DE102016223750A1 - Rotor, electric machine including such a rotor, and method of manufacturing a rotor - Google Patents

Abstract

The invention relates to a rotor and an electric machine (10), in particular for the motorized adjustment of a movable part in the motor vehicle, and to a method for producing such a rotor, comprising a rotor shaft (14) on which a rotor core (16) and an axially thereto spaced commutator for receiving a rotor winding (24) is fixed, wherein the rotor winding (24) at selected, limited areas of the rotor core (16) is glued to this directly by means of adhesive (50).

Description

State of the art

The invention relates to a rotor, an electric machine including a rotor, and a method for manufacturing a rotor according to the preamble of the independent claims.

With the EP 0 895 668 B1 is a DC motor has become known in which a disk pack is mounted on an armature shaft. After assembly of the lamellar plates, they are coated with an epoxy resin, which isolates the anchor packet from the winding wires. In this case, the commutator is pressed axially to fix it against the epoxy resin on the armature shaft, whereby after cooling, a positive connection is generated.

The DE19840149A1 shows a rotor of an electric machine with a laminated core and a collector, wherein the collector is a felt-like element is arranged, which is impregnated with a curable agent to firmly fix the electric coil wire to the collector. For this purpose, after the winding of the rotor synthetic resin is dripped onto the corresponding wire sections, wherein the felt is soaked with synthetic resin and solidified after drying.

In such electric motors, it may come through an external load, especially when using thin armature shafts, to their deflection. As a result, there is a risk that the wires of the armature winding break with strong external shaking load.

Disclosure of the invention

Advantages of the invention

The rotor according to the invention, the electric machine, as well as the manufacturing method according to the invention of such a rotor, with the features of the independent claims have the advantage that on the one hand a relative movement of the winding to the rotor core can be prevented by the targeted sticking of the electrical winding at certain points of the rotor core and on the other hand, in other areas a certain elastic compensation movement of the winding is maintained on the rotor. This combination can be prevented in an application with high shaking and a large temperature range of the rotor, that the winding wire - especially in the area between the rotor core and the commutator - breaks, which can not be prevented even with a full encapsulation of the rotor core. As a result, the electric machine according to the invention is also suitable for use in the engine compartment of a motor vehicle, preferably for attachment to the engine block, in which a long-lasting vibration is transmitted to the electric machine.

The measures listed in the dependent claims advantageous refinements and improvements of the features specified in the independent claims are possible. It is particularly advantageous to attach adhesive to the axial end face facing the commutator by means of which the individual winding wires are reliably fastened to the axial end face of the rotor core. This prevents the electrical winding on the front side from moving relative to the armature packet, thereby reducing the loading of the winding wire on the commutator hook.

Particularly advantageously, the adhesive can be sprayed as an adhesive bead on the axial end face of the rotor teeth before the winding process begins. For this purpose, the adhesive is advantageously pasty and stable. When winding the adhesive is distributed by pressing the winding wires according to the front side of the rotor core, wherein adhesive is also pressed axially into the rotor grooves. As a result, the winding wires in the area from the transition of the winding head to the rotor core are reliably glued to this. Of particular advantage, this adhesive method for a so-called tendon winding, in which the winding wire is inserted from the one Rotornut not in the immediately adjacent Rotornut, but for example in the next but one or in the third or fourth Rotornut. In such a tendon winding, with relatively long tendons along the end face of the rotor core, it is particularly important to reliably adhere these chords of the winding head to the end face of the rotor core.

The rotor core is preferably stacked from individual punched laminations in the axial direction and connected to each other for example by means of plastically shaped beads in the axial direction. To isolate the contact surfaces between the rotor core and the winding wire, these contact surfaces are electrically isolated. For this purpose, the grooves and the end faces are coated, for example, with an epoxy resin, in particular by means of an inductive powder coating method. The adhesive can be applied directly to the insulation layer. When using an epoxy layer as insulation while the adhesive is very firmly connected via the epoxy layer with the rotor core. In order to allow the winding wires between the rotor core and the commutator elastic movement, the winding wires are preferably not stuck in this axial region. This means that the winding wires in this area are located radially on the armature shaft support but a relative movement between the winding wires and the rotor shaft is still possible. By means of this combination of elastic ranges of movement and fixed fixing on the front side of the rotor core, external shocks can be damped particularly well. This avoids that break the winding wires in the commutator by a too rigid fixation.

