U.S. patent application number 16/753017 was filed with the patent office on 2020-12-10 for method for honing a stator and machine for carrying out the method.
This patent application is currently assigned to Gehring Technologies GmbH. The applicant listed for this patent is Gehring Technologies GmbH. Invention is credited to Gerhard Flores, Michael Schafer, Andy van Boven, Andreas Wiens.
Application Number | 20200384599 16/753017 |
Document ID | / |
Family ID | 1000005048425 |
Filed Date | 2020-12-10 |
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United States Patent
Application |
20200384599 |
Kind Code |
A1 |
van Boven; Andy ; et
al. |
December 10, 2020 |
METHOD FOR HONING A STATOR AND MACHINE FOR CARRYING OUT THE
METHOD
Abstract
The invention relates to a method for machining a stator opening
of a stator and a bearing opening of an electromechanical
converter, in particular an electric motor, the method comprising
the steps of honing the stator opening using a honing tool and
machining, preferably honing, the bearing opening.
Inventors: |
van Boven; Andy; (South
Lyon, MI) ; Schafer; Michael; (Howell, MI) ;
Wiens; Andreas; (Sachsenheim, DE) ; Flores;
Gerhard; (Ostfildern, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Gehring Technologies GmbH |
Ostfildern |
|
DE |
|
|
Assignee: |
Gehring Technologies GmbH
Ostfildern
DE
|
Family ID: |
1000005048425 |
Appl. No.: |
16/753017 |
Filed: |
September 19, 2018 |
PCT Filed: |
September 19, 2018 |
PCT NO: |
PCT/EP2018/075287 |
371 Date: |
April 2, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B24B 33/02 20130101 |
International
Class: |
B24B 33/02 20060101
B24B033/02 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 2, 2017 |
DE |
10 2017 122 893.4 |
Claims
1. A method for machining a stator opening of a stator and a
bearing opening of an electromechanical converter, the method
comprising the steps of honing the stator opening using a honing
tool and machining the bearing opening, characterized in that a
tool for machining the bearing opening is aligned coaxially with
the stator opening during the machining of the bearing opening via
a centering device which engages in the stator opening, or in that
the honing tool for honing the stator opening is aligned coaxially
with the bearing opening via a centering device which engages in
the bearing opening.
2. The method according to claim 1, characterized in that the
stator is joined to a housing section which comprises the bearing
opening during the honing of the stator opening.
3. The method according to claim 1, characterized in that the
stator is not joined to a housing section which comprises the
bearing opening during the honing of the stator opening.
4. The method according to claim 1, characterized in that the
stator opening is honed before the bearing opening is machined.
5. The method according to claim 1, characterized in that the
honing of the stator opening and the machining of the bearing
opening take place simultaneously.
6. The method according to claim 1, characterized in that the
method after the honing of the first bearing opening, the stator
opening comprises the attachment of a second housing section having
a second bearing opening to the first housing section, which
comprises the first bearing opening.
7. The method according to claim 1, characterized in that the
method after the honing of the stator opening and the machining of
the first bearing opening comprises the machining of the second
bearing opening, a tool for machining the second bearing opening
being aligned coaxially with the stator opening or the first
bearing opening via a centering device which engages in the stator
opening or the first bearing opening during the machining of the
second bearing opening.
8. The method according to claim 1, characterized in that the
machining of the first bearing opening and, where applicable, the
second bearing opening comprises at least one of the machining
steps among honing, fine boring and reaming.
9. The method according to claim 1, characterized in that the
stator opening is honed using honing stones with diamond as the
cutting material and/or that the stator opening is honed using
honing stones that have a cutting material with an average grain
size that is smaller than the thickness of the lamina of the
stator, and that the stator opening is honed using honing stones
which have a cutting agent concentration of at most 20 vol %.
10. The method according to claim 1, characterized in that the
stator opening is honed with a honing angle of less than
30.degree..
11. The method according to claim 1, characterized in that a
centering device is used that is designed to be radially
adjustable.
