The invention relates to a commutator motor according to the preamble of Claim 1 . A commutator motor of this kind is known, in particular, as a constituent part of a wiper motor, wherein the armature of said wiper motor has 12 armature slots which serve to receive windings of a winding wire which form armature coils. One aspect of the commutator motor known from the prior art which can be improved is, in particular, its noise behaviour, in the case of which the armature causes the housing of the wiper motor to vibrate for example.

Furthermore, the prior art discloses not only commutator motors which have two permanent magnet elements (a so-called 2-pole motor) but also commutator motors which have four permanent magnet elements (a so- called 4-pole motor). The last-mentioned 4-pole motors have, in particular, the advantage of an increased power density, so that a corresponding commutator motor permits savings in respect of material use and also a reduction in the overall size with the same performance.

Disclosure of the invention

Proceeding from the described prior art, the invention is based on the object of developing a commutator motor according to the preamble of Claim 1 in such a way that the said commutator motor has an improved noise behaviour and is equally suitable in conjunction with two and with four permanent magnet elements. According to the invention, this object is achieved in the case of a commutator motor, in particular a wiper motor, having the features of Claim 1 in that the armature of the commutator motor has 14 armature slots. The use of an armature with 14 armature slots has, in particular, the advantage that the noise behaviour changes as a result of the increased number of armature slots in relation to the prior art (12 armature slots) causing the excitation frequencies of the armature to shift when it rotates in the direction of more favourable frequency bands. Furthermore, fluctuations in the torque are avoided since the ratio of commutating armature coils to active armature coils is improved by two additional active armature coils. Furthermore, it is considered to be advantageous that the slot latching moment of the de-energized armature is reduced by the additional number of armature teeth on the circumference, this resulting in an additional reduction in noise.

Advantageous developments of the commutator motor, in particular wiper motor, according to the invention are indicated in the dependent claims. All combinations of at least two of the features disclosed in the claims, the description and/or the figures are covered by the scope of the invention .

In a first structural refinement of the commutator motor, it is proposed that two permanent magnet elements are provided, and that the windings are arranged in two armature slots, between which five armature slots are arranged, which are not provided with these windings. An arrangement of this kind allows either the windings to be wound on the armature by means of a single so-called flyer, or else two different windings to be wound on the armature at the same time (when using two flyers), without this resulting in disruptive contact between the individual windings and flyers.

However, as an alternative, it is also possible for two permanent magnet elements to be provided, and for the windings to be arranged in two armature slots, between which six armature slots are arranged, which are not provided with these windings.

In a yet further alternative structural refinement, it is provided that four permanent magnet elements are provided, and that the windings are arranged in two armature slots, between which two armature slots are arranged, which are not provided with these windings. An arrangement of the windings of this kind allows the individual windings to be wound on the armature both with one and with two flyers, without this resulting in a disturbance in the winding process when using two flyers. In all of the types of windings presented up until this point, it can be provided that the respective start and the respective end of a winding wire is connected to a commutator hook, which is arranged at least almost in the middle between the armature teeth, about which the respective winding is wound. An arrangement of this kind has the advantage of particularly short connections between the winding region and the respective commutator hook.

However, as an alternative to this, it can be provided that the respective start and the respective end of a winding wire is connected to a commutator hook which is arranged outside the region of the armature teeth, about which the respective winding is wound. A design of this kind has the advantage that particularly good and defined guidance of the winding wire between the winding region and the commutator hook is possible, so that the said winding wire bears, for example, against a subregion of the armature, as a result of which particularly high rotation speeds of the armature can be achieved, without this resulting in mechanical loading or overloading of the corresponding section of the winding wires.

In a further refinement of the invention, it can also be provided that two different windings are wound about two armature teeth.

In order to reduce the number of brush elements required in the case of a (4-pole) motor having four permanent magnet elements, it is provided that two brush elements are provided, and that two commutator hooks each, which are each connected to a start and an end of a winding wire, are connected to one another in an electrically conductive manner. As a result, the same commutator hook can be electrically connected to armature coils or windings which are wound about different armature teeth. In particular, this relates to windings and armature coils which are arranged in a manner offset through 180° in relation to one another.

