JP5936997B2 - Electric motor - Google Patents

Description

  The present invention relates to an electric motor used for driving a vehicle oil pump, for example.

  In this type of electric motor, a plurality of magnets are arranged on the inner peripheral surface of a bottomed cylindrical yoke, and an armature is rotatably provided radially inward of the magnet. The armature includes an armature core that is externally fixed to a rotating shaft and wound with a winding, and a commutator in which a plurality of segments are disposed. A winding is connected to the commutator, and a brush is slidably contacted with each segment of the commutator. This brush is electrically connected to an external power source, and a current is supplied to the winding through the brush and the segment. When a current is supplied to the winding, a magnetic field is formed, and the armature is rotated by a magnetic attractive force or a repulsive force generated between the magnetic field and the magnet.

Here, since it is conceivable that water is scattered in the electric motor provided in the vehicle, various techniques for draining water that has entered the electric motor to the outside have been proposed.
For example, a technique is disclosed in which a drainage passage is formed between a yoke and a magnet, and a drainage hole (drain) is directly formed on the bottom surface of the yoke within the range of the passage (for example, a patent) Reference 1).

JP-A-8-107648

However, in the above-described prior art, since the drainage hole is directly formed on the bottom surface of the yoke, for example, when water is sprayed from below on the electric motor due to high-pressure washing, the water enters the electric motor. Easy to penetrate. That is, there is a problem that the waterproof property of the electric motor is poor against scattering of water due to high-pressure washing or the like from below.
On the other hand, it is also conceivable to attach a drain tube or the like to the drainage hole formed in the yoke. However, even in the case of such a configuration, water may enter from the attachment portion of the drain tube during high-pressure cleaning.

  Therefore, the present invention has been made in view of the above-described circumstances, and provides an electric motor that can improve waterproofness against scattering of water due to high-pressure washing or the like from below.

  In order to solve the above-mentioned problems, an electric motor according to the present invention includes a yoke having a cylindrical portion provided with a plurality of magnetic poles on an inner peripheral surface, and a radially inner side of the yoke. A rotatable armature, a brush holder disposed at the end of the yoke opening and holding a brush for supplying power to the armature, and the yoke opening from the outside of the brush holder. A bracket provided so as to cover, and a connector portion for electrically connecting the brush and an external power source to an outer side portion of the brush holder toward a radially outer side than the cylindrical portion of the yoke Protruding and providing a seal part at least around the base part of the connector part so that the armature is along the vertical direction and the bracket faces downward in the vertical direction An electric motor is provided, and a protrusion projecting radially outward with respect to the shaft of the armature from the seal portion is provided at a portion of the bracket corresponding to a lower portion in the vertical direction of the connector portion. The portion covers the side surface of the connector portion in the vertical direction, and a drain hole for draining water that has entered between the convex portion and the connector portion is formed in the convex portion. To do.

Thus, by covering the lower part in the vertical direction of the connector part where water easily enters with the convex part, the waterproofness of the electric motor can be improved against scattering of water due to high-pressure washing or the like from below.
Also, even if water enters between the convex portion and the connector portion, the drainage hole is formed in the convex portion, so that water can be efficiently drained without collecting water in the electric motor. Can do. For this reason, the waterproofness of an electric motor can be improved further.

  In the electric motor according to the present invention, the connector portion protrudes radially outward from the outer portion of the brush holder with respect to the axis of the armature, and includes a base portion having the root portion and a tip of the base portion. A bent portion that is bent toward the axial direction of the armature; and a fitting portion that is provided at a tip of the bent portion and that is fitted with a connector extending from the external power source. A waterproof wall extending in the vertical direction is provided on the tip side of the portion where the hole is formed, and at least a part of the bent portion is covered by the waterproof wall.

  By comprising in this way, it can prevent reliably that the water splashed by the high voltage | pressure washing | cleaning etc. from the lower part penetrate | invaded between a connector part and a convex part by a waterproof wall. For this reason, the waterproofness of an electric motor can be improved more reliably.

  The electric motor according to the present invention is characterized in that the drain hole is formed so as to penetrate the convex portion along the vertical direction and has a labyrinth portion therein.

  By comprising in this way, even if it is a case where the water between a convex part and a connector part permeates, it can drain efficiently. Further, it is possible to prevent water from entering the inside through the drain hole.

  The electric motor according to the present invention is characterized in that the seal portion is provided around the base portion of the connector portion at a location corresponding to the opening edge portion of the drain hole.

