Permanently excited DC motor for a drive device for adjusting a vehicle assembly

Abstract

Permanently excited DC motor (20) for a drive device for adjusting a vehicle assembly, with a stator (203) having a plurality of stator magnets (207, 207A, 207B) distributed around a motor axis (M), and a rotor (204) rotatable about the motor axis (M) relative to the stator (203), which rotor has a plurality of rotor poles (205) and rotor windings (206) arranged on the rotor poles (205), characterized in that side edges (209) of the stator magnets (207, 207A, 207B) are aligned obliquely to the motor axis (M) and / or that a first group of stator magnets (207, 207A, 207B) distributed around the motor axis (M) and a second group of stator magnets (207, 207A, 207B) distributed around the motor axis (M) and axially offset to the first group have an angular offset (β) around the motor axis (M) relative to one another.

Description

[0001] The invention relates to a permanent magnet DC motor for a drive device for adjusting a vehicle assembly according to the preamble of claim 1. The invention also relates to a door drive device.

[0002] Such a permanent-magnet DC motor comprises a stator having a plurality of stator magnets distributed around a motor axis, and a rotor rotatable about the motor axis relative to the stator, which rotor has a plurality of rotor poles and rotor windings arranged at the rotor poles. The stator magnets permanently excite the DC motor, meaning it has an excitation field generated at the stator by the stator magnets. By feeding a direct current into the rotor windings arranged at the rotor poles, a torque is generated at the rotor during operation, causing the rotor to rotate around the motor axis.

[0003] Such a permanent-magnet DC motor can be used, in particular, in a door drive device for adjusting a vehicle door, in particular a vehicle side door or a tailgate. However, such a permanent-magnet DC motor can also be used in other drive devices for adjusting a vehicle assembly, for example, in a vehicle interior.

[0004] A permanent-magnet DC motor of the type in question here can be used, in particular, as a small drive in a drive device. When used in a vehicle, there is a fundamental need for low-noise operation. The acoustics of a permanent-magnet DC motor are determined in particular by the magnetic reaction of the rotor, known as cogging torque or pole sensitivity. The change in the air gap when changing from rotor pole to rotor slot relative to a stator magnet varies the magnetic resistance and thus the force acting on the stator, which can contribute to noise generation during operation.

[0005] It is therefore desirable to keep the cogging torque of a permanent magnet DC motor as low as possible. However, this should not, if possible, result in increased costs or more complex manufacturing and assembly.

[0006] One design of a door drive device is known, for example, from WO 2021 / 023893 A1.

[0007] The object of the present invention is to provide a permanent magnet DC motor for use in a drive device for adjusting a vehicle assembly, which enables favorable acoustic behavior while still being simple to manufacture and assemble and which can also be manufactured cost-effectively.

[0008] This object is achieved by an article having the features of claim 1.

[0009] Accordingly, side edges of the stator magnets are aligned obliquely to the motor axis and / or a first group of stator magnets distributed around the motor axis and a second group of stator magnets distributed around the motor axis, axially offset to the first group, have an angular offset around the motor axis relative to each other.

[0010] To reduce the cogging torque in a permanent-magnet DC motor, the present proposal is to stator magnets or to provide them with an axial angular offset relative to each other in groups. This ensures that the magnetic interaction of the stator magnets, viewed axially along the motor axis, is not uniform. Rather, at different axial positions, a different interaction occurs between the rotor poles with the rotor windings arranged thereon, on the one hand, and the stator magnets, on the other.

[0011] This can be achieved in different ways.

[0012] For example, the stator magnets can be offset such that the side edges of the stator magnets are aligned obliquely to the motor axis and thus not parallel to the motor axis. Each stator magnet is defined by two side edges facing away from each other (with respect to a circumferential direction around the motor axis), each of which points toward an adjacent stator magnet. These side edges are not aligned parallel to the motor axis, but obliquely to it, resulting in a varying interaction axially along the motor axis between the rotor poles with the rotor windings arranged thereon and the stator magnets formed by permanent magnets.

[0013] In another embodiment, the side edges can each be aligned parallel to the motor axis. However, the stator magnets are angularly offset from one another in groups such that a first group of stator magnets distributed around the motor axis has an angular offset relative to a second group of stator magnets distributed around the motor axis, which is axially offset from the first group. A stator magnet of the first group and a stator magnet of the second group are therefore not axially aligned with one another, but are angularly offset relative to one another in pairs. Accordingly, the stator magnets are not axially aligned with one another, but are offset from one another along a circumferential direction around the motor axis.

