Reducer housing

Abstract

The present invention provides a reducer housing that inhibits water from staying on the housing. The fourth housing of the main housing has a boss-shaped connecting portion for connecting to an actuator on the outer peripheral surface, i.e., the surface, of the peripheral wall portion. In the fourth housing, a pattern having a hydrophobic effect is added in the area around the connecting portion.

Description

Technical Field

[0001] The present invention relates to a speed reducer housing. Background Art

[0002] Some electrical components such as the controller of the speed reducer are arranged above the housing that houses the speed change mechanism. The electrical components are electrically connected to the speed change mechanism via a connection portion provided on the upper surface of the housing (for example, Patent Document 1).

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2013-147046 Summary of the Invention

[0006] Technical Problem to be Solved by the Invention

[0007] Rainwater or the like may accumulate on the upper surface of the housing. Since rainwater contains impurities such as salts, when the accumulated rainwater dries, salts and other impurities will precipitate.

[0008] For example, when salt precipitation occurs around the connection portion of the housing, the salt will corrode the connection portion. As a result, there is a risk of causing problems with the electrical components.

[0009] Therefore, it is desirable to suppress the water adhering to the housing from staying on the housing.

[0010] Technical Solution for Solving the Technical Problem

[0011] A certain aspect of the present invention is a housing,

[0012] which has a connection portion for connecting to an electrical component on the outer peripheral surface,

[0013] and a pattern having a hydrophobic effect is added around the connection portion.

[0014] Effects of the Invention

[0015] According to a certain aspect of the present invention, it is possible to suppress water from staying on the housing. Brief Description of the Drawings

[0016] Figure 1 It is a schematic structural diagram of a power transmission device.

[0017] Figure 2 It is a perspective view of the fourth housing.

[0018] Figure 3 It is a perspective view of the fourth housing.

[0019] Figure 4It is a top view of the periphery of the connecting portion of the fourth housing as viewed from above.

[0020] Figure 5 It is a sectional view of the main components of the fourth housing.

[0021] Figure 6 It is a sectional view of the main components of the fourth housing.

[0022] Figure 7 It is a sectional view of the main components of the fourth housing.

[0023] Figure 8 It is a sectional view of the main components of the fourth housing.

[0024] Figure 9 It is a diagram showing the state of water droplets on the area where a pattern with a hydrophobic effect is attached.

[0025] Figure 10 It is a diagram showing the state of water droplets on the area where a pattern with a hydrophobic effect is not attached. Detailed implementation mode

[0026] Hereinafter, taking the case of the reduction gear housing (fourth housing 14) of the power transmission device 1 mounted on a vehicle as an example, the implementation mode of the present invention will be described.

[0027] Figure 1 It is a schematic structural diagram of the power transmission device 1. In Figure 1 it schematically shows the main components of each structure of the power transmission device 1.

[0028] Figure 2 It is a perspective view of the fourth housing 14 as viewed obliquely from above. In Figure 2 the actuator ACT and the plate member 8 are separated from the fourth housing 14 for display.

[0029] As Figure 1 shown, the main housing 10 of the power transmission device 1 is composed of a first housing 11 that houses the motor 2, a second housing 12 that is externally inserted into the first housing 11, a third housing 13 that is mounted on the first housing 11, and a fourth housing 14 that is mounted on the second housing 12.

[0030] The motor 2 has a rotor core 21 and a stator core 22, and the output rotation of the motor 2 is output from the motor shaft 20 that rotates integrally with the rotor core 21.

[0031] In the power transmission device 1, along the transmission path of the output rotation of the motor 2, a parking mechanism 3, a planetary reduction gear 4 (reduction mechanism), a differential mechanism 5, and drive shafts 6A and 6B are provided.

[0032] The planetary reduction gear 4 reduces the output rotation of the motor 2 and inputs it to the differential mechanism 5.

