METHOD AND DEVICE FOR PRODUCING A CONDUCTOR SEGMENT

Abstract

A method for producing a conductor segment includes: passing a copper bar in a predetermined direction of movement through a rotating first work roll and a second work roll rotating in the opposite direction to the first work roll; rotating a first backup roll in the opposite direction to the first work roll to brace the first work roll against the copper bar with an adjustable first force directed perpendicularly to the direction of movement; rotating at least one second backup roll in the opposite direction to the second work roll to brace the second work roll against the copper bar with an adjustable second force directed counter to the first force; and adjusting the first and second forces such that the work rolls give the conductor bar a thickness that varies along its length. Also described is a corresponding device and a corresponding method for producing an electric machine.

Claims

1. A method for producing a conductor segment of predetermined length, comprising the steps of: passing a copper bar in a predetermined direction of movement through a rotating first work roll and a second work roll rotating in an opposite direction to the first work roll; rotating at least one first backup roll in the opposite direction to the first work roll to brace the first work roll against the copper bar with an adjustable first force (F.sub.a2) directed perpendicularly to the direction of movement; rotating at least one second backup roll in the opposite direction to the second work roll to brace the second work roll against the copper bar with an adjustable second force (F.sub.b2) directed counter to the first force (F.sub.a2); and adjusting the first force (F.sub.a2) and the second force (F.sub.b2) such that the work rolls give the conductor bar a thickness that varies along a length of the conductor bar.

2. The method as claimed in claim 1, further comprising passing the copper bar through the work rolls at a temperature of the copper bar below 200 C.

3. The method as claimed in claim 1, further comprising heating the copper bar using an inductive heater before the copper bar passes through the work rolls.

4. The method as claimed in claim 1, further comprising: applying a settable third force (F.sub.a1) on a pivot bearing of the first work roll, applying a settable fourth force (F.sub.b1) on a pivot bearing of the second work roll, and adjusting the third force (F.sub.a1) and the fourth force (F.sub.b1) such that the work rolls furthermore give the conductor bar a curve that varies along the length.

5. The method as claimed in claim 4, further comprising: positioning the first backup roll at a settable first setting angle () with respect to the first work roll, positioning the first work roll at a settable second setting angle () with respect to the direction of movement, positioning the second work roll at a settable third setting angle () with respect to the direction of movement, positioning the second backup roll at a settable fourth setting angle () with respect to the second work roll; and adjusting the first setting angle (), the second setting angle (), the third setting angle () and the fourth setting angle () such that the curve has a predetermined shape.

6. The method as claimed in claim 1, further comprising: adjusting the first force (F.sub.a2) at the first backup roll; and adjusting the second force (F.sub.b2) at the second backup roll.

7. A method for producing an electric machine using straight copper bars, comprising the steps of: profiling the copper bars using the rolls according to the method as claimed in claim 1, insulating the conductor bars with enamel, cutting the conductor bars, bending the conductor bars, insulating the conductor bars; and inserting the conductor bars into a stator slot.

8. A method for producing the electric machine using copper bars from a reel, comprising the steps of: unrolling the copper bars from the reel, straightening the copper bars; and producing the machine as claimed in claim 7.

9. A device for producing a conductor segment, comprising: a rotatably mounted first work roll, a rotatably mounted second work roll that is separated from the first work roll by a rolling gap, a first backup roll that bears against the first work roll on a side of the first work roll opposite from the rolling gap, a second backup roll that bears against the second work roll on a side of the second work roll opposite from the rolling gap, a first regulator for exerting a first force (F.sub.a2), directed toward the first work roll, on the first backup roll, a second regulator for exerting a second force (F.sub.b2), directed toward the second work roll, on the second backup roll, and an adjuster, connected to the first regulator and the second regulator, configured such that the work rolls give the conductor segment a thickness that varies along a length of the conductor segment.

10. The device as claimed in claim 9, wherein the work rolls have a profile such that the work rolls produce a predetermined curve on the conductor segment.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Exemplary embodiments of the invention are illustrated in the drawings and described in more detail in the following text.

[0025] FIG. 1 shows a side view of a first device during the production of a conductor segment.

[0026] FIG. 2 shows a perspective view of a second device.

[0027] FIG. 3 shows a perspective view, corresponding to FIG. 2, of a third device.

[0028] FIG. 4 schematically shows a first method according to aspects of the invention.

