motor

Abstract

To provide a motor capable of preventing occurrence of a short circuit.SOLUTION: A holder projection part 521a includes a terminal through-hole 521b that is positioned on a radially outer side of a motor housing and penetrates in an axial direction. A bus bar unit includes a bus bar terminal 65 and a bus bar holder. The bus bar terminal 65 is connected to a bus bar, extends to an axially lower side to pass through the terminal through-hole 521b, and protrudes to the axially lower side from a lower surface of the holder projection part 521a. A circuit board 83 includes a circuit terminal 84. The circuit terminal 84 extends to an axially lower side to pass through the terminal through-hole 521b, and protrudes to the axially lower side from a lower surface of the holder projection part 521a and is connected to the bus bar terminal 65. The bus bar holder includes a cylinder-shaped terminal guide part 61c. The terminal guide part 61c extends in the axial direction and is positioned in the interior of the terminal through-hole 521b, and houses the bus bar terminal 65 and the circuit terminal 84 such that they are in contact with each other.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present invention relates to a motor.

Background Art

[0002] A conventional motor includes a rotor, a stator, a bearing, a case (housing), a bracket (bearing holder), and a busbar unit. The rotor has a rotor shaft extending in the axial direction. The stator faces the rotor in the radial direction. The bearing rotatably supports the rotor shaft. The case houses the stator. The bracket covers the opening of the case and the bearing is fixed thereto. Further, the bracket has a welding work hole (terminal through hole) penetrating in the axial direction.

[0003] The busbar unit has a main body portion (busbar) connected to a lead wire drawn from the stator, and a busbar terminal extending in the axial direction from the main body portion. The busbar terminal is connected to a connection terminal (circuit terminal) connected to an external power source within the welding work hole (for example, see Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in a conventional motor, there is a possibility that the busbar terminal and the connection terminal contact the bracket and a short circuit occurs.

[0006] Therefore, an object of the present invention is to provide a motor capable of preventing the occurrence of a short circuit.

Means for Solving the Problems

[0007] An exemplary motor of the present invention comprises a rotor, a stator, bearings, a motor housing, a bearing holder, a busbar unit, and a circuit board. The rotor has a shaft extending along the axis of rotation. The stator is radially opposite to the rotor. The bearings rotatably support the shaft. The motor housing accommodates the stator and has an axial opening on the upper side. The bearing holder holds the bearings and covers the opening of the motor housing. The busbar unit is electrically connected to the stator and is positioned on the bearing holder. The circuit board is positioned axially above the busbar unit and is electrically connected to the busbar unit. The bearing holder has a holder projection. The holder projection protrudes radially outward from the motor housing and has a terminal through-hole that penetrates axially. The busbar unit comprises busbars, busbar terminals, and a busbar holder. The busbars are positioned around the bearings and are connected to conductors drawn from the stator. The busbar terminals are connected to the busbar, extend axially downward, pass through the terminal through-hole, and protrude axially downward from the lower surface of the holder projection. The busbar holder covers the outer surfaces of the busbar and busbar terminals and is made of insulating material. The circuit board has circuit terminals. The circuit terminals extend axially downward, pass through the terminal through-hole, protrude axially downward from the lower surface of the holder projection, and are connected to the busbar terminals. The busbar holder has a cylindrical terminal guide portion. The terminal guide portion extends axially and is positioned inside the terminal through-hole, bringing the busbar terminals and circuit terminals into contact and housing them inside. [Effects of the Invention]

[0008] According to an exemplary version of the present invention, it is possible to provide a motor capable of preventing short circuits. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a perspective view of a motor according to an embodiment of the present invention. [Figure 2] Figure 2 is an exploded perspective view of a motor according to an embodiment of the present invention. [Figure 3]Figure 3 is a longitudinal cross-sectional perspective view of a motor according to an embodiment of the present invention. [Figure 4] Figure 4 is a longitudinal cross-sectional view showing an enlarged portion of a motor according to an embodiment of the present invention. [Figure 5] Figure 5 is an exploded perspective view of the motor housing according to an embodiment of the present invention. [Figure 6] Figure 6 is a perspective view of a motor busbar unit according to an embodiment of the present invention. [Figure 7] Figure 7 is an exploded perspective view of a motor busbar unit according to an embodiment of the present invention. [Figure 8] Figure 8 is a longitudinal cross-sectional view showing an enlarged portion of a motor according to an embodiment of the present invention. [Figure 9] Figure 9 is a longitudinal cross-sectional view showing an enlarged portion of a motor according to an embodiment of the present invention. [Figure 10] Figure 10 is a perspective view of a busbar cover according to an embodiment of the present invention. [Modes for carrying out the invention]