[0033] The differential mechanism 5 transmits the rotation input from the planetary reduction gear 4 to the drive shafts 6A and 6B. Thereby, the output rotation of the motor 2 is finally transmitted to the left and right drive wheels 9, 9 of the vehicle equipped with the power transmission device 1, causing the vehicle to travel.

[0034] The parking mechanism 3 includes a parking gear 31 and a parking lever 32.

[0035] The parking gear 31 is externally inserted and fixed to the motor shaft 20. The parking gear 31 rotates integrally with the motor shaft 20.

[0036] The parking lever 32 is rotatably supported by a support shaft 71 provided on the plate body 7.

[0037] The parking lever 32 has an engaging portion 32a at a position radially outside the swing axis Xa. The engaging portion 32a is linked to the swing of the parking lever 32, causing the engaging portion 32a to engage with and disengage from the outer periphery of the parking gear 31.

[0038] When the engaging portion 32a engages with the outer periphery of the parking gear 31, the rotation of the motor shaft 20 is restricted, and the vehicle equipped with the power transmission device 1 is in a state where travel is restricted (a state where travel is restricted).

[0039] When the engaging portion 32a disengages from the outer periphery of the parking gear 31, the rotation of the motor shaft 20 is allowed, and the vehicle equipped with the power transmission device 1 is in a state where it can travel (a state where it can travel).

[0040] The power transmission device 1 includes an actuator ACT (electrical component) for driving the parking mechanism 3.

[0041] The actuator ACT rotates the manual shaft SH around the axis Y based on an instruction from a control device (not shown). When the manual shaft SH rotates around the axis Y, the parking lever 32 swings around the swing axis Xa in linkage with the rotation of the manual shaft SH. Thereby, the engaging portion 32a of the parking lever 32 engages with and disengages from the outer periphery of the parking gear 31, and the vehicle switches between a state where travel is restricted and a state where it can travel.

[0042] It should be noted that the mechanism that causes the parking lever 32 to swing in linkage with the rotation of the manual shaft SH is a currently well-known mechanism, so the description thereof is omitted here.

[0043] As an example, this type of mechanism has a manual plate (not shown) that rotates integrally with the manual shaft SH, a parking link (not shown) that moves forward and backward in linkage with the rotation of the manual plate, and a cam (not shown) that causes the parking lever to swing in linkage with the forward and backward movement of the parking link.

[0044] The actuator ACT is located outside the fourth housing 14.

[0045] The fourth housing 14 has a peripheral wall portion 141 surrounding the outer periphery of the planetary reduction gear 4 (reduction mechanism).

[0046] In the peripheral wall portion 141, a through hole 15 is provided in the upper region with respect to the installation state of the power transmission device 1 to the vehicle as a reference. The through hole 15 penetrates the peripheral wall portion 141 in the thickness direction. A boss-shaped connecting portion 16 surrounding the through hole 15 is provided on the outer periphery of the peripheral wall portion 141.

[0047] In the through hole 15, a manual shaft SH extending from the actuator ACT penetrates from the outside to the inside of the peripheral wall portion 141.

[0048] As Figure 2 shown, in the peripheral wall portion 141, bolt bosses 17, 18 are provided on one side (left side in the figure) and the other side (right side in the figure) sandwiching the connecting portion 16.

[0049] The bolt bosses 17, 18 extend upward from the peripheral wall portion 141, and a plate member 8 supporting the actuator ACT is placed on the upper ends of the bolt bosses 17, 18.

[0050] The actuator ACT is fixed to the outer periphery of the fourth housing 14 by screwing bolts B, B penetrating the plate member 8 into the bolt bosses 17, 18.

[0051] As Figure 1 shown, when the actuator ACT is fixed to the outer periphery of the fourth housing 14, the main body portion of the actuator ACT is joined to the upper end of the connecting portion 16. In this state, the gap between the joint surfaces of the main body portion and the connecting portion 16 is sealed by a sealing ring.

