JP2008079468A - Brushless motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance the workability by improving settlement of the lead wire of a resolver and to protect the joint of the lead wire and the resolver against external tensile force. <P>SOLUTION: In the brushless motor 1 comprising a stator 2 having a case 4 for containing a stator core 5 applied with a stator coil 6, a bracket 24 fixed to one end side of the case 4, a rotor 3 arranged rotatably on the inside of the stator 2, and a resolver 31 for detecting the rotational position of the rotor 3, a bracket holder unit 35 having a recessed guide portion 55 for containing the lead wire 36a of the resolver 31 is provided on the inner side of motor of the bracket 24. In the guide portion 55, a plurality of ribs 59 are provided to project toward the axial direction. The lead wire 36a is pushed between the ribs 59 and wired in the guide portion 55 and clamped between the bracket 24 and the bracket holder unit 35. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a brushless motor, and more particularly to a lead wire routing structure of a rotor position detection device in a brushless motor.

  Generally, in a brushless motor, the rotational position of a rotor is detected, and based on the detected rotor rotational position, a stator-side coil (stator coil) is sequentially excited to rotate the rotor. Conventionally, a sensor device using an encoder, Hall IC, resolver, etc. has been used to detect the rotational position of the rotor. A lead wire is connected to the sensor device to output a rotor position detection signal to the outside of the motor. Yes. FIG. 12 is a cross-sectional view showing a configuration of a conventional brushless motor 100 (hereinafter abbreviated as “motor 100”). Here, a resolver 102 is used as a sensor device for detecting the rotational position of the rotor 101.

  The resolver 102 includes a resolver stator 103 and a resolver rotor 104, and an exciting coil 105 is wound around the stator. On the other hand, a resolver rotor 104 made of a magnetic material is disposed on the rotor side, and the resolver rotor 104 is fixed to the rotor shaft 106 of the motor 100. In such a resolver 102, when a high-frequency signal is applied to the stator-side excitation coil 105, the phase of the signal flowing through the stator-side detection coil (not shown) changes depending on the rotational position of the rotor 101. The rotational position of the rotor 101 is detected by comparing the detection signal with the reference signal.

A detection signal from the resolver stator 103 is transmitted via a lead wire 107 to a control device (not shown) provided outside the motor. A system in which the lead wire 107 and the resolver stator 103 are electrically connected by welding and fixing the lead wire 107 to a terminal provided on the resolver stator 103 is generally used, but like the motor 100 in FIG. There are also some connector connection types. In the motor 100, a connector 108 is attached to the end of the lead wire 107 and is connected to a connector 109 provided on the resolver stator 103. The other end side of the lead wire 107 is routed through the motor housing 111 and then led out of the motor and connected to the control device.
JP 2005-210837 A

  However, in the motor 100 of FIG. 12 and the like, the lead wire 107 floats in the air inside the motor housing 111, so that the lead wire 107 is shaken by vibration and rubs against other members. There was a problem. Further, when the lead wire 107 is pulled from the outside, the force is directly applied to the connection portion between the lead wire 107 and the resolver stator 103, and there is a problem that the connection portion may be damaged. For example, when the lead wire 107 is fixed by welding, a tensile force is applied to the welded portion, and the welded portion may be damaged. Moreover, even if the connector is connected, the connector may come off or be damaged.

  In addition, in the configuration in which the lead wire 107 is routed in the space inside the motor housing 111, there is a problem that the lead wire 107 does not fit in the housing and the lead wire 107 may be rubbed against other parts. If the lead wire 107 is in a floating state in the housing, there is a problem that the lead wire 107 becomes an obstacle when assembling other parts, which hinders work.

  An object of the present invention is to improve the workability by improving the fit of the lead wires of the rotor position detecting device. Another object of the present invention is to protect a connecting portion between a lead wire and a rotor position detecting device from a tensile force.

