JP2019041496A - Geared motor and pointer type display device - Google Patents

Abstract

To provide a geared motor which can prevent or suppress breakage of a joint state between a resin-made gear and a metal-made shaft part constituting an output member.SOLUTION: A geared motor 2 includes a motor part 31, an output member 5, and a gear train 32 for transmitting rotation of the motor part 31 to the output member 5. The output member 5 includes a resin-made gear part 35 having a shaft hole 71, and a metal-made shaft part 6 which penetrates through the shaft hole 71 and is fixed to the gear part 35. The output member 5 is manufactured by insert molding, and an inner peripheral surface of the shaft hole 71 and an outer peripheral surface 6a of the shaft part 6 are brought into close contact with each other. The shaft part 6 includes a first recess 73 and a second recess 74 in two portions that are separated from each other in an axis L direction of the outer peripheral surface 6a. The gear part 35 includes a first projection 86 fitted into the first recess 73 and a second projection 87 fitted into the second recess 74, on the inner peripheral surface of the shaft hole 71.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a geared motor that outputs rotation of a motor unit from an output member including a gear unit and a shaft unit. The present invention also relates to a pointer type display device that drives a pointer by such a geared motor.

  A pointer-type display device that drives a pointer with a geared motor is described in Patent Document 1. In this document, a geared motor has a motor part, an output member, a gear train, and a case. The output member includes a resin gear portion having a shaft hole, and a metal shaft portion fixed to the gear portion while penetrating the shaft hole. The gear train transmits the rotation of the motor unit to the gear unit. The case houses the motor part, the gear train, and the gear part of the output member. The case also includes a support portion that rotatably supports the shaft portion of the output member. The support portion includes a through hole, and the shaft portion of the output member includes a protruding portion that protrudes from the through hole to the outside of the case. The pointer is attached to the protruding portion of the shaft portion. The pointer indicates the zero point (origin position) when the motor unit is stopped.

JP, 2006-101014, A

  In the pointer type display device, when the pointer attached to the protruding portion does not indicate the origin position, the pointer is once removed from the protruding portion, and after adjusting the angular position around the axis, it can be attached to the protruding portion again. is there. When removing the pointer from the protruding portion or attaching the pointer to the protruding portion, an external force in the axial direction or a circumferential direction around the axial line is applied to the shaft portion (protruding portion) of the output member.

  On the other hand, an output member including a resin gear portion and a metal shaft portion is manufactured by insert molding. In insert molding, in order to increase the bonding strength between the gear portion and the shaft portion, a knurl is provided in a portion of the shaft portion located on the inner peripheral side of the gear portion. Here, for example, when martensitic stainless steel is used as the material of the shaft portion, it is not easy to form a knurled groove deeply by rolling. If the knurled groove is shallow, the joint strength between the gear portion and the shaft portion is reduced, so when an external force is applied to the shaft portion, the joint state between the gear portion and the shaft portion is broken, and the gear portion and the shaft portion are However, there is a problem that the shaft moves relatively in the axial direction of the shaft portion or relatively rotates around the shaft line of the shaft portion.

  In view of the above problems, an object of the present invention is to provide a geared motor that can prevent or suppress the breakage of the joint state between the resin gear and the metal shaft portion constituting the output member. Another object of the present invention is to provide a pointer type display device that drives a pointer by such a geared motor.

In order to solve the above-described problems, a geared motor according to the present invention includes a motor portion, an output member, and a gear train, and the output member includes a resin gear portion having a shaft hole and the shaft hole. A metal shaft portion fixed to the gear portion in a state of passing through the gear portion, the gear train transmits rotation of the motor portion to the gear portion, and an inner peripheral surface of the shaft hole of the gear portion. The outer peripheral surface portion located on the inner peripheral side of the shaft hole is in close contact with the outer peripheral surface of the shaft portion, and the shaft portion has concave portions at a plurality of locations separated in the axial direction of the outer peripheral surface portion. The gear portion is provided with a plurality of protrusions that fit into the recesses on the inner peripheral surface of the shaft hole.

