HK1222948B - Compressible motor, implantation arrangement, and method for positioning the motor - Google Patents

Description

Compressible motor, implantable device, and method for positioning motor

Technical Field

The invention belongs to the fields of mechanical and electrical engineering and can be used with particular advantage in the field of micromechanics. Among other fields, its application is particularly advantageous in medical engineering.

Background Art

When introducing components into a channel system or a particularly difficult-to-access location, similar to the situation when implanting a component into a patient, problems often arise because this type of component must be delivered to its target location through the narrowest possible opening or channel, but once there, especially through the largest size, it will have the most significant effect.

In medical engineering, this is achieved by compressing the corresponding components before they are introduced into the patient's body to their target location, inserting them in a compressed state, and then subsequently deploying them. This technology has previously been used in deployable cardiac assist catheter pumps and implantable stents. In non-medical applications, for example, examination cradles can be delivered via tubes and similarly deployed once they reach a larger cavity, or used to deliver suitable tools or sensors.

Until now, in medical implants, drivable, deployable components have been driven by an external motor via a flexible shaft. For example, in a heart-assist blood pump, the pump rotor is connected to the external motor via a flexible shaft, for example via a port, with the flexible shaft extending through a hollow catheter within a blood vessel. The demands placed on such transmission systems are sometimes very high, for example on the flexible shaft, because these high rotational speeds must be transmitted for a considerable period of time without significant losses, which usually requires lubrication, which is not optimal. Therefore, it would be very advantageous to avoid such transmission systems.

Summary of the Invention

Therefore, in view of the existing background technology, the object of the present invention is to design a motor so that it can be transported through a narrow channel.

According to the invention, the electric machine comprises a stator and an axially drivable rotor, wherein, for this purpose, at least one of the stator and the rotor, in particular the stator, can be radially compressed and expanded, wherein the stator has a winding arrangement through which current can flow.

Within the scope of the present invention, the term "radial compressibility" is understood to mean that the diameter of the element can be reduced at least partially relative to the axis of rotation of the motor, which can include all possible uniform diameter reductions, in which only the diameter of the cylinder changes, while the shape remains unchanged. However, radial compressibility can also be understood as meaning that the diameter of the stator and/or rotor is reduced in only one axial direction, for example by flattening the element or, if the element (stator and/or rotor) consists of different discs, by tilting the discs relative to the axis of rotation. In particular, the diameter decreases in a first direction perpendicular to the axis of rotation while remaining constant in a direction perpendicular to the first direction.

Such a compressible stator has a winding arrangement through which an electric current can flow, a solution not known from the prior art. According to the invention, the winding arrangement itself can be compressed, in particular in the radial direction. Such a winding arrangement can be compressed before being introduced into the channel, in particular when the stator determines the outer diameter of the motor, the overall diameter of the motor is reduced. For example, in the operating state, the stator can coaxially surround the rotor. In this case, the radial compression of the stator corresponds to the radial compression of the motor. The stator can also be surrounded by a housing, which can, for example, be elastic and can then be compressed and expanded along with the stator. For example, the housing can essentially consist of an elastic membrane that stretches along the stator. However, the motor can also have no housing.

When the stator coaxially surrounds the rotor, the possibility of the stator being compressed is affected by the narrow confines of the built-in rotor. For example, the stator can be further compressed when the rotor and stator can be moved relative to each other between a first position and a second position in the axial direction, wherein the stator in the first position can be radially compressed and the stator in the second position can be radially expanded. In this case, in order to compress the stator, the rotor can first be slid out in the axial direction, after which the stator can be compressed, such as to the outer diameter of the rotor. The stator and rotor can then be slid axially to the target position in succession through the channel. If the rotor itself is not compressible, some exemplary embodiments do not provide or cannot achieve further compression of the stator within the outer size constraints of the rotor.

If the stator and rotor have reached the target position, the stator can be unfolded again or can be unfolded automatically and the rotor can be pulled axially into the stator.

Since the rotor is placed or pulled into the stator, which is radially expanded during the displacement movement, the stator can also be radially expanded. For this purpose, the rotor can be formed at least partially in a conically tapering manner.

