Shaft bearings for mounting rotor laminations on a rotor shaft

Abstract

The invention relates to a shaft bearing for mounting rotor laminations on a rotor shaft, comprising at least the following components: - a shaft holder for holding the rotor shaft; and - a bearing connection. The shaft bearing is characterized primarily by the fact that the shaft receptacle is radially movable and axially secured at the bearing connection. Here is a proposed shaft bearing for holding a rotor shaft of an electric drive machine during the assembly of rotor laminations, which enables safe, cost-effective and efficient assembly of the rotor laminations.

Description

[0001] The invention relates to a shaft bearing for mounting rotor laminations on a rotor shaft, and to a rotor shaft mounting unit with such a shaft bearing for mounting rotor laminations on a rotor shaft.

[0002] The production of high-power electric machines requires specific manufacturing and assembly processes. These processes aim to minimize costs and component scrap. For example, rotor lamination stacks must be attached to the rotor shaft of the electric machine. This is done, for instance, using press fits.

[0003] Due to the high torque requirements, for example, high overlaps of the press connections are necessary to prevent the lamination stacks from slipping on the rotor shaft during operation.

[0004] In industrial practice, it is known to either mount the laminated cores onto the shaft or the shaft into the laminated cores. This is done, for example, at room temperature or thermally, for instance by heating the laminated cores and / or cooling the rotor shaft. In this process, the laminated cores and the rotor shaft are rigidly guided relative to each other and move along a concentric rigid axis.

[0005] Due to tolerances in the joining tools, rotor shaft, and lamination stacks, coaxiality deviations occur. This results in high joining forces, which can even lead to component damage. Minimizing these joining forces often necessitates thermal processes, which result in high energy consumption.

[0006] Based on this, the present invention aims to overcome, at least partially, the disadvantages known from the prior art. The features of the invention are defined in the independent claims, for which advantageous embodiments are shown in the dependent claims. The features of the claims can be combined in any technically meaningful way, whereby the explanations in the following description and features from the figures, which comprise supplementary embodiments of the invention, can also be used.

[0007] The invention relates to a shaft bearing for mounting rotor laminations on a rotor shaft, comprising at least the following components: - a shaft holder for holding the rotor shaft; and - a storage connection.

[0008] The shaft bearing is characterized primarily by the fact that the shaft receptacle is radially movable and axially secured at the bearing connection.

[0009] The following text refers to the aforementioned axis of rotation of the rotor shaft whenever the axial direction, radial direction, or direction of rotation and corresponding terms are used, unless explicitly stated otherwise. Ordinal numbers used in the preceding and subsequent descriptions serve solely for unambiguous identification and do not indicate any order or ranking of the components referred to. An ordinal number greater than one does not necessarily imply the presence of another such component.

[0010] A shaft bearing for an electric drive motor is proposed here. Such an electric drive motor is, for example, a synchronous motor or an asynchronous motor. Preferably, the electric drive motor is a permanent magnet electric drive motor. Preferably, the electric drive motor is a drive motor or traction motor for a motor vehicle.

[0011] The shaft bearing is designed to support a rotor shaft during the assembly of rotor laminations. Preferably, these rotor laminations are joined to form laminated stacks during assembly. The rotor laminations or laminated stacks are preferably attached to the rotor shaft by means of an interference fit.

[0012] For example, the rotor laminations or lamination stacks are applied to the rotor shaft using a lamination assembly unit. The press fit is created thermally and / or mechanically.

[0013] The shaft bearing has a shaft receptacle and a bearing connection.

[0014] The shaft receptacle is designed to hold the rotor shaft during the rotor lamination assembly described above. Preferably, the shaft receptacle has an axial opening for this purpose. Preferably, the opening is designed such that one end of the rotor shaft can be inserted axially into it. Preferably, the opening is located on a side facing away from the bearing connection along the axial direction.

[0015] The bearing connection forms an anchor for the shaft mounting. Preferably, the bearing connection is fixed in place, for example, firmly anchored in a machine bed.

[0016] The shaft mount is radially movable and axially secured at the bearing connection. In other words, the shaft mount is held by the bearing connection, but is movable relative to the bearing connection, at least in the radial direction. Preferably, the shaft mount is movable by a radial clearance large enough to compensate for at least one coaxiality deviation between the rotor shaft and the rotor laminations, i.e., corresponding to the radial tolerances of the rotor laminations, lamination stacks, rotor shaft, and / or lamination assembly. Thus, deviations from the coaxiality of the rotor laminations to the rotor shaft can be at least partially reduced or compensated for, and component stresses in the rotor laminations can be reduced or avoided.

[0017] The shaft mount is axially fixed to the bearing connection. For example, the shaft mount is fixed to the bearing connection with axial play.

[0018] Preferably, the shaft bearing is designed to transmit axial forces between the shaft receptacle and the bearing connection. Preferably, the shaft bearing is further preferably designed to transmit only damping forces or spring forces in the radial direction between the shaft receptacle and the shaft bearing, so that the shaft receptacle is radially movable relative to the shaft bearing.

