WO2021249248A1 - 一种电机及其转子 - Google Patents

一种电机及其转子 Download PDF

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Publication number
WO2021249248A1
WO2021249248A1 PCT/CN2021/097756 CN2021097756W WO2021249248A1 WO 2021249248 A1 WO2021249248 A1 WO 2021249248A1 CN 2021097756 W CN2021097756 W CN 2021097756W WO 2021249248 A1 WO2021249248 A1 WO 2021249248A1
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WO
WIPO (PCT)
Prior art keywords
rotor
motor
magnetic pole
core
iron core
Prior art date
Application number
PCT/CN2021/097756
Other languages
English (en)
French (fr)
Inventor
李越
廖燕飞
华海军
张宁
Original Assignee
广东德昌电机有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 广东德昌电机有限公司 filed Critical 广东德昌电机有限公司
Publication of WO2021249248A1 publication Critical patent/WO2021249248A1/zh

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Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K1/00—Details of the magnetic circuit
    • H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
    • H02K1/22—Rotating parts of the magnetic circuit
    • H02K1/27—Rotor cores with permanent magnets
    • H02K1/2706—Inner rotors
    • H02K1/272—Inner rotors the magnetisation axis of the magnets being perpendicular to the rotor axis
    • H02K1/274—Inner rotors the magnetisation axis of the magnets being perpendicular to the rotor axis the rotor consisting of two or more circumferentially positioned magnets
    • H02K1/2753—Inner rotors the magnetisation axis of the magnets being perpendicular to the rotor axis the rotor consisting of two or more circumferentially positioned magnets the rotor consisting of magnets or groups of magnets arranged with alternating polarity
    • H02K1/278—Surface mounted magnets; Inset magnets
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K1/00—Details of the magnetic circuit
    • H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
    • H02K1/12—Stationary parts of the magnetic circuit
    • H02K1/14—Stator cores with salient poles
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K1/00—Details of the magnetic circuit
    • H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
    • H02K1/12—Stationary parts of the magnetic circuit
    • H02K1/14—Stator cores with salient poles
    • H02K1/146—Stator cores with salient poles consisting of a generally annular yoke with salient poles
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K1/00—Details of the magnetic circuit
    • H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
    • H02K1/22—Rotating parts of the magnetic circuit
    • H02K1/27—Rotor cores with permanent magnets
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K3/00—Details of windings
    • H02K3/04—Windings characterised by the conductor shape, form or construction, e.g. with bar conductors
    • H02K3/28—Layout of windings or of connections between windings
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K2201/00—Specific aspects not provided for in the other groups of this subclass relating to the magnetic circuits
    • H02K2201/03—Machines characterised by aspects of the air-gap between rotor and stator
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K2213/00—Specific aspects, not otherwise provided for and not covered by codes H02K2201/00 - H02K2211/00
    • H02K2213/03—Machines characterised by numerical values, ranges, mathematical expressions or similar information

Definitions

  • the invention relates to the technical field of electric motors, in particular to a permanent magnet electric motor and its rotor.
  • all the magnetic poles of the rotor are formed by permanent magnets, that is, the number of permanent magnets is equal to the number of magnetic poles, which results in a large amount of permanent magnets used and high manufacturing costs.
  • the present invention aims to provide a rotor and a motor with the rotor that can solve the above-mentioned problems.
  • one aspect of the present invention provides a motor rotor, which includes a rotor core and a permanent magnet fixed on the surface of the rotor core, the permanent magnet serves as the first magnetic pole of the rotor, and the rotor further includes a virtual first pole.
  • the second magnetic pole is integrally formed with the rotor core and alternately distributed with the first magnetic pole along the circumferential direction of the rotor core.
  • a protrusion is formed on the outer peripheral surface of the rotor core, and the protrusion is used to form the second magnetic pole, and a groove is also provided between the first magnetic pole and the second magnetic pole.
  • the pole arc angle corresponding to the first magnetic pole is less than or equal to the pole arc angle corresponding to the second magnetic pole.
  • the radial height of the first magnetic pole relative to the bottom wall of the groove is smaller than the radial height of the second magnetic pole relative to the bottom wall of the groove.
  • the first magnetic pole and the second magnetic pole are both arc-shaped, and the diameter of the circle where the first magnetic pole is located is different from the diameter of the circle where the second magnetic pole is located.
  • the rotor iron core includes a plurality of substantially fan-shaped iron core sections arranged at intervals along the circumferential direction, and the outer peripheral surface of each iron core section is provided with one permanent magnet and one protrusion And the groove between the permanent magnet and the protrusion is formed on the outer peripheral surface of each iron core section.
  • the distance between two adjacent iron core sections gradually increases from the outer circumferential surface of the rotor iron core toward the axis of the rotor iron core.
  • the two circumferentially opposed side surfaces of the iron core section adopt one of the following groups with respect to the radial direction of the rotor iron core:
  • One of the two circumferentially opposite side surfaces of the iron core section is along the radial direction of the rotor iron core, and the other of them is at a predetermined inclination angle with the radial direction of the rotor iron core.
  • the motor rotor further includes a rotating shaft or a bearing penetrating the rotor iron core, and the rotating shaft or the bearing and the rotor iron core are integrally connected by overmolding using plastic.
  • the present invention also provides a motor including a stator and the rotor.
  • the stator includes a plurality of teeth and three-phase windings wound on the plurality of teeth, and each phase winding includes at least two windings connected in series and wound on different teeth.
  • the design of the virtual second magnetic pole in the rotor provided by the present invention enables the opposite magnetic pole to the adjacent permanent magnet. Therefore, compared with the prior art, in the case of forming the same number of poles, only half of the existing permanent magnets are needed, which effectively reduces the amount of permanent magnets and reduces the manufacturing cost.
  • Fig. 1A is a top view of a motor according to a first embodiment of the present invention.
  • Fig. 1B is an exploded view of the motor shown in Fig. 1A.
  • Fig. 1C is a partial enlarged view of the motor shown in Fig. 1A.
  • Fig. 1D is a connection embodiment of the A-phase winding of the motor shown in Fig. 1A.
  • Fig. 1E is another connection embodiment of the A-phase winding of the motor shown in Fig. 1A.
  • Fig. 1F is another connection embodiment of the A-phase winding of the motor shown in Fig. 1A.
  • Fig. 1G is an embodiment of another motor relative to the motor shown in Fig. 1A.
  • Fig. 2A is a top view of a motor according to a second embodiment of the present invention.
  • Fig. 2B is an exploded view of the motor shown in Fig. 2A.
  • Fig. 3A is a top view of a motor according to a third embodiment of the present invention.
  • Fig. 3B is an exploded view of the motor shown in Fig. 3A.
  • Fig. 3C is a partial enlarged view of the motor shown in Fig. 3A.
  • Fig. 4A is a top view of a motor according to a fourth embodiment of the present invention.
  • Fig. 4B is an exploded view of the motor shown in Fig. 4A.
  • Fig. 5A is a top view of a motor according to a fifth embodiment of the present invention.
  • Fig. 5B is an exploded view of the motor shown in Fig. 5A.
  • Fig. 6A is a top view of a motor according to a sixth embodiment of the present invention.
  • Fig. 6B is an exploded view of the motor shown in Fig. 6A.
  • Fig. 7A is a top view of a motor according to a seventh embodiment of the present invention.
  • Fig. 7B is an exploded view of the motor shown in Fig. 7A.
  • Fig. 8A is a top view of a motor according to an eighth embodiment of the present invention.
  • Fig. 8B is an exploded view of the motor shown in Fig. 8A.
  • Fig. 9A is a top view of a motor according to a ninth embodiment of the present invention.
  • Fig. 9B is an exploded view of the motor shown in Fig. 9A.
  • a motor 100 includes an annular stator 10 having a receiving cavity 13 and a rotor 20 that is received in the receiving cavity 13 and can rotate relative to the stator 10.
  • the rotor 20 includes a rotor core 30 made of a magnetically conductive metal material, and a permanent magnet 40 fixed on the outer circumferential surface of the rotor core 30.
  • the permanent magnet 40 serves as the first magnetic pole 41 of the rotor 20.
  • a virtual second magnetic pole 31 is integrally formed on the rotor core 30. In other words, the second magnetic pole 31 is not formed by the permanent magnet 40.
  • the second magnetic poles 31 and the first magnetic poles 41 are alternately arranged along the circumferential direction of the rotor core 30.
  • the virtual second magnetic pole 31 is designed so that it functions as an opposite magnetic pole relative to the adjacent permanent magnet 40.
  • all the permanent magnets 40 may function as N poles or S poles, and accordingly, the second magnetic pole 31 functions as the opposite S pole or N pole. Therefore, compared with the prior art, in the case of forming the same number of poles, only half of the existing permanent magnets are needed, which effectively reduces the amount of permanent magnets and reduces the manufacturing cost.
