CN111828597A

CN111828597A - Waterproof structure of gear box and motor with speed reducer

Info

Publication number: CN111828597A
Application number: CN202010302717.7A
Authority: CN
Inventors: 植西英史; 村井刚史
Original assignee: Mabuchi Motor Co Ltd
Current assignee: Mabuchi Motor Co Ltd
Priority date: 2019-04-19
Filing date: 2020-04-16
Publication date: 2020-10-27
Also published as: JP7139280B2; JP2020176695A

Abstract

Prevent the distortion of the sealing gasket during the assembly, ensure waterproof performance's waterproof construction and take motor of reduction gear of gear box. A waterproof structure for a gear box into which a connector (5) is fitted, comprising: a recess provided in one of the connector and the gear case; a convex portion (10) which is provided on the other of the connector and the gear case and which is fitted into the concave portion; a mounting surface (13) which is provided so as to surround the convex portion and extends in a direction intersecting the protruding direction of the convex portion; a gasket (30) which is in a ring shape surrounding the convex portion and is assembled in contact with both the side surface (11) and the mounting surface of the convex portion in a state before the concave portion and the convex portion are fitted; and a rib (14) which is provided so as to protrude in the same direction as the protruding direction at the outer peripheral end (13a) of the mounting surface and has a corner portion that comes into contact with the gasket. The protruding height of the rib is set to be 1/4 or less of the height dimension of the gasket.

Description

Waterproof structure of gear box and motor with speed reducer

Technical Field

The present invention relates to a waterproof structure for a gear box into which a connector is fitted, and a motor with a reduction gear to which the waterproof structure is applied.

Background

Conventionally, in products requiring airtightness and waterproofness, a sealing member such as a gasket or an O-ring is sandwiched between parts to be connected, thereby preventing foreign matter from entering from the outside and moisture from entering. The same applies to a motor with a speed reducer, and for example, in patent document 1, a ring-shaped waterproof rubber is attached to a connector portion, and the connector portion is inserted into an extension portion of a speed reduction housing incorporating a speed reduction mechanism, thereby preventing water from entering.

[ Prior Art document ]

Patent document 1: japanese laid-open patent application No. 2001 and 268841

Problems to be solved by the invention

In the case of sealing a connection portion between a gear case (housing, case) incorporating a reduction mechanism and a connector, as in patent document 1, an assembly method is considered in which a gasket is fitted around a convex portion of the connector and the convex portion is fitted into a concave portion of the gear case. However, the gasket may be twisted depending on the posture of the gasket at the time of assembly.

If this assembling step is performed manually, an operation of correcting the distortion of the gasket is required, which leads to deterioration of workability and complication. In addition, when the assembly process is automatically performed by an automatic machine, it is necessary to inspect a sensor for detecting whether or not the gasket is distorted, a device for eliminating the distorted state of the gasket, and the like, which causes the device structure to be complicated. If the gasket is clamped while being maintained in a twisted state, the gasket is not clamped at a desired compression rate, and the waterproof performance may be insufficient.

Disclosure of Invention

The present invention has been made in view of the above problems, and one of the objects of the present invention is to prevent the gasket from being twisted during assembly and to ensure waterproof performance. It is to be noted that the present invention is not limited to this object, and another object of the present invention is to achieve the operational effects by the respective configurations described in the embodiments described later and the operational effects that cannot be obtained by the conventional technology.

Means for solving the problems

(1) Here, a waterproof structure of a gear box according to the present invention is a waterproof structure of a gear box to which a connector is fitted, the waterproof structure of the gear box including: a recess provided in one of the connector and the gear case; a convex portion provided on the other of the connector and the gear case and fitted into the concave portion; a mounting surface provided so as to surround the convex portion and extending in a direction intersecting a protruding direction of the convex portion; a gasket that is in a ring shape surrounding the convex portion and is assembled in contact with both the side surface of the convex portion and the mounting surface before the concave portion is fitted to the convex portion; and a rib provided so as to protrude in the same direction as the protruding direction at an outer peripheral end portion of the mounting surface, the rib having a corner portion that contacts the gasket. The protruding height of the rib is set to be 1/4 or less of the height dimension of the gasket.

