Rotor and manufacturing process for this

Abstract

Rotor comprising: a rotor shaft (4) through which a rotor axis (A) is defined; and a laminated core (6) arranged around the rotor shaft (4) along a longitudinal section (L) of the rotor axis (A), characterized in that the rotor shaft (4) has, in cross-section along the longitudinal section (L), both a first surface area (10) whose shape describes a circular cylinder, and a second surface area formed by structural elements (12) which extend radially outwards with respect to the rotor axis (A) above the first surface area (10), wherein the structural elements (12) each have an outwardly convex shape in a section transverse to the rotor axis (A), wherein the structural elements (12) have a maximum height (h) with respect to the circular cylinder which is between 0.05 and 5 mm, wherein the laminated core (6) is provided with a bore (14) for receiving the rotor shaft (4).wherein the bore (14) has a bore radius which is larger by a small dimension d than the radius r of the circular cylinder, wherein the small dimension d is between 0.001 mm and 2 mm, wherein the structural elements (12) in longitudinal section have a height which increases from an end region.

Description

[0001] The invention relates to a rotor with a rotor shaft by which a rotor axis is defined, and with a laminated core arranged around the rotor shaft along a longitudinal section of the rotor axis. The invention further relates to a manufacturing method for such a rotor.

[0002] With such a rotor, it is generally desirable or required that the laminated core is so firmly connected to the rotor shaft that during regular use of the rotor, for example as an element of an electric motor, no relative rotation can occur between the laminated core and the rotor shaft.

[0003] To manufacture such a rotor, it is known to shrink the laminated core onto the rotor shaft. However, this is comparatively time-consuming and expensive. In particular, this process requires extensive machining of the rotor shaft before shrinking.

[0004] The invention is based on the objective of providing a corresponding rotor that is easier to manufacture, as well as a manufacturing process for such a rotor.

[0005] This problem is solved according to the invention with the subject matter specified in the independent claims. Specific embodiments of the invention are specified in the dependent claims.

[0006] According to the invention, a rotor is provided which has a rotor shaft by which a rotor axis is defined, and a laminated core arranged around the rotor shaft along a longitudinal section of the rotor axis. Along the longitudinal section, the rotor shaft has a first surface region whose shape describes a circular cylinder, and a second surface region formed by structural elements that rise radially outwards with respect to the rotor axis above the first surface region.

[0007] To manufacture the rotor, the laminated core can be slid over the rotor shaft and pressed against the structural elements in such a way that the laminated core is plastically deformed, thereby creating a positive-locking connection between the rotor shaft and the laminated core. In this way, a reliable and torsion-resistant connection between the laminated core and the rotor shaft can be created particularly easily from a manufacturing perspective. In other words, a positive-locking connection produced through forming is achieved.

[0008] If the structural elements are designed parallel to the rotor axis, the laminated core can be slid over the rotor shaft without rotation during rotor manufacturing; this allows deformations of the laminated core to be created that are also designed parallel to the rotor shaft, so that a particularly reliable positive fit is formed.

[0009] Advantageously, the structural elements are designed such that they extend along the rotor axis over at least half, preferably at least two-thirds, and particularly preferably at least three-quarters of the longitudinal section. This allows for a comparatively large area of ​​positive locking and thus a particularly reliable positive locking connection.

[0010] Particularly advantageous are between three and one hundred, preferably between five and fifty, structural elements which are arranged evenly around the circumference of the rotor shaft.

[0011] It has proven advantageous if the structural elements, with respect to the circular cylinder, have a maximum height between 0.05 and 5 mm, preferably between 0.1 and 2 mm.

[0012] Advantageously, the structural elements in a cross-section perpendicular to the rotor axis each exhibit an outwardly curved shape. This promotes material displacement within the lamination stack during manufacturing, resulting in a particularly reliable positive-locking connection.

[0013] Furthermore, the rotor shaft is preferably designed such that – viewed in a section perpendicular to the axis of rotation – the angular regions covered by the first surface region are larger, preferably at least one and a half times larger, than the other angular regions covered by the second surface region. In this way, ample space can be provided between two adjacent structural elements to accommodate displaced material from the lamination stack, which in turn promotes the stability of the positive-locking connection.

[0014] According to another aspect of the invention, an electric motor is provided which has a rotor according to the invention.

