U.S. patent application number 13/014000 was filed with the patent office on 2011-07-28 for method for hardening the surface of a component in a wind turbine.
Invention is credited to Klaus Ventzke.
Application Number | 20110179843 13/014000 |
Document ID | / |
Family ID | 44307917 |
Filed Date | 2011-07-28 |
United States Patent
Application |
20110179843 |
Kind Code |
A1 |
Ventzke; Klaus |
July 28, 2011 |
Method for hardening the surface of a component in a wind
turbine
Abstract
A method for hardening a surface of a component in a wind
turbine is disclosed. The component to be hardened includes a
surface and the surface is applied with a blasting material by
ultrasound waves. The component is a part of a drive or a drive
housing, a bearing surface, a gear wheel or a pinion. The
ultrasound waves are emitted with the aid of a piezo electric
transducer.
Inventors: |
Ventzke; Klaus; (Langerwehe,
DE) |
Family ID: |
44307917 |
Appl. No.: |
13/014000 |
Filed: |
January 26, 2011 |
Current U.S.
Class: |
72/53 |
Current CPC
Class: |
C21D 9/32 20130101; C21D
7/06 20130101; C21D 10/00 20130101; C21D 9/40 20130101 |
Class at
Publication: |
72/53 |
International
Class: |
C21D 7/06 20060101
C21D007/06 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 28, 2010 |
DE |
10 2010 006 094.1 |
Claims
1.-9. (canceled)
10. A method for hardening a surface of a component in a wind
turbine, comprising: applying a blasting material by ultrasound
waves with the surface of the component.
11. The method as claimed in claim 10, wherein the component is a
part of a drive or a drive housing, a bearing surface, a gear wheel
or a pinion.
12. The method as claimed in claim 10, wherein the ultrasound waves
are emitted by a piezo electric transducer.
13. The method as claimed in claim 10, wherein the ultrasound waves
are emitted in a frequency between 10 kHz and 30 kHz.
14. The method as claimed in claim 10, wherein the ultrasound waves
are amplified.
15. The method as claimed in claim 10, wherein the blasting
material comprises a tungsten carbide.
16. The method as claimed in claim 10, wherein the blasting
material comprises a ball.
17. The method as claimed in claim 10, wherein the ball has a
diameter of more than 1 mm.
18. The method as claimed in claim 17, wherein the ball has a
diameter of more than 5 mm.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority of German application No.
10 2010 006 094.1 filed Jan. 28, 2010, which is incorporated by
reference herein in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to a method for hardening the
surface of a component in a wind turbine, in particular the surface
outer layer of a component in a wind turbine.
BACKGROUND OF THE INVENTION
[0003] Microscopic cracks in the respective part frequently appear,
as a result of high Hertzian pressure, in heavily loaded regions of
drives, for instance in heavily stressed regions of bearing
surfaces of drives or tooth flanks of gear wheels. Microscopic
cracks of this type may result in premature faults and
corresponding failures of the respective part. The crack formation
frequently occurs on the outer surfaces and/or in the region of the
periphery of the heavily loaded contact surfaces. Micro defects of
this type reduce the operating time and the service life of the
respective part, for instance of the drive and the drive housing.
In numerous plants, for instance in wind turbines, the thus
necessary replacement of the respective component, for instance of
the drive or parts thereof, is generally complicated and
expensive.
[0004] The hardening processes and processing technologies used to
date, such as rolling, hard turning or blasting material peening,
do not achieve increased internal stress particularly of the
heavily loaded contact regions and therefore reduce the high
tensile load. Only internal stresses of a maximum of 400 MPa can
currently be achieved.
[0005] DE 10 2007 009 470 A1 and WO 93/20247 A1 describe methods
for the surface peening, in particular for the ultrasound ball
peening of a part, in particular a gas turbine. Ultrasound blasting
material peening is characterized in that a sub-region of the
surface of a part is hardened by applying a blasting material. The
blasting material preferably consists of small balls with a
diameter of less than 4 mm.
SUMMARY OF THE INVENTION
[0006] The object of the present invention consists in providing an
advantageous method for hardening the surface of a component in a
wind turbine. This object is achieved by a method as claimed in the
independent claim. The dependent claims contain further
advantageous embodiments of the invention.
