JP3804721B2 - Seal member with filter and turbomolecular pump using the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a turbo molecular pump in which gas is exhausted by a rotor blade and / or a thread groove rotor rotating at high speed.
[0002]
[Prior art]
FIG. 4 shows a conventional general structure of a turbo molecular pump. This includes a rotor R having a main shaft 10 and a rotating cylindrical portion 12 rotating integrally therewith, a stator S having a fixed cylindrical portion 14 surrounding the main shaft 10, and a cylindrical casing surrounding the rotating cylindrical portion 12. 16 are assembled on the base B. A filter for preventing intrusion of dust is disposed at the intake port 50 of the turbo molecular pump having such a configuration.
[0003]
Such a filter 52 is configured by stretching a mesh 56 around a ring-shaped frame 54, and is placed on a support ring 58 fixed inside the air inlet 50. Between the intake port 50 and the exhaust port 60 of the processing apparatus to be exhausted, a seal ring 62 is provided for maintaining airtightness between the two. The seal ring 62 is configured such that an elastic ring 68 is sandwiched between an inner ring 64 and an outer ring 66 each made of a metal material.
[0004]
Grooves 64a and 66a having a circular cross section along the shape of the elastic ring 68 are formed in the circumferential direction on the opposing surfaces of the inner ring 64 and the outer ring 66, respectively. The thickness t of the inner ring 64 and the outer ring 66 is set to be smaller than the diameter r of the elastic ring. Therefore, when the intake port 50 and the exhaust port 60 are fixed with bolts or the like with the elastic ring 68 interposed therebetween, they are elastic. The ring 68 is pushed and crushed and brought into close contact, thereby ensuring airtightness.
[0005]
[Problems to be solved by the invention]
However, in such a conventional technique, in order to provide the support ring 58 of the filter 52 at the intake port 50, the cost of parts and the installation cost are required, and dust or the like is likely to adhere to the support ring 58 portion. Therefore, it is necessary to take measures such as worrying about contamination of the device by the garbage and cleaning work frequently.
[0006]
In view of the above problems, an object of the present invention is to provide a turbo molecular pump in which the structure of a connecting portion between devices to be evacuated is simplified and the cost and workability are improved.
[0007]
[Means for Solving the Problems]
According to the first aspect of the present invention, an elastic ring made of an elastic body is disposed along the outer peripheral surface of the inner ring, and a filter that prevents solids from passing through is attached to the inner opening of the inner ring. the inner ring, Ri Do from an outer portion in which the resilient ring along the outer circumferential surface at thinner than the cylindrical inner portion and the inner portion of the small old outer diameter Ri by mounting inner diameter of the other member is disposed, the the thickness of the outer portion of the inner ring is a filter with the seal member characterized that you have been set smaller than the diameter of said elastic ring.
[0008]
This eliminates the need for providing a separate structure for supporting the filter, and simplifies the configuration and maintenance. The filter may be fixed to the ring member by welding or the like, or may be detachably fixed with an appropriate jig.
[0009]
The invention according to claim 2, wherein the filter is a filter with the seal member according to claim 1, characterized in that is freely mounted et removably to the inner surface of the inner ring.
[0010]
The invention according to claim 3 is the seal member with a filter according to claim 1 or 2 , wherein an outer ring is arranged outside the elastic ring.
According to a fourth aspect of the present invention, there is provided a turbo molecular pump characterized in that the sealing member with a filter according to any one of the first to third aspects is disposed at an intake port .
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 includes a rotor R having a main shaft 10 and a rotating cylindrical portion 12 that rotates integrally therewith, a stator S having a fixed cylindrical portion 14 surrounding the main shaft 10, and a rotating cylinder. A cylindrical casing 16 surrounding the shaped portion 12 is assembled on the base B. A filter-sealed seal member 70 is provided at the intake port 50 of the casing 16.
[0012]
A drive motor 22 is disposed between the main shaft 10 and the fixed cylindrical portion 14, and an upper radial bearing 24 and a lower radial bearing 26 are provided above and below the drive motor 22. An axial bearing 32 including a target disk 28 at the lower end of the main shaft 10 and upper and lower coils 30 on the stator S side is disposed below the main shaft 10. As a result, the rotor R rotates at high speed while receiving 5-axis active control as the drive motor 22 is driven.
[0013]
The upper outer circumference of the rotating tubular portion 12 rotates blades 34 are provided integrally constitute the impeller, whereas, on the inner surface of the casing 16, the fixed blade 38 is provided to be arranged alternately with rotor blades 34 Yes. As a result, a blade exhaust portion 40 is formed to perform exhaust by the interaction between the rotating blade 34 rotating at high speed and the stationary blade 38 stationary.
[0014]
Further, the rotating cylindrical portion 12 is integrally provided with a screw groove portion 42 that extends downward along the outer periphery of the fixed cylindrical portion 14, and a screw groove 44 is provided on the outer peripheral surface of the screw groove portion 42. . On the other hand, the stator S is provided with a thread groove spacer 46 surrounding the outer periphery of the thread groove 42. As a result, a thread groove exhaust portion 48 that exhausts by a drag action of the thread groove 44 of the thread groove portion 42 that rotates at high speed is formed between the blade exhaust portion 40 and the exhaust port .
[0015]