[0015] According to a further aspect of the invention, a method for manufacturing a rotor is provided, comprising a rotor shaft through which a rotor axis is defined, and a laminated core arranged around the rotor shaft along a longitudinal section of the rotor axis. The rotor shaft has, along this longitudinal section, a first surface area whose shape describes a circular cylinder, and a second surface area formed by structural elements that extend radially outward with respect to the rotor axis above the first surface area. To connect the laminated core to the rotor shaft, the laminated core is pressed against the structural elements in such a way that the laminated core undergoes deformation.

[0016] Advantageously, the structural elements of the rotor shaft are formed by forming during the manufacturing process of the rotor shaft.

[0017] Furthermore, it is advantageous that during the manufacturing of the laminated core, the core is provided with a bore for receiving the rotor shaft, so that the core has a round inner diameter. The bore has a radius that is slightly larger than the radius of the circular cylinder, with this slight difference being less than or equal to the maximum height of the structural elements relative to the circular cylinder. This provides particularly suitable space between the structural elements for the deformation of the laminated core; this contributes to the formation of a particularly reliable connection between the laminated core and the rotor shaft.

[0018] Preferably, the smaller dimension is between 0.001 mm and 2 mm, preferably between 0.01 mm and 1 mm.

[0019] Advantageously, the method is a method for manufacturing a rotor according to the invention.

[0020] The invention will be explained in more detail below with reference to an exemplary embodiment and the drawings. The drawings show:

[0021] Fig. 1 a schematic cross-sectional sketch of a rotor according to the invention,

[0022] Fig. 2 the rotor shaft of the in Fig. 1 sketched rotors,

[0023] Fig. 3 a cross-sectional sketch through the rotor shaft,

[0024] Fig. 4 an excerpt from Fig. 3 with a corresponding proportion of the sheet metal package,

[0025] Fig. 5 a section of the rotor shaft and the associated laminated core,

[0026] Fig. 6 an isolated section of the rotor shaft,

[0027] Fig. 7 an isolated section of the sheet metal stack,

[0028] Fig. 8 an example of a stationary asynchronous motor and

[0029] Fig. 9 a welded sheet metal package.

[0030] A rotor according to the invention is suitable, for example, as the rotor of an electric motor, such as that found in Fig. Figure 8 is shown in the form of a stationary asynchronous motor. Fig. Figure 9 shows an example of a welded sheet metal package.

[0031] Fig. Figure 1 shows in a very schematic form an embodiment of a rotor according to the invention. 2 The rotor 2 a rotor shaft 4 on, which in Fig. 2 is shown in isolation. Through the rotor shaft 4 A rotor axis A is defined. Furthermore, the rotor has 2 a sheet metal package 6 on, which along a longitudinal section L of the rotor axis A around the rotor shaft 4 is arranged around it.

[0032] In Fig. 3 is a cross-section of the rotor shaft4 sketched in the area of ​​the longitudinal section L. The rotor shaft 4 has a first surface area within the longitudinal section L 10 on, whose shape describes a circular cylinder, as well as a second surface area defined by structural elements 12 is formed, which extends radially outwards with reference to the rotor axis A over the first surface area 10 raise. In Fig. 3 is the radius of the circular cylinder, denoted by r, and the maximum height of the structural elements. 12 with reference to the level of the circular cylinder with h.

[0033] Fig. Figure 4 shows an enlarged section from Fig. 3, including the corresponding part of the sheet metal package 6 is outlined.

[0034] To connect the sheet metal stack 6 with the rotor shaft 4 will the sheet metal package 6 such against the structural elements 12pressed or pressed so that the sheet metal package 6 This results in a deformation. In particular, this can be used to manufacture the rotor. 2 the sheet metal package 6 first with a drilling 14 to accommodate the rotor shaft 4 to be provided and in a subsequent step the sheet metal package 6 by a movement along the rotor axis A via the rotor shaft 4 be pressed until the desired relative arrangement between the sheet metal stack is achieved. 6 and rotor shaft 4 has been achieved. The structural elements 12 This can cause near-surface areas of the inner wall of the borehole to become affected. 14 through interaction with the structural elements 12 deform, so that a positive-locking connection is created as a result. In

[0035] Fig. 4 are corresponding changes caused by material displacements or deformations of the sheet metal stack. 6 caused accumulations16 or ramparts shown schematically.

