JP2010057278A - Brushless motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a brushless motor that is miniaturized irrespective of a wire connecting system of a coil. <P>SOLUTION: A stator 3 to which a coil 19 of a plurality of phases is wound, a rotor 4 which is freely rotatably installed with respect to the stator 3 and a power distribution panel 30 for supplying power to the coil 19 are disposed in a motor case 2. In the brushless motor 1, the power distribution panel 30 includes a coil wire connection part 31 for connecting a terminal part 19a of the coil 19 and a harness wire connection part 32 for connecting one end of a motor harness 58 which is electrically connected to an external power supply. The harness wire connection part 32 is formed to position on an outer side in a radial direction compared to the motor case 2. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a brushless motor including a power distribution board for supplying power to a coil.

  In general, an inner rotor type brushless motor has a stator that is fitted and fixed in a motor case, and a rotor that is disposed at the center in the radial direction of the motor case and is rotatably supported by the stator. A plurality of permanent magnets are disposed on the outer peripheral surface of the rotor. The stator includes a substantially cylindrical stator core and a plurality of teeth projecting radially inward from the stator core.

Each tooth is provided with an insulator, which is an insulating material, and a coil is wound through the insulator. When power from an external power supply is supplied to the coil, an attractive force or a repulsive force is generated between the magnetic flux generated in the coil and the permanent magnet, and the rotor rotates.
Each coil is connected by being connected to a power distribution board (bus bar) arranged at one axial end of the stator. That is, the winding start end and winding end end, which are terminal portions of each coil, are connected via the power distribution board in accordance with a connection method such as a star connection method.

Here, if the brushless motor is miniaturized, the circumferential interval between the terminal portions of the coils is narrowed, so that it is difficult to connect the terminal portions of the coils to the power distribution board. For this reason, the power distribution board is composed of a first power distribution board for supplying power from an external power source to each coil and a second power distribution board for connecting neutral points, and each power distribution board is a corresponding coil. There has been proposed a technique that can be arranged at the position of the terminal portion (see, for example, Patent Document 1).
In this way, each coil and the distribution board can be arranged by allowing the first distribution plate of the distribution board and the connection place (terminal part) of the second distribution board to be arranged at substantially the same place as the corresponding terminal part of the coil. I am trying to improve the wiring workability.
JP 2007-325481 A

  However, in the above-described prior art, although the connection workability between the terminal portion of each coil and the distribution board can be improved, the connection work between the external power source and the distribution board is difficult. That is, the external power supply and the power distribution board are connected to each other via a harness or the like, but it is necessary to provide a space for connecting the harness on the power distribution board, that is, in the motor case. For this reason, there is a problem that it is difficult to reduce the size of the brushless motor by securing a space for connecting the harness.

  In particular, when connecting each coil by star connection, the space for connecting the harness can be set to a relatively small space, but the so-called power that can be supplied to each phase coil can be controlled. In the case of independent connection, since it is necessary to connect the coils for each phase in an independent state, it is necessary to secure a large connection space. For this reason, there exists a subject that a brushless motor will enlarge depending on a connection system.

  Accordingly, the present invention has been made in view of the above-described circumstances, and provides a brushless motor that can be miniaturized regardless of the coil connection method.

In order to solve the above-mentioned problem, the invention described in claim 1 includes a stator in which coils of a plurality of phases are wound in a motor case, a rotor provided rotatably with respect to the stator, In the brushless motor comprising a power distribution board for supplying power to the coil, the power distribution board includes a coil connection part for connecting a terminal part of the coil and one end of a harness electrically connected to an external power source. And a harness connection part for connection, wherein the harness connection part is formed to be located radially outside of the motor case.
In this case, as in the invention described in claim 2, the driving circuit has a driving circuit capable of independently energizing each phase coil, and the driving circuit has two switching elements in series with the external power supply. A bridge circuit having two connected arms in parallel with the external power source and electrically connecting one end of the coil between the switching elements of each arm one by one for each phase of the coil You may have.
Thus, it is necessary to provide a space for connecting the harness and the power distribution board and a space for wiring the harness in the motor case by positioning the harness connection portion radially outside the motor case. Disappear.
Further, it is possible to secure a sufficient space for the connection on the outer side in the radial direction of the motor case without providing a space for connecting the harness and the power distribution board in the motor case.