According to a further advantageous variant of the present invention, the rotor can be compressed in the radial direction. If the rotor can also be compressed in the radial direction, the rotor in this variant can remain in the stator and the rotor and stator can be radially compressed together, or the rotor can be removed from the stator and the rotor and stator can be radially compressed separately.

For example, the rotor may include a plurality of magnets, which may be referred to as magnet elements, that are reversibly movable relative to one another, particularly in the axial direction. The rotor may include, for example, permanent magnets or electromagnets with ferromagnetic cores, both of which are referred to as magnet elements. Each of these magnets may be divided into magnet segments, allowing individual magnet segments to be moved relative to one another, thereby reducing the rotor diameter by reducing the radial size of the magnets.

For example, at least one magnet may consist of wedge-shaped segments that can be pushed together and apart in the axial direction, and when pushed apart, the entire magnet occupies less space in the radial direction than when pushed together. However, other divisions in different planes may also be provided, wherein it is conceivable to move individual segments of the magnet in the circumferential direction of the rotor and/or in the radial direction of the motor. A segment of a magnet may also be referred to as a magnet element, so the term "magnet element" includes both magnet segments and the entire magnet.

It is important that the described movement of the magnets or magnet segments results in a reduction in diameter which can be reversed in a simple manner, facilitating subsequent unfolding of the rotor.

To enable radial compression of the stator in the simplest manner, the winding arrangement may preferably include at least one sub-winding, for example, a reversibly deformable sub-winding. For example, such a sub-winding may be elastic, for example, comprising a spring-loaded wire, to allow for temporary deformation of the sub-winding. Such deformation may be elastic or plastic.

The winding arrangement can also have at least two sub-windings that are reversibly movable relative to one another. Such sub-windings can be uncast or cast from a rigid or elastic casting material, particularly in the circumferential direction of the rotor, so that they can fit one inside the other like a tile when the stator is radially compressed. However, it is also conceivable to allow the sub-windings to rotate or swivel about an axis if the rotor is removed from the stator.

To improve the deformability of the winding arrangement, the winding arrangement may include, for example, at least one sub-winding cast from an elastic material. For example, the sub-winding may be cast from an elastomer, such as a silicone elastomer or a rubber material. Larger components of the winding arrangement, or even the entire winding arrangement, may also be cast from such an elastic material.

To increase the effectiveness, the elastic base body can be provided with a ferromagnetic filler, in particular on the outside.

If the individual components of the winding arrangement are cast separately, the elastic deformability can be combined with the displacement capability, for example if the partial windings have elastic conductors and/or are cast from an elastic material.

For example, a winding arrangement can also at least partially include wires composed of a memory alloy. In this case, for example, by selecting a target temperature setting, a sub-winding or the entire winding arrangement can be adapted to a desired shape and size at a target location. In medical applications, for example, an alloy can be provided so that the winding arrangement can achieve the desired target and shape once the patient's body temperature has been reached.

When the winding arrangement consists of a plurality of sub-windings that are movable relative to one another, in order to ensure that compression and expansion can be repeated and that the paths of the compression and expansion movements are reproducible, the winding arrangement may also preferably have bending and/or kinking regions defined between the elements that are movable relative to one another. Such bending and/or kinking regions may be provided in the form of soft and/or flexible conductor parts, for example, by forming a length portion of the conductor as a stranded conductor or a particularly thin conductor region.

For the aforementioned type of motor, in order to enable the rotor and stator to be moved relative to each other to a desired position even from a distance, the present invention preferably provides a connecting element extending outward from the motor and enabling the rotor and stator to be moved axially relative to each other. The connecting element can be a typical control element, such as a Bowden cable, wherein different portions of the connecting element can be connected to both the stator and the rotor simultaneously.

The connecting element allows the stator and rotor to be displaced relative to each other, so that the rotor can be pulled into the stator in a target position, wherein the stator is either already expanded beforehand or radially expanded by pulling the rotor into the stator.

The present invention also relates to an implantable device comprising a hollow catheter and a stator and a rotor arranged in a compressed manner within the hollow catheter. Within the scope of such an implantable device, a radially compressible motor can be easily pulled into the hollow catheter, wherein the motor is usually received in a compressed form in the hollow catheter. The hollow catheter can be introduced into a patient's blood vessels, for example, via a port and moved therein, and then delivered to the target location, for example, into the aortic arch, into a heart valve or into a ventricle. The hollow catheter can then be retracted, wherein the motor slides out of it and radially expands during or after the process.

