BR112016009614B1 - PROCESS FOR THE PRODUCTION OF A SHORT WINDING HEAD AND ROTOR FOR AN ELECTRICAL MACHINE FOR THE EXECUTION OF THE PROCESS - Google Patents

Abstract

PROCESS FOR PRODUCTION OF A SHORT WINDING HEAD AND ROTOR FOR AN ELECTRICAL MACHINE FOR THE EXECUTION OF THE PROCESS. The present invention relates to a process and a rotor for producing a short winding head (6), where conductor segments (5) of a rotor winding exit on the front side of the base body (2) of a rotor (1) are bent towards a commutator (7), where the ends of the conductors (14, 15) aligned parallel to the axis of the conductor segments (51, 52) are transferred from a first radial position, originally external, to a second inner radial position, where conductor segments (51) leading to the end of the conductor (14) are folded over a bend edge (11) of a bend ring (10) disposed on the front side of the base body (2), and are aligned at least more or less parallel with the front side (4) of the base body (2).

Description

[001] The present invention relates to a process for producing a short winding head, according to the preamble of the invention, and to a rotor for carrying out the process with the characteristics of the invention.

State of the art

[002] In order to be able to carry out the construction length of electrical machines that have a rotor with a commutator with the shortest possible construction length, the aim is to configure the winding heads between the blade pack that constitutes the base body of the rotor and commutator as flat as possible. The rotor winding conductors that come out of the base body on the front side are soldered with the commutator, which is also called current inverter, at the ends of the lines.

[003] In order to be able to establish a desired interconnection with a winding, the conductors need to be connected to the switch in a certain way. The ends of the various conductors that project out of the base body of the rotor need to be placed, through locking and bending, in the corresponding position where they can be connected with the various contact surfaces of the commutator, so as to conduct electricity. In this process, the lower and upper conductors are both locked and bent at the same time.

[004] Braking constitutes a limit to the height of the winding head. After this processing step, the lower and upper conductors lie on top of each other, further locking of the conductors to obtain a smaller winding head is no longer possible.

[005] Those with this conventional bending process, where the conductors projecting out of the base body of the rotor are respectively bent towards the commutator, present the disadvantage that, by virtue of the geometric limits mentioned in the braking, the conductors cannot be aligned parallel or nearly parallel to the end blade of the blade pack. On the contrary, a conical winding head can only be produced using conventional bending processes.

[006] To obtain a flat winding head for the rotor of an electrical machine, the conductors that constitute the rotor winding can be produced before mounting on the rotor with line segments bent at right angles. A rotor with prefabricated conductor elements is known from DE 199 56 347 A1. Pre-fabrication of right-angled bent conductor elements and subsequent insertion into rotor slots require expensive assembly steps.

Presentation of the present invention

[007] The process according to the present invention for manufacturing a short winding head on a rotor of an electrical machine with the features of the invention has the advantage that the segments of conductors bent over a bending edge of a ring of bending arranged on the front side of the rotor base body, or directly on the end blade of the blade pack, can be placed in an alignment at least approximately parallel to the front face of the base body. With this, a short construction length for the winding head between the base body and the commutator can be obtained, without the conductors constituting the rotor winding having to be pre-bent in a specific braking process, connected upstream. . This results in a correspondingly short construction length for the electrical machine, which preferably serves as a starting machine for an internal combustion engine, which in vehicle construction is particularly advantageous. Due to the shorter construction length, the electric machine also achieves a lighter weight.

[008] When bending the line segments, they are preferably bent beyond a 90° angle, so that excess bending occurs. This means that, even in the case of a small elastic resilience, after the bending step, the bent segment runs parallel to the front side of the rotor base body, thus achieving an optimal shortening of the construction length in the winding head area. The bending process preferably consists of overlapping movements of the rotor and the respective line end of a conductor segment to be bent. In the superimposed movement, the rotor is rotated around a corresponding angular position and at the same time performs a stroke movement in the axial direction. The bending process can be carried out alternatively with the rotor stationary and the tool respectively moving. The distance of the end of the conductor from the front side of the base body is thereby reduced and the angular position of the end of the conductor is changed in such a way that it can later be welded or otherwise connected by conducting electricity with the respective contact surface of the conductor. switch. In addition, the respective conductor end is displaced in the direction of the rotor axis of rotation.

