WO2017088993A1 - Superconducting rolling bearing and rolling bearing arrangement - Google Patents

Abstract

The invention relates to a rolling bearing and to an arrangement comprising two or more such rolling bearings. The substantial components of the rolling bearing, for example an inner ring, an outer ring, and the rolling elements by means of which the rings are rotatable with respect to one another, are superconducting, such that electrical current can be transmitted largely without losses via said components of the bearing. The rolling bearing arrangement has two such superconducting rolling bearings and a rotor having a superconducting conductor and a stator having means for generating a magnetic field. The conductor of the rotor is connected to the rotatable components of the rolling bearing, such that electrical current can be transmitted. The arrangement can also be designed as a direct current or unipolar machine.

Description

description

The invention relates to a rolling bearing and to an arrangement which has two or more such rolling bearings.

The operation of an electrical machine is based on a movement of an electrical conductor in a magnetic field, accompanied by the occurrence of the so-called Lorentz force. Depending on the operating state of the electric machine as a generator or as an electric motor, either the movement of the conductor is caused from the outside, so that the Lorentz force acts on the charges in the conductor and thus a current flow is generated, or a current flow is from the outside with a corresponding power source fed into the conductor, so that the Lorentz force triggers the movement of the conductor itself.

In both operating states, the movement of the conductor is usually a rotational movement, wherein, for example, a coil in an external magnetic field of a permanent or a

Electromagnet turns. In both operating states of the electric machine, it proves to be problematic that electric current has to be transmitted between a static and a rotating component. Typically, this grinding or brush contacts are used. However, this solution is subject to comparatively high losses. In order for high currents to flow via the sliding contact, a high contact pressure must be ensured, which in turn results in a high frictional resistance, which has a negative effect on the efficiency of the corresponding machine.

Alternatively, rolling bearings can be used to allow transmission of current between the static and rotating components. Rolling bearings are bearings with which a first component mounted, for example. An inner ring, and a second component mounted, for example. An outer ring relative to each other rotatable or rotatable. Well-known subgroups of Rolling bearings are, for example, ball bearings or roller bearings, with combined designs are possible, such as. In the

DE102006044802A1 described. In a radial roller bearing, the inner ring and the outer ring are typically arranged concentrically with an annular gap in the radial direction between the inner ring and the outer ring. In the annular gap are between the radially inner surface of the outer ring and the radial outer surface of the inner ring rolling elements, so that inner ring and outer ring are rotatable relative to each other by rolling on the rolling elements. Depending on the type of rolling bearing, the rolling elements may, for example, be formed as balls or rollers or rollers. The structure and operation of such rolling bearings are well known, are therefore not further explained. A corresponding arrangement results in an axial roller bearing, in which the first and the second component are arranged one behind the other in the axial direction. Both components are annular with substantially the same radii. The rolling elements are also here in a gap, which is in the axial direction between see the two components.

With such roller bearings, a transmission of electricity is possible, but due to the small contact surfaces between the Wälz- bodies and the first and second components, the transmittable current densities are relatively low.

It is therefore an object of the present invention to provide a way to transfer high currents between static and mobile components.

This object is achieved by the rolling bearing described in claim 1 and by the rolling bearing assembly described in claim 6. The subclaims describe advantageous embodiments.

The concept underlying the invention is to equip the rolling bearing with superconducting components. The rolling bearing is a cryogenic rolling bearing, in particular a superconducting rolling bearing which has cryogenic components which can be cooled to a cryogenic temperature by means of a coolant which can be supplied to the rolling bearing and thus to the components. The cryogenic components have a conductivity at the cryogenic temperature which is increased or improved by at least an order of magnitude compared to their conductivity at room temperature or, for example, at 0 ° C.

Here and below, the term cryogenic rolling bearing means that some components of the rolling bearing, for example. The rolling elements and electrical conductors which are mounted on the mutually rotatable components of the rolling bearing, are cryogenically cooled and, accordingly, on a cryogenic, i. are at an extremely low temperature, in which the conductivity is improved over the room temperature, for example by a factor of 3 or more. In an analogous manner, for example, the term cryogenic component is to be understood as meaning that this component is cryogenically cooled.

For example. it is conceivable to make the cryogenic component from copper or aluminum and to cool it to a temperature of 21K. These metals are not yet super conductive at this temperature, but their resistance drops with suitable purity by up to three orders of magnitude compared to the resistance at room temperature, which is already a huge advantage. Furthermore, it is part of the invention to carry out the cryogenic components of a superconducting material. Such materials are characterized in that they go into the superconducting state falls below the typical for this material transition temperature. In the superconducting state, direct current through superconductors can flow without resistance and no electrical heat losses occur. Accordingly, the term superconducting rolling bearing means that some components of the rolling bearing, For example, again the rolling elements and the electrical conductors are superconducting or consist of a material that passes into the superconducting state when falling below the typical for this material transition temperature. In an analogous manner, the term superconducting component is also to be understood, for example, as meaning that this component consists of a material which changes into the superconducting state when the critical temperature, which is typical for this material, is undershot.

Furthermore, the term superconducting component should include both the case that the affected component is itself and as a whole superconducting or consists of the corresponding material or has such, as well as the case that a component is attached to this component, which is superconducting or that the component has such a component. The latter case can be realized, for example, in the form of a coating of the respective component with a superconducting material.

