WO2009013312A2

WO2009013312A2 - Electrical machine

Info

Publication number: WO2009013312A2
Application number: PCT/EP2008/059654
Authority: WO
Inventors: Klaus Herbold; Christoph Schwarzkopf; Helmut Kreuzer
Original assignee: Robert Bosch Gmbh
Priority date: 2007-07-24
Filing date: 2008-07-23
Publication date: 2009-01-29
Also published as: DE102007034325A1; WO2009013312A3

Abstract

An electrical machine, in particular a generator, is specified which has a stator (12) with a laminated stator core (121) clamped in between two bearing plates (14, 15), and a polyphase stator winding (13) which is held therein and has winding sections, each with a section start (A) and a section end (E), and has a rectifier, which is composed of rectifier diodes, and a connecting plate (34), which is arranged on a bearing plate (14), in order to make the electrical connection between the rectifier (30) and the stator winding (13), on which connecting lugs which lead to the rectifier diodes are provided. In order to provide a five-phase stator winding (13) with operationally reliable electrical connections between the individual winding sections and the rectifier, which electrical connections can be produced using a low-cost manufacturing process which can be automated, the section end (E) of one winding section and the section start (A) of the following winding section are each connected to one another by being twisted at least in places, to form a winding connection (28), the winding connections (28) are passed through mutually aligned openings (37, 38) in the bearing plate (14) and the connecting plate (34) to a respective connecting lug on the connecting plate (34), and are welded to the connecting lug.

Description

description

title

Electric machine

State of the art

The invention is based on an electrical machine, in particular a generator, according to the preamble of claim 1.

In a known alternator (DE 37 28 081 Al), the rectifier diodes of the rectifier are divided into a plate-like positive heat sink and a plate-shaped negative heat sink and the connection plate, also called circuit board or printed circuit board, disposed between the plus and minus heatsink. The said, sandwiched stacked components are connected together and attached as so-called. Rectifier unit from the outside to the slip ring side bearing plate. The rectifier diodes are connected to the

Diode housing, which form the one terminal of the rectifier diodes used. The other diode connection form so-called head wires that emerge from the rectifier diodes. The positive heat sink and the minus heat sink lie with a connection plate arranged therebetween, and the head wires penetrate opposite holes in the respective other heat sink. In the designed as a plastic injection molded connection plate is a

Inserted lead frame and implemented in this conductor tracks, which are provided with contact tabs for establishing the connection between the diode head wires and with terminal lugs for establishing the connection with the six strand beginnings and strand ends of the winding strands of the three-phase stator winding. The contact lugs and terminal lugs are at right angles to the connection plate.

In the terminal plate following the periphery so-called quiver in the form of hollow tubes are provided, which are integrally formed on the terminal plate and extending from the terminal plate in the direction of stator core and pass through openings in the bearing plate. Through this quiver coming from the winding strands connecting wires are guided. Each quiver also contains a contact lug or a terminal lug of the stamped grid. The terminal ends of the contact tabs and terminal lugs are hammer-like, so that it is possible to bend the terminal ends to a U-shape. Depending on the requirement, two diode head wires or diode head wire and connecting wire of the winding strands or the connecting wires of the winding strands to be combined to the star point are inserted into the U end of the contact lug or connecting lug. The U-shape is compressed, ie crimped, and then preferably welded in the resistance welding process.

Disclosure of the invention

The erfϊndungsgemäße electrical machine with the features of claim 1 has the advantage that in a five-phase stator winding, which places high demands on installation space and winding stiffness, reliable, electrical connections of the individual

Winding strands of the stator winding can be achieved in a cost-effective, automatable manufacturing process. The wiring of the winding strands is made at the already required interfaces to the rectifier by twisting the beginnings and ends of the winding strands, and minimizes the number of connections to be made by the self-welding with the terminal lugs of the rectifier. Due to the twisting, the positions of the winding terminals with respect to the rectifier terminals are fixed in position-safe manner and produced by soft transitions of the wire bends favorable conditions for the vibration load during operation without additional components. The prefabricated stand can also be transported, stored and installed without damage during the manufacturing process, as the position and orientation of the winding connections are ensured by the twisting of the strand ends and strand starts. After mounting the end shield and rectifier with connection plate, the connection lugs and winding connections are compatible with each other and are easily accessible for welding tongs, both in radial and in axial arrangement. The defined position of winding connections of the stator winding and terminal lugs of the connection plate guarantees a high-quality weld and avoids additional