  • the rotor core 30 is an annular integral piece.
  • the rotor core 30 is formed by stacking a plurality of annular rotor laminations.
  • a mounting hole 32 penetrating the rotor core 30 in the axial direction is formed in the middle of the rotor core 30.
  • a plurality of grooves 33 arranged at intervals are formed on the outer peripheral side of the rotor core 30.
  • Each groove 33 penetrates the rotor core 30 in a direction parallel to the axis of the rotor core 30.
  • An arc-shaped protrusion 34 is formed between one circumferential side of each groove 33 and its adjacent groove 33, and a mounting portion 35 is formed between the other circumferential side and its adjacent groove 33.
  • the protrusion 34 is used to form the virtual second magnetic pole 31.
  • the mounting portion 35 is used to fix the permanent magnet 40. That is, the permanent magnet 40 in this embodiment is fixed on the outer peripheral side of the rotor core 30.
  • the motor 100 in this embodiment is a surface mount permanent magnet motor (SPM).
  • the groove 33 is designed so that the adjacent first magnetic pole 41 and the second magnetic pole 31 are spaced apart in the circumferential direction to reduce end leakage.
  • the plurality of grooves 33 are equally angularly spaced in the circumferential direction.
  • the bottom wall 330 of each groove 33 is preferably a flat surface.
  • the mounting portion 35 and the protrusion 34 have different heights in the radial direction compared to the bottom wall 330 of the groove 33.
  • the protrusion 34 has a radial height H1 compared to the bottom wall 330 of the groove 33. It is greater than the radial height H2 of the mounting portion 35 compared to the bottom wall 330 of the groove 33.
  • the outer peripheral side 340 of the protrusion 34 is arc-shaped.
  • the two side surfaces 341 and 342 of the protrusion 34 opposite in the circumferential direction are planar, and preferably extend obliquely to the bottom wall 330 of the corresponding groove 33 at a first obtuse angle ⁇ 1.
  • the outer peripheral side 350 of the mounting portion 35 is flat.
  • the two side surfaces 351 and 352 of the mounting portion 35 opposite in the circumferential direction are planar, and preferably extend obliquely to the bottom wall 330 of the groove 33 at a second obtuse angle ⁇ 2 equal to the first obtuse angle ⁇ 1.
  • the permanent magnet 40 is made of a rare earth magnet such as neodymium iron boron. Compared with permanent magnets 40 made of ferrite magnets, permanent magnets 40 made of rare earth magnets have stronger magnetic properties, and the resulting rotor 20 is more compact and lighter in weight.
  • the permanent magnet 40 is substantially in the shape of a strip, and includes an inner peripheral side 42 and an outer peripheral side 43 opposite in the radial direction, two side surfaces 44, 45 opposite in the circumferential direction, and tops opposite in the axial direction. ⁇ 46 ⁇ 47 ⁇ Surface 46 and bottom surface 47.
  • the top surface 46 and the bottom surface 47 of the permanent magnet 40 are planar, and are preferably flush with the top surface 353 and the bottom surface 354 of the mounting portion 35 respectively.
  • the two side surfaces 44, 45 of the permanent magnet 40 are planar, and preferably are in the same plane as the two side surfaces 351, 352 of the mounting portion 35, respectively.
  • the inner peripheral side 42 of the permanent magnet 40 is planar, and preferably completely overlaps the outer peripheral side 350 of the mounting portion 35.
  • the outer peripheral side 43 of the permanent magnet 40 is arc-shaped, and is preferably on the same cylindrical surface as the outer peripheral side 340 of the protrusion 34. More preferably, the pole arc angle ⁇ 4 corresponding to the first magnetic pole 41 formed by the permanent magnet 40 and the pole arc angle ⁇ 3 corresponding to the second magnetic pole 31 formed by the protrusion 34 are not equal, for example, ⁇ 4 ⁇ ⁇ 3.
  • the rotor 20 of this embodiment includes 8 magnetic poles, that is, the number of pole pairs is 4.
  • all the permanent magnets 40 can be fixed (for example, glued) on the mounting portion 35 in such a manner that the radially inner part thereof is used as the S pole and the radially outer part is used as the N pole.
  • the permanent magnet 40 is magnetized along the radial direction of the rotor core 30, so that the radial inner side and the radial outer side of the permanent magnet 40 have different polarities.
  • the first magnetic pole 41 formed by the permanent magnet 40 is an N pole.
  • the second magnetic pole 31 formed by the protrusion 34 is an S pole, thereby forming an N pole and an S pole alternately arranged in the circumferential direction. Or vice versa.
  • the rotating shaft or the bearing is assembled to the mounting hole 32 of the rotor core 30.
  • position the rotating shaft in the mounting hole 32 at this time an annular space is formed between the rotating shaft and the wall of the mounting hole 32
  • plastic such as PPS, PA66 or PBT, etc.
  • the rotating shaft and the rotor core 30 are integrally connected.
  • the outer periphery of the permanent magnet 40 and the protrusion 34 can also be covered with plastic, so that the permanent magnet 40 and the rotor core 30 are more firmly connected.
  • the stator 10 includes a stator core 50, an insulating frame (not shown) coated on the stator core 50, and multiple sets of windings (not shown) wound on the insulating frame.
  • the stator core 50 includes an annular yoke 51 and a plurality of teeth 52 connected inside the yoke 51.
  • a winding slot 53 is formed between adjacent teeth 52 for accommodating windings.
  • Each tooth 52 is correspondingly wound with a winding.
  • the stator 10 includes three-phase windings: A-phase windings, B-phase windings, and C-phase windings. Each winding of each phase winding is at least partially connected in series to make the back electromotive force symmetric.
  • an 8-pole 12-slot motor is taken as an example for description, and each phase winding includes 4 windings.
  • the stator 10 in this embodiment includes 12 windings.
  • 12 winding slots 53 are formed on the stator.
  • the A-phase winding includes 4 windings wound on the teeth 1, 2, 7, and 8
  • the B-phase winding includes 4 windings wound on the teeth 3, 4, 9, and 10.
  • the C-phase winding includes 4 windings arranged on the teeth 5, 6, 11, and 12.
  • the following takes A-phase winding as an example to illustrate the connection of each winding.
  • the windings on the tooth 1 and the windings on the tooth 8 are connected in series, the windings on the tooth 2 and the windings on the tooth 7 are connected in series, and the serial teeth 1, 8 The upper winding is then connected in parallel with the windings on the series teeth 2 and 7.
  • 1E in another embodiment, the windings on the tooth 1 and the windings on the tooth 7 are connected in series, the windings on the tooth 2 and the windings on the tooth 8 are connected in series, and the teeth 1 in series are connected in series.
  • the windings on 7 are then connected in parallel with the windings on the series teeth 2 and 8.
  • 1F in yet another embodiment, the windings on the teeth 1, 2, 7, and 8 are all connected in series.
  • the windings of the B-phase winding and the C-phase winding can refer to the foregoing embodiments, which will not be repeated here.
  • the motor 100 in this embodiment is an 8-pole 12-slot motor. Understandably, in other embodiments, motors with other numbers of poles and slots, such as 10 poles and 12 slots, can also be used.
  • the following fifth embodiment to ninth embodiment give some examples of other applications.
  • an uneven air gap may be used between the rotor and the stator to make the back electromotive force of the motor be a symmetrical sine wave, so as to reduce the noise and vibration of the motor.
  • a motor 100' of another embodiment is similar to the motor 100 of the first embodiment, and the similarities are not repeated here.
  • the main difference between the motor 100' of another embodiment and the motor 100 of the first embodiment is that the diameter of the circle where the first magnetic pole 40' of the rotor 20' is located is different from the diameter of the circle where the second magnetic pole 31 is located.
  • the outer surfaces of the first magnetic pole 40' and the second magnetic pole 31 are arc-shaped, and the radial height and H3 of the first magnetic pole 40' and the mounting portion 35 compared to the bottom wall of the groove 33 are smaller than the second magnetic pole.
  • the diameter of the circle where the first magnetic pole 40' is located is smaller than the diameter of the circle where the second magnetic pole 31 is located. Therefore, the radial air gap between the stator 10 and the first magnetic pole 40 ′ is larger than the radial air gap between the stator 10 and the second magnetic pole 31.
  • the diameter of the circle where the first magnetic pole is located is larger than the diameter of the circle where the second magnetic pole is located. It is also possible to change the shape of the stator teeth so that the radial inner circumferential surface of the stator teeth does not form an uneven air gap between the stator and the rotor on the same circumference.
  • the motor 200 of the second embodiment of the present invention is similar to the motor 100 of the first embodiment, and is also an 8-pole 12-slot surface-mount permanent magnet motor, and the similarities are not repeated here.
