JPH05321879A - Vacuum pump - Google Patents

Abstract

PURPOSE:To keep a balance of a rotary body sufficiently without impairing corrosion resistance by providing a part in a rotor so as to adjust the balance when the rotor is rotated. CONSTITUTION:A member 7 being a different member from a rotor 4 and having corrosion resistance even if metal plating is not applied, is installed in the rotor 4 so as to adjust a balance of the rotor 4, and the balance is adjusted by means of the part. In this way, since the rotor 4 is still in a metal plating applied condition and the metal plating surface is not cut to adjust the balance, the corrosion resistance can be kept sufficiently. Since the different member 7 being installed in the rotor 4 is formed of a corrosion resistant construction material from the beginning, even if it is cut when the balance is adjusted, the corrosion resistance is not impaired so that the balance can be kept sufficiently as a rotary body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum pump whose exhaust port is operated at atmospheric pressure, and is particularly suitable for use in a semiconductor manufacturing process that uses a lot of corrosive chlorine-based gas or fluorine-based gas. Regarding a dry vacuum pump.

[0002]

2. Description of the Related Art A dry vacuum pump has an excellent feature that a clean vacuum can be obtained because there is no oil or water in a flow path through which a gas flowing from a suction port passes, and it is often used in a semiconductor manufacturing process. . Among the semiconductor manufacturing processes, the gas used in the etching process is often a corrosive gas. Therefore, in order to provide corrosion resistance, stainless steel was used for the parts in contact with the gas. However, due to recent diversification of processes, corrosion resistance of stainless steel is not sufficient, and more corrosion-resistant plating has been applied.

Since the rotor rotates at a high speed, it is necessary to maintain a dynamic balance. However, even if the rotor is balanced in advance before plating, the balance comes after plating and the balance is corrected again. If the balance is corrected after plating, the plating will be scraped and the material will be exposed. When the material is exposed, that part needs to be plated again, and once plated, the balance must be corrected again, so
Conventionally, there has been a problem that the balance cannot be sufficiently balanced, or that there is a part where there is no plating and corrosion resistance is not sufficient.

[0004]

When plating the rotor, which is a rotating body, if the dynamic balance is emphasized, the balance correction portion becomes insufficient in terms of corrosion resistance, and if the corrosion resistance is emphasized, balance adjustment becomes insufficient. There was a problem.

An object of the present invention is to provide a vacuum pump which can sufficiently maintain the corrosion resistance of the rotor and can also perform the balance correction sufficiently.

[0006]

In order to achieve the above-mentioned object, the present invention mounts a member having corrosion resistance to the rotor for correcting the balance of the rotor without plating with a member different from the rotor, and balances at that portion. I was able to fix it.

[0007]

[Function] The rotor remains plated.
Corrosion resistance can be sufficiently secured because the plated surface is not scraped by the balance correction. Since the separate member attached to the rotor is a material having corrosion resistance in the first place, it does not impair corrosion resistance even if it is shaved at the time of balance correction, and the rotor can be well balanced.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG.

In FIG. 1, in a casing 3 having an intake port 1 and an exhaust port 2, from a rotor 4 supported by a bearing 6 and driven by a motor 8, and a stator 5 mounted so as to surround the rotor 4. The rotor 4 is provided with a balance correction member 7.

The rotor 4 supported by the bearing 6 is rotated by a motor 8. The gas sucked from the suction port 1 is subjected to a compression action in the flow path of the stator 5 by the rotational force of the rotor 4, and is sequentially compressed from the upper stage to the exhaust port 2
Exhausted to the atmosphere.

When the vacuum pump is used in the silicon etching step of the semiconductor manufacturing process, a fluorine-based gas flows in through the suction port 1. The nickel-based metal has a corrosion resistance against the fluorine-based gas.
A nickel-based metal is suitable for the cylindrical balance correction member 7 that is shrink-fitted into. Electroless nickel plating is applied to the rotor 4, and the balance of the rotor 4 is adjusted by the balance correction member 7.
By taking the above step, the corrosion resistance can be ensured and a sufficient balance can be obtained.

The gas used varies depending on various processes, and thus the material having corrosion resistance may vary. For the balance correction member 7, an optimum material can be selected for corrosion resistance.

FIG. 2 shows another embodiment of the present invention, which is a rotor 4
The attachment of the balance correction member 7 to the above is also satisfied by fastening with a screw structure.

FIG. 3 shows a rotor 4 according to another embodiment of the present invention.
The balance correction member 7 may be attached to the cover 10 and the bolt 11 as long as the rotating body has no problem in strength.

[0015]

According to the present invention, the rotating body can be well balanced without sacrificing corrosion resistance.

[Brief description of drawings]

FIG. 1 is a sectional view of a vacuum pump showing an embodiment of the present invention.

FIG. 2 is a partial sectional view of a rotor showing a second embodiment of the present invention.

FIG. 3 is a partial sectional view of a rotor showing a third embodiment of the present invention.

[Explanation of symbols]

1 ... Suction port, 2 ... Exhaust port, 3 ... Casing, 4 ... Rotor, 5 ... Stator, 7 ... Balance correction member.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Masahiro Mase Inventor Masahiro Mase 603 Jinritsucho, Tsuchiura City, Ibaraki Pref.

Claims (1)

[Claims] 1. A vacuum pump in which a low-pressure gas sucked from an intake port is compressed by a pump section made up of a rotor and a stator provided in a casing and exhausted to the atmosphere from an exhaust port to correct the balance when the rotor rotates. A vacuum pump, wherein a portion to be provided is provided on the rotor.