JP2016167943A - Brushless motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brushless motor in which falling out of a motor shaft can be suppressed, while reducing the manufacturing cost.SOLUTION: A brushless motor 10 includes a motor shaft 12, a rotor housing 26 having a bottomed cylindrical outer cylinder 32, a stator core 40 housed on the inside of the outer cylinder 32, and a center piece 18 having a body 62 disposed oppositely to the opening of the outer cylinder 32. A spacer 94 having a press-fit hole 102 is used for fixing the motor shaft 12. When a spacer 94 is fixed to the body 62 of the center piece 18, while press-fitting the motor shaft 12 in the press-fit hole 102 of the spacer 94, the motor shaft 12 is fixed to the body 62 of the center piece 18. The spacer 94 is formed of the same material as that of the motor shaft 12.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a brushless motor.

  2. Description of the Related Art Conventionally, there is an outer rotor type brushless motor that includes a motor shaft, a rotor housing that is rotatably supported by the motor shaft via a bearing, and a stator that is accommodated inside the rotor housing.

  Among these types of brushless motors, there is a brushless motor that has a main body that faces the opening of the rotor housing and includes a center piece that holds a motor shaft and a stator (see, for example, Patent Document 1). In this brushless motor, the motor shaft is press-fitted into a shaft housing portion formed in the main body portion of the center piece.

JP 2014-36525 A

  By the way, in a brushless motor provided with such a center piece, the motor shaft may be made of iron and the center piece may be made of aluminum. However, when the motor shaft is made of iron and the center piece is made of aluminum, it is assumed that the motor shaft comes out of the shaft housing portion due to a difference in linear expansion between iron and aluminum.

  Therefore, in order to prevent the motor shaft from coming off from the shaft housing portion, it is conceivable to integrally mold the iron motor shaft to the aluminum center piece by casting. However, in this case, a dedicated die casting machine is required, and the manufacturing cost increases.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a brushless motor capable of suppressing the removal of the motor shaft while suppressing the manufacturing cost.

  In order to solve the above-mentioned problem, a brushless motor according to claim 1 is provided with a motor shaft, a cylindrical bearing housing portion provided on a radially outer side of the motor shaft, and a radially outer side of the bearing housing portion. A rotor housing having an outer cylinder portion formed; a bearing housed in the bearing housing portion; and a bearing assembled to the motor shaft; an annular portion provided on a radially outer side of the bearing housing portion; A plurality of teeth formed radially around the annular portion; a stator core housed inside the outer tube portion; an annular insulating portion covering the annular portion; and each of the plurality of teeth portions. An insulator having a plurality of covering teeth insulating portions, a plurality of winding winding portions wound around the teeth portions via the teeth insulating portions, and a book arranged to face the opening of the outer cylinder portion And a spacer that is formed of the same material as the motor shaft, has a press-fitting hole into which the motor shaft is press-fitted, and is fixed to the main body. And comprising.

  According to this brushless motor, a spacer having a press-fitting hole is used. Then, in a state where the motor shaft is press-fitted into the press-fitting hole of the spacer, the spacer is fixed to the main body portion of the center piece, whereby the motor shaft is fixed to the main body portion of the center piece. Therefore, there is no need to integrally mold the motor shaft by casting (casting) on the center piece, and the motor shaft can be fixed to the main body of the center piece with a simple structure using a spacer, thereby reducing the manufacturing cost. it can.

  The spacer is made of the same material as the motor shaft. Therefore, since it can suppress that a linear expansion difference arises in a spacer and a motor shaft, the omission of a motor shaft can be suppressed.

  A brushless motor according to a second aspect is the brushless motor according to the first aspect, wherein a screw hole that opens to the stator core side is formed in the main body portion, and an axial direction of the motor shaft is formed in the stator core and the spacer. Through-holes that communicate with the screw holes are formed, and the stator core and the spacer are screwed into the screw holes so that the stator core and the spacer are screwed into the screw holes. It is fixed.

