Classifications

• • 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
  • F16C32/0474—Active magnetic bearings for rotary movement
  • F16C32/0493—Active magnetic bearings for rotary movement integrated in an electrodynamic machine, e.g. self-bearing motor
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D17/00—Radial-flow pumps, e.g. centrifugal pumps; Helico-centrifugal pumps
  • F04D17/08—Centrifugal pumps
  • F04D17/10—Centrifugal pumps for compressing or evacuating
  • F04D17/12—Multi-stage pumps
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D25/00—Pumping installations or systems
  • F04D25/02—Units comprising pumps and their driving means
  • F04D25/06—Units comprising pumps and their driving means the pump being electrically driven
  • F04D25/0606—Units comprising pumps and their driving means the pump being electrically driven the electric motor being specially adapted for integration in the pump
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D29/00—Details, component parts, or accessories
  • F04D29/05—Shafts or bearings, or assemblies thereof, specially adapted for elastic fluid pumps
  • F04D29/056—Bearings
  • F04D29/058—Bearings magnetic; electromagnetic
• • 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
  • F16C2380/00—Electrical apparatus
  • F16C2380/26—Dynamo-electric machines or combinations therewith, e.g. electro-motors and generators

Definitions

• Rotodynamic machine for conveying a fluid
• the invention relates to a rotodynamic machine for conveying a fluid, in particular a turbomachine or a centrifugal pump, according to claim 1 and a method for operating a rotodynamic machine according to claim 12.
• a bearingless motor can, for example, be designed similar to a synchronous motor in that the rotor has a permanent magnet running in the radial direction and the stator has a rotating field winding, also referred to as a drive winding, for generating a rotating field which drives the rotor rotating about its axis of rotation.
• the stator has a control winding in order to control the position of the rotor in a plane running perpendicular to the axis of rotation, the position of the rotor or the magnetic flux being detected by sensors and the control winding being controlled via a control device in such a way that the rotor in the plane perpendicular to the axis of the stator is held in the stator without contact.
• a so-called bearingless motor designed in this way has a drive winding with a number of pole pairs p and a control winding with a number of pole pairs p + 1 or p-1.
• the bearingless motor can also be designed as an induction motor or an asynchronous motor, the rotor being designed, for example, as a squirrel-cage rotor with a short-circuited cage, so that an induced current can be generated in the squirrel-cage rotor by alternating magnetic fields.
• the rotodynamic machine according to the invention such as a turbo machine or a centrifugal pump, comprises at least one drive and bearing device, which device is designed as an electrical machine with a magnetically mounted rotor, the windings which effect the torque and the magnetic bearing force are arranged together in a stator, and a reluctance motor or an induction motor or an asynchronous motor.
• the rotor of the bearingless motor is held in contact-free manner in the stator at least in a plane running perpendicular to the axis of rotation by magnetically acting forces.
• the electromagnetic coils can be controlled such that the position of the rotor in a plane running perpendicular to the axis of rotation of the rotor can be actively influenced.
• the position of the rotor is monitored by sensors and the electromagnetic coils are controlled in a controllable manner with a correspondingly configured control device such that the rotor is held in the stator without contact with respect to the planes running perpendicular to the axis of rotation of the rotor.
• a corresponding actuation of the electromagnetic coils of the stator can generate a torque on the rotor or the rotor, so that the rotor is rotated about its axial axis.
• the rotor of such a so-called bearing-free motor can thus be actively controlled with regard to three degrees of freedom, namely the position in the x and y directions and the rotation about its axis.
• a bearing-free motor having these properties can be designed by different construction forms.
• a bearingless motor can be considered a
• Reluctance motor can be configured in that the rotor is designed, for example, in a cross shape, and the stator is designed from a plurality of coils which can be controlled individually and can be driven in the radial direction and are arranged in the circumferential direction around the rotor.
