JP2024036053A - Motor with reduction mechanism - Google Patents

Abstract

An object of the present invention is to reduce material costs and processing costs while ensuring high output shaft torque in a motor with a speed reduction mechanism. A motor with a speed reduction mechanism includes a motor section having a rotating shaft and a gear section having a speed reduction mechanism. The gear section includes a worm wheel and an output shaft 26 that outputs the rotation of the worm wheel to the outside. The output shaft 26 includes a metal shaft portion 27 and a resin serration portion (sawtooth portion) 28 provided at one end of the shaft portion 27 in the axial direction A1. The shaft portion 27 is formed with a rotation direction locking portion 29 that locks the rotation of the serration portion 28 relative to the shaft portion 27, and on the other end side of the shaft portion 27 in the axial direction A1, and receives the rotational force from the worm wheel. and a pivot support 31 provided between the rotational direction locking part 29 and the coupling part 30. [Selection diagram] Figure 6

Description

The present invention relates to a motor with a speed reduction mechanism, which includes a motor section having a rotating shaft, and a gear section having a speed reducing mechanism that slows down the rotation of the rotating shaft.

BACKGROUND OF THE INVENTION A motor with a speed reduction mechanism that is small but can provide a large output is used as a drive source for a power window device installed in a vehicle such as an automobile. Such a motor with a speed reduction mechanism includes a motor section having a rotating shaft, and a gear section having a speed reducing mechanism that reduces rotation of the rotating shaft. Then, by driving the motor section, the rotation of the rotating shaft is reduced to a predetermined speed by the reduction mechanism in the gear section, and this reduced speed and high torque output is directed to a window regulator etc. via the output shaft. Output.

As a motor equipped with the above-mentioned speed reduction mechanism, for example, Patent Document 1 discloses a worm part that rotates by driving the motor part, an output gear part that is engaged with the worm part and can rotate integrally with the output shaft, A structure with .

Japanese Patent Application Publication No. 2010-148276

In the motor described in Patent Document 1, a metal output shaft (output shaft) and an output gear part have an integral structure. When the metal output shaft and output gear part are integrated, in order to guarantee the dimensions of the serrated part (output gear part) of the product shape, the serrated part is machined to a larger size by forging in advance, and the serrated part is made larger after machining. The serrations are machined to the desired size by cutting off the unnecessary portions of the serrations. Specifically, when the serrated portion is formed by forging, sagging occurs on both ends of the serrated portion, and this sag must be removed by cutting.

As a result, waste occurs in material costs and processing costs in manufacturing the motor.

An object of the present invention is to provide a motor with a speed reduction mechanism that reduces material costs and processing costs while ensuring high output shaft torque.

One aspect of the present invention is a motor with a speed reduction mechanism including a motor section having a rotating shaft, and a gear section having a speed reducing mechanism that slows down rotation of the rotating shaft, the gear section being configured to a worm wheel that is rotated by a worm wheel; and an output shaft that outputs the rotation of the worm wheel to the outside; a serrated portion made of a metal material, and the shaft portion has a rotational direction locking portion that is embedded in the serrated portion and locks rotation of the serrated portion with respect to the shaft portion, and an axis of the shaft portion. a connecting portion formed on the other end side in the direction, into which the rotational force from the worm wheel is input; and a connecting portion provided between the rotational direction locking portion and the connecting portion, and a shaft attached to a gear frame supporting the gear portion. A pivot support is supported.