The invention also relates to an electric motor of the above-mentioned type, an implantable device, and a method for positioning an electric motor of the above-mentioned type, wherein the stator and the rotor are moved through a channel to a target position, wherein at least the stator is radially compressed and at least the stator is then radially expanded.

According to a preferred embodiment of the method, once moved to the target position, the stator and the rotor are moved axially relative to each other.

The present invention also relates to a pump, in particular a blood pump, comprising a motor having a stator and an axially drivable rotor, wherein at least one of the stator and the rotor, in particular the stator, can be radially compressed and expanded, and wherein the stator has a winding arrangement through which current can flow. The motor and the pump are preferably highly integrated with each other. This allows for the production of a particularly compact pump; in particular, it is advantageous to transport a pump having a small radial diameter to its point of use and to radially expand there to provide precise pump performance.

Here, according to one embodiment, the rotor is connected to a pump rotor, wherein the pump rotor has blades for conveying fluid. For example, the pump rotor may be physically mounted on the magnetic rotor or radially surround the magnetic rotor, but the two may also be connected to each other in other ways, for example, the magnetic rotor may be cast or embedded in the pump rotor.

According to a further embodiment, the pump rotor is at least partially located within the stator during operation. This provides a radially layered configuration in operation, with the arrangement arranged radially from the outermost portion toward the center being: 1. stator, 2. pump rotor, 3. magnetic rotor. In other embodiments, the pump rotor and magnetic motor are interconnected and may be configured in various ways.

According to a preferred embodiment, the pump rotor is radially compressible, in particular radially elastically compressible. Here, according to a variant, primarily the blades of the pump rotor are elastically compressible, for example towards the center of the pump rotor.

According to the invention, different variants of the pump can be realized, wherein according to the invention all variants of the electric motor can be used for the pump.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be described below based on exemplary embodiments, which are shown in the accompanying drawings.

FIG1 is a schematic diagram of a longitudinal section of an electric machine having a rotor and a stator;

FIG2 is a compressed version of the motor shown in FIG1 , wherein the stator and rotor are axially separated from each other;

FIG3 shows a modified form of a single conductor having a winding configuration with a helical or meandering section with a reserved length;

FIG4 a shows an axial view of a winding arrangement, which is compressed in the form of a spiral wire on the left side of the drawing and expanded on the right side of the drawing;

FIG4 b shows an axial view of a winding arrangement which is compressed in the form of a bent wire on the left side of the drawing and radially expanded on the right side of the drawing;

FIG5 shows a three-dimensional view of a winding configuration having a plurality of sub-windings, wherein the plurality of sub-windings generally have a diamond or trapezoidal design in an unrolled state;

FIG6 is a schematic three-dimensional view of a single winding direction of the sub-winding shown in FIG5 ;

FIG7 is a schematic diagram of different sub-windings arranged relative to each other on the periphery of the winding arrangement in a radially expanded state in the axial direction;

FIG8 is a sub-winding configuration in a radially compressed state shown in FIG7 ;

FIG9 shows a longitudinal section of an electric machine having a stator and a rotor, wherein the rotor is encapsulated in an assembled, unfolded state;

FIG10 shows the motor shown in FIG9 axially separated and in a compressed state;

Figure 11 shows a stator and a rotor arranged axially in sequence, wherein the stator is radially compressed and both the stator and the rotor have control devices;

FIG12 shows a cross section of a stator, wherein the winding arrangement is circumferentially divided into four sub-windings;

FIG13 shows the stator shown in FIG12 in a compressed state, wherein the sub-windings have been mechanically altered inwards under radial pressure;

FIG14 shows the stator shown in FIG12 and FIG13 in a further compressed state;

FIG15 is an axial schematic diagram of a rotor having two magnets;

FIG16 is a side view of a segmented and radially compressible rotor magnet;

FIG17 shows a stator with an axially divisible winding configuration;

FIG18 shows the expanded state of the stator with the rotor inside, wherein the compressible pump rotor is arranged on the rotor;

FIG19 shows the device shown in FIG18 in a compressed state; and

20 is a side view of the stator with the pump rotor axially removed from the stator.