  • the main difference between the motor 200 of this embodiment and the motor 100 of the first embodiment is that the rotor core 130 in this embodiment includes a plurality of core sections 132 arranged at intervals in the circumferential direction, and each core section 132 Permanent magnets 40 are fixed on the outer peripheral side of the In other words, the rotor core 130 in this embodiment is not an integral piece, but a segmented core structure.
  • the segmented iron core structure of the rotor iron core 130 reduces the magnetic leakage between the iron core sections 132, improves the efficiency of the motor, and reduces the noise of the motor. In addition, the use of a segmented core structure also helps to reduce the amount of rotor core 130 used and reduce costs.
  • the rotor core 130 in this embodiment is annular as a whole, and includes several (four in this embodiment) core sections 132 evenly spaced in the circumferential direction.
  • Each core section 132 may be formed by stacking several laminations.
  • Each core section 132 is roughly fan-shaped, and includes an inner circumferential side 1320 and an outer circumferential side 1321 opposite in the radial direction, first and second side surfaces 1322, 1323 opposite in the circumferential direction, and top surfaces opposite in the axial direction. Bottom surface 1324, 1325.
  • the inner peripheral side 1320 of the iron core section 132 is an arc-shaped curved surface, and the inner peripheral sides 1320 of the four iron core sections 132 are preferably on the same cylindrical surface.
  • a groove 133 is formed on the outer peripheral side 1321 of the core section 132.
  • One circumferential side of the groove 133 is a protrusion 134 for forming the second magnetic pole, and the other circumferential side of the groove 133 is a mounting portion 135 for installing the permanent magnet 40.
  • the first side surface 1322 of the iron core section 132 connects an end of the protrusion 134 away from the groove 133 and the inner peripheral side 1320 of the iron core section 132.
  • the second side surface 1323 of the iron core section 132 is connected to an end of the mounting portion 135 away from the groove 133 and the inner peripheral side 1320 of the iron core section 132.
  • the length of the first side surface 1322 (from the end of the protrusion 134 away from the groove 133 to the inner peripheral side 1320 of the core section 132) is less than the length of the second side surface 1323 (from the mounting portion 135 The end of the side away from the groove 133 to the inner peripheral side of the core section 132 (1320).
  • the area of the rotor core corresponding to the permanent magnet 40 is smaller than the area of the rotor core corresponding to the protrusion 134, so that the magnetic circuit can be optimized, and the interval between two adjacent core segments 132 is compared
  • the symmetrically arranged iron core section is larger, which helps to reduce magnetic leakage, improve motor efficiency and reduce noise.
  • the angle ⁇ 1 formed between the first side surface 1322 and the radial direction of the motor (the line connecting the motor shaft and the outer peripheral end point of the iron core) is smaller than the angle ⁇ 1 formed between the second side surface 1323 and the radial direction of the motor.
  • Angle ⁇ 2 this configuration can also make the rotor reach a balance of rotation and reduce vibration.
  • the area of the rotor core corresponding to the permanent magnet 40 is smaller than the area of the rotor core corresponding to the protrusion 134, which can have the same effect as this embodiment.
  • first and second side surfaces 1322, 1323 can have the same or different angles relative to the radial direction of the motor (the line connecting the motor shaft and the outer peripheral end point of the iron core), or one of the first and second side surfaces 1322, 1323
  • the side surface is arranged along the radial direction of the motor, and the other side surface is at a predetermined inclination angle with the radial direction of the motor.
  • the permanent magnet 40 When assembling, the permanent magnet 40 can be fixed to the corresponding iron core section 132, and then each iron core section 132 with the permanent magnet 40 and the rotating shaft are positioned in the prefabricated mold, and then the plastic is injected through the overmolded In this way, the rotating shaft or bearing and each iron core section 132 are integrally connected. At this time, the plastic fills the space between the rotating shaft and the core section 132 and the space between the adjacent core sections 132.
  • the permanent magnet 40 and the protrusion 134 can also be covered with plastic, so that the permanent magnet 40 and the corresponding iron core section 132 are more firmly connected.
  • Each iron core section 132 may be provided with an axial through hole.
  • each core section 132 may also be axially fixed by pins or rivets.
  • first and second side surfaces 1322, 1323 may also be curved surfaces, as long as the distance between two adjacent iron core sections 132 is increased from the outer peripheral surface toward the axis, so that the adjacent The width in the tangential direction between the two core sections 132 widens from the outer circumferential surface to the axis. With this configuration, the leakage flux between the iron core sections 132 can be reduced, and the torque output of the motor can be further improved.
  • the motor 300 of the third embodiment of the present invention is similar to the motor 100 of the first embodiment, and is also an 8-pole 12-slot motor, and the similarities are not repeated here.
  • the main difference between the motor 300 of this embodiment and the motor 100 of the first embodiment is that the permanent magnet 240 in this embodiment is built in the rotor core 230.
  • the motor 300 in this embodiment is a built-in permanent magnet motor.
  • the rotor core 230 in this embodiment itself is an annular integral piece, and its radially outer part is formed with a plurality of strip-shaped grooves 231 penetrating through itself in the axial direction.
  • four strip-shaped slots 231 are formed in the rotor core 230.
  • the four strip-shaped grooves 231 are evenly spaced along the circumferential direction.
  • Each slot 231 contains a permanent magnet 240 so that the rotor core outside the permanent magnet 240 forms a first magnetic pole.
  • a spacer 232 is formed between adjacent strip-shaped grooves 231 to form a second magnetic pole, so that the first magnetic pole and the second magnetic pole formed by the spacer 232 are alternately distributed in the circumferential direction.
  • the strip-shaped groove 231 includes a straight middle groove 233 perpendicular to the radial direction, and two arc-shaped spacing grooves 234 respectively located at two ends of the middle groove 233.
  • the permanent magnet 240 is received in the intermediate groove 233 and is separated from the corresponding partition 232 in the circumferential direction by the interval groove 234.
  • the permanent magnet 240 is in the shape of a rectangular parallelepiped, and the two surfaces on which the length and the width of the permanent magnet 240 are located respectively abut against the radial inner wall 2330 and the radial outer wall 2331 of the middle groove 233.
  • the radially inner wall 2330 and the radially outer wall 2331 of the intermediate groove 233 are preferably planar, so as to stably fix the permanent magnet 240.
  • the length of the radially inner wall 2330 and the radially outer wall 2331 of the intermediate groove 233 is slightly larger than the length of the permanent magnet 240 (visible in FIG. 3A).
  • the axial top surface 246 and the axial bottom surface 247 of the permanent magnet 240 are flush with the axial top surface 235 and the axial bottom surface 236 of the rotor core 230, respectively.
  • the radial inner wall 2340 of the spacer groove 234 is arc-shaped, and smoothly connects the radial inner wall 2330 of the intermediate slot 233 with a preferably straight circumferential side 2320 of the corresponding spacer 232.
  • the radially outer wall of the spacing groove 234 includes two planes 2341 and 2342 arranged at an angle, and the first junction 2343 of the two planes 2341 and 2342 is recessed toward the radial inner wall 2340 of the spacing groove 234, and the spacing groove 234
  • the design can effectively reduce side-end magnetic leakage.
  • the second junction 237 between the radially outer circumferential surface of the rotor core 230 facing the first magnetic pole and the second interfacing portion 237 of the rotor core 230 facing the radially outer circumferential surface of the second magnetic pole is recessed radially inward, and preferably radially
  • the first junction 2343 facing the two planes 2341 and 2342 makes an uneven gap between the rotor and the stator.
  • the first magnetic pole and the second magnetic pole can be arc-shaped, and the outer diameter of the arc of the first magnetic pole and the second magnetic pole is the largest at the center of the magnetic pole and the smallest at the pole end. .
  • the motor 400 of the fourth embodiment of the present invention is similar to the motor 200 of the second embodiment, it is also an 8-pole 12-slot motor, and the rotor core 331 also includes a plurality of irons arranged at intervals in the circumferential direction. For the core section 332, the similarities are not repeated here.
  • the main difference between the motor 400 of this embodiment and the motor 200 of the second embodiment is that the permanent magnets 343 in this embodiment are built in the rotor core 331 and arranged along the radial direction of the motor.
  • the motor 400 in this embodiment is a built-in permanent magnet motor.
  • the rotor core 331 has a ring shape as a whole, and includes 4 sets of core sections 332 evenly spaced in the circumferential direction.
  • Each group of iron core sections 332 includes two independent sub-sections 3326.
  • a strip-shaped permanent magnet 343 is arranged between the two sub-sections 3326, and the length of the permanent magnet 343 is parallel to the radial direction of the rotor core 331.