Manufacturing steps, such as crimping. The connection of several wires of the winding strands within a weld can be done with or without tinning the wire ends. The electric machine according to the invention can be realized particularly advantageously with a stand whose stator core has 60 or 80 axial grooves for receiving the stator winding and whose five-phase stator winding is made of edgewise rolled endless lamellae or 360 ° full lamellae or lamellar segments or in flat-pack technology. The winding connections resulting from the twisting of the strand ends and beginning are either distributed, for example with a circumferential spacing of 30 ° to 50 °, or are led out centrally in an angular window of eg 30 ° to 90 °. The winding strands of the stator winding are designed as a wave or loop winding with 6 to 30 conductors or wires per groove. The winding wire preferably has a diameter of 0.5 to 2.0 mm.

The measures listed in the further claims advantageous refinements and improvements of the claim 1 electrical machine are possible.

Brief description of the drawings

The invention is explained in more detail in the following description with reference to an embodiment shown in the drawings. Show it:

1 shows a longitudinal section of an electric machine with stator and claw-pole rotor, shown schematically,

2 is a circuit diagram of a five-phase stator winding of the stator of the electric machine in Fig. 1 with a rectifier connected,

3 is a perspective, schematic representation of a stator segment of the

Stand of the electric machine in Figure 1 with stator core and winding head of the stator winding and an outgoing from the winding head winding terminal,

4 shows a detail of a perspective view of a segment of the stator of the electric machine in FIG. 1 with mounted, brush-side end shield,

5 shows a similar representation as in FIG. 4 with rectifier unit mounted on the end plate, Fig. 6 is a same view as in Fig. 5 with a welding guns in the axial

Arrangement for welding a winding and rectifier connection,

7 shows a detail of a section along the line VII - VII in Fig. 5 after completion of the welding operation in Fig. 6,

FIG. 8 a detail of a rectifier unit with a modification of FIG

Insulated quiver and terminal lug design.

The electrical machine shown schematically in longitudinal section in FIG. 1 with claw-pole rotor 11 is used in particular as a synchronous generator with regulated electrical excitation of the claw-pole rotor 11 in motor vehicles.

The electric machine has in a known manner a stand 12 with a hollow cylindrical, designed as a stator core 121, laminated stator iron and an in-line stator or Ankernuten the Ständerbleckpakets 121 inserted, designed as a five-phase winding stator or armature winding 13, the winding heads 131 at both ends of the stator core 121 project from this. The stator core 121 is disposed between two axially spaced apart bearing plates 14, which are clamped together by means of screws 29. The upper bearing plate 14 in FIG. 1 is referred to below as slip ring side bearing plate and the lower bearing plate 15 in FIG. 1 on the drive side bearing plate. In each bearing plate 14, 15 a pivot bearing 16 is centrally arranged. In the two pivot bearings 16, a rotor shaft 17 of the claw pole 11 is added. On the rotor shaft 17, two mutually axially spaced, identically formed Polräder 18 are fixed in a known manner, between which a seated on the rotor shaft 17 iron core 19 is arranged. On the iron core 19 sits a Feldregerspule 20 which is wound annularly and with its two coil ends to a beyond the slip ring side bearing plate 14 mounted on the rotor shaft 17 slip ring pair, consisting of the slip rings 21 and 22, is connected. A brush holder 23, which rests with its brushes 24, 25 on the slip rings 21, 22, provides for the power supply of

Feldregerspule 20. Each flywheel 18 has an equal number of axially over the field exciting coil 20 cross-claw poles 181, the claw poles 181 of the opposite pole wheels 18 are telescoped together, so seen in the circumferential direction always a claw pole 181 of a flywheel 18 a claw pole 181 of another pole wheel 18 follows. The claw poles 181 one and the same pole wheel 18 have the same polarity, so that always alternates over the circumference of the claw pole 11 a north pole with a south pole. The outer surfaces of the claw poles 181, together with the cylindrical inner surface of the stator core 121, define the working air gap 26 of the machine.

