Motor and method for manufacturing motor

Abstract

To provide a motor which does not corrode due to water on common lines.SOLUTION: The motor has a connecting part 35 in which common lines of a plurality of coil groups are electrically connected and coupled. The connecting part extends in a slot 313, which is a part between teeth 312 circumferentially adjacent to each other, from an inner side in a radial direction to an outer side in the radial direction or vice versa, and has a sealing part 36 for sealing at least the connecting part.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a motor and a method for manufacturing a motor. [Background technology]

[0002] Conventional motors have a base portion that has a lead-out hole through which a common wire included in multiple lead-out wires of a coil is drawn out (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-135076 Summary of the Invention [Problem to be solved by the invention]

[0004] There is an increasing demand for motors to be operated in environments where moisture is likely to adhere, and in motors with conventional configurations, there is a risk of corrosion if moisture adheres to the common wire.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a motor that can suppress corrosion of the common wire due to adhesion of moisture. [Means for solving the problem]

[0006] An exemplary motor of the present invention includes a rotor that rotates about a central axis and a stator having multiple coil groups arranged on multiple teeth that radially face the rotor. Each of the coil groups includes at least one coil formed from a continuous conductor and a common wire that is provided at the end of the conductor and has an exposed conductive portion. The common wires of the multiple coil groups are electrically connected and have a coupling portion that links them. The coupling portion extends from the radial inside to the radial outside or vice versa within a slot that is a portion between circumferentially adjacent teeth. The stator also has a sealing portion that seals at least the coupling portion. [Effects of the Invention]

[0007] According to the exemplary motor of the present invention, corrosion of the connection portion that electrically connects the common wires to each other due to adhesion of moisture can be suppressed. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic cross-sectional view of a motor according to an embodiment. [Figure 2] FIG. 2 is a schematic perspective view of the stator. [Figure 3] FIG. 3 is a diagram showing the connection state of a plurality of coil groups. [Figure 4] FIG. 4 is a schematic diagram showing the structure of the conductor wire. [Figure 5] FIG. 5 is a schematic perspective view of a connecting portion that bundles together the common wires. [Figure 6] FIG. 6 is an enlarged cross-sectional view of the stator core to which the connecting portion is fixed, taken along a plane including the central axis. [Figure 7] FIG. 7 is a bottom view of the circuit board as seen from below in the axial direction. [Figure 8] FIG. 8 is an enlarged cross-sectional view of the U-phase lead wire attached to the U-phase land. [Figure 9] FIG. 9 is a flowchart of the motor manufacturing process. [Figure 10] FIG. 10 is a schematic diagram showing the state in which the common wire is inserted into the solder bath. [Figure 11] FIG. 11 is a schematic diagram showing a state in which a lead wire is inserted into a solder bath. [Figure 12] FIG. 12 is a cross-sectional view of the motor of the first modification. [Figure 13] FIG. 13 is a cross-sectional view of the motor of the second modification. [Figure 14] FIG. 14 is a cross-sectional view of a motor according to the third modification. [Figure 15] FIG. 15 is a schematic perspective view showing the stator of the motor shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, a motor unit according to an embodiment of the present invention will be described with reference to the drawings. Note that the scope of the present invention is not limited to the following embodiment, and can be modified as desired within the scope of the technical concept of the present invention.

[0010] In this specification, the direction parallel to the central axis Ax of the shaft 10 of the motor 100 is referred to as the "axial direction." The direction perpendicular to the central axis Ax is referred to as the "radial direction," and the circumferential direction about the central axis Ax is referred to as the "circumferential direction." In the following description, the upper side will be referred to as the axially upper side and the opposite side as the axially lower side, based on the state shown in FIG. 1.

[0011] In this specification, the term "annular" refers not only to a shape that is continuous and uninterrupted throughout the entire circumferential direction around the central axis Ax, but also to a shape that has one or more interruptions in a portion of the entire area around the central axis Ax. It also refers to a shape that describes a closed curve on a curved surface that intersects with the central axis Ax.

[0012] Furthermore, in this specification, the term "parallel direction" includes not only completely parallel directions but also substantially parallel directions. Furthermore, when referring to "extending along" a predetermined direction or plane, it includes not only extending strictly in the predetermined direction but also extending in a direction tilted by less than 45° relative to the strict direction. Furthermore, "perpendicular" and "orthogonal" each include not only a state in which the two intersect at 90 degrees with each other, but also a state in which they are substantially perpendicular and a state in which they are substantially orthogonal. In other words, "parallel," "perpendicular," and "orthogonal" each include a state in which there is an angular deviation in the positional relationship between the two to an extent that does not deviate from the spirit of the present invention.

[0013] It should be noted that these are names used merely for the purpose of explanation and do not limit the actual positional relationship, direction, names, etc.

[0014] <Motor 100> A motor 100 according to an exemplary embodiment of the present invention will be described below with reference to the drawings. Fig. 1 is a schematic cross-sectional view of the motor 100 according to the embodiment. Fig. 1 shows the cross-sectional structure of the motor 100 when it is virtually cut along a plane including the central axis.

[0015] 1, motor 100 includes a shaft 10, a rotor 20, a stator 30, a base plate 40, a circuit board 50, and bearings 60. Motor 100 is a so-called outer rotor type brushless DC motor.