Specifically, a superconducting rolling bearing having a first, static component and a rotatably mounted on the first component by means of rolling elements of the rolling bearing second component is proposed, wherein the first component, the second component and the rolling elements are superconducting and electrically connected to each other, so that a electrical current between the first and the second component via the rolling elements is transferable. In this case, the term "superconductive", which relates to the components or to the rolling elements, should include the case in which the affected component itself and as a whole is superconducting or consists of or comprises the corresponding material, as well as the case, that an object which is superconducting is fastened to this component or that the component has such an object, for example a wire, a conductor track or a special layer in the corresponding component. The rolling elements may have a superconductive coating, while the interior of the rolling elements is in each case made of a non-superconducting material. To realize the superconductivity of the components, the first component has a first superconducting electrical conductor arrangement and the second component has a second superconducting electrical conductor arrangement. The electrical current is transferable between the first and the second electrical conductor arrangement via the rolling elements. In this case, the respective component itself can represent the superconducting electrical conductor arrangement if the component as a whole consists of or comprises a superconducting material. Alternatively, the respective component may, for example, have an integrated conductor track or a wire connection.

Each of the first and second superconductive electrical conductor assemblies has a superconducting portion on a contact path of the respective component with the rolling elements. Thus, therefore, the electric current can be transmitted from the rolling elements to the respective component. The first component and the second component are arranged concentric with each other in the manner of a roller bearing, that there is a gap between the first component and the second component, in which the rolling bodies are arranged. The rolling elements are in contact with a first surface of the first component and with a second surface of the second component, the first and second surfaces facing each other and facing each other. Upon rotation of the second component, the rolling elements also rotate, each rolling over a path on the first and second surfaces. These tracks therefore represent the contact points of the rolling elements with the first and the second component. The contact tracks are therefore in each case on one of the rolling elements facing surface of the respective component. The first component and the second component each have an electrical connection for establishing an electrical connection with one or more further electrical devices, for example with an electrical consumer or with a source of electrical energy. In this case, the respective electrical connection with the respective superconducting electrical conductor arrangement of the components is electrically connected. All mentioned electrical connections of the rolling bearing are consequently also superconducting.

A roller bearing assembly according to the invention has at least a first and a second such superconducting rolling bearing. Furthermore, the rolling bearing assembly comprises a relative to the first components of the superconducting rolling bearings rotatable about a rotation axis rotor, wherein the rotor has at least one superconducting electrical conductor which rotates with rotation of the rotor. The electrical conductor of the rotor extends between a first conductor section and a second conductor section, wherein between the first and the second conductor section of the electrical conductor of the rotor there is a middle conductor section, which connects the first and the second conductor section to one another electrically. In addition, the first conductor section is electrically connected to the second superconducting conductor arrangement of the second component of the first rolling bearing, while the second conductor section is electrically connected to the second superconducting conductor arrangement of the second component of the second rolling bearing. Thus, electric current can be transmitted between the first component of the first rolling bearing and the first component of the second rolling bearing. This electrical current between the first components of the two rolling bearings flows in this or in the reverse order over the rolling elements of the first rolling bearing, the second component of the first rolling bearing, the first conductor section, the middle conductor section, the second conductor section, the second component of the second roller bearing and the rolling elements of the second rolling bearing. The electrical conductor of the rotor is thus electrically connected to the superconducting rolling bearings such that the second component of the first rolling bearing, the first conductor section, the middle conductor section, the second conductor section and the second component of the second rolling bearing are connected in series. Since all these components are superconducting, there are only minimal losses and thus a very high efficiency of the roller bearing assembly, which in this embodiment can be used as an electric machine.

The rolling bearing assembly further comprises a stator comprising means for generating a magnetic field, wherein the rotor with the electrical conductor of the rotor relative to the stator is rotatable about the axis of rotation, wherein the electrical conductor of the rotor is arranged on the rotor and in the magnetic field in that, as the rotor rotates, a Lorentz force acts on charges in the electrical conductor of the rotor. The stator, the first component of the first rolling bearing and the first component of the second rolling bearing, however, are arranged in such a way and possibly rigidly connected to each other that they can not perform mutual rotations. With this constellation, the rolling bearing assembly realizes an electric machine which is operable either in a generator mode or as an electric motor.

The stator has a superconducting coil arrangement for generating the magnetic field. Accordingly, all current-carrying parts of the electrical machine are superconducting, so that a high efficiency and a high power density can be achieved.

DC offers the advantage over AC that some loss mechanisms, such as the skin effect,

Hystereverluste, the proximity effect among other things omitted. In a superconductor occur virtually no losses, which can be a significant advantage, especially for the generation and transmission of high performance. Accordingly, the Rolling bearing assembly be constructed in one embodiment such that the superconducting electrical conductor of the rotor is so pronounced and arranged on the rotor, that the first conductor portion is circular or annular and in the region of a central point of the rotor through which the axis of rotation extends , The second conductor portion is annular and lies in a radially spaced from the central point edge region of the rotor, so that the first and the second conductor portion are arranged concentrically and the superconducting conductor of the rotor in the radial direction between the central region and the edge region of the rotor Rotor extends. The rotor and the electrical conductor of the rotor are arranged and oriented with respect to the stator and the generatable magnetic field such that charges in the conductor of the rotor upon rotation of the disk in the magnetic field in a radial direction between the central point and the edge region of the rotor experienced Lorentz force experienced. There is one on one

Cross-sectional area of the electrical conductor of the rotor perpendicular standing normal vector oriented parallel to the axis of rotation and the axis of rotation is largely parallel to the field lines of the magnetic field oriented, at least. Field lines in the space area in which the field lines are largely parallel to each other, which is, for example, in the vicinity of the axis of rotation of the case. In this context, "largely parallel" means that at least one component of the vector which describes the orientation of the axis of rotation is parallel to the field lines of the magnetic field, but to ensure high efficiency, the axis of rotation and the field lines ideally close an angle of at most 10 The basic function is, however, also guaranteed at larger angles, as long as the axis of rotation and the field lines are not perpendicular to each other.The cross-sectional area is defined by the plane defined by the radial conductor tracks of the middle conductor section

Cross-sectional area of the plane in which the annular second conductor section lies. The middle conductor section has a multiplicity of essentially radially extending thin conductor tracks, which electrically connect the first and the second conductor section to one another. The interconnects are therefore arranged essentially in a star shape around the first conductor section. Since in this embodiment, with a rotating rotor

Lorentz force acts in the radial direction, the radial orientation of the tracks ensures an ideal geometry.

