JPS63280893A - Turbo vacuum pump - Google Patents

Abstract

PURPOSE:To provide a compact pump by forming swirl pump stages of swirl blade stages provided on a rotor sequentially to have different diameters and ventilating paths provided on a stator to have different diameters and providing an intake port leading to a front stage ventilating path and a discharge port leading to a plurality of ventilating paths on the stator. CONSTITUTION:A rotor 1 is provided on the front end with swirl blades 6 having sequentially different diameters and a stator 8 is provided with ventilating paths 9 having different diameters corresponding to the swirl blades 6. An intake port 11 and a discharge port 12 are provided in front and rear of a partition portion 10 provided at a peripheral portion of stator 8. And a seal portion 13 is provided on the end face 1A of rotor 1 and the end face of stator. Thus, the axial seal portion does not need to be provided between pump stages so that the axial length of pump can be shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a turbo vacuum pump, and particularly to a compact and high performance turbo vacuum pump.

[Conventional technology]

Conventional turbo vacuum pumps generally use axial flow blades that have excellent pumping performance in the molecular flow region. On the other hand, in recent years, turbo vacuum pumps using multiple stages of vortex blades capable of obtaining a large compression ratio in a viscous flow region have been proposed, for example, in Japanese Patent Laid-Open Nos. 62-29796 and 62-29797.

In the turbomolecular pump described in Japanese Patent Application Laid-Open No. 62-29796, the stator has a half-split structure so that the stator forming the ventilation passage is inserted inside the tip diameter of the rotor blade. Further, a turbo-molecular pump described in Japanese Patent Application Laid-Open No. 62-29797 has a rotor having swirl blades inside a stator which is not of half-split structure.

[Problem that the invention seeks to solve]

In the above-mentioned Japanese Patent Laid-Open No. 62-29796, the stator has a half-split structure, which increases the number of parts and does not provide good assembly. Also, JP-A-62-2979
Although the pump disclosed in Publication No. 7 is easy to assemble, it is necessary to form a seal portion along the outer peripheral surface of the rotor in the axial direction, which increases the length of the pump in the axial direction and does not provide good compactness.

As mentioned above, conventional technology does not take into consideration both manufacturability and compactness, and if it is compact, there is a problem with manufacturability, and if manufacturability is good, it is not compact. was there.

An object of the present invention is to provide a compact, high-performance turbo vacuum pump with good operability.

[Means for solving problems]

The first aspect of the present invention is a turbo vacuum pump in which a plurality of pump stages each consisting of a rotor and a stator facing the rotor are provided in a casing having an intake port and an exhaust port, and these pump stages perform an evacuation action. A multi-stage vortex pump stage is formed by a plurality of vortex blade stages of different diameters provided on the rotor and ventilation passages of different diameters provided on the stator facing the vortex blade stages, and the stator is further provided with a ventilation passage of a previous stage. This is achieved by providing an inlet that communicates with a passageway and an outlet that communicates with a plurality of ventilation passages.

The second aspect of the present invention is a turbo vacuum pump in which a plurality of pump stages each consisting of a rotor and a stator facing the rotor are provided in a casing having an intake port and an exhaust port, and these pump stages perform an exhaust action. , a multi-stage vortex pump stage is constituted by a plurality of vortex blade stages of different diameters provided on the rotor and ventilation passages of different diameters provided on the stator and opposite to the vortex blade stages, and further a ventilation passage of a previous stage is provided on the stator. This is achieved by providing an inlet that communicates with the vortex pump stage and an outlet that communicates with the ventilation path at the subsequent stage, and providing an axial flow pump stage on the intake side of the vortex pump stage.

[Effect]

By configuring the rotor in multiple stages so that the outer diameter of the rotor having the swirl blades and the inner diameter of the stator having the ventilation passages are successively different, a slit seal portion can be formed between each rotor end face and the stator end face. As a result, since the axial length of the pump can be shortened and compactness can be achieved, the vortex blade can be made more compact without changing the performance of the vortex blade. High performance can be achieved. Therefore, a compact and high-performance turbo vacuum pump can be obtained. In addition, the rotor having swirl blades and the stator having a cylindrical ventilation passage do not require a half-split structure, resulting in good manufacturability and ease of assembly.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the invention, in which a rotor 1 is placed in a casing 2 and shrink-fitted onto a shaft 3. In FIG. The outer diameter of the rotor 1 is gradually different from the intake port 4 toward the exhaust port 5, and becomes smaller stepwise.