[0010] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. The direction in which the central axis C of the motor 1 shown in Figure 1 extends will be simply referred to as the "axial direction," and the radial and circumferential directions centered on the central axis C of the motor 1 will be simply referred to as the "radial direction" and "circumferential direction," respectively. Note that "axial direction," "radial direction," and "circumferential direction" are merely descriptive terms and do not limit the actual positional relationships or directions.

[0011] <1. Motor Configuration> A motor according to an exemplary embodiment of the present invention will be described. Figures 1 and 2 are perspective views and exploded perspective views of motor 1 according to an embodiment of the present invention. Figure 3 is a longitudinal perspective view of motor 1, and Figure 4 is a longitudinal cross-sectional view showing an enlarged portion of motor 1. Figure 5 is an exploded perspective view of housing 50.

[0012] The motor 1 has a motor body 100 and a control unit 200 housed and integrated in a housing 50. The motor body 100 includes a rotor 20, a stator 30, an upper bearing (bearing) 41, a lower bearing 42, a bearing holder 52, and a busbar unit 60.

[0013] The control unit 200 is located axially above the motor body 100 and controls the rotation of the rotor 20. The control unit 200 includes a first circuit board 80, a second circuit board (circuit board) 83, and a connector unit 82. The connector unit 82 is electrically connected to the first circuit board 80 and supplies drive current from an external power source to the first circuit board 80 and the second circuit board 83.

[0014] The motor body 100 and the control unit 200 are electrically connected by the connection between a circuit terminal 84 connected to the second circuit board (circuit board) 83 and the busbar unit 60. The connection structure between the circuit terminal 84 and the busbar unit 60 will be described in detail later.

[0015] The housing 50 houses the motor body 100 and the control unit 200 and has a motor housing 51, a bearing holder 52, and a cover 53.

[0016] That is, the motor 1 includes a rotor 20, a stator 30, an upper bearing (bearing) 41, a motor housing 51, a bearing holder 52, a busbar unit 60, and a second circuit board (circuit board) 83.

[0017] <2-1. Structure of Motor Housing> The motor housing 51 is formed in a bottomed cylindrical shape and houses the rotor 20 and the stator 30 inside. The motor housing 51 has a side wall portion 511 and a bottom wall portion 512. The side wall portion 511 extends upward in the axial direction and is formed in a cylindrical shape. The upper surface of the side wall portion 511 is open to form an opening 51a. The lower surface of the side wall portion 511 is covered by a plate-shaped bottom wall portion 512. The bottom wall portion 512 has a lower bearing holding portion 512a. The lower bearing holding portion 512a is disposed on the central axis C, and its upper surface is recessed in the axial direction. The lower bearing 42 is accommodated and held in the lower bearing holding portion 512a. A bottom wall through hole 512b penetrating in the axial direction is formed in the bottom surface of the lower bearing holding portion 512a.

[0018] <2-2. Structure of Bearing Holder> The bearing holder 52 holds the upper bearing (bearing) 41 and covers the opening of the motor housing 51. The bearing holder 52 is disposed on the upper side in the axial direction of the motor housing 51 and is formed in a bottomed cylindrical shape. The bearing holder 52 houses a bus bar unit 60 and the upper bearing 41 inside. The bearing holder 52 has an intermediate wall portion 521, a peripheral wall portion 522, an upper cylindrical portion 523a, a lower cylindrical portion 523b, a recess 524, a bearing holder through hole 525, an annular connecting portion 526, and a holder flange portion 527.

[0019] The intermediate wall portion 521 is formed in a plate shape and covers the opening 51a of the motor housing 51. The intermediate wall portion 521 has a holder protruding portion 521a. That is, the bearing holder 52 has a holder protruding portion 521a. The holder protruding portion 521a protrudes radially outward from the motor housing 51. A terminal through hole 521b penetrating in the axial direction is formed in the holder protruding portion 521a. The terminal through hole 521b is covered by a bus bar cover 528 from the lower surface of the holder protruding portion 521a.

