JP2013032139A - In-wheel motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an in-wheel motor that suppresses a connection part from interfering with a wheel and prevents the upsizing of the wheel.SOLUTION: An in-wheel motor M includes: a motor case 30 that houses a stator 11 and a rotor 12 and at least part of which is arranged in an inner region of the wheel 41; an attachment part 51 that is located in an outer region of the wheel 41 so that the motor case 30 is attached to a vehicle side member S; and the connection part 52 that connects the motor case 30 to the attachment part 51. The connection part 52 has a plurality of ribs which are integrally formed with respect to an outer surface 31b of the motor case 30 and are extended to the outer region of the wheel 41.

Description

  The present invention relates to an in-wheel motor for driving a wheel, and more particularly to a mounting structure for a vehicle body side member such as a trailing arm, a lower arm, or a shock absorber.

  2. Description of the Related Art Conventionally, an in-wheel motor in which a drive motor is provided inside a wheel that supports a tire and an axle function is added to a motor case that houses the drive motor is known (see, for example, Patent Document 1).

JP 2002-247713 A

  However, in the conventional in-wheel motor, a pedestal is provided on the upper and lower outer surfaces of the motor case, and an attachment connected to the suspension mechanism is fixed to the pedestal with a screw or the like. Therefore, it is necessary to increase the wheel inner diameter so that the attachment enters the inner region of the wheel and the wheel and the attachment do not interfere with each other.

  The present invention has been made paying attention to the above problem, and an object thereof is to provide an in-wheel motor that does not increase the wheel size.

In order to achieve the above object, the in-wheel motor of the present invention includes a motor case, a mounting portion, and a coupling portion.
The motor case accommodates a stator and a rotor, and is at least partially disposed in an inner region of the wheel.
The attachment portion is located in an outer region of the wheel in order to attach the motor case to the vehicle body side member.
The coupling portion includes a plurality of ribs that couple the motor case and the mounting portion, and the plurality of ribs are integrally formed with respect to the outer surface of the motor case and extended to the outer region of the wheel. .

In the in-wheel motor of the present invention, a motor case and a mounting portion for attaching the motor case to the vehicle body side member are integrally formed on the outer surface of the motor case and are extended to the outer region of the wheel. It is couple | bonded by the coupling | bond part which has this rib.
That is, the motor case and the mounting portion are coupled with a plurality of ribs, and each rib is integrally formed with the motor case. As a result, the stress acting on the coupling portion acts in a distributed manner on the plurality of ribs protruding from the outer surface of the motor case. Therefore, stress can be supported without enlarging each rib. That is, the size of the coupling portion can be reduced. Furthermore, since this coupling | bond part is extended | stretched to the outer side area | region of the wheel, the clearance gap with respect to a wheel can be ensured.
As a result, the coupling portion is less likely to interfere with the motor wheel, and an in-wheel motor that does not increase the wheel size can be obtained.

1 is a cross-sectional plan view illustrating an in-wheel motor according to a first embodiment. It is a perspective view which shows the principal part of the in-wheel motor of Example 1. FIG. It is a top view from the arrow A direction in FIG. It is a perspective view which shows the in-wheel motor of a 1st comparative example. It is a figure which shows the in-wheel motor of a 2nd comparative example, (a) is a perspective view, (b) is sectional drawing which shows the positional relationship with a wheel. (a) is a perspective view which shows the principal part of the in-wheel motor of Example 2, (b) is a top view which shows a puddle part, (c) is a side view which shows a puddle part. is there. (a) is a perspective view showing the main part of the in-wheel motor of the comparative example, (b) is a schematic diagram showing a molten metal path through which the molten metal in the in-wheel motor of the comparative example flows, (c), It is explanatory drawing which shows generation | occurrence | production of the shrinkage nest in the in-wheel motor of a comparative example. (a) is a schematic diagram which shows the molten metal path | route through which the molten metal in the in-wheel motor of Example 2 flows, (b) is explanatory drawing which shows generation | occurrence | production of the shrinkage nest in the in-wheel motor of Example 2. FIG. It is a schematic diagram which shows the flow of the molten metal in Example 2, and the flow of the entrained air.

  EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing the in-wheel motor of this invention is demonstrated based on Example 1 and Example 2 which are shown in drawing.

  First, the configuration of the in-wheel motor of the present invention will be described by dividing it into “the overall configuration of the in-wheel motor” and “the configuration of the in-wheel motor mounting mechanism”.

[Overall configuration of in-wheel motor]
FIG. 1 is a cross-sectional plan view illustrating the in-wheel motor according to the first embodiment.

  An in-wheel motor M shown in FIG. 1 is applied to, for example, an electric vehicle, and is disposed in an inner region of a wheel 41 that supports the tire 40, and drives the tire 40 together with the wheel 41. Here, the inner region of the wheel 41 is a region surrounded by the rim 42 of the wheel 41 and the wheel disc 46.

  The in-wheel motor M includes a motor 10, a speed reducer 20, and a motor case 30.

  The motor 10 includes an annular outer peripheral stator (hereinafter simply referred to as “stator”) 11 fixed inside a motor case 30, and an inner periphery arranged concentrically with a radial gap in the inner periphery of the stator 11. And a rotor (hereinafter simply referred to as “rotor”) 12.

  The speed reducer 20 is a planetary gear type speed reducer, and includes an input shaft 21 and an output shaft 22 arranged so as to be coaxially opposed to each other, a sun gear 23, and a ring gear 24 arranged concentrically with respect to the sun gear 23 in the axial direction. The stepped planetary pinion 25 meshes with the sun gear 23 and the ring gear 24, and the carrier 26 rotatably supports the stepped planetary pinion 25.

The input shaft 21 is provided with a sun gear 23 integrally formed on the outer peripheral surface, and a rotor 12 is fixed to a portion extending from the sun gear 23 via a motor coupling portion 21a so that the input shaft 21 can rotate integrally with the rotor 12. It is supported.
One end of the output shaft 22 is connected to a carrier 26 that is an output member of the speed reducer 20, and the other end protrudes from the motor case 30 to be coupled with a wheel 41.

The ring gear 24 is fixed to the inner peripheral surface of the motor case 30 so as not to rotate but to come off.
The stepped planetary pinion 25 integrally includes a large-diameter gear portion 25 a that meshes with the sun gear 23 and a small-diameter gear portion 25 b that meshes with the ring gear 24. Note that only one stepped planetary pinion 25 is shown here, but three sets of stepped planetary pinions 25 are arranged at equal intervals in the circumferential direction as a set of three, and rotated by the carrier 26 while maintaining equal intervals in the circumferential direction. It is supported freely.
The carrier 26 is an output rotation member of the speed reducer 20, and is disposed between the input shaft 21 and the output shaft 22 at a position coaxial with both the shafts 21 and 22. In addition, a butt end portion 21b of the input shaft 21 is inserted into the inner end 26a of the carrier 26 via a bearing 27 so as to be relatively rotatable.

In this manner, the input / output shafts 21 and 22 constitute a shaft unit capable of relative rotation, and this shaft unit simultaneously includes the carrier 26 and the stepped planetary pinion 25 as the same unit. When the shaft units of the input / output shafts 21 and 22 thus unitized are rotatably supported with respect to the motor case 30, the bearings 28a and 28b are used at two positions spaced apart in the axial direction.
Here, of the bearings 28 a and 28 b, the motor-side bearing 28 a is interposed between the inner periphery of the center hole of the motor case 30 and the outer periphery of the corresponding end of the input shaft 21 at substantially the same axial position as the motor case 30. . The wheel-side bearing 28 b is interposed between the inner periphery of the bearing support 29 attached to the motor case 30 and the outer periphery of the wheel hub 43 fitted to the output shaft 22 protruding from the motor case 30.

