Vacuum pump, magnetic bearing device, and rotor

Patent metadata

Field	Value
Publication number	US-11536280-B2
Application number	US-201816604936-A
Country	US
Kind code	B2
Filing date	Apr 11, 2018
Priority date	Apr 20, 2017
Publication date	Dec 27, 2022
Grant date	Dec 27, 2022

Abstract

Provided are a vacuum pump, a magnetic bearing device, and a rotor that suppress swinging and vibration of a rotor. A vacuum pump includes, in the following order in the exhaust direction of a gas, the center of gravity of a rotor, an active radial bearing that supports the rotor in the radial direction in a non-contact manner by using a magnetic force, and a passive radial bearing that supports the rotor in the radial direction in a non-contact manner using a magnetic force.

First claim

What is claimed is:

1. A vacuum pump provided with a magnetic bearing device, the vacuum pump comprising:
a plurality of radial magnetic force generation means for supporting a rotor for exhausting gas in a radial direction in a non-contact manner by using a magnetic force; and
a radial displacement detection means for detecting displacement of the rotor in the radial direction, wherein
two of the radial magnetic force generation means are provided on an outlet port side with respect to a center of gravity of the rotor in an exhaust direction of the gas,
the radial magnetic force generation means disposed on an inlet port side is controlled based on a detection value of the radial displacement detection means, and
the radial displacement detection means is provided on the outlet port side with respect to the center of gravity of the rotor in the exhaust direction of the gas.

2. The vacuum pump according to claim 1 , wherein a first radial magnetic force generation means disposed on the inlet port side of the exhaust direction of the gas actively supports the rotor, and a second radial magnetic force generation means disposed on the outlet port side of the exhaust direction of the gas passively supports the rotor.

3. The vacuum pump according to claim 2 , wherein a center of the first radial magnetic force generation means and a center of the radial displacement detection means are arranged on the same plane across an axis of the rotor.

4. A magnetic bearing device for use in a vacuum pump, the magnetic bearing device comprising:
a plurality of radial magnetic force generation means for supporting a rotor for exhausting gas in a radial direction in a non-contact manner by using a magnetic force; and
a radial displacement detection means for detecting displacement of the rotor in the radial direction, wherein
two of the radial magnetic force generation means are provided on an outlet port side with respect to a center of gravity of the rotor in an exhaust direction of the gas,
the radial magnetic force generation means disposed on an inlet port side is controlled based on a detection value of the radial displacement detection means, and
the radial displacement detection means is provided on the outlet port side with respect to the center of gravity of the rotor in the exhaust direction of the gas.

5. A rotor for use in a vacuum pump, the vacuum pump comprising
a plurality of radial magnetic force generation means for supporting a rotor for exhausting gas in a radial direction in a non-contact manner by using a magnetic force; and
a radial displacement detection means for detecting displacement of the rotor in the radial direction, wherein
the rotor has a center of gravity located on an inlet port side with respect to two of the radial magnetic force generation means in an exhaust direction of the gas,
the radial magnetic force generation means disposed on the inlet port side is controlled based on a detection value of the radial displacement detection means, and
the radial displacement detection means is provided on an outlet port side with respect to the center of gravity of the rotor in the exhaust direction of the gas.

6. The magnetic bearing device according to claim 4 , wherein a first radial magnetic force generation means disposed on the inlet port side of the exhaust direction of the gas actively supports the rotor, and a second radial magnetic force generation means disposed on the outlet port side of the exhaust direction of the gas passively supports the rotor.

7. The magnetic bearing device according to claim 6 , wherein a center of the first radial magnetic force generation means and a center of the radial displacement detection means are arranged on the same plane across an axis of the rotor.

8. The rotor according to claim 5 , wherein a first radial magnetic force generation means disposed on the inlet port side of the exhaust direction of the gas actively supports the rotor, and a second radial magnetic force generation means disposed on the outlet port side of the exhaust direction of the gas passively supports the rotor.

9. The rotor according to claim 8 , wherein a center of the first radial magnetic force generation means and a center of the radial displacement detection means are arranged on the same plane across an axis of the rotor.

Assignees

• Edwards Japan Ltd

Inventors

• Kawashima Toshiaki

Classifications

• F16C2233/00

  Monitoring condition, e.g. temperature, load, vibration · CPC title

• F16C32/0408

  Passive magnetic bearings · CPC title

• F16C2360/00

  Engines or pumps · CPC title

• F16C2360/45

  Turbo-molecular pumps · CPC title

• F04D29/668

  damping or preventing mechanical vibrations · CPC title