• Coils can be controlled in such a way that the rotor and thus the entire shaft are held in suspension with respect to a plane running perpendicular to the axis of rotation, and the rotor can also be driven to rotate about its axis of rotation - 6 -
• turbomachine can be completely encapsulated in a housing, since the drive and bearing device effects both the bearing of the shaft and the drive of the shaft. It is therefore no longer necessary to have the shaft protrude from the housing in order to drive the shaft of the turbomachine or of the centrifugal pump by means of a drive device arranged outside the housing.
• FIG. 1 shows a turbomachine or a centrifugal pump with two drive and bearing devices
• FIG. 2 shows a turbomachine or a centrifugal pump with two drive and bearing devices and symmetrically arranged compression wheels or impellers;
• FIG. 3 shows a further turbomachine with a plurality of compression wheels
• 5a shows a further exemplary embodiment of an axial bearing
• Fig. 6 is a schematic cross section through a
• Stator of a drive and bearing device and a corresponding control device wherein the rotor forms part of the shaft of the turbomachine, and wherein a control device that controls the two windings is provided, such that the one winding can generate a magnetic load-bearing force acting on the rotor in order to keep the shaft in the radial direction without contact, and that a torque acting on the rotor can be generated with the other winding.
• This rotodynamic machine such as a turbo machine or a centrifugal pump has the advantage that the drive and bearing device, which, among other things, generates the magnetic load-bearing capacity for the shaft, can be designed to be relatively wide or long in the direction of the shaft. This resulting, relatively wide and thus large storage area allows higher static and dynamic loads to be borne as well as to compensate for dynamically changing load components. Thanks to the large bearing surface, relatively large bearing forces can be generated, so that the control device that drives the drive and bearing device controls the
• Load capacity can be specified and / or changed according to the state of the turbomachine or the centrifugal pump.
• An advantage of the invention can be seen in the fact that the shaft of the rotodynamic machine, such as a turbomachine or a centrifugal pump with at least two drive and bearing devices distributed over the shaft, can be held without contact in the radial direction. Two or more compressor wheels or impellers can be arranged next to one another on the shaft. Another advantage can be seen in the fact that the drive and bearing device allows the dynamic behavior of the shaft to be influenced, which is why a plurality of compressor wheels and drive - 8th -
• the principle of operation of the drive and bearing device 1 is designed as a synchronous or asynchronous induction machine, with three-phase windings arranged in the stator.
• the stator winding consists of two galvanically separated three-phase windings 15, 16 with the number of pole pairs pl and p2.
• the number of pole pairs p 1 and p 2 of the two three-phase windings 15, 16 forming the stator winding differ by one.
• the two different-pole windings 15, 16 can be arranged in the stator radially one above the other or nested, i.e. with coils belonging to one or the other winding alternately in the circumferential direction.
• the torque required to drive the rotor 4b is generated by the winding 15 which has the same number of pole pairs as the rotor 4b.
• the rotor 4b is designed as a squirrel-cage rotor. No drive torque is generated by the rotating field of the other winding 16, since in
• Runner 4b lacks a corresponding number of pole pairs. Due to the interaction of the two rotating poles with different poles, but excited by the control device 7 with the same frequency, rotating in the same direction, a spatially fixed, one-sided magnetic tensile force is caused on the rotor 4b in the air gap of the drive and bearing device 1, which serves to support it. The amount and the direction of the magnetic bearing force can be adjusted by changing the size and the phase position of the voltages feeding the windings 15, 16 with respect to one another.
• the drive and bearing device 1 can be configured as a synchronous machine, the rotor 4b being designed as a permanent magnet or reluctance rotor Fig. 7 shows a cross section through a radial bearing.
• FIG. 1 schematically shows a turbomachine 2, which, encapsulated in a pressure-resistant housing 8, has a common shaft 4 as well as two compression stages and two drive and bearing devices 1.
• the pressure-resistant housing 8 is dimensioned according to the internal pressure of the compression stages. For the sake of clarity, only the two compressor wheels 3 of the compression stages are shown, which are firmly connected to the shaft 4.
• the two drive and bearing devices are provided.
