JP6594602B2 - Rotor, vacuum pump, and vacuum pump assembly method - Google Patents

Description

  The present invention relates to a rotor and a vacuum pump, and in particular, has a rotor cylindrical portion reinforcing ring that reinforces a rotating body cylindrical portion of the rotor, and further has a structure that facilitates positioning of the rotor cylindrical portion reinforcing ring, The present invention relates to a vacuum pump containing a rotor and a method for assembling the vacuum pump.

Various vacuum pumps include turbo molecular pumps and thread groove pumps that are frequently used to realize a high vacuum environment.
A vacuum pump that realizes this high vacuum environment includes a casing that forms an exterior body having an intake port and an exhaust port. And the structure which makes the said vacuum pump exhibit an exhaust function is accommodated in the inside of this casing. The structure that exhibits the exhaust function is roughly divided into a rotating part (rotor part) that is rotatably supported and a fixed part (stator part) fixed to the casing.
For example, in the case of a turbo molecular pump, the rotating part includes a rotating shaft and a rotating body fixed to the rotating shaft, and rotor blades (moving blades) provided radially are arranged in multiple stages on the rotating body. ing. In the fixed portion, stator blades (stator blades) are arranged in multiple stages alternately with respect to the rotor blades.
In addition, a motor for rotating the rotating shaft at high speed is provided, and when the rotating shaft rotates at high speed by the action of this motor, gas is sucked from the intake port due to the interaction between the rotor blade and the stator blade, and from the exhaust port. It is supposed to be discharged.

In recent years, in such a high-speed rotating machine such as a vacuum pump, further high-speed rotation is required from the viewpoint of performance improvement and downsizing.
However, while high-speed rotation improves performance, when the vacuum pump is broken due to abnormal vibration from the outside or internal abnormal situations, the destruction energy (breaking torque) may increase. Is an urgent need.

Further, such a high-speed rotating machine such as a vacuum pump requires high assembly performance.
In particular, in the threaded groove exhaust part of the turbo molecular pump, the rotating part and the fixed part are configured with a very narrow clearance in order to achieve a desired exhaust performance.
Here, as a countermeasure for reducing the breaking torque when the vacuum pump is abnormal, there is a technique described in the following prior art.

JP2011-214558A

Patent Document 1 describes a structure of a vacuum pump in which a ring member is provided on the outer periphery of a rotor, and an attachment method for attaching the ring member to a rotor cylindrical portion.
More specifically, in Patent Document 1 described above, the ring member is provided on the circumferential portion of the rotor, so that the ring member can be used even when a fracture occurs due to a crack or the like generated in the rotor of the vacuum pump. Once installed, the crack can be temporarily stopped to prevent the crack from progressing. Also, since the ring member is a separate member from the rotor, the breaking torque is greatly reduced even if the ring member itself is split. The technology that can be described.

However, in the configuration of Patent Document 1, the following problems (1) to (3) occur in practical use.
FIG. 12 is a diagram for explaining the prior art.
(1) When the ring member 2002 is fitted into the rotor cylinder outer peripheral portion 2001 of the turbo molecular pump 2000 having a long cylindrical structure in the axial direction as shown in FIG. It is possible to become. For example, if the ring member 2002 is attached at an angle, the balance of the rotor is lost (the balance becomes worse), and as a result, the turbo molecular pump 2000 may not be able to operate stably.
Moreover, although the attachment method by shrink fitting is described, there is a possibility that the shrink fitting operation becomes difficult as the vacuum pump becomes large in the attachment method by shrink fitting.
(2) Since there is no positioning structure for determining the position where the ring member 2002 is disposed on the cylindrical outer peripheral portion 2001 of the rotor, a dedicated jig or the like is required to accurately fix the ring member 2002 at a predetermined position.
(3) When the outer diameter of the ring member 2002 is larger than the outer diameter of the rotor cylindrical outer peripheral portion 2001, the clearance with the thread groove spacer 2003 is greater than in the conventional case (that is, when the ring member 2002 is not provided). As a result, the exhaust performance may be deteriorated. In particular, when the ring member 2002 is provided on the lower side of the rotor cylindrical outer peripheral portion 2001, there is a high possibility that the rate of performance degradation of the turbo molecular pump 2000 due to such an increase in clearance will increase.

  Accordingly, the present invention provides a rotor having a rotor cylindrical portion reinforcing ring and further having a structure that facilitates positioning of the reinforcing ring, a vacuum pump containing the rotor, and a method of assembling the vacuum pump. For the purpose.

