Motor with a defined detent torque
Patent Information
- Application Number
- EP2024704372
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2023-04-06
- Filing Date
- 2024-02-07
- Publication Date
- 2026-02-11
AI Technical Summary
Brushless motors with reduced or no cogging torque often cause belt slippage when power is lost, making them unsuitable for applications requiring high torque, while stepper or reluctance motors lack sufficient torque for component supply stations in pick-and-place machines.
A brushless motor design with extended stator teeth, which increases the magnetic flux linkage and cogging torque, ensuring a preferred locking position without affecting motor performance, achieved by varying the length of stator teeth and air gaps between stator and rotor poles.
The motor provides a high torque with defined cogging torque, ensuring reliable operation and self-locking, suitable for applications like component supply stations, without the need for additional components, thus maintaining low costs.
Smart Images
Figure EP2024053045_10102024_PF_FP_ABST
Abstract
Description
[0001] Motor with defined cogging torque'
[0002] The invention relates to a brushless motor, in particular for driving a component supply station of a pick-and-place machine. The motor is particularly flat and has a high number of poles.
[0003] Brushless motors (also known as BLDC motors or EC motors) are available in a variety of designs. Commutation is electronic, which is why such motors are characterized by a longer service life and higher speeds.
[0004] In the slotted design (slotted BLDC motor), the coils are wound in slots around the circumference of the stator. The slots allow for a higher magnetic flux density, resulting in higher power and higher torque. The cogging torque of slotted motors depends on many parameters, including the number of rotor pole pairs and the stator teeth. For most applications, efforts are made to minimize cogging torque. Brushless motors with a high number of poles thus have high torque with low cogging torque. These motors are therefore particularly suitable for applications that require high performance and smooth running, such as direct drives.
[0005] These properties are also desirable for drives in automation or handling technology, e.g., for driving a component supply station (feeder) of a pick-and-place machine. However, in a pick-and-place machine, using a brushless motor with no or reduced cogging torque can cause the belt to slip when the motor is de-energized. Therefore, stepper or reluctance motors are typically used for such applications. However, these often lack sufficient torque.
[0006] Based on the aforementioned prior art, the invention is based on the object of specifying a motor, in particular for driving a component supply station of an automatic pick and place machine, which motor generates a sufficiently high cogging torque amplitude with a high number of cogging ripples and at the same time provides a high torque.
[0007] The aforementioned object is achieved in a generic, brushless motor according to the characterizing part of claim 1 in that at least one stator tooth of at least a first phase of the winding is designed as an extended stator tooth. The extended stator tooth has a longitudinal extent in the radial direction, in particular along a longitudinal axis L of the stator tooth, which is greater than a longitudinal extent of at least one stator tooth of the remaining stator teeth of the first phase. In particular, it is also provided that the extended stator tooth is longer than all the remaining stator teeth of the first phase. Preferably, it is provided that at least or exactly two stator teeth of the first phase are designed as extended stator teeth, and that the two extended stator teeth are longer than all the remaining stator teeth of the first phase.In particular, the extended stator teeth are arranged opposite each other on the circumference of the stator.
[0008] Alternatively or additionally, it is provided that the extended stator tooth has a longitudinal extension in the radial direction that is greater than a longitudinal extension of at least one stator tooth of another phase, in particular the second phase or the third phase. For example, it is provided that the longitudinal extension of the extended stator tooth is greater than the longitudinal extension of all stator teeth of the second phase and / or the third phase. Preferably, the first phase has at least or exactly two stator teeth that are designed as extended stator teeth and that are longer than all stator teeth of the second phase and / or the third phase.
[0009] It is also provided that each phase has at least one extended stator tooth, in particular at least two extended stator teeth, each of which is longer than the remaining stator teeth of the respective phase.
[0010] The brushless motor according to the present invention comprises at least one stator, at least one rotor, and at least one shaft. The shaft is advantageously rotatably mounted within the stator. The shaft is mounted in the motor housing, for example, with bearings, in particular ball bearings. The motor is preferably designed as a synchronous machine, in particular as a permanent magnet synchronous motor (PMSM).