  According to the present invention, the shaft portion of the output member includes a plurality of concave portions in the outer peripheral surface portion located on the inner peripheral side of the shaft hole. Here, if a concave portion is provided in the outer peripheral surface portion of the shaft portion by cutting, the depth of the concave portion can be made larger than the depth of the knurled groove formed on the surface of the shaft portion by rolling. Easy. Further, if the concave portion is deep, when the output member is manufactured by insert molding, the protruding amount of the protruding portion provided on the inner peripheral surface of the shaft hole of the gear portion becomes large. Accordingly, the pulling strength for preventing the shaft portion from coming off from the gear portion is increased. In addition, since the shaft portion is provided with recesses at a plurality of positions spaced apart in the axial direction, it is easy to increase the pull-out strength compared to the case where there is one recess.

  In the present invention, each recess is preferably a notch having a recess bottom surface parallel to the axis. In this way, the anti-rotation strength that prevents the shaft portion from rotating with respect to the gear portion increases.

  In the present invention, the bottom surface of the recess is preferably rectangular, and the height in the axial direction is preferably longer than the width in the circumferential direction. In this way, it is easy to increase the detent strength.

  In the present invention, it is desirable that the plurality of notches are provided at the same angular position around the axis. If it does in this way, it will become easy to form a plurality of crevice in the peripheral surface of a shaft part by cutting.

  In the present invention, the gear portion includes a disc-shaped gear portion having teeth provided on an outer peripheral surface, a first protruding portion protruding from the gear portion in a first axial direction, and the axial direction from the gear portion. A second projecting portion projecting in a second direction opposite to the first direction, and the shaft hole passes through the gear portion, the first projecting portion and the second projecting portion, The shaft portion includes a first recess and a second recess as the plurality of recesses, and when viewed from a direction orthogonal to the axis, the first recess overlaps the first projecting portion, and the second recess Is overlapped with the second protruding portion, and a portion where the concave portion is not provided between the first concave portion and the second concave portion on the outer peripheral surface of the shaft portion overlaps with the gear portion. It is desirable to have a feature. If it does in this way, since it can suppress that a gear part becomes thick, a gear part can be shape | molded accurately.

  In the present invention, it has a case, and the case includes a support part that accommodates the motor part, the gear part of the output member, and the gear train and rotatably supports the shaft part of the output member, It is preferable that the support portion includes a through hole, and the shaft portion includes a protruding portion that protrudes from the through hole to the outside of the case. If it does in this way, an output member can be supported rotatably.

  Next, the pointer type display device of the present invention includes the above-mentioned geared motor and a pointer attached to the protruding portion of the shaft portion of the output member, and the pointer is fitted to the protruding portion. A fitting hole is provided.

  According to the present invention, the pointer can be attached to the shaft portion by press-fitting the protruding portion of the shaft portion into the fitting hole of the pointer. Even when an external force is applied to the shaft when the projecting part of the shaft is press-fitted into the fitting hole of the pointer or when a situation occurs such that the pointer attached to the shaft is pulled out, the gear portion It can prevent or suppress that the joining state of a shaft part breaks.

  According to the geared motor of the present invention, the shaft portion of the output member includes a plurality of concave portions in the outer peripheral surface portion located on the inner peripheral side of the shaft hole. Here, if the concave portion is provided in the outer peripheral surface portion of the shaft portion by cutting, it is easy to increase the depth. Further, if the concave portion is deep, when the output member is manufactured by insert molding, the protruding amount of the protruding portion provided on the inner peripheral surface of the shaft hole of the gear portion becomes large. Accordingly, the pulling strength for preventing the shaft portion from coming off from the gear portion is increased. Further, since the shaft portion is provided with recesses at a plurality of locations separated in the axial direction, it is easy to increase the pull-out strength as compared with the case where there is one recess.

  Moreover, according to the pointer type display device of the present invention, the pointer can be attached to the shaft portion by press-fitting the protruding portion of the shaft portion into the fitting hole of the pointer. Even when an external force is applied to the shaft when the projecting part of the shaft is press-fitted into the fitting hole of the pointer or when a situation occurs such that the pointer attached to the shaft is pulled out, the gear portion It can prevent or suppress that the joining state of a shaft part breaks.

