Motor with reduction mechanism

Abstract

To provide a motor with a reduction mechanism capable of improving water exposure reliability while simplifying the structure and suppressing the occurrence of manufacturing defects.SOLUTION: Since rib members 93 projecting radially outward of a tubular member 92 and extending in the axial direction of the tubular member 92 are integrally provided, at the time of molding a gear cover 80, the defective rate can be reduced by spreading a melted plastic material over narrow portions of the mold forming the tubular member 92 and the rib member 93 respectively. In addition, when the gear cover 80 is wet, rainwater or the like flows along the tubular member 92 and the rib member 93, respectively, thereby simultaneously reaching the opening 92a of the tubular member 92 with rainwater or the like is suppressed, and as a result, formation of a water film on the opening 92a can be prevented. Therefore, it is possible to improve the water exposure reliability.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a motor with a speed reduction mechanism, which includes a motor section having a rotating shaft and a speed reduction mechanism section having a speed reduction mechanism that reduces the rotation speed of the rotating shaft. [Background technology]

[0002] Motors with speed reduction mechanisms are used, for example, as drive sources for wiper devices, power window devices, and the like. In particular, motors with speed reduction mechanisms used as drive sources for wiper devices are installed in engine compartments with high-temperature atmospheres and operate continuously for relatively long periods of time. Therefore, the motors with speed reduction mechanisms become hot, and if they are exposed to water in this state, they will cool down rapidly. This creates negative pressure within the housing, which may allow rainwater or the like to enter the housing. Therefore, Patent Document 1, for example, describes a motor with speed reduction mechanisms that is provided with a so-called "breathing function" to prevent negative pressure from building up within the housing.

[0003] The motor with a reduction mechanism described in Patent Document 1 includes a gear case (housing) and a gear cover (housing), and a reduction mechanism that reduces the rotation of an armature shaft (rotating shaft) is housed inside the gear case and the gear cover. The gear case is provided with a cylindrical member that connects the inside and outside of the gear case. The gear case is also provided with a water-prevention wall that partially covers the periphery of the cylindrical member. The water-prevention wall prevents rainwater and the like from reaching the cylindrical member. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-065790 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the motor with a reduction gear mechanism described in Patent Document 1, a water-blocking wall is provided around the periphery of the cylindrical member at a predetermined interval (gap). As a result, when molding (casting) the gear case, the molten material does not reach the narrow portions of the mold that form the cylindrical member and the water-blocking wall, which can result in a manufacturing defect known as a "short shot."

[0006] An object of the present invention is to provide a motor with a reduction mechanism that can improve water-resistant reliability while simplifying the structure and reducing the occurrence of manufacturing defects. [Means for solving the problem]

[0007] In one aspect of the present invention, a motor with a reduction mechanism includes a motor section having a rotating shaft and a reduction mechanism section having a reduction mechanism that reduces the rotation speed of the rotating shaft, the motor including: a housing that accommodates the reduction mechanism; a communication hole provided in the housing that connects the inside and outside of the housing; a cylindrical member provided on the outside of the housing, extending in the axial direction of the communication hole and having its radially inner side communicated with the communication hole; and a rib member that is integrally provided on the radially outer side of the cylindrical member, protruding radially outward from the cylindrical member and extending in the axial direction of the cylindrical member. A first recessed portion recessed toward the base end side of the rib member in the axial direction of the cylindrical member is provided between the cylindrical member and the rib member on the tip end side of the rib member in the axial direction of the cylindrical member. It is characterized by the following. In another aspect of the present invention, there is provided a motor with a reduction mechanism comprising a motor section having a rotating shaft and a reduction mechanism section having a reduction mechanism for slowing down the rotation of the rotating shaft, the motor comprising: a housing for accommodating the reduction mechanism; a communication hole provided in the housing for connecting the inside and outside of the housing; a cylindrical member provided on the outside of the housing, extending in the axial direction of the communication hole and having its radially inner side communicating with the communication hole; and a rib member integrally provided on the radially outer side of the cylindrical member, protruding radially outward from the cylindrical member and extending in the axial direction of the cylindrical member, wherein the length dimension of the rib member in the axial direction of the cylindrical member is greater than the length dimension of the cylindrical member. [Effects of the Invention]

[0008] According to the present invention, a rib member that protrudes radially outward from the tubular member and extends in the axial direction of the tubular member is integrally provided on the radially outer side of the tubular member, so that when molding the housing, it is possible to spread molten material throughout the narrow parts of the mold (casting mold or metal die) that forms the tubular member and the rib member (reducing the defect rate).