In this case, the edge region of the rotor itself may be the second component of the second rolling bearing. Alternatively, a separate second component would be required, which would rotate with the rotor and which would have to be electrically connected to the edge region of the rotor or to the second conductor section. The measure proposed here makes it possible to dispense with such a separate component.

The rotor further comprises a shaft which supports the rotation of the rotor and transmits in this function, depending on the operating state of the electric machine as an electric motor or as a generator torque from or to the rotor, that carries the mechanical load of the rotor, said Shaft represents the second component of the first bearing.

In an alternative embodiment, the middle conductor section is arranged in the form of a conductor loop, in particular in the form of a coil which rotates in the magnetic field of the stator during rotation of the rotor. The conductor loop is oriented in such a way that a normal vector, which is perpendicular to a cross-sectional area of the conductor loop, is perpendicular to the axis of rotation. The axis of rotation is in turn perpendicular to the field lines of the magnetic field, in turn at least respect. Field lines in the space area in which the field lines are largely parallel to each other, which is the case, for example, in the vicinity of the axis of rotation. The rotor, the second component of the first rolling bearing and the second component of the second rolling bearing are arranged and possibly mechanically connected to each other that they rotate together.

In addition, at least one conventional, non-superconducting rolling bearing for supporting the mechanical load of the rotor is provided, wherein the superconducting rolling bearings substantially only for transmitting the electric current between see the respective first and second electrical components via the rolling elements. The conventional rolling bearing can, for example, store the shaft.

The concept presented here reveals a multitude of advantages. It is possible to transmit low power current between a rotating and a stationary body. While superconductors can conduct DC currents largely loss-free up to a very high critical current density, rolling bearings permit a largely lossless execution of a rotational movement of two

Body against each other. In order to allow the lowest possible losses in rolling bearings, the coefficient of friction should be kept small, which can be realized by a small contact surface between rolling elements and rings of the bearing. Because superconductors have large current densities of orders of magnitude

> lkA / mm2, a small contact area is sufficient to transport large amounts of electricity.

The main advantages of the presented concept are the lower weight and the greatly reduced mechanical and electrical losses of a superconducting ball bearing, in particular with respect to the use of brushes. The mechanical losses of a rolling bearing are below the friction losses of brushes. A weight reduction results from the fact that the superconductor can transmit high current densities, which is why significantly less material is required for the construction of the bearing. Such a superconducting rolling bearing permits the use of large electrical machines, in particular with direct current, which leads to a reduction of the reactive power, the ac losses and the transmission losses in high power lines.

In the following the invention and exemplary embodiments will be explained in more detail with reference to a drawing. Show it:

1 shows a ball bearing designed as a rolling bearing in a

 Frontal view,

 2 shows the ball bearing in a first embodiment in a side view,

 3 shows a rolling body in a first embodiment in a side or sectional view,

4 shows a plan view of a radially inner surface of an outer ring of the ball bearing,

5 shows the ball bearing in a second embodiment in a side view,

6 shows a rolling bearing arrangement in a first embodiment,

 7 shows a rolling bearing arrangement in a second embodiment,

 8 shows a plan view of a superconducting conductor disk, FIG. 9 shows a first variant of a rotor,

10 shows a second variant of a rotor. Like reference numerals in different figures indicate like components. It should also be noted that terms such as "axial" and "radial" refer to the rotational axis ROT used in the respective example described or in the respective figure.

1 and 2 show a rolling bearing 100, which is formed in the in the context of the following description of the figures in particular as a ball bearing. Accordingly, rolling elements 130 of the rolling bearing 100 is formed as balls 130. 1 shows the ball bearing 100 in a front view, while it is shown in a side section in FIG. 2, corresponding to the line II in FIG. 1.

The ball bearing 100 has a first, static component 110 and a second component 120 rotatably mounted on the first component 110 with the aid of the balls 130. The first 110 as well as the second component 120 are annular and arranged concentrically about an axis of rotation ROT. In this case, the first, static component 110 has a larger radius than the second in the case shown here,

rotatable component 120. In the axial direction, the first and second components 110, 120 are at the same position. The second, rotatable component 120 is therefore arranged within the first, static component 110. As a result, the second component 120 may be referred to as an inner ring while the first component 110 is an outer ring. According to the known manner of operation of a ball bearing, the second component 120 can rotate with respect to the first component 110, wherein the second component 120 rolls with its radially outer surface 121 on the balls 130 and wherein the balls 130 in turn on the radially inner surface 111 the first component 110 roll. As can be seen in the sections shown in FIGS. 2 and 5, both the first 110 and the second component 120 each have a concave shape on the surfaces 111, 121 on which the balls 130 roll, thereby causing them in that the balls 130 are held in the ball bearing 100 even during rotation. This concept of a roller or ball bearing is known per se and will therefore not be described in detail below.

Depending on the application and possibly more favorable geometry, the ball bearing 100 can also be constructed such that the first, static component 110 as an inner ring and the second, rotatable component 120 is formed as an outer ring, in which case the first component 110 has a smaller radius than the second component 120. Accordingly, the first component 110 would be disposed within the second component 120.

