JP6794764B2 - Manufacturing method of speed reducer, motor with speed reducer, and speed reducer - Google Patents

Description

The present invention relates to a speed reducer, a motor with a speed reducer, and a method for manufacturing the speed reducer.

Conventionally, there is a motor with a speed reducer including a motor body and a speed reducer (see, for example, Patent Document 1). The reduction gear includes a worm that rotates integrally with the rotation shaft of the motor body, a first gear (worm wheel) that meshes with the worm, and a second gear (output wheel) that meshes with the first gear. These are housed in the housing part of the gear housing (gear case). The opening of the accommodating portion of the gear housing is covered with a housing cover (gear cover), and the first and second gears are supported across both the gear housing and the housing cover members. The first gear is pivotally supported by a shaft member (worm wheel shaft) supported by a gear housing at one end and a housing cover at the other end.

Japanese Unexamined Patent Publication No. 2013-29150

By the way, if the support state of the shaft member is not sufficient, the shaft member may be tilted due to the reaction force generated between the front and rear gears of the first gear. If the shaft member is tilted, there is a concern that the meshing with the front and rear gears of the first gear may be deteriorated.

The present invention has been made to solve the above problems, and an object of the present invention is to maintain the posture of a gear even when a reaction force due to meshing acts, and to maintain good meshing with the gear. It is an object of the present invention to provide a speed reducer, a motor with a speed reducer, and a method for manufacturing the speed reducer.

The speed reduction device that solves the above problems includes a speed reduction mechanism composed of gear trains using a plurality of gears, a gear housing that houses the speed reduction mechanism in a housing portion in the opening, and a housing cover that covers the opening of the gear housing. Among the plurality of gears provided with a housing member, in a gear in which a shaft member is fitted into a support hole provided in the gear and is pivotally supported with respect to the shaft member, the first end portion of the shaft member is the gear housing. press-fitted into the first press-fitting portion which forms a concave shape provided in, a reduction gear which is press-fitted to the second press-fitting portion which forms a concave shape in which the second end is provided in the housing cover, wherein the A through hole is provided in the bottom surface of the first and second press-fitting portions, and an annular protrusion surrounding the through hole is erected on the bottom surface of at least one of the first and second press-fitting portions. The tip of the shaft member is in contact with the shaft member .

According to this configuration, both end portions of the shaft member for supporting the gears, because it is press-fitted respectively to the first and second press-fit portion concave shape provided in the gear housing and the housing cover, the shaft member Tilt is prevented. As a result, even if a reaction force generated by meshing with other gears acts, the shaft member can always maintain a good posture, and meshing with other gears can be maintained well.
According to this configuration, when the shaft member is press-fitted into the concave first and second press-fitting portions, air is discharged from the through holes provided in each press-fitting portion, and the press-fitting resistance can be reduced.
According to the same configuration, an annular protrusion surrounding the through hole is erected on the bottom surface of at least one of the first and second press-fitting portions, and the tip portion of the protrusion is in contact with the shaft member. The path toward the through hole of the grease provided between the shaft member and the gear is blocked, and the grease is prevented from leaking to the outside from the through hole.
The speed reduction device that solves the above problems includes a speed reduction mechanism composed of gear trains using a plurality of gears, a gear housing that houses the speed reduction mechanism in a housing portion in the opening, and a housing cover that covers the opening of the gear housing. Among the plurality of gears provided with a housing member, in a gear in which a shaft member is fitted into a support hole provided in the gear and is pivotally supported with respect to the shaft member, the first end portion of the shaft member is the gear housing. The reduction gear is fixed to the concave first press-fitting portion provided in the above by press fitting, and the second end portion is fixed to the concave second press-fitting portion provided in the housing cover by press fitting. The second press-fitting portion is provided with a through hole on the bottom surface thereof, and a mark portion is provided on the end surface of the shaft member corresponding to the through hole provided on the bottom surface of the first and second press-fitting portions. ..
According to this configuration, both ends of the shaft member that pivotally supports the gear are press-fitted and fixed to the concave first and second press-fitting portions provided on the gear housing and the housing cover, respectively, so that the shaft member tilts. Is prevented. As a result, even if a reaction force generated by meshing with other gears acts, the shaft member can always maintain a good posture, and meshing with other gears can be maintained well.
According to this configuration, when the shaft member is press-fitted into the concave first and second press-fitting portions, air is discharged from the through holes provided in each press-fitting portion, and the press-fitting resistance can be reduced.
According to this configuration, the mark portion is provided on the end face of the shaft member corresponding to the through hole provided on the bottom surface of the first and second press-fitting portions, so that the shaft is formed from the mutual relationship between the through hole and the mark portion. The posture (tilt) and misalignment of the member can be easily checked from the outside of the housing member.
The speed reduction device that solves the above problems includes a speed reduction mechanism composed of a gear train using a plurality of gears, a gear housing that houses the speed reduction mechanism in a housing portion in the opening, and a housing cover that covers the opening of the gear housing. A reduction gear provided with a housing member, and among the plurality of gears, in a gear in which a shaft member is fitted into a support hole provided in the gear and is pivotally supported by the shaft member, the first gear of the shaft member. The end is fixed by press-fitting to the concave or hole-shaped first press-fitting portion provided in the gear housing, and the second end is fixed to the concave or hole-shaped second press-fitting portion provided in the housing cover by press-fitting. The shaft member has a flange portion extending outward in the radial direction in order to regulate the press-fitting amount by contacting the periphery of the first and second press-fitting portions.
According to this configuration, both ends of the shaft member that pivotally supports the gear are press-fitted and fixed to the concave or hole-shaped first and second press-fitting portions provided in the gear housing and the housing cover, respectively. The member is prevented from tilting. As a result, even if a reaction force generated by meshing with other gears acts, the shaft member can always maintain a good posture, and meshing with other gears can be maintained well.
According to this configuration, the flange portion provided on the shaft member comes into contact with the periphery of the first and second press-fitting portions to regulate the press-fitting amount, so that the press-fitting state is excessive and the gear is excessively pressed against the peripheral member. It is possible to stabilize the characteristics of the speed reducer by suppressing contact with the gear.