In order to couple the wheel 41 to the output shaft 22, first, the brake drum 44 is concentrically overlapped with the wheel hub 43, and passes through the wheel hub 43 and the brake drum 44 so as to protrude in the axial direction. A plurality of wheel bolts 45 are planted.
Then, the wheel disk 46 is brought into close contact with the side surface of the brake drum 44 so that the wheel bolt 45 penetrates into a bolt hole (not shown) formed in the wheel disk 46 of the wheel 41, and in this state, the wheel nut 47 is attached to the wheel bolt 45. Tighten and tighten. Thereby, the wheel 41 is attached to the output shaft 22.

  The motor case 30 is a metal housing that houses the motor 10 and the speed reducer 20 and is at least partially disposed inside the wheel 41. The motor case 30 includes a case main body 31, a rear cover 32, and an extension case 33.

  The case main body 31 has a cylindrical shape in which a shaft opening 31 a is formed at one end that enters the inner region of the wheel 41 and the other end protruding from the inner region of the wheel 41 is open. The stator 11 is fixed to the inner peripheral surface of the case body 31. Also, on the outer surface 31b of the case body 31 facing the rim 42, mounting mechanisms 50 and 50 for mounting the motor case 30 to the vehicle body side member S are integrally formed by casting. Here, the vehicle body side member S is, for example, a shock absorber of a suspension mechanism held by a side member or the like, a trailing arm held by a cross member or the like.

  The rear cover 32 is provided so as to close the open end portion of the case body 31 protruding from the inner region of the wheel 41. The rear cover 32 is provided with a connector of a three-phase AC harness connected to the motor 10 and the motor-side bearing 28a described above.

  The extension case 33 has a cylindrical shape with both ends surrounding the periphery of the shaft opening 31a open, and is provided around the shaft opening 31a. As a result, the extension case 33 is disposed in the inner region of the wheel 41.

  [Configuration of in-wheel motor mounting mechanism]

  FIG. 2 is a perspective view illustrating a main part of the in-wheel motor according to the first embodiment. FIG. 3 is a plan view from the direction of arrow A in FIG.

  The attachment mechanism 50 is integrally formed with the case body 31 of the motor case 30, and includes an attachment portion 51 located in the outer region of the wheel 41, and a joint portion 52 that couples the attachment portion 51 and the motor case 30. Have. Here, the outer region of the wheel 41 is a region located on the vehicle inner side than the region surrounded by the rim 42 of the wheel 41 and the wheel disk 46.

  The mounting portion 51 has a shape that can be connected to the vehicle body side member S. Here, the mounting portion 51 is located on the vehicle front side or the vehicle rear side of the motor case 30, and the axial direction substantially coincides with the vehicle vertical direction, and both ends thereof are It has an open cylindrical shape.

The coupling portion 52 has a plurality of ribs 53 </ b> A, 53 </ b> B, and 53 </ b> C that extend from the outer surface 31 b of the case body 31 of the motor case 30 located in the inner region of the wheel 41 to the outer region of the wheel 41.
The rib 53A is a side rib that connects the motor case 30 and one end 51a of the mounting portion 51 facing the vehicle.
The rib 53B is a side rib that connects the motor case 30 and the other end 51b of the mounting portion 51 facing the vehicle below.
The rib 53C is a central rib that is disposed between the ribs 53A and 53B and connects the motor case 30 and the intermediate portion of the mounting portion 51 in the vehicle vertical direction.
The ribs 53A and the ribs 53B are separated from each other toward the motor case 30 from the attachment portion 51, and are inclined in opposite directions with the attachment portion 51 as a center. Therefore, as shown in FIG. 3, when viewed from the wheel 41 side, the region surrounded by the ribs 53A, the ribs 53B, and the case body 31 is substantially triangular.

Next, the operation will be described.
First, “the mounting structure of the in-wheel motor of the comparative example and its problems” will be described, and then “the wheel non-interference action” in the in-wheel motor of the first embodiment will be described.

[In-wheel motor mounting structure of comparative example and its problems]
FIG. 4 is a perspective view showing the in-wheel motor of the first comparative example. FIG. 5 is a view showing an in-wheel motor of a second comparative example, (a) is a perspective view, and (b) is a cross-sectional view showing a positional relationship with a wheel.

