JP6128866B2 - Geared motor - Google Patents

Description

  The present invention relates to a geared motor used for opening / closing driving of an opening / closing body.

Recently, toilet seats, toilet lids, and washing machine lids have been required to have geared motors in order to reduce the user's labor for opening and closing them as much as possible and improve usability.
In such a geared motor, a reduction gear train is provided to increase the output of the motor. However, in order to make the whole compact, a reduction gear train using a small gear made of resin is used. Many.
Here, if the user suddenly opens and closes the toilet seat, etc. while the motor is stopped, or opens / closes the toilet seat, etc. in the direction opposite to the direction driven by the motor, the motor, each gear, its support shaft or support boss, etc. Excessive force may be applied and damage may occur. As a countermeasure, a torque limiter that rotates relatively when a predetermined torque or more is applied is incorporated in the reduction gear train.
As a geared motor provided with such a torque limiter, there exists a thing as disclosed by Unexamined-Japanese-Patent No. 2006-95120, for example.

JP 2006-95120 A

The geared motor torque limiter disclosed in Japanese Patent Application Laid-Open No. 2006-95120 has a corrugated spring disposed between two members, transmits torque by frictional force, and slides and rotates relatively when large torque is applied. It is the structure to make.
However, since the torque transmission limit is not clear and easily fluctuates with a simple frictional force, the stability and reliability of the operation are low.
For this reason, it is conceivable to form a torque limiter with a ratchet that combines an elastic arm and a cam. According to this, the torque transmission limit can be accurately set based on the deformation characteristics of the elastic arm and the inclination of the cam, and stable operation can be expected.
Accordingly, an object of the present invention is to provide a highly reliable geared motor including a stable torque limiter using a ratchet.

The geared motor of the present invention is a geared motor configured by housing a motor and a reduction gear train for transmitting the rotation of the motor to an output gear in a case, wherein one gear in the reduction gear train is a preceding gear. A large-diameter gear that meshes with a small-diameter gear that meshes with a rear-stage gear, and the large-diameter gear has a drum shape in which an outer cylinder is extended from an end wall, and has teeth on the outer periphery of the outer cylinder and a cam on the inner periphery. A bearing part having a shaft hole at the center of the end wall, the bearing part of the large-diameter gear extends into the outer cylinder to form an inner cylinder, and the small-diameter gear axially connects the ratchet member and the pinion And the ratchet member includes a base and a connection portion extending in the axial direction from the base, the base includes a through-hole penetrating the support shaft, and the ratchet member and the pinion are connected to the connection portion. Detent constructed between pinions Is configured to be integrally rotated by part, from the base of the ratchet member extending arms of the elastic with a claw at the distal end in the circumferential direction, the first gear, cam and pawl disposed arm into the barrel of the large diameter gear A ratchet type torque limiter is formed by engaging the surface, and the large-diameter gear and the small-diameter gear are directly supported by a common support shaft in each shaft hole.

  According to the present invention, since the large-diameter gear and the small-diameter gear of the gear having the ratchet mechanism formed therein are directly supported by the support shaft, respectively, when one of the two gears is supported by the support shaft via the other As a result of reducing the mutual inclination in comparison, fluctuation of the transmission torque due to the irregular engagement of the arm claw and the cam surface due to the inclination is suppressed, and the original stable operation of the torque limiter by the ratchet mechanism is obtained. The meshing between the gear and the front and rear gears is also maintained smoothly in a normal posture.

It is a figure which shows the external appearance of the geared motor of embodiment. It is a perspective view of the geared motor which removes and shows an upper cover. It is an expanded sectional view of the 1st gear. It is a bottom view of an upper cover. It is a top view of the upper housing which attached the middle cover. It is a perspective view which shows the upper surface of the upper housing which removed the middle cover. It is a perspective view which shows the lower surface of an upper housing. It is a perspective view which turns over a middle cover and shows a lower surface. It is a top view which shows arrangement | positioning of the reduction gear in a lower housing. It is a bottom view of the reduction gear shown with the lower housing removed. It is the perspective view which looked at the lower housing from diagonally forward. It is the perspective view which looked at the lower housing from diagonally lower left. It is a perspective view which shows the upper surface of a lower cover. It is a figure which shows a 3rd gear. It is a figure which shows an output gear. It is an expanded view of a reduction gear train. It is a partial top view which shows the output rotation control mechanism. It is sectional drawing which shows arrangement | positioning of an angle sensor. It is a bottom view of the geared motor shown by removing the lower cover.

Next, an embodiment in which the present invention is applied to a geared motor for opening and closing such as a toilet seat and a toilet lid will be described.
1A and 1B show the appearance of the embodiment, in which FIG. 1A is a perspective view from the upper front side, FIG. 1B is a perspective view from the lower front side, and FIG.
That is, in the following description of the embodiment, the left front side in FIG. 1A is the front, the right back side is the rear, the left back side is the right, the right front side is the left, and the upper side is the top.
The geared motor 1 accommodates a DC motor 2, a reduction gear train 6, and an angle sensor 180, which will be described later, in a case 7 including a resin upper cover 10, a middle cover 30, an upper housing 40, a lower housing 70, and a lower cover 110. Configured. The planar shape of the case 7 is a substantially rectangular shape with a rounded front side.

The upper housing 40 is overlaid on the lower housing 70, and the upper cover 10 is overlaid on the upper housing 40. The middle cover 30 is overlaid on a predetermined portion of the upper housing 40.
An output hole 84 through which an output shaft member (not shown) connected to a hinge shaft such as a toilet lid is inserted is formed in the bottom wall 71 of the lower housing 70.
The lower cover 110 covers a part of the bottom wall 71 of the lower housing 70 except for the periphery of the output hole 84.

At the lower end of the upper cover 10, a mounting portion 14a is provided at the approximate center of the front wall 12a and at the corner between the right wall 12c (see FIG. 4) and the rear wall 12d, and the corner between the left wall 12b and the rear wall 12d. The attachment part 14b is provided in the front part of the part and the left wall 12b.
The attachment portions 14a and 14b are set in a flange shape within a substantially rectangular outline formed by the peripheral walls (the front wall 12a, the left wall 12b, the right wall 12c, and the rear wall 12d).
The upper cover 10 and the upper housing 40 (and the middle cover 30) are coupled to the lower housing 70 by fastening together with screws 8a and 8b at the attachment portions 14a and 14b.
Upper portions of the attachment portions 14a and 14b on the peripheral wall of the upper cover 10 are recessed portions 23 that extend to the top wall 11 as a passing space for a driver that tightens the screws 8a and 8b.

At the center in the width direction of the front wall 72a of the lower housing 70, a straight groove 73 extends from the bottom surface of the bottom wall 71 to a height of a little over 1/2.
The rear wall 72d of the lower housing 70 has a bank portion 74 in which an intermediate portion in the width (left and right) direction bulges up and down.
The external wiring 107 from the DC motor 2 and the angle sensor 180 inside the case 7 is drawn out from the lower end side portion of the bank portion 74.

  As will be described later, the reduction gear train 6 includes a second gear 126, a third gear 130, a fourth gear 150, and an output gear 155 that are sequentially connected from the first gear 121 that meshes with the pinion gear 120 of the DC motor 2. Each gear except for the third gear 130 is made of resin, and in particular, the first, second, and fourth gears 121, 126, 150 are each integrally provided with a large-diameter gear and a small-diameter gear. The third gear 130 will be described separately.