[0036] The structural elements become advantageous from a manufacturing technology perspective. 12 the rotor shaft 4 during the manufacturing of the rotor shaft 4 formed by a transformation.

[0037] In Fig. Figure 5 shows a section of the rotor shaft from a perspective view. 4 and the associated sheet metal package 6 shown, in Fig. 6 an isolated section of the rotor shaft 4 and in Fig. 7 an isolated section of the sheet metal stack 6 In Fig. The 7 are, to give an indication, the accumulations. 16 to recognize.

[0038] As exemplified in the Fig. 1 and Fig. As outlined in section 2, it may be intended that the structural elements 12 are formed parallel to the rotor axis A. This allows the lamination stack to be slid on in a straight line. 6 on the rotor shaft 4– without rotation – this allows for the formation of linear accumulations. 16 form, so that an overall particularly effective form fit can be created.

[0039] It may be provided that the structural elements 12 are designed such that they extend along the rotor axis A over at least half, preferably at least two-thirds, particularly preferably at least three-quarters of the longitudinal section L, for example, over at least 80% or 90% of the longitudinal section L. The longer the structural elements 12 The longer the accumulations, the greater the duration. 16 can be achieved; with increasing length of the accumulations 16 In turn, it is generally possible to achieve an increasingly stable positive-locking connection.

[0040] In particular, it may be provided that the structural elements 12have the same cross-section along their entire length along the rotor axis A. This is advantageous from a manufacturing perspective. For example, it can be provided that the rotor axis 4 has a uniform cross-section over at least 80% or 90% of the longitudinal section L.

[0041] For example, a total of between three and one hundred, preferably between five and fifty, structural elements can be used. 12 be present, evenly distributed around the circumference of the rotor shaft 4 are arranged. Furthermore, it has proven advantageous if the structural elements 12 with reference to the circular cylinder, have a maximum height h which is between 0.05 and 5 mm, preferably between 0.1 and 2 mm.

[0042] Advantageous with regard to the material displacement of the sheet metal stack 6 The structural elements 12In a section viewed perpendicular to the rotor axis A, each structural element has an outwardly curved shape; in particular, it can be provided that each of the structural elements 12 It has no edge and preferably consists exclusively of an outwardly curved surface. The structural elements 12 They can therefore take the form of "bumps". This, viewed in cross-section, affects the material displacement of the sheet metal stack. 6 on the two sides of a corresponding structural element 12 supported; this material displacement is in Fig. 4 is indicated by the two small, bold arrows.

[0043] The structural elements can also 12 Viewed in longitudinal section, it should be shaped without an edge. This allows, in particular, a "lead-in chamfer" for inserting the rotor shaft. 4 into the bore 14 be educated.

[0044] It may be provided that the structural elements 12or humps, viewed in longitudinal section, have a height that increases from one end region. Furthermore, it is possible that the rotor is designed such that the number of structural elements 12 or the hump increases over a longitudinal section of the longitudinal axis. This facilitates the pressing of the sheet metal stack. 6 achieve.

[0045] For manufacturing purposes, it may be intended that the sheet metal package 6 with the drilling 14 to accommodate the rotor shaft 4 The bore is provided with a radius slightly larger than the radius r of the circular cylinder. This allows for a suitably dimensioned space for the formation of the accumulations. 16to ensure this. Advantageously, the bore radius is slightly larger than the radius r of the circular cylinder by a small dimension d, where this small dimension d is equal to or preferably smaller than the maximum height h of the structural elements. 12 with reference to the circular cylinder. For example, the relationship h / 3 < d < 2h / 3 can be provided. In absolute terms, d can be, for example, between 0.001 mm and 2 mm, preferably between 0.01 mm and 1 mm.

[0046] Furthermore, the design of the rotor shaft can 4 such that – viewed in a section perpendicular to the axis of rotation A – those angular ranges that are separated from the first surface area 10 are covered, are larger, preferably at least one and a half times larger, than those other angular regions covered by the second surface region. This can be demonstrated by Fig. 3 is illustrated by example. There, w 10the angular range that is defined by a part of the first surface area 10 is covered and with w 12 the angular range that is defined by an adjoining structural element 12 is covered. Due to the symmetrical design across the circumference, it follows that in the example shown, the ratio of those angular areas that are covered by the first surface area 10 are covered to those angular areas that are covered by the second surface area 12 covered are equal to w 10 / w 12 is, therefore, according to the drawing, greater than 1. As in turn, from Fig. As can be clearly seen in section 4, this design ensures that the formation of the accumulations 16 Sufficient space is ensured, which in turn supports the stability of the positive locking connection.