In a preferred embodiment of the rotor, the adhesive is applied not only to the front side of the rotor core, but also to other spatially limited locations of the rotor core. For example, the winding wires can also be glued in certain axial end regions of the rotor grooves or on the opposite, the commutator facing away from end face. In a further embodiment, the winding can be selectively glued to the rotor shaft or to certain contact areas with the commutator.

The bonding process can be carried out cleanly and reliably by means of a simple adhesive. For this purpose, an adhesive is used, which is pasty and stable. The adhesive is distributed quite well during winding between the individual winding wires without running away. Thereafter, the adhesive can be thermally cured later in a simple manner, and thereafter remains temperature stable over a long time over a wide temperature range.

In addition, the winding wire may be coated with a baked enamel, so that when the rotor is heated and then re-cooled, the individual winding wires are firmly connected to one another via the baked enamel. In this case, the baked enamel can be heated in a favorable process in the same process step with the curing of the adhesive, or in a separate process step. Alternatively, it is also possible to use a standard wire without a baked enamel which is adhesively bonded to the rotor pact.

The gluing of the winding on the rotor core according to the invention is particularly advantageous for rotors in which the rotor shaft has such a thin diameter that, in the case of an external shaking load, the commutator can execute elastic oscillations with respect to the rotor core. By this bending of such a thin rotor shaft, the load of the winding between the rotor core and the commutator is particularly high. If the winding is now glued reliably on the end face of the rotor stack, the electrical winding between the end face and the commutator can perform a certain compensating movement for bending the rotor shaft, whereby the shearing load of the winding wires on the commutator is reduced. Such an elastic bending of the rotor shaft occurs, for example, in rotor shafts with a diameter smaller than 5 mm, in particular smaller than 4 mm. By sticking the rotor winding to the first end face, a relative movement of the rotor winding to the rotor core caused by a rotor shaft bend, a rotor twist, a so-called rigid body movement of the entire rotor winding can be avoided.

If such a rotor is installed in an electric machine, in particular an electric motor, such an electric motor can be fastened, for example, directly to the engine block of a motor vehicle. By gluing the electric winding according to the invention on the rotor assembly, such an electric motor can withstand high shaking loads and large temperature fluctuations without destruction.

In the manufacturing method of the invention, the rotor is first preassembled by fixing the rotor core and the commutator on the rotor shaft. For this purpose, the rotor core can preferably be pressed onto the rotor shaft by means of a press fit, which optionally has longitudinal notches for the laminations. The commutator can also be pressed or fastened by means of epoxy material on the rotor shaft. Thereafter, the rotor core - and optionally also the axial region of the rotor shaft between the rotor core and the commutator - isolated. This is preferably carried out by means of an epoxy coating. In this case, the axial region between the rotor core and the commutator can also be insulated by means of the epoxy coating. Thereafter, adhesive can be applied to the end face of the rotor packet, before then the rotor core is wound with conventional winding method. In this case, the adhesive is distributed between the winding wires and the end face of the rotor core and forms after curing a reliable fixation of the individual winding wires on the front side of the rotor core.

When winding the rotor core can get into the rotor slots with the winding wires, whereby the winding wires - especially at the axial edge of the rotor teeth in the transition to the rotor groove - reliably glued and thus vibration-free connected to the front side of the rotor core.

For optimum metering of the adhesive, it can be sprayed on in the form of so-called adhesive beads or adhesive beads on the front side of the rotor core. These adhesive beads preferably extend over the entire radial extent of the rotor teeth.

In a further embodiment of the invention, after the winding process, additional adhesive may additionally be applied at certain points of the rotor in order to improve the adhesive effect between the winding wire and the rotor. For example, at the end face of the rotor core at the radially outer region between the winding and the heads of the stator teeth, additional adhesive can be inserted in the contact region between the winding and the stator core. It is also possible to introduce adhesive after winding at certain points of the rotor grooves or on the opposite side of the rotor package. In a further embodiment, the adhesive can also be supplemented between the rotor shaft and the rotor winding or between selected points of the commutator and the winding.

When winding the rotor of the winding wire is preferably inserted into Kommutatorhaken and then soldered or welded, for example. As a result, the winding wire is rigidly connected on the one hand to the commutator hook and on the other hand by sticking to the end face of the rotor core, wherein in the axial region between the commutator and the end face of the rotor core, the winding wires are preferably not rigidly connected to the rotor shaft.