It is explanatory drawing of the pointer type display apparatus to which this invention is applied. It is sectional drawing of the geared motor to which this invention is applied. It is the disassembled perspective view which looked at the geared motor from the output side. It is the disassembled perspective view which looked at the geared motor from the non-output side. It is a perspective view of the output member of a geared motor. It is sectional drawing of an output member. It is a perspective view of the axial part of an output member. It is the perspective view of the gear part of an output member, a top view, and a side view.

  A pointer type display device and a geared motor to which the present invention is applied will be described below with reference to the drawings.

(Guideline display device)
FIG. 1 is an explanatory view of a pointer type display device to which the present invention is applied. FIG. 1A is a perspective view of the pointer-type display device as viewed from the side of the first direction in the axial direction of the output member, and FIG. 1B is a view opposite to the first direction of the pointer-type display device. It is a perspective view at the time of seeing from the 2nd direction side. The pointer type display device 1 includes a geared motor 2 and a pointer 3. The geared motor 2 includes a flat cylindrical case 4. A shaft portion 6 of the output member 5 protrudes from the case 4. A pointer 3 is attached to a protruding portion 7 protruding from the case 4 in the shaft portion 6. In the following description, the direction along the axis L of the shaft portion 6 is the axial direction. Further, in the direction of the axis L, the side from which the shaft portion 6 protrudes from the case 4 is defined as a first direction L1 (output side), and the opposite side is defined as a second direction L2 (counter output side).

  The pointer 3 includes a pointer tube portion 8 attached to the protruding portion 7 and a needle portion 9 protruding from the pointer tube portion 8 in a direction orthogonal to the axis L. The center hole of the pointer cylinder portion 8 is a fitting hole 8 a that fits into the protruding portion 7 of the shaft portion 6. The pointer 3 is fixed to the protruding portion 7 by press-fitting the protruding portion 7 into the fitting hole 8a.

(Geared motor)
FIG. 2 is a cross-sectional view of the geared motor 2 taken along the axis L. FIG. 3A is an exploded perspective view of the geared motor 2 viewed from the first direction L1, and FIG. 3B shows the geared motor 2 in the first direction L1 with the first case omitted. It is a disassembled perspective view at the time of seeing from the side. FIG. 4A is an exploded perspective view of the geared motor 2 as viewed from the second direction L2, and FIG. 4B shows the geared motor 2 in the second direction with the second case member omitted. It is a disassembled perspective view at the time of seeing from the L2 side.

  As shown in FIG. 1, the case 4 includes a non-output side case member 11 (second case) and an output side case member 12 (first case) stacked in the axis L direction. The output side case member 12 is located in the first direction L1 of the non-output side case member 11.

  The non-output side case member 11 includes an end plate portion 14 and a cylindrical side plate portion 15 that protrudes from the outer edge of the end plate portion 14 in the first direction L1. On the outer peripheral surface of the side plate portion 15, hooks 16 are formed at a plurality of locations in the circumferential direction. The output side case member 12 includes an end plate portion 21 and a cylindrical side plate portion 22 that protrudes from the outer edge of the end plate portion 21 toward the second direction L2. Engaging protrusions 23 are formed at a plurality of locations in the circumferential direction of the side plate portion 22. The non-output side case member 11 and the output side case member 12 constitute the case 4 by engaging the hook 16 and the engagement protrusion 23.

  A cylindrical first support portion 17 that supports the end portion of the shaft portion 6 in the first direction L1 protrudes from the end plate portion 14 of the non-output-side case member 11 in the second direction L2. From the end plate portion 21 of the output side case member 12, a cylindrical second support portion 18 that supports a middle portion of the shaft portion 6 in the axis L direction protrudes in the first direction L1. The protruding portion 7 of the shaft portion 6 protrudes from the second support portion 18 in the first direction L1.

  As shown in FIGS. 2 to 4, the case 4 houses a motor unit 31 and a gear train 32. Further, the case 4 accommodates a gear portion 35 fixed to the shaft portion 6. The shaft portion 6 and the gear portion 35 constitute the output member 5. The gear train 32 transmits the rotation of the motor unit 31 to the gear unit 35 of the output member 5.