DETAILED DESCRIPTION

FIG1 is a schematic diagram of a longitudinal section of a rotor 1 and a stator 2 of an electric machine. For the sake of clarity, further components and details are omitted. The stator has a winding configuration as shown in the figure, which can be composed of one or more sub-windings. The rotor 1 has at least one permanent magnet and a hub connected to the shaft 3. The magnetic poles of the rotor 1 or the magnet can be driven by the magnetic field of the stator 2. The shaft 3 is usually rotatably mounted at one or more points in a sliding or rolling bearing. The bearing can be fixedly connected to the stator 2 or the stator housing (not shown) or the motor to form an integral unit. As shown in FIG1 , it can be seen that the diameter of the stator in the radially expanded state, which is concentric and coaxial around the rotor 1, is D.

FIG2 shows the components of the electric machine shown in FIG1 , specifically the winding arrangement of the rotor 1 and stator 2 , wherein the rotor and stator are separated from each other in the axial direction 4 . In this state, the stator and rotor do not overlap each other in the axial direction. The stator is radially compressed as a whole by the winding arrangement to a diameter d that is equal to or smaller than the outer diameter of the rotor 1 .

It is therefore clear that, due to the divisibility of the electrical machine and the displaceability of the stator relative to the rotor, the stator can be radially compressed once the rotor is removed therefrom.

In another configuration, independent of the above, the rotor can also be radially compressed. In this case, the stator and rotor can also be radially compressed together in the assembled state, or they can be axially displaced relative to each other and radially compressed separately. In the latter case, it is advantageous but not essential that both components, i.e., the stator and rotor, are compressed to approximately the same outer diameter.

The upper portion of FIG. 3 shows a first conductor 5 of a winding arrangement for an electric machine according to the present invention in a compressed state, wherein the conductor extends helically. If a winding arrangement or a sub-winding is formed from this helically extending conductor, and the winding conductor 5 is extended and then radially compressed again, the winding arrangement or sub-winding can be radially expanded. The lower portion of FIG. 3 shows a conductor 6, which has a curved shape in the compressed state and can be expanded when it is in the expanded state.

The left side of Figure 4a schematically illustrates the conductor 5 in a compressed state in a spiral shape. Also shown in the figure, it is in a circular shape in this compressed state, representing the winding configuration. The right side of Figure 4a shows an axial view of the stator in an expanded form, with the winding conductors in an extended state and, accordingly, the winding configuration and/or sub-windings in an expanded state. The stator on the right side of Figure 4a has an enlarged diameter D, while in the compressed state shown on the left side of Figure 4a, it has a reduced diameter d.

In FIG4 b , the compressed wire 6 is shown in a curved shape, which is arranged in a ring-like manner in the axial direction and represents the winding configuration of the stator. This configuration has a compressed outer diameter d. The right side of FIG4 b shows the same stator in a radially expanded state, in which the winding wire is extended, or at least further expanded than in its compressed state.

The compressed state and the expanded state of the stator can be achieved by applying a force, for example, wherein the stator is compressed under the action of radial external pressure, and when the external radial compression force is removed, it automatically expands elastically again.

Conversely, the diameter of the stator can also be reduced when no force is applied, and can be expanded when force is applied.

In a further alternative, the winding arrangement may include wires made of known memory alloys, which, for example, change their shape when the temperature changes and can recover their shape within a certain temperature range. Such memory alloys may be, for example, NiTi (nickel-titanium; Nitinol), NiTiCu (nickel-titanium-copper), copper-zinc (copper-zinc), copper-zinc-aluminum (copper-zinc-aluminum), copper-aluminum-nickel (copper-aluminum-nickel), iron-nickel-aluminum (iron-nickel-aluminum), or iron-manganese-silicon (iron-manganese-silicon). Such alloys are also known as superelastic alloys.

