Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K7/00—Arrangements for handling mechanical energy structurally associated with dynamo-electric machines, e.g. structural association with mechanical driving motors or auxiliary dynamo-electric machines
  • H02K7/08—Structural association with bearings
  • H02K7/09—Structural association with bearings with magnetic bearings
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
  • F16C32/00—Bearings not otherwise provided for
  • F16C32/04—Bearings not otherwise provided for using magnetic or electric supporting means
  • F16C32/0406—Magnetic bearings
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
  • F16C32/00—Bearings not otherwise provided for
  • F16C32/04—Bearings not otherwise provided for using magnetic or electric supporting means
  • F16C32/0406—Magnetic bearings
  • F16C32/044—Active magnetic bearings
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K11/00—Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection
  • H02K11/20—Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection for measuring, monitoring, testing, protecting or switching
  • H02K11/21—Devices for sensing speed or position, or actuated thereby
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K5/00—Casings; Enclosures; Supports
  • H02K5/24—Casings; Enclosures; Supports specially adapted for suppression or reduction of noise or vibrations
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K7/00—Arrangements for handling mechanical energy structurally associated with dynamo-electric machines, e.g. structural association with mechanical driving motors or auxiliary dynamo-electric machines
  • H02K7/04—Balancing means
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K2207/00—Specific aspects not provided for in the other groups of this subclass relating to arrangements for handling mechanical energy
  • H02K2207/03—Tubular motors, i.e. rotary motors mounted inside a tube, e.g. for blinds
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K2213/00—Specific aspects, not otherwise provided for and not covered by codes H02K2201/00 - H02K2211/00
  • H02K2213/12—Machines characterised by the modularity of some components