  By comprising in this way, it can prevent that the location used as a bag path is formed by a brush holder, a connector part, and a seal part. In other words, it is possible to prevent a portion where water is accumulated between the brush holder and the connector portion. For this reason, the waterproofness of the electric motor can be further improved.

  The electric motor according to the present invention is characterized in that the drain hole is formed such that a minimum horizontal gap is 3.2 mm or more and a vertical minimum gap is 4 mm or more.

  By comprising in this way, it can prevent that water accumulates in a drain hole, and the water which passes a drain hole can be drained reliably.

  According to the present invention, the waterproofness of the electric motor can be improved against the scattering of water due to high-pressure washing or the like from below by the convex portions formed on the bracket. Even if water enters between the convex portion and the connector portion, the drainage hole is formed in the convex portion, so that water can be efficiently drained without entering the electric motor. be able to. For this reason, the waterproofness of an electric motor can be improved further.

It is a longitudinal cross-sectional view of the electric motor in embodiment of this invention. It is the front view which looked at the electric motor in the embodiment of the present invention from the bracket side. It is a perspective view of the brush holder in the embodiment of the present invention. It is a disassembled perspective view of the brush holder and bracket in embodiment of this invention. It is a longitudinal cross-sectional view of the yoke in the embodiment of this invention, a brush holder, and a bracket. It is A arrow directional view of FIG. It is explanatory drawing for determining the horizontal minimum gap and the vertical minimum gap of the drain hole in the embodiment of the present invention. It is action | operation explanatory drawing of the convex part in embodiment of this invention.

(Electric motor)
Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a longitudinal sectional view of the electric motor, and FIG. 2 is a front view of the electric motor as viewed from the bracket side.
As shown in FIGS. 1 and 2, the electric motor 1 is provided in a differential device 80 of a vehicle (not shown), and an oil pump 81 provided to apply pressure to oil in the differential device 80. It is for driving.

  The electric motor 1 includes a bottomed cylindrical yoke 2, an armature 3 rotatably supported in the yoke 2, a brush holder 17 disposed on the opening 2 a side end of the yoke 2, And a bracket 18 provided so as to cover the opening 2 a from the outside of the brush holder 17. The electric motor 1 is arranged at a position above the differential device 80 so that the rotation shaft 5 of the armature 3 is along the vertical direction and the bracket 18 is directed downward in the vertical direction.

  The cylindrical portion 2b of the yoke 2 is provided with a plurality of permanent magnets 4 on the inner peripheral surface so that the magnetic poles are in order in the circumferential direction. Further, an outer flange portion 22 that bends and extends radially outward is integrally formed in the opening 2 a of the yoke 2. The brush holder 17 is placed on the outer flange portion 22. Further, a bearing housing 21 that protrudes upward in the axial direction is integrally formed on the bottom portion 2c of the yoke 2 so as to rotatably support the upper end of the rotary shaft 5 of the armature 3. A bearing 16 is press-fitted.

  In addition to the rotary shaft 5, the armature 3 includes an armature core 6 that is externally fitted and fixed to the rotary shaft 5, a plurality of armature coils 7 that are wound around teeth 9 described later of the armature core 6, and a rotary shaft. 5 and a commutator 13 that is fitted and fixed to the brush holder 17 side of the armature core 6. The armature core 6 is obtained by laminating a plurality of ring-shaped metal steel plates 8 in the axial direction. A plurality of T-shaped teeth 9 are formed at equal intervals along the circumferential direction on the outer peripheral portion of the metal steel plate 8.

  By fitting a plurality of metal steel plates 8 to the rotary shaft 5, dovetail-shaped slots (not shown) are formed between adjacent teeth 9 on the outer periphery of the armature core 6. Each tooth 9 has an enamel-wrapped winding 12 wound around a slot (not shown) via an insulating member. As a result, a plurality of armature coils 7 are formed on the outer periphery of the armature core 6.

  The commutator 13 is disposed at a position slightly protruding from the opening 2 a of the yoke 2. A plurality of segments 14 made of a conductive material are provided on the outer peripheral surface of the commutator 13. The segments 14 are made of plate-like metal pieces that are long in the axial direction, and are fixed at equal intervals along the circumferential direction in a state of being insulated from each other. A riser 15 is integrally formed at the end of each segment 14 on the armature core 6 side so as to be folded outward in the radial direction.