FIG. 2 is a perspective view in which the upper cover 10 is removed and a part of the reduction gear train 6 is seen obliquely from the upper right rear.
At the rear of the upper housing 40, a pinion gear 120 of the DC motor 2 attached to the lower surface side with a screw 29 protrudes to the upper surface side, and is arranged on the left side and is a large-diameter gear 121a of the first gear 121 supported by the support shaft 124. Meshes with the pinion gear 120.
The small-diameter gear 121b of the first gear 121 and the large-diameter gear 126a of the second gear 126 arranged on the front portion of the upper housing 40 and supported by the support shaft 127 mesh with each other, and are arranged on the right side with the small-diameter gear 126b of the second gear 126. The large-diameter gear 130a of the third gear 130 supported by the support shaft 149 is engaged.

FIG. 3 is an enlarged cross-sectional view of the first gear 121.
In the first gear 121, a small-diameter gear 121b extends upward from the large-diameter gear 121a, and a shaft hole 122 penetrates from the large-diameter gear 121a to the small-diameter gear 121b.
A narrow ring protrusion 123 surrounding the opening of the shaft hole 122 is formed on the lower end surface of the large diameter gear 121a, and a ring protrusion 123 surrounding the opening of the shaft hole 122 is also formed on the upper end surface of the small diameter gear 121b. Yes.
Although not shown in detail, a lower end surface of a small-diameter gear 126b of a second gear 126, a lower end surface of a small-diameter gear 130b of a third gear 130, an upper end surface of a large-diameter gear 150a of a fourth gear 150, and a small-diameter gear 150b. A similar ring projection surrounding the opening of each shaft hole is also formed on the lower end surface of each.

FIG. 4 is a bottom view of the upper cover 10.
An attachment hole 15a that allows the screw 8a to pass therethrough penetrates the attachment portion 14a at the lower end of the peripheral wall, and an attachment hole 15b that penetrates the screw 8b passes through the attachment portion 14b. The diameter of the attachment hole 15a is larger than that of the attachment hole 15b.
The top wall 11 of the upper cover 10 has a support boss 16 for supporting the support shaft 124 of the first gear 121, a support boss 18 for supporting the support shaft 127 of the second gear 126, and a third gear 130. A support boss 20 for supporting the support shaft 149 is provided.
Shaft holes 17, 19, and 21 into which the upper ends of the support shafts 124, 127, and 149 are inserted are opened at the lower end surfaces of the support bosses 16, 18, and 20.
The lower portion of the support boss 20 is partially cut away to avoid interference with the large-diameter gear 126a of the second gear 126.

The above-described support boss 16 and the like are integrally formed when the upper cover 10 is resin-molded. The same applies to each support boss described later in the upper housing 40, the middle cover 30, and the lower housing 70.
Further, each member constituting the case 7 is formed with a plurality of ribs for securing rigidity, but the description thereof will be omitted.

FIG. 5 is a top view of the upper housing 40 to which the middle cover 30 is attached.
The middle cover 30 is overlaid on the left front portion of the upper housing 40.
An attachment portion 31a having an attachment hole 32a corresponding to the attachment hole 15a of the upper cover 10 is provided at the front end portion of the middle cover 30, and an attachment having an attachment hole 32b corresponding to the attachment hole 15b of the upper cover 10 is provided at the left end portion. A portion 31b is provided.
The upper housing 40 is provided with an attachment portion 41a having an attachment hole 42a corresponding to the attachment hole 15a of the upper cover 10 and an attachment portion 41b having an attachment hole 42b corresponding to the attachment hole 15b.

The upper cover 10 is set so that the corresponding mounting portions 14a and 14b of the upper cover 10 are seated on the upper surfaces of the mounting portions 31a and 31b of the middle cover 30 and the mounting portions 41a and 41b of the upper housing 40 when the upper cover 10 is stacked. is there.
The peripheral edge of the section from the attachment part 31a to the attachment part 31b of the middle cover 30 is cut out by a predetermined amount, and the corresponding peripheral edge of the upper housing 40 is also cut out in the same manner.
A lower end of the peripheral wall of the upper cover 10 extends in the section of the middle cover 30, and an upper end of the peripheral wall of the lower housing 70 extends and covers the section of the upper housing 40.

In the rear part of the upper housing 40, a motor shaft through hole 44 and a mounting hole 45 are provided at a point symmetrical position with the motor shaft through hole 44 interposed therebetween. The DC motor 2 is fixed to the lower surface of the upper housing 40 by tightening the screws 29 through the mounting holes 45 in the screw holes 5 (see FIG. 9) provided in the upper end wall of the DC motor 2.
A support boss 46 for supporting the support shaft 124 of the first gear 121 rises further to the front left side of the motor shaft through hole 44 in the upper housing 40, and the lower end of the support shaft is inserted into the upper end surface of the support boss 46. A shaft hole 47 is opened.
A gear through hole 48 through which the third gear 130 passes is provided on the right side of the center of the upper housing 40 in the front-rear direction.

A support boss 33 for supporting the support shaft 127 of the second gear 126 is raised on the middle cover 30. A shaft hole 34 into which the lower end of the support shaft 127 is inserted is opened at the upper end surface of the support boss 33.
A positioning pin 49 is formed at an intermediate position between the support boss 46 and the gear through hole 48, and a positioning hole 35 is formed at the rear end portion of the middle cover 30 so as to be aligned therewith. This ensures the positional accuracy between the support boss 46 (shaft hole 47) of the first gear 121 formed in the upper housing 40 and the support boss 33 (shaft hole 34) of the second gear 126 formed in the middle cover 30. Is done.

6 is a perspective view of the upper surface of the upper housing 40 from which the middle cover 30 is removed as viewed obliquely from the upper left front, FIG. 7 is a perspective view of the lower surface of the upper housing 40 as viewed from the obliquely lower left front, and FIG. It is a perspective view which turns over 30 and shows the lower surface.
As shown in FIG. 6, a substantially circular concave portion 50 is formed in the front portion on the upper surface side of the upper housing 40, and a cylindrical portion 52 rises from the bottom wall 51 of the concave portion 50.
Cut portions 53 (53a, 53b) having a predetermined width extending from the upper end to the vicinity of the bottom wall 51 are formed at two locations facing the cylindrical portion 52 in the substantially front-rear direction.
The cylindrical portion 52 extends downward and protrudes from the lower surface of the upper housing 40 by a predetermined length. The lower portion of the cylindrical portion 52 below the lower end of the notch 53 has a smaller diameter than the upper portion, and serves as an upper bearing portion 55 of the output gear 155.

  In the upper housing 40, the middle cover 30 overlaps with a mounting portion 41a having a mounting hole 42a corresponding to the mounting hole 15a of the upper cover 10 and a mounting portion 41b having a mounting hole 42b corresponding to the mounting hole 15b. It has been. The attachment hole 42a and the attachment hole 42b are aligned with the attachment hole 32a and the attachment hole 32b of the middle cover 30, respectively.

As shown in FIG. 8, the lower surface of the middle cover 30 is provided with a ring groove 36 that accommodates the upper end of the cylindrical portion 52 of the upper housing 40.
A bridge crosses the ring groove 36 in the radial direction. That is, a small-width bridge 37a that can be received by the notch 53a is provided at a position corresponding to one notch 53a of the cylindrical portion 52, and a position that corresponds to the other notch 53b is substantially larger than the width of the notch 53b. A bridge 37b is provided. The large bridge 37b is set at a position corresponding to the lower surface of the support boss 33 on the upper surface side.
As shown in FIG. 6, a notch 54 having a width for receiving a large bridge 37b of the middle cover 30 is formed at the upper end of the cylindrical portion 52 of the upper housing 40 with the notch 53b at the center.
The lower surface of the upper housing 40 will be described later.

9 is a top view showing the arrangement of the reduction gear train 6 in the lower housing 70, and FIG. 10 is a bottom view of the reduction gear train 6 under the upper housing 40 as viewed from below with the lower housing 70 removed. FIG. 9 also shows a third gear 130 vertically passing through the gear through hole 48 of the upper housing 40.
On the lower side of the upper housing 40, the small-diameter gear 130 b of the third gear 130 and the large-diameter gear 150 a of the fourth gear 150 arranged on the front right side of the case 7 and supported by the support shaft 151 mesh with each other. The small gear 150b and the output gear 155 arranged on the left side of the front part mesh with each other.