As shown diagrammatically in FIG. 2, the stator winding 13 has five winding branches 27, each of which is designed as a loop or wave winding. In the top in Fig. 1 winding head 131, which is facing the slip ring-side end plate 14 and is referred to in the following slip ring side winding head 131, respectively the strand beginning A and the strand ends E of the five winding strands 27 of the stator winding 13 are led out, namely - as this is outlined in Fig. 3 - the strand beginning A of the individual winding strands 27 inside the winding head 131 and the strand ends E outside led out the winding head 131. In each winding strand 271, its strand end E lies on an outer circle and its strand beginning A on an inner circle with a smaller radius relative to the outer circle. In each case, the strand ends E of a winding strand 27 are bent in the circumferential direction and bent to the likewise bent strand beginning A of the following winding strand 27. The adjoining strand ends E and strand starts A form a winding connection 28. In this case strand end E and strand beginning A are twisted together up to the free end section 281 and protrude axially from the slip ring end winding 131. As can be seen from FIG. 3, in the exemplary embodiment each winding strand 27 is wound with two parallel winding wires 271, 272, so that in each case two winding wires 271, 272 adjoin one another at the strand beginning A and strand end E. The winding wire pairs of strand beginning A and strand end E are twisted together to form the winding connection 28.

As the circuit diagram in Fig. 2 shows, the five-phase stator winding is connected to a rectifier 30, consisting of ten rectifier diodes 31, at whose output the desired DC voltage can be removed. The rectifier diodes 31 are distributed to a so-called. Minuskühlkörper 32 and a plus heat sink 33. Between the plate-like heat sinks 32, 33 a connection plate 34 is arranged made of plastic (Fig. 7). In the interior of the connection plate 34 31 leading printed conductors are integrated with the rectifier diodes, which with on the top of the

Connection plate 34 bent at right angles terminal lugs 35 (Fig. 2 and 6) for connecting the stator winding 13 are connected. The sandwich-type construction of minus heat sink 32, connection plate 34 and plus heat sink 33 forms the so-called rectifier unit 40, which is located on the outside attached to the slip ring side bearing plate 14 and is covered by a protective cap 36 (Fig. 1). Protective cap 36 and end shields 14, 15 are provided with air passage slots.

To connect the stator winding 13 to the rectifier 30, there are openings 37 (FIGS. 4 to 7) along the periphery of the sliding ring-side end shield 14, which are arranged such that they are aligned with the winding terminals 28 projecting axially from the slip ring end winding head 131. The openings 37 are for this purpose on a divider circuit with the same radius as the divider circuit of the five winding terminals 28 and have an equal pitch as the winding terminals 28. In the connecting plate 34 openings are arranged in the same way on a pitch circle with the same radius, which have an equal pitch as the openings 37 in the bearing plate 14 and thus aligned with positionally correct placement of the rectifier unit 40 on the bearing plate 14 with the openings 37. Each opening 37 is enclosed by an insulating quiver 38, which is integrally molded onto the connection plate 34 and penetrates the associated opening 37 when the rectifier unit 40 is seated on the end shield 14 (FIG. 7).

When placing the slip ring side bearing plate 14 on the stator core 121, the former is aligned so that the winding terminals 28 pass through the openings 37, as shown for a winding terminal 28 in Fig. 4. When placing the rectifier unit 40 of minus heat sink 32 and plus heat sink 33 with rectifier diodes 31 and terminal plate 34 on the slip ring side bearing plate 14, the winding terminals 28 pass with their twisted sections through the Isolierköcher 38 and protrude with their untwisted end portions 281 of the Isolierköchern 38 out. The terminal lugs 35 of the rectifier unit 40 are designed and arranged such that they lie flush with the surface of the flag ends of the projecting from the Isolierköchern 38, untwisted end portions 281 of the winding terminals 28 (Fig. 5). Now, as shown in Fig. 6, welding guns 39 attached to the untwisted end portions 281 and the adjacent portions of the terminal lugs 35 and made by a resistance welding process, a welded joint between each of a winding terminal 28 and a terminal lug 35 which electrically and mechanically from high quality.

