JP2019207001A - Gear, and motor with reduction gear - Google Patents

Abstract

To provide gears with good meshing of teeth by making the shape with a good molding accuracy, and a motor with a reduction gear.SOLUTION: On a flat plate part 52B, a contact plate 61 of a contactor 60 for detecting the rotational position of the flat plate part 52B is disposed. When the first end face F1 facing the one side in the thickness direction of the flat plate part 52B is formed smoothly, on the second end face F2 facing the other side in the thickness direction, a rib 70 protruding in the thickness direction is formed, the rib 70 extends radially along the radial direction when viewed from the other side. The first end face F1 of the flat plate part 52B is located on the inner side in the thickness direction with respect to the one end part in the thickness direction of the tooth part 52A; the connection part 52C is located in the intermediate part in the thickness direction of the tooth part 52A; and the rib 70 is located on the inner side in the thickness direction from the other end part in the thickness direction.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a gear and a motor with a reduction gear.

For example, in order to transmit rotation of a shaft member such as an output shaft, a gear may be provided on the shaft member. Further, in order to detect the rotational position of the gear, a contact plate of the contactor may be arranged on one side in the thickness direction of the gear.
As described above, since the contact plate is disposed on the end face on one side of the gear, the rotational position of the gear can be detected by the contactor. As a result, for example, in a device for driving a wiper provided in a vehicle or the like, it is possible to determine the automatic stop position (gear stop position) of the wiper based on the detection result of the contactor.

International Publication No. 2016/072008

  By the way, in the conventional gear, in order to smoothly contact the contactor and the gear, the end face on one side in the thickness direction of the gear and the surface of the contact plate are substantially flush with the contact plate attached. It was necessary to form so that. For this reason, the rib for reinforcing a gear is formed in the end surface of the other side of the gear thickness direction. If comprised in this way, the deviation of volume arises with the position of the axial direction of a gear. This separation becomes a factor in biasing the shrinkage of the resin material depending on the position of the gear when the gear is formed by, for example, injection molding. As the dimensional accuracy of the gear varies due to the uneven shrinkage of the resin material, the meshing of the tooth portions in the gear may be deteriorated.

  An object of this invention is to provide the gear with a good mesh | engagement of a tooth | gear part, and a motor with a reduction gear by setting it as a shape with a sufficient shaping | molding precision.

  In order to solve the above-mentioned problem, a gear according to the present invention is made of a resin having a disk-shaped flat plate portion and a tooth portion formed through a connecting portion over the entire outer circumference in the radial direction of the flat plate portion. A contact plate of a contactor for detecting a rotational position of the gear is disposed on the flat plate portion, and a first end surface of the flat plate portion facing one side in the thickness direction of the flat plate portion is smooth. And a rib projecting toward the other side is formed on the second end surface facing the other side in the thickness direction, and the rib extends along the radial direction when viewed from the other side. The first end surface of the flat plate portion is located on the other side in the thickness direction with respect to the end portion on the one side in the thickness direction of the tooth portion, and the connecting portion is the tooth portion. In the middle in the thickness direction and The end portion of the other side of the thickness direction of, and being located on one side of the thickness direction.

  Thus, since the first end face facing one side of the thickness direction in the flat plate portion of the gear (hereinafter, the thickness direction of the flat plate portion is simply referred to as the thickness direction) is formed smoothly, the contactor is formed on the first end surface. Contact plates can be arranged. Further, since the radially extending ribs are formed on the second end surface facing the other side in the thickness direction of the flat plate portion, the strength of the gear can be ensured.

Further, since the first end face is located on the inner side in the thickness direction than the end portion on the one side in the thickness direction of the tooth portion, the resin material constituting the gear is biased to one side in the thickness direction. It is possible to prevent the amount of shrinkage after molding of the gear from being biased depending on the position in the thickness direction.
Moreover, the flow of the resin to the tooth part at the time of shaping | molding can be made uniform because a connection part is located in the intermediate part of the thickness direction in a tooth part.

Moreover, since the connection part located between a rib and a tooth | gear part is located inside the thickness direction rather than the edge part of the other side of the thickness direction in a rib, a rib and a tooth | gear part are radial direction. It becomes discontinuous. Thereby, even if the rib contracts inward in the radial direction due to contraction after molding, it is possible to suppress the influence of the contraction on the tooth part.
As described above, by ensuring the moldability, it is possible to provide a gear with good meshing of the teeth.

  Further, the rib in the gear according to the present invention extends along the circumferential direction of the flat plate portion, and a plurality of annular ribs disposed around the rotation center of the gear, and the plurality of annular ribs extending in the radial direction. A plurality of radial ribs connected to each other in the circumferential direction, the plurality of radial ribs being discontinuously arranged in the radial direction via the annular rib. It may be.