[0016] <Shaft 10> The shaft 10 extends axially along the central axis Ax and has a cylindrical shape centered on the central axis Ax. At least a portion of the shaft 10 is disposed inside a holding portion 41 (described later) of the base plate 40 and is rotatably supported by the holding portion 41 via a bearing 60. In other words, the shaft 10 is a rotating shaft that can rotate around the central axis Ax. Note that in the motor 100, the shaft 10 may be a fixed shaft that is fixed to the base plate 40. In this case, the bearing 60 is disposed between the shaft 10 and the rotor 20, and the rotor 20 is rotatably supported relative to the shaft 10.

[0017] <Rotor 20> 1, the rotor 20 includes a rotor case 21 and a rotor magnet 22. The rotor case 21 is made of a magnetic material and has a cylindrical shape with a lid, and includes a rotor hub 211 and a rotor cylindrical portion 212.

[0018] The rotor hub 211 has a cylindrical rotor boss 213 that extends axially downward from its radial center. The rotor hub 211 is flat and extends radially. The rotor boss 213 is cylindrical and extends along the central axis Ax, with its center line overlapping the central axis Ax. The upper axial end of the shaft 10 is fixed to the rotor boss 213. This fixes the shaft 10 to the rotor case 21.

[0019] Here, the rotor boss 213 and the shaft 10 are fixed by press-fitting, but this is not a limitation. The method of fixing the rotor boss 213 and the shaft 10 can be widely adopted, for example, by bonding, welding, screwing, or other methods that can firmly fix the rotor boss 213 to the shaft 10. In this way, the rotor 20 is fixed to the shaft 10. Therefore, the rotor 20 rotates around the central axis Ax.

[0020] The rotor tubular portion 212 is cylindrical and extends axially downward from the radial outer edge of the rotor hub 211. A plurality of rotor magnets 22 are fixed to the inner peripheral surface of the rotor tubular portion 212. The plurality of rotor magnets 22 are cylindrical. The rotor magnets 22 surround the stator 30 (particularly the stator core 31 described below) from the radial outside and face each other in the radial direction. The plurality of rotor magnets 22 are arranged in the circumferential direction. The magnetic poles (N and S poles) on the radially inner side of adjacent rotor magnets 22 in the circumferential direction are alternately different. Note that although the rotor 20 is configured to have a plurality of rotor magnets 22, it is also possible to employ cylindrical magnets in which the magnetic poles on the inner peripheral surface are arranged with N and S poles alternately arranged in the circumferential direction.

[0021] As described above, the cylindrical rotor tube portion 212 is made of a magnetic material, and when the rotor magnet 22 is attached to the inner peripheral surface, the rotor tube portion 212 serves as a rotor yoke.

[0022] <Stator 30> Fig. 2 is a schematic perspective view of the stator 30. As shown in Figs. 1 and 2, the stator 30 has a stator core 31, an insulator (not shown), and a plurality of coil groups 32U, 32V, and 32W. The stator core 31 is a laminated body formed by stacking electromagnetic steel sheets in the axial direction. Note that the stator core 31 is not limited to a laminated body formed by stacking electromagnetic steel sheets, and may be a single member formed by, for example, sintering or casting powder.

[0023] The stator core 31 has an annular core back 311 and a plurality of teeth 312. An inner peripheral surface 310 of the annular core back 311 is fixed to a holding portion 41 of the base plate 40. This causes the center of the stator core 31 to overlap the central axis Ax of the motor 100. Note that a fixing member may be interposed between the core back 311 and the holding portion 41.

[0024] The teeth 312 extend radially outward from the outer peripheral surface of the core back 311. The teeth 312 are arranged at equal intervals in the circumferential direction. The outer peripheral surfaces of the teeth 312 face the inner peripheral surface of the rotor magnet 22 of the rotor 20 in the radial direction. The insulator is formed of an insulating material such as resin.

[0025] The stator 30 has a plurality of coil groups 32U, 32V, and 32W arranged on a plurality of teeth 312 that are radially opposed to the rotor 20. In the motor 100, currents of different phases are supplied to each of the coil groups 32U, 32V, and 32W at appropriate timing, thereby generating an attractive or repulsive force between the coil groups and the rotor magnet, causing the rotor 20 to rotate. The plurality of coil groups are referred to as a U-phase coil group 32U, a V-phase coil group 32V, and a W-phase coil group 32W, and the currents supplied to each coil group are referred to as a U-phase current IU, a V-phase current IV, and a W-phase current IW.

[0026] FIG. 3 is a diagram showing the connection state of multiple coil groups 32U, 32V, and 32W. As shown in FIG. 3, stator 30 has 15 teeth 312, and U-phase coil group 32U has five coils 33U. In U-phase coil group 32U, the five coils 33U are connected in series. V-phase coil group 32V has five coils 33V. In V-phase coil group 32V, the five coils 33V are connected in series. W-phase coil group 32W has five coils 33W. In W-phase coil group 32W, the five coils 33W are connected in series. That is, each of coil groups 32U, 32V, and 32W has at least one coil 33U, 33V, and 33W formed from a continuous conductor 34.

[0027] One of the conductors 34 extending from both ends of U-phase coil group 32U, to which coil 33U is connected in series, is U-phase common wire 321U, and the other is U-phase lead wire 322U. Similarly, one of the conductors 34 at both ends of V-phase coil group 32V is V-phase common wire 321V, and the other is V-phase lead wire 322V. Furthermore, one of the conductors 34 at both ends of W-phase coil group 32W is W-phase common wire 321W, and the other is W-phase lead wire 322W. That is, coil groups 32U, 32V, and 32W have common wires 321U, 321V, and 321W that are provided at the ends of conductors 34 and have exposed conductive portions 341.