[0052] At one end of the peripheral wall portion 141 on the side of the second housing 12 (left side in the figure), a flange-shaped joint portion 142 is provided, and a wall portion 143 is provided at the other end.

[0053] The joint portion 142 surrounds the opening on the side of the second housing 12 of the peripheral wall portion 141 throughout the circumference and extends radially outward from the outer periphery of the peripheral wall portion 141.

[0054] The joint portion 142 of the fourth housing 14 and the joint portion 122 of the second housing 12 are connected by bolts (not shown).

[0055] The wall portion 143 extends toward the inner diameter side from the other end of the peripheral wall portion 141. An insertion through hole 143a for the drive shaft 6B opens toward the inner diameter side of the wall portion 143. A cylindrical support wall portion 144 surrounding the insertion through hole 143a is provided on the outer periphery of the wall portion 143. The drive shaft 6B is rotatably supported by the support wall portion 144 via a bearing Ba.

[0056] Inside the peripheral wall portion 141, a support wall portion 144 is provided on the inner diameter side of the through hole 15.

[0057] The support wall portion 144 is provided with a space Sa interposed between it and the inner circumference of the peripheral wall portion 141. In the support wall portion 144, a support hole 144a opens on the upper surface facing the peripheral wall portion 141.

[0058] The front end of a manual shaft SH that penetrates the through hole 15 is inserted into the support hole 144a and is rotatably supported.

[0059] The base end side of the manual shaft SH projects from the connection portion 16 on the outer circumference of the fourth housing 14 to the outside of the fourth housing 14. An actuator ACT is connected in the region where the manual shaft SH projects.

[0060] Figure 3 is a perspective view of the fourth housing 14 as viewed obliquely from above. In Figure 3 the movement locus of the water droplet W attached to the surface of the peripheral wall portion 141 is indicated by an arrow.

[0061] Figure 4 is a top view of the fourth housing 14 as viewed from above, and is a view enlarging the periphery of the connection portion 16. In Figure 4 the region R1 to which a pattern having a hydrophobic effect is added is indicated by cross-hatched lines.

[0062] Figure 5 is a cross-sectional view of the fourth housing 14 cut along the A-A line of Figure 4

[0063] Figure 6 is a cross-sectional view of the fourth housing 14 cut along the B-B line of Figure 4

[0064] Figure 7 is a cross-sectional view of the fourth housing 14 cut along the C-C line of Figure 4

[0065] Figure 8 is a cross-sectional view of the fourth housing 14 cut along the D-D line of Figure 4

[0066] As Figure 3 shown, in the fourth housing 14, the connection portion 16 projects from the outer peripheral surface of the peripheral wall portion 141, that is, the surface 141a.

[0067] Specifically, in the peripheral wall portion 141, the connection portion 16 projects upward from the surface 141a of the region located on the upper side with reference to the installation state of the power transmission device 1 in the vehicle.

[0068] As Figure 4 ​​​​As shown in the top view of the fourth housing 14 observed from above, in the peripheral wall portion 141, when observed from the connecting portion 16, a rib body 146 is provided on the side of the joint portion 142 (the left side in the figure).

[0069] As Figure 5 shown, the rib body 146 is a portion surrounding the screw hole 145 that opens at the end face 142a of the joint portion 142. The rib body 146 bulges upward from the surface 141a of the fourth housing 14.

[0070] As Figure 4 and Figure 5 shown, the rib body 146 extends from the end face 142a of the joint portion 142 to the vicinity of the connecting portion 16 along a straight line Xc. Here, the straight line Xc is a straight line parallel to the rotation axis X and is a straight line along the joining direction of the fourth housing 14 and the second housing 12.

[0071] A recess 147 is formed between the rib body 146 in the direction of the straight line Xc and the connecting portion 16.

[0072] As Figure 6 shown, in the cross-section, the recess 147 has an arcuate cross-section with the vertex P facing the inner diameter side. The region connecting the recess 147 and the surface 141a of the peripheral wall portion 141 has an arcuate cross-section with the vertex facing the outer diameter side.