  A terminal portion of the winding 12 is wound around each riser 15, and this terminal portion is electrically joined by welding means such as fusing. Thereby, the segment 14 and the coil | winding 12 corresponding to this are electrically connected. Further, the tip of a brush 41 (see FIGS. 3 and 4) held by the brush holder 17 is in sliding contact with the segment 14.

(Brush holder)
FIG. 3 is a perspective view of the brush holder.
As shown in FIG. 1 and FIG. 3, the brush holder 17 is made of, for example, an insulating resin, and has a holder main body 42 formed in a substantially disc shape and a holder main body 42 on one side. And a connector part 43 formed integrally.
In the electric motor 1, the side on which the connector portion 43 is disposed is the rear side, the side opposite to the side on which the connector portion 43 is disposed is simply the front side, the front side is directed, the right side is simply the right side, and the front side is directed. In some cases, the left side is simply referred to as the left side.

  The outer diameter of the holder main body 42 is set to be slightly larger than the inner diameter of the opening 2 a of the yoke 2. Of the end surface 42 b on the yoke 2 side of the holder main body 42, a portion near the outer peripheral surface 42 a is in contact with the outer flange portion 22 of the yoke 2.

Further, a yoke-side spigot portion 47 that is inlay-fitted into the opening 2 a of the yoke 2 is erected on the end surface 42 b of the holder body 42. On the other hand, on the opposite side of the holder body 42 from the yoke 2, that is, on the end surface 42 c on the bracket 18 side, a bracket side inlay portion 57 that fits into the bracket 18 is erected.
The holder body 42 has an end surface 42b near the outer peripheral surface 42a in contact with the outer flange portion 22 of the yoke 2, and an outer peripheral surface 47a of the yoke side inlay portion 47 in contact with the inner peripheral surface of the cylindrical portion 2b of the yoke 2. It becomes a state.

Here, a series of ventilation grooves 48 are formed on the end surface 42 b of the holder main body 42 near the outer peripheral surface 42 a and the outer peripheral surface 47 a of the yoke side spigot 47. That is, the ventilation groove 48 includes a first groove 48 a formed on the end surface 42 b near the outer peripheral surface 42 a of the holder body 42, and a second groove 48 b formed on the outer peripheral surface 47 a of the yoke side spigot portion 47. The first groove 48a and the second groove 48b communicate with each other.
By forming the ventilation groove 48, even when the brush holder 17 is placed in the opening 2 a of the yoke 2, the inner peripheral surface 47 b side of the yoke side inlay portion 47 and the outer peripheral surface 42 a of the holder main body 42 are formed. And communicated with each other.

  In addition, an insertion hole 44 into which the commutator 13 can be inserted is formed in the center of the holder body 42 in the radial direction. A pair of brush boxes 45, 45 that can accommodate the brushes 41 are disposed opposite to the end surface 42 b of the holder body 42 on both sides of the insertion hole 44. The brush box 45 rises from the holder main body 42 and straddles between a pair of side walls 45a and 45a extending along the radial direction of the holder main body 42 and the side edges of the side walls 45a and 45a opposite to the holder main body 42. The upper wall 45b is integrally formed.

The brush box 45 and the holder main body 42 form a storage section 46 having a quadrangular cross section, and the brush 41 is stored in such a manner that the brush 41 can protrude and retract toward the radial center.
In addition, on the end surface 42 b of the holder main body 42, support columns 54 are provided upright in front of the brush box 45. A torsion coil spring 55 is inserted into each of the columns 54.

One end of the torsion coil spring 55 abuts against the proximal end side of the brush 41. As a result, a pressing force is always applied to the brush 41 radially inward, so that the tip of the brush 41 is in sliding contact with the segment 14 of the commutator 13 with certainty.
A slit 49 is formed in the upper wall 45b of the brush box 45. A pigtail 50 having one end connected to the brush 41 extends through the slit 49. The other end of the pigtail 50 is connected to a terminal 51 provided in the connector portion 43.

  The connector part 43 includes a base part 91 extending from the one side of the holder body 42 toward the radially outer side than the cylindrical part 2b of the yoke 2, a bent part 92 provided at the tip of the base part 91, and a bent part. The fitting portion 93 provided at the tip of the portion 92 is integrally formed, and the terminal 51 is laid in the base portion 91, the bent portion 92, and the fitting portion 93.

The base portion 91 is formed in a plate shape so that the width in the left-right direction is longer than the width in the front-rear direction. The bent portion 92 is formed so as to be bent from the tip of the base portion 91 toward the axial yoke 2 side, that is, upward in the axial direction.
Furthermore, the fitting portion 93 is formed in a cylindrical shape so that an external connector extending from an external power source (not shown) can be fitted, and the opening is directed upward. One end of the terminal 51 is exposed in the fitting portion 93.