In a structural development of the last-mentioned idea, it can be provided that the connection of two commutator hooks is effected through a separate wire connection, that is to say the respective winding wire ends at the corresponding commutator hook and is not guided from there to a another commutator hook. Furthermore, it can be provided that the direction of rotation of the armature upon energizing of the winding wires is adjusted through the arrangement of the starts and the ends of the windings to a commutator hook. In other words, this means that a direction of rotation of a commutator motor can be reversed upon energizing by a simple exchange of starts and ends of winding wires to the commutator hooks.

Further advantages, features and details of the invention can be gathered from the following description of preferred exemplary embodiments and also with reference to the drawing.

In the drawing: Fig. 1 shows a longitudinal section through a commutator motor according to the invention in the form of a wiper motor

Fig. 2 shows a cross section through the commutator motor according to Fig. 1 in the armature region,

Fig. 3 shows a detailed side view of an armature which is used in the commutator motor according to Fig. 1

Fig. 4 shows a cross section through the armature according to

Fig. 3 in the region of the armature laminations,

Fig. 5 shows a perspective view of an armature, the windings of the said armature being wound by means of two flyers, and

Fig. 6

to

Fig. 20 each show illustrations of different types of windings on a commutator motor according to the invention which has 14 armature slots, and also an end view of the respective armature.

Identical elements or elements with the same function are provided with the same reference numerals in the figures. Fig. 1 shows a commutator motor 10 according to the invention in the form of a wiper motor. The commutator motor 10 is accommodated within a housing 1 of the wiper motor and comprises an armature 15 with an armature shaft 2 which is rotatably mounted in a plurality of bearing devices 3, 4 within the housing 1 . As shown, in particular, with reference to Fig. 2, four permanent magnet elements 1 1 to 14, between which gaps which each run in the longitudinal direction and separate the permanent magnet elements 1 1 to 14 from one another are formed, are arranged within the housing 1 against the inner wall of the said housing by way of example. The commutator motor 10 is therefore in the form of a so-called 4-pole motor.

In a modification to the illustrated exemplary embodiment, it can of course be provided that, instead of four permanent magnet elements 1 1 to 14, only two permanent magnet elements 1 1 to 14, which are approximately in the form of a half-shell and between which corresponding longitudinal slots or spaces are likewise formed in the longitudinal direction, are used. In a known manner, a multiplicity of armature laminations 5 which are stacked one above the other and are arranged in alignment in relation to one another are located on the armature 15. According to the invention, it is provided that, according to the illustration of Fig. 2, the armature laminations 5, which are connected to one another by a stove enamel for example, have 14 armature teeth Z1 to Z14, which project radially outward at uniform angular distances, and 14 armature slots N1 to N14 which are arranged between the armature teeth Z1 to Z14. The armature teeth Z1 to Z14 are, in a known manner, widened in the manner of a T at their radially outer end region, in order to prevent windings C1 to C14 which are arranged in the armature slots N1 to N14 from slipping out or moving to the outside. A winding C1 to C14 is in each case formed by a winding wire 20 in the form of a multiplicity of windings wound about armature teeth Z1 to Z14. It is clear from looking at Figs 3 and 4 together that the armature 15 further has, as is likewise known from the prior art, fourteen commutator hooks H1 to H14 which are electrically connected to the windings C1 to C14, for example by a welded or soldered connection of the corresponding start 21 and end 22 of the winding wire 20 to the commutator hooks H1 to H14. The commutator hooks H1 to H14 are connected to current laminations 7 in an electrically conductive manner, the said current laminations in turn interacting with a brush device which, in accordance with Fig 1 , has two brush elements B1 , B2 in the form of carbon brushes which, by way of example but not in a limiting manner, are arranged in a manner offset through 180° in relation to one another and which are acted on with force by spring force against the current laminations 7. Fourteen windings C1 to C14 can be wound onto an armature 15 of this kind having fourteen armature slots N1 to N14 in a wide variety of ways. According to Fig. 5, this is done in practice either by means of a single flyer or, as illustrated, by means of two flyers F1 and F2 which are designed to hold the winding wire 20 and to wind the said winding wire about the armature teeth Z1 to Z14 and which allow in each case two windings C1 to C14 to be wound at the same time. Then, different types of windings are illustrated and explained by way of example, and in a non- limiting manner, with reference to Figs 6 to 20. In Figs 6 to 20, a schematic winding scheme is illustrated on the left-hand side of the corresponding figure, wherein, in order to be able to better identify the individual windings C1 to C14, the winding C1 is illustrated in bold in each case, while the other windings C2 to C14 are each illustrated using a thin line. When two flyers F1 and F2 are used at the same time, the windings C1 to C14 are wound by the second flyer F2, illustrated using a dotted line. Furthermore, it is noted that only some of the windings C1 to C14 are illustrated in all of the illustrated exemplary embodiments, but the armature 15 is in each case provided with fourteen windings C1 to C14, this not being illustrated in detail only for reasons of better clarity. An end view of the armature 15 is shown in the right-hand-side drawing of the individual Figs 6 to 20 in each case. Furthermore, it is noted that the individual armature teeth Z1 to Z14 in Figs 6 to 20 are shown in the respective left-hand-side drawing as rectangular boxes which are numbered between 1 and 14. The armature teeth in Fig. 6 are provided, by way of example, with the corresponding designations Z1 and Z8 merely for the sake of improved clarity. This is likewise provided with reference to the commutator hooks H1 to H14 which have been designated in detail only in Fig. 6. The type of winding illustrated in Fig. 6 and the winding scheme of the armature 15 are distinguished in that a respective winding C1 to C14 is wound about in each case six armature teeth Z1 to Z14 in such a way that, for example, the winding C1 is wound about the armature teeth Z1 and Z6, so that five armature slots N1 to N5 are arranged between the armature teeth Z1 and Z6, the winding C1 not being arranged in these armature slots. The winding wire 20 of the winding C1 is connected to the commutator hook H3 by way of its start 21 , while the end 22 of the winding wire 20 of the winding C1 is connected to the commutator hook H4. The individual windings C1 to C14 are each arranged such that they immediately follow one another, that is to say there is no free armature slot N1 to N14 between two windings C1 to C14 which follow one another. The order of production of the windings C1 to C14, designated the winding scheme in the text which follows, can be as follows: C1 -C2-C3-....