The invention described in claim 3 is provided for a harness capable of inserting one end of the harness into the harness connection portion while providing a coil through hole into which the terminal portion of the coil can be inserted in the coil connection portion. A through hole is provided.
By comprising in this way, the terminal part of a coil or the end of a harness is inserted in each through-hole, and each connection operation | work can be completed by performing soldering etc. here, for example.

The invention described in claim 4 is characterized in that the harness through-holes are arranged along the circumferential direction, and the adjacent harness through-holes are arranged so as to be shifted from each other in the radial direction. To do.
By comprising in this way, a harness connection part can be reduced compared with the case where all the through-holes for harnesses are arranged in parallel with the circumferential direction.
In addition, it is possible to secure a sufficient insulation distance of each harness through-hole while reducing the harness connection portion.

The invention described in claim 5 is characterized in that a cutout portion capable of routing another harness is formed on the power distribution board.
By configuring in this way, for example, when a device for detecting the rotation angle of the rotor is provided in the motor case and another harness for this device needs to be routed in the motor case, the motor case is made large. It becomes possible to route other harnesses straddling the power distribution board in the axial direction without making them.

According to the first and second aspects of the invention, the space for connecting the harness and the power distribution board in the motor case by positioning the harness connection portion radially outside the motor case. It is not necessary to provide a space for routing the harness. For this reason, for example, even if it is a case where it connects so that it can electrically energize each independently to the coil for every phase like an independent connection, it becomes possible to miniaturize a brushless motor.
Further, it is possible to secure a sufficient space for the connection on the outer side in the radial direction of the motor case without providing a space for connecting the harness and the power distribution board in the motor case. For this reason, wire connection workability | operativity can be improved, aiming at size reduction of a brushless motor.

  According to the third aspect of the present invention, it is possible to complete each connection work by inserting a terminal portion of a coil or one end of a harness into each through hole and soldering, for example. For this reason, it is possible to further improve the connection workability while saving the connection work space.

According to the invention described in claim 4, the harness connection portion can be reduced in size as compared with the case where all the through-holes for harness are arranged in the circumferential direction. For this reason, the space required for installing the brushless motor can be reduced.
In addition, it is possible to secure a sufficient insulation distance of each harness through-hole while reducing the harness connection portion. For this reason, a more reliable brushless motor can be provided.

  According to the invention described in claim 5, for example, when a device for detecting the rotation angle of the rotor is provided in the motor case, and another harness for this device needs to be routed in the motor case, the motor Without increasing the size of the case, other harnesses can be routed across the power distribution board in the axial direction. For this reason, the degree of freedom of pulling out each harness from the motor case is increased, and not only the beauty of the brushless motor is improved, but also an increase in the size of the brushless motor can be suppressed.

Next, embodiments of the present invention will be described with reference to the drawings. In the following description, the left side of FIG. 1 and the lower side of FIG. 2 are the front side, and the right side of FIG. 1 and the upper side of FIG.
As shown in FIGS. 1 and 2, the brushless motor 1 is a so-called inner rotor having a stator 3 formed in a substantially cylindrical shape in a motor case 2 and a rotor 4 rotatably provided inside the stator 3. Type DC brushless motor.

  The motor case 2 includes a front bracket 5 including a case main body 10 in which the stator 3 is fitted and fixed, a front bracket 5 that closes openings at both ends of the case main body 10, and a rear bracket 6, and a rear bracket. 6 is fastened and fixed to each other by three bolts 14, and the case body 10 is sandwiched between the front bracket 5 and the rear bracket 6.

  The stator 3 is formed by laminating metal plates 50 made of a magnetic material in the axial direction, and has a substantially cylindrical stator core 15 that is fitted and fixed to the case body 10. In the stator core 15, recesses (not shown) for avoiding interference with the bolts 14 on the outer peripheral side (for allowing the bolts 14 to pass through the stator core 15 in the axial direction) are equally spaced at three locations in the circumferential direction. Is formed.