  In the in-wheel motor 100 of the first comparative example shown in FIG. 4, a pedestal portion 103 is formed on the outer surface 101 a of the motor case 101, and a coupling portion 102 formed separately from the motor case 101 is formed on the pedestal portion 103. It is fixed with a plurality of bolts 104.

  In the in-wheel motor 100 of the first comparative example, the stress acting on the coupling portion 102 is concentrated on the fixed portion by the plurality of bolts 104. Here, since the motor case 101 and the coupling portion 102 are separate, the strength against stress is relatively low, and in order to increase the strength, measures such as increasing the diameter of the bolt 104 are required. For this reason, it is difficult to reduce the wheel size because the coupling portion 102 becomes large.

  Moreover, in the in-wheel motor 100 of this 1st comparative example, the motor case 101 and the coupling | bond part 102 are made into a different body, The problem that an assembly man-hour will also increase while a component increases.

  On the other hand, the in-wheel motor 200 of the second comparative example shown in FIG. 5 has a coupling portion 202 that protrudes from the outer surface 201a of the motor case 201 and has an attachment portion 202a that is attached to the vehicle body side member at the tip. . That is, in the in-wheel motor 200 of the second comparative example, the coupling portion 202 is integrated with the motor case 201. Therefore, the in-wheel motor 200 of the second comparative example can improve the strength against the stress acting on the coupling portion 202 and can reduce the number of parts compared to the in-wheel motor 100 of the first comparative example, so that it is inexpensive. Structure.

  However, since stress concentrates on the base portion 202b of the joint portion 202, the joint portion 202 cannot be downsized in order to maintain strength. Therefore, as shown in part B of FIG. 5B, the coupling part 202 and the wheel H are likely to interfere with each other, and there is a problem that the layout cannot be established unless a large wheel size is secured.

[Wheel non-interference action]
As shown in FIG. 1, the in-wheel motor M of the first embodiment is supported by the vehicle body side member S in the outer region of the wheel 41 via the mounting mechanism 50 in a state where the wheel 41 that supports the tire 40 is mounted. Is done.

  At this time, the weight of the tire 40, the wheel 41, and the in-wheel motor M itself is supported by the attachment mechanism 50. That is, a stress that is pulled in the direction of gravity acts on the coupling portion 52 of the attachment mechanism 50.

  Here, in the in-wheel motor M of the first embodiment, the coupling portion 52 protrudes integrally from the outer surface 31b of the motor case 30 and extends to the outer region of the wheel 41, and the case main body 31 and the mounting portion of the motor case 30 are attached. A plurality of ribs 53A, 53B, and 53C are provided to join 51.

  Therefore, the stress acting on the coupling portion 52 acts in a distributed manner on the plurality of ribs 53A, 53B, 53C. Thereby, stress can be supported without enlarging each rib 53A, 53B, 53C. As a result, since the coupling portion 52 can be reduced in size, the coupling portion 52 is less likely to interfere with the rim 42 of the wheel 41, and the in-wheel motor M can be obtained without increasing the wheel size.

  Further, by reducing the size of the coupling portion 52, it is possible to contribute to weight reduction, and by using the plurality of ribs 53A, 53B, 53C, the surface area of the coupling portion 52 increases, so that heat dissipation from the motor case 30 is achieved. It can also improve the performance. Furthermore, the case main body 31 and the attachment mechanism 50 are integrally formed by casting, and a member such as a bolt for connecting the motor case 30 and the coupling portion 52 becomes unnecessary. Therefore, it is possible to reduce the number of parts and to manufacture at a low cost. Moreover, by using the coupling portion 52 as the plurality of ribs 53A, 53B, and 53C, there are a plurality of paths through which the molten metal flows between the case body 31 and the attachment portion 51. Therefore, the hot water flow property between the case main body 31 and the mounting portion 51 is improved, and it becomes difficult for filling failure and hot water boundary to occur. Furthermore, waste meat is reduced and the occurrence of shrinkage can be suppressed.

  Further, in the in-wheel motor M of the first embodiment, the coupling portion 52 includes ribs 53A and 53B serving as a pair of side ribs that couple the case main body 31 of the motor case 30 and both end portions 51a and 51b of the mounting portion 51. Have.