A swirl blade 6 is provided at the tip of each diameter. A stator 8 is supported on the base 7 so as to face the rotor 1 . The stator 8 has an inner diameter that is sequentially made different in accordance with a change in the outer diameter of the rotor 1, and becomes smaller in a stepwise manner. A ventilation passage 9 is provided on the inner diameter surface of the stator 8 facing each swirl blade 6 .

A partition portion 10 is provided at one location in the circumferential direction of the stator 8, as shown in FIG. A suction port 11 and a discharge port 12 are provided before and after the partition portion 10 . The end face IA of each rotor 1 with a different diameter and the stator 8 with a different diameter opposite thereto
A slit seal portion 3 extending perpendicularly to the rotor axis is formed between the end face 8A and the rotor axis. The shaft 3 is supported by a ball bearing 14 on the base 7 and a ball bearing 15 on the lower base 16. The bearings are lubricated by a self-contained structure in which oil 18 stored in an oil tank 17 is sucked up by a conical tube 19 and supplied to the bearings 14 and 15 through the inside of the shaft 3. The rotor 1 is driven at high speed by a high frequency motor rotor 20 shrink-fitted to the shaft 3 and a high frequency motor stator 22 supported by a motor casing 21.

Next, the operation of the embodiment of the present invention described above will be explained.

When the rotor 1 is driven at high speed, gas is exhausted from the intake port 4 to the exhaust port 5 due to the action of the swirl blades 6.

In order to effectively perform this exhaust action, it is necessary to minimize leakage between the crotches, but in this embodiment, seal portions 13 are provided on the end surfaces of the rotor 1 and stator 8, which have different diameters, that is, on the surfaces perpendicular to the rotor axis. Therefore, leakage between pump stages can be reduced by the action of this seal portion 13. Therefore, there is no need to provide an axial seal between the pump stages, and the axial length of the pump can be shortened by 0 or more, which allows the pump to rotate at a higher speed by that much. This makes it possible to improve the performance of the impeller.

Furthermore, in this embodiment, since the outer diameter of the rotor 1 is made smaller from the intake port 4 side to the exhaust port 5 side, there is an advantage that the capacity of the remoter with small disk friction loss can be selected to be small.

FIG. 3 shows another embodiment of the invention.

In the diagram, parts with the same symbols as in FIG. 1 are the same parts. In this embodiment, the outer diameter of the rotor 1' and the stator 8'
The inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the FEATURES is increased from the intake side to the exhaust side. According to this embodiment, the disk friction loss of the rotor 1' is larger than the embodiment shown in FIG. , since the pump action is performed by the centrifugal force of the rotor 1', the sealing effect is superior to that of the seal portion 13 of the embodiment shown in FIG. 1, and other than that, the same effect as the embodiment shown in FIG. 1 is achieved. .

FIG. 4 shows another embodiment of the present invention,
In this figure, the same reference numerals as in FIG. 1 are the same parts. This embodiment differs from the embodiment shown in FIG. 1 in that a centrifugal rotor 26. A centrifugal pump consisting of a centrifugal stator 27 and an axial rotor 28 on the suction side of the centrifugal pump. An axial flow pump consisting of an axial flow stator 29 is provided.

With this configuration, the suction port 4 can be made to have a higher vacuum than the embodiment shown in Fig. 1 by the evacuation action of the centrifugal pump and the axial pump, so it is possible to evacuate from atmospheric pressure to high vacuum with one pump. becomes. In this way, when the vortex vane 6 is configured by stacking vanes of other exhaust principles on the intake side, the fact that the vortex pump stage is axially compact and has a high compression ratio means that the vortex vanes 6 are stacked with vanes of other exhaust principle. In addition to having the effect of reducing the number of stages, high-speed rotation can also be facilitated, which is an effective advantage in terms of performance.

In the above description, a centrifugal pump was used as a component provided on the intake side of the swirl vane 6, but a thread groove pump may be used instead of the centrifugal pump.

In addition, in the above-mentioned embodiment, the slit seal portion 13.1
3' is provided in a direction perpendicular to the rotor axis, but as shown in FIG.
It is also possible to provide a labyrinth seal 30 or a thread groove as shown in FIG. 6 on at least one surface constituting 3.13'. The provision of this sealing means further reduces leakage between pump stages and further improves the performance of the swirl vane. Alternatively, as shown in FIGS. 7 and 8, a core 30 may be provided in the ventilation passage 9 constituting the vortex pump stage to effectively form a vortex in the flow within the ventilation passage 9. good.