On the other hand, a plurality of teeth 17 projecting radially inward are provided at equal intervals in the circumferential direction on the inner circumferential side of the stator core 15. The teeth 17 are formed in a substantially T shape in an axial plan view. An insulator 18 is attached to the teeth 17, and a coil 19 is wound through the insulator 18.
The coil 19 is composed of three phases of U phase, V phase, and W phase, and has two coils 19U, 19V, and 19W for each phase. A winding start end and a winding end end, which are the terminal portions 19a of the coil 19, protrude rearward from the rear end of the stator 3, and are connected to a power distribution board 30 described later.

  In the rotor 4, a permanent magnet 21 is provided on a stepped rotary shaft 20. The permanent magnet 21 is formed in a substantially cylindrical shape, and is fitted and fixed to the center in the axial direction of the rotary shaft 20. Further, the permanent magnet 21 is magnetized so that the magnetic poles change in order in the circumferential direction. A rotary 51 constituting one of the optical encoders 53 is fastened and fixed to the rotary shaft 20 by a bolt 60 at the end on the rear bracket 6 side. The rotary 51 is formed in a substantially disk shape, and a rotary scale 54 is disposed on the surface of the rotary 51 opposite to the rotating shaft 20. An optical pattern such as a slit is formed on the rotary scale 54.

  The front bracket 5 is formed in a substantially disk shape, and a bearing housing 28a is formed on the inner surface side of the substantially radial center. A bearing 28b for rotatably supporting the front end portion of the rotating shaft 20 is press-fitted and fixed to the bearing housing 28a. Further, a recess 61 is formed on the inner surface side of the front bracket 5 on the outer peripheral side of the bearing housing 28a. The recess 61 is formed at a portion corresponding to the coil 19 of the stator 3, and the recess 61 prevents interference between the front bracket 5 and the coil 19.

  On the outer surface of the front bracket 5, a counterbore portion 7 capable of receiving the head of the bolt 14 is formed at a portion corresponding to the bolt 14 for fastening and fixing the front bracket 5. The counterbore portion 7 is formed with a bolt hole (not shown) through which the bolt 14 can be inserted. A plurality of mounting seats 62 for mounting the brushless motor 1 to an external device (not shown) are provided on the peripheral surface of the front bracket 5 at equal intervals in the circumferential direction.

  On the other hand, the rear bracket 6 is formed in a bottomed cylindrical shape, and a bearing housing 29 a is formed on the inner surface side in the center in the radial direction of the end portion (bottom portion) 8. A bearing 29b for rotatably supporting the rear end portion of the rotating shaft 20 is press-fitted and fixed to the bearing housing 29a.

The end portion 8 of the rear bracket 6 is provided with a female screw portion (not shown) at a portion corresponding to the bolt 14, and the bolt 14 is screwed into the female screw portion. .
Furthermore, a sensor cover 48 is fixed to the end 8 of the rear bracket 6 on the outer surface side. Inside the sensor cover 48, a sensor module 52 constituting the other of the optical encoder 53 is disposed. That is, the sensor cover 48 closes the rear end of the rotary shaft 20 and the sensor module 52.

  The sensor module 52 is provided with a light receiving / emitting section 55 on the surface of the rotary 51 that faces the rotary scale 54. The light receiving / emitting unit 55 irradiates the rotary scale 54 with laser and receives reflected light from the rotary scale 54. Further, the sensor module 52 is provided with an IC (Integrated Circuit) 56 on the surface opposite to the rotary scale 54. The IC 56 detects the rotation angle of the rotary shaft 20 based on the output signal from the light receiving / emitting unit 55.

  As shown in FIGS. 2 to 4, a power distribution board 30 is provided around the bearing housing 29 a on the inner surface side of the rear bracket 6. The power distribution board 30 is for supplying power from the external power source E (see FIG. 6) to each coil 19 wound around the stator 3. The power distribution board 30 includes a coil connection portion 31 formed in a substantially annular shape in plan view so as to avoid the bearing housing 29a of the rear bracket 6, and a harness connection portion 32 formed so as to protrude radially outward from the coil connection portion 31. Each of which is integrally molded.