[0019] The shaft bearing proposed here enables a particularly safe, cost-effective and efficient mounting of the rotor laminations or lamination stacks.

[0020] In an advantageous embodiment of the shaft bearing, it is further proposed that the shaft bearing has a damping device by means of which a damping force can be transmitted between the shaft receptacle and the bearing connection.

[0021] According to this embodiment, the shaft receptacle is held against the bearing connection in a damping manner. Thus, a damping force counteracts any relative movement between the shaft receptacle and the bearing connection.

[0022] The shaft bearing includes a damping device which acts between the bearing connection and the shaft receptacle and is preferably arranged.

[0023] In an advantageous embodiment of the shaft bearing, it is further proposed that the damping device comprises hydrodynamic damping, pneumatic damping, magnetic damping and / or spring elements.

[0024] Such a damping device includes, for example, hydrodynamic damping, pneumatic damping, magnetic damping, and / or spring elements. For instance, the shaft mount and the bearing connection have magnets with opposite poles. Alternatively or additionally, a fluid chamber filled with a fluid is formed between the bearing connection and the shaft mount. The fluid chamber is sealed for the respective fluid, for example, by means of a seal between the bearing connection and the shaft mount, such as a sealing ring. For example, such a fluid could be hydraulic oil.

[0025] In a further advantageous embodiment of the shaft bearing, it is proposed that the shaft receptacle or the bearing connection has an undercut receptacle, and the other component of the bearing connection and shaft receptacle has a retaining projection which projects axially into the undercut receptacle and engages it radially behind.

[0026] According to this embodiment, the shaft bearing has an undercut receptacle. The undercut receptacle is preferably formed by the bearing terminal. Alternatively, the undercut receptacle is formed by the shaft receptacle. Preferably, the undercut receptacle is formed by an axial opening from which a circumferential groove extends radially outwards. For example, the axial opening is a bore and / or annular.

[0027] Furthermore, the shaft bearing has a retaining projection. The retaining projection engages with the undercut receptacle. For example, the retaining projection comprises a cylindrical section extending along the axial direction and a flanged section extending radially, preferably radially outward, from the cylindrical section. Preferably, the flanged section is arranged in the groove of the undercut receptacle.

[0028] For example, the holding projection is L-shaped in cross-section when viewed parallel to the axial direction.

[0029] Preferably, the retaining projection is formed by the shaft receptacle. Alternatively, the retaining projection is formed by the bearing connection. In each case, the retaining projection is formed by the opposite component of the bearing connection and shaft receptacle than the undercut receptacle.

[0030] According to another aspect, a rotor shaft assembly unit is proposed for mounting rotor laminations onto a rotor shaft, comprising at least the following components: - a shaft bearing according to an embodiment as described above; and - a rotor shaft held or sustained in the shaft receptacle, wherein the rotor shaft is designed to accommodate a plurality of rotor laminations.

[0031] A rotor shaft assembly unit for mounting rotor laminations onto a rotor shaft is proposed here. The rotor shaft assembly unit includes a shaft bearing and a rotor shaft.

[0032] The shaft bearing is designed according to the above description.

[0033] The rotor shaft is a rotor shaft for an electric drive machine. Such an electric drive machine is, for example, a synchronous machine or an asynchronous machine. Preferably, the electric drive machine is a permanent magnet electric drive machine.

[0034] Rotor laminations can be mounted on the rotor shaft. Preferably, these rotor laminations are joined to form lamination stacks during assembly. The rotor laminations or lamination stacks are preferably attached to the rotor shaft by means of an interference fit.

[0035] For assembly, the rotor shaft is held accordingly by the shaft holder. For example, the shaft holder has an axial shaft receiving opening in which one end of the rotor shaft is received or can be received.

[0036] Preferably, the shaft mounting is movable by a radial clearance in relation to the bearing connection, which corresponds at least to the radial tolerance of the rotor laminations, lamination stacks, rotor shaft and / or lamination assembly unit.

[0037] Thus, deviations from the coaxiality of the laminations to the rotor shaft can at least be partially reduced or compensated for, and therefore component stresses in the rotor laminations can be reduced or avoided.

[0038] In an advantageous embodiment of the rotor shaft assembly unit, it is further proposed that a sheet metal assembly unit be used for axially sliding and mounting the majority of rotor laminations onto the rotor shaft.

[0039] According to this embodiment, the rotor shaft assembly unit further comprises a lamination assembly unit. The lamination assembly unit is designed to axially slide rotor laminations or lamination stacks onto the rotor shaft. Preferably, the lamination assembly unit is designed to fasten the rotor laminations or lamination stacks to the rotor shaft, particularly preferably by means of an interference fit.

[0040] For example, the lamination assembly unit is designed to mount the rotor laminations purely mechanically (e.g., at room temperature) or thermally, for example, by heating the lamination stacks and / or cooling the rotor shaft. In this process, the lamination stacks and the rotor shaft are rigidly guided relative to each other and are moved along a concentric rigid axis in the axial direction.

