Permanent magnet synchronous motor with flux collectors with multiple pole sections

Abstract

Synchronous motor (10), in particular a permanent magnet synchronous motor, with a stator (12) and a rotor (30) arranged to rotate relative to the stator (12) about an axis of rotation (32), wherein the stator (12) has at least one coil (14) wound around a core for generating a moving magnetic traveling field, wherein the core of the at least one coil (14) has a first flux collector (22) for guiding the magnetic flux towards or away from the rotor (30) and a second flux collector (24) for guiding the magnetic flux away from or towards the rotor (30), and wherein the rotor (30) has magnetic poles arranged around the axis of rotation (32) which interact with the traveling field generated by the at least one coil (14), characterized in that the second flux collector (24) has at least two pole sections (46) facing the rotor (30), and that the first flux collector (22) has a pole section (38) which is arranged between the two pole sections (46) of the second flux collector (24).

Description

[0001] The invention relates to a synchronous motor, in particular a permanent magnet synchronous motor with a stator and a rotor arranged to rotate relative to the stator about a rotational axis, wherein the stator has at least one coil wound around a core to generate a moving magnetic traveling field, wherein the core of the at least one coil has a first flux collector for guiding the magnetic flux towards or away from the rotor and a second flux collector for guiding the magnetic flux away from or towards the rotor, wherein the rotor has magnetic poles arranged around the rotational axis which interact with the traveling field generated by the at least one coil.

[0002] Such motors with multiple coils and associated flux collectors are used primarily as servo motors, actuators, stepper motors, or drive motors. The rotor's magnetic field is combined with the moving rotating or traveling field of the stator in such a way that the rotor is pulled "forward" a certain distance by the traveling field and repelled "from behind." Once the rotor has reached a certain position to which it was pulled or pushed, the traveling field continues to rotate, so that a pole formed by the traveling field pushes the rotor, or rather its magnetic poles, away from this position and attracts it to the next pole of the traveling field.

[0003] It has been shown that such motors, if they are sufficiently large, have a corresponding number of poles and can thus generate correspondingly high torques. However, if the motors are to be built relatively small, especially as miniature motors, achieving a sufficient number of poles is problematic. A comparatively small number of poles results in comparatively low torque.

[0004] A synchronous motor with a permanent magnet rotor is known from US 2007 / 0138898A1.

[0005] The invention is based on the object of providing a synchronous motor as mentioned above, which is comparatively small in size and yet provides a sufficiently high torque.

[0006] This problem is solved by a synchronous motor having the features of patent claim 1.

[0007] The invention therefore provides that the first flux collector has at least two pole sections facing the rotor or the second flux collector has at least two pole sections facing the rotor, and that the second flux collector or the first flux collector has at least one pole section which is arranged between the two pole sections of the other flux collector.

[0008] This makes it possible to provide multiple pole sections via a flux collector in a comparatively small installation space, with the pole sections of the other flux collector being provided between the pole sections of one flux collector. Although only two flux collectors are provided, multiple pole sections can be provided. Due to the higher number of pole sections, the magnetic flux ultimately flows through smaller or shorter magnetic circuits, thus providing increased torque.

[0009] It is advantageous if the first flux collector has at least two pole sections facing the rotor, and if the second flux collector has at least two pole sections facing the rotor, with at least one pole section of one flux collector being arranged between two pole sections of the other flux collector. Overall, this further increases the number of pole sections.

[0010] Advantageously, two or more coils are provided, each with two flux collectors and associated pole sections, and the pole sections of the respective flux collectors are arranged such that no pole sections associated with another coil are provided between the pole sections associated with one coil. The pole sections of one flux collector of one coil therefore interact exclusively with the pole sections of the other flux collector of the same coil. This also makes it possible to create shorter magnetic circuits, while overall providing increased torque. The flux collectors of the different coils can each cover an angular range of the rotor; with three coils, for example, three angular ranges of less than 120° can be covered by the flux collectors of each coil.

