Rotor with fixing means for fixing the tie rods, method for producing the rotor and electrical machine with the rotor

Abstract

A rotor 3 for an electrical machine 1 is proposed, comprising a rotor carrier 4 which is mounted for rotation about an axis of rotation 100; comprising a rotor body 5 formed from at least two partial laminated cores 6, wherein the partial laminated cores 6 are arranged on the rotor carrier 4 rotated relative to one another in the circumferential direction about the axis of rotation 100 by a helix angle 102; comprising a plurality of tie rods 8 distributed in the circumferential direction, each of which is guided in the axial direction with respect to the axis of rotation 100 through a tie rod receptacle 11 of the rotor body 5, wherein the tie rod receptacles 11 are formed by elongated holes 14 in the partial laminated cores 6 which are offset from one another in the circumferential direction by the helix angle 102, wherein the tie rods 8 are each fixed within the tie rod receptacles 11 by at least one fixing means 16 in order to reduce deflection of the tie rod 8 within the tie rod receptacle 11 during operation of the electrical machine 1.

Description

[0001] The invention relates to a rotor for an electrical machine having the features of claim 1. Furthermore, the invention relates to a method for producing the rotor and to an electrical machine having the rotor.

[0002] Rotors for electrical applications are known which are constructed from several laminated cores which are connected or clamped together via several fastening bolts. The laminated cores are each formed from several individual sheets stacked on top of one another, which are joined by punching and joining to form the respective laminated core. It is also known that several of these laminated cores can be arranged with a slant to one another in the circumferential direction. For this purpose, the laminated cores are rotated relative to one another in their circumferential direction, resulting in a slant of the laminated cores. The resulting slant of the rotor poles can optimize the noise behavior, in particular the noise-vibration-harshness (NVH) behavior, as well as rotational irregularities of the rotor.

[0003] The publication DE 10 2010 044 521 A1 describes a rotor of an electrical machine, comprising a rotor carrier and a rotor core. The rotor core has a recess that penetrates the rotor core in the axial direction. The rotor carrier is arranged axially adjacent to the rotor core, and the rotor core is firmly connected to the rotor carrier via a fastening bolt that penetrates the recess in the rotor core in the axial direction. The recess can be configured as an elongated hole such that the fastening bolt firmly connects a first laminated core stack and a second laminated core stack, adjacent in the axial direction and rotated by an angle, to the rotor carrier through the recess.

[0004] The object of the invention is to create a rotor of the type mentioned above which is characterized by improved operating behavior.

[0005] This object is achieved by a rotor having the features of claim 1, a method having the features of claim 11, and an electrical machine having the features of claim 15. Further features, advantages, and effects of the invention are described in the subclaims and the description with the accompanying figures.

[0006] The invention relates to a rotor that is designed and / or suitable for an electric machine. In particular, the electric machine is designed as an internal rotor, with the rotor arranged radially within a stator.

[0007] The rotor has a rotor carrier that is mounted for rotation about a rotational axis. For example, the rotor carrier can be mounted for rotation in a housing of the electric machine via at least one or exactly one rotor bearing. The rotor carrier is preferably designed as a rotor shaft. Specifically, the rotational axis is defined by a rotational axis of the rotor carrier or the rotor shaft.

[0008] The rotor has a rotor body formed from at least or exactly two partial laminated cores. In particular, the at least two partial laminated cores are arranged together on the rotor carrier in the axial direction with respect to the axis of rotation, one after the other and / or in a rotationally fixed manner. For this purpose, the partial laminated cores can each have a central through-opening which is designed and / or suitable for receiving the rotor carrier. For example, the rotor body can comprise more than two, preferably more than four, in particular more than six of the partial laminated cores. The partial laminated cores are preferably each formed from a plurality of individual laminations stacked on top of one another in the axial direction. The electrical machine is preferably designed as a permanently excited machine, wherein for this purpose a plurality of pole-generating magnets, in particular permanent magnets, are arranged in the rotor body or in the partial laminated cores.For this purpose, the partial laminated cores preferably each have a plurality of receiving pockets distributed in the circumferential direction, in each of which at least one of the magnets is arranged.

[0009] The partial lamination stacks are arranged on the rotor carrier rotated relative to one another by a helix angle in the circumferential direction around the axis of rotation. The rotor body therefore has a discrete twist. In other words, the partial lamination stacks are arranged discretely twisted relative to one another. A twist is generally understood to be an "oblique" course of the rotor poles, with poles of the same polarity being arranged at different angular positions or at different positions on the circumference over an axial length of the rotor. The discrete twist can be designed either in a linear form or in a V-shape. With a linear twist, the skew of the poles of the same polarity runs linearly from one axial end face to the opposite axial end face. In other words, a linear twist is understood to be a uniform offset of the partial lamination stacks arranged one behind the other.In a V-shaped twist, the skew of the poles of the same polarity runs in a V-shape from one axial end face to the opposite axial end face. In other words, a V-shaped twist is understood as an offset with different offset directions of the partial laminated cores arranged one behind the other.

[0010] Optionally, the rotor can have two end plates that are non-rotatably connected to the rotor carrier and arranged at each end on an axial end face of the rotor body. The two end plates are, in particular, formed separately from the laminated core and the rotor carrier. Alternatively, however, one of the end plates can also be formed integrally with the rotor carrier. The end plates are preferably designed as so-called balancing plates.