In addition to the aforementioned properties of the winding arrangement, it is also possible to provide a casting of the entire winding arrangement or individual sub-windings made of an elastic material, such as an inherently elastically deformable silicone elastomer or rubber. Alternatively, such a casting of the winding arrangement may be omitted, or a casting of a non-elastic material may be used, where the individual sub-winding castings are operated independently, while the sub-windings, along with their respective casting materials, are movable relative to one another. Such an arrangement will be discussed in further detail below.

FIG5 shows a perspective view of a generally hollow cylindrical winding arrangement consisting of a plurality of sub-windings. Each sub-winding consists of a plurality of windings of wire and has two electrical terminals for providing voltage and input current. The winding arrangement as a whole may also have terminal wires or electrical terminals.

Each sub-winding of the winding arrangement shown in the un-expanded state has a basic rhombus shape. The individual sub-windings overlap one another in the circumferential direction of the winding arrangement. The individual sub-windings 7, 8 of the winding arrangement in FIG5 have electrical terminals 9, 10 for supplying current to the stator winding arrangement.

FIG6 shows a single sub-winding 7, represented by a single winding of winding wire, designated by reference numeral 11. Sub-winding 11 has two electrical connections 12, 13 for supplying current. FIG6 schematically shows a hollow cylinder with partially cylindrical sub-windings distributed around its outer circumference, said sub-windings overlapping one another and offset relative to one another in the circumferential direction.

FIG7 shows a schematic axial view of a winding arrangement of multiple sub-windings 7 and 8. Each individual sub-winding 7 and 8 has a radially outer portion 7 a and a radially inner portion 7 b, wherein each radially inner portion is covered by the following sub-winding 8, more specifically, by the radially outer portion. In this manner, a roof tile-like nesting of sub-windings is provided along the outer periphery of the stator.

If the sub-windings are movable relative to one another, they can be further slid onto one another like tiles, thereby reducing the diameter of the overall arrangement and the circumference of the winding arrangement. FIG8 shows an example of a compression state of the compression movement, in which one of the two windings 7, 8 slides onto the other, completely overlapping each other in the circumferential direction of the winding arrangement. For both non-cast and cast sub-windings, it is also conceivable for the individual sub-windings to slide onto one another. If the individual sub-windings are cast, preferably the casting material allows the castings to slide easily relative to one another.

FIG9 shows a longitudinal section through an electric machine with a radially extended stator 2 and rotor 1. The rotor comprises a hollow cylinder as enclosure 14, which surrounds the rotor's magnets and is provided with, for example, bearings 15, 16. The rotor shaft 3 is mounted in low-friction bearings 15, 16, which can be plain bearings or ball bearings. According to FIG9 , D is the diameter of the entire electric machine in the extended, assembled state, ready for operation.

In contrast, the same motor having the same elements, namely the stator 2 and the rotor enclosed in the enclosure 14, with the winding arrangement, is shown in its compressed state in FIG10 , wherein the stator 2 has been moved axially relative to the rotor 1 so that the rotor is located outside the stator. The stator 2 can then be radially compressed independently of the rotor 1 to the rotor's outer diameter.

FIG11 shows the design of an electric machine having a rotor 1′ and a stator 2′, wherein the rotor 1′ and the stator 2′ are axially distant from each other in the compressed position shown. The rotor 1′ has an enclosure, in which the magnet arrangement of the rotor is supported by two bearings and can rotate. The enclosure of the rotor has a conically tapered portion 17 and is connected to a divided control element 18, which is fixed to the enclosure or the bearings so that the rotor can move axially relative to the stator 2′. At the same time, the stator 2′ is connected to a second control element 19, for example in the form of a tube or a hose, through which the control element 18 can be guided. The control elements 18, 19, which together form a connection element to the electric machine, can be jointly driven from a remote location to perform a relative movement of the stator and the rotor, for example, by inserting the enclosure of the rotor 1′ into the winding arrangement of the stator 2′ so that the stator and the rotor are radially spread out.

Figure 12 shows a specific winding configuration consisting of four separate sub-windings 20, 21, 22, 23, each of which is cast from an elastic material. Each sub-winding forms a portion of a hollow cylinder, and the sub-windings can be assembled with their main body to form a complete hollow cylinder.

