ARRANGEMENT FOR INSTALLING ROTOR SUBSTITUTES

Abstract

Arrangement that includes: a rotor arrangement (40) with a rotor outer diameter (56) and a rotor shaft (42) which extends along an axis of rotation (A) of the rotor arrangement (40); a mandrel (46) with a mandrel outer diameter (48) extending between a proximal end (62) and a distal end (64), wherein a rotor engagement surface is present at the distal end (64) of the mandrel (46), wherein the mandrel outer diameter (48) has a first cylindrical section (48A) adjacent to the proximal end (62) and a conical section (48B) distal to the first cylindrical section (48A), wherein a first transition section (48T) connects the first cylindrical section (48A) to the conical section (48B), the first transition section (48T) having a radius of curvature; and a sleeve (50) with a sleeve inner diameter which, in the unextended state, is smaller than the rotor outer diameter (56); characterized by the fact that the rotor arrangement (40) includes a rotor stack (44); wherein a flange (66) is arranged on an outer circumference of the distal end (64) of the mandrel (46), wherein a radially inner side surface of the flange (66) defines a part of a circumferential channel (68) which is inserted into the distal end (64) of the mandrel (46).

Description

INTRODUCTION

[0001] The present invention relates to electrical machines and in particular to an arrangement according to the preamble of claim 1 for installing rotor sleeves of the type known from US 2014 / 0117742A1.

[0002] Further state of the art can be found in the documents US 5 144 735 A, US 2013 / 0081 260 A1, US 6 047 461 A and DE 10 2019 108 946 A1.

[0003] Electric vehicles (EVs), such as battery electric vehicles (BEVs), hybrid vehicles, and / or fuel cell vehicles, contain one or more electric machines and a battery system. The battery system supplies power to the one or more electric machines and receives energy from the one or more electric machines and / or a power supply unit. The battery system contains one or more battery cells, battery modules, and / or battery packs. A power control system is used to manage the charging and / or discharging of the battery system during charging and / or driving.

[0004] Electrical machines consist of a rotor and a stator. During the manufacturing process, a reinforcing sleeve can be installed on an outer surface of the rotor to prevent expansion of the rotor assembly during operation. SUMMARY

[0005] According to the invention, an arrangement is presented which is characterized by the features of claim 1.

[0006] Another aspect of the invention may consist in an inner diameter of a mandrel engaging with an outer diameter of a bearing reference on the rotor assembly, wherein a fastening element engaging with the bearing reference to fasten the mandrel to the rotor assembly.

[0007] Another aspect of the invention may consist in the mandrel having a second cylindrical section distal to the conical section, wherein the second cylindrical section is connected to the conical section by a second transition section.

[0008] Another aspect of the invention may consist in the fact that the second transition section on the mandrel also has a radius of curvature.

[0009] Another aspect of the invention may consist in the fact that the radius of curvature is greater than the thickness of the sleeve divided by twice the maximum material strain of a material of the sleeve.

[0010] Another aspect of the invention may include a polymer ring having a drive contact surface on a first axial end face and a sleeve contact surface on a second axial end face configured to engage with a proximal end of the sleeve.

[0011] Another aspect of the invention may include a press comprising a sleeve drive with a body section defining a central opening for surrounding the mandrel and a distal end with a ring engagement surface for the engagement of the drive contact surface on the polymer ring and a pressure relief hole passing through and defined by the body section.

[0012] Another aspect of the invention may include a mounting base having a cylindrical body that defines a central opening for receiving a part of the rotor shaft of the rotor assembly.

[0013] Another aspect of the invention may consist in the fact that the rotor outer diameter and the mandrel outer diameter are each covered with a continuous material coating and the continuous material coating comprises a radially outer surface that lies radially outside the rotor outer diameter and the mandrel outer diameter relative to the axis of rotation.

[0014] Another aspect of the invention may consist in the distal end of the mandrel comprising at least one projection configured to fit into a corresponding alignment opening defined by part of the rotor assembly.

[0015] Furthermore, a method for installing a sleeve on a rotor assembly is described. The method includes aligning the mandrel's outer diameter relative to the rotor's outer diameter. The mandrel's outer diameter comprises a first cylindrical section adjacent to a proximal end, a conical section distal to the first cylindrical section, and a first transition section connecting the first cylindrical section to the conical section. The method also includes pressing the sleeve, with a drive on a press, over the mandrel's outer diameter and onto the rotor assembly, the sleeve being configured to exert a compressive force on a portion of the rotor assembly surrounded by the sleeve.

[0016] Another aspect of the invention may include positioning a polymer ring between a proximal end of the sleeve and a distal end of the drive.