[0014] In this configuration, two or more groups can be present. For example, three, four, or more groups of stator magnets can also be present, each of which has several stator magnets distributed around the motor axis and which are angularly offset relative to one another.

[0015] A set and a group-wise angular offset can also be combined. For example, stator magnets in different groups can each have side edges aligned at an angle to the motor axis, and the stator magnets in different, axially offset groups can also exhibit an angular offset relative to each other.

[0016] In one embodiment, the side edges of each stator magnet, viewed along a shell plane extending circumferentially around the motor axis, are aligned at a set angle relative to an axis running axially along the shell plane and parallel to the motor axis. The side edges of each stator magnet are thus not aligned parallel to the motor axis, but obliquely to an axis parallel to the motor axis and running along the shell plane. The set angle is measured along the shell plane and can be, for example, greater than 0° and less than 45°, for example in a range between 10° and 40°, for example between 15° and 25°. The set angle can in particular be selected such that, with the set stator magnets, viewed along a circumferential direction around the motor axis, an advantageous coverage of the circumference by the stator magnets can be achieved while also making the stator magnets easier to manufacture.

[0017] In a configuration with multiple groups of stator magnets, the angular offset is measured along a circumferential plane extending around the motor axis. The angular offset is measured, for example, between associated side edges of axially adjacent stator magnets and can be greater than 0° and less than 45°, for example, in a range between 10° and 40°, for example, between 15° and 25°.

[0018] In one embodiment, the stator magnets, when projected onto a projection plane perpendicular to the motor axis, each cover an overlap angle of less than or equal to 120°. For example, if four stator magnets are provided circumferentially distributed around the motor axis, each stator magnet can cover an overlap angle of less than or equal to 120° in the projection plane. Such a design of the stator magnets can be particularly advantageous for simple and cost-effective production, for example, by sintering.

[0019] In one embodiment, adjacent stator magnets overlap when viewed in the projection plane. If the stator magnets are projected onto the projection plane (perpendicular to the motor axis), the stator magnets are therefore not spatially separated from one another in the projection plane, but rather overlap. Adjacent stator magnets generally have opposite polarization, with the stator magnets pointing towards the rotor with different poles. In a transition region between the adjacent stator magnets, viewed in the axial direction, a field change occurs due to the superposition, caused by the fact that in one axial region one stator magnet acts and points towards the rotor, and in another axial region the other stator magnet acts and points towards the rotor.

[0020] In one embodiment, the stator has at least four stator magnets distributed around the motor axis. Particularly with offset stator magnets, four or more stator magnets can be grouped and evenly distributed around the motor axis, with the stator magnets each having obliquely aligned side edges.

[0021] In a configuration with multiple groups of stator magnets, each group of stator magnets can have four stator magnets distributed around the motor axis. Each group of stator magnets is thus assigned at least four stator magnets, with the different groups of stator magnets being angularly offset relative to one another.

[0022] In a configuration with multiple groups of stator magnets, the stator magnets of the first group have a first axial length, and the stator magnets of the second group have a second axial length that differs from the first axial length. In this way, a pitch of the stator magnets can be used in the axial direction that deviates from an equal pitch. For example, the stator magnets can be pitched in a ratio of 1 / 3 to 2 / 3 or 1 / 4 to 3 / 4 in the axial direction, although other pitch ratios are also conceivable and possible.

[0023] If more than two groups of stator magnets are provided, the stator magnets of each group can have a different axial length. It is also possible, for example, for the stator magnets in two groups to have the same axial length, but the stator magnets in a third group to have a different axial length.

[0024] The following applies to designs with offset stator magnets as well as designs with several groups of stator magnets offset at an angle to one another.

[0025] In one embodiment, the stator magnets are formed by magnetic shells curved around the motor axis. The stator magnets are curved, in particular, along the shell plane extending circumferentially around the motor axis and concentric with the motor axis, so that the stator magnets have a curvature that is adapted to the curvature of the shell plane. The stator magnets thus form permanent magnet shells. Such magnetic shells can have slanted side edges or can be arranged in several groups axially offset from one another and thereby with an angular offset relative to one another.