  According to this brushless motor, the stator core and the spacer are inserted into the through holes formed in the stator core and the spacer, and the screws are inserted into the screw holes formed in the main body to thereby fix the stator core and the spacer to the main body of the center piece. Can be fixed to. Accordingly, for example, the structure can be simplified and the number of assembling steps can be reduced as compared with a structure in which the stator core and the spacer are separately fixed to the main body portion of the center piece, so that the cost can be reduced.

  A brushless motor according to a third aspect is the brushless motor according to the first or second aspect, wherein the spacer is formed in an annular shape along a cylindrical portion having the press-fitting hole and a circumferential direction of the cylindrical portion. And extending to the outside in the radial direction of the cylindrical portion, and formed in the body portion in an annular shape along the circumferential direction of the motor shaft, and in the axial direction of the motor shaft A water stop wall extending from the main body portion toward the extension portion and having a tip portion facing the extension portion in the axial direction of the motor shaft is formed, and the extension portion and the water stop wall are formed. Constitutes a labyrinth structure positioned radially inward of the plurality of winding portions.

  According to this brushless motor, the labyrinth structure is constituted by the extending portion formed in the spacer and the water blocking wall extending from the main body portion of the center piece toward the extending portion. Therefore, for example, even when water droplets entering from the gap between the opening peripheral edge of the rotor housing and the main body portion of the center piece pass between the stator core and the main body portion toward the bearing, It can be prevented by the labyrinth structure. Thereby, the wetness of a bearing can be suppressed.

  In addition, the labyrinth structure is located on the radially inner side of the plurality of winding portions arranged in an annular shape. Therefore, since the labyrinth structure is not arranged in the flow path of the cooling air that cools the winding portion and is discharged to the outside in the radial direction of the brushless motor, the cooling air flow is obstructed by the labyrinth structure. Can be suppressed.

  The brushless motor according to a fourth aspect is the brushless motor according to the third aspect, wherein the radially outer end portion of the extending portion is radially outer of the extending portion than the distal end portion of the water blocking wall. It is something that protrudes.

  According to this brushless motor, the radially outer end portion of the extending portion protrudes radially outward of the extending portion from the distal end portion of the water blocking wall. Therefore, water droplets can be more effectively prevented at the portion protruding outward in the radial direction from the water blocking wall in the extending portion, so that the water blocking performance of the labyrinth structure can be improved.

  A brushless motor according to a fifth aspect is the brushless motor according to the third or fourth aspect, wherein the brushless motor is formed in an annular shape along a circumferential direction of the first water stop wall as the water stop wall and the motor shaft. And a second water stop wall extending from the annular insulating portion toward the main body portion along the axial direction of the motor shaft, and an annular shape along the circumferential direction of the motor shaft, A third water stop wall extending from the main body part toward the annular insulating part along the axial direction of the motor shaft, and the extension part and the first water stop wall are the labyrinth structure. An inner labyrinth structure, wherein the second water blocking wall and the third water blocking wall are located radially outside the plurality of winding winding portions and radially outside the inner labyrinth structure. What constitutes the structure A.

  According to this brushless motor, the outer labyrinth structure is provided in addition to the inner labyrinth structure on the radially inner side of the plurality of winding portions. Therefore, the double labyrinth structure can more effectively suppress the wetness of the bearing.

  In addition, this outer labyrinth structure is also located radially inward of the plurality of winding winding portions arranged in an annular manner, like the above-described inner labyrinth structure. Therefore, since the outer labyrinth structure is not arranged in the flow path of the cooling air that cools the winding portion and is discharged to the outside in the radial direction of the brushless motor, the flow of the cooling air is hindered by the outer labyrinth structure. This can be suppressed.

  A brushless motor according to a sixth aspect of the present invention is the brushless motor according to the fifth aspect, wherein the tip end side of the second water blocking wall overlaps the tip side of the third water blocking wall in the axial direction of the motor shaft. It is a thing.

  According to this brushless motor, the front end side of the second water stop wall overlaps the front end side of the third water stop wall in the axial direction of the motor shaft. Thereby, since the flow path in an outer side labyrinth structure is bent and a flow path length becomes long, the water stop performance of an outer side labyrinth structure can be improved more.