[0028] Each of the coils 33U, 33V, and 33W is formed by winding a conductor around a tooth 312 covered with an insulator (not shown). FIG. 4 is a schematic diagram showing the structure of the conductor 34. As shown in FIG. 4, the conductor 34 has a conductive portion 341 and an insulating coating 342. The conductor 34 has a configuration in which the outer surface of the conductive portion 341 is covered with the insulating coating 342. Note that the conductor 34 may be a so-called enameled wire in which the conductive portion 341 made of copper is covered with the insulating coating 342 made of enamel resin, but is not limited to this. The conductor 34 may be any conductor in which the outer periphery of a conductive material with low resistance is covered with an insulating material.

[0029] The coils 33U, 33V, and 33W are all connected to one another by conductors 34. The conductors connecting the coils, known as crossover wires, are attached to attachment portions (not shown) formed on the insulator. This prevents the crossover wires from sagging, and prevents the sagging crossover wires from coming into contact with the shaft 10 and rotor 20 and breaking.

[0030] In the motor 100, the U-phase common wire 321U of the U-phase coil group 32U, the V-phase common wire 321V of the V-phase coil group 32V, and the W-phase common wire 321W of the W-phase coil group 32W are connected together. That is, in the motor 100, the three coil groups 32U, 32V, and 32W are star-connected. The U-phase common wire 321U, the V-phase common wire 321V, and the W-phase common wire 321W are electrically connected together by a connecting portion 35. The connecting portion 35 will be described in detail later.

[0031] Furthermore, the ends of U-phase lead wire 322U, V-phase lead wire 322V, and W-phase lead wire 322W have exposed portions 343 where insulating coating 342 has been removed. That is, coil groups 32U, 32V, and 32W have lead wires 322U, 322V, and 322W that are provided at the ends of conductor wire 34 and have conductive portions 341 exposed. Solder-up portions 323U, 323V, and 323W are formed by applying solder to the surfaces of exposed portions 343. Solder-up portions 323U, 323V, and 323W are electrically connected by solder 56 to lands 531U, 531V, and 531W provided on circuit board 50. The connection of U-phase lead wire 322U, V-phase lead wire 322V, and W-phase lead wire 322W to circuit board 50 will be described in detail below.

[0032] <Base plate 40> The base plate 40 has a flat plate shape that extends in a direction perpendicular to the central axis Ax. The base plate 40 is disposed axially lower than the rotor 20 and the stator 30. The base plate 40 has a cylindrical holding portion 41 in the radial center that extends upward along the axial direction. The holding portion 41 and the base plate 40 are integrally formed. Alternatively, the holding portion 41 may be formed separately from the base plate 40 and fixed to the base plate 40.

[0033] Two bearings 60 are arranged side by side in the axial direction on the inner peripheral surface 411 of the holding portion 41, and the two bearings 60 rotatably support the shaft 10 relative to the holding portion 41. The stator core 31 is fixed to the holding portion 41 with the inner peripheral surface of the core back 311 of the stator core 31 in contact with the outer peripheral surface 412 of the holding portion 41. The method for fixing the holding portion 41 and the core back 311 here is press-fitting. However, the method for fixing the holding portion 41 and the core back 311 is not limited to press-fitting, and a wide variety of fixing methods that can firmly fix the holding portion 41 and the core back 311 can be used, such as adhesive bonding, welding, melt-adhesion, and screw fastening.

[0034] <Connection part 35> 5 is a schematic perspective view of a coupling portion 35 that combines the common wires 321U, 321V, and 321W. As shown in FIG. 5, the insulating coating 342 is removed from the tips of the U-phase common wire 321U, the V-phase common wire 321V, and the W-phase common wire 321W, and the tips are twisted. Then, the conductive portions 341 at the tips of the twisted and integrated common wires 321U, 321V, and 321W are soldered to form the coupling portion 35. That is, the coupling portion 35 electrically connects the multiple common wires 321U, 321V, and 321W to each other, and the multiple common wires 321U, 321V, and 321W are soldered together to form the coupling portion 35. Therefore, the common wires 321U, 321V, and 321W can be electrically connected to each other at the coupling portion 35.

[0035] The U-phase common wire 321U, the V-phase common wire 321V, and the W-phase common wire 321W are electrically connected via the connecting portion 35. That is, the stator 30 has the connecting portion 35 to which the common wires 321U, 321V, and 321W of the multiple coil groups 32U, 32V, and 32W are electrically connected and linked.

[0036] Here, a description will be given of how the connecting portion 35 is fixed to the stator core 31. Fig. 6 is an enlarged cross-sectional view of the stator core 31 to which the connecting portion 35 is fixed, taken along a plane including the central axis Ax.

[0037] As shown in FIGS. 2 and 6 , the connecting portion 35 is disposed inside a slot 313 formed between circumferentially adjacent teeth 312. More specifically, since the motor 100 of this embodiment is an outer rotor motor, the teeth 312 of the stator core 31 extend radially outward from the core back 311 disposed radially inward. Therefore, the common wires 321U, 321V, and 321W are continuous with the respective coils radially inward in the stator core 31. The connecting portion 35 extends radially outward within the slot 313. That is, the connecting portion 35 is positioned radially outward toward the tip. The connecting portion 35 may be disposed in a skewed position with respect to the central axis Ax.