In addition to the common components 110, 120, 130 described above, the ball bearing 100 furthermore has a first electrical connection 112 and a second electrical connection 122 for producing an electrical connection of the ball bearing 100 to an electrical device 300. Such an electrical device 300 is shown by way of example in FIGS. 6, 7. The first terminal 112 is attached to and electrically connected to the first static component 110 while the second terminal 122 is attached to and connected to the second rotatable component 120 such that the second terminal 122 rotates when the second component 120 is rotated co-rotates. The first and second components 110, 120 and the balls 130 are electrically conductive, so that it is possible by the described constellation, an electric current between the first terminal 112 and the second terminal 122 via the first static component 110, the balls 130th and transmit the second component 120. Accordingly, the ball bearing 100 may serve to transfer electrical current between a static component electrically connected to the first terminal 112 and a component connected to the second terminal 122 and rotating relative to the static component. The static component may, for example, be the already mentioned electrical device 300, while the rotating component may, for example, be a rotor of an electrical machine. Such a constellation is also shown in FIGS. 6, 7.

The ball bearing 100 or the first component 110, the second component 120 and the balls 130 are designed to improve the electrical conductivity as superconducting components. piert. In this case, the term "superconducting" referred to the components 110, 120 or the balls 130 should include both the case that the affected component 110, 120, 130 itself and as a whole is superconducting or consists of the corresponding material or Such as the case that this component 110, 120, 130 has an object which is superconducting, or that such an object is attached to the component special layer in the corresponding component.

In the embodiments illustrated in FIGS. 1 and 2, the balls 130 as well as the first and second components 110, 120 and with them their surfaces 111, 121 consist of the superconducting material. Consequently, the terminals 112, 122 are also superconducting or consist of such a material, so that the electrical current can be transmitted largely lossless between the terminals 112, 122.

Formally, the first component 110 of the ball bearing 100 for realizing the superconductivity of the first component 110 has a first superconducting electrical conductor arrangement 115, while the second component 120 accordingly has a second superconducting electrical conductor arrangement 125. In a first embodiment of the ball bearing 100, the components 110, 120 themselves consist of a superconducting material or comprise such a material. Accordingly, the first 110 and the second component 120 in the first embodiment of the ball bearing 100 itself represent the corresponding superconducting conductor assemblies 115, 125. The superconducting conductor assemblies 115, 125 and the first and the second components 110, 120 are on the one hand the superconducting balls 130 and on the other with the superconducting electrical see connections 112, 122 in electrical contact, so that the electric current largely lossless between the terminals 112, 122 can be transmitted. FIG. 3 shows an alternative possible embodiment of one of the balls 130 of the superconducting ball bearing 100. The ball 130 here is not made entirely of superconducting material, but has a superconducting coating 131. The interior 132 of the ball 130 is made of a non-superconducting material, with the superconducting coating 131 completely surrounding the interior 132. The non-superconductive material may be, for example, a ceramic or a metal alloy.

FIGS. 4 and 5 show a second embodiment of the superconducting ball bearing 100 in which the components 110 and 120 are not completely made of superconducting material, in which the components therefore have, in addition to the superconducting electrical conductor arrangements 115, 125 further, non-superconducting material, eg again a ceramic or a metal alloy. For example. For example, the first component 110 may include a support 116 of such non-superconducting material into which a first superconducting conductor assembly 115 is embedded. The second component 120 has a second carrier 126 made of non-superconducting material that corresponds to the first carrier 116 and a second superconducting conductor arrangement 125. The functions of such carriers 116, 126 may be to stabilize the ball bearing 100 and to give it increased mechanical strength.

The superconducting conductor assemblies 115, 125 are constructed and attached to the respective carrier 116, 126 so as to be in electrical contact with the superconducting balls 130 and with the superconducting electrical terminals 112, 122 so that the electric current is as much as possible lossless between the terminals 112, 122 can be transmitted.

For this purpose, the first superconducting conductor arrangement 115 has a first superconducting section 113 which is disposed on the surface 111 of the first component 110 in the region of a conformation. Tact track of the balls 130 is arranged with the surface 111. As already mentioned, the first component 110 as well as the second component 120 are arranged concentrically with respect to one another such that there is a gap between the first component 110 and the second component 120 in which the balls 130 are arranged. The balls 130 are in contact with the first surface 111 of the first component 110 and with the second surface 121 of the second component 120, the first 111 and second surfaces 121 facing each other and facing each other. Upon rotation of the second component 120 relative to the first component 110, the balls 130 also rotate, each rolling over the first 111 and second surfaces 121. These tracks thus represent the contact pads of the balls with the first 110 and second components 120th

Ideally, the first superconducting portion 113 extends along the full circumference of the contact track on the first surface 111 of the first component 110. Similarly, the second superconducting conductor assembly 125 also has a second superconducting portion 123 attached to the surface 121 of the second component 120 is arranged in the region of the contact path of the balls 130 with the second surface 121. As mentioned, upon rotation of the second component with respect to the first component, the balls 130 roll on the contact tracks and on the first and second superconducting sections 113, 123, respectively. The first 113 and second superconducting sections 123 may be in the form of a coating, for example be realized with a superconducting material on the first 111 and second surface 121.

In this context, FIG. 4 shows, by way of example, the view indicated in FIG. 1 by the arrow IV, that is to say one

Top view of the radially inner first surface 111 of the first component 110. In FIG. 4, only a section of the mentioned surface 111 is shown. In addition to the first superconductive portion 113, the first superconducting conductor assembly 115 has a first superconducting compound 114 electrically connecting the first portion 113 to the first terminal 112. Accordingly, the second superconductive conductor arrangement 125 has a second superconducting connection 124, which in turn electrically connects the second section 123 to the second connection 122. In this case, the first and the second superconducting connection 114, 124 extend from the surfaces 111, 121 through the respective carriers 116, 126 to the terminals 112, 122. The connections 114, 124 may, for example, be in the form of a wire or else a flat conductor be.

Accordingly, in its second embodiment, the ball bearing 100 allows a largely lossless transmission of electric current between the first terminal 112 and the second terminal 122 via the first superconducting compound 114, the first superconducting portion 113, the balls 130, the second superconducting portion 123 and the second superconducting compound 124.