In a motor with a speed reduction mechanism, it is possible to reduce material costs and processing costs while ensuring high torque of the output shaft.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram illustrating an overview of a power window device including a motor with a speed reduction mechanism according to the present invention. FIG. 2 is an external perspective view illustrating the structure of the motor with a speed reduction mechanism shown in FIG. 1. FIG. 3 is a plan view illustrating the internal structure of the motor with a speed reduction mechanism shown in FIG. 2. FIG. FIG. 4 is a plan view illustrating the internal structure of the gear part of the motor with a speed reduction mechanism shown in FIG. 3; 3 is a side view showing the structure of an output shaft provided in the motor with a speed reduction mechanism shown in FIG. 2. FIG. FIG. 6 is a side view showing a joined state of the shaft portion and the serration portion in the output shaft of FIG. 5, partially in section. 7 is a side view showing the structure of the shaft portion of FIG. 6. FIG. 8 is a perspective view showing the structure of a rotational locking portion and an axial locking portion in the shaft portion of FIG. 7. FIG. FIG. 3 is a cross-sectional view illustrating the internal structure of a gear portion of the motor with a speed reduction mechanism shown in FIG. 2. FIG. FIG. 9 is a schematic diagram illustrating the inertial force generated in the gear portion of FIG. 9. FIG. FIG. 10 is an exploded perspective view of the internal structure of the gear portion of FIG. 9 viewed from the lock plate side. 10 is an exploded perspective view of the internal structure of the gear portion shown in FIG. 9, viewed from the worm wheel side. FIG. FIG. 6 is a partial cross-sectional view showing the shape of the end face of the serration portion of the output shaft of FIG. 5. FIG.

Hereinafter, embodiments of the present invention will be described in detail using the drawings.

As shown in FIG. 1, a cable-type power window device 11 is mounted on an opening/closing door 10 provided on the side of a vehicle such as an automobile. The power window device 11 is configured to open and close a window glass 12 provided in a door frame 10a forming an opening/closing door 10.

The power window device 11 includes a power window motor 20 and a window regulator 40. The power window motor 20 of this embodiment is a motor with a speed reduction mechanism, and includes a motor section 21 and a gear section 22. The gear portion 22 is provided with a drum 23 around which the drive cable 14 is wound. The window regulator 40 includes a guide rail 41 that extends in the vertical direction of the opening/closing door 10, that is, in the opening/closing direction of the window glass 12. At the upper and lower sides of the guide rail 41 in the figure, there are upper pulleys that fold back the moving direction of the drive cable 14. 42 and a lower pulley 43 are each rotatably provided.

A carrier plate 44 that supports the lower end of the windshield 12 is slidably provided on the guide rail 41, and the carrier plate 44 has one side of the drive cable 14 folded back by the upper pulley 42 and the lower pulley 43. The end 14a and the other end 14b are connected.

Then, by "opening" an operation switch (not shown) provided in the vehicle interior, the power window motor 20 is rotationally driven in the forward direction, and the drum 23 is rotated clockwise. As a result, the other end 14b of the drive cable 14 is pulled in the direction of the broken line arrow in the figure, the carrier plate 44 is lowered along the guide rail 41, and the windshield 12 is moved in the direction of the broken line arrow in the figure. do. As a result, the window glass 12 can be opened (opening operation).

On the other hand, by "closing" the operation switch, the power window motor 20 is rotated in the opposite direction, and the drum 23 is rotated counterclockwise. As a result, the one end 14a of the drive cable 14 is pulled in the direction of the solid line arrow in the figure, the carrier plate 44 rises along the guide rail 41, and the windshield 12 moves in the direction of the solid line arrow in the figure. do. As a result, the window glass 12 can be closed (closing operation).

Next, the power window motor (motor with speed reduction mechanism) 20 of this embodiment will be explained. As shown in FIGS. 2 to 4, the power window motor 20 includes a motor section 21 having a rotating shaft 24, a gear frame 32 assembled to the motor section 21, and a gear frame 32 that is housed in the gear frame 32 and rotates the rotating shaft 24. and a gear section 22 having a deceleration mechanism 25 that decelerates the speed. Further, a worm 24a is integrally provided on the outer periphery of a rotating shaft (worm shaft) 24 of the motor section 21.