[0011] The rotor has a plurality of tie rods distributed in the circumferential direction, each of which is guided in the axial direction through a tie rod receptacle of the rotor body. The tie rods serve to apply a prestress, preferably a tensile stress, to the partial laminated cores, acting at least partially in the axial direction with respect to the axis of rotation. In particular, the partial laminated cores are non-positively connected to one another and / or to the end plates in the axial direction by the clamping means. The rotor can have more than two, preferably more than four, in particular more than six of the clamping means. In particular, the end plates each have a tie rod opening for receiving the tie rods.

[0012] For example, the tie rod openings can be designed as through holes which are arranged in pairs in alignment with each other in the axial direction.

[0013] The tie rod receptacles are each formed by elongated holes in the partial laminated cores that are offset from one another in the circumferential direction by the helix angle. In particular, the elongated holes are arranged so as to overlap and / or partially cover one another in the circumferential direction. Thus, with tie rods inserted, the partial laminated cores can only be rotated relative to one another in the circumferential direction to the extent permitted by the elongated holes. In other words, a maximum helix offset or a maximum helix angle over the entire length of the rotor is predetermined by the longitudinal extent of the elongated holes. The longitudinal extent of the elongated holes preferably extends in the circumferential direction and / or tangential direction.

[0014] Within the scope of the invention, it is proposed that the tie rods are fixed within the tie rod receptacles by at least one or exactly one fixing means in order to reduce deflection of the tie rod within the tie rod receptacle during operation of the electrical machine. In particular, the fixing means serves to support the tie rod in the radial and / or axial direction and / or in the circumferential direction relative to the axis of rotation. In other words, the fixing means compensates for or reduces movement and / or bending of the tie rod within a tolerance gap formed in the tie rod receptacle. The tolerance gap is determined on the one hand by the longitudinal extent of the elongated holes and on the other hand by a clearance fit of the tie rods. The fixing means can be designed for the positive and / or non-positive and / or materially bonded fixation of the tie rod within the respective tie rod receptacle.The fixing means can be designed as a separate component. Alternatively, the fixing means can form an integral part of the rotor body, in particular of one of the partial laminated cores.

[0015] The invention is based on the finding that the long tie rods are inserted into the tie rod receptacles with a certain tolerance in order to, on the one hand, enable the partial laminated cores to be rotated in the circumferential direction and, on the other hand, to simplify assembly of the tie rods. During operation of the electrical machine, the tie rods are loaded by centrifugal forces and the axial preload force. Since the long tie rods can bend further due to the forces acting within the tolerance gap of the tie rod receptacles, the tie rods are exposed to extreme loads, which in the worst case can lead to fatigue failure or fatigue fracture of the tie rods. This problem increases with the size of the tolerance gap. In addition, the tie rod can cause noise or vibrations within the tie rod receptacle. Furthermore, the tie rods can deform or break unevenly within the tolerance gap.bend, causing an imbalance.

[0016] The advantage of the invention is that the at least one fixing means fixes the tie rod at at least one point within the tie rod receptacle, whereby the tie rod is supported at least once over the entire axial length of the rotor. This can, on the one hand, significantly reduce the deflection of the tie rod and thus the load on the tie rod during operation. On the other hand, vibrations and the associated noise can be reduced or eliminated. Furthermore, due to the low deflection, the imbalance can be significantly reduced. A rotor is thus proposed which is characterized by improved operating behavior.

[0017] In a specific embodiment, at least one or exactly one fixing means is arranged centrally in the respective tie rod receptacle in the axial direction relative to the rotation axis. Preferably, if there is an even number of partial lamination stacks, the fixing means are arranged between the two central partial lamination stacks. If there is an odd number of partial lamination stacks, the fixing means can be arranged centrally in the middle partial lamination stack. The central arrangement of the fixing means allows the tie rod to be supported at the point of greatest deflection, thereby significantly reducing the deflection.

[0018] Alternatively or optionally in addition, it is provided that a plurality of the fixing means are arranged in the tie rod receptacle evenly distributed in the axial direction over the entire axial length of the rotor body. In particular, the rotor body has more than two, preferably more than three, especially more than five of the fixing means per tie rod receptacle. Alternatively or optionally in addition, the rotor body has n / 2 fixing means per tie rod receptacle, where “n” corresponds to an even number of partial laminated cores. In other words, every second partial laminated core has the fixing means. Alternatively or optionally in addition, each of the partial laminated cores has at least or exactly one fixing means per tie rod receptacle. By arranging a plurality of fixing means distributed in the axial direction, the deflection can be further reduced.The number of fixing means in the axial direction can be selected, for example, depending on the axial length of the rotor.

[0019] In an alternative embodiment, it is provided that the at least one fixing means extends over the entire axial length of the rotor body. In particular, the fixing means extends in the axial direction between the axial end faces and / or the axial end plates. Preferably, the fixing means extends continuously and / or uninterruptedly in the axial direction. Particularly preferably, the tie rod rests against the fixing means in the radial direction and / or in the circumferential direction in sections or over the entire axial length without play. A fixing means is thus proposed which supports the tie rod for the most part or over the entire length of the rotor body. As a result, deflection of the tie rod can be significantly reduced or prevented. In addition, the noise behavior can be significantly improved.