• Bearing devices 1 are arranged in the area of the end of the shaft 4 and have the task of contactlessly supporting the rotors 4a and thus also the shaft 4 fixedly connected to the rotors 4a in the radial direction by magnetically acting forces and driving the shaft 4.
• the drive and bearing device 1 has a rotor 4 a, which forms part of the shaft 4.
• the mass flow 9a to be compressed enters the interior of the housing 8 via an inlet opening 8a, the mass flow 9b flowing through the compression wheels 3 leaving the housing 8 again via the outlet opening 8b as an emerging mass flow 9c.
• Each drive and bearing device 1 is designed as an electrical machine with a magnetically mounted rotor 4a, two windings 15, 16 which effect the torque and the magnetic bearing force being arranged in the stator of the drive and bearing device.
• the rotor 4a forms part of the shaft 4 of the turbomachine 2.
• the two windings 15, 16 are controlled by a control device 7 in such a way that one winding 16 can generate a magnetic load-bearing force acting on the rotor 4a, around the shaft 4 in a radial direction Direction to keep contactless, and that with - 10 -
• FIG. 1 also schematically shows an exemplary embodiment of a centrifugal pump 2a, the shaft 4 carrying two impellers 3c which are spaced apart in the axial direction.
• the shaft 4 is held and driven contactlessly by the two drive and bearing devices 1.
• the axial bearing 13 has an interior space 13c to which a pressure p can be applied, as well as one
• a dry gas seal 13e is arranged toward the shaft 4 between the housing wall of the interior 13c and the disk 13d.
• the axial position of the shaft 4 is detected by a sensor and the pressure p of a fluid is regulated on the basis of the axial bearings of the shaft in such a way that an axial thrust is generated on the shaft 4 in order to hold the shaft 4 in a predeterminable position.
• an axial bearing with the same technical effect namely to hold the shaft 4 in a predeterminable position, can be achieved in that a floating ring seal with a corresponding liquid is arranged instead of the dry gas seal.
• the dry gas seal is thus replaced by a so-called wet seal.
• the impellers 3 are firmly connected to the shaft 4.
• the drive and bearing device 1 can also be designed as an asynchronous machine, the rotor 4b having one or more short-circuited loop or wave winding or a winding closed with resistors, the number of pole pairs pl of the number of pole pairs pl of the winding 15.
• the winding can in particular be arranged in a sinusoidal distribution on the rotor 4b.
• 6 also shows two sensors 6 arranged in the drive and bearing device 1 for detecting the position of the rotor 4a. The sensors are connected to the control device 7 via electrical lines 6a.
• the rotor 4a rotates at an angular velocity ⁇ , or a torque M is caused by the winding 15 on the rotor 4a.
• FIG. 1 An axial bearing which compensates for the forces which are caused by the compressor wheels 3 and run in the axial direction in order to keep the shaft 4 stationary in the axial direction. Also not shown is the usual compensation of the axial forces by an appropriately sized one
• Compensating piston. 5 shows such a thrust bearing 13, which in the exemplary embodiment shown is designed as a magnetic thrust bearing 13, with a disk 13a, electromagnets 13b and sensors for detecting the axial position of the shaft 4.
• Different thrust bearings can be used for the axial bearing of the shaft 4.
• further axial bearings are suitable.
• the drive and bearing device 1 has a certain axial bearing capacity per se.
• the drive and bearing device 1 can be configured with a conical rotor 4a and a correspondingly adapted stator, which is used in FIG - 12 -
• FIG. 3 shows a further exemplary embodiment of a turbomachine 2 with a shaft 4 and a plurality of drive devices 1 and 12 arranged in series
• Compressor wheels 3 which all have a common shaft 4.
• the position of the shaft 4 is detected by sensors 6 and the windings 15, 16 of the drive and bearing device 1 are controlled by the control device 7 such that the shaft 4 is at least radial
• the rotor dynamic behavior of the shaft 4 can be influenced via the windings 15, 16 during the operation of the turbomachine 2 by the
• Windings 15, 16 generated, magnetically acting forces can be varied. These forces can be influenced, for example, in the opposite direction to gravity.