(2) Preferably, the protruding height of the rib is set to be greater than or equal to 1/6 of the height dimension of the gasket.

(3) Preferably, the width of the rib is set to 2/5 or less of the width of the gasket.

(4) Preferably, the width of the rib is set to be greater than or equal to 1/4 of the width of the gasket.

(5) Preferably, a fillet is provided at the corner of the rib.

(6) Preferably, the plurality of ribs are arranged at intervals along the outer peripheral end portion of the placement surface.

(7) Here, the motor with a reduction gear according to the present invention includes: a motor unit including a rotor and a stator; and a reduction mechanism including a worm that transmits rotation of the motor unit and a worm wheel that meshes with the worm, wherein the waterproof structure of the gear box according to any one of the above (1) to (6) is applied to a fitting portion that accommodates the gear box of the reduction mechanism and a connector that is fitted to the gear box.

Effects of the invention

According to the invention, since the distortion of the gasket can be prevented when the gear housing and the connector are assembled, the waterproof performance can be ensured.

Drawings

Fig. 1 is a plan view of a motor with a reduction gear according to an embodiment, showing a state before a connector is fitted to a gear box.

Fig. 2 is a perspective view of a connector for explaining a waterproof structure of the embodiment.

Fig. 3 is a perspective view showing a state in which a gasket is fitted to the connector of fig. 2.

Fig. 4 is a cross-sectional view of a structure in which a state in which the fitting portion of the connector is inserted halfway in the fitting hole portion of the gear housing is cut along the insertion direction.

Fig. 5 is a cross-sectional view (a cross-sectional view of fig. 4, which is upside down) showing a state where the gasket is attached to the convex portion, and shows a relationship between the shape of the rib and the shape of the gasket.

Fig. 6 is a side view for explaining a process of fitting the gasket at the convex portion.

Fig. 7 is a diagram schematically showing the result of analyzing the pressure acting on the gasket of fig. 3 in the state where the convex portion and the concave portion are fitted.

Description of reference numerals:

1 motor (motor with reducer);

2a motor part;

a 2B rotor;

a 2C stator;

3, a speed reducing mechanism;

a worm of 3A;

3B worm wheel;

4a gear case;

5a connector;

10 convex parts;

11 side face;

12 a top surface;

13 step surface (carrying surface);

13a outer peripheral end portion;

13b a waterproof surface;

14 ribs;

14a corner portion;

20 a recess;

30 a gasket;

the height of the Hp gasket;

the height of the Hr rib (the protrusion height of the rib).

Detailed Description

An example in which the waterproof structure of the gear box according to the embodiment is applied to a motor with a reduction gear will be described with reference to the drawings. The embodiments described below are merely examples, and are not intended to exclude the application of various modifications and techniques not explicitly described in the embodiments below. The respective configurations of the present embodiment can be variously modified and implemented without departing from the scope of the above-described gist. Further, they can be selected as necessary or appropriately combined.

[1. Structure ]

[1-1. Motor with speed reducer ]

As shown in fig. 1, the motor 1 with a speed reducer of the present embodiment (hereinafter referred to as "motor 1") is applied to, for example, a power window system of a vehicle. The motor 1 includes a motor unit 2 that generates an output and a reduction mechanism 3 that reduces the rotation speed of the motor unit 2. The waterproof structure of the present embodiment is applied to a fitting portion between the gear case 4 accommodating the reduction mechanism 3 and the connector 5 fitted to the gear case 4. Fig. 1 shows a state before the connector 5 is fitted (assembled) to the gear housing 4.

The motor unit 2 is, for example, a brushed DC motor, and has a rotor 2B and a stator 2C incorporated in a casing 2D. One end of a rotating shaft 2A of the motor unit 2 is axially supported by the casing 2D, and the other end thereof is extended in a gear box 4 coupled to the casing 2D. The case 2D has a bottomed cylindrical shape, and is fastened to the gear case 4 by fastening the flange portion 2f provided around the opening (not shown) to the fastening portion 4a of the gear case 4.

