KR102577383B1 - Rotor, electric machine including the rotor, and method of manufacturing the rotor - Google Patents

Abstract

The present invention relates to rotors and, in particular, to an electric machine (10) for power steering moving parts in a motor vehicle, and to a method of manufacturing said rotors. The rotor comprises a rotor shaft (14), a rotor packet (16) on the rotor shaft (14), and a rotor winding (24) axially spaced relative to the rotor packet (16). A commutator for receiving is fixed, and the rotor winding 24 is glued directly to a selected, limited area of the rotor packet 16 by adhesive 50.

Description

Rotor, electric machine including the rotor, and method of manufacturing the rotor

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

EP 0 895 668 B1 discloses a direct current motor in which a disk pack is fixed on an armature shaft. After assembly of the laminated plates, the laminated plates are coated with an epoxy resin that insulates the armature packets to the windings. In this case, the commutator is pressed axially against the epoxy resin on the armature shaft for fixation of the commutator, thereby forming a shape-fit joint after cooling.

DE 19840149A1 presents a rotor of an electric machine with a laminated core and a collector, on which a felt-like element is arranged, the felt-like element being impregnated with a hardenable agent for securely fastening the electrical coil wire to the collector. . For this, after winding the rotor, synthetic resin flows onto the corresponding wire sections, the felt is soaked with synthetic resin and solidifies after drying.

In these electric motors, deformation may occur due to external loads, especially when using thin armature shafts. As a result, there is a risk of the wires of the armature winding breaking under strong external vibration loads.

The object of the invention is to glue the electrical windings to certain points of the rotor packet, so that, on the one hand, the relative movement of the windings with respect to the rotor packet is prevented, and on the other hand, a certain elastic compensatory movement of the windings on the rotor is achieved in other areas. The object of this invention is to provide a rotor, an electric machine, and a method of manufacturing the rotor.

The rotor, the electric machine and the inventive manufacturing method of said rotor according to the invention comprising the features of the independent claims are achieved by gluing electrical windings to specific points of the rotor packet, on the one hand, windings to the rotor packet. This has the advantage that, on the one hand, relative movements of By the above combination, even in applications with high vibration loads and a wide temperature range of the rotor, winding breaks can be prevented, especially in the area between the rotor packet and the commutator, which is also prevented by complete encapsulation of the rotor packet. It can't be. As a result, the electric machine according to the invention is suitable for use in the engine compartment of a motor vehicle, preferably for fastening to the engine block through which long-lasting vibrations are transmitted to the electric machine.

By means of the measures suggested in the dependent claims, advantageous improvements in the features presented in the independent claims are possible. It is particularly advantageous to provide an adhesive on the axial end face facing the commutator that securely secures the individual windings to the axial end face of the rotor packet. This prevents the electrical winding from moving relative to the armature packet at this end face, resulting in a reduced load on the winding on the commutator hook.

It is particularly preferred that the adhesive, as an adhesive crawler, is sprayed onto the axial end faces of the rotor teeth before starting the winding process. For this purpose the adhesive is preferably paste and stable. During winding, the adhesive is distributed on the end faces of the rotor packet by squeezing the windings, and the adhesive is pressed axially into the rotor slots. As a result, the windings are securely adhered to the rotor packet in the transition area from the winding head to the rotor packet. This bonding method allows for the so-called fractional pitch winding, where the winding is not inserted from one rotor slot into the immediately adjacent rotor slot, but, for example, into the next, third or fourth rotor slot. It is especially desirable. In such disconnected windings with relatively long cords along the end face of the rotor packet, it is particularly important to securely adhere the cord of the winding head to the end face of the rotor packet.

The rotor packet is preferably axially stacked from punched individual laminated plates and axially connected to each other, for example by plastic beads. To isolate the contact surfaces between the rotor packet and the winding, the contact surfaces are electrically insulated. For this purpose, the slots and end faces are coated, for example, with epoxy resin, especially by inductive powder coating. The adhesive may be applied directly to the insulating layer. When using an epoxy layer as an insulator, the adhesive is very firmly connected to the rotor packet through the epoxy layer. The winding is preferably not glued to the axial region so that the winding can move elastically between the rotor packet and the commutator. This means that the windings are supported radially on the armature shaft in this area, but relative movement between the windings and the rotor shaft is still possible. By this combination of rigid fixation and elastic movement areas on the end face of the rotor packet, external impacts can be damped particularly well. This prevents the winding from being broken by too strong clamping in the area of the commutator.