  A brushless motor according to the present invention is provided with a stator having a core around which a coil is wound and a case for housing the core, a bracket attached to one end side of the case, and a rotatable arrangement inside the stator. A brushless motor having a rotor and a rotor rotational position detecting means for detecting the rotational position of the rotor, the brushless motor being attached to the inside of the motor of the bracket, wherein the lead wire of the rotor rotational position detecting means is accommodated It has the bracket holder unit in which the guide part to be formed was formed.

  In the present invention, since the bracket holder unit including the guide portion that accommodates the lead wire of the rotor rotation position detecting means is provided in the brushless motor, the lead wire can be accommodated and wired well. For this reason, the lead wire fits better than the conventional motor, and the lead wire does not float in the air. Further, when assembling other parts, the lead wire does not get in the way, and the workability at the time of assembling the motor is improved.

  In the brushless motor, the lead wire may be sandwiched between the bracket and the bracket holder unit. Moreover, you may form the said guide part by denting along the circumferential direction in the outer periphery vicinity of the said bracket holder unit.

  Furthermore, a rib piece projecting in the axial direction may be provided on the guide portion, and the rib piece may be extended along the circumferential direction and disposed between the lead wires. As a result, the fit of the lead wire is further improved, and even if the lead wire is pulled from the outside, the tensile force is not directly applied to the connecting portion between the lead wire and the rotation position detecting means, and the lead wire is connected by pulling from the outside. It is possible to prevent the part from being damaged. In this case, a plurality of the rib pieces may be formed in the guide portion and arranged on different circumferences without overlapping each other in the radial direction.

  Further, a protruding piece may be formed on the guide portion so as to cover the upper portion of the guide portion, and the lead wire may be wired below the protruding piece. As a result, the lead wire can be easily assembled to the guide portion, and workability can be improved. In this case, the guide portion may be further provided with a protrusion protruding in the axial direction, and the protrusion may extend along the radial direction and be disposed on both sides of the protrusion. At that time, the lead wire may be wired on the upper side of the projection and the lower side of the projection piece, so that even if the lead wire is pulled from the outside, the connection portion between the lead wire and the rotational position detecting means is connected. This tensile force is not directly applied, and the lead wire connecting portion can be prevented from being damaged by an external pull.

  In addition, a resolver may be used as the rotor rotation position detecting means. In this case, the resolver rotor that is attached to the shaft of the rotor and rotates together with the rotor is disposed on the brushless motor, and is disposed outside the resolver rotor. And a resolver stator having a detection coil whose output signal phase changes with rotation of the resolver rotor, and the lead wire may be a sensor lead wire connected to the resolver stator.

  According to the brushless motor of the present invention, a stator including a case that accommodates a core around which a coil is wound, a bracket that is attached to one end of the case, a rotor that is rotatably disposed inside the stator, In a brushless motor having a rotor rotational position detecting means for detecting the rotational position of the rotor, a bracket holder in which a guide portion for accommodating the lead wire of the rotor rotational position detecting means is formed on the inner side of the bracket motor By providing the unit, the lead wires can be accommodated and wired well. For this reason, it is possible to prevent the lead wire from floating in the air like a conventional motor, and to prevent the lead wire from rubbing against or hitting other parts. It becomes possible. Further, when assembling other parts, the lead wire does not get in the way, the workability at the time of motor assembly is improved, and the number of assembly steps can be reduced.

  Further, according to the brushless motor of the present invention, the rib piece is provided on the guide portion and disposed between the lead wires, so that even if the lead wire is pulled from the outside, the lead wire and the rotational position detecting means It is possible to prevent a tensile force from being directly applied to the connecting portion. For this reason, it is possible to prevent the lead wire connecting portion from being damaged by pulling from the outside, and to improve the reliability of the motor.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a sectional view of a brushless motor that is Embodiment 1 of the present invention, and FIG. 2 is an exploded perspective view of the brushless motor of FIG. As shown in FIG. 1, a brushless motor 1 (hereinafter abbreviated as “motor 1”) is an inner rotor type brushless motor in which a stator 2 is arranged on the outside and a rotor 3 is arranged on the inside. The motor 1 is used, for example, as a power source of a column assist type electric power steering device (EPS), and applies an operation assisting force to a steering shaft of an automobile. The motor 1 is attached to a speed reduction mechanism provided on the steering shaft, and the rotation of the motor 1 is transmitted to the steering shaft by being decelerated by the speed reduction mechanism.