The speed reduction mechanism 3 includes a worm 3A that transmits rotation of the motor unit 2 and a worm wheel 3B that has a tooth portion that meshes with the worm 3A. The worm 3A is a helical gear fixed to the other end of the rotary shaft 2A and rotating integrally with the rotary shaft 2A. The worm wheel 3B is a helical gear that meshes with the worm 3A. An output gear (both not shown) that drives the driven member by meshing with a gear provided in the driven member is coupled to the worm wheel 3B. Examples of the driven member include a window regulator. The motor 1 amplifies the output of the motor unit 2 by decelerating the rotation of the rotary shaft 2A by the reduction mechanism 3, and outputs a high-output rotational driving force from the output gear.

The gear box 4 is a housing that houses the reduction mechanism 3, and has a portion that houses the worm 3A, a portion that houses the worm wheel 3B, a portion to which the power supply unit 2 is coupled, and a portion to which the connector 5 is fitted. The connector 5 has a function of supplying power from the outside to the motor unit 2 and a function of outputting a detection signal of the motor unit 2. The connector 5 of the present embodiment includes a pair of terminals 5b provided to protrude from a fitting portion 5a fitted into a fitting hole 4b of the gear housing 4. As shown by the open arrows in fig. 1, when the flange portion 5c provided at the base end portion of the fitting portion 5a is inserted to a position in contact with the peripheral end face of the fitting hole portion 4b, the connector 5 is fitted to the gear case 4.

[1-2. waterproof Structure ]

Fig. 2 and 3 are perspective views showing the periphery of the fitting portion 5a of the connector 5 in an enlarged manner, fig. 2 shows the connector 5 before the gasket 30 is fitted, and fig. 3 shows the connector 5 in a state where the gasket 30 is fitted. The gasket 30 is a member for sealing a fitting portion between the gear case 4 and the connector 5, and has an annular outer shape. As shown in fig. 5, the vertical cross-sectional shape of the gasket 30 of the present embodiment cut in the direction orthogonal to the circumferential direction is a rounded hexagonal shape. Fig. 5 is a cross-sectional view showing a state where the gasket 30 is mounted on the convex portion 10.

As shown in fig. 2, the fitting portion 5a of the connector 5 has a stepped surface 13 (mounting surface) formed in the middle of the direction of insertion into the fitting hole 4b (hereinafter referred to as "insertion direction"), and the outer shape of the tip end side of the fitting portion 5a of the connector 5 is smaller by one turn with the stepped surface 13 as a boundary. Hereinafter, the portion of the fitting portion 5a on the tip end side of the stepped surface 13 is referred to as a convex portion 10, and the direction toward the tip end side of the convex portion 10 is referred to as a "projecting direction". The protruding direction is the same direction as the insertion direction described above. Fig. 4 is a cross-sectional view obtained by cutting the structure in the state where the fitting portion 5a is inserted halfway in the fitting hole portion 4b in the insertion direction. As shown in fig. 4, the convex portion 10 is fitted into a concave portion 20 provided in the gear case 4.

As shown in fig. 2, the convex portion 10 of the present embodiment has a block shape, and has a side surface 11 extending in the protruding direction and a top surface 12 extending in a direction orthogonal to the protruding direction. The convex portion 10 has a substantially rectangular shape when viewed from the protruding direction. The terminals 5b protrude from the top surface 12. The step surface 13 is provided so as to surround the convex portion 10 and extends in a direction intersecting the protruding direction. In the connector 5 of the present embodiment, the top surface 12 and the step surface 13 are provided as parallel surfaces. As shown in fig. 3, the stepped surface 13 functions as a surface on which the gasket 30 is placed. That is, the gasket 30 is fitted so as to surround the convex portion 10, and is disposed in contact with both the side surface 11 and the step surface 13 of the convex portion 10.

As shown in fig. 4, the recess 20 is provided as a part of the fitting hole portion 4b of the gear case 4. The concave portion 20 is provided with a first receiving surface 22 that receives the top surface 12 when the convex portion 10 is fitted thereto, and a second receiving surface 23 that faces the step surface 13. The first receiving surface 22 and the second receiving surface 23 are parallel to each other and extend in a direction orthogonal to the insertion direction. That is, a step is formed on the inner surface 21 of the recess 20. The second receiving surface 23 is a surface that sandwiches and compresses the gasket 30 together with the step surface 13.