[0073] Therefore, in the cross-section, the surface 141a of the peripheral wall portion 141 is continuously connected to the recess 147 without a step.

[0074] As Figure 4 and Figure 5 shown, in the peripheral wall portion 141, when observed from the connecting portion 16, a recess 148 is formed on the side opposite to the rib body 146 (the right side in the figure). The recess 148 extends along the straight line Xc to the wall portion 143 of the fourth housing 14.

[0075] As Figure 8 shown, in the cross-section, the recess 148 has an arcuate cross-section with the vertex P facing the inner diameter side. The region connecting the recess 147 and the surface 141a of the peripheral wall portion 141 has an arcuate cross-section with the vertex facing the outer diameter side.

[0076] Therefore, in the cross-section, the surface 141a of the peripheral wall portion 141 is continuously connected to the recess 148 without a step.

[0077] As Figure 7 shown, arc-shaped recesses 149, 149 are formed on both sides of the connecting portion 16 along the outer periphery of the connecting portion 16. In the cross-section, the recess 149 has an arcuate cross-section with the vertex P facing the inner diameter side. As Figure 4As shown, when viewed from the connecting portion 16, the recess 147 on one side and the recess 148 on the other side are connected to each other via an arcuate recess 149.

[0078] As Figure 5 shown, the surface of the recess 148 is slightly inclined with respect to the horizontal line HL. In a cross-section, the recess 148 is inclined in a direction such that the wall portion 143 side (right side in the figure) is slightly lower than the connecting portion 16 side (left side in the figure).

[0079] The recess 147 is located closer to the outer diameter side than the virtual line Lm passing through the deepest position of the recess 148, and the depth of the recess 147 from the surface 141a is shallower than that of the recess 147.

[0080] In the power transmission device 1, the surface of the main body housing 10 has undulations caused by rib bodies, bosses, etc. When water such as rain acts on the main body housing 10, moisture may remain locally on the surface of the main body housing 10 due to the undulations.

[0081] When the moisture remaining on the surface of the main body housing 10 evaporates, salts and the like contained in the moisture accumulate. The accumulated salts may cause corrosion.

[0082] For example, since it is required to have the support stability of the electrical fitting for the connecting portion to the electrical fitting, i.e., the mounting boss, it is not preferable to have moisture remaining around the mounting boss and salts accumulate (salt out).

[0083] Therefore, in the main body housing 10 of the present embodiment, a pattern having a hydrophobic effect is attached to the surface of the main body housing 10, at least to the surface of the area where moisture is not desired to remain.

[0084] As an example, in the fourth housing 14, the connecting portion 16 is provided as a mounting boss for the actuator ACT.

[0085] In the fourth housing 14, a pattern having a hydrophobic effect is attached to the surface of the area around the connecting portion 16.

[0086] Specifically, as Figure 4 shown, a pattern having a hydrophobic effect is attached to the hatched area R1 around the connecting portion 16. In this area R1, the connecting portion 16 is located at approximately the central portion. Further, the area R1 is set within the range where the straight line Xc crosses from one side to the other side, and the recesses 147 and 148 are located at approximately the central portion in the orthogonal direction of the straight line Xc.

[0087] Figure 9 Is Figure 3 a cross-sectional view of the area A, and is a view for explaining the state of the water droplet W in the area where the pattern MK having a hydrophobic effect is attached.

[0088] In Figure 9 it, a cross-section of a region where a pattern MK having a hydrophobic effect is attached is schematically enlarged and shown.

[0089] Figure 10 It is a diagram for explaining the state of the water droplet W in a region where the pattern MK having a hydrophobic effect is not attached.

[0090] As Figure 9 shown, in the present embodiment, a so-called matte pattern (a matte-like pattern) is adopted as the pattern MK having a hydrophobic effect.