[0011] It is advantageous if the pole sections each have a free end facing the rotor, with the end faces of the pole sections being arranged along a circular path around the rotor. The magnetic flux can then flow toward or away from the rotor via the respective end faces.

[0012] It is advantageous if the first flux collector has three pole sections, with two adjacent pole sections arranged equidistantly. The magnetic flux of the flux collector is thus spread out into the three pole sections or combined from the three pole sections, whose end faces are directed toward the rotor.

[0013] The first flux collector of a coil can extend over an angle in the range of 60° to 120°, and preferably in the range of 90°. This angle range is advantageous when a three-phase synchronous motor is to be provided.

[0014] It can be provided that the respective adjacent pole sections of the first flux collector enclose an angle in the range of 40° to 60°, and preferably in the range of 45°. The respective first flux collector, which preferably extends over a total of 90°, then has the three pole sections, with the adjacent pole sections each enclosing an angle of 45°.

[0015] Preferably, the second flux collector of each coil has two pole sections, with the two pole sections of the second flux collector then being arranged between two adjacent pole sections of the first flux collector. Such "alternating interlocking" of the pole sections allows a sufficient number of different pole sections to be provided in a small installation space.

[0016] It is advantageous if the two pole sections of the second flux collector enclose an angle in the range of 40° to 60° and preferably an angle in the range of 45°.

[0017] Furthermore, it is advantageous if the pole sections of the first flux collector form an angle in the range of 10° to 25°, and preferably in the range of 15°, with the pole sections of the second flux collector. Such an offset of the pole sections of the first flux collector and the second flux collector can provide an advantageous magnetic traveling field for driving the rotor.

[0018] Furthermore, it is advantageous if the pole sections extend over the entire axial extent of the rotor. In this context, it is advantageous if the first flux collector has a bridging section that runs axially alongside the rotor and opens into the pole sections, and if the second flux collector has a bridging section that runs axially alongside the rotor on the side of the rotor facing away from the bridging section of the first flux collector and opens into the pole sections of the second flux collector. Such a design allows the magnetic flux generated by the coil to be guided to the pole sections in a favorable manner via the respective flux collectors.

[0019] To provide a 2-phase motor, it is advantageous to use two coils, each with first flux collectors and associated pole sections, and each with second flux collectors and associated pole sections. According to the invention, it is particularly advantageous to use three coils, each with first flux collectors and associated pole sections, and each with second flux collectors and associated pole sections, to form a 3-phase motor. The individual phases can then be controlled accordingly to rotate the rotor.

[0020] It is also advantageous if four coils, each with first flux collectors and associated pole sections, and each with second flux collectors and associated pole sections, are provided to form a three-phase motor, with two coils with flux collectors and associated pole sections forming the third phase. The third phase is thus divided into two coils with associated flux collectors and pole sections. This allows for a space-saving three-phase motor.

[0021] To further optimize installation space, the coil axes can be arranged parallel to the rotor's rotational axis and / or perpendicular to the rotor's rotational axis. It is conceivable that the coil of one phase is arranged parallel to the rotor's rotational axis, and the coil of another phase is arranged perpendicular to the rotor's rotational axis.

[0022] A further advantageous embodiment results when the rotor and the coils with the flux collectors occupy a cuboid-shaped installation space with a narrow central longitudinal plane, with the rotor's rotational axis arranged in the region of the central longitudinal plane and the coils arranged on the side of the rotor facing away from the central longitudinal plane. This makes it possible to provide a space-saving, slim-line synchronous motor in which no coils are provided in the region of the central longitudinal plane.

[0023] It is also advantageous if the rotor has teeth arranged on a circular path around an axis of rotation and permanent magnets arranged between the teeth.

[0024] Further details and embodiments of the invention can be found in the following description, on the basis of which an embodiment of the invention is described and explained in more detail.

[0025] They show: Fig. 1 a plan view of a synchronous motor; Fig. 2 the bottom view of the synchronous motor according to Fig. 1; Fig. 3 the rotor of the synchronous motor according to Fig. 1 with first river collectors; Fig. 4 the rotor of the synchronous motor according to Fig. 1 with second river collectors; Fig. 5 the rotor of the synchronous motor according to Fig. 1 with a first and a second river collector; Fig. 6 the top view of the rotor of the synchronous motor according to Fig. 1 with first and second river collectors; Fig. 7 the synchronous motor according to Fig. 1 with a different rotor.