[0011] The rotor and the stator are arranged, in particular, in a motor housing. The rotor is attached to the shaft and has at least one permanent magnet with a plurality of magnetic rotor poles. It is also contemplated that the rotor has a plurality of individual permanent magnets, for example, between 5 and 30 permanent magnets, in particular exactly 20 permanent magnets.
[0012] The stator has a plurality of stator teeth. Each stator tooth is at least partially, in particular completely, wound with at least one stator coil. The stator teeth are preferably arranged radially around the shaft and in particular evenly spaced from one another. The stator teeth extend in the direction of the rotor. Furthermore, the rotor poles are also arranged radially around the shaft. In particular, the rotor poles or the discrete permanent magnets are evenly spaced from one another. In particular, the rotor poles are arranged concentrically with the stator teeth. The air gap is formed between the stator teeth and the rotor poles.
[0013] The stator teeth are formed, for example, on a magnetic yoke. In particular, the magnetic yoke is designed as a laminated core. The stator coils on the stator teeth form a motor winding with at least three phases. The stator coils are interconnected, in particular, on at least one printed circuit board.
[0014] At least one phase, preferably each phase, has at least two stator teeth, of which preferably at least one is designed as an extended stator tooth. An extended stator tooth has a greater longitudinal extent in the radial direction than at least one of the other stator teeth of the first phase and / or than at least one stator tooth of at least one of the further phases. Because at least one tooth is designed as an extended stator tooth, an air gap between the extended stator tooth and an oppositely arranged rotor pole is smaller than the air gap at the other stator teeth of the first phase of the winding. This locally increases the magnetic flux linkage and thus increases the cogging torque between the extended stator tooth and the opposite rotor pole. This reduces the local cogging torques of the individual rotor pole orPermanent magnet - stator tooth combinations do not cancel each other out to a large extent, but a significant cogging torque remains, resulting in a preferred position or cogging position for the rotor, which does not significantly affect the performance of the motor, but ensures sufficient holding force.
[0015] It is preferably provided that the air gap between the extended stator tooth, in particular its end face oriented in the direction of the rotor, and an oppositely arranged rotor pole is between 0.1 and 1.5 mm.
[0016] The brushless motor preferably has at least one rotary encoder, in particular the rotary encoder is designed as an absolute rotary encoder. For example, the motor may have at least one magnetic rotary encoder, which is designed in particular as a magnetic absolute rotary encoder. An absolute rotary encoder has the advantage of enabling sinusoidal commutation with simultaneous cogging torque compensation during operation.
[0017] It is further preferred that the rotor be designed as an inner rotor radially enclosed by the stator. Alternatively, the rotor may be designed as an outer rotor radially enclosing the stator.
[0018] The invention has the advantage over the prior art that it allows for the provision of a very powerful, efficient motor that can also be used in applications requiring a cogging torque. The different air gaps ensure at least one preferred position or a cogging position with a higher magnetic flux linkage, resulting in a defined cogging torque and, in particular, self-locking in this position. To achieve this advantage, the motor requires no additional components, thus keeping the motor costs low.
[0019] According to one embodiment of the motor, each phase of the winding has at least or exactly four, at least or exactly six, or at least or exactly eight stator teeth with a stator coil, wherein the stator teeth of a phase are arranged in pairs in groups radially opposite one another. Preferably, each of the phases has the same number of stator teeth with a stator coil.
[0020] A particularly preferred motor design is one with six stator teeth per phase, with three stator teeth of each phase arranged side by side and circumferentially opposite the other three stator teeth of the phase. A motor with a total of eighteen stator teeth is therefore particularly advantageous.
[0021] Furthermore, it is preferably provided that the rotor has at least or exactly 8, 10, 14, 16, 20, 22, 26, or at least or exactly 28 rotor poles. The number of rotor poles is preferably unequal to the number of stator teeth or stator slots. Preferably, the number of rotor poles of the motor is always two greater or lesser than the number of stator teeth. In combination with eighteen stator teeth, twenty rotor poles are particularly preferably provided. For example, the twenty rotor poles are realized by twenty permanent magnets.