• the winding 15, 16 can also be controlled in such a way that the magnetically induced force vector is generated by the
• Control device 7 specifies a radially extending direction, or that the orientation of the radially extending force vector is changed over time.
• the amount of the force vector can also be changed. Since the position of the shaft 4 can be measured with sensors 6, the
• Windings 15, 16 can be controlled via a control device 7 such that the rotor-dynamic behavior of the shaft 4 or the turbomachine can be influenced.
• the turbomachine 2 has a housing 8, which is designed such that all fixed and rotating parts are arranged encapsulated in the interior of the housing 8.
• the entering mass flow 9a reaches the interior of the housing 8 through an inlet opening 8a
• Compaction wheels 3 are firmly connected to one another to form a common shaft 4.
• the common shaft 4 can be mechanically separated by the rotor 4a and the shaft 4b being releasably connected to one another by mechanical means.
• the entire shaft 4 with compression wheels 3 attached to it is supported in a contactless manner by the two drive and bearing devices 1 arranged in the end region of the shaft 4.
• the torque caused on the shaft 4 is also generated by the drive and bearing devices 1.
• the drive and bearing devices 1 can be controlled such that the torque is generated either by only one or by both drive and bearing devices 1, with two torque-generating drive and bearing devices 1, the total torque in any ratio to the individual drive and Storage devices 1 can be divided.
• Fig. 2 shows a further turbo machine 2 or a centrifugal pump 2a with two drive and bearing device 1 arranged directly next to one another with a common shaft 4 with rotor 4a and compression wheels 3 or impellers 3c arranged symmetrically on both sides, which are driven by the drive and bearing device 1 and are stored contactless at least in the radial direction.
• the two compression wheels 3 or impellers 3c are arranged against one another on the shaft 4, which has the advantage that the forces running in the axial direction are mutually compensated for at least approximately.
• the drive and bearing device 1 can be designed and controlled in such a way that it can generate a certain controllable axial force, so that in the exemplary embodiment according to FIG. 2 no additional axial bearing may be required.
• the compression wheel 3 or the impeller 3c points for the conveyed - 14 -
• a liquid or a gas 22, e.g. Nitrogen to cool the drive and storage device 1 and to keep the corrosive medium away.
• the device 20, 21 is flowed around from the outside by the corrosive medium 9b, so that the drive and bearing device 1 is arranged protected from this medium 9b.
• FIG. 4 shows a further exemplary embodiment of a multi-stage process compressor with a common shaft 4 and a plurality of compressor wheels 3 as well as drive and bearing devices 1.
• a control arrangement with control device 7 is shown.
• the state of the turbomachine 2 is detected using sensors 6.
• the sensors 6 can, for example, detect the position of the shaft 4 with respect to the stator of the drive device 1, or the position of the shaft 4 in the case of a compressor stage 3 and the angular velocity of the shaft 4.
• the signals from the sensors 6 are fed to a control device 7 via electrical lines 6a.
• the drive and bearing devices 1 are controlled via electrical lines 7a, 7b in accordance with the specifications of the control device 7.
• a magnetic radial bearing 12 is also arranged, with a winding 19 for generating a load capacity acting on the shaft 4.
• the radial bearing 12 is connected to the control device 7 via electrical lines 12a.
• the deflection or the dynamic behavior of the shaft 4 can be influenced in a wide range by an appropriate arrangement and control of the drive and bearing devices 1 and any radial bearings 12 that may be arranged.
• the drive and bearing devices 1 and / or the magnetic radial bearings 12 are controlled by the control device 7 such that the rotor dynamic behavior as a mass flow 9b, a plurality of compressor wheels 3, enters an cooling device 10 via an outlet opening 8c, where the cooled mass flow 9e is in turn fed via an inlet opening 8d as an incoming mass flow 9f to a further compressor wheel 3, and then via an outlet opening 8b as an emerging mass flow 9c to leave the turbomachine 2.
• Intercooling with a cooler 10 has the advantage that the volume of the mass flow can be reduced.