During thermal curing of the adhesive can advantageously simultaneously - or optionally also in separate processes - and the baked enamel of the winding wire are heated so that it forms a rigid connection between the winding wires after cooling.

list of figures

Embodiments of the invention are illustrated in the drawings and explained in more detail in the following description.

• 1: Ein erstes Ausführungsbeispiel eines erfindungsgemäßen Rotors,
• 2: ein weiteres Ausführungsbeispiel eines Rotors vor dem Bewickeln, und
• 3: und nach dem Bewickeln.

Show it

• 1 A first embodiment of a rotor according to the invention,
• 2 a further embodiment of a rotor before winding, and
• 3 : and after the winding.

In 1 is schematically an electrical machine 10 shown in which a rotor 12 inside a stator 13 is stored. The rotor 12 has a rotor shaft 14 on, on which a rotor package 16 is fastened, which consists of individual laminations 18 is composed, with respective end plates 19 the first and second end faces 40 . 42 of the rotor package 16 form. The laminations 18 are usually punched out of an electrical sheet. The rotor package 16 is for example on the rotor shaft 14 Pressed and rotatably mounted on this. Around an axial area 20 spaced from the rotor core 16 is a commutator 22 on the rotor shaft 14 attached. This is also, for example, rotationally fixed to the rotor shaft 14 pressed. On the rotor package 16 is an electrical winding 24 arranged electrically with the commutator 22 connected is. This is indicated by the commutator 22 commutator 23 on, the electrical contact with the individual commutator bars 26 represent. The electrical winding 24 includes several coils 25 , each with a pair of commutator blades 26 are connected. By means not shown brushes, which are connected to the commutator 26 can abut the coils 25 be energized to with a magnetic field of the stator 13 co. The rotor package 16 points in the axial direction 70 rotor grooves 30 on, between corresponding radial rotor teeth 32 are formed. At the radially outer periphery, the rotor teeth 32 one tooth head each 34 on. The first front page 40 of the rotor package 16 is the commutator 22 facing and the opposite second end face 42 is the commutator 22 away. The electrical winding 24 lies at contact surfaces 44 on the rotor package 16 at, with these contact surfaces 44 with an insulating layer 45 are provided to make a short circuit between the electrical winding 24 and the rotor package 16 to prevent. The individual coils 25 run in the axial direction 70 in the rotornuts 30 and form at the two end faces 40 . 42 a so-called winding head 46 , In the embodiment of 1 is the electrical winding 24 at the first end 40 that the commutator 22 facing, glued. This is the electrical winding 24 at the first end 40 rigid with the rotor package 16 connected so that at the first end face 40 no relative movement between the electrical winding 24 and the rotor package 16 is possible. About the axial distance 20 between the first end face 40 and the commutator 22 is the electrical winding 24 not with the rotor shaft 14 bonded. This allows the electrical winding 24 in this axial region 20 perform an elastic compensation movement with external shaking loads and large temperature fluctuations. At the commutator 22 is the electrical winding 24 at the commutator hook 23 For example, by means of welding or hot pressing (so-called "hot staking") fixed mechanically rigid.

In a further embodiment according to 2 It can be seen that before winding the rotor package 16 along the radial rotor teeth 32 adhesive 50 at the first end 40 is applied. The adhesive 50 is here in the form of adhesive beads 52 formed, preferably over the entire radial extent of the rotor teeth 32 extend. The diameter of the adhesive beads 52 is here, for example, larger than the diameter of the winding wire 54 that after applying of the adhesive 50 on the first front side 40 the glue 50 in the axial direction 70 against the first face 40 pressed. During the winding process, the adhesive spreads 50 the adhesive beads 52 over the entire first face 40 and in particular also becomes axial in the rotor slots during winding 30 pressed. The adhesive 50 has a soft consistency, so that the glue 50 during the winding process between the bearing surfaces 44 and the individual winding wires 54 distributed.