(Motor part)
The motor unit 31 is a stepping motor and is a drive source that drives the output member 5. As shown in FIG. 3, the motor unit 31 includes a rotor 41 and a stator 42 disposed around the rotor 41. The rotor 41 is rotatably supported by a support shaft 43 extending in the direction of the axis L. As shown in FIG. 3B, the end portion of the support shaft 43 on the second direction L2 side is held in a shaft hole 44 formed in the end plate portion 14 of the counter-output side case member 11. As shown in FIG. 4B, the end portion of the support shaft 43 on the first direction L1 side is held in a shaft hole 45 formed in the end plate portion 21 of the output side case member 12. An axis L0 of the support shaft 43 is a rotation center line of the rotor 41.

  The rotor 41 includes a pinion 47 (see FIG. 4) provided at an end portion on the second direction L2 side in the axis L0 direction, and a cylindrical magnet 48. The pinion 47 is made of resin. On the outer peripheral surface of the magnet 48, S poles and N poles are alternately formed at equal angular intervals. The magnet 48 and the pinion 47 are integrated by insert molding.

  The stator 42 includes a stator core 51 having a plurality of salient poles that face the outer peripheral surface of the magnet 48 with a gap therebetween. Of the plurality of salient poles, a coil 53 is wound around two salient poles (main poles) via a coil bobbin 52. The stator core 51 has a plate shape and is configured by stacking a plurality of magnetic plates punched into a predetermined shape. The stator core 51 is formed with a hole 63 through which a support shaft 62 of a compound gear 61 described later passes. The coil bobbin 52 holds a plurality of terminal pins 55 to which the end portions of the coils 53 are connected, and the end portions of the terminal pins 55 are formed on the end plate portion 21 of the output side case member 12. It protrudes in the first direction L1 through the hole 21a.

The gear train 32 decelerates the rotation of the rotor 41 and transmits it to the output member 5. In this example, the gear train 32 includes a pinion 47 and a compound gear 61 that meshes with the pinion 47. The compound gear 61 includes a large-diameter gear 65 that meshes with the pinion 47 of the rotor 41, and a small-diameter gear 66 that is smaller in diameter than the large-diameter gear 65 and provided coaxially in the first direction L <b> 1 of the large-diameter gear 65. The compound gear 61 is rotatably supported on the support shaft 62. The end portion of the support shaft 62 on the second direction L2 side is held in a shaft hole 67 formed in the end plate portion 14 of the non-output-side case member 11 as shown in FIG. As shown in FIG. 4B, the end portion of the support shaft 62 on the first direction L1 side is in a shaft hole 69 formed in the cylindrical portion 68 formed in the end plate portion 21 of the output side case member 12. Is retained. The small gear 66 meshes with the gear portion 35 of the output member 5.

(Output member)
FIG. 5 is a perspective view of the output member 5. FIG. 6 is a cross-sectional view of the output member 5. FIG. 7 is a perspective view of the shaft portion 6. 8A is a perspective view when the gear portion 35 is viewed from the first direction L1, and FIG. 8B is a plan view when the gear portion 35 is viewed from the first direction L1. FIG. 8C is a side view of the gear portion 35. The output member 5 includes a resin gear portion 35 and a metal shaft portion 6. The shaft portion 6 is martensitic stainless steel. The gear portion 35 includes a tooth portion 70 on the outer peripheral surface and a shaft hole 71 at the center. The shaft portion 6 passes through the shaft hole 71 and is fixed to the gear portion 35. The shaft portion 6 protrudes from the gear portion 35 in the first direction L1 and the second direction L2. The gear portion 35 is located closer to the second direction L2 than the center of the shaft portion 6 in the axis L direction.

  As shown in FIG. 6, the shaft portion 6 includes a first recess 73 and a second recess at two locations spaced apart in the axis L direction of the outer peripheral surface portion 6 b located on the inner peripheral side of the gear portion 35 on the outer peripheral surface 6 a. 74. The second recess 74 is located in the first direction L1 of the first recess 73. As shown in FIG. 7, each of the first recess 73 and the second recess 74 is a notch provided by notching the shaft portion 6 from the outside in the radial direction. The first recess 73 and the second recess 74 have the same shape. The first recess 73 and the second recess 74 are provided around the axis L at the same angular position.