From the lower surface of the upper housing 40, as shown in FIG. 7, a support boss 58 for supporting the upper end of the support shaft 151 of the fourth gear 150 is provided on the right side of the front portion, and a shaft hole 59 is opened at the lower end surface. ing. Further, on the left side of the front portion, a cylindrical upper bearing portion 55 for the output gear 155 extends further downward from substantially the same level as the lower end surface of the support boss 58. A notch 56 having a predetermined width in the circumferential direction is formed from the base to the lower end at a portion of the upper bearing portion 55 facing the support boss 58.
A rear portion of the lower surface of the upper housing 40 is a motor upper housing portion 60 that houses the DC motor 2.

FIG. 11 is a perspective view of the lower housing 70 as viewed obliquely from above and front.
On the peripheral wall of the lower housing 70, there are provided mounting portions 77a and 77b that bulge inward from the inner surface and have screw holes 78a and 78b corresponding to the mounting holes 15a and 15b of the upper cover 10 opened at the upper end surface. Yes.
The upper end surfaces of the attachment portions 77a and 77b are positioned at the upper end of the peripheral wall, and are set so that the lower surfaces of the attachment portions 41a and 41b of the upper housing 40 are seated when the upper housing 40 is overlapped.
The opening of the screw hole 78a of the mounting portion 77a is surrounded by a protruding ring 79. The inner diameters of the mounting hole 15a of the upper cover 10, the mounting hole 32a of the middle cover 30 and the mounting hole 42a of the upper housing 40 are the same. The upper cover 10, the middle cover 30, the upper housing 40 and the lower housing 70 are positioned relative to each other by fitting each mounting hole to the protruding ring 79.

A motor lower housing part 80 surrounding the outer periphery of the DC motor 2 is provided at the rear part of the bottom wall 71 of the lower housing 70, and the motor lower housing part 80 has a large through hole.
A circular bearing-shaped lower bearing portion 82 for the output gear 155 is provided on the front left side of the bottom wall 71, and an output hole 84 passes through the center of the lower end wall 83 of the lower bearing portion 82. The output hole 84 has a slightly larger diameter than the connection hole 161 so that an output shaft member can be inserted into a connection hole 161 (described later) of the output gear 155 (see FIGS. 16 and 19).
A support boss 90 that supports the support shaft 151 of the fourth gear 150 is provided adjacent to the lower bearing portion 82 and on the front right side of the bottom wall 71, and a shaft hole 91 is opened at the upper end surface thereof.

Further, a support boss 85 for supporting the support shaft 149 of the third gear 130 is provided behind the support boss 85, and a shaft hole 86 is opened at the upper end surface thereof.
The first region S1 where the support boss 85 rises is offset above the second region S2 where the lower bearing portion 82 is opened and the support boss 90 is formed, and a space is formed below the first region S1. . The stepped portion due to the offset is formed as a cutout window 88 over a predetermined range sandwiched between the support boss 85 and the support boss 90, and communicates the upper and lower spaces.
For reference, FIG. 11 shows a sensor gear 187, which will be described later, facing the notch window 88. FIG.
A rotation sensor mounting seat 92 is provided on the lower surface side corresponding to a predetermined range of the first region S 1, and a corner portion of the mounting seat 92 protrudes from the lower end of the motor lower housing portion 80.

FIG. 12 is a perspective view of the lower housing 70 as viewed obliquely from the lower left.
In the bottom wall 71, a region excluding a predetermined range including the output hole 84 from the front to the left is offset upward from the outer surface (bottom surface) to form a lower cover mounting surface 97. An access window 98 is opened in the lower cover mounting surface 97, and the mounting seat 92 positioned above the lower cover mounting surface 97 by a predetermined distance is viewed.
From the mounting seat 92, pins 93a and 93b extend downward. The pins 93a and 93b have different diameters.
Further, the mounting seat 92 is formed with an upward recessed portion 94, and the top wall 95 of the recessed portion 94 forms a part of the first region S1 on the upper surface, and the shaft 188a of the sensor gear 187 (see FIG. 18) A shaft hole 96 is provided to support (see). The cutout window 88 extends from the side wall of the recess 94 to the vicinity of the shaft hole 96 of the top wall 95.

The peripheral edge of the access window 98 on the lower cover mounting surface 97 is a seal surface 97a offset downward by a predetermined amount. A seal ring 119 (see FIG. 19) is disposed on the seal surface 97a.
Screw holes 99a and 99b are opened at four corners of the lower cover mounting surface 97. Among them, the right front and left rear screw holes 99a have large-diameter recesses 100 at the open ends.
The lower cover mounting surface 97 is formed with a guide groove 102 for guiding the external wiring 107 along the rear wall 72d (the bank portion 74), and one end thereof is connected to the access window 98 across the seal surface 97a at a substantially intermediate position in the left-right direction. The other end is opened to the outside from a notch 103 provided at the lower end of the rear wall 72d in the vicinity of the screw hole 99a in the left rear part.

FIG. 13 is a perspective view showing the upper surface of the lower cover 110.
The lower cover 110 has an outer shape that matches the contour of the lower cover mounting surface 97 of the lower housing 70, and the corners thereof correspond to the screw holes 99a and 99b of the lower housing 70 and the mounting holes 112a and 112b through which the screws 25 pass. There are provided mounting portions 111a and 111b.
The right front and left rear mounting holes 112 a are provided with projecting rings 113 corresponding to the large-diameter recesses 100 of the screw holes 99 a of the lower housing 70 at the opening ends, and by fitting the projecting rings 113 and the large-diameter recesses 100 to each other. The lower cover 110 is accurately positioned with respect to the lower housing 70.

A flange 114 having a predetermined height is formed inside the outer peripheral edge of the lower cover 110, and the outer peripheral surface of the flange 114 is set along the hole edge of the access window 98 of the lower housing 70. The seal ring 119 is disposed between the seal surface 118 and the seal surface 97 a of the lower housing 70.
On the inner side of the flange 114, pressing bosses 115a and 115b are provided at positions corresponding to the pins 93a and 93b of the lower housing 70. The heights of the holding bosses 115a and 115b are such that when the lower cover 110 is attached to the lower cover attachment surface 97 in a state where the later-described substrate 181 of the angle sensor 180 is attached to the attachment seat 92 of the lower housing 70, the upper end surface is the substrate 181. It is set so that it contacts the lower surface. Holes 116a and 116b for receiving pins 93a and 93b are opened on the upper end surfaces of the holding bosses 115a and 115b.
In the figure, reference numeral 117 denotes an escape portion for avoiding interference between the rib and the shaft 188b (see FIG. 18) of the sensor gear 187 of the angle sensor 180.

14A and 14B show details of the third gear 130, wherein FIG. 14A is a longitudinal sectional view, FIG. 14B is a sectional view taken along the line AA in FIG. 14A, and FIG. 14B is a sectional view taken along the line BB in FIG. is there.
The third gear 130 is composed of, for example, a large-diameter gear 130a made of polyacetal resin and a small-diameter gear 130b that is separate from this, and the small-diameter gear 130b is further sintered with a ratchet member 137 made of the same resin as the large-diameter gear 130a. It consists of a metal pinion 146.
The large-diameter gear 130a includes a ring-shaped end wall 132 and a drum-shaped outer cylinder 131 that extends downward from the outer peripheral edge of the end wall 132, and has a cup shape with an open bottom. A tooth is provided on the outer periphery of the outer cylinder 131, and a bearing portion 133 having a shaft hole 134 at the center extends downward from the center of the end wall 132 to form an inner cylinder 133a. That is, the shaft hole 134 is continuously formed from the upper end of the end wall 132 to the lower end of the inner cylinder 133a, and functions as a radial bearing. The large-diameter gear 130a is directly supported by a support shaft 149 inserted through the shaft hole 134 and is rotatable.
Compared with the shaft hole of the wall thickness of the end wall 132, the shaft hole 134 is remarkably longer by the amount of the inner cylinder 133a. Therefore, the axial center accuracy is high and the support shaft 149 is not tilted (inclined). .