  • the permanent magnet 343 is magnetized in a direction perpendicular to the radial direction, so that the outer peripheral surfaces of the sub-sections 3326 on both sides of the permanent magnet 343 have different polarities.
  • the 8-pole motor uses only 4 permanent magnets, so the number of permanent magnets can be reduced and the cost can be reduced.
  • the two sub-sections 3326 of each group of iron core sections 332 are symmetrical along the radial direction of the motor.
  • Each sub-section 3326 is roughly triangular, and its first side 3320 is spaced from the other sub-section 3326 of the same group of iron core sections 332 and extends along the radial direction of the motor.
  • the second side 3322 is connected to the adjacent group of iron
  • a sub-section 3326 of the core section 332 is opposite to each other, and the third side 3321 that is the radially outer peripheral side 3321 connects the first side 3320 and the second side 3322.
  • the permanent magnets 343 are arranged between the two first sides 3320 of the two sub-sections 3326 of each group of iron core sections 332.
  • each sub-section 3326 includes a central protrusion 334 and a radially concave groove 333 formed on both sides of the protrusion 334.
  • the outer peripheral side of the protrusion 334 is arc-shaped.
  • Each groove 333 penetrates the sub-section 3326 in the axial direction and circumferentially penetrates to the corresponding first side 3320 or the second side 3322.
  • the bottom wall of the groove 333 is flat, and the side wall of the groove 333 is perpendicular to the bottom wall of the groove 333.
  • the second side 3322 of each subsection and the second side 3322 of a subsection 3326 of the adjacent group of iron core sections 332 are symmetrical with respect to the radial direction of the motor, and two adjacent groups of iron core sections are adjacent to each other.
  • the distance between the core sections 332 gradually increases radially inward from the outer circumferential surface to reduce the magnetic leakage between the core sections 332, thereby increasing the torque output of the motor.
  • the permanent magnet 343 has a rectangular parallelepiped shape and is in contact with or abuts against the first side 3320 of the two sub-sections 3326.
  • the radially inner side 3430 and the radially outer side 3431 of the permanent magnet 343 are respectively flush with the inner peripheral side of the core section 332 and the bottom wall of the groove 333, and the axial top surface 3432 and the axial bottom surface of the permanent magnet 343 3433 are respectively flush with the axial top surface 3324 and the axial bottom surface 3325 of the core section 332.
  • the permanent magnet 343 may also be arranged in the iron core section with other structures and/or structures, and accordingly, the iron core section will also be adjusted adaptively.
  • each group of iron core sections 332 with permanent magnets 343 and the rotating shaft or bearing are positioned in a prefabricated mold, and then plastic is injected to integrally connect the rotating shaft and each iron core section 332 by overmolding. At this time, the plastic fills the space between the rotating shaft and the core section 332 and the space between the adjacent core sections 332.
  • the outer peripheral surface of the iron core section 332 can also be covered with plastic, so that the permanent magnet 343 and the corresponding iron core section 332 are connected more firmly.
  • the motor 500 of the fifth embodiment of the present invention is similar to the motor 100 of the first embodiment, it is also a surface-mount permanent magnet motor, and the rotor core 430 itself is also a ring-shaped one-piece, the same I won't repeat it here.
  • the main difference between the motor 500 of this embodiment and the motor 100 of the first embodiment is that the motor in this embodiment is a 10-pole 12-slot motor.
  • the rotor in this embodiment includes five strip-shaped permanent magnets 440.
  • the outer peripheral side of the rotor core 430 is formed with 5 mounting portions 435 for fixing the permanent magnet 440, 5 projections 434 for forming the second magnetic pole, and 10 mounting portions 435 and projections formed on adjacent mounting portions 435.
  • the five permanent magnets 440 are fixed on the corresponding mounting portion 435, and are alternately distributed with the five protrusions 434 in the circumferential direction, thereby forming 10 magnetic poles alternately distributed in the circumferential direction.
  • the number of pole pairs of the rotor in this embodiment is 5.
  • the motor 600 of the sixth embodiment of the present invention is similar to the motor 200 of the second embodiment, it is also a surface-mount permanent magnet motor, and the rotor core 530 itself also adopts a segmented core structure, the same I will not repeat the details here.
  • the main difference between the motor 600 of this embodiment and the motor 200 of the second embodiment is that the motor 600 in this embodiment is a 10-pole 12-slot motor.
  • the rotor in this embodiment includes five strip-shaped permanent magnets 540.
  • the rotor core 530 includes five core sections 532 arranged at intervals in the circumferential direction.
  • the outer peripheral side 5321 of each core section 532 is formed with a mounting portion 535 for fixing the permanent magnet 540 and a protrusion 534 for forming the second magnetic pole, and a portion formed between the mounting portion 535 and the protrusion 534 The groove 533.
  • the five permanent magnets 540 are fixed on the corresponding mounting portion 535 and are alternately distributed with the five protrusions 534 in the circumferential direction, thereby forming 10 magnetic poles alternately distributed in the circumferential direction.
  • this embodiment The number of pole pairs of the rotor in is 5.
  • each core section 532 is formed with a through hole 5326 penetrating through itself in the axial direction.
  • the radially inner part of each core section 532 is formed with two through holes 5326.
  • One of the two through holes 5326 is close to the first side of the core section 532, and the other of them is close to the second side of the core section 532.
  • the injected plastic flows into the axial through hole 5326 to fix the rotor core 530.
  • each iron core section 532 may also be axially fixed by a pin or a rivet passing through the through hole.
  • the motor 700 of the seventh embodiment of the present invention is similar to the motor 300 of the third embodiment, it is also a built-in permanent magnet motor, and the rotor core 630 itself is also a ring-shaped one-piece, the similarities are I won't repeat it here.
  • the main difference between the motor 700 in this embodiment and the motor 300 in the third embodiment is that the motor 700 in this embodiment is a 10-pole 12-slot motor.
  • the rotor in this embodiment includes five rectangular parallelepiped permanent magnets 640.
  • the radially outer portion of the rotor core 630 is formed with five strip-shaped grooves 631 extending through itself in the axial direction.
  • the five strip-shaped grooves 631 are evenly spaced in the circumferential direction.
  • a spacer 632 is formed between adjacent strip grooves 631 for forming the second magnetic pole.
  • each strip-shaped groove 631 includes a straight middle groove 633 perpendicular to the radial direction, and two spaced grooves 634 that are respectively connected to the two ends of the middle groove 633 at an angle.
  • the permanent magnet 640 is received in the intermediate groove 633, and is separated from the corresponding spacer 632 in the circumferential direction by a spacer groove 634.
  • the length of the permanent magnet 640 is equal to the length of the radially inner wall and the radially outer wall of the intermediate groove 633. More preferably, the radially inner wall of the intermediate groove 633 is recessed to form a recess 6330, and the radial inner side of the permanent magnet 640 is received in the recess 6330. In this way, the side wall of the recess 6330 can limit the permanent magnet 640. effect.
  • the radial width of the spacing groove 634 is greater than the radial width of the intermediate groove 633.
  • the motor 800 of the eighth embodiment of the present invention is similar to the motor 400 of the fourth embodiment. It is also a built-in permanent magnet motor, and the rotor core 730 itself also adopts a segmented core structure. I won't repeat it here.
  • the main difference between the motor 800 in this embodiment and the motor 400 in the fourth embodiment is that the motor 800 in this embodiment is a 10-pole 12-slot motor.
  • the rotor in this embodiment includes five rectangular parallelepiped permanent magnets 740.
  • the rotor core 730 includes 5 sets of core sections 732 arranged at intervals in the circumferential direction.
  • Each set of core sections 732 includes two subsections 7326 symmetrical in the radial direction of the motor.
  • a strip of permanent magnet 740 is arranged between the two sub-sections 7326, and the permanent magnet 740 is magnetized in a direction perpendicular to the radial direction.
  • the outer peripheral side 7321 of each sub-section 7326 only forms a groove 733 at its end close to the first side.
  • each sub-section 7326 is preferably formed with a protruding pillar 7327 to facilitate the arrangement of the through hole 7323, so that the second side of each sub-section 7326 has a curved shape.
  • the distance between the iron core sections 732 of the adjacent groups gradually increases radially inward from the outer circumferential surface, and gradually decreases at the boss 7327 and then gradually increases until the iron core section 732 Radially inside.
  • the radial inner side 7430 and the radial outer side 7431 of the permanent magnet 740 are respectively flush with the radial inner side 7320 and the bottom wall of the groove 733 of the core section 732.
  • the axial bottom surface 7432 of the permanent magnet 740 is flush with the axial bottom surface 7324 of the core section 732, and the axial top surface 7433 of the permanent magnet 740 is lower than the axial top surface 7325 of the core section 732.