[0026] In one embodiment, the stator magnets are manufactured by sintering. Sintering is a process for producing metal or ceramic parts in which a fine- or coarse-grained green body is created by pressing a powdered starting material, which is then solidified into a solid workpiece by subsequent heat treatment. Sintering produces the stator magnets as a single piece, although the stator magnets are preferably produced individually and thus separately from one another.

[0027] In other embodiments, the stator magnets can be manufactured by plastic injection molding or an additive process, for example 3D printing.

[0028] In one embodiment, the stator magnets are made of a ferrite material. The stator magnets form permanent magnets. Ferrite magnets, preferably produced by sintering, are used for the stator magnets. Such ferrite magnets are inexpensive to manufacture and can be flexibly formed into a desired shape, in particular a curved shell shape, by sintering.

[0029] In one embodiment, the stator magnets are designed as separate elements. Each stator magnet is thus manufactured as a single piece, but separately from another stator magnet. This further simplifies production. Each stator magnet is attached to a stator body of the stator and is thus firmly attached to the stator body in a normal operating state.

[0030] The stator magnets are, for example, glued to the stator body and thus secured to the stator body. Additionally or alternatively, fastening elements in the form of spring elements can be used, for example, to secure the stator magnets to the stator body.

[0031] In one embodiment, the rotor body comprises a rotor body manufactured in one piece by sintering. While individual laminations are typically joined together to manufacture the rotor, thus forming the rotor from a stack of laminations joined together, the present proposal is to sinter the rotor from one piece. A soft magnetic material, in particular an iron material, is preferably used as the material.

[0032] In one embodiment, slots that run between the rotor poles and in which the rotor windings are accommodated are aligned parallel to the motor axis. The rotor poles protrude radially from the rotor body. Slots are arranged between the rotor poles, which separate the rotor poles from one another, viewed along a circumferential direction around the motor axis, and provide a space in which a winding wire is accommodated to form a respective rotor winding. The rotor windings are wound around the rotor poles and thus lie in the slots between the rotor poles. The fact that the slots extend axially parallel to the motor axis results in a simple design of the rotor, particularly compared to obliquely running slots. A reduction in the cogging torque is achieved here by the obliquely aligned side edges of the stator magnets or by the angular offset between axially offset groups of stator magnets.

[0033] Because the slots are aligned parallel to the motor axis, a simple winding process is also achieved for winding a winding wire around each rotor pole to form a rotor winding. Therefore, no adjustment to the manufacturing process with regard to attaching the rotor windings to the rotor poles, and accordingly, no adjustment to the winding machine, is required.

[0034] In one embodiment, the rotor has a commutator, and the stator has an arrangement of brushes that interact with the commutator in a sliding manner to feed a direct current into the rotor windings. The brushes are in sliding contact with the commutator, whereby – in a conventional manner – different contacts of the commutator are supplied with a current depending on the rotational position of the rotor, and thus different rotor windings are supplied with a direct current depending on the rotational position of the rotor. The commutator, in conjunction with the brushes, causes a current reversal during electrical operation of the DC motor.

[0035] In one embodiment, a door drive device for adjusting a vehicle door comprises a permanently excited DC motor of the type described above.

[0036] The vehicle door can be formed, for example, by a vehicle side door, such as a front or rear vehicle side door. However, the vehicle door can also be formed by a tailgate of a vehicle.

[0037] Such a door drive device can, in particular, be configured as a spindle drive, in that the door drive device comprises a spindle rotatable about a longitudinal axis and a push rod. The permanent-magnet DC motor is operatively connected to the spindle. During operation, the spindle is driven by the permanent-magnet DC motor and can be rotated about the longitudinal axis, thereby moving the push rod relative to the spindle to adjust the vehicle door.

[0038] For example, the door drive device is arranged on the side of the vehicle door. In particular, the DC motor can be attached to the vehicle door. The push rod, which is longitudinally adjustable via the rotatable spindle, is coupled to the vehicle body, so that adjusting the push rod can cause a relative movement between the vehicle door and the vehicle body, thus introducing an adjusting force into the vehicle door for adjustment relative to the vehicle body.