12-15. (canceled)
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a method for machining a
stator opening of a stator and a bearing opening of an
electromechanical converter, in particular of an electric motor,
wherein the method comprises the steps of honing the stator opening
using a honing tool and machining, preferably honing, the bearing
opening. The bearing opening serves to receive the rotor (or a
rotor shaft on which the rotor is arranged) of the
electromechanical converter.
[0002] With electromechanical converters, especially electric
motors, the gap width between the outer circumference of the rotor
and the inner circumference of the stator affects the efficiency of
the electromechanical converter. A smaller gap width increases
efficiency.
[0003] A lower limit for the achievable gap widths results from the
need to avoid rubbing against the rotor during operation and to
keep the machining effort for the surfaces, in particular the
stator, to an economically/technically reasonable level.
SUMMARY OF THE INVENTION
[0004] The object of the present invention is to provide a method
with which the stator and the bearing opening, which serves to
receive the rotor, can be machined in a way that enables the
smallest possible gap width between rotor and stator. In addition
to a small gap width, coaxial positioning of the rotor and stator
with respect to one another should preferably also be achieved in
order to ensure a parallel position of the functional surfaces of
the rotor and stator.
[0005] This object is achieved by a method according to claim 1.
The method according to the invention is characterized in that a
tool for machining the bearing opening is aligned coaxially with
the stator opening via a centering device which engages in the
stator opening during the machining of the bearing opening, or in
that the honing tool for honing the stator opening is aligned
coaxially with the bearing opening via a centering device which
engages in the bearing opening. A centering device for the tool for
machining the bearing opening is to be understood as a device
which, via mechanical engagement in the stator opening,
predetermines an alignment of the axis of the machining of the
bearing opening. For example, the centering device may comprise a
centering mandrel which detects the position of the stator opening
and is mechanically coupled to the tool for machining the bearing
opening in such a way that it predetermines its axial position. It
is also conceivable that the centering device comprises the honing
tool that is provided for machining the stator opening. In this
case, the honing tool can be coupled to the tool for machining the
bearing opening in such a way that both are aligned coaxially with
one another and ensure a coaxial course of the stator opening and
bearing opening during simultaneous machining of the stator opening
and bearing opening.
[0006] A centering device for the honing tool for honing the stator
opening is to be understood as a device which, via mechanical
engagement in the bearing opening, predetermines an alignment of
the axis for honing the stator opening. For example, the centering
device may comprise a centering mandrel that detects the alignment
of the bearing opening and is mechanically coupled to the honing
tool for machining the stator opening in such a way that it
predetermines its axial position.
[0007] It is optionally possible in the sense of the invention that
the honing tool for machining the stator opening and the tool for
machining the bearing opening is a multi-tiered honing tool. Such a
multi-tiered honing tool may comprise a first honing section with a
first set of honing stones and a second honing section with a
second set of honing stones. The arrangement of the two honing
sections on one tool axis always ensures coaxial machining of the
stator opening and the bearing opening. When using such a
multi-tiered honing tool, the honing section that is used to
machine the stator opening represents not only the honing tool for
machining the stator opening, but also the centering device in the
sense of the present invention.
[0008] According to the invention, if a multi-tiered tool is used
for the machining of the stator opening and the bearing opening
that comprises a first honing section with a first set of honing
stones, wherein the first honing section may comprise passive
centering bars which can be extended after a honing operation has
been completed, wherein the honing stones can be retracted. The
centering bars can then act as a centering device and the
multi-tiered tool can comprise a second honing section with a
second set of honing stones which can be extended after the honing
of the stator opening and can hone or machine the bearing opening,
while the centering bars ensure the coaxial course of the second
honing section for the stator opening.
[0009] The stator comprises stacked lamina, between which there is
insulation material. During the machining of the inner surface of
the stator, burrs can be produced which can contact the adjacent
lamina. The function of the stator, however, requires avoiding
contacting the individual lamina in order to avoid the formation of
eddy currents. There is therefore a need for the lamina edges on
the inside of the stator to be largely free of burrs. This is
achieved by the honing operation or honing operations described
above. This also enables the machining of the individual lamina to
a uniform diameter and the removal of paint residues on the curved
inner surface of the stator.