[0022] In order to ensure, in particular, symmetrical running behavior of the rotor, a further embodiment of the motor provides that at least one further stator tooth of the first phase, in particular all remaining stator teeth of the first phase, are shortened in such a way that the flux linkage of the first phase is aligned with that of the other phases and symmetry is thus maintained. In particular, the shortened stator tooth is shorter in a longitudinal extent along the longitudinal axis than the stator teeth of at least one phase without an extended stator tooth. In particular, the stator teeth of a phase without an extended stator tooth have the same length. Preferably, all stator teeth of the second phase and the third phase are the same length, in particular longer than a shortened stator tooth and shorter than an extended stator tooth.
[0023] Preferably, an amount of the length of the extended stator tooth that the extended stator tooth is longer than the length of a stator tooth of a phase without an extended stator tooth is compensated for by a shortening of at least one stator tooth of the phase or of all stator teeth of the phase by a total of approximately the same amount. If, for example, the winding has six stator teeth per phase, each with three stator teeth arranged next to one another, it has proven advantageous if the middle stator tooth is designed as an extended stator tooth. It is further advantageous that at least one of the two adjacent teeth, preferably both adjacent stator teeth, is designed as shortened stator teeth. The shortened stator teeth are in particular shorter than the stator teeth of at least one phase in which no extended stator tooth is formed.Preferably, the two extended stator teeth of a phase are arranged opposite each other on the circumference. This advantageously ensures that the flux linkage of all three phases is equal.
[0024] According to a further embodiment of the motor, it has proven particularly advantageous if the extended stator tooth has, at its free end pointing toward the rotor, a shoulder region with an end face pointing toward the rotor. For example, a stator tooth, in particular the shoulder region, has a rectangular or square cross-section. The shoulder region is in particular formed integrally with the stator tooth or, alternatively, is attached to the stator tooth, for example, by a material bond, in order to extend the stator tooth.
[0025] The end face is advantageously concave and has a radius dimensioned such that an air gap of uniform extent is formed between the end face and an oppositely arranged rotor, i.e., the distance between the end face and the rotor, in particular the rotor poles, is constant. The curvature of the end face is thus adapted to the outer radius of the rotor, resulting in an overall air gap of uniform extent over the extension of the extended stator tooth. In particular, the attachment area protrudes from the stator coil of the extended stator tooth.
[0026] A further embodiment of the motor provides that the attachment region has at least two opposing side surfaces. The side surfaces are preferably arranged such that the side surfaces each extend in a plane parallel to the rotational axis of the motor. The side surfaces are inclined to a longitudinal axis L of the stator tooth running centrally through the stator tooth. The side surfaces preferably each have the same inclination. In particular, the side surfaces are inclined such that the side surfaces converge towards one another in the direction of the rotational axis. In particular, an angle α of between 5° and 30°, in particular approximately 10°, is formed between a side surface and the longitudinal axis L of the extended stator tooth. This inclination has a beneficial influence on the magnetic flux and thus on the cogging torque.For example, it is intended that the two side surfaces, each arranged in a plane intersected by the rotational axis at only one point, are also inclined. For example, the attachment area has a square cross-section that decreases in size toward the rotor.
[0027] According to a further advantageous embodiment of the motor, a transition between at least one side surface of the attachment region and an end face of the extended stator tooth oriented toward the rotor has at least one chamfer or a rounded portion. Preferably, the rounded portion has a radius of less than or equal to 2 mm. For example, the radius is between 0.05 mm and 2 mm. The chamfer or rounded portion also advantageously influences the magnetic flux within the stator tooth and thus the cogging torque.
[0028] It has proven particularly advantageous for motor assembly if, according to a further embodiment, the stator teeth are formed on at least one iron back plate, and the iron back plate extends out of a motor housing on at least one side to serve as a mounting flange for securing the motor. The iron back plate is advantageously designed as a laminated core.
