WO2019219881A1

WO2019219881A1 - Permanent-magnetic radial rotating joint

Info

Publication number: WO2019219881A1
Application number: PCT/EP2019/062744
Authority: WO
Inventors: Xiang Li
Original assignee: Kardion Gmbh
Priority date: 2018-05-16
Filing date: 2019-05-16
Publication date: 2019-11-21
Also published as: DE102018207624A1

Abstract

The invention relates to a permanent-magnetic radial rotating joint (100) comprising: a first cylindrical permanent magnet (102) and a second permanent magnet (104) substantially in the form of a hollow cylinder, wherein the inner diameter of the second permanent magnet (104) is larger than the outer diameter of the first permanent magnet (102), the first permanent magnet (102) and the second permanent magnet (104) are coaxially arranged, both the first permanent magnet (102) and the second permanent magnet (104) are mounted such that they can rotate about the common axis, both the first permanent magnet (102) and the second permanent magnet (104) comprise at least two pole pairs, and the first permanent magnet (102) has the same number of pole pairs as the second permanent magnet (104). According to the invention, the second permanent magnet (104) has a thickening between respective adjacent pole boundaries (107). The invention also relates to a permanent magnet (102, 104) for a permanent-magnetic radial rotating joint (100), to a segment (120) for a permanent magnet (102, 104), and to a pump comprising such a radial rotating joint (100), such a permanent magnet (102, 104) and/or such a segment (120).

Description

PERMANENT MAGNETIC RADIAL STROKE COUPLING

description

The present invention relates to a permanent magnetic radial rotary coupling, a permanent magnet for such a permanent magnet radial rotary joint, a segment for such a permanent magnet and a pump with such a radial rotary coupling, such a permanent magnet and / or such a segment. In the prior art, magnetic, in particular permanent magnetic, radial rotary joints are known, with which a torque can be transmitted without contact from a driving shaft to a driven shaft. A main objective of a magnetic coupling is to transmit the highest possible torque for a given limited space. The use of such a magnetic coupling in a liquid pump is also known in the art. Two major categories of magnetic couplings are known in the art. These are axial and radial couplings, which are named after the direction of the magnetic flux inside the magnet.

The prior art also discloses the problem that parts of the abovementioned permanent magnets, which have a thin thickness, are prone to demagnetization. This reduces the transmittable torque and thus also the efficiency of the magnetic coupling. The demagnetization is caused by high temperatures and / or strong causing opposite magnetic fields. In the case of the abovementioned permanent-magnetic radial rotational couplings, the external and mostly hollow-cylindrical permanent magnet is often affected by the problem mentioned, since it usually has a thinner strength than the internal permanent magnet, which is usually cylindrical. The demagnetization is particularly strong when opposite poles on the inner and the outer Pemnanentmagne- th a radial rotary coupling opposite.

The object of the invention is to provide an improved permanent magnetic radial coupling.

In particular, it is an object of the invention to provide a pemnanentmagne- tische radial coupling, which is particularly suitable for use in a cardiac assist system in the body of a patient and at prevailing temperatures in a small space that for driving an impeller for delivering blood torques to be supplied permanently, ie can transmit with a long service life.

This object is achieved by a specified in claim 1 permanent magnetic radial clutch, a permanent magnet with the features of claim 5 and the specified in claim 7 segment for a permanent magnet.

Advantageous embodiments of the invention are specified in the dependent claims.

A permanent magnet radial rotational coupling according to the invention serves for the non-contact transmission of torques, in particular of a pemnan magnet driven by means of a rotational movement, to a rotatably mounted other permanent magnet. A permanent magnetic radial rotational coupling according to the invention has a first cylindrical permanent magnet and a second substantially hollow cylindrical permanent magnet. In this case, the inner diameter of the second permanent magnet is greater than the outer diameter of the first permanent magnet and the first permanent magnet and the second permanent magnet are arranged coaxially. Furthermore, both the first permanent magnet and the second permanent magnet are rotatably mounted about the common axis. In addition, both the first permanent magnet and the second permanent magnet have at least two pole pairs and the first permanent magnet has the same number of pole pairs as the second permanent magnet.

The number of pole pairs used depends on the requirements of the torque to be transmitted and the axial force to be set.

The second permanent magnet each has a thickening between adjacent pole boundaries. For example, for a permanent magnet radial rotary joint with two pole pairs, there is a pole boundary every 90 ° for both the first and the second permanent magnets. At the points between the pole boundaries, the outer second permanent magnet can be demagnetized particularly easily.

