Electric motor for vehicle, electric motor bearing holder tube part with water drain structure concave recessed parts

An electric motor for vehicle including a stator; a stator support member; a rotation shaft; a rotor including a bottom wall and a peripheral wall, in which the peripheral wall is provided with a magnet and the bottom wall is configured to be combined with the rotation shaft; and a bearing holder including a tube part, and a water drip hole is formed on a vertically lower side of the tube part, the stator support member being provided with a bearing holder insertion part including a boss part into which the tube part is configured to be inserted, wherein a water drain structure configured to drain a water drop from the water drip hole is provided along a circumferential direction of an inner circumferential surface of the boss part in a vertically lower area of the inner circumferential surface of the boss part.

TECHNICAL FIELD

The present invention relates to an electric motor for vehicle.

Priority is claimed on Japanese Patent Application No. 2015-122044, filed on Jun. 17, 2015, the contents of which are incorporated herein by reference.

BACKGROUND ART

Conventionally, as an electric motor used for vehicle such as automobiles, for example, there is a motor disclosed in the Patent Literature 1. This includes a stator around which coil is wound, a stator support member configured to support the stator, a rotation shaft rotatably supported by the stator support member via a bearing and extends in a horizontal direction and a rotor configured to be in a cylinder-like shape so as to cover the stator, in which a peripheral wall part thereof is provided with a magnet, and a bottom wall part is configured to be integrally-rotatably combined with the rotation shaft. In the Patent Literature 1, in order to easily drain a water drop infiltrated inside toward outside, a water drip structure is provided in a vertically lower area of a stator fixing pipe of a cylinder-like shape extending along a rotation shaft so that the water drop from the water drip structure is drained toward outside along a stator support member.

On the other hand, in recent years, enhancement of layout characteristic at a time of attaching an electric motor for vehicle to a vehicle, enhancement of connecting operability with an external connector of a vehicle or the like is desired. For example, an attachment angle to a vehicle around a rotation shaft of an electric motor for vehicle is desired to be flexibly adjustable.

PRIOR ART DOCUMENTS

Patent Documents

SUMMARY OF INVENTION

Problems to be Solved by the Invention

In the electric motor for vehicle in the Patent Literature 1, the water drip structure corresponds with only a predetermined attachment angle. That is why, there is a problem in which a quality of the water drip structure of the electric motor for vehicle is diminished when the attachment angle of the electric motor for vehicle to a vehicle is changed for such reasons as layout characteristic to the vehicle or connecting operability with external connector of the vehicle.

The present invention is an electric motor for vehicle provided with a water drain structure to drain a water drip infiltrated inside toward outside to enhance layout characteristic at a time of attaching and connecting operability with an external connector of a vehicle without diminishing the quality of the water drain structure.

Means for Solving the Problems

As a means for solving the problem described above, an aspect of the invention is an electric motor for vehicle including a stator around which coil is wound; a stator support member configured to support the stator; a rotation shaft rotatably supported by the stator support member via a bearing and extends in a horizontal direction; a rotor including a bottom wall of a disc-like shape that covers one side of the stator in an axial line direction of the rotation shaft and a peripheral wall of a cylinder-like shape that rises from an outer circumferential end of the bottom wall and covers an outer circumferential side of the stator, in which the peripheral wall is provided with a magnet and the bottom wall is configured to be integrally-rotatably combined with the rotation shaft; and a bearing holder including a tube part of a cylinder-like shape configured to support the bearing in an inner circumferential side thereof, and a water drip hole is formed on a vertically lower side of the tube part, the stator support member being provided with a bearing holder insertion part including a boss part of a cylinder-like shape into which the tube part is configured to be inserted, wherein a water drain structure configured to drain a water drop from the water drip hole toward outside is provided along a circumferential direction of an inner circumferential surface of the boss part in a vertically lower area of the inner circumferential surface of the boss part.

An aspect of the invention is the electric motor for vehicle wherein the water drain structure is a plurality of concave parts recessed from the inner circumferential surface of the boss part toward outside in a radial direction and are communicated to an outside of the boss part.

An aspect of the invention is the electric motor for vehicle wherein the plurality of concave parts are disposed, being aligned in a circumferential direction in one part of the inner circumferential surface of the boss part.

An aspect of the invention is the electric motor for vehicle wherein the stator support member is provided with an immersion restriction wall in a cylinder-like shape that covers an outer circumference of an end part of an opening side of the peripheral wall of the rotor, and a water drain concave part configured to drain toward outside a water drop flowed to the immersion restriction wall is provided over a scope corresponding to the water drain structure in a vertically lower area of an inner circumferential surface of the immersion restriction wall.

An aspect of the invention is the electric motor for vehicle wherein the stator support member and a base member include a water drain path configured to drain a water drop infiltrated inside toward outside, and a labyrinth structure having a foreign substance intrusion preventing part configured to prevent intrusion of a foreign substance into the water drain path is provided.

An aspect of the invention is the electric motor for vehicle wherein the water drain path includes a base side water drain path opening toward one side of the base member in the axial direction, and the foreign substance intrusion preventing part includes a rise wall that rises in a vertically upper direction from a part, facing the base side water drain path, of the stator support member, and that covers the base side water drain path from one side of the base side water drain path in the axial line direction.

An aspect of the invention is the electric motor for vehicle wherein the bearing holder further includes a flange part in a circular shape, rising from the tube part toward outside in the radial direction, and the flange part is provided with an attachment part configured to be able to adjust an attachment angle of the stator support member centering around the rotation shaft in a state in which the water drip hole is disposed on the vertically lower side of the tube part.

An aspect of the invention is the electric motor for vehicle wherein the electric motor for vehicle is used as a drive source of an electric fan for cooling a radiator for vehicle.