[0039] In one embodiment, the assembly comprises a spindle nut element for moving the push rod. The spindle nut element is threadedly connected to the spindle such that, by rotating the spindle, the spindle nut element can be moved along the longitudinal axis relative to the spindle. The spindle has an external thread and engages with a threaded opening of the spindle nut element such that, due to the threaded connection, the spindle nut element is adjusted longitudinally along the longitudinal axis on the spindle when the spindle is rotated.

[0040] In one embodiment, the push rod is connected to the spindle nut element in an articulated manner. The push rod can, in particular, be connected to the spindle nut element in an articulated manner about a joint axis perpendicular to the longitudinal axis, so that the position of the push rod can be adjusted during operation about the longitudinal axis relative to the spindle nut element.

[0041] In one embodiment, the assembly includes a guide rail for guiding the spindle nut element. The spindle nut element is guided longitudinally along the door drive device via the guide rail. When the spindle is rotated, the spindle nut element is not rotated along with it, but is moved longitudinally along the guide rail, thereby adjusting the push rod and creating an adjusting force between the vehicle door and the vehicle body.

[0042] The concept underlying the invention will be explained in more detail below with reference to the exemplary embodiments illustrated in the figures. They show: Fig. 1 is a schematic view of a vehicle door on a vehicle body; Fig. 2 a view of an embodiment of a door drive device for adjusting the vehicle door relative to the vehicle body, in an extended position of a push rod; Fig. 3 another view of the door drive device; Fig. 4 a view of the door drive device, without a guide rail; Fig. 5 another view of the arrangement according to Fig. 4; Fig. 6 a view of the door drive device (without the guide rail), in a retracted position of the push rod; Fig. 7 a schematic view of a permanent magnet DC motor; Fig. 8 a schematic principle view of a permanent magnet DC motor; Fig. 9 is a partial sectional view of an embodiment of a permanent magnet DC motor with offset stator magnets; Fig. 10 is a schematic projection view of a permanent magnet DC motor of conventional design with non-rotated stator magnets; Fig. 11 is a schematic projection view of a permanent magnet DC motor with offset stator magnets; Fig. 12 a separate view of a stator magnet formed by a magnetic shell; Fig. 13 a view of a stator; Fig. 14 is a front view of a stator magnet; Fig. 15 a sectional view through a permanent magnet DC motor along the line AA according to Fig. 13; Fig. 16 is a view of another embodiment of a permanent magnet DC motor with two axially offset groups of stator magnets; and Fig. 17 is a schematic view illustrating an angular offset between stator magnets of the two groups according to Fig. 16.

[0043] Fig. 1 shows a schematic view of a section of a vehicle 1 having a vehicle body 10 and a vehicle door 11 arranged on the vehicle body 10 so as to be pivotable about a hinge axis 114.

[0044] The vehicle door 11 is pivotable about the hinge axis 114 relative to the vehicle body 10 in order to close an opening in the vehicle body 10 in a closed position or to release it in an open position, so that a user can enter or exit the vehicle 1. The vehicle door 11 can in particular be a front vehicle side door or a rear vehicle side door.

[0045] The vehicle door 11 has an outer door panel 110 and an inner door panel 113, which together with a door module 111 fastened to the inner door panel 113 defines a door box that encloses a door interior 112.

[0046] In the illustrated embodiment, a door drive device 2 is arranged within the vehicle door 11, which is designed for the electric motor-assisted adjustment of the vehicle door 11 relative to the vehicle body 10 or at least for the electric motor-assisted, manual adjustment of the vehicle door 11 relative to the vehicle body 10.

[0047] In the illustrated embodiment, the door drive device 2 has a motor 20 implemented by a permanent magnet DC motor and a push rod 21 which can be adjusted by the motor 20 in order to thereby produce an adjusting force between the vehicle door 11 and the vehicle body 10.

[0048] Fig. 2-6 show views of an embodiment of a door drive device 2 configured for adjusting a vehicle door 11 relative to a vehicle body 10. The door drive device 2 comprises a motor 20 implemented by a permanent magnet DC motor, a push rod 21, an adapter element 22, a guide rail 23, a spindle 24, a gear 25, a control device 26, and a housing assembly 28 implementing a gear housing.