  Thereby, the attaching part 51 will be supported by the both ends 51a and 51b, and the intensity | strength of this attaching part 51 can be improved.

  Further, as shown in FIG. 3, the ribs 53 </ b> A and 53 </ b> B that form a pair of side ribs are separated from each other as they go from the attachment portion 51 to the motor case 30, and are inclined in opposite directions around the attachment portion 51. To do. As a result, when viewed from the wheel 41 side, the region surrounded by the ribs 53A, the ribs 53B, and the case body 31 is substantially triangular. Therefore, the strength of the attachment portion 51 can be further improved.

  A rib 53C is formed between the ribs 53A and 53B as a central rib that connects the case main body 31 of the motor case 30 and the intermediate portion of the mounting portion 51. Thereby, the intensity | strength of the attaching part 51 can further be improved.

Next, the effect will be described.
In the in-wheel motor of the first embodiment, the following effects can be obtained.

(1) a motor case 30 that houses the stator 11 and the rotor 12 and that is at least partially disposed in the inner region of the wheel 41;
In order to attach the motor case 30 to the vehicle body side member S, an attachment portion 51 located in an outer region of the wheel 41;
A plurality of ribs 53A, 53B, and 53C for coupling the motor case 30 and the mounting portion 51 are provided, and the plurality of ribs 53A, 53B, and 53C are integrally formed with the outer surface 31b of the motor case 30. A coupling portion 52 extending to the outer region of the wheel 41;
It was set as the structure provided with.
For this reason, it is possible to reduce the size of the coupling portion 52 so that the coupling portion 52 and the wheel 41 are less likely to interfere with each other, and the in-wheel motor M can be obtained without increasing the wheel size.

(2) The coupling portion 52 includes a pair of side ribs 53A and 53B that couple the motor case 30 and both end portions 51a and 51b of the mounting portion 51.
For this reason, the strength of the coupling portion 52 can be improved, and further the size of the coupling portion 52 can be reduced.

(3) The pair of side ribs 53 </ b> A and 53 </ b> B are configured such that they are separated from each other toward the motor case 30 from the attachment portion 51, and are inclined in opposite directions around the attachment portion 51.
For this reason, the strength of the coupling portion 52 can be further improved.

(4) The coupling portion 52 includes a central rib 53C that is disposed between the pair of side ribs 53A and 53B and couples the motor case 30 and the intermediate portion of the mounting portion 51.
For this reason, the strength of the coupling portion 52 can be further improved.

Example 2 is an example in which a hot water reservoir is provided on a rib formed on a motor case.
FIG. 6A is a perspective view showing the main part of the in-wheel motor of the second embodiment, FIG. 6B is a plan view of the hot water reservoir, and FIG. 6C is a side view of the hot water reservoir.

  In the in-wheel motor of the second embodiment, the motor case 60 is formed by casting, and the heated metal (molten metal) is poured into the casting mold, cooled and solidified, and then removed from the casting mold. The attachment mechanism 70 is integrally formed with the main body 61.

  The case body 61 has a disk-like outer end surface (outer surface) 61c that is one end portion that enters an inner region of a wheel (not shown here), and a peripheral portion of the outer end surface 61c toward the inside of the vehicle. It has a cylindrical shape that is open to the inside of the vehicle and has a peripheral surface (outer surface) 61d that rises and faces a rim (not shown here). A shaft opening 61a is formed at the center of the outer end surface 61c. Further, the open end that protrudes to the outer region of the wheel and opens to the inside of the vehicle is closed by a rear cover (not shown).

  The mounting mechanism 70 is provided on the peripheral surface 61 d of the case main body 61, and includes a mounting portion 71 located in the outer region of the wheel, and a coupling portion 72 that couples the mounting portion 71 and the motor case 60.

  The attachment portion 71 is a portion connected to a vehicle body side member (not shown here) such as a shock absorber. As in the first embodiment, the mounting portion 71 is located on the vehicle front side or the vehicle rear side of the motor case 60 and has a cylindrical shape in which the axial direction substantially coincides with the vehicle vertical direction and both ends are open. ing.