Advantageous Effects of Invention

According to the aspect of the invention, a water drain structure configured to drain a water drop from the water drip hole toward outside is provided along a circumferential direction of an inner circumferential surface of the boss part in a vertically lower area of the inner circumferential surface of the boss part. In this case, at the time of attaching an electric motor for vehicle to a vehicle, a quality of the water drip structure of the electric motor for vehicle is secured in a setting range of the water drain structure along the circumferential direction of the inner circumferential surface of the boss part even in a case in which the attachment angle centering around the rotation shaft of the electric motor for vehicle to a vehicle is adjusted with respect to the vehicle. Also, in the setting range of the water drain structure along the circumferential direction of the inner circumferential surface of the boss part, the attachment angle centering around the rotation shaft of the electric motor for vehicle is possible to adjust with respect to the vehicle at a predetermined angle. Accordingly, it is possible to enhance the layout characteristic at a time of attaching the electric motor for vehicle to the vehicle without diminishing the quality of the water drain structure. In addition, it is possible to enhance the connecting operability with an external connector of the vehicle.

According to the aspect of the invention, the water drain structure is a plurality of concave parts recessed from the inner circumferential surface of the boss part toward outside in a radial direction and are communicated to an outside of the boss part. In this case, at the time of attaching an electric motor for vehicle to a vehicle, even in a case in which the attachment angle centering around the rotation shaft of the electric motor for vehicle to a vehicle is adjusted with respect to the vehicle, it is possible to drain water toward outside smoothly from each concave part. Also, in comparison with a case in which a single concave part continuous in the circumferential direction of the inner circumferential surface of the boss part is provided, it is possible to enhance support strength by the boss part of the tube part. Therefore, it is possible to support the bearing holder stably.

According to the aspect of the invention, the plurality of concave parts are disposed, being aligned in a circumferential direction in one part of the inner circumferential surface of the boss part. In this case, it is satisfactory to form the water drip hole formed in the tube part only in a scope corresponding to the disposition (one part of the tube part in the vertically lower side of the tube part), it is not necessary to form excessive water drip holes. In this way, it is easier to secure roundness of the tube part, and possible to enhance processing precision of the bearing holder.

According to the aspect of the invention, a water drain concave part configured to drain toward outside a water drop flowed to the immersion restriction wall is provided over a scope corresponding to the water drain structure in a vertically lower area of an inner circumferential surface of the immersion restriction wall. In this case, at the time of attaching an electric motor for vehicle to a vehicle, a quality of the water drain concave part is secured in the setting range of the water drain structure along the circumferential direction of the inner circumferential surface of the boss part even in a case in which the attachment angle centering around the rotation shaft of the electric motor for vehicle to a vehicle is adjusted with respect to the vehicle.

According to the aspect of the invention, a labyrinth structure having a foreign substance intrusion preventing part configured to prevent intrusion of a foreign substance into the water drain path is provided. In this case, it is possible to prevent a foreign substance from intruding into the water drain path and to prevent a clog in the water drain path, therefore, it is possible to smoothly drain water through the water drain path.

According to the aspect of the invention, the foreign substance intrusion preventing part includes a rise wall that rises in a vertically upper direction from a part, facing the base side water drain path, of the stator support member, and that covers the base side water drain path from one side of the base side water drain path in the axial line direction. In this case, it is possible to prevent a foreign substance from intruding into the base side water drain path and to prevent a clog in the base side water drain path, therefore, it is possible to smoothly drain water through the base side water drain path.

According to the aspect of the invention, the flange part of the bearing holder is provided with an attachment part configured to be able to adjust an attachment angle of the stator support member centering around the rotation shaft in a state in which the water drip hole is disposed on the vertically lower side of the tube part. In this case, it is possible to attach the bearing holder to the stator support member without forming more water drip holes. In this way, it is easier to secure roundness of the tube part, and possible to enhance processing precision of the bearing holder.

According to the aspect of the invention, the electric motor for vehicle is used as a drive source of an electric fan for cooling a radiator for vehicle. In this case, it is possible to make the water drain structure effective.

DESCRIPTION OF EMBODIMENT

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

TheFIGS. 1 to 3show an example of an electric motor1(an electric motor for vehicle) of the embodiment. In addition, a reference numeral CP in the drawings indicates a center of an output shaft20(a rotation shaft) of a brushless motor2. Also, a reference numeral CL in the drawings indicates an axial line of the output shaft20. Hereinafter, the center of the output shaft20is referred to as “motor center”, a direction along the axial line CL is referred to as “motor axial direction”, and a direction orthogonal to the axial line CL is referred to as “motor radial direction”, a direction around the axial line CL is referred to as “motor circumferential direction”. In this point, the motor axial direction corresponds with an axial direction in the claims.

Also, a reference numeral V1in the drawings indicates one side of the motor axial direction, while a reference numeral V2indicates the other side of the motor axial direction respectively. Also, a reference numeral V3in the drawings indicates an upper side in the vertical direction (vertically upper side), while a reference numeral V4indicates a lower side in the vertical direction (vertically lower side) respectively.

The electric motor1includes a brushless motor2(a driven body) and a controller3configured to control the brushless motor2. The electric motor1is used, for example, as a drive source of an electric fan for cooling a radiator for vehicle, and is installed, being fixed, to a vehicle side via flange parts80band82bso that a fan main body (not shown) fixed to the output shaft20to be described later faces a radiator (not shown) of the vehicle.

Hereinafter, description will be made with reference to theFIG. 1and theFIG. 3. The brushless motor2includes the output shaft20extending in a horizontal direction and in a front and rear direction of a vehicle and forming the axial line CL, a rotor21that is rotatable together with the output shaft20, a stator22that is capable of generating a magnet field to rotate the rotor21together with the output shaft20.

The rotor21includes a bottom wall21aof a disc-like shape that covers one side V1of the stator22in the motor axial direction, a peripheral wall21bof a cylinder-like shape that rises from an outer circumferential end of the bottom wall21aand covers an outer circumferential side of the stator22, forming an opening part21iin the other side V2of the stator22in the motor axial direction and an anchor part21dof a circular ring-like shape that rises from an end part of a side of the opening part21iof the peripheral wall21btoward an outer side in the radial direction. In a center part of the bottom wall21ain the radial direction, a boss part21hof a cylinder-like shape that penetrates through the output shaft20.

The bottom wall21ais configured to be integrally-rotatably combined with the output shaft20. For example, by press-fitting the output shaft20into the boss part21h, the rotor21is configured to be rotatable together with the output shaft20. in an inner surface in the radial direction of the peripheral wall21b, a plural number of magnets are provided by an adhesive agent or the like. The rotor21is configured to be rotatable together with the output shaft20by receiving the magnet field that the stator22generates.