  On the other hand, an exposure window 56 is formed at a portion corresponding to the terminal 51 on the connector portion 43 side of the holder main body 42, and the other end of the terminal 51 is exposed through the exposure window 56. One end of the pigtail 50 is connected to the exposed part of the other end of the terminal 51.

(Seal part)
4 is an exploded perspective view of the brush holder and the bracket, and FIG. 5 is a longitudinal sectional view of the yoke, the brush holder and the bracket.
As shown in FIGS. 4 and 5, the brush holder 17 is provided with a seal portion 30 made of a rubber material. In the seal portion 30, a first seal body 31 attached to the end surface 42 b near the outer peripheral surface 42 a of the holder body 42 and a second seal body 32 attached to the base portion 91 a of the base portion 91 in the connector portion 43 are integrally formed. It is a thing.

The first seal body 31 has a holder body packing 33 that contacts the end surface 42 b of the holder body 42. The holder main body packing 33 is sandwiched between the holder main body 42 of the brush holder 17 and the outer flange portion 22 (see FIG. 1) of the yoke 2. The holder main body packing 33 is formed so that the outer peripheral portion is located slightly inward in the radial direction from the outer peripheral edge of the outer flange portion 22 of the yoke 2.
A holder body O-ring 34 is integrally formed on the outer periphery of the holder body packing 33. The holder main body O-ring 34 is sandwiched between the outer flange portion 22 of the yoke 2 and a peripheral edge portion 64 of an opening portion 61a of the bracket 18 described later, and ensures sealing performance.

  In the second seal body 32, a grommet 35 formed so as to surround the base portion 91a of the base portion 91 and a connector O-ring 36 formed so as to surround the periphery of the grommet 35 are integrally formed. Is. The grommet 35 and the connector O-ring 36 are sandwiched between the base portion 91 and the outer flange portion 22 of the yoke 2 and between the base portion 91 and the bracket 18 to ensure sealing performance. is there.

  In order to attach the seal part 30 to the brush holder 17 under such a configuration, first, the fitting part 93 of the connector part 43 is passed from the first seal body 31 side of the second seal body 32. Then, after the second seal body 32 is mounted on the base portion 91 of the connector portion 43, the first seal body 31 is attached to the end surface 42 b near the outer peripheral surface 42 a of the holder body 42. Thereby, attachment of the seal part 30 to the brush holder 17 is completed.

(bracket)
As shown in FIGS. 1 and 3 to 5, the bracket 18 is formed by, for example, aluminum die casting, and is formed in a substantially bowl shape so as to cover the brush holder 17 from the outside. The bracket 18 includes a brush holder housing portion 61 that houses the brush holder 17, a packing placement portion 62 that is formed with a reduced diameter on the bottom 18 a side of the brush holder housing portion 61, and a packing placement portion 62. Also, on the bottom 18a side, there is a brush holder internal fitting portion 63 formed with a reduced diameter by a step.

  The bracket 18 is arranged with the opening 61a of the brush holder housing 61 facing the yoke 2 so that the peripheral edge 64 of the opening 61a and the outer flange 22 of the yoke 2 come into contact with each other. It has become. Further, three pedestal portions 65 are provided on the outer peripheral surface 18b of the bracket 18 at substantially equal intervals in the circumferential direction. Each pedestal portion 65 is integrally formed with the bracket 18. Each pedestal portion 65 is formed with an insertion hole 65a through which a bolt (not shown) can be inserted, and a female screw portion 65b for fixing the yoke 2.

  On the other hand, an insertion hole (not shown) is formed in the outer flange portion 22 of the yoke 2 at a position corresponding to the insertion hole 22a through which a bolt (not shown) can be inserted and the female screw portion 65b of the bracket 18. The yoke 2 is fixed by screwing a not-shown screw into the female screw portion 65 b of the bracket 18 through the insertion hole of the yoke 2. Further, a bolt (not shown) is inserted through the insertion hole 65a of the bracket 18 and the insertion hole 22a of the yoke 2, and the bolt is fastened and fixed to a female screw portion (not shown) formed in the differential device 80. The electric motor 1 is fixed.

