Abstract
A rotor (2) of an electrical machine (60) has a laminated rotor core (4). A fan (18), which is arranged at the end face in the laminated rotor core (4) is provided for cooling purposes. The fan has a fan blade (21) and a supporting element (20) for the fan blade (21), wherein the fan blade (21) extends by way of a first section (31) beyond the supporting element (20) in a first axial direction and extends by way of a second section (33) beyond the supporting element (20) in a second axial direction (34) which is opposite the first axial direction (32).
Claims
1. A rotor of an electrical machine, said rotor comprising: a laminated rotor core; and a fan arranged at an end face of the laminated rotor core, said fan having a fan blade and a supporting element for support of the fan blade, said fan blade having a first section sized to extend beyond the supporting element in a first axial direction and a second section sized to extend beyond the supporting element in a second axial direction which is opposite the first axial direction, wherein the supporting element is joined to the fan blade by a welded connection or bonded connection, and wherein the center of mass of the fan blade is located in a central area of the bonded connection or welded connection, with the bonded connection or welded connection having a radial orientation.
2. The rotor of claim 1, wherein the first section has a first mass and the second section has a second mass, said first and second masses establishing a center of mass of the fan blade which center of mass is located in an area of the supporting element.
3. The rotor of claim 1, wherein the supporting element is an annular disk.
4. The rotor of claim 1, wherein the fan blades are designed as sheet metal parts and attached to the supporting element.
5. The rotor of claim 1, wherein the second section has a thickness which is smaller than a thickness of the first section.
6. An electrical machine, comprising: a stator; a rotor interacting with the stator and including a laminated rotor core, and a fan arranged at an end face of the laminated rotor core, said fan having a fan blade and a supporting element for support of the fan blade, said fan blade having a first section sized to extend beyond the supporting element in a first axial direction and a second section sized to extend beyond the supporting element in a second axial direction which is opposite the first axial direction, wherein the electrical machine is a traction motor of a vehicle, wherein the supporting element is joined to the fan blade by a welded connection or bonded connection, and wherein the center of mass of the fan blade is located in a central area of the bonded connection or welded connection, with the bonded connection or welded connection having a radial orientation.
Description
BRIEF DESCRIPTION OF THE DRAWING
(1) The invention is explained in more detail hereinafter with reference to figures. The figures show:
(2) FIG. 1 a longitudinal section of an electrical machine;
(3) FIG. 2 a cross section of a rotor core;
(4) FIG. 3 a fan of the electrical machine of FIG. 1 viewed transversely to a rotational axis;
(5) FIG. 4 a vehicle with an electrical machine;
(6) FIG. 5 an embodiment of a fan blade;
(7) FIG. 6 a further embodiment of a fan blade;
(8) FIG. 7 a further embodiment of a fan blade;
(9) FIG. 8 a further embodiment of a fan blade;
(10) FIG. 9 a further embodiment of a fan blade;
(11) FIG. 10 a further embodiment of a fan blade;
(12) FIG. 11 a further embodiment of a fan blade;
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
(13) The diagram according to FIG. 1 shows an electrical machine 60 with a stator 1 and a rotor 2. The rotor 2 has a rotor shaft 3 and a laminated rotor core 4. The rotor shaft 3 is mounted in bearings 5 so that the rotor shaft 3, and with it the entire rotor 2, can be rotated around a rotational axis 6 of the electrical machine.
(14) Insofar as the terms “axial”, “radial” and “tangential” are used, they relate to the rotational axis 6. The term “axial” means a direction parallel to the rotational axis 6. The term “radial” means a direction orthogonal to the rotational axis 6 towards or away from the rotational axis 6. The term “tangential” means a direction orthogonal to the rotational axis 6 and orthogonal to the radial direction, in other words, at a constant radial distance from the rotational axis 6 in a circle around the rotational axis 6.
(15) As a rule, in accordance with the diagram of FIG. 1 the rotor 2 is arranged radially inside the stator 1. The electrical machine is therefore designed as an internal rotor. In individual cases, however, the rotor 2 can alternatively be arranged radially outside the stator 2. In this case, the electrical machine is designed as an external rotor.