The stator22is disposed in an inner side in the radial direction of the peripheral wall21bof the rotor21. The stator22is fixed to a bracket8(a stator support member) by a bolt22d. In an inner side in the radial direction of the stator22, a bearing holder24configured to fit in a pair of bearings23that function as bearings of the output shaft20. The bearing holder24is fixed together with the stator22by the bolt22d.

The stator22includes a stator core22aof a cylinder-like shape, an insulator22bof insulation properties attached to both sides in the motor axial direction of a plural number of teeth parts installed in a protruding manner toward the outer side in the radial direction, and a coil22cof conductive properties wound over the insulator22. The coil22ccorresponds to 3 phases of U-phase, V-phase and W-phase. The brushless motor2of the present embodiment is a 3 phase brushless motor including the coil22cof 3 phases of U-phase, V-phase and W-phase.

A terminal part of the coil22cis pulled out from the opening part21iside of the rotor21and is connected to a bus bar unit25that is disposed in the opening part21iside so as to penetrate through an opening80mof the bracket8. The bus bar unit25has a function to supply an electric power from outside to the coil22c. For example, the bus bar unit25includes a bus bar for the U-phase, a bus bar for the V-phase and a bus bar for the W-phase, that is connected to starting ends of winding (not shown) of each phase of the coil22c(hereinafter referred to as “bus bars for the U to W-phase”) and also includes a bas bar for a neutral point, that is connected to terminating ends of winding (not shown) of each phase of the coil22c. Among the bas bars, the bus bars for the U to W-phase include three electricity supply terminals25aextending along the motor axial direction toward a controller3from the opening part21i. Each of the electricity supply terminals25ais electrically connected to a motor side end part125of a three phase bus bar fixedly disposed to a base member5by resistance welding or the like.

The controller3includes a terminal4containing a plural number of bus bars100, the base member5made of resin to which the terminal4is fixedly disposed, a plural number of electrical elements65and66electrically connected to each of the plural number of bus bar100, a power device7configured to supply electricity to the brushless motor2and control a drive of the brushless motor2, the bracket8mounted to the base member5and covers9and10(a main body cover9and a terminal cover10) those cover the base member5. In the base member5, a control circuit for controlling the brushless motor2is configured.

Hereinafter, description will be made with reference to theFIG. 2and theFIG. 3. The base member5includes a base main body50having a width in the motor axial direction and being in a rectangular board-like shape in a plan view seen from the motor axial direction. The base member5includes a first connector51and a second connector52, in the plan view, projecting from the base main body50toward the vertically upper side V3and a terminal connection part53projecting from the base main body50toward the vertically lower side V4. For example, the plural number of bus bars100are fixedly disposed inside the base member5by insert molding using insulating material such as resin or the like. In a facing position to the output shaft20in the terminal connection part53, an opening part53hopening (penetrating through) in a width direction of the base member5is formed.

Between the base main body50and the terminal connection part53, a flange part50fextending along an inclined angle part (a tapered part) in the vertically lower side V4in the plan view and having an outline extending along an outer circumferential part of the terminal connection part53is formed.

In an angle part in the vertically upper side V3of the base main body50, a flange part50gof a triangle-like shape having a rounded corner in a top part in the plan view is formed.

In the flange part50fand the flange part50g, through holes, not shown in the drawings, opening (penetrating through) in the width direction of the base member5are formed. For example, it is possible to fasten to fix the base member5to the bracket8by having a bolt18penetrate through the through holes of each of the flange50fand the flange50gand screwing the bolt18in each of attachment holes (not shown) of the bracket8.

Hereinafter, description will be made with reference to theFIG. 1and theFIG. 3. the bracket8includes a bracket main body80in a shape formed along an outer shape of the base main body50in the motor axial direction, a bearing holder insertion part81in a shape formed along an outer shape of the terminal connection part53and a motor bracket part82in a shape formed along an outer shape of the brushless motor2. For example, the bracket8is formed of such metal material of high heat conductivity as aluminum or the like.

The bracket main body80includes a main body base part80a(refer to theFIG. 3) having a flat surface in the other side V2in the motor axial direction, a plural number of flange parts80b(refer to theFIG. 1) projecting from both end parts of the main body base part80ain the width direction toward outside in the width direction (for example, one at each end part in the both ends, two in total, in the present embodiment), a plural number of pin-like shape radiation fins80c(refer to theFIG. 3) on a surface of the main body base part80projecting toward the one side V1in the motor axial direction, a linkage rib80d(refer to theFIG. 3) extending in a linear-like manner so as to link between the plural number of radiation fins80cadjoining each other in the vertical direction and a plural number of convex-shaped radiation fins80e(refer to theFIG. 1) projecting from both end parts of the main body base part80ain the width direction. In the flange part80b, a through hole80hopening in the motor axial direction is formed.

In the bearing holder insertion part81, an opening part81hopening in the motor axial direction is formed. A bearing holder insertion boss part81a(boss part) in a cylinder-like shape, into which a cylinder part24aof the bearing holder24is configured to be inserted, is provided at a portion facing the opening part81h(refer to theFIG. 3) in the bearing holder insertion part81. The bearing holder insertion boss part81ais configured to function as a motor linkage boss part, to which the brushless motor2is integrally linked.

A motor bracket part82includes a base part82a(refer to theFIG. 3) having a flat surface in the other side V2in the motor axial direction, a plural number (three, for example, in the present embodiment) of flange parts82bprojecting from an outer circumferential part of the base part82atoward outside in the motor axial direction, a plural number of pin-like shape radiation fins82c(refer to theFIG. 3) on a surface of the base part80projecting toward the other side V2in the motor axial direction. In the flange part82b, a through hole82hopening in the motor axial direction is formed.

For example, it is possible to fasten to fix the electric motor1to a vehicle not shown in drawings by penetrating through bolts not shown in drawings into the through hole80hand the through hole82hrespectively of the flange part80band flange part82bof the bracket8and by screwing the bolt (not shown in the drawings) into attachment holes (not shown in the drawings) in the vehicle side, respectively. In addition, an attachment posture, more specifically, an attachment angle of the electric motor1with respect to the vehicle centering around the output shaft20is configured to be adjustable at a predetermined angle.