  A projecting portion 66 having a substantially square cross section that projects outward in the radial direction is integrally formed on the outer peripheral surface 18 b of the bracket 18. An air passage 67 is formed at the center of the cross section of the protrusion 66 along the longitudinal direction of the protrusion 66. The distal end side of the air passage 67 is opened at the distal end of the protruding portion 66, while the proximal end side of the air passage 67 is opened at the inner peripheral surface of the brush holder internal fitting portion 63. Thereby, the inside and outside of the bracket 18 are communicated with each other via the air passage 67.

  Further, a breather pipe 90 is press-fitted and fixed to the air passage 67 from the outside of the bracket 18. The breather pipe 90 is formed in a substantially L shape, and is attached so that the tip thereof faces upward in the vertical direction, and a breather hose (not shown) is attached to the tip, and is arranged upward of the vehicle body. Thereby, it is possible to prevent water and oil from entering the electric motor 1 through the opening of the breather pipe 90.

  The inner diameter of the brush holder housing 61 is set to be slightly larger than the outer diameter of the holder main body 42 of the brush holder 17. Thereby, the brush holder 17 is accommodated in the brush holder accommodating portion 61. In a state where the brush holder 17 is stored, a slight gap is formed between the outer peripheral surface 42 a of the holder body 42 of the brush holder 17 and the inner peripheral surface of the brush holder storage portion 61.

  An O-ring groove 69 that can receive the holder body O-ring 34 of the seal portion 30 is formed on the inner edge side of the peripheral edge portion 64 of the bracket 18. When the brush holder 17 is stored in the brush holder storage 61 of the bracket 18, the holder main body O-ring 34 is placed in the O-ring groove 69. Thereby, the sealing performance between the outer flange portion 22 of the yoke 2 and the peripheral portion 64 of the bracket 18 is ensured.

  As shown in detail in FIG. 5, the packing arrangement portion 62 formed on the bottom 18a side of the brush holder storage portion 61 has a circular shape when viewed from the axial direction on the inner peripheral surface 62b side of the bottom surface 62a. An annular recess 71 is formed. As a result, the packing arrangement portion 62 as a whole has a two-stage structure. A bracket packing 70 formed so as to correspond to a two-stage structure is placed on the bottom surface 62 a of the packing arrangement portion 62.

  On the bracket packing 70, the end face 42c of the holder main body 42 in the brush holder 17 is placed. Further, an annular portion 76 is formed on the end surface 42 c of the holder main body 42 in the brush holder 17 at a portion corresponding to the concave portion 71 of the bracket 18. The annular portion 76 faces the recess 71 of the bracket 18, and the tip of the annular portion 76 is in contact with the bracket packing 70.

  That is, the brush holder 17 is held by the yoke 2 and the bracket 18 via the seal portion 30 and the bracket packing 70, respectively. In other words, the brush holder 17 is held in a floating state between the yoke 2 and the bracket 18 by the seal portion 30 and the bracket packing 70.

  Further, the first seal body 31 of the seal portion 30 includes a holder body packing 33 that holds between the holder body 42 of the brush holder 17 and the outer flange portion 22 (see FIG. 1) of the yoke 2, and the holder body 42. The holder main body O-ring 34 is sandwiched between the outer flange portion 22 of the yoke 2 located on the radially outer side and the peripheral edge portion 64 of the bracket 18 to ensure the sealing performance. For this reason, airtightness inside the electric motor 1 is ensured with a so-called double seal structure.

A bracket side inlay portion 57 of the brush holder 17 is inlay-fitted to the brush holder inner fitting portion 63 formed on the bottom portion 18a side with respect to the packing arrangement portion 62.
Further, a bearing housing 72 is integrally formed in the brush holder inner fitting portion 63 at the center in the radial direction. The bearing housing 72 holds a bearing 73 for rotatably supporting the lower end side of the rotary shaft 5.

  Further, a cylindrical seal holding portion 74 is erected on the bottom portion 18a of the bracket 18 downward in the axial direction. An oil seal 75 is attached to the seal holding portion 74. The lower end of the rotating shaft 5 extends toward the differential device 80 via a bearing 73 and an oil seal 75. A drive shaft 84 of the oil pump 81 is connected to the lower end of the rotary shaft 5 via a joint member 83.

(Convex)
6 is a view taken in the direction of arrow A in FIG.
Here, as shown in FIGS. 4 to 6, on the outer peripheral surface 18 b of the bracket 18, a convex portion 101 that protrudes radially outward is integrally formed at a location corresponding to the connector portion 43. The width of the convex portion 101 in the left-right direction is formed larger than the width of the base portion 91 of the connector portion 43 in the left-right direction. A concave portion 102 that receives the base portion 91 and the bent portion 92 of the connector portion 43 is formed in most of the convex portion 101.