[0026] In the Fig. 1 and Fig. 2 shows a permanent-magnet synchronous motor 10. The synchronous motor 10 has a stator 12 with coils 14, wherein in the embodiment shown, a total of coils 14.1, 14.2, 14.3, and 14.4 are provided. Each of the coils 14.1, 14.2, 14.3, and 14.4 is assigned first flux collectors 22 and second flux collectors 24, wherein—corresponding to the number of coils—a total of four first flux collectors 22.1, 22.2, 22.3, 22.4 and four second flux collectors 24.1, 24.2, 24.3, 24.4 are provided, which are intended to conduct the magnetic flux generated by the coils 14.1, 14.2, 14.3, and 14.4 toward a rotor 30 or away from the rotor 30. The rotor 30, which is mounted so as to be rotatable about the rotational axis 32, has, in the Fig. 1, the rotor has teeth 34 arranged around the rotational axis 32 and permanent magnets 36 arranged in a star shape around the rotational axis between adjacent teeth to form rotor-side magnetic poles.

[0027] While in the top view according to Fig. 1 the second river collectors 24.1, 24.2, 24.3, 24.4 are clearly visible, are shown in the bottom view according to Fig. 2 the first river collectors 22.1, 22.2, 22.3, 22.4 are clearly visible.

[0028] In the Fig. 3 only the first flux collectors 22.1, 22.2, 22.3, 22.4 are shown together with the rotor 30, while in the Fig. 4 only the second flux collectors 24.1, 24.2, 24.3, 24.4 are shown with the rotor 30. As can be seen from the Fig. 3, the first flux collectors 22.1, 22.2 each have three pole sections 38 facing the rotor 30, wherein the two flux collectors 22.3 and 22.4 each form a pole section 38. The individual pole sections 38 are designed like webs parallel to the axis of rotation 32 and extend over the entire axial extent of the rotor 30. The pole sections 38 each have a free end face 40 facing the rotor 30, wherein the individual end faces 40 of the pole sections 38 extend along a circular path 42 running around the rotor 30, which in Fig. 6 is indicated by dashed lines.

[0029] From the Fig. 4 clearly shows that the flux collectors 24.1, 24.2, 24.3, and 24.2 each form two pole sections 46. The pole sections 46 of the flux collectors 24.1 to 24.4 also extend over the axial extent of the rotor 30.

[0030] In the Fig. 5, the rotor 30 together with the first flux collector 22.1 and the second flux collector 24.1 is without the Fig. 1, the coil 14.1 is shown, in whose core the two flux collectors 22.1 and 24.1 engage. It is clear that a pole section 46 of the second flux collector 24.1 is provided between each two adjacent pole sections 38 of the first flux collector 22.1. Accordingly, a pole section 38 of the first flux collector 22.1 is provided between the adjacent pole sections 46 of the second flux collector 24.1.

[0031] Since the flux collectors 22.2 and 24.2 are designed similarly to the flux collectors 22.1 and 24.1, a pole section 46 of the second flux collector 24.2 is also provided between two pole sections 38 of the first flux collector 22.2. In the flux collectors 22.3 and 24.3, as well as 22.4 and 24.4, the design is such that one pole section 38 of the flux collectors 22.3 and 22.4 is provided between two pole sections 46 of the flux collectors 24.3 and 24.4.

[0032] As can be seen from the top view according to Fig. 6, the first flux collectors 22.1 and 22.2 each extend over an angle α of approximately 90°, with the adjacent pole sections 38 of the first flux collectors 22.1 and 22.2 each arranged equidistant from one another and each enclosing an angle β of approximately 45° with respect to the rotation axis 32. Accordingly, the adjacent pole sections 46 of the second flux collectors 24.1, 24.2, 24.3, 24.4 enclose an angle γ of approximately 45°. The pole sections 38 each enclose an angle δ of approximately 15° with the nearest pole sections 46. By suitable selection of the angles, the arrangement of the magnets 36 on the rotor 30 and by appropriate control of the coils 14, the magnetic flux introduced by the flux collectors 22, 24 leads to the desired rotation of the rotor 30.