Hereinafter, description will be made with reference to theFIG. 2and theFIG. 3. Seen from the other side V2in the motor axial direction, the main body cover9is in a rectangular-like shape formed along an outer shape of the base main body50. The main body cover9includes a ceiling part90covering the base main body50and a cover wall part91rising from the ceiling part90toward the base main body50. The cover wall part91is formed in a rectangular and circular shape, seen from the other side V2in the motor axial direction and surrounds the base main body50.

To the ceiling part90, a latch part92(refer to theFIG. 2) configured to latch the main body cover9to the base main body50is provided. A plural number (for example, two each at the both ends in the width direction, four in total, in the present embodiment) of latch parts92are provided at both end parts in the width direction of the ceiling part90.

The latch part92includes a pair of leg parts92aextending from the ceiling part90toward the base main body50and a linkage part92bfor linking terminal end parts of the pair of the leg parts92a.

In the base main body50, a nail part50j(refer to theFIG. 2) configured to latch the linkage part92bis provided. A plural number (for example, two each at the both ends in the width direction, 4 in total, in the present embodiment) of nail parts50jare provided at both end parts in the width direction of the base main body50so as to face the latch part92of the main body cover9.

Seen from the other side V2in the motor axial direction, the terminal cover10is in a shape formed along an outer shape of the terminal connection part53. The terminal cover10is disposed in a position to cover a motor side end part125of the three phase bus bar fixedly disposed to the base member5and also to cover a fastening part20jof the output shaft20. Accordingly, the terminal cover10covers an electrical connection part between three of the electricity supply terminals25aof the brushless motor2(bus bars for the U to W-phase) and corresponding motor side end part125. Between the terminal connection part53and the terminal cover10, a seal material40in a ring-like shape is provided.

The terminal cover10includes a ceiling part11covering the terminal connection part53and a cover wall part12rising from the ceiling part11toward the terminal connection part53. The cover wall part12includes a cover wall part12, surrounding the terminal connection part53, in a ring-like shape seen from the other side V2in the motor axial direction. The terminal connection part53includes a base wall part53ain a ring-like shape in contact with an outer circumference side of the cover wall part12via the a seal material40.

Hereinafter, description will be made with reference to theFIG. 2, theFIG. 3and theFIG. 4. The bearing holder24includes a cylinder part24ain a cylinder-like shape supporting a pair of the bearings23in an inner circumference side and a flange part24din a circular ring-like shape that rises from an end part in the one side V1in the motor axial direction of the cylinder part24atoward the outer side in the radial direction. The cylinder part24aincludes a first cylinder part24bin a cylinder-like shape configured to support one bearing in the one side V1in the motor axial direction among the pair of the bearings23and a second cylinder part24c, forming a cylinder-like shape with a shrunken diameter compared to that of the first cylinder part24b, configured to support another bearing the other side V2in the motor axial direction among the pair of the bearings23. In a portion of the second cylinder part24cthat is in the vertically lower side V4and close to the first cylinder part24b, a water drip hole24his formed, that opens (penetrates through) in a thickness direction of the second cylinder part24cand is in a long hole-like shape formed along a circumferential direction of an inner circumferential surface of the second cylinder part24c.

In the flange part24d, a through hole24i, a through hole24jand a through hole24k, those are in a circle shape seen from the motor axial direction and open (penetrate through) in the thickness direction of the second cylinder part24c, are formed. At this point, the through holes correspond to an example of “an attachment part” described in the claim. In addition, the reference numeral24min the drawings indicates a notch part formed in the flange part24d.

A plural number (for example, three for each, nine in total, in the present embodiment) of the through hole24i, the through hole24jand the through hole24kare provided. The through hole24i, the through hole24jand the through hole24kare disposed in a center part in the motor radial direction along a motor circumferential direction, being spaced with predetermined intervals. Seen from the motor axial direction, the through hole24i, the through hole24jand the through hole24kare respectively disposed, being spaced with approximately equal intervals in the motor circumferential direction (for example, an interval of the extent of 120 degree).

Seen from the motor axial direction, the through hole24jand the through hole24kare respectively disposed, being spaced with predetermined intervals (for example, intervals of the extent of 45 degree) with respect to the through hole24iin the motor circumferential direction. In theFIG. 5, reference numerals H1, H2and H3respectively indicate linear lines passing through a center in the motor CP and respectively a center P1of the through hole24i, a center P2of the through hole24jand a center P3of the through hole24k. Also, a reference numeral θ1indicates an angle formed by the linear line H1and the linear line H2, and a reference numeral θ2indicates an angle formed by the linear line H1and the linear line H3. In addition, the angle θ1and the angle θ2respectively correspond to a disposition angle of the through hole24jand a disposition angle of the through hole24kwith respect to the through hole24i, and the angle θ1and the angle θ2are of the extent of 45 degree in the present embodiment. In a state in which the water drip hole24his disposed on the vertically lower side of the cylinder part24a, each of the through hole24i, the through hole24jand the through hole24kmakes an attachment angle of the bracket8adjustable with respect to the center in the motor CP. In the present embodiment, the attachment angle of the bracket8is configured to be adjustable by an angle A1and by an angle A2as indicated in theFIG. 6(45 degree toward one side and 45 degree toward the other side respectively with a center line in a bracket width direction CP as a reference) with respect to the center in the motor CP.

<Attachment Structure of Bearing Holder>

With reference to theFIG. 6also, seen from the one side V1in the motor axial direction, the bearing holder insertion part81is provided with a plural number (three in the present embodiment) of bearing holder attachment parts89projecting from an outer circumference part of the bearing holder insertion part81toward outside in the motor radial direction. Each of the bearing holder attachment parts89are respectively disposed, being spaced with approximately equal intervals in the motor circumferential direction (for example, an interval of the extent of 120 degree). In each of the bearing holder attachment parts89, an attachment hole89hthat opens (penetrates through) toward the motor axial direction and is configured in a circle shape seen from the motor axial direction.

For example, it is possible to fasten to fix by fastening the bearing holder24together with the stator22to the bracket8by having a bolt22dpenetrate through each of the through hole24i(or the through hole24j, the through hole24k) of the flange part24dof the bearing holder24and screwing the bolt22dvia the stator22into each of the attachment hole89hof the bearing holder attachment part89(refer to theFIG. 8).