It is a longitudinal cross-sectional view of the brushless motor which concerns on one Embodiment of this invention. It is a disassembled perspective view of the brushless motor shown by FIG. It is a perspective view of one insulator and spacer which are shown by FIG. It is a perspective view of the peripheral part of the spacer shown by FIG. It is a longitudinal cross-sectional view of the peripheral part of the inner side labyrinth structure shown by FIG. 4, and an outer side labyrinth structure.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, a brushless motor 10 according to an embodiment of the present invention includes a motor shaft 12, a rotor 14, a stator 16, a center piece 18, a circuit board 20, a connector member 22, and a board. And a case 24.

  The rotor 14 includes a rotor housing 26 and a rotor magnet 28. The rotor housing 26 includes a cylindrical bearing housing portion 30 provided on the radially outer side of the motor shaft 12 and a bottomed cylindrical outer tube portion 32 formed on the radially outer side of the bearing housing portion 30. ing. A rotor magnet 28 is provided on the inner peripheral surface of the outer cylindrical portion 32.

  One side in the axial direction of the outer cylinder part 32 is opened, and a bottom wall part 34 is formed on the other side in the axial direction of the outer cylinder part 32. The above-described bearing accommodating portion 30 extends from the center portion of the bottom wall portion 34 toward the center piece 18 side. A plurality of air holes 36 are formed in the bottom wall portion 34.

  A pair of bearings 38 are accommodated in the bearing accommodating portion 30, and the motor shaft 12 is assembled to the pair of bearings 38. Both sides in the axial direction of the bearing housing part 30 are opened, and one end of the motor shaft 12 protrudes from the bearing housing part 30 toward the center piece 18 through an opening on one axial side of the bearing housing part 30.

  The stator 16 includes a stator core 40, a pair of insulators 42 and 44, and a plurality of windings 46. The stator core 40 has an annular portion 48 provided on the radially outer side of the bearing housing portion 30 and a plurality of teeth portions 50 formed radially around the annular portion 48. The stator core 40 is accommodated inside the outer cylindrical portion 32 and is disposed between the bearing accommodating portion 30 and the rotor magnet 28 in the radial direction.

  The pair of insulators 42 and 44 are divided in the axial direction of the stator core 40, and are fixed to the stator core 40 from both axial sides of the stator core 40. The pair of insulators 42 and 44 include an annular insulating portion 56 that covers the annular portion 48 and a plurality of tooth insulating portions 58 that cover each of the plurality of tooth portions 50. Of the pair of insulators 42, 44, one insulator 42 arranged on one side in the axial direction of the stator core 40 (that is, the center piece 18 side) is an example of the “insulator” in the present invention.

  The plurality of windings 46 have a plurality of winding winding parts 60 wound around the tooth part 50 via the tooth insulating part 58. The winding winding part 60 may be a concentrated winding wound around one tooth part 50, or may be a distributed winding wound around a plurality of tooth parts 50.

  The center piece 18 is made of, for example, aluminum. The center piece 18 has a flat plate-like main body 62. The main body portion 62 is disposed to face the opening of the outer cylinder portion 32. The motor shaft 12 and the stator core 40 are fixed to the main body 62 by a fixing structure 80 described later.

  The circuit board 20 is fixed on the opposite side of the main body 62 from the stator core 40. The circuit board 20 is formed with an electronic circuit for switching energization to the plurality of winding winding portions 60 described above. The connector member 22 is provided on one side of the main body 62. The connector member 22 is provided with a connector portion 70, and the connector terminal provided on the connector portion 70 is electrically connected to an electronic circuit formed on the circuit board 20.

  The substrate case 24 is formed in a flat box shape, and is assembled to the main body 62 from the side opposite to the stator core 40 with respect to the main body 62. An accommodation space 72 is formed between the substrate case 24 and the main body 62, and the circuit board 20 is accommodated in the accommodation space 72.

  The brushless motor 10 is preferably used as a fan motor for a vehicle, for example, and is fixed to the vehicle body so that the motor shaft 12 is disposed along the horizontal direction.

