Brushless permanent magnet motor

Abstract

A permanent magnet rotor is fixed on a motor shaft, and a stator assembly, a Hall element and a PCB (printed circuit board) are mounted on the inner wall of a casing. The stator assembly is composed of a circular ring iron core stator and a winding coil, the circular ring iron core stator is formed by connecting front and rear sections of a first circular ring iron core stator and a second circular ring iron core stator, and the winding coil is tightly attached to the inner wall (inner rotor structure) of the circular ring iron core stator or wraps the outer side (outer rotor structure) of the circular ring iron core stator. The winding coil is in a cylindrical shape defined by N (three or more) independent coils, a V-shaped gap is formed in the adjacent combination portion of the two independent coils, and each independent coil accounts for one Nth of the circumference. And a plurality of independent coils are spliced to manufacture the winding coil, so that the manufacturing efficiency of the motor winding coil is greatly improved. A mounting gap exists between the winding coil and the second circular ring iron core stator, so that the problems of wire breakage, short circuit, incapability of being matched with the iron core stator and the like caused by disorder and pressing deformation of outgoing lines are solved.

Description

Technical Field

[0001] The patent of this invention relates to the field of motor technology, specifically a brushless permanent magnet motor. Background Art

[0002] Slotless brushless permanent magnet motors have been widely used in various industries due to their unique advantages such as high efficiency, strong overload, and excellent controllability. The winding coils are mainly diamond-shaped, hexagonal, straight-wound I-shaped, oblique-wound, etc., and each winding type has a different range of application. However, the current production cost of slotless hollow cup motors with high power, thick wire diameter, and large-size coils is high, which makes large-scale production difficult and cannot be widely used in the market.

[0003] The production of existing slotless hollow cup motors is mainly restricted by: (1) The equipment required for winding and subsequent shaping of the winding coils to form a cylindrical coil as a whole has a low degree of automation, many processes, slow speed, and is time-consuming and labor-intensive.

[0004] (2) Most brushless motors use Hall sensors as the electrical commutation method. The general application is to weld the Hall element onto the PCB board as a whole, corresponding to a certain position of the coil winding, so that the Hall element can output the correct commutation signal of the motor when the rotor rotates. However, the cylindrical coil winding and the annular core of the slotless hollow cup brushless motor do not have obvious reference positions and positioning structures, making it impossible to determine the position of the PCB board. The usual process is to connect the circuit and the detection instrument, manually or by equipment to rotate the PCB board (the Hall element is welded on the PCB board), find a certain signal point to determine the position of the PCB board (that is, the corresponding position of the Hall element and the coil winding) and fix it. The operation is cumbersome and inefficient, and it takes up a lot of man-hours. It is far from being comparable to the simplicity of using the slotted brushless motor to directly locate the Hall element using the notch of the stator core or locate the PCB board (indirectly locate the Hall element on the PCB board).

[0005] Therefore, the structure and winding method of the coil winding of the existing slotless motor should be improved, and the structure of other related components should be improved so that the coil production and the assembly of the coil and the iron core stator can be quickly and efficiently mass-produced; at the same time, the rapid positioning of the Hall element of the Hall type slotless motor should be solved in order to break through the bottleneck of the production of slotless hollow cups. Summary of the invention

[0006] The present invention mainly solves the coil winding, the process structure of the stator core suitable for assembly, the installation and fixation of the coil lead wire, and the process structure that facilitates the rapid and accurate positioning of the PCB board of the slotless brushless motor with Hall element type.

[0007] A brushless permanent magnet motor, the motor includes a motor shaft, a front bearing, a rear bearing, a housing and a motor tail cover, the permanent magnet rotor is fixed on the motor shaft, and is installed in the housing through the front bearing and the rear bearing, and the stator assembly, the Hall element and the PCB board are installed on the inner wall of the housing. The stator assembly is composed of a circular iron core stator and a winding coil, the circular iron core stator is composed of a first circular iron core stator and a second circular iron core stator connected in front and back, the winding coil is tightly attached to the inner wall of the circular iron core stator (inner rotor structure) or wrapped around the outside of the circular iron core (outer rotor structure). The winding coil is surrounded by N (three or more) individual coils to form a cylindrical shape, the edges of each individual coil are adjacent to each other, the adjacent joint of two individual coils is a V-shaped gap, and each individual coil occupies one Nth of the circumference. The individual coils are a racetrack structure made of single, multiple or twisted enameled wires wound concentrically from the inside to the outside. The H section of the incoming wire end of each individual coil is attached to one side of the coil, and the whole has an arc and is concentric with the annular iron core stator.