[0009] Furthermore, when the housing is exposed to water, rainwater and other liquids flow along the cylindrical member and the rib member, preventing the rainwater and other liquids from reaching the opening of the cylindrical member all at once (simultaneously), and thus preventing a water film from forming at the opening. This effectively prevents rainwater and other liquids from being sucked into the housing (improving water resistance). [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram of a vehicle equipped with a wiper motor. [Figure 2] FIG. 2 is a perspective view showing the wiper motor of FIG. 1. [Figure 3] 3 is a diagram showing the internal structure of the wiper motor shown in FIG. 2. [Figure 4] 3 is an enlarged perspective view of the periphery of a cylindrical member of the wiper motor of FIG. 2. FIG. [Figure 5] FIG. [Figure 6] 5A and 5B are enlarged cross-sectional views illustrating the state of the wiper motor when it is wetted with water. [Figure 7] FIG. 10 is an enlarged perspective view of the periphery of a cylindrical member in a wiper motor according to a second embodiment. [Figure 8] FIG. 11 is an enlarged perspective view of the periphery of a cylindrical member in a wiper motor according to a third embodiment. [Figure 9] FIG. 10 is an enlarged perspective view of the periphery of a cylindrical member in a wiper motor according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, the first embodiment of the present invention will be described in detail with reference to the drawings.

[0012] Figure 1 shows a schematic diagram of a vehicle equipped with a wiper motor, Figure 2 shows an oblique view of the wiper motor of Figure 1, Figure 3 shows a diagram showing the internal structure of the wiper motor of Figure 2, Figure 4 shows an enlarged oblique view of the area around the cylindrical member of the wiper motor of Figure 2, Figure 5 shows an enlarged oblique view of the cylindrical member, and Figures 6(a) and (b) show enlarged cross-sectional views explaining the state of the wiper motor when it is wet.

[0013] As shown in FIG. 1 , a wiper device 20 is mounted in an engine compartment (not shown) at the front side of a vehicle 10 such as an automobile. The wiper device 20 swings a pair of wiper members 30 provided corresponding to a driver's seat side (Driver) and a passenger seat side (Assist). The wiper member 30 includes a wiper arm 31 formed in a substantially rod shape, and a base end side of the wiper arm 31 in the longitudinal direction is fixed to a pivot shaft 11 that is rotatably provided on the vehicle 10. A wiper blade 32 is attached to a tip end side of the wiper arm 31 in the longitudinal direction. As a result, by driving the wiper device 20, the wiper arm 31 swings over the windshield 12.

[0014] The wiper device 20 includes a wiper motor (motor with a speed reducer) 40. The wiper motor 40 also includes an output shaft 41, and a link mechanism 42 is provided between the output shaft 41 and the pair of pivot shafts 11 to convert the rotational motion of the output shaft 41 into the swinging motion of the pair of pivot shafts 11. As a result, when the wiper motor 40 is operated, the rotational motion of the output shaft 41 is converted into the swinging motion of the pivot shafts 11 via the link mechanism 42, and the wiper blades 32 perform a reciprocating wiping motion within their respective wiping ranges 13.

[0015] Here, the wiper motor 40 is attached to the vehicle 10 such that the output shaft 41 of the wiper motor 40 faces upward of the vehicle 10. That is, in the wiper motor 40, the gear case 70 side (see FIG. 4) from which the output shaft 41 protrudes faces upward of the vehicle 10, and the gear cover 80 side (see FIG. 4) that closes the gear case 70 faces downward of the vehicle 10.

[0016] As shown in Fig. 2, the wiper motor 40 forming the wiper device 20 includes a motor section 50 and a reduction mechanism section 60. The motor section 50 includes a yoke (motor case) 51 formed into a substantially cylindrical shape with a bottom by deep drawing a steel plate or the like, and a total of four magnets 52 (only two are shown in the figure) are fixed to the radially inner side of the yoke 51, as shown in Fig. 3. Furthermore, an armature core 53 is rotatably provided radially inner side of each magnet 52 via a predetermined gap (air gap).

[0017] An armature shaft (rotating shaft) 54 made of a round steel rod is fixed to the center of rotation of the armature core 53. The armature shaft 54 ​​rotates together with the rotation of the armature core 53. A pair of worms 55 are integrally provided on the tip end side (left side in Figure 3) of the armature shaft 54, and the twisting directions of the respective worms 55 are opposite to each other.

[0018] Furthermore, a commutator 56 is fixed between the worm 55 and the armature core 53 in the longitudinal direction of the armature shaft 54. A total of three brushes 57 (only two are shown in the figure) are in sliding contact with the outer periphery of the commutator 56. In this way, the wiper motor 40 is an electric motor with brushes, and is driven to rotate in the forward or reverse direction by the supply of drive current from a battery (not shown) or the like installed in the engine room or the like.