Further, when the convex portion 10 to which the gasket 30 is attached is fitted into and assembled with the concave portion 20 of the gear case 4, the gasket 30 may be twisted. This is because the imaginary perpendicular line drawn from the top portion of the gasket 30 on the side opposite to the step surface 13 (in the present embodiment, the corner K of the rounded hexagonal shape shown in fig. 5) to the side surface 11 is not completely parallel to the top surface 12 of the convex portion 10. That is, the portion offset from the corner K is pressed in the protruding direction of the convex portion 10 by the stepped surface 13 and the second receiving surface 23, and a rotational force is generated in the circumferential direction with respect to the gasket 30, and the gasket 30 may be twisted. The more the gasket 30 is spaced apart from the side surface 11 of the convex portion 10, the more easily the distortion occurs.

In contrast, in the waterproof structure of the present embodiment, the rib 14 for preventing the gasket 30 from being twisted at the time of assembly is provided. As shown in fig. 2 and 3, the rib 14 is a projection provided to project in the same direction as the projecting direction at the outer peripheral end 13a of the stepped surface 13. In the connector 5 of the present embodiment, a plurality of ribs 14 are provided to protrude at intervals along the outer peripheral end portion 13 a. The outer peripheral end 13a of the convex portion 10 of the present embodiment is formed of two long and short sides, two ribs 14 are provided at intervals between the short sides, and three ribs 14 are provided at intervals between the long sides.

As shown in fig. 2 and 5, each rib 14 has a substantially rectangular parallelepiped shape elongated in the circumferential direction of the convex portion 10, and has a corner portion 14a that contacts the gasket 30. The corner portion 14a is formed by a plane facing the side face 11 side and parallel to the side face 11 and a plane parallel to the top face 12. The corner 14a of the rib 14 of the present embodiment is rounded. The plane of the rib 14 parallel to the side surface 11 and opposite to the plane facing the side surface 11 is flush with the side surface of the fitting portion 5 a.

Here, a process of fitting the gasket 30 to the convex portion 10 will be described with reference to fig. 6. The left side view in fig. 6 shows a state before the gasket 30 comes into contact with the step surface 13, and the right side view in fig. 6 shows a state after the gasket 30 is fitted to the convex portion 10 (a state in which the gasket 30 is completely fitted). As shown on the left side in the figure, the annular gasket 30 is fitted into the convex portion 10 from the top surface 12 side, and is bent at approximately 90 degrees at four corners of the convex portion 10, but abuts against the rib 14 in the vicinity of the step surface 13, and prevents the gasket 30 from expanding outward. As shown on the right side in the drawing, in the assembled state, the position of the outer end portion of the gasket 30 is limited by the rib 14, and the gasket 30 is placed on the step surface 13. Among the stepped surfaces 13, the surface that comes into surface contact with the gasket 30 and exhibits a waterproof function is referred to as a waterproof surface 13 b. The waterproof surface 13b is a surface of the stepped surface 13 other than the outer peripheral end portion 13 a.

Hereinafter, as shown in fig. 5, the dimension of the rib 14 in the projecting direction is referred to as "rib height Hr", and the dimension in the direction perpendicular to the projecting direction and crossing the step surface 13 (width direction) is referred to as "rib width Wr". Similarly, the dimension in the protruding direction (height dimension) of the gasket 30 is referred to as "gasket height Hp", and the dimension in the same direction (width direction) as the direction of the width Wr of the rib 14 is referred to as "gasket width Wp". As shown in fig. 2, the dimension of the rib 14 in the circumferential direction of the outer peripheral end 13a (the direction orthogonal to both the projecting direction and the width direction) is referred to as a "rib length Lr".