According to the first aspect of the present invention, the rotor is provided inside the exterior body and used for a gas transfer mechanism that transfers gas from the intake port to the exhaust port. The gas transfer mechanism includes a screw groove spacer and a rotor. consists screw type rotor pump which is formed in the cylindrical portion, the screw groove spacer only include screw type pump unit screw groove is formed, the reinforcing ring member is disposed in the cylindrical portion, the reinforcing ring or member is disposed at the lower end of the cylindrical portion, or the lower side than the reinforcing ring member is disposed portions of the cylindrical portion, said reinforcing ring member of the cylindrical portion toward the downward disposed been and tapered portion is provided with a reduced diameter than the portion, the reinforcing ring member is in said cylindrical portion, said screw groove pump portion or the screw type extended extender unit to the pump unit or et lower It is arranged in The rotor includes a positioning structure for setting a position where the reinforcing ring member is disposed, and the positioning structure is formed on a side surface of the cylindrical portion of the rotor so as to contact the reinforcing ring member. Alternatively , a rotor having at least one of the tapered portions is provided.
According to a second aspect of the present invention, the positioning structure has a tapered shape that decreases in diameter toward the lower side at a position where the reinforcing ring member is disposed on the side surface of the cylindrical portion of the rotor. A rotor according to claim 1 is provided.
The invention according to claim 3 is characterized in that the reinforcing ring member is provided with at least one of C chamfering, R shape, or taper shape on the side facing the side surface of the cylindrical portion of the rotor. A rotor according to claim 1 or claim 2 is provided.
According to a fourth aspect of the present invention, the reinforcing ring member is formed on the side that does not face the side surface of the cylindrical portion of the rotor such that the outer diameter decreases toward the exhaust port side. providing rotor as claimed in any one of claims 3, characterized in.
In the invention of claim 5, wherein said reinforcing ring member provides a rotor according to any one of claims 1 to 4, characterized in that it is made in the fiber-reinforced member.
According to a sixth aspect of the present invention, the reinforcing ring member includes a fitting portion that is fitted to the cylindrical portion by press fitting, shrink fitting, or cold fitting, or an adhesive portion that is bonded to the cylindrical portion by adhesion. providing rotor according to any one of claims 1 to 5, wherein.
In the invention of claim 7, wherein forming a rotor as claimed in any one of claims 6, and the outer body is disposed inside the outer body, the gas transfer mechanism together with said rotor There is provided a vacuum pump characterized by comprising a fixing part.
According to an eighth aspect of the present invention, the fixing portion further includes an inner diameter dimension changing portion formed by a long inner diameter portion and a short inner diameter portion formed to have an inner diameter smaller than the long inner diameter portion. Item 8. A vacuum pump according to Item 7 .
According to a ninth aspect of the present invention, the inner diameter dimension changing portion of the fixed portion is formed by the reinforcing ring member fitted to the cylindrical portion of the rotor and the fixed portion by the long inner diameter portion and the short inner diameter portion. The vacuum pump according to claim 8 , wherein the clearance is kept constant.
The invention according to claim 10 further includes rotating blades arranged radially from an outer peripheral surface of the rotor, and the positioning structure is a lowermost rotating blade of the rotating blade. A vacuum pump according to any one of claims 7 to 9 is provided.
According to an eleventh aspect of the present invention, the rotor further includes a rotary blade arranged radially from the outer peripheral surface of the rotor, and the positioning structure is formed by integrally forming the protrusion and the lowermost rotary blade of the rotary blade. The vacuum pump according to any one of claims 7 to 9 , wherein the vacuum pump is provided.
According to a twelfth aspect of the present invention, when the outermost diameter portion of the reinforcing ring member is set larger than the short inner diameter portion of the fixing portion, at least the short inner diameter portion of the fixing portion is vertically 10. The vacuum pump assembling method according to claim 8 or 9 , wherein the vacuum pump is assembled by being divided into two parts.

ADVANTAGE OF THE INVENTION According to this invention, the rotor which has a rotor cylindrical part reinforcement ring and has a structure which makes positioning of the said reinforcement ring easy can be provided.
Moreover, the vacuum pump containing the said rotor and the assembly method of a vacuum pump can be provided.

It is the figure which showed the schematic structural example of the turbo-molecular pump which concerns on 1st-5th embodiment of this invention. It is an enlarged view of the positioning structure which concerns on 1st Embodiment of this invention. It is an enlarged view of the positioning structure which concerns on the modification of 1st Embodiment of this invention. It is an enlarged view of the rotor cylindrical part which concerns on 2nd Embodiment of this invention. It is a figure for demonstrating the clearance constant structure which concerns on 3rd Embodiment of this invention. It is a figure for demonstrating the case where the structure which concerns on 3rd Embodiment of this invention exists in the axial direction lower side in a rotor cylindrical part. It is a figure for demonstrating the rotor cylindrical part reinforcement ring which concerns on 4th Embodiment of this invention. It is a figure for demonstrating the rotor cylindrical part reinforcement ring which concerns on 5th Embodiment of this invention. It is a figure for demonstrating the division | segmentation structure which concerns on 6th Embodiment of this invention. It is a figure for demonstrating the division | segmentation structure which concerns on 6th Embodiment of this invention. It is the figure which showed the schematic structural example of the thread groove type pump which concerns on 1st-6th embodiment of this invention. It is a figure for demonstrating a prior art.

(I) Outline of Embodiment The vacuum pump according to the embodiment of the present invention has the following technical features (1) to (6) in order to solve the problems described above.
(1) A rotor cylindrical portion reinforcing ring positioning structure is provided so that the rotor cylindrical portion reinforcing ring (ring member) can be easily positioned.
(2) A positioning structure in which a taper is provided on the cylindrical portion of the rotor is provided so that the fitting operation between the rotor and the rotor cylindrical portion reinforcing ring is easily performed.
(3) A structure (that is, a constant clearance structure) that matches the shape of the rotor cylindrical portion reinforcing ring is provided on the thread groove spacer so that the clearance between the rotor cylindrical portion and the fixed portion facing the rotor does not widen.
(4) At least one of the following fitting simplification structures (a) to (d) is provided on the inner peripheral side of the rotor cylindrical portion reinforcing ring so that the fitting operation between the rotor and the rotor cylindrical portion reinforcing ring is easily performed. The provided positioning structure is provided.
(A) C chamfering (b) R shape (c) Taper shape (5) The outer peripheral side of the rotor cylindrical portion reinforcing ring is formed into a streamline shape (a shape obtained by cutting the lower side) so that the conductance of the pump does not decrease.
(6) When assembling a vacuum pump provided with the positioning structure of said (1)-(5), a part of fixing part of the said vacuum pump is made into the vertically divided structure.