[0020] The peripheral wall portion 522 extends upward in the axial direction from the periphery of the intermediate wall portion 521 and is formed in a cylindrical shape. The upper surface of the peripheral wall portion 522 is open to form a bearing holder opening 52a.

[0021] The upper cylindrical portion 523a surrounds the central axis C and extends axially upward from the upper surface of the intermediate wall portion 521, forming a cylindrical shape. The magnet holding portion 90 and the sensor magnet 91, which will be described later, are arranged inside the upper cylindrical portion 523a.

[0022] The lower cylindrical portion 523b surrounds the central axis C and extends axially downward from the lower surface of the intermediate wall portion 521, forming a cylindrical shape. The upper bearing 41 is housed and held in the lower cylindrical portion 523b. The upper cylindrical portion 523a and the lower cylindrical portion 523b are in axial communication.

[0023] The recess 524 is located radially outward from the upper cylindrical portion 523a and the lower cylindrical portion 523b, and recesses downward in the axial direction from the upper surface of the intermediate wall portion 521. In a top view, the recess 524 is formed in an annular shape surrounding the upper cylindrical portion 523a and the lower cylindrical portion 523b. The bearing holder through hole 525 is formed by penetrating the bottom surface of the recess 524 in the axial direction. Multiple bearing holder through holes 525 are arranged in the circumferential direction. In this embodiment, 12 bearing holder through holes 525 are provided.

[0024] The annular connecting portion 526 protrudes axially downward from the lower surface of the intermediate wall portion 521 and is formed in an annular shape surrounding the recess 524. The annular connecting portion 526 is press-fitted into the inner surface of the side wall portion 511 of the motor housing 51 with an O-ring 540 interposed on its outer circumferential surface. As a result, the annular connecting portion 526 fits into the opening of the motor housing 51, fixing the bearing holder 52 and the motor housing 51 together.

[0025] The holder flange portion 527 protrudes radially outward from the upper end of the peripheral wall portion 522. Four holder flange portions 527 are provided on the outer circumference of the peripheral wall portion 522. The holder flange portion 527 is provided with holder screw holes 527a that extend in the axial direction.

[0026] <2-3. Cover Composition> The cover 53 is formed in a plate shape and covers the bearing holder opening 52a. The cover 53 has a cover flange portion 531. The cover flange portion 531 protrudes radially outward from the outer circumference of the cover 53. There are four cover flange portions 531 on the outer circumference of the cover 53. The cover flange portion 531 is provided with a cover hole 531a that penetrates axially. The cover 53 and the bearing holder 52 are fixed together by aligning the cover hole 531a with the holder screw hole 527a and fastening with screws.

[0027] <3. Rotor Configuration> The rotor 20 comprises a shaft 21, a rotor core 22, and a rotor magnet 23. The shaft 21 forms a rotation axis extending along the central axis C and is formed in a columnar shape. That is, the rotor 20 has a shaft 21 extending along the rotation axis. The shaft 21 is rotatably supported around its axis by an upper bearing 41 and a lower bearing 42.

[0028] The lower end of the shaft 21 protrudes to the outside of the motor housing 51 through the bottom wall through hole 512b. The upper end of the shaft 21 is located inside the upper cylindrical portion 523a.

[0029] The rotor core 22 is formed in a cylindrical shape, and the shaft 21 is fixed inside by press-fitting. The rotor magnets 23 are provided on the radially outer surface of the rotor core 22 and are arranged in a plurality in the circumferential direction. The rotor core 22 and rotor magnets 23 rotate together with the shaft 21.

[0030] <4. Stator Configuration> The stator 30 is positioned radially outward from the rotor 20. That is, the stator 30 faces the rotor 20 radially. The stator 30 is formed in a cylindrical shape, and the rotor 20 is positioned inside the stator 30. The stator 30 comprises a core back portion 31, a teeth portion 32, a coil portion 33, and an insulating member 34.

[0031] The core back portion 31 is cylindrical and concentric with the shaft 21. The outer circumferential surface of the core back portion 31, i.e., the outer circumferential surface of the stator 30, is fitted to the inner circumferential surface of the side wall portion 511 of the motor housing 51.