Hereinafter, description will be made with reference to theFIG. 7and theFIG. 8. In a vertically lower area of an inner circumferential surface of the bearing holder insertion boss part81a, a plural number (three in the present embodiment) of concave parts81i,81jand81kwhich drain water drips from the water drip hole24htoward outside are formed. The plural number of the concave parts81i,81jand81kare disposed, aligned in a circumferential direction, in one part in an inner circumferential surface of the bearing holder insertion boss part81a. In this point, the plurality of the concave parts corresponds to an example of “a water drain structure” in the claims.

In a case in which the electric motor1is used as a drive source of an electric fan for cooling a radiator for a vehicle, the electric motor1is likely to be disposed in an engine room at vehicle front, which is a site in an environment of undergoing water by rain water blown in or poured from traveling wheels. That is why, effective water drain structure is desired in the electric motor1.

Each of the concave parts81i,81jand81kare recessed in a U-shape seen from the motor axial direction from an inner circumferential surface of the bearing holder insertion boss part81atoward the outer side in the radial direction. Each of the concave parts81i,81jand81kextends along the motor axial direction and, in a site facing the second cylinder part24c, are communicated to an outside (opening in the other side V2in the motor axial direction) of the bearing holder insertion boss part81a. In this way, even in a case in which a water drop infiltrates inside the bearing holder24by rain water blown in or water poured from traveling wheels, it is possible to drain the water drop from the water drip hole24hthrough each of the concave parts81i,81jand81ktoward outside.

Hereinafter, description will be made also with reference to theFIG. 6. A linear line passing the center in the motor CP and also passing a center of the bracket8in the width direction is referred to as “a center line in the bracket width direction”. A reference numeral C1in the drawings indicates the center line in the bracket width direction. Seen from the motor axial direction, the concave part81iis disposed so that a bottom part (the deepest portion) of the concave part81iis positioned in the center line in the bracket width direction CP. Seen from the motor axial direction, each of the concave parts81jand81kare disposed, being spaced with a predetermined interval (for example, an interval of the extent of 45 degree), with respect to the concave part81i. In theFIG. 6, reference numerals L1and L2respectively indicate linear lines passing the center in the motor CP and the bottom parts (the deepest parts) of each concave part81jand81k. Also, the reference numeral A1indicates an angle formed by the center line in the bracket width direction CP and the linear line L1, and the reference numeral A2indicates an angle formed by the center line in the bracket width direction CP and the linear line L2. In addition, the angle A1and the angle A2respectively correspond to disposition angles of each of the concave part81jand the concave part81kwith respect to the concave part81i, and the angle A1and the angle A2are of the extent of 45 degree in the present embodiment.

<Flow of Drained Water According to the Attachment Angle of the Bracket>

Hereinafter, description will be made with reference to theFIG. 5, theFIG. 8and theFIG. 9. In theFIG. 9, the reference numeral W10indicates a flow of drained water by the concave part81i. By configuring a place to have the bolt22dpenetrate through at each of the through holes24iof the flange part24d, it is possible to realize a state in which the water drip hole24his disposed on the vertically lower side of the cylinder part24ain a state in which the center line in the bracket width direction C1is along the vertical direction.

As shown in theFIG. 9, in the state in which the center line in the bracket width direction C1is along the vertical direction, the concave part81iis disposed in the lowest part (directly under the water drip hole24h) in the vertically lower side of the bearing holder insertion boss part81a. In this way, it is possible to allow a water drop from the water drip hole24hflow toward the vertically lower side V4as shown by an arrow sign W10and drain the water drop toward outside in the state in which the center line in the bracket width direction C1is along the vertical direction.

Hereinafter, description will be made with reference to theFIG. 5, theFIG. 8and theFIG. 10. In theFIG. 10, the reference numeral W11indicates a flow of drained water by the concave part81j. By configuring a place to have the bolt22dinserted at each of the through holes24jof the flange part24d, it is possible to realize a state in which the water drip hole24his disposed on the vertically lower side of the cylinder part24ain a state in which the center line in the bracket width direction C1is inclined toward one side in the bracket width direction with respect to the vertical direction (for example, a state in which being inclined 45 degree toward one side with the center line in a bracket width direction CP as a reference).

As shown in theFIG. 10, in the state in which the center line in the bracket width direction C1is inclined toward the one side in the bracket width direction with respect to the vertical direction, the concave part81jis disposed in the lowest part (directly under the water drip hole24h) in the vertically lower side of the bearing holder insertion boss part81a. In this way, it is possible to allow a water drop from the water drip hole24hflow toward the vertically lower side V4as shown by an arrow sign W11and drain the water drop toward outside in the state in which the center line in the bracket width direction C1is inclined toward the one side in the bracket width direction with respect to the vertical direction.

Hereinafter, description will be made with reference to theFIG. 5, theFIG. 8and theFIG. 11. In theFIG. 11, the reference numeral W12indicates a flow of drained water by the concave part81k. By configuring a place to have the bolt22dinserted at each of the through holes24kof the flange part24d, it is possible to realize a state in which the water drip hole24his disposed on the vertically lower side of the cylinder part24ain a state in which the center line in the bracket width direction C1is inclined toward the other side in the bracket width direction with respect to the vertical direction (for example, a state in which being inclined 45 degree toward the other side with the center line in a bracket width direction CP as a reference).

As shown in theFIG. 11, in the state in which the center line in the bracket width direction C1is inclined toward the other side in the bracket width direction with respect to the vertical direction, the concave part81kis disposed in the lowest part (directly under the water drip hole24h) in the vertically lower side of the bearing holder insertion boss part81a. In this way, it is possible to allow a water drop from the water drip hole24hflow toward the vertically lower side V4as shown by an arrow sign W12and drain the water drop toward outside in the state in which the center line in the bracket width direction C1is inclined toward the other side in the bracket width direction with respect to the vertical direction.