[0007] The inventive method for hardening the surface of a
component in a wind turbine is characterized in that the component
to be hardened has a surface and the surface is applied with a
blasting material by means of ultrasound waves. The component to be
hardened can be in particular parts of bearings or the drive of the
wind turbine. In particular, the component can include a part of a
drive or a drive housing, a bearing surface, in particular of a
bearing, for instance a bearing surface of a roller bearing, or of
a drive, a gear wheel or a pinion, in particular a drive pinion.
The component to be hardened can be in particular a tooth flank of
a gear wheel.
[0008] By means of ultrasound blasting material peening, in other
words applying the surface to be hardened with a blasting material
by means of ultrasound waves, the internal stress of the respective
component is increased and the susceptibility to cracking is thus
reduced. The service life and the operating time of the respective
component are increased in this way by approximately 20%.
[0009] The ultrasound waves can preferably be emitted with the aid
of a piezo electric transducer. For instance, ultrasound waves can
be emitted with a frequency between 10 kHz and 30 kHz, preferably
20 kHz. It is particularly advantageous if the ultrasound waves are
amplified. This can take place for instance with the aid of an
acoustic amplifier.
[0010] The blasting material can preferably include a relatively
heavy material, like for instance tungsten carbide, and/or consist
of tungsten carbide. In addition, the blasting material can include
balls. The blasting material can preferably include balls with a
diameter of more than 1 mm, advantageously with a diameter of more
than 5 mm, or can exclusively consist of blasting balls with a
diameter of more than 1 mm, advantageously with a diameter of more
than 5 mm. It has emerged that the use of tungsten carbide balls
and the use of balls with a relatively large diameter, in
particular of more than 5 mm, can achieve particularly high
internal compressive stress results, since the balls are in this
case embodied in a relatively large and heavy fashion.
[0011] With the aid of the inventive method, internal stresses, in
particular of bearing surfaces of wind turbine bearings and wind
turbine drives, for instance gear wheel drive systems, of more than
800 MPa can be achieved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Further features, characteristics and advantages of the
present invention are described in more detail below with reference
to an exemplary embodiment with respect to the appended figures.
Here the described features are advantageous both individually and
also in combination with one another.
[0013] FIG. 1 shows a schematic representation of a wind power
plant.
[0014] FIG. 2 shows a schematic representation of a first
cross-section through a part of an apparatus for implementing the
inventive method on a gear wheel.
[0015] FIG. 3 shows a schematic representation of a second
cross-section through a part of an apparatus for implementing the
inventive method on a gear wheel.
[0016] FIG. 4 shows a schematic representation of a first
cross-section through a part of an apparatus for implementing the
inventive method on the interior surface of a roller bearing outer
ring.
[0017] FIG. 5 shows a schematic representation of a second
cross-section through a part of an apparatus for implementing the
inventive method on the inner surface of a roller bearing outer
ring.
[0018] FIG. 6 shows a schematic representation of a first
cross-section through a part of an apparatus for implementing the
inventive method on the outer surface of a roller bearing inner
ring.
[0019] FIG. 7 shows a schematic representation of a second section
through a part of an apparatus for implementing the inventive
method on the outer surface of a roller bearing inner ring.
DETAILED DESCRIPTION OF THE INVENTION
[0020] An exemplary embodiment of the invention is described in
more detail below with the aid of FIGS. 1 to 7. FIG. 1 shows a
schematic representation of a wind power plant 1. The wind power
plant 1 includes a tower 2, a pod 3 and a rotor hub 4. The pod 3 is
arranged on the tower 2. The rotatably mounted rotor hub 4 is
arranged on the pod 3. At least one rotor blade 5 is fastened to
the rotor hub 4. The wind power plant 1 typically includes two or
three rotor blades 5.
[0021] The wind power plant 1 also includes at least a rotational
axis 6, a main bearing 30, a drive 7, a brake 8 and a generator 9.
The rotational axis 6, the main bearing 30, the drive 7, the brake
8 and the generator 9 are arranged inside the pod 3. A center to
center difference is essentially possible in the drive 7. Different
components can therefore have different rotational axes. In
addition, the wind power plant 1 can also be embodied without
drives.
[0022] FIG. 2 shows a schematic representation of a cross-section
through part of an apparatus for implementing the inventive
ultrasound shot peening method. The apparatus includes a peening
chamber 10, within which the shot peening is implemented. Part of a
component to be hardened, in the present exemplary embodiment part
of a drive pinion 11, is arranged within the peening chamber 10.
