Compressor

A compressor having a compressor housing, a compressor rotor mounted in the compressor housing, which includes a shaft and moving blades forming multiple compressor stages. Between two compressor stages a magnetic bearing and a safety bearing are arranged, which, as split bearings, are each mounted on the shaft designed as one-piece shaft.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a compressor.

2. Description of the Related Art

Compressors, in terms of the present invention, are employed in industrial plants, for example in air separation plants. Compressors comprise a compressor housing and a compressor rotor mounted in the compressor housing, which provides multiple compressor stages.

To provide a desired compression of a medium to be compressed with a compressor, a multiplicity of compressor stages, seen in the flow direction of the medium to be compressed, are arranged one behind the other are required under certain conditions, which causes a relatively long design of a shaft of the compressor rotor. Long shafts of the compressor rotor however have a tendency towards vibrations, as a result of which the compressor dynamics are negatively affected. However, in order to provide relatively long shafts of compressor rotors that are less susceptible to vibration it is nevertheless usual in practice to embody the shafts with a larger diameter, as a result of which a larger and heavier design of the compressors is brought about on the whole. Alternatively, multiple compressors are connected in series.

Both the embodiment of shafts with larger diameter and also the embodiment series-connection of multiple compressors cause high costs and are therefore disadvantageous.

SUMMARY OF THE INVENTION

There is a need for a long design of the shaft, even on compressors the compressor rotors of which increase a length of a shaft with a relatively small diameter, to ensure a high number of compressor stages, specifically without negatively affecting the compressor dynamics.

The present invention is based on creating a new type of compressor.

According to one aspect of the invention, a magnetic bearing and a safety bearing are arranged between two compressor stages, which in each case are mounted as split bearings on the shaft formed as a one-piece shaft.

According to one aspect of the invention it is proposed to form a magnetic bearing and a safety bearing between two compressor stages, wherein the magnetic bearing and the safety bearing are embodied as split bearings mounted on the one-piece shaft of the compressor rotor. By way of the magnetic bearing, vibrations of the shaft of the compressor rotor can be dampened, wherein by way of the split embodiment of magnetic bearing and safety bearing the shaft can be embodied in one piece. This provides a compressor with a multiplicity of compressor stages having a one-piece shaft for the compressor rotor, which is of long design and with a small diameter.

According to a further development of the invention, the magnetic bearing and the safety bearing are received in a common bearing housing, wherein the bearing housing in section delimits a flow path between the two compressor stages, between which the magnetic bearing and the safety bearing are arranged. Because of this, the unit of magnetic bearing and safety bearing can be particularly advantageously integrated in the compressor.

Preferentially, stator-side elements of the magnetic bearing are received on a magnetic bearing carrier and stator-side elements of the safety bearing on a safety bearing carrier, wherein the magnetic bearing carrier and the safety bearing carrier are connected to one another and are preferentially mounted in the common bearing housing via the safety bearing carrier or via the magnetic bearing carrier. Preferentially, an adjustable support element acts on the safety bearing carrier or on the magnetic bearing carrier, via which the stator-side elements of magnetic bearing and safety bearing are jointly mounted on the bearing housing and are jointly alignable relative to the shaft. This allows a simple assembly of magnetic bearing and safety bearing on the common bearing housing and in addition to this an advantageous alignment of magnetic bearing and safety bearing relative to the shaft via the common support element.

Preferentially, the magnetic bearing is an active magnetic bearing that comprises a sensor for detecting shaft vibrations and an actuator for damping shaft vibrations. With the help of an active magnetic bearing, shaft vibrations of the shaft of the compressor rotor can be particularly advantageously dampened.

According to a further development of the invention, the bearing housing is received in a recess of the compressor housing and connected to the compressor housing, wherein preferentially on an upstream side of the bearing housing, housing-side diffuser blades and on a downstream side of the bearing housing, housing-side recirculation blades are arranged. The diffuser blades and recirculation blades absorb bearing forces, discharging these into the compressor housing.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

The invention present here relates to a compressor, for example to a compressor for an industrial plant, such as for example an air separation plant.

FIGS. 1 and 2show details of a compressor10according to one aspect of the invention, wherein inFIG. 1a compressor rotor11of the compressor10is shown. The compressor rotor11is mounted via bearings12in a compressor housing13which is not shown inFIG. 1, however is visible inFIG. 2.