[0020] In a specific embodiment, it is provided that at least one of the fixing means is formed by a potting compound which fills a tolerance gap formed by the elongated holes. In particular, the potting compound fills the tolerance gap largely or completely. Particularly preferably, the tie rod is embedded in the potting compound without play. In particular, the tie rod is fixed by the potting compound in a form-fitting and / or material-fitting manner in the radial direction and / or in the circumferential direction within the tie rod receptacle. For example, the potting compound can be formed by an adhesive, a plastic injection molding, a casting resin, preferably epoxy resin, an expansion compound or the like. In principle, the potting compound can be dimensionally stable and / or solid after solidification. This enables the tie rod to be fixed in place over the entire axial length of the rotor body in a simple manner.In addition, the tie rod can be supported in all spatial directions, but preferably in the radial and circumferential directions, in the tie rod holder. Embedding the tie rod in the casting compound also enables axial securing of the tie rod due to the bond strength.

[0021] In an alternative or optionally additional embodiment, it is provided that at least one of the fixing means is designed as an insert element which is received in an insert receptacle formed on at least or exactly one of the partial laminated cores, wherein the insert element has a receiving opening in which the tie rod is received in a form-fitting and / or force-fitting manner at least in the radial direction. Optionally, the tie rod can be received in the receiving opening in a form-fitting and / or force-fitting manner in the circumferential direction and / or in the axial direction. In particular, the insert element is received in the insert receptacle in an axial and / or radial direction and / or in the circumferential direction in a form-fitting and / or material-fitting manner, preferably in a captive manner. Alternatively, however, the insert element can also be movably received in the insert receptacle. In particular, the tie rod is received in the receiving opening with a precise fit and / or with an interference fit.The insert element thus provides a simple way of fixing the tie rod at one or more points on the tie rod holder.

[0022] In one specific embodiment, the insert element is designed as a plastic part arranged in the insert receptacle without any play, via which the tie rod is supported, preferably without any play, in the insert receptacle, at least in the radial direction. The receiving opening is preferably arranged congruently and / or flush with the elongated holes of the associated partial laminated core. The receiving opening of the plastic part can be designed as a bore or an elongated hole. The receiving opening is dimensioned such that the tie rod is received in a form-fitting and / or force-fitting manner, at least in the radial direction and optionally in the circumferential direction. For this purpose, an opening diameter of the receiving opening can be smaller than or equal to a diameter of the tie rod, at least in the radial direction. In principle, the tie rod can be fixed in the receiving opening by means of a press fit.Alternatively, the tie rod can also be fixed in the receiving opening via a threaded connection. For this purpose, the tie rod has an external thread at least in the area of ​​the receiving opening, which cuts a thread into the receiving opening during assembly. Alternatively, or optionally in addition, the tie rod can be fixed in the receiving opening by plastic deformation of the plastic part. If necessary, the rotor body can be heated before assembly of the tie rod, which softens the plastic part and facilitates assembly of the tie rod. By arranging one or more plastic parts, the tolerance gap can be reduced and thus the bending of the tie rod can be reduced. In addition, the tie rods can be inserted particularly easily through the plastic parts, which simplifies assembly. By cutting a thread, axial securing of the tie rod can be enabled, similar to a screw lock.

[0023] In an alternative embodiment, the insert element is designed as a snap ring which is movably arranged in the insert receptacle and which is elastically deformable when the tension rod is installed in the receiving opening, so that the tension rod is supported in the insert receptacle via the snap ring, at least in the radial direction, preferably without play. In particular, a snap ring is understood to be an open or slotted ring which expands when the tension rod is installed. For this purpose, an opening diameter of the receiving opening can be smaller than a diameter of the tension rod. During assembly, the snap ring is automatically expanded when the tension rod is inserted into the receiving opening. Preferably, the snap ring is expanded so far in the installed state of the tension rod that the tension rod is supported in a form-fitting and / or force-fitting manner within the insert receptacle, at least in the radial direction.Preferably, the snap ring is movably received in the insert receptacle when the tie rod is disassembled, so that the snap ring automatically centers itself relative to the tie rod when the tie rod is assembled. The insert receptacle is preferably designed as an annular groove concentric with the elongated hole of the associated partial laminated core. In particular, the snap ring can be pre-positioned in the insert receptacle by filling a tolerance gap within the insert receptacle with a malleable material, such as adhesive or paper. The snap ring can be made of a resilient material, e.g., an aluminum alloy, spring steel, plastic, or the like. Thus, an insert element is proposed which, on the one hand, enables simple assembly of the tie rod and, at the same time, ensures a tight fit between the tie rod and the partial laminated core in the assembled state.The snap ring thus forms a support point within the tie rod holder, which reduces the deflection of the tie rod.

[0024] In an alternative or optionally additional embodiment, it is provided that at least or exactly one of the fixing means is designed as a fixing contour formed integrally on one of the laminations of a partial laminated core, which fixes the tie rod in a form-fitting and / or force-fitting manner at least in the radial direction. In this case, "integral" means that the fixing contour and the lamination are made from a common section of material. Optionally, the tie rod is fixed in the tie rod receptacle in a form-fitting and / or force-fitting manner, preferably without play, in the circumferential direction by the fixing contour. Preferably, the tie rod can be resiliently supported in the radial direction and / or in the circumferential direction via the fixing contour. In particular, the fixing contour is elastically or plastically deformed to fix the tie rod.The fixing contour enables particularly simple and cost-effective fixation of the tie rod using one or more of the sheet metal lamellas. Furthermore, the fixing contour allows the tie rod to be secured particularly securely and permanently in the tie rod holder.