In the fitted state of the convex portion 10 and the concave portion 20, a space (hereinafter referred to as "compression space") surrounded by the side surface 11 of the convex portion 10, the step surface 13, the inner surface 21 of the concave portion 20, and the second receiving surface 23 is formed, and a volume Va of the compression space is a constant value determined by the shapes of the convex portion 10 and the concave portion 20. The volume Vp of the gasket 30 is also determined by the shape thereof, and therefore is a constant value. Therefore, if the sum of the volume Vp of the gasket 30 and the volume Vr of all the ribs 14 is not equal to or less than the volume Va of the compression space, the gasket 30 cannot be accommodated in the compression space. Therefore, the size, shape, and number of the ribs 14 are set so that the volume Vr of all the ribs 14 is equal to or less than a value obtained by subtracting the volume Vp of the gasket 30 from the volume Va of the compression space (Vr. ltoreq. Va-Vp).

From such a viewpoint, in the present embodiment, as shown in fig. 5, the rib height Hr (protrusion height) is set to 1/4 or less of the gasket height Hp. In other words, the upper limit value of the rib height Hr is half of the gasket height Hp (Hp/2). Thus, the ratio of the sum of the volume Vp of the gasket 30 and the volume Vr of the rib 14 to the volume Va of the compression space (hereinafter referred to as "occupancy") can be easily set to 100% or less.

The rib height Hr in the present embodiment is set to 1/6 or more of the gasket height Hp. In other words, the lower limit value of the rib height Hr is 1/3 that is half (Hp/2) of the gasket height Hp. This is because the lower the rib height Hr, the lower the ability (pressing force, seizing) of the gasket 30 to be pressed toward the side surface 11 side. That is, the rib 14 serves to prevent the gasket 30 fitted to the convex portion 10 from being twisted, as described above, and therefore needs to be set to a height that can achieve this function.

Fig. 7 shows the result of analyzing the pressure acting on the gasket 30 when the rib height Hr is set to be equal to or higher than 1/6 and equal to or lower than 1/4 of the gasket height Hp and the convex portion 10 and the concave portion 20 are in the fitted state. The analysis of fig. 7 is performed in a state (worst state) in which the tolerance of the rib 14 is set to the upper tolerance limit or the lower tolerance limit in the direction in which the waterproof performance is deteriorated. Specifically, the analysis is performed in a state where the rib height Hr is set to the upper tolerance limit, the rib width Wr is set to the upper tolerance limit, and the gasket width Wp is set to the lower tolerance limit. The dot pattern in fig. 7 indicates the level of the pressure applied to the gasket 30, and indicates that the pressure is higher in the portion where the dot pattern is thicker.

As shown in fig. 7, the pressure of the gasket 30 is increased in the portion in contact with the waterproof surface 13b and the portion in contact with the rib 14, and the former is higher than the latter as a whole. When the pressure of the portion in contact with the waterproof surface 13b is compared in the circumferential direction (longitudinal direction) of the gasket 30, the pressure is 1.54MPa at the lowest portion and 1.71MPa at the highest portion. That is, as a result of the analysis, it is found that when the rib height Hr is set to 1/6 or more and 1/4 or less of the gasket height Hp, the difference in pressure (difference between the maximum pressure and the minimum pressure) acting on the contact surface of the gasket 30 with the waterproof surface 13b (hereinafter referred to as "waterproof contact surface") is 0.2MPa or less. Therefore, it is clear that by setting the rib height Hr within the above range, the pressure difference in the circumferential direction of the gasket 30 is small, and a good waterproof structure can be obtained.

As shown in fig. 5, in the waterproof structure of the present embodiment, the rib width Wr is set to 2/5 or less of the gasket width Wp. As described above, the step surface 13 is constituted by the outer peripheral end portion 13a from which the rib 14 protrudes and the waterproof surface 13b that is in surface contact with the gasket 30, and therefore, the width of the step surface 13 is equal to the sum of the width of the outer peripheral end portion 13a (i.e., the rib width Wr) and the width Wf of the waterproof surface 13 b. Therefore, by setting the rib width Wr to 2/5 or less of the gasket width Wp, the width Wf of the waterproof surface 13b is larger than half of the gasket width Wp, and thus waterproofness can be ensured.