  Further, since the inner cylinder 133a extends in the axial direction until it overlaps with the arm 139 and the claw 140 described later in the radial direction, the axial hole 134 is lengthened without increasing the axial size of the entire third gear 130. Can do. That is, the inner cylinder 133 a is arranged using a part of the arm 139 and the inner periphery of the claw 140. Since the inner cylinder 133a is extended in the axial direction until it overlaps with the arm 139 and the claw 140 in the radial direction, a concave portion having a cylindrical large meridian part 142 is provided below the center of the upper end surface of the ratchet member 137. Since the large portion 142 is longer than the axial length of the inner cylinder 133 a, the lower end of the inner cylinder 133 a does not come into contact with the bottom of the concave portion formed by the large diameter portion 142 of the ratchet member 137.

Note that the cervical part 142 also extends in the axial direction until it overlaps the arm 139 and the claw 140 in the radial direction. That is, the concave portion constituted by the large diameter portion 142 extends to the inner periphery of the base portion 138. For this reason, the radial thickness of the upper part of the base 138 is smaller than the radial thickness of the lower part of the base 138. However, the length of the large meridian portion 142 extending to the inner peripheral side of the arm 139 and the claw 140 is less than half of the axial thickness of the arm 139 and the claw 140, and the concave portion constituted by the large diameter portion 142 causes the arm 138 to extend. Since it is positioned in the opposite direction (upward) to the connecting portion 143 side (downward) described later as a reference, the strength from the connecting portion 143 side to the arm 138 is ensured, and the inclination of the arm 139 and the claw 140 can be reduced.
A predetermined range surrounding the opening of the shaft hole 134 slightly protrudes from the upper surface of the end wall 132 to form a ring protrusion 132a. The radial end of the large gear 126a of the second gear 126 extends to above the ring protrusion 132a.
A cam surface 135 is formed from the open end, that is, the lower end of the outer cylinder 131 to the lower surface of the end wall 132 on the inner surface of the outer cylinder 131, that is, the inner periphery of the large-diameter gear 130 a.

The ratchet member 137 includes a base portion 138 and a cylindrical connection portion 143 that extends downward from the lower end of the base portion 138 and has a spline 144 (FIG. 14C) having the same cross-sectional shape as the teeth of the pinion 146 on the inner surface. Become. Pinion 146 teeth and splines 144 extend axially.
From the outer periphery of the base portion 138, particularly as shown in FIG. 14B, three arms 139 each having a claw 140 that engages with the cam surface 135 of the large-diameter gear 130a at the tip end are equally spaced in the circumferential direction. It extends in the circumferential direction.
The axial position of the arm 139 is set so as to have a predetermined gap between the upper end of the base portion 138 and the connecting portion 143.

A large passage 142 located above the through hole 141 in which a through hole 141 through which the support shaft 149 passes is formed in the shaft center of the base 138 is an outer periphery of the inner cylinder 133a protruding from the end wall 132 of the large diameter gear 130a. And facing with a gap. In the present embodiment, the gap between the large meridian part 142 and the inner cylinder 133a is made twice or more wider than the gap between the shaft hole 147 of the pinion 146 and the support shaft 149, which will be described later.
In addition, since the outer periphery of the base portion 138 extends in the axial direction until reaching the end wall 132 in spite of the provision of the meridian portion 142, the arm 139 remains on the base portion 138 with the same thickness as the axial direction thickness of the claw 140. It is lined up. For this reason, the inclination of the nail | claw 140 with respect to the base 138 by the arm 139 inclining by the radial direction force which the nail | claw 140 receives from the cam surface 135 can be reduced.

Thus, the support shaft 149, the through hole 141, the base 138, the arm 139, and the claw 140 overlap in the radial direction from the inner peripheral side.
The upper end surface of the large meridian part 142 and the lower surface of the end wall 132 face each other in the axial direction and function as a thrust bearing that regulates the axial position of the large diameter gear 130a and the small diameter gear 130b.
In addition, the ring protrusion 132a of the large gear 130a and the support boss 20 of the upper cover 10 face each other in the axial direction and function as a thrust bearing that regulates the axially upper position of the third gear 130, and the lower side of the pinion 146 The ring projection 148 and the support boss 85 of the lower housing 70 face each other in the axial direction and function as a thrust bearing that regulates the axially lower position of the third gear 130.

When the ring projection 132a of the large-diameter gear 130a and the support boss 20 of the upper cover 10 abut on each other in the axial direction, and the ring projection 148 on the lower side of the pinion 146 and the support boss 85 of the lower housing 70 abut, The upper end surface of the end and the lower surface of the end wall 132 are opposed to each other with a gap in the axial direction. In this state, the lower end of the claw 140 is positioned above the lower end of the cam surface 135. For this reason, even if the relative position in the axial direction of the large-diameter gear 130a and the small-diameter gear 130b is shifted, the entire area of the claw 140 in the axial thickness (from the upper end to the lower end) is engaged with the cam surface 135.
Since the upper end of the cervical part 142 extends above the upper ends of the claw 140 and the arm 139, the upper ends of the claw 140 and the arm 139 remain on the end wall 132 even if the upper end surface of the cervical part 142 contacts the lower surface of the end wall 132. Do not touch the bottom surface.

The pinion 146 has teeth on the outer periphery, and the shaft center functions as a bearing. The pinion 146 has a cylindrical shaft hole 147 that passes through the shaft center, and is rotatably supported by a support shaft 149 inserted through the shaft hole 147. A ring protrusion 148 surrounding the opening of the shaft hole 147 is formed on the lower end surface of the pinion 146.
An upper portion of the pinion 146 is press-fitted into the connection portion 143 of the ratchet member 137, and a rotation preventing portion is formed by spline coupling so that the pinion 146 can rotate integrally. It meshes with the radial gear 150a. At this time, only the tooth surface of the pinion 146 is press-fitted into the spline 144, and the tooth tip and the tooth bottom have a gap in the radial direction from the spline 144.
Since the ring protrusion 148 is also formed on the upper end surface of the pinion 146 and has an axially symmetrical shape, it is not necessary to confirm the orientation of the pinion 146 when coupled with the ratchet member 137.

  The small gear 130b in which the ratchet member 137 and the pinion 146 are integrated is supported by the support shaft 149 in the shaft hole 147 of the pinion 146, so that the through-hole 141 of the ratchet member 137 is supported by the support shaft 149 ( It does not need to function as a radial bearing. Conversely, a gap is provided between the through-hole 141 and the support shaft 149 so that the small-diameter gear 130b (ratchet member 137) is prevented from tilting with respect to the support shaft 149 by the contact between the through-hole 141 and the support shaft 149. . In the present embodiment, the gap between the through hole 141 and the support shaft 149 is more than twice as large as the gap between the shaft hole 147 of the pinion 146 and the support shaft 149. This is because the arm 139 extends from the outer periphery of the base portion 138 and the sink of the base portion 138 due to resin molding may become uneven, and the roundness of the through hole 141 decreases, so the through hole 141 and the support shaft 149 do not contact each other. This is because a large gap is required.