[0029] FIG. 5 schematically shows a second method according to aspects of the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0030] FIG. 1 illustrates a device (10) according to aspects of the invention for producing a conductor segment. The device (10) shown in this case comprises a rotating first work roll (11) and a second work roll (12) that is separated from the first work roll (11) by a rolling gap and rotates in the opposite direction thereto. A first backup roll (13) that likewise rotates in the opposite direction to the first work roll (11) and bears against the latter on the opposite side from the rolling gap braces the first work roll (11), perpendicularly to the direction of movementhorizontal according to the figureof a copper bar running through the work rolls (11, 12), against said copper bar. The same goes for a second backup roll (14) that rotates in the opposite direction to the second work roll (12) and bears against the latter on the opposite side from the rolling gap.

[0031] Regulators (not illustrated in the drawing) in this case exert on the first backup roll (13) and the second backup roll (14) a mechanical force that is directed from above onto the first work roll (11) according to the figure and from below onto the second work roll (12) according to the figure, such that the backup rolls (13, 14) press the work rolls (11, 12) against the copper bar with a settable force that is directed perpendicularly to the direction of movement of the latter. To this end, an adjuster (likewise not depicted) connected to the first regulator and the second regulator is configured such that the work rolls (11, 12) give the conductor segment emerging from the rolling gap the desired thickness that varies along its length. The work rolls (11, 12) additionally have a profile (not discernible in FIG. 1) such that they furthermore give the conductor segment a predetermined curvature.

[0032] An inductive heater (15) heats the copper bar, before it passes through the work rolls (11, 12), to a working temperature that is above its recrystallization temperature of approximately 200 C., but under its melting point of approximately 1085 C.

[0033] FIG. 2 illustrates a corresponding device (20), which now works as a cold roll at a temperature of below 200 C.

[0034] FIG. 3 uses a third device (30) to illustratefrom a perspective matching that of FIG. 2the following eight temporally variable parameters (F.sub.a1, F.sub.a2, F.sub.b1, F.sub.b2, , , , ) for adjusting the shape and thickness of the conductor segment: [0035] i. a first force (F.sub.a2), acting on the first backup roll (33), for setting the thickness, [0036] ii. a second force (F.sub.b2), acting on the second backup roll (34), for setting the thickness, [0037] ii. a third force (F.sub.a1), acting on the suspension points of the first work roll (31), for setting the curvature on the top side according to the figure (and the thickness), wherein high pressure increases the curvature, [0038] iv. a fourth force (F.sub.b1), acting on the suspension points of the second work roll (32), for setting the curvature on the underside according to the figure (and the thickness), wherein, again, high pressure increases the curvature, [0039] v. a first setting angle () of the first backup roll (33) for setting the curvature on the top side according to the figure, wherein a small setting angle () with respect to the first work roll (31) decreases the curvature thereof, [0040] vi. a second setting angle () of the first work roll (31) for setting the curvature on the top side according to the figure, wherein a small setting angle () causes a convex curvature and a large setting angle () causes a concave curvature, [0041] vii. a third setting angle () of the second work roll (32) for setting the curvature on the underside according to the figure, wherein, likewise, a small setting angle () causes a convex curvature and a large setting angle () causes a concave curvature, and [0042] viii. a fourth setting angle () of the second backup roll (34) for setting the curvature on the underside according to the figure, wherein a small setting angle () with respect to the second work roll (34) decreases the curvature thereof.

[0043] A production method (40) according to aspects of the invention for an electric machine will now be explained with reference to FIG. 4. The starting point is formed by the above-described profiling of the conductor segments by way of rolls (43). Following the rolling step (43), enamel insulation (44) of the conductor surface takes place (for example with polyimides or polyurethane, preferably in accordance with IEC 60317), which can be combined with a baking step (not reproduced in FIG. 4). Optionally, this is followed by cutting to length (45) of the conductor segments thus obtained. After they have been bent (46) it is optionally possible for further insulation (47) to precede the insertion (48) of the conductor segments into the rotor slot or stator slot of the machine.

[0044] While this embodiment presupposes the use of substantially straight copper bars, the method (50) according to FIG. 5 expands the concept according to aspects of the invention to bars from a reel: In this case, in preparation, the copper bars are unrolled (51) and straightened (52) before they are supplied for profiling by rolls (53). The remaining method steps (54, 55, 56, 57, 58) correspond largely to those of the method (40) according to FIG. 4.