[0008] The coil winding of the present invention is assembled by N individual racetrack-shaped coils. The equipment for making such individual coils using self-adhesive wires is very popular and the winding speed is very fast. The individual coils can achieve very high dimensional accuracy through subsequent tooling finalization. Each individual coil can be assembled into a cylindrical winding simply by loading it into the stator core, which greatly reduces the difficulty of equipment, process steps and technology, and improves the production speed. In addition, the stator winding assembled by the racetrack-shaped coils has extremely high electromagnetic parameter performance. In the coil structure of various slotless brushless hollow cup motors, the power density is equal to or slightly exceeds that of the precision diamond winding type winding, and is only slightly inferior to the electromagnetic parameters of the straight-wound I-shaped winding, which has great application value and practicality. The use of multiple individual coils to assemble the winding coils greatly improves the production efficiency of the motor winding coils.

[0009] The lead-out wire end of the winding coil of the present invention is provided with an annular support frame, one end face of the support frame is provided with a positioning column, and the other end face is provided with a plurality of positioning protrusions, the positioning column is used to install the PCB board, and the positioning protrusion is positioned and snapped into the V-shaped gap position of the coil winding; the Hall element 8 is welded on the PCB board 10 as a whole. If the positioning column (19) of the support frame (17) and the Hall element are both at X° of the circumference, the positioning protrusion (18) of the support frame (17) is at X+60°. The PCB board is provided with holes or slots corresponding to the lead-out wires of the individual coils, which are used to fix the lead-out wires of each individual coil.

[0010] The racetrack coil used in the present invention is wound with a universal self-adhesive enameled wire, and has high physical size accuracy after molding. The H-segment portion of the winding lead can be accurately fixed at the designed position of the edge of a single coil by means of self-adhesion or dispensing. The distance (or angle) between this position and the electromagnetic center of the individual coil is accurate, so that the subsequent assembly of the PCB board can be accurately positioned (that is, the electromagnetic commutation position of the Hall element on the PCB board and the individual coil can be accurately positioned), including: 1) When the coil winding uses a thinner enameled wire, a support frame as shown in the figure is used. The V-shaped groove gap naturally formed at the joint after the runway-type coil is assembled is used as the positioning structure of the protruding structure on the support frame. The positioning structure on the support frame is then used to position the PCB board. This allows the Hall element position calculated by geometry to accurately match the electromagnetic commutation position of the coil winding; 2) When the coil winding uses thicker enameled wire, the above-mentioned support frame method can be used to position the PCB board. Alternatively, the rigidity of the thick wire can be used to directly use the lead-out part of the H segment of the individual coil as the positioning point, and the lead-out wire can be fixed to the corresponding hole or slot of the PCB board. This can also ensure that the Hall element position calculated by geometry is accurately consistent with the electromagnetic commutation position of the coil winding. The above structure omits the step of manually or using other equipment to adjust the PCB board to determine the corresponding electromagnetic commutation position of the Hall element and the coil winding during the motor assembly process, which will greatly improve the production speed and is also highly practical.

[0011] The first annular iron core stator (4) and the second annular iron core stator (7) of the stator core of the present invention are formed by laminating thin sheets of annular single-piece magnetic conductive material or by rolling or die-casting of conductive tape-shaped material. The first annular iron core stator (4) is a perfect circle without slots. When the second annular iron core stator (7) is used as an inner rotor, a plurality of slots (13) are provided on the inner ring. When the second annular iron core stator (7) is used as an outer rotor, a plurality of slots (13) are provided on the outer ring. The H section of the wire inlet end (14) of each individual coil is installed in the slot (13) of the annular iron core stator (7). During assembly, the H section of the winding coil and the lead wire can be inserted into the slot to position and lead out, thereby avoiding problems such as the lead wire being messy, being pressed and deformed to cause wire breakage, short circuit, and being unable to cooperate with the iron core stator. Alternatively, both sections of the iron core are standard slotless rings. When used for the inner rotor, the inner diameter φX of the first annular iron core stator (4) is smaller than the inner diameter ΦY of the second annular iron core stator (7). When used for the outer rotor, the inner diameter φX of the first annular iron core stator (4) is larger than the inner diameter ΦY of the second annular iron core stator (7). The H section of the wire inlet end (14) of each individual coil is installed in the annular iron core stator (7). During assembly, the H section and the lead-out wire portion of the winding coil are installed at the second annular iron core stator. There is an installation gap between the winding coil and the second annular iron core stator, which facilitates the placement of the H section and the lead-out wire, and avoids problems such as the lead-out wire being messy, being pressed and deformed, causing the wire to break, short circuit, and being unable to match the iron core stator.