The coil connection portion 31 is a portion to which the terminal portion 19 a of the coil 19 wound around the stator 3 is connected, and the outer diameter is set slightly smaller than the inner peripheral surface of the rear bracket 6. Six patterns 33 are laminated on the coil connection portion 31 so as to correspond to the terminal portions 19a of the coils 19 of each phase (U phase, V phase, W phase), that is, the number of winding start ends and winding end ends. ing.
Each pattern 33 has an annular pattern body 34 formed in the center. Each pattern body 34 is provided with two tongue piece patterns 35 projecting outward from the outer periphery in the radial direction. The tongue pattern 35 is disposed at a portion corresponding to the terminal portion 19a of the coil 19 of each phase.

  Here, the coil 19 is composed of three phases of U phase, V phase, and W phase, and has two coils 19U, 19V, and 19W for each phase. There are four terminal portions 19a, that is, two winding start ends and two winding end ends. Therefore, since each pattern 33 has two tongue piece patterns 35, twelve tongue piece patterns 35 are formed in the entire coil connection portion 31. Each tongue pattern 35 is provided with a coil through hole 36.

The terminal portion 19 a of the coil 19 is inserted into the coil through hole 36. That is, each coil 19 is connected to the power distribution board 30 by inserting the terminal portion 19a through the coil through hole 36 and performing soldering, for example.
Further, the coil connection part 31 is formed with a notch part 57 for avoiding interference with the bolt 14 on the outer peripheral side.

The harness connection part 32 is a part to which one end of the motor harness 58 electrically connected to the external power source E is connected, and is formed in a substantially rectangular shape in plan view. Since the harness connection part 32 is formed so as to protrude radially outward from the coil connection part 31, the harness connection part 32 is positioned on the radially outer side than the rear bracket 6 of the motor case 2.
In the harness connection part 32, six harness through-holes 37 are formed corresponding to the number of laminated coil connection parts 31. Each harness through-hole 37 is connected to the pattern main body 34 of the corresponding coil connection portion 31 via a connection pattern 38.

Here, the six harness through holes 37 formed in the harness connection portion 32 are arranged along the circumferential direction, and the adjacent harness through holes 37 are arranged so as to be shifted from each other in the radial direction. That is, the harness through holes 37 are arranged in a zigzag in order along the circumferential direction in plan view.
The harness connection portion 32 is formed with a notch 39 for routing the sensor harness 59 whose one end is connected to the optical encoder 53 (see FIG. 4).

As shown in FIGS. 1, 2, 4, and 5, an opening 40 is formed in the peripheral wall 9 of the rear bracket 6 at a portion corresponding to the harness connection portion 32 of the power distribution board 30. The harness connection part 32 protrudes radially outward through the opening 40 of the rear bracket 6. The rear bracket 6 is provided with a cover 41 formed so as to surround the opening 40 and the harness connection part 32.
More specifically, the cover 41 is formed in a substantially U-shape in the circumferential cross section, and includes a rear end wall 43 extending along the end portion 8 of the rear bracket 6 and a peripheral edge of the rear end wall 43. The case body 10 has a side wall 44 extending to substantially the center in the axial direction, and an opening 46 is formed at the front end.

Here, the sensor cover 48 provided at the end portion 8 of the rear bracket 6 is formed so as to correspond to the case main body 10 and the cover 41. That is, the sensor cover 48 closes the rear end of the rotary shaft 20 and the sensor module 52 and also closes the rear end of the cover 41.
A ridge 45 for positioning the sensor cover 48 in the circumferential direction is formed on the rear end wall 43 of the cover 41. Further, a notch (not shown) for routing the sensor harness 59 having one end connected to the optical encoder 53 is formed in the rear end wall 43 of the cover 41.

The case body 10 of the motor case 2 is provided with a mounting seat 42 having a substantially rectangular shape in plan view at a portion corresponding to the front end portion of the cover 41. The mounting seat 42 is provided with two female screw portions (not shown), and the cover 41 is fastened and fixed to the case body 10 by screwing two bolts 47 respectively. ing.
The ground wire 70 of the motor harness 58 is fastened to one of the two bolts 47.