  The fan 130 has a fixed portion 132 provided at the center of the fan 130 and a plurality of blades 134 provided around the fixed portion 132. Similar to the rotor housing 26, the fixing portion 132 has an outer cylinder portion 142 and a bottom wall portion 144, and is fixed to the rotor housing 26 so as to cover the rotor housing 26.

  In the brushless motor 10, when energization to the plurality of winding portions 60 is switched by an electronic circuit formed on the circuit board 20, a rotating magnetic field is formed in the stator 16. The rotor 14 is rotated by the suction and repulsive force acting in between.

  Further, when the fan 130 rotates together with the rotor 14, a flow of the cooling air W that cools the winding winding part 60 through the slot formed between the plurality of tooth parts 50 is formed. The cooling air W is exhausted to the outside of the rotor housing 26 through the air holes 36 formed in the bottom wall portion 34 of the rotor housing 26, and between the fixing portion 132 and the bottom wall portions 34 and 144 of the rotor housing 26 and outside. It is discharged to the outside in the radial direction of the brushless motor 10 through the tube portions 32 and 142.

  Next, the fixing structure 80 for fixing the motor shaft 12 and the stator core 40 to the main body 62 of the center piece 18 in the brushless motor 10 according to the embodiment of the present invention will be described.

  As shown in FIGS. 1 and 2, a fixing portion 82 that protrudes inward in the radial direction of the annular portion 48 is formed on the inner peripheral surface of the annular portion 48 of the stator core 40. A through hole 86 that penetrates along the axial direction of the motor shaft 12 and through which the screw 84 is inserted is formed.

  A concave shaft housing portion 88 that opens to the bearing housing portion 30 side is formed at the center of the body portion 62 of the center piece 18, and on the radially outer side of the shaft housing portion 88 in the body portion 62, A boss portion 90 that protrudes toward the stator core 40 along the axial direction of the motor shaft 12 is formed. A plurality of the boss portions 90 are provided at intervals in the circumferential direction of the shaft housing portion 88. A screw hole 92 that opens to the stator core 40 side is formed in the boss portion 90.

  In the fixing structure 80, a spacer 94 is used for fixing the motor shaft 12 to the main body 62. The spacer 94 is made of the same material as the motor shaft 12. The spacer 94 and the motor shaft 12 are made of, for example, iron. The spacer 94 includes a cylindrical portion 96, an extending portion 98, and a plurality of fixed pieces 100. The inside of the cylindrical portion 96 is formed as a press-fit hole 102, and the motor shaft 12 is press-fit into the press-fit hole 102.

  The extending portion 98 is formed in an annular shape along the circumferential direction of the cylindrical portion 96 and extends outward in the radial direction of the cylindrical portion 96. The plurality of fixed pieces 100 are formed at intervals in the circumferential direction of the extending portion 98 and extend outward in the radial direction of the extending portion 98. The fixed piece 100 is formed with the axial direction of the motor shaft 12 as the thickness direction, and the fixed piece 100 is formed with a through-hole 104 penetrating along the axial direction of the motor shaft 12.

  The through hole 104 formed in the spacer 94 and the through hole 86 formed in the stator core 40 described above are formed at positions that align with the screw holes 92 formed in the boss part 90 of the main body part 62 of the center piece 18. Has been.

  In the fixing structure 80, when the plurality of fixing pieces 100 are placed on the upper surfaces of the plurality of boss portions 90 in a state where the motor shaft 12 is press-fitted into the press-fitting holes 102 of the spacer 94, the cylindrical portion 96 of the spacer 94 and The motor shaft 12 is accommodated in the shaft accommodating portion 88. Further, when the plurality of fixing portions 82 formed in the stator core 40 are placed on the plurality of fixing pieces 100, the through holes 104 formed in the spacer 94 and the through holes 86 formed in the stator core 40 are screw holes. 92 is communicated.

  The screws 84 are inserted into the through holes 86 and 104, and the screws 84 are screwed into the screw holes 92, whereby the stator core 40 and the spacer 94 are fixed to the main body portion 62 of the center piece 18. In addition, the spacer 94 is fixed to the main body 62 in this manner, so that the motor shaft 12 is fixed to the main body 62 via the spacer 94.