In order to bring the ball bearing 100 or at least its corresponding components to a sufficiently low temperature for the entry and the maintenance of superconductivity, it can be operated, for example, in a nitrogen bath.

FIG. 6 shows a first embodiment of a rolling bearing arrangement 200 which, for example, can be used as an electrical machine. This rolling bearing arrangement or the electric machine has a first 100 and a second superconducting ball bearing 100 ', wherein both ball bearings 100, 100' according to the superconducting rolling or ball bearings 100, 100 'described in FIGS. The ball bearings 100, 100 'shown in FIG. 6 are, in particular, ball bearings according to the first embodiment, in which the first components 110, 110' and second components 120, 120 'themselves consist of a superconducting material or such exhibit. Of course it is also conceivable that in this application ball bearings 100, 100 'according to the second embodiment are used.

The first and the second ball bearing 100, 100 'of the roller bearing assembly 200 each have a first, static component 110, 110', which are not rotatable relative to an environment of the rolling bearing assembly 200. The rolling bearing assembly 200 further includes a shaft 210 which is rotatably mounted relative to the environment. For example, additional ball bearings 211, 212, which carry the mechanical load of the overall arrangement, can be used for storage. This has the advantage that the superconducting ball bearings 100, 100 'can be largely freed from mechanical load and essentially only for transmitting an electric current between the respective first 110, 110' and second electrical components 120, 120 'via the balls 130, 130 'serve.

The second component 120 of the first ball bearing 100 and the second component 120 'of the second ball bearing 100' are fixedly connected to the shaft 210 so that they rotate with a rotation of the shaft 210. On the shaft 210, a rotor 220 is further attached, which also rotates with the shaft 210, so that in the case of the occurrence of rotation, the shaft 210, the rotor 220 and the second components 120, 120 'of the ball bearings 100, 100' rotate together ,

The rotor 220 carries a superconducting electrical conductor 221, which also rotates with rotation of the rotor 220. The electrical conductor 221 of the rotor 220 extends between a first superconducting conductor section 222 and a second superconducting conductor section 223, wherein a middle superconducting conductor section 224 is located between the first 222 and the second conductor section 223. The middle conductor section 224 is arranged in the form of a conductor loop, in particular in the form of a coil which rotates during rotation of the rotor 220, wherein a normal vector which is perpendicular to a cross-sectional surface of the conductor loop 224 is perpendicular to the axis of rotation ROT. The first conductor section 222 is in turn electrically connected to the second electrical connection 122 of the second component 120 of the first ball bearing 100, while the second conductor section 223 is electrically connected to the second electrical connection 122 'of the second component 120' of the second ball bearing 100 ' in that electrical current can be transmitted between the first component 110 of the first ball bearing 100 and the first component 110 'of the second ball bearing 100'.

This electrical current between the first components 110, 110 'of the two ball bearings 100, 100' flows in this or in the reverse order over the balls 130 of the first ball bearing 100, the second component 120 of the first ball bearing 100, the second connection 122 of FIG first ball bearing 100, the first conductor section 222, the middle conductor section 224, the second conductor section 223, the second connection 122 'of the second ball bearing 100', the second component 120 'of the second ball bearing 100' and the balls 130 'of the second ball bearing 100' ,

The rolling bearing assembly 200 further comprises a stator 230 with means 231, 232 for generating a magnetic field with magnetic field lines 235. The stator 230, the first component 110 of the first ball bearing 100 and the first component 110 'of the second ball bearing 100' are arranged such that they do not perform mutual rotations. For this they can possibly be rigidly connected to each other.

The rotor 220 with the electrical conductor 221 is disposed within the stator 230 and rotatable relative to the stator 230 about the axis of rotation ROT. In this case, the electrical conductor 221 of the rotor 220 and in particular its middle section 224 or the conductor loop 224 rotates in the magnetic field, so that upon rotation of the rotor 220 a

Lorentz force on charges in the middle conductor section 224 and thus in the electrical conductor 221 of the rotor 220 acts. _{2 Q}

For this purpose, the rotor 220 and the middle conductor section 224 are arranged such that the normal vector perpendicular to the cross-sectional surface of the conductor loop 224 is perpendicular to the rotation axis ROT and the rotation axis ROT is perpendicular to the field lines of the magnetic field 235, at least with respect to FIG. Field lines in that region of space in which the field lines are largely parallel to each other.

The means for generating the magnetic field may be, for example, permanent magnetic poles 231, 232. Alternatively, the stator 230 may include a solenoid for generating the magnetic field (not shown). Ideally, this electromagnet is equipped with superconducting coils.

The electrical conductor 221 of the rotor 220 is thus electrically connected to the superconducting ball bearings 100, 100 'such that the second component 120 of the first ball bearing 100, the first conductor section 222, the middle conductor section 224, the second conductor section 223 and the second component 120 'of the second ball bearing 100' are connected in series. Since all these components are superconducting, there are only minimal losses and thus a very high efficiency of the rolling bearing assembly 1, which may find application in this embodiment as an electric machine.

For this purpose, the rolling bearing assembly 200 is electrically connected to the aforementioned electrical device 300. The device 300 has a first 301 and a second electrical connection 302. The first terminal 301 is electrically connected to the first electrical terminal 112 of the first, static component 110 of the first ball bearing 100, while the second terminal 302 is electrically connected to the first electrical terminal 112 'of the first component 110' of the second ball bearing 100 ', such that electric current can flow between the first and second terminals 301, 302 of the electrical device. In one application of the electrical device 300 with the rolling bearing assembly 200 as a generator, the electrical device 300 represents an electrical load. The shaft 210 and with it the rotor 220 and the second components 120, 120 'of the ball bearings 100, 100' are set in rotation. By the interaction with the magnetic field of the stator 230, an electrical voltage is induced in the conductor loop 224, which is finally made available to the electrical device 300 or the electrical load at its terminals 301, 302.

