METHOD AND DEVICE FOR MACHINING A SHAFT OF AN APPARATUS AT A BEARING POINT OF THE SHAFT

Abstract

The method and the device are used for processing a shaft of an apparatus which supports the shaft in rotation. The device is provided with a drive unit which can be attached to the apparatus and has a drive element that can be driven in rotation by a motor and is suitable for coupling to an end of the shaft to be machined. The device also has a holding unit, which can likewise be attached to the apparatus, for at least one of the following units: a supporting bearing unit for supporting the shaft 464 to be machined; a material removal unit for removing material from the shaft to be machined at its bearing point; a material application unit for applying material to the shaft to be machined at its bearing point; and a grinding unit for grinding down the material applied to the bearing point of the shaft to be machined.

The supporting bearing unit, the material removal unit, the material application unit and the grinding unit are operable during rotation of the shaft to be machined by means of the drive unit.

Claims

1. A device for machining a shaft of an apparatus at a bearing point at which the shaft is rotatably supported in a bearing of the apparatus to be replaced, comprising a drive unit which can be attached to the apparatus and has a drive element that can be driven in rotation by a motor and is suitable for coupling to an end of the shaft to be machined, a holding unit for a support bearing unit for supporting the shaft to be machined when the shaft is rotated with the bearing of the apparatus removed, the holding unit being adapted to be mounted to the apparatus, the holding unit for holding the support bearing unit is provided together with at least one or more or all of the following units: a material removal unit for removing material from the shaft to be machined at its bearing point, a material application unit for applying material to the shaft to be machined at its bearing point; and a grinding unit for grinding down the material applied to the bearing point of the shaft to be machined, the supporting bearing unit, the material removal unit, the material application unit and the grinding unit being operable during rotation of the shaft to be machined by means of the drive unit.

2. The device according to claim 1, characterized in that a feed unit can be mounted on the holding unit, the feed unit comprising a tool slide which is adjustable in the direction of the extension of the shaft to be machined, as well as radially to the same, on which the material removal unit, the material application unit and the grinding unit can be selectively mounted.

3. The device according to claim 1, wherein the holding unit has a plurality of receptacles for a variable positioning of the support bearing unit and/or the material removal unit and/or the material application unit and/or the grinding unit of the drive unit.

4. The device according to claim 1, wherein the material removal unit is designed as a unit for machining the shaft by removing chips using a plane or a milling tool, or as a material erosion unit, in particular in the form of a spark erosion unit.

5. The device according to claim 1, wherein the material application unit is designed as an electric welding unit, an arc welding unit, an inert gas welding unit or a laser welding unit, or as a flame spraying unit.

6. The device according to claim 1, wherein the grinding unit comprises a rotationally drivable grinding and/or polishing tool.

7. The device according to claim 1, wherein the support bearing unit comprises at least one bearing block and/or the support bearing unit includes a lubricant and/or the support bearing unit comprises a lubricant supply means.

8. The device according to claim 1, wherein the support bearing unit comprises a guide unit to radially guide and adjust as well as fix the at least one bearing block, the guide unit being mountable to the holding unit.

9. The device according to claim 1, wherein the drive unit comprises an electric motor and an output gear wheel adapted to be connected in a torque-proof manner with the shaft to be machined, and an input gear wheel, in particular in the form of a cone gear wheel, arranged orthogonally to the output gear wheel and adapted to be driven by the electric motor.

10. A method for machining a shaft of an apparatus to be machined at a bearing point at which the shaft is rotatably supported in a bearing of the apparatus to be replaced, wherein, with the shaft bearing arrangement being dismounted, according to the method, the shaft is held in its operating position by means of a support bearing unit, the shaft is caused to rotate by means of a drive unit mounted on the apparatus, using a material removal unit, material is removed at the bearing point of the shaft to be machined while the same is rotated, using a material application unit, material is applied onto the bearing point of the shaft to be machined, and using a grinding unit, the shaft to be machined is ground and/or polished at the bearing point.