The winding scheme shown in Fig. 7 differs from the winding scheme according to Fig 6 in that the start 21 of the winding wire 20, for example of the winding C1 , is connected to the commutator hook H4 in an electrically conductive manner, and the end 22 of the winding wire 20 of the winding C1 is connected to the commutator hook H3 in an electrically conductive manner. When the respective start 21 and the respective end 22 of the winding wires of the windings C1 to C14 on the commutator hooks H1 to H14 are exchanged in this way, the direction of rotation is reversed, that is to say the armature 15 rotates, for example, in the anticlockwise direction instead of in the clockwise direction, when the armature 15 is energized in the same way.

In the two winding schemes according to Figs 6 and 7, it is provided that only one of the windings C1 to C14 is wound on the armature 15 by means of one flyer F1 , F2 at the same time.

Fig. 8 shows a winding scheme which differs from the winding scheme according to Fig. 6 only in that in each case two windings C1 to C14 are wound by means of two flyers F1 and F2 at the same time. This reduces the winding time on the armature 15 by approximately half. The winding scheme can be described by: (C1 +C8) - (C2+C9) - (C3+C10) This means that the windings C1 and C8 are wound at the same time, then the two windings C2 and C9, then the two windings C3 and C10 etc.

The winding scheme according to Fig. 9 differs from the winding scheme according to Fig. 6 in that the start 21 and the end 22 of the winding wire 20 of the respective winding C1 to C14 is connected to a commutator hook H1 to H14 which is not arranged in alignment with the commutator hooks H1 to H14 which are in alignment with the armature teeth Z1 to Z14. It is provided in particular that commutator hooks H1 to H14 are used, these commutator hooks being arranged for example opposite the armature teeth Z1 to Z14 about which the respective winding C1 to C14 is wound. The winding scheme of the windings C1 to C14 in Fig. 9 is: C1 -C2-C3...

The winding scheme according to Fig. 10 differs in that half of the winding wire 20 of the winding C1 is initially wound about the armature teeth Z6 and Z1 (in the anticlockwise direction), and that the second half of the winding wire 20 of the winding C1 is then again wound about the armature teeth Z8 and Z13 (in the clockwise direction). Therefore, the armature slots N1 to N14 are each filled by winding wires 20 of two different windings C1 to C14. The winding scheme can be represented by: C1 (C1 ' - C1 ^* )-C2(C2'-C2")-...

The winding scheme of Fig. 1 1 differs from the winding scheme according to Fig. 6 only in that a winding C1 to C14 is guided about two armature teeth Z1 to Z14, between which there is a spacing of seven armature teeth Z1 to Z14. The winding scheme is: C1 -C2-...