[0012] The H-segment part of the winding inlet end 14 of the racetrack-shaped coil is naturally formed by winding and overlaps with one side of the coil as a whole. After multiple coils are assembled into a cylindrical shape and loaded into the stator core, the H-segment part is between the core wall and a single coil side, resulting in a bulge in the inner diameter of the coil side (inner rotor structure) or a bulge in the outer diameter of the coil (outer rotor structure), which will occupy the air gap between the inner diameter of the coil (inner rotor structure) or the outer diameter (outer rotor structure) and the rotor, and has a great risk of sweeping the coil. Especially for large-diameter and small-size windings, this bulge is not allowed. If the coil is forced to be squeezed and shaped, the H-segment will be squeezed and damaged, causing wire breakage or short circuit between the turns of the wire on the coil side. If the method of reducing the wall thickness of the coil winding or reducing the rotor diameter to ensure the size of the air gap between the coil and the rotor is used to avoid rotor sweeping coils and avoid wire breakage and short circuit of the lead wire, this will reduce the magnetic properties of the rotor and reduce the winding slot full rate, greatly weakening the performance of the motor. Therefore, the present invention adopts a two-section structure of the iron core stator, which is a combination of a first circular iron core stator and a second circular iron core stator. A slot is opened on the second circular iron core stator, thereby providing space for placing the H-segment portion of the coil. The advantage of this structure is that it ensures that the overall dimensions of the inner and outer diameters of the assembled cylindrical coil winding are not affected by the H-segment portion, solves the hidden dangers of lead wire breakage and short circuit, and maximizes the coil winding slot fill rate. This structure is indispensable, especially for thick-diameter winding coils. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is the schematic diagram of the motor structure; Figure 2 is a schematic diagram of the coil winding structure; Figure 3 It is a schematic diagram of a single coil; Figure 4 It is a schematic diagram of the stator core of the slotless brushless motor with inner rotor structure; Figure 5 is a schematic diagram of the stator assembly; Figure 6 is a schematic diagram of the support frame; Figure 7 It is a schematic diagram of the assembly of the support frame and the coil winding; Figure 8 This is a schematic diagram of the PCB board and the Hall element; Fig. 9 It is a schematic diagram of the coil winding, support frame, and PCB board assembly; Fig.10 It is a schematic diagram of the stator core of the slotless brushless motor with inner rotor structure; The reference numerals are: 1 motor shaft, 2 front bearing, 3 housing, 4 first ring stator core, 5 winding coil, 6 permanent magnet rotor, 7 second ring stator core, 8 Hall element, 9 motor tail cover, 10 PCB board, 11 rear bearing, 13 notch, 14 wire inlet, 17 support frame, 18 positioning protrusion, 19 positioning column, slot 21, 22 separate coil. Implementation

[0014] The present invention will be further described below in conjunction with specific embodiments and the accompanying drawings. The specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0015] Embodiment: A brushless permanent magnet motor, such as Figure 1 As shown, it is composed of a motor shaft 1, a front bearing 2, a rear bearing 11, a housing 3, a first iron core stator 4, a second iron core stator 7, a permanent magnet rotor 6, a Hall element 8, a motor tail cover 9 and a PCB board 10. The permanent magnet rotor 6 is fixed on the motor shaft 1, and is installed in the housing 3 through the front bearing 2 and the rear bearing 11. The stator assembly is installed on the inner wall of the housing 3, the Hall element 8 is installed on the PCB board 10, and the PCB board is fixed to the rear end of the stator assembly. The tail cover 9 supports the rotor together with the front bearing through the rear bearing.