In a preferred embodiment of the rotor, adhesive is provided not only on the end faces of the rotor packet but also at other spatially confined points of the rotor packet. For example, the windings are glued to a specific axial end region of the rotor slot or to an end face opposite the commutator. In further embodiments, the windings may be glued to the rotor shaft or to specific contact areas with the commutator. The bonding process can be performed cleanly and reliably using simple adhesives. For this purpose, a paste and stable adhesive is used. The adhesive is distributed very well between the individual windings during winding and does not escape from them. The adhesive can then be subsequently heat cured in a simple manner, after which the adhesive remains temperature stable over a large temperature range over a long period of time.

Additionally, the windings are coated with baked enamel, so that upon heating and subsequent re-cooling of the rotor the individual windings can be tightly connected to each other via the baked enamel. In this case, the baked enamel can advantageously be heated in the same process step as the curing of the adhesive or in a separate process step, which is advantageous in terms of process technology. As an alternative, standard wire bonded to the rotor packet by adhesive may be used without baked enamel.

Bonding the windings to the rotor packet according to the invention is particularly advantageous for rotors where the rotor shaft has a small diameter, so that in case of external vibration loads the commutator can perform elastic oscillations relative to the rotor packet. Due to this bending of the thin rotor shaft, the load on the windings between the rotor packet and the commutator is particularly large. With the winding now securely glued to the end face of the rotor packet, the electrical winding between said end face and the commutator can perform a certain compensating movement to bend the rotor shaft, thereby reducing the shear load on the winding on the commutator. do. This elastic bending of the rotor shaft occurs for example in rotor shafts with a diameter of less than 5 mm, especially less than 4 mm. By gluing the rotor winding to the first end face, relative movements of the rotor winding with respect to the rotor packet, caused by rotor shaft bending, rotor torsion, so-called rigid body movement of the entire rotor winding, can be prevented. .

When such a rotor is installed into an electric machine, in particular an electric motor, the electric motor can be fixed directly to the engine block of a motor vehicle, for example. By gluing the electrical windings to the rotor packet according to the invention, the electric motor can withstand high vibration loads and large temperature fluctuations without destruction.

In the manufacturing method according to the invention, the rotor is first pre-assembled by fastening the rotor packet and the commutator to the rotor shaft. For this purpose, the rotor packet can be pressed onto the rotor shaft, preferably by an interference fit, which optionally has longitudinal notches for lamination. The commutator may also be pressurized or fixed to the rotor shaft by epoxy material. Thereafter, the rotor packet and optionally also the axial region of the rotor shaft between the rotor packet and the commutator are insulated. This is preferably done by epoxy coating. In this case, the axial area between the rotor packet and the commutator can also be insulated by an epoxy coating. Afterwards, the end faces of the rotor packets are provided with adhesive, and then the rotor packets are wound by a conventional winding method. In this case, the adhesive is distributed between the windings and the end faces of the rotor packet and, after curing, forms a reliable fixation of the individual windings to the end faces of the rotor packet.

During winding of the rotor packet, the adhesive can reach into the rotor slots due to the windings, so that the windings are securely adhered to the axial edges of the rotor teeth, especially at the transition to the rotor slot, so that the end faces of the rotor packet connected without vibration.

For optimal adhesive dosing, the adhesive can be sprayed onto the end faces of the rotor packets in the form of so-called adhesive crawlers or adhesive beads. The adhesive crawler preferably extends over the entire radial extent of the rotor teeth.

In another embodiment of the invention, after the winding process, adhesive may additionally be provided at certain points of the rotor to improve the adhesion effect between the winding and the rotor. Additional adhesive may be inserted into the contact area between the stator packet and the winding, for example in the radially external area between the winding and the head of the stator tooth at the end face of the rotor packet. It is also possible to introduce adhesive after winding at specific points in the rotor slots or on opposite sides of the rotor packet. In other embodiments, adhesive may be added between the rotor shaft and the rotor winding or between selected points of the commutator and the winding.

During winding of the rotor, the winding is preferably inserted into the commutator hook and subsequently soldered or welded, for example. Due to this, the winding is tightly connected on the one hand to the commutator hook and on the other hand to the end face of the rotor packet by gluing, and in the axial area between the commutator and the end face of the rotor packet the winding is preferably rotated. It is not connected tightly to the electronic shaft.