[0091] As an example, the matte-like pattern is formed by providing a plurality of recesses 141b in a region R1 (refer to Figure 4 ) of the surface 141a of the peripheral wall portion 141. On the surface 141a within the region R1, the recesses and the protrusions are alternately continuous and have an uneven shape in cross-section.

[0092] The recesses 141b may be formed during the casting of the fourth housing 14, but may also be formed by performing a surface treatment on the cast fourth housing 14.

[0093] Here, the width ΔL of the recess 141b is set to a width such that the water droplet W attached to the surface does not enter the inside of the recess 141b, for example, 5 to 15 μm. The interval ΔT between adjacent recesses 141b is set to, for example, 20 to 30 μm.

[0094] When set in this way, it is possible to appropriately prevent the attached water droplet W from entering the recess 141b, and an air Air layer caused by the recess 141b is formed at the interface Wb between the water droplet W and the surface 141a.

[0095] At the interface Wb of the water droplet W, the regions in contact with the surface 141a and the air Air inside the recess 141b are in an alternately repeating state (Cassie - Baxter state).

[0096] In the Cassie - Baxter state, the angle φ (the angle formed by the straight line Lp and the straight line Lq. Also marked as the contact angle φ) formed by the interface Wb of the water droplet W and the surface Wa is 90 degrees or more (refer to Figure 9 ).

[0097] When the contact angle φ is 90 degrees or more, it has a lotus effect, and the wettability of the water droplet W on the surface 141a is reduced, that is, the hydrophobicity of the surface 141a within the region R1 is increased.

[0098] It should be noted that the pattern MK having a hydrophobic effect may be any pattern that can make the water droplet W in the Cassie - Baxter state, and is not limited to the matte-like pattern.

[0099] The pattern of the recesses may be randomly arranged at intervals that can achieve the Cassie-Baxter state. Alternatively, a hairline pattern may be used instead of a frosted pattern.

[0100] The function of the fourth housing 14 having the region R1 on the surface of which the pattern MK having a water-repellent effect is applied will be described.

[0101] When moisture adheres to the surface of the main body case 10 of the power transmission device 1 , the surface 141 a of the fourth case 14 has high hydrophobicity in the region R1 to which the pattern MK having a hydrophobic effect is applied, so that a plurality of water droplets W are formed on the surface.

[0102] When the vehicle is running, wind caused by the running is generated along the surface of the main body housing 10 , and vibrations and the like generated by the running act on the main body housing 10 .

[0103] Since the wettability of the water droplets W generated in the region R1 to the surface 141 a is low, the water droplets W are moved along the surface 141 a of the fourth housing 14 by the wind and do not stay at a specific position on the surface 141 a .

[0104] For example, in Figure 3 In this case, water droplets generated on the surface 141a with increased hydrophobicity move toward the recessed portion 148, and are discharged to the outside from the fourth housing 14 through the recessed portion 148 (see arrows in the figure).

[0105] In addition, the water droplets W also move due to the vibration acting on the main body casing 10 .

[0106] For example, water droplets generated on the highly hydrophobic surface 141a and around the recess 148 slide into the recess 148 due to vibration, move along the slight inclination of the recess 148, and are finally discharged to the outside from the fourth housing 14. Therefore, the retention of water droplets W can be appropriately suppressed.

[0107] In this way, the water droplets W are retained at specific positions on the fourth housing 14, and after the retained water droplets W evaporate, the precipitation of salt (salting out) at the positions where the water droplets W once retained can be appropriately suppressed. Therefore, the corrosion of the fourth housing 14 by the precipitated salt can be appropriately prevented.

[0108] As described above, the pattern having a water-repellent effect is provided around the connection portion 16 with the actuator ACT. Therefore, it is possible to suppress the occurrence of salt precipitation in the connection portion 16 due to the water remaining around the connection portion 16. Thus, the stability of the support of the actuator ACT (electrical accessory) by the connection portion 16 can be ensured.

