Rotor armature stator excitation AC synchronous motor

Abstract

The alternating-current synchronous motor comprises a stator shell and a rotor, the stator shell is arranged on the ground, the rotor is arranged in the stator shell through an end cover and an insulating bearing, the rotor comprises a rotating shaft and a rotor iron core, the rotor iron core is arranged on the rotating shaft, and a tooth groove set is formed in the rotor iron core in a concave mode. The tooth groove group is composed of a plurality of adjacent tooth grooves, and the windings are arranged in the tooth grooves. The motor has the advantages that the relative positions of the stator and the rotor tooth grooves are collected through the rotor position sensor, the current of the three-phase alternating current and rated torque input are collected through the current sensor, the magnitude of the current of the three-phase synchronous alternating current is controlled, the torque of the motor is controlled, and winding arrangement is optimized, so that the reliability of the motor is improved. In the working process, the magnetic potential direction of the rotor is perpendicular to the magnetic potential direction of the stator at any position, then the maximum torque under the current is output, and meanwhile, the stator permanent magnet cannot be demagnetized due to the change of the magnetic field of the rotor.

Description

Technical Field

[0001] This invention specifically relates to an AC synchronous motor with rotor armature and stator excitation. Background Technology

[0002] A three-phase AC synchronous motor is a type of motor that requires three-phase AC power. Because three-phase permanent magnet synchronous motors have the good characteristic of maintaining a constant speed even when the power supply voltage fluctuates or the load torque changes, they are widely used in driving mechanical equipment that does not require speed regulation and has high power. In current three-phase permanent magnet synchronous motors, the torque is determined not only by the armature current but also by the angle difference between the armature and the excitation magnetic field poles. However, the angle difference between the poles makes it relatively difficult to control the torque of the synchronous motor. Furthermore, when the excitation magnetic field is a permanent magnet, if the armature and excitation magnetic field poles are not perpendicular to each other, the permanent magnet will demagnetize, which is even more detrimental to controlling the torque of the synchronous motor. Therefore, a motor that can keep the armature and excitation magnetic field poles perpendicular at all times and facilitate the control of the torque of the synchronous motor is needed. Summary of the Invention

[0003] The technical problem to be solved by the present invention is that the angle between the excitation magnetic field and the magnetic pole of the existing three-phase permanent magnet synchronous motor is difficult to control to be perpendicular to each other, the permanent magnet is prone to demagnetization and the motor torque control is inconvenient.

[0004] To address the aforementioned technical problems, an AC synchronous motor with rotor armature and stator excitation is proposed. This is achieved through the following technical solution: An AC synchronous motor with rotor armature and stator excitation includes a stator housing and a rotor. The stator housing is mounted on the ground via a base. The rotor is mounted inside the stator housing via end caps at both ends and insulating bearings. A rotor position sensor is mounted on the rotor shaft. The rotor includes a shaft and a rotor core. The rotor core is mounted on the shaft. A set of toothed slots is recessed perpendicular to the arc-shaped surface of the rotor core. The set of toothed slots consists of multiple adjacent slots, and windings are disposed within the slots.

[0005] In this invention, by collecting the relative position of the stator and rotor slots and the current of the three-phase AC power, the current and synchronous frequency of the three-phase synchronous AC power supplied to the rotor are controlled, thereby controlling the torque of the motor at different speeds. At the same time, through the optimization of the winding arrangement, the direction of the rotor's magnetomotive force is perpendicular to the direction of the stator's magnetomotive force at any position during operation, thereby outputting the maximum torque under this current. At the same time, the stator permanent magnet will not demagnetize due to changes in the rotor's magnetic field.

[0006] In a preferred embodiment of the present invention, the depths of two adjacent slots within the slot group are different, and the angle between two adjacent slots within the slot group varies regularly with the number of turns of the winding in the first slot within the slot group. The different depths of two adjacent slots within the slot group allow the slot to accommodate the corresponding number of turns thickness, thus avoiding the generation of excess air gap leakage flux. The regularly varying number of turns in the winding within the slot ensures that when any turn in the slot on the rotor rotates to the point of maximum stator excitation flux density, the same maximum torque can be output.