[0010] Honing the stator opening achieves a high surface quality
and roundness of the stator opening; moreover, the method according
to the invention ensures that the bearing opening is aligned
coaxially with the stator opening and that the rotor can
accordingly be aligned coaxially with the stator, so that a minimal
gap width between the rotor and the stator can be achieved. As a
result, a correspondingly machined electromechanical converter can
be efficiently designed.
[0011] By minimizing the gap width, the electrical field strength
and thus the efficiency of the electromechanical converter increase
and the electromechanical converter runs smoothly.
[0012] It is optional if the stator is joined to a housing section
that comprises the bearing opening during the honing of the stator
opening. The stator can thus already be inserted or pressed into
the housing during the machining of the stator opening. The honing
of the stator opening can be carried out, for example, at the same
time as the machining of the bearing opening.
[0013] It is optional if the stator is not joined to a housing
section that comprises the bearing opening during the honing of the
stator opening. The stator can be handled individually and can only
be inserted into the housing after the honing has been completed.
As a result, the method step of honing the stator can be carried
out on a conventional honing machine with a conventional honing
awl.
[0014] It is optional if the stator opening is honed before the
bearing opening is machined, preferably honed. As a result, a
conventional honing tool can be used for honing the stator
opening.
[0015] It is optional if the honing of the stator opening and the
machining of the bearing opening take place, preferably with the
bearing opening being honed, in particular with the stator opening
and the bearing opening taking place simultaneously using a tiered
honing tool having two honing sections separated from one another.
This can reduce the cycle time during machining. In particular
during the simultaneous honing of the bearing opening and the
stator opening, the method according to the invention can thereby
be carried out in a particularly time-efficient manner.
[0016] It is optional if the method--after the honing of the stator
opening and the machining of the first bearing opening--comprises a
machining, preferably honing, of a second bearing opening, a tool
for machining the second bearing opening being aligned coaxially
with the stator opening or the first bearing opening via a
centering device which engages in the stator opening or the first
bearing opening during the machining of the second bearing opening.
The stator of the electromechanical converter can then be mounted
in two bearing openings, both of which are aligned coaxially with
the stator opening. This variant of the method according to the
invention can be implemented particularly easily if a honing tool
is used which comprises a centering section which is introduced
into the first bearing opening and a honing section which is
introduced into the second bearing opening. The centering section
can be aligned with respect to the first bearing opening via
centering strips and is mechanically coupled to the honing section
in such a way that the centering section aligns the honing section
coaxially with the first bearing opening, so that the second
bearing opening is aligned coaxially with the first bearing opening
by the honing operation. After completion of the method variant
just described, the stator opening and both bearing openings are
then aligned coaxially with one another and have a high surface
quality and roundness.
[0017] It is optional if the machining of the first bearing opening
and, where applicable, the second bearing opening comprises at
least one of the machining steps among honing, fine boring and
reaming. The aforementioned methods allow the position of the
bearing opening to be influenced sufficiently to ensure coaxial
alignment.
[0018] It is optional if the stator opening is honed using honing
stones with diamond as the cutting material and/or if the stator
opening is honed using honing stones that use a cutting material
with a medium grain size (FEPA standard for diamond micro-grain
sizes (11.1977, chap. 2.1): "The grain size is defined by
measurement parameters from measurements on the enlarged image of
the single grain, as seen in the microscope. The grain size is
determined by the diameter of the smallest circle that completely
surrounds the microscopic image."), which grain size is smaller
than the thickness of the stator lamina and/or, if the stator
opening is honed using honing stones that have a cutting agent
concentration of at most 20 vol %, in particular 17.5 vol %, in
particular 15 vol %, in particular 12.5 vol %. Diamond is
particularly suitable as a cutting material for the honing stones
during the machining of the stator, since this cutting agent is
particularly hard and prevents bridging between the lamina of the
stator. The use of a cutting material having an average grain size
that is smaller than the thickness of the lamina also counteracts
bridging between the lamina of the stator. The aforementioned
concentrations of cutting agent ensure that there is always sharp
cutting material on the surface of the honing stones, which also
has a positive effect on preventing bridging between the lamina of
the stator.