  That is, the convex portion 101 is provided so as to protrude outward in the radial direction from the second seal body 32 attached to the base portion 91 a of the base portion 91. The convex portion 101 covers the periphery of the connecting portion between the lower side surface 91b of the base portion 91 and the base portion 91 of the bent portion 92.

On the rear side of the concave portion 102, a drain hole 103 is formed that penetrates in the thickness direction of the convex portion 101, that is, in the vertical direction. The width in the left-right direction of the opening 103 a of the drain hole 103 is formed so as to substantially match the width of the recess 102.
That is, the drainage hole 103 is formed in a substantially rectangular shape so that the opening 103a is elongated in the left-right direction. The front side surface 103b, the rear side surface 103c facing the front side surface 103b, the front side surface 103b, and the rear side It has a right side surface 103d and a left side surface 103e that connect the side surface 103c and face each other in the left-right direction.

Here, the drain hole 103 is formed so that the position of the upper edge portion of the front side surface 103 b substantially coincides with the position of the connector O-ring 36 of the seal portion 30.
Further, a first ridge 104 that protrudes rearward is formed on the front side surface 103b of the drain hole 103 at the bottom. The first ridge 104 is formed over the entire horizontal direction of the drain hole 103.

Furthermore, an overhanging portion 107 that projects downward from the first ridge 104 is integrally formed at the lower rear end of the protrusion 101. And the 2nd protruding item | line part 105 which protrudes toward the front is formed in the rear side surface 103c of this overhang | projection part 107. As shown in FIG. The second ridge 105 is also formed over the entire horizontal direction of the drain hole 103.
A labyrinth portion 106 is formed in the drain hole 103 by these two ridge portions 104 and 105.

Here, the gap S1 between the rear side surface 103c of the drain hole 103 and the first ridge 104 (in other words, the horizontal minimum gap S1 of the drain hole 103) is:
S1 ≧ 3.2 mm (1)
It is set to satisfy.
Further, in a state where the brush holder 17 is housed in the brush holder housing portion 61 of the bracket 18, the gap S <b> 2 between the base portion 91 of the connector portion 43 and the first protruding strip portion 104 (in other words, the drain hole 103. The minimum vertical clearance S2) of
S2 ≧ 4 mm (2)
It is set to satisfy.

Based on FIG. 7, Formula (1) and Formula (2) will be described in detail.
FIG. 7 is an explanatory diagram for determining the horizontal minimum gap and the vertical minimum gap of the drain hole.
As shown in the figure, when the horizontal minimum gap S1 is smaller than 3.2 mm, the water droplets W exist over both sides of the minimum gap S1 due to the surface tension of the water drops W. For this reason, water droplets W accumulate in the minimum gap S1. On the other hand, when the horizontal minimum gap S1 reaches 3.2 mm, the water droplets W are cut and water droplets W are formed on both side surfaces. For this reason, the water droplets W pass through the minimum gap S1 without the water drops W collecting in the minimum gap S1.

  On the other hand, when the vertical minimum gap S2 is smaller than 4 mm, the surface of the water drop W causes the water drop W to straddle on both side surfaces of the minimum gap S2. For this reason, water droplets W accumulate in the minimum gap S2. On the other hand, when the minimum gap S2 in the vertical direction reaches 4 mm, the water droplets W are cut and water droplets W are formed on both side surfaces. For this reason, the water droplets W pass through the minimum clearance S2 without the water droplets W accumulating in the minimum clearance S2.

  From this, equations (1) and (2) were determined. When the horizontal minimum gap S1 satisfies the formula (1) and the vertical minimum gap S2 satisfies the formula (2), the water droplets W in the drain hole 103 can pass smoothly.

  As shown in detail in FIGS. 4 and 6, a waterproof wall 108 is provided at the rear end of the convex portion 101 of the bracket 18 so as to surround the periphery of the bent portion 92 of the connector portion 43. More specifically, the waterproof wall 108 rises from the peripheral edge of the rear end side of the recess 102 along the vertical direction, and has a substantially U-shape when viewed from the rear. The waterproof wall 108 is a wall for preventing water from entering between the concave portion 102 and the connector portion 43.