  On the other hand, since the pinion 146 is made of metal, the inner surface of the shaft hole 147 can be easily obtained with high accuracy. The clearance between the inner surface of the shaft hole 147 of the pinion 146 and the support shaft 149 is narrower than the clearance between the through hole 141 and the support shaft 149 in order to suppress the inclination of the small-diameter gear 130b (ratchet member 137). That is, even when it is difficult to improve the accuracy of the through-hole 141 of the ratchet member 137, the inclination of the pinion 146 is reduced by the shaft hole 147 of the pinion 146 having a small gap between the support shafts 149. Therefore, the pinion 146 is integrated with the pinion 146. The inclination of the ratchet member 137 configured as described above is also reduced. Since the pinion 146 supports the ratchet member 137 engaged with the large-diameter gear 150a at the upper end, the longer the overall length, the higher the axial accuracy. Further, since the pinion 146 is a spur gear whose teeth are radially formed from the axis, the pinion 146 is less likely to be deformed by sintering molding, and the dimensional accuracy can be increased. The same effect can be obtained even when the pinion 146 is formed by resin molding.

When the third gear 130 is configured by integrally molding the ratchet member 137 and the pinion 146 with resin, the third gear 130 has a complicated shape, for example, the arm 139 is configured from the outer periphery of the base 138. In addition, deformation due to sink marks is likely to occur in a contact portion (bearing) with the support shaft 149.
In the present embodiment, since the ratchet member 137 and the pinion 146 are separated, the contact portion (shaft hole 147) of the pinion 146 with the support shaft 149 can be formed with high accuracy.

The small-diameter gear 130b is positioned in the axial direction by bringing the upper end of the base portion 138 of the ratchet member 137 into contact with the lower surface of the end wall 132 of the large-diameter gear 130a, and makes the arm 139 face the cam surface 135.
As a result, the small diameter gear 130b and the large diameter gear 130a normally rotate in a locked state, but the arm 139 is elastically deformed when a predetermined relative rotational torque is applied between the large diameter gear 130a and the small diameter gear 130b. Thus, a torque limiter TL is formed in which the claw 140 slides on the cam surface 135 and relatively rotates.

The cam surface 135 of the large-diameter gear 130a is a surface (small diameter) that engages with the claw 140 when the small-diameter gear 130b rotates in the direction in which the arm 139 extends from the base portion 138 (clockwise in FIG. 14B). When the small-diameter gear 130b rotates in a direction opposite to the direction in which the arm 139 extends from the base 138 (counterclockwise in FIG. 14B) with a small inclination (with respect to the circumference around the rotation center of the gear 130b). The inclination of the surface engaged with the claw 140 is large. Thereby, the torque by which the arm 139 is elastically deformed and the claw 140 slides and rotates relative to the cam surface 135 is the same regardless of the rotation direction of the small-diameter gear 130b. For this reason, the arm 139 is elastically deformed when a predetermined relative rotational torque is applied between the large diameter gear 130a and the small diameter gear 130b, both when the toilet seat and the toilet lid are suddenly opened and when the toilet lid is suddenly closed. The claw 140 slides on the cam surface 135 and rotates relative to it.
The relative rotational torque above the predetermined value is set to a torque larger than the torque that can lift the toilet seat and the toilet lid.

Next, details of the output gear 155 will be described.
The output gear 155 includes a resin gear body 156 and an adapter 165, respectively.
15A and 15B show the output gear 155. FIG. 15A is an external view, FIG. 15B is a longitudinal sectional view, FIG. 15C is a top view, FIG. 15D is a bottom view, and FIG.
The gear body 156 has an axial center aligned with a base 157 having teeth on the outer periphery, and an upper shaft 158 extending in the axial direction and a lower shaft 160 extending in the axial direction.
The upper shaft 158 has a cylindrical shape and is provided with spline teeth 159 on the inner surface thereof, and a large-diameter portion 158a having a diameter larger than that of the upper shaft 158 is provided at the base of the outer periphery.
The outer periphery of the lower end of the lower shaft 160 is a seal holding portion 160b that holds a seal ring 175 with a step.
A connection hole 161 for inserting the output shaft member is opened at the lower end center of the lower shaft 160. In particular, as shown in FIG. 15D, the connecting hole 161 has a two-surface width portion 162, and a key groove 163 is formed in the center of the two-surface width portion 162 in the axial direction. The connecting hole 161 extends into the base 157.

In particular, as shown in FIGS. 15B and 15E, the adapter 165 is configured by extending a connecting portion 167 having a smaller diameter than the head 166 from the head 166 having substantially the same diameter as the upper shaft 158 downward in the axial direction. Spline teeth 168 corresponding to the spline teeth 159 of the upper shaft 158 are provided on the outer periphery of the connecting portion 167.
In the head 166, pin holding grooves 169 extending in the axial direction are formed on the outer peripheral surface on the diameter line. The pin holding groove 169 has a semicircular cross section.
The adapter 165 has a lightening hole 170 over its entire length.
The adapter 165 is integrated with the gear body 156 by spline coupling, with the connecting portion 167 being inserted into the upper shaft 158 until the lower end surface of the head 166 contacts the upper end surface of the upper shaft 158.

FIG. 16 is a development view of the reduction gear train 6 formed in the case 7.
The DC motor 2 includes a protruding portion 4 having a circular outer periphery coaxial with the motor output shaft 3 on the upper end wall thereof, and the protruding portion 4 is fitted into the motor shaft through hole 44 of the upper housing 40 so that the motor output shaft 3 is fitted. The inserted pinion gear 120 is positioned.
The first gear 121 in which the large-diameter gear 121 a meshes with the pinion gear 120 is rotatable around a support shaft 124 supported at both upper and lower ends by the support boss 16 of the upper cover 10 and the support boss 46 of the upper housing 40.

Hereinafter, the second gear 126 that sequentially meshes with the first gear 121 is rotatable around a support shaft 127 supported at both upper and lower ends by the support boss 18 of the upper cover 10 and the support boss 33 of the middle cover 30, and the third gear 130. Is rotatable about a support shaft 149 supported at both upper and lower ends by a support boss 20 of the upper cover 10 and a support boss 85 of the lower housing 70.
That is, the upper ends of the support shafts 124, 127, and 149 of the first, second, and third gears are supported by support bosses formed on the upper cover 10 that is a common case member.
The fourth gear 150 is rotatable around a support shaft 151 supported at both upper and lower ends by the support boss 58 of the upper housing 40 and the support boss 90 of the lower housing 70.

At the shaft end of the first gear 121 (here, the lower end surface of the large diameter gear 121a) facing the upper end surface of the support boss 46, an opening of the shaft hole 122 through which the support shaft 124 passes is provided as shown in FIG. A ring protrusion 123 having a narrow width is formed, and a ring protrusion 123 that surrounds the opening of the shaft hole 122 is also formed on the shaft end (the upper end surface of the small-diameter gear 121b) facing the lower end surface of the support boss 16. The friction at the time is reduced.
Similarly, the lower end surface of the small diameter gear 126b of the second gear 126 facing the upper end surface of the support boss 33, the lower end surface of the small diameter gear 130b (pinion 146) of the third gear 130 facing the upper end surface of the support boss 85, and Since ring projections are also formed on the lower end surface of the small-diameter gear 150b facing the upper end surface of the support boss 90 of the fourth gear 150 and the upper end surface of the large-diameter gear 150a facing the lower end surface of the support boss 58, respectively. Friction during rotation is reduced.

The first gear 121 to the fourth gear 150 are arranged such that when one of the upper and lower shaft ends comes into contact with the end surface of the corresponding support boss, the other shaft end faces the end surface of the corresponding support boss most recently. Thus, the respective axial direction (vertical direction) positions are regulated by the support bosses that support the vertical direction of the support shaft.
That is, in the case of the third gear 130, the lower end (ring protrusion 148) of the pinion 146 constituting the small-diameter gear 130b faces the upper end surface of the support boss 85 of the lower housing 70, and the upper end of the large-diameter gear 130a is the upper cover. The axial direction is positioned facing the lower end surface of the ten support bosses 20.