[0019] It is optional if the stator opening is honed using honing
stones with cBN (cubic crystalline boron nitride) as the cutting
material. The use of honing stones with conventional cutting
materials, such as silicon carbide and/or corundum, is also
conceivable.
[0020] It is optional if the stator opening is honed with a honing
angle of less than 30.degree.. This counteracts bridging between
the lamina of the stator. The specified range of honing angles
ensures that the cutting movement with a small axial component
predominantly runs in the circumferential direction, and, thus, the
honing operation takes place predominantly in the direction of the
lamina of the stator, so that bridging between the lamina of the
stator is effectively prevented. The honing angle is the angle
between the vectors of the cutting speed with respectively reversed
axial movement. The horizontal line, which corresponds to the
course of the stator lamina and corresponds to the direction of the
purely rotary movement of the honing tool, represents the bisector
of the honing angle. The honing angle is visible on the finished
honed components at the resulting honing marks, which run in a
cross-cut pattern typical of honing.
[0021] Optionally, a centering device is used in the method
according to the invention and is designed to be radially
adjustable.
[0022] Part of the present invention is also a machine tool which
is set up and designed to machine the stator opening of a stator
and the bearing opening of an electromechanical converter according
to any one of the above-described variants of the method according
to the invention. In particular, such a machine tool may comprise a
tool for machining the bearing opening, which tool comprises a
centering device via which the tool for machining the bearing
opening can engage in the stator opening during the machining of
the bearing opening and can align the tool coaxially with the
stator opening.
[0023] Optionally, the machine tool has a centering device that is
designed to be radially adjustable.
[0024] Preferably, the machine tool is characterized in that it
comprises a workpiece holder and an assembly device, the workpiece
holder being designed to hold a first housing section of a housing
of an electromechanical converter comprising a first bearing
opening and the assembly device being designed to attach a second
housing section of a housing of an electromechanical converter
comprising the second bearing opening to the first housing section.
"Attach" here is to be understood as meaning that the second
housing section is placed on the first housing section in an
intended assembly position. The machine tool preferably also
includes a joining device which is designed to join the first
housing section to the second housing section, for example to weld,
glue or screw them into one another.
[0025] The machine tool preferably has a rotary table. The rotary
table can be designed, for example, to transport the
electromechanical converter from one machining station to the next.
For example, the tool for machining the first bearing opening and
the tool for machining the second bearing opening, and preferably
also the honing tool for machining the stator opening, can be
arranged at different machining stations of the machine tool. The
aforementioned assembly device can be arranged at one of the
machining stations at which the honing tool for machining the
stator opening or one of the tools for machining the first or the
second bearing opening is arranged. However, the assembly device
can also be arranged at a separate further machining station.
[0026] However, the rotary table can also be designed to bring
different tools into a machining position at a machining station
than the electromechanical converter. For example, the rotary table
can move the honing tool for machining the stator opening and/or
one or both of the tools for machining the first or the second
bearing opening and/or the assembly device into a machining
position relative to the electromechanical converter.
[0027] The machine tool may also include a workpiece manipulation
device, which is designed to move the housing of the
electromechanical converter from a first machining position, in
which the first bearing opening is aligned for the machining, into
a second machining position, in which the second bearing opening is
aligned for machining.
[0028] Advantageously, the machine tool may include a workpiece
holder, which is designed to hold an electromechanical converter
and the electromechanical converter held therein to move,
preferably rotate the housing of the electromechanical converter
from a first machining position, in which the first bearing opening
is aligned for machining, into a second machining position, in
which the second bearing opening is aligned for machining. In this
case, the workpiece holder more or less forms a workpiece
manipulation device.