  A recess 63 is formed in a portion corresponding to the opening 46 of the cover 41 in the mounting seat 42 provided in the case body 10. In the space formed by the opening 46 and the recess 63, a rubber-like grommet 64 is provided to close the space. The grommet 64 is for preventing dust from entering the brushless motor 1 from the outside, and is formed in a substantially rectangular shape so as to correspond to the opening 46 and the recess 63.

  A flange portion 66 is formed at the rear end of the grommet 64 to restrict the direction in which the grommet 64 is pulled out. Therefore, a stepped portion (not shown) corresponding to the flange portion 66 of the grommet 64 is formed at a portion corresponding to the flange portion 66 of the mounting seat 42.

  The grommet 64 is formed with a plurality of insertion holes 65 through which the motor harness 58 and the sensor harness 59 are inserted. That is, the other ends of the motor harness 58 and the sensor harness 59 are drawn out from the inside of the brushless motor 1 through the grommet 64. The plurality of insertion holes 65 are formed to correspond to the covering 58a of the motor harness 58 and the covering 59a of the sensor harness 59 (see FIG. 4). For this reason, compared with the case where each harness 58 and 59 is penetrated to the grommet 64 in the state which peeled each coating | cover 58a and 59a, the improvement of the insertion workability | operativity of each harness 58 and 59 is achieved.

Under such a configuration, as shown in FIG. 6, the coils 19U, 19V, and 19W of each phase wound around the stator 3 are connected to the external power supply via the power distribution board 30, the motor harness 58, and the drive circuit 71. E is connected.
The drive circuit 71 switches energization to the coils 19U, 19V, and 19W of each phase, and has an H bridge circuit provided for each phase. That is, the drive circuit 71 includes a first bridge circuit 81 that controls the U-phase coil 19U, a second bridge circuit 82 that controls the V-phase coil 19V, and a third bridge that controls the W-phase coil 19W. And a bridge circuit 83.

  The first bridge circuit 81 includes an arm 84 composed of two switching elements Su81 and Su82 connected in series to the external power supply E, and an arm 85 connected in parallel to the arm 84 with respect to the external power supply E. The arm 85 includes two switching elements Su83 and Su84 connected in series. A winding start end and a winding end end, which are terminal portions 19a of the U-phase coil 19U, are respectively provided at a midpoint between the switching elements Su81 and Su82 of the arm 84 and a midpoint between the switching elements Su83 and Su84 of the arm 85. Are connected one by one. Each of the switching elements Su81 to Su84 is configured by combining a field effect transistor and a diode for passing a reflux current.

Thus, for example, when only the switching element Su81 and the switching element Su84 are turned on, current flows in the U-phase coil 19U in the positive direction, whereas when only the switching element Su83 and the switching element Su82 are turned on, the current flows in the opposite direction. Current flows.
A driving signal is input to the switching elements Su81 and Su82 of the arm 84 through one gate driver (not shown). A driving signal is input to the switching elements Su83 and Su84 of the arm 85 through the other gate driver (not shown).

  The second bridge circuit 82 and the third bridge circuit 83 have the same configuration. The second bridge circuit 82 includes a terminal 19a (start of winding) of the V-phase coil 19V at each of a midpoint between the switching elements Sv81 and Sv82 of the arm 84 and a midpoint between the switching elements Sv83 and Sv84 of the arm 85. End and end of winding) are connected one by one. The third bridge circuit 83 includes a terminal portion 19a (start of winding) of a W-phase coil 19W at each of a midpoint between the switching elements Sw81 and Sw82 of the arm 84 and a midpoint between the switching elements Sw83 and Sw84 of the arm 85. End and end of winding) are connected one by one.

Thus, the coils 19U, 19V, and 19W of each phase are connected to the bridge circuits 81, 82, and 83 independently, that is, in a so-called independent connection state. It is possible to control the currents flowing through the coils 19U, 19V, and 19W.
Moreover, in order to connect the coils 19U, 19V, and 19W for each phase independently to the respective bridge circuits 81, 82, and 83, the harness connection portion 32 of the power distribution board 30 is connected to the terminal portion 19a of the coil 19 for each phase. Six harness through-holes 37 for the number, that is, three phases are required (see FIG. 3).