  As shown in FIG. 6, the coupling portion 72 has a first rib 72A, a second rib 72B, and a third rib 72C, which are a plurality of ribs. One end of each of the ribs 72A, 72B, 72C is integrated with the case body 61, and the other end is extended to the outer region of the wheel (not shown) and coupled to the mounting portion 71.

  The first rib 72A is a side rib that couples the motor case 60 and one end 71a of the mounting portion 71 facing the vehicle. One end of the first rib 72 </ b> A on the case body 61 side rises from the peripheral surface 61 d of the case body 61.

  The second rib 72B is a side rib that couples the motor case 60 and the other end 71b of the mounting portion 71 facing the vehicle. One end of the second rib 72B on the case body 61 side rises from the peripheral surface 61d of the case body 61.

The third rib 72 </ b> C is a central rib that is disposed between the first rib 72 </ b> A and the second rib 72 </ b> B and connects the intermediate portion of the motor case 60 and the attachment portion 71. The third rib 72C has a rising rib portion 73, an extension rib portion 74, and an annular rib portion 75.
The rising rib portion 73 is erected from the peripheral surface 61 d of the case main body 61, and the tip is integrated with the central portion of the mounting portion 71. The extension rib portion 74 is a portion that continues to the case main body side end portion of the rising rib portion 73 and extends toward the center of the case main body 61 along the outer end surface 61c. The annular rib portion 75 is a portion that continues from the extended rib portion 74 and surrounds the shaft opening 61a.
Further, the third rib 72 </ b> C is formed with a hot water reservoir (hot water reservoir shape) 76 in the middle of the extended rib portion 74 along the outer end surface 61 c of the case body 61. The hot water pool portion 76 is a portion in which both side surfaces 74 a and 74 a of the intermediate portion of the extension rib portion 74 are widened by projecting along the outer end surface 61 c of the case body 61.
The rising dimension H1 from the outer end surface 61c of the hot water pool portion 76 is smaller than the rising dimension H2 from the outer end surface 61c of the extension rib portion 74 (see FIG. 6C). Further, the side surface 76a of the hot water reservoir 76 rising from the outer end surface 61c is a curved surface (see FIG. 6B).

  Here, a casting mold (not shown) for casting the case main body 61 and the attachment mechanism 70 is located at a position facing the opening end surface 61b of the shaft opening 61a (position indicated by A in FIG. 6A). ) Is formed with a pouring gate 78 (see FIG. 8) into which the molten metal is poured. That is, the hot water reservoir portion 76 is provided from the pouring gate 78 of the casting mold to a midway position of the extension rib portion 74 along the outer end surface 61 c of the case body 61.

Next, the operation will be described.
First, “the mounting structure of the in-wheel motor of the comparative example and its problems” will be described, and then “the shrinkage nest generation preventing function” in the in-wheel motor of the second embodiment will be described.

[In-wheel motor mounting structure of comparative example and its problems]
FIG. 7A is a perspective view showing a main part of the in-wheel motor of the comparative example, and FIG. 7B is a schematic diagram showing a molten metal path through which the molten metal flows in the in-wheel motor of the comparative example. These are explanatory drawings which show generation | occurrence | production of a shrinkage nest in the in-wheel motor of a comparative example.

  In the in-wheel motor 300 of the comparative example shown to Fig.7 (a), the motor case 301, the attaching part 302, and the coupling | bond part 303 are integrally molded by casting. Here, the coupling portion 303 is erected on the peripheral surface 304a of the case main body 304, and an attachment portion 302 attached to the vehicle body side member is integrated at the tip.

  Here, the coupling portion 303 in the in-wheel motor 300 of this comparative example has a case main body side end 303a extending from the peripheral surface 304a and extending toward the center of the case main body 304 along the outer end surface 304b. Yes. At this time, the radial width W1 of the portion along the outer end face 304b is constant in the extending direction. That is, the coupling portion 303 extends while maintaining the width W of the mounting portion 302 in the vehicle vertical direction.