[0038] That is, the connecting portion 35 extends from the radially inner side to the radially outer side in the slot 313, which is a portion between circumferentially adjacent teeth 312. The connecting portion 35 may be configured to extend in a direction intersecting the central axis Ax. Furthermore, the connecting portion 35 may extend in a radial direction centered on the central axis Ax.

[0039] The U-phase common wire 321U, the V-phase common wire 321V, and the W-phase common wire 321W are arranged in the axially upper portion of the stator 30. Therefore, as shown in FIG. 5 , the connecting portion 35, which is formed by twisting and bundling the common wires, is arranged in the axially upper portion of the slot 313.

[0040] As described above, the conductive wires 34 that make up the connecting portion 35 are soldered after the insulating coating 342 arranged around the outer periphery is removed. If the soldered portion of the connecting portion 35 is exposed, there is a risk of corrosion, or rust, occurring due to the influence of external moisture. In particular, in the case of a motor 100 operated in a high-temperature, high-humidity environment, rust is likely to occur in the connecting portion 35. For this reason, the motor 100 has a sealing portion 36 that seals the connecting portion 35. In other words, the stator 30 of the motor 100 has a sealing portion 36 that seals at least the connecting portion 35.

[0041] Here, the sealing portion 36 will be described. The sealing portion 36 is a member that covers the connecting portion 35. The sealing portion 36 can be made of a resin formed from a material that prevents moisture from passing through. This prevents moisture from reaching the connecting portion 35 from the outside. Examples of the sealing portion 36 include an ultraviolet-curable resin that has the property of preventing moisture from passing through and is cured by ultraviolet irradiation, a thermosetting resin that is cured by heating, and a resin that is cured by a chemical reaction. Because the sealing portion 36 is made of resin, the connecting portion 35 can be easily sealed. This allows the number of parts to be kept small, and the number of steps in the manufacturing process to be reduced.

[0042] The sealing portion 36 is disposed between both ends of the coils 33U and 33V along the central axis Ax. This configuration prevents the sealing portion 36 from protruding outward beyond both ends of the stator 30 along the central axis Ax. This reduces contact between the rotor 20 and the sealing portion 36. The connecting portion 35 is disposed offset to one side of the center of the slot 313 along the central axis Ax. Therefore, the sealing portion 36 is disposed to one side of the center of the slot 313 along the central axis Ax. This configuration allows the sealing portion 36 to be formed after the connecting portion 35 is disposed inside the slot 313. Because the sealing portion 36 is formed near the axial opening of the slot 313, resin can be easily filled around the connecting portion 35. As a result, the sealing portion 36 can be easily formed.

[0043] The sealing portion 36 covers the connecting portion 35 and is fixed to the coils 33U, 33V wound around the teeth 312 adjacent to the slots 313. The sealing portion 36 may also be fixed to the teeth 312. That is, the sealing portion 36 is fixed to the teeth 312 circumferentially adjacent to the slots 313 in which the sealing portion 36 is arranged, or to the coils 33U, 33V arranged on the teeth 312. This fixes the connecting portion 35, thereby suppressing movement of the connecting portion 35 during operation of the motor 100 and suppressing contact of the connecting portion 35 with the rotor 20. In the motor 100, the connecting portion 35 may also be arranged at the axial lower end of the slots 313.

[0044] By configuring the connecting portion 35 and the sealing portion 36 as described above, the sealing portion 36 can prevent moisture from adhering to the connecting portion 35. This can prevent corrosion of the connecting portion 35 due to moisture. With this configuration, it is possible to provide a motor 100 that can be used in places where moisture is likely to adhere to the connecting portion 35 or where condensation is likely to occur.

[0045] <Circuit board 50> FIG. 7 is a bottom view of the circuit board 50 as viewed from below in the axial direction. As shown in FIG. 1, the circuit board 50 is disposed between the stator core 31 of the holding portion 41 and the base plate 40. As shown in FIG. 7, the circuit board 50 has a semicircular plate shape. The outer periphery of the circuit board 50 has a linear portion and an arc-shaped portion. A concave mounting portion 51 is formed in the center of the linear portion of the circuit board 50. The mounting portion 51 comes into contact with the outer circumferential surface 412 of the holding portion 41, thereby fixing the circuit board 50 to the holding portion 41. Note that the circuit board 50 of this embodiment may be annular.

[0046] The axial lower surface of the circuit board 50 is a pattern surface 52, and a wiring pattern 53 made of a conductive film having electrical conductivity is formed on the pattern surface 52. A plurality of electronic components Tp are mounted on the wiring pattern 53 to form a circuit. That is, the circuit board 50 has the wiring pattern 53 formed on at least one surface in the thickness direction to form the circuit. The electronic components Tp are arranged on the pattern surface 52 and are surface-mounted such that their terminals are electrically connected to the pattern wiring. Note that the mounting of the electronic components Tp is not limited to surface mounting and may be through-hole mounting.

[0047] The motor drive circuit has a control circuit, a driver circuit, an inverter circuit, etc., and supplies U-phase current IU, V-phase current IV, and W-phase current IW of appropriate current values and timing (phase) to U-phase coil group 32U, V-phase coil group 32V, and W-phase coil group 32W, respectively, based on external signals that indicate the rotational speed and torque of motor 100. In other words, circuit board 50 is connected to each of coil groups 32U, 32V, and 32W to drive each of coil groups 32U, 32V, and 32W.