(Ii) Details of Embodiments Hereinafter, preferred embodiments of the present invention will be described in detail with reference to FIGS.
In the present embodiment, as an example of a vacuum pump, a so-called composite turbo molecular pump including a turbo molecular pump unit and a thread groove type pump unit will be described.
Further, the present embodiment may be applied to a vacuum pump (FIG. 10) having only a thread groove type pump section or a vacuum pump having a thread groove provided on the rotating body side.

FIG. 1 is a diagram showing a schematic configuration example of a turbo molecular pump 1 according to the first embodiment of the present invention.
1 shows a cross-sectional view of the turbo molecular pump 1 in the axial direction.
The casing 2 of the turbo molecular pump 1 has a substantially cylindrical shape, and constitutes an exterior body of the turbo molecular pump 1 together with a base 3 provided at the lower part of the casing 2 (exhaust port 6 side). And the gas transfer mechanism which is a structure which makes the turbo molecular pump 1 exhibit an exhaust function is accommodated in the exterior body.
This gas transfer mechanism is roughly divided into a rotating part (rotor part) that is rotatably supported and a fixed part fixed to the exterior body.
Although not shown, a controller for controlling the operation of the turbo molecular pump 1 is connected to the outside of the exterior body of the turbo molecular pump 1 through a dedicated line.

An inlet 4 for introducing gas into the turbo molecular pump 1 is formed at the end of the casing 2. A flange portion 5 is formed on the end surface of the casing 2 on the intake port 4 side so as to project to the outer peripheral side.
The base 3 is formed with an exhaust port 6 for exhausting gas from the turbo molecular pump 1.

The rotating part is provided on the shaft 7 which is a rotating shaft, the rotor 8 disposed on the shaft 7, a plurality of rotating blades 9 provided on the rotor 8, and the exhaust port 6 side (screw groove type pump part). The rotor cylindrical portion 10 is configured. The shaft 7 and the rotor 8 constitute a rotor part.
Each rotor blade 9 is composed of blades extending radially from the shaft 7 at a predetermined angle from a plane perpendicular to the axis of the shaft 7.
The rotor cylindrical portion 10 is a cylindrical member having a cylindrical shape concentric with the rotation axis of the rotor 8.
Further, the rotor cylindrical portion 10 according to the embodiment of the present invention is provided with a ring-shaped rotor cylindrical portion reinforcing ring 90.
In this embodiment, the rotor cylindrical portion reinforcing ring 90 is disposed by press-fitting, shrink fitting (the rotor cylindrical portion reinforcing ring 90 is warmed and expanded, and the difference in thermal expansion is utilized to make the rotor cylindrical portion 10 It is conceivable to cool the rotor cylindrical portion 10 and put it into the rotor cylindrical portion reinforcing ring 90, or to use an adhesive.
Here, the material of the rotor cylindrical portion reinforcing ring 90 is preferably a material having a Young's modulus higher than that of the rotor cylindrical portion 10 and a low linear expansion coefficient (expansion), and specifically, a fiber reinforced composite material (fiber reinforced composite material). Plastic materials, Fiber Reinforced Plastics), stainless steel, titanium, and the like.
In particular, when a fiber reinforced composite material is used for the rotor cylindrical portion reinforcing ring 90, press fitting is often used. That is, the rotor cylindrical portion reinforcing ring 90 manufactured using a fiber reinforced plastic material is manufactured slightly smaller than the rotor cylindrical portion 10 and is press-fitted into the rotor cylindrical portion 10. Note that fibers used for the fiber-reinforced composite material include aramid fibers (AFRP), boron fibers (BFRP), glass fibers (GFRP), carbon fibers (CFRP), polyethylene fibers (DFRP), and the like.

A motor portion 20 for rotating the shaft 7 at a high speed is provided in the middle of the shaft 7 in the axial direction, and is included in the stator column 80.
Further, radial magnetic bearing devices 30 and 31 for supporting the shaft 7 in a radial direction (radial direction) in a non-contact manner on the intake port 4 side and the exhaust port 6 side with respect to the motor portion 20 of the shaft 7. An axial magnetic bearing device 40 for supporting the shaft 7 in the axial direction (axial direction) in a non-contact manner is provided at the lower end of the shaft 7.

A fixing portion is formed on the inner peripheral side of the exterior body. The fixed portion includes a plurality of fixed blades 50 provided on the intake port 4 side (turbo molecular pump portion), a thread groove spacer 70 provided on the inner peripheral surface of the casing 2, and the like.
Each fixed blade 50 is composed of a blade that is inclined by a predetermined angle from a plane perpendicular to the axis of the shaft 7 and extends from the inner peripheral surface of the exterior body toward the shaft 7.
The fixed wings 50 at each stage are fixed by being separated from each other by a cylindrical fixed wing spacer 60.
In the turbo molecular pump unit, the fixed blades 50 and the rotary blades 9 are alternately arranged and formed in a plurality of stages in the axial direction.