  Accordingly, as shown in FIG. 7 (b), a molten metal path (portion serving as a basic skeleton of the product cavity) 305A that extends from the molten metal inlet 305 into which heated metal (hereinafter referred to as molten metal) flows is provided. The width (thickness) is constant from 305 to the attachment portion 302. Therefore, when the molten metal is poured into the molten metal path 305A, if the air around the outside of the molten metal gate 305 is entrained, the entrained air causes a relatively large shrinkage HS near the attachment portion 302 that is the end of the mold. May occur (see FIG. 7C).

  That is, the air entrained in the molten metal path 305A when flowing the molten metal flows along the side surface of the molten metal path 305A due to the flow of the molten metal. Then, this air is pushed and accumulated up to the vicinity of the end of the mold (attachment portion 302) along the side surface of the molten metal path 305A. As a result, a relatively large shrinkage nest HS is generated in the vicinity of the attachment portion 302.

[Preventing shrinkage nest]
FIG. 8A is a schematic diagram illustrating a molten metal path through which the molten metal flows in the in-wheel motor of the second embodiment, and FIG. 8B is an explanatory diagram illustrating generation of shrinkage cavities in the in-wheel motor of the second embodiment. . FIG. 9 is a schematic diagram illustrating the flow of the molten metal and the flow of entrained air in the second embodiment.

  In the in-wheel motor of the second embodiment, the third rib 72 </ b> C has a hot water reservoir 76 formed at a midpoint of the extension rib 74. And in order to form this hot water pool part 76, as shown to Fig.8 (a), the molten metal path | route (product cavity of a product cavity) from which the molten metal is extended from the spout 78 which pours the heated metal (henceforth a molten metal) is poured. The portion (the basic skeleton) 77 is wide at the position where the hot water reservoir 76 is formed.

  As a result, when the molten metal is poured from the gate 78, even if the air around the outside of the gate 78 is entrained, the entrained air is accumulated in the hot water reservoir 76. For this reason, the air entrained in the molten metal is prevented from flowing to the rising rib portion 73 and the mounting portion 71 provided at the tip thereof. As a result, as shown in FIG. 8B, it is possible to prevent a large shrinkage nest from being generated in the vicinity of the attachment portion 71, and it is possible to manufacture a high-quality product.

  That is, as shown in FIG. 9, air (bubbles) K entrained in the molten metal path 77 when flowing the molten metal is lighter than the molten metal, and therefore flows along the side surface 77a of the molten metal path 77 in the upper position in the gravity direction. . The air K flows into the hot water reservoir 76 along the side surface 77 a of the molten metal path 77. Here, since the hot water reservoir 76 is wide, the molten metal generates turbulent flow inside the hot water reservoir 76. Therefore, the air K that has flowed into the hot water pool portion 76 stays inside the hot water pool portion 76 by being caught in the turbulent flow. As a result, air is removed from the molten metal flowing to the downstream side of the molten metal flow from the hot water reservoir portion 76, that is, from the rising rib portion 73 and the mounting portion 71, and the air K hardly flows downstream from the hot water reservoir portion 76. Therefore, it is possible to prevent a large shrinkage nest from being generated in the vicinity of the attachment portion 71 (the position indicated by the portion B in FIG. 8B).

  In particular, in the second embodiment, since the side surface 76 a of the hot water reservoir 76 is a curved surface, the air K can easily flow into the hot water reservoir 76, and the molten metal flowing from the molten metal flowing downstream of the hot water reservoir 76 can be prevented. The removal rate of the air K can be improved.

Next, the effect will be described.
In the in-wheel motor according to the second embodiment, the following effects can be obtained.

(5) The motor case 60, the mounting portion 71, and the coupling portion 72 are integrally formed by casting,
At least one of the plurality of ribs (first to third ribs) 72A, 72B, 72C (third rib 72C) of the coupling portion 72 is between the pouring gate 78 of the casting mold and the mounting portion 71. The hot water reservoir 76 is provided.
For this reason, it can prevent that a shrinkage nest generate | occur | produces in the attachment part 71 vicinity.