[0048] 7, circuit board 50 has through holes 54U, 54V, and 54W that penetrate in the thickness direction. U-phase lead wire 322U penetrates through hole 54U. V-phase lead wire 322V penetrates through hole 54V. W-phase lead wire 322W penetrates through hole 54W. That is, lead wires 322U, 322V, and 322W penetrate through holes 54U, 54V, and 54W.

[0049] Wiring pattern 53 has a U-phase land 531U, a V-phase land 531V, and a W-phase land 531W. U-phase land 531U is arranged at a position away from through-hole 54U, V-phase land 531V is arranged at a position away from through-hole 54V, and W-phase land 531W is arranged at a position away from through-hole 54W. In other words, through-holes 54U, 54V, and 54W are arranged to avoid being located above wiring pattern 53.

[0050] The lead wires 322U, 322V, and 322W are drawn out to positions away from the through holes 54U, 54V, and 54W, and exposed portions 343 of the lead wires 322U, 322V, and 322W are brought into contact with the wiring patterns 531U, 531V, and 531W to be fixed. In this manner, it is sufficient that at least a portion of the exposed portions 343 of the lead wires 322U, 322V, and 322W is brought into contact with the wiring patterns 531U, 531V, and 531W, and therefore the exposed portions 343 can be shortened.

[0051] Exposed portion 343 of U-phase lead wire 322U is electrically connected to U-phase land 531U, exposed portion 343 of V-phase lead wire 322V is electrically connected to V-phase land 531V, and exposed portion 343 of W-phase lead wire 322W is electrically connected to W-phase land 531W. That is, exposed portions 343 of lead wires 322U, 322V, and 322W are electrically connected to wiring pattern 53. A motor drive circuit is connected to U-phase land 531U, V-phase land 531V, and W-phase land 531W.

[0052] Next, the connection state between the U-phase lead wire 322U, the V-phase lead wire 322V, and the W-phase lead wire 322W and the U-phase land 531U, the V-phase land 531V, and the W-phase land 531W will be described with reference to the drawings. The U-phase lead wire 322U, the V-phase lead wire 322V, and the W-phase lead wire 322W all have the same configuration. The U-phase land 531U, the V-phase land 531V, and the W-phase land 531W all have the same configuration. Therefore, the description will be made with reference to the U-phase lead wire 322U and the U-phase land 531U as representative examples. FIG. 8 is an enlarged cross-sectional view of the U-phase lead wire 322U attached to the U-phase land 531U.

[0053] 8, stator core 31 is disposed axially above circuit board 50. Therefore, U-phase lead wire 322U is routed from the upper side to the lower side of circuit board 50 in the axial direction. U-phase lead wire 322U then passes through through-hole 54U formed in circuit board 50 from the upper side to the lower side in the axial direction.

[0054] An exposed portion 343 is formed at the tip of the U-phase lead wire 322U, with the insulating coating 342 removed. This positions the exposed portion 343 at the tip of the U-phase lead wire 322U outside the through-hole 54U. The outer surface of the exposed portion 343 at the tip of the U-phase lead wire 322U is covered with solder to form a solder-removed portion 323U. The solder-removed portion 323U is then brought into contact with the U-phase land 531U and electrically connected thereto by solder. Similarly, the V-phase lead wire 322V and the W-phase lead wire 322W are electrically connected to the V-phase land 531V and the W-phase land 531W. This configuration allows a U-phase current IU to be supplied to the U-phase coil group 32U via the U-phase land 531U and the U-phase lead wire 322U. Similarly, a V-phase current IV is supplied to the V-phase coil group 32V, and a W-phase current IW is supplied to the W-phase coil group 32W.

[0055] The circuit board 50 has a cover member 55. The cover member 55 covers at least the wiring pattern 53 of the circuit board 50. In the circuit board 50 according to this embodiment, the cover member 55 is configured to cover the entire pattern surface 52. The cover member 55 seals the exposed portions 343 of the leads 322U, 322V, and 322W.

[0056] The cover member 55 is made of, for example, resin, which allows the cover member 55 to be shaped to match the wiring pattern 53 formed on the circuit board 50.

[0057] This makes it possible to prevent foreign matter such as water, dirt, and dust from adhering to wiring pattern 53 and U-phase lead wire 322U, V-phase lead wire 322V, and W-phase lead wire 322W attached to wiring pattern 53. With this configuration, it is possible to provide motor 100 that can be used in places where moisture is likely to adhere to the connecting portions or where condensation is likely to occur.

[0058] The cover member 55 is not limited to resin, and a wide variety of configurations can be used that have insulating properties and can reliably cover the wiring pattern 53. In the motor 100 according to this embodiment, the cover member 55 is made of a resin with fluidity, and may be formed by pouring the resin onto the pattern surface 52 of the circuit board 50 and then hardening it.

[0059] Furthermore, the portion of conductor 34 that constitutes U-phase lead wire 322U and that is covered with insulating coating 342 is disposed inside through hole 54U. Similarly, the portion of conductor 34 that constitutes V-phase lead wire 322V and that is covered with insulating coating 342 is disposed inside through hole 54V. The portion of conductor 34 that constitutes W-phase lead wire 322W and that is covered with insulating coating 342 is disposed inside through hole 54W. That is, the portions of conductor 34 that are covered with insulating coating 342 of lead wires 322U, 322V, and 322W are disposed inside through holes 54U, 54V, and 54W.