The winding scheme according to Fig.6 to Fig.1 1 is used in commutator motors 10 with two permanent magnet elements 1 1 to 14.

In contrast, Fig. 12 shows a winding scheme in which the commutator motor 10 has four permanent magnet elements 1 1 to 14, and wherein the armature 15 is wound by means of two flyers F1 and F2 at the same time. The said figure shows, in particular, that a winding C1 to C14 is in each case wound about three armature teeth Z1 to Z14. Furthermore, a spacing of four free armature teeth Z1 to Z14 is provided between two windings C1 to C14 which are wound at the same time. The winding scheme can be described by: (C1 +C8) - (C2+C9) - ... The winding scheme according to Fig.13 is produced by means of a single flyer F1 , F2, wherein four brush elements are provided, which brush elements are arranged in a manner offset in relation to one another through in each case 90° in particular. The winding scheme can be described by: C1 (C1 ' -C1 " -C1 " ' -C ^** ) - C2 (C2' -C2" - C2" ' -C2" ") - ...

The winding scheme according to Fig. 14 corresponds to the winding scheme according to Fig. 12, but only two brush elements B1 , B2 are used. To this end, it is provided that in each case a start 21 of the winding wire 20 of a first winding C1 to C14 is connected by means of an additional wire connection 23 to the start 21 of the winding wire 20 of the winding C1 to C14 which is produced at the same time. This additional wire connection 23 is formed from the winding wire 20 of the respective winding C1 to C14. The winding scheme can be described by: (C1 +C8) - (C2+C9) - ...

The winding scheme according to Fig. 15 corresponds substantially to the winding scheme according to Fig. 14, wherein separate equalizers Eq are provided between the commutator hooks H1 to H14. This means that the respective start 21 and the respective end 22 of a winding wire 20 of a winding C1 to C14 is connected to the corresponding commutator hook H1 to H14, and then a separate equalizer Eq is produced as an electrically conductive connection between commutator hooks H1 to H14. The winding scheme can be described by: C1 - Eq - C9 -Eq - C3 - Eq - C1 1 - Eq - C5 - Eq - C13 - Eq - C7 - Eq - cut - C2 - cut - C4 - cut - C6 - cut - C8 - cut - C10 - cut - C12 - cut - C14.

The winding scheme shown in Fig. 16 is produced using one flyer F1 , F2 for a 4-pole motor, wherein two brush elements B1 , B2 are provided, and wherein a split winding C1 to C14 is provided. The winding scheme can be described by: C1 (C1 ' -C1 ") -C2(C2' -C2")

The winding scheme shown in Fig. 17 is used in a 4-pole motor using one flyer F1 , F2, which 4-pole motor has two brush elements B1 , B2. Its winding scheme can be described by: (CV +C1 ") - Eq - (C9' +C9") - Eq - The winding scheme shown in Fig. 18 is used in a 4-pole motor with two brush elements B1 , B2, the armature 15 of which 4-pole motor is wound using one flyer F1 , F2. Its winding scheme can be described by: (C1 ' +C1 ") - Eq - (C9' +C9") - Eq - ...

The winding scheme shown in Fig. 19 is used in a 4-pole motor which has two brush elements B1 , B2. Split windings C1 to C14 are provided, it being possible for these split windings to have different numbers of windings. Its winding scheme can be described by: C1 (C1 ' -C1 ") -C2(C2' -C2")

Finally, Fig. 20 shows a winding scheme with a 4-pole motor which likewise has two brush elements B1 , B2, wherein a different number of armature slots N1 to N14 is provided between the individual partial windings. Its winding scheme can be described by: C(C1 ' -C1 ") -C2(C2' - C2") -...

In addition, it should be noted that yet further winding schemes can be provided or formed, these winding schemes being produced, for example, by modifying the winding schemes shown in Figs 6 to 20.

List of reference symbols

1 Housing

2 Armature shaft

3 Bearing

4 Bearing

5 Armature plate

7 Current laminations

10 Commutator motor

1 1 - 14 Permanent magnet element

15 Armature

20 Winding wire

21 Start

22 End

23 Wire connection

Z1 - Z14 Armature tooth

N1 - N14 Armature slot

C1 - C14 Winding

H1 -H14 Commutator hook

B1 , B2 Brush element

F1 , F1 Flyer

Eq Equalizer