METHOD AND DEVICE FOR PRESSING A REINFORCING SLEEVE ONTO A ROTOR OF AN ELECTRIC MOTOR

Abstract

A method for pressing a reinforcing sleeve onto a rotor of an electric motor, including: affixing a press ring having a stop to the reinforcing sleeve so that the stop abuts an end face of the reinforcing sleeve, and at least one annular and/or ring-segment-shaped section of the press ring embraces at least one annular and/or ring-segment-shaped section of the reinforcing sleeve that terminates at the end face of the reinforcing sleeve; and pressing the reinforcing sleeve onto the rotor, the reinforcing sleeve being centered relative to the rotor so that a longitudinal axis of the reinforcing sleeve is aligned with a longitudinal axis of the rotor, and a pressing force being applied to the pressing ring affixed to the reinforcing sleeve.

Claims

1-10. (canceled)

11. A method for pressing a reinforcing sleeve onto a rotor of an electric motor, the method comprising: affixing a press ring having a stop to the reinforcing sleeve, so that the stop abuts an end face of the reinforcing sleeve, and at least one annular and/or ring-segment-shaped section of the press ring embraces at least one annular and/or ring-segment-shaped section of the reinforcing sleeve that terminates at the end face of the reinforcing sleeve; and pressing the reinforcing sleeve onto the rotor, the reinforcing sleeve being centered relative to the rotor so that a longitudinal axis of the reinforcing sleeve is aligned with a longitudinal axis of the rotor, and a pressing force being applied to the press ring affixed to the reinforcing sleeve in the direction of the aligned longitudinal axes so that the pressing force is introduced into the reinforcing sleeve via the stop.

12. The method according to claim 11, wherein a fiber-reinforced plastic sleeve is used as the reinforcing sleeve.

13. The method according to claim 11, wherein an outer diameter of the reinforcing sleeve is smaller than 50 mm, in particular smaller than 25 mm; and/or wherein an inner diameter of the reinforcing sleeve is smaller than an outer diameter of the rotor by at least 0.1 mm, in particular by at least 0.2 mm.

14. The method according to claim 11, wherein the pressing force is at least 20 kN, in particular at least 30 kN.

15. The method according to claim 11, wherein the reinforcing sleeve is centered relative to the rotor and/or pressed onto the rotor via a centering cone disposed between the reinforcing sleeve and the rotor and widening towards the rotor.

16. The method according to claim 15, wherein a largest outer diameter of the centering cone is larger than an inner diameter of the reinforcing sleeve and/or is at least as large as an outer diameter of the rotor.

17. A device for pressing a reinforcing sleeve onto a rotor of an electric motor, the device comprising: a press ring having a stop, the press ring being affixable to the reinforcing sleeve such that the stop abuts an end face of the reinforcing sleeve and at least one annular and/or ring-segment-shaped section of the press ring embraces at least one annular and/or ring-segment-shaped section of the reinforcing sleeve that terminates at the end face of the reinforcing sleeve; and a press for applying a pressing force to the press ring affixed to the reinforcing sleeve.

18. The device according to claim 17, wherein the press ring has at least one slot connecting a first end face of the press ring to a second end face of the press ring opposite the first end face, and an adjustment device for adjusting a width of the slot.

19. The device according to claim 18, wherein the press ring has two ribs on its outer surface, each rib extending along a longitudinal edge of the slot; wherein the adjustment device is configured to compress the two ribs together so that the width of the slot is reduced.

20. The device according to claim 17, wherein the stop comprises an annular and/or ring segment-shaped stop surface extending at least partially along an inner circumference of the press ring.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0031] Advantageous embodiments of the invention are further explained below with reference to the accompanying drawings, in which neither the drawings nor the explanations are to be construed as limiting the invention in any way.

[0032] FIG. 1 shows a device for pressing a reinforcing sleeve onto of a rotor of an electric motor according to an embodiment of the present invention.

[0033] FIG. 2 shows a rear view of a press ring from FIG. 1.

[0034] FIG. 3 shows a sectional view through the press ring of FIG. 1 along a line of intersection III-III.

[0035] The figures are merely schematic and not to scale. Identical reference signs in the different drawings denote identical or identically acting features.

DETAILED DESCRIPTION

[0036] FIG. 1 shows a device 1 with a press 2, which in this example comprises a horizontal supporting surface 3 and a pressing piece 4 which may be moved in the vertical direction. A rotor 5 of an electric motor (not shown) is positioned on the supporting surface 3. A reinforcing sleeve 6 is disposed between the rotor 5 and the pressing piece 4, in this case a carbon-fiber-reinforced plastic sleeve, with which the rotor 5 is to be bandaged by pressing the reinforcing sleeve 6 axially, in this case in the vertical direction, onto the rotor 5.

