DE102013012341A1 - Rotor for an electric machine - Google Patents

Abstract

The present invention relates to a rotor (1) for an electric machine, comprising - an impeller (2) of bronze, in particular aluminum bronze, and - at least one at least partially hollow cylindrical outer layer (6) made of iron-containing metal, wherein the outer layer (6) is positively connected to the impeller (2).

Description

The invention relates to a rotor for an electric machine.

There are many rotors in the prior art. Most of these devices are usually not resistant to corrosion and have no optimal efficiency. The iron-containing rotor parts must therefore always be laboriously protected against corrosion.

The object of the present invention is to overcome the disadvantages of the prior art. With the present invention, the corrosion resistance should be improved and a higher efficiency should be ensured. Furthermore, the known from the prior art manufacturing steps in the manufacture of the rotor are to be reduced.

• – ein Laufrad aus Bronze, insbesondere aus Aluminiumbronze, und
• – mindestens eine zumindest teilweise hohlzylindrisch ausgebildete äußere Schicht aus eisenhaltigem Metall, wobei die äußere Schicht mit dem Laufrad formschlüssig verbunden ist.

The object is achieved by a rotor having the features of claim 1:
Rotor for an electric machine, comprising

• - An impeller made of bronze, in particular aluminum bronze, and
• - At least one at least partially hollow cylindrical outer layer formed of iron-containing metal, wherein the outer layer is positively connected to the impeller.

Advantageous developments are defined in the subclaims.

A rotor is the rotating (rotating) part of a machine or aggregate. The counterpart to the rotor in electric machines is the stator, which is understood as a fixed and immovable part.

An impeller is a moving (rotating) part of a rotor. The impeller is preferably storable by means of a shaft which extends axially in the longitudinal direction, in order to extract or supply work to flowing fluids or liquids.

Particularly preferably, the impeller is designed without a shaft. The bearing function of the rotor can then be ensured by sliding bearings on the outer diameter of the rotor and in the stator housing.

An impeller blade (impeller blade or rotor blade) is part of the impeller. Preferably, the impeller is formed einschauflig. Particularly preferably, the impeller has at least two impeller blades. Particularly preferably, the impeller blades are arranged approximately symmetrically distributed in the impeller to ensure a smooth running of the rotor.

The envisaged at least partially hollow cylindrical outer layer, which is positively connected to the impeller, helps the rotor to increase the rotational capacity and increase the efficiency.

The outer layer (iron-containing back) is preferably formed as a hollow cylinder. This design ensures a continuous sheathing of the impeller. Particularly preferably, the outer layer has a thickness of about 10% to 20%, preferably about 15% of the rotor diameter.

Preferably, the outer layer has extensions (projecting portions) in the longitudinal direction, which contribute to an improved positive connection with the bronze. The extensions are preferably formed step-like and arranged symmetrically along the hollow cylinder edge.

Particularly preferably, the outer layer has at least two annular portions. In this case, at least two annular, hollow-cylindrical outer layers are formed around the impeller, which are at a distance from each other. This design ensures a partial sheathing of the impeller. This results in an improved positive connection, because bronze can also be introduced between the annular portions.

In a further particularly preferred embodiment, the outer layer is formed like a segment. That is, that the outer layer of ferrous metal is partially formed as a hollow cylinder. In this case, the outer layer is defined by arranged in the axial longitudinal direction and cylindrically shaped sections. This results in an improved positive connection, because bronze between the cylindrically shaped sections can be introduced.

By using bronze, especially aluminum bronze, a corrosion-resistant impeller can be produced.

Preferably, in the case of the bronze, a ratio of copper to tin of between 95% / 5% and 85% / 15% is selected. At a ratio of 90% copper to 10% tin and a melting temperature of over 900 ° C, the best results for the positive connection with the ferrous metal of the outer layer have resulted.

Particularly preferably, the rotor is made of aluminum bronze. Aluminum bronze has copper, iron and nickel and the main alloying additive is about 10% aluminum. Aluminum bronzes have the advantage that they are very resistant to corrosion.

Tin bronze is also particularly preferably used for the rotor. Tin bronze has copper, tin and lead. Tin bronzes have the advantage that they are also very resistant to corrosion.

In a further particularly preferred embodiment of the invention also resistant plastics and stainless steel can be used as materials for the impeller.

Preferably, the impeller has a cylindrically formed layer of bronze, which radially bounds the impeller. Due to the radial limitation a positive connection with the outer layer is better accessible. The thickness of the layer corresponds to approximately 5% to 25%, preferably 15% of the rotor diameter.

Particularly preferably, the outer layer with the impeller over the impeller radially encapsulating layer shed. Here, a stable and positive connection between the impeller and the outer layer can be produced.