In the speed reduction device, the gear that is pivotally supported by the shaft member is preferably made of resin.
As described above, since the shaft member is prevented from tilting and the meshing with other gears can be maintained well, sufficient reliability can be obtained even if a resin gear is used. Further, using a resin gear leads to a reduction in the cost of the reduction gear.

In the reduction gear, the gears pivotally supported by the shaft member are integrally composed of first and second gear portions having different diameters, and have a larger diameter than the second gear portion on the smaller diameter side. At the boundary portion with the first gear portion on the side, it is preferable that the second gear portion is connected to the first gear portion by an inclined surface extending radially outward.

According to this configuration, a boundary portion between both gear portions is formed by connecting the second gear portion on the smaller diameter side to the first gear portion on the larger diameter side by an inclined surface extending outward in the radial direction. Therefore, local stress concentration is suppressed at the boundary portion, and the durability of the gear can be improved. In particular, the application to resin gears is very effective.

In the speed reducer, the shaft member is preferably made of metal.
According to this configuration, the strength of the shaft member can be improved.
In the speed reducing device, the first and second press-fitting portions have a concave shape, and in the press-fitting state of the shaft member, between the bottom surface of at least one side of the first and second press-fitting portions and the shaft member. Are preferably arranged so as to be spaced apart in the axial direction.

According to this configuration, in the press-fitted state of the shaft member, the first and second end portions of the shaft member and at least one side of the first and second press-fitted portions are separated in the axial direction, so that the dimensional accuracy of the shaft member is relaxed. Therefore, the shaft member can be easily manufactured.

In the speed reducing device, it is preferable that a regulating portion for restricting the movement of the shaft member in the direction orthogonal to the axis is provided between the gear housing and the housing cover.
According to this configuration, the movement of the shaft member in the direction orthogonal to the axis is restricted by the regulating portion provided between the gear housing and the housing cover, so that the shaft member can be prevented from tilting after assembly and the shaft member can be prevented during the assembly process. It becomes easy to press-fit into each press-fitting part.

A motor with a speed reducer that solves the above problems is integrally configured by driving and connecting the speed reducer and the motor body.
According to this configuration, it is possible to provide a motor with a reduction gear in which the fall of the gear is suppressed and the meshing with other gears is good.

A method for manufacturing a reduction gear that solves the above problems is a reduction mechanism composed of gear trains using a plurality of gears, a gear housing that accommodates the reduction mechanism in an accommodation portion in the opening, and a housing that covers the opening of the gear housing. It is a reduction gear having a cover and a housing member that is assembled by engaging the engaging portions with each other. Among the plurality of gears, the shaft member is fitted into a support hole provided in the gear and the shaft member thereof. It is a method of manufacturing a reduction gear including a gear that is pivotally supported by the gear housing, and the first end portion of the shaft member is set to a position in front of the normal position with respect to the concave first press-fitting portion provided in the gear housing. After the first step of press-fitting and temporarily fixing, and after the first step, the second end portion of the shaft member is press-fitted into the concave second press-fitting portion provided on the housing cover, and the press-fitting is performed. A second step that is prioritized over press-fitting of one end, and after the second step, along with re-press-fitting the first end of the shaft member, the gear housing and the engaging portions provided on the housing cover are brought into contact with each other. In the first step, the distance from the bottom surface of the second press-fitting portion to the second end of the shaft member is the housing cover, including the third step of assembling the gear housing and the housing cover by engaging the gear housing and the housing cover. A gap is provided between the first end portion of the shaft member and the bottom surface of the first press-fitting portion so as to be shorter than the distance from the engaging portion of the gear housing to the engaging portion of the gear housing, and the gear housing is temporarily fixed.

According to this configuration, when the first end portion of the shaft member is temporarily fixed to the first press-fitting portion, the distance from the bottom surface of the second press-fitting portion to the second end portion of the shaft member is the distance from the engaging portion of the housing cover. The shaft member is press-fitted by providing a gap between the first end portion of the shaft member and the bottom surface of the first press-fitting portion so as to be shorter than the distance to the engaging portion of the gear housing. Further, since the press-fitting of the second end portion of the shaft member into the second press-fitting portion is preferentially performed, the timing at which the second end portion of the shaft member finishes press-fitting into the second press-fitting portion depends on the housing cover. It precedes the timing when the joint and the engaging part of the gear housing come into contact with each other. That is, it is possible to press-fit the second end portion of the shaft member into the second press-fitting portion while maintaining the horizontality of the housing cover.

In the method for manufacturing the speed reducer, it is preferable that the press-fitting allowances of the first and second press-fitting portions are different to give priority to press-fitting between the first and second end portions of the shaft member.
According to this configuration, when giving priority to press-fitting between the first and second end portions of the shaft member, it can be realized simply by making the press-fitting allowances of the first and second press-fitting portions different, which is easily performed. It is possible.

A method for manufacturing a speed reducer that solves the above problems is when the first end portion of the shaft member is press-fitted into the first press-fitting portion, and the second end portion of the shaft member is press-fitted into the second press-fitting portion. The press-fitting crushing step of crushing the entire circumference of the tip end portion of the protrusion by the shaft member is included at least one of the times.