[0032] The teeth portion 32 extends radially inward from the inner circumferential surface of the core back portion 31. Multiple teeth portions 32 are provided and are arranged at equal intervals in the circumferential direction on the inner circumferential surface of the core back portion 31. In this embodiment, 12 teeth portions 32 are provided.

[0033] The coil section 33 is constructed by winding a conductor 33a around an insulating member 34. The insulating member 34 is attached to each tooth section 32. The ends of the conductor 33a wound around each tooth section 32 extend axially upward, pass through each bearing holder through hole 525, and are connected to the second circuit board 83 via a busbar unit 60 located inside the bearing holder 52.

[0034] When a drive current is supplied to the coil section 33, a magnetic field is generated, and this magnetic field causes the rotor 20 to rotate.

[0035] <5. Sensor Magnet Configuration>

[0036] The sensor magnet 91 is an annular permanent magnet, with its north and south poles positioned on the surface facing the sensor 81. The sensor magnet 91 is fitted to the inner circumferential surface of the cylindrical magnet holder 90, and the magnet holder 90 is fitted to the upper end of the shaft 21.

[0037] In this embodiment, the sensor magnet 91 is fixed inside the magnet holder 90. This connects the sensor magnet 91 to the shaft 21 via the magnet holder 90, allowing it to rotate together with the shaft 21. Alternatively, the magnet 91 may be directly fixed to the tip of the shaft 21 using an adhesive or the like.

[0038] <6. Configuration of the first and second circuit boards> The first circuit board 80 and the second circuit board (circuit board) 83 are housed within the bearing holder 52. The first circuit board 80 and the second circuit board (circuit board) 83 are positioned axially above the busbar unit 60.

[0039] The first circuit board 80 and the second circuit board 83 extend perpendicularly to the central axis C and are formed in a plate shape. The second circuit board 83 is positioned above the first circuit board 80 in the axial direction, with a predetermined gap between them. When viewed from the axial direction, the first circuit board 80 and the second circuit board 83 are positioned overlapping each other.

[0040] The lower surface of the first circuit board 80 and the upper surface of the upper cylindrical portion 523a of the bearing holder 52 face each other in the axial direction with a gap in between. The first circuit board 80 and the second circuit board 83 are electrically connected by connecting pins (not shown).

[0041] A motor cover 70 is positioned between the first circuit board 80 and the upper surface of the upper cylindrical portion 523a. The motor cover 70 is formed in a disc shape and is positioned axially above the busbar unit 60. This prevents dust from adhering to the busbar unit 60.

[0042] A circuit terminal 84 is connected to the lower surface of the second circuit board 83. The circuit terminal 84 extends axially downward, passes through the terminal through hole 521b, and protrudes axially downward from the lower surface of the holder projection 521a to connect to the busbar terminal 65, which will be described later. In this way, the second circuit board 83 is electrically connected to the busbar unit 60. The first circuit board 80 and the second circuit board 83 output motor drive signals to the stator 40 via the busbar unit 60.

[0043] A sensor 81 for detecting the rotational position of the rotor 20 is mounted on the lower surface of the first circuit board 80. The sensor 81 is positioned axially above the sensor magnet 91. Therefore, the distance between the sensor 81 and the sensor magnet 91 is short, making it suitable for using a magnetoresistive element in the sensor 81.

[0044] Sensor 81 detects the rotational position of rotor 20 by detecting the magnetic flux of sensor magnet 91. This allows it to output a motor drive signal corresponding to the rotational position of rotor 20, controlling the drive current supplied to coil 33. Thus, the drive of motor 1 can be controlled.

[0045] <7. Busbar Unit Configuration> Figures 6 and 7 are perspective and exploded perspective views of the busbar unit 60. The busbar unit 60 is electrically connected to the stator 30 and is positioned on the bearing holder 52. The busbar unit 60 is also positioned radially outward of the upper bearing 41 on the bearing holder 52.