• An advantage of the embodiment according to FIG. 3 is that the housing 8 has no further openings apart from the openings 8a, 8b, 8c, 8d.
• the openings 8a, 8b, 8c, 8d mentioned can be connected in a completely sealed manner to further supply and discharge lines by means of correspondingly shaped connecting pieces.
• a further advantage of the embodiments according to FIGS. 1 to 3 can be seen in the fact that the shaft 8 located inside the housing 8 makes the pressurized housing 8 completely sealable, and that the turbomachine 2 can be operated oil-free and in particular the shaft 4 is stored oil-free.
• Corresponding sealing devices between housing 8 and shaft 4 are required at the passage point. Dry gas seals are particularly suitable as such sealing devices.
• This device 20 is in the form of a toroidal sleeve 20 with seals on the shaft 4 and with an inlet and outlet opening 21 - 16 -
• the shaft 4 is influenced, in particular in such a way that the natural vibrations of the rotor can be actively damped individually at axially different locations.
• the electrical leads 7a, 7b, 12a and the electrical conductors 6a are guided through the housing 8 through gas-tight bushings (not shown in all the figures) and are supplied to the control device 7 outside the housing 8.
• Fig. 7 shows a cross section through a
• Embodiment of a radial bearing 12 which has a laminated core 17 with magnetic poles 17a, 17b arranged distributed in the circumferential direction. Furthermore, the shaft 4 and the magnetic flux 18 running over the bleck packet 17 and the shaft 4 are shown. By means of electrical windings 19 acting on the laminated core 17, of which only a single one is shown, a radial force acting on the shaft 4 can be generated by appropriate control. This force can be used for the contact-free mounting of the shaft 4 or also for the compensation of forces acting dynamically on the shaft 4.
• one of the two drive and bearing devices 1 can each be replaced by a radial bearing 12.
• the common shaft 4 can also be subdivided, for example in such a way that the shaft 4 is severed between the radial bearing 12 and the compressor wheel 3 arranged on the right, and the turbomachine thus has two separate shafts 4.
• Rotodynamic machine characterized in that the torque-generating winding (15) has a number of pole pairs n, and that the magnetic bearing force-causing winding (16) has a number of pole pairs n + 1 or n-l.
• Rotodynamic machine characterized in that at least one compressor wheel (3) or one impeller (3c) is arranged on the shaft (4).
• Rotodynamic machine characterized in that the rotor (4a) is designed as a reluctance, a permanent magnet or an electrically excited rotor (4a).
• Rotodynamic machine characterized in that the rotor (4a), the stator and the electrical windings (15, 16) are mutually configured in such a way, and that the electrical windings (15, 16) are of such
• a control device (21) can be controlled such that the rotor (4a) of the bearingless motor (20) can be driven according to the functional principle of a reluctance motor, a synchronous motor or an induction motor.
• Rotodynamic machine characterized in that the rotor (4a) has a multi-phase winding with a number of pole pairs n, the winding being arranged in particular sinusoidally distributed and being short-circuited or terminated with resistors.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Structures Of Non-Positive Displacement Pumps (AREA)
• Magnetic Bearings And Hydrostatic Bearings (AREA)
• Connection Of Motors, Electrical Generators, Mechanical Devices, And The Like (AREA)

Applications Claiming Priority (3)

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• 1996
  • 1996-10-04 US US09/051,259 patent/US6043580A/en not_active Expired - Fee Related
  • 1996-10-04 WO PCT/CH1996/000350 patent/WO1997013986A1/de not_active Application Discontinuation
  • 1996-10-04 JP JP9514595A patent/JPH11513558A/ja active Pending
  • 1996-10-04 CZ CZ19981040A patent/CZ293543B6/cs not_active IP Right Cessation
  • 1996-10-04 EP EP96931718A patent/EP0853735A1/de not_active Withdrawn
  • 1996-10-04 CA CA002233998A patent/CA2233998C/en not_active Expired - Fee Related

Non-Patent Citations (1)

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