[0029] Particularly preferably, the iron return spring extends out of a motor housing on at least two sides, in particular on two opposite sides, to serve as a mounting flange. Preferably, at least one, preferably two, recesses for screwing the motor are provided in each of the areas extending out of the motor housing. Extending the iron return spring out of the motor housing further has the advantage of reducing the overall size. Furthermore, heat is advantageously dissipated from the motor housing.
[0030] In particular, it has an advantageous effect on the size of the motor if, according to a further embodiment, at least one printed circuit board with components of the motor electronics is provided, and the printed circuit board serves as at least one housing surface or part of a motor housing, in particular as the rear of the housing. The stator coils are interconnected on the printed circuit board, for example. Furthermore, it is preferably provided that the rotary encoder, in particular the magnetic rotary encoder, is arranged at least partially on the printed circuit board. By using the printed circuit board, in particular a rear side, as at least one housing surface or part of a motor housing, in particular an outer surface of the motor housing, the installation space required for the motor, in particular a thickness of the motor, is reduced, so that the motor is advantageously flat.Preferably, the circuit board forms a motor cover on the back of a motor housing.
[0031] It has a beneficial effect on the manufacturing costs of the motor if, according to a further embodiment of the motor, at least one material is molded onto the iron back plate of the stator to form a motor housing. The molding takes place, for example, using a forming process, such as injection molding or an additive process, e.g., a 3D printing process. For example, at least one plastic is molded onto the iron back plate, with the plastic forming the motor housing. Molding onto the iron back plate is advantageous because it saves installation space and eliminates the need for complex assembly of a motor housing.
[0032] A further embodiment of the motor provides for at least two adjacent stator coils of a phase to be wound contiguously. Consequently, the stator coils are not wound directly onto the stator teeth, but rather wound externally in a "chain" of at least two stator coils. During assembly, the chain of stator coils is fanned out and pushed over adjacent stator teeth. Preferably, the adjacent coils of a phase are wound contiguously. For example, if a phase has six coils, three stator coils are wound contiguously and, in particular, pushed out onto the adjacent stator teeth after winding.
[0033] This design has the advantage of allowing for a simpler winding technique. Furthermore, the complexity of wiring the stator coils is reduced, as the continuous winding reduces the number of winding taps.
[0034] The above-mentioned object is further achieved by the use of a brushless motor according to one of the described embodiments for driving a conveyor belt, in particular for driving a component supply station of an automatic pick and place machine.
[0035] The invention is not limited to the illustrated and described embodiments, but also encompasses all equivalent embodiments within the meaning of the invention. It is expressly emphasized that the embodiments are not limited to all features in combination; rather, each individual partial feature can also have an inventive significance in itself, independently of all other partial features. Furthermore, the invention is not yet limited to the combination of features defined in claim 1, but can also be defined by any other combination of specific features of all the individual features disclosed as a whole. This means that, in principle, practically every individual feature of claim 1 can be omitted or replaced by at least one individual feature disclosed elsewhere in the application.
[0036] Further advantageous embodiments of the invention will become apparent from the following description of the figures and the dependent claims. They show:
[0037] Fig. 1 shows an embodiment of a motor according to the invention in a perspective exploded view, Fig. 2 shows the embodiment according to Fig. 1 in a partially assembled state in a plan view,
[0038] Fig. 2a is an enlargement of Fig. 2 in area A,
[0039] Fig. 3 is a section through the embodiment according to Fig. 1, and
[0040] Fig. 4 is a plan view of the rear side of the embodiment according to Fig. 1 in the assembled state.
[0041] In the various figures of the drawing, identical parts are always provided with the same reference symbols.
[0042] With regard to the following description, it is claimed that the invention is not limited to the exemplary embodiments and not to all or several features of described combinations of features, but rather each individual partial feature of the / each exemplary embodiment is also important for the subject matter of the invention, even independently of all other partial features described in connection therewith, and also in combination with any features of another exemplary embodiment.
[0043] Fig. 1 to Fig. 4 show an embodiment of a brushless motor 1. Fig. 1 shows the embodiment in a perspective exploded view, Fig. 2 in a partially assembled state in plan view, Fig. 2a shows an enlargement of Fig. 2 in the area A, Fig. 3 shows a section through the rotation axis R and Fig. 4 shows a plan view from the back of the motor 1.