[0046] The busbar unit 60 includes a busbar holder 61, busbars 62U, 63V, and 64W, and busbar terminals 65. The busbars 62U, 63V, and 64W are made of conductive plate-shaped members and have different shapes from each other. The busbars 62U, 63V, and 64W correspond to the U-phase, V-phase, and W-phase, respectively. In this embodiment, busbar 62U corresponds to the U-phase, busbar 63V corresponds to the V-phase, and busbar 64W corresponds to the W-phase.

[0047] <7-1. Busbar Configuration> The busbar 62U has a base portion 62a, a connecting portion 62b, and a terminal portion 62c. The base portion 62a extends in the circumferential direction and is formed in an arc shape when viewed from above.

[0048] The connecting portion 62b protrudes radially inward from the radially inner surface of the base portion 62a, and its tip is bent downward in the axial direction. Four connecting portions 62b are provided and are arranged at equal intervals in the circumferential direction. The connecting portion 62b has a conductor holding portion 621b. The conductor holding portion 621b protrudes radially inward from the tip of the connecting portion 62b and is formed in a substantially U-shape when viewed from above. The terminal portion 62c extends linearly radially outward from the radially outer surface of the base portion 62a.

[0049] The busbar 63V has a base portion 63a, a connecting portion 63b, and a terminal portion 63c. The base portion 63a extends in the circumferential direction and is formed in an arc shape when viewed from above.

[0050] The connecting portion 63b protrudes radially inward from the radially inner surface of the base portion 63a, and its tip is bent downward in the axial direction. Four connecting portions 63b are provided and are arranged circumferentially at equal intervals. The connecting portion 63b has a conductor holding portion 631b. The conductor holding portion 631b protrudes radially inward from the tip of the connecting portion 63b and is formed in a substantially U-shape when viewed from above. The terminal portion 63c protrudes axially upward from the radially outer surface of the base portion 63a, and its tip extends bent radially outward.

[0051] The busbar 64W has a base portion 64a, a connecting portion 64b, and a terminal portion 64c. The base portion 64a extends in the circumferential direction and is formed in an arc shape when viewed from above.

[0052] The connecting portion 64b protrudes radially inward from the radially inner surface of the base portion 64a, and its tip is bent downward in the axial direction. Four connecting portions 64b are provided and are arranged circumferentially at equal intervals. The connecting portion 64b has a conductor holding portion 641b. The conductor holding portion 641b protrudes radially inward from the tip of the connecting portion 64b and is formed in a substantially U-shape when viewed from above. The terminal portion 64c protrudes axially upward from the radially outer surface of the base portion 64a, and its tip extends with a bend radially outward.

[0053] Base portions 64a, 63a, and 62a are formed in a thin plate shape and stacked sequentially in the axial direction via spacers (not shown). This allows the busbar unit 60 to be made thinner in the axial direction. The spacers are made of an insulating material such as resin.

[0054] When the base portion 64a, base portion 63a, and base portion 62a are stacked, the connecting portions 62b, 63b, and 64b are arranged sequentially in the circumferential direction at equal intervals. At this time, the lower ends of the connecting portion 62b, 63b, and 64b are positioned at approximately the same height in the axial direction. Furthermore, the multiple connecting portions 62b, 63b, and 64b, which are arranged sequentially in the circumferential direction at equal intervals, protrude radially inward from the radial inner surface of each base portion 62a, 63a, and 64a, allowing the busbar unit 60 to be miniaturized in the radial direction.

[0055] The wire holding parts 621b, 631b, and 641b are electrically connected to the tip of the wire 33a extending axially upward from the stator 30 by laser welding or the like. Specifically, the connecting part 62b extends axially downward from the base part 62a and is connected to the wire 33a. The connecting part 63b extends axially downward from the base part 63a and is connected to the wire 33a. The connecting part 64b extends axially downward from the base part 64a and is connected to the wire 33a.

[0056] <7-2. Busbar Terminal Configuration> The busbar terminal 65 is formed in an L-shape, with one end extending radially. One end of each of the multiple busbar terminals 65 is connected and fixed to terminal sections 62c, 63c, and 64c by welding. As a result, the busbar terminal 65 is connected to busbars 62U, 63V, and 64W, respectively. The other end of the busbar terminal 65 extends axially downward and is electrically connected to circuit terminal 84. The connection structure between the busbar terminal 65 and circuit terminal 84 will be described in detail later. In this embodiment, the busbar terminal 65 and terminal sections 62c, 63c, and 64c are formed separately, but this is not limited to this. For example, terminal section 62c and busbar terminal 65, terminal section 63c and busbar terminal 65, and terminal section 64c and busbar terminal 65 may be formed integrally.