In an application of the electric device 300 with the rolling bearing assembly 200 as an electric motor for driving an object, the electric device 300 represents a source of electric power provided to the rolling bearing assembly 200 via the terminals 301, 302. The electrical current thus flowing through the conductor loop 224, in interaction with the magnetic field 235 of the stator 230, causes a Lorentz force on the conductor loop 224, resulting in a rotation of the rotor 220 and the shaft 220. The shaft 220 may be connected to the object to be driven (not shown), for example, a propeller, so that it is also rotated. It should be noted that the arrangement and orientation of

Conductor loop 224 in FIG. 6 merely symbolically or by way of example stands for the fact that the rotor 220 carries such a conductor loop 224 which can conduct an electric current, so that in interaction with the magnetic field of the magnetic field

Stators 230 may occur a Lorentz force. The same applies to the indicated magnetic field lines 235, which are likewise to be understood merely symbolically in order to indicate the presence of a magnetic field. The specific arrangement and orientation of the conductor loop 224 also depends on which functional principle the roller bearing assembly 200 or the electrical machine is to operate. For example. For example, the machine 200 may be an axial or a radial flow machine. Also to be considered in the construction, whether the machine 200 operates with DC or AC, DC operation being preferable because the superconductivity is subject to losses in AC operation. FIG. 7 shows a second embodiment of a rolling bearing arrangement 200, which likewise can be used, for example, as an electric machine. This rolling bearing assembly 200 and the electric machine has a first 100 and a second superconducting ball bearing 100 ', wherein both ball bearings 100, 100' according to the described in Figures 1 to 5 superconducting rolling or ball bearings 100, 100 'are formed. The ball bearings 100, 100 'illustrated in FIG. 7 are, in particular, ball bearings according to the first embodiment, in which the balls 130, 130', the first, stationary components 110, 110 'and second, rotatable components 120, 120 themselves consist of a superconducting material or have such. Of course, it is also conceivable that in this application ball bearings 100, 100 'according to the second embodiment are used.

The first and the second ball bearing 100, 100 'of the rolling bearing assembly 200 each have a first, static component 110, 110', which are not rotatable relative to an environment of the rolling bearing assembly 200. The rolling bearing assembly 200 further comprises a shaft 210 and a rotor 210 fixed to the rotor 220, which are rotatably mounted relative to the environment together about a rotational axis ROT. For storage, for example, additional ball bearings 211, 212 may be used, which carry the mechanical load of the overall arrangement. This has the advantage that the superconducting ball bearings 100, 100 'can be largely freed from mechanical load and essentially only for transmitting an electric current between the respective first 110, 110' and second electrical components 120, 120 'via the balls 130, 130 'serve. Furthermore, the rolling bearing assembly 200 has a stationary relative to the environment stator 230 with means 231, 232 for generating a magnetic field with field lines 235. In the case of the occurrence of a rotation rotate the shaft 210, the rotor 220 and the second components

120, 120 'of the ball bearings 100, 100' together with respect to the environment and in particular with respect to the stator 230 and its magnetic field.

The second, rotatable component 120 of the first ball bearing 100 and the second component 120 'of the second ball bearing 100' are electrically conductive and also firmly connected to the shaft 210 so that they rotate with a rotation of the shaft 210. In FIG 7, the second component 120 of the first ball bearing 100 is shown as a radial projection on the shaft 210, which on the radially outer side

121, on which the balls 130 roll, having the above-mentioned, typical concave cross-section. If necessary, the use of the radial projections can be dispensed with and the concave surface 121 can be integrated directly into the shaft 210. In this case, therefore, the shaft 210 itself constitutes the second, rotatable component 120 of the first ball bearing 100. This measure saves space since the first ball bearing 100 can be realized with a smaller radius, but also reduces the stability of the shaft 210.

In the second embodiment of the rolling bearing assembly 200, the second ball bearing 100 'is realized such that its second rotatable component 120' is a component or a portion of the rotor 220. As indicated in FIG. 7, the rotor 220 itself or, in particular, its radially outer edge region constitutes the second component 120 'of the second ball bearing 100', on which the balls 130 'of the second ball bearing 100' roll. Accordingly, the

Edge region of the rotor 220 radially outward on a concave surface 121 'for guiding the balls 130' on.

The rotor 220 carries a superconducting electrical conductor 221, which also rotates with rotation of the rotor 220 and which is electrically connected to the shaft 210. The superconducting conductor 221, which is shown in a top view in FIG. 8, extends between a first superconducting device. the conductor section 222 and a second superconducting conductor section 223 of the conductor 221, wherein a middle superconducting conductor section 224 is located between the first 222 and the second conductor section 223.

The first conductor section 222 is located in the region of a central point of the rotor 220, through which the axis of rotation ROT extends, and the second conductor section 223 lies in a radially spaced from the central point edge region of the rotor 220, so that the conductor 221 of the rotor 220 extends in the radial direction between the central region and the edge region of the rotor 220. The first 222 and the second conductor portion 223 are annular. In an extreme case, the extent of the second superconducting conductor section 223 may be limited to a superconducting coating on the radially outer surface 121 'of the rotor 220, for example comparable to the superconducting section 123 in FIG

130 'roll upon rotation of the rotor 220. Also, the first conductor portion 222 may have the shape of a full circle instead of the circular ring shape. The central conductor section 224 consists of a plurality of radially extending, thin conductor tracks 227, which electrically connect the first 222 and the second conductor section 223. For the sake of clarity, only a few of the tracks 227 are provided with reference numerals in FIG. The first conductor portion 222 is electrically connected to the shaft 210. Since the shaft 210 is in turn electrically connected to the second component 120 of the first ball bearing 100, there is an electrical connection between the first conductor portion 222 of the conductor 221 of the rotor 220 and the second component 120 of the first ball bearing 100. The second conductor portion 223 is in turn is electrically connected to the second component 120 'of the second ball bearing 100' or represents this second component 120 'itself. Ultimately, there is a superconducting, electrical connection between the first, static component 110 of the first ball bearing 100 and the first, static component 110 'of the second ball bearing 100'.