[0109] On the other hand, in the case where the region R1 where a pattern having a hydrophobic effect is not set on the surface 141a of the fourth housing 14, an air layer as shown in Figure 9 is not formed at the interface Wb where the surface 141a contacts the water droplet W. Figure 9 is not formed at the interface Wb where the surface 141a contacts the water droplet W.

[0110] In this case, as shown in Figure 10 , the contact angle φ between the water droplet W and the interface Wb of the surface 141a and the surface Wa of the water droplet is 0 degrees or more and less than 90 degrees. In this case, since the lotus effect is not present, the wettability of the water droplet W with respect to the surface 141a increases. That is, the hydrophobicity of the surface 141a decreases. Figure 10 In this case, since the lotus effect is not present, the wettability of the water droplet W with respect to the surface 141a increases. That is, the hydrophobicity of the surface 141a decreases.

[0111] When the lotus effect is not present, the contact angle of the water droplet W on the surface 141a is small, so it is difficult to move even under the influence of wind and vibration.

[0112] In this way, when the water droplet W stays locally and the retained water droplet W evaporates, salts contained in the water droplet are likely to precipitate in the area where the water droplet W has stayed.

[0113] As described above, in the region R1 where a pattern having a hydrophobic effect is added, the water droplet W attached to the surface is difficult to stay locally. Therefore, by setting the region R1 where a pattern having a hydrophobic effect is added to surround the region of the fourth housing 14 where salting out is desired to be avoided, salting out in the region where salting out is desired to be avoided can be appropriately suppressed.

[0114] In the present embodiment, the case where the region R1 where a pattern MK having a hydrophobic effect is added is set around the connecting portion 16 is illustrated. The region R1 where the pattern MK having a hydrophobic effect is added is not limited to the above-described manner.

[0115] It may also be added by covering the entire surface of the fourth housing 14. It may also be provided only in the region on the upper side of the surface of the fourth housing 14 with respect to the installation state of the power transmission device 1 to the vehicle.

[0116] In addition, in the region R1 of Figure 4 , it is provided only in the region where the density of the hatching is large, that is, on the side of the wall portion 143 (the right region in the figure) viewed from the connecting portion 16, so that only the water droplet W in a specific region is discharged from the fourth housing 14 to the outside. Figure 4 In addition, in the region R1 of Figure 4 , it is provided only in the region where the density of the hatching is large, that is, on the side of the wall portion 143 (the right region in the figure) viewed from the connecting portion 16, so that only the water droplet W in a specific region is discharged from the fourth housing 14 to the outside.

[0117] Since the addition of the pattern MK having a hydrophobic effect can also be performed in post-processing, a pattern MK having a hydrophobic effect can be added to a desired portion of the fourth housing 14 to suppress salting out.

[0118] In addition, a guiding portion (concave portions 147, 148, 149) for guiding the water droplets W to the outside of the fourth housing 14 may be provided, and a region R1 where a pattern MK having a hydrophobic effect is added is set in the guiding portion on the surface 141a and the region adjacent to the guiding portion.

[0119] In this case, the generated water droplets W can be actively discharged to the outside of the fourth housing 14.

[0120] In addition, in addition to the connecting portion 16, when it is desired to prevent salting out around other portions of the fourth housing 14 (for example, other bolt boss portions 19, refer to Figure 3 ), by further adding a pattern MK having a hydrophobic effect to surround the bolt boss portion 19, the bolt boss portion 19 can also be appropriately maintained.

[0121] As described above, the fourth housing 14 (reducer housing) of the present embodiment has the following structure.

[0122] (1) The fourth housing 14 has a boss-shaped connecting portion 16 for connecting to the actuator ACT (electrical fitting) on the outer peripheral surface of the peripheral wall portion 141, that is, the surface 141a.

[0123] In the fourth housing 14, a pattern MK having a hydrophobic effect is added around the connecting portion 16.