  The stator 2 includes a bottomed cylindrical case 4, a stator core 5, a stator coil 6 wound around the stator core 5 (hereinafter abbreviated as coil 6), and a bus bar unit (terminal unit) 7 attached to the stator core 5. It is configured. The case 4 is formed in a bottomed cylindrical shape with iron or the like, and a bracket 24 made of aluminum die cast is attached to an opening of the case 4 with a fixing screw 23. The stator core 5 includes a plurality of divided cores 8 and has a configuration in which nine divided cores 8 are assembled in the circumferential direction. The split core 8 is formed by stacking core pieces made of electromagnetic steel plates, and an insulator 9 made of synthetic resin is attached around the core.

  A coil 6 is wound around the outside of the insulator 9, and an end portion 6 a of the coil 6 is drawn out in the radial direction on one end side of the stator core 5. A bus bar unit 7 in which a copper bus bar is insert-molded in a synthetic resin main body is attached to one end side of the stator core 5. Around the bus bar unit 7, a plurality of power supply terminals 11 protrude in the radial direction, and when the bus bar unit 7 is attached, the coil end 6 a is welded to the power supply terminal 11. In the bus bar unit 7, the number of bus bars corresponding to the number of phases of the motor 1 (here, three for U phase, V phase, W phase) is provided, and each coil 6 is a power supply terminal corresponding to that phase. 11 is electrically connected. After the bus bar unit 7 is attached, the stator core 5 is press-fitted into the case 4 and bonded and fixed to the inner peripheral surface of the case.

  A rotor 3 is inserted inside the stator 2. The rotor 3 has a rotor shaft 21, and the rotor shaft 21 is rotatably supported by bearings 22a and 22b. The bearing 22 a is fixed to the center of the bottom of the case 4, and the bearing 22 b is fixed to the center of the bracket 24. A cylindrical rotor core 25 is fixed to the rotor shaft 21, and a segment type magnet (permanent magnet) 26 is attached to the outer periphery thereof. A magnet holder 27 made of synthetic resin is inserted on the rotor shaft 21, and the magnet 26 is disposed on the outer periphery of the rotor core 25 in a form held by the magnet holder 27. In the motor 1, six magnets 26 are arranged along the circumferential direction, and a bottomed cylindrical magnet cover 28 is attached to the outside of the magnet 26.

  A rotor (resolver rotor) 32 of a resolver 31 serving as a rotor rotation position detecting means is attached to the end of the magnet holder 27. On the other hand, the stator (resolver stator) 33 of the resolver 31 is press-fitted into a metal resolver holder 34 and is fixed to the bracket holder unit 35 in that state. A sensor harness 36 for transmitting a signal output as the rotor 32 rotates is fixed to the resolver stator 33. The sensor harness 36 is welded to the terminal portion 33a of the stator 33, and an insulator 37 made of synthetic resin is attached to the terminal portion 33a. The sensor harness 36 is drawn between the bracket 24 and the bracket holder unit 35 along the circumferential direction, and is drawn out of the apparatus from the outer peripheral portion of the bracket 24 via the rubber grommet 38.

  In the motor 1, the resolver holder 34 is formed in a bottomed cylindrical shape, and is inserted and mounted in the central portion of the bracket holder unit 35. On the other hand, the opening side end portion where the flange portion 34 a is formed is lightly press-fitted into the outer periphery of the end portion of the rib 39 provided on the bracket 24. The rib 39 projects in a cylindrical shape toward the axial direction at the center of the bracket 24, and a bearing 22 b that supports the rotor shaft 21 is fixed to the inside of the rib 39. Therefore, by lightly press-fitting the resolver holder 34 into the rib 39, the resolver stator 33 is mounted concentrically with the rotor shaft 21, the core accuracy of the stator 33 and the rotor 32 of the resolver 31 is improved, and the rotor position detection accuracy is improved. Is planned.