[0044] 1 to 4, the motor 1 has a stator 2, a rotor 3, and a shaft 4. The shaft 4 is rotatably mounted within the stator 2, for example, as shown in FIG. 3, and the rotor 3 is fastened to the shaft 4. The rotor 3 has a plurality of permanent magnets 5 that form a plurality of magnetic rotor poles 5a. The permanent magnets 5 are arranged in a hub 17 of the rotor 3. The permanent magnets 5 are arranged in receiving pockets 18 in the hub 17. The receiving pockets 18 are evenly distributed over the circumference of the hub 17. The rotor 3 further has a first bearing 19, a second bearing 20, a bearing flange 21, and a rotor yoke 22. The stator 2 has a plurality of stator teeth 6 formed on an iron yoke 13. Each stator tooth 6 is at least partially wound with a stator coil 7, wherein the stator coils 7, in particular according to Fig. 2, form a winding 8 with three phases P1, P2, P3.
[0045] According to Fig. 2, a first phase P1 comprises six stator teeth 6, a second phase P2 comprises six stator teeth 6, and a third phase P3 also comprises six stator teeth 6. Three of the stator teeth 6 of each phase P1, P2, and P3 are arranged opposite one another on the circumference of the stator 2. The stator teeth 6 with the stator coils 7 are evenly distributed over the circumference of the stator 2.
[0046] According to the invention, two stator teeth 6a of the first phase P1 are designed as extended stator teeth 6a, which, with respect to their longitudinal extent along the longitudinal axis L - see in particular Fig. 2a - of a stator tooth 6, 6a, are longer than the remaining stator teeth 6b of the first phase P1. The two extended stator teeth 6, 6a are longer than all stator teeth of the second phase P2 and the third phase P3. All stator teeth 6 of the second phase P2 and the third phase P3 are of the same length.
[0047] In particular, according to Fig. 2 and the enlargement in Fig. 2a, the air gap 11 between a stator tooth 6, 6a and the opposite rotor 3 is locally reduced by the extended stator teeth 6a, whereby the rotor 3 is given a preferred or detent position at which a defined detent torque prevails. In this exemplary embodiment, the extended stator teeth 6a are arranged in the center between the two other stator teeth 6b of the first phase P1. The two extended stator teeth 6a of the first phase are arranged opposite one another on the circumference of the stator 2.
[0048] To ensure symmetrical running behavior of the rotor 3, the remaining stator teeth 6b of the first phase P1 are designed as shortened stator teeth 6, 6b. The shortened stator teeth 6, 6b are shorter than the stator teeth 6 of the second phase P2 and the third phase P3. The four shortened stator teeth 6, 6b are of equal length. This results in an advantageous locking position and advantageous symmetrical running behavior of the rotor 3. The extended stator teeth 6a have, for example according to Figs. 2 and 2a, a shoulder region 9 which is oriented in the direction of the rotor 3 and, in the case of the extended stator teeth 6, 6a, protrudes from the stator coil 7 in the direction of the rotor 3. The shoulder region 9 is formed integrally with the stator tooth 6, 6a, for example by being punched out as an extended stator tooth 6, 6a.
[0049] The attachment region 9 has an end face 10 pointing in the direction of the rotor 3, which is concavely curved in order to make the air gap 11 uniform over the extension of the extended stator tooth 6a to the rotor 3. The air gap 11 has a uniform extension across the width of the attachment region 9, and the end face 10 is at a constant distance from the rotor 3. Furthermore, two side faces 12 are formed on the attachment region 9, each of which is arranged in an imaginary plane to which the rotor axis R is parallel. The side faces 12 are inclined at an angle a of approximately 10° to the longitudinal axis L of the extended stator tooth 6, 6a. The longitudinal axis L is a radial to the axis of rotation R. In this exemplary embodiment, a chamfer (not shown in detail) is formed in both transitions 12a from the side faces 12 to the end face 10.