[0007] In a preferred embodiment of the technical solution of the present invention, the main features of the rotor, the number of turns of the first slot winding with the most turns and the minimum number of turns of the slot winding with the fewest turns are calculated by the following formula: In the formula: b——The minimum number of turns in the winding with the fewest turns in the cogging group; a——Number of turns of the winding in the first tooth slot within the tooth group; Where a > b.

[0008] In a preferred embodiment of the technical solution of the present invention, the main feature of the rotor is that the angle between the first slot with the most winding turns in the slot group and the slot between the maximum and minimum number of winding turns is calculated by the following formula: In the formula: β—The angle between the first tooth in the tooth group and the tooth with the corresponding number of turns c in the winding; a——Number of turns of the winding in the first tooth slot within the tooth group; c—The actual number of turns selected in the winding within the toothed group; When two phase windings are contained within the same slot, the ratio of the number of turns between the phase with more turns and the phase with fewer turns is calculated using the following formula: x∶y=sin(120°+β)∶sin(β) In the formula: x — Phase with more turns; y — the phase with fewer turns; β—The angle between the first tooth groove in the tooth groove group and the tooth groove itself.

[0009] In a preferred embodiment of the present invention, the windings include a W-phase winding, a U-phase winding, and a V-phase winding. The windings are arranged in slots, and there are at most two types of windings in the same slot. This arrangement ensures that when one slot rotates to the N-pole side of the stator excitation magnetic field, the opposite slot must be located on the S-pole side of the stator excitation magnetic field, and the currents are opposite, thereby outputting torque.

[0010] In a preferred embodiment of the present invention, multiple slots are uniformly arranged on the rotor core within a 360° range along the rotor core axis. This arrangement optimizes the winding layout, so that when any turn on the rotor rotates to the point where the stator excitation flux density is the largest, the same maximum torque can be output.

[0011] In a preferred embodiment of the present invention, the rotor position sensor is mounted on the rotating shaft. The rotor position sensor monitors the relative position of each slot on the rotor core with the magnetic pole of the permanent magnet on the stator. This arrangement facilitates monitoring the position of the rotor core through the rotor position sensor, thereby enabling effective control of the current and synchronization frequency of the three-phase synchronous AC power supplied to the rotor, making it convenient to use.

[0012] In a preferred embodiment of the present invention, the stator housing includes end caps and a housing. Two end caps are respectively disposed at both ends of the housing. Permanent magnets with the same number of magnetic poles as the rotor are disposed inside the housing and on the inner side of the end caps. This arrangement facilitates the complete coverage of the rotor winding area by the magnetic potential of the permanent magnets, thereby improving torque and making the device convenient to use.

[0013] The beneficial effects of this invention compared to the prior art are: The technical solution of this invention uses a rotor position sensor to collect the relative position of the stator and rotor slots, controls the frequency of the three-phase synchronous AC current supplied to the rotor, and uses a current sensor to collect the current and rated torque input of the three-phase AC current, controls the magnitude of the current supplied to the rotor, and thus controls the motor torque. Furthermore, by optimizing the winding arrangement, the direction of the rotor's armature magnetomotive force is perpendicular to the direction of the stator excitation magnetomotive force at any position during operation, thereby outputting the maximum torque under that current. At the same time, the stator permanent magnet will not demagnetize due to changes in the rotor's magnetic field. Attached Figure Description

[0014] Figure 1 This is a three-dimensional schematic diagram of the present invention; Figure 2 This is a three-dimensional schematic diagram of the rotor; Figure 3 This is a cross-sectional view of the rotor; Figure 4 for Figure 3 Enlarged view of point A in the middle; Figure 5 for Figure 3 Enlarged view at point B in the middle; Figure 6 for Figure 3 Enlarged view at point C; Figure 7 This is a cross-sectional view of the present invention; Figure 8 This is an exploded view of the present invention; Explanation of reference numerals in the attached drawings: 1-Stator housing, 11-End cover, 12-Casing, 13-Base, 14-Permanent magnet, 15-Insulated bearing, 2-Rotor, 21-Shaft, 22-Rotor core, 23-Rotor position sensor, 24-Groove group, 25-Winding, 26-Groove, 27-W-phase winding, 28-U-phase winding, 29-V-phase winding. Detailed Implementation

[0015] The following will refer to the appendices in the embodiments of the present invention. Figure 1-8 The technical solutions in the embodiments of the present invention will be described in detail below. Example 1

[0016] like Figure 1 , 7 As shown in Figure 8, an AC synchronous motor with rotor armature and stator excitation includes a stator housing 1 and a rotor 2.