  FIG. 3 is a perspective view showing the configuration of the bracket holder unit 35. The bracket holder unit 35 is formed of a synthetic resin, and a metal female screw portion 41 is insert-molded. A mounting screw 42 is screwed into the female screw portion 41 from a resolver fixing hole 48 b provided in the bracket 24, whereby the resolver holder 34 is fixed inside the bracket 24. A mounting hole 34b formed in the flange portion 34a of the resolver holder 34 is a long hole extending in the circumferential direction, and the position of the resolver holder 34 can be finely adjusted in the circumferential direction.

  The motor 1 according to the present invention is different from the motor 100 of FIG. 12 in that the resolver 31 is disposed on the inner side of the bearing 22b attached to the bracket 24, and when aligning the resolver holder 34, the mounting screw 42 is provided from the outside of the motor. The structure that tightens is adopted. Therefore, in the motor 1, the bracket holder unit 35 in which the female screw portion 41 is insert-molded is arranged in the motor, and the female screw portion (nut) for receiving the mounting screw 42 is provided in the motor. Thereby, the structure which fastens the attachment screw 42 from the outside of a motor is attained, and the brushless motor which has arrange | positioned the resolver 31 inside the bearing 22b like FIG. 1 is realizable.

  The bracket holder unit 35 is also provided with three external power feeding terminals 43. The external power supply terminal 43 is provided for each phase of U, V, and W, and when the bracket holder unit 35 is assembled to the bracket 24, the external power supply terminal 43 is provided so as to protrude in the radial direction from the side surface of the bracket 24. It has been. Each external power feeding terminal 43 (43U, 43V, 43W) is electrically connected to a connection terminal 44 (44U, 44V, 44W) provided in the bracket holder unit 35. Each connection terminal 44 protrudes from the main body 45 of the bracket holder unit 35 in the axial direction, and is welded to a bus bar terminal 46 (46U, 46V, 46W) provided on the bus bar unit 7.

  The bus bar terminal 46 also projects from the main body 47 of the bus bar unit 7 in the axial direction, and when the motor 1 is assembled, the bus bar terminal 46 and the connection terminal 44 face each other in parallel. In the motor 1, after the bracket 24 is attached to the case 4, the bus bar terminal 46 and the connection terminal 44 are fixed by welding. A welding work hole 48a is formed in the bracket 24, and a bracket cap 49 is attached to the welding work hole 48a after the welding process.

  On the other hand, a guide portion 55 is formed in the bracket holder unit 35 in the vicinity of the outer peripheral edge along the circumferential direction. The guide portion 55 accommodates a sensor lead wire 36a of the sensor harness 36 (hereinafter abbreviated as a lead wire 36a). As shown in FIG. 3, a terminal accommodating portion 57 that accommodates the terminal portion 33 a of the resolver stator 33 is recessed in the end face 56 on the bracket 24 side of the bracket holder unit 35. The guide portion 55 is formed from the terminal accommodating portion 57 by about one third of the circumference in the circumferential direction, and extends to a lead wire lead-out portion 58 that is notched at the outer peripheral edge.

  FIG. 4 is a perspective view showing the bracket holder unit 35 in a state where the lead wire 36 a is accommodated in the guide portion 55. As shown in FIG. 4, the terminal accommodating portion 57 accommodates the terminal portion 33 a of the resolver stator 33, and the lead wire 36 a connected to the terminal portion 33 a is guided in the circumferential direction by the guide portion 55 and is led out. To 58. Thereafter, the lead wire 36 a is drawn out from the lead wire drawing portion 58 to the outer peripheral side of the bracket holder unit 35. The lead wire 36a drawn to the outer periphery of the bracket holder unit 35 is drawn out of the apparatus from the bracket 24 via the rubber grommet 38.