If a force is applied from the outside to the radial direction of the winding configuration, FIG13 shows the distribution of the force, wherein the individual castings and the sub-windings can rotate radially inward. The individual castings of the sub-windings can be movably connected to each other by movable hinges. In the state shown in FIG13 , the winding configuration in the radial direction occupies less space than the form shown in FIG12 . With further radial compression, the individual sub-windings are further compressed radially inward, and the deformation of the casting increases the possibility of compression. FIG14 shows the fully compressed state. Canceling the radially inward compressive force can automatically unfold and restore to the form shown in FIG12 , wherein the restoring force can be provided by the elastically deformed casting, by the winding wire itself, or by a combination of both. If the individual sub-windings are not cast, the corresponding deformation of the winding wire can also be performed reversibly in each sub-winding.

Figure 15 shows two magnets 24, 25 arranged at right angles to each other in the axial direction, which can be driven by the magnetic field of the winding arrangement. The magnets 24, 25 are fixedly connected to the rotor shaft 3.

FIG16 shows a division of the magnet 24 along the surface 26, thereby producing two segments 24a, 24b of the magnet 24, each of which forms a magnet element. The magnet 24 in the state shown in solid lines is rectangular. The series of figures showing the movement of the segment 24 relative to the segment 24b along the surface 26 in the axial direction 4 is shown in dotted lines. An axial expansion of the magnet 24 is provided, and as shown on the right side of FIG16 , a radial compression from diameter D to diameter d is provided. Due to the rotor construction shown, radial compression is also possible, so that the motor can be compressed in the assembled state by the joint compression of the stator and rotor, or can be compressed only by radial compression of the axially separated stator.

Thus, the motor can be compressed for delivery to a location of use; for example, the motor can be an implantable blood pump driver that can be moved in a compressed state within a patient's blood vessel to a location of use. At the location of use, the motor can be expanded, for example, to generate the necessary torque or power to drive the pump.

FIG17 shows a design variant in which the winding arrangement is divided into a plurality of sub-windings 27, 28, each of which is designed as a ring and arranged axially in sequence to form a hollow cylindrical winding arrangement. If the ring-shaped sub-windings are tilted in this arrangement, the winding arrangement has an elliptical cross-section, but the diameter is compressed relative to the non-tilted arrangement on axis 29. On axis 30, which is arranged at right angles thereto, the diameter remains unchanged. However, this tilted arrangement can provide a more favorable positioning of the motor. The tilt can be reversed at any time as the motor is positioned.

FIG18 shows the device shown in FIG7 , which comprises a stator having the windings 7 and 8 described above. A magnetic rotor 1″ is located within the stator, and a radially compressible pump rotor 29 is connected to the magnetic rotor 1″ and is rotatable coaxially with the rotor 1″. In this exemplary embodiment, the pump rotor is formed from an elastic, preferably highly resilient, plastic material, so that when the stator is compressed, the pump rotor 29 collapses, and when the stator is expanded, the pump rotor 29 elastically or superelastically expands, returning to its original form.

Figure 19 schematically shows a stator in a compressed manner similar to Figure 8, wherein the pump rotor 29 also has a compressed form. Here, the blades of the pump rotor are folded around the rotor axis and supported by the hub of the pump rotor.

In principle, the arrangement is formed so that the rotor 1 ″ together with the pump rotor 29 can be axially removed from the rotor in a manner corresponding to FIG. 20 . The pump rotor 29 and the stator are thus axially mounted one after the other. In this state, the stator and the pump rotor can be compressed together, so that the compressed diameter is further reduced compared to the embodiment shown in FIG. 19 .

In principle, the pump rotor can be formed in various ways. In addition to the deformations shown in Figures 18 and 19, which are formed from elastic or highly elastic plastic materials, various other deformations are known from the prior art, for example from US 4,753,221; US 5,749,855; US 7,393,181; US 2009/0062597A1; EP 2047873A1; US 2011/0275884A1; EP 2229965A1; WO 2010 149393A1; EP 2299119A1; EP 2338540A1; EP 2338541A1; EP 2363157; EP 2407185A1; EP 2407187A1; EP 2407186A1.