  • the two sub-sections 7326 of each group of iron core sections 732 are respectively formed with a through hole 7323 which penetrates through itself in the axial direction.
  • the through hole 7323 is located at the center position corresponding to the protruding pillar 7327 to improve the strength of each sub-section 7326. More preferably, the through hole 7323 is close to the radial inner side 7320 of the core section 732 relative to the groove 733.
  • the injected plastic flows into the axial through hole 7326 to fix the rotor core 730.
  • the motor 900 of the ninth embodiment of the present invention is similar to the motor 200 of the second embodiment, it is also a surface-mount permanent magnet motor, and the rotor core 830 itself also adopts a segmented core structure. I will not repeat the details here.
  • the main difference between the motor 900 in this embodiment and the motor 200 in the second embodiment is that the motor 900 in this embodiment is a 14-pole 12-slot motor.
  • the rotor in this embodiment includes 7 strip-shaped permanent magnets 840.
  • the rotor core 830 includes 7 core sections 832 arranged at intervals in the circumferential direction.
  • the outer peripheral side of each core section 832 is formed with a mounting portion 835 for fixing the permanent magnet 840, a protrusion 834 for forming the second magnetic pole, and a recess formed between the mounting portion 835 and the protrusion 834.
  • the 7 permanent magnets 840 are fixed on the corresponding mounting portions 835, and are alternately distributed with the 7 protrusions 834 in the circumferential direction, thereby forming 14 magnetic poles alternately distributed in the circumferential direction.
  • the number of pole pairs of the rotor of the motor in this embodiment is 7.

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  • Engineering & Computer Science (AREA)
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  • Permanent Field Magnets Of Synchronous Machinery (AREA)
  • Iron Core Of Rotating Electric Machines (AREA)

Abstract

本发明涉及一种电机及其转子，所述转子包括转子铁芯以及固定在所述转子铁芯表面上的永磁体，所述永磁体作为转子的第一磁极，所述转子还包括虚拟的第二磁极，所述第二磁极与所述转子铁芯一体形成并与所述第一磁极沿所述转子铁芯的周向交替分布。本发明提供的转子中采用虚拟的第二磁极，有效减少了永磁体的用量，降低了制造成本。

Description

一种电机及其转子 技术领域
本发明涉及电机技术领域，具体涉及一种永磁电机及其转子。
 背景技术
常见的永磁电机, 转子的全部磁极均由永磁体形成，即永磁体的数量和磁极的数量相等，导致永磁体的使用量较大，制造成本高。
 技术问题
有鉴于此，本发明旨在提供一种可以解决上述问题的转子及具有该转子的电机。
 技术解决方案
为此，本发明一方面提供一种电机转子，包括转子铁芯以及固定在所述转子铁芯表面上的永磁体，所述永磁体作为转子的第一磁极，所述转子还包括虚拟的第二磁极，所述第二磁极与所述转子铁芯一体形成并与所述第一磁极沿所述转子铁芯的周向交替分布。
优选的，所述转子铁芯的外周表面形成有凸起，所述凸起用于形成所述第二磁极，所述第一磁极和所述第二磁极之间还设有凹槽。
优选的，所述第一磁极对应的极弧角度小于等于所述第二磁极对应的极弧角度。
优选的，所述第一磁极相对于所述凹槽的底壁的径向高度小于所述第二磁极相对于所述凹槽的底壁的径向高度。
优选的，所述第一磁极和所述第二磁极均呈弧形，且所述第一磁极所在的圆的直径与第二磁极所在的圆的直径不同。
优选的，所述转子铁芯包括沿周向间隔布置的多个概呈扇形的铁芯区段，每一所述铁芯区段的外周表面设有一个所述永磁体及一个所述凸起，且每一所述铁芯区段的外周表面上形成有一位于所述永磁体和所述凸起之间的所述凹槽。
优选的，相邻两所述铁芯区段之间的距离从所述转子铁芯的外周面朝向所述转子铁芯的轴心逐渐增加。
优选的，所述铁芯区段的沿周向相对的两个侧面相对所述转子铁芯的径向采用以下组中的其中一种：
1）所述铁芯区段的沿周向相对的两个侧面与所述转子铁芯的径向之间的角度相同；
2）所述铁芯区段的沿周向相对的两个侧面与所述转子铁芯的径向之间的角度不同；
3）所述铁芯区段的沿周向相对的两个侧面的其中之一沿所述转子铁芯的径向，其中之另一与所述转子铁芯的径向呈一预定倾斜角度。
优选的，所述电机转子还包括贯穿所述转子铁芯的转轴或者轴承，所述转轴或者轴承与所述转子铁芯利用塑料通过包覆成型的方式一体连接。
又一方面，本发明还提供一种电机，包括定子、以及所述转子。
优选的，所述定子包括多个齿部以及绕设于所述多个齿部上的三相绕组，且每相绕组至少包括串联连接的两个缠绕于不同齿部上的绕组。
优选的，所述定子和所述转子之间为不均匀气隙。
 有益效果
本发明提供的转子中的虚拟的第二磁极的设计使得相对于邻近的永磁体起到相反磁极的作用。因此，与现有技术相比，在形成相同极数的情况下，仅需要现有的数量一半的永磁体即可，有效减少了永磁体的用量，降低了制造成本。
 附图说明
图1A是本发明第一实施例的电机俯视图。
图1B是图1A所示电机爆炸图。
图1C是图1A所示电机的局部放大图。
图1D是图1A所示电机的A相绕组的一种连接实施方式。
图1E是图1A所示电机的A相绕组的另一种连接实施方式。
图1F是图1A所示电机的A相绕组的又一种连接实施方式。
图1G是相对于图1A所示电机的另一种电机的实施方式。
图2A是本发明第二实施例的电机的俯视图。
图2B是图2A所示电机的爆炸图。
图3A是本发明第三实施例的电机的俯视图。
图3B是图3A所示电机的爆炸图。
图3C是图3A所示电机的局部放大图。
图4A是本发明第四实施例的电机的俯视图。
图4B是图4A所示电机的爆炸图。
图5A是本发明第五实施例的电机的俯视图。
图5B是图5A所示电机的爆炸图。
图6A是本发明第六实施例的电机的俯视图。
图6B是图6A所示电机的爆炸图。
图7A是本发明第七实施例的电机的俯视图。
图7B是图7A所示电机的爆炸图。
图8A是本发明第八实施例的电机的俯视图。
图8B是图8A所示电机的爆炸图。
图9A是本发明第九实施例的电机的俯视图。