[0057] <7-3. Busbar Holder Configuration> The busbar holder 61 is formed of an insulating material such as resin. The busbar holder 61 covers the outer surfaces of the busbars 62U, 63V, 64W and the busbar terminals 65, including the base portions 62a, 63a, 64a and terminal portions 62c, 63c, 64c. In this embodiment, the busbars 62U, 63V, 64W and the busbar terminals 65 are embedded and fixed in the busbar holder 61 by insert molding. As a result, the busbars 62U, 63V, and 64W are insulated from each other via the busbar holder 61.

[0058] The busbar holder 61 includes a base holder 61a, a terminal holder 61b, and a terminal guide portion 61c. The base holder 61a covers the base portions 62a, 63a, and 64a which overlap in the axial direction, and is formed in a substantially annular shape when viewed from the axial direction.

[0059] The terminal holder 61b extends linearly radially outward from the radially outer surface of the base holder 61a. The terminal holder 61b is provided in three locations in the circumferential direction and covers the terminal portions 62c, 63c, and 64c, which are arranged in a circumferential direction, and one end of the radially extending busbar terminal 65, respectively.

[0060] The terminal guide portion 61c is connected to the radially outer end of each terminal holder 61b. The terminal guide portion 61c extends axially and is formed in a cylindrical shape. The upper and lower surfaces of the terminal guide portion 61c are open. The terminal guide portion 61c covers the other end of each axially extending busbar terminal 65. As a result, each busbar terminal 65 connected to the U phase, V phase, and W phase is insulated from each other via the terminal guide portion 61c.

[0061] Each busbar terminal 65 is partially exposed inside the terminal guide portion 61c and is not covered by the terminal guide portion 61c (see Figure 8).

[0062] The terminal guide section 61c has a terminal insertion opening 61d on its upper surface and a terminal exit opening 61e on its lower surface (see Figure 8).

[0063] <8. Connection structure between busbar terminals and circuit terminals> Figure 8 is an enlarged cross-sectional perspective view showing the busbar terminal 65 and circuit terminal 84, and Figure 9 is an enlarged cross-sectional perspective view showing the terminal guide portion 61c. The terminal guide portion 61c is located inside the terminal through-hole 521b. The circuit terminal 84 is inserted into the terminal insertion opening 61d and makes contact with the busbar terminal 65. As a result, the busbar terminal 65 and the circuit terminal 84 are electrically connected within the terminal guide portion 61c.

[0064] The busbar terminals 65 and circuit terminals 84 pass through the terminal through-holes 521b while being housed inside the terminal guide portion 61c. Therefore, the busbar terminals 65 and circuit terminals 84 are reliably insulated from the bearing holder 52, preventing short circuits.

[0065] Furthermore, the busbar terminals 65 and circuit terminals 84 protrude axially downward from the terminal outlet 61e, and the lower ends of the busbar terminals 65 and circuit terminals 84 are securely connected by welding. At this time, the lower ends of the busbar terminals 65 and circuit terminals 84 are located axially below the lower surface of the bearing holder 52. This improves the efficiency of welding work when the busbar cover 528 is removed.

[0066] Furthermore, the lower end 61e of the terminal guide portion 61c is located axially lower than the lower end P of the terminal through-hole 521b. This ensures that the circuit terminal 84 and busbar terminal 65 have sufficient insulation distance from the bearing holder 52, further preventing short circuits.

[0067] The terminal guide portion 61c has an inclined portion 61f. The inclined portion 61f is inclined inward on the inner circumferential surface of the terminal guide portion 61c as it extends axially downward from the terminal insertion opening 61d. This allows the circuit terminal 84 to be smoothly guided from the terminal exit 61e along the inclined portion 61f into the interior of the terminal guide portion 61c. Therefore, the assembly workability of the motor 1 and the second circuit board 83 is improved. In addition, by making the terminal insertion opening 61d large, the lower end of the circuit terminal 84 can be reliably guided into the interior of the terminal guide portion 61c even if it wobbles radially or circumferentially during insertion.