[0025] In one specific embodiment, the fixing contour is formed by at least one clamping lug which projects radially into the tie rod receptacle and clamps the tie rod in place at least in the radial direction. In particular, the clamping lugs are elastically and / or plastically deformed or deformable. In principle, the clamping lug projects at least far enough into the tie rod receptacle that a radial tolerance gap is compensated for by the clamping lug. However, the clamping lug preferably projects far enough into the tie rod receptacle that it is plastically and / or elastically deformed when the tie rod or a corresponding tool is inserted into the tie rod receptacle. In particular, a clamping force of the clamping lug acting on the tie rod can be adjusted by the radial extension or the radial overlap with the tie rod. In principle, the fixing contour can be formed by a single clamping lug.Alternatively, the fixing contour can also be formed by two opposing clamping tabs. This proposes a fixing contour that allows the tie rod to be clamped particularly reliably in the tie rod receptacle. This allows the tolerances of the tie rods in the tie rod receptacles to be reliably compensated.

[0026] In an alternative embodiment, the fixing contour is formed by two clamping tabs that project radially into the tie rod receptacle and enclose the tie rod on both sides. In particular, the clamping tabs are flexible and / or elastically deformable. Preferably, the tie rod is non-positively fixed between the two clamping tabs. In particular, the two clamping tabs form a receiving opening for the tie rod, the opening diameter of which is smaller than a diameter of the tie rod. For this purpose, the clamping tabs are preferably curved or sickle-shaped. In other words, the clamping tabs form a slotted and / or interrupted ring. During assembly, the clamping tabs are expanded so that the tie rod is non-positively clamped by the two clamping tabs.A fixing contour is therefore proposed which realises the tolerances between the tie rod and the tie rod holder by encompassing the tie rod, thus allowing the tie rod to be reliably fixed both in the radial direction and in the circumferential direction.

[0027] Another subject matter of the invention relates to a method for producing a rotor, as already described above, in which at least two partial laminated cores are arranged on a rotor carrier rotated relative to one another in the circumferential direction by a helix angle, a plurality of tie rods are guided axially with respect to a rotational axis through a tie rod receptacle, and the partial laminated cores are clamped with a prestressing force, wherein the tie rods are each fixed within the tie rod receptacle by at least one fixing means. In particular, the fixing means can be used during or after assembly of the tie rod. For this purpose, the fixing means can be mounted or formed either before or after assembly of the tie rod.

[0028] In a specific implementation, a potting compound is introduced into the tie rod holder before the tie rod is installed. Either the tie rod or a preform is inserted into the potting compound and the potting compound is cured to form the fixing agent. In particular, the tie rod holder can be completely filled with the potting compound, with excess material being displaced when the tie rod or preform is inserted. This ensures that the entire tolerance gap between the tie rod and the tie rod holder is filled with the potting compound. Alternatively, the tie rod can be coated with the potting compound before assembly and then inserted into the tie rod holder. In particular, the potting compound can be introduced together with potting of the magnets in order to save costs.For example, the tie rods and the magnets can be embedded in the respective holder using the same potting compound.

[0029] In an alternative implementation, prior to the installation of the tie rods in at least one of the partial laminated cores, at least one insert element per tie rod receptacle is inserted into the respective insert receptacle. The insert element is elastically and / or plastically deformed during installation of the tie rod for fixing purposes. In particular, the tie rod is pressed or screwed into the insert element designed as a plastic part, thereby plastically deforming the plastic part. Alternatively, the tie rod is pressed into the insert element designed as a snap ring, thereby elastically deforming the snap ring.

[0030] In a further alternative implementation, it is provided that a plurality of individual laminations are punched out using a punching tool to form the partial laminated cores. In particular, the partial laminated cores are produced separately from one another in a manufacturing process, e.g. by punching and stacking, and then arranged successively on the rotor carrier in the axial direction with respect to the axis of rotation according to the described method. The elongated holes and / or the magnet receptacles and / or the shaft receptacle are preferably punched out by the punching tool. According to this implementation, it is provided that at least or exactly one lamination is punched out to form the partial laminated core using a further punching tool to form the fixing contour, wherein the fixing contour is elastically and / or plastically deformed for fixing during assembly of the tie rod.In particular, the tie rod is inserted into the tie rod receptacle, whereby the fixing contour, designed as a clamping tab or clamping tabs, is elastically and / or plastically deformed directly by the tie rod. Alternatively, however, it can also be provided that at least the fixing contour, designed as a clamping tab, is plastically deformed by a tool before the tie rod is installed.

[0031] Another subject matter of the invention relates to an electric machine with the rotor as described above. In particular, the electric machine is designed and / or suitable for an electric axle drive and / or for driving a motor vehicle. For example, the electric machine can be designed as a traction machine, also known as a separate motor generator (SMG). Particularly preferably, the electric machine is designed as a permanent magnet synchronous machine, or PSM for short. The electric machine has a stator, wherein the rotor is preferably arranged radially within the stator.