According to the same method, in the press-fitting press-fitting step, at least one of the time when the first end portion of the shaft member is press-fitted into the first press-fitting portion and the case where the second end portion of the shaft member is press-fitted into the second press-fitting portion. In addition, the entire circumference of the tip of the protrusion is crushed by the shaft member. In this way, for example, even if the height of the tip of the protrusion varies in the circumferential direction due to a manufacturing error or the like, the tip of the protrusion can be brought into close contact with the shaft member over the entire circumference. Therefore, the path toward the through hole of the grease provided between the shaft member and the gear is further blocked, and the grease is further prevented from leaking to the outside from the through hole.

According to the reduction gear, the motor with the reduction gear, and the method for manufacturing the reduction gear of the present invention, the posture of the gear can be maintained even if the reaction force due to the meshing acts, and the meshing with the gear can be maintained well.

It is a front view of the motor with a reduction gear of one Embodiment. It is sectional drawing which follows the AA line of FIG. It is a perspective view of the 1st reduction gear and the 2nd reduction gear of one Embodiment. It is sectional drawing along the line BB of FIG. It is a perspective view of the housing cover of one Embodiment. It is sectional drawing for demonstrating the manufacturing method of the reduction gear of one Embodiment. It is sectional drawing for demonstrating the manufacturing method of the reduction gear of one Embodiment. It is sectional drawing for demonstrating the manufacturing method of the reduction gear of one Embodiment. It is sectional drawing of the reduction gear of another example. It is a partially enlarged sectional view of the reduction gear of another example. (A) is a partially enlarged cross-sectional view of another example housing cover. (B) is a partially enlarged bottom view of a housing cover of another example. It is a partially enlarged sectional view of the housing cover of another example. It is a partially enlarged sectional view of the housing cover of another example.

Hereinafter, an embodiment of a motor with a speed reducer will be described.
As shown in FIG. 1, the motor 10 is composed of a motor main body 20 and a speed reducing device 30 connected to the motor main body 20.

The motor body 20 includes a substantially bottomed tubular yoke 21, a magnet (not shown) fixed to the inner surface of the yoke 21, and an armature 22 housed in the yoke 21, and rotationally drives the armature 22. The tip side of the rotating shaft 23 of the armature 22 projects from the opening of the yoke 21 into the speed reducing device 30.

The speed reduction device 30 includes a housing member 31, a speed reduction mechanism 32, and an output unit 33.
As shown in FIGS. 1 and 2, the housing member 31 includes a gear housing 41 and a housing cover 42. The gear housing 41 is made of, for example, resin. The gear housing 41 is formed by opening a side end portion (the right end portion in FIG. 1) that is connected and fixed to the yoke 21, and the rotating shaft is located behind the opening (the left side in FIG. 1). A worm housing portion 41a extending coaxially with the 23 in a tubular shape is formed. The worm accommodating portion 41a accommodates the worm 51 that forms a part of the speed reduction mechanism 32. The worm 51 is rotatably supported inside the worm accommodating portion 41a, and is connected to the rotating shaft 23 so as to rotate integrally with the rotating shaft 23.

Further, in the gear housing 41, a first gear accommodating portion 41b communicating with the worm accommodating portion 41a is formed in the axial direction orthogonal to the worm accommodating portion 41a (downward in FIG. 1). The first gear accommodating portion 41b is formed in a substantially bottomed tubular shape with one end side (front side of the paper surface in FIG. 1) open. Further, the second gear accommodating portion 41c communicating with the first gear accommodating portion 41b on the radial side of the first gear accommodating portion 41b and in the axial direction orthogonal to the worm accommodating portion 41a (downward in FIG. 1). Is formed. Similar to the first gear accommodating portion 41b, the second gear accommodating portion 41c is formed in a substantially bottomed tubular shape with one end side (front side of the paper surface in FIG. 1) open. Further, the second gear accommodating portion 41c is formed to have a larger diameter than the first gear accommodating portion 41b. The openings of the first gear accommodating portion 41b and the second gear accommodating portion 41c are closed by the housing cover 42.

As shown in FIGS. 1 and 4 to 8, the housing cover 42 has a first cover portion 42a formed of resin and having a substantially disk shape corresponding to an opening of the first gear accommodating portion 41b, and a first cover portion 42a. It has a second cover portion 42b that is integrally formed with the cover portion 42a and has a substantially disk shape corresponding to the opening of the second gear housing portion 41c. The second cover portion 42b is formed to have a larger diameter than the first cover portion 42a. Further, in the housing cover 42, four engaging claws 42c extending in the axial direction of the second cover portion 42b are formed on the peripheral edge portion of the second cover portion 42b. Further, in the housing cover 42, the screw fixing portion 42d extends to a total of three locations, one on the peripheral edge of the first cover portion 42a and two locations on the boundary portion between the first cover portion 42a and the second cover portion 42b. It is installed. In the housing cover 42, these engaging claws 42c snap-fit engage with the engaging protrusions 41d formed on the outer peripheral surface of the second gear accommodating portion 41c (see FIG. 4), and the three screws 43 are screwed together. It is fixed to the gear housing 41 by penetrating the portion 42d and screwing into the gear housing 41.