[0049] The spindle 24 extends longitudinally along a longitudinal axis L and is rotatable relative to the housing assembly 28 about the longitudinal axis L. For example, a gear wheel in the form of a spur gear of the gear 25 is connected in a rotationally fixed manner to the spindle 24. A drive worm arranged on a motor shaft of the motor 20 is in toothed engagement with the gear wheel such that by rotating the motor shaft with the drive worm arranged thereon, the gear wheel can be rotated about the longitudinal axis L and thus the spindle 24 can be set into a rotational movement about the longitudinal axis L.

[0050] A spindle nut element 27 is arranged on the spindle 24 and has a spindle nut section 271 and a sliding section 270. The spindle nut element 27 is guided in the guide rail 23 via the sliding section 270. The spindle nut section 271 forms a threaded opening through which the spindle 24 extends and which is in threaded engagement with an external thread 240 of the spindle 24. The threaded engagement is such that upon a rotational movement of the spindle 24 about the longitudinal axis L, the spindle nut element 27 is adjusted longitudinally along the longitudinal axis L on the spindle 24.

[0051] The push rod 21 is pivotally connected to the spindle nut element 27 at one end 211. At an end remote from the end 211, the push rod 21 is pivotally connected to a connecting element 210, via which the push rod 21 (when the door drive device 2 is arranged on the vehicle door 11) can be connected to the vehicle body 10, so that the push rod 21, in the ready-to-operate state in a vehicle 1, is supported between the vehicle door 11 on the one hand and the vehicle body 10 on the other hand, and by moving the spindle nut element 27 and by correspondingly moving the push rod 21, the vehicle door 11 can be moved relative to the vehicle body 10.

[0052] Fig. 2-5 show the door drive device 2 with the push rod 21 in an extended position in which the spindle nut element 27 is approached to the housing assembly 28 and the push rod 21 is extended accordingly in an adjustment direction V.

[0053] Fig. 6, in contrast, shows the push rod 21 in a retracted position in which the spindle nut element 27 is removed from the housing assembly 28 opposite to the adjustment direction V and the push rod 21 is correspondingly retracted into the guide rail 23.

[0054] The push rod 21 extends through an opening 220 in the adapter element 22 and can be moved by moving the spindle nut element 27 relative to the adapter element 22.

[0055] The guide rail 23 is connected to the adapter element 22. For this purpose, the guide rail 23 can be fixed to the adapter element 22 via a mounting bracket 230 (see Fig. 6) be fastened, in particular screwed, to the adapter element 22, so that the guide rail 23 is fixed relative to the adapter element 22.

[0056] In addition, the housing assembly 28 is attached to the adapter element 22. The housing assembly 28 forms a motor interface to which the motor 20 is attached, for example, by screwing the motor 20 to the housing assembly 28.

[0057] The adapter element 22 serves to connect the door drive device 2, in the illustrated embodiment, to the vehicle door 11. For this purpose, fastening elements 221 in the form of screws are arranged on the adapter element 22, via which the adapter element 22 can be screwed to the inner door panel 113 on the inside of the door box enclosed by the vehicle door 11.

[0058] The control device 26 serves to control the door drive device 2 during operation. For example, the control device 26, which may have electronics for this purpose, can process sensor signals for detecting a motor movement and a motor position and thus for detecting a position or movement of the push rod 21.

[0059] In a Fig. In the schematically illustrated embodiment of a permanent-magnet DC motor 20 in Figure 7—particularly for use in a door drive device 2, as described above—a stator 203 is arranged stationary, for example, relative to the housing assembly 28 of the door drive device 2. A motor shaft 200 is rotatably mounted about a motor axis M. A rotor 204 rotates in the stator 203. Also arranged on the motor shaft 200 is a commutator 201, which is in sliding contact with brushes 202 of a brush system such that an electrical direct current can be fed into the commutator 201 via the brushes 202 and, via this, into rotor windings at rotor poles of the rotor 204.

[0060] Fig. Figure 8 shows a schematic diagram of such a permanent magnet DC motor 20. Rotor poles 205 are formed on a rotor body 204A of the rotor 204, which are radially aligned with respect to the motor axis M and project radially outward from the rotor body 204A. Rotor windings 206 are arranged on the rotor poles 205, which, during operation, are supplied with a direct current in a current-inverting manner controlled by the commutator 201.

[0061] During operation, the commutator 201 rotates together with the rotor 204 and is in sliding contact with brushes 202 which are arranged stationary relative to the stator 203.