Finally, the output gear 155 that meshes with the small-diameter gear 150b of the fourth gear 150 holds the elastic seal ring 175 in the seal holding portion 160b, and the lower shaft 160 is supported by the lower bearing portion 82 of the lower housing 70. The shaft 158 is supported by the upper bearing portion 55 of the upper housing 40 and is rotatable.
In the output gear 155, the lower end surface of the lower shaft 160 is seated on the lower end wall 83 of the lower bearing portion 82, and the upper end surface of the upper portion 158 a of the upper shaft 158 is closest to the lower end surface of the cylinder forming the upper bearing portion 55. Oppositely, the axial position is regulated.
An output shaft member (not shown) is inserted into the connection hole 161 of the output gear 155, and the output shaft member and the output gear 155 can rotate together.
Each gear of the reduction gear train 6 is configured such that its rotation center and each support shaft are all parallel.
The support shafts 124, 127, 149, 151 that support the first gear 121 to the fourth gear 150 are made of metal (steel) such as SUS.

Next, the adapter 165 of the output gear 155 has a head 166 extending through the upper bearing portion 55 and extending into the cylindrical portion 52 on the upper surface of the upper housing 40 to restrict the rotation angle range of the output gear 155. It constitutes a part of RL.
FIG. 17 is a partial top view showing the rotation restricting mechanism RL around the adapter 165 (head 166) with the middle cover 30 removed.
A ring-shaped gap having a predetermined width W is provided between the head 166 and the cylindrical portion 52 of the upper housing 40, and a metal cylinder 174 is fitted on the outer periphery of the cylindrical portion 52.
A roller pin 172 is disposed in the pin holding groove 169 of the head 166, and a roller pin 173 is also disposed in the notches 53 a and 53 b of the cylindrical portion 52. The roller pin 172 disposed in the pin holding groove 169 having a semicircular cross section has a half cross section protruding from the outer peripheral surface of the head 166 into the ring-shaped gap, and the predetermined width W of the ring-shaped gap is set to be substantially equivalent to the radius of the roller pin 172. The roller pin 172 is held by the pin holding groove 169 and rotates together with the head 166 around the axis of the output gear 155 without dropping.

The wall thickness of the cylindrical portion 52 is set to be smaller than the diameter of the roller pin 173, and the roller pin 133 that is restricted from moving outward by the cylinder 174 protrudes from the inner surface of the cylindrical portion 52 into the ring-shaped gap. As a result, the output gear 155 is configured such that the roller pin 172 held in the pin holding groove 169 contacts the roller pin 173 arranged in one of the two cuts 53a and 53b of the cylindrical portion 52 and the roller pin 173 arranged in the other. The maximum rotatable range is restricted to an angle of slightly less than 180 ° to the position where it abuts on.
If the roller pins 172 and 173 have the same size and the same length and are symmetrical in the axial direction, management becomes easy and there is no fear of assembly errors.
As shown in FIG. 16, the upper end of the cylindrical portion 52 of the upper housing 40 is accommodated in the ring groove 36 on the lower surface of the middle cover 30 so that it does not fall down even if it is thin.

The rotation of the DC motor 2 is decelerated and transmitted to the output gear 155 by the reduction gear train 6 configured as described above, and the toilet seat or toilet lid connected to the output gear 155 via the output shaft member is connected to the rotation restricting mechanism RL. Can be driven from a substantially horizontal position to a predetermined angular position exceeding 90 °.
In addition, since a torque limiter TL is formed that rotates relatively between the large-diameter gear 130a and the small-diameter gear 130b when a torque exceeding a predetermined value is applied to the third gear 130, the toilet seat and the like are suddenly opened and closed when the DC motor 2 is stopped. Even when the toilet seat or the like is opened and closed in the direction opposite to the driving direction of the DC motor 2, damage due to excessive force applied to the DC motor 2, each gear, its support shaft, or the support boss is prevented.

The angle sensor 180 is disposed in association with the fourth gear 150.
As shown in FIG. 18, the angle sensor 180 includes a potentiometer 185 below a rigid board 181 printed with wiring, a sensor gear 187 having upper and lower shafts 188a and 188b, and a lower shaft 188b upward. To the substrate 181 and the potentiometer 185.
The board 181 is provided with pin holes 182a and 182b (see FIG. 19) corresponding to the pins 93a and 93b of the lower housing 70. By fitting the pin holes 182a and 182b into the pins 93a and 93b, a fourth gear is provided. The angle sensor 180 is positioned with respect to 150. At this time, since the pins 93a and 93b have different diameters, they are not erroneously assembled.
Further, since the pressing bosses 115a and 115b of the lower cover 110 receive the pins 93a and 93b and press the substrate 181 against the mounting seat 92, the angle sensor 180 is also positioned in the vertical direction.

The upper shaft 188 a of the sensor gear 187 is rotatably supported by a shaft hole 96 formed in the top wall 95 of the recess 94 in the lower housing 70.
The lower end portion of the fourth gear 150 (small-diameter gear 150b) faces the notch window 88 formed in the lower housing 70, and the sensor gear 187 meshes with this.
The rotation center of the sensor gear 187 and the shafts 188 a and 188 b are parallel to the gears of the reduction gear train 6.
The potentiometer 185 is configured such that an internal rotary unit (not shown) rotates integrally with a lower shaft 188b of the sensor gear 187, and detects and outputs the rotation angle. Specifically, the potentiometer 185 is a variable resistor and has a resistance value corresponding to the rotation angle of the sensor gear 187, that is, the rotation angle of the output gear 155.

Since the potentiometer 185 has a detectable absolute angle range limited to one rotation (360 °), when the output gear 155 rotates to an angle within the maximum rotatable range, the output gear 155 moves the fourth gear 150. Then, the number of teeth is set so that the rotation angle of the sensor gear 187 due to the speed increase ratio between the sensor gear 187 and the sensor gear 187 is less than 360 °.
The reduction gear train 6 includes a torque limiter TL. The torque limiter TL is formed on the third gear 130 on the DC motor 2 side from the fourth gear 150 with which the sensor gear 187 is engaged. And the fourth gear 150 are not slipped, and the rotational position of the output gear 155 can always be detected by the angle sensor 180 with high accuracy.

FIG. 19 is a bottom (bottom) view of the geared motor 1 with the lower cover 110 removed.
A connection hole 161 of the lower shaft 160 of the output gear 155 faces the output hole 84.
From the access window 98, the lower end of the DC motor 2 held in the motor lower housing 80 and the angle sensor 180 having the substrate 181 attached to the pins 93a and 93b are viewed.
In the figure, reference numeral 119 denotes a seal ring disposed on the seal surface 97a (see FIG. 12) along the periphery of the access window 98.
The external wiring 107 is not shown.

The geared motor 1 is assembled by first inserting the output gear 155 (lower shaft 160), the support shaft 151, and the support shaft 149 disposed in the lower housing 70 into the lower bearing portion 82, the support boss 90, and the support boss 85 for support. Let
A seal ring 175 is fitted into the seal holding portion 160 b of the lower shaft 160.
The support shafts 151 and 149 may be press-fitted.
Then, after the fourth gear 150 is inserted through the support shaft 151, the upper housing 40 to which the DC motor 2 is attached in advance is overlapped, and the upper shaft 158 of the output gear 155 and the upper bearing portion 55 and the support boss 58 on the lower surface side are overlapped. The upper end of the support shaft 151 is inserted. Since it is a non-visual operation, it is preferable to set the support shaft 151 to non-press-fit. The support shaft 149 protrudes to the upper surface side of the upper housing 40.