A spiral groove is formed in the thread groove spacer 70 on the surface facing the rotor cylindrical portion 10.
The thread groove spacer 70 faces the outer peripheral surface of the rotor cylindrical portion 10 with a predetermined clearance. When the rotor cylindrical portion 10 rotates at a high speed, the gas compressed by the turbo molecular pump 1 rotates the rotor cylindrical portion 10. As a result, the air is sent to the exhaust port 6 while being guided by a screw groove (spiral groove). That is, the thread groove is a flow path for transporting gas. The screw groove spacer 70 and the rotor cylindrical portion 10 face each other with a predetermined clearance to constitute a gas transfer mechanism that transfers gas through the screw groove.
In addition, in order to reduce the force by which the gas flows backward to the intake port 4, the smaller the clearance, the better.
The direction of the spiral groove formed in the thread groove spacer 70 is the direction toward the exhaust port 6 when the gas is transported in the spiral groove in the rotational direction of the rotor 8.
Further, the depth of the spiral groove becomes shallower as it approaches the exhaust port 6, and the gas transported through the spiral groove is compressed as it approaches the exhaust port 6. As described above, the gas sucked from the intake port 4 is compressed by the turbo molecular pump unit, further compressed by the thread groove type pump unit, and discharged from the exhaust port 6.
The turbo molecular pump 1 configured as described above performs a vacuum evacuation process in a vacuum chamber (not shown) disposed in the turbo molecular pump 1.

(Ii-1) First embodiment (positioning structure of rotor cylindrical portion reinforcing ring)
FIG. 2 is an enlarged view of the rotor cylindrical portion 10 having the positioning structure A according to the first embodiment of the present invention.
As shown in each drawing of FIG. 2, in the turbo molecular pump 1 according to the first embodiment of the present invention, the position of the rotor cylindrical portion reinforcing ring 90 is determined in the rotor cylindrical portion 10 (that is, the rotor cylindrical portion 10 has the rotor A positioning structure A (which fixes the cylindrical portion reinforcing ring 90).
FIG. 2A is a view showing a case where the positioning structure A according to the first embodiment of the present invention is disposed on the upper portion of the rotor cylindrical portion 10. In this case, the rotor cylindrical portion reinforcing ring 90 is disposed on the upper portion (the intake port 4 side) of the rotor cylindrical portion 10.
More specifically, in the positioning structure A according to the first embodiment of the present invention, a part of the rotor cylindrical portion 10 on the side facing the rotor blade 9 is directed to the lower portion (exhaust port 6 side) of the rotor cylindrical portion 10. A protruding portion 100 that protrudes from the extending side surface is formed.
With the above-described configuration, the turbo molecular pump 1 according to the first embodiment of the present invention includes the rotor cylindrical portion reinforcing ring 90, and further includes the protrusion 100 as the positioning structure A for fixing the rotor cylindrical portion reinforcing ring 90. Therefore, the progress of cracks generated in the rotor 8 and the rotor cylindrical portion 10 of the turbo molecular pump 1 can be reduced, and the rotor 8 (rotor cylindrical portion 10) can be prevented from being divided. Furthermore, positioning during the fitting operation is facilitated, and assemblability can be improved.

FIG. 2B is a view showing a case where the positioning structure A according to the first embodiment of the present invention is disposed in the lower portion of the rotor cylindrical portion 10. In this case, the rotor cylindrical portion reinforcing ring 90 is disposed at the lower portion (exhaust port 6 side) of the rotor cylindrical portion 10.
More specifically, the positioning structure A according to the first embodiment of the present invention is formed by a long outer diameter portion 111 and a short outer diameter portion 112 at the lower portion (exhaust port 6 side) of the rotor cylindrical portion 10. A stepped portion 110 is formed (outer diameter dimension changing portion). Note that the outer diameters of the long outer diameter portion 111 and the short outer diameter portion 112 both mean the outer diameter of the rotor cylindrical portion 10.
Further, in the turbo molecular pump 1, an adhesive or the like may be used to add a mass for correcting the balance. If the rotor cylindrical portion reinforcing ring 90 is disposed at the lower part of the rotor cylindrical portion 10 as shown in FIG. 2B, the balance is adjusted by cutting the rotor cylindrical portion reinforcing ring 90 as a weight. (Correction) may be used.
With the above-described configuration, the turbo molecular pump 1 according to the first embodiment of the present invention includes the rotor cylindrical portion reinforcing ring 90 and further includes the stepped portion 110 as the positioning structure A for fixing the rotor cylindrical portion reinforcing ring 90. Therefore, the progress of cracks generated in the rotor 8 and the rotor cylindrical portion 10 of the turbo molecular pump 1 can be reduced, and the rotor 8 (rotor cylindrical portion 10) can be prevented from being divided. Furthermore, positioning during the fitting operation is facilitated, and assemblability can be improved. In addition, the balance can be corrected.

FIG. 2C shows a case where the positioning structure A according to the first embodiment of the present invention is disposed between the upper part (FIG. 2: a) and the lower part (FIG. 2: b) of the rotor cylindrical part 10. FIG.
Thus, the rotor cylindrical portion reinforcing ring 90 is not limited to the upper portion or the lower portion of the rotor cylindrical portion 10, but the middle portion (that is, the upper portion (FIG. 2: a) and the lower portion (FIG. 2: b)) It is also possible to adopt a configuration arranged between the two.