[0062] In the illustrated embodiment, the rotor 204 rotates within the stator 203. Stator magnets 207 in the form of permanent magnets are arranged on a stator body 203A, so that permanent excitation is effected on the stator 203 by the excitation field of the stator magnets 207.

[0063] The stator magnets 207 point alternately with different poles towards the rotor 204, so that, viewed along a circumferential direction around the motor axis M, a permanent magnetic excitation field alternating in its polarization is provided on the stator 203 for interaction with a magnetic field generated by the rotor windings 206 during operation on the rotor 204.

[0064] During operation, the motor 20 generates noise, particularly due to a so-called cogging torque, which is caused by a changing magnetic resistance between the stator 203 and the rotor 204 with the rotor poles 205 arranged thereon during a rotational movement of the rotor 204. For low-noise operation, it is desirable to keep such a cogging torque as small as possible.

[0065] For this reason, it is proposed in one aspect to use stator magnets 207 in a permanent magnet DC motor 20 for use in particular in a door drive device 2 for adjusting a vehicle door 11, the side edges 209 of which are aligned obliquely to the motor axis M, as is clear from Fig. 9 can be seen.

[0066] The side edges 209 laterally delimit each stator magnet 207. Because the side edges 209 are not aligned along an axis M' parallel to the motor axis M, but rather obliquely thereto at a set angle γ, each stator magnet 207 is not aligned linearly parallel to the motor axis M, but rather has a set angle relative to the motor axis M.

[0067] This results in the stator magnets 207 being more Fig. 10, can each cover a larger angular range, relative to a projection onto a projection plane perpendicular to the motor axis M, as shown in Fig. 11. Thus, the stator magnets 207 can, in the projection, be closely adjacent to one another (relative to a circumferential direction around the motor axis M) or even overlap.

[0068] Such a twist of the stator magnets 207 results in the magnetic conditions on the stator 203 changing axially along the motor axis M. In this way, upon rotation of the rotor 204, the position of the rotor pole 205 on the rotor slot 208 relative to a stator magnet 207 does not change sharply at a discrete angle of rotation, but rather in a range of angles of rotation determined by the twist of the stator magnets 207.

[0069] The stator magnets 207 can in particular each be manufactured as separate components in one piece, for example by sintering.

[0070] The stator magnets 207 each have the shape of a magnetic shell, as shown in a spatial representation in Fig. 12 is shown.

[0071] Each stator magnet 207 can, in particular, be made of a ferrite material by sintering. This results in simple production even when the stator magnets 207 are shaped as magnetic shells curved in an arc around the motor axis M.

[0072] Fig. 13 shows a view into a stator 203 with stator magnets 207 arranged on the stator body 203A. The stator magnets 207 are formed by separate elements and are each fastened to the stator body 203A, for example by gluing the stator magnets 207 to the stator body 203A.

[0073] How this Fig. 9, the side edges 209 of each stator magnet 207 are aligned at an angle γ to an axis M' parallel to the motor axis M. The stator magnets 207 are arranged in a row along a circumferential plane ME, which extends concentrically to the motor axis M around the motor axis M, and are curved with respect to the circumferential plane ME. On an inner surface facing the motor axis M, the stator magnets 207 each have a radius R, for example with a value in a range between 10 mm and 20 mm, for example between 13 mm and 16 mm.

[0074] In cross-section at a specific axial position, each stator magnet 207 describes how Fig. 14, an angle α1, for example in a range between 40° and 80°, for example between 60° and 70°. However, due to the oblique orientation of the side edges 209, the respective stator magnet 207 covers an overlap angle α2 in its projection that is significantly larger than the angle α1, for example in a range between 50° and 120°, for example between 80° and 100°. The angle α3 corresponds to the overlap angle α2 minus the angle α1 and describes the angle with respect to the motor axis M over which each oblique side edge 209 extends.

[0075] An overlap angle α2 <= 120° is particularly advantageous for sintering production. This ensures a favorable pressure distribution across the entire workpiece during sintering, i.e., during the compression of the sintered material, which is originally in powder form.

[0076] Fig. 15 shows a sectional view along the line AA according to Fig. 13. It can be seen that, due to the twist, the stator magnets 207 can extend in a certain axial region but not in another axial region, so that a varying magnetization results axially along the motor axis M, in particular in the region of the side edges 209 of the stator magnets 207.

