each other and connected by two side rails at right angles thereto. This seal is for example a single piece or is discontinuous at the height of the side rail.

The previously mentioned seal is made of rubber, for example. They are, for example, press or injection molded.

In the example of FIGS. 1 and 3 , all stator elements 10 , 11 , 12 are produced by the assembly of two individual half-shells 100 a , 100 b , 110 a , 110 b , 120 a , 120 b that meet along the assembly surface 8 .

Figure 10 shows another exemplary embodiment in which at least one sub-element 34 is a single piece.

For example, the vacuum pump 1 has one or two one-piece stator elements.

The one-piece stator element 34 forms, for example, at least partially the first pumping stage 3a and/or the last pumping stage 3e. In fact, the stator element located at the end of the vacuum pump 1 can be more difficult to machine in the form of a half shell.

As for the previous exemplary embodiments, the interstage channels and sealing properties of the vacuum pump 1 can be produced by different means.

When the vacuum pump 1 includes a one-piece seal 20 , the end annular portion 21 a is interposed between the one-piece stator element 34 and the stator element 11 .

In the example illustrated in FIG. 10 , the vacuum pump 1 includes five pumping stages 3a to 3e and three stator elements 34, 11, and 12. The one-piece seal 20 consists of a first end annular portion 21a, which is inserted between the one-piece stator element 34 on the one hand and the stator element 11 on the other hand; and a second end annular portion 21b, which is inserted between between the end piece 14 on the one hand and the stator element 12 on the other hand; and the intermediate annular portion 22a, which is inserted between the two stator elements 11, 12 with half shells.

1: Dry main vacuum pump 2:Stator 3a, 3b, 3c, 3d, 3e, 3f: pumping stage 4: Suction 5: Emissions 6:Rotor 7: Shaft 8: Assembly surface 9: Inter-level passage 10:Stator components 10a: Transverse plane 10b: transverse plane 11:Stator components 11a: Transverse plane 11b: Transverse plane 12:Stator components 12a: Transverse plane 12b: transverse plane 13:First end piece 13a: Transverse plane 14:Second end piece 14a: Transverse plane 15: Transverse separation wall 16: Axial depression 17: Axial nasal process 18: Axial collar 19: Thermal decoupling spacer 20:Sealing 21a: First terminal ring part 21b: Second terminal ring part 22a: middle annular part 22b: middle annular part 23a:Side rail 23b: Side rail 24: Peripheral annular groove 25:Longitudinal groove 28:Coupler 29: Straight connection strap 30: Bend connection strap 31: Straight connection strap 32: Bent connection strap 33: Rectangular section 34:Stator components 34a: transverse plane 100a,100b,110a,110b,120a,120b: half shell

Other advantages and features will become apparent upon reading the following description of specific, but non-limiting, embodiments of the invention and the accompanying drawings.

[Fig. 1] is a schematic exploded view of components of a dry main vacuum pump according to a first exemplary embodiment.

[Fig. 2] is a perspective view of the rotor shaft of the vacuum pump in Fig. 1.

[Fig. 3] is a diagram similar to Fig. 1 without showing the rotor shaft.

[Fig. 4] is a perspective view of the half shell of the stator element of the vacuum pump of Fig. 1. [Fig.

[Fig. 5A] is a perspective view of a specific change of the half shell of the stator element.

[Fig. 5B] is a partial perspective view of the two half-shells assembled together according to the specific aspect of Fig. 5A.

[Fig. 6] is a perspective view of the seal of the vacuum pump in Fig. 1.

[Fig. 7] is an enlarged view of the details of the seal of Fig. 6.

[Fig. 8] is a diagram similar to Fig. 6, which is a second exemplary concrete aspect of the seal.

[Fig. 9] is an enlarged view of the details of the seal of Fig. 8.

[Fig. 10] is a schematic exploded view of a dry main vacuum pump according to a second exemplary embodiment.

In these drawings, the same or similar components carry the same reference numerals.

The schema has been simplified because the preferences are clear. Only elements necessary for an understanding of the invention are presented.

1: Dry main vacuum pump

2:Stator

3a, 3b, 3c, 3d, 3e, 3f: pumping stage

4: Suction

5: Emissions

6:Rotor

7: Shaft

8: Assembly surface

10:Stator components

10a: Transverse plane

10b: transverse plane

11:Stator components

11b: Transverse plane

12:Stator components

12b: transverse plane

13:First end piece

13a: Transverse plane

14:Second end piece

14a: Transverse plane

15: Transverse separation wall

16: Axial depression

17: Axial nasal process

18: Axial collar

20:Sealing

21a: First terminal ring part

21b: Second terminal ring part

22a: middle annular part

22b: middle annular part

23a:Side rail

23b: Side rail

24: Peripheral annular groove

25:Longitudinal groove

100a,100b,110a,110b,120a,120b: half shell

Claims (15)