During the thermal curing of the adhesive, preferably simultaneously or optionally in a separate process, the baked enamel of the windings is heated and after cooling forms a tight connection between the windings.

Embodiments of the invention are illustrated in the drawings and described in greater detail in the description below.

1 shows a first embodiment of a rotor according to the invention,
Figure 2 shows another embodiment of the rotor before winding,
Figure 3 shows another embodiment of the rotor after winding.

Figure 1 schematically shows an electric machine 10 with a rotor 12 mounted in a stator 13. The rotor 12 comprises a rotor shaft 14 on which is fixed a rotor packet 16 made up of individual laminations 18, each end lamination 19 of the rotor packet 16. and second end faces 40, 42. The laminations 18 are generally punched from a single electrical sheet. The rotor packet 16 is, for example, pressed onto the rotor shaft 14 and fixed incapable of relative rotation thereto. In order to space the axial region 20 away from the rotor packet 16, a commutator 22 is fixed to the rotor shaft 14. The commutator 22 is pressed onto the rotor shaft 14, for example without relative rotation. On the rotor packet 16, an electrical winding 24 is arranged, which is electrically connected to a commutator 22. For this purpose, the commutator 22 comprises commutator hooks 23 which form electrical contact with the individual commutator segments 26 . The electrical winding 24 includes a number of coils 25 each connected to a pair of rectifier segments 26. By means of brushes (not shown), which may be adjacent to the rectifier segments 26, the coils 25 are energized to cooperate with the magnetic field of the stator 13. The rotor packet 16 comprises rotor slots 30 in the axial direction 70 , which are formed between corresponding radial rotor teeth 32 . The rotor teeth 32 each have one tooth head 34 on the radial periphery. The first end face 40 of the rotor packet 16 faces the commutator 22 and the opposite second end face 42 is away from the commutator 22 . The electrical windings 24 are adjacent to a support surface 44 on the rotor packet 16, the support surface 44 having an insulating layer to prevent short circuits between the electrical windings 24 and the rotor packet 16. (45) is provided. The individual coils 25 extend axially 70 in the rotor slots 30 and form at their two end faces 40 , 42 a so-called winding head 46 . 1, the electrical winding 24 is glued to the first end face 40 facing the commutator 22. As a result, the electrical winding 24 is tightly connected to the rotor packet 16 at the first end face 40, such that there is a gap between the electrical winding 24 and the rotor packet 16 at the first end face 40. Relative movement is impossible. Over the axial distance 20 between the first end face 40 and the commutator 22 , the electrical winding 24 is not adhered to the rotor shaft 14 . As a result, the electrical winding 24 in this axial region 20 can perform elastically compensated movements in the case of external vibration loads and large temperature fluctuations. In the commutator 22, the electrical winding 24 is mechanically fastened to the commutator hook 23, for example by welding or hot forming (so-called “hot staking”).

In another embodiment according to Figure 2, it can be seen that before winding the rotor packet 16 along the radial rotor teeth 32, adhesive 50 is applied to the first end face 40. . The adhesive 50 is here preferably formed in the form of adhesive beads 52 extending over the entire radial extent of the rotor teeth 32 . The diameter of the adhesive bead 52 may be adjusted, for example, by applying the adhesive 50 to the first end face 40 and then pressing the adhesive 50 axially 70 against the first end face 40. larger than the diameter of the winding 54. During the winding process, the adhesive 50 of the adhesive beads 52 is distributed over the entire first end face 40 and is pressed axially during winding, especially into the rotor slots 30 . Because the adhesive 50 has a soft consistency, the adhesive 50 is distributed between the support surface 44 and the individual windings 54 during the winding process.