In a preferred embodiment of the present invention, the radially extending outer layer of steel, preferably made of calmed steel, more preferably from S355J2 + N, according to EN 10025 ; DIN 17100 Old national: St52-3N.

Due to the higher melting point of the tempered steel, the casting of the bronze merely involves heating, without melting, of the steel. This results in a positive connection of the bronze with the steel. The shrinkage / shrinkage of the bronze during cooling of the melt also leads to a frictional connection.

Preferably, the iron-containing metal to other metals or metal alloys, such as copper, tin, nickel, lead, manganese and / or brass. As a result, physical properties such as hardness, melting point, weight, corrosion resistance, etc. can be influenced.

Preferably, the steel St52-3N has alloying elements such as nickel and manganese.

In a further preferred embodiment of the present invention, the outer layer on its inner side (inner circumferential surface) depressions, elevations, beads, and / or journals. As a result, the liquid bronze can penetrate into the hollow regions of the outer layer, so as to achieve an improved form-fitting and force-fit.

Preferably, the outer layer has extensions (projecting portions) in the axial direction. These contribute to an improved positive connection with the bronze after the casting of the bronze. Preferably, the extensions are step-like and arranged symmetrically along the hollow cylinder edge. Preferably, after the casting on the impeller, suitably configured receiving possibilities for the extensions of the outer layer are formed so as to create a positive connection with the outer layer.

In a further preferred embodiment of the present invention, the outer layer on its outer side recesses, recesses and / or beads. The recesses, recesses and / or beads on the outside (outer circumferential surface) are used to hold magnets.

Preferably, magnets in the recesses, recesses and / or beads can be introduced. The holding / fixing of the magnets is achieved on the one hand by the attraction (magnetism) between the iron-containing outer layer and the corresponding magnets. On the other hand, with adhesives, preferably resinous adhesives, an additional holding force can be generated, which fixes the magnets on the outer layer.

Particularly preferably, the magnets are permanent magnets.

Particularly preferably, the outer layer by means of a cover air-tight and waterproof sealable / closable. Through this cover, rusting of the corrosion-prone iron / steel can be prevented. Preferably, the cover is tubular and is preferably made of plastic material or stainless steel.

In a further embodiment of the invention, the rotor is used in an electric machine in a pump, preferably in water turbines.

In this case, preferably a stator is used, which is used as a stationary, immovable part of the respective device as a counterpart to the rotor.

• – Einbringen einer zumindest teilweise hohlzylindrischen äußeren Schicht aus eisenhaltigem Metall in eine Gussform,
• – Eingießen von Bronze in die Gussform,
• – Abkühlen der Bronze,
• – Entnahme des fertig vergossenen Rotors und
• – spanende Bearbeitung des Rotors.

Furthermore, the object is achieved by a method having the features of claim 10: A method for producing a rotor, comprising the steps

• Introducing an at least partially hollow-cylindrical outer layer of ferrous metal into a casting mold,
• Pouring bronze into the mold,
• - cooling the bronze,
• - Removal of the finished potted rotor and
• - Machining the rotor.

A variety of manufacturing steps, as they are known from the prior art, thus falls away.

Preferably, the melting point of the bronze, corresponding to the ratio of copper to tin, between about 232 ° C and 1084 ° C. Due to the higher melting point of the iron-containing metal back, the casting of the bronze merely involves heating, without melting, of the steel.

The outer steel layer maintains its position in the mold. Only the bronze is let into the mold to spread around the steel.

The pouring of bronze into the mold is preferably carried out within a short period of 2 to 5 minutes, more preferably within 3 minutes, to effect uniform cooling of the potted bronze.

Preferably, a mechanical reworking of the finished molded rotor takes place with corresponding devices so that, for example, unevenness or disturbing cast residues can be removed from the rotor.

• – Einbringen von Magneten in Ausnehmungen, Aussparungen und/oder Sicken entlang der Mantelfläche der äußeren Schicht und
• – Versiegeln der äußeren Schicht mittels einer luft- und wasserdichten Abdeckung.

The method furthermore preferably comprises the following steps:

• - Introducing magnets in recesses, recesses and / or beads along the outer surface of the outer layer and
• - Seal the outer layer by means of an airtight and watertight cover.

The recesses, recesses and / or beads are preferably introduced by means of milling or drilling heads in the outer surface of the outer layer.

With the present invention, improved corrosion resistance and higher efficiency can be achieved.