[0017] Another aspect of the invention may consist in the fact that pressing the sleeve over the mandrel outer diameter includes widening a radial dimension of the sleeve to align it with a radial dimension of an outer surface of the rotor assembly.

[0018] Another aspect of the invention may include attaching the mandrel to a bearing reference on a shaft of the rotor assembly in order to align a rotor outer diameter on a rotor stack with the mandrel outer diameter. An inner diameter of the mandrel engages with an outer diameter of a bearing reference on the rotor assembly.

[0019] Another aspect of the invention may consist in the mandrel having a second cylindrical section distal to the conical section and being connected to the conical section by a second transition section.

[0020] Another aspect of the invention may consist in a distal end of the mandrel having a flexible flange that encloses an outer circumference of the distal end and bends to align with a radially outer surface of the rotor assembly.

[0021] Another aspect of the invention may include overforming the mandrel and rotor assembly with a polymer coating and machining the polymer layer across the mandrel and rotor assembly to provide a uniform transition for the sleeve in the radial direction between the mandrel and the rotor assembly.

[0022] Another aspect of the invention may include applying a lubricant to the mandrel outer diameter and the rotor outer diameter and pressing the sleeve over the mandrel and rotor assembly at a speed equal to or greater than the hydrodynamic lubrication speed of the applied lubricant.

[0023] A press arrangement for mounting a sleeve onto a rotor assembly is disclosed here. The press arrangement comprises a press with a drive and a mounting for supporting the rotor assembly. The rotor assembly includes a rotor stack with a rotor outer diameter and a rotor shaft extending along an axis of rotation of the rotor assembly. The press arrangement further comprises a mandrel with a mandrel outer diameter extending between a proximal end and a distal end, and with a rotor engagement surface at the distal end of the mandrel. The mandrel outer diameter comprises a first cylindrical section adjacent to the proximal end, a conical section distal to the first cylindrical section, and a first transition section connecting the first cylindrical section to the conical section. The sleeve has a sleeve inner diameter that, in the unextended state, is smaller than the rotor outer diameter. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 represents an exemplary press arrangement for arranging an exemplary rotor arrangement. Fig. Figure 2 shows an enlarged view of a mandrel that is attached to the rotor assembly of Fig. 1 is aligned, it shows. Fig. Figure 3 shows an enlarged view of a cross-sectional surface of the mandrel. Fig. 2 with the rotor arrangement of Fig. 1 dar. Fig. Figure 4 shows an enlarged view of a cross-sectional area of ​​another exemplary mandrel and the rotor arrangement of Fig. 1 dar. Fig. Figure 5 represents yet another exemplary mandrel, aligned with another exemplary rotor arrangement. Fig. Section 6 presents a method for arranging a sleeve on the rotor assembly of Fig. 1 or the rotor arrangement of Fig. 5 dar.

[0024] The present invention can be modified or embodied in alternative forms, with representative embodiments shown in the drawings and described in detail below. DETAILED DESCRIPTION

[0025] Referring to the figures in which the same reference symbols denote the same parts, and referring to the drawings in which the same reference symbols refer to the same components, shows Fig. Figure 1 shows a schematic view of a press assembly 20 used to position a sleeve 50 on a rotor assembly 40 using a mandrel 46. In the example shown, the press assembly 20 comprises an upper frame support 22 and a lower frame support 24. The upper frame support 22 carries at least a portion of a press arm 26, such as a servo press, with a sleeve drive 28 attached to a distal end of the press arm 26 to move the sleeve 50 relative to the rotor assembly 40.

[0026] In the illustrated example, the rotor arrangement 40 comprises a stack of laminations forming a rotor stack 44 with a rotor outer diameter 56, wherein a rotor shaft 42 extends along a rotational axis A ( Fig. 2) of the rotor assembly 40. During assembly, the rotor assembly 40 is supported by a mounting base 32, which is located on the lower frame support 24. The mounting base 32 comprises a cylindrical body with a central opening 34 for receiving a portion of the rotor assembly 40. In the illustrated example, the mounting base 32 receives a portion of a rotor shaft 42 in the central opening 34. A distal end of the mounting base 32 opposite the lower frame support 24 comprises a rib that engages with an edge of the rotor stack 44 to prevent longitudinal movement of the rotor assembly 40 relative to the axis of rotation A.

[0027] As in the Fig. 1 and Fig. As shown in Figure 2, the mandrel 46 is pressed onto the rotor assembly 40 and can be fastened with or without a fastening element 54, such as a screw. In the illustrated example, the fastening element 54 engages in thread with a bearing reference 58 at one end of the rotor shaft 42, and an inner diameter 46D of the mandrel 46 engages with an outer diameter of the bearing reference 58. A feature of this fastening arrangement is improved alignment between a rotor outer diameter 56 on the rotor stack 44 and a mandrel outer diameter 48 on the mandrel 46.