Further, as shown in FIG. 3, each of the positioning structures A according to the first embodiment described above can be configured as follows in order to reduce the occurrence of stress concentration.
(Modification 1 of the first embodiment)
3A and 3B are enlarged views of the rotor cylindrical portion 10 having the positioning structure B according to Modification 1 of the first embodiment of the present invention.
In Modification 1 of the first embodiment of the present invention, when the positioning structure A according to the first embodiment of the present invention is the protrusion 100, as shown in FIG. The sumi portion S formed by the side surface extending to the exhaust port 6 side of the cylindrical portion 10 has a smooth positioning structure B. That is, in order not to cause a steep step, the curved portion is formed from the most end portion of the protrusion 100 (that is, where the outer diameter of the rotor cylindrical portion 10 is the largest) to the rotor cylindrical portion 10 (R shape).
On the other hand, when the positioning structure A according to the first embodiment of the present invention is the stepped portion 110, as shown in FIG. 3B, the surface on the exhaust port side 6 of the long outer diameter portion 111 and the short outer diameter. The sumi portion S formed by the portion 112 is configured to have a smooth positioning structure B. That is, the corner from the long outer diameter portion 111 to the short outer diameter portion 112 is configured with a curve so as not to cause a steep step (R shape).
With the above-described configuration, in the turbo molecular pump 1 having the positioning structure B according to the first modification of the first embodiment of the present invention, the summit portion S of the protruding portion 100 or the stepped portion 110 is provided with an R shape. The occurrence of stress concentration can be reduced.

(Modification 2 of the first embodiment)
FIG.3 (c) is an enlarged view of the rotary blade 9 and the rotor cylindrical part 10 which have the positioning structure C which concerns on the modification 2 of 1st Embodiment of this invention.
In the second modification of the first embodiment of the present invention, as shown in FIG. 3C, the positioning structure A according to the first embodiment of the present invention or the positioning structure according to the first modification of the first embodiment. B and the lowermost blade (rotary blade) of the rotary blade 9 of the turbo molecular pump 1 are integrated. That is, the rotor cylindrical portion reinforcing ring 90 is disposed in contact with the bottom surface of the lowermost stage of the rotary blade 9, and the blade itself of the rotary blade 9 also serves as the protrusion 100.
With the above-described configuration, in the turbo molecular pump 1 having the positioning structure C according to the second modification of the first embodiment of the present invention, the lowermost blade of the rotor blade 9 is integrated with the protrusion 100 and the rotor cylindrical portion reinforcing ring. Since the positioning of 90 is performed, the positioning of the fitting operation becomes possible.
In addition, when the above-described Sumi portion S is configured to have an R shape (that is, when this configuration is applied to the positioning structure B), the occurrence of stress concentration can be further reduced.

In the first embodiment and each modification described above, the rotor cylindrical portion reinforcing ring 90 and the positioning structure (A, B, or C) are disposed at the upper portion (the intake port 4 side) or the lower portion of the rotor cylindrical portion 10. (Exhaust port 6 side), but not limited to this. It can be disposed anywhere as long as it is a side surface of the rotor cylindrical portion 10, and may be, for example, the central portion or the entire surface of the rotor cylindrical portion 10. Or you may arrange | position to the outer periphery of the rotary blade 9. FIG.
Further, if the vacuum pump is a type in which a screw groove is provided on the rotor cylindrical portion 10 side, a configuration in which the screw groove is formed in the rotor cylindrical portion reinforcing ring 90 can also be adopted.

(Ii-2) 2nd Embodiment (providing a taper in a rotor cylindrical part)
FIG. 4 is an enlarged view of the rotor cylindrical portion 10 according to the second embodiment of the present invention.
In the second embodiment of the present invention, as shown in FIG. 4, on the exhaust port 6 side of the rotor cylindrical portion 10 of the turbo molecular pump 1 including at least one of the positioning structures A to C according to the first embodiment. Provides a tapered shape (taper θ).
Note that the taper θ according to the second embodiment of the present invention has a configuration in which the fitting portion α in the positioning structures A to C is flat in order to improve dimensional management and work reproducibility. However, the present invention is not limited to this, and the taper θ may be formed over the entire side surface of the rotor cylindrical portion 10. In that case, the rotor cylindrical portion reinforcing ring 90 is also provided with a tapered shape at a portion where the rotor cylindrical portion reinforcing ring 90 contacts the rotor cylindrical portion 10 (that is, the side surface on the inner diameter side of the rotor cylindrical portion reinforcing ring 90). Is desirable.
With the above-described configuration, in the turbo molecular pump 1 according to the second embodiment of the present invention, when the rotor cylindrical portion reinforcing ring 90 is inserted and fitted from the exhaust port 6 side of the cylindrical rotor portion 10, the rotor cylindrical portion 10. Since the tapered shape (taper θ) is formed on the exhaust port 6 side, the fitting operation is facilitated. Furthermore, by configuring the fitting portion α in the positioning structures A to C to be flat, it is possible to improve dimensional management and work reproducibility, and the rotor cylindrical portion reinforcing ring 90 is attached to the rotor cylindrical portion 10. It can be fixed more reliably.