In 3 is the same rotor 12 according to 2 shown after it is finished wound. It can be seen that the electrical winding 24 not designed as a single tooth winding, but every single coil 25 always at least two rotor teeth 32 encloses. The individual coils overlap 25 so these too on the front ends 40 . 42 are arranged axially above one another. By the amount of adhesive 50 on the first front 40 is applied, it can be influenced that the adhesive 50 not just directly between the first face 40 and the electrical winding 24 but also between the individual winding wires 54 the electrical winding 24 is pressed during winding. This also makes the relatively long tendons of the winding wire 54 at the tendon winding at the first end 40 fixed relatively firmly. After winding the rotor 12 This is heated to the adhesive 50 cure. The winding wire 54 is coated in the second embodiment by means of a baked enamel. The baked enamel also softens when heated, so that during subsequent cooling of the baked enamel of the individual winding wires 54 connecting them together. The rotor 12 according to 3 For example, has eight rotor teeth 32 and accordingly eight intermediate rotor grooves 30 on. The individual coils 25 Here, for example, enclose three rotor teeth 32 so that the coil 25 from the Rotornut number 1 to the Rotornut number 4 runs. The entire electrical winding 24 is radially inside the tooth heads 34 arranged, the electric winding 24 radially reliable on the rotor 12 hold. Both ends 40 . 42 , as well as the insides of the Rotornuten 30 are in this embodiment with an epoxy layer 48 as an insulating layer 45 educated. This epoxy layer 48 adheres very firmly to the rotor package 16 so that too is the glue 50 directly onto the epoxy layer 48 is applied, the electrical winding 24 reliable with the rotor package 16 rigidly connects. In this embodiment are also the rotor grooves 32 completely with the epoxy layer 48 as an insulating layer 45 overdrawn. In addition, also the axial area 20 between the first end face 40 and the commutator 22 with the epoxy layer 48 be covered. Optionally, also the commutator 22 and / or the laminations 18 by means of the epoxy layer 48 on the rotor shaft 14 be attached. Here are the end plates 19 preferably also by means of ring staking on the rotor shaft 14 pressed. Thus, for example, on longitudinal notches on the rotor shaft 14 for the rotor package 16 be waived.

In an alternative embodiment, the electrical winding 24 in addition to other contact surfaces 44 between the electrical winding 24 and the rotor 12 be stuck. For example, the electrical winding 24 also on the second front side 42 that the commutator 22 is turned away, glued. In addition, the electrical winding 24 also on the second front side 42 directly with the rotor shaft 14 be glued. Optionally, it is further conceivable that the winding wire 54 also at the commutator 22 , in particular at the commutator hook 23 , is stuck. It is also possible that only after the finished winding of the rotor 12 at specific points of the bearing surface 44 subsequently adhesive 50 is applied. This is then combined with the adhesive applied before winding 50 thermally cured. In particular, at the radial peripheral region 60 the electrical winding 24 between this and the contact surface 44 the first front side 40 subsequently adhesive 50 be inserted.

The rotor shaft 14 For example, has a diameter of 3.0 to 5.0 mm, but preferably a diameter that is not greater than 4.0 mm. However, the invention can also find application for rotor shafts with larger diameters, in which the rotor is exposed in operation to a large temperature fluctuation, for example from -40 ° C to + 180 ° C. By gluing the invention, the so-called rigid body vibration of the entire rotor winding relative to the rotor core can be prevented. The rotor shaft 14 is in a housing of the stator 13 and on the other hand, for example, in a bearing plate between the stator 13 and a transmission housing stored. On the rotor shaft 14 is an unillustrated output element - for example, a rotor screw - arranged, which generates the torque of the electric machine 10 via a mechanism, for example, transmits to a throttle actuator, which is arranged in the engine compartment of a motor vehicle.

It should be noted that, with regard to the exemplary embodiments shown in the figures and in the description, a variety of possible combinations of the individual features are possible with one another. For example, the adhesive 50 before and after winding on the contact surfaces 44 the electrical winding 24 be applied. In addition to sticking the electrical winding 24 at the first end 40 of the rotor package 16 , can the electric winding 24 specifically also in other places, such as the second end face 42 and / or the rotor grooves 30 be stuck. Likewise, the winding wire 54 also optional on the commutator 22 by means of adhesive 50 be securely fixed. The number and axial length of the rotor grooves 30 and the type of electrical winding 24 can according to the power requirements of the electric machine 10 be varied. This can be the insulation 45 of the rotor package 16 by epoxy resin 48 or by means of separately manufactured insulation masks. The electric machine 10 preferably finds application for actuators in the motor vehicle, for example as an engine compartment plate, in particular for a throttle valve - but is not limited to such applications.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 0895668 B1 [0002]
• DE 19840149 A1 [0003]