  The first recess 73 and the second recess 74 include recess bottom surfaces 73a and 74a that are parallel to the axis L, respectively. The recess bottom surface 73a of the first recess 73 and the recess bottom surface 74a of the second recess 74 are each rectangular, and the height dimension in the axis L direction is longer than the width dimension in the circumferential direction. The concave bottom surface 73a and the concave bottom surface 74a face the same angular direction. In the shaft portion 6, a cross-sectional shape when a portion where the first recess 73 and the second recess 74 are formed is cut along a plane orthogonal to the axis L is a so-called D-shape. That is, each cross-sectional shape of the first concave portion 73 and the second concave portion 74 includes an arc contour portion whose contour extends over 180 ° and a straight contour portion connecting the open ends of the arc contour portions. .

  As shown in FIGS. 5 and 8, the gear portion 35 includes a disk-shaped gear portion 76 having teeth on the outer peripheral surface, and a counter-output side protrusion that protrudes in the second direction L <b> 2 from the central portion of the gear portion 76. It has the part 77 (2nd protrusion part), and the output side protrusion part 78 (1st protrusion part) which protrudes from the center part of the gear part 76 in the 1st direction L1. The gear portion 76, the non-output-side protruding portion 77, and the output-side protruding portion 78 are provided coaxially. The shaft hole 71 passes through the gear portion 76, the non-output side protruding portion 77 and the output side protruding portion 78.

The gear portion 76 includes a groove 81 penetrating in the direction of the axis L on the outer peripheral side in the radial direction from the non-output-side protruding portion 77 and the output-side protruding portion 78. As shown in FIG. 8B, the groove 81 includes an outer peripheral side extending portion 81a extending around one axis in the circumferential direction around the axis L, and an inner peripheral side from one end of the outer peripheral side extending portion 81a. A curved portion 81b having a circular arc shape and an inner peripheral side extending portion 81c extending from the inner peripheral side end of the curved portion 81b to the other side in the circumferential direction. As a result, the portion surrounded by the groove 81 in the gear portion 76 is a plate spring 82 whose other end in the circumferential direction is connected to the gear portion 76. A protruding portion 83 protruding in the first direction L1 is formed on the distal end side of the plate spring 82. In this example, the plate springs 82 are formed to extend in the same direction at two equiangular intervals in the circumferential direction, and the angular pitch of the two plate springs 82 is 180 °.

  The gear portion 35 protrudes radially outward from the output-side protruding portion 78 at an angular position sandwiched by two plate springs 82 in the circumferential direction, and the end in the second direction L2 continues to the gear portion 76. A gear-side protrusion 85 is provided. The gear-side protrusion 85 constitutes a stopper mechanism 90 that limits the movable range when the gear part 35 rotates counterclockwise CCW (one side in the circumferential direction) by contacting a case-side protrusion 97 described later. To do.

  Here, the output member 5 is manufactured by insert molding in which a resin is injected and the shaft portion 6 and the gear portion 35 are integrally formed with the shaft portion 6 disposed in a mold. Therefore, as shown in FIG. 6, the inner peripheral surface of the shaft hole 71 of the gear portion 35 and the outer peripheral surface portion 6 b located on the inner peripheral side of the gear portion 35 in the outer peripheral surface 6 a of the shaft portion 6 are in close contact with each other. . In addition, the gear portion 35 has, on the inner peripheral surface of the shaft hole 71, a first protrusion 86 that fits in the first recess 73 of the shaft portion 6 and a second protrusion that fits in the second recess 74 of the shaft portion 6. Part 87.

  In this example, when viewed from the direction orthogonal to the axis L, the first recess 73 overlaps with the non-output-side protruding portion 77 and the second recess 74 overlaps with the output-side protruding portion 78. Further, when viewed from a direction orthogonal to the axis L, a part of the first recess 73 in the first direction L1 overlaps with the gear portion 76. Further, when viewed from the direction orthogonal to the axis L, the annular outer peripheral surface portion 6c (the concave portion is provided between the first concave portion 73 and the second concave portion 74 in the outer peripheral surface portion 6b of the shaft portion 6. The non-exposed portion overlaps the gear portion 76.