Next, based on FIG. 2, FIG. 4, the connection method of the coil 19 and the motor harness 58 to the power distribution board 30 is demonstrated.
As shown in FIGS. 2 and 4, first, the stator 3 is fitted and fixed to the case body 10 of the motor case 2, and then the power distribution board 30 is set on the rear end side of the stator 3. At this time, since the terminal portions 19a of the coils 19 of the respective phases protrude from the rear end side of the stator 3, the terminal portions 19a are inserted into the coil through holes 36 of the corresponding coil connection portions 31, respectively. .

After inserting the terminal portion 19a of the coil 19 of each phase into the coil through hole 36, the coil through hole 36 and the terminal portion 19a of the coil 19 are connected by soldering or the like.
Next, the rotor 4 is inserted inside the stator 3 in the radial direction, and the opening portions at both ends of the case body 10 are closed by the front bracket 5 and the rear bracket 6.
Subsequently, one end of the motor harness 58 is inserted into the harness through hole 37 of the harness connection portion 32 of the power distribution board 30 from the front side. Then, one end of the motor harness 58 and the harness through hole 37 are connected from the rear surface of the power distribution board 30 by soldering or the like. Thereby, the connection of the coil 19 and the motor harness 58 to the power distribution board 30 is completed.

Here, even after the front bracket 5 and the rear bracket 6 are attached to the case main body 10, the harness connection portion 32 protrudes radially outward from the motor case 2, so that connection work is possible.
Moreover, since the harness connection portion 32 protrudes radially outward from the motor case 2, a large connection space can be secured, and one end of the motor harness 58 can be connected from the front side to the harness through-hole 37 of the harness connection portion 32. Can be plugged into. That is, only the space necessary for soldering or the like may be secured on the rear surface side of the harness connection portion 32. Specifically, for example, when performing a soldering operation, the protruding length T of one end of the motor harness 58 from the power distribution board 30 (see FIG. 4) is preferably set to a length of about 1 mm or more. This space should be secured.

  In connecting the motor harness 58 to the power distribution board 30, the motor harness 58 and the sensor harness 59 may be inserted through the grommet 64 in advance. Further, the motor harness 58 and the harness through hole 37 may be connected before the front bracket 5 and the rear bracket 6 are attached to the case body 10. If the rear bracket 6 is attached in advance before this connection, the optical encoder 53 may be set before the connection.

Therefore, according to the above-described embodiment, the connection of the motor harness 58 and the power distribution board 30 is connected in the motor case 2 by positioning the harness connection portion 32 of the power distribution board 30 on the radially outer side than the motor case 2. There is no need to provide a space for carrying out and a space for routing the motor harness 58. Therefore, for example, even when the number of connections between the motor harness 58 and the power distribution board 30 is large as in the case of so-called independent connection (see FIG. 6), the brushless motor 1 can be downsized. it can.
In addition, since the space for connecting the motor harness 58 and the power distribution board 30 can be sufficiently secured while reducing the size of the brushless motor 1, the connection workability is improved.

  Further, the terminal portion 19a of the coil 19 is inserted into the coil through hole 36 of the power distribution board 30, and one end of the motor harness 58 is inserted into the harness through hole 37, and each wiring operation is completed simply by soldering them. Can be made. For this reason, it is possible to further improve the connection workability while saving the connection work space.

Furthermore, since the harness through-holes 37 are arranged in a zigzag in order along the circumferential direction in plan view, the harness connection portion is reduced in size as compared with the case where all of the harness through-holes 37 are arranged in the circumferential direction. it can. For this reason, the cover 41 formed so as to surround the opening 40 of the rear bracket 6 and the harness connection part 32 can be reduced in size. Therefore, since the part which protrudes from the case main body 10 to radial direction can be made small, the space required in order to install the brushless motor 1 can be made small.
In addition, it is possible to sufficiently secure the insulation distance of each harness through-hole 37 while reducing the size of the harness connection portion 32. For this reason, the brushless motor 1 with higher reliability can be provided.

