US 12,117,009 B2
Vacuum pump including magnetic bearing and motor bearing operable as radial magnetic bearing, motor, and thrust magnetic bearing
Takahiro Mori, Kyoto (JP); Tsunehiro Inoue, Kyoto (JP); and Tomoo Ota, Kyoto (JP)
Assigned to SHIMADZU CORPORATION, Kyoto (JP)
Appl. No. 17/604,230
Filed by Shimadzu Corporation, Kyoto (JP)
PCT Filed Apr. 25, 2019, PCT No. PCT/JP2019/017724
§ 371(c)(1), (2) Date Oct. 15, 2021,
PCT Pub. No. WO2020/217407, PCT Pub. Date Oct. 29, 2020.
Prior Publication US 2022/0205449 A1, Jun. 30, 2022
Int. Cl. F04D 19/04 (2006.01); F16C 32/04 (2006.01)
CPC F04D 19/042 (2013.01) [F04D 19/048 (2013.01); F16C 32/0489 (2013.01); F16C 32/0497 (2013.01); F16C 2360/45 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A vacuum pump comprising:
a rotary body including a rotary shaft, the rotary shaft having a first end and a second end, the rotary shaft extending in an axial direction thereof, a blade support connected to the first end of the rotary shaft, the blade support having a shape extending such that an inner diameter thereof increases from the first end side toward the second end side in the axial direction of the rotary shaft, and a rotor blade provided on an outer peripheral surface of the blade support; and
a rotation mechanism including a motor configured to rotationally drive the rotary body, first and second radial magnetic bearings each configured to support the rotary body in a radial direction of the rotary shaft, and a thrust bearing configured to support the rotary body in the axial direction; wherein
the rotation mechanism includes:
a magnetic bearing unit provided around the rotary shaft between the rotary shaft and the blade support, the magnetic bearing unit having a first outer diameter, the magnetic bearing unit being operable as the first radial magnetic bearing; and
a motor unit provided around the rotary shaft on the second end side of the rotary shaft relative to the magnetic bearing unit, the motor unit having a second outer diameter larger than the first outer diameter, the motor unit being operable as both the motor and the second radial magnetic bearing, wherein
the thrust bearing includes a thrust magnetic bearing provided around the rotary shaft;
the thrust magnetic bearing includes a magnet and a thrust coil, both of which are configured to generate magnetic fluxes that pass through the rotary shaft in the axial direction, respectively,
the magnetic bearing unit is further operable as the thrust magnetic bearing, and
the magnetic bearing unit includes a first coil configured to form the first radial magnetic bearing, the thrust coil configured to form the thrust magnetic bearing, and a magnet configured to generate the magnetic flux that interacts with both a magnetic flux of the first coil and a magnetic flux of the thrust coil, and the magnet is provided in common with respect to the first coil and the thrust coil.