[0050] According to Figs. 1 to 4, the motor 1 has a magnetic yoke 13 on which the stator teeth 6 are formed. The magnetic yoke 13 is designed as a laminated core and extends from a motor housing 16 on two opposite sides. The regions of the magnetic yoke protruding from the motor housing 16 each form a mounting flange 14, each with two recesses 23 for securing the motor 1. The motor housing 16 is molded onto the magnetic yoke using a molding process, in this case, injection molding. The motor housing 16 is made of a plastic.
[0051] The motor housing 16 is closed at a front side, where the shaft 4 emerges from the motor housing 16, by a front motor cover 16a. At the rear of the motor housing 16, a printed circuit board 15 forms the rear housing part of the motor housing 16. The coils 7 are interconnected on the printed circuit board 15. A sensor chip 26 of the magnetic absolute rotary encoder - not shown in detail - is arranged on the printed circuit board 15. A magnetic ring 27 of the absolute rotary encoder, i.e. its measuring embodiment, is shown in Fig. 3. The magnetic ring 27 is fastened to the hub 17. According to Fig. 1 and Fig. 4, the printed circuit board 15 is screwed to the motor housing 16 with a plurality of screws 25. The front motor cover 16a is also screwed to the motor housing 16. Because the circuit board 15 forms the rear housing part of the motor housing 16, the overall height of the motor 1 can be significantly reduced.
[0052] The shaft 4 is supported by the first bearing 19 and the second bearing 20 via a bearing flange 21 in the motor housing 16. The bearing flange 21 is arranged in a recess in the front motor cover 16a. A pinion 24 is connected to the shaft 4 outside the motor housing 16. The pinion 24 serves to connect the motor 1 to an application.
[0053] Fig. 4 shows a rear view of the motor 1. The motor housing 16 is closed at the rear with the circuit board 15, which is screwed to the motor housing 16 with screws 25. The iron return 13 protrudes laterally from the motor housing 16 to serve as a mounting flange 14 for securing the motor 1 with two recesses 23 each.
[0054] The invention is not limited to the illustrated and described embodiments, but also encompasses all equivalent embodiments within the meaning of the invention. It is expressly emphasized that the embodiments are not limited to all features in combination; rather, each individual feature can also have an inventive significance in isolation from all other features. Furthermore, the invention is not yet limited to the combination of features defined in claim 1, but can also be defined by any other combination of specific features of all the individual features disclosed overall. This means that, in principle, practically every individual feature of claim 1 can be omitted or replaced by at least one individual feature disclosed elsewhere in the application.
[0055] 1 engine
[0056] 2 Stator
[0057] 3 Rotor
[0058] 4th wave
[0059] 5 Permanent magnet
[0060] 5a Rotor pole
[0061] 6 stator teeth
[0062] 6a Extended stator tooth
[0063] 6b Shortened stator tooth
[0064] 7 Stator coil
[0065] 8 windings
[0066] 9 Attachment area
[0067] 10 Frontal surface
[0068] 11 Air gap
[0069] 12 side surface
[0070] 12a transition
[0071] 13 Iron conclusion
[0072] 14 Mounting flange
[0073] 15 circuit board
[0074] 16 Engine housing
[0075] 16a Front engine cover
[0076] 17 Hub
[0077] 18 Recording pocket
[0078] 19 First Camp
[0079] 20 Second Camp
[0080] 21 Bearing flange
[0081] 22 Rotor yoke
[0082] 23 Recess
[0083] 24 pinions
[0084] 25 Screw 26 Sensor chip
[0085] 27 Magnetic ring a angle
[0086] L Longitudinal axis
[0087] R rotation axis
[0088] P1 First Phase
[0089] P2 Second Phase
[0090] P3 Third Phase
Claims
Claims 1. Motor (1), comprising at least one stator (2), at least one rotor (3), at least one shaft (4) and at least one winding (8), wherein the rotor (3) is fastened to the shaft (4), wherein the rotor (3) has at least one permanent magnet (5) with a plurality of magnetic rotor poles (5a), wherein the stator (2) has a plurality of stator teeth (6), wherein each stator tooth (6) is at least partially wound by at least one stator coil (7), and wherein the stator coils (7) supply the winding (8) with at least three phases (P1, P2.P3), characterized in that at least one stator tooth (6, 6a) of at least one first phase (P1) of the winding (8) is designed as an extended stator tooth (6, 6a), and in that the extended stator tooth (6, 6a) has a longitudinal extent in the radial direction which is greater than a longitudinal extent of at least one stator tooth (6, 6b) of remaining stator teeth (6, 6b) of the first phase (P1) and / or which is greater than a longitudinal extent of at least one stator tooth (6) of at least one of the remaining phases (P2, P3).