  In addition, a cutout portion 39 for routing the sensor harness 59 is formed in the harness connection portion 32 of the power distribution board 30. Therefore, even when the brushless motor 1 is provided with the optical encoder 53, the sensor harness 59 is routed across the power distribution board 30 in the axial direction without increasing the size of the rear bracket 6 of the motor case 2. Is possible. Therefore, the degree of freedom of pulling out the harnesses 58 and 59 from the motor case 2 is increased. That is, for example, the harnesses 58 and 59 can be pulled out to the front side of the brushless motor 1 as in this embodiment. Moreover, not only the beauty of the brushless motor 1 is improved, but also an increase in the size of the brushless motor 1 can be suppressed.

The present invention is not limited to the above-described embodiment, and includes various modifications made to the above-described embodiment without departing from the spirit of the present invention.
In the above-described embodiment, the case where the brushless motor 1 is provided with the optical encoder 53 as a device for detecting the rotation angle of the rotating shaft 20 of the rotor 4 has been described. However, the present invention is not limited to this, and the brushless motor 1 may be provided with a magnetic encoder, a resolver, a Hall IC and a sensor magnet, or may be sensorless.

  Furthermore, in the above-described embodiment, the case where the coils 19U, 19V, and 19W of each phase are independently connected to the bridge circuits 81, 82, and 83, that is, independently connected, has been described. However, the present invention is not limited to this, and a star connection, a delta connection, or the like may be adopted as a connection method of the coil 19.

  And in the above-mentioned embodiment, the coil 19 was comprised by three phases, U phase, V phase, and W phase, and demonstrated the case where it had two coils 19U, 19V, and 19W of each phase. . However, the present invention is not limited to this, and various coil configurations (for example, a 5-phase configuration) can be employed. In this case, the coil connection part 31 and the harness connection part 32 of the power distribution board 30 are formed so as to appropriately set the number of through holes 36 and 37 according to the coil configuration and the connection method, respectively. That's fine.

It is a perspective view of the brushless motor in the embodiment of the present invention. It is a longitudinal cross-sectional view of the brushless motor in embodiment of this invention. It is a top view of a power distribution board in an embodiment of the present invention. It is a perspective view of a power distribution board in an embodiment of the present invention. It is the A section enlarged view of FIG. It is a block diagram of the control circuit in the embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Brushless motor 2 Motor case 3 Stator 4 Rotor 5 Front bracket 6 Rear bracket 10
19, 19U, 19V, 19W
19a Terminal part 30 Power distribution board 31 Coil connection part 32 Harness connection part 36 Through hole for coil 37 Through hole for harness 39 Notch part 58 Motor harness (harness)
59 Sensor harness (other harnesses)
71 Drive circuit 81 First bridge circuit (bridge circuit)
82 Second bridge circuit (bridge circuit)
83 Third bridge circuit (bridge circuit)
84, 85 Arm E External power supply Su81, Su82, Su83, Su84 Switching element

Claims (5)

In the motor case,
In a brushless motor comprising a stator around which coils of a plurality of phases are wound, a rotor provided rotatably with respect to the stator, and a power distribution board for supplying power to the coils,
The power distribution board is:
A coil connection part for connecting a terminal part of the coil;
A harness connection part for connecting one end of a harness electrically connected to an external power source;
The brushless motor, wherein the harness connection portion is formed to be positioned radially outside of the motor case. It has a drive circuit that can be energized independently to each phase coil,
The drive circuit is
Two arms connected in series to the external power supply are connected in parallel to the external power supply, and one end of the coil is electrically connected between the switching elements of each arm. The brushless motor according to claim 1, further comprising a bridge circuit connected to each phase of the coil. In the coil connection part, while providing a through-hole for a coil into which the terminal part of the coil can be inserted,
The brushless motor according to claim 1, wherein a harness through hole into which one end of the harness can be inserted is provided in the harness connection portion. The harness through-hole is
Arranged along the circumferential direction,
The adjacent through hole for harness is
The brushless motor according to any one of claims 1 to 3, wherein the brushless motor is arranged so as to be shifted from each other in the radial direction. The brushless motor according to any one of claims 1 to 4, wherein a notch portion in which another harness can be routed is formed on the power distribution board.

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