[0019] As shown in Fig. 2, the reduction mechanism 60 includes a gear case 70 and a gear cover 80. The gear case 70 and the gear cover 80 correspond to the housing in the present invention. As shown in Fig. 3, the reduction mechanism SD is housed inside the gear case 70 and the gear cover 80. The reduction mechanism SD is formed of a pair of worms 55 provided on the armature shaft 54, a pair of counter gears 61 meshed with the worms 55, and a single spur gear 62 meshed with the counter gears 61.

[0020] The pair of worms 55 are meshed with the large diameter tooth portions 61a of the pair of counter gears 61, respectively. As a result, the pair of counter gears 61 are rotated in the same direction (counterclockwise) as indicated by arrow R2 in conjunction with the rotation of the armature core 53 (see arrow R1). Furthermore, the small diameter tooth portions 61b of the pair of counter gears 61 are meshed with the tooth portions 62a of the spur gear 62. As a result, the spur gear 62 is rotated clockwise as indicated by arrow R3.

[0021] As a result, the high-speed rotation of the armature core 53 (armature shaft 54) is decelerated by the pair of worms 55 and the pair of counter gears 61, causing the spur gear 62 to rotate at a low speed. As a result, a high-torque rotational force is output from the output shaft 41 fixed to the rotation center of the spur gear 62 toward the link mechanism 42 (see FIG. 1).

[0022] 2, the gear case 70 that forms the reduction mechanism 60 is formed by pouring molten aluminum material into a mold, and is generally bowl-shaped with a case bottom wall 71. Also, as shown in Fig. 4, the gear cover 80 that forms the reduction mechanism 60 is formed by pouring molten plastic material into a mold (not shown), and is generally bowl-shaped with a cover bottom wall 81.

[0023] When the gear case 70 and the gear cover 80 are butted against each other, a hollow portion 63 (see FIG. 6) is formed therein, and the reduction mechanism SD (see FIG. 3) is housed inside the hollow portion 63. When the motor section 50 and the reduction mechanism section 60 are assembled, the inside of the hollow portion 63 and the inside of the yoke 51 (not shown) are in communication with each other.

[0024] Furthermore, the connecting portion (butting portion) between the gear case 70 and the gear cover 80, and the connecting portion (butting portion) between the gear case 70 and the yoke 51 are sealed with each other via a sealing member (not shown) such as an O-ring, thereby preventing rainwater and the like from entering the inside of the wiper motor 40 through these connecting portions.

[0025] 2, a total of three mounting legs 72 are integrally provided on the case bottom wall 71 of the gear case 70. These mounting legs 72 are provided on the outside of the gear case 70 and are arranged at approximately 120-degree intervals around the output shaft 41. The mounting legs 72 are fixed to a mounting bracket (not shown) provided on the vehicle 10. A mounting bolt (not shown) is threadedly coupled to each mounting leg 72, thereby enabling the wiper motor 40 to be firmly fixed to the mounting bracket without any rattle.

[0026] The tip of the output shaft 41 fixed to the spur gear 62 protrudes from approximately the center of the case bottom wall 71. A sealing member (not shown) such as an O-ring is provided between the case bottom wall 71 and the output shaft 41. This prevents rainwater and the like from entering the inside of the wiper motor 40 from between the output shaft 41 and the case bottom wall 71.

[0027] As shown in FIG. 2, the central shafts 61c of the pair of counter gears 61 are also rotatably supported on the case bottom wall 71 of the gear case 70, similar to the output shaft 41 of the spur gear 62.

[0028] 2 and 4, a connector connection portion 82 is integrally provided on the gear cover 80. An external connector (not shown) provided on the vehicle 10 is connected to the tip portion (right side in FIG. 4) of the connector connection portion 82. This allows a drive current to be supplied to the wiper motor 40 from a battery or the like of the vehicle 10. The external connector is connected to the connector connection portion 82 from the side opposite to the motor unit 50 side of the gear cover 80. In other words, the connector connection portion 82 is disposed approximately coaxially with the motor unit 50, as shown in FIG. 2.

[0029] 4, a breathing mechanism 90 is provided near the connector connection portion 82 of the gear cover 80. The breathing mechanism 90 is provided integrally with the gear cover 80 and is formed at the same time as the gear cover 80 is molded. The breathing mechanism 90 has the function of providing the wiper motor 40 with a breathing function in order to suppress pressure fluctuations inside and outside the wiper motor 40.

[0030] Specifically, the breathing mechanism 90 allows air to smoothly enter and exit (breathe) in response to pressure fluctuations inside and outside the wiper motor 40, while also functioning to prevent rainwater and the like from entering the interior due to pressure fluctuations inside and outside the wiper motor 40. To obtain an ideal breathing mechanism 90, it is necessary to achieve both of the contradictory phenomena described above, namely, facilitating "breathing" and preventing the intake of rainwater and the like.