[0032] Further features, advantages, and effects of the invention will become apparent from the following description of preferred embodiments of the invention. These show: Fig. 1 a schematic sectional view of a rotor along a rotational axis with a fixing means designed as a casting compound; Fig. 2 an axial detailed view of the rotor Fig. 1 without the fixative; Fig. 3 an alternative embodiment of the rotor in a perspective sectional view with two fixing means designed as a plastic part; Fig. 4 a detailed view of the sectional view of the rotor from Fig. 3 without tie rods; Fig. 5 a further alternative embodiment of the rotor in a perspective sectional view with two fixing means designed as snap rings without tie rods; Fig. 6 an axial detailed view of the rotor design variant from Fig. 5 with tie rod; Fig. 7 a further alternative embodiment of the rotor in a highly simplified sectional view with three fixing means designed as clamping tabs; Fig. 8 an axial detailed view of the rotor design variant from Fig. 7 when installing the tie rod; Fig. 9 a detailed sectional view of the rotor from Fig. 7 when installing the tie rod; Fig. 10 shows a further alternative embodiment of the rotor in an axial detailed view with a fixing means formed by two clamping tabs without tie rods; Fig. 11 an axial detailed view of the rotor variant from Fig. 10 with tie rod.

[0033] Fig. Figure 1 shows an electric machine 1 as an exemplary embodiment of the invention, which is designed, for example, as a permanent magnet synchronous machine. The electric machine 1 can be designed or suitable as a drive motor of an electric vehicle.

[0034] The electric machine 1 is designed as an internal rotor, wherein the electric machine 1 has a stator 2 and a rotor 3 mounted radially within the stator 2 for rotation about a rotation axis 100. The stator 2 forms a stationary or fixed part, which is firmly connected to a housing (not shown) of the electric machine 2.

[0035] The rotor 3 has a rotor support 4 designed as a rotor shaft, which is rotatably mounted about the rotational axis 100 and can be connected, for example, to a drive or transmission system with a gear (not shown). The rotor 3 has a rotor body 5, which is composed of several, in particular exactly six, partial laminated cores 6 and is connected to the rotor support 4 in a rotationally fixed manner.

[0036] To form the rotor body 5, the partial laminated cores 6 are arranged one behind the other on the rotor carrier 4 in the axial direction with respect to the rotational axis 100 and are rotated relative to one another in the circumferential direction, so that a discrete set is formed within the rotor body 5. For example, the rotor body 5 can have a linear set, which is generated by an identical offset or helix angle of the partial laminated cores 6 in a circumferential direction around the rotational axis 100 of the partial laminated cores 6. Alternatively, the rotor body 5 can have a V-shaped set, which is generated by two linear sets with different offsets in the circumferential direction or with different offset directions around the rotational axis 100 of the partial laminated cores 6.

[0037] The partial laminated cores 6 can each have a plurality of receiving pockets (not shown) distributed around the rotation axis 100, with at least one pole-generating magnet (not shown) being arranged in each of the receiving pockets. For example, the magnets are each designed as rod-shaped permanent magnets.

[0038] Furthermore, the rotor 3 has two end plates 7a, 7b, which are arranged at each end on an axial end face of the rotor body 5 coaxially to the rotation axis 100. The end plates 7a, 7b are formed separately from the rotor body 5 and the rotor carrier 4 and are connected in a rotationally fixed manner to the rotor carrier 5. For example, the end plates 7a, 7b are designed as so-called balancing plates.

[0039] The partial laminated cores 6 and the two end plates 7a, 7b are subjected to a preload in the axial direction relative to the rotation axis 100 by a plurality of tension rods 8 distributed in the circumferential direction, acting at least partially in the axial direction relative to the rotation axis 100. For this purpose, the tension rods 8 are each formed by a screw bolt 9, in particular a threaded bolt, which is secured at the end by a securing means 10, e.g., a screw nut. For example, the preload can be adjusted by a tightening torque of the screw nut.

[0040] The rotor body 4 has a tie rod receptacle 11 for each tie rod 8, through which the respective tie rod 8 or the screw bolt 9 is guided in the axial direction relative to the rotation axis 100 or a bolt axis 101. Furthermore, the two end plates 7a, 7b each have a tie rod opening 12a, 12b for each tie rod 8, which are arranged coaxially and / or congruently with one another relative to the bolt axis 101. For example, the tie rod openings 12a, 12b are each formed as a through-bore through which the respective tie rod 8 is guided in a form-fitting manner.

[0041] The partial laminated cores 6 are each formed by a plurality of individual sheets 13 stacked one above the other in the axial direction with respect to the rotation axis 100, wherein the individual sheets 13 each have an elongated hole 14 for forming the tie rod receptacles 11 for each tie rod 8, as in Fig. 2. The elongated holes 14 are arranged congruently within a partial laminated core 6, wherein the elongated holes 14 of at least two adjacent partial laminated cores 6 are arranged offset relative to one another in the circumferential direction by a helix angle 102 to form the set. The elongated holes 14 of all partial laminated cores 6 are arranged overlapping or partially overlapping, so that an axially continuous tie rod receptacle 11 is formed, through which the tie rod 8 can be inserted axially unhindered.