(Ii-3) Third Embodiment (Constant Clearance Structure Matching the Shape of Rotor Cylindrical Reinforcing Ring to Thread Groove Spacer)
FIG. 5 is a diagram for explaining the structures D, E, and F having a constant clearance structure while ensuring a predetermined strength in the rotor cylindrical portion reinforcing ring 90 according to the third embodiment of the present invention. It is.
The turbo molecular pump 1 according to the third embodiment of the present invention is configured so that the rotor cylindrical portion 10 (that is, the portion where the rotor cylindrical portion reinforcing ring 90 is fitted) is secured to the rotor cylindrical portion reinforcing ring 90 while ensuring a predetermined strength. In order to prevent the clearance with the thread groove spacer 70 from expanding, a constant clearance structure is provided to keep the clearance constant.
FIG. 5A is a view for explaining a structure D according to the third embodiment of the present invention.
Specifically, the structure D according to the third embodiment of the present invention has a rotor having a predetermined cross-sectional area, which is formed on the intake port 4 side of the rotor cylindrical portion 10 to ensure the strength of the rotor cylindrical portion 10. The cylindrical portion reinforcing ring 90 and a screw groove spacer stepped portion 700 formed on the screw groove spacer 70 in accordance with a change in the outer diameter of the rotor cylindrical portion reinforcing ring 90 are configured.
The rotor cylindrical portion reinforcing ring 90 and the thread groove spacer stepped portion 700 according to the structure D of the third embodiment of the present invention are the clearance between the rotor cylindrical portion reinforcing ring 90 and the thread groove spacer 70 positioned by the protrusion 100. Is formed to keep constant. More specifically, the thread groove spacer stepped portion 700 includes a long inner diameter portion 701 in which the inner diameter of the thread groove spacer 70 is formed larger and a short inner diameter portion in which the inner diameter of the thread groove spacer 70 is smaller than the long inner diameter portion 701. 702.
With this configuration, as shown in FIG. 5A, the rotor cylindrical portion reinforcing ring 90 can have a large cross-sectional area or volume, so that it has a predetermined strength without using an expensive material such as titanium. You can have Further, the thread groove spacer stepped portion 700 serves to keep the clearance between the rotor cylindrical portion reinforcing ring 90 positioned by the protrusion 100 and the thread groove spacer 70 constant, and does not deteriorate the exhaust performance of the vacuum pump. Is possible.
The clearance formed by the long inner diameter portion 701 and the rotor cylindrical portion reinforcing ring 90 and the clearance formed by the short inner diameter portion 702 and the rotor cylindrical portion 10 are preferably formed to be equal.
Subsequently, FIG. 5B is a diagram illustrating a structure E according to the third embodiment of the present invention.
Specifically, in the structure E according to the third embodiment of the present invention, the outer diameter gradually changes toward the exhaust cylinder side of the rotor cylinder part 10 formed on the intake cylinder 4 side of the rotor cylinder part 10. The rotor cylindrical portion reinforcing ring 90 and a thread groove spacer stepped portion 700 formed on the thread groove spacer 70 in accordance with a change in the outer diameter of the rotor cylindrical portion reinforcing ring 90 are configured.
The rotor cylindrical portion reinforcing ring 90 and the thread groove spacer stepped portion 700 according to the structure E of the third embodiment of the present invention are the clearance between the rotor cylindrical portion reinforcing ring 90 and the thread groove spacer 70 that are positioned by the protrusion 100. Is formed to keep constant. More specifically, the outer diameter of the rotor cylindrical portion reinforcing ring 90 is changed so as to gradually decrease from the intake port 4 side toward the exhaust port 6 side. In accordance with the change, the inner diameter portion formed in the thread groove spacer 70 is configured to gradually change to 721, 722, and 723.
With this configuration, as shown in FIG. 5B, the thread groove spacer stepped portion 700 is secured to the rotor cylindrical portion reinforcing ring 90 positioned by the protruding portion 100 while ensuring the strength of the rotor cylindrical portion reinforcing ring 90. The clearance with the thread groove spacer 70 can be kept constant.
The clearance formed by the long inner diameter portion 701 and the rotor cylindrical portion reinforcing ring 90 and the clearance formed by the short inner diameter portion 702 and the rotor cylindrical portion 10 are preferably formed to be equal.
Further, in the structure E of the rotor cylindrical portion reinforcing ring 90 and the thread groove spacer stepped portion 700, the rotor cylindrical portion reinforcing ring 92 and the stepped inner diameter portion 720 have three steps, but the structure is limited to this. There is no.
Further, as in the structure F shown in FIG. 5C, the stepped portion may be a tapered structure.
Note that the clearances of the structures D, E, and F according to the third embodiment of the present invention are usually set in a range of about 0.1 mm to 0.5 mm in view of various conditions.

In the structure D of the third embodiment of the present invention, the region to be formed is the inlet 4 side, but is not limited thereto.
FIG. 6 is a view for explaining a case where the structure D of the third embodiment is on the lower side in the axial direction (exhaust port 6 side) in the rotor cylindrical portion 10.
For example, as shown in FIG. 6, when the rotor cylindrical portion reinforcing ring 90 is disposed on the lower side in the axial direction of the rotor cylindrical portion 10, the above-described case is disposed on the upper side in the axial direction (on the intake port 4 side). In comparison, the positions of the long inner diameter portion 701 and the short inner diameter portion 702 in the thread groove spacer stepped portion 700 may be switched.

With the above-described configuration, in the turbo molecular pump 1 according to the third embodiment of the present invention, the rotor cylindrical portion 10 is provided with a predetermined cross-sectional area in the rotor cylindrical portion reinforcing ring (90, 91, 92) and ensuring strength. And the clearance between the thread groove spacer 70 and the clearance can be kept constant without increasing the exhaust performance.
In addition, in order to reduce the force by which the gas flows backward to the intake port 4, the smaller the clearance, the better.