(6) At least one of the plurality of ribs (first to third ribs) 72A, 72B, 72C (third rib 72C) of the coupling portion 72 is an outer surface (circumferential surface) 61d of the motor case 60. A rising rib portion 73 that is erected from the top and is integrally formed with the mounting portion 71 at the tip; an extension rib portion that is continuous with the rising rib portion 73 and extends along the outer side surface (outer end surface) 61c of the motor case 60; Have
The hot water reservoir 76 is provided between the hot water gate 78 and the intermediate position of the extension rib portion 74.
For this reason, insufficient strength of the rib (third rib 72C) due to the formation of the hot water reservoir 76 can be suppressed.

  As mentioned above, although the in-wheel motor of this invention has been demonstrated based on Example 1 and Example 2, it is not restricted to these Examples about a concrete structure, Each claim of a claim Design changes and additions are allowed without departing from the gist of the invention.

  In the first embodiment, the attachment portion 51 is located on the vehicle front side or the vehicle rear side of the motor case 30, but is not limited thereto. Depending on the position of the vehicle body side member S, it may be positioned above or below the motor case 30. One or more attachment portions 51 may be provided around the motor case 30 and in the outer region of the wheel 41.

  In the first embodiment, the coupling portion 52 includes a plurality of ribs 53A, 53B, and 53C. However, for example, the coupling portion 52 may include only the ribs 53A and 53B that are side ribs. The number may be increased.

  In the first embodiment, as shown in FIG. 3, the ribs 53A, 53B, and 53C are independent. For example, intermediate portions of the ribs 53A, 53B, and 53C may be connected to each other. In this case, the strength of the coupling portion 52 can be further improved and the size can be reduced.

  Further, in the second embodiment, the hot water reservoir 76 is widened in the middle of the extended rib portion 74 of the third rib 72C, and the side surface 76a is curved, but for example, the rib is not simply made wide, You may make it the shape which enables fastening of brackets provided in the wheel vicinity. Thereby, the occurrence of shrinkage can be prevented by the hot water pool portion, and at the same time, the hot water pool portion can be used as a fastening portion of the brackets.

M In-wheel motor 10 Motor 11 Stator 12 Rotor 20 Reducer 30 Motor case 31 Case main body 31b Outer side surface 32 Rear cover 33 Extension case 40 Tire 41 Wheel 42 Rim 50 Mounting mechanism 51 Mounting portion 51a End portion 51b End portion 52 Connecting portion 53A Rib (Side rib)
53B rib (side rib)
53C rib (central rib)

Claims (6)

A motor case that houses the stator and the rotor and that is at least partially disposed in the inner region of the wheel;
In order to attach the motor case to the vehicle body side member, an attachment portion located in an outer region of the wheel;
A plurality of ribs for coupling the motor case and the mounting portion; and a plurality of the ribs integrally formed with respect to the outer surface of the motor case, and a coupling portion extending to the outer region of the wheel;
An in-wheel motor comprising: The in-wheel motor according to claim 1,
The in-wheel motor is characterized in that the coupling portion includes a pair of side ribs that couple the motor case and both ends of the mounting portion. The in-wheel motor according to claim 2,
The pair of side ribs are separated from each other toward the motor case from the mounting portion, and are inclined in opposite directions with the mounting portion as a center. In the in-wheel motor according to claim 2 or claim 3,
The in-wheel motor is characterized in that the coupling portion includes a central rib that is disposed between the pair of side ribs and couples the motor case and an intermediate portion of the mounting portion. In the in-wheel motor according to any one of claims 1 to 4,
The motor case, the mounting portion, and the coupling portion are integrally formed by casting,
An in-wheel motor, wherein at least one of the plurality of ribs of the coupling portion has a hot water pool portion between a pouring gate of a casting mold and the mounting portion. The in-wheel motor according to claim 5,
At least one of the plurality of ribs of the coupling portion is formed from an outer side surface of the motor case, the rising rib portion in which the attachment portion is integrally formed at a tip, and the continuous rib portion and the rising rib portion. An extension rib along the outer surface of the motor case,
The in-wheel motor according to claim 1, wherein the hot water pool portion is provided between the pouring gate and an intermediate position of the extension rib.