[0031] The breathing mechanism 90 is disposed in a portion of the gear cover 80 away from the motor unit 50. As a result, even if rainwater or the like enters the inside of the wiper motor 40 via the breathing mechanism 90, the entered rainwater or the like is less likely to reach the commutator 56 or the brushes 57 (see FIG. 3). This effectively prevents the wiper motor 40 and the controller (not shown) that controls the wiper motor 40 from being damaged by an overcurrent.

[0032] The breathing mechanism 90 includes a communication hole 91 provided in the gear cover 80, a cylindrical member 92 extending in the axial direction of the communication hole 91 (the axial direction of the output shaft 41), and a pair of rib members 93 provided integrally on the radially outer side of the cylindrical member 92. As shown in Fig. 4, on the radial side of the cylindrical member 92 opposite to the side on which the pair of rib members 93 are provided, a cover side wall 83 forming the gear cover 80 and a base end portion (on the left side in Fig. 4) of the connector connection portion 82 are arranged close to each other.

[0033] As shown in Fig. 5, the communication hole 91 is provided in a cover flat surface portion 84 that is offset in the axial direction of the output shaft 41 (see Fig. 4) from the cover bottom wall 81 of the gear cover 80. Specifically, the communication hole 91 is provided in a portion of the gear cover 80 that is closest to the gear case 70 in the axial direction of the output shaft 41 (upper side in the figure). The inner diameter of the communication hole 91 is approximately 10 mm. The communication hole 91 communicates between the inside and outside of the gear cover 80 (wiper motor 40) and functions as a so-called "breathing hole."

[0034] 5, a cylindrical member 92 is provided integrally with the cover flat surface portion 84 of the gear cover 80. Specifically, the axial base end side of the cylindrical member 92 is fixed to the cover flat surface portion 84. The cylindrical member 92 is provided outside the gear cover 80, and its axial tip side extends on the opposite side to the gear case 70 side in the axial direction of the output shaft 41. In other words, the cylindrical member 92 extends in the axial direction of the communication hole 91 (output shaft 41).

[0035] The cylindrical member 92 is disposed coaxially with the communication hole 91, and the radially inner side of the cylindrical member 92 is in communication with the communication hole 91. The inner diameter of the cylindrical member 92 is also approximately 10 mm. As a result, the inside and outside of the wiper motor 40 are in communication with each other via the cylindrical member 92 and the communication hole 91, and air flows through the cylindrical member 92 and the communication hole 91.

[0036] The length H1 of the cylindrical member 92 from the cover flat surface portion 84 is approximately equal to the height of the cover side wall 83 in the axial direction of the output shaft 41. That is, the axial tip side portion of the cylindrical member 92 approximately reaches the cover bottom wall 81 of the gear cover 80. This prevents the cylindrical member 92 from protruding significantly in the axial direction of the communication hole 91, thereby preventing the wiper motor 40 from becoming larger. In other words, the breathing mechanism 90 is disposed in a relatively large dead space DS (see FIGS. 4 and 5) formed in the gear cover 80.

[0037] By providing the cylindrical member 92 communicating with the communication hole 91 in this way, when the wiper motor 40 is submerged in water, rainwater or the like that runs down the surface of the wiper motor 40 from above in the figure runs down the surface of the cylindrical member 92. Therefore, even if the wiper motor 40 is submerged in water, the rainwater or the like is less likely to reach the communication hole 91.

[0038] 5, a pair of rib members 93 are arranged radially outward of the cylindrical member 92 at approximately 90-degree intervals in the circumferential direction of the cylindrical member 92. These rib members 93 have approximately the same thickness as the cylindrical member 92 and are formed in the shape of a substantially rectangular plate.

[0039] Specifically, a pair of short side portions 93a of the rib member 93 extend in the radial direction of the cylindrical member 92, and the short side portion 93a on the base end side of the rib member 93 in the axial direction of the cylindrical member 92 is fixed to the cover flat portion 84. In addition, a pair of long side portions 93b of the rib member 93 extend in the axial direction of the cylindrical member 92, and the long side portion 93b on the base end side of the rib member 93 in the radial direction of the cylindrical member 92 is fixed to the cylindrical member 92.

[0040] In this way, the thickness of the rib member 93 is approximately the same as that of the cylindrical member 92, and one short side 93a and one long side 93b of the rib member 93 are integrated with the cover flat surface portion 84 and the cylindrical member 92, respectively. Therefore, when molding the gear cover 80, it is possible to easily and evenly distribute molten material into the narrow portions of the mold that form the cylindrical member 92 and the pair of rib members 93. This prevents the occurrence of manufacturing defects known as "short shots."