(16) According to FIG. 1, the laminated rotor core 4 extends in an axial direction viewed from a first axial end face 7 of the laminated rotor core 4 to a second axial end face 8 of the laminated rotor core 4. The laminated rotor core 4 has a multiplicity of rotor cores 9 which are stacked on top of each other in an axial direction.
(17) According to FIGS. 1 and 2, apart from recesses for e.g. cooling channels, the laminated rotor core 4 has further recesses 10. According to FIG. 2, the further recesses 10 are distributed around the rotational axis 6. The further recesses 10 extend in an axial direction continuously through the laminated rotor core 4, in other words, from the first axial end face 7 to the second axial end face 8. A tension rod 11 is inserted into each of the further recesses 10. The tension rods 11 are longer than the laminated rotor core 4.
(18) The tension rods 11 therefore extend axially beyond the end faces 7, 8 of the laminated rotor core 4. The further
(19) According to FIG. 1, a fan 18 is mounted at the first axial end face 7 of the laminated rotor core 4 on the tension rod 11. According to the diagram in FIG. 1, in particular the fan 18 can be mounted on the fastening element 12 located at the first axial end face 7. In this case the fastening elements 12 are arranged between the first end face 7 and the fan 18. The fan 18 can be attached to the tension rods 11 in particular by means of further fastening elements 19, for example, by means of nuts 19.
(20) FIG. 2 shows a possible embodiment of the rotor cores 9. In particular, according to FIG. 2 the rotor cores 9 each have a yoke 14 on their side facing away from the rotational axis 6 and a sheet metal hub 15 on their side facing the rotational axis 6. The yokes 14 and the sheet metal hubs 15 of the rotor core 9 are connected to each other via respective sheet metal spokes 16. The use of the adjunct “sheet metal” in the designation of the sheet metal hubs 15 and the sheet metal spokes 16 serves to linguistically distinguish the aforementioned elements from other hubs and spokes. The adjunct “sheet metal” does not have a more detailed meaning in this connection.
(21) The fan 18 can be designed as required. According to FIGS. 1 and 3, the fan preferably has an annular disk 20 as a supporting element and fan blades 21. The annular disk 20 is orthogonal to the rotational axis 6. The fan blades 21 protrude from the annular disk 20. In particular, they can protrude orthogonally from the annular disk 20.
(22) It is possible that the annular disk 20 is identical to an outer ring 22. The outer ring 22 is essentially arranged at the same radial distance as the yokes 14 of the rotor core 9. The fan blades 21 are arranged on the outer ring 22. According to FIG. 3, however, in addition to the outer ring 22 the annular disk 20 also has a disk hub 23. In this case, the outer ring 22 is arranged on the side facing away from the rotational axis 6 of the annular disk 20, the disk hub 23 on the side facing the rotational axis 6 of the annular disk 20. The outer ring 22 and the disk hub 23 are connected to each other via disk spokes 24. The use of the adjunct “disk” in the designation of the disk hub 23 and the disk spokes 24 serves to linguistically distinguish the aforementioned elements from other hubs and spokes. The adjunct “disk” does not have a more detailed meaning in this connection.
(23) If the annular disk 20 comprises the outer ring 22, the disk hub 23 and the disk spokes 24, the contour of the annular disk 20 preferably corresponds to that of a rotor core 9.
(24) The disk hub 23 can be connected to the rotor shaft 3 in a torque-proof manner. Preferably, however, the annular disk 20 is dimensioned such that the disk hub 23 is not connected to the rotor shaft 3 in a torque-proof manner. The disk hub 23 therefore serves solely as a positioning and centering aid for the installation of the fan 18.
(25) In an embodiment the fan blades 21 are designed as sheet metal parts. The annular disk 20 can also be designed as a sheet metal part. The fan blades 21 can, for example, be mounted on the annular disk 20. The fan blades 21 are preferably mounted radially from the inside to the outside on the annular disk 20.
(26) The fan blades 21 can be connected to the annular disk 20 in any manner. The fan blades 21 are preferably welded to the annular disk 20.