〔Effect of the invention〕

According to the present invention, it is possible to reduce the axial distance between the stages of the swirl vanes, which is easy to manufacture, and therefore it is possible to provide a compact and high-performance turbo vacuum pump.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of one embodiment of the present invention, FIG. 2 is a cross-sectional view of FIG. 1, and FIG. 3 is a longitudinal cross-sectional view of another embodiment of the present invention.
FIG. 4 is a longitudinal cross-sectional view of another embodiment of the present invention, FIGS. 5 and 6 are longitudinal cross-sections showing an embodiment of the slit seal portion constituting the present invention, and FIG. 7 is a longitudinal cross-sectional view of another embodiment of the present invention. A cross-sectional view showing another example of the vortex pump stage constituting the invention, FIG. 8 is a cross-sectional view taken along the line -■ in FIG. 7. DESCRIPTION OF SYMBOLS 1... Rotor, 2... Casing, 3... Shaft, 4... Intake port, 5... Exhaust port, 6... Whirlpool blade, 7... Base, 8... Stator , 9... Ventilation passage, 10... Partition part, 11... Suction port, 12... Discharge port, 13.13'... Slit seal part, 14.15.
...Ball bearing, 16...Lower base 517...Oil tank, 18...Oil, 19...Conical tube body, 20...
・Motor rotor, 21...Motor casing, 22・
...Motor stator, 25...Labyrinth, 26...
・Centrifugal rotor, 27...Centrifugal stator, 28.../
3...#Chen Sheets LfP 2nd field//,...Ro! :Ln\mouth/2...mouth" 181 mouth 3rd mouth Rotor δ'...stay 75' ・Kumuryo Seal Kichiya 6th mouth 25... Ubirin rail 7th mouth 8th

Claims (1)

[Claims] 1. A turbo vacuum pump in which a plurality of pump stages each consisting of a rotor and a stator facing the rotor are provided in a casing having an intake port and an exhaust port, and these pump stages perform an exhaust action. , a multi-stage vortex pump stage is formed by a plurality of vortex blade stages of different diameters provided on the rotor and ventilation passages of different diameters provided on the stator and opposite to the vortex blade stages, and further a ventilation passage of a previous stage is provided on the stator. A turbo vacuum pump characterized by being provided with an inlet that communicates with the air passageway, and a discharge outlet that communicates with the ventilation path at the rear stage. 2. In the turbo vacuum pump according to claim 1, a slit seal portion is provided between the end face between each of the swirl vane stages and the end face between the opposing ventilation passages having different diameters. Characteristic turbo vacuum pump. 3. The turbo vacuum pump according to claim 2, wherein the slit seal portion is formed at an end face parallel to a radial line with respect to the rotor axis. 4. The turbo vacuum pump according to claim 2, wherein the slit seal portion is formed at an end face intersecting a radial line with respect to the rotor axis. 5. The turbo vacuum pump according to claim 3 or 4, characterized in that a labyrinth is provided on at least one surface constituting the slit seal portion. 6. The turbo vacuum pump according to claim 3 or 4, characterized in that a thread groove is provided on at least one surface constituting the slit seal portion. 7. A turbo vacuum pump according to any one of claims 1 to 6, characterized in that a core ring is provided in the ventilation passage. 8. In a turbo vacuum pump in which a plurality of pump stages each consisting of a rotor and a stator opposing the rotor are provided in a casing having an intake port and an exhaust port, and these pump stages perform an exhaust action, A multi-stage vortex pump stage is formed by a plurality of vortex blade stages having sequentially different diameters and a ventilation passage having a different diameter and facing the vortex blade stage provided on a stator, and further includes an inlet in the stator that communicates with the ventilation passage in the previous stage; What is claimed is: 1. A turbo vacuum pump comprising: a discharge port communicating with a downstream ventilation passage; and an axial flow pump stage provided on the suction side of the vortex pump stage. 9. In the turbo vacuum pump according to claim 8, a slit seal portion is provided between the end face between each of the swirl vane stages and the end face between the opposing ventilation passages having different diameters. Characteristic turbo vacuum pump. 10. The turbo vacuum pump according to claim 9, wherein the slit seal portion is formed at an end face parallel to a radial line with respect to the rotor axis. 11. The turbo vacuum pump according to claim 9, wherein the slit seal portion is formed at an end face intersecting a radial line with respect to the rotor axis. 12. The turbo vacuum pump according to claim 10 or 11, characterized in that a labyrinth is provided on at least one surface constituting the slit seal portion. 13. The turbo vacuum pump according to claim 10 or 11, characterized in that a thread groove is provided on at least one surface constituting the slit seal portion. 14. A turbo vacuum pump according to any one of claims 8 to 13, characterized in that a core ring is provided in the ventilation passage.