The invention relates to a method for producing a rotor carrier
for an electric machine according to the
The preamble of claim 1 and a rotor carrier according to the
Preamble of claim 8.
State of the art
Rotors of large-sized electric machines, such as
for example of electric machines of hybrid drives of
Motor vehicles, the rotor is often hollow
Rotor carrier instead of a massive rotor shaft,
so that in the interior of the rotor or the rotor carrier space
for other components of the electric machine or
for components of adjacent components of the hybrid drive,
such as a clutch is created. As with smaller ones
electric machines, the rotor consists of a lamellar or
Rotor laminated core, which is on a cylindrical outer
Peripheral surface of the rotor carrier is attached,
and a rotor winding or permanent magnets in the grooves
the lamella or rotor core are housed. The rotor carrier
usually consists of a hollow cylindrical peripheral wall part
and a rotatably connected to the peripheral wall part, in outline circular
Floor panels. The bottom wall part can either be at a front end
be arranged of the peripheral wall part, so that the cup-shaped rotor carrier
a cylindrical cavity open on one side in the axial direction
encloses, or may be closer to the middle of
Be arranged peripheral wall part, so that the double cup-shaped
Rotor carrier two cylindrical sides open to opposite sides
Encloses cavities. Such integrally formed
As a rule rotor armors are usually made by casting
or by forming from a solid material and by a subsequent
However, in terms of
the relatively large space requirement and the relatively high investment costs
the facilities required for the production of disadvantage
is. Moreover, the known methods do not allow
for different parts of the rotor carrier different, on
to use materials adapted to the respective requirements.
This is the object of the invention, a method
and a rotor carrier of the type mentioned in the effect
to improve that a production of the rotor carrier from several,
optionally consisting of different materials items
Disclosure of the invention
The object is achieved according to the invention
that the rotor carrier from at least two parts joined together
is firmly connected by friction welding
Invention is based on the idea, not the rotor carrier
by casting or forming from a solid material and by
to produce a subsequent machining,
but instead of several items, previously separated
by casting, forming, stamping and / or machining
Machining have been made and then the assembly of the rotor carrier by
Friction welding are firmly connected. Thereby
The items can also be made of different materials
are manufactured, which optimally to the respective requirements
are adapted in different sub-areas of the rotor carrier.
For example, one of the parts may be aluminum or an aluminum alloy
are manufactured to the rotating mass of the rotor carrier
to keep as small as possible while another
parts exposed to high loads, made of steel
preferred embodiment of the invention provides that it is at
the parts connected by friction welding on the one hand
is a hollow cylindrical peripheral wall part of the rotor carrier,
on which the lamella or rotor laminated core with the rotor winding
is attached, as well as on the other to a bottom and / or intermediate wall part, the
the limited by the peripheral wall portion cavity at a front end of the
Rotor carrier closes or closer to
its center divided into two separate cavities. In
In this case eliminates the otherwise required bending radii at the transition
between the peripheral wall part and the bottom or intermediate wall part,
whereby at the same length and the same diameter of the
Rotor a larger space inside the rotor carrier
can be provided.
According to a further preferred embodiment of the invention, the two parts are rotated during friction welding under mutual pressure in relation to each other about an axis of rotation which corresponds to the axis of rotation of the later rotor. It is on the one hand possible to fix one of the two parts stationary and to put the other of the two parts in rotation and to press against the fixed part. Alternatively, however, one of the parts may also be rotated about the axis of rotation and the other part may be pressed against the rotating part in the axial direction of the axis of rotation, or both parts may be rotated in reverse direction rotated and pressed axially against each other.
be the parts with two opposite ring or
circular faces pressed against each other,
around at least one of the two parts in the area of these surfaces
melt by the resulting frictional heat and
when solidifying the molten material butt to weld.