On the other hand, the gear part 22 is formed with a worm wheel 38 that engages with the worm 24a and is rotated by the rotating shaft 24, and a housing part that accommodates the worm wheel 38, and a gear frame that is assembled to the motor part 21. 32 are provided. Specifically, the worm 24a and the teeth 38a of the worm wheel 38 (see FIG. 10 described later) are engaged with each other, and the rotation of the rotating shaft 24 is decelerated by the worm 24a and the worm wheel 38, thereby increasing the torque. . That is, the worm 24a and the worm wheel 38 form the deceleration mechanism 25. The worm 24a and the worm wheel 38 are rotatably provided within the gear frame 32.

Further, the gear section 22 is provided with an output shaft 26 that outputs the rotation of the worm wheel 38 to the outside. In the deceleration mechanism 25, the rotational direction of the rotating shaft 24 is converted by 90 degrees by the worm 24a and the worm wheel 38 and is transmitted to the output shaft 26. Note that one end side of the output shaft 26 is exposed to the outside of the gear frame 32, and a serration portion (sawtooth portion) 28 is provided in this exposed portion. A drum 23 shown in FIG. 1 is engaged with this serration portion 28.

As described above, in the power window motor 20, the worm 24a and the worm wheel 38 decelerate the rotation of the rotating shaft 24 to a predetermined speed to increase the torque, and transmit this high torque rotation to the outside of the gear frame 32. It is designed to output to a provided drum 23 via an output shaft 26. Note that, as shown in FIG. 2, the serration portion 28 exposed from the gear frame 32 is provided so as to be rotatable in both directions (rotation direction R1).

Next, the detailed structure of the output shaft 26 will be explained.

As shown in FIGS. 5 to 7, the output shaft 26 includes a metal shaft portion 27 and a resin serration portion (sawtooth portion) 28 provided at one end of the shaft portion 27 in the axial direction A1. , has. Specifically, the serration portion 28 is made of resin and has a substantially cylindrical shape. The serration portion 28 is provided with a plurality of tooth portions 28a and tooth grooves 28b alternately in the rotational direction R1 of the shaft portion 27 (see FIG. 8), and has a gear shape. In other words, the serration portion 28 is provided with a plurality of tooth portions 28a at predetermined intervals in the rotational direction R1 of the shaft portion 27.

On the other hand, the shaft portion 27 is made of metal and has a substantially cylindrical rod shape. The shaft portion 27 includes a rotational direction locking portion 29 that is embedded in the serration portion 28 and locks the rotation of the serration portion 28 with respect to the shaft portion 27 . As shown in FIG. 8, this rotational direction locking portion 29 includes a plurality of tooth portions 29a and tooth grooves 29b that are alternately provided in the rotational direction R1 of the shaft portion 27. Specifically, the rotation direction locking portion 29 includes a plurality of teeth 29a provided at predetermined intervals in the rotation direction R1 of the shaft portion 27, and the teeth 29a and the adjacent teeth 29a are It consists of a tooth groove 29b provided in between.

Since the rotation direction locking part 29 is embedded in the resin serration part 28 as shown in FIG. 6, the resin forming the serration part 28 is embedded in each of the plurality of tooth grooves 29b. For example, the rotational locking portion 29 of the metal shaft portion 27 is embedded in the resin serration portion 28 by insert molding. As a result, the resin of the serration portion 28 is in a state where the tooth grooves 29b of the rotational direction locking portion 29 are stuck with high strength, and the bonding strength between the serration portion 28 and the rotational direction locking portion 29 can be increased. That is, when the shaft portion 27 rotates, the serration portion 28 can be prevented from spinning idle, and the output shaft 26 can generate high output.