[0041] The invention described above is explained in detail below against the relevant technical background with reference to the accompanying drawings, which show preferred embodiments. The invention is in no way limited by the purely schematic drawings, although it should be noted that the drawings are not dimensionally accurate and are not suitable for defining size relationships. It is illustrated in Fig. 1: A rotor shaft during the assembly of rotor laminations in a schematic representation; Fig. 2: A detailed view of the rotor shaft after Fig. 1; and Fig. 3: a shaft bearing after Fig. 1 of a schematic cross-sectional view.

[0042] In Fig. Figure 1 shows a rotor shaft 3 during the assembly of rotor laminations 2 in a schematic diagram. The rotor shaft 3 is for an electric drive machine. During assembly, rotor laminations 2, which are joined into lamination bundles, are applied to the rotor shaft 3 and connected to it by means of an interference fit. This is done using a lamination assembly unit (not shown here).

[0043] The rotor laminations 2 are pushed onto the rotor shaft 3 from one end along an axial direction 18, as indicated by the dashed arrow. The opposite shaft end 10 of the rotor shaft 3 is held in a shaft receptacle 4 by means of a shaft receptacle opening 9.

[0044] Due to the tolerances of both the joining tools or the sheet metal assembly unit, as well as the rotor shaft 3 and the lamination stacks 11, coaxiality deviations 17 occur, which in Fig. 2 are shown in detail.

[0045] In Fig. 2 is a detailed view of the rotor shaft 3 after Fig. Figure 1 shows the coaxiality deviation 17 between the lamination stack 11 and the rotor shaft 3. If the rotor shaft 3 is held radially immovable, axially parallel guidance of the lamination stack 11 leads to component stress due to the coaxiality deviation 17 shown. This is prevented by the radially movable bearing of the shaft mount 4 (see Figure 1). Fig. 3).

[0046] In Fig. 3 is a shaft bearing 1 according to Fig.Figure 1 shows a schematic cross-sectional view. The shaft bearing 1 has the shaft receptacle 4 and a bearing connection 5. The bearing connection 5 is fixed in a stationary position, for example on a machine bed. The shaft receptacle 4 is held radially movable within the bearing receptacle. In other words, the shaft receptacle 4 is movable along the radial direction 19 within the bearing connection 5.

[0047] The shaft bearing 1 has a damping device 6. The damping device 6 is designed here in the form of a fluid chamber 12 between the bearing connection 5 and the shaft receptacle 4. The fluid chamber 12 is filled with hydraulic oil as the hydraulic fluid and is sealed against the environment by means of a seal 13 between the bearing connection 5 and the shaft receptacle 4.

[0048] The bearing connection 5 has an undercut receptacle 7. The undercut receptacle 7 comprises an annular, axial opening from which a groove 16 extends radially outwards.

[0049] The shaft receptacle 4 forms a retaining projection 8, which has an L-shaped cross-section. The retaining projection 8 comprises a cylindrical section 15 and a flanged section 14 extending radially outwards from the cylindrical section 15. The flanged section 14 engages in the groove 16 of the undercut receptacle 7. The groove 16 has a larger radius than the flanged section 14. Thus, the shaft receptacle 4 is held in the bearing connection 5 with damped radial movement and is axially fixed.

[0050] Here is a proposed shaft bearing for holding a rotor shaft of an electric drive machine during the assembly of rotor laminations, which enables safe, cost-effective and efficient assembly of the rotor laminations. Reference symbol list 1 shaft bearing 2 Rotor laminations 3 Rotor shaft 4 shaft recording 5 bearing connection 6 Damping device 7 Undercut shot 8 Holding projection 9 shaft receiving opening 10 Wave end 11 sheet metal package 12 Fluid chamber 13 Seal 14 Flange section 15 Cylinder section 16 Nut 17 Coaxiality deviation 18 Axial direction 19 Radial direction

Claims

Shaft bearing (1) for mounting rotor laminations (2) on a rotor shaft (3), comprising at least the following components: - a shaft receptacle (4) for holding the rotor shaft (3); and - a bearing connection (5), characterized in that the shaft receptacle (4) is mounted radially movable and axially secured on the bearing connection (5). Shaft bearing (1) according to claim 1, wherein the shaft bearing (1) has a damping device (6) by means of which a damping force can be transmitted between the shaft receptacle (4) and the bearing connection (5). Shaft bearing (1) according to claim 2, wherein the damping device (6) comprises hydrodynamic damping, pneumatic damping, magnetic damping and / or spring elements. Shaft bearing (1) according to one of the preceding claims, wherein the shaft receptacle (4) or the bearing connection (5) has an undercut receptacle (7), and the other component of the bearing connection (5) and shaft receptacle (4) has a retaining projection (8) which projects axially into the undercut receptacle (7) and engages it radially behind. Rotor shaft assembly unit for mounting rotor laminations (2) on a rotor shaft (3), comprising at least the following components: - a shaft bearing (1) according to one of the preceding claims; and - a rotor shaft (3) held or sustained in the shaft receptacle (4), wherein the rotor shaft (3) is designed to accommodate a plurality of rotor laminations (2). Rotor shaft assembly unit according to claim 5, further comprising a sheet metal assembly unit for axially sliding and mounting the plurality of rotor sheets (2) onto the rotor shaft (3).

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