[0016] like Figure 5 As shown, the stator assembly is composed of a toroidal core stator and a winding coil 5, and the winding coil 5 is closely attached to the inner wall of the toroidal core stator (inner rotor structure). Figure 2 As shown, the winding coil 5 is formed into a cylindrical shape by three individual coils 22, the sides of each individual coil are adjacent to each other, the adjacent joint of two individual coils forms a V-shaped gap, and each individual coil occupies one third of the circumference. Figure 3As shown, the individual coil 22 is a racetrack structure that is concentrically wound from the inside to the outside by a single, multiple or twisted enameled wire. The H section of the wire inlet end 14 of each individual coil is attached to one side of the coil, and the whole has an arc and is concentric with the toroidal core stator. Figure 4 As shown, the annular core stator is composed of a first annular core stator 4 and a second annular core stator 7 connected in front and back. The first annular core stator 4 and the second annular core stator 7 are made of annular single-piece magnetic conductive material sheets laminated or rolled or die-cast from conductive tape-shaped materials. The first annular core stator 4 is a perfect circle without slots. When the second annular core stator 7 is used as an inner rotor, the inner ring is provided with three slots 13, which correspond to the number of individual coils. The H section of the inlet end 14 of each individual coil 22 is installed in the slot 13 of the annular core stator 7. Or as Fig.10 As shown, both sections of the iron core are standard slotless rings. When used for the inner rotor, the inner diameter φX of the first annular iron core stator 4 is smaller than the inner diameter φY of the second annular iron core stator 7. When used for the outer rotor, the inner diameter φX of the first annular iron core stator (4) is larger than the inner diameter φY of the second annular iron core stator (7). The H section of the incoming wire end (14) of each individual coil 22 is installed in the second annular iron core stator (7). There is a gap between the winding coil and the second annular iron core stator 7, which is convenient for placing the H section and lead wire of the winding coil.

[0017] The lead-out wire end of the winding coil 5 is provided with an annular support frame 17, such as Figure 6 As shown, one end face of the support frame 17 is provided with a plurality of positioning posts 19, and the other end face is provided with three positioning protrusions 18. The positioning posts 19 are used to install the PCB board and cooperate with the positioning holes 23 on the PCB board; the positioning protrusions 18 are positioned and snapped into the V-shaped gap position of the coil winding 5. The assembly structure of the winding coil 5 and the support frame 17 is as shown in FIG. Figure 7 The corresponding PCB board 10 structure is as shown Figure 8 As shown, a ring plate is used, a positioning hole 23 is set on the plate for installation, and three slots 21 for fixing the lead wire are set, the Hall element 8 is installed on the PCB board 10 as a whole, the PCB board 10 is fixed to the support frame 17, and is assembled with the winding coil 5 as a whole. The assembly structure is as shown in FIG. Fig. 9 As shown, the lead wire of each individual coil 22 passes through the slot 21 on the PCB board 10. Using the positioning structure of the support frame, the position of the installed Hall device and the PCB board corresponds to the electrical commutation position of the winding coil (this can be designed and calculated. For example, the position of the Hall element 8 in this example needs to be aligned with the center line of the individual coil, then the positioning column 19 of the support frame 17 and the Hall element are both at X° of the circumference, and the positioning protrusion 18 of the support frame 17 is at (X+60°), so that when the motor is running, the signal output by the Hall element is the correct electromagnetic commutation signal, making the installation positioning accurate, fast and efficient.

[0018] The present invention utilizes the high physical dimension accuracy of the racetrack-shaped coil after forming, the winding lead wire can be accurately fixed at a certain position of the edge of a single coil by means of glue dispensing, and the structural characteristics of the single coil H wire installed in the stator core slot and the winding lead wire, etc., so as to achieve: 1) When using thicker diameter enameled wire for winding, the lead-out part of the H line segment of the above-mentioned single coil can be used as the positioning point on the PCB board; 2) When winding with thinner enameled wire, you can use Figure 6 The support frame 17 utilizes the V-shaped groove gap naturally formed at the joint after the racetrack-shaped coil is assembled as the positioning of the protruding structure 18 on the support frame 17, and then uses the positioning structure 19 on the support frame 17 to position the PCB board. This allows the Hall element position calculated by geometry to be accurately matched with the electrical commutation position of the coil winding, which greatly simplifies the positioning operation process of the Hall element and can greatly improve the production speed.