  In this case, since the rib includes a plurality of annular ribs and a plurality of radial ribs, the gear can be reinforced strongly. Further, the plurality of radial ribs are discontinuously arranged in the radial direction via the annular rib. For this reason, the amount of contraction in the radial direction when the radial rib contracts after molding can be suppressed as compared with a configuration in which a plurality of radial ribs are continuously arranged in the radial direction. Thereby, it can suppress that a hub deform | transforms toward an inner side of radial direction because a rib shrink | contracts.

  Moreover, the said connection part in the gear which concerns on this invention is depressed toward the other side of the said thickness direction rather than the said 1st end surface of the said flat plate part, The said contact plate is formed with the sintered metal. Also good.

  In this case, the lubricant used for the contact plate formed of the sintered metal and the lubricant used for the teeth may be different materials. In such a case, when the lubricant used for the tooth portion flows inward in the radial direction, the connecting portion is located between the flat plate portion and the tooth portion and is recessed toward the other side in the thickness direction. It is possible to prevent different lubricants from mixing with each other.

  A motor with a speed reducer according to the present invention includes a gear described above, a speed reduction mechanism portion having an output shaft fixed to the rotation center of the gear, a motor portion having a rotation shaft, and the motor portion being freely rotatable. A motor case accommodated in the motor unit, a power supply circuit electrically connected to the motor unit, a gear case that accommodates the rotating shaft and is coupled to the motor case, and the speed reduction mechanism unit includes: It is housed in a gear case, and the number of rotations of the rotating shaft is reduced and transmitted to the output shaft.

  In this case, each effect mentioned above can be produced in the motor with a reduction gear.

  According to the present invention, it is possible to provide a gear with good meshing of teeth and a motor with a speed reducer by adopting a shape with good molding accuracy.

It is a perspective view which shows the state which removed the gear case among the motors with a reduction gear which concerns on one Embodiment of this invention. It is a perspective view of the gear shown in FIG. FIG. 3 is a top view of the gear shown in FIG. 2. FIG. 4 is a cross-sectional view taken along line AA of the gear shown in FIG. 3. FIG. 3 is a bottom view of the gear shown in FIG. 2.

Hereinafter, with reference to FIGS. 1-6, the motor 1 with a reduction gear which concerns on one Embodiment of this invention is demonstrated.
As shown in FIG. 1, the motor 1 with a speed reducer has a motor unit 10 having a rotation axis O1, a power supply circuit (not shown) electrically connected to the motor unit 10, and the rotation speed of the rotation axis O1. And a speed reduction mechanism unit 20 that decelerates and transmits the speed to the gear shaft 51. The rotation axis O1 of the motor and the rotation axis O2 of the gear shaft 51 of the speed reduction mechanism unit 20 are orthogonal to each other.
In the following description, a direction along the rotation axis O2 of the gear shaft 51 is referred to as an axial direction, a direction orthogonal to the axial direction is referred to as a radial direction, and a direction around the rotation axis O2 is referred to as a circumferential direction.

The motor 1 with a speed reducer has a motor case 30 that accommodates the motor unit 10 rotatably, and a gear case 40 that accommodates the rotation shaft O1 and is connected to the motor case 30.
The speed reduction mechanism unit 20 includes a gear 50 that rotates around the rotation axis O <b> 2 and a contactor 60 that detects a rotational position of the gear 50 (a flat plate portion 52 </ b> B described later), and is accommodated in the gear case 40.

As shown in FIGS. 2, 3, and 4, the gear 50 includes a gear shaft 51 that extends in the axial direction, and a disc-shaped gear body 52 that is disposed at one end of the gear shaft 51 in the axial direction. It is equipped with.
The gear shaft 51 is made of, for example, a gold material. A spline groove 51 </ b> A extending in the axial direction is formed on the outer peripheral surface of one end of the gear shaft 51.

The gear main body 52 is a worm gear that meshes with the worm shaft 31 disposed at the end of the motor unit 10. The worm shaft 31 rotates around the rotation axis O1.
The gear body 52 is made of a resin material. The gear body 52 is formed by insert formation using the gear shaft 51 as an insert member. In insert molding, the gear main body 52 is engaged with the spline groove 51A of the gear shaft 51, whereby the gear shaft 51 and the gear main body 52 are engaged in the circumferential direction.