  Next, the inner labyrinth structure 110 and the outer labyrinth structure 120 provided in the brushless motor 10 according to the embodiment of the present invention will be described.

  As shown in FIGS. 1 to 5, the brushless motor 10 is provided with an inner labyrinth structure 110 and an outer labyrinth structure 120. The inner labyrinth structure 110 is formed by an extension part 98 formed in the spacer 94 and a first water blocking wall 114 formed in the main body part 62.

  The first water blocking wall 114 is formed in an annular shape along the circumferential direction of the motor shaft 12. The first water blocking wall 114 extends from the main body portion 62 (the peripheral portion of the shaft housing portion 88) toward the extending portion 98 along the axial direction of the motor shaft 12. The distal end portion of the first water blocking wall 114 is opposed to the extending portion 98 in the axial direction of the motor shaft 12. A gap is secured between the extending portion 98 and the distal end portion of the first water blocking wall 114. Further, the radially outer end 98 </ b> A (see FIG. 5) of the extended portion 98 protrudes radially outward of the extended portion 98 from the tip portion of the first water blocking wall 114.

  The inner labyrinth structure 110 formed by the extending portion 98 and the first water blocking wall 114 is located on the radially inner side of the plurality of winding winding portions 60, and more specifically, the bearing housing portion 30. And the main body portion 62 (the peripheral portion of the shaft housing portion 88) are positioned between the axial directions (see FIG. 1). The first water blocking wall 114 is an example of the “water blocking wall” in the present invention, and the inner labyrinth structure 110 is an example of the “labyrinth structure” in the present invention.

  The outer labyrinth structure 120 is formed by a second water stop wall 122 and a third water stop wall 124 that are formed annularly along the circumferential direction of the motor shaft 12. The second water stop wall 122 and the third water stop wall 124 are located on the radially outer side of the extending portion 98 and the first water stop wall 114.

  The second water blocking wall 122 extends along the axial direction of the motor shaft 12 from the annular insulating portion 56 formed in the one insulator 42 toward the main body portion 62. On the other hand, the third water blocking wall 124 extends from the main body 62 toward the annular insulating portion 56 along the axial direction of the motor shaft 12.

  The second water stop wall 122 is disposed on the radially outer side of the third water stop wall 124, and the front end side of the second water stop wall 122 and the front end side of the third water stop wall 124 are located on the motor shaft 12. It is overlapped in the axial direction. A gap is secured between the second water stop wall 122 and the third water stop wall 124 in the radial direction.

  The distal end portion of the second water blocking wall 122 is opposed to the main body portion 62 in the axial direction of the motor shaft 12. Further, the tip end portion of the third water blocking wall 124 faces the annular insulating portion 56 in the axial direction of the motor shaft 12. Clearances are secured between the front end portion of the second water stop wall 122 and the main body portion 62 and between the front end portion of the third water stop wall 124 and the annular insulating portion 56.

  The outer labyrinth structure 120 formed by the second water blocking wall 122 and the third water blocking wall 124 is positioned radially outside the inner labyrinth structure 110 inside the plurality of winding winding portions 60. (See FIG. 1).

  Next, the operation and effect of one embodiment of the present invention will be described.

  As described above in detail, according to the brushless motor 10 according to the embodiment of the present invention, the spacer 94 having the press-fitting hole 102 is used. The motor shaft 12 is fixed to the main body 62 of the center piece 18 by fixing the spacer 94 to the main body 62 in a state where the motor shaft 12 is press-fitted into the press-fitting hole 102 of the spacer 94. . Therefore, there is no need to integrally mold the motor shaft 12 to the center piece 18 by casting (casting), and the motor shaft 12 can be fixed to the main body 62 of the center piece 18 with a simple structure using the spacer 94. Manufacturing cost can be reduced.

  The spacer 94 is formed of the same material as the motor shaft 12. Therefore, since it is possible to suppress a difference in linear expansion between the spacer 94 and the motor shaft 12, it is possible to suppress the motor shaft 12 from coming off.

  As described above, according to the brushless motor 10 according to the embodiment of the present invention, it is possible to suppress the motor shaft 12 from dropping while suppressing the manufacturing cost.