2. Motor (1) according to claim 1, characterized in that each phase (P1, P2, P3) of the winding (8) has at least or exactly two, at least or exactly four, at least or exactly six or at least or exactly eight stator teeth (6) with stator coil (7), that the stator teeth (6) of a phase (P1, P2, P3) are each arranged in pairs radially opposite one another, preferably that each of the phases (P1, P2, P3) has the same number of stator teeth (6) with stator coil (7).
3. Motor (1) according to claim 2, characterized in that each phase (P1, P2, P3) of the winding (8) has six stator teeth (6), so that three stator teeth (6) are arranged opposite one another, and in that the two middle stator teeth (6) of at least the first phase (P1) are designed as an extended stator tooth (6, 6a).
4. Motor (1) according to one of the preceding claims, characterized in that at least one further stator tooth (6) of the first phase (P1) is designed as a shortened stator tooth (6, 6b) in such a way that the rotor (3) as a whole has the most symmetrical running behavior possible, in particular that the shortened stator tooth (6, 6b) is shorter than stator teeth (6) of at least one phase (P2, P3) without an extended stator tooth (6, 6a).
5. Motor (1) according to one of the preceding claims, characterized in that the extended stator tooth (6, 6a) has, at its free end pointing in the direction of the rotor (3), a shoulder region (9) with an end face (10) pointing in the direction of the rotor (3), that the end face (10) is concave and has a radius, and that the radius is dimensioned such that an air gap (11) of uniform extent is formed between the end face (10) and an oppositely arranged rotor (3).
6. Motor (1) according to claim 5, characterized in that the extended stator tooth (6, 6a) has, at its free end pointing in the direction of the rotor (3), a shoulder region (9) with at least two opposite side surfaces (12), and in that the side surfaces (12) are inclined to a longitudinal axis (L) of the extended stator tooth (6, 6a), in particular that an angle (α) of between 5° and 30° is formed between a side surface (12) and the longitudinal axis (L) of the extended stator tooth (6, 6a).
7. Motor () according to claim 5 or 6, characterized in that a transition (12a) between at least one side surface (12) of the attachment region (9) and an end face (10) of the extended stator tooth (6, 6a) oriented in the direction of the rotor (3) has at least one chamfer or a rounding, preferably a rounding with a radius less than or equal to 2 mm, for example the radius is between 0.05 mm and 2 mm.
8. Motor (1) according to one of the preceding claims, characterized in that the stator teeth (6) are formed on at least one iron back plate (13), and that the iron back plate (13) is led out of a motor housing (16) on at least one side in order to serve as a mounting flange (14) for fastening the motor (1), in particular that the iron back plate (13) is designed as a laminated core.
9. Motor (1) according to one of the preceding claims, characterized in that at least one printed circuit board (15), in particular with components of the motor electronics, is present, and that the printed circuit board (15) serves as at least one housing surface of a motor housing (16), in particular as the rear side of the motor housing (16).
10. Motor (1) according to one of the preceding claims, characterized in that at least one material is molded onto an iron return (13) of the stator (2) in order to form a motor housing, in particular that the material is at least one plastic.
11. Motor (1) according to one of the preceding claims, characterized in that at least two, in particular at least or exactly three, stator coils (7) of one phase (P1, P2, P3) arranged next to one another are wound together, in particular that the stator coils (7) have been pushed together onto stator teeth (6) arranged next to one another after winding.
12. Use of a brushless motor (1) according to one of the preceding claims for driving a component supply station of an automatic pick and place machine.