  In the motor 1 according to the present invention, a plurality of rib pieces 59 are provided in the guide portion 55. As shown in FIG. 3, the rib piece 59 protrudes from the bottom surface 55a of the guide portion 55 toward the axial direction (upward in the figure), and extends about 10 ° along the circumferential direction. ing. Four rib pieces 59 are provided in the guide portion 55 (59a to 59d), and two rib pieces 59 are arranged on the circumferences of different diameters. Here, the rib pieces 59a and 59c and the rib pieces 59b and 59d are arranged on a circumference having the same diameter, and the rib pieces 59a and the rib pieces 59b are arranged on a circumference having different diameters. The rib pieces 59a to 59d extend along the circumferential direction, but are alternately arranged at positions that do not overlap in the radial direction. Here, the center positions of the rib piece 59a and the rib piece 59b are about 15 ° apart, and a gap of about 5 ° is provided between the rib piece 59a and the rib piece 59b.

  The lead wire 36 a is wired in the guide portion 55 so as to be pushed lightly between the side walls 55 b and 55 c of the guide portion 55 and the rib pieces 59 or between the rib pieces 59. At this time, since the rib pieces 59a to 59d are alternately arranged along the circumferential direction, the lead wire 36a can be easily pushed into the guide portion 55, and the workability is also good. FIG. 5 is an explanatory diagram showing a state in which the lead wire 36 a is wired in the guide portion 55. As shown in FIG. 5, the lead wires 36a are wired in upper and lower two stages and three rows, and the rib pieces 59 are arranged between the lead wires 36a. Thereby, the lead wire 36a is accommodated in the guide part 55 so as to be sandwiched between the guide part side walls 55b and 55c and the rib piece 59. As shown in FIG. 6, the bracket holder unit 35 to which the lead wire 36 a is wired is attached to the motor inner surface of the bracket 24 with the guide portion 55 facing the bracket 24.

  FIG. 7 is a cross-sectional view showing a state of the lead wire 36 a when the bracket holder unit 35 is attached to the bracket 24. As shown in FIG. 7, the lead wire 36 a is sandwiched between the inner end surface 24 a of the bracket 24 and the bracket holder unit 35 while being accommodated in the guide portion 55. In other words, in the motor 1, the lead wire 36 a can be sandwiched and fixed between the bracket 24 and the bracket holder unit 35 by providing the bracket holder unit 35 in the motor. For this reason, the lead wire 36a fits better than the conventional motor, the lead wire 36a does not float in the air, the lead wire 36a rubs against other parts, and is unnecessary. There is no chance to win. Furthermore, since the lead wire 36a is held in an orderly manner between the bracket 24 and the bracket holder unit 35, the lead wire 36a does not get in the way when assembling other components, and the workability during motor assembly is also good. Assembling man-hours can be reduced.

  In the bracket holder unit 35, a rib piece 59 is provided, and the lead wire 36a is wired so as to be sandwiched between the guide portion side walls 55b and 55c and the rib piece 59. For this reason, the fit of the lead wire 36a is improved, and even if the lead wire 36a is pulled from the outside, a tensile force is not directly applied to the welded portion between the lead wire 36a and the terminal portion 33a. In this case, the tensile force applied to the lead wire 36a first acts on the resin rib piece 59 and does not act directly on the welded portion. Therefore, an excessive stress due to the tensile force is not generated in the welded portion between the lead wire 36a and the terminal portion 33a, and the lead wire connecting portion can be prevented from being damaged by an external pull, thereby improving the product reliability. Figured. In the motor 1, since the stress of the lead wire connecting portion is relieved by a simple configuration in which the rib piece 59 is protruded from the bracket holder unit 35, the motor 1 can be reduced without significant design change of components. Measures against tensile force can be taken at cost.

  Such a motor 1 is assembled as follows. First, the stator 2, the rotor 3, and the bracket assembly 51 are assembled individually. In this case, the bracket assembly 51 is an assembly product in which the bracket 24 in which the bearing 22 b is incorporated and the bracket holder unit 35 in which components related to the resolver stator 33 are assembled, and are fixed by a tapping screw 52. The stator 2 is an assembly product in which a bus bar unit 7 is attached to a stator core 5 around which a coil 6 is wound, and a power supply terminal 11 and a coil end 6 a are welded and accommodated in a case 4. The rotor 3 is an assembly product in which the rotor core 25 is fixed to the rotor shaft 21, the magnet holder 27 is attached, the magnet 26 is press-fitted and the magnet cover 28 is attached, and the resolver rotor 32 is press-fitted and fixed to the magnet holder 27. It is.