[0124] According to the above structure, the water around the connecting portion 16 of the fourth housing 14 (reducer housing) can be quickly discharged.

[0125] Since there is no water staying around the connecting portion 16 and the water around the connecting portion 16 can move quickly, the influence of salting out caused by the staying moisture can be suppressed. Therefore, the supporting stability of the actuator ACT (electrical fitting) of the connecting portion 16 can be ensured.

[0126] (2) The actuator ACT (electrical fitting) is an electrical fitting for driving the manual shaft SH of the parking mechanism 3.

[0127] The manual shaft SH penetrates through the through hole 15 of the connecting portion 16.

[0128] According to the above structure, the water around the connecting portion 16 penetrated by the manual shaft SH can be quickly discharged.

[0129] (3) The pattern MK having a hydrophobic effect is a frosted pattern.

[0130] According to the above structure, the surface 141a of the peripheral wall portion 141 can obtain a hydrophobic effect by the surface of the frosted pattern around the connecting portion 16.

[0131] (4) The frosted pattern is formed by concave and convex shapes in the cross-section of the surface.

[0132] According to the above structure, by providing concavities and convexities on the surface of the fourth housing 14 (reducer housing), a frosted pattern can be formed on the outer peripheral surface of the fourth housing 14, i.e., the surface 141a, so that the area of the surface 141a provided with the frosted pattern has a hydrophobic effect.

[0133] In the above embodiment, an example is shown in which a pattern (frosted pattern) having a hydrophobic effect is added to the surface of the reducer housing (fourth housing 14) that houses the reduction mechanism among the four housings (first housing 11, second housing 12, third housing 13, fourth housing 14) of the main body housing 10 of the power transmission device 1.

[0134] In the case where there are also areas that need to be protected to avoid salting out on the surfaces of the second housing 12 and the third housing 13 having surfaces exposed to the outside, a pattern having a hydrophobic effect can also be added to the areas to be protected on the surfaces of the above-mentioned second housing 12 and third housing 13.

[0135] The present invention is not limited to the above embodiment. It includes various changes and improvements that can be made within the scope of its technical idea.

[0136] Description of Reference Numerals

[0137] 1 Power transmission device; 10 Main body housing; 14 Fourth housing; 141 Peripheral wall portion; 141a Surface; 141b Concave portion; 143 Wall portion; 146 Rib body; 147, 148, 149 Concave portions; 15 Through hole; 16 Connecting portion; 17, 18 Bolt boss portions; 2 Motor; 3 Parking mechanism; 4 Planetary reduction gear; 5 Differential mechanism; 31 Parking gear; 32 Parking lever; 32a Engaging portion; 71 Support shaft; ACT Actuator; MK Pattern having a hydrophobic effect; R1 Region; SH Manual shaft; W Water droplet

Claims

1. A speed reducer housing, having: A peripheral wall portion that surrounds the speed reduction mechanism; A wall portion that is provided at an end of the peripheral wall portion and extends toward the inner diameter side from the end of the peripheral wall portion; A connecting portion that is used for connecting with an electrical fitting in an upper region of the outer peripheral surface of the peripheral wall portion, A part of the upper region of the outer peripheral surface around the connecting portion has a peripheral wall portion with a pattern having a hydrophobic effect added thereto, characterized in that, In the region of the outer peripheral surface of the speed reducer housing where the pattern having the hydrophobic effect is added, a recess extending in a direction away from the connecting portion is provided, The recess is inclined in a direction of increasing depth as it moves away from the connecting portion and extends to the wall portion.

2. The speed reducer housing according to claim 1, characterized in that, The electrical fitting is an electrical fitting for driving a manual shaft of a parking mechanism, The manual shaft penetrates through a through hole of the connecting portion.

3. The speed reducer housing according to claim 1 or 2, characterized in that, The pattern is a matte finish.

4. The speed reducer housing according to claim 3, characterized in that, The matte finish pattern is formed by an uneven shape in a cross-section of the surface.

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