In the present context, the term "thickening" in connection with the essentially hollow cylindrical shape means that the essentially hollow cylindrical shape is thicker than a comparable flooding cylinder. Thus, the thickening can be understood as a deviation from a hollow cylindrical shape. At the same time it is clear that the substantially hollow cylindrical shape is not thickened at the pole boundaries, in particular does not deviate from the hollow cylindrical shape. For the above-mentioned deviation from the hollow cylindrical shape, therefore, a single point is sufficient to be regarded as a thickening. The permanent magnet radial rotational coupling advantageously achieves that the second external permanent magnet is less prone to demagnetization. This is due to the radial thickening of the second permanent magnet between adjacent pole boundaries.

The geometry and volume of thickening, d. H. the volume of the permanent magnets has an influence on the demagnetization of the outer permanent magnet. The geometry and the volume of the thickening are dependent on the specific requirements of the radial rotation coupling, d. H. the material properties, the manufacturing process and the forces to be set in the bearing selected.

According to a preferred embodiment, the radial rotary coupling may be a coupling of a cardiac assisting system, in particular a pump of such a system.

According to a preferred embodiment, the thickening is that on an inner side of the second permanent magnet between a first point on the inside of the second permanent magnet, which lies on a first pole boundary, and a second point on the inner side of the second permanent magnet, which on a to the first adjacent pole boundary, a radius of curvature is greater than for the case that the second permanent magnet is hollow cylindrical. The above-mentioned construction refers to a view along the common axis of the radial rotary joint. The thickening referred to here is therefore cylindrical and has the same thickening at each point along the common axis of the radial rotary coupling. The thickening according to this feature is advantageously easy to produce, and in a somewhat more simple manner achieves a massive thickening of the second pemnary magnet. As an alternative or in addition to the thickening just mentioned, the thickening may also be such that on an outer side of the second permanent magnet between a first point on the outside of the second permanent magnet, which lies on a first pole boundary, and a second point on the outside of the second Permanent magnet, which is on a first adjacent pole boundary, a radius of curvature is smaller than in the case that the second permanent magnet is hollow cylindrical. The above construction also refers to a view along the common axis of the radial rotational coupling. The thickening referred to here is therefore cylindrical and has the same thickening at each point along the common axis of the radial rotary coupling. The thickening according to this feature is advantageously easy to manufacture and easily achieves a massive thickening of the second permanent magnet, which substantially improves the problem of demagnetization.

According to a preferred embodiment, for each thickening, a difference between outer diameter and inner diameter of the substantially hollow cylindrical shape of the second permanent magnet is at most 30% greater than a difference between the outer diameter and inner diameter of a hollow cylindrical shape, which is just as large at the pole boundaries essentially hollow cylindrical shape of the second permanent magnet. It is advantageously achieved by this feature that the second permanent magnet is not substantially thicker than a comparable hollow cylinder and, nevertheless, a significant improvement in the problem of demagnetization is achieved.

The permanent magnet is provided for a permanent magnetic radial rotary coupling, in particular a permanent magnetic radial rotary coupling described above. The permanent magnet is substantially hollow cylindrical and has at least two pole pairs.

Furthermore, the permanent magnet in each case has a thickening between adjacent pole boundaries. In this case, the permanent magnet may be an internal permanent magnet like the first permanent magnet of the above-described radial rotational coupling. Further, the permanent magnet may also be an outboard permanent magnet such as the permanent magnet of the above-described radial rotary joint.

The permanent magnet, like the abovementioned permanently magnetic radial rotary coupling, advantageously achieves that the pemnan magnet tends to be less susceptible to demagnetization.

Similarly as described above, according to a preferred embodiment of the permanent magnet, the thickening may consist in that on an inner side of the permanent magnet between a first point on the inside of the permanent magnet, which is on a first pole boundary, and a second point on the inside of Permanent magnets, which lies on a first adjacent pole boundary, a radius of curvature is greater than in the event that the permanent magnet is hollow cylinder-shaped.