(Ii-4) Fourth Embodiment (Modified Example of Rotor Cylindrical Reinforcing Ring: Fits on Inner Peripheral Side to Provide Simplified Structure)
7A to 7C are views for explaining rotor cylindrical portion reinforcing rings 90a, 90b, and 90c according to the fourth embodiment of the present invention.
In the turbo molecular pump 1 according to the fourth embodiment of the present invention, the rotor cylindrical portion reinforcing ring 90 positioned on the rotor cylindrical portion 10 performs a fitting operation for fitting the rotor cylindrical portion 10 and the rotor cylindrical portion reinforcing ring 90 together. Equipped with a simple fitting structure for easy operation.
In the following description, the rotor cylindrical portion reinforcing rings 90a to 90c will be described based on the above-described rotor cylindrical portion reinforcing ring 90 (FIG. 2). However, the rotor cylindrical portion reinforcing rings 91 and 92 described above are applied. It is also possible.
FIG. 7 (a) shows a rotor cylindrical portion reinforcing ring 90a having a C chamfering L on the inner peripheral side that is disposed on the intake port 4 side as a simple fitting structure.
FIG. 7 (b) shows a rotor cylindrical portion reinforcing ring 90b having an R shape M on the inner peripheral side that is disposed on the intake port 4 side as a simple fitting structure.
FIG. 7C illustrates a rotor cylindrical portion reinforcing ring 90c having a tapered shape N formed from the intake port 4 side toward the exhaust port 6 side on the inner peripheral side as a simple fitting structure.

In addition, the fourth embodiment can be combined with the first embodiment, the second embodiment, or the third embodiment described above.
When the positioning structure B according to the fourth embodiment and the first embodiment is combined (that is, when an R shape (curve) is provided in both the rotor cylindrical portion reinforcing ring 90b and the sumi portion S of the positioning structure B). The R shape formed in the rotor cylindrical portion reinforcing ring 90b is preferably larger than the R shape formed in the sumi portion S of the positioning structure B facing each other.

(Ii-5) Fifth embodiment (variation example of rotor cylindrical portion reinforcing ring: a streamline shape is provided on the outer periphery)
FIG. 8 is a view for explaining a rotor cylindrical portion reinforcing ring 90d according to a fifth embodiment of the present invention.
FIG. 8 shows a rotor cylindrical portion reinforcing ring 90d in which a streamline shape O having a reduced outer diameter on the outer peripheral side (exhaust port 6 side) is formed as a structure for preventing a reduction in exhaust performance. Has been. More specifically, it is cut (removed) so as to have a shape along the flow of the gas transferred from the intake port 4. With this configuration, when fitted, the flow path area can be narrowed, and a decrease in conductance (ease of gas flow) can be suppressed.
The configurations of the rotor cylindrical portion reinforcing rings including the rotor cylindrical portion reinforcing rings 90a to 90c of the fourth embodiment and the rotor cylindrical portion reinforcing rings 90d and 91, 92 of the fifth embodiment may be combined. Good.
As described above, since the turbo molecular pump 1 according to the fifth embodiment has a structure that prevents a decrease in conductance, the exhaust performance of the pump is reduced while ensuring the strength of the rotor cylindrical portion reinforcing ring. Can be prevented.
As another effect, the outer diameter of the lower axis (exhaust port 6 side) is reduced in this way, so that when the rotor 8 fluctuates due to a disturbance or the like, the screw groove spacer 70 or the like can be fixed. It can reduce contacting with a part.

  The first to fifth embodiments described above can be combined to form various types of positioning structures.

(Ii-6) Sixth Embodiment (The thread groove spacer has a vertically divided structure)
9 and 10 are diagrams for explaining a divided structure according to the sixth embodiment of the present invention.
As an example, the sixth embodiment of the present invention will be described using the positioning structure D (FIG. 6) of the third embodiment of the above-described embodiments of the present invention.
FIG. 9 is a view showing the turbo molecular pump 1 in which the rotor cylindrical portion reinforcing ring 90 and the positioning structure D are arranged.
Here, as shown in FIG. 9, the outer diameter of the rotor cylindrical portion reinforcing ring 90 is configured to be larger than the inner diameter of the thread groove spacer 70. Therefore, in this configuration, when the rotor 8 is to be assembled from above the axis (from the intake port 4 side), the rotor cylindrical portion reinforcing ring 90 and the short inner diameter portion 702 of the thread groove spacer stepped portion 700 constituting the positioning structure D Interfering portions I that interfere with each other are formed. For this reason, the assembly method of the thread groove spacer 70 is limited.
Therefore, the rotor cylindrical portion reinforcing ring 90 must be disposed after the rotor 8 is assembled. Then, operations such as press fitting and shrink fitting become very difficult. The work efficiency is better when the rotor cylindrical portion reinforcing ring 90 is assembled after being disposed on the rotor cylindrical portion 10.
Therefore, in the sixth embodiment of the present invention, as shown in FIG. 10, the thread groove spacer 70 is divided into vertical thread groove spacers 71.
With the split screw groove spacer 71 according to the sixth embodiment of the present invention, even if there is the interference portion I described above, it is possible to assemble from the outer peripheral side, so that interference does not occur. In addition, about a division | segmentation, at least one part should just be divided vertically in a thread groove type pump part (for example, a semicircle division | segmentation, multiple equal division | segmentation etc.).
At this time, it is conceivable that gas leaks from the gap between the divided thread groove spacers 71 and the exhaust performance of the pump deteriorates. However, a seal member such as an O-ring may be provided on the outer periphery of the thread groove spacer 71. Thus, it is possible to prevent a decrease in pump performance.
In the sixth embodiment, the combination of the first embodiment and the third embodiment is used as an example. However, the present invention is not limited to this, and the positioning structure is provided on the exhaust port 6 side of the rotor cylindrical portion 10. If it is the structure which is, it can respond to the structure of other various combinations.
With the above-described structure, the contact between the rotor cylindrical portion reinforcing ring 90 and the divided thread groove spacer 71 can be prevented, so that the assembly can be easily performed regardless of the arrangement position of the rotor cylindrical portion reinforcing ring 90. Become.