[0042] Due to the tolerance gap 15 thus formed, the tie rod 8 is arranged with play in the radial direction and in the circumferential direction within the tie rod receptacle 11, as a result of which the tie rod 8 can deform within the tolerance gap 15 during operation of the electrical machine 1 due to the centrifugal forces acting thereon. It is therefore proposed to arrange a fixing means 16 within the tie rod receptacle 11, by means of which the tie rod 8 is fixed in the radial direction and / or in the circumferential direction at one or more points within the tie rod receptacle 11. This can, on the one hand, reduce or prevent deflection of the tie rod 8 within the tie rod receptacle 11. At the same time, vibrations caused by the tie rod 8 oscillating within the tie rod receptacle 11 can be prevented, thereby reducing noise.

[0043] As in Fig. 1, the fixing means 16 is formed by a potting compound 17, which largely or completely fills the tolerance gap 15. The potting compound 17 extends over the entire axial length of the rotor body 5, so that the tie rod 8 is embedded in the potting compound 17 within the tie rod receptacle 11 without any play. The potting compound 17 can be formed by an adhesive, an epoxy resin, a plastic injection molding, or the like. The potting compound allows the tie rod 8 to be securely fixed in the tie rod receptacle 11 over the entire axial length of the rotor body 5. This advantageously prevents deflection of the tie rod 8 during operation.

[0044] To produce the fixing means 16, the casting compound 17 is introduced into the tie rod receptacle 11 before the tie rod 8 is installed. The tie rod 8 can then be inserted, whereby excess material is displaced. After the casting compound 17 has hardened, the tie rod 8 is firmly embedded in the casting compound. Alternatively, instead of the tie rod 8, a structurally identical or geometrically similar preforming tool (not shown) can be inserted into the tie rod receptacle 11 provided with the casting compound 17, which is then removed again after the casting compound 17 has hardened. The tie rod 8 can then be inserted into the opening formed by the preforming tool. Alternatively, the casting compound 17 or a coating can be applied to the part arranged within the tie rod receptacle 11 before the tie rod 8 is installed.

[0045] As in the Fig. 3 to 6, the fixing means 16 can alternatively also be formed by at least one insert element 18, which is received without play in an insert receptacle 19. The insert element 18 is arranged centrally in the tie rod receptacle 11 in the axial direction with respect to the axis of rotation 100, wherein the tie rod 8 is fixed at least in the radial direction in a form-fitting and / or force-fitting manner by the insert element 18. For this purpose, the insert element 18 has a central receiving opening 20 through which the tie rod 8 is guided in the axial direction.

[0046] As in Fig. 3, the insert element 18 is formed by a plastic part 21, which is inserted into an insert receptacle 19 formed on one of the partial laminated cores 6. For example, the two middle partial laminated cores 6 each have an insert receptacle 19, which forms a common insert receptacle for one or more plastic parts 21. The insert receptacle 19 is designed as a recess surrounding the bolt axis 101, in which, for example, two separate plastic parts 21 are arranged in a form-fitting manner in the axial, radial and tangential directions with respect to the rotation axis 100. The plastic parts 21 or the insert receptacles 19 extend in the axial direction over several of the laminations 13 of the respectively associated partial laminated core 6. For example, the plastic parts 21 are designed as identical parts.

[0047] As in Fig. 4, the receiving openings 20 of the two plastic parts 21 are designed as elongated holes, which are arranged coaxially to one another and / or congruent with the elongated holes 14 of the respective associated partial laminated core 6. The receiving openings 20 can have an opening diameter d1, at least in the radial direction, which is smaller than or equal to a bolt diameter d2, as in Fig. 3, of the screw bolt 9. Thus, the tie rod 8 is fixed within the tie rod receptacle 11 by the plastic parts 21 in a form-fitting and / or force-fitting manner, at least in the radial direction.

[0048] During assembly, the screw bolt 9 can be inserted or pressed into the receiving opening 20 in the axial direction relative to the bolt axis 101. Alternatively, the screw bolt 9 can also be screwed into the receiving opening 20, whereby the screw bolt 9 cuts a thread into the receiving opening 20 with an external thread. For example, the rotor body 5 can be heated before assembly, which softens the plastic parts 21 and simplifies the assembly of the tie rod 8.

[0049] As in Fig. 5, the insert element 18 is formed by a snap ring 22, which is mounted in an insert receptacle 19 formed on one of the partial laminated cores 6. For example, the two middle partial laminated cores 6 each have a separate insert receptacle 19 in the axial center, in each of which a snap ring 22 is mounted. The insert receptacles 19 are each designed as an annular groove surrounding the bolt axis 101, in which the respective snap ring 22 is movably arranged. The snap rings 22 or the insert receptacles 19 each extend in the axial direction over one or more sheet metal laminations 13. For example, the snap rings 22 are designed as slotted sheet metal disks.

[0050] As in Fig. 6, the insertion receptacles 19 are designed as elongated holes, which are arranged coaxially to one another and / or congruent with the elongated holes 14 of the respective associated partial laminated core 6. The snap ring 22 defines a receiving opening 20, in which the tension rod 8 is received in a form-fitting and / or force-fitting manner. For this purpose, the receiving opening 20 has an opening diameter d1, which is smaller than or equal to the bolt diameter d2, as in Fig. 3, of the screw bolt 9. The snap ring 22 is elastically deformable in the radial direction with respect to the bolt axis 101, so that the snap ring 22 is expanded in the assembled state of the tension rod 8 and is supported within the insert receptacles 19 in a form-fitting and / or force-fitting manner at least in the radial direction.