Alternatively, it is also possible, the two parts along
two with respect to the rotation axis rotationally symmetrical peripheral surfaces
To weld together, by the outside
facing peripheral surface of a part of a slightly larger
Gives diameter than the inward-facing peripheral surface
the other part and then the parts under mutual rotation
pressed in the axial direction of the rotation axis against each other. These
axial contact pressure of the two parts in the region of their peripheral surfaces
then leads to at least one of the parts
melted adjacent to the peripheral surface wall area
becomes. By softening this wall area approach
the parts continue as a result of the sustained axial contact pressure
to each other, until the outward-facing peripheral surface
completely from the inward facing peripheral surface
Brief description of the drawings
Following is the invention with reference to some shown in the drawing
Embodiments explained in more detail.
1 a schematic perspective view of a rotor carrier of an electric machine;
2 a longitudinal sectional view of the rotor carrier 1 ;
3 an enlarged view of section III 2 ;
4 a schematic perspective view of a slightly different rotor carrier;
5 a longitudinal sectional view of the rotor carrier 4 ;
6 an enlarged view of the section VI 5 ;
7 a longitudinal sectional view of another rotor carrier.
The rotor carrier shown only schematically and simplified in the drawing 2 serve to support a rotor (not shown) of a large-sized electric machine for a hybrid drive of a motor vehicle. The rotor consists in a known manner of one or more lamellae or rotor lamination packages, the rotationally fixed on a cylindrical outer peripheral surface 4 the rotor carrier 2 be attached, as well as a rotor winding or permanent magnets, which are introduced after mounting of the lamella or rotor laminations in receiving grooves of the same or the same.
To inside the rotor carrier 2 To create space for other components of the electric machine or for other components of the hybrid drive, such as for clutches, with the help of the rotor arm 2 can be coupled with an output shaft of the electric machine, limit the rotor carrier 2 a cylindrical cavity open on one side in the axial direction 6 ( 1 and 2 ) or two separate cylindrical cavities open in opposite axial directions 8th . 10 ( 3 ).
The in the 1 to 3 illustrated rotor carrier 2 consists essentially of a hollow cylindrical peripheral wall part produced in one piece from a metallic material by a casting or forming process 12 , on the outer peripheral surface 4 the rotor is fixed, as well as a produced by a machining process of the same or another metallic material, in outline circular flat bottom wall part 14 that the cavity 6 at a front end of the rotor carrier 2 closes.
The bottom wall part 14 is there with a radially outer edge 16 its the peripheral wall part 12 facing front broadside surface 18 against one of the two ends of the peripheral wall part 12 and is along the entire outer edge 16 fixed to the peripheral wall part 12 connected.
About the cavity 6 opposite rear broadside surface 20 of the bottom wall part 14 there is a stub shaft 22 over, rigid with the bottom wall part 14 is connected and as well as the peripheral wall part 12 and the bottom wall part 14 coaxial with a rotation axis 24 of the rotor is aligned.
The production of the rigid non-rotatable connection between the outer edge 16 of the bottom wall part 14 and the adjacent front end of the peripheral wall part 12 done by friction welding. In this case, the peripheral wall part 12 with one in the cavity 6 introduced, radially expandable clamping device (not shown) fixed to an axial and / or rotational movement of the peripheral wall part 12 to prevent. The over the bottom wall part 14 protruding stub shaft 22 is clamped in an axially movable chuck (not shown) with rotary drive. Subsequently, the chuck is set in rotation and by an axial movement of the chuck of the bottom wall part 14 with the edge 16 the broadside surface 18 against the front end of the peripheral wall part 12 pressed. The during the rotation of the bottom wall part 14 in relation to the peripheral wall part 12 at the contact surface 16 between the two parts 12 . 14 resulting frictional heat causes the metallic material of the peripheral wall part 12 and / or the bottom wall part 14 along the contact surface 16 melts. Once the rotary motion of the bottom wall part 14 is stopped, the molten material cools again, where it solidifies and the bottom wall part 14 rigid with the peripheral wall part 12 combines.
To ensure that the weld produced by friction welding allows the transmission of large torques, the outer edge 16 of the bottom wall part 14 and the opposite end face of the peripheral wall part 12 before welding the two parts 12 . 14 with complementary circumferential grooves or ribs 26 . 28 be provided, which have a substantially wedge-shaped cross section, as in 3 shown. These ribs 26 . 28 grab the approach of the two parts 12 . 14 finger-like into one another, which not only leads to an additional centering of the two parts in the region of the weld, but also after the contact of the two parts 12 . 14 a considerable increase in the contact area 16 and as a result of the slope of the ribs 26 . 28 also an increase in the contact pressure and thus the friction forces.