The rib width Wr of the present embodiment is set to be equal to or greater than 1/4 of the gasket width Wp. This is because the smaller the rib width Wr is, the larger the width Wf of the waterproof surface 13b is, but if the rib width Wr is too small, the capability (pressing force, seizing) of pressing the gasket 30 to the side surface 11 side is reduced. That is, the rib 14 functions to prevent the gasket 30 fitted to the convex portion 10 from being twisted as described above, and therefore, it is necessary to set the width capable of exerting the function.

In the present embodiment, the rib heights Hr of the plurality of ribs 14 are all set to be the same, and the rib widths Wr of the plurality of ribs 14 are also all set to be the same. On the other hand, the rib length Lr may not be the same for all the ribs 14. For example, as shown in fig. 2, two ribs 14 disposed on the short sides of the convex portion 10 may be set longer than three ribs 14 disposed on the long sides of the convex portion 10. The rib length Lr can be appropriately set in accordance with the relationship between the interval and number of the ribs 14 arranged in an island shape along the outer peripheral end portion 13a and the occupancy ratio.

[2. Effect ]

(1) According to the waterproof structure described above, the fitted state of the gasket 30 fitted to the convex portion 10 can be appropriately maintained by the rib 14. That is, when the convex portion 10 and the concave portion 20 are fitted to each other, the portion of the gasket 30 that is offset from the corner K can be prevented from being compressed by the stepped surface 13 and the second receiving surface 23, and the gasket 30 can be prevented from being twisted. Even if the outer surface of the gasket 30 (the surface of the gasket 30 opposite to the surface thereof in contact with the side surface 11) comes into contact with the inner surface 21 of the recess 20 and a force in the shear direction acts on the gasket 30, the corner portion 14a of the rib 14 can prevent the gasket 30 from being twisted.

Since the rib height Hr is set to 1/4 or less of the gasket height Hp, the occupancy can be suppressed to 100% or less. That is, according to the waterproof structure described above, the gasket 30 fitted to the convex portion 10 can be prevented from being twisted when the gear case 4 and the connector 5 are assembled, and therefore, the waterproof performance can be ensured. Since the ribs 14 are present, the behavior of the gasket 30 fitted to the convex portion 10 spreading outward can be prevented, and the posture of the gasket 30 can be appropriately maintained in a state before assembly.

(2) In the waterproof structure described above, the rib height Hr is set to be equal to or higher than 1/6 of the gasket height Hp, and therefore, as described above with reference to fig. 7, the difference in pressure (difference between the maximum pressure and the minimum pressure) acting on the waterproof contact surface of the gasket 30 can be suppressed to 0.2MPa or less. That is, according to the waterproof structure described above, the difference in pressure acting on the waterproof contact surface of the gasket 30 in the circumferential direction can be reduced, and substantially the same pressure acts at any position, so that excellent waterproof performance can be ensured.

(3) In the waterproof structure described above, since the rib width Wr is set to 2/5 or less of the gasket width Wp, the waterproof surface 13b provided on the step surface 13 can be sufficiently ensured, and the waterproof performance can be ensured.

(4) In the waterproof structure described above, since the rib width Wr is set to 1/4 or more of the gasket width Wp, the gasket 30 can be prevented from being twisted. Thereby also ensuring waterproof performance.

(5) Further, since the corner portion 14a of the rib 14 is provided with a rounded corner, it is possible to contact the gasket 30 with a wide surface, and it is possible to effectively prevent the gasket 30 from being twisted.

(6) The rib 14 is disposed in an island shape at the outer peripheral end 13a of the stepped surface 13. Thus, the ribs 14 are not provided on the entire outer peripheral end portion 13a (the entire circumference), but the ribs 14 are arranged at a plurality of positions with intervals therebetween, whereby the volume Vr of the ribs 14 can be reduced. Therefore, the proportion of the rib 14 in the compression space can be suppressed, and the gasket 30 can be prevented from expanding outward and from twisting during assembly.

(7) According to the motor 1, the waterproof structure is applied to the fitting portion between the gear case 4 and the connector 5 that house the reduction mechanism 13, and therefore, the gasket 30 can be prevented from being twisted when the gear case 4 and the connector 5 are assembled, and the waterproof performance of the fitting portion can be ensured.