Definitions

• the disclosure relates generally to rotating electric machines. More particularly, the disclosure relates to an electric machine system that can be adapted to different mechanical loads. Furthermore, the disclosure relates to a product set for implementing an electric drive.
• the working machine may direct static and/or time varying axial and/or radial forces to the shaft of the electric machine.
• the working machine can be for example a compressor, a turbine, a pump, or some other mechanical device which is run by an electric motor or which runs an electric generator.
• the above-mentioned axial and/or radial forces directed to the shaft of the electric machine are dependent on properties of the working machine. Therefore, different working machines having a same mechanical power may direct significantly different radial and/or axial forces to the shaft of a connected electric machine.
• the bearings of an electric machine need to be suitable for carrying different static and/or time varying radial and/or axial forces in order that the electric machine would be compatible with different working machines.
• An electric machine system that can act as a motor or as a generator.
• An electric machine system according to the invention comprises an electric machine that comprises:
• stator comprising a frame structure and an electromagnetically active part inside the frame structure
• a rotor comprising a shaft and an electromagnetically active part for producing torque in co-operation with the electromagnetically active part of the stator
• the electric machine system further comprises a magnetic bearing module arranged to support the shaft and attached to an outer surface of the frame structure so that the frame structure and the magnetic bearing module are axially successive.
• the magnetic bearing module is a replaceable component which is non-destructively detachable from the frame structure.
• the electric machine can be adapted to different working machines by selecting a suitable magnetic bearing module.
• the above-mentioned bearings of the electric machine may comprise for example magnetic bearings. It is however also possible that a magnetic bearing module of the kind mentioned above is used for adapting an electric machine having bearings other than magnetic bearings, e.g. gas bearings, to be compatible with a working machine.
• a product set according to the invention comprises an electric machine that comprises:
• stator comprising a frame structure and an electromagnetically active part inside the frame structure
• a rotor comprising a shaft and an electromagnetically active part for producing torque in co-operation with the electromagnetically active part of the stator
• the product set further comprises:
• first magnetic bearing module for supporting the shaft and attachable to an outer surface of the above-mentioned frame structure so that the frame structure and the magnetic bearing module are axially successive and non- destructively detachable from each other
• the second magnetic bearing module for supporting the shaft and attachable to a same place on the outer surface of the frame structure as the first magnetic bearing module so that the frame structure and the second magnetic bearing module are axially successive and non-destructively detachable from each other, the second magnetic bearing module having force-generating magnetic elements dimensioned differently than corresponding force-generating magnetic elements of the first magnetic bearing module.
• figure 1 illustrates an electric machine system according to an exemplifying and non- limiting embodiment of the invention
• figures 2a and 2b illustrate a product set according to an exemplifying and non- limiting embodiment of the invention for implementing an electric drive.
• FIG. 1 shows a schematic section view of an electric machine system according to an exemplifying and non-limiting embodiment of the invention.
• the section plane is parallel with the yz-plane of a coordinate system 199.
• the electric machine system comprises an electric machine 100 that comprises a stator 101 and a rotor 104.
• the stator 101 comprises a frame structure 102 and an electromagnetically active part 103 inside the frame structure 102.
• the electromagnetically active part 103 may comprise for example a ferromagnetic core structure and multiphase windings installed in slots of the ferromagnetic core structure.
• the rotor 104 comprises a shaft 105 and an electromagnetically active part 106 for producing torque in co-operation with the electromagnetically active part 103 of the stator.
• the electromagnetically active part 106 of the rotor 104 may comprise for example permanent magnets, wound windings, a cage winding and/or other electrically conductive structures, and/or ferromagnetic structures providing saliency.
• the electric machine 100 can be for example an electrically excited synchronous machine, a permanent magnet machine, an induction machine, or a reluctance machine.
• the shaft 105 of the electric machine 100 is coupled to a working machine 124 with the aid of a coupling 123.
• the working machine 124 can be for example a compressor, a turbine, a pump, or some other mechanical device which is run by the electric machine 100 when the electric machine acts as a motor or which runs the electric machine 100 when the electric machine acts as a generator.
• the electric machine 100 comprises bearings 107, 108, and 109 which are located inside the frame structure 102 of the stator 101 .
• the bearings 107-109 are arranged to support the rotor 104 rotatably with respect to the stator 101 .
• the bearings 107 and 108 are radial magnetic bearings which are located, in the axial direction, on opposite sides of the electromagnetically active part 106 of the rotor.
• the bearing 109 is an axial magnetic bearing that comprises a rotor-disc 120.
• the electric machine 100 further comprises position sensors 1 17 and 1 18 for producing position signals which are indicative of the position of the rotor 104 with respect to a reference position in axial and radial directions.
• an electric machine of an electric machine system comprises magnetic bearings different from those illustrated in figure 1 .
• the magnetic bearings may comprise for example conical magnetic bearings.
• the electric machine 100 advantageously further comprises touchdown bearings, e.g. ball or sliding bearings, for carrying the rotor in a case of failure of the magnetic bearings.
• the touchdown bearings are not shown in figure 1 .
• an electric machine of an electric machine system according to an exemplifying and non-limiting embodiment comprises some other bearings than magnetic bearings, e.g. gas bearings.
• the electric machine system further comprises a magnetic bearing module 1 10 which is arranged to support the shaft 105 and attached to an outer surface of the frame structure 102 of the electric machine 100 so that the frame structure and the magnetic bearing module are axially successive.
• the magnetic bearing module 1 10 is a replaceable component which is non-destructively detachable from the frame structure 102.
• the electric machine 100 can be adapted to different working machines by selecting a suitable magnetic bearing module.
• the magnetic bearing module 1 10 may comprise one or more touchdown bearings, e.g. ball or sliding bearings, for carrying the shaft in a case of failure of the magnetic bearings of the magnetic bearing module 1 10. The touchdown bearings are not shown in figure 1 .
• the frame structure 102 comprises a tubular part 1 1 1 surrounding the electromagnetically active part 103 of the stator and an end-shield 1 12 attached to the tubular part and having an aperture for the shaft 105.
• the magnetic bearing module 1 10 is attached to the end-shield 1 12.