As an alternative or in addition to the thickening just mentioned, the thickening may also consist in that on an outside of the permanent magnet between a first point on the outside of the permanent magnet, which lies on a first pole boundary, and a second point on the outside of the permanent magnet, which lies on a first adjacent pole boundary, a radius of curvature is smaller than in the case that the permanent magnet is hollow cylindrical. How advantages of such a permanent magnet are similar to the advantages of the above-mentioned radial rotary joint. The thickening according to this feature is advantageously easy to manufacture and easily achieves a massive thickening of the second permanent magnet, which substantially improves the problem of demagnetization.

The segment of a permanent magnet mentioned above is characterized in that the corresponding permanent magnet has at least two pole pairs and the segment of the permanent magnet is substantially hollow-cylinder segment-shaped. It follows that all segments can be combined to form a hollow cylindrical permanent magnet.

In general, a segment of a permanent magnet having a predetermined number of pole pairs sweeps 180 ° divided by the number of pole pairs. For example, for a pole pair, the pole boundaries are each 180 ° apart. In this case, one segment also passes over 180 °, which indicates that it needs two segments to assemble the permanent magnet.

Similar to the above-mentioned permanent magnet, the segment has a thickening between its ends compared to a hollow cylinder segment shape.

The segment of the permanent magnet, like the abovementioned permanent magnet and the abovementioned permanent magnetic radial rotational coupling, advantageously achieves that the segment is less susceptible to demagnetization.

Similarly as already described above, according to a preferred embodiment of the segment, the thickening may consist in that on an inner side of the segment of the permanent magnet, between a first point on the inside of the segment of the permanent magnet, which is on a first pole boundary, and a second point on the inside of the segment of the permanent magnet, which is on a first adjacent pole boundary, a radius of curvature is greater than in the case that the segment of the permanent magnet is hollow cylinder segment-shaped.

As an alternative or in addition to the thickening just mentioned, the thickening may likewise consist in that on an outer side of the segment of the permanent magnet between a first point on the outer side of the segment of the permanent magnet, which lies on a first pole boundary, and a second point Point on the outside of the segment of the permanent magnet, which is on a first adjacent pole boundary, a radius of curvature is smaller than in the case that the segment of the permanent magnet is a hollow cylinder segment-shaped.

How advantages of such a segment of a permanent magnet are similar to the advantages of the above permanent magnet and the above-mentioned radial rotary joint. The thickening according to this feature is advantageously easy to manufacture and in a simple manner achieves a massive thickening of the second permanent magnet, which substantially improves the problem of demagnetization.

One way to produce a permanent magnet is as follows. A powder of a raw material, for example, sintered neodymium-iron-boron, is first pressed into a predetermined shape of a segment of the permanent magnet, whereupon the magnetization process starts. After the segments have been produced, all segments are assembled and glued together to form a ring.

The pump has a permanent magnet radial rotary coupling described above and / or a permanent magnet described above on. Thus, this pump also achieved that the problem of demagnetization is significantly improved.

Advantageous embodiments of the invention are explained in more detail with reference to the schematic drawings in the following description.

1A shows a permanent magnetic radial rotary joint according to the prior art, wherein the pole pairs of the first permanent magnet are oriented as well as the pole pairs of the second permanent magnet.

Fig. 1B shows the same embodiment of the permanent magnetic

Radial rotary coupling as shown in Fig. 1A, but wherein the pole pairs of the first permanent magnet are rotated by 90 ° relative to the pole pairs of the second permanent magnet.

FIG. 2A shows a permanent magnetic radial rotational coupling according to an embodiment of the invention with a thickened inner side.

FIG. 2B shows a permanent magnetic radial rotational coupling according to an embodiment of the invention with a thickened outside. FIG. 2C shows a permanent magnetic radial rotational coupling according to an embodiment of the invention with a thickened inner side and a thickened outer side. FIG.

Fig. 3 shows a segment according to an embodiment of the invention of a permanent magnet for a permanent magnet radial Radial rotary coupling. FIG. 1A shows a permanent magnet radial rotary coupling 100 according to the prior art.

In this case, both the first permanent magnet 102 and the second permanent magnet 104 have two pole pairs. By small arrows each of the course of the magnetic field is indicated. The first permanent magnet 102 is disposed on a driving shaft 106. The second permanent magnet 104 is mounted on a housing 108.

In FIG. 1A, the two pole pairs of the first permanent magnet 102 are oriented in the same way as the pole pairs of the second permanent magnet 104.