[0051] During assembly, the screw bolt 9 can be inserted or pressed into the receiving opening 20 in the axial direction with respect to the bolt axis 101, whereby the snap ring 22 is expanded in the radial direction with respect to the bolt axis 101 and closes the tolerance gap 15 between the tie rod 8 and the insert receptacle 19, at least in the radial direction. This can form a positive and / or non-positive connection in the radial direction. In order to align the snap ring 22 in the correct position in the circumferential direction or coaxially with the bolt axis 101, the tolerance gap 15 formed in the circumferential direction can be filled with a moldable filler material 23, such as adhesive or paper.

[0052] As in the Fig. As shown in Figures 7 to 11, the fixing means 16 can alternatively also be formed by a fixing contour 24 formed integrally on one or more of the laminations 13 of one or more partial lamination stacks 6, which extends radially into the tie rod receptacle 11 and fixes the tie rod 8 in a form-fitting and / or force-fitting manner, at least in the radial direction. For this purpose, the fixing contour 24 can be elastically and / or plastically deformed. For example, several of the fixing contours 24 can be distributed in the axial direction relative to the rotation axis 100 within the tie rod receptacle 11.

[0053] As in Fig. As shown in Figure 7, three of the partial laminated cores 6 each have a fixing contour 24, wherein the fixing contours 24 are each formed by a clamping tab 25 integrally formed on one of the laminated cores 13. The clamping tabs 25 extend radially inward into the access receptacle 11 and are elastically and / or plastically deformed in the axial direction with respect to the bolt axis 100, whereby the tie rod 8 is fixed in a form-fitting and / or force-fitting manner, preferably by clamping, at least in the radial direction.

[0054] As in Fig. 8, clamping tabs 25 extend, prior to assembly of the tie rod 8, in a radial plane of the bolt axis 101 over more than 40%, preferably more than 50%, of the radial opening diameter d1 of the respective elongated hole 14. Thus, viewed in the axial direction, the clamping tab 25 is arranged at least partially covering or overlapping the tie rod 8. In other words, the clamping tab 25 extends in the radial direction over more than the radial tolerance gap 15.

[0055] As in Fig. 9, the clamping tab 25 is formed on one of the laminations 13 of a partial laminated core 6, wherein in an assembly direction 103, several, e.g., three, subsequent further laminations 13 have a recess 26 in the region of the clamping tab 25, into which the clamping tab 25 is partially formed in the assembled state of the tie rod 8. For example, the clamping tab 25 can be arranged in the axial direction with respect to the bolt axis 101 within the partial laminated core 6 such that the clamping tab 25 is supported on the tie rod 8 centrally or at least approximately centrally with respect to the axial length of the partial laminated core 6 in the assembled state of the tie rod 8.

[0056] During assembly, the screw bolt 9 or alternatively a forming tool, not shown, can be pushed into the tie rod receptacle 11 in an axial direction with respect to the bolt axis 101 or in the assembly direction 103, whereby the clamping tabs 25 are successively formed in the assembly direction 104 and at least in the radial direction bridge the tolerance gap 15 between the tie rod 8 and the tie rod receptacle 11 or clamp the tie rod 8 in place.

[0057] As in Fig. 10, the fixing contour 24 is formed by two clamping tabs 27 formed integrally on one of the sheet metal laminations 13. The clamping tabs 27 extend radially inward into the tie rod receptacle 11 and are elastically and / or plastically deformable in the radial direction with respect to the bolt axis 101 or in the tangential direction with respect to the rotation axis 100, whereby the tie rod 8 can be fixed in a form-fitting and / or force-fitting manner, preferably by clamping, at least in the radial direction. The two clamping tabs 27 define a receiving opening 20 into which the tie rod 8 is received in a form-fitting and / or force-fitting manner. For this purpose, the clamping tabs 27 are curved or crescent-shaped.

[0058] As in Fig. 11, the tie rod 8 is encompassed on both sides by the two clamping tabs 27 in the assembled state. For this purpose, the receiving opening 20 formed by the clamping tabs 27 can be arranged coaxially to the bolt axis 101 and / or concentrically to the elongated holes 14 of the associated partial laminated core 6. The receiving opening 20 has an opening diameter d1 which is smaller than or equal to the bolt diameter d2, as in Fig. 3, of the screw bolt 9. The clamping tabs 27 are designed to be flexible or resiliently deformable so that they adapt to the shape and / or position of the tension rod 8.