Hereinafter, description will be made with reference to theFIG. 6and theFIG. 8. At an outer circumferential edge of the motor bracket part82in the one side V1in the motor axial direction, an immersion restriction wall85in a cylinder-like shape that covers an outer circumference of an end part of the opening part21iside of the peripheral wall21b(the anchor part21d) of the rotor21is formed. The immersion restriction wall85is disposed concentrically with the bearing holder insertion boss part81a.

The immersion restriction wall85causes a water drop, which is to immerse from the vertically upper side V3into the center in the motor CP side where electrical connecting points and the controller3are disposed, fall down in drop along an outer circumferential surface toward the vertically lower side V4, and accordingly functions to restrict the immersion of the water drop toward the center in the motor CP.

In addition, the anchor part21dof the rotor21functions as a restriction wall configured to restrict a water drop fallen down in drop on the outer circumferential surface of the peripheral wall21bfrom flowing into the opening part21iside of the peripheral wall21b, and also functions as an reinforcement part for the peripheral wall21b.

On the one side V1in the motor axial direction of the motor bracket part82, a first cylinder wall86configured to be in a cylinder-like shape of a smaller diameter than that of the immersion restriction wall85and a second cylinder wall87configured to be in a cylinder-like shape of a smaller diameter than that of the first cylinder wall86are formed. The first cylinder wall86and the second cylinder wall87are respectively disposed concentrically with the bearing holder insertion boss part81a. In an inner side in the radial direction of the first cylinder wall86and the second cylinder wall87, an inclination surface86aand an inclination surface87a, those are as inclined toward the outer side in the radial direction as far they go toward the one side V1in the motor axial direction, are formed.

The first cylinder wall86and the second cylinder wall87, like the immersion restriction wall85, cause a water drop, which is to immerse from the vertically upper side V4into the center in the motor CP side where electrical connecting points and the controller3are disposed, fall down in drop along an outer circumferential surface toward the vertically lower side V4. Thus, the first cylinder wall86and the second cylinder wall87function to restrict the immersion of the water drop toward the center in the motor CP. In this way, immersion of a water drop into the center in the motor CP is restricted in a double or triple manner.

As shown in theFIG. 6, seen from the one side V1in the motor axial direction, in an area which is in the one side V1in the motor axial direction of the base part82aof the motor bracket part82and which is surrounded by the second cylinder wall87, a plural number of ribs81rextending radially from the bearing holder insertion boss part81aare formed.

Hereinafter, description will be made with reference to theFIG. 6and theFIG. 8. In a vertically lower area of the inner circumferential surface of the immersion restriction wall85, a water drain concave part85bconfigured to drain out the water drop flown to the immersion restriction wall85toward outside is provided over a scope corresponding to the plural number of the concave parts81i,81jand81k(water drain structure) of the bearing holder insertion boss part81a. Seen from the one side V1in the motor axial direction, the scope of setting the water drain concave part85bis configured to be a larger scope of an angle than an angle formed by the linear line L1and the linear line L2(to the extent of 90 degree in the present embodiment). In addition, a scope of setting of the opening80mof the bracket8is also configured to be a larger scope of an angle than the angle formed by the linear line L1and the linear line L2(to the extent of 90 degree in the present embodiment).

Seen from the one side V1in the motor axial direction, the immersion restriction wall85is formed to be a curved surface in a round shape for an entire area of an inner circumferential surface except for the water drain concave part85b. Hereinafter, a portion having the inner circumferential surface configured to be the curved surface in the round shape, except for the water drain concave part85b, in the immersion restriction wall85is referred to as “a general part”. The water drain concave part85bis formed to be recessed toward the outer side in the radial direction with respect to the general part85a, and to be along a circumferential direction of the inner circumferential direction of the immersion restriction wall85. The water drain concave part85bis formed in a scope over from a root part side (V2side in theFIG. 8) to an extending end (V1side in theFIG. 8) of the immersion restriction wall85, and communicates with the outside (the opening of the one side V1in the motor axial direction).

For example, even in a case in which a water drop adheres to a corner of the root part side of the immersion restriction wall85within the water drain concave part85bby a surface tension, and the water drop adhered is frozen to form a piece of ice, a deepness of a recession of the water drain concave part85bis set at such deepness that the piece of the ice does not come to contact with the end part of the opening part21iside of the peripheral wall21b(the anchor part21d) of the rotor21.

Hereinafter, description will be made with reference to theFIG. 1. In a state in which the brushless motor2is attached to the bracket8, the inner circumferential surface of the immersion restriction wall85is faced to the end part of the opening part21iside of the peripheral wall21b(the anchor part21d) of the rotor21with an interval. The water drain concave part85bis recessed toward the outer side in the radial direction with respect to the general part85a, a width of the interval from the end part of the opening part21iside of the peripheral wall21b(the anchor part21d) of the rotor21is partially enlarged along the water drain concave part85b, with respect to the general part85a.

Hereinafter, description will be made with reference to theFIG. 8. A water drain path70includes a motor side water drain path71, a base side water drain path72and an opening side water drain path73. The motor side water drain path71is surrounded by an outer circumferential surface of the second cylinder part24cin the bearing holder24and by the plural number of the concave parts81i,81jand81kof the bearing holder insertion boss part81a, and extends in the motor axial direction. The base side water drain path72opens toward the one side V1of the base member5in the axial direction. The opening side water drain path73projects toward the one side V1in the motor axial direction from the base member5and is formed between a surface of the vertically lower side of a base side convex part53bsurrounded by the opening80mand an upper surface of a rise wall88a(a surface facing the opening80m) to be described later. The water drain path70bends in a crank-like manner and forms a labyrinth structure.

Hereinafter, description will be made with reference to theFIG. 6and theFIG. 8. Above-described labyrinth structure has a foreign substance intrusion preventing part88configured to prevent a foreign substance from intruding into the water drain path70. The foreign substance intrusion preventing part88rises toward the vertically upper side from a portion facing the base side water drain path72in the immersion restriction wall85, and includes the rise wall88acovering the base side water drain path72from the one side V1in the motor axial direction. The rise wall88ais formed in a portion of the vertically lower side in an opening-forming part which forms the opening80mof the bracket8. An upper edge of the rise wall88a(an end edge in the side of the opening80m) is configured to be in a mild U-shape, seen from the motor axial direction (the one side V1in the motor axial direction).