(Output member support structure and stopper mechanism)
Here, as shown in FIGS. 3 and 4, the end plate portion 14 of the non-output side case member 11 has a cylindrical portion 91 protruding in the first direction L1 and a cylindrical shape protruding in the second direction L2. The first support portion 17 is formed coaxially. The counter-output side case member 11 is provided with a shaft hole 92 that penetrates the end plate portion 14, the cylindrical portion 91, and the first support portion 17 in the direction of the axis L.

  On the other hand, the end plate portion 21 of the output side case member 12 is provided with a cylindrical second support portion 18 in the first direction L1. As shown in FIG. 2, the second support portion 18 includes a through hole 94 at the center. The through hole 94 is a shaft hole that rotatably supports a middle portion of the shaft portion 6 of the output member 5 in the axis L direction. The shaft portion 6 penetrates the through hole 94 and protrudes to the outside of the case 4 on the first direction L1 side.

  4B, in the end plate portion 21 of the output side case member 12, the cylindrical portion surrounding the output side protruding portion 78 of the gear portion 35 is formed on the surface on the second direction L2 side. 95 and plate-like ribs 96a to 96d extending from the cylindrical portion 95 toward the radially outer side are formed. A through hole 94 of the second support portion 18 is provided at the center of the cylindrical portion 95 in the end plate portion 21. The inner diameter of the cylindrical portion 95 is larger than the outer diameter of the output side protruding portion 78 of the gear portion 35, and the inner surface of the cylindrical portion 95 is not in contact with the output side protruding portion 78 of the gear portion 35. The ribs 96a to 96d are formed at four positions that are equiangularly spaced around the cylindrical portion 95. Of the four ribs 96, the three ribs 96a, 96b, 96c are connected to the side plate part 22, and the remaining one rib 96d is connected to the columnar part 68 in which the shaft hole 69 is formed.

  Here, the gear portion 35 is prevented from moving in the second direction L2 because the counter-output side protruding portion 77 abuts on the cylindrical portion 91 of the counter-output side case member 11. Further, the gear portion 35 has the protrusion 83 of the plate spring 82 elastically abuts against the end surface 95a on the second direction L2 side of the cylindrical portion 95 of the output side case member 12, and moves to the first direction L1 side. Is limited. Therefore, the gear portion 35 and the output member 5 are prevented from rattling in the direction of the axis L.

  Next, a case side protrusion 97 extending from the end plate portion 21 in the direction of the axis L and reaching the end surface 95a of the cylindrical portion 95 is provided at a part of the cylindrical portion 95 in the circumferential direction of the inner peripheral surface. The case side protrusion 97 protrudes from the inner peripheral surface of the cylindrical portion 95 toward the output side protruding portion 78 of the output member 5. Here, the case side protrusion 97 and the gear side protrusion 85 provided on the output side protruding portion 78 limit the movable range when the gear part 35 rotates counterclockwise CCW (one side in the circumferential direction). A stopper mechanism 90 is configured.

(Operation)
In the geared motor 2 and the pointer type display device 1 configured as described above, when the pointer 3 is stopped at the zero point (origin position) and the coil 53 is supplied with power through the terminal pin 55, the rotor 41 rotates. . The rotation of the rotor 41 is transmitted to the gear portion 35 of the output member 5 via the gear train 32. Accordingly, the pointer 3 connected to the output member 5 rotates clockwise CW. At that time, by inputting a predetermined number of drive pulses to the coil 53, the angular position of the pointer 3 is switched, and the pointer 3 can be rotated clockwise CW to the target position and then stopped. Further, if a driving pulse for reverse rotation is supplied, the pointer 3 can be rotated counterclockwise CCW to another target position.

  Here, since the pointer type display device 1 of this example includes the stopper mechanism 90, when the pointer 3 rotates counterclockwise CCW and reaches the origin position indicating the zero point, the gear side protrusion 85 and the case The side protrusions 97 come into contact with each other, and the needle 3 is restricted from rotating in the CCW.