As shown in FIG. 2, the first gear accommodating portion 41b accommodates a first reduction gear 61 made of resin, which constitutes a part of the reduction mechanism 32. As shown in FIG. 3, the first reduction gear 61 is composed of a disc-shaped worm wheel 62 and a small diameter gear portion 63 having a diameter smaller than that of the worm wheel 62 and rotating integrally with the worm wheel 62. The axis center of the worm wheel 62 and the axis center of the small diameter gear portion 63 coincide with each other. The small-diameter gear portion 63 is a helical gear in which teeth are engraved diagonally with respect to the axis, and is integrally formed on one end surface of the worm wheel 62 in the axial direction. Further, an inclined surface 63b extending from the tooth bottom surface 63a to the adjacent tooth surface and further to one end surface of the worm wheel 62 is formed in the portion (base end portion) of the small diameter gear portion 63 on the worm wheel 62 side. The inclined surface 63b is higher (thicker) than the tooth bottom surface 63a, spreads radially outward toward the worm wheel 62 side, and gradually becomes lower (thinner).

Further, a support hole 64 is formed in the shaft center portion of the first reduction gear 61 so as to penetrate the first reduction gear 61 in the axial direction. Then, the first shaft 65 made of a cylindrical metal shaft member fixed across the gear housing 41 and the housing cover 42 is fitted into the support hole 64, so that the first reduction gear 61 becomes the first shaft 65. It is pivotally supported (rotatably supported). The first reduction gear 61 is located in the first gear accommodating portion 41b so that the worm wheel 62 is located on the bottom side of the first gear accommodating portion 41b and the small diameter gear portion 63 is located on the first cover portion 42a side. Have been placed. Further, the worm wheel 62 meshes with the worm 51.

The first shaft 65 is fixed to the gear housing 41 by press-fitting the lower end portion 65a on the gear housing 41 side into the first press-fitting recess 44 recessed in the bottom portion of the gear housing 41. At this time, the lower end portion 65a and the bottom surface 44a of the first press-fitting recess 44 are separated from each other in the axial direction. On the other hand, the upper end portion 65b of the first shaft 65 on the housing cover 42 side protrudes from the upper end surface 63c of the small diameter gear portion 63. Then, in the housing cover 42, the housing cover 42 is press-fitted into the second press-fitting recess 45 recessed at a position corresponding to the first press-fitting recess 44, and is fixed to the housing cover 42. Both the first and second press-fitting recesses 44 and 45 have a circular cross section, and the inner diameter of the second press-fitting recess 45 is set to be slightly larger than the inner diameter of the first press-fitting recess 44, that is, the second press-fitting recess 45. The press-fitting allowance is set to be smaller than that of the first press-fitting recess 44.

The bottom surface 44a of the first press-fitting recess 44 of the gear housing 41 and the bottom surface 45a of the second press-fitting recess 45 of the housing cover 42 have through holes 46, 47 having an inner diameter sufficiently smaller than the diameters of the bottom surfaces 44a, 45a, respectively. It is formed. The through holes 46, 47 have a function of releasing the air trapped in the press-fitting recesses 44, 45 and the first shaft 65 to the outside when the first shaft 65 is press-fitted into the press-fitting recesses 44, 45. By press-fitting and fixing the first shaft 65 to the first and second press-fitting recesses 44 and 45 of the gear housing 41 and the housing cover 42 in this way, the first reduction gear 61 can rotate about the first shaft 65 as the rotation center. It has become.

Further, at the center of the end faces of both end portions 65a and 65b of the first shaft 65, a cross section having an inner diameter smaller than that of the through holes 46 and 47 provided in the bottom surfaces 44a and 45a of the first and second press-fitting recesses 44 and 45. A circular recess 65c is formed. This is because when at least the first shaft 65 is concealed after the gear housing 41 and the housing cover 42 are assembled, the recess 65c of the first shaft 65 and the through hole 46 on the gear housing 41 and the housing cover 42 side, It is provided to grasp the posture (tilt) and misalignment of the first axis 65 from the mutual relationship with 47 and the like. From the outside of the gear housing 41 and the housing cover 42, the interrelationship between the through holes 46 and 47 and the recess 65c of the first shaft 65 can be examined by image analysis by a photographing device or by visual inspection by an operator to determine the state of the first shaft 65. It is possible to grasp.

As shown in FIG. 4, the second gear accommodating portion 41c accommodates the second reduction gear 71 made of resin, which constitutes a part of the reduction mechanism 32. As shown in FIG. 3, the second reduction gear 71 has a disc-shaped large-diameter gear portion 72 and a substantially cylindrical second shaft 73 integrally formed at the central portion in the radial direction of the large-diameter gear portion 72. It is composed of and.

As shown in FIGS. 3 and 4, the large-diameter gear portion 72 is formed to have a larger diameter than the small-diameter gear portion 63. The large-diameter gear portion 72 includes an annular thin-walled portion 72a extending radially outward from the outer peripheral surface of the second shaft 73, and an annular base portion 72b integrally provided on the outer periphery of the thin-walled portion 72a with the thin-walled portion 72a. And a plurality of teeth 72c protruding radially outward from the base 72b. The thin-walled portion 72a is formed to be thinner in the axial direction than the base portion 72b. Further, the plurality of the teeth 72c are carved diagonally with respect to the axis line.

The second shaft 73 projects at the center of the shaft of the large-diameter gear portion 72 on both sides in the axial direction of the large-diameter gear portion 72. Further, the second shaft 73 is formed with an output hole 73a that penetrates itself in the axial direction. The shaft-shaped output unit 33 that rotates integrally with the second reduction gear 71 is inserted into the output hole 73a. The output unit 33 projects outward from both ends in the axial direction of the second shaft 73.