In FIG. 3 a rotor 12 identical to the rotor according to FIG. 2 is shown after being fully wound. It can be seen that the electrical winding 24 is not designed as a single tooth winding, but each individual coil 25 always surrounds at least two rotor teeth 32 . Here, the individual coils 25 overlap, so that they are arranged in an axial stack on the end faces 40, 42. The amount of adhesive 50 provided on the first end face 40 allows the adhesive 50 to be applied directly between the first end face 40 and the electrical windings 24 as well as individually on the electrical windings 24 . The pressing during winding can also be adjusted between the windings 54 . This ensures that the relatively long cord of winding 54 in the case of disconnected winding is relatively tightly fixed to the first end face 40 . After winding the rotor 12, the rotor 12 is heated to cure the adhesive 50. The winding 54 is coated by baked enamel in the second embodiment. Baked enamel softens when heated so that during subsequent cooling the baked enamel of the individual windings 54 connects them to each other. The rotor 12 according to FIG. 3 has for example eight rotor teeth 32 and correspondingly eight rotor slots 30 lying therebetween. The individual coils 25 here surround for example three rotor teeth 32 , so that the coils 25 extend from rotor slot number 1 to rotor slot number 4. The entire electrical winding 24 is arranged radially inside the toothed head 34 , which positively supports the electrical winding 24 radially on the rotor 12 . The two end faces 40, 42 and the inner surface of the rotor slot 30 comprise an epoxy layer 48 as an insulating layer 45 in this embodiment. This epoxy layer 48 is so tightly bonded to the rotor packet 16 that the adhesive 50 provided directly on the epoxy layer 48 securely and tightly connects the electrical windings 24 to the rotor packet 16. do. In this embodiment, the rotor slots 32 are completely covered with an epoxy layer 48 as an insulating layer 45. Additionally, the axial region 20 between the first end face 40 and the commutator 22 may also be coated with an epoxy layer 48. Optionally, commutator 22 and/or lamination 18 may be secured to rotor shaft 14 by an epoxy layer 48. In this case, the end laminations 19 are preferably pressed onto the rotor shaft 14 by ring caulking. Thus, for example, longitudinal notches on the rotor shaft 14 for the rotor packet 16 may be omitted.

In other embodiments, the electrical winding 24 may be additionally bonded to another support surface 44 between the electrical winding 24 and the rotor 12. For example, the electrical winding 24 may also be glued to the second end face 42 away from the commutator 22. Additionally, the electrical winding 24 may be directly bonded to the rotor shaft 14 also at the second end face 42 . Optionally, it is possible for the winding 54 to also be glued to the commutator 22 , in particular to the commutator hook 23 . It is also possible that adhesive 50 is subsequently applied to certain points of the support surface 44 only after complete winding of the rotor 12 . This adhesive is then heat cured together with the provided adhesive 50 before winding. In particular, an adhesive 50 can subsequently be inserted between the bearing surface 44 of the first end face 40 and the electrical winding 24 in the radially peripheral area 60 of the electrical winding 24 .

The rotor shaft 14 has a diameter, for example, between 3,0 and 5,0 mm, preferably less than 4,0 mm. However, the invention can also be applied to rotor shafts with a relatively large diameter, where the rotor is exposed to large temperature fluctuations during operation, for example from -40° C. to +180° C. By means of the bonding according to the invention, so-called rigid body oscillations of the entire rotor winding relative to the rotor packet can be prevented. The rotor shaft 14 is mounted within the housing of the stator 13 and on the other side, for example in a bearing shield between the stator 13 and the transmission housing. On the rotor shaft 14 an output element not shown, for example a rotor screw, is arranged, which transmits the generated torque of the electric machine 10 through a mechanism to a throttle arranged in the engine room of the automobile. It is transmitted to the valve regulator.

In relation to the embodiments presented in the drawings and description, there are various possibilities for combinations of individual features. For example, adhesive 50 may be provided on the support surface 44 of the electrical winding 24 before and after winding. In addition to adhering the electrical windings 24 to the first end face 40 of the rotor packet 16, the electrical windings 24 may be attached to other points, such as the second end face 42 and/or the coil. It can also be adhered to the electronic slot 30. Likewise, winding 54 may optionally be securely secured to commutator 22 by adhesive 50 . The number and axial length of rotor slots 30 and the type of electrical windings 24 may vary depending on the performance requirements of the electric machine 10. In this case, the insulator 45 of the rotor packet 16 can be formed by epoxy resin 48 or a separately manufactured insulating mask. The electric machine 10 is preferably used for actuators in automobiles, for example as an engine room regulator, in particular for throttle valves, but is not limited to this application.