Since the adapter 165 (head 166) faces the cylindrical portion 52 on the upper surface side of the upper housing 40, the roller pin 172 is inserted into the pin holding groove 169, and the cylindrical portion 174 is fitted to the outer periphery of the cylindrical portion 52. The roller pin 173 is inserted into the notches 53a and 53b of 52. Thereafter, the middle cover 30 is overlaid on the upper housing 40.
The support shaft 127 and the support shaft 124 are inserted into and supported by the support boss 33 of the middle cover 30 and the support boss 46 of the upper housing 40. The support shafts 124 and 127 may be press-fitted.

Then, the third gear 130 is inserted into the support shaft 149, and the small-diameter gear 130 b extends from the gear through hole 48 of the upper housing 40 into the lower housing 70 and meshes with the fourth gear 150. A pinion gear 120 is press-fitted into the motor output shaft 3.
Then, the first gear 121 and the second gear 126 are sequentially inserted through the support shaft 124 and the support shaft 127 to mesh with each other.

  Next, the upper cover 10 is overlaid on the upper housing 40 (and the middle cover 30), and the first gear 121, the second gear 126, and the third gear are inserted into the shaft holes 17, 19, and 21 of the support bosses 16, 18, and 20, respectively. The upper ends of the 130 support shafts 124, 127, and 149 are inserted and supported. In this case as well, it is a non-visual operation, so it is preferable to set the upper ends of the support shafts 124, 127, and 149 to non-press-fit.

  When the upper cover 10, the middle cover 30, the upper housing 40 and the lower housing 70 are overlapped with each other, the protruding ring 79 of the screw hole 78 a of the lower housing 70 is attached to each of the upper cover 10, the middle cover 30 and the upper housing 40. The holes 15a, 32a and 42a are fitted and positioned. As a result, the screws 8a and 8b are tightened together from the mounting holes 15a and 15b of the upper cover 10 into the screw holes 78a and 78b of the lower housing 70, and are fastened together.

  Thereafter, the output shaft member is inserted into the connection hole 161 of the output gear 155 and rotated, and the output gear 155 is positioned at one end of the initial angular position, for example, the maximum rotatable range where the roller pins 172 and 173 abut. The angle sensor 180 having the potentiometer 185 as the initial position is attached to the mounting seat 92 from the access window 98 on the bottom surface of the lower housing 70, and the sensor gear is connected to the small-diameter gear 150b of the fourth gear 150 facing the recess 94 from the notch window 88. 187 are engaged.

Finally, after the external wiring 107 from the angle sensor 180 and the DC motor 2 is drawn out through the guide groove 102, the lower cover 110 in which the seal ring 119 is fitted to the outer periphery of the flange 114 is screwed to the lower cover mounting surface 97 of the lower housing 70. Attach with 25.
The lower cover 110 is positioned by fitting the protruding ring 113 of the mounting hole 112a through which the screw 25 passes through the large diameter recess 100 of the screw hole 99a of the lower cover mounting surface 97. Thereby, the holding bosses 115a and 115b easily receive the pins 93a and 93b of the mounting seat 92 and press the substrate 181 of the angle sensor 180.

In the present embodiment, the DC motor 2 corresponds to the motor in the invention, the third gear 130 corresponds to the first gear, the second gear 126 corresponds to the front gear, and the fourth gear 150 corresponds to the rear gear.
The pinion 146 corresponds to a tooth portion, and the support shaft 149 corresponds to a common support shaft.
The spline 144 and the pinion 146 of the connection part 143 constitute a rotation preventing part.

The present embodiment is configured as described above, and in the reduction gear train 6 of the geared motor 1, the third gear 130 engages with the second gear 126 at the front stage and the small gear with the fourth gear 150 at the rear stage. 130b,
The large-diameter gear 130a has a drum shape in which the outer cylinder 131 is extended from the end wall 132, has teeth on the outer periphery of the outer cylinder 131 and a cam surface 135 on the inner periphery, and has a shaft hole 134 in the center of the end wall 132. A bearing part 133 having
The small-diameter gear 130b has a base portion 138 and a pinion 146 arranged in the axial direction and has a shaft hole 147. From the base portion 138, an elastic arm 139 having a claw 140 at the tip is extended in the circumferential direction.
A ratchet torque limiter TL is formed on the third gear 130 by disposing the arm 139 in the outer cylinder 131 of the large-diameter gear 130a and engaging the claw 140 with the cam 135.
The large diameter gear 130a and the small diameter gear 130b are directly supported by a common support shaft 149 in the respective shaft holes 134, 147,
It is assumed that the teeth of the pinion 146 mesh with the fourth gear 150.
As a result, since both the large-diameter gear 130a and the small-diameter gear 130b are directly supported by the support shaft 149, the mutual inclination is reduced. As a result, the claw 140 and the cam surface of the arm 139 are adopted regardless of the ratchet type. The fluctuation of the transmission torque due to the irregular engagement of 135 is suppressed, and the meshing with the front and rear second gear 126 and the fourth gear 150 is also smoothly held in a normal posture. (Effects corresponding to claim 1)

In particular, the bearing part 133 of the large diameter gear 130a extends into the outer cylinder 131 to form the inner cylinder 133a, and the inclination of the large diameter gear 130a is increased by the length of the shaft hole 134 supported by the support shaft 149. The prevention effect is great. (Effects corresponding to claim 2)
Furthermore, since the bearing portion 133 extends in the axial direction until it overlaps with the claw 140 in the radial direction to form the inner cylinder 133a, the shaft without particularly increasing the axial size of the third gear 130 (one gear). The hole 134 can be lengthened. (Effects corresponding to claim 3)
Further, since the arm 139 extends to both ends of the claw 140 in the axial direction, the inclination of the claw 140 with respect to the base 138 can be reduced. (Effects corresponding to claim 4)

In particular, the large-diameter gear 130a is made of resin, and the small-diameter gear 130b is composed of a resin ratchet member 137 and a metal pinion 146.
The ratchet member 137 includes a base portion 138 having an arm 139 and a cylindrical connection portion 143 that extends in the axial direction from the base portion 138 and has a spline 144 corresponding to the teeth of the pinion 146 on the inner surface. The base portion 138 is supported. Having a through hole 141 through which the shaft 149 passes,
The pinion 146 has a shaft hole 147 and has teeth on the outer periphery, and is prevented from rotating so as to rotate integrally with the ratchet member 137.
Since the shaft hole 147 of the pinion 146 is directly supported by the support shaft 149 as described above, the ratchet member 137 can easily realize the elastic arm 139, while being on the speed reducing side (from the large-diameter gear 130a ( The pinion 146 located on the output side) can have high-strength teeth, and the inner surface of the shaft hole 147 can be made with high accuracy and the support rigidity by the support shaft 149 can be increased. For this reason, the space | interval of the inner surface of the support shaft 149 and the shaft hole 147 can be made small, and the inclination of the small diameter gear 130b with respect to the support shaft 149 is reduced. Therefore, the mutual inclination of the support shaft large-diameter gear 130a and the small-diameter gear 130b directly supported by the common support shaft 149 is reduced. (Effects corresponding to claims 5 and 6)

  Since the connection portion 143 and the pinion 146 are press-fitted and fixed by a rotation preventing portion, and the through hole 141 of the base portion 138 of the ratchet member 137 has a predetermined gap between the support shaft 149, the support shaft 149 (common support The support shaft 149 can be prevented from interfering with the through-hole 141 of the base 138 even when the inclination of the pinion 146 (small gear 130b) is reduced by reducing the gap between the shaft) and the shaft hole 147 of the pinion 143. (Effect corresponding to claim 7)

  Further, when the base 138 and the arm 139 overlap in the radial direction, and the base 138 and the arm 139 are integrally molded with resin, the resin is formed between the portion where the arm 139 is formed on the base 138 and the portion where the arm 139 is not formed on the base 138. The amount of sink marks exerted on the through hole 141 of the base 138 is different. Even in such a case, since the through hole 141 of the base portion 138 of the ratchet member 137 has a predetermined gap between the support shaft 149, the support shaft 149 is prevented from interfering with the through hole 141 of the base portion 138. it can. (Effect corresponding to claim 8)