The compressor10comprises a shaft14and multiple moving blades15mounted on the shaft14. The moving blades15form multiple moving blade rings and thus multiple compressor stages16. In the exemplary embodiment shown inFIG. 1, the moving blades15form a total of six compressor stages16which, seen in the axial direction of the shaft14, are arranged on the shaft14one behind the other.

A magnetic bearing17and a safety bearing18are arranged between two compressor stages16, in the shown exemplary embodiment approximately in the axial centre of the shaft14between two compressor stages16. It is pointed out that the arrangement of magnetic bearing17and safety bearing18need not be necessarily arranged in the region of the axial centre of the shaft14, but this arrangement of magnetic bearing17and safety bearing18can also be moved in the direction of an axial end or an axial side of the shaft14of the compressor rotor11.

Magnetic bearing17and safety bearing18in this case are embodied as split bearings, namely split in the horizontal direction, so that the magnetic bearing17and the safety bearing18can be mounted on the shaft of the compressor rotor11formed as one-piece shaft14between two compressor stages16.

According toFIG. 2, the magnetic bearing17and the safety bearing18are received in a common bearing housing19. The bearing housing19is inserted in a recess in the compressor housing13, wherein the bearing housing19in sections delimits a flow path20between the two compressor stages16, between which the bearing housing19and thus the magnetic bearing17and the safety bearing18are arranged.

FromFIG. 2it is evident that on an upstream side of the bearing housing19, housing-side diffuser blades21and on a downstream side of the bearing housing19, housing-side recirculation blades22are arranged, which are integrated in the flow path20delimited in sections by the bearing housing19. Bearing forces which, emanating from the magnetic bearing17and safety bearing18, can be introduced into the bearing housing19, can be discharged into the compressor housing13via the housing-side diffuser blades21and housing-side recirculation blades22.

In the shown, preferred exemplary embodiment, the magnetic bearing17is embodied as an active magnetic bearing that comprises a sensor23for detecting shaft vibrations of the shaft14and an actuator24for damping the shaft vibrations. Both the magnetic bearing17and also the safety bearing18comprise rotor-side elements and stator-side elements. The rotor-side elements are assigned to the shaft14of the shaft rotor11and rotate together with the shaft14. The the stator-side elements of magnetic bearing17and safety bearing18are mounted on the stator-side bearing housing19.

The stator-side elements of the magnetic bearing17are mounted on a magnetic bearing carrier25and the stator-side elements of the safety bearing18on a safety bearing carrier26. Magnetic bearing carrier25and safety bearing carrier26in this case are connected to one another via fastening elements27which preferentially extend in the axial direction of the shaft14, wherein the same are mounted on the bearing housing19with the help of a support element27either via the magnetic bearing17or, as shown, preferentially via the safety bearing carrier26.

By way of the common support element27, which is designed as adjustable support element and inFIG. 2acts on the safety bearing carrier26, safety bearing carrier26and magnetic bearing carrier25and thus the stator-side elements of magnetic bearing17and safety bearing18can be jointly aligned relative to the shaft14of the compressor rotor11.

As already explained, the magnetic bearing17in the preferred exemplary embodiment is designed as active magnetic bearing, which comprises the sensor23and the actuator24. Stator-assemblies of the sensor23in this case are preferentially fastened to a sensor carrier28of the magnetic bearing carrier25and stator-side elements of the actuator24on an actuator carrier29of the magnetic bearing carrier25, wherein the sensor carrier28is fastened on the actuator carrier29and the actuator carrier29on the safety bearing carrier26in order to be mounted on the bearing housing19via the support element27acting on the safety bearing carrier26.

FIG. 2, furthermore, shows cables30,31, wherein a first cable31leads to the actuator24and a second cable30to the sensor23of the magnetic bearing17. Both cables30,31can be connected via connectors32,33to a control device which is not shown, which evaluates shaft vibrations detected by the sensor23and, dependent on this, activates the actuator24of the magnetic bearing17for damping the shaft vibrations.

With the invention it is possible to provide a compressor whose compressor rotor11in the axial direction has a relatively long and in the radial direction a relatively thin shaft14, in order to provide a multiplicity of compressor stages16with a compressor that is small in design, namely without negatively affecting the dynamics of the compressor rotor11. To this end, a magnetic bearing17and a safety bearing18are mounted on the one-piece shaft14of the compressor rotor11between two compressor stages16, which in each case are embodied as split bearings, in order to be able to easily mount the same between the two compressor stages16.