FIG. 11 is a diagram showing a schematic configuration example (cross-sectional view) of the thread groove type pump according to the embodiment of the present invention.
In each of the above-described embodiments (1 to 6), the turbo molecular pump 1 has been described as an example of the vacuum pump. However, the embodiment is applied to the thread groove type pump 1000 illustrated in FIG. 11 except for the modification 2 of the first embodiment. It is also possible to do.

DESCRIPTION OF SYMBOLS 1 Turbo molecular pump 2 Casing 3 Base 4 Intake port 5 Flange part 6 Exhaust port 7 Shaft 8 Rotor 9 Rotary blade 10 Rotor cylindrical part 20 Motor part 30, 31 Radial direction magnetic bearing apparatus 40 Axial direction magnetic bearing apparatus 50 Fixed blade 60 Fixed Blade spacer 70 Thread groove spacer 71 Split thread groove spacer 700 Thread groove spacer step 701 Long inner diameter part (Thread groove spacer)
702 Short inner diameter (thread groove spacer)
710 Reduced inner diameter (thread groove spacer)
711 Gradually decreasing inner diameter (thread groove spacer)
712 Short inner diameter (thread groove spacer)
720 Stepped inner diameter (Thread groove spacer)
721 Long inner diameter (thread groove spacer)
722 Long inner diameter part (Thread groove spacer)
723 Long inner diameter (thread groove spacer)
80 Stator column 90 Rotor cylindrical portion reinforcing ring 91 Rotor cylindrical portion reinforcing ring 92 Rotor cylindrical portion reinforcing ring 90a Rotor cylindrical portion reinforcing ring 90b Rotor cylindrical portion reinforcing ring 90c Rotor cylindrical portion reinforcing ring 90d Rotor cylindrical portion reinforcing ring 100 Protrusion (rotor Cylindrical part)
110 Stepped portion (rotor cylindrical portion)
111 Long outer diameter (rotor cylindrical part)
112 Short outer diameter (rotor cylindrical part)
1000 Screw groove type pump 2000 Turbo molecular pump (conventional)
2001 Rotor cylinder outer circumference (conventional)
2002 Ring member (conventional)
2003 Thread groove spacer (conventional)

Claims (12)

A rotor that is provided inside the exterior body and is used in a gas transfer mechanism that transfers gas from an intake port to an exhaust port,
The gas transfer mechanism includes a thread groove type pump portion formed of a thread groove spacer and a thread groove type pump rotor formed in a cylindrical portion of the rotor, and includes a thread groove type pump portion in which a thread groove is formed only in the thread groove spacer. A reinforcing ring member is disposed on the part,
Or the reinforcing ring member is disposed at the lower end of the cylindrical portion, or the lower side than the reinforcing ring member is disposed portions of the cylindrical portion, said reinforcing ring member of the cylindrical portion toward the downward Is provided with a taper portion that is smaller in diameter than the portion where
It said reinforcing ring member is in said cylindrical portion, is disposed in the extension portion which is extended to the screw groove pump portion or the screw groove pump section or et lower,
The rotor includes a positioning structure for setting a position where the reinforcing ring member is disposed;
The positioning structure is
The rotor having at least one of a projecting portion and a tapered portion formed so as to contact the reinforcing ring member on a side surface of the cylindrical portion of the rotor. 2. The rotor according to claim 1 , wherein the positioning structure has a tapered shape that decreases in diameter toward a lower position at a position where the reinforcing ring member is disposed on the side surface of the cylindrical portion of the rotor. . The reinforcing ring member, on the side facing the side surface of said cylindrical portion of said rotor, C chamfered, R shape or claim 1 or claim 2, wherein at least one of the tapered shape is subjected The rotor described in 1. The reinforcing ring member, on the side not the side surface facing said cylindrical portion of said rotor, from claim 1, wherein a shape as an outer diameter decreases are subjected as it goes to the side of the exhaust port The rotor according to claim 3 . It said reinforcing ring member is a rotor according to any one of claims 1 to 4, characterized in that it is made in the fiber-reinforced member. It said reinforcing ring member is press fit, shrink fit, or cold fitting portion fitted with the cylindrical portion by fitting, or according claim 1, characterized in that it comprises an adhesive portion which is adhered to the cylindrical portion by an adhesive 6. The rotor according to any one of items 5 . The rotor according to any one of claims 1 to 6 , the exterior body, and a fixing portion that is disposed inside the exterior body and forms the gas transfer mechanism together with the rotor. A vacuum pump characterized by The vacuum pump according to claim 7 , wherein the fixing portion further includes an inner diameter dimension changing portion formed by a long inner diameter portion and a short inner diameter portion formed to have an inner diameter smaller than the long inner diameter portion. The inner diameter dimension changing portion of the fixed portion maintains a constant clearance formed by the reinforcing ring member fitted to the cylindrical portion of the rotor and the fixed portion by the longer inner diameter portion and the shorter inner diameter portion. The vacuum pump according to claim 8 . And further including rotor blades arranged radially from the outer peripheral surface of the rotor;
The vacuum pump according to any one of claims 7 to 9 , wherein the positioning structure is a lowermost rotor blade of the rotor blade. And further including rotor blades arranged radially from the outer peripheral surface of the rotor;
The vacuum pump according to any one of claims 7 to 9 , wherein in the positioning structure, the protrusion and the lowermost rotor blade of the rotor blade are integrally formed. When the outermost diameter portion of the reinforcing ring member is set larger than the short inner diameter portion of the fixing portion, at least the short inner diameter portion of the fixing portion is vertically divided and assembled. A method for assembling the vacuum pump according to claim 8 or 9 .

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