[0017] The stator housing 1 includes an end cover 11, a housing 12, and a base 13. The housing 12 is a cylindrical hollow metal shell with openings at both ends. The rotor 2 is installed inside the housing 12. To facilitate heat dissipation, multiple heat dissipation fins are provided on the outer surface of the housing 12 along the axial direction of the housing 12. On the arc-shaped surface of the housing 12, a base 13 is welded perpendicular to the arc-shaped surface along the extension direction of the housing 12. A circular through hole is opened on the base 13, through which the housing 12 can be fixed to the mounting surface.

[0018] A permanent magnet 14 is provided on the inner wall of the housing 12 along the inner wall contour. The permanent magnet 14 and the housing 12 form an excitation stator. The rotor 2 is inserted into the housing 12 and fixed by the end cover 11.

[0019] The end cover 11 is a circular metal cover. There are two end covers 11, which are fixed to both ends of the housing 12 by screws. Permanent magnets 14 with the same number of magnetic poles as the rotor 2 are provided on the inner side wall of the end cover 11. This arrangement makes it easier to cover the area where the rotor coils are located with the permanent magnets as completely as possible, thereby improving the torque. At the same time, in order to facilitate the installation of the rotor 2, the inner diameter of the end cover 11 is larger than the outer diameter of the rotor shaft 21 on the rotor 2. This arrangement makes it easier to fix the rotor shaft 21 on the end cover 11 by means of the insulating bearing 15, so that the rotor 2 can rotate around the axis of the insulating bearing 15 on the end cover 11.

[0020] like Figure 2 , 3 As shown in Figures 4, 5, 6 and 7, the rotor 2 includes a rotating shaft 21 and a rotor core 22, with the rotor core 22 fixed on the rotating shaft 21.

[0021] The rotating shaft 21 is a cylindrical metal rod. A rotor position sensor 23 is installed at one end of the rotating shaft 21. The rotor position sensor 23 includes a Hall sensor set on the end cover 11 at this end and a magnetic head gear set on the rotating shaft 21 at this end. The number of teeth of the magnetic head gear is the same as the number of tooth slots 26 on the rotor core 22, and each tooth on each rotor position sensor 23 corresponds to the tooth slot 26. In this way, the relative position of the stator and the tooth slots 26 on the rotor 2 can be collected by the rotor position sensor 23 composed of the Hall sensor and the magnetic head gear, and the frequency of the three-phase synchronous AC power supplied to the rotor can be controlled. Then, the current of the three-phase AC power and the rated torque input are collected by the current sensor, and the magnitude of the three-phase synchronous AC power supplied to the rotor can be controlled, thereby controlling the motor torque.

[0022] Both the rotor position sensor 23 and the current sensor are existing devices, which are technologies known to those skilled in the art and can be used directly.

[0023] Three three-phase copper conductors are fixed at the other end of the shaft 21, and three-phase brushes are installed on the end cover 11 at this end. The three-phase AC current is introduced into the rotor coil by sliding contact between the three-phase brushes and the three three-phase copper conductors on the shaft 21.

[0024] On the rotor core 22, a plurality of sets of tooth slots 24 are recessed inward along the extension direction of the rotor core 22, perpendicular to the arc surface of the rotor core 22, and a winding 25 is wound in the tooth slots 24.

[0025] Multiple sets of toothed slots 24 are uniformly arranged on the rotor core 22 within a radial range of 360°. In this embodiment, it is preferred that there are 6 sets of toothed slots 24, each set consisting of multiple slots 26. In this embodiment, each set of toothed slots 24 preferably includes 6 slots 26, and the concave depth of each pair of adjacent slots 26 on the rotor core 22 is different. The concave depth of the slot 26 is determined by the number of turns of the winding 25 within that slot. The different depths of two adjacent slots 26 within the toothed slot set 24 make... The toothed slot 26 can accommodate the thickness of the corresponding number of turns to avoid the generation of excess air gap leakage flux. The regular variation of the number of winding turns in the toothed slot 26 ensures that when any turn in the toothed slot 26 of the rotor 2 rotates to the point where the stator excitation flux density is the largest, the same maximum torque can be output. At the same time, it also ensures that the magnetomotive force direction of the rotor 2 is perpendicular to the stator magnetomotive force direction at any position during operation, so that the permanent magnet 14 on the stator will not demagnetize due to the change of the magnetic field of the rotor 2, thus improving the service life of the motor.