Claims (16)

Rotor (12), in particular an electric machine (10) for motorized adjustment of a movable part in the motor vehicle, with a rotor shaft (14) on which a rotor core (16) and an axially spaced commutator for receiving a rotor winding (24) is attached , characterized in that the rotor winding (24) is glued to selected, limited areas of the rotor core (16) on this directly by means of adhesive (50). Rotor (12) after Claim 1 , characterized in that the rotor core (16) has a first axial end face (40) facing the commutator (22), to which the rotor winding (24) is glued to the rotor core (16). Rotor (12) according to one of Claims 1 or 2 , characterized in that the rotor core (16) has a plurality of radial rotor teeth (32) with rotor grooves (30) disposed therebetween, and the adhesive (50) is disposed along the radial rotor teeth (32). Rotor (12) according to one of the preceding claims, characterized in that the rotor winding (24) comprises a plurality of electrical coils (25) which are contacted with commutator hooks (23) of the commutator (22), wherein in particular the coils (25) as a tendon winding always always comprise at least two rotor teeth (32). Rotor (12) according to one of the preceding claims, characterized in that the rotor core (16) is composed of individual, stacked laminations (18), and an end plate (19) forms the end face (40) of the rotor core (16), wherein the Rotor package (16) - in particular at the contact surfaces (44), where the rotor winding is applied - with an insulating layer (45) - preferably of epoxy (48) - coated. Rotor (12) according to one of the preceding claims, characterized in that the rotor winding (24) in the axial region (20) between the rotor core (16) and the commutator (22) not fixed to the rotor shaft (14) - in particular not glued - is, whereby the rotor winding (24) can perform within certain limits in this area an elastic compensation movement in external shocks. Rotor (12) according to any one of the preceding claims, characterized in that the rotor winding (24) in addition to the end face at other limited areas on the rotor core (16) - in particular in the rotor grooves (30) or the commutator (22) facing away from front side ( 42) - or glued to the rotor shaft (14) or the commutator (22). Rotor (12) according to any one of the preceding claims, characterized in that the adhesive (50) is temperature-resistant and curable and pasty and stable - and is preferably a one-component adhesive. Rotor (12) according to any one of the preceding claims, characterized in that the rotor winding (24) is wound with a baked enamel wire, wherein the baked enamel after heating the rotor (12) - in particular for curing the adhesive (50) - the individual Winding wires (54) interconnects. Rotor (12) according to one of the preceding claims, characterized in that the rotor shaft (14) has a diameter (15) of 3.0 - 5.0 mm - preferably not greater than 4.0 mm - has. Electric machine (10) with a rotor (12) according to one of the preceding claims, characterized in that the rotor (12) is arranged radially inside a permanent magnet stator (40), wherein the electric machine (10) preferably in the engine compartment of a motor vehicle - In particular to a throttle plate - is attached. Method for producing a rotor (12) according to one of the preceding claims, characterized in that soft adhesive (50) is applied after assembly and insulation of the rotor core (16) at the first end face (40) facing the commutator (22), and then the rotor core (16) is wound with the rotor winding (24), wherein the rotor winding (24) abuts at least partially axially on the first end face (40), and then the rotor (12) is heated to the adhesive (50) cure. Method according to one of the preceding claims, characterized in that when winding the rotor core (16) of the adhesive (50) from the first end face (40) is pressed axially into the rotor grooves (30), whereby the rotor winding (24) also at the axial Ends of the rotor grooves (30) is glued into this. Method according to one of the preceding claims, characterized in that the adhesive (50) in the form of adhesive beads (52) is applied radially along the rotor teeth (32). Method according to one of the preceding claims, characterized in that after the winding of the rotor core (16) additional adhesive (50) on bearing surfaces (44) between the Rotor winding (24) and the rotor core (16) - preferably at one of the end faces (40, 42) punctually at the radial transition regions of the rotor winding (24) to the Rozahn (32) or on the rotor grooves (32) - is applied. Method according to one of the preceding claims, characterized in that when winding the rotor winding (24) to the commutator hook (23) of the commutator (22) fixed - and in particular subsequently welded - is, wherein the rotor winding (24) in the axial region (20). between the first end face (40) and the commutator (22) is not glued to the rotor shaft (14).

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