On the other hand, a first support portion 41f forming an annular shape is formed at the central portion in the radial direction of the bottom portion of the second gear accommodating portion 41c. Further, a second support portion 42f forming an annular shape and pairing with the first support portion 41f is formed at the axial center portion of the second cover portion 42b. Then, one end in the axial direction of the second shaft 73 (lower end in FIG. 4) is inserted into the first support 41f, and the other end in the axial direction of the second shaft 73 (upper end in FIG. 4). ) Is inserted into the second support portion 42f, so that the second shaft 73 is rotatably supported with its own rotation center. An external load will be connected to the output unit 33. Further, the large-diameter gear portion 72 has an axial center parallel to the small-diameter gear portion 63 and meshes with the small-diameter gear portion 63.

Further, as shown in FIG. 4, the housing cover 42 has a first axial length X1 in which the second press-fitting recess 45 supports the first shaft 65, and the second support portion 42f has the second shaft 73. It has a rib 42g that comes into contact with the inner wall surface 41g of the first gear accommodating portion 41b in a range X3 longer than the second axial length X2 that supports the first gear housing portion 41b.

Specifically, as shown in FIGS. 4 and 5, first, the first cover portion 42a of the housing cover 42 is inserted into the first gear accommodating portion 41b while avoiding the small diameter gear portion 63 and the large diameter gear portion 72. A bulging portion 42h that bulges in an arc shape when viewed from the axial direction (of the first shaft 65) is formed. The bulging portion 42h is formed so that its outer wall surface is slightly separated from the inner wall surface 41g of the first gear accommodating portion 41b. Then, the bulging portion 42h is formed with ribs 42g that project radially outward from the outer surface and project axially from the axial end surface and come into contact with the inner wall surface 41g of the first gear accommodating portion 41b in the range X3. ing. Seven ribs 42g are formed, and adjacent ribs 42g are spaced apart from each other over a range larger than 180 ° with respect to the axis center of the second press-fitting recess 45 (first shaft 65) of the first cover portion 42a. Is arranged with.

Further, both the open end portion of the first gear accommodating portion 41b and the tip end portion of the rib 42g have the housing cover 42 with respect to the first gear accommodating portion 41b in the direction orthogonal to the axis of the first axis 65 (its normal direction). It has guide surfaces 41h and 42j that can guide to the position). The guide surfaces 41h and 42j are formed so as to be inclined toward the bottom side of the first gear accommodating portion 41b toward the first shaft 65 side, so that the housing cover 42 can be guided.

Next, an assembly method centering on the first shaft 65 will be described for assembling the speed reducer 30. In order not to complicate the drawings in FIGS. 6 to 8, the first reduction gear 61 and the second reduction gear 71 are not shown.

As shown in FIG. 6, first, the lower end portion 65a of the first shaft 65 is press-fitted into the first press-fitting recess 44 of the gear housing 41 and temporarily fixed to the gear housing 41. At this time, the lower end portion 65a of the first shaft 65 is press-fitted from the normal press-fitting completion position to the first press-fitting recess 44 to an intermediate position in front of the axial direction, and the lower end portion 65a of the first shaft 65 and the first press-fitting recess are formed. A gap 48 is provided so that the bottom surface 44a of the 44 is separated from the normally assembled state. The first reduction gear 61 and the second reduction gear 71 are housed in the gear housing 41 in this state or by the time the state is reached.

Next, as shown in FIG. 7, by moving the housing cover 42 so as to be relatively close to the gear housing 41 in the axial direction of the first shaft 65, the upper end portion 65b of the first shaft 65 becomes the housing cover. It is press-fitted until it comes into contact with the bottom surface 45a of the second press-fitting recess 45 of 42. In this case, as described above, since the second press-fitting recess 45 has a smaller press-fitting allowance than the first press-fitting recess 44, it corresponds to the press-fitting of the upper end portion 65b of the first shaft 65 into the second press-fitting recess 45. With a small press-fitting, the press-fitting of the upper end portion 65b of the first shaft 65 into the second press-fitting recess 45 is performed with priority over the press-fitting of the lower end portion 65a of the first shaft 65 into the first press-fitting recess 44.

Here, the gap 48 has an axial distance Y1 from the bottom surface 45a of the second press-fitting recess 45 to the upper end portion 65b of the first shaft 65 from the engaging claw 42c of the housing cover 42 to the engaging projection 41d of the gear housing 41. The axial length of the gap 48 (the amount of press-fitting of the lower end portion 65a of the first shaft 65 at the time of temporary fixing) is set so as to be shorter than the axial distance Y2 up to. That is, in the press-fitting process of the upper end portion 65b of the first shaft 65 with respect to the second press-fitting recess 45, the housing cover 42 until the upper end portion 65b of the first shaft 65 abuts on the bottom surface 44a of the second press-fitting recess 45 and is completely press-fitted. The engaging claw 42c of the housing cover 42 does not come into contact with the engaging projection 41d of the gear housing, so that the horizontality of the housing cover 42 is maintained.

Further, when the housing cover 42 is moved close to the gear housing 41, the first shaft 65 is stably press-fitted by the guidance of the inner wall surface 41 g of the first gear accommodating portion 41b including the guide surfaces 41h and 42j and the rib 42g. Will be done. Then, when the upper end portion 65b of the first shaft 65 reaches the bottom surface 45a of the second press-fitting recess 45, the press-fitting is completed.

Then, as shown in FIG. 8, the lower end portion 65a of the first shaft 65, which was in the middle of press-fitting, is press-fitted into the first press-fitting recess 44 again by the closer operation of the housing cover 42 with respect to the gear housing 41. At the same time, the engaging claw 42c of the housing cover 42 is snap-fit engaged with the engaging projection 41d of the gear housing 41. Upon completion of this snap-fit engagement, the relative operation of the housing cover 42 is stopped, and the press-fitting of the lower end portion 65a of the first shaft 65 into the first press-fitting recess 44 is also completed. In this way, the lower end portion 65a and the upper end portion 65b of the first shaft 65 are press-fitted and fixed to the gear housing 41 and the housing cover 42, respectively, and the gear housing 41 and the housing cover 42 are assembled to form the motor 10. At least the assembly of the speed reducer 30 is completed.