[0068] The inclined portion 61f has a first inclined surface 611f and a second inclined surface 612f in the direction opposite to the busbar terminal 65 and the circuit terminal 84. The first inclined surface 611f is positioned on the busbar terminal 65 side. The second inclined surface 612f is positioned on the circuit terminal 84 side. The inclination angle of the second inclined surface 612f with respect to the axial direction is greater than the inclination angle of the first inclined surface 611f with respect to the axial direction. This allows the upper end of the second inclined surface 612f to be formed radially away from the busbar terminal 65, so that even if the lower end of the circuit terminal 84 wobbles radially or circumferentially during insertion, it can be guided more reliably into the terminal guide portion 61c.

[0069] Furthermore, the axial length of the second inclined surface 612f is longer than the axial length of the first inclined surface 611f. This allows the upper end of the second inclined surface 612f to be formed further radially away from the busbar terminal 65, thereby more reliably guiding the circuit terminal 84 toward the busbar terminal 65.

[0070] <9. Busbar Cover Configuration> The busbar cover 528 is, for example, a molded resin part. The busbar cover 528 is positioned on the lower surface of the holder projection 521a and covers the terminal through hole 521b. This prevents the lower ends of the welded circuit terminals 84 and busbar terminals 65 from being exposed to the outside of the bearing holder 52. The busbar cover 528 is installed after the lower ends of the circuit terminals 84 and busbar terminals 65 have been welded.

[0071] The busbar cover 528 has a cylindrical cover portion 528a and a flange portion 528b. The cover portion 528a covers the lower ends of the busbar terminals 65 and circuit terminals 84, and its upper surface is open. The flange portion 528b extends outward from the upper peripheral edge of the cover portion 528a and is fixed to the lower surface of the holder projection 521a.

[0072] The flange portion 528b has a flange projection 528c and a pair of fixing pins 528d. The flange projection 528c protrudes axially upward from the upper surface of the flange portion 528b and is formed in an annular shape surrounding the opening of the cover portion 528a. The pair of fixing pins 528d protrude axially upward from the upper surface of the flange portion 528b and are positioned on either side of the flange projection 528c.

[0073] The holder projection 521a has a sealing recess 521c and a fixing recess 521d (see Figure 8). The fixing recess 521d is recessed axially upward from the lower surface, and a fixing pin 528d is positioned inside it. By press-fitting the fixing pin 528d into the fixing recess 521d, the busbar cover 528 can be easily fixed to the lower surface of the holder projection 521a.

[0074] The seal recess 521c is recessed axially upward from the lower surface of the holder projection 521a and is formed in an annular shape surrounding the terminal through hole 521b. The flange projection 528c is positioned inside the seal recess 521c, which is filled with sealing material. This improves the sealing performance between the upper surface of the flange portion 528b and the lower surface of the holder projection 521a.

[0075] In this embodiment, the sealing material is an adhesive, and in addition to its sealing function, the busbar cover 528 is fixed to the peripheral wall portion 522 of the busbar holder 52. Furthermore, since it takes time for the adhesive to set securely when used, the fixing pin 528d is press-fitted into the fixing recess 521d, which also functions as temporary fixing. This allows the busbar cover 528 to maintain its position relative to the busbar holder 52. In addition, multiple crush ribs extending in the axial direction are formed on the outer circumference of the fixing pin 528.

[0076] The embodiments described above are merely illustrative examples of the present invention. The configuration of the embodiments may be modified as appropriate without exceeding the technical spirit of the present invention. Furthermore, embodiments and multiple modifications may be combined to the extent possible. [Industrial applicability]

[0077] The motor of the present invention can be used, for example, in an electric power steering system used to assist in steering the steering of a vehicle such as an automobile. Furthermore, while the present invention is suitable for power steering systems, it can also be used in other applications such as blowers. [Explanation of Symbols]

