MAGNETIC BEARING APPARATUS

• US 20070273219A1
• Filed: 09/07/2006
• Published: 11/29/2007
• Est. Priority Date: 07/04/2003
• Status: Active Grant

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: SHIMADA, Akihiro
• Granted Patent: US 7,315,101 B2
• Time in Patent Office: Days
• US Class Current: 310/52
• CPC Class Codes: B23Q 1/70 Stationary or movable members for carrying working-spindles for attachment of tools or work B23Q1/01 takes precedence; designed to be moved by using particular mechanisms B23Q1/44
• CPC Class Codes: B23Q 11/127 for cooling motors or spindles
• CPC Class Codes: F16C 2322/39 General buildup of machine tools, e.g. spindles, slides, actuators
• CPC Class Codes: F16C 32/047 Details of housings; Mounting of active magnetic bearings
• CPC Class Codes: F16C 32/0489 with active support of five degrees of freedom, e.g. two radial magnetic bearings combined with an axial bearing
• CPC Class Codes: F16C 37/005 of magnetic bearings
• CPC Class Codes: H02K 7/083 radially supporting the rotary shaft at both ends of the rotor H02K7/086, H02K7/09 take precedence
• CPC Class Codes: H02K 7/09 with magnetic bearings
• CPC Class Codes: H02K 9/06 with fans or impellers driven by the machine shaft

Abstract

In order to obtain a magnetic bearing apparatus in which a large cooling effect is exerted by a simple configuration, fins 15 which form an air flow in a rearward direction are disposed in a rear portion and outer diameter of a rotary shaft 1, a generator 16 which converts an air flow produced by rotation of the fins 15 to a compressed vortex flow, and which has an axial through hole is fixed with being separated from the fins 15 by an appropriate gap, and a tube 20 in which the inner diameter is larger than the diameter of the through hole 19 of the generator 16, and which has a control valve 21 at the rear end is provided in rear of the generator 16. Cooling wind is produced by a driving force of the rotary shaft 1. Cooling wind flow paths 22 through which the cooling wind is to be passed, and which axially elongate are formed in the rotary shaft 1.

Claims

1. A magnetic bearing apparatus comprising:

a rotatable rotary shaft to which a radial magnetic bearing rotor and an axial magnetic bearing disc are secured;

electromagnets which are arranged with forming a small gap with respect to said radial magnetic bearing rotor and said axial magnetic bearing disc; and

a case housing them, wherein

said apparatus further comprises;

cooling wind producing means that produces cooling wind of a low temperature, and that has;

fins which are disposed on said axial magnetic bearing disc, and which produces an air flow directed in an outer radial direction of said axial magnetic bearing disc;

a supply port which is positioned in an outer circumferential portion of said fins, and through which the air flow produced by said fins is introduced and ejected as a high-speed air flow in the outer radial direction;

a generator which converts the high-speed air flow ejected from said supply port, to a vortex flow;

an air flow path through which the high-speed vortex flow produced by said generator is to flow; and

a control valve which is disposed on a side of said air flow path opposite to said generator; and

a cooling wind flow path through which the low-temperature cooling wind produced by said cooling wind producing means is to flow into said magnetic bearing apparatus.

2. A magnetic bearing apparatus according to claim 1, wherein a guide portion which guides the low-temperature cooling wind to a rotary shaft portion is disposed.

3. A magnetic bearing apparatus according to claim 1, wherein said cooling wind flow path has:

a cooling wind flow path which is disposed in said case, and through which the low-temperature cooling wind produced by said cooling wind producing means is to flow;

a guide plate which guides the cooling wind that has been passed through said cooling flow path, to a rotary shaft portion; and

a cooling wind flow path which is disposed in said rotary shaft portion, and through which the cooling wind that has been guided by said guide plate is to axially flow, thereby cooling said rotary shaft portion.

4. A magnetic bearing apparatus comprising:

a rotatable rotary shaft to which a radial magnetic bearing rotor and an axial magnetic bearing disc are secured;

electromagnets which are arranged with forming a small gap with respect to said radial magnetic bearing rotor and said axial magnetic bearing disc; and

a case housing them, wherein

said apparatus further comprises;

cooling wind producing means that produces cooling wind of a low temperature, and that has;

fins which are disposed on said axial magnetic bearing disc, and which produces an air flow directed in an outer radial direction of said axial magnetic bearing disc;

a supply port which is positioned in an outer circumferential portion of said fins, and through which the air flow produced by said fins is introduced and ejected as a high-speed air flow in the outer radial direction;

an air flow path through which the high-speed air flow ejected from said supply port is to flow;

a generator which converts the high-speed air flow ejected from said air flow path, to a vortex flow;

a tube through which the high-speed vortex flow produced by said generator is to flow; and

a control valve which is disposed on a side of said tube opposite to said generator; and

a cooling wind flow path through which the low-temperature cooling wind produced by said cooling wind producing means is to flow into said magnetic bearing apparatus.