[0060] With this configuration, exposed portions 343 of conducting wires 34 are not disposed within through holes 54U, 54V, 54W, and therefore even if moisture flows into through holes 54U, 54V, 54W, adhesion of moisture to U-phase lead wire 322U, V-phase lead wire 322V, and W-phase lead wire 322W is suppressed, thereby suppressing corrosion. Furthermore, even if the inner diameters of through holes 54U, 54V, 54W are small and the resin constituting cover member 55 does not flow in, corrosion of U-phase lead wire 322U, V-phase lead wire 322V, and W-phase lead wire 322W is suppressed.

[0061] 8, the shortest distance between U-phase land 531U and through hole 54U is longer than the length of exposed portion 343 formed at the tip of U-phase lead 322U. Similarly, the shortest distance between V-phase land 531V and through hole 54V is longer than the length of exposed portion 343 formed at the tip of V-phase lead 322V. The shortest distance between W-phase land 531W and through hole 54W is longer than the length of exposed portion 343 formed at the tip of W-phase lead 322W. In other words, the shortest distance between wiring patterns 531U, 531V, and 531W, to which exposed portions 343 of lead 322U, 322V, and 322W are connected, and through holes 54U, 54V, and 54W through which lead 322U, 322V, and 322W pass is longer than the length of exposed portions 343 of lead 322U, 322V, and 322W.

[0062] This configuration can prevent exposed portions 343 of conducting wires 34 constituting U-phase lead wire 322U, V-phase lead wire 322V, and W-phase lead wire 322W from being disposed in through holes 54U, 54V, and 54W. Furthermore, exposed portions 343 are disposed at positions that axially overlap pattern surface 52 of circuit board 50. As a result, exposed portions 343 are reliably sealed when cover member 55 is disposed, and corrosion of exposed portions 343 due to adhesion of moisture thereto can be prevented.

[0063] In the motor 100 of this embodiment, the circuit board 50 is disposed between the stator 30 and the base plate 40, but is not limited to this. For example, the circuit board 50 may be disposed on the opposite side of the stator 30 from the base plate 40 in the axial direction.

[0064] <Method of manufacturing the motor 100> A manufacturing method of motor 100 will be described with reference to the drawings. Fig. 9 is a flowchart showing the manufacturing process of motor 100. As shown in Fig. 9, the manufacturing process of motor 100 first performs a coil group generating process (step S101) in which conductor wire 34 is wound around a plurality of teeth 312 extending radially of stator core 31 to generate coil groups 32U, 32V, and 32W. After step S101, the manufacturing process of motor 100 also performs a coupling portion generating process (step S102) in which insulating coating 342 is removed from the ends of conductor wire 34 of coil groups 32U, 32V, and 32W to expose conductive portions 341 to generate common wires 321U, 321V, and 321W, and the conductive portions 341 of common wires 321U, 321V, and 321W are brought into contact with each other and coupling portions 35 are generated with solder. In addition, when soldering the portions where the common wires 321U, 321V, and 321W are in contact with each other, this may be done by inserting the bundled common wires 321U, 321V, and 321W into a solder bath Pp1 filled with molten solder Wp (see Figure 10).

[0065] After step S102, the manufacturing process of motor 100 includes a coupling portion arranging process (step S103) in which coupling portion 35 is arranged in slot 313, which is the portion between circumferentially adjacent teeth 312, so as to extend from the radial inside to the radial outside, or vice versa. At this time, coupling portion 35 is arranged so as to extend from the radial inside to the radial outside. After step S103, the manufacturing process of motor 100 includes a sealing portion creating process (step S104) in which a fluid resin is poured into the portion of slot 313 where coupling portion 35 is arranged and the resin is solidified to create sealing portion 36.

[0066] Furthermore, after step S104, the manufacturing process of the motor 100 includes a lead wire generation process (step S105) in which the insulating coating 342 at the end of the conductor 34 of the coil groups 32U, 32V, 32W is removed to expose the conductive portion 341, thereby generating lead wires 322U, 322V, 322W having exposed portions 343.

[0067] After step S105, the manufacturing process of motor 100 includes a solder-raised portion forming step (step S106) in which a portion of the tip of exposed portion 343 of lead wires 322U, 322V, 322W is immersed in solder bath Pp2 filled with molten solder Wp to form solder-raised portions 323U, 323V, 323W (see FIG. 11). The length of solder-raised portions 323U, 323V, 323W can be, for example, 5 mm or less.

[0068] After step S106, the manufacturing process of motor 100 includes a circuit connection process (step S107) in which soldering portions 323U, 323V, 323W are inserted into through holes 54U, 54V, 54W formed in circuit board 50, and exposed portion 343 is soldered to wiring patterns 531U, 531V, 531W formed on circuit board 50.

[0069] After step S107, the manufacturing process of motor 100 includes a cover member generating step (step S108) of generating cover member 56 that covers pattern surface 52 of circuit board 50. Note that cover member 56 only needs to be configured to cover at least wiring pattern 53.

[0070] In addition, in this embodiment, steps S105 to S108 are performed after steps S102 to S104, but the steps may be performed in the reverse order, or may be performed simultaneously.