图9B是图9A所示电机的爆炸图。
 本发明的实施方式
以下将结合附图以及具体实施方式对本发明进行详细说明，以使得本发明的技术方案及其有益效果更为清晰明了。可以理解，附图仅提供参考与说明用，并非用来对本发明加以限制，附图中显示的尺寸仅仅是为了便于清晰描述，而并不限定比例关系。
参考图1A至图1C，本发明第一实施例的电机100包括具有一收容腔13的环形定子10、以及收容于所述收容腔13内并可相对所述定子10转动的转子20。所述转子20包括由导磁金属材料制成的转子铁芯30、以及固定于所述转子铁芯30外周面上的永磁体40。所述永磁体40作为转子20的第一磁极41。本实施例中，所述转子铁芯30上一体形成有虚拟的第二磁极31。换言之，第二磁极31不是由永磁体40形成的。所述第二磁极31与所述第一磁极41沿转子铁芯30的周向交替配置。本实施例中，虚拟的第二磁极31的设计使得相对于邻近的永磁体40起到相反磁极的作用。例如，所有永磁体40可以作为N极或S极发挥作用，相应地，第二磁极31作为与之相反的S极或N极发挥作用。因此，与现有技术相比，在形成相同极数的情况下，仅需要现有的数量一半的永磁体即可，有效减少了永磁体的用量，降低了制造成本。
本实施例中，所述转子铁芯30为一环形的一体件。优选地，转子铁芯30由若干环形的转子叠片叠置而成。转子铁芯30的中部形成有沿轴向贯穿其自身的安装孔32。转子铁芯30的外周侧形成有多个间隔布置的凹槽33。各凹槽33沿平行于转子铁芯30的轴线的方向贯穿转子铁芯30。每一凹槽33的周向一侧与其相邻凹槽33之间形成弧形凸起34，周向另一侧与其相邻凹槽33之间形成安装部35。所述凸起34用于形成所述虚拟的第二磁极31。所述安装部35用于固定所述永磁体40。即，本实施例中的永磁体40固定在转子铁芯30的外周侧。换言之，本实施例中的电机100为表贴式永磁电机（SPM）。凹槽33的设计使得相邻的第一磁极41和第二磁极31在周向上隔开，以减少端部漏磁。优选地，多个凹槽33在周向上等角度地间隔。每一凹槽33的底壁330优选为一平面。所述安装部35与凸起34相较于凹槽33的底壁330在径向上具有不同的高度，优选地，所述凸起34相较于凹槽33的底壁330的径向高度H1大于安装部35相较于凹槽33的底壁330的径向高度H2。
优选地，所述凸起34的外周侧340呈弧形。凸起34的在周向上相对的两个侧面341、342呈平面状，并优选以第一钝角θ1倾斜地延伸至相应凹槽33的底壁330。优选地，所述安装部35的外周侧350呈平面状。安装部35的在周向上相对的两个侧面351、352呈平面状，并优选以与所述第一钝角θ1相等的第二钝角θ2倾斜地延伸至凹槽33的底壁330。
优选地，所述永磁体40由稀土磁铁如钕铁硼制成。相比于由铁氧体磁铁制成的永磁体40，由稀土磁铁制成的永磁体40磁性更强，得到的转子20更加紧凑、重量更轻。本实施例中，所述永磁体40大致呈条状，包括在径向上相对的内周侧42和外周侧43、在周向上相对的两个侧面44、45、以及在轴向上相对的顶面46和底面47。永磁体40的顶面46和底面47呈平面状，并优选分别与所述安装部35的顶面353和底面354齐平。永磁体40的两个侧面44、45呈平面状，并优选与安装部35的两个侧面351、352分别处于同一平面。永磁体40的内周侧42呈平面状，并优选完全重合在所述安装部35的外周侧350上。永磁体40的外周侧43呈弧形，并优选与所述凸起34的外周侧340处于同一圆柱面上。更优地，永磁体40形成的第一磁极41对应的极弧角度θ4与凸起34形成的第二磁极31对应的极弧角度θ3不相等，例如，θ4 ≤ θ3。
本实施例中，转子铁芯30的外周侧固定有4个永磁体40，并相应形成有4个凸起34，4个永磁体40和4个凸起34沿周向一一交替分布。换言之，本实施例的转子20包括8个磁极，即极对数为4。
装配时，可将所有永磁体40以其径向内侧部分作为S极，径向外侧部分作为N极的方式固定（例如胶粘）在安装部35上。换言之，本实施例中永磁体40沿转子铁芯30的径向方向被磁化，使得永磁体40的径向内侧和径向外侧具有不同极性。在这种情况下，由永磁体40形成的第一磁极41为N极。相应地，由凸起34形成的第二磁极31为S极，从而形成在周向上交替布置的N极和S极。或者，反之亦然。然后将转轴或轴承装配至转子铁芯30的安装孔32。例如将转轴定位至安装孔32内（此时转轴与安装孔32孔壁之间形成一环形空间），然后用塑料（例如PPS、PA66或者PBT等）使用包覆成型（Over-Mold）的方式将转轴以及转子铁芯30一体连接。其他实施方式中，也可使塑料包覆永磁体40及凸起34的外周部，使得永磁体40和转子铁芯30连接更加牢固。
所述定子10包括定子磁芯50、包覆在定子磁芯50上的绝缘架（未示出）、以及绕设在绝缘架上的多组绕组（未示出）。所述定子磁芯50包括环形的轭部51、以及连接在所述轭部51内侧的多个齿部52。相邻齿部52之间形成一绕线槽53，用于收容绕组。每一齿部52对应绕设一绕组。本实施例中，所述定子10包括三相绕组：A相绕组、B相绕组、以及C相绕组，每相绕组的各个绕组至少部分串联连接，以使反电动势对称。本实施例中，以8极12槽电机为例进行说明，每相绕组包括4个绕组。本实施例中的定子10包括12个绕组。相应地，定子上形成有12个绕线槽53。如图1A所示，A相绕组包括绕设在齿部1、2、7、8上的4个绕组，B相绕组包括绕设在齿部3、4、9、10上的4个绕组，C相绕组包括绕设在齿部5、6、11、12上的4个绕组。下面以A相绕组为例进行说明各绕组的接法。
参考图1D，在一种实施方式中，齿部1上的绕组和齿部8上的绕组串联连接，齿部2上的绕组和齿部7上的绕组串联连接，串联的齿部1、8上的绕组再和串联的齿部2、7上的绕组并联连接。参考图1E，在另一种实施方式中，齿部1上的绕组和齿部7上的绕组串联连接，齿部2上的绕组和齿部8上的绕组串联连接，串联的齿部1、7上的绕组再和串联的齿部2、8上的绕组并联连接。参考图1F，在又一种实施方式中，齿部1、2、7、8上的绕组全部串联连接。B相绕组和C相绕组的各绕组可参考前述的各实施方式，在此不再赘述。
由上可知，本实施例中的电机100为8极12槽电机。可以理解地，在其他实施例中，也可以采用其他极数和槽数的电机如10极12槽等。后续的第五实施例至第九实施例给出了部分其他应用的示例。
而且，其他实施方式中，转子和定子之间还可以采用不均匀气隙以使电机的反电动势呈对称的正弦波，以减少电机的噪音及震动。例如，参考图1G所示，另一实施方式的电机100'与第一实施例的电机100相似，相同之处在此不再赘述。另一实施方式的电机100'与第一实施例的电机100的主要区别在于：转子20'的第一磁极40'所在的圆的直径与第二磁极31所在的圆的直径不同。具体地，第一磁极40'和第二磁极31的外表面均呈弧形，且第一磁极40'与安装部35相较于凹槽33的底壁的径向高度和H3小于第二磁极31相较于凹槽33的底壁的径向高度H1，从而使得第一磁极40'所在的圆的直径小于第二磁极31所在的圆的直径。因此，定子10与第一磁极40'的径向气隙大于与第二磁极31径向气隙。这种布置可使电机的反电动势呈对称的正弦波。可以理解地，在其他实施例中，也可以是第一磁极所在的圆的直径大于第二磁极所在的圆的直径。还可以变更定子齿部的形状使定子齿部径向内周面不在同一圆周上形成定子及转子间的不均匀气隙。
参考图2A和图2B，本发明第二实施例的电机200与第一实施例的电机100相似，也为8极12槽的表贴式永磁电机，相同之处在此不再赘述。本实施例的电机200与第一实施例的电机100的主要区别在于：本实施例中的转子铁芯130包括沿周向间隔布置的多个铁芯区段132，每一铁芯区段132的外周侧固定有永磁体40。换言之，本实施例中的转子铁芯130本身不是一个一体件，而采用分段式铁芯结构。分段式铁芯结构的转子铁芯130使得各铁芯区段132之间的磁泄露减小，提高电机的效率，减小电机的噪音。此外，采用分段式铁芯结构也有助于减少转子铁芯130的使用量，降低成本。