[0028] Furthermore, several lifting screws 60 are arranged radially outside the fastening element 54 and engage in threaded engagement with the mandrel 46 along a shaft of the lifting screws 60. The lifting screws 60 assist in removing the mandrel after the sleeve 50 has been installed by extending to capture part of the rotor assembly 40.

[0029] The mandrel outer diameter 48 on the mandrel 46 extends between a proximal end 62 of the mandrel 46 and a distal end 64 of the mandrel 46. The distal end 64 comprises a rotor engagement surface that directly abuts a portion of the rotor assembly 40. As shown in Fig. As shown in Figure 2, the mandrel outer diameter 48 comprises a first cylindrical section 48A adjacent to the proximal end 62, a conical section 48B distal to the first cylindrical section 48A, and a second cylindrical section 48C adjacent to the distal end 64. A first transition section 48T connects the first cylindrical section 48A to the conical section 48B, and a second transition section 48T connects the conical section 48B to the second cylindrical section 48C. The inner diameter of the sleeve 50 can be greater than or equal to the diameter of the first cylindrical section 48A and less than the diameter of either the conical section 48B or the second cylindrical section 48C. This allows the sleeve 50 to be easily fitted over the proximal end 62 of the mandrel 46 during installation.

[0030] At least one of the first transition sections 48T or the second transition section 48T in the mandrel 46 has a radius of curvature that connects the first and second cylindrical sections 48A and 48C to the conical section 48B. A feature of the transition sections 48T is to prevent damage to the socket 50 during installation when the socket 50 moves over parts of the mandrel 46 with different conical shapes. For example, the radius of curvature of the transition sections 48T is greater than or equal to the thickness of the socket 50 divided by twice the maximum material strain of one of the socket 50 materials.

[0031] As in Fig. As shown in Figure 1, a ring 52, such as a polymer ring made of nylon or Torlon, is arranged at a proximal end of the sleeve 50. The ring 52 comprises a first axial end face, which defines a drive contact surface for engagement at a distal end of the sleeve drive 28, and a second axial end face, which defines a sleeve contact surface for engagement at a proximal end of the sleeve 50. One feature of the ring 52 is to reduce lateral loads on the sleeve 50 and to exert uniform pressure on the sleeve 50 to reduce damage to the sleeve 50. Another feature of the ring 52 is that it expands with the sleeve 50 to exert an axial force on the sleeve 50 as the sleeve 50 expands. In particular, the sleeve 50 is designed with a significantly greater strength in the circumferential direction than in the longitudinal direction in order to exert compressive stress on the rotor stack 44 at a low weight.In one example, the sleeve 50 is made of a carbon fiber material. Furthermore, the distal end of the mandrel 46 and the proximal end of the rotor assembly 40 can have a groove or radius of curvature along their outer diameter to facilitate the transition and prevent damage to the sleeve 50 as it passes between them.

[0032] As in Fig. As shown in Figure 1, the press arm 26 includes the sleeve drive 28 at a distal end with a body section 29 for engaging the ring 52 and pressing the sleeve 50 onto the rotor assembly 40. The distal end 28D of the sleeve drive 28 defines a ring engagement surface that surrounds an inner chamber 31 for receiving the mandrel 46 when pressing the sleeve 50 over the mandrel 46 and onto the rotor assembly 40. A pressure relief hole 30 extends through and is defined by part of the body section 29 to relieve the pressure built up in the inner chamber 31.

[0033] As in the Fig. 2 and Fig. As shown in Figure 3, a flange 66, for example a flexible flange, is arranged on an outer circumference of the distal end 64 of the mandrel 46. A radially inner side of the flange 66 defines a portion of a circumferential channel 68 that is recessed into the distal end 64 of the mandrel 46. A feature of the flange 66 is that it is deflectable radially inward relative to a longitudinal axis of the mandrel 46 to provide improved alignment between the mandrel 46 and the rotor assembly 40.

[0034] Due to manufacturing limitations, it can be difficult to machine and install the mandrel 46 with tolerances between the mandrel outer diameter 48 and the rotor outer diameter 56 that do not damage the sleeve 50 during installation. The sleeve 50 can be prone to failure during installation because its circumferential strength is significantly greater than its longitudinal strength. The compressive force of the sleeve 50 can cause the flange 66 to deflect or bend radially inward during installation and align itself with the rotor outer diameter 56. Furthermore, this can necessitate manufacturing the mandrel outer diameter 48 at the distal end 64 with a larger tolerance than the rotor diameter 56 to allow the flange 66 to compensate for diameter variations.