[0047] Finally, according to the invention, an electric motor with a rotor according to the invention is provided.

[0048] The rotor according to the invention is particularly easy to manufacture, thus resulting in particularly low manufacturing and production costs, while still offering a reliable, torsion-resistant connection between the rotor shaft and the lamination stack. This connection is ensured by a form-fit achieved through forming technology.

Claims

[1] Rotor, comprising – a rotor shaft ( 4 ), by which a rotor axis (A) is defined and – a sheet metal package ( 6 ), which extends along a longitudinal section (L) of the rotor axis (A) around the rotor shaft ( 4 ) is arranged around, characterized by , that the rotor shaft ( 4 ) along the longitudinal section (L) a first surface area ( 10 ) has a shape that describes a circular cylinder, as well as a second surface area defined by structural elements ( 12 ) is formed, which extends radially outwards with reference to the rotor axis (A) over the first surface area ( 10 ) raise. [2] Rotor according to claim 1, wherein the structural elements ( 12 ) are formed parallel to the rotor axis (A). [3] Rotor according to claim 1 or 2, wherein the structural elements ( 12) are designed such that they extend along the rotor axis (A) over at least half, preferably at least two-thirds, particularly preferably at least three-quarters of the longitudinal section (L). [4] Rotor according to one of the preceding claims, wherein between three and one hundred, preferably between five and fifty structural elements ( 12 ) are present, which are evenly distributed around the circumference of the rotor shaft ( 4 are arranged. [5] Rotor according to one of the preceding claims, wherein the structural elements ( 12 ) with reference to the circular cylinder have a maximum height (h) which is between 0.05 and 5 mm, preferably between 0.1 and 2 mm. [6] Rotor according to one of the preceding claims, wherein the structural elements ( 12 ) in a section perpendicular to the rotor axis (A) each have an outwardly curved shape. [7] Rotor according to one of the preceding claims, wherein, viewed in a section transverse to the axis of rotation (A), those angular regions which are separated from the first surface region ( 10 ) are covered, are larger, preferably at least one and a half times larger than those other angular areas that are covered by the second surface area. [8] Electric motor comprising a rotor according to any of the preceding claims. [9] Method for manufacturing a rotor which includes a rotor shaft ( 4 ) has a rotor axis (A) defined by which a lamination stack is defined ( 6 ), which extends along a longitudinal section (L) of the rotor axis (A) around the rotor shaft ( 4 ) is arranged around, characterized by that the rotor shaft ( 4 ) along the longitudinal section (L) a first surface area ( 10) has a shape that describes a circular cylinder, as well as a second surface area defined by structural elements ( 12 ) is formed, which extends radially outwards with reference to the rotor axis (A) over the first surface area ( 10 ) raise, where the connection of the sheet metal stack ( 6 ) with the rotor shaft ( 4 ) the sheet metal package ( 6 ) against the structural elements ( 12 ) is pressed so that the sheet metal stack ( 6 ) undergoes a deformation as a result. [10] Method according to claim 9, wherein the structural elements ( 12 ) the rotor shaft ( 4 ) as part of the manufacturing of the rotor shaft ( 4 ) are formed by a transformation. [11] Method according to claim 9 or 10, wherein during the manufacture of the sheet metal stack ( 6 ) the sheet metal package ( 6 ) with a bore ( 14 ) to accommodate the rotor shaft ( 4) is provided, wherein the bore ( 14 ) has a bore radius that is a small measure (d) larger than the radius (r) of the circular cylinder, where the small measure (d) is less than or equal to the maximum height (h) of the structural elements ( 12 ) with reference to the circular cylinder. [12] Method according to claim 11, wherein the small dimension (d) is between 0.001 mm and 2 mm, preferably between 0.01 mm and 1 mm. [13] Method according to any one of claims 9 to 12, wherein the rotor is a rotor according to any one of claims 1 to 7.

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