Further, in the state after the gear housing 41 and the housing cover 42 assembled in this way are assembled, that is, in a state where the internal accommodation space is concealed, the through holes 46 and 47 provided in each of these members and the penetration thereof. The posture (tilt), misalignment, etc. of the first shaft 65 are within the normal range from the mutual relationship between the recesses 65c of both ends 65a and 65b of the first shaft 65 when the inside is viewed through the holes 46 and 47. It is possible to easily check whether or not it is.

Next, the characteristic effects of this embodiment will be described.
(1) Both ends 65a and 65b of the first shaft 65 that pivotally supports the first reduction gear 61 are provided with respect to the concave first and second press-fitting recesses 44 and 45 provided in the gear housing 41 and the housing cover 42, respectively. Since it is press-fitted and fixed, the first shaft 65 is prevented from tilting. As a result, even if the reaction force generated by the meshing with the other gears (worm 51 and the second reduction gear 71) acts, the first shaft 65 can always maintain a good posture and mesh with the other gears. It can be maintained well.

(2) The first reduction gear 61 is made of resin, but as described above, the tilt of the first shaft 65 is prevented and the meshing with other gears can be maintained well, so that the reliability is sufficient. You can get sex. Further, by using the first reduction gear 61 made of resin, the cost of the reduction gear 30 can be reduced.

(3) The boundary portion between the small diameter gear portion 63 and the worm wheel 62 is connected by an inclined surface 63b extending radially outward from the small diameter gear portion 63 on the small diameter side toward the worm wheel 62 on the large diameter side. Since it is configured, local stress concentration is suppressed at the boundary portion thereof, and the durability of the first reduction gear 61 can be improved. In particular, the application to the first reduction gear 61 made of resin is very effective.

(4) Since the first shaft 65 is made of metal, the strength of the first shaft 65 can be improved.
(5) In the press-fitting state of the first shaft 65, the lower end portion 65a of the first shaft 65 and the first press-fitting recess 44 are separated in the axial direction, so that the dimensional accuracy of the first shaft 65 is relaxed and the first shaft 65 is pressed. Is easy to manufacture.

(6) Since the rib 42g provided between the gear housing 41 and the housing cover 42 restricts the movement of the first shaft 65 in the direction orthogonal to the axis, it is possible to prevent the first shaft 65 from tilting after assembly and the assembly process. In, press-fitting into the press-fitting recesses 44 and 45 of the first shaft 65 becomes easy.

(7) When the first shaft 65 is press-fitted into the concave first and second press-fitting recesses 44 and 45, air is discharged from the through holes 46 and 47 provided in the respective press-fitting recesses 44 and 45. , The press-fitting resistance can be reduced.

(8) Recesses 65c are provided on the end faces of both end portions 65a and 65b of the first shaft 65 corresponding to the through holes 46 and 47 provided in the bottom surfaces 44a and 45a of the first and second press-fitting recesses 44 and 45. As a result, the posture (tilt) and misalignment of the first shaft 65 can be easily checked from the outside of the gear housing 41 and the housing cover 42 from the mutual relationship between the through holes 46 and 47 and the recess 65c.

(9) It can be provided as a motor 10 with a reduction gear in which the first reduction gear 61 is suppressed from falling and meshes well with other gears.
(10) When the lower end portion 65a of the first shaft 65 is temporarily fixed to the first press-fitting recess 44, the axial distance Y1 from the bottom surface 45a of the second press-fitting recess 45 to the upper end portion 65b of the first shaft 65 is the housing cover. A gap between the lower end portion 65a of the first shaft 65 and the bottom surface 44a of the first press-fitting recess 44 so as to be shorter than the axial distance Y2 from the engaging claw 42c of the 42 to the engaging protrusion 41d of the gear housing 41. A 48 is provided and the first shaft 65 is press-fitted. Further, since the press-fitting of the upper end portion 65b of the first shaft 65 into the second press-fitting recess 45 is preferentially performed, the timing at which the upper end portion 65b of the first shaft 65 finishes press-fitting into the second press-fitting recess 45 is determined. The timing is earlier than the timing at which the engaging claw 42c of the housing cover 42 and the engaging projection 41d of the gear housing 41 come into contact with each other. That is, it is possible to press-fit the upper end portion 65b of the first shaft 65 into the second press-fitting recess 45 while maintaining the horizontality of the housing cover 42.

(11) The press-fitting priority can be given between the lower end portion 65a and the upper end portion 65b of the first shaft 65 by an easy method of making the press-fitting allowances of the first and second press-fitting recesses 44 and 45 different.
The above embodiment may be changed as follows.

-In the above embodiment, the first and second press-fitting portions have the first and second press-fitting recesses 44 and 45, that is, concave shapes, but may have a hole shape.
-In the above embodiment, the difference in the press-fitting allowance (press-fitting) with respect to the first and second press-fitting recesses 44 and 45 of the first shaft 65 is that the inner diameters of the first and second press-fitting recesses 44 and 45 have different diameters. However, it may be adjusted by changing the diameters of the ends 65a and 65b of the first shaft 65. In this case, the diameter of the upper end portion 65b of the first shaft 65 may be smaller than the diameter of the lower end portion 65a.