[0071] In the manufacturing method of motor 100 using the steps described above, after forming coil groups 32U, 32V, and 32W of stator 30 and creating connecting portion 35, soldering and creation of sealing portion 36 are performed, so connecting portion 35 can be reliably sealed even if variations occur due to the shape and dimensions of motor 100. This makes it possible to suppress corrosion of connecting portion 35 due to adhesion of moisture.

[0072] Furthermore, since soldering, through-hole mounting, and production of cover member 56 are performed after forming coil groups 32U, 32V, and 32W of stator 30 and producing lead portions 322U, 322V, and 322W, exposed portions 343 of lead wires 322U, 322V, and 322W can be reliably sealed even if variations occur due to the shape and dimensions of motor 100. This makes it possible to suppress corrosion of lead wires 322U, 322V, and 322W due to adhesion of moisture.

[0073] Because the U-phase land 531U, the V-phase land 531V, and the W-phase land 531W are positioned away from the through-holes 54U, 54V, and 54W, they only need to penetrate the through-holes 54U, 54V, and 54W. Therefore, the solder-raising portions 323U, 323V, and 323W may be short. The length of the solder-raising portions 323U, 323V, and 323W may be, for example, 5 mm. By shortening the length of the solder-raising portions 323U, 323V, and 323W, contact of the stator 30 with the solder bath Pp2 can be prevented when the exposed portions 343 at the tips of the lead wires 322U, 322V, and 322W are immersed in the solder bath Pp2 containing molten solder Wp. This allows the solder-raising portions 323U, 323V, and 323W to be safely fabricated.

[0074] <Variation 1> As shown in motor 100A in Fig. 12, coupling portion 35A may be configured such that its radially outer side is positioned axially lower than its radially inner side. Fig. 12 is a cross-sectional view of motor 100A according to Modification 1. Note that when coupling portion 35A is positioned at the axially lower end of slot 313, its radially outer side may be positioned radially higher than its radially inner side.

[0075] <Variation 2> Furthermore, as shown in motor 100B in Fig. 13, coupling portion 35B may have a portion that curves radially outward and axially downward, with a portion of its tip extending radially inward. Fig. 13 is a cross-sectional view of motor 100B according to Modification 2. Note that when coupling portion 35B is disposed at the axially lower end of slot 313, coupling portion 35B may be curved upward and have a portion of its tip extending radially inward.

[0076] By configuring motor 100A and motor 100B in this manner, even if the length of coupling portions 35A, 35B is longer than the radial length of slot 313, they can be accommodated inside slot 313. This allows coupling portions 35A, 35B to be entirely sealed with sealing portion 36, making it possible to suppress corrosion of coupling portions 35A, 35B due to moisture.

[0077] <Variation 3> Fig. 14 is a cross-sectional view of a motor 100C of Modification 3. Fig. 15 is a schematic perspective view showing a stator 30C of the motor 100C shown in Fig. 14. As shown in Fig. 14, the motor 100C has a shaft 10C, a rotor 20C, a stator 30C, a housing 40C, a circuit board 50C, and a bearing 60C.

[0078] The motor 100C has a housing 40C, which includes a base plate 41C and a housing main body 42C. The housing main body 42C is cylindrical with a cover, and in the motor 100C, the housing main body 42C is cylindrical and extends along the axial direction. The upper axial end of the housing main body 42C has a cover portion that expands radially inward. The lower axial end of the housing main body 42C is attached to a base plate 41C. The housing main body 42C is fixed to the base plate 41C.

[0079] Motor 100C is an inner rotor type DC brushless motor, and stator 30C is fixed to the inner peripheral surface of housing main body 42C. Shaft 10C fixed to rotor 20C is supported by the lid portion of housing main body 42C and base plate 41C via bearing 60C so as to be rotatable about central axis Ax.

[0080] 15, the stator 30C includes a stator core 31C and a plurality of coil groups 32C. The plurality of coil groups 32C have the same configuration as the U-phase coil group 32U, the V-phase coil group 32V, and the W-phase coil group 32W. Each coil group 32C includes the same number of coils 33C.

[0081] 15, the stator core 31C has a core back 311C and multiple teeth 312C. The core back 311C is cylindrical. The multiple teeth 312C extend radially inward from the core back 311C. That is, the connecting portion 35C extends from the radially outer side to the radially inner side within a slot 313C, which is a portion between circumferentially adjacent teeth 312C.

[0082] The common wires of each coil group 32C are disposed on an insulator (not shown) disposed on the core back 311C, and a connecting portion 35C, where the common wires are soldered together, is disposed in a slot 313C formed between circumferentially adjacent teeth 312C. The connecting portion 35C extends from the radially outer side to the radially inner side in the slot 313C. The connecting portion 35C is sealed with a sealing portion 36C made of resin or the like, and is fixed to the coil 33C disposed on the tooth 312C circumferentially adjacent to the slot 313C by the sealing portion 36C.

[0083] The connecting portion 35C is disposed at the upper or lower axial end of the slot 313C. With this configuration, when resin is poured to form the sealing portion 36C, the resin can be reliably distributed around the connecting portion 35C. This reliably seals the connecting portion 35C, suppresses moisture from adhering to the connecting portion 35C, and also suppresses corrosion due to moisture.

[0084] In the above examples, motors 100, 100A, 100B, and 100C are brushless DC motors, but are not limited to this and may be any motors having a configuration in which a coil is arranged on a stator.

[0085] <Summary> The present invention has the following configuration.