[0078] 1 motor 20 rotors 21 Shaft 22 rotor cores 23 Rotor Magnet 30 staters 31 Core back section 32 Teeth section 33 Coil section 33a conductor 34 Insulating material 41 Upper bearing (bearing) 42 Lower bearing 50 Housing 51 Motor Housing 51a opening 52 Bearing holder 52a Bearing holder opening 53 Cover 60 Busbar Unit 61 Busbar Holder 61a Base holder 61b Terminal holder 61c Terminal guide section 61d Terminal socket 62U, 63V, 64W busbar 62a, 63a, 64a base 62b, 63b, 64b connection section 62c, 63c, 64c terminal section 65 Busbar terminals 70 Motor Cover 80 1st circuit board 81 Sensors 82 Connector section 83. Second circuit board (circuit board) 84 circuit terminal 90 Magnet holder 91 Sensor Magnet 92 resin 100 Motor body 200 Control Unit 511 Side wall section 512 Bottom wall section 512a Lower bearing retainer 512b Bottom wall through hole 521 Intermediate wall section 521a Holder protrusion 521b Terminal through hole 521c Seal recess 521d Fixing recess 522 Peripheral wall section 523a Upper cylinder part 523b Lower cylinder part 524 recess 525 Bearing holder through hole 526 Annular connecting section 527 Holder flange section 527a Holder screw hole 528 Bus bar cover 528a Cover section 528b Flange section 528c Flange protrusion 528d Fixing pin 531 Cover flange section 531a Cover hole 540 O-rings 611f 1st slope 612f 2nd slope 621b, 631b, 641b Conductor holding part C center axis P lower end

Claims

1. A rotor having a shaft extending along the axis of rotation, A stator facing the rotor in the radial direction, A bearing that rotatably supports the aforementioned shaft, A motor housing that houses the stator and has an opening on the axial upper side, A bearing holder that holds the bearing and covers the opening of the motor housing, A busbar unit is electrically connected to the stator and positioned on the bearing holder, The busbar unit comprises a circuit board positioned axially above the busbar unit and electrically connected to the busbar unit, The bearing holder is, It has a holder projection that protrudes radially outward from the motor housing, The holder projection has a terminal through-hole that penetrates in the axial direction. The aforementioned busbar unit is A busbar is arranged around the bearing and connected to a wire drawn out from the stator, A busbar terminal connected to the busbar, extending downward in the axial direction, passing through the terminal through hole, and protruding downward in the axial direction from the lower surface of the holder projection, The busbar and the busbar terminals have a busbar holder made of an insulating material that covers the outer surface of the busbar and the busbar terminals, The aforementioned circuit board is It has a circuit terminal that extends axially downward, passes through the inside of the terminal through hole, protrudes axially downward from the lower surface of the holder projection, and is connected to the busbar terminal, The aforementioned busbar holder is A motor having a cylindrical terminal guide portion that extends axially and is positioned inside the terminal through-hole, bringing the busbar terminal and the circuit terminal into contact and housing them inside.

2. The motor according to claim 1, wherein the lower end of the terminal guide portion is located axially lower than the lower end of the terminal through hole.

3. The motor according to claim 1 or claim 2, wherein the terminal guide portion has a terminal insertion opening on its upper surface into which the circuit terminals are inserted, and a terminal outlet opening on its lower surface from which the busbar terminals and the circuit terminals protrude.

4. The motor according to claim 3, wherein the terminal guide portion has an inclined portion on its inner circumferential surface that slopes inward as it extends axially downward from the terminal insertion opening.

5. The motor according to claim 4, wherein the inclined portion has a first inclined surface located on the busbar terminal side and a second inclined surface located on the circuit terminal side in the direction opposite to the busbar terminal and the circuit terminal, and the angle of inclination of the second inclined surface with respect to the axial direction is greater than the angle of inclination of the first inclined surface with respect to the axial direction.

6. The motor according to claim 5, wherein the axial length of the second inclined surface is longer than the axial length of the first inclined surface.

7. The busbar cover is further provided, which is positioned on the lower surface of the holder projection and covers the terminal through-hole. The aforementioned busbar cover is A cylindrical cover portion that covers the lower ends of the busbar terminal and the circuit terminal, with an open top surface, It has a flange portion that extends outward from the upper peripheral edge of the cover portion and is fixed to the lower surface of the holder projection portion, The flange portion has an annular flange projection that protrudes axially upward from the upper surface. The holder projection is recessed axially upward from the lower surface and has an annular sealing recess surrounding the terminal through hole. The motor according to any one of claims 1 to 6, wherein the flange protrusion is disposed inside the seal recess which is filled with sealing material.

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