<Flow of Drained Water according to the Labyrinth Structure>

In theFIG. 8, arrow signs W, W1, W2, W3and W4indicate flows of drained water. For example, a water drop fallen down in drop from the water drip hole24hflows into the motor side water drain path71as the arrow sign W indicates. The water drop flown into the motor side water drain path71flows inside the motor side water drain path71toward the other side V2in the motor axial direction as the arrow sign W1indicates. The water drop flown toward the other side V2in the motor axial direction, as the dotted-lined arrow sign W2indicates, diverts toward a back side in a sheet page or a front side in the sheet page of the base side convex part53band flows toward the vertically lower side V4and flows into the opening side water drain path73.

On the other hand, a water drop infiltrated into the terminal cover10flows, as indicated by the arrow sign W4, through the base side water drain path72and flows into the opening side water drain path73. The water drop flown into the opening side water drain path73, as indicated by the arrow sign W3, while going along a portion in the one side V1in the motor axial direction of the rise wall88aor the like, flow toward the vertically lower side V4. And the water drop goes through such water drain guide walls as the second cylinder wall87, the first cylinder wall86and the water drain concave part85bof the immersion restriction wall85, and is drained toward outside.

As indicated in theFIG. 1, a plural (eight, for example, in the present embodiment) number of through holes26and through holes27, which open (penetrate through) in a width direction of the bottom wall21aare formed in the bottom wall21aof the rotor21. The plural number of through holes26and through holes27are disposed along an outer circumference of the bottom wall21aof a disc-like shape, being spaced with intervals. Seen from the motor axial direction (the one side V1in the motor axial direction), each of the through holes26and through holes27are configured to be in a long hole-like shape that extends like an arch along an outer circumferential edge of the disk-like the bottom wall21a. In this way, it is possible to aim at weight saving of the rotor21, comparing to a case in which a shape of each of the through holes are configured to be a circle shape seen from the motor axial direction.

Among the plurality of through holes26and through holes27, the through holes27having different shapes from those of the through holes26(“a different shape hole”) function as positioning holes for the rotor21. Hereinafter, a through hole that functions as a positioning hole for the rotor21is referred to as “a rotor positioning hole”. There is only one rotor positioning hole27is provided. In this way, when assembling the rotor21, it has to focus attention only to one rotor positioning hole27. Therefore, it is possible to further prevent a mounting error, compared to a case in which a plural number (two, for example) of rotor positioning holes are provided.

As shown in theFIG. 12, the rotor positioning hole27includes a long hole part27athat is configured to be in a long hole-like shape that extends like the arch along the outer circumferential edge of the disk-like the bottom wall21aseen from the motor axial direction, a first cutout part27bthat is formed in the one side of the motor circumferential direction of the long hole part27aand a second cutout part27cthat is formed in the other side of the motor circumferential direction of the long hole part27a. In this way, a weight balance of the rotor21in the motor circumferential direction is maintained, compared to a case in which a cutout part is formed only in the one side of a long hole part in the motor circumferential direction. Accordingly, it is possible to prevent noise and vibration or the like from occurring.

In an inner portion in the motor radial direction of a portion of the bottom wall21athat forms the long hole part27a, a thick-walled part28configured to be a moderate convex toward the long hole part27a(outside in the motor axial direction) is formed. A reference numeral S1in the drawing indicates a volume of a decreased amount by the first cutout part27b. A reference numeral S2in the drawing indicates a volume of a decreased amount by the second cutout part27c. A reference numeral S3in the drawing indicates a volume of an increased amount by the thick-walled part28.

For example, the volume S3is set to offset as much as a total amount of the decreased amount S1and the decreased amount S2. That is to say, a weight of the thick-walled part28is set to offset as much weight as a weight decreased by the first cutout part27band the second cutout part27c. In this way, a weight balance between the rotor positioning hole27and other through holes26is maintained, compared to a case in which only the first cutout part27band the second cutout part27care formed (a case in which the thick-walled part28is not formed). Accordingly, it is possible to prevent noise and vibration or the like from occurring.

As shown in theFIG. 9, the first connector51and the second connector52provided in the base member5project toward the vertically upper side V3in a state in which the center line in the bracket width direction C1is along the vertical direction. At this point, for example, in case there is a restriction of layout in the upper side of the electric motor1, layout in a posture of theFIG. 9is difficult, considering the installation space problem or the connecting operability with an external connector of the vehicle. However, in the present embodiment, it is possible to adjust the attachment angle of the electric motor1to any angle as shown in theFIG. 10or theFIG. 11, etc. In this way, even in case there is a restriction of layout in the upper side of the electric motor1, it is possible to layout the electric motor1within a restricted installation space, and it is possible to enhance the connecting operability with an external connector of the vehicle as may be necessary.

As described above, the above-described embodiment is the electric motor1including the stator22around which the coil22cis wound; the bracket8configured to support the stator22; the output shaft20rotatably supported by the bracket8via the bearing23and extends in the horizontal direction; the rotor21including the bottom wall21aof the disc-like shape that covers one side of the stator22in the axial line direction of the output shaft20and the peripheral wall21bof the cylinder-like shape that rises from the outer circumferential end of the bottom wall21aand covers the outer circumferential side of the stator22, in which the bottom wall21ais configured to be integrally-rotatably combined with the output shaft20and the peripheral wall21bis provided with a magnet21c; and a bearing holder24including the cylinder part24aof the cylinder-like shape configured to support the bearing23in the inner circumferential side thereof, and the water drip hole24his formed on the vertically lower side of the cylinder part24a, the bracket8being provided with the bearing holder insertion part81aincluding the bearing holder insertion boss part81aof the cylinder-like shape into which the cylinder part24ais configured to be inserted, wherein a water drain structure configured to drain a water drop from the water drip hole24htoward outside is provided along the circumferential direction of the inner circumferential surface of the bearing holder insertion boss part81ain the vertically lower area of the inner circumferential surface of the bearing holder insertion boss part81a.