  Further, the screw 84 is inserted into the through holes 86 and 104 formed in the stator core 40 and the spacer 94 and the screw 84 is screwed into the screw hole 92 formed in the main body portion 62, so that the stator core 40 and the spacer 94 are inserted. Can be fixed to the main body 62 of the center piece 18. Accordingly, for example, the structure can be simplified and the number of assembling steps can be reduced as compared with a structure in which the stator core 40 and the spacer 94 are separately fixed to the main body portion 62 of the center piece 18. be able to.

  Further, the inner labyrinth structure 110 is configured by the extending portion 98 formed in the spacer 94 and the first water blocking wall 114 extending from the main body portion 62 of the center piece 18 toward the extending portion 98. . Therefore, for example, even when the water droplet L entering from the gap between the opening peripheral edge of the rotor housing 26 and the main body 62 of the center piece 18 passes between the stator core 40 and the main body 62 toward the bearing 38, The penetration of the water droplet L can be prevented by the inner labyrinth structure 110 described above. Thereby, the moisture of the bearing 38 can be suppressed.

  Moreover, the inner labyrinth structure 110 is positioned on the radially inner side of the plurality of winding winding portions 60 arranged in an annular shape. Therefore, since the inner labyrinth structure 110 is not arranged in the flow path of the cooling air W that cools the winding portion 60 and is discharged to the radially outer side of the brushless motor 10, the flow of the cooling air W is the inner labyrinth. Inhibition by the structure 110 can be suppressed.

  Further, the radially outer end 98 </ b> A (see FIG. 5) of the extended portion 98 protrudes radially outward of the extended portion 98 from the tip portion of the first water blocking wall 114. Therefore, since the water droplet L can be more effectively prevented by the portion protruding radially outward from the first water stop wall 114 in the extension portion 98, the water stop performance of the inner labyrinth structure 110 can be improved. it can.

  In addition to the inner labyrinth structure 110, an outer labyrinth structure 120 is provided on the radially inner side of the plurality of winding portions 60. Therefore, the wetness of the bearing 38 can be further effectively suppressed by this double labyrinth structure.

  Further, the outer labyrinth structure 120 is also located on the radially inner side of the plurality of winding winding portions 60 arranged in an annular shape, similarly to the inner labyrinth structure 110 described above. Therefore, since the outer labyrinth structure 120 is not arranged in the flow path of the cooling air W that cools the winding portion 60 and is discharged to the radially outer side of the brushless motor 10, the flow of the cooling air W is the outer labyrinth. Inhibition by the structure 120 can be suppressed.

  Further, the distal end side of the second water blocking wall 122 is overlapped with the distal end side of the third water blocking wall 124 in the axial direction of the motor shaft 12. Thereby, since the flow path in the outer labyrinth structure 120 is bent and the flow path length becomes longer, the water stop performance of the outer labyrinth structure 120 can be further improved.

  Next, a modification of one embodiment of the present invention will be described.

  In the above-described embodiment of the present invention, the brushless motor 10 is more preferably used as a fan motor for a vehicle, but may be used for applications other than a fan motor for a vehicle.

  The stator core 40 is more preferably fixed to the main body 62 of the center piece 18 together with the spacer 94 to which the motor shaft 12 is assembled. However, the stator core 40 and the spacer 94 are separately provided on the main body 62 of the center piece 18. It may be fixed to.

  The brushless motor 10 more preferably includes the outer labyrinth structure 120 in addition to the inner labyrinth structure 110, but may not include the outer labyrinth structure 120.

  In the outer labyrinth structure 120, the second water stop wall 122 is disposed on the radially outer side of the third water stop wall 124, but the second water stop wall 122 is on the radially inner side of the third water stop wall 124. It may be arranged.

  Although one embodiment of the present invention has been described above, the present invention is not limited to the above, and other various modifications can be made without departing from the spirit of the present invention. It is.