[0077] In the illustrated embodiment, a total of four stator magnets 207 are present on the stator 203, distributed around the motor axis M. However, more than four stator magnets 207 can also be used.

[0078] The rotor 204, for example, is manufactured from one piece by sintering.

[0079] In the illustrated embodiment, the rotor 204 has six rotor poles 205 with rotor windings 206 arranged thereon. However, a different number of rotor poles 205 with rotor windings 206 arranged thereon may also be present.

[0080] In the illustrated embodiment, the rotor poles 205 are aligned radially to the motor axis M on the rotor body 204A. The grooves 208 formed between the rotor poles 205 are aligned axially along the motor axis M. This results in a simple shape of the rotor 204, in which, in particular, the rotor windings 206 can be easily wound on the rotor poles 205 by conventional winding methods using conventional winding machines.

[0081] According to another, additional or alternative aspect, as in Fig. 16 and Fig. 17, there may be several groups of stator magnets 207A, 207B which are axially offset from one another and have an angular offset β about the motor axis M relative to one another.

[0082] In the illustrated embodiment, each group of stator magnets 207A, 207B has a plurality of stator magnets 207A, 207B distributed circumferentially around the motor axis M, for example four or more stator magnets 207A, 207B each.

[0083] The stator magnets 207A, 207B of the two groups can have different axial lengths L1, L2. In the axial direction, the stator magnets 207A, 207B are therefore not necessarily evenly distributed. For example, the length ratio of the lengths L1, L2 of the stator magnets 207A of one group and the stator magnets 207B of the other group can be 1 / 3 to 2 / 3 or 1 / 4 to 3 / 4. Other pitch ratios are also possible.

[0084] Fig. Figure 17 illustrates in a schematic view the angular offset β between the different groups of stator magnets 207A, 207B. The angular offset β is measured between the side edges 209 of two axially offset stator magnets 207A, 207B that are adjacent to each other in the circumferential direction.

[0085] The measures according to Fig. 9-15 and Fig. 16, Fig. 17 can also be combined with each other. Thus, several groups of stator magnets 207A, 207B, as in the embodiment according to Fig. 16 and Fig. 17, which are axially offset from one another and also have an angular offset β relative to one another about the motor axis M. In addition, the stator magnets 207A, 207B of each group can be offset by extending the side edges 209 of the stator magnets 207A, 207B obliquely to the motor axis M.

[0086] The idea underlying the invention is not limited to the embodiments described above, but can also be implemented in other ways.

[0087] A permanent-magnet DC motor of the type described above can advantageously be used in a door drive device for adjusting a vehicle door, in particular a vehicle side door. However, such a DC motor can also be used to adjust another vehicle assembly in or on a vehicle, for example, in the vehicle interior. List of reference symbols 1 vehicle 10 Vehicle body 11 Vehicle door 110 outer door panel 111 Door module 112 Door interior 113 inner door panel 114 Hinge axis 2 door drive device 20 Permanent magnet DC motor 200 Motor shaft 201 Commutator 202 Brush arrangement 203 Stator 203A Stator body 204 Rotor 204A rotor body 205 rotor poles 206 rotor windings 207, 207A, 207B stator magnets 208 grooves 209 side edges 21 Push rod 210 connecting element 211 End 22 Adapter element 220 opening 221 fasteners 23 Guide rail 230 mounting brackets 24 spindle 240 threads 25 gearboxes 26 Control unit 27 Spindle nut element 270 sliding section 271 Spindle nut section 28 Housing assembly α1, α2, α3, β angles γ set angle L Longitudinal axis L1, L2 length M motor axle M' Axis parallel to the motor axis ME shell level R radius V Adjustment direction QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This 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

[0000] WO 2021 / 023893 A1

[0006]