As indicated above, the rotor 220 carries the superconducting conductor 221. The superconducting conductor 221 may be integrated in a first variant of the rotor 220 in a carrier body 225 of the rotor 220, wherein the electrical connection of the first conductor portion 222 with the shaft 210, for example via a Superconducting compound 226 is accomplished. This variant is shown in FIG. 9 in a lateral sectional view. In a second variant, indicated in FIG. 10, the superconducting conductor 221 is placed on an axial surface 228 of the rotor 220 or of the carrier body 225. In both variants, the carrier body 225 essentially serves to carry mechanical and thermal loads of the rotor. As a result, electric current can be transmitted between the first component 110 of the first ball bearing 100 and the first component 110 'of the second ball bearing 100'. Specifically, the transmission of the current between the first components 110, 110 'of the two ball bearings 100, 100' in this or in reverse order over the balls 130 of the first ball bearing 100, the second component 120 of the first ball bearing 100, the shaft 210, the first conductor portion 222, the middle conductor portion 224, the second conductor portion 223 and the second component 120 'of the second ball bearing 100' and the balls 130 'of the second ball bearing 100'. The electrical conductor 221 of the rotor 220 is thus electrically connected to the superconducting ball bearings 100, 100 'such that the second component 120 of the first ball bearing 100, the first conductor section 222, the middle conductor section 224, the second conductor section 223 and the second component 120 'of the second ball bearing 100' are connected in series. Since all these components as well as required connections are superconducting, only minimal ",

 Λ6

Luste and thus a very high efficiency of the rolling bearing assembly 200, which may find application in this embodiment as an electric machine. For this purpose, the rolling bearing assembly 200 is electrically connected to the aforementioned electrical device 300. The device 300 has a first 301 and a second electrical connection 302. The first terminal 301 is electrically connected to the first electrical terminal 112 of the first static component 110 of the first ball bearing 100, while the second terminal 302 is electrically connected to the first electrical terminal 112 'of the first component 110' of the second ball bearing 100 ' is such that electric current can flow between the first and the second terminal 301, 302 of the electrical device.

The operation of the second embodiment of the rolling bearing assembly 200 is based on the operation of a homo- or unipolar machine. The rotor 220 and the conductor plate 221 are arranged and oriented with respect to the stator 230 and the generatable magnetic field 235 in such a way that a normal vector N perpendicular to a cross-sectional surface of the disc 221 is oriented parallel to the axis of rotation ROT. Furthermore, the axis of rotation ROT is oriented parallel to the field lines 235 of the magnetic field, at least with respect to. the field lines 235 in that region in which the field lines 235 are largely parallel to one another, which is the case, for example, in the vicinity of the axis of rotation ROT. Ideally, the means 231, 232 of the magnetic field generating stator 230 extend so far in the radial direction that the field lines 235 are parallel to each other in the entire space region in which the rotor 220 and the conductor plate 221 are located.

In one application of the electrical device 300 with the rolling bearing assembly 200 as a generator, the electrical device 300 represents an electrical load. The shaft 210 and with it the rotor 220 together with the conductor plate 221 and the second components 120, 120 'of the ball bearings 100, 100' are rotated by a motor (not shown). As a result of the interaction with the magnetic field of the stator 230, the charges in the conductor plate 221 experience a Lorentz force in the radial direction, so that a direct current is tapped at electrical connections 112, 112 'of the first components 110, 110' of the ball bearings 100, 100 ' and the electrical load 300 can be provided at its terminals 301, 302.

In one application of the electrical device 300 with the rolling bearing assembly 200 as an electric motor for driving an object, the electrical device 300 represents a source of electrical energy, in particular in the form of a DC voltage, which is available to the rolling bearing assembly 200 via the terminals 301, 302 is provided. The electrical current thus flowing through the conductor plate 221, in interaction with the magnetic field 235 of the stator 230, causes a Lorentz force on the conductor plate 221, which results in a rotation of the rotor 220 and the shaft 220. The shaft 220 may be connected to an object to be driven (not shown), for example, a propeller, so that it is also rotated.

In both embodiments of the rolling bearing assembly 200, in the case that the rolling bearing assembly 1 is used as an electric machine and in particular as a generator, the electrical device 300 may be an electrical load. In the other case, in which the rolling bearing assembly 1 or electric machine is used as an electric motor, the electrical device 300 is a source of electrical energy. In an alternative, but not shown, the rolling bearing 100 can be known to be designed as a roller bearing or as a combined ball roller bearing. It should be noted that training as a roller bearing 100 for here to be described, in that the rollers 130 provide a larger area of contact with the first and second components 110, 120 of the rolling bearing 100 than the balls 130, so that better transfer of current between the components 110, 120 over the Rolling element is possible. On the other hand, in the case of using rollers instead of balls, the friction coefficient is larger, so that the rotation becomes more difficult, which adversely affects the overall efficiency and also causes a higher heat development. It is therefore to decide depending on the particular application, whether the rolling bearing 100 should be designed as a ball bearing with balls as rolling elements 130 or as a roller bearing with rollers as rolling elements 130. As superconducting materials, for example. YBCO, BSCCO, MgB2 as high-temperature superconductor for applications at 20K-77K in question, the corresponding cooling, for example. With liquid nitrogen, neon or hydrogen can be ensured. Also suitable materials such as niobium in cooling with liquid helium in question.

In order to realize the cooling required to achieve the superconductivity, for example, coolant could be supplied via the interior of the shaft 210 or else the respective device 100, 100 200 to be cooled could be stored in a nitrogen bath.