[009] Due to the rotation and lifting movement combined with a superimposed displacement movement, a very short process duration results for the essentially right-angled bending of the conductor segments. The braking process step can thus be dispensed with.

[0010] The bending process can be performed using a positioning tool that strikes at the wire end of the respective wire segment to be bent. In this, the positioning tool maintains the end of the conductor preferably in an alignment parallel to the axis, displacing it to a smaller radial distance from the rotor rotation axis and to another angular position. The movements of the rotor and the positioning tool can be combined to carry out the bending process, if this seems suitable or advantageous from a process point of view. Depending on the requirement for carrying out the bending process, through a combination or corresponding selection of positioning and lifting movements, the bending process can be adapted to existing general conditions.

[0011] In the case of a rotor with inner and outer conductors arranged with a small radial distance from each other distributed in two different circle radii that constitute the rotor winding, first the inner conductors can be bent through the bending ring, and then , the outer conductors over the already bent inner conductor. Here too there is the possibility that the outer conductors, through an excess bending above a 90° angle, can be placed in a parallel alignment with the front side of the base body. Thus, then, the bending process for the outer conductors takes place with the same process steps as is the case for the inner conductors that are directly adjacent to the bending ring. For the execution of the bending process, in this case, the same rotation and lifting movements or positioning movements as described above can be carried out.

[0012] In place of individual positioning tools for the various conductor segments and their conductor ends, lowering and shifting tools can also be used that simultaneously bend all conductors projecting out of the rotor base body into a desired final position, so that its conductor ends can be connected by conducting electricity with the contact surfaces of the commutator. The simultaneous bending of all conductors has the advantage of shortening the production process, but this also requires a correspondingly complex handling tool. The conductors or segments of conductors projecting out of the rotor base body are preferably U-shaped conductor segments which with their two U-shaped tabs are arranged in different grooves in the rotor base body.

[0013] The rotor according to the present invention with the characteristics of the invention has the advantage that a bending ring which is preferably executed as an insulating ring of an electrically insulating material enables an optimal bending of the conductor segments leaving the rotor base body on the front side. For this purpose, the bend ring features a bend edge with a bend radius that ensures that the wire segments bent into it are not damaged and can be placed in a direction that runs parallel to the front side of the base body with a radius bend defined from axis-parallel orientation. For this purpose, the internal radius of the bending ring is preferably greater than the circumferential radius of the switch. With this it is possible that the ends of the conductors that need to be placed in a position that allows an electrical connection with the commutator, during the bending process in the axial direction, can be pressed into the inner ring spec, with which a excess bending of the conductor segments to be bent over a 90° angle. This excess bending, as already described above, results in an especially short construction form for the winding head facing the tap changer.

[0014] A bending of the conductors to the desired position, in principle, can also be performed without the bending ring, directly on the edges of the blades.

[0015] Next, the present invention will be described in more detail with the help of an execution example shown in the drawing. The figures show:

[0016] Figure 1 shows a rotor of an electrical machine, in simplified representation.

[0017] Figure 2 shows an enlarged detail V1 of the rotor of figure 1, partially in section.

[0018] Figure 3 shows the base body of the rotor of figure 1 with conductor segments bent on the front side.

[0019] Figures 4a to 7a respectively show a side view of the rotor to illustrate the various steps of the process of bending conductor segments.

[0020] Figures 4b to 7b respectively show a view from the front side on the base body of the rotor, to illustrate the process steps in the bending of conductor segments.

[0021] Figure 1 shows the basic construction of a rotor that can also be called induced, of an electrical machine that can be used, for example, as a starter for an internal combustion engine.

[0022] The rotor 1 has a base body 2 that consists of a large number of grooved blades, so that longitudinal grooves 3 result to receive electrical conductors that constitute the rotor winding 1. On the front side 4, in the right figure , from the base body 2 there is a winding head 6 formed by several conductor segments 5 whose conductor ends, not visible here, are inserted into a switch 7 which, like the base body 2, is fixed on a common shaft 8 of rotor 1. The ends of conductors of conductor segments 5 are electrically connected with contact surfaces 9 of commutator 7.