Further, the shaft portion 27 is connected to a connecting portion 30 that is formed on the other end side of the shaft portion 27 in the axial direction A1 and receives rotational force from a worm wheel 38 shown in FIG. A shaft support 31 is provided between the portion 29 and the connecting portion 30 and is pivotally supported by a gear frame 32 that supports the gear portion 22. The connecting portion 30 includes a plurality of teeth 30a provided at predetermined intervals in the rotational direction R1 of the shaft portion 27, and cuts provided along the rotational direction R1 of the shaft portion 27 with respect to the plurality of teeth 30a. A recessed portion 30b is formed. That is, the connecting portion 30 is also formed in a gear shape. As shown in FIG. 9, a metal lock plate 35 is engaged with the plurality of teeth 30a of the connecting portion 30. A C ring 37 is fitted into the notch 30b to fix the lock plate 35 and the connecting portion 30 of the shaft portion 27.

The shaft support 31 is located between the rotational locking portion 29 and the connecting portion 30, and is rotatably supported in a hole 32a of the gear frame 32, as shown in FIG. Furthermore, in order to prevent foreign matter from entering the gear frame 32 between the hole 32a and the shaft support 31, an O-ring 36 is fitted into the end of the shaft support 31 on the installation side of the serration section 28. There is.

The lock plate 35 is held by a plate holding member 39 made of resin, and is assembled to the worm wheel 38 together with a damper member 33, which will be described later. When the worm wheel 38 rotates, the lock plate 35 also rotates and the shaft portion 27 rotates via the connecting portion 30.

Further, a gear cover 13 that covers the worm wheel 38 and the lock plate 35 is fixed to the gear frame 32.

According to the power window motor 20 of the present embodiment, the rotation direction locking portion 29 is provided in the portion of the metal shaft portion 27 that is embedded in the resin serration portion 28, so that the output shaft 26 is High torque can be ensured. Further, since the serration portion 28 of the output shaft 26 is made of resin by molding, the material cost and processing cost for manufacturing the power window motor 20 can be reduced. That is, the material cost and processing cost for manufacturing the power window motor 20 can be reduced while ensuring high torque of the output shaft 26, which is the output shaft, in the power window motor 20.

Further, since the serration portion 28 of the output shaft 26 is made of resin, the weight of the output shaft 26 can be reduced. Thereby, the characteristics of the power window motor 20 can be improved.

Furthermore, in the production of the output shaft 26 of the power window motor 20, the use of a cutting machine used for cutting the metal shaft portion 27 can be reduced, and the driving energy of the cutting machine for cutting can be reduced. It becomes possible to do so. As a result, it will be possible to achieve Goal 7 and Goal 13 in the Sustainable Development Goals (SDGs) set by the United Nations.

Here, in the power window motor 20, as shown in FIG. 9, a damper member 33 is provided between the worm wheel 38 and the output shaft 26, and is elastically deformed by the relative rotation of the worm wheel 38 and the output shaft 26. ing. The damper member 33 is a substantially ring-shaped rubber member as shown in FIGS. 11 and 12. The damper member 33 includes six damper pieces 33b and six connecting portions 33c that connect adjacent damper pieces 33b to each other. The six damper pieces 33b and the six connecting parts 33c are arranged alternately at equal intervals (30° intervals) along the circumferential direction of the worm wheel 38, and each damper piece 33b has a diameter relative to each connecting part 33c. It is provided so as to protrude radially outward. Further, a damper accommodating portion 38c is formed inside the worm wheel 38, and the damper member 33 is accommodated in the damper accommodating portion 38c. Further, the damper housing portion 38c of the worm wheel 38 is provided with a torque output portion 38b. On the other hand, the lock plate 35 is provided with a torque receiving portion 35a. In the assembled state of the gear section 22 shown in FIG. and the torque receiving portion 35a. That is, the torque output portions 38b and the torque receiving portions 35a are alternately arranged between adjacent damper pieces 33b.

Here, each damper piece 33b is held (pinched) between the torque output part 38b and the torque receiving part 35a in a slightly elastically deformed state. Thereby, both sides of the damper piece 33b along the circumferential direction of the gear part 22 are in close contact with the torque output part 38b and the torque receiving part 35a, respectively.

