Vacuum pump and magnetic-bearing-integrated motor

A magnetic-bearing-integrated motor comprising:

• a rotor including a rotary shaft having an axial direction;
• and
• a magnetic-bearing-integrated stator including at least a first coil and configured to apply a rotational force to rotationally drive the rotor and a bearing force to magnetically support the rotor;
• wherein
• the rotor includes:
• a pair of spacer members;
• a support member provided on an outer circumference of the rotary shaft to receive a pressure applied in the axial direction during assembly via contact with each of the pair of spacer members;
• a permanent magnet provided so as to contact and surround an outer circumference of the support member;
• and
• a non-conductive protective ring having an annular shape, the protective ring being provided on an outer circumference of the permanent magnet in non-contact with the pair of spacer members in the axial direction;
• and
• in the axial direction of the rotary shaft, the support member has a mechanical strength higher than that of the protective ring, wherein:
• the pair of spacer members are arranged so as to sandwich the support member in the axial direction, and
• the support member, the permanent magnet, and the non-conductive protective ring are arranged in this stated order from inside in a radial direction of the rotor.

A vacuum pump comprising:

• an intake port positioned to receive a gas;
• a rotor including a rotary shaft extending in an axial direction;
• a rotor blade provided on the rotary shaft and configured to suck in the gas through the intake port;
• an exhaust port configured to output the gas;
• and
• a magnetic-bearing-integrated stator configured to apply a rotational force to rotationally drive the rotor and a bearing force to magnetically support the rotor;
• wherein:
• the rotor includes:
• a first spacer member and a second spacer member, the first spacer member having a first axial end surface and the second spacer member having a second axial end surface spaced apart from and facing the first axial end surface in the axial direction;
• a support member provided on an outer circumference of the rotary shaft and contacting the first spacer member and second spacer member, the support member being sandwiched in the axial direction between the first spacer member and the second spacer member;
• a permanent magnet provided so as to surround an outer circumference of the support member and to also be sandwiched in the axial direction between the first spacer member and the second spacer member;
• and
• a non-conductive protective ring having an annular shape, the protective ring being provided on an outer circumference of the permanent magnet to have a first axial end surface facing the first axial end surface of the first spacer member and a second axial end surface facing the second axial end surface of the second spacer member, at least one of the first axial end surface and the second axial end surface of the non-conductive protective ring being in non-contact with a corresponding first or second axial end surface of the first or second spacer member.