A dry main vacuum pump (1), which includes: a stator (2), which includes at least one end piece (14, 15) and at least two stator elements (10; 34, 11, 12), each stator element (10; 34 , 11, 12) are assembled axially with another stator element (10; 34, 11, 12) or with an end piece (14, 15) to form a suction (4) and a discharge installed in series in the vacuum pump (1) (5) between at least two pumping stages (3a~3f), the two shafts (7) of the rotor (6) are constructed to rotate synchronously in opposite directions in the pumping stages (3a~3f), To drive gas to be pumped between the suction (4) and the discharge (5); the vacuum pump (1) is characterized in that at least one sub-element (10, 11, 12) is pumped along the assembly surface (8 ) are produced by the assembly of two complementary half-shells (100a, 100b, 110a, 110b, 120a, 120b) that meet. Vacuum pump (1) according to claim 1, wherein the stator element (10; 34, 11, 12) is assembled by axially assembling its transverse surfaces (34a; 10a, 10b, 11a, 11b, 12a, 12b, 13a, 14a) When assembled together or with the at least one end piece (13, 14), the transverse face (34a; 10a, 10b, 11a, 11b, 12a, 12b, 13a, 14a) has complementary mating elements. Vacuum pump (1) according to claim 2, wherein the complementary mating element comprises: an axial recess (16) formed in the transverse face of at least one stator element (10; 34, 11, 12) and formed in the end The axial nose (17) or shape of the transverse surfaces of the members (13, 14) An axial collar (18) formed on the transverse face of the stator element (10; 34, 11), the axial nose (17) or the axial collar (18) is adapted to fit into the axial recess (16) in. Vacuum pump (1) according to any one of claims 1 to 3, wherein at least one subelement (10; 34, 11, 12) includes at least one separating transverse wall (15) to at least partially form at least two pumping stages (3a ~3f). Vacuum pump (1) according to any one of claims 1 to 3, wherein all the stator elements (10, 11, 12) are provided by two individual half-shells (100a, 100b, 110a, 110b, 120a, 120b) produced by the assembly. Vacuum pump (1) according to any one of claims 1 to 3, wherein at least the stator element (34) is a one-piece stator element (34). Vacuum pump (1) according to claim 6, wherein the one-piece stator element (34) at least partially forms the first pumping stage (3a) and/or the last pumping stage (3e), the first pumping stage (3a) is connected to the suction (4) and the final pumping stage (3e) is connected to the discharge (5). Vacuum pump (1) according to any one of claims 1 to 3, wherein at least one transverse face (34a; 10a, 10b, 11a, 11b, 12a, 12b) of the stator element (10; 34, 11, 12) includes at least Two thermal decoupling spacers (19). Vacuum pump (1) according to any one of claims 1 to 3, wherein the half-shells (100a, 100b, 110a, 110b, 120a, 120b) are glued together and the stator element (10; 34, 11, 12 ) glue together. Vacuum pump (1) according to any one of claims 1 to 3, further comprising a one-piece seal (20) comprising a first and a second end annular portion (21a, 21b), at least one intermediate annular portion (22a, 22b), and two side rails (23a, 23b) connecting the end and the intermediate annular portion (21a, 21b, 22a, 22b) ), which terminal annular portion (21a, 21b) is inserted between the terminal portion (14, 15) or single-piece stator element (34) on the one hand and the stator element (10, 11, 12) on the other hand, The middle annular portion (22a, 22b) is inserted between the two stator elements (10, 11, 12), and the side rails (23a, 23b) are inserted between at least two half shells (100a, 100b, 110a, 110b, 120a ,120b). The vacuum pump (1) according to claim 3, further comprising a one-piece seal (20), the seal (20) including first and second end annular portions (21a, 21b), at least one intermediate annular portion (22a , 22b), and two side rails (23a, 23b) connecting the end and the middle annular portion (21a, 21b, 22a, 22b). The end annular portion (21a, 21b) is inserted into the end portion ( 14, 15) or between the one-piece stator element (34) on the other hand and the stator element (10, 11, 12) on the other hand, the intermediate annular portion (22a, 22b) is inserted between the two stator elements (10, 11, 12) 12), and the side rails (23a, 23b) are inserted between at least two half-shells (100a, 100b, 110a, 110b, 120a, 120b); the axial nose (17) of at least one end piece and/or the axial collar (18) of at least one stator element (10; 34, 11, 12) includes a peripheral annular groove receiving the terminal annular portion (21a, 21b) of the seal (20) Or the middle annular portion (22a, 22b). Vacuum pump (1) according to claim 10, wherein at least one side rail (23a, 23b) of the seal (20) includes at least a portion with a rectangular section (33) housed in a longitudinal direction with a complementary rectangular section Grooves(25) middle. Vacuum pump (1) according to claim 10, wherein the seal (20) includes at least one coupler (28) connecting the intermediate annular portion (22a, 22b) to the side rails (23a, 23b), the coupler (28) includes a straight connecting strap (29; 31) and a curved connecting strap (30; 32) paired with the straight connecting strap (29; 31). Vacuum pump (1) according to claim 13, wherein at least the straight connecting strip (31) has a cross-section at least partially inscribed in a rectangle, which is accommodated in a groove with a complementary rectangular cross-section. Vacuum pump (1) according to claim 13, wherein the straight connecting strap (29; 31) of the coupler (28) is inserted into the end ring located on the side of the suction (4) of the vacuum pump (1) between the portion (21a) and the curved connecting strip (30) of the coupler (28).

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