11. The method according to claim 10, wherein after the machining of the shaft, the drive unit, the material removal unit, the material application unit, the grinding unit and the support bearing unit are removed and the apparatus is provided with a new shaft bearing.

12. The method according to claim 10, wherein the shaft bearing to be replaced is disassembled prior to the machining of the shaft.

Description

[0037] The invention is described in more detail below by means of an exemplary embodiment and with reference to the drawing, in which In the Figures:

[0038] FIG. 1 is a heavily schematized side view of the drive train in the nacelle of a wind turbine for the generator thereof,

[0039] FIG. 2 schematically shows the structure of the drive unit for the rotating drive of the generator shaft to be machined during the machining thereof,

[0040] FIG. 3 is a top plan view on the end face of the generator housing with the shaft bearing arrangement removed to illustrate the function of the support bearing unit, and

[0041] FIGS. 4 to 6 schematically show the situations in which the various tools and components for machining the bearing point of the shaft are arranged on a feed unit which itself is arranged on a holding unit attached to the housing.

[0042] As one of a number of applications for the implementation of the invention, FIG. 1 schematically shows a nacelle 10 of a wind turbine, the rotor 12 of which drives the shaft 16 of a generator 18 through a gearing 14. The generator 18 thus is an example for an apparatus 20 with a shaft 16 rotating relatively fast. In this embodiment, the shaft 16 is supported at both end faces 22, 24 of the housing 26 of the generator 18, for which purpose the generator 18 has a shaft bearing arrangement 28, 30 at the respective end faces.

[0043] FIG. 2 shows the assembly of a drive unit 32 on the end face 24 of the generator 18. A so-called bearing plate 34, at which the actual bearing 36 of the shaft arrangement 28 is located, is provided on the generator housing 26. A frame 38 of the drive unit 32 is mounted on this bearing plate 34, the drive unit comprising an electric motor 40 with a cone gear wheel 42 rotated by the electric motor 40. An output gear 46 is located on a coupling element 44 of the drive unit 32, which gear rotates the coupling element 44. The coupling element 44 is connected to the end of the shaft 16 in a clamping manner, for example, and thus in a torque-proof manner In this context, a form-fitting connection or the like would also be conceivable. The two gear wheels 42, 46 form a gearing 47.

[0044] It is now possible to rotate the shaft 16 bx means of the drive unit 32 while the shaft is machined.

[0045] The situation during the machining of the shaft 16 on the other end face 22 of the generator housing 26 is shown in FIGS. 3 to 6. In the top plan view on this end face 22 in FIG. 3, the shaft 16 can be seen which is arranged in a hole 48 in which the already disassembled bearing 36 was located before. The space previously occupied by the bearing plate 50 (see FIG. 2) is used to mount a holding unit 52, which in this embodiment is a multi-part holding unit, which can comprise a plurality of mounting plates 54, 56, 58, each in the shape of a partial disk. However, a one-piece mounting plate can also be used.

[0046] As can be seen in particular in FIG. 3, the shaft 16 is supported by a support bearing unit 60 and is held in such a position that it is possible to rotate the haft 16 despite the shaft bearing arrangement 28 being removed. The support bearing unit 60 has two bearing blocks 62 in the form of, for example, steady rests, which are provided with lubricant and are radially displaceable and adjustable in different radial positions. For this purpose, the support bearing unit 60 has a guide unit 64 provided with two guide elements 66 which are arranged in a displaceable manner on the mounting plate 58, for example (see also the double-headed arrows in FIG. 3).