[0035] Fig. Figure 4 shows another exemplary mandrel 146 adjacent to the rotor assembly 40. The mandrel 146 is similar to the mandrel 46, except that the mandrel 146 does not include the flange 66 with the adjacent channel 68. Similar or identical components between the mandrel 46 and the mandrel 146 have an added leading “1”.

[0036] In the illustrated example, both the mandrel outer diameter 148 of the mandrel 146 and the rotor outer diameter 56 of the rotor assembly 40 are covered with a continuous coating or material layer 70. In one example, the material coating comprises a polymer material. The continuous material coating 70 comprises a radially outer surface that extends radially outside the rotor outer diameter 56 and the mandrel outer diameter 48 relative to the axis of rotation A. The material coating 70 provides a continuous surface on which the sleeve 50 can slide. In one example, the material coating 70 can be machined after it has been applied to both the mandrel 146 and the rotor assembly 40. After the sleeve 50 has been installed, the mandrel 146 can be separated from the rotor assembly by breaking up the material coating 70.The material coating 70 can be removed from the mandrel 146 so that the mandrel 146 can be attached to a different rotor arrangement 40.

[0037] Fig. Figure 5 shows another exemplary mandrel 246 and another exemplary rotor assembly 240. The mandrel 246 and the rotor assembly 240 are similar to the mandrel 46 and the rotor assembly 40, respectively, except for the differences described below or shown in the drawings. Similar or identical components between the mandrel 46 and the rotor assembly 40 and the mandrel 246 and the rotor assembly 240 have an added leading '2'.

[0038] The mandrel 246 comprises a proximal end 262 and a distal end 264, which is in butt contact with a rotor stack 244 in the rotor assembly 240. The rotor assembly 240 comprises a rotor shaft 242. The distal end 264 of the mandrel 246 comprises at least one projection 265, such as a pin with a round or oval cross-section, which engages with an alignment opening 245 or recess in the rotor stack 244 in the rotor assembly 240. The interface between the at least one projection 265 and the alignment opening 245 ensures improved alignment between the mandrel's outer diameter 248 on the mandrel 246 and the radially outer surface 256 on the rotor stack 244 of the rotor assembly 240.

[0039] Fig. Figure 6 shows an exemplary method 300 for arranging the sleeve 50 on the rotor assembly 40. Method 300 also applies to arranging the sleeve 50 on the rotor assembly 240, with the differences specified below. Method 300 begins in block 302 by positioning one of the rotor assemblies 40 in the mounting base 32. This allows the rotor assembly 40 to float laterally in the mounting base 32 to facilitate improved alignment during the pressing of the sleeve 50, as explained below.

[0040] In block 304, the mandrel 46 is aligned with the rotor assembly 40. The mandrel 46 is aligned with the rotor assembly 40 by aligning its outer diameter relative to the rotor's outer diameter. This alignment can be achieved by aligning a central longitudinal axis of the mandrel 46 with the axis of rotation A of the rotor assembly 40. This ensures that deviations between the mandrel's outer diameter and the rotor's outer diameter are minimized, thus reducing the risk of damage to the sleeve 50 during installation. In the case of the rotor assembly 240 and the mandrel 246, the projection 265 on the mandrel 246 is inserted into the alignment opening 245 on the rotor assembly 240.

[0041] The mandrel 46 can be attached to the rotor assembly 40, with the fastening element 54 engaging in the bearing reference 58 on the rotor assembly 40. While the in the Fig. 1, Fig. 2 and Fig. As shown in the example 5, which shows two lifting screws 60, four or more lifting screws 60 can be arranged circularly around the bearing reference 58 and used to remove the mandrel 46 from the rotor assembly 40 after the sleeve has been installed.

[0042] In another example, aligning the mandrel 46 with the rotor assembly 40 involves overforming the mandrel 46 and the rotor assembly 40 with the material coating 70. The material coating 70 can be machined to create a smooth transition for the sleeve 50 in the radial direction between the mandrel 46 and the rotor assembly 40.

[0043] In block 306, the sleeve 50 is arranged around a proximal end of the mandrel 46. Since the mandrel 46 has a first cylindrical section 48A with a diameter that is less than or equal to the inner diameter of the sleeve 50, the sleeve 50 can be arranged relatively easily on the mandrel 46 and the ring 52 can be arranged on the sleeve 50.