A flange portion 66 as shown in FIG. 9 may be provided on the first shaft 65 of the above embodiment.
On the first shaft 65 shown in FIG. 9, an annular flange portion 66 extending radially outward is integrally formed on the outer peripheral surface on the upper end portion 65b side. The flange portion 66 has an upper end portion 65b of the bottom surface 45a of the second press-fitting recess 45 in order to prevent the upper end portion 65b of the first shaft 65 from being excessively press-fitted with respect to the second press-fitting recess 45 of the housing cover 42. It comes into contact with the periphery of the second press-fitting recess 45 substantially at the same time as it comes into contact with the bottom surface of the housing. As a result, an appropriate clearance can be set between the second reduction gear 71 and the housing cover 42 and the gear housing 41, so that it is possible to prevent the second reduction gear 71 from excessively contacting the surrounding members, and the reduction gear It is possible to stabilize the characteristics of 30 and, by extension, the characteristics of the entire motor 10.

In the above example, the flange portion 66 is integrally formed with the first shaft 65, but the flange portion 66 may be formed by mounting a C ring or the like on the outer peripheral surface of the first shaft 65. .. Further, the flange portion 66 does not have to be annular like the C ring or the like.

In the above embodiment, the upper end portion 65b of the first shaft 65 is in contact with the bottom surface 45a of the second press-fitting recess 45, and the lower end portion 65a is press-fitted so as to be separated from the bottom surface 44a of the first press-fitting recess 44. The contact and separation relationships may be reversed. Further, both may be in contact with each other and both may be separated from each other.

-In the above embodiment, a circular recess 65c is formed at the center of the end faces of both end portions 65a and 65b of the first shaft 65, but the shape is not limited to this. For example, it may have a convex shape or a polygonal shape. Further, the recess 65c may not be formed.

An annular protrusion surrounding the through holes 46, 47 is erected on the bottom surfaces 44a, 45a of the first press-fitting recess 44 and the second press-fitting recess 45 of the above embodiment, and the tip of the protrusion and the first shaft 65 are attached to each other. It may be configured to be in contact with each other.

Specifically, for example, as shown in FIG. 10, it may be changed. In this example, an annular protrusion 81 surrounding the through hole 47 is erected on the bottom surface 45a of the second press-fitting recess 45, and the tip end portion of the protrusion 81 is in contact with the upper end portion 65b of the first shaft 65. By doing so, the path toward the through hole 47 of the grease provided between the first shaft 65 and the first reduction gear 61 is blocked, and the grease is prevented from leaking to the outside from the through hole 47. Grease.

Further, in the manufacturing method of this example, when the upper end portion 65b of the first shaft 65 is press-fitted into the second press-fitting recess 45, the entire circumference of the tip portion of the protrusion 81 is crushed by the first shaft 65 (upper end portion 65b). It includes a press-fitting and crushing step.

Specifically, as shown in FIGS. 11 (a) and 11 (b), the protrusion 81 of this example is in a state before the first shaft 65 is assembled (a state in which the housing cover 42 is only molded). The width in the radial direction becomes narrower toward the tip, and the inner diameter is constant, and the outer diameter gradually becomes smaller toward the tip, and the tip is sharpened. Then, when the upper end portion 65b of the first shaft 65 is press-fitted into the second press-fitting recess 45, each dimension is set so that the entire circumference of the tip portion of the protrusion 81 is crushed by the first shaft 65 (upper end portion 65b). In the assembled state (see FIG. 10), the tip of the protrusion 81 is configured to be in surface contact with the upper end portion 65b of the first shaft 65. In this way, for example, even if the height of the tip of the protrusion 81 (in the state of being just molded) varies in the circumferential direction due to a manufacturing error or the like, the tip of the protrusion 81 is fully aligned with the first axis 65. It can be brought into close contact over the circumference. Therefore, the path toward the through hole 47 of the grease provided between the first shaft 65 and the first reduction gear 61 is further blocked, and the grease is further prevented from leaking to the outside from the through hole 47.

The shape of the protrusion 81 in the state before the first shaft 65 is assembled (the state in which the housing cover 42 is only molded) may be changed to another shape.
For example, as shown in FIG. 12, the protrusion 82 may be formed in a shape in which the inner diameter gradually increases toward the tip and the outer diameter gradually decreases toward the tip.

Further, for example, as shown in FIG. 13, a protrusion 83 having an arcuate cross-sectional shape at the tip may be used.
Further, of course, an annular protrusion surrounding the through hole 46 was similarly erected on the bottom surface 44a of the first press-fitting recess 44, and the tip end portion of the protrusion was brought into contact with the first shaft 65 (lower end portion 65a). It may be configured.

-Although it was applied to a motor 10 with a speed reducer having a speed reducer 30 integrally, it may be applied to a simple speed reducer.

10 ... motor, 20 ... motor body, 30 ... reduction gear, 31 ... housing member, 32 ... reduction mechanism, 41 ... gear housing, 41b ... first gear accommodation (accommodation), 41c ... second gear accommodation (accommodation) Part), 41d ... Engagement protrusion (engagement part), 42 ... Housing cover, 42c ... Engagement claw (engagement part), 42g ... Rib (regulation part), 44 ... First press-fitting recess (first press-fitting part) , 45 ... 2nd press-fitting recess (second press-fitting part), 46, 47 ... through hole, 48 ... gap, 51 ... worm (gear row), 61 ... 1st reduction gear (gear, gear row), 62 ... worm wheel (1st gear part), 63 ... Small diameter gear part (2nd gear part), 63b ... Inclined surface, 64 ... Support hole, 65 ... 1st shaft (shaft member), 65a ... Lower end part (1st end part), 65b ... Upper end (second end), 65c ... Recess (mark), 66 ... Flange, 71 ... Second reduction gear (gear row), 81-83 ... Protrusion, Y1, Y2 ... Axial distance (distance) ).