[0059] During assembly, the screw bolt 9 can be inserted into the receiving opening 20 in the axial direction relative to the bolt axis 101, whereby the two clamping tabs 27 are expanded in the radial direction relative to the bolt axis 101 and fix the tie rod 8 to the radial inner side of the tie rod receptacle 11. This can create a positive and / or force-locking connection in the radial direction. Reference symbol 1 electric machine 2 Stator 3 Rotor 4 rotor arms 5 rotor body 6 partial sheet packages 7a, b end plates 8 tie rods 9 screw bolts 10 securing devices 11 Tie rod holder 12a, b tie rod opening 13 sheet metal slats 14 slot 15 Tolerance gap 16 Fixatives 17 Potting compound 18 Insert element 19 Insert holder 20 receiving opening 21 Plastic part 22 snap ring 23 Filling material 24 Fixation contour 25 clamping tab 26 recess 27 Staple tab 100 axis of rotation 101 bolt axis 102 helix angle 103 Mounting direction d1 opening diameter d2 bolt diameter QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2010 044 521 A1

[0003]

Claims

[1] Rotor (3) for an electrical machine (1), - with a rotor carrier (4) which is rotatably mounted about an axis of rotation (100); - with a rotor body (5) formed from at least two partial laminated cores (6), wherein the partial laminated cores (6) are arranged on the rotor carrier (4) rotated relative to one another in the circumferential direction about the axis of rotation (100) by a helix angle (102); - with a plurality of tie rods (8) distributed in the circumferential direction, which are guided in the axial direction with respect to the axis of rotation (100) through a tie rod receptacle (11) of the rotor body (5), wherein the tie rod receptacles (11) are formed by elongated holes (14) in the partial laminated cores (6) offset from one another in the circumferential direction by the helix angle (102), characterized bythat the tie rods (8) are fixed within the tie rod receptacles (11) by at least one fixing means (16) in each case in order to reduce deflection of the tie rod (8) within the tie rod receptacle (11) during operation of the electrical machine (1). [2] Rotor (3) according to claim 1, characterized by that the at least one fixing means (16) is arranged centrally in the tie rod receptacle (11) in the axial direction with respect to the axis of rotation (100) and / or several of the fixing means (16) are arranged in the tie rod receptacle (11) in an axial direction evenly distributed over the entire axial length of the rotor body (5). [3] Rotor (3) according to claim 1, characterized by that the at least one fixing means (16) extends over the entire axial length of the rotor body (5) in the tie rod receptacle (11). [4] Rotor (3) according to one of the preceding claims, characterized bythat at least one of the fixing means (16) is formed by a casting compound (17) which fills a tolerance gap (15) formed by the elongated holes (14). [5] Rotor (3) according to one of the preceding claims, characterized by that at least one of the fixing means (16) is designed as an insert element (21) which is received in an insert receptacle (19) formed on at least one of the partial laminated cores (6), wherein the insert element (21) has a receiving opening (20) in which the tension rod (8) is received in a form-fitting and / or force-fitting manner at least in the radial direction. [6] Rotor (3) according to claim 5, characterized by that the insert element (21) is designed as a plastic part (21) arranged without play in the insert receptacle (19), via which the tie rod (8) is supported at least in the radial direction in the insert receptacle (19). [7] Rotor (3) according to claim 5, characterized bythat the insert element (21) is designed as a snap ring (22) which is movably arranged in the insert receptacle (19) and which is elastically deformable when the tension rod (8) is mounted in the insert receptacle (19), so that the tension rod (8) is supported in the insert receptacle (19) via the snap ring (22) at least in the radial direction. [8] Rotor (3) according to one of the preceding claims, characterized by that at least one of the fixing means (16) is designed as a fixing contour (24) formed integrally on at least one lamination (13) of at least one partial lamination stack (6), which fixes the tie rod (8) in a form-fitting and / or force-fitting manner at least in the radial direction. [9] Rotor (3) according to claim 8, characterized by that the fixing contour (24) is designed as a clamping tab (25) projecting radially into the tie rod receptacle (11) and clampingly fixing the tie rod (8) at least in the radial direction. [10] Rotor (3) according to claim 8, characterized by that the fixing contour (24) is formed by two clamping tabs (27) projecting radially into the tie rod receptacle (11) and clasping the tie rod (8) on both sides. [11] A method for producing a rotor (3) according to any one of the preceding claims, in which: - at least two partial laminated cores (6) are arranged on a rotor carrier (5) rotated relative to one another in the circumferential direction by a helix angle (102), - a plurality of tie rods (8) are guided axially with respect to a rotation axis (100) through a tie rod receptacle (11) each, and the partial laminated cores (6) are clamped with a prestressing force, wherein the tie rods (8) are fixed within the tie rod receptacle (11) by at least one fixing means (16) each. [12] Method according to claim 11, characterized bythat before the tie rods (8) are mounted, a casting compound (17) is introduced into the tie rod receptacles (11), wherein either the tie rod (8) or a preform body is inserted into the casting compound (17) and the casting compound (17) is cured to form the fixing means (16). [13] Method according to claim 11 or 12, characterized by that before the tie rods (8) are mounted in at least one of the partial laminated cores (6), at least one insert element (16) for each tie rod receptacle (11) is inserted into a respective insert receptacle (19) formed in the partial laminated core (6), wherein the insert element (16) is elastically and / or plastically deformed during mounting of the tie rod (8) in order to fix the tie rod (8). [14] Method according to one of claims 11 to 13, characterized byin that, to form the partial laminated cores (6), a plurality of individual laminated laminations (13) are punched out by means of a punching tool and at least one laminated lamination (13) is punched out by means of a further punching tool to form a fixing contour (24) projecting radially into the elongated hole (14), wherein the fixing contour (24) is elastically and / or plastically deformed during assembly of the tie rod (8) to fix the tie rod (8). [15] Electrical machine (1) with a rotor (3) according to one of claims 1 to 10 and / or manufactured by a method according to one of claims 11 to 14.

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