Claims (23)

1. An electric motor having a stator (2, 2') and a rotor (1, 1') that can be driven about an axial direction (4), characterized in that at least one of the stator and the rotor is radially compressible and expandable, wherein the stator has a winding configuration (7, 8, 20, 21, 22, 23, 27, 28) through which current can pass, the winding configuration (7, 8, 20, 21, 22, 23, 27, 28) having at least one sub-winding (7, 8, 20, 21, 22, 23, 27, 28) that can be reversibly deformed. 2. The motor according to claim 1, wherein the stator is radially compressible and expandable. 3. The motor according to claim 1 or 2, characterized in that the rotor (1, 1') and the stator (2, 2') are movable relative to each other between a first position and a second position in the axial direction (4), wherein the stator (2, 2') is radially compressed in the first position and the stator is radially expanded in the second position. 4. The motor according to claim 1 or 2, wherein the rotor (1, 1') can be radially compressed. 5. The motor according to claim 4, characterized in that the rotor (1, 1') has a plurality of magnetic elements (24, 24a, 24b, 25), the plurality of magnetic elements being reversibly movable relative to each other. 6. The motor according to claim 4, characterized in that the rotor (1, 1') has a plurality of magnetic elements (24, 24a, 24b, 25), which are reversibly movable relative to each other in the axial direction (4). 7. The motor according to claim 1 or 2, characterized in that the winding configuration (7, 8, 20, 21, 22, 23, 27, 28) has at least two sub-windings (7, 8, 20, 21, 22, 23, 27, 28) that can be reversibly moved relative to each other. 8. The motor according to claim 7, wherein the sub-windings can be arranged in a tile-like manner, with one sub-winding wrapped around another. 9. The motor according to claim 1 or 2, characterized in that the winding configuration (7, 8, 20, 21, 22, 23, 27, 28) has at least one sub-winding cast from an elastic material. 10. The motor according to claim 1 or 2, characterized in that the different sub-windings (7, 8, 20, 21, 22, 23, 27, 28) of the winding configuration are cast into a plurality of individual sub-bodies that can move relative to each other. 11. The motor according to claim 1 or 2, characterized in that the winding configuration (7, 8, 20, 21, 22, 23, 27, 28) has conductors (5, 6) that are at least partially composed of shape memory alloy. 12. The motor according to claim 1 or 2, characterized in that the winding configuration (7, 8, 20, 21, 22, 23, 27, 28) has bending and/or folding regions defined between elements that can move relative to each other. 13. The motor according to claim 1 or 2, characterized in that the connecting element (18, 19) extends outward from the motor, and the rotor (1, 1') and stator (2, 2') are movable relative to each other in the axial direction (4) via the connecting element. 14. An implantable device having a hollow conduit and a motor according to claim 1 or any of the following claims, wherein the motor is compressed within the hollow conduit. 15. A method for positioning an electric motor according to any one of claims 1 to 12, characterized in that the stator (2, 2') and the rotor (1, 1') are moved to a target position via a channel, wherein at least the stator is radially compressed, further characterized in that at least the stator is subsequently radially expanded. 16. The method according to claim 15, characterized in that once the stator (2, 2') and the rotor (1, 1') move to the target position, the stator and the rotor move relative to each other in the axial direction (4). 17. A blood pump comprising an electric motor having a stator (2, 2') and a rotor (1, 1') that can be driven about an axial direction (4), wherein at least one of the stator and the rotor is radially compressible and deployable, wherein the stator has a winding configuration (7, 8, 20, 21, 22, 23, 27, 28) through which current can pass, the winding configuration (7, 8, 20, 21, 22, 23, 27, 28) having at least one sub-winding (7, 8, 20, 21, 22, 23, 27, 28) that can be reversibly deformed. 18. The blood pump according to claim 17, wherein the stator is radially compressible and expandable. 19. The blood pump according to claim 17 or 18, wherein the rotor is connected to a pump rotor, wherein the pump rotor has blades for conveying liquid. 20. The blood pump according to claim 19, wherein the pump rotor in operation is at least partially located in the stator. 21. The blood pump according to claim 19, wherein the pump rotor can be radially compressed. 22. The blood pump according to claim 19, wherein the pump rotor can be radially elastically compressed. 23. A pump having a compressible pump rotor, wherein the pump rotor is mounted on an electric motor according to claim 1 or 2.