Claims

[1] Permanently excited DC motor (20) for a drive device for adjusting a vehicle assembly, with a stator (203) having a plurality of stator magnets (207, 207A, 207B) distributed around a motor axis (M), and a rotor (204) rotatable about the motor axis (M) relative to the stator (203), which rotor has a plurality of rotor poles (205) and rotor windings (206) arranged on the rotor poles (205), characterized by that side edges (209) of the stator magnets (207, 207A, 207B) are aligned obliquely to the motor axis (M) and / or that a first group of stator magnets (207, 207A, 207B) distributed around the motor axis (M) and a second group of stator magnets (207, 207A, 207B) distributed around the motor axis (M) and axially offset to the first group have an angular offset (β) around the motor axis (M) relative to one another. [2] Permanent magnet DC motor (20) according to claim 1, characterized by that the end edges (209) of each stator magnet (207, 207A, 207B), viewed along a jacket plane (ME) extending circumferentially around the motor axis (M), are aligned at a set angle (y) relative to an axis (M') running axially along the jacket plane (ME) and parallel to the motor axis (M). [3] Permanent magnet DC motor (20) according to claim 2, characterized by that the set angle (y) is greater than 0° and less than 45°. [4] Permanent magnet DC motor (20) according to one of claims 1 to 3, characterized by that the stator magnets (207, 207A, 207B), in a projection onto a projection plane perpendicular to the motor axis (M), each cover an overlap angle (α2) which is less than or equal to 120°. [5] Permanent magnet DC motor (20) according to claim 4, characterized bythat adjacent stator magnets (207, 207A, 207B), viewed in the projection plane, overlap each other. [6] Permanent magnet DC motor (20) according to one of the preceding claims, characterized by that the stator has at least four stator magnets (207, 207A, 207B) distributed around the motor axis (M) or that the first group of stator magnets (207A) and the second group of stator magnets (207B) each have four stator magnets (207, 207A, 207B) distributed around the motor axis (M). [7] Permanent magnet DC motor (20) according to one of the preceding claims, characterized by that the stator magnets (207, 207A, 207B) of the first group have a first axial length (L1) and the stator magnets (207, 207A, 207B) of the second group have a second axial length (L2) different from the first axial length (L1). [8] Permanent magnet DC motor (20) according to one of the preceding claims, characterized bythat the stator magnets (207, 207A, 207B) are formed by magnetic shells curved around the motor axis (M). [9] Permanent magnet DC motor (20) according to one of the preceding claims, characterized by that the stator magnets (207, 207A, 207B) are manufactured by sintering, plastic injection molding or 3D printing. [10] Permanent magnet DC motor (20) according to one of the preceding claims, characterized by that the stator magnets (207, 207A, 207B) are made of a ferrite material. [11] Permanent magnet DC motor (20) according to one of the preceding claims, characterized by that the stator magnets (207, 207A, 207B) are designed as separate elements and are each attached to a stator body (203A) of the stator (203). [12] Permanent magnet DC motor (20) according to claim 11, characterized by that the stator magnets (207, 207A, 207B) are glued to the stator body (203A). [13] Permanent magnet DC motor (20) according to one of the preceding claims, characterized by that the rotor (204) has a rotor body (203A) which is manufactured in one piece by sintering. [14] Permanent magnet DC motor (20) according to one of the preceding claims, characterized by that slots (208) which run between the rotor poles (205) and in which the rotor windings (206) are accommodated are aligned parallel to the motor axis (M). [15] Permanent magnet DC motor (20) according to one of the preceding claims, characterized by that the rotor (204) has a commutator (201) and the stator (203) has an arrangement of brushes (202) which interact in a sliding manner with the commutator (201) for feeding a direct current into the rotor windings (206). [16] Door drive device (2) for adjusting a vehicle door (11) with a permanently excited DC motor (20) according to one of the preceding claims. [17] Door drive device (2) according to claim 16, characterized by a spindle (24) rotatable about a longitudinal axis (L) and a push rod (21), wherein the permanent-magnet DC motor (20) is operatively connected to the spindle (24) and the spindle (24) is driven by the permanent-magnet DC motor (20) and can be rotated about the longitudinal axis (L) in order to move the push rod (21) to adjust the vehicle door (11). [18] Door drive device (2) according to claim 17, characterized by a spindle nut element (27) for moving the push rod (21), wherein the spindle nut element (27) is threadedly connected to the spindle (24) such that by rotating the spindle (24) the spindle nut element (27) is movable along the longitudinal axis (L) relative to the spindle (24). [19] Door drive device (2) according to claim 18, characterized by that the push rod (21) is articulated to the spindle nut element (27). [20] Door drive device (2) according to claim 18 or 19, characterized by a guide rail (23) for guiding the spindle nut element (27).

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