10 electric machine
12 rotor
14 rotor shaft
16 rotor packets
19 End lamination
22 commutator
23 commutator hook
24 rotor windings
25 coil
30 rotor slots
32 rotor teeth
40 first end face
44 support surface
45 insulation layer
50 glue

Claims (16)

A rotor (12), comprising a rotor shaft (14), a rotor packet (16) on the rotor shaft (14), and a rotor packet (16) axially spaced relative to the rotor packet (16). In the rotor (12), on which a commutator (22) for receiving the winding (24) is fixed,
The rotor winding 24 is directly glued to a selected, limited area of the rotor packet 16 by adhesive 50, positioning the rotor winding 24 at a specific point of the rotor packet 16. By gluing, on the one hand the relative movement of the rotor winding 24 with respect to the rotor packet 16 is prevented, and on the other hand the rotor winding 24 on the rotor 12 in other areas. The rotor (12), characterized in that a predetermined elastic compensation movement of is maintained. According to claim 1,
The rotor packet 16 includes a first axial end face 40 facing the commutator 22, on which the rotor winding 24 extends towards the rotor. Rotor (12), characterized in that it is glued to the packet (16). According to claim 2,
The rotor packet 16 includes a plurality of radial rotor teeth 32 and rotor slots 30 disposed therebetween, and the adhesive 50 is applied to the radial rotor teeth ( The rotor (12), characterized in that it is arranged along 32). The method of claim 1 or 2,
The rotor winding 24 includes a plurality of electrical coils 25, the coils 25 contacting the commutator hook 23 of the commutator 22, and the coils 25 are disconnected from each other. Characterized in that each rotor (12) always surrounds at least two rotor teeth (32). According to claim 2,
The rotor packet (16) is comprised of stacked individual laminations (18), wherein an end lamination (19) forms the first axial end face (40) of the rotor packet (16), Rotor (12), characterized in that the packets (16) are coated with an insulating layer (45). The method of claim 1 or 2,
The rotor winding 24 is not glued to the rotor shaft 14 in the axial region 20 between the rotor packet 16 and the commutator 22, and thereby the rotor winding 24 ) is a rotor (12), characterized in that elastic compensation movement can be performed within a predetermined limit during external vibration in the above region. According to claim 3,
In addition to the first axial end face, the rotor winding 24 is located on another limited area on the rotor packet 16, on an end face away from the rotor slot 30 or the commutator 22. 42) or on the rotor shaft 14 or on the commutator 22. The method of claim 1 or 2,
Rotor (12), characterized in that the adhesive (50) is heat-resistant, curable, pasty and stable. The method of claim 1 or 2,
Rotor (12), characterized in that the rotor winding (24) is wound with baked enamel wire, the baked enamel connecting the individual windings (54) to each other after heating of the rotor (12). The method of claim 1 or 2,
Rotor (12), characterized in that the rotor shaft (14) has a diameter (15) of 3,0 - 5,0 mm. Electrical machine (10) comprising a rotor (12) according to claim 1 or 2, wherein the rotor (12) is arranged radially inside a stator (40) comprising permanent magnets, said Electric machine (10), characterized in that the electric machine (10) is fixed in the engine compartment of a motor vehicle. Method for manufacturing a rotor (12) according to claim 1 or 2, wherein, after assembly and insulation of the rotor packet (16), the first end face of the rotor packet (16) faces the commutator (22). A soft adhesive (50) is provided on (40), and subsequently the rotor packet (16) is wound into a rotor winding (24), which is at least partially connected to the first end face. axially adjacent to (40), characterized in that the rotor (12) is subsequently heated to harden the adhesive (50). According to claim 12,
During winding of the rotor packet 16 the adhesive 50 is pressed axially from the first end face 40 into the rotor slot 30, thereby causing the rotor winding 24 to A method of manufacturing a rotor, characterized in that it is glued to the axial end of the electronic slot (30). According to claim 12,
A method of manufacturing a rotor, characterized in that the adhesive (50) is provided radially along the rotor teeth (32) in the form of adhesive beads (52). According to claim 14,
After winding the rotor packet 16, additional adhesive 50 is applied to the support surface 44 between the rotor winding 24 and the rotor packet 16, on one of the end faces 40, 42. A method of manufacturing a rotor, characterized in that provided exactly in the radial transition area from the rotor winding (24) to the rotor teeth (32) or in the rotor slot (30). According to claim 12,
During winding the rotor winding 24 is secured to the commutator hook 23 of the commutator 22, the rotor winding 24 being positioned along an axis between the first end face 40 and the commutator 22. Method for manufacturing a rotor, characterized in that there is no adhesion to the rotor shaft (14) in the orientation area (20).

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