The invention will now be illustrated by way of example with reference to a drawing. Hereby shows:

1 a view of a rotor according to the invention in longitudinal section,

2 a perspective view of the outer layer of the rotor 1 before pouring and

3 a perspective view of the impeller of the rotor according to the invention 1 ,

The 1 shows a view of a rotor according to the invention in longitudinal section.

The rotor 1 includes an impeller 2 , where the impeller 2 Fan blades 3 , a wave 4 and one the impeller 2 radially limiting layer 5 having. The layer 5 has a continuous hollow cylindrical design. In the area of the impeller 2 radially limiting layer 5 is a hollow cylindrical outer layer 6 appropriate. The wave 4 serves for the storage of the rotor 1 in order to be stored, for example, in a pumping device with a stator.

Alternatively, the construction could also be carried out without a shaft. In this case, plain bearings on the outer surface of the rotor (and in the stator) can be introduced, so that the rotor can be performed directly in a stator housing (not shown).

The impeller 2 and the layer 5 are made of bronze.

The outer layer 6 is with the wheel 2 over the layer 5 connected by pouring the bronze form-fitting.

The outer layer 6 has on its inside recesses, elevations, beads, and / or journals (not shown). As a result, an additional form-fit can be achieved.

In 2 is a perspective view of the outer layer of the rotor 1 presented before casting with the bronze.

The outer layer 6 has extensions (protruding sections) 7 in the longitudinal direction. These contribute to an improved form-fitting with the bronze. Here are the extensions 7 formed step-like and arranged symmetrically along the hollow cylinder edge.

The 3 shows a perspective view of the impeller of the rotor according to the invention 1 ,

The impeller 2 includes impeller blades 3 , the wave 4 and the impeller 2 radially limiting layer 5 ,

The impeller 2 bronze has correspondingly designed recording options for the extensions 7 the outer layer 6 on, allowing a positive connection with the outer layer 6 is reached.

After joining the outer layer of the 2 with the wheel 2 from the 3 results in a rotor assembly according to the 1 ,

The outer layer 6 may have on its outer side (lateral surface) recesses, recesses and / or beads (not shown). The recesses, recesses and / or beads serve to receive magnets, preferably permanent magnets.

Particularly preferred is the outer layer 6 by means of a cover air and waterproof sealed. By sealing the corrosion-prone iron layer is still a tubular cover preferably made of plastic material, stainless steel or other corrosion-resistant material on the rotor 1 to apply (not shown).

LIST OF REFERENCE NUMBERS

1

rotor

2

Wheel

3

Impeller blade, rotor blade

4

impeller shaft

5

the impeller radially bounding layer

6

outer layer

7

renewal

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited non-patent literature

• EN 10025 [0022]
• DIN 17100 [0022]

Claims (11)

Rotor ( 1 ) for an electrical machine, comprising - an impeller ( 2 ) of bronze, in particular aluminum bronze, and - at least one at least partially hollow cylindrical outer layer ( 6 ) of ferrous metal, the outer layer ( 6 ) with the impeller ( 2 ) is positively connected. Rotor ( 1 ) according to claim 1, wherein the impeller ( 2 ) a cylindrically formed layer ( 5 ) made of bronze, the impeller ( 2 ) is limited radially. Rotor ( 1 ) according to one of the preceding claims, wherein the outer layer ( 6 ) with the impeller ( 2 ) over which the impeller ( 2 ) radially limiting layer ( 5 ) is shed. Rotor ( 1 ) according to one of the preceding claims, wherein the radially extending outer layer ( 6 ) is made of steel, preferably of soaked steel, more preferably of S355J2 + N. Rotor ( 1 ) according to one of the preceding claims, wherein the outer layer ( 6 ) on its inside recesses, elevations, beads, and / or journals. Rotor ( 1 ) according to one of the preceding claims, wherein the outer layer ( 6 ) has on its outer side recesses, recesses and / or beads. Rotor ( 1 ) according to claim 6, wherein magnets in the recesses, recesses and / or beads can be introduced. Rotor ( 1 ) according to one of the preceding claims, wherein the outer layer ( 6 ) by means of a cover air and water resistant sealable. Use of a rotor ( 1 ) in an electric machine according to one of the preceding claims in a pump, in particular in water turbines. Method for producing a rotor ( 1 ), comprising the steps of - introducing an at least partially hollow cylindrical outer layer ( 6 ) of ferrous metal in a casting mold, - pouring of bronze into the casting mold, - cooling of the bronze, - removal of the finished molded rotor ( 1 ) and - machining the rotor. Method for producing a rotor ( 1 ) according to claim 10, further comprising the steps of - introducing magnets into recesses, recesses and / or beads along the outer surface of the outer layer ( 6 ) and - sealing the outer layer ( 6 ) by means of an air and watertight cover.

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