[0086] (1) A rotor that rotates around a central axis; a stator having a plurality of coil groups arranged on a plurality of teeth that are radially opposed to the rotor, Each of the coil groups includes: at least one coil formed from a continuous conductor; a common line provided at an end of the conductor line and having an exposed conductive portion; the common wires of the plurality of coil groups are electrically connected and have a connecting portion where they are connected together; The connecting portion extends from the inside in the radial direction to the outside in the radial direction or vice versa within a slot that is a portion between the teeth adjacent in the circumferential direction, The motor has a sealing portion that seals at least the connecting portion.

[0087] (2) The motor according to (1), wherein the connecting portion extends in a direction intersecting the central axis.

[0088] (3) The motor according to (2), wherein the connecting portion extends in a radial direction centered on the central axis.

[0089] (4) The motor according to any one of (1) to (3), wherein the connecting portion electrically connects the common wires together and is configured by soldering the common wires together.

[0090] (5) A motor described in any one of (1) to (4), wherein the sealing portion is fixed to the tooth or the coil arranged on the tooth that is circumferentially adjacent to the slot in which the sealing portion is arranged.

[0091] (6) The motor according to any one of (1) to (5), wherein the sealing portion is made of resin.

[0092] (7) The motor according to any one of (1) to (6), wherein the sealing portion is disposed between both ends of the coil in a direction along the central axis.

[0093] (8) A motor according to any one of (1) to (7), wherein the sealing portion is arranged on one side of the center of the slot in the direction along the central axis.

[0094] (9) a coil group generating step of generating a plurality of coil groups by winding a conducting wire around a plurality of teeth extending in a radial direction of the stator; a connecting portion creating step of removing insulating coatings from the ends of the conductors of the plurality of coil groups to expose conductive portions to create common wires, bringing the conductive portions of the common wires into contact with each other, and creating connecting portions by soldering; a coupling portion arranging step of arranging the coupling portion in a slot between the teeth adjacent in the circumferential direction, the coupling portion extending from the inside in the radial direction to the outside in the radial direction or vice versa; a sealing portion creation process for pouring a fluid resin into the portion of the slot where the connecting portion is located and solidifying the resin to create a sealing portion. [Explanation of symbols]

[0095] 100, 100A, 100B, 100C motors 10, 10C shaft 20, 20C rotor 21 rotor case 211 rotor hub 212 Rotor cylinder 213 Rotor Boss 22 rotor magnet 30, 30C Stator 31, 31C stator core 311, 311C Coreback 312, 312C Teeth 313, 313C slots 32U U-phase coil group 32V V-phase coil group 32W W-phase coil group 321U U phase common wire 321V V-phase common wire 321W W-phase common wire 322U U phase leader line 322V V phase lead wire 322W W phase leader wire 33U, 33V, 33W, 33C coils 34 Conductor 341 Conductive part 342 Insulation coating 343 Exposed part 35, 35A, 35B, 35C connection part 36, 36C Sealing part 40 base plate 41 Holding part 411 Inner surface 412 Outer surface 40C Housing 41C Base Plate 42C housing body 50, 50C circuit board 51 Mounting part 52 Patterned Surface 53 Wiring Pattern 531U U-phase Land 531V V-phase land 531W W-phase land 54U, 54V, 54W through hole 55 Cover member 60, 60C bearings Ax center axis IU U phase current IV V phase current IW W phase current Tp electronic components

Claims

1. a rotor that rotates around a central axis; a stator having a plurality of coil groups arranged on a plurality of teeth that are radially opposed to the rotor, Each of the coil groups includes: At least one coil formed from a continuous conductive wire; a common line provided at an end of the conductor line and having an exposed conductive portion; the common wires of the plurality of coil groups are electrically connected and have a connecting portion where they are connected together; The connecting portion extends from the inside in the radial direction to the outside in the radial direction or vice versa within a slot that is a portion between the teeth adjacent in the circumferential direction, The motor has a sealing portion that seals at least the connecting portion.

2. The motor according to claim 1 , wherein the connecting portion extends in a direction intersecting the central axis.

3. The motor according to claim 2 , wherein the connecting portion extends in a radial direction about the central axis.

4. The motor according to claim 1 , wherein the connecting portion electrically connects the plurality of common wires together and the plurality of common wires are soldered together.

5. The motor according to claim 1 , wherein the sealing portion is fixed to the tooth or the coil arranged on the tooth that is adjacent in the circumferential direction to the slot in which the sealing portion is arranged.

6. The motor according to claim 5 , wherein the sealing portion is made of resin.

7. The motor according to claim 1 , wherein the sealing portion is disposed between both ends of the coil in a direction along the central axis.

8. The motor according to claim 1 , wherein the sealing portion is disposed on one side of a center of the slot in the direction along the central axis.

9. a coil group generating step of generating a plurality of coil groups by winding a conducting wire around a plurality of teeth extending in a radial direction of the stator; a connecting portion creating step of removing insulating coatings from the ends of the conductors of the plurality of coil groups to expose conductive portions to create common wires, bringing the conductive portions of the common wires into contact with each other, and creating connecting portions by soldering; a coupling portion arranging step of arranging the coupling portion in a slot between the teeth adjacent in the circumferential direction, the coupling portion extending from the inside in the radial direction to the outside in the radial direction or vice versa; a sealing portion creation process for pouring a fluid resin into the portion of the slot where the connecting portion is located and solidifying the resin to create a sealing portion.

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