As a result, when the worm wheel 38 is rotated in the forward or reverse direction, rotational force is transmitted from the torque output section 38b to the torque receiving section 35a via the damper piece 33b. At this time, by crushing the damper piece 33b in the rotational direction, the transmission of impact between the torque output section 38b and the torque receiving section 35a when the motor is driven can be alleviated.

Further, the damper member 33 has a convex portion 33a that contacts the worm wheel 38 and the lock plate 35 in the axial direction A1 of the shaft portion 27, and further contacts the inner wall of the worm wheel 38 in the radial direction of the damper member 33. (Contact at contact portion B1).

Thereby, elastic force is applied to the worm wheel 38 from the damper member 33 in the axial direction A1 and the radial direction. Further, the output shaft 26 and the lock plate 35 are assembled in a state in which an elastic force is applied from the damper member 33 at the contact portion B1 in the axial direction A1, and the output shaft 26 and the lock plate 35 are in a state in which they are urged downward in FIG. It becomes. In other words, the serrations 28 of the output shaft 26 are always pressed against the upper surface of the gear frame 32.

Note that the damper member 33 reduces the inertia force applied to the worm wheel 38 when the window glass 12 shown in FIG. 1 moves up and down and stops. Further, as shown in FIG. 10, loads F1, F2, and F3 are applied to the worm wheel 38 even during rotation (rotation in the rotation direction R1). At this time, the load generated on the output shaft 26 in the axial direction A1 becomes the largest. Since the serrations 28 of the output shaft 26 are always pressed against the upper surface of the gear frame 32, a force acts on the serrations 28 to cause them to come off the shaft 27.

Therefore, the shaft portion 27 includes an axial locking portion 34 that locks the movement of the serration portion 28 in the axial direction A1 with respect to the shaft portion 27, as shown in FIG. This axial locking portion 34 prevents the serration portion 28 from coming off against the force that constantly presses the upper surface of the gear frame 32 (the force that pulls the serration portion 28 downward in FIG. 9). This is the part to do. Specifically, the upward movement of the serration section 28 in FIG. 9 can be restrained by the side wall 34a of the axial locking section 34 shown in FIG. That is, the resin portion of the serration portion 28 that has entered the tooth groove 29b of the rotational locking portion 29 is held in place by the side wall 34a of the axial locking portion 34 even when the serration portion 28 is pulled downward in FIG. 28 can be restrained from moving upward in FIG.

Therefore, by providing the axial locking portion 34, even when stress is applied to the serration portion 28 in the direction (axial direction A1) in which it comes off from the shaft portion 27 due to the elastic force from the damper member 33, the serration portion 28 can be prevented from coming off from the shaft portion 27.

Note that the axial locking portion 34 is preferably provided at a position closer to the end than the rotational locking portion 29 in the axial direction A1 of the shaft portion 27 . In other words, the position where the axial locking portion 34 is provided in the axial direction A1 of the shaft portion 27 is preferably a position closer to the distal end than the rotational locking portion 29, and is preferably provided at the end. Specifically, when forming the shaft portion 27 by forging, the axial locking portion 34 is formed at a location closer to the inside of the shaft portion 27 when forming the shaft portion 27 using a forging die. It is difficult to obtain the precision of the tooth portion 29a and the tooth groove 29b. Therefore, by providing the axial locking portion 34 at a position closer to the end than the rotational locking portion 29 in the axial direction A1 of the shaft portion 27, preferably at the end, the shaft portion 27 is formed using a heading mold. The accuracy of the tooth portion 29a and the tooth groove 29b can be easily achieved.

Further, as shown in FIG. 13, a circular recess 28d recessed along the axial direction A1 of the shaft portion 27 is formed in the end surface 28c of the serration portion 28. The recess 28d is preferably formed such that the diameter D1 of the end of the shaft portion 27 and the diameter D2 of the recess 28d are equal (D1=D2).