  After assembling such assemblies, the rotor 3 is attached to the bracket assembly 51, the stator 2 is externally mounted thereon, and the case 4 and the bracket 24 are fastened by the fixing screws 23. Next, the bus bar terminal 46 and the connection terminal 44 are welded and fixed via the welding work hole 48a. In this state, motor resistance, insulation check, etc. are performed, and then the origin of the resolver 31 is adjusted. The origin adjustment is performed by finely adjusting the position of the resolver holder 34 from the outside of the bracket 24 in the circumferential direction by using the long attachment hole 34b. A resolver adjustment hole 48c is formed in the bracket 24, and the origin adjustment is performed from the resolver adjustment hole 48c. At that time, an adjusting jig (not shown) is inserted into the resolver adjusting hole 48c, the position of the resolver holder 34 is finely adjusted in the circumferential direction using the mounting hole 34b, and the origin of the resolver 31 is adjusted.

  After the origin is adjusted, the mounting screw 42 is inserted from the outside of the bracket 24 through the resolver fixing hole 48b, and is screwed and fixed to the female screw portion 41. As a result, the flange portion 34 a of the resolver holder 34 is fixed so as to be sandwiched between the bracket 24 and the bracket holder unit 35. After tightening the attachment screw 42, the bracket cap 49 is attached. Thus, the assembly work of the motor 1 is completed, after which various characteristic checks and the like are performed to obtain a finished product.

  Next, a brushless motor that is Embodiment 2 of the present invention will be described. FIG. 8 is an explanatory view showing the configuration of the bracket holder unit 62 used in the brushless motor 61 of the second embodiment, and FIG. 9 is a cross-sectional view taken along the line AA of FIG. The brushless motor of the following embodiment differs from the motor 1 of FIG. 1 only in the configuration of the bracket holder unit, and the other configurations are the same as those of the motor 1 described above. Therefore, in the following embodiments, the description of the configuration of the motor itself is omitted, and the same members and portions as those of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  In the bracket holder unit 62, three pressing pieces (projections) 63 are provided in the guide portion 55 along the circumferential direction instead of the rib pieces 59 (63a to 63c). As shown in FIG. 9, the pressing piece 63 protrudes in a cantilever shape in the radial direction from the upper ends of the guide portion side walls 55 b and 55 c so as to cover the upper portion of the guide portion 55. A gap 64 is provided between the distal end portion of the pressing piece 63 and the upper ends of the guide portion side walls 55b and 55c facing the pressing piece 63. The width B of the gap 64 is slightly larger than the outer diameter of the lead wire 36 a, and the lead wire 36 a can be inserted from the gap 64 below the pressing piece 63. In addition, a molding hole 65 is formed in the guide portion 55 below the pressing piece 63 so that the pressing piece 63 can be easily formed when the bracket holder unit is formed.

  Also in the guide portion 55 of the bracket holder unit 62, the lead wires 36a are wired in upper and lower two stages and three rows, as in the first embodiment. In FIG. 9, the right two wires 36a are arranged facing the gap 64 and are detachable from the guide portion 55. However, as shown in FIG. The upper ends of the side walls 55 b and 55 c are alternately arranged on the inner diameter side and the outer diameter side, and the two previous lead wires 36 a are also held in the guide portion 55 by the other pressing pieces 63. The bracket holder unit 62 is attached to the bracket 24 in a state where the lead wire 36a is held in the guide portion 55 in this manner. As a result, the lead wire 36 a is sandwiched between the bracket 24 and the bracket holder unit 62.