具体地，本实施例中的转子铁芯130整体呈环形，包括若干个（本实施例中为4个）沿周向均匀间隔分布的铁芯区段132。每一铁芯区段132可以由若干叠片叠置而成。各铁芯区段132大致呈扇形，包括在径向上相对的内周侧1320和外周侧1321、在周向上相对的第一、第二侧面1322、1323、以及在轴向上相对的顶面和底面1324、1325。铁芯区段132的内周侧1320为一弧形曲面，且4个铁芯区段132的内周侧1320优选在同一圆柱面上。铁芯区段132的外周侧1321形成一凹槽133。凹槽133的周向一侧为用于形成第二磁极的凸起134，凹槽133的周向另一侧为用于安装永磁体40的安装部135。铁芯区段132的第一侧面1322连接凸起134的远离凹槽133的一端以及铁芯区段132的内周侧1320。铁芯区段132的第二侧面1323连接安装部135的远离凹槽133的一端以及铁芯区段132的内周侧1320。优选地，第一侧面1322的长度（从凸起134的远离凹槽133的一侧的端部到铁芯区段132的内周侧1320）小于第二侧面1323的长度（从安装部135的远离凹槽133的一侧的端部到铁芯区段132的内周侧1320）。换言之，与永磁体40对应的转子铁芯的面积小于与凸起134对应的转子铁芯的面积，这样可以优化磁路，而且，相邻的两个铁芯区段132之间的间隔相比于对称设置的铁芯区段更大，有助于减少漏磁，提高电机效率并减少噪音。本实施例中，第一侧面1322与电机的径向（连接电机轴与铁芯的外周端点的连线）之间形成的夹角α1小于第二侧面1323与电机的径向之间形成的夹角α2，这样配置还可以使转子达到转动平衡，减少震动。当然，其他实施方式中，与上述实施方式刚好相反，与永磁体40对应的转子铁芯的面积小于与凸起134对应的转子铁芯的面积，可以与本实施方式具有同样的效果。即第一、第二侧面1322、1323相对于电机的径向（连接电机轴与铁芯的外周端点的连线）可以具有相同或不同的角度，或者第一、第二侧面1322、1323其中一个侧面沿电机径向设置，另一侧面与电机径向呈一预定倾斜角度。
装配时，可先将永磁体40固定至相应的铁芯区段132，然后将带有永磁体40的各铁芯区段132以及转轴定位至预制的模具中，再注入塑料通过包覆成型的方式将转轴或轴承以及各铁芯区段132一体连接。此时，塑料填充至转轴和铁芯区段132之间的空间、以及相邻铁芯区段132之间的空间。其他实施方式中，也可使塑料包覆永磁体40及凸起134，使得永磁体40和相应铁芯区段132连接更加牢固。各铁芯区段132上可以设置轴向通孔，包覆成型时，注入的塑料流入轴向通孔将转子铁芯固定，如附图6A及6B。其他实施方式中，各铁芯区段132也可以通过销钉或铆钉轴向固定。本领域技术人员可以理解，所述第一、第二侧面1322、1323也可以为曲面，只要使相邻两个铁芯区段132之间的距离从外周面开始朝向轴心增加，使相邻两个铁芯区段132之间的沿切向方向上的宽度从外周面向轴心变宽。使用此配置，可以减小铁芯区段132之间的漏磁通，可以进一步提高电机的扭矩输出。
参考图3A和图3B，本发明第三实施例的电机300与第一实施例的电机100相似，也为8极12槽电机，相同之处在此不再赘述。本实施例的电机300与第一实施例的电机100的主要区别在于：本实施例中的永磁体240内置于转子铁芯230内。换言之，本实施例中的电机300为内置式永磁电机。
具体地，本实施例中的转子铁芯230本身为一环形的一体件，其径向外侧部分形成有多个沿轴向贯穿其自身的条形槽231。本实施例中，转子铁芯230内形成有4个所述条形槽231。优选地，4个条形槽231沿周向均匀间隔分布。每一条形槽231内收容一永磁体240，从而使得由永磁体240外侧的转子铁芯形成第一磁极。相邻条形槽231之间形成一间隔部232，用于形成第二磁极，从而使得第一磁极和由间隔部232形成的第二磁极在周向上交替分布。
优选地，所述条形槽231包括垂直于径向的平直的中间槽233、以及分别位于所述中间槽233两端的两个弧形的间隔槽234。永磁体240收容于所述中间槽233内，并通过所述间隔槽234与相应的间隔部232在周向上隔开。优选地，所述永磁体240呈长方体状，且永磁体240的长度和宽度所在的两个面分别抵靠中间槽233的径向内壁2330和径向外壁2331。相应地，所述中间槽233的径向内壁2330和径向外壁2331优选呈平面状，以稳定地固定永磁体240。优选地，中间槽233的径向内壁2330和径向外壁2331的长度略大于永磁体240的长度（图3A中可见）。永磁体240的轴向顶面246和轴向底面247分别与转子铁芯230的轴向顶面235和轴向底面236齐平。本实施例中，间隔槽234的径向内壁2340呈弧形，并平滑地连接中间槽233的径向内壁2330和相应的间隔部232的一优选平直的周向侧2320。优选地，间隔槽234的径向外壁包括两个呈角度布置的平面2341、2342，且两个平面2341、2342的第一交接部2343朝向间隔槽234的径向内壁2340凹入，间隔槽234的设计可以有效减少边端漏磁。而且，转子铁芯230的正对第一磁极的径向外周面与转子铁芯230的正对第二磁极的径向外周面的第二交接部237径向向内凹入，并优选径向正对两个平面2341、2342的第一交接部2343，使转子与定子之间呈不均匀间隙。可以理解地，在其他实施例中，可使所述第一磁极及第二磁极为弧形，所述第一磁极及第二磁极的弧形的外径在磁极中心最大、在磁极端部最小。
参考图4A和图4B，本发明第四实施例的电机400与第二实施例的电机200相似，也为8极12槽电机，且转子铁芯331也包括沿周向间隔布置的多个铁芯区段332，相同之处在此不再赘述。本实施例的电机400与第二实施例的电机200的主要区别在于：本实施例中的永磁体343内置于转子铁芯331内，并沿电机的径向设置。换言之，本实施例中的电机400为内置式永磁电机。
具体地，本实施例中，转子铁芯331整体呈环形，包括4组沿周向均匀间隔分布的铁芯区段332。每一组铁芯区段332包括两个独立的子区段3326，两子区段3326之间设置一条状的永磁体343，且永磁体343以其长度方向平行于转子铁芯331的径向方向的方式布置，永磁体343沿垂直径向的方向被磁化，使得永磁体343两侧的子区段3326的外周表面具有不同的极性。根据以上配置，8极电机只使用4块永磁体构成，所以使用永磁体的数量可以减少，降低成本。
本实施例中，每组铁芯区段332的两个子区段3326沿电机的径向对称。每一子区段3326大致呈三角形，其第一边3320与同一组铁芯区段332的另一子区段3326间隔相对并沿电机的径向延伸，第二边3322与相邻组的铁芯区段332的一子区段3326相对，第三边3321即径向外周侧3321连接所述第一边3320和所述第二边3322。所述永磁体343布置于每组铁芯区段332的两个子区段3326的两个第一边3320之间。优选地，每一子区段3326的外周侧3321包括中部的凸起334及形成于凸起334两侧的径向内凹的凹槽333。本实施例中，所述凸起334的外周侧呈弧形。各凹槽333沿轴向贯穿子区段3326并周向贯穿至相应的第一边3320或者第二边3322。凹槽333的底壁呈平面状，凹槽333的侧壁垂直于凹槽333的底壁。本实施例中，每一子区段的第二边3322与相邻组的铁芯区段332的一子区段3326的第二边3322相对于电机的径向对称，且相邻两组铁芯区段332之间的距离从外周面沿径向向内逐渐增加，以减小铁芯区段332之间的漏磁，进而提高电机的扭矩输出。
本实施例中，所述永磁体343呈长方体状，并与两个子区段3326的第一边3320接触或抵靠。优选地，永磁体343的径向内侧3430和径向外侧3431分别与铁芯区段332的内周侧和凹槽333的底壁齐平，永磁体343的轴向顶面3432和轴向底面3433分别与铁芯区段332的轴向顶面3324和轴向底面3325齐平。可以理解地，在其他实施例中，永磁体343也可以采用其他结构和/或构造布置于铁芯区段内，相应地，铁芯区段也将作适应性调整。
装配时，将带有永磁体343的各组铁芯区段332以及转轴或轴承定位至预制的模具中，再注入塑料通过包覆成型的方式将转轴以及各铁芯区段332一体连接。此时，塑料填充至转轴和铁芯区段332之间的空间、以及相邻铁芯区段332之间的空间。也可使塑料填包覆铁芯区段332的外周面，使得永磁体343和相应铁芯区段332连接更加牢固。
参考图5A和5B，本发明第五实施例的电机500与第一实施例的电机100相似，也为表贴式永磁电机，且转子铁芯430自身也为一环形的一体件，相同之处在此不再赘述。本实施例的电机500与第一实施例的电机100的主要区别在于：本实施例中的电机为10极12槽电机。
具体地，本实施例中的转子包括5个条状的永磁体440。相应地，转子铁芯430的外周侧形成有5个用于固定永磁体440的安装部435、5个用于形成第二磁极的凸起434、以及10个形成于相邻安装部435和凸起434之间的凹槽433。5个永磁体440固定在相应的安装部435上，并与5个凸起434在周向上一一交替分布，从而形成在周向上交替分布的10个磁极。换言之，本实施例中的转子的极对数为5。
参考图6A和6B，本发明第六实施例的电机600与第二实施例的电机200相似，也为表贴式永磁电机，且转子铁芯530自身也采用分段式铁芯结构，相同之处在此不再赘述。本实施例的电机600与第二实施例的电机200的主要区别在于：本实施例中的电机600为10极12槽电机。
具体地，本实施例中的转子包括5个条状的永磁体540。相应地，转子铁芯530包括5个沿周向间隔布置的铁芯区段532。每一铁芯区段532的外周侧5321形成一用于固定永磁体540的安装部535和一用于形成第二磁极的凸起534、以及一形成于安装部535和凸起534之间的凹槽533。5个永磁体540固定在相应的安装部535上，并与5个凸起534在周向上一一交替分布，从而形成在周向上交替分布的10个磁极，换言之，本实施例中的转子的极对数为5。