[0029] The machine tool can also be designed such that the tool for
machining the first bearing opening is arranged on a different side
of the electromechanical converter than the tool for machining the
second bearing opening, the the tool for machining the first
bearing opening preferably machining the first bearing opening from
a different side than the tool for machining the second bearing
opening machines the second bearing opening. For example, the tool
for machining the first bearing opening can be arranged in the
machine tool above the electromechanical converter and machine the
first bearing opening from above, and the tool for machining the
second bearing opening can be arranged below the electromechanical
converter and machine the second bearing opening from below.
[0030] Part of the present invention is also an electromechanical
converter having a housing in which the stator of the converter is
accommodated, the housing comprising at least one bearing opening,
preferably two bearing openings, the bearing opening or bearing
openings serving to receive a rotor or the rotor shaft of the
electromechanical converter, the stator opening and a bearing
opening, where applicable two bearing openings, being machined
according to any one of the above-described variants of the method
according to the invention. Such an electromechanical converter can
have a particularly high degree of efficiency since its gap width
can be made minimal.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] Further features, possible applications and advantages of
the invention result from the following description of exemplary
embodiments of the invention, which are explained with reference to
the drawing, where the features may be essential for the invention,
both on their own and in different combinations, without being
explicitly mentioned again. Shown in the drawings are:
[0032] FIG. 1 an electromechanical converter in a schematic
sectional view;
[0033] FIG. 2 a stator in a schematic sectional view,
[0034] FIG. 3 a further stator in a perspective view;
[0035] FIG. 4 different steps of a method according to the
invention;
[0036] FIG. 5 different steps of an alternative method according to
the invention;
[0037] FIG. 6 different steps of an alternative method according to
the invention;
[0038] FIG. 7 a machining station of a machine tool;
[0039] FIG. 8 a further machining station of the machine tool;
[0040] FIG. 9 a rotation of the electromechanical converter in the
machine tool by means of a workpiece manipulation device of the
machine tool;
[0041] FIG. 10 a further machining station of the machine tool;
and
[0042] FIG. 11 the machine tool in a schematic representation.
DETAILED DESCRIPTION
[0043] Corresponding components and elements bear the same
reference characters in the following figures. For the sake of
clarity, not all reference characters are shown in all figures.
[0044] FIG. 1 shows a schematic sectional illustration of an
electromechanical converter 10. The electromechanical converter 10
comprises a housing 12. The housing 12 comprises a first bearing
opening 14 in a first housing section 15 and a second bearing
opening 16 in a second housing section 17. A rotor 18 is arranged
in the housing 12. The rotor 18 is arranged on a rotor shaft 19.
The rotor shaft 19 is received in the bearing openings 14, 16. The
rotor shaft 19 comprises a first shaft section 20 and a second
shaft section 22, the shaft sections 20, 22 being received in the
respective bearing openings 14, 16 and being rotatably mounted.
[0045] A stator 24 of the electromechanical converter 10 is
arranged around the rotor 18 within the housing 12. In other words,
the rotor 18 is arranged in a stator opening 26.
[0046] A gap width between the rotor 18 and the stator 24 is
exaggerated in its representation here and bears the reference
symbol 28.
[0047] The stator opening 26 is honed in the present case according
to any one of the methods described below. The bearing openings 14,
16 are machined according to any one of the methods described
below.
[0048] FIG. 2 shows the stator 24 in the perspective of FIG. 1
individually in a sectional view. Individual lamina of the stator
24 each have the reference symbol 30 and are each separated from
one another by an insulation layer 32.
[0049] The stator opening 26 has a plurality of interruptions 34.
An alternative embodiment with more opening interruptions 34 of the
stator 24 is shown in FIG. 3, FIG. 3 showing a perspective view of
such a stator 24.
[0050] FIG. 4 shows an illustration of a method according to the
invention.