[0041] The pair of rib members 93 each extend a length H2 from the cover flat surface 84 in the axial direction of the cylindrical member 92. The length H2 of these rib members 93 is smaller than the length H1 of the cylindrical member 92 from the cover flat surface 84 (H2

[0042] Furthermore, each of the pair of rib members 93 is provided with a recess 93c recessed toward the base end side of the rib member 93 in the axial direction of the cylindrical member 92 (communicating hole 91). The recess 93c is provided on the tip side of the rib member 93 in the axial direction of the cylindrical member 92, and is provided between the cylindrical member 92 and the rib member 93. Here, the recess 93c corresponds to the first recess in the present invention.

[0043] In this way, by providing a pair of rib members 93 on the radially outer side of the cylindrical member 92, when the wiper motor 40 is wet, rainwater or the like running down the surface of the gear case 70 will run not only around the cylindrical member 92 but also on the surfaces of these rib members 93. This makes it possible to prevent the flow of rainwater or the like that reaches the opening 92a of the cylindrical member 92 from being disturbed and to prevent the formation of a water film that blocks the opening 92a.

[0044] In particular, a recess 93c is provided on the tip side of the rib member 93 and between the cylindrical member 92 and the rib member 93, so that the position where rainwater or the like drips down the surface of the rib member 93 can be moved away from the cylindrical member 92 toward the radial outside thereof, thereby making it possible to further suppress the formation of a water film that blocks the opening 92a.

[0045] Next, the breathing function and the function when wetted of the wiper motor 40 formed as above will be described in detail with reference to FIGS. 6(a) and 6(b).

[0046] ​6(a) shows an enlarged cross-sectional view of a portion of the cylindrical member 92 (excluding the rib member 93), and FIG. 6(b) shows an enlarged cross-sectional view of the cylindrical member 92 including the rib member 93. As shown in FIG.

[0047] First, the breathing function of the wiper motor 40 will be described.

[0048] When the wiper motor 40 installed in the engine compartment is driven, the internal temperature of the wiper motor 40 rises due to the heat generated by the wiper motor 40 and the high-temperature atmosphere in the engine compartment. If rainwater WA splashes on the wiper motor 40 in this state, the wiper motor 40 is rapidly cooled. This causes a temperature difference between the inside and outside of the wiper motor 40. As a result, the temperature of the hollow portion 63 (inside) of the wiper motor 40 becomes lower than the temperature of the outside of the wiper motor 40. This creates a negative pressure in the hollow portion 63, and air AR outside the gear case 70 flows into the hollow portion 63 via the tubular member 92 and the communication hole 91 (see the dashed arrow in the figure). This prevents a pressure difference from occurring inside and outside the wiper motor 40.

[0049] On the other hand, when the internal temperature of the wiper motor 40 rises significantly due to, for example, operating the wiper motor 40 at high speed for a long period of time, and the internal temperature of the wiper motor 40 exceeds the external temperature, the hollow portion 63 becomes relatively hotter than the outside of the wiper motor 40. Then, contrary to the above, the hollow portion 63 becomes under positive pressure, and the air AR inside the hollow portion 63 is discharged to the outside through the communication hole 91 and the cylindrical member 92 (see the solid arrow in the figure). This suppresses the generation of a pressure difference between the inside and outside of the wiper motor 40.

[0050] However, the inside and outside of the wiper motor 40 are always in communication with each other via the cylindrical member 92 and the communication hole 91. Therefore, the air AR does not suddenly move between the inside and outside of the wiper motor 40.

[0051] Next, the function of the wiper motor 40 when it is wet will be described.

[0052] When the vehicle 10 is traveling in heavy rain, rainwater WA enters the engine compartment and wets the wiper motor 40. Then, as shown by arrows M1 and M2 in the figure, the rainwater WA runs down the surface of the wiper motor 40 from the gear case 70 side toward the gear cover 80. At this time, the rainwater WA is separated into rainwater running down the surface of the cylindrical member 92 (arrow M1) and rainwater running down the surface of the rib member 93 (arrow M2), and then drips directly below (below) the breathing mechanism 90. In this case, the recess 93c between the cylindrical member 92 and the rib member 93 prevents the rainwater running down the surface of the rib member 93 from merging with the rainwater running down the surface of the cylindrical member 92.

[0053] This disrupts the flow of rainwater or the like that reaches the opening 92a of the cylindrical member 92, making it difficult for a water film to form at the opening 92a. Even if a water film does form at the opening 92a, the thickness of the water film is unstable and the water film is easily broken. This prevents rainwater or the like from entering the interior (hollow portion 63) of the wiper motor 40.