[0019] The slotless brushless hollow cup motor made by this patent is suitable for various size ranges and has the advantages of relatively simple equipment, relatively simple process, excellent motor electromagnetic parameters, high production efficiency and conducive to large-scale production.

[0020] In summary, the above are preferred embodiments of the present invention. Any changes made according to the technical solution of the present invention, as long as the functional effects produced do not exceed the scope of the technical solution of the present invention, belong to the protection scope of the present invention.

Claims

1. A brushless permanent magnet motor, comprising a motor shaft (1), a front bearing (2), a rear bearing (11), a housing (3) and a motor tail cover (9), wherein a permanent magnet rotor (6) is fixed on the motor shaft (1) and installed in the housing (3) via the front bearing (2) and the rear bearing (11), a stator assembly is installed on the inner wall of the housing, and a Hall element (8) is directly inserted or surface mounted on a PCB (10); the characteristics are: The stator assembly is composed of a circular iron core stator and a winding coil (5), wherein the circular iron core stator is composed of a first circular iron core stator (4) and a second circular iron core stator (7) connected in front and back sections, and the winding coil (5) is closely attached to the inner wall of the circular iron core stator (inner rotor structure) or wrapped around the outside of the circular iron core (outer rotor structure); The winding coil (5) is formed into a cylindrical shape by N (three or more) individual coils (22), the edges of each individual coil are adjacent to each other, the adjacent joint of two individual coils forms a V-shaped gap, and each individual coil occupies one Nth of the circumference; the individual coil (22) is a runway-shaped structure wound concentrically from the inside to the outside by a single, multiple or twisted enameled wire, the H section of the wire inlet end (14) of each individual coil winding is attached to one edge of the coil, and the whole has an arc and is concentric with the annular iron core stator; An annular support frame (17) is provided at the lead-out end of the winding coil (5); a positioning column (19) is provided on one end face of the support frame (17); a plurality of positioning protrusions (18) are provided on the other end face; the positioning column (19) is used to install a PCB board; the positioning protrusions (18) are positioned and snapped into the V-shaped gap position of the coil winding (5); the Hall element (8) is a direct plug or patch type welded on the PCB board (10) as a whole; if the positioning column (19) and the Hall element of the support frame (17) are both at X° of the circumference, the positioning protrusions (18) of the support frame (17) are at X+60°.

2. A brushless permanent magnet motor according to claim 1, characterized in that: The first annular iron core stator (4) and the second annular iron core stator (7) are formed by laminating thin sheets of annular single-piece magnetic conductive material or rolling conductive tape-shaped material or die-casting magnetic conductive material. The first annular iron core stator (4) is a perfect circle without slots. When the second annular iron core stator (7) is used as an inner rotor, a plurality of slots (13) are arranged on the inner ring. When the second annular iron core stator (7) is used as an outer rotor, a plurality of slots (13) are arranged on the outer ring. The H section of the wire inlet end (14) of the winding of each individual coil (22) is installed in the slot (13) of the annular iron core stator (7).

3. A brushless permanent magnet motor according to claim 1, characterized in that: The first annular iron core stator (4) and the second annular iron core stator (7) are formed by laminating thin sheets of annular single-piece magnetic conductive material or by rolling a magnetic conductive tape-shaped material or by die-casting a magnetic conductive material. When used as an inner rotor, the inner diameter φX of the first annular iron core stator (4) is smaller than the inner diameter φY of the second annular iron core stator (7); when used as an outer rotor, the inner diameter φX of the first annular iron core stator (4) is larger than the inner diameter φY of the second annular iron core stator (7). The H section of the wire inlet end (14) of the winding of each individual coil (22) is installed in the annular iron core stator (7) section.

4. The brushless permanent magnet motor according to claim 1, characterized in that: The PCB board (10) is provided with holes or slots (21) corresponding to the lead wires (14), (15), (16) of the individual coils (22), and is used to fix the lead wires of each individual coil (22).

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