[0044] In block 308, the sleeve 50 is pressed onto the press arm 26 by the sleeve drive 28, over the mandrel 46, and onto the rotor assembly 40. The sleeve drive 28 engages the ring 52 to exert uniform pressure on the sleeve 50 during pressing, thus reducing the possibility of damage to the sleeve 50 during installation. Since the mandrel 46 has a cylindrical section and a conical section, the sleeve 50 expands radially as it moves over the transition section to conform to the outer diameter of the conical section. As the sleeve 50 is pressed over the mandrel 46, compressed air can build up in the inner chamber 31. This pressure can be released through the pressure relief hole 30 in the sleeve drive 28.

[0045] When the sleeve 50 is pressed over the mandrel 46 and onto the rotor assembly 40, lubricant can be applied to the mandrel diameter 48 and / or the rotor outer diameter 56. As shown in Fig. As shown in Figure 1, spray nozzles 80 can be used to apply the lubricant 82 to the outer diameters 48, 56. While two spray nozzles 80 are shown in the illustrated example, additional spray nozzles 80 could be arranged circularly around the mandrel 46 and the rotor assembly 40 to provide additional lubrication during the pressing process. In another example, the rotor assembly 40 and / or the mandrel 46 include internal passages 84 ( Fig. 1) for distributing the lubricant along the outer diameters 48, 56.

[0046] Furthermore, the sleeve 50 is pressed over the mandrel 46 and the rotor assembly 40 at a speed sufficient to achieve a hydrodynamic lubrication velocity in the lubricant 82. In one example, the velocity is more than 0.5 to 1 meter per second at a sleeve pressure of 30 MPa.

[0047] In block 310, the sleeve drive 28 is retracted from the mandrel 46 and the ring 52 is removed from its position around the rotor assembly 40 and the mandrel 46. The mandrel 46 can then be separated from the rotor assembly 40 in block 312, with the sleeve 50 enclosing the rotor outer diameter 56 and exerting a compressive force on the rotor assembly 40.

Claims

[1] Arrangement comprising: a rotor arrangement (40) with a rotor outer diameter (56) and a rotor shaft (42) which extends along an axis of rotation (A) of the rotor arrangement (40); a mandrel (46) with a mandrel outer diameter (48) extending between a proximal end (62) and a distal end (64), wherein a rotor engagement surface is present at the distal end (64) of the mandrel (46), wherein the mandrel outer diameter (48) has a first cylindrical section (48A) adjacent to the proximal end (62) and a conical section (48B) distal to the first cylindrical section (48A), wherein a first transition section (48T) connects the first cylindrical section (48A) to the conical section (48B), the first transition section (48T) having a radius of curvature; and a sleeve (50) with a sleeve inner diameter which, in the unextended state, is smaller than the rotor outer diameter (56); characterized by , that the rotor arrangement (40) includes a rotor stack (44); wherein a flange (66) is arranged on an outer circumference of the distal end (64) of the mandrel (46), wherein a radially inner side surface of the flange (66) defines a part of a circumferential channel (68) which is inserted into the distal end (64) of the mandrel (46). [2] Arrangement according to claim 1, wherein an inner diameter of the mandrel engages with an outer diameter of a bearing reference (58) on the rotor arrangement (40) and a fastening element (54) engages with the bearing reference (58) to fasten the mandrel (46) to the rotor arrangement (40). [3] Arrangement according to claim 2, wherein the mandrel (46) has a second cylindrical section (48C) distal to the conical section (48B), wherein the second cylindrical section (48C) is connected to the conical section (48B) via a second transition section (48T). [4] Arrangement according to claim 3, wherein the second transition section (48T) on the mandrel (46) also has a radius of curvature. [5] Arrangement according to claim 1, comprising a polymer ring (52) with a drive contact surface on a first axial end face and a sleeve contact surface on a second axial end face, configured to engage with a proximal end of the sleeve (50). [6] Arrangement according to claim 5, comprising a press comprising a sleeve drive (28) with a body section (29) defining a central opening (34) for surrounding the mandrel (46) and a distal end with an annular engagement surface for engagement of the drive contact surface on the polymer ring (52) and a pressure relief hole (30) passing through and defined by the body section (29). [7] Arrangement according to claim 1, comprising a mounting base (32) with a cylindrical body defining a central opening (34) for receiving a part of the rotor shaft (42) of the rotor arrangement (40). [8] Arrangement according to claim 1, wherein the rotor outer diameter (56) and the mandrel outer diameter (48) are each covered with a continuous material coating (70) and the continuous material coating (70) has a radially outer surface which is radially outside the rotor outer diameter (56) and the mandrel outer diameter (48) relative to the axis of rotation (A).

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