[0023] Figure 2 shows an enlarged detail of figure 1 which is marked there with V1. The enlarged representation shows, in the interest of better visibility, only two conductor segments 51, 52 which are aligned parallel to the front side 4 of the base body 2.

[0024] Directly adjacent to the inner conductor segment 51, a bending ring 10 is arranged on the front side 4 which is shown here in longitudinal section. The bending ring 10 is produced from an electrically insulating material and has on the edge facing the conductor segment 51 a bending edge 11 with a bending radius that corresponds more or less to the diameter of the conductor segments 51, 52.

[0025] Before the conductor segments 51, 52 are placed in the orientation shown in figure 2, these conductor segments project essentially parallel to the axis from the front side 4 of the base body 2. Then first the segments of inner conductors, such as the inner conductor segment 51 shown here, are placed around the bend edge 11 of the bend ring 10 in the orientation shown. Once all the inner conductor segments, which are evenly distributed in an inner circle on the front side 4, have been respectively bent, the outer conductor segments, such as the outer conductor segment 52 shown here, are placed across the conductor segments. internals in the orientation shown. In this, the conductor segments 51, 52 are overlapped or over-bent, that is, they are bent beyond the 90° angle shown here, the areas 12 of the conductor segments 51, 52 leading to the switch 7 being pressed at least slightly into the annular opening 13 of the bending ring 10. The excess bending of the conductor segments 51, 52, in this case, occurs to such a degree that they, by virtue of the repositioning force still remaining, arrive at the alignment shown .

[0026] The ends of the conductors 14, 15 of the conductor segments 51, 52 are shown here with broken lines inside the commutator 7. The ends of the conductors 14, 15 are aligned parallel to the axis of the rotor 1, and are preferably fixed to the surfaces contact point 9 of switch 7 by means of soldering or fine soldering.

[0027] The perspective representation of figure 3 shows the base body 2 of rotor 1 of figure 1, however, without commutator 7 and without shaft 8 of figure 1. Figure 3 shows the cross orientation of the conductor segments 5 or segments conductor 51, 52 which thus provide a very flat winding head 6. The ends of the conductors 14, 15, as shown in Figure 2, are displaced inwardly by smaller circle radii.

[0028] In the side view of figure 4a is shown a rotor 1 with a conductor segment 51 that projects parallel to the axis on the front side 4 of the base body 2. The conductor end of the conductor segment 51 is received by a tool positioning device 16. The rotor 1 is arranged on a rotating elevator unit 17 which can lift the rotor 1 in an axial direction and rotate it around a desired angle.

[0029] The bending ring 10 is concentrically fixed on the front side 4 and its bending edge 11 (figure 2) directly follows the conductor segment 51. The bending ring 10 has a bending radius at its bending edge 11, as shown in figure 2, so that the conductor segment 51, through this bend edge 11, can be bent to a position with the respective bend radius, as shown in figure 5a.

[0030] Figure 4b shows the front side view of the arrangement shown in figure 4a. The bending ring 10 arranged on the front side 4 has a relatively narrow front surface 19 visible here on which, in a next process step, the conductor segment 51 is folded to assume the orientation shown in figure 5a.

[0031] In figures 4a to 5b, respectively, only a single segment of conductor 51 is shown, in order to better illustrate the bending process. The bending of all the conductor segments takes place in the same way as that of the conductor segment 51 shown, in order to obtain a flat winding head as a whole, as is visible in figures 7a and 7b.

[0032] To place the conductor segment 51 in an essentially right-angled position, as shown in figure 5a, rotor 1 is lifted in the direction of arrow 18 relative to the position of figure 4a, and at the same time is rotated at an angle α towards the arrow 20, as shown in the front side view of figure 5b. Superimposed on this lifting and rotating movement that the lifting rotary unit 17 performs, the positioning tool 16 is moved in the direction of the arrow 21 towards the axis of rotation 22, so that the positioning tool 16 reaches the position shown in figure 5a. and figure 5b.