FIG. 1B shows the same embodiment of the permanent magnetic radial rotary coupling as in FIG. 1A, but with the pole pairs of the first being rotated by 90 ° with respect to the pole pairs of the second permanent magnet. It can be seen that the arrows between the first permanent magnet 102 and the second permanent magnets 104 are opposite, which leads to a demagnetization, in particular of the second permanent magnet 104, since this has a lower strength than the first permanent magnet 102.

2A shows a permanent magnetic radial rotational coupling 100 according to an embodiment of the invention with a thickened inner side 1 10. This can be seen from the enlarged radius of curvature of the inner side 110, which is illustrated by arrow 14, which indicates the radius of curvature. The corresponding radius of curvature 16 of the outer side 12 is identical to the radius of a hollow cylinder and terminates on the one hand in the center of the shaft 106, which is identical to the common axis of the two permanent magnets.

The first permanent magnet 102 and the second permanent magnet 104 are arranged coaxially. Further, both the first permanent magnet 102 and the second permanent magnet 104 rotatably supported about the common axis. The first permanent magnet 102 and the second permanent magnet 104 each have two pole pairs.

The second permanent magnet 104 has between each Polgren- zen 107 each have a thickening, which in the present case on the inner side 1 10 of the second permanent magnet 104 is attached.

The second permanent magnet 104 of the radial rotational coupling 100 of FIG. 2A has in comparison to a hollow cylindrical permanent magnet, for. B. the outer permanent magnet of FIG. 1A or 1B an inhomogeneous thickening, wherein the radius of curvature on the inner side by about 22% larger and the radius of the second permanent magnet 104 is up to 30% thicker.

A simulation showed that with this second permanent magnet 104, the transmittable torque was increased by about 30% at a rotation angle of 90 °. A further simulation revealed that the thickening improved the demagnetization ratio of the second permanent magnet 104 compared with the embodiment of FIG. 1A or 1B.

Fig. 2B shows another embodiment of the permanent magnetic radial rotary coupling 100 with a thickened outer side 1 12. This can be seen in the reduced radius of curvature of the outer side 1 12, which is illustrated by arrow 1 16, which indicates the radius of curvature. The corresponding radius of curvature 1 14 of the inner side 1 10 is identical to the radius of a Flohlzylinders and ends on the one hand in the center of the shaft 106, which is identical to the common axis of the two permanent magnets.

FIG. 2C shows a further embodiment of the permanent magnetic radial rotational coupling with a thickened inner side 110 and one Thickened outer side 1 12. This embodiment is a commission of the embodiments 2A and 2B, so to speak, wherein the inner side 1 10 of the embodiment of Fig. 2A and the outer side 1 12 of the embodiment of Fig. 2B has been taken. Furthermore, a segment 120 of the second permanent magnet 104 is shown, which is also shown in FIG.

FIG. 3 shows a segment 120 of the second permanent magnet 104 of the embodiment of FIG. 2C. The segment 120 has a thickening both on the inner side 1 10 and on the outer side 1 12 between the pole boundaries 107 of the second permanent magnet 104.

In particular, the following is to be noted: The invention relates to a permanent magnetic radial rotary coupling 100, a permanent magnet 102, 104 for a permanent magnetic Radialdrehkupp- 100, a segment 120 for a permanent magnet 102, 104 and a pump with such a radial rotary coupling 100, with such Permanent magnet 102, 104 and / or with such a segment 120. The permanent magnetic rotary coupling 100 has a first cylindrical permanent magnet 102 and a second substantially hollow cylindrical permanent magnet 104, wherein the inner diameter of the second permanent magnet 104 is greater than the outside - Diameter of the first permanent magnet 102 is. The first permanent magnet 102 and the second permanent magnet 104 are arranged coaxially, wherein both the first permanent magnet 102 and the second permanent magnet 104 are rotatably mounted about the common axis. Both the first permanent magnet 102 and the second permanent magnet 104 have at least two pole pairs, wherein the first permanent magnet 102 has the same number of pole pairs as the second permanent magnet 104. The second permanent magnet 104 has a thickening between adjacent pole boundaries 107.

Claims

claims

A permanent magnet radial rotary joint (100) comprising:

a first cylindrical permanent magnet (102) and a second substantially hollow cylindrical permanent magnet

(104)

wherein the inner diameter of the second permanent magnet (104) is larger than the outer diameter of the first permanent magnet (102);

the first permanent magnet (102) and the second permanent magnet

(104) are arranged coaxially;

both the first permanent magnet (102) and the second permanent magnet (104) are rotatably mounted about the common axis; both the first permanent magnet (102) and the second permanent magnet (104) have at least two pole pairs;

the first permanent magnet (102) has the same number of pole pairs as the second permanent magnet (104); characterized in that the second permanent magnet (104) between adjacent Polgren- zen (107) each having a thickening.