DESCRIPTION OF SYMBOLS 10 ... Brushless motor, 12 ... Motor shaft, 14 ... Rotor, 16 ... Stator, 18 ... Center piece, 20 ... Circuit board, 22 ... Connector member, 24 ... Board case, 26 ... Rotor housing, 28 ... Rotor magnet, 30 ... Bearing housing part 32 ... Outer cylinder part 34 ... Bottom wall part 36 ... Vent hole 38 ... Bearing 40 ... Stator core 42, 44 ... Insulator 46 ... Winding 48 ... Ring part 50 ... Teeth part 56: annular insulating part, 58 ... teeth insulating part, 60 ... winding winding part, 62 ... main body part, 70 ... connector part, 72 ... accommodating space, 80 ... fixing structure, 82 ... fixing part, 84 ... screw, 86 DESCRIPTION OF SYMBOLS ... Through-hole, 88 ... Shaft accommodating part, 90 ... Boss part, 92 ... Screw hole, 94 ... Spacer, 96 ... Cylindrical part, 98 ... Extension part, 100 ... Fixed piece, 102 ... Press-fit hole, 104 ... Through-hole 110: inner labyrinth structure (an example of labyrinth structure), 114: first water blocking wall (an example of water blocking wall), 120: outer labyrinth structure, 122: second water blocking wall, 124: third water blocking wall, 130 ... Fan, 132 ... Fixed part, 134 ... Blade, 142 ... Outer cylinder part, 144 ... Bottom wall part, L ... Water droplet, W ... Cooling air

Claims (6)

A motor shaft;
A rotor housing having a cylindrical bearing housing provided on the radially outer side of the motor shaft, and an outer cylinder formed on the radially outer side of the bearing housing;
A bearing housed in the bearing housing and assembled to the motor shaft;
A stator core having an annular portion provided on a radially outer side of the bearing accommodating portion, and a plurality of teeth portions formed radially around the annular portion, and accommodated inside the outer cylindrical portion;
An insulator having an annular insulating portion covering the annular portion, and a plurality of teeth insulating portions covering each of the plurality of teeth portions;
A plurality of winding winding parts wound around the teeth part via the teeth insulating part;
A center piece having a main body portion disposed opposite to the opening of the outer cylinder portion, and having the stator core fixed thereto;
A spacer that is formed of the same material as the motor shaft, has a press-fitting hole into which the motor shaft is press-fitted, and is fixed to the main body.
Brushless motor with The main body is formed with a screw hole that opens to the stator core side,
The stator core and the spacer are each formed with a through hole penetrating along the axial direction of the motor shaft and communicating with the screw hole.
The stator core and the spacer are fixed to the main body portion by screwing a screw inserted into the through hole into the screw hole.
The brushless motor according to claim 1. The spacer is
A cylindrical portion having the press-fitting hole;
An extending portion that is formed annularly along the circumferential direction of the cylindrical portion and extends radially outward of the cylindrical portion;
Have
The main body portion is formed in an annular shape along the circumferential direction of the motor shaft, and extends from the main body portion toward the extending portion along the axial direction of the motor shaft. A water blocking wall facing the extending portion is formed in the axial direction of the motor shaft,
The extension part and the water blocking wall constitute a labyrinth structure located on the radially inner side of the plurality of winding winding parts,
The brushless motor according to claim 1 or 2. The radially outer end of the extended portion protrudes radially outward of the extended portion from the tip of the water blocking wall.
The brushless motor according to claim 3. A first water stop wall as the water stop wall;
A second water stop wall formed in an annular shape along the circumferential direction of the motor shaft and extending from the annular insulating portion toward the main body portion along the axial direction of the motor shaft;
A third water stop wall formed in an annular shape along the circumferential direction of the motor shaft and extending from the main body portion toward the annular insulating portion along the axial direction of the motor shaft;
With
The extension part and the first water blocking wall constitute an inner labyrinth structure as the labyrinth structure,
The second water stop wall and the third water stop wall constitute an outer labyrinth structure positioned radially outside the inner labyrinth structure on the radially inner side of the plurality of winding winding parts.
The brushless motor according to claim 3 or 4. The front end side of the second water stop wall is overlapped with the front end side of the third water stop wall in the axial direction of the motor shaft.
The brushless motor according to claim 5.

Images