(Operation of electric motor and oil pump)
With this configuration, when an external connector (not shown) extending from an external power source is fitted into the connector portion 43 of the brush holder 17, the terminal 51, the pigtail 50, the brush 41, and the segment 14 of the commutator 13. A current is supplied to the armature coil 7 via the. Then, a magnetic field is generated in each tooth 9 of the armature core 6, and a magnetic attractive force and a repulsive force are generated in the magnetic field and the permanent magnet 4 of the yoke 2. As a result, the armature 3 rotates, and further, the drive shaft 84 of the oil pump 81 connected to the rotation shaft 5 of the armature 3 rotates, and the oil pump 81 is driven.

(Operation of convex part of bracket)
Next, based on FIG. 8, the effect | action of the convex part 101 currently formed in the location corresponding to the connector part 43 of the bracket 18 is demonstrated.
FIG. 8 is an explanatory diagram of the operation of the convex portion.
Here, as shown in the figure, for example, a case where water by high-pressure washing or the like is scattered around the connector portion 43 of the electric motor 1 from below is described.

  In such a case, the lower surface 91b of the base portion 91 of the connector portion 43 and the periphery of the connection portion between the bent portion 92 and the base portion 91 are covered with the convex portion 101. In addition, no water is directly applied to the vicinity of the second seal main body 32 of the seal portion 30. For this reason, it is possible to prevent water from entering the inside of the electric motor 1 from between the connector portion 43 (brush holder 17) and the bracket 18.

  A waterproof wall 108 is provided at the rear end of the convex portion 101 of the bracket 18. Here, the waterproof wall 108 is formed so as to surround the periphery of the bent portion 92 of the connector portion 43. That is, when the electric motor 1 is viewed obliquely from below, the waterproof wall 108 is in a state where the space between the base portion 91 of the connector portion 43 and the concave portion 102 formed in the convex portion 101 is closed. For this reason, it is further difficult for water to enter from between the connector portion 43 (brush holder 17) and the bracket 18.

Next, a case where water enters between the connector portion 43 and the convex portion 101 will be described.
In such a case, since the drain hole 103 is formed in the convex portion 101, the water droplet W hangs down through the drain hole 103. For this reason, it is possible to prevent water from accumulating between the connector portion 43 and the convex portion 101 and corrosion of the bracket 18.

  Further, the drain hole 103 is formed so that the position of the upper edge portion of the front side surface 103 b substantially coincides with the position of the connector O-ring 36 of the seal portion 30. For this reason, the base part 91 (lower side surface 91b) of the connector part 43, the convex part 101, and the connector O-ring 36 of the seal part 30 do not form a portion that becomes a bag path. In other words, a portion where the water droplets W accumulate is not formed between the base portion 91 and the convex portion 101 of the connector portion 43 (see A portion in FIG. 8). For this reason, the water droplet W does not stay in the drain hole 103 and falls down.

  Furthermore, the gap S1 between the rear side surface 103c of the drain hole 103 and the first ridge 104 is set to satisfy the formula (1), and the base 91 and the first ridge 104 of the connector 43 are Since the gap S <b> 2 is set so as to satisfy the formula (2), the water droplets W smoothly pass through the drain hole 103. That is, the water droplet W does not accumulate in the drain hole 103 and falls down.

  Here, since the drain hole 103 is formed so as to penetrate in the thickness direction of the convex portion 101, that is, in the vertical direction, when water is scattered from below by high pressure washing or the like, the drain hole 103 is below the drain hole 103. There is a risk of water intrusion. However, since the labyrinth part 106 is formed in the lower part of the drain hole 103, it becomes difficult for water to enter from below the drain hole 103.

(effect)
Therefore, according to the above-mentioned embodiment, since the convex part 101 was integrally formed in the outer peripheral surface 18b of the bracket 18 in the location corresponding to the connector part 43, the waterproof property of the connector part 43 which is easy to permeate water in the vertical direction. Can be improved. Moreover, since the drain hole 103 is formed in the convex part 101, it can prevent that water accumulates between the connector part 43 and the convex part 101, and can drain efficiently. For this reason, it becomes possible to improve the waterproofness of the electric motor 1 against scattering of water due to high-pressure washing or the like from below.

In addition, since the waterproof wall 108 that rises in the vertical direction is provided at the rear end of the convex portion 101 so as to surround the periphery of the bent portion 92 of the connector portion 43, water is interposed between the connector portion 43 and the convex portion 101. Intrusion can be prevented more reliably.
Furthermore, since the labyrinth part 106 is formed in the lower part of the drain hole 103, it is possible to suppress the intrusion of water from below the drain hole 103, and to improve the waterproof property of the electric motor 1.