Fig. 7 shows a section of a section through rectifier unit 40 and schleifringseitigem winding head 131, in which the welded joint 41 of a winding terminal 28 of Ständerwicklung 13 is indicated with a terminal lug 35 of the rectifier unit 40 after the resistance welding, wherein the welding is done with tinned ends.

Fig. 8 shows an alternative embodiment of the terminal lugs 35 '. Whose ends in contact with the untwisted end portions 281 of the winding terminals 28 are U-shaped and take between their U-legs 351 and 352 respectively the untwisted end portions 281 of a winding terminal 28 in the embodiment four winding wires 271, 272, which are lined up side by side , on. For resistance welding then the welding guns 39 are attached to the two U-legs 351, 352 of the terminal lugs 35 '. Incidentally, in Fig. 8 with the components described above are identical

Components provided with the same reference numerals, so the negative heat sink 32, the plus heat sink 33 and the intermediate connection plate 34 with integrally molded insulating 38, the shape of which is modified compared to the embodiment described above.

Claims

claims

1. Electrical machine, in particular a generator, with a stand (12), a between two end shields (14, 15) clamped stator core (121) and a recorded therein, multi-phase stator winding (13), each with a strand beginning (A) and a strand end (E) having winding strands (27), wherein the strand starts (A) and the

Strand ends (E) protrude axially on a front side of the stator core (121), with a rectifier diode (31) having rectifier (30) and with a on the side facing away from the stator core (121) side of a bearing plate (14) arranged connecting plate (34) for establishing the electrical connection between the rectifier (31) and the stator winding (13), at the terminal lugs leading to the rectifier diodes (31)

(34) are present, characterized in that the stator winding (13) is five-phase and each strand end (E) of the one winding strand (27) and the strand beginning (A) of the following winding strand (27) by at least partially twisting each other to a winding connection (28) are connected and that the winding connections (28) through openings (37) in the bearing plate (14) and openings in the connection plate (34) passed through in each case a terminal lug (35) of the connection plate (34) and with the connection lug

(35) are welded.

2. Electrical machine according to claim 1, characterized in that in each case the strand end (E) of the one winding strand (27) is bent in the circumferential direction and to the strand beginning

(A) of the following winding strand (27) is bent.

3. Electrical machine according to claim 1 or 2, characterized in that the arrangement of the openings (37) in the bearing plate (14) and in the connection plate (34) on the one hand and the winding terminals (28) on the other hand and the terminal lugs (35) on the connection plate

(34) is made in such a way that they all lie on divisor circles with the same radii and have an equal division.

4. Electrical machine according to one of claims 1 to 3, characterized in that the openings in the connection plate (34) are integrally formed on the connection plate (34) integrally formed Isolierköchern (38), in the openings (37) in the end shield ( 14), and in that the winding connections (28) are passed through the insulation quivers (38) and on the upper side facing away from the bearing plate (14)

Terminal plate (34) from the Isolierköchern (38) with an end portion (281) protrude.

5. Electrical machine according to claim 4, characterized in that the strand ends (E) and strand starts (A) of the winding strands (27) in the from the Isolierköchern (38) protruding end portions (281) of the winding terminals (28) are untwisted and lie flat against each other ,

6. Electrical machine according to claim 4 or 5, characterized in that the connection lugs (35) of the connection plate (34) are arranged on the quiver openings and project at right angles from the connection plate (34).

7. Electrical machine according to claim 6, characterized in that the terminal lugs (35) have flat flag ends, which lie flush against the end portions (281) of the winding terminals (28).

8. Electrical machine according to claim 6, characterized in that the terminal lugs (35 ') have U-shaped curved end of the flag and that the winding terminals (28) are each received between two U-legs (351, 352).

9. Electrical machine according to one of claims 4 to 8, characterized in that the

Welded connection between the winding terminals (28) and the terminal lugs (35) of the terminal plate (34) at the end portions (281) of the winding terminals (28) is made.

10. Electrical machine according to one of claims 1 to 9, characterized in that the

Welded connections between the winding terminals (28) and the terminal lugs (35) of the terminal plate (34) is made by resistance welding.