A filter-sealed seal member 70 is disposed at the inlet 50 of the turbo molecular pump to prevent intrusion of dust and maintain airtightness between the turbo molecular pump and a device to be evacuated. . The seal member 70 with a filter is sandwiched between an inner ring 72 and an outer ring 74 made of a metal material, as shown in FIG. 2A and the components in FIG. And an elastic ring 76 and a mesh-like filter 78 attached integrally inside the inner ring 72 so as to cover the inner opening.
[0016]
The inner ring 72 is formed of a suitable metal material, such as stainless steel, for example, an outer portion 80 sandwiched between the turbomolecular pump and the device to be evacuated, the exhaust port 60 and the turbo of the device to be evacuated. A cylindrical inner portion 82 having an outer diameter slightly smaller than the inner diameter of the inlet 50 of the molecular pump. The outer ring 74 is also made of a metal material such as Al. The elastic ring 76 is made of, for example, a fluororesin. The filter 78 is usually made of a metal mesh, and is fixed to the inner surface of the inner ring 72 by brazing or an adhesive.
[0017]
Grooves 72a and 74a having a circular cross section along the shape of the elastic ring 76 are formed in the circumferential direction on the opposing surfaces of the inner ring 72 and the outer ring 74, respectively. The thickness t of the inner ring 72 and the outer ring 74 is set to be smaller than the diameter r of the elastic ring. The cross-sectional area of the space between the inner ring and the outer ring is set smaller than the cross-sectional area of the elastic ring 76. Therefore, when the intake port 50 and the exhaust port 60 of the apparatus are fixed with bolts or the like across the elastic ring 76, the elastic ring 76 is pressed and crushed by these, and protrudes up and down from the space between the inner ring 72 and the outer ring 74. To do. This is in close contact with the surface of the turbo molecular pump and the device to be evacuated, thereby ensuring airtightness between them.
[0018]
The operation of the turbo molecular pump having the filter-equipped seal member configured as described above will be described. As shown in FIG. 2B, the three parts of the outer ring 74, the elastic ring 76, and the inner ring 72 with a filter are combined as shown in FIG. This is sandwiched between the intake port 50 of the turbo molecular pump and the exhaust port 60 of the apparatus so that the inner portion 82 of the inner ring 72 is fitted to each other, and the turbo molecular pump and the apparatus are fastened by bolts or the like. Since the diameter r of the elastic ring 76 is larger than the thickness t of the inner ring 72 and the outer ring 74, the elastic ring 76 is pushed and crushed, and is in close contact with the surfaces of the intake port 50 of the turbo molecular pump and the exhaust port 60 of the apparatus. To do. When the filter 78 is replaced, an inner ring 72 to which a new filter 78 is fixed in advance is prepared, and the inner ring 72 may be performed together.
[0019]
Thus, with this turbo molecular pump, the replacement work of the filter 78 is easy. Further, since it is not necessary to provide a filter support ring at the intake port 50, the parts cost and the installation cost are unnecessary, and the configuration of this part is simplified and the maintenance is simplified.
[0020]
FIG. 2C shows an inner ring 72A of another embodiment, in which a filter 78 is detachably attached. That is, a groove 84 extending in the circumferential direction is formed on the inner peripheral surface of the inner ring 72A. After the filter 78 is placed on the inner ring 72A, an elastic pressing member 86 is attached to the groove 84 to fix the filter 78. This facilitates the replacement of the filter 78 and eliminates the need to replace the entire inner ring, thus reducing the component cost.
[0021]
The outer ring 74 is preferably intended to prevent the elastic ring 76 from expanding outward, but the gist of the present invention can be achieved without it. Moreover, in the said embodiment, although the sealing member with a filter was attached to the inlet 50 of a turbo-molecular pump, it cannot be overemphasized that you may use in the arbitrary places where both a seal | sticker and a filter function are required.
[0022]
【The invention's effect】
As described above, according to the present invention, it is not necessary to provide a structure for supporting the filter separately, the structure of the connecting portion between the devices to be evacuated is simplified, and the cost and workability are improved. A compact turbo molecular pump can be provided.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a turbo molecular pump according to one embodiment of the present invention.
2A is a cross-sectional view showing an embodiment of a sealing member with a filter according to the present invention, FIG. 2B is a diagram showing its components, and FIG. 2C is a diagram showing components of another embodiment.
3 is a plan view of the sealing member with a filter in FIG. 2. FIG.
FIG. 4 is a cross-sectional view showing a conventional turbo molecular pump.
[Explanation of symbols]
50 Inlet 72 Inner ring 74 Outer ring 76 Elastic ring 78 Filter

Claims (4)

An elastic ring made of an elastic body is disposed along the outer peripheral surface of the inner ring,
A filter that prevents solids from passing through is attached to the inner opening of the inner ring,
The inner ring, Ri Do from an outer portion in which the resilient ring along the outer circumferential surface at thinner than the cylindrical inner portion and the inner portion of the small old outer diameter Ri by attaching inner diameter is disposed in the other member,
The thickness of the outer portion, the filter with the seal member, wherein that you have been set smaller than the diameter of the elastic ring of the inner ring.   The seal member with a filter according to claim 1, wherein the filter is detachably attached to an inner surface of the inner ring.   The seal member with a filter according to claim 1, wherein an outer ring is disposed outside the elastic ring.   A turbo-molecular pump, characterized in that the sealing member with a filter according to any one of claims 1 to 3 is disposed at an intake port.

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