  The drain hole 103 is formed so that the position of the upper edge portion of the front side surface 103b substantially coincides with the position of the connector O-ring 36 of the seal portion 30. Therefore, the drain hole 103 protrudes from the base portion 91 of the connector portion 43. It can prevent that the location where the water droplet W accumulates between the parts 101 is formed. For this reason, water droplets W can be drained downward without remaining in the drain hole 103, and corrosion of the bracket 18 and the like can be prevented.

  Further, the clearance S1 between the rear side surface 103c of the drain hole 103 and the first ridge 104 is set to satisfy the formula (1), and the base 91 and the first ridge 104 of the connector 43 are Since the gap S2 is set so as to satisfy the formula (2), the water droplets W in the drain hole 103 can be smoothly drained downward. For this reason, corrosion etc. of the bracket 18 can be reliably prevented.

The present invention is not limited to the above-described embodiment, and includes various modifications made to the above-described embodiment without departing from the spirit of the present invention.
For example, in the above-described embodiment, the case where the electric motor 1 is assembled to the differential device 80 and the electric motor 1 is used to drive the oil pump 81 provided in the differential device 80 has been described. However, it is not restricted to this, The electric motor 1 can be used for various uses.

  In the above-described embodiment, the brush holder 17 is provided with the seal portion 30, and the seal portion 30 is attached to the holder main body 42 and the second seal main body attached to the base portion 52 of the connector portion 43. The case where 32 is integrally molded has been described. However, the present invention is not limited to this, and the first seal body 31 and the second seal body 32 may be configured separately.

  Furthermore, in the above-described embodiment, the case where the drainage hole 103 is formed so as to penetrate in the thickness direction of the convex portion 101, that is, the vertical direction has been described. However, the present invention is not limited to this, and the drain hole 103 only needs to have a structure capable of draining water that has entered between the connector portion 43 and the convex portion 101.

DESCRIPTION OF SYMBOLS 1 Electric motor 2 Yoke 2b Tube part 3 Armature 4 Permanent magnet (magnetic pole)
5 Rotating shaft (axis)
17 Brush holder 18 Bracket 30 Seal portion 31 First seal body 32 Second seal body 41 Brush 43 Connector portion 91 Base portion 91a Base portion 91b Lower side surface 92 Bent portion 93 Fitting portion 101 Convex portion 103 Drain portion 103a Opening portion 103b Front side 103c Rear side 106 Labyrinth part 108 Waterproof wall

Claims (5)

A yoke having a cylindrical portion provided with a plurality of magnetic poles on the inner peripheral surface;
An armature disposed radially inside the yoke and provided rotatably with respect to the yoke;
A brush holder disposed at an end of the opening of the yoke and holding a brush for supplying power to the armature;
A bracket provided to cover the opening of the yoke from the outside of the brush holder;
On the outer part of the brush holder, a connector part for electrically connecting the brush and an external power source is provided projecting radially outward from the cylindrical part of the yoke,
At least a seal part is provided around the base part of the connector part,
An electric motor arranged so that the armature is along a vertical direction and the bracket is directed downward in the vertical direction;
A convex portion that protrudes radially outward with respect to the axis of the armature from the seal portion is provided at a portion of the bracket corresponding to the lower portion of the connector portion in the vertical direction. Cover the bottom side,
An electric motor, wherein a drainage hole for draining water that has entered between the convex portion and the connector portion is formed in the convex portion. The connector portion;
A base portion that protrudes radially outward from the outer portion of the brush holder with respect to the axis of the armature, and has the root portion;
A bent portion formed by bending from the tip of the base portion toward the axial direction of the armature;
It is provided at the tip of this bent portion, and is constituted by a fitting portion to which a connector extending from the external power source is fitted,
A waterproof wall along the vertical direction is provided on the tip side of the portion where the drain hole of the convex portion is formed, and at least a part of the bent portion is covered by the waterproof wall. The electric motor according to claim 1.   The electric drain according to claim 1 or 2, wherein the drain hole is formed so as to penetrate the convex portion along the vertical direction, and has a labyrinth portion therein. motor.   The seal portion is provided around the base portion of the connector portion at a location corresponding to the opening edge of the drain hole. The electric motor described in 1.   5. The drainage hole according to claim 1, wherein the drain hole is formed so that a minimum horizontal gap is 3.2 mm or more and a vertical minimum gap is 4 mm or more. The electric motor described.