According to this configuration, a water drain structure configured to drain the water drop from the water drip hole24htoward outside is provided along the circumferential direction of the inner circumferential surface of the bearing holder insertion boss part81ain the vertically lower area of the inner circumferential surface of the bearing holder insertion boss part81a. In this way, at the time of attaching the electric motor1to a vehicle, a quality of the water drip structure is secured in a setting range of the water drain structure along the circumferential direction of the inner circumferential surface of the bearing holder insertion boss part81aeven in a case in which the attachment angle centering around the output shaft20of the electric motor1to a vehicle is adjusted with respect to the vehicle. Also, in the setting range of the water drain structure along the circumferential direction of the inner circumferential surface of the bearing holder insertion boss part81a, the attachment angle centering around the output shaft20of the electric motor1is possible to adjust with respect to the vehicle at a predetermined angle. Accordingly, it is possible to enhance the layout characteristic at a time of attaching to the vehicle without diminishing the quality of the water drain structure, and it is possible to enhance the connecting operability with an external connector of the vehicle.

According to the above-described embodiment, the water drain structure is the plural number of the concave parts81i,81jand81krecessed from the inner circumferential surface of the bearing holder insertion boss part81atoward outside in the radial direction and are communicated to the outside of the bearing holder insertion boss part81a. In this way, at the time of attaching the electric motor1for vehicle to a vehicle, even in a case in which the attachment angle centering around the output shaft20of the electric motor1to a vehicle is adjusted with respect to the vehicle at a predetermined angle, it is possible to drain water toward outside smoothly from each of the concave parts81i,81jand81k. Also, in comparison with a case in which a single concave part continuous in the circumferential direction of the inner circumferential surface of the bearing holder insertion boss part81ais provided, it is possible to enhance support strength of the cylinder part24aby the bearing holder insertion boss part81a. Therefore, it is possible to support the bearing holder24stably.

Also, according to the above-described embodiment, the plurality of the concave parts81i,81jand81kare disposed, being aligned in the circumferential direction in one part of the inner circumferential surface of the bearing holder insertion boss part81a. In this way, it is satisfactory to form the water drip hole24hformed in the cylinder part24aonly in the scope corresponding to the disposition (the part of the cylinder part24ain the vertically lower side), it is not necessary to form excessive water drip holes. In this way, it is easier to secure roundness of the cylinder part24a, and possible to enhance processing precision of the bearing holder24.

Also, according to the above-described embodiment, the water drain concave part85bconfigured to drain toward outside a water drop flowed to the immersion restriction wall85is provided over the scope corresponding to the water drain structure in the vertically lower area of the inner circumferential surface of the immersion restriction wall85. In this way, at the time of attaching the electric motor1to a vehicle, a quality of the water drain concave part85bis secured in the setting range of the water drain structure along the circumferential direction of the inner circumferential surface of the bearing holder insertion boss part81aeven in a case in which the attachment angle centering around the output shaft20of the electric motor1to a vehicle is adjusted with respect to the vehicle at a predetermined angle.

Also, according to the above-described embodiment, there is the water drain path70in the bracket8and the base member5, and the labyrinth structure having the foreign substance intrusion preventing part88configured to prevent intrusion of a foreign substance into the water drain path70is provided. In this way, it is possible to prevent a foreign substance from intruding into the water drain path70and to prevent a clog in the water drain path70, therefore, it is possible to smoothly drain water through the water drain path70.

Also, according to the above-described embodiment, the foreign substance intrusion preventing part88includes the rise wall88athat rises in the vertically upper direction from the part, facing the base side water drain path72, of the bracket8, and that covers the base side water drain path72from one side of the base side water drain path72in the motor axial direction. In this way, it is possible to prevent a foreign substance from intruding into the base side water drain path72and to prevent a clog in the base side water drain path72, therefore, it is possible to smoothly drain water through the base side water drain path72.

Also, according to the above-described embodiment, the flange part24dof the bearing holder24is provided with the attachment part (the through hole24i, the through hole24jand the through hole24k) configured to be able to adjust the attachment angle of the bracket8centering around the output shaft20in a state in which the water drip hole24his disposed on the vertically lower side of the cylinder part24a. In this way, it is possible to attach the bearing holder24to the bracket8without forming more water drip holes24h.

Also, according to the above-described embodiment, the electric motor1is used as the drive source of the electric fan for cooling the radiator for vehicle. In this way, it is possible to make the water drain structure effective.

In addition, the technical scope of the present invention is not limited to the above-described embodiment, and it is possible to conduct various changes without departing from the main point of the invention.

For example, in the above-described embodiment, the water drain structure is configured to be the plural number of the concave parts81i,81jand81krecessed from the inner circumferential surface of the bearing holder insertion boss part81atoward outside in the radial direction and are communicated to the outside of the bearing holder insertion boss part81a. However, not limited to this, and it may be configured to be a single concave part continuous in the circumferential direction of the inner circumferential surface of the bearing holder insertion boss part81a, for example.

Also, in the above-described embodiment, the number of disposing the concave parts81i,81jand81kis configured to be three, however not limited thereto. In addition, the number of disposing each of the through hole24i, the through hole24jand the through hole24k, and the number of disposing the bearing holder attachment parts89is not limited to three.

Also, in the above-described embodiment, the foreign substance intrusion preventing part88is configured to include the rise wall88athat rises in the vertically upper direction from the part, facing the base side water drain path72, of the bracket8, and that covers the base side water drain path72from one side of the base side water drain path72in the motor axial direction. However, not limited thereto, and a wall part in a separated body from the bracket8as a foreign substance intrusion preventing part may be provided in a part facing the base side water drain path72, for example.

Also, in the above-described embodiment, connecting between the motor side end part125of the three phase bus bar and each of the electricity supply terminals25ais conducted by resistance welding. However, not limited thereto, and it may be conducted by an arc welding such as a TIG welding or a laser welding, or the like, for example.

Also, material or shape or the like of the base member5, the bracket8, the main body cover9, the terminal cover10, the brushless motor2or the bus bar100, etc. are not limited to the above-described embodiment. For example, the bus bar100may be formed of aluminum. Also, the bracket8may be formed of metal material such as iron (carbon steel) or the like.

Also, the case in which the electric motor1is used as the drive source of the electric fan for cooling the radiator for vehicle, however it is not limited thereto in the above-described embodiment.

Other than above, without departing from the scope of the present invention, it is possible to arbitrarily replace elements of the above-described embodiment with known elements.

REFERENCE NUMERALS