Compact turbomachine with magnetic bearings and auxiliary bearings

Patent metadata

Field	Value
Publication number	US-10208759-B2
Application number	US-201414224401-A
Country	US
Kind code	B2
Filing date	Mar 25, 2014
Priority date	Mar 25, 2014
Publication date	Feb 19, 2019
Grant date	Feb 19, 2019

Abstract

A turbo-machine for compressing or expanding a fluid comprises a housing, a rotary shaft, an electric machine, an impeller mounted at an end of the rotary shaft, radial magnetic bearings, an axial magnetic bearing, an axial detector, radial detectors, a control circuit, and auxiliary bearings. An auxiliary bearing is integrated within a stator portion of the axial magnetic bearing and this stator portion of the axial magnetic bearing is located opposite a rotor armature of the axial magnetic bearing. The rotor armature is made of iron or of a material which is adapted to be attracted in a magnetic field and is constituted by a rear face of the impeller.

First claim

The invention claimed is:

1. A turbo-machine for compressing or expanding a fluid, comprising:
a housing;
a rotary shaft mounted within the housing;
an electric machine associated with the rotary shaft;
at least one impeller for compressing or expanding the fluid, the at least one impeller being mounted at a first end of the rotary shaft;
radial magnetic bearings arranged to radially support the rotary shaft in a contactless manner;
at least one axial magnetic bearing;
at least one axial detector located and configured to sense the axial position of the rotary shaft;
radial detectors located and configured to sense the radial position of the rotary shaft;
a control circuit for controlling the at least one axial magnetic bearing and the radial magnetic bearings from information signals outputted by the at least one axial detector and the radial detectors;
at least one auxiliary bearing;
a first stator portion comprising a ferromagnetic core and coils; and
a first rotor armature, made of a magnetically attracted material and constituted by a rear face of the at least one impeller,
wherein the first stator portion is assembled between the housing and the auxiliary bearings, the auxiliary bearings being directly mounted to a radially interior surface of the first stator portion, the ferromagnetic core and coils of the first stator portion extending outward from the auxiliary bearings in a radial direction and the ferromagnetic core and coils of the first stator portion, the housing and the at least one auxiliary bearing each passing through a same radial plane, the housing being directly mounted to a radially exterior surface of the first stator portion,
wherein the ferromagnetic core and coils at least partially overlapping the auxiliary bearings in an axial direction,
wherein an interior diameter of the auxiliary bearings is positioned proximate an exterior surface of the rotary shaft,
wherein the first stator portion of the at least one axial magnetic bearing is located opposite and facing, in an axial direction, the first rotor armature of the at least one axial magnetic bearing.

2. The turbo-machine according to claim 1 , wherein the first rotor armature is constituted by a separate element which is mounted on the at least one impeller to constitute the rear face, the at least one impeller made of a material which is not adapted to be attracted in a magnetic field.

3. The turbo-machine according to claim 1 , wherein the first rotor armature is an integral part of the first impeller and is made of one of iron or a material adapted to be attracted in a magnetic field.

4. The turbo-machine according to claim 3 , wherein the at least one impeller has a diameter that is larger than an average diameter of the rotary shaft.

5. The turbo-machine according to claim 4 , further comprising an insert made of a non-magnetic material which is interposed between the first stator portion of the at least one axial magnetic bearing and the at least one auxiliary bearing integrated within the first stator portion of the at least one axial magnetic bearing.

6. The turbo-machine according to claim 5 , wherein the at least one auxiliary bearing is one of a ball bearing, a needle roller bearing, or a sliding bearing.

7. The turbo-machine according to claim 5 , wherein the at least one auxiliary bearing is a sliding bearing,
wherein the at least one impeller is configured to provide one of a radial compression or a radial expansion of the fluid.

8. The turbo-machine according to claim 5 , wherein the at least one auxiliary bearing is a sliding bearing,
wherein the at least one impeller is configured to provide one of an axial compression or an axial expansion of the fluid.

9. The turbo-machine according to claim 8 , further comprising:
a second impeller for compressing or expanding the fluid, the second impeller being mounted at a second end of the rotary shaft,
a second axial magnetic bearing, wherein
a second auxiliary bearing is integrated within a second stator portion of the second axial magnetic bearing and
wherein the second stator portion of the second axial magnetic bearing is located opposite a second rotor armature of the second axial magnetic bearing, the second rotor armature being made of iron or of a material adapted to be attracted in a magnetic field and constituted by a rear face of the second impeller.

10. An axial magnetic bearing for a turbo-machine for compressing or expanding a fluid, the turbo-machine comprising:
at least one impeller mounted at a first end of a rotary shaft supported in a contactless manner by radial magnetic bearings;
an axial magnetic bearing including a rotor armature and a stator portion and being adapted to be controlled by a control circuit receiving information signals outputted by at least one axial detector configured for sensing the axial position of the rotary shaft;
the rotor armature, is made of a magnetically attracted material and is constituted by a rear face of the at least one impeller;
a first stator portion comprising a ferromagnetic core and coils;
wherein the first stator portion is assembled between a housing and auxiliary bearings, the auxiliary bearing being directly mounted to a radially interior surface of the first stator portion, the ferromagnetic core and coils of the first stator portion extending outward from the auxiliary bearings in a radial direction and the ferromagnetic core and coils of the first stator portion, the housing and the auxiliary bearings each passing through a same radial plane, the housing being directly mounted to a radially exterior surface of the first stator portion;
wherein the ferromagnetic core and coils at least partially overlapping the auxiliary bearings in an axial direction;
wherein an interior diameter of the auxiliary bearings is positioned proximate an exterior surface of the rotary shaft;
wherein the stator portion of the axial magnetic bearing is located opposite the rotor armature in an axial direction.

11. The axial magnetic bearing according to claim 10 , wherein the rotor armature being made of iron or of a material which is adapted to be attracted in a magnetic field is constituted by a separate element which is mounted on the at least one impeller to constitute the rear face of the at least one impeller,
wherein the at least one impeller being made of a material which is not a magnetically attracted material.

12. The axial magnetic bearing according to claim 10 , wherein the first rotor armature being constituted by the rear face of the at least one impeller is an integral part of the first impeller which is made of a magnetically attracted material.

13. A turbo-machine for compressing or expanding a fluid, comprising:
a housing;
a rotary shaft mounted within the housing;
an electric machine associated with the rotary shaft;
at least one impeller for compressing or expanding the fluid, the at least one impeller being mounted at a first end of the rotary shaft;
radial magnetic bearings arranged to radially support the rotary shaft in a contactless manner;
at least one axial magnetic bearing;
at least one axial detector located and configured to sense the axial position of the rotary shaft;
radial detectors located and configured to sense the radial position of the rotary shaft;
a control circuit for controlling the at least one axial magnetic bearing and the radial magnetic bearings from information signals outputted by the at least one axial detector and the radial detectors;
at least one auxiliary bearing; and
a first stator portion comprising a ferromagnetic core and coils,
wherein the first stator portion

Assignees

• Carrasco Eduardo
• Helene Eric
• Skf Magnetic Mechatronics

Inventors

• Carrasco Eduardo
• Helene Eric

Classifications

• F04D29/051

  Axial thrust balancing · CPC title

• F04D29/048

  magnetic; electromagnetic · CPC title

• F04D29/622

  Adjusting the clearances between rotary and stationary parts · CPC title

• F04D17/10

  for compressing or evacuating · CPC title

• F04D25/06

  the pump being electrically driven (F04D25/08 takes precedence) · CPC title