Since the diameter D2 of the recess 28d formed in the end surface 28c of the serration part 28 is equal to the diameter D1 of the end part of the shaft part 27, when the serration part 28 is molded with resin, the tooth part 28a of the serration part 28 is It is also possible to suppress the resin from being pulled toward the end surface 28c at the corner C1 of the tooth groove 28b. Thereby, the thickness of the resin portion formed from the tooth portion 28a and the tooth groove 28b to the end surface 28c side of the serration portion 28 can be made uniform, and the molding accuracy of the serration portion 28 can be improved.

It goes without saying that the present invention is not limited to the embodiments described above, and can be modified in various ways without departing from the spirit thereof. For example, when forming the shaft portion 27, the axial locking portion 34 may be formed not at the end of the shaft portion 27 but at a location closer to the inside in the axial direction A1 of the shaft portion 27.

Further, the recessed portion 28d formed in the end surface 28c of the serration portion 28 is not limited to a circular shape, but may be a polygonal shape or the like.

10: opening/closing door, 10a: door frame, 11: power window device, 12: window glass, 13: gear cover, 14: drive cable, 14a: one end, 14b: other end, 20: power window motor ( (motor with reduction mechanism), 21: motor section, 22: gear section, 23: drum, 24: rotating shaft, 24a: worm, 25: reduction mechanism, 26: output shaft, 27: shaft section, 28: serration section (sawtooth 28a: Tooth portion, 28b: Tooth groove, 28c: End surface, 28d: Recessed portion, 29: Rotation direction locking portion, 29a: Tooth portion, 29b: Tooth groove, 30: Connecting portion, 30a: Tooth portion, 30b: Notch, 31: Axial support, 32: Gear frame, 32a: Hole, 33: Damper member, 33a: Convex portion, 33b: Damper piece, 33c: Connecting portion, 34: Axial locking portion, 34a : Side wall, 35: Lock plate, 35a: Torque receiving part, 36: O ring, 37: C ring, 38: Worm wheel, 38b: Torque output part, 38c: Damper accommodating part, 39: Plate holding member, 40: Wind Regulator, 41: Guide rail, 42: Upper pulley, 43: Lower pulley, 44: Carrier plate, A1: Axial direction, B1: Contact portion, C1: Corner, D1, D2: Diameter, F1, F2, F3: Load, R1: Rotation direction

Claims (4)

A motor with a speed reduction mechanism, comprising a motor section having a rotating shaft, and a gear section having a speed reducing mechanism that reduces rotation of the rotating shaft,
The gear part is
a worm wheel rotated by the rotating shaft;
an output shaft that outputs the rotation of the worm wheel to the outside,
The output shaft is
A metal shaft part,
a sawtooth portion made of resin provided at one end in the axial direction of the shaft portion;
The shaft portion is
a rotational direction locking part that is embedded in the serrated part and locks rotation of the serrated part with respect to the shaft part;
a connecting portion formed on the other axial end side of the shaft portion, into which rotational force from the worm wheel is input;
a shaft support provided between the rotational direction locking part and the connection part and pivotally supported by a gear frame that supports the gear part;
A motor with a reduction mechanism. The motor with a speed reduction mechanism according to claim 1,
A damper member that is elastically deformed by relative rotation between the worm wheel and the output shaft is provided between the worm wheel and the output shaft,
The shaft portion includes an axial locking portion that locks the serrated portion from moving in the axial direction of the shaft portion with respect to the shaft portion. A circular concave portion recessed along the axial direction of the shaft portion is formed on an end surface of the serrated portion,
The motor with a speed reduction mechanism according to claim 1 or 2, wherein the diameter of the end of the shaft portion and the diameter of the recess are equal. The motor with a speed reduction mechanism according to claim 2, wherein the axial locking portion is provided closer to an end than the rotational locking portion in the axial direction of the shaft portion.

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