Magnetic bearing device and fluid mechanical system

Patent metadata

Field	Value
Publication number	US-10895282-B2
Application number	US-201616325976-A
Country	US
Kind code	B2
Filing date	Aug 18, 2016
Priority date	Aug 18, 2016
Publication date	Jan 19, 2021
Grant date	Jan 19, 2021

Abstract

A controller performs, in a first mode, a first operation for controlling composite electromagnetic force of electromagnets such that a target member moves within a predetermined moving range, and a second operation for acquiring temperature drift correlation information indicative of a correlation between a reference value and an input-output characteristic of a position sensor, based on the reference value and the input-output characteristic of the position sensor in the first operation. The controller performs, in a second mode, a third operation for controlling the composite electromagnetic force of the electromagnets according to a signal level of a detection signal from the position sensor, and a fourth operation for compensating the input-output characteristic of the position sensor in the third operation, based on the temperature drift correlation information and the reference value in the third operation.

First claim

The invention claimed is:

1. A magnetic bearing device, comprising:
a magnetic bearing including a plurality of electromagnets and configured to support a target member in a contactless manner using composite electromagnetic force of the plurality of electromagnets;
a position sensor configured to output a detection signal having a signal level according to a position of the target member in a predetermined position detection direction;
a controller having a first mode and a second mode and configured to acquire a reference value that correlates with a change in an input-output characteristic of the position sensor following a change in an ambient temperature of the position sensor; and
a touchdown bearing configured to come into contact with the target member moving toward the magnetic bearing in a space between the plurality of electromagnets, thereby avoiding contact between the target member and the magnetic bearing, wherein
the controller performs
in the first mode, a movement control operation for controlling the composite electromagnetic force of the plurality of electromagnets such that the target member moves within a predetermined moving range in the predetermined position detection direction, and an information acquisition operation for acquiring temperature drift correlation information indicative of a correlation between the reference value and the input-output characteristic of the position sensor, based on the reference value and the input-output characteristic of the position sensor in the movement control operation, and
in the second mode, a magnetic levitation control operation for controlling the composite electromagnetic force of the plurality of electromagnets in accordance with the signal level of the detection signal from the position sensor, and a temperature compensation operation for compensating the input-output characteristic of the position sensor in the magnetic levitation control operation, based on the temperature drift correlation information and the reference value in the magnetic levitation control operation, and

the controller performs the movement control operation in the first mode such that the target member moves from one end to another end of a movable range in the position detection direction restricted by the touchdown bearing.

2. The magnetic bearing device according to claim 1 , wherein
the target member has an axial form,
the plurality of electromagnets include first and second electromagnets facing each other in a radial direction of the target member with the target member interposed therebetween, and third and fourth electromagnets facing each other in the radial direction of the target member with the target member interposed therebetween, the direction in which the third and fourth electromagnets face each other intersecting with the direction in which the first and second electromagnets face each other,
the position detection direction of the position sensor corresponds to the direction in which the first and second electromagnets face each other,
the touchdown bearing is a radial touchdown bearing through which the target member is inserted,
the radial touchdown bearing is configured to come into contact, on an inner peripheral surface thereof, with the target member moving in a radial direction of the radial touchdown bearing, thereby avoiding contact between the target member and the magnetic bearing, and
the controller performs the movement control operation in the first mode such that the target member moves in a circumferential direction of the radial touchdown bearing while remaining in contact with the inner peripheral surface of the radial touchdown bearing.

3. A fluid mechanical system, comprising:
the magnetic bearing device of claim 2 ;
a fluid machine;
a rotary electric machine; and
a rotation shaft coupling the fluid machine and the rotary electric machine, wherein
the magnetic bearing device is configured to support a target portion of the rotation shaft in a contactless manner using composite electromagnetic force of the plurality of electromagnets.

4. The magnetic bearing device according to claim 1 , wherein
the target member has a disk form,
the plurality of electromagnets include first and second electromagnets facing each other in an axial direction of the target member,
the position detection direction of the position sensor corresponds to a direction in which the first and second electromagnets face each other,
the touchdown bearing includes first and second thrust touchdown bearings facing each other in the axial direction of the target member with the target member interposed therebetween,
the first and second thrust touchdown bearings are configured to come into contact, on their surfaces facing each other, with the target member moving in the direction in which the first and second thrust touchdown bearings face each other, thereby avoiding contact between the target member and the magnetic bearing, and
the controller performs the movement control operation in the first mode such that the target member moves from the surface of one of the first and second thrust touchdown bearings to the surface of the other thrust touchdown bearing, the surfaces facing each other.

5. A fluid mechanical system, comprising:
the magnetic bearing device of claim 4 ;
a fluid machine;
a rotary electric machine; and
a rotation shaft coupling the fluid machine and the rotary electric machine, wherein
the magnetic bearing device is configured to support a target portion of the rotation haft in a contactless manner using composite electromagnetic force of the plurality of electromagnets.

6. A fluid mechanical system, comprising:
the magnetic bearing device of claim 1 ;
a fluid machine;
a rotary electric machine; and
a rotation shaft coupling the fluid machine and the rotary electric machine, wherein
the magnetic bearing device is configured to support a target portion of the rotation shaft in a contactless manner using composite electromagnetic force of the plurality of electromagnets.

Assignees

• Daikin Ind Ltd

Inventors

• Hirata Kazuya
• Sakawaki Atsushi

Classifications

• F16C32/0444 Primary

  Details of devices to control the actuation of the electromagnets · CPC title

• F16C2380/26

  Dynamo-electric machines or combinations therewith, e.g. electro-motors and generators · CPC title

• F16C32/0476

  with active support of one degree of freedom, e.g. axial magnetic bearings · CPC title

• F16C32/0474

  for rotary movement · CPC title

• F16C32/047

  Details of housings; Mounting of active magnetic bearings · CPC title