[0051] FIG. 4 a) shows a first step of a method according to the
invention.
[0052] In this first step, the stator 24 or the stator opening 26
is machined in the present embodiment of the method. In the variant
of FIG. 4a), the stator 24 is not joined to a housing 12. In this
case, the stator is not joined to the first housing section 15.
Alternatively, the stator 24 can be arranged in the housing 12 or
joined to it, in particular pressed into it. In this case, the
stator is joined to the first housing section 15. The variant
described last is shown in FIG. 4b). FIGS. 4a) and 4b) thus show
alternatives of the first step of the method. In this first step,
the stator opening 26 is honed using a honing tool 36. The honing
tool 36 in the present case has a plurality of honing stones
38.
[0053] The stator opening 26 can be honed using honing stones 38
having diamond as the cutting material 40. The honing of the stator
opening 26 can also or additionally be carried out using honing
stones 38, which have cutting material 40 with an average grain
size that is smaller than the thickness of the lamina 30 of the
stator 24. The honing of the stator opening 24 can also or
additionally be carried out using honing stones 38 which have a
cutting agent concentration of at most 20 vol %, in particular 17.5
vol %, in particular 15 vol %, in particular 12.5 vol %.
[0054] The honing of the stator opening 24 can also or additionally
be carried out with a honing angle of less than 30.degree..
[0055] The honing tool 36 is joined to a honing spindle 42. The
joining to the honing spindle 42 is achieved via a joint 44 on the
spindle side and a joint 46 on the tool side as well as an
articulated rod 48. The articulated joint makes it possible for the
honing tool 36 to follow the axial alignment of the stator opening
26 and machine just its surface without significantly affecting the
axial position. The articulated rod 48 offers the necessary degrees
of freedom for aligning the tool 36 with the stator opening 26 and
enables machining on the same axis.
[0056] In the method variant shown in FIG. 4, the first bearing
opening 14 is machined after the machining or honing of the stator
opening 26 has been completed.
[0057] In the variant of the method according to the invention
shown in FIG. 4, the first bearing opening 14 is also honed.
However, other machining operations are also within the meaning of
the present invention.
[0058] To machine the bearing opening 14, a tool 50, which is
designed here as a honing tool 50, has a centering device 52, which
in the present case comprises a centering mandrel 54.
[0059] During the machining of the first bearing opening 14, the
tool 50 for machining the bearing opening 14 is aligned coaxially
with the stator opening 26 via the centering device 52 which
engages in the stator opening 26. This is illustrated by the common
central axis 56 of the stator opening 26 and the bearing opening
14. The tool 50 is more or less aligned coaxially with the stator
opening 26 by the centering device 52 in its axial position and
machines the bearing opening 14 such that its central axis falls on
the central axis of the stator opening 26.
[0060] Following the method step from FIG. 4c), the second bearing
opening 16 can optionally be machined in accordance with the method
step from FIG. 4d).
[0061] In this case, after the honing of the stator opening 26 and
the machining or honing of the first bearing opening 14, the method
comprises the machining, preferably honing, of the second bearing
opening 16. A tool 58, which is designed here as a honing tool 58,
for machining the second bearing opening 16 is aligned coaxially
with the first bearing opening 14 during the machining of the
second bearing opening 16 via a centering device 60 which engages
in the first bearing opening 14. Because of the coaxial alignment
with the already machined first bearing opening 14, the tool 58 is
also aligned coaxially with the stator opening 26.
[0062] The tool 58 is more or less aligned coaxially with the first
bearing opening 14 or stator opening 26 by the centering device 60
in its axial position and machines the second bearing opening 16
such that its central axis coincides with the central axis of the
stator opening 26 or the first bearing opening 14. The tool 58 is
an articulated honing tool 58. This enables machining on the same
axis. This means that there is coaxial alignment between the
bearing opening 14 and the tool 58 with the centering device
60.
[0063] A centering device 60 can advantageously be designed to be
radially adjustable in order to enable play-free guiding.