[0026] Regarding the depth arrangement of the slots 26 within each slot group 24, in this embodiment, 6 slot groups 24 are set within a 360° range. Therefore, each slot group 24 occupies an angle of 60°, meaning that there is exactly one slot group 24 within every 60° range starting from 0°. Each slot group 24 includes 6 slots 26. In the clockwise direction on the end face of the rotor core 22, the first slot 26 within the slot group 24 has the deepest depth, and this slot 26 is named the 0° slot 26. The fourth slot 26 has the shallowest depth. The depth of the second slot 26 is less than the depth of the 0° slot 26, the depth of the third slot 26 is less than the depth of the second slot 26, the depth of the fourth slot 26 is less than the depth of the third slot 26, the depth of the second slot 26 is the same as the depth of the sixth slot 26, and the depth of the third slot 26 is the same as the depth of the fifth slot 26.

[0027] The depth of the slot 26 is related to the number of windings 25. The more windings 25 there are (or the thicker they are), the deeper the slot 26 will be.

[0028] The winding 25 includes a W-phase winding 27, a U-phase winding 28, and a V-phase winding 39. One end of the W-phase winding 27, the U-phase winding 28, and the V-phase winding 39 are respectively connected to three three-phase copper conductors on the rotating shaft 21, and the other end passes through the slot 26 and is connected to one of the other two phases. Only one type of winding 25 with a maximum of two phases can be set in one slot 26.

[0029] Taking a rotor with a single magnetic pole pair as an example, the relationship between the number of turns of the winding 25 in the 0° slot 26 with the most turns in the inner winding 25 of the slot group 24 and the minimum number of turns of the winding 25 in the inner winding 25 of the slot group 24 with the fewest turns is calculated by the following formula:

[0030] In the formula: b——The minimum number of turns in the inner winding 25 of the inner winding 25 of the inner winding 26 of the inner winding 25 of the inner winding 24; a——Number of turns of winding 25 within 0° tooth groove 26 of tooth group 24; Where a > b; The winding 25 in the 0° slot 26 has the most turns. For example, when the winding 25 in the 0° slot 26 has 100 turns, then according to the above formula, the winding 25 in the slot 26 (the fourth slot 26 in this embodiment) has the fewest turns, which is at least 86.6 (one decimal place). In addition, since the number of turns should be an integer, the actual number of turns c of the winding 25 in the fourth slot 26 should be a value between 86.6 and 100, which can be selected according to the requirements, for example, 87. At this time, the number of turns in the second slot 26 adjacent to the 0° slot 26 should be within the range of the number of turns in the fourth slot 26 and the 0° slot 26, that is, the number of turns d of the winding in the second slot 26 should meet the condition c < d < a, that is, d should be a value between 100 and 87, which can be selected according to the requirements, for example, 96.

[0031] The number of windings in the third slot 26 adjacent to the second slot 26 is within the range of the number of turns in the fourth slot 26 and the second slot 26. That is, the number of turns e in the third slot 26 should meet the condition c < e < d, that is, e should be a value in the range of 96 and 87, which can be selected according to the requirements, for example, 92.

[0032] Since the 0° slot 26 in the slot group 24 has the deepest depth and the fourth slot 26 has the shallowest depth, and the depth of the second slot 26 is the same as the depth of the sixth slot 26, and the depth of the third slot 26 is the same as the depth of the fifth slot 26, and since the depth of the slot 26 is related to the number of turns of the winding, the number of turns in the second slot 26 is the same as the number of turns in the sixth slot 26, and the number of turns in the third slot 26 is the same as the number of turns in the fifth slot 26. Thus, the number of turns in all slots 26 in one slot group 24 has been determined.