[0033] As further stated Fig. As is clear from Figure 6, between the pole sections 38, 46 of the flux collectors 22 and 24 of each coil 14.1, 14.2, 14.3, 14.4, no pole sections 38, 46 are provided that are assigned to the flux collectors 22, 24 of another coil 14.1, 14.2, 14.3, 14.4. Consequently, a magnetic flux is introduced into or discharged from the rotor 30 via each of the coils 14.1, 14.2, 14.3, 14.4, independently of the magnetic fluxes of the other coils 14.1, 14.2, 14.3, 14.4.

[0034] The first flux collectors 22.1, 22.2, 22.3, 22.4 each have a bridging section 48 which is arranged axially next to the rotor 30, and in Fig. 3 above the rotor 30. Accordingly, the second flux collectors 24.1, 24.2, 24.3, 24.4 have bridging sections 44 that extend axially adjacent to the rotor 30 on the side of the rotor 30 facing away from the bridging sections 44.

[0035] The one in the Fig. The synchronous motor 10 shown in Figures 1 to 6 is further configured such that a first phase is introduced via the coil 14.1 and the associated flux collectors 22.1, 24.1, and a second phase is introduced via the coil 14.2 and the associated flux collectors 22.2 and 24.2 to rotate the rotor 30. A third phase is distributed between the coils 14.3 and 14.4 and is introduced via the associated flux collectors 22.3, 24.3, 22.4, and 24.4.

[0036] By dividing the third phase between the two coils 14.3 and 14.4, the synchronous motor 10 can be built comparatively small and narrow. As can be seen from the Fig. 1 to 6, the rotor 30 and the coils 14 with the flux collectors 22 and 24 occupy a cuboid-shaped space, which has a Fig. 2 has a narrow central longitudinal plane E. As can be seen from Fig. 2, the axis of rotation 32 lies in the central longitudinal plane E. The two coils 14.2 and 14.3 lie on one side of the rotor 30 facing away from the central longitudinal plane E and the coils 14.1, 14.4 lie on the other side of the rotor 30 facing away from the central longitudinal axis.

[0037] As further shown for example in Fig. 2, the axes of the coils 14.1 and 14.2 run parallel to the axis of rotation 32 and the axes of the coils 14.3 and 14.4 run perpendicular to the axis of rotation 32 of the rotor 30.

[0038] In the Fig. 7 shows another synchronous motor 10, which is connected to the synchronous motor 10 according to the Fig. 1 to 6, wherein the rotor 30 has magnets 36 which are circular in shape and extend concentrically around the axis of rotation 32.