Claims (12)

A reduction mechanism consisting of a gear train using multiple gears,
The accommodating portion in the opening includes a gear housing accommodating the deceleration mechanism and a housing member having a housing cover covering the opening of the gear housing .
Among the plurality of gears, the gear is rotatably supported relative to the shaft member fitted to the shaft member to a support hole provided in itself, the concave-shaped first end portion of the shaft member is provided in the gear housing press-fitted into the first press-fit portion formed, a reduction gear which is press-fitted to the second press-fitting portion which forms a concave shape in which the second end is provided in the housing cover,
The first and second press-fitting portions are provided with through holes on the bottom surface thereof.
An annular protrusion surrounding the through hole is erected on the bottom surface of at least one of the first and second press-fitting portions, and the tip portion of the protrusion and the shaft member are in contact with each other. apparatus. A reduction mechanism consisting of a gear train using multiple gears,
The accommodating portion in the opening includes a gear housing accommodating the deceleration mechanism and a housing member having a housing cover covering the opening of the gear housing.
Among the plurality of gears, in a gear in which a shaft member is fitted into a support hole provided in the gear and is pivotally supported by the shaft member, the first end portion of the shaft member forms a concave shape provided in the gear housing. A reduction gear that is fixed to the first press-fitting portion by press-fitting, and the second end portion is fixed to the concave second press-fitting portion provided on the housing cover by press-fitting.
The first and second press-fitting portions are provided with through holes on the bottom surface thereof.
A speed reducing device characterized in that a mark portion is provided on an end surface of the shaft member corresponding to a through hole provided on the bottom surface of the first and second press-fitting portions. A reduction mechanism consisting of a gear train using multiple gears,
A housing member having a gear housing for accommodating the reduction mechanism in an accommodating portion in the opening and a housing cover for covering the opening of the gear housing.
It is a speed reducer equipped with
Among the plurality of gears, in a gear in which a shaft member is fitted into a support hole provided in the gear and is pivotally supported by the shaft member, the first end portion of the shaft member is a concave or hole provided in the gear housing. It is fixed by press-fitting to the first press-fitting portion having a shape, and the second end portion is fixed to the second press-fitting portion having a concave or hole shape provided in the housing cover by press-fitting.
The shaft member is a speed reducing device having a flange portion extending outward in the radial direction in order to regulate the press-fitting amount by contacting the periphery of the first and second press-fitting portions. In the speed reducing device according to any one of claims 1 to 3 .
A speed reducing device characterized in that the gear pivotally supported by the shaft member is made of resin. In the speed reducing device according to any one of claims 1 to 4 .
The gears that are pivotally supported by the shaft member are composed of first and second gear portions having different diameters integrally, and the second gear portion on the smaller diameter side and the first gear on the larger diameter side. A speed reducing device characterized in that the second gear portion is connected to the first gear portion by an inclined surface extending radially outward at a boundary portion with the portion. In the speed reducing device according to any one of claims 1 to 5 .
The shaft member is a reduction gear characterized in that it is made of metal. The speed reducer according to any one of claims 1 to 6 .
The first and second press-fitting portions have a concave shape, and in the press-fitting state of the shaft member, the bottom surface of at least one side of the first and second press-fitting portions and the shaft member are separated in the axial direction. A speed reducer characterized by being arranged in a row. In the speed reducing device according to any one of claims 1 to 7 .
A speed reducing device characterized in that a regulating portion for restricting the movement of the shaft member in the direction orthogonal to the axis is provided between the gear housing and the housing cover. A motor with a speed reducer, wherein the speed reducer according to any one of claims 1 to 8 and a motor body are driven and connected to be integrally configured. It has a reduction mechanism consisting of gear trains using a plurality of gears, a gear housing that accommodates the reduction mechanism in an accommodating portion in the opening, and a housing cover that covers the opening of the gear housing, and engages with each other. A speed reduction device including a housing member that is assembled by engagement, and includes a gear that fits a shaft member into a support hole provided in the plurality of gears and is pivotally supported by the shaft member. It is a manufacturing method of
The first step of press-fitting the first end portion of the shaft member into a position in front of the normal position with respect to the concave first press-fitting portion provided in the gear housing and temporarily fixing the shaft member.
After the first step, the second end portion of the shaft member is press-fitted into the concave second press-fitting portion provided on the housing cover, and the press-fitting is performed preferentially over the press-fitting of the first end portion. 2 steps and
After the second step, the gear housing and the housing cover are assembled by re-pressing the first end portion of the shaft member and engaging the engaging portions provided on the gear housing and the housing cover with each other. Including 3 steps
In the first step, the distance from the bottom surface of the second press-fitting portion to the second end portion of the shaft member is shorter than the distance from the engaging portion of the housing cover to the engaging portion of the gear housing. A method for manufacturing a speed reducing device, which comprises providing a gap between a first end portion of the shaft member and a bottom surface of the first press-fitting portion and temporarily fixing the shaft member. The method of manufacturing a reduction gear transmission according to claim 1 0,
A method for manufacturing a speed reducer, characterized in that the press-fitting allowances of the first and second press-fitting portions are made different to give priority to press-fitting between the first and second end portions of the shaft member. The method for manufacturing a speed reducer according to claim 1 .
At least one of the time when the first end portion of the shaft member is press-fitted into the first press-fitting portion and the time when the second end portion of the shaft member is press-fitted into the second press-fitting portion of the protrusion. A method for manufacturing a speed reducer, which comprises a press-fitting crushing step of crushing the entire circumference of the tip portion by the shaft member.

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