(27) According to FIG. 1, the fan blades 21 have axial inner sections 25 and axial outer sections. An axial outer section is also called the first section, the axial inner section also being called the second section. According to FIG. 1 the axial inner sections 25 of the fan blade 21 are arranged between the annular disk 20 and the first axial end face 7. The axial height of the axial inner sections 25 is preferably measured in such a way that the axial inner sections 25 fit closely against the first axial end face 7 under compressive strength. The distance of the annular disk 20 or the outer ring 22 from the first axial end face 7 therefore exhibits a slight waviness in a circumferential direction viewed around the rotational axis 6, wherein the minima are found in the area of the tension rods 11 and the maxima in the area of the fan blades 21.
(28) According to FIG. 1 in order to remove an imbalance on at least one of the tension rods 11, (at least) one balancing weight 17 can be attached.
(29) In principle, an electrical machine according to the invention can be used for any purpose. The electrical machine according to FIG. 4 is preferably used as a traction motor 26 of a vehicle 27. The vehicle 27 can, for example, be designed as a railroad vehicle or as a road vehicle.
(30) The electrical machine according to FIG. 1 shows that the fan blade 21 can support the laminated rotor core 4. Vibration dampening can also be achieved by means of the fan blades 21.
(31) The diagram according to FIG. 5 shows a section of one embodiment of a fan 18 connected to the rotor of an electrical machine. A laminated rotor core 4 with a cooling channel 38 is shown in a sectional view. Further, a part of a fan 18 with a fan blade 21 is shown. The fan blade is supported by a supporting element 20 which can be rotated around a rotational axis 6. The fan blade 21 has a first section 31 in an axial outer section 35 and a second section 33 in an axial inner section 25. The second section 33 is facing the end face 7. The mass distribution of the fan blade 21 results in a center of gravity 45 of the mass as shown. The closer the center of gravity 45 moves to an area 41, the smaller the stress of a connection between the fan blade 21 and the annular disk 20. In the following figures variants of an embodiment of the fan 18 are shown. The same reference characters are used for similar parts.
(32) The diagram according to FIG. 6 shows a fan blade 21 which is attached to the supporting element 20 by means of welded seams 37. The first section 31, aligned in a first axial direction 32, has a welded connection and the second section 33, aligned in a second axial direction, also has a welded connection. The second section 33 with the axial inner section 25 extends into the cooling channel 38. The cooling channel 38 and the second section 33 of the fan blade 21 therefore overlap axially in an extension section 40. As a result of the second section 33 extending into the cooling channel 38, compared to FIG. 5 the center of gravity 45 shifts to the end face 7 of the laminated rotor core 4. The center of gravity 45 is thus located in the disk section area 42, resulting in the welded seams being less stressed during operation of the electrical machine than in the case of FIG. 5.
(33) The diagram according to FIG. 7 shows that the recess 38 can also extend in the end portion of the laminated rotor core 4 and the second section 33 extends there. The recess 38 into which the second section extends is not necessarily a cooling channel. The recess may also not have a passage from one end face to the other end face of the laminated rotor core.
(34) The diagram according to FIG. 8 shows a graduated embodiment of the second section 33 protruding into the cooling channel 38. A shift in the center of gravity to the axis 6 can thus be achieved.
(35) The diagram according to FIG. 9 shows that the first section 31 has a thickness 54 and the second section a thickness 53, which is different from the thickness 54. As the thickness 53 is greater than the thickness 54, the center of gravity is also altered in comparison with similar thicknesses.
(36) The diagram according to FIG. 10 shows a second section 33 which has a section of the extension 40 which is longer than the radial cross section of the recess 38. The second section 33 has an end portion 56 which is rounded off. The radius or the various radii of the curvature are at the level at which the second section 33 extends into the recess.
(37) The diagram according to FIG. 11 is a top view of a fan blade 21 to show the thickness ratios. As in the preceding figures, the fan blade has an axial inner section 25 and an axial outer section between which the disk section 41 is located. In a section 40 in which the blade 21 extends into a recess, the thickness 51 is less than, for example, in the axial outer section, the thickness 52 of which is comparatively greater.
(38) Although the invention was illustrated and described in more detail by the preferred exemplary embodiment, the invention is not limited by the disclosed examples and other variations may be derived therefrom by an expert without departing from the scope of the invention.