Claims

[1] Synchronous motor (10), in particular a permanent magnet synchronous motor, with a stator (12) and a rotor (30) arranged to rotate relative to the stator (12) about an axis of rotation (32), wherein the stator (12) has at least one coil (14) wound around a core for generating a moving magnetic traveling field, wherein the core of the at least one coil (14) has a first flux collector (22) for guiding the magnetic flux towards or away from the rotor (30) and a second flux collector (24) for guiding the magnetic flux away from or towards the rotor (30), and wherein the rotor (30) has magnetic poles arranged around the axis of rotation (32) which interact with the traveling field generated by the at least one coil (14), characterized by that the second flux collector (24) has at least two pole sections (46) facing the rotor (30), and that the first flux collector (22) has a pole section (38) which is arranged between the two pole sections (46) of the second flux collector (24). [2] Synchronous motor (10) according to claim 1, characterized by that the first flux collector (22) has at least two pole sections (38) facing the rotor (30), wherein at least one pole section (46) of the second flux collector (24) is arranged between two pole sections (38) of the first flux collector (22). [3] Synchronous motor (10) according to claim 1, characterized by that two or more coils (14.1, 14.2, 14.3, 14.4) with flux collectors (22, 24) and associated pole sections (38, 46) are provided and that the pole sections (38, 46) associated with a coil (14) are arranged such that no pole sections (38, 46) associated with another coil (14) are provided between the pole sections (38, 46) associated with a coil (14). [4] Synchronous motor (10) according to claim 1 or 2, characterized bythat the pole sections (38, 46) each have a free end face (40) facing the rotor (30), wherein the end faces (40) of the pole sections (38, 46) are arranged along a circular path (42) running around the rotor (30). [5] Synchronous motor (10) according to claim 1, 2 or 3, characterized by that the first flux collector (22.1, 22.2) has three pole sections (46), wherein two adjacent pole sections (46) are arranged equidistantly. [6] Synchronous motor (10) according to one of the preceding claims, characterized by that the first flux collector (22.1, 22.2) extends over an angle α in the range of 60° and 120° and preferably in the range of 90°. [7] Synchronous motor (10) according to one of the preceding claims, characterized by that the respective adjacent pole sections of the first flux collector (22.1, 22.2) enclose an angle in the range of 40° to 60° and preferably in the range of 45°. [8] Synchronous motor (10) according to one of the preceding claims, characterized by that the second flux collector (24.1, 24.2, 24.3, 24.4) has two pole sections (46), wherein both pole sections (46) of the second flux collector (24.1, 24.2, 24.3, 24.4) are arranged between two adjacent pole sections (38) of the first flux collector (22.1, 22.2, 22.3, 22.4). [9] Synchronous motor (10) according to claim 7, characterized by that the two pole sections of the second flux collector (24.1, 24.2, 24.3, 24.4) enclose an angle in the range of 40° to 60° and preferably in the range of 45°. [10] Synchronous motor (10) according to one of the preceding claims, characterized by that the pole sections of the first flux collector (22.1, 22.2, 22.3, 22.4) enclose an angle in the range of 10° to 25° and preferably in the range of 15° with the nearest pole sections of the second flux collector (24.1, 24.2, 24.3, 24.4). [11] Synchronous motor (10) according to one of the preceding claims, characterized by that the first flux collector (22.1, 22.2, 22.3, 22.4) has a bridging section (46) which runs axially next to the rotor (30) and that the second flux collector (24.1, 24.2, 24.3, 24.4) has a bridging section (44) which runs axially next to the rotor (30) on the side of the rotor (30) facing away from the bridging section of the first flux collector (22.1, 22.2, 22.3, 22.4). [12] Synchronous motor (10) according to one of the preceding claims, characterized bythat two coils (14), each with first flux collectors (22) and associated pole sections (38) and each with second flux collectors (24) and associated pole sections (46), are provided to form a 2-phase motor; or that at least three coils (14), each with first flux collectors (22) and associated pole sections (38) and each with second flux collectors (24) and associated pole sections (46), are provided to form a 3-phase motor. [13] Synchronous motor (10) according to one of the preceding claims, characterized by in that four coils (14.1, 14.2, 14.3, 14.4), each with first flux collectors (22.1, 22.2, 22.3, 22.4) and associated pole sections (38) and each with second flux collectors (24.1, 24.2, 24.3, 24.4) and associated pole sections (46) are provided to form a 3-phase motor, wherein two coils (14.3, 14.4) with flux collectors (22.3, 22.4; 24.3, 24.4) and associated pole sections (38, 46) form the third phase. [14] Synchronous motor (10) according to one of the preceding claims, characterized by that the coil axes are arranged parallel to the axis of rotation (32) of the rotor (30) and / or perpendicular to the axis of rotation (32) of the rotor (30). [15] Synchronous motor (10) according to one of the preceding claims, characterized by that the rotor (30) and the coils (14) with the flux collectors (22, 24) occupy a cuboid-shaped installation space with a narrow central longitudinal plane (E), wherein the axis of rotation (32) of the rotor (30) is arranged to run in the region of the central longitudinal plane (E) and the coils (14) are arranged on the sides of the rotor (30) facing away from the central longitudinal plane (E).

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