[0037] In order to preload the rotor 5 by means of the press-fitted reinforcing sleeve 6 in the radial direction with a sufficiently high preload force, the reinforcing sleeve 6 is significantly underdimensioned compared to the rotor 5, so that a correspondingly high pressing force is required to press-fit the reinforcing sleeve 6, for example a pressing force of at least 20 kN, in particular at least 30 kN. The reinforcing sleeve 6 may have an outer diameter D.sub.1 of less than 50 mm, in particular of 25 mm or less, and an inner diameter D.sub.2 that is smaller than an outer diameter D.sub.3 of the rotor 5 by at least 0.1 mm, for example by at least 0.2 mm.

[0038] To prevent damage to the reinforcing sleeve 6, the pressing force is not transferred directly from the pressing piece 4 to the reinforcing sleeve 6, but via a press ring 7 which is affixed to an annular outer section 8 of the reinforcing sleeve 6 facing towards the pressing piece 4. The outer section 8 is embraced by a ring-segment-shaped inner section 9 of the press ring 7.

[0039] The size ratios shown in FIG. 1 between the outer section 8 and the rest of the reinforcing sleeve 6, and between the inner section 9 and the rest of the press ring 7, respectively, are to be understood merely as examples and may differ significantly from FIG. 1 depending on the application.

[0040] Furthermore, the press ring 7 has a stop 10, the reinforcing sleeve 6 being inserted into the press ring 7 to an extent such that its end face 11 abuts the stop 10.

[0041] In this example, the press ring 7 has an axial slot 12 extending continuously between the two end faces of the press ring 7. A rib 13 (see FIG. 2 and FIG. 3) projecting radially outwards from the press ring 7 extends along each of the longitudinal edges of the slot 12. To reduce the width of the slot 12, the two ribs 13 may be braced together by means of two screw connections 14.

[0042] By bracing the ribs 13, it is also possible, for example, to clamp the press ring 7 to the reinforcing sleeve 6, for example in such a way that the outer section 8 is preloaded with a radial clamping force via the inner section 9.

[0043] During the actual pressing process, the reinforcing sleeve 6 is centered relative to the rotor 5 so that their respective longitudinal axes L are aligned with each other. In this example, centering is carried out with the aid of a centering cone 15 which is placed between the rotor 5 and the reinforcing sleeve 6 and which becomes increasingly wide towards the rotor 5. To prevent the reinforcing sleeve 6 from tilting and to suitably widen the reinforcing sleeve 6, the centering cone 15 has its largest outer diameter D.sub.4 at its end facing towards the rotor 5, the largest outer diameter D.sub.4 expediently being at least as large as the outer diameter D.sub.3 of the rotor 5.

[0044] By reducing a vertical distance between the pressing piece 4 and the supporting surface 3, for example hydraulically or mechanically, the press ring 7 is subjected to the required pressing force, the pressing force being introduced into the reinforcing sleeve 6 exclusively, or at least for the most part, via the stop 10, so that the reinforcing sleeve 6 is pressed onto the rotor 5. The fact that the outer section 8 is compressed by the press ring 7 during the pressing process effectively prevents radial expansion of the outer section 8, for example by buckling or bulging, even under very high axial loads.

[0045] Due to the elastic screw connections 14, the press ring 7 may follow the increasing expansion of the reinforcing sleeve 6 by means of the centering cone 15 without breaking or otherwise damaging the press ring 7.

[0046] The sectional view of the press ring 7 in FIG. 3 shows that the stop 10 may comprise a ring-segment-shaped stop surface 16 which, in this example, extends continuously along an inner circumference 17 of the press ring 7, with the exception of the slot 12. (For the sake of clarity, the screw connections 14 have been omitted from FIG. 3).

[0047] Finally, it is pointed out that terms such as having, comprising etc. do not exclude other elements or steps, and terms such as one or a do not exclude a plurality. It should further be noted that features or steps that have been described with reference to one of the above embodiments may also be used in combination with other features or steps of the above embodiments described above. Reference signs in the claims are not to be considered as limitations.

LIST OF REFERENCES

[0048] 1 Device [0049] 2 Press [0050] 3 Support [0051] 4 Pressing piece [0052] 5 Rotor [0053] 6 Reinforcing sleeve [0054] 7 Press ring [0055] 8 Outer section [0056] 9 Inner section [0057] 10 Stop [0058] 11 End face [0059] 12 Slot [0060] 13 Rib [0061] 14 Screw connection [0062] 15 Centering cone [0063] 16 Stop surface [0064] 17 Inner circumference [0065] D.sub.1 Outer diameter of the reinforcing sleeve [0066] D.sub.2 Inner diameter of the reinforcing sleeve [0067] D.sub.3 Outer diameter of the rotor [0068] D.sub.4 Largest outer diameter of the centering cone [0069] L Longitudinal axis