Claims

claims A superconducting rolling bearing (100, 100 having a first component (110, 110 and a first component (110, 110 with the aid of rolling elements (130, 130 rotatably mounted second component (120, 120, characterized in that the first component (110, 110, the second component (120, 120 and the rolling elements (130, 130 are superconducting and electrically connected to each other, so that an electric current between the first (110, 110 and the second component (120, 120 on the Rolling elements (130, 130 is transferable. 2. Rolling bearing (100, 100 according to claim 1, wherein the rolling bodies (130, 130 have a superconducting coating (131). 3. rolling bearing (100, 100 according to one of claims 1 to 2, wherein the first component (110, 110 has a first supr e tende electrical conductor arrangement (115) and the second component (120, 120 a second superconducting electrical conductor arrangement (125) wherein the electrical current between the first (115) and the second electrical conductor arrangement (125) via the rolling elements (130, 130 is transferable. 4. Rolling bearing (100, 100 according to claim 3, wherein the first (115) and the second superconducting electrical conductor arrangement (125) each have a superconducting section (113, 123) on a contact path of the respective component (110, 110, 120, 120 with the rolling elements (130, 130). 5. rolling bearing (100, 100 according to one of claims 3 to 4, wherein the first component (110, 110 and the second component (120, 120 each have an electrical connection (112, 122)), wherein the respective electrical connection (112, 122) is electrically connected to the respective superconductive electrical conductor arrangement (115, 125). 6. Rolling bearing assembly (200) with  at least a first (100) and a second superconducting rolling bearing (100 according to claim 1, - A relative to the first components (110, 110 of the superconducting rolling bearing (100, 100 rotatable about a rotation axis (ROT) rotatable rotor (200), wherein the rotor (200) has at least one superconducting electrical conductor (221), which upon rotation of the rotor (200) co-rotated, wherein  the superconducting electrical conductor (221) of the rotor (200) extends between a first conductor section (222) and a second conductor section (223), a middle conductor section (224) being arranged between the first (222) and the second conductor section (223) ) connecting the first (222) and second conductor sections (223) to each other, and  - The first conductor portion (222) with the second component (120) of the first rolling bearing (100) is electrically connected and the second conductor portion (223) with the second component (120 of the second rolling bearing (100) is electrically connected. 7. Rolling arrangement (200) according to claim 6, further comprising a stator (230) having means (231, 232) for generating a magnetic field (235), wherein  - The rotor (220) is rotatable with the superconducting electrical conductor (221) of the rotor (220) relative to the stator (230) about the axis of rotation (ROT), wherein the superconducting electrical conductor (221) of the rotor (220) on the rotor (20) and in the magnetic field (235) is arranged such that upon rotation of the rotor (220) a Lorentz force acts on charges in the superconducting electrical conductor (221) of the rotor (220),  - The stator (230), the first component (110) of the first Rolling bearing (100) and the first component (110 of the two- th bearing (100 are arranged so that they do not perform mutual rotations. A rolling bearing assembly (200) according to claim 7, wherein the stator (230) for generating the magnetic field (235) comprises a superconductive coil assembly (231, 232). 9. rolling bearing assembly (200) according to any one of claims 7 or 8, characterized in that the superconducting electrical conductor (221) of the rotor (220) is so pronounced and arranged on the rotor (220) that  the first conductor section (222) lies in the region of a central point of the rotor (220) through which the axis of rotation (ROT) extends, - The second conductor section (223) is annular and lies in a radially spaced from the central point edge region of the rotor (220),  - The rotor (220) and the superconducting electrical conductor (221) of the rotor (220) with respect to the stator (230) and the generatable magnetic field (235) are arranged and oriented such that charges in the conductor (221) of the rotor (220 ) experiences a Lorentz force oriented in the radial direction between the central point and the edge region of the rotor (220) in the magnetic field (235) during rotation of the rotor (220), in which  - A normal on a cross-sectional area of the superconducting electrical conductor (221) of the rotor (220) perpendicular normal vector is oriented parallel to the axis of rotation and  - The axis of rotation is largely oriented parallel to the field lines of the magnetic field. 10. Rolling bearing arrangement (200) according to claim 9, characterized in that the central conductor section (224) has a plurality of substantially radially extending conductor tracks (227) electrically interconnecting the first (222) and the second conductor section (223) connect. 11. rolling bearing assembly (200) according to claim 9 or 10, characterized in that the edge region of the rotor (220) itself, the second component (120 of the second rolling bearing (100 represents. 12. rolling bearing assembly (200) according to any one of claims 9 to 11, characterized in that the rotor (220) has a shaft (210) which supports the rotation of the rotor (210), wherein the shaft (210), the second component ( 120) of the first rolling bearing (100). 13. rolling bearing assembly (200) according to any one of claims 7 or 8, characterized in that the central conductor portion (224) is arranged in the form of a, in particular in the form of a coil which upon rotation of the rotor (220) in the magnetic field (235) of the stator (1230), wherein  - The conductor loop (224) is oriented such that a normal to a cross-sectional area of the conductor loop (224) normal vector is perpendicular to the axis of rotation (ROT) and  - The axis of rotation (ROT) is perpendicular to the field lines of the magnetic field (235). 14. rolling bearing assembly (200) according to any one of claims 6 to 13, wherein the rotor (220), the second component (120) of the first rolling bearing (100) and the second component (120 of the second rolling bearing (100) are arranged so that they rotate together. 15. Rolling bearing arrangement (200) according to one of claims 6 to 14, wherein at least one conventional, non-superconducting roller bearing (211, 212) is provided for supporting the mechanical load of the rotor (220), wherein the superconducting roller bearings (100, 100) substantially only for the transmission of electrical current between the respective first (110 , 110 and second electrical components (120, 120 via the rolling elements (130, 130 serve.