[0064] The honing tool 58 for machining the second bearing opening
16 is joined to a honing spindle 62. The joining to the honing
spindle 62 is achieved via a joint 64 on the spindle side and a
joint 66 on the tool side as well as an articulated rod 68.
[0065] In the method variants illustrated in FIG. 4, the tool 50
for machining the first bearing opening 14 is aligned coaxially
with the stator opening 26 via the centering device 52, which
engages in the stator opening 26 (FIG. 4c), and the tool 58 for
machining the second bearing opening 16 is aligned coaxially with
the first bearing opening 14 via the centering device 60, which
engages in the first bearing opening 14 (FIG. 4d). Instead of the
variant shown in FIG. 4d), however, it is also possible to align
the tool 58 for the machining of the second bearing opening 16 via
the centering device 60 coaxially with the stator opening 26, in
which tool the centering device 60 engages in the stator opening
26. In order to do justice to the geometrical relationships
illustrated in FIG. 4, the centering device 60 can, for example, be
designed with expandability.
[0066] 5 shows an alternative variant of the method according to
the invention. In the variant of FIG. 5 or FIG. 5a), the honing
tool 36 for machining the stator opening 26 is rigidly joined to
the tool 50 for machining the first bearing opening 14. The honing
tool 36 and the tool 50, which in the present case is also designed
as a honing tool, together form a tiered honing tool 51, the honing
tool 36 and the tool 50 each forming a honing section of the tiered
honing tool 51. In the method step shown in FIG. 5a), the honing
tool 36 for machining the stator opening 26 simultaneously forms a
centering device 52 which engages in the stator opening 26 and
aligns the tool 50 for machining the first bearing opening 14
coaxially with the stator opening 26. In the method step
illustrated in FIG. 5a), the honing of the stator opening 26 and
the machining, in the present case the honing, of the first bearing
opening 14 are carried out simultaneously. (In the method shown in
FIG. 5a), the tool 50 can also be seen at the same time as a
centering device which engages in the first bearing opening 14 and
which aligns the honing tool 36 for machining the stator opening 26
coaxially with the first bearing opening 14).
[0067] FIG. 5b) shows an optional further method step. If the
method step shown in FIG. 5 b) is carried out, after the honing of
the stator opening 26 and the first bearing opening 14, the method
comprises the machining, preferably honing, of the second bearing
opening 16. The tool 58, which is designed here as a honing tool
58, for machining the second bearing opening 16 is aligned
coaxially with the first bearing opening 14 during the machining of
the second bearing opening 16 via the centering device 60, which
engages in the first bearing opening 14. Because of the coaxial
alignment with the already machined first bearing opening 14, the
tool 58 is also aligned coaxially with the stator opening 26.
[0068] The tool 58 is more or less aligned coaxially with the first
bearing opening 14 or stator opening 26 by the centering device 60
in its axial position and machines the second bearing opening 16
such that its central axis coincides with the central axis of the
stator opening 26 or the first bearing opening 14. The tool 58 is
articulated. The honing tool 58 for machining the second bearing
opening 16 is joined to a honing spindle 62. The joining to the
honing spindle 62 is achieved via a joint 64 on the spindle side
and a joint 66 on the tool side as well as an articulated rod
68.
[0069] FIG. 6 shows an alternative variant of the method according
to the invention. In the variant of FIG. 6, the first bearing
opening 14 is first machined, in the present case honed.
[0070] In a next step, which is shown in FIG. 5b), the stator
opening 26 is honed. The honing tool 36 for machining the stator
opening 26 is rigidly joined to a centering device 72 in this
variant of the method. The centering device 72 comprises a
plurality of centering strips 74 which engage in the already
machined first bearing opening 14 and align the honing tool 36
coaxially with the first bearing opening 14.
[0071] FIG. 6c) shows an optional further method step which
corresponds to the method step of FIG. 5b).