[0033] To calculate the angles between multiple slots 26 within the slot group 24, taking a single-pole pair rotor as an example, the angle between the 0° slot 26 with the most turns of the winding 25 and the slot 26 between the maximum and minimum turns of the winding 25 within the slot group 24 is calculated using the following formula:

[0034] In the formula: β—The angle between the first tooth 26 in the tooth group 24 and the tooth 26 of the winding 25 with the corresponding number of turns c; a——Number of turns of winding 25 in the first tooth slot 26 within tooth group 24; c——The actual number of turns selected for the inner winding 25 of the tooth group 24; The winding 25 inside the 0° slot 26 has the most turns. For example, when the winding 25 inside the 0° slot 26 has 100 turns, according to the previous calculation formula, the actual number of turns c of the winding 25 inside the fourth slot 26 should be a value between 86.6 and 100, which can be selected according to the needs, for example, 87. At this time, the included angle between the 0° slot 26 and the fourth slot 26 should be 24.5° (retain one decimal place) according to the above formula. The angle between the second slot 26 adjacent to the 0° slot 26 and the 0° slot 26 can also be calculated according to the above formula, but you only need to substitute the number of turns of the winding 25 inside the second slot 26. For example, d=96. At this time, substitute the value of d into c in the formula. At this time, the angle α between the second slot 26 and the 0° slot 26 is 4.4° (retain one decimal place).

[0035] Similarly, for example, if e=92, substituting the value of e into c in the formula, the angle γ between the third tooth groove 26 and the 0° tooth groove 26 is 10.3 (retain one decimal place). Since the angle β between the fourth tooth groove 26 and the 0° tooth groove 26 is 24.5°, the angle between the third tooth groove 26 and the fourth tooth groove 26 is 14.2°.

[0036] Since the 0° tooth groove 26 in tooth groove group 24 has the deepest depth and the fourth tooth groove 26 has the shallowest depth, and the depths of the second tooth groove 26 and the sixth tooth groove 26 are the same, and the depths of the third tooth groove 26 and the fifth tooth groove 26 are the same, the angles between the second and fourth tooth grooves 26 and the sixth tooth groove 26 and the fourth tooth groove 26 in tooth groove group 24 are the same, and the angles between the third and fourth tooth grooves 26 and the fifth tooth groove 26 and the fourth tooth groove 26 are the same. That is, the second and sixth tooth grooves 26 are symmetrical with respect to the fourth tooth groove 26, and the third and fifth tooth grooves 26 are symmetrical with respect to the fourth tooth groove 26. Therefore, the angular position of each tooth groove 26 in tooth groove group 24 can be determined.

[0037] According to the above winding method, in the slot groups 24 opened on the rotor core 22, three slot groups 24 contain slots 26 that are all single-phase windings 25, while the remaining slot groups 24 contain slots 26 that contain two-phase windings 25. There are a total of 15 slots 26 containing two-phase windings 25 in these slot groups 24. When the same slot 26 contains two-phase windings 25, the ratio of the number of turns between the phase with more turns and the phase with fewer turns is calculated using the following formula: x∶y=sin(120°+β)∶sin(β) In the formula: x — Phase with more turns; y — the phase with fewer turns; β—The angle between the first tooth groove 26 in the tooth groove group 24 and the tooth groove 26.

[0038] For example, when the number of turns of winding 25 in the second slot 26 is 96, according to the formula, β=4.4° (retain one decimal place). At this time, the ratio of the phase with more turns to the phase with fewer turns in slot 26 is 32:3.

[0039] The angles mentioned above refer to the rotor of a single-pole-pair synchronous motor. For the rotor of a multi-pole-pair synchronous motor, the angles mentioned above should be divided by the number of pole pairs.

[0040] The winding method in this embodiment is as follows: Regarding the winding method of the winding 25 on the rotor core 22, each phase of the winding 25 is connected by a set of copper wires wound together. The copper wires that are respectively connected from the three phase copper conductors on the shaft 21 start winding from the slots 26 that are 60° apart. Taking one phase winding copper wire as an example, it passes around the slots 26 on the same side and the 180° opposite side, and winds one wire. Then, it winds from the slot 26 on the 180° opposite side to the next slot 26 clockwise on the same side and the slot 26 on the 180° opposite side of the corresponding slot 26, and adds a set of windings. This continues until the number of winding turns reaches half the number of copper wires that the slot 26 can accommodate. When the copper wire winds to the top of the slot 26, one wire is removed for each next slot 26 until the last wire is wound to the top of the slot 26. Then, the copper wire is connected to the phase before its starting phase.