  The gear body 52 includes a tooth portion 52A formed on the entire outer circumference in the radial direction, a flat plate portion 52B on the inner side in the radial direction of the tooth portion 52A, the contact plate 61 of the contactor 60 being disposed, 52A and the flat part 52B are provided with the connection part 52C which connects the radial direction.

  At the center portion in the radial direction of the flat plate portion 52B, a top-covered cylindrical covering portion 52D that covers the gear shaft 51 is formed. The covering portion 52D is engaged with the end portion on one side of the gear shaft 51 in the axial direction in the circumferential direction.

  In the flat plate portion 52B, the first end face F1 facing one side in the thickness direction (the axial direction, in the following description, the thickness direction of the flat plate portion 52B may be simply referred to as the thickness direction) is formed smoothly. Yes. A contact plate 61 is disposed on the first end face F1. The contact plate 61 has a square shape in plan view as viewed from one side in the thickness direction. The contact plate 61 is made of sintered metal.

  Along with the rotation of the gear 50, the power feeding circuit and the contact plate 61 are switched between a short circuit state in which they are electrically connected to each other and a non-short circuit state in which the connection is interrupted. Thereby, the rotational position of the gear 50 can be detected. The contact plate 61 is impregnated with a grease different from the grease applied to the tooth portion 52A.

  As shown in FIGS. 4 and 5, a rib 70 protruding in the thickness direction is formed on the second end face F2 facing the other side in the thickness direction of the flat plate portion 52B. The ribs 70 extend radially along the radial direction when viewed from the other side.

The ribs 70 extend in the circumferential direction, and include a plurality of annular ribs 71 disposed coaxially with the gear shaft 51, and a plurality of radial ribs 72 that extend in the radial direction and connect the plurality of annular ribs 71 to each other. I have. The plurality of radial ribs 72 are arranged at intervals in the circumferential direction.
The plurality of radial ribs 72 are discontinuously arranged in the radial direction via the annular rib 71.

The first end face F1 of the flat plate portion 52B is located on the inner side in the thickness direction than the one end portion in the thickness direction of the tooth portion 52A.
The connecting portion 52C is located in the middle portion of the tooth portion 52A in the thickness direction. The connecting portion 52 </ b> C is also located on the inner side in the thickness direction from the other end portion of the rib 70 in the thickness direction. Thus, a first groove 81 that is recessed toward one side in the thickness direction is formed in a portion surrounded by the tooth portion 52A, the coupling portion 52C, and the annular rib 71.

  Further, the connecting part 52C is recessed toward the other side in the thickness direction from the first end face F1 of the flat plate part 52B. For this reason, the recessed part 82 recessed toward the other side of the thickness direction is formed in the part enclosed by the tooth | gear part 52A, the connection part 52C, and the 1st end surface F1.

  As described above, since the first end face F1 facing the one side in the thickness direction of the flat plate portion 52B of the gear 50 is formed smoothly, the contact plate 61 of the contactor 60 can be disposed on the first end face F1. it can. Further, since the radially extending ribs 70 are formed on the second end face F2 facing the other side in the thickness direction of the flat plate portion 52B, the strength of the gear 50 can be ensured.

Further, since the first end face F1 is located on the inner side in the thickness direction with respect to the end portion on one side in the thickness direction of the tooth portion 52A, the resin material constituting the gear 50 is placed on one side in the thickness direction. It is possible to prevent the bias and prevent the shrinkage amount after the molding of the gear 50 from being biased depending on the position in the thickness direction.
Further, since the connecting portion 52C is positioned at the intermediate portion in the thickness direction of the tooth portion 52A, the flow of the resin to the tooth portion 52A at the time of molding can be made uniform.

Further, since the connecting portion 52C located between the rib 70 and the tooth portion 52A is located on the inner side in the thickness direction from the other end portion in the thickness direction of the rib 70, the rib 70 and the tooth portion. 52A becomes discontinuous in the radial direction. Thereby, even if the rib 70 contracts inward in the radial direction due to the contraction after the molding, it is possible to suppress the influence of the contraction from reaching the tooth portion 52A.
As described above, it is possible to provide the gear 50 with good meshing of the tooth portions 52A by ensuring the moldability.

  Further, since the rib 70 includes a plurality of annular ribs 71 and a plurality of radial ribs 72, the gear 50 can be reinforced strongly. A plurality of radial ribs 72 are discontinuously arranged in the radial direction via the annular rib 71. For this reason, the amount of radial contraction when the radial ribs 72 contract after the molding can be suppressed as compared with the configuration in which the plurality of radial ribs 72 are continuously arranged in the radial direction. Thereby, it can suppress that a hub deform | transforms toward the inner side of radial direction because the rib 70 shrink | contracts.