  As described above, in the brushless motor 61 according to the second embodiment, since the holding piece 63 is provided on the guide portion 55 and wiring is performed by inserting the lead wire 36a below the guide piece 55, the lead wire 36a can be easily assembled to the guide portion 55. It becomes possible to improve workability. Also in the brushless motor 61, the lead wire 36a can be sandwiched and fixed between the bracket holder unit 62 and the bracket 24, and the lead wire 36a can be accommodated and wired well. For this reason, the lead wire 36a does not float in the air, and the lead wire 36a does not rub against other parts in the motor or unnecessarily hits it. Furthermore, when assembling other parts, the lead wire 36a does not get in the way, and the workability at the time of motor assembly is also improved.

  Furthermore, a brushless motor that is Embodiment 3 of the present invention will be described. FIG. 10 is an explanatory view showing a configuration of a bracket holder unit 67 used in the brushless motor 66 of the third embodiment, and FIG. 11 is a cross-sectional view taken along the line BB of FIG. As described above, in the motor of the first embodiment, the tensile force from the outside is received by the rib pieces 59 to prevent the welded portion from being damaged. However, the brushless motor 61 of the second embodiment has the guide portion side wall 55b, Since the structure receives the tensile force at 55c and the holding piece 63, the stress relaxation effect of the welded portion is slightly lowered. Therefore, in the third embodiment, a protrusion 68 is provided in the guide portion 55 in addition to the pressing piece 63, and the protrusion 68 receives a tensile force applied to the lead wire 36a.

  The protrusion 68 protrudes from the bottom surface 55 a of the guide portion 55 in the axial direction, and extends along the radial direction so as to cross the inside of the guide portion 55. The protrusions 68 are provided at two locations in the guide portion 55 (68a, 68b), and are disposed on both sides of the central pressing piece 63b. Here, as shown in FIG. 10, the lead wire 36a is wired so as to pass through the upper side of the protrusion 68 and the lower side of the pressing piece 63b. Therefore, when a tensile force is applied to the lead wire 36a, the force first acts on the protrusion 68 and does not directly act on the welded portion.

  As described above, in the brushless motor 66 according to the third embodiment, the guide portion 55 is provided with the protrusion 68 together with the pressing piece 63, and wiring is performed so that the lead wire 36a is sandwiched between the protrusion 68 and the pressing piece 63b. For this reason, the tensile force of the lead wire 36a does not directly act on the welded portion, and no excessive stress due to the tensile force is generated in the welded portion between the lead wire 36a and the terminal portion 33a. It is possible to prevent the connection portion from being damaged. Also in the brushless motor 66, as in the previous embodiment, the lead wire 36a can be fixed between the bracket holder unit 62 and the bracket 24, and the lead wire 36a can be accommodated and wired well.

  The protrusions 68 may be formed not only on both sides of the pressing piece 63b but also on both sides of the other pressing pieces 63a and 63c. In that case, the protrusion 68 near the center of the pressing pieces 63a and 63c may be used as the protrusions 68a and 68b. Further, the protrusion 68 on the outer side of the holding pieces 63a and 63c (on the lead wire lead-out portion 58 and the terminal accommodating portion 57 side) may be formed lower than the protrusion 68 closer to the center in consideration of the wiring state of the lead wire 36a. good.

It goes without saying that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention.
For example, in the above-described embodiment, the guide portion 55 has four rib pieces 59, three pressing pieces 63, and two protrusions 68. However, the number of rib pieces, pressing pieces, protrusions, The arrangement interval and the like are not limited to the above example. Further, although the case where the number of lead wires 36a is six is shown, the number of lead wires themselves is not limited to this. Needless to say, the situation and the wiring state of the lead wire 36a can be changed as appropriate.

  Furthermore, in the above-described embodiment, the brushless motor used in the column assist type EPS is shown, but the present invention can be applied to other types of EPS motors. In addition to EPS and various in-vehicle electric motors, the present invention can be widely applied to general brushless motors, and can also be applied to motors with brushes and electric devices.