[0033] Figures 6a and 6b now show all the wire segments bent over the bending ring 10 whose ends of the conductors 14 project parallel to the axis with respect to the axis of rotation 22. Figures 6a and 6b show the segments internally arranged conductors that directly follow the bending ring.

[0034] In figures 7a and 7b it is visible how the outer conductor segments are crossed over the inner conductor segments, together forming a flat winding head 6. Herein, the outer conductor segments, of which in figure 2 a conductor segment 52 is shown, a so-called upper layer of the winding head 6, while the conductor segments visible in figure 6a constitute a so-called lower layer of the winding head. winding 6. All ends of conductors 14, 15 projecting upwards are connected to contact surfaces of a switch not shown here.

Claims (12)

1. Process for the production of a short winding head (6), wherein the conductor segments (5) of a rotor winding that come out on the front side of the base body (2) of a rotor (1) are bent towards a switch (7), where the ends of the conductors (14, 15) aligned parallel to the axis of the conductor segments (51, 52) are transferred from a first radial, originally outer position, to a second inner radial position, characterized in that the conductor segments (5) exiting the base body (2) of a rotor (1) are U-shaped segments, and conductor segments (51) leading to the end of the conductors (14). ) are folded over a bending ring (10) arranged on the front side of the base body (2) and are aligned at least more or less parallel with the front side (4) of the base body (2), whereby when folding of the conductor segments (51, 52) there is respectively an excess bending of the conductor segments tor (51, 52), which exceeds an angle of 90°. 2. Process according to claim 1, characterized in that during the bending of a conductor segment (51, 52), the angle position of the conductor end (14, 15) in relation to the base body (2) changes, and the distance of the conductor end (14, 15) from the front side (4) of the base body (2) is reduced to a minimum. 3. Process according to claim 1 or 2, characterized in that during the bending of a conductor segment (51, 52), the base body (2) of the rotor (1) axially executes an upward movement towards the ends of the conductors (14, 15). Process according to any one of the preceding claims, characterized in that during the bending of a conductor segment (51, 52), a positioning tool (16) moves the conductor end (14, 15) to a smaller radial distance from the axis of rotation (22) of the rotor (1). Process according to any one of the preceding claims, characterized in that during the bending of a conductor segment (51, 52), a positioning tool (16) moves the conductor end (14, 15) in towards the front side (4) of the base body (2). 6. Process according to any of the previous claims, characterized in that in a rotor (1) with internal and external conductors, arranged in small radial distances from each other in two different radii of circle, which present conductor segments ( 51, 52) coming out of the base body (2) on the front side, the inner conductor segments (51) are first folded over the bending ring (10) and then the outer conductor segments (52) are folded over the inner conductor segments (51), which have already been bent. 7. Process according to any one of the preceding claims, characterized in that all inner and outer conductor segments (51, 52) are bent by means of a lowering and shifting tool, in a common bending process, to the final position. A rotor for an electrical machine for carrying out the process, as defined in any one of claims 1 to 7, comprising a base body (2) with grooves (3) for receiving rotor windings and a commutator (7), the commutator (7) is connected to conduct electricity with the rotor windings, the individual conductor segments (51, 52) exiting on the front side (4) facing the commutator (7) bent towards the commutator (7), characterized in that a bending ring (10) follows directly with a bending edge (11) the inner side pointing towards the axis of rotation (22) of conductor segments (51, 52) exiting the front side (4) of the base body (2), the conductor segments have an excess bend, being greater than an angle of 90°. 9. Rotor, according to claim 8, characterized in that the bending ring (10) consists of an electrically insulating material. 10. Rotor, according to claim 8 or 9, characterized in that the thickness of the bending ring (10) is 1 to 2 times the diameter of the conductor segments (51,52). 11. Rotor according to any one of claims 8 to 10, characterized in that the fold edge (11) in the cross section constitutes a quarter of a circle. 12. Rotor, according to any one of claims 8 to 11, characterized in that the internal diameter of the bending ring (10) is greater than the diameter of the commutator (7).

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