[0072] Various machining stations of a machine tool 75 according to
the invention are shown in FIGS. 7-10. The machine tool 75 itself
is shown schematically in FIG. 11, the machine tool 75 being
designed and set up to carry out the method according to the
invention. The machine tool 75 comprises a machine base 84 and an
upper machine section 86. A rotary table 88 is arranged on the
machine base 84 as a machine-internal transfer system. The rotary
table 88 comprises a plurality of workpiece receptacles 76, which
are arranged centrally around an axis of rotation of the rotary
table 88. The rotary table 88 moves the electromechanical converter
10 held in the workpiece holder 76 from one machining station to
the next via a rotary movement.
[0073] In general, the machine tool 75 can have a rotary table 88
as a machine-internal transfer system or be designed as a linear
transfer machine. For example, the electromechanical converters 10
can be moved through the machine tool 75 via a linear conveyor
belt. A robot-assisted, machine-internal transfer system is also
conceivable. It is also conceivable for the workpieces to be moved
manually through the machine tool 75.
[0074] During the machining of an electromechanical converter 10,
it is held in one of the workpiece holders 76 and thereby fixed,
preferably mechanically clamped. The machine tool 75 is shown here
set up in a machining station in FIG. 7 for carrying out a
simultaneous machining of the stator opening 26 and the first
bearing opening 15 in accordance with the method illustrated in
FIG. 5. For this purpose, the machine tool comprises the tiered
honing tool 51. However, the machine tool can also be designed with
a honing tool 36 for honing the stator opening 26 and with a tool
50 separate therefrom for machining the bearing opening 14. These
two tools are then preferably arranged in different machining
stations. However, they can also be arranged in a single machining
station and can be positioned, for example, via a tool changer in a
machining position relative to the electromechanical converter
10.
[0075] A further machining station of the machine tool is shown in
FIG. 8. An assembly device 78 is arranged in this machining
station. In the present case, the assembly device 78 can be moved
flexibly via an articulated arm 80. In the illustration in FIG. 8,
the assembly device 78 attaches the second housing section 17 of
the housing 12 having the second bearing opening 16 to the first
housing section 15. Following the attachment of the second housing
section 17, the latter is joined to the first housing section 15.
This joining can be done frictionally, positively and/or
integrally, for example by gluing, welding, soldering, clamping,
riveting and/or screwing.
[0076] In order to move the housing 12 or the electromechanical
converter 10 from one machining station to the next, the machine
tool 75 has the rotary table 88. Other transfer systems are
conceivable. For example, the tool 50 for machining the first
bearing opening 14, the tool 58 for machining the second bearing
opening 16 and the honing tool 36 for machining stator opening 26
can be arranged at different machining stations of the machine tool
75. The assembly device 78 can be arranged at a separate machining
station.
[0077] However, the rotary table 88 can also be designed to bring
different tools into a machining position at a machining station
than the electromechanical converter 10. The electromechanical
converter 10 is then advantageously arranged immovably in the
workpiece holder 76. The rotary table 88 is then advantageously
arranged on the machine upper section 86 and rotates the tools
relative to the electromechanical converter 10.
[0078] The machine tool 75 may also comprise a workpiece
manipulation device 90, which is designed to move, preferably
rotate, the housing 12 of the electromechanical converter 10 from a
first machining position (FIGS. 7 and 8), in which the first
bearing opening 14 is aligned for machining, into a second
machining position (FIG. 10), in which the second bearing opening
16 is aligned for machining. The workpiece manipulation device 90
is preferably designed in order to be able to rotate the
electromechanical converter 10 by 180.degree.. Such a movement, or
in the present case rotation, is illustrated in FIG. 9.
[0079] A further machining station of the machine tool is shown in
FIG. 10. In this machining station, the tool 58 for machining the
second bearing opening 16 machines the bearing opening 16.
[0080] The workpiece manipulation device 90 can be provided at a
dedicated machining station or, as shown in FIG. 11, centrally, so
that it can move the electromechanical converter from one machining
position to the other in at least one, preferably all, of the
machining stations of the machine tool 75.
* * * * *