The drive pinion 11 includes a rotational axis 13. FIG. 2 shows a
cross-section through the drive pinion 11 along the rotational axis
13, in other words an axial cross-section. The drive pinion 11
includes a number of teeth 24, of which at least one part is
arranged within the peening chamber 10. The surface to be hardened
of the teeth 24 of the gear pinion 11 is identified with reference
character 26.
[0023] At least one part of a sonotrode 17 is also arranged within
the peening chamber 10. The sonotrode 17 is preferably arranged
opposite the surface 26 to be hardened. The sonotrode 17 is
connected to an amplifier 16, preferably an acoustic amplifier. The
amplifier 16 is also connected to a transducer, preferably in the
form of a piezo electric emitter.
[0024] A cavity 27 is disposed between the sonotrode 17 and the
drive pinion 11 within the peening chamber 10. A number of balls 18
are arranged in this cavity 27. The balls 18 preferably consist of
tungsten carbide. The balls 18 advantageously have a diameter of
more than 1 mm, preferably of more than 5 mm. A homogenous
hardening of the surface 26 is herewith achieved.
[0025] In order to implement the inventive method, ultrasound waves
with a frequency between 30 kHz and 10 kHz, advantageously with a
frequency of 20 kHz, are generated with the aid of the transducer
14. The ultrasound waves are then amplified with the aid of the
acoustic amplifier 16. The amplified ultrasound waves are
transmitted by means of the sonotrode into the peening chamber 10,
and/or into the cavity 27 disposed therein. The ultrasound waves
cause the balls 18 inside the peening chamber 10 to vibrate and
move inside the peening chamber 10. The balls 18 are in this way
reflected by the surface of the sonotrode 17, by the surface 26 to
be hardened and by the walls of the peening chamber 10. In
addition, the balls 18 collide with one another. As a result of the
random scattering of the balls 18, a homogenous treatment of the
surface 26 to be hardened is achieved.
[0026] FIG. 3 shows a schematic representation of a cross-section
according to FIG. 2 through an apparatus for implementing the
inventive method. Contrary to FIG. 2, the drive pinion 12 is shown
in FIG. 3 in a radial cross-section, in other words in a
cross-section at right angles to the rotational axis 13. The view
of the remaining parts in FIG. 3 can essentially correspond to the
cross-section shown in FIG. 2, with only the part 11 and/or 12 to
be hardened being arranged differently. Alternatively the
cross-section shown in FIG. 3, in respect of all parts, may be a
cross-section at right angles to the cross-section shown in FIG. 2.
The longitudinal axis of the apparatus is identified in both FIGS.
2 and 3 with reference character 15.
[0027] The teeth 24 of the drive pinion 12 shown in FIG. 3 include
tooth flanks 25. With the aid of the inventive method, the tooth
flanks 25 can in particular be effectively hardened, since as a
result of the random scattering of the balls, the whole surface to
be hardened can be evenly treated.
[0028] FIGS. 4 and 5 show a cross-section through part of an
apparatus for implementing the inventive method. FIGS. 4 and 5 show
the hardening of the inner bearing surface 21 of a roller bearing
outer ring 19 and/or 20. Here the roller bearing outer ring 19 in
FIG. 4 is shown in an axial cross-section in respect of a
rotational axis 23. FIG. 5 shows the roller bearing outer ring 20
in a radial cross-section in respect of the rotational axis 23.
Similarly to the embodiments rendered in conjunction with FIGS. 2
and 3, FIGS. 4 and 5 may be two cross-sections arranged at right
angles to one another and the same arrangement or however the same
cross-section, with the roller bearing outer ring 19 and/or 20
being arranged differently.
[0029] The same applies to FIGS. 6 and 7, in which a cross-section
is shown through an apparatus for hardening the outer bearing
surface 22 of a roller bearing ring 28 and/or 29. FIG. 6 shows part
of the roller bearing inner ring 28 in an axial cross-section in
respect of the rotational axis 23, while FIG. 7 shows part of the
roller bearing inner ring 29 in a radial cross-section in respect
of the rotational axis 23.
[0030] The inventive method described in conjunction with FIG. 2
can be implemented in a similar fashion with the aid of the
embodiments shown in FIGS. 3 to 7.
[0031] As a result, an internal stress of the surface of the drive
pinion 11, 12, in particular of the surface of the tooth flanks 25,
of the outer bearing surface 22 and of the inner bearing surface 21
of the roller bearing ring 19, 20, 28, 29 of more than 800 MPa can
be achieved with the aid of the inventive method.
* * * * *