In addition, the connecting portion 143 forms a spline 144 corresponding to the teeth of the pinion 146 on the inner surface, and the pinion 146 engages with the spline 144 to form a rotation preventing portion, whereby the connecting portion 143 between the pinion 146 and the ratchet member 137 is formed. Therefore, the inclination of the ratchet member 137 with respect to the pinion 146 can be reduced. (Effects corresponding to claim 9)
Further, the pinion 146 has teeth on the outer peripheral surface extending over the entire length, and has ring protrusions 148 at both ends so as to be axially symmetric, thereby eliminating the need for checking the direction of the pinion 146 when press-fitting into the ratchet member 137. Thus, workability is improved. (Effects corresponding to claim 10)

  Further, the sensor gear 187 of the angle sensor 180 that detects the rotation angle of the output gear 155 is arranged so as to mesh with the fourth gear 150 at the rear stage of the third gear 130 in which the torque limiter TL in the reduction gear train 6 is formed. Therefore, even if the torque limiter TL is activated and slip occurs between the large diameter gear 130a and the small diameter gear 130b of the third gear 130, the rotation angle of the output gear 155 can always be detected accurately. (Effects corresponding to claim 11)

In the embodiment, the motor is a DC motor. However, the present invention is not limited to this, and a stepping motor or other appropriate one can be selected according to the control purpose.
The reduction gear train 6 includes the first gear 121 to the fourth gear 150 between the pinion gear 120 and the output gear 155 of the DC motor 2 to form a five-stage reduction mechanism. Any number of stages can be selected.
Although the torque limiter TL is formed in the third gear 130, it can also be formed in an arbitrary gear.

  The sensor gear 187 of the angle sensor 180 meshes with the fourth gear 150 that is one stage before the output gear 155. However, even if the sensor gear 187 meshes with an appropriate gear as long as it is on the output gear side of the gear that forms the torque limiter TL. Good. However, it is advantageous to mesh with the final gear that meshes with the output gear 155 in that the accumulated backlash from the output gear 155 to the sensor gear 187 is smaller.

In the embodiment, the support shaft that supports each gear of the reduction gear train 6 is a fixed shaft, and the gear rotates with respect to the support shaft. However, is the support shaft a fixed shaft or a rotation shaft? It doesn't matter. Therefore, the gear may be fixed to the support shaft.
In addition, the pinion 146 of the third gear 130 is formed by molding and sintering metal powder, but it can also be formed by cutting or made of resin.
Further, although the small-diameter gear 130b of the third gear 130 is composed of the ratchet member 137 and the pinion 146 that are separate from each other, it can also be made of, for example, a resin integral as necessary.

  Further, the rotation restricting mechanism RL is in contact with the roller pin 172 held by the head 166 of the adapter 165 coupled to the output gear 155 and the roller pin 173 held by fitting the metal cylinder 174 to the cylindrical portion 52 on the case 7 side. However, the present invention is not limited to this. For example, a protrusion is integrally formed on the output gear, and a stopper that can contact the protrusion is integrally formed on the case side. It is also possible to reduce the number of parts and the cost.

In the embodiment, the anti-rotation portion is configured by engaging the pinion 146 with the spline 144. However, the anti-rotation portion is not limited to this, and the pinion 146 and the ratchet member 137 may be rotated together. Other configurations may be used. However, if a spline joint in which the engagement portions of the connection portions 143 of the pinion 146 and the ratchet member 137 are configured at equal intervals in the circumferential direction is used, loads applied to the respective engagement portions cancel each other. The inclination of the ratchet member 137 can be reduced.
Further, although the upper portion of the pinion 146 is press-fitted into the connecting portion 143 of the ratchet member 137 so that the ratchet member 137 and the pinion 146 can rotate integrally, a minute gap may be formed between the pinion 146 and the spline 144. However, the inclination of the ratchet member 137 with respect to the pinion 146 can be further reduced by fixing the pinion 146 and the spline 144 by press fitting.

  Although the embodiment has been described as a geared motor for opening / closing driving such as a toilet seat and a toilet lid, the present invention can also be applied to a cover of a washing machine, a door of a refrigerator, and a geared motor for other uses.

1 Geared motor 2 DC motor (motor)
6 Reduction gear train 7 Case 126 Second gear (front gear)
130 3rd gear (1 gear)
130a Large-diameter gear 130b Small-diameter gear 131 Outer cylinder 132 End wall 133 Bearing part 133a Inner cylinder 134 Shaft hole 135 Cam surface 137 Ratchet member 138 Base part 139 Arm 140 Claw 141 Through hole 143 Connection part 144 Spline 146 Pinion (tooth part)
147 Shaft hole 149 Support shaft (common support shaft)
150 4th gear (back gear)
155 Output gear 180 Angle sensor 187 Sensor gear TL Torque limiter

Claims (10)

In a geared motor configured to house a motor and a reduction gear train that transmits rotation of the motor to an output gear in a case,
A large-diameter gear in which one gear in the reduction gear train meshes with a front gear and a small-diameter gear meshed with a rear gear;
The large-diameter gear has a drum shape in which an outer cylinder is extended from an end wall, has teeth on the outer periphery of the outer cylinder, has a cam surface on the inner periphery, and has a shaft hole in the center of the end wall. A bearing portion of the large-diameter gear extends into the outer cylinder to form an inner cylinder,
The small-diameter gear has a shaft hole and a ratchet member and a pinion arranged in the axial direction,
The ratchet member includes a base portion and a connection portion extending in the axial direction from the base portion, and the base portion has a through hole that penetrates the support shaft,
The ratchet member and the pinion are configured to be integrally rotatable by a detent formed between the connection portion and the pinion,
From the base portion of the ratchet member, an elastic arm having a claw at the tip is extended in the circumferential direction,
Said first gear, by engaging it said pawl to said cam surface to place the arm in the outer cylinder of the large diameter gear, ratcheting of the torque limiter is formed,
The geared motor, wherein the large-diameter gear and the small-diameter gear are directly supported by a common support shaft in each of the shaft holes. The geared motor according to claim 1, wherein the inner cylinder of the bearing portion extends in the axial direction until the inner cylinder overlaps the claw in the radial direction . The arms are geared motor according to claim 1 or 2, characterized in that Ru extends to both axial ends of the claw. The large-diameter gear is made of resin, and the ratchet member and the pinion of the small-diameter gear are made of different materials,
The pinion has a shaft hole and has teeth on the outer periphery,
The shaft hole of the pinion is directly supported by the support shaft as the shaft hole of the small diameter gear,
The geared motor according to any one of claims 1 to 3, wherein teeth of the pinion mesh with the rear gear . The geared motor according to claim 4 , wherein the ratchet member is made of resin, and the pinion is made of metal . The pinion and the connecting portion is press-fitted in the detent portions, according to claim 4 or 5 holes of said base portion is characterized that you have a predetermined gap between the supporting shaft Geared motor. Geared motor according to claim 6 through hole of the base overlap with the arm in a radial direction, the said base arm, wherein Rukoto is integrally molded with resin. The connection portion forms a spline corresponding to the teeth of the pinion to the inner surface, any one of claims 1 to 7 for the pinion to the spline characterized that you configure the rotation stop portion engaged Geared motor as described in Geared motor according to any one of claims 1 to 8 wherein the pinion is characterized by axially symmetrical der Rukoto. An angle sensor for detecting a rotation angle of the output gear;
The geared motor according to any one of claims 1 to 9, wherein a sensor gear of the angle sensor meshes with a gear subsequent to the one gear in which the torque limiter in the reduction gear train is formed .

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