[0054] As described above in detail, according to the wiper motor 40 of this embodiment, the rib members 93 that protrude radially outward from the cylindrical member 92 and extend in the axial direction of the cylindrical member 92 are provided integrally with the cylindrical member 92 on the radially outer side thereof, so that it is possible to ensure that the molten plastic material reaches the narrow portions of the mold that form the cylindrical member 92 and the rib members 93 when molding the gear cover 80. This makes it possible to prevent the occurrence of manufacturing defects known as "short shots," thereby achieving a reduction in the defect rate.

[0055] Furthermore, when the gear cover 80 is exposed to water, rainwater and the like flows along the cylindrical member 92 and the rib member 93, preventing the rainwater and the like from reaching the opening 92a of the cylindrical member 92 all at once (simultaneously). This prevents a water film from forming at the opening 92a. This effectively prevents rainwater and the like from being sucked into the gear cover 80, thereby improving water resistance.

[0056] Furthermore, according to the wiper motor 40 of this embodiment, a recess 93c recessed toward the base end of the rib member 93 in the axial direction of the cylindrical member 92 is provided on the tip side of the rib member 93 in the axial direction of the cylindrical member 92 and between the cylindrical member 92 and the rib member 93. This makes it possible to move the position where rainwater, etc. running down the surface of the rib member 93 drips away from the cylindrical member 92 to the radially outer side thereof. This further reduces the occurrence of a water film that forms to block the opening 92a.

[0057] Furthermore, the wiper motor 40 according to this embodiment can reduce the defect rate by suppressing the occurrence of manufacturing defects, and can also improve water-repellent reliability to extend the product's lifespan, thereby reducing manufacturing energy consumption and extending the product's life cycle. This contributes to the achievement of the United Nations' Sustainable Development Goals (SDGs), particularly Goal 7 (Ensure access to affordable, reliable, sustainable and modern energy) and Goal 13 (Take urgent action to combat climate change and its impacts).

[0058] Next, a second embodiment of the present invention will be described in detail with reference to the drawings. Note that parts having the same functions as those in the first embodiment are given the same reference numerals, and detailed description thereof will be omitted.

[0059] FIG. 7 is an enlarged perspective view of the periphery of a cylindrical member in a wiper motor according to the second embodiment.

[0060] As shown in Fig. 7, the wiper motor (motor with a speed reducer) 100 of the second embodiment differs from the wiper motor 40 of the first embodiment (see Fig. 5) in the structure of the breathing mechanism 110. Specifically, it differs from the first embodiment in that a total of three notches 111 are additionally provided in the cylindrical member 92 that forms the breathing mechanism 110.

[0061] These cutouts 111 are formed in a substantially rectangular shape, are provided on the axial tip side (lower side in the figure) of the cylindrical member 92, and are recessed to a predetermined depth toward the axial base end side of the cylindrical member 92. Here, the cutouts 111 correspond to the second recesses in the present invention, and their depth dimension D is substantially equal to the value obtained by subtracting the length dimension H2 of the rib member 93 from the cover flat surface portion 84 from the length dimension H1 of the cylindrical member 92 from the cover flat surface portion 84 (D ≈ H1 - H2).

[0062] Furthermore, the three cutouts 111 are arranged at approximately 90-degree intervals in the circumferential direction of the cylindrical member 92, and are arranged at positions offset by approximately 45 degrees from the pair of rib members 93 in the circumferential direction of the cylindrical member 92. In other words, when the cylindrical member 92 is viewed from the axial direction, the cutouts 111 and the rib members 93 are alternately arranged at approximately equal intervals (approximately 45-degree intervals) in the circumferential direction of the cylindrical member 92.

[0063] The second embodiment configured as described above can also achieve substantially the same effects as the first embodiment. In addition, in the second embodiment, a total of three notches 111 recessed to a predetermined depth toward the base end of the axial direction of the cylindrical member 92 are provided on the axial tip side of the cylindrical member 92, which further prevents rainwater and the like from simultaneously reaching the opening 92a of the cylindrical member 92. Therefore, it is possible to further prevent a water film from forming on the opening 92a.

[0064] Next, a third embodiment of the present invention will be described in detail with reference to the drawings. Note that parts having the same functions as those in the first embodiment are given the same reference numerals, and detailed description thereof will be omitted.

[0065] FIG. 8 is an enlarged perspective view of the periphery of a cylindrical member in a wiper motor according to the third embodiment.

[0066] As shown in Fig. 8, wiper motor (motor with speed reduction mechanism) 120 of embodiment 3 differs from wiper motor 40 of embodiment 1 (see Fig. 5) in the structure of breathing mechanism 130. Breathing mechanism 130 includes a long rib member 131 having a pair of short sides 131a and a pair of long sides 131b. A length dimension H3 in the longitudinal direction of rib member 131 is greater than a length dimension H2 in the longitudinal direction of rib member 93 of embodiment 1 (see Fig. 5) (H3>H2).