  Further, the lubricant used for the contact plate 61 made of sintered metal is different from the lubricant used for the tooth portion 52A. When the lubricant used for the tooth portion 52A flows inward in the radial direction, the connecting portion 52C is located between the flat plate portion 52B and the tooth portion 52A and is recessed toward the other side in the thickness direction. It is possible to prevent different lubricants from mixing with each other.

  Further, a crested cylindrical covering portion 52D is formed in the central portion in the radial direction of the flat plate portion 52B. Accordingly, the gear shaft 51 is inserted so that one end of the gear shaft 51 is covered with the covering portion 52 </ b> D and is fixed to the gear 50. Here, although the volume of the gear main body 52 on one side in the thickness direction increases, as described above, the rib 70 and the connecting portion 52C are formed on the one side in the thickness direction on the gear main body 52. It is possible to prevent the volume of the gear body 52 from being biased.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

  For example, in the said embodiment, although the motor 1 with a reduction gear showed the structure which is a wiper motor, it is not restricted to such an aspect. The motor 1 with a reduction gear may be used in a different application from the wiper motor.

  Moreover, in the said embodiment, although the rib 70 showed the structure provided with the annular rib 71 and the radial rib 72, it is not restricted to such an aspect. For example, the rib 70 may include only one of the annular rib 71 and the radial rib 72, or may have a shape that is neither annular nor radial.

  Moreover, in the said embodiment, although the contact plate 61 showed the structure formed with the sintered metal, it is not restricted to such an aspect. The contact plate 61 may be formed of a metal plate such as brass, for example.

  Moreover, although the connection part 52C showed the structure depressed toward the other side of the thickness direction rather than the 1st end surface F1 of the flat plate part 52B in the said embodiment, it is not restricted to such an aspect. The connecting portion 52C may not be recessed toward the other side in the thickness direction from the first end face F1 of the flat plate portion 52B.

  Moreover, it is not restricted to the said embodiment, For example, you may form the protrusion wall which protrudes toward the other side of the thickness direction in the outer peripheral part of the 1st end surface in the flat plate part 52B over the perimeter. Thereby, it is possible to effectively avoid the grease that has flowed into the connecting portion 52C from the tooth portion 52A from being mixed with the grease impregnated in the contact plate 61.

  In addition, it is possible to appropriately replace the constituent elements in the embodiment with known constituent elements without departing from the spirit of the present invention, and the above-described modified examples may be appropriately combined.

DESCRIPTION OF SYMBOLS 1 Motor with reduction gear 10 Motor part 20 Reduction mechanism part 30 Motor case 40 Gear case 50 Gear 51 Gear shaft 52 Gear main body 52A Tooth part 52B Flat plate part 52C Connection part 60 Contactor 61 Contact plate 70 Rib 71 Annular rib 72 Radial rib

Claims (4)

A resin gear having a disk-shaped flat plate portion and a tooth portion formed through a connecting portion over the entire outer circumference in the radial direction of the flat plate portion,
In the flat plate portion, a contact plate of a contactor for detecting the rotational position of the flat plate portion is disposed,
Among the flat plate portions, the first end surface facing the one side in the thickness direction of the flat plate portion is formed smoothly, and the second end surface facing the other side in the thickness direction protrudes to the other side. Ribs are formed,
The ribs extend radially along the radial direction in a plan view seen from the other side,
The first end surface of the flat plate portion is located on the other side in the thickness direction than the end portion on the one side in the thickness direction of the tooth portion,
The connecting portion is located in an intermediate portion of the tooth portion in the thickness direction, and is located on one side in the thickness direction from an end portion on the other side of the rib in the thickness direction. Characteristic gear. The ribs extend along the circumferential direction of the flat plate portion, and a plurality of annular ribs arranged around the rotation center of the gear;
A plurality of radial ribs extending in the radial direction to connect the plurality of annular ribs and spaced apart in the circumferential direction; and
The gear according to claim 1, wherein the plurality of radial ribs are discontinuously arranged in the radial direction via the annular rib. The connecting portion is recessed toward the other side in the thickness direction from the first end surface of the flat plate portion,
The gear according to claim 1, wherein the contact plate is formed of a sintered metal. A reduction gear mechanism unit including the gear according to any one of claims 1 to 3, and an output shaft fixed to a rotation center of the gear;
A motor unit having a rotating shaft;
A motor case for rotatably accommodating the motor unit;
A power feeding circuit electrically connected to the motor unit;
A housing that houses the rotating shaft and is coupled to the motor case;
The speed reduction mechanism unit is housed in the gear case, and decelerates the number of rotations of the rotation shaft and transmits it to the output shaft.

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