[0041] The above embodiments are merely illustrative of the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solutions based on the technical concept proposed in this invention shall fall within the scope of protection of this invention.

Claims

1. A rotor armature stator excited AC synchronous motor, characterized by: The stator housing (1) and rotor (2) are included. The stator housing (1) is set on the ground by a base (13). The rotor (2) is set inside the stator housing (1) by end caps (11) and insulating bearings (15) at both ends of the stator housing (1). A rotor position sensor (23) is set on the shaft (21) of the rotor (2). The rotor (2) includes a shaft (21) and a rotor core (22). The rotor core (22) is set on the shaft (21). A toothed groove group (24) is recessed on the arc-shaped surface of the rotor core (22) perpendicular to the rotor core (22). The toothed groove group (24) is composed of multiple adjacent toothed grooves (26). The winding (25) is set in the toothed groove (26).

2. The rotor armature-stator excited AC synchronous motor of claim 1, wherein: The depths of two adjacent tooth slots (26) in the tooth slot group (24) are different, and the angle between two adjacent tooth slots (26) in the tooth slot group (24) and the number of turns of the winding (25) in the first tooth slot (26) in the tooth slot group (24) change regularly.

3. The AC synchronous motor with rotor armature and stator excitation according to claim 2, characterized in that: The main characteristics of the rotor, the number of turns of the winding (25) in the first slot (26) with the most turns in the inner winding (25) of the slot group (24) and the minimum number of turns of the winding (25) in the inner winding (26) of the slot group (24) with the fewest turns are calculated by the following formula: In the formula: b——The minimum number of turns in the inner winding (25) of the inner winding (26) of the inner winding (25) of the inner winding (24); a——The number of turns of the winding (25) in the first tooth (26) of the tooth group (24); Where a > b.

4. The AC synchronous motor with rotor armature and stator excitation according to claim 2, characterized in that: The main characteristic of the rotor is that the angle between the first slot (26) with the most turns of the winding (25) in the slot group (24) and the slot (26) between the maximum and minimum number of turns of the winding (25) is calculated by the following formula: In the formula: β——The angle between the first tooth (26) in the tooth group (24) and the tooth (26) with the corresponding number of turns c in the winding (25); a——The number of turns of the winding (25) in the first tooth (26) of the tooth group (24); c——The actual number of turns selected for the inner winding (25) of the toothed group (24); When two phase windings (25) are contained within the same tooth slot (26), the ratio of the number of turns between the phase with more turns and the phase with fewer turns is calculated using the following formula: x∶y=sin(120°+β)∶sin(β) In the formula: x — Phase with more turns; y — the phase with fewer turns; β——The angle between the first tooth groove (26) in the tooth groove group (24) and the tooth groove (26).

5. The AC synchronous motor with rotor armature and stator excitation according to claim 1, characterized in that: The winding (25) includes a W-phase winding (27), a U-phase winding (28) and a V-phase winding (29). The winding (25) is arranged in a tooth slot (26), and there are at most two types of windings (25) in the same tooth slot (26).

6. The AC synchronous motor with rotor armature and stator excitation according to claim 1, characterized in that: Multiple toothed slots (24) are evenly arranged on the rotor core (22) within a 360° range along the axial direction of the rotor core (22).

7. The AC synchronous motor with rotor armature and stator excitation according to claim 1, characterized in that: A rotor position sensor (23) is mounted on the rotating shaft (21) and monitors the relative position of each tooth slot (26) on the rotor core (22) with the magnetic pole of the permanent magnet (14) on the stator.

8. The AC synchronous motor with rotor armature and stator excitation according to claim 1, characterized in that: The stator housing (1) includes an end cover (11) and a housing (12). The end cover (11) has two parts respectively located at both ends of the housing (12). Permanent magnets (14) with the same number of magnetic poles as the rotor (2) are provided inside the housing (12) and on the inner side of the end cover (11).

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