It is sectional drawing of the brushless motor which is Example 1 of this invention. It is a disassembled perspective view of the brushless motor of FIG. It is a perspective view which shows the structure of a bracket holder unit. It is a perspective view which shows the bracket holder unit of the state which accommodated the lead wire in the guide part. It is explanatory drawing which shows a mode that the lead wire was wired in the guide part. It is a perspective view which shows the state which attached the bracket holder unit to the bracket. It is sectional drawing which shows the mode of a lead wire when a bracket holder unit is attached to a bracket. It is explanatory drawing which shows the structure of the bracket holder unit used for the brushless motor of Example 2. FIG. It is sectional drawing along the AA line of FIG. It is explanatory drawing which shows the structure of the bracket holder unit used for the brushless motor of Example 3. FIG. It is sectional drawing along the BB line of FIG. It is sectional drawing which shows the structure of the conventional brushless motor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Brushless motor 2 Stator 3 Rotor 4 Case 5 Stator core 6 Stator coil 6a Coil end 7 Bus bar unit 8 Divided core 9 Insulator 11 Feeding terminal 21 Rotor shaft 22a, 22b Bearing 23 Fixing screw 24 Bracket 24a Inner end surface 25 Rotor core 26 Magnet 27 Magnet holder 28 Magnet cover 31 Resolver (rotor rotational position detecting means)
32 Rotor 33 Stator 33a Terminal portion 34 Resolver holder 34a Flange portion 34b Mounting hole 35 Bracket holder unit 36 Sensor harness 36a Sensor lead wire 37 Insulator 38 Rubber grommet 39 Rib 41 Female thread portion 42 Mounting screw 43 External power supply terminal 44 Connection terminal 45 Main body Portion 46 Bus bar terminal 47 Body 48a Welding hole 48b Resolver fixing hole 48c Resolver adjustment hole 49 Bracket cap 51 Bracket assembly 52 Tapping screw 55 Guide portion 55a Bottom surface 55b, 55c Guide portion side wall 56 End surface 57 Terminal accommodating portion 58 Lead wire lead portion 59 Rib pieces 59a to 59d Rib piece 61 Brushless motor 62 Bracket holder unit 63 Presser piece (projection piece)
63a to 63c Holding piece 64 Air gap 65 Molding hole 66 Brushless motor 67 Bracket holder unit 68 Protrusion 68a, 68b Protrusion
100 brushless motor
101 rotor
102 resolver
103 Resolver stator
104 Resolver rotor
105 excitation coil
106 Rotor shaft
107 Lead wire
108 connector
109 connector
111 Motor housing B gap width

Claims (8)

A stator having a core around which a coil is wound and a case for housing the core; a bracket attached to one end of the case; a rotor rotatably disposed inside the stator; A brushless motor having a rotor rotational position detecting means for detecting a rotational position,
A brushless motor having a bracket holder unit attached to the bracket inside the motor and formed with a guide portion for accommodating a lead wire of the rotor rotational position detecting means.   The brushless motor according to claim 1, wherein the lead wire is sandwiched between the bracket and the bracket holder unit.   3. The brushless motor according to claim 1, wherein the guide portion is recessed along the circumferential direction in the vicinity of the outer peripheral edge of the bracket holder unit.   4. The brushless motor according to claim 1, wherein the guide portion has a rib piece projecting in an axial direction, and the rib piece extends along a circumferential direction. 5. The brushless motor is disposed between the lead wires.   5. The brushless motor according to claim 4, wherein a plurality of the rib pieces are formed in the guide portion and are arranged on different circumferences without overlapping each other in the radial direction.   4. The brushless motor according to claim 1, wherein the guide portion has a projecting piece formed to cover an upper portion of the guide portion, and the lead wire is provided under the projecting piece. A brushless motor characterized by being wired on the side.   The brushless motor according to claim 6, wherein the guide portion further includes a protrusion projecting in the axial direction, the protrusion extending along the radial direction and disposed on both sides of the projecting piece, The brushless motor, wherein the lead wire is wired above the protrusion and below the protrusion.   The brushless motor according to any one of claims 1 to 7, wherein the rotor rotation position detection means is a resolver, and the brushless motor is further attached to a shaft of the rotor and rotates with the rotor. A resolver stator provided with a detection coil disposed outside the resolver rotor and having a phase of an output signal that changes with rotation of the resolver rotor, and the lead wire is connected to the resolver stator. A brushless motor characterized by being a lead wire.

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