[0067] Additionally, the length dimension H3 of the rib member 131 in the axial direction of the cylindrical member 92 is greater than the length dimension H1 of the cylindrical member 92 (H3>H1>H2). Furthermore, in the third embodiment, since the length dimension H3 of the rib member 131 is made greater than the length dimension H1 of the cylindrical member 92, the recessed portion 93c (see FIG. 5) between the cylindrical member 92 and the rib member 93 in the first embodiment is omitted.

[0068] The third embodiment configured as described above can also achieve substantially the same effects as the first embodiment. In addition, in the third embodiment, the length dimension H3 of the rib member 131 in the axial direction of the cylindrical member 92 is greater than the length dimension H1 of the cylindrical member 92, so that rainwater and the like can be collected at the longitudinal tip side (lower side in the figure) of the rib member 131. This makes it difficult for rainwater and the like to reach the opening portion 92a of the cylindrical member 92. This makes it possible to further prevent a water film from forming at the opening portion 92a.

[0069] Next, a fourth embodiment of the present invention will be described in detail with reference to the drawings. Note that parts having the same functions as those in the first embodiment will be given the same reference numerals, and detailed description thereof will be omitted.

[0070] FIG. 9 is an enlarged perspective view of the periphery of a cylindrical member in a wiper motor according to the fourth embodiment.

[0071] As shown in Fig. 9, in the wiper motor (motor with a speed reduction mechanism) 140 of the fourth embodiment, the structure of the breathing mechanism 150 is different from that of the wiper motor 40 (see Fig. 5) of the first embodiment. The breathing mechanism 150 has a breathing cylinder 151 having a communication hole 151a inside the cylindrical member 92 in the radial direction. The breathing cylinder 151 is provided outside the gear cover 80 and protrudes in the same direction as the cylindrical member 92. And the length dimension H4 of the breathing cylinder 151 from the cover flat portion 84 is smaller than the length dimension H1 of the cylindrical member 92 from the cover flat portion 84 (H4 < H1). Thereby, when the cylindrical member 92 is viewed from the outside in the radial direction, the breathing cylinder 151 is hidden by the cylindrical member 92.

[0072] Further, the cylindrical member 92 is provided with a rib member 152 having a rib body 152a and a tapered portion 152b. The tapered portion 152b is provided on the tip side of the rib member 152 in the axial direction of the cylindrical member 92, and is formed so as to gradually reduce the height dimension of the rib member 152 in the radial direction of the cylindrical member 92 as it goes toward the tip side of the rib member 152.

[0073] Here, the length dimension H5 of the tapered portion 152b in the axial direction of the cylindrical member 92 is smaller than the length dimension H6 of the rib body 152a from the cover flat portion 84 (H5 < H6). Also, the length dimension H4 of the breathing cylinder 151 is smaller than the length dimension H6 + H5 of the rib member 152 (H4 < H6 + H5). Furthermore, the length dimension H6 + H5 of the rib member 152 is smaller than the length dimension H1 of the cylindrical member 92 (H6 + H5 < H1).

[0074] Also, in the fourth embodiment, with the provision of the tapered portion 152b on the rib member 152, the recessed portion 93c (see Fig. 5) between the cylindrical member 92 and the rib member 93 in the first embodiment is omitted.

[0075] Further, the cylindrical member 92 is provided with a pair of slits 153 extending in the axial direction of the cylindrical member 92. These slits 153 are arranged at positions offset by approximately 45 degrees in the circumferential direction on one side and the other side of the circumferential direction of the cylindrical member 92 with respect to one rib member 152 (the right side in the drawing). And the opening width W of the slit 153 is smaller than the wall thickness dimension T of the rib member 152 (W < T). Thereby, while suppressing rainwater or the like from entering the radially inner side of the cylindrical member 92, rainwater or the like that has entered the radially inner side of the cylindrical member 92 can be quickly discharged to the outside of the cylindrical member 92.

[0076] Even in the fourth embodiment formed as described above, substantially the same operational effects as those of the first embodiment described above can be achieved. In addition to this, in the fourth embodiment, a tapered portion 152b is provided on the tip side of the rib member 152 in the axial direction of the cylindrical member 92, and the height dimension of the rib member 152 in the radial direction of the cylindrical member 92 gradually decreases as it goes toward the tip side of the rib member 152. Therefore, the mold used when injection molding the gear cover 80 or the like can be easily demolded. Thus, it becomes possible to further improve the moldability of the gear cover 80.