2. Permanent magnet radial rotational coupling (100) according to claim 1, characterized in that the thickening consists in that on an inner side (110) of the second permanent magnet (104) between a first point on the inside of the second Pemnanent- magneten (104) , which is located on a first pole boundary (107), and a second point on the inside (110) of the second pemnary magnet (104) which lies on a first adjacent pole boundary (107), a radius of curvature (114) greater is as in the case that the second permanent magnet (104) is hollow cylindrical.

3. permanent magnetische radial rotary joint (100) according to claim 1 or 2, characterized in that the thickening is that on an outer side (112) of the second permanent magnet (104) between a first point on the outer side (112) of the second

Permanent magnet (104), which is located on a first pole boundary (107), and a second point on the outer side (112) of the second permanent magnet (104), which is on a first adjacent pole boundary (107), a radius of curvature (116) smaller is as in the case that the second permanent magnet (104) is hollow cylindrical.

4. Permanent magnetic radial rotary coupling (100) according to one of the preceding claims, characterized in that for each thickening, a difference between the outer diameter and inner diameter of the substantially hollow cylindrical shape of the second permanent magnet (104) is at most 30% greater than a difference between outer diameter and inner diameter of a hollow cylindrical shape, which is the same at the pole boundaries (107) as the substantially hollow cylindrical shape of the second permanent magnet (104).

5. permanent magnet (102, 104) for a permanent magnetic radial rotation coupling (100), characterized in that

the permanent magnet (102, 104) is substantially hollow cylindrical in shape;

the permanent magnet (102, 104) has at least two pole pairs; and

the permanent magnet (102, 104) between adjacent pole boundaries

(107) each having a thickening. Permanent magnet (102, 104) according to the preceding claim, characterized in that

the thickening consists in that on an inner side (110) of the permanent magnet (102, 104) between a first point on the inner side (110) of the permanent magnet (102, 104) which lies on a first pole boundary, and a second point on the inner side (110) of the permanent magnet (102, 104) which lies on a first adjacent pole boundary (107), a radius of curvature (1 14) is greater than in the case that the permanent magnet (102, 104) is hollow cylindrical,

and or

on an outer side (1 12) of the permanent magnet (102, 104) between a first point on the outer side (1 12) of the permanent magnet (102, 104), which lies on a first pole boundary (107), and a second one Point on the outside (1 12) of the permanent magnet (102, 104), which is on a first adjacent pole boundary (107), a radius of curvature (1 16) is smaller than in the case that the permanent magnet (102, 104 ) is hollow cylindrical.

Segment (120) for a permanent magnet (102, 104) according to one of claims 5 or 6 for a permanent magnetic radial rotary coupling (100),

characterized in that

the permanent magnet (102, 104) has at least two pole pairs; the segment (120) of the permanent magnet (102, 104) is substantially hollow cylinder segment-shaped; and

the segment (120) has a thickening between its ends compared to a hollow cylindrical segment shape.

Segment (120) according to the preceding claim,

characterized in that

the thickening is that on an inner side of the segment (120) of the permanent magnet (102, 104) between a first point on the inside (110) of the segment (120) of the permanent magnet (102, 104) lying on a first pole boundary (107), and a second point on the inside (110) of the segment (120) of the permanent magnet (102,

104), which lies on a first adjacent pole boundary (107), a radius of curvature (114) is greater than in the case that the segment (120) of the permanent magnet (102, 104) is hollow cylindrical, and / or

on an outer side (112) of the segment (120) of the permanent magnet (102, 104) between a first point on the outer side (112) of the segment (120) of the permanent magnet (102, 104) which is located on a first pole boundary (107 ), and a second point on the outside (112) of the segment (120) of the permanent magnet (102, 104) which lies on a first adjacent pole boundary (107), a radius of curvature (116) is smaller than for the Case that the segment (120) of the permanent magnet (102, 104) is hollow cylindrical.

9. pump with a permanent magnetic radial rotary coupling (100) according to one of claims 1 to 4, a permanent magnet (102,

104) according to any one of claims 5 or 6 and / or a segment (120) according to claim 7 or 8.