[0047] FIGS. 4 to 6 show different situations during the machining of the shaft 16 for the repair of the damages at the bearing point 68 thereof. At its front end face 22, the housing 26 of the generator 18 is provided with the holding unit 52. The mounting plates 54, 56 and 58 used ion this case are provided with receptacles to retain various tools and units, as well as components required for the machining of the bearing point 68 of the shaft 16. Ideally, a feed unit 70 is mounted on the holding unit 52 for this purpose, which feed unit comprises a tool slide 72 which can be displaced by motor and/or manually in the direction of the extension of the shaft 16 as well as orthogonally thereto (the latter in at least one dimension). For this purpose, the feed unit 70 is provided with a guide bar 73 comprising, for example, a motor 74 and an adjustment spindle 76, by which a transversely extending guide bar 78 can be displaced, on which the tool slide 72 can be longitudinally displaced by operating a manual wheel 80 with a spindle 82, for example. According to FIG. 4, a material removal unit 84 is mounted on the tool slide 72, which comprises a milling tool 86 in the form of a rotationally drivable milling head. This milling head 86 is moved by the feed unit 70 until it arrives in the intermediate space between the shaft 16 and the housing 26 of the generator 18 in order to now remove material from the bearing point 68 of the shaft 16 and to thereby prepare the bearing point 68 for subsequent working steps.

[0048] FIG. 5 shows the situation of FIG. 4, however, with a laser welding unit 88 being mounted on the tool slide 72 as a material application unit 90. This material application unit 90 can be used to apply material onto the (later) bearing point 68 of the shaft 16, which will then be worked with a grinding unit 92 with respect to the surface, as shown in FIG. 6, for example. The grinding unit 92 has a rotationally drivable grinding disc 94, the diameter of which is adapted to the size of the distance between the shaft 16 and the generator housing 26 at the end face 22 thereof.

[0049] After the shaft 16 has been machined as described above, the holding unit 52 is removed from the end face 22 of the generator housing 26 so that the new shaft bearing arrangement 30 with the associated bearing plate 50 can be mounted on the end face 22.

[0050] The invention has been described above with reference to the replacement of a bearing and the machining of the shaft of a generator. However, the invention is also useful in repairing or replacing the bearing of the main or rotor shaft of a wind turbine. In this case, the holding unit for the (auxiliary) support bearing unit and for the assembly of the shaft machining units is configured as a unit supported in the nacelle of the wind turbine (e.g. as a block or a frame), on which unit the support bearing unit with its auxiliary bearings (e.g. bearing blocks with steady rests) is located. The main shaft is driven by an auxiliary motor, for example, which drives e.g. the output shaft of the gearing leading to the generator, for which purpose the generator should be separated from the gearing, but does not necessarily have to be separated therefrom. With wind turbines having no gearing, the auxiliary motor would have to act upon the main shaft, which would also be possible with wind turbines having a transmission (namely after separation of the drive train between the main shaft and the generator).

LIST OF REFERENCE NUMERALS

[0051] 10 nacelle [0052] 12 rotor [0053] 14 transmission [0054] 16 shaft [0055] 18 generator [0056] 20 apparatus [0057] 22 end face [0058] 24 end face [0059] 26 generator housing [0060] 28 shaft bearing arrangement at the end face [0061] 30 shaft bearing arrangement at the end face [0062] 32 drive unit [0063] 34 bearing plate [0064] 36 bearing [0065] 38 frame [0066] 40 electric motor [0067] 42 cone gear wheel [0068] 44 coupling element [0069] 46 output gear wheel [0070] 47 transmission [0071] 48 hole [0072] 50 bearing plate [0073] 52 holding unit [0074] 54 partial disc-shaped mounting plates [0075] 56 partial disc-shaped mounting plates [0076] 58 partial disc-shaped mounting plates [0077] 60 support bearing unit [0078] 62 bearing block [0079] 64 guide unit [0080] 66 guide element [0081] 68 bearing point [0082] 70 feed unit [0083] 72 tool slide [0084] 73 guide bar [0085] 74 motor [0086] 76 adjustment spindle [0087] 78 guide bar [0088] 80 manual wheel [0089] 82 spindle [0090] 84 material removal unit [0091] 86 milling tool [0092] 88 laser welding unit [0093] 90 material application unit [0094] 92 grinding unit [0095] 94 grinding wheel