[0077] It is needless to say that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist thereof. For example, in each of the above-described embodiments, the breathing mechanisms 90, 110, 130, 150 are shown provided on the gear cover 80, respectively, but the present invention is not limited to this. For example, in the case of an attachment posture in which the gear case 70 side faces downward with respect to the vehicle 10, a breathing mechanism may be provided on the gear case 70.

[0078] Also, in each of the above-described embodiments, nothing is provided in the communication holes 91, 151a in order to exhibit a sufficient breathing function, but the present invention is not limited to this, and a porous membrane (such as made of a fluororesin) that blocks the communication hole and allows air to pass through but does not allow water to pass through can also be provided.

[0079] Furthermore, in each of the above-described embodiments, the wiper motors 40, 100, 120, 140 are applied to a front wiper device that wipes the wiping area 13 on the windshield 12, but the present invention is not limited to this and can also be applied to a rear wiper device that wipes the wiping area on the rear windshield.

[0080] Furthermore, in each of the above-described embodiments, the wiper motors 40, 100, 120, and 140 have been used as examples, but the present invention is not limited to these, and can also be applied to motors with reduction mechanisms for other applications that have a similar mounting position and are subject to water exposure.

[0081] Furthermore, in each of the above-described embodiments, the motor section 50 is an electric motor with brushes, but the present invention is not limited to this, and the motor section may be a brushless electric motor.

[0082] Furthermore, the material, shape, dimensions, number, installation location, etc. of each component in each of the above-described embodiments are arbitrary as long as they can achieve the present invention, and are not limited to the above-described embodiments. [Explanation of symbols]

[0083] 10: vehicle, 11: pivot shaft, 12: windshield, 13: wiping area, 20: wiper device, 30: wiper member, 31: wiper arm, 32: wiper blade, 40: wiper motor (motor with reduction mechanism), 41: output shaft, 42: link mechanism, 50: motor section, 51: yoke, 52: magnet, 53: armature core, 54: armature shaft (rotating shaft), 55: worm, 56: commutator, 57: brush, 60: reduction mechanism section, 61: counter gear, 61a: large diameter tooth section, 61b: small diameter tooth section, 61c: central shaft, 62: spur gear, 62a: tooth section, 63: hollow section, 70: gear case (housing), 71: case bottom wall, 72: mounting leg, 80: gear cover (housing), 81: cover bottom wall, 82: Connector connection part, 83: cover side wall, 84: cover flat part, 90: breathing mechanism, 91: communication hole, 92: cylindrical member, 92a: opening part, 93: rib member, 93a: short side part, 93b: long side part, 93c: recessed part (first recessed part), 100: wiper motor (motor with reduction mechanism), 110: breathing mechanism, 111: notch part (second recessed part), 120: wiper motor (motor with reduction mechanism), 130: breathing mechanism, 131: rib member, 131a: short side part, 131b: long side part, 140: wiper motor (motor with reduction mechanism), 150: breathing mechanism, 151: breathing tube, 151a: communication hole, 152: rib member, 152a: rib main body, 152b: tapered part, 153: slit, AR: air, DS: dead space, SD: reduction mechanism, WA: rainwater

Claims

1. a motor unit having a rotation shaft; a speed reduction mechanism unit having a speed reduction mechanism that reduces the rotation speed of the rotary shaft; A motor with a reduction mechanism, a housing that accommodates the reduction mechanism; a communication hole provided in the housing for communicating the inside and outside of the housing; a cylindrical member provided outside the housing, extending in the axial direction of the communication hole, and having a radially inner side communicating with the communication hole; a rib member provided integrally on the radially outer side of the cylindrical member, protruding radially outward from the cylindrical member and extending in the axial direction of the cylindrical member; and a first recessed portion recessed toward a base end side of the rib member in the axial direction of the cylindrical member, the first recessed portion being provided between the cylindrical member and the rib member on the tip side of the rib member in the axial direction of the cylindrical member, Motor with reduction mechanism.

2. 2. The motor with a reduction mechanism according to claim 1, a second recessed portion recessed toward a base end side in the axial direction of the cylindrical member is provided on a tip end side in the axial direction of the cylindrical member, Motor with reduction mechanism.

3. A motor unit having a rotating shaft; a speed reduction mechanism unit having a speed reduction mechanism that reduces the rotation speed of the rotary shaft; A motor with a reduction mechanism, a housing that accommodates the reduction mechanism; a communication hole provided in the housing for communicating the inside and outside of the housing; a cylindrical member provided outside the housing, extending in the axial direction of the communication hole, and having a radially inner side communicating with the communication hole; a rib member provided integrally on the radially outer side of the cylindrical member, protruding radially outward from the cylindrical member and extending in the axial direction of the cylindrical member; and The length of the rib member is greater than the length of the cylindrical member in the axial direction of the cylindrical member. Motor with reduction mechanism.

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