此外，本实施例中，每一铁芯区段532的径向内侧部分形成有沿轴向贯穿其自身的通孔5326。优选地，每一铁芯区段532的径向内侧部分形成有两个所述通孔5326。两个通孔5326的其中之一靠近铁芯区段532的第一侧，其中之另一靠近铁芯区段532的第二侧。包覆成型时，注入的塑料流入轴向通孔5326将转子铁芯530固定。其他实施方式中，各铁芯区段532也可以通过销钉或铆钉穿过通孔轴向固定。
参考图7A和7B，本发明第七实施例的电机700与第三实施例的电机300相似，也为内置式永磁电机，且转子铁芯630自身也为一环形的一体件，相同之处在此不再赘述。本实施例的电机700与第三实施例的电机300的主要区别在于：本实施例中的电机700为10极12槽电机。
具体地，本实施例中的转子包括5个长方体状的永磁体640。相应地，转子铁芯630的径向外侧部分形成有5个沿轴向贯穿其自身的条形槽631。5个条形槽631沿周向均匀间隔分布。相邻条形槽631之间形成一间隔部632，用于形成第二磁极。本实施例中，每一条形槽631包括垂直于径向的平直的中间槽633、以及分别呈角度地与所述中间槽633的两端连通的两个间隔槽634。永磁体640收容于中间槽633内，并通过一所述间隔槽634与相应的间隔部632在周向上隔开。优选地，永磁体640的长度等于中间槽633的径向内壁和径向外壁的长度。更优地，中间槽633的径向内壁内凹形成一凹陷部6330，永磁体640的径向内侧收容于凹陷部6330内，如此，凹陷部6330的侧壁可对永磁体640起到限位作用。所述间隔槽634的径向宽度大于所述中间槽633的径向宽度。
参考图8A和8B，本发明第八实施例的电机800与第四实施例的电机400相似，也为内置式永磁电机，且转子铁芯730自身也采用分段式铁芯结构，相同之处在此不再赘述。本实施例的电机800与第四实施例的电机400的主要区别在于：本实施例中的电机800为10极12槽电机。
具体地，本实施例中的转子包括5个长方体状的永磁体740。相应地，转子铁芯730包括5组沿周向间隔布置的铁芯区段732。每一组铁芯区段732包括沿电机的径向对称的两个子区段7326。两子区段7326之间设置一条状的永磁体740，且永磁体740沿垂直径向的方向被磁化。与第四实施例不同地，本实施例中，每一子区段7326的外周侧7321只在其靠近第一边的一端形成一凹槽733。每一子区段7326的第二边还优选地突出形成有一凸柱7327便于设置通孔7323，使得每一子区段7326的第二边呈曲线形状。本实施例中，相邻组的铁芯区段732之间的距离从外周面沿径向向内逐渐增加，并在凸柱7327处逐渐减小后又逐渐增大，直至铁芯区段732的径向内侧。优选地，永磁体740的径向内侧7430和径向外侧7431分别与铁芯区段732的径向内侧7320和凹槽733底壁齐平。本实施例中，永磁体740的轴向底面7432与铁芯区段732的轴向底面7324齐平，永磁体740的轴向顶面7433低于铁芯区段732的轴向顶面7325。
此外，本实施例中，各组铁芯区段732的两个子区段7326内还分别形成有一沿轴向贯穿其自身的通孔7323。优选地，所述通孔7323位于所述凸柱7327对应的中心位置，以提高各子区段7326的强度。更优地，所述通孔7323相对凹槽733靠近铁芯区段732的径向内侧7320。包覆成型时，注入的塑料流入轴向通孔7326将转子铁芯730固定。
参考图9A和9B，本发明第九实施例的电机900与第二实施例的电机200相似，也为表贴式永磁电机，且转子铁芯830自身也采用分段式铁芯结构，相同之处在此不再赘述。本实施例的电机900与第二实施例的电机200的主要区别在于：本实施例中的电机900为14极12槽电机。
具体地，本实施例中的转子包括7个条状的永磁体840。相应地，转子铁芯830包括7个沿周向间隔布置的铁芯区段832。每一铁芯区段832的外周侧形成一用于固定永磁体840的安装部835和一用于形成第二磁极的凸起834、以及一形成于安装部835和凸起834之间的凹槽833。7个永磁体840固定在相应的安装部835上，并与7个凸起834在周向上一一交替分布，从而形成在周向上交替分布的14个磁极。换言之，本实施例中电机的转子的极对数为7。
可以理解地，上述实施例并非穷举。各实施例中的各个特征在没有技术冲突或矛盾的前提下，可以相互结合。
在本发明的描述中，需要理解的是，术语“上”、“下”、“前”、“后”、“左”、“右”等指示的方位或位置关系为基于附图所示的方位或位置关系，仅是为了便于描述本发明和简化描述，而不是指示或暗示所指的装置或元件必须具有特定的方位、以特定的方位构造和操作，因此不能理解为对本发明的限制。此外，术语“第一”、“第二”等仅用于描述目的，而不能理解为指示或暗示相对重要性或者隐含指明所指示的技术特征的数量。由此，限定有“第一”、“第二”等的特征可以明示或者隐含地包括一个或者更多个该特征。在本发明的描述中，除非另有说明，“多个”的含义是两个或两个以上。
以上所述仅为本发明较佳的具体实施方式，本发明的保护范围不限于以上列举的实施例，任何熟悉本技术领域的技术人员在本发明披露的技术范围内，可显而易见地得到的技术方案的简单变化或等效替换均落入本发明的保护范围内。

Claims (12)

  1. 一种电机转子（20，200），包括转子铁芯（30）以及固定在所述转子铁芯（30）表面上的永磁体（40），其特征在于，所述永磁体（40）作为转子（20）的第一磁极（41），所述转子（20）还包括虚拟的第二磁极（31），所述第二磁极（31）与所述转子铁芯（30）一体形成并与所述第一磁极（41）沿所述转子铁芯（30）的周向交替分布。
  2. 根据权利要求1所述的电机转子（20，200），其特征在于，所述转子铁芯（30）的外周表面形成有凸起（34），所述凸起（34）用于形成所述第二磁极（31），所述第一磁极（41）和所述第二磁极（31）之间还设有凹槽（33）。
  3. 根据权利要求1所述的电机转子（20，200），其特征在于，所述第一磁极（41）对应的极弧角度小于等于所述第二磁极（31）对应的极弧角度。
  4. 根据权利要求2所述的电机转子（20，200），其特征在于，所述第一磁极（41）相对于所述凹槽（33）的底壁的径向高度小于所述第二磁极（31）相对于所述凹槽（33）的底壁的径向高度。
  5. 根据权利要求2所述的电机转子（20，200），其特征在于，所述第一磁极（41）和所述第二磁极（31）均呈弧形，且所述第一磁极（41）所在的圆的直径与第二磁极（31）所在的圆的直径不同。
  6. 根据权利要求2所述的电机转子（20，200），其特征在于，所述转子铁芯（30）包括沿周向间隔布置的多个概呈扇形的铁芯区段（130），每一所述铁芯区段（130）的外周表面设有一个所述永磁体（40）及一个所述凸起（34），且每一所述铁芯区段（130）的外周表面上形成有一位于所述永磁体（40）和所述凸起（34）之间的所述凹槽（33）。
  7. 根据权利要求6所述的电机转子（20，200），其特征在于，相邻两所述铁芯区段（130）之间的距离从所述转子铁芯（30）的外周面朝向所述转子铁芯（30）的轴心逐渐增加。
  8. 根据权利要求6所述的电机转子（20，200），其特征在于，所述铁芯区段（130）的沿周向相对的两个侧面相对所述转子铁芯（30）的径向采用以下组中的其中一种：
    1）所述铁芯区段（130）的沿周向相对的两个侧面与所述转子铁芯（30）的径向之间的角度相同；
    2）所述铁芯区段（130）的沿周向相对的两个侧面（1322，1323）与所述转子铁芯（30）的径向之间的角度不同；
    3）所述铁芯区段（130）的沿周向相对的两个侧面（1322，1323）的其中之一沿所述转子铁芯（30）的径向，其中之另一与所述转子铁芯（30）的径向呈一预定倾斜角度。
  9. 根据权利要求1所述的电机转子（20），其特征在于，所述电机转子（20）还包括贯穿所述转子铁芯（30）的转轴或者轴承，所述转轴或者轴承与所述转子铁芯（30）利用塑料通过包覆成型的方式一体连接。
  10. 一种电机，其特征在于，包括定子（10）、以及根据权利要求1-9中任一项所述的转子（20）。
  11. 根据权利要求10所述的电机，其特征在于，所述定子（10）包括多个齿部（52）以及绕设于所述多个齿部（52）上的三相绕组，且每相绕组至少包括串联连接的两个缠绕于不同齿部（52）上的绕组。
  12. 根据权利要求10所述的电机，其特征在于，所述定子（10）和所述转子（20）之间为不均匀气隙。
PCT/CN2021/097756 2020-06-09 2021-06-01 一种电机及其转子 WO2021249248A1 (zh)

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