As alternatives to a rotation of the bottom wall part 14 with respect to the fixed peripheral wall part 12 can also be the peripheral wall part 12 rotated together with the tensioning device and against the fixed bottom wall part 14 be pressed, or it can both parts 12 . 14 driven in the opposite direction of rotation while being pressed against each other in the axial direction.
The in the 4 to 6 illustrated rotor carrier 2 has in addition to a hollow cylindrical peripheral wall part made of metal 12 also a flat, circular, consisting of the same or another metal bottom wall part 14 on, in the vicinity of the one end face of the peripheral wall part 12 but at a small axial distance from its end face 30 rotatably with the peripheral wall part 12 is welded.
To the two parts 12 . 14 by friction welding together, here is the outer diameter of the bottom wall part 14 so selected that it is slightly larger than the inner diameter of the peripheral wall part 12 is. Subsequently, the two parts 12 . 14 again coaxial with the axis of rotation 24 aligned, whereupon the bottom wall part 14 around the axis of rotation 24 set in rotation and in the axial direction of the axis of rotation 24 against the adjacent front end of the peripheral wall part 12 is pressed. This is an outermost edge 32 of the bottom wall part 14 at the front end of the peripheral wall part 12 with its inner wall 34 in contact, eliminating the inner wall 34 is melted due to the frictional heat in the region of the contact, provided that the peripheral wall part has a lower melting point. The melting of the inner wall 34 leads together with the on the bottom wall part 14 exerted sustained axial compressive force that the bottom wall part 14 increasingly further into that of the peripheral wall part 12 limited cavity 6 moved in until its outer peripheral surface 38 completely from the peripheral wall part 12 surrounded and its rear broadside 20 at a distance from the face 30 the peripheral wall part 12 is arranged as in 5 and 6 shown. When moving molten metal from the outermost edge 16 displaced, with a greater part of this material due to centrifugal and adhesive forces in a gusset 36 between the inner wall 34 and the broadside surface 18 collects, while a smaller part on the peripheral surface 38 of the bottom wall part 14 over to its rear broadside 20 passes and gets in a corresponding gusset 40 collects. When the rotation of the bottom part 14 stopped in this position, are the two parts 12 . 14 not only along the peripheral surface 38 of the bottom part 14 fused together, but also in the area of the gusset 36 . 40 that the bottom part 14 In addition, hold in the axial direction and provide a firmer connection due to the larger contact surface between the two parts.
As with the rotor carrier off 1 and 2 can either the bottom wall part 14 or the peripheral wall part 12 or both parts 12 . 14 are rotated before they are pressed against each other.
A combination of referring to the 1 to 3 respectively. 4 to 6 described method is also possible if a bottom wall part 14 is used with a stepped edge (not shown), which after welding in both the radial and in the axial direction against the adjacent front end of the peripheral wall part 12 is applied.
The in 7 illustrated rotor carrier 2 be consists of two previously made by forming from a solid material, integrally formed cup-shaped parts 46 . 48 whose plane, facing each other and the axis of rotation 24 coaxial circular bottom wall parts 50 . 52 are non-rotatably connected by friction welding and one between the two cavities 8th . 10 form arranged partition.
The production of the welded connection takes place in the same way as before for the rotor carrier 2 in the 1 to 3 described by the two parts 46 . 48 rotated with respect to each other and the opposite end faces of the bottom wall parts 50 . 52 be pressed axially against each other.
After welding the two parts 12 . 14 respectively. 46 . 48 If necessary, they are first subjected to low-stress annealing in an oven before they are optionally subjected to machining in order to achieve required manufacturing tolerances of the rotor carrier 2 to ensure.
QUOTES INCLUDE IN THE DESCRIPTION
The documents listed by the applicant have been automated
generated and is solely for better information
recorded by the reader. The list is not part of the German
Patent or utility model application. The DPMA takes over
no liability for any errors or omissions.
Cited patent literature
- DE 102005040771 A1