• the magnetic bearing module 1 10 comprises a radial magnetic bearing 1 13 and an axial magnetic bearing 1 14 having a rotor-disc 1 15. Furthermore, the magnetic bearing module 1 10 comprises a position sensor 1 16 for generating a position signal indicative of a radial position of the shaft with respect to a reference position fixed to the magnetic bearing module and/or an axial position of the shaft with respect to a reference position fixed to the magnetic bearing module.
• An electric drive comprising the electric machine system shown in figure 1 comprises a controller system 130 for controlling the magnetic bearings 107-109, 1 13, and 1 14 based on the position signals produced by the position sensors 1 16, 1 17, and 1 18.
• the magnetic bearings of the magnetic bearing module 1 10 and the magnetic bearings of the electric machine 100 can be controlled according to a multivariable control so that there are connections between the levitation control loops of the magnetic bearing module 1 10 and the levitation control loops the electric machine 100. It is also possible that the magnetic bearing module 1 10 is controlled with its own levitation control loop which is separate from the levitation control loops of the electric machine 100.
• the magnetic bearings of the magnetic bearing module 1 10 and the magnetic bearings of the electric machine 100 are advantageously controlled in a coordinated way so as to avoid e.g. situations in which the radial and/or axial magnetic bearings of the magnetic bearing module 1 10 act against radial and/or axial magnetic bearings of the electric machine 100.
• the magnetic bearing module 1 10 can be used for damping harmful vibrations of the shaft. The vibration damping can be done using a coordinated multivariable control for all the magnetic bearings or using a separate control for the magnetic bearing unit 1 10, if the control for the magnetic bearings 107-109 of the electric machine 100 should not be changed due the magnetic bearing unit 1 10.
• controller 130 for controlling the magnetic bearing unit 1 10 and a second controller 130b for controlling the magnetic bearings 107-109 of the electric machine 100.
• the implementation of the controller system 130 i.e. the controllers 130a and 130b, can be based on one or more analogue circuits, one or more digital processing circuits, or a combination thereof.
• Each digital processing circuit can be a programmable processor circuit provided with appropriate software, a dedicated hardware processor such as for example an application specific integrated circuit "ASIC", or a configurable hardware processor such as for example a field programmable gate array "FPGA”.
• the controller system 130 i.e. the controllers 130a and 130b, may comprise one or more memory circuits each of which can be for example a Random-Access Memory "RAM" circuit.
• Figure 2a illustrates a product set according to an exemplifying and non-limiting embodiment of the invention for implementing an electric drive.
• the product set comprises an electric machine 200 and magnetic bearing modules 210a, 210b, and 210c.
• Each of the magnetic bearing modules 210a-210c is attachable to the electric machine 200 so that the electric machine 200 and the magnetic bearing module are axially successive and non-destructively detachable from each other.
• the electric machine 200 and the magnetic bearing modules 210a-210c are presented with schematic section views where a section plane is parallel with the yz-plane of a coordinate system 299.
• the electric machine 200 comprises a stator 201 and a rotor 204.
• the stator 201 comprises a frame structure 202 and an electromagnetically active part 203 inside the frame structure.
• the rotor 204 comprises a shaft 205 and an electromagnetically active part 206 for producing torque in co-operation with the electromagnetically active part 203 of the stator.
• the electric machine 200 comprises radial magnetic bearings 207 and 208 and an axial magnetic bearing 209 for supporting the rotor 204 rotatably with respect to the stator 201 .
• the magnetic bearings 207-208 are located inside the frame structure 202.
• the above-mentioned frame structure 202 comprises a tubular part 21 1 surrounding the electromagnetically active part 203 of the stator and an end-shield 212 attached to the tubular part 21 1 and having an aperture for the shaft 205.
• Each of the magnetic bearing modules 210a-210c is attachable to the end-shield 212.
• the magnetic bearing modules 210a-210c have different force-generating magnetic elements.
• the electric machine 200 can be adapted to different requirements by selecting a suitable one of the magnetic bearing modules 210a-210c.
• the magnetic bearing module 210a comprises a radial magnetic bearing and a position sensor for producing a position signal indicative of a radial position of the shaft 205 in the axial coverage area of the magnetic bearing module 210a.
• the position sensor can be for example an inductive sensor.
• the magnetic bearing module 210a comprises a rotor element 240 that can be assembled around the shaft 205 for example with a thermal interference fit.
• the rotor element 240 comprises advantageously a laminated portion constituted by electrically insulated ferromagnetic sheets which are stacked in the axial direction. Compared to solid steel, the laminated portion reduces eddy currents which would cause power losses and disturb the operation of the radial magnetic bearing as well as the operation of the inductive position sensor.
• the magnetic bearing module 210b comprises a conical magnetic bearing 219 and a position sensor for producing a position signal indicative of the radial position of the shaft 205 in the axial coverage area of the magnetic bearing module 210a and of the axial position of the shaft 205.
• the magnetic bearing module 210b is suitable for cases in which an external mechanical system directs a unidirectional axial force to the shaft 205.
• the magnetic bearing module 210c comprises a radial magnetic bearing which is axially longer than that of the magnetic bearing module 210a.
• the magnetic bearing module 210c does not comprise a position sensor, and it is assumed that a position signal produced by a position sensor of the electric machine 200 is utilized in the control of the magnetic bearing module 210c.
• the magnetic bearing modules 210a-210c are mere examples and a product set according to an exemplifying embodiment of the invention may comprise magnetic bearing modules different from the magnetic bearing modules 210a-210c.
• a magnetic bearing module of a product set according to an embodiment of the invention may have a stator part that comprises at least two sectors that are attachable to each other to surround a shaft.
• the stator part of the magnetic bearing module can be installed without a need for a free end of the shaft.
• the magnetic bearing module 210c has a stator part that comprises two sectors that are attachable to each other to surround the shaft 205.
• Figure 2b shows the magnetic bearing module 210c when seen along the positive z-direction of the coordinate system 299.
• the sectors of the magnetic bearing module 210c are denoted with references 221 a and 221 b.

Landscapes

• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Magnetic Bearings And Hydrostatic Bearings (AREA)
• Motor Or Generator Frames (AREA)
• Connection Of Motors, Electrical Generators, Mechanical Devices, And The Like (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=62631129

Family Applications (1)

Country Status (6)

Cited By (1)

Families Citing this family (2)

Citations (3)

Family Cites Families (16)

• 2017
  • 2017-06-30 FI FI20175638A patent/FI128651B/en active IP Right Grant
• 2018
  • 2018-05-31 EP EP18731882.9A patent/EP3646447B1/en not_active Not-in-force
  • 2018-05-31 CN CN201880043886.4A patent/CN111052563B/zh active Active
  • 2018-05-31 JP JP2019572153A patent/JP7130258B2/ja active Active
  • 2018-05-31 US US16/627,051 patent/US11329530B2/en active Active
  • 2018-05-31 WO PCT/FI2018/050411 patent/WO2019002663A1/en not_active Ceased

Patent Citations (3)

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