[3. other ]

The waterproof structure is an example, and is not limited to the above structure. For example, the above-described ribs 14 are arranged three on the long side of the convex portion 10 and two on the short side of the convex portion 10, but one rib may be provided on each of the portions other than the four corners of the convex portion 10. In this case, if the rib is disposed at the center of each side, the volume of the rib can be reduced and the expansion and twisting of the gasket 30 can be effectively prevented.

The corner 14a of the rib 14 may not be rounded. In this case, the corner portions of the ribs 14 are easily bitten into the gasket 30, and therefore the posture of the gasket 30 can be easily maintained. In the above-described waterproof structure, the rib heights Hr of the plurality of ribs 14 are all set to be the same, and the rib widths Wr of the plurality of ribs 14 are also all set to be the same, but the rib heights Hr and the rib widths Wr may be set to different values depending on the position.

For example, the rib disposed on the long side of the convex portion 10 where the gasket 30 is likely to expand may be made higher than the rib disposed on the short side, and the rib on the short side may be made thinner than the rib on the long side in order to secure a wider waterproof surface 13 b. Thus, when the size of the rib is changed depending on the position, for example, there may be a rib in which the rib width Wr is not less than 2/5 of the gasket width Wp, or a rib in which the rib height is not more than 1/6 and not more than 1/4 of the gasket height Hp.

In the waterproof structure described above, the stepped surface 13 is formed in the fitting portion 5a of the connector 5 and the convex portion 10 is provided on the distal end side, but the shape of the connector 5 may not be the above shape. For example, the surface on which the gasket 30 is placed may not be formed as the stepped surface 13. The irregularities may be reversed from the above configuration. In other words, even in the case where the convex portion is provided in the gear case and the concave portion is provided in the connector, the same structure as that of the waterproof structure described above can be applied.

The shape of the gasket 30 is an example, and the vertical cross-sectional shape may be, for example, a circle, an ellipse, or a polygon instead of the rounded hexagon. The above-described structure of the motor 1 is an example, and the structure of the motor unit 2 and the reduction mechanism 3 may not be the above-described structure. The position of the connector 5 with respect to the gear case 4 is not limited to the position shown in fig. 1.

Claims

1. A waterproof structure of a gear box is used for embedding a connector and is characterized in that,

this waterproof construction of gear box possesses:

a recess provided in one of the connector and the gear case;

a convex portion provided on the other of the connector and the gear case and fitted into the concave portion;

a mounting surface provided so as to surround the convex portion and extending in a direction intersecting a protruding direction of the convex portion;

a gasket that is in a ring shape surrounding the convex portion and is assembled in contact with both the side surface of the convex portion and the mounting surface before the concave portion is fitted to the convex portion; and

a rib provided so as to protrude in the same direction as the protruding direction at an outer peripheral end portion of the mounting surface and having a corner portion that contacts the gasket,

the protruding height of the rib is set to be 1/4 or less of the height dimension of the gasket.

2. The waterproof structure of a gearbox according to claim 1,

the protruding height of the rib is set to be greater than or equal to 1/6 of the height dimension of the gasket.

3. The waterproof structure of a gearbox according to claim 1 or 2,

the width of the rib is set to 2/5 or less of the width of the gasket.

4. The waterproof structure of a gearbox according to claim 3,

the width of the rib is set to be greater than or equal to 1/4 of the width of the gasket.

5. The waterproof structure of a gearbox according to any one of claims 1 to 4,

rounded corners are provided at the corners of the ribs.

6. The waterproof structure of a gearbox according to any one of claims 1 to 5,

the ribs are arranged at intervals along the outer peripheral end of the mounting surface.

7. A motor with a speed reducer is characterized in that,

the motor with a speed reducer comprises:

a motor unit including a rotor and a stator; and

a speed reduction mechanism including a worm to which rotation of the motor unit is transmitted, and a worm wheel meshed with the worm,

the waterproof structure for a gear box according to any one of claims 1 to 6 is adapted to accommodate a fitting portion between the gear box of the reduction mechanism and a connector fitted to the gear box.