(Function and effect)
According to this example, the shaft portion 6 of the output member 5 includes the two concave portions 73 and 74 in the outer peripheral surface portion 6b. Here, when the concave portions 73 and 74 are provided on the outer peripheral surface 6a of the shaft portion 6 by cutting, the depth of the concave portions 73 and 74 is set to the depth of the knurled groove formed on the surface of the shaft portion 6 by rolling processing. Compared to depth, it can be increased. Moreover, if the recessed parts 73 and 74 are deep, when the output member 5 is manufactured by insert molding, the protrusions of the protrusions 86 and 87 provided on the inner peripheral surface of the shaft hole 71 of the gear part 35 will increase. Therefore, the pull-out strength for preventing the shaft portion 6 from coming off from the gear portion 35 is increased. Therefore, when the external force which pulls out the shaft part 6 in the direction of the axis L is applied to the gear part 35, it is possible to prevent or suppress the joint state between the gear part 35 and the shaft part 6 from being broken.

  In addition, since the outer peripheral surface portion 6b of the shaft portion 6 is provided with the concave portions 73 and 74 at two locations that are separated in the direction of the axis L, compared to the case where the concave portion is provided at one location, it is removed. It is easy to increase the strength.

  Furthermore, in this example, each recessed part 73 and 74 is a notch, and is provided with the recessed part bottom face 73a and 74a parallel to the axis line L. FIG. Therefore, the detent strength that prevents the shaft portion 6 from rotating relative to the gear portion 35 is increased. Therefore, even when an external force that relatively rotates the shaft portion 6 around the axis L with respect to the gear portion 35 is applied, it is possible to prevent or suppress the breakage of the joint state between the gear portion 35 and the shaft portion 6.

  Moreover, since each recessed part 73 and 74 is provided in the same angular position around the axis line L, it is easy to form the two recessed parts 73 and 74 in the outer peripheral surface 6a of the axial part 6 by cutting. .

  Further, in this example, the recess bottom surfaces 73a and 74a of the recesses 73 and 74 are rectangular, and the height dimension in the axis L direction is longer than the width dimension in the circumferential direction. Therefore, when an external force is applied to the gear portion 35 in the direction of rotating the shaft portion 6 about the axis L, it is easy to prevent or suppress the breakage of the joint state between the gear portion 35 and the shaft portion 6.

  Furthermore, in this example, when viewed from a direction orthogonal to the axis L, the first recess 73 of the shaft portion 6 overlaps with the non-output-side protruding portion 77 of the gear portion 35, and the second recess 74 of the shaft portion 6 is the gear. It overlaps with the output side protruding portion 78 of the portion 35. Further, an annular outer peripheral surface portion 6 c located between the first concave portion 73 and the second concave portion 74 overlaps with the gear portion 76 on the outer peripheral surface 6 a of the shaft portion 6. Thereby, when viewed from the direction orthogonal to the axis L, it is possible to avoid the entire first recess 73 or the second recess 74 from overlapping the gear portion 76. In other words, it is possible to avoid a protrusion having a width dimension equal to or larger than the width dimension of the gear portion 76 in the axis L direction on the inner peripheral side of the gear portion 76. Therefore, it can suppress that the gear part 76 becomes thick. Therefore, the gear portion 76 can be accurately formed by insert molding.

  In this example, the case 4 of the geared motor 2 includes the motor unit 31, the gear unit 35 of the output member 5, and the gear train 32, and the second support unit 18 that rotatably supports the shaft unit 6. . Further, the shaft portion 6 penetrates the through hole 94 of the second support portion 18 and protrudes to the outside of the case 4. Therefore, the output member 5 can be rotatably supported by the case 4.

  Next, in the pointer type display device 1 of this example, the pointer 3 can be attached to the shaft portion 6 by press-fitting the protruding portion 7 of the shaft portion 6 into the fitting hole 8 a of the pointer 3.

  Here, in the pointer type display device 1, when the pointer 3 attached to the protruding portion 7 of the shaft portion 6 does not indicate the origin position, the pointer 3 is once removed from the protruding portion 7, and the angle around the axis L After adjusting the position, it may be attached to the protruding portion 7 again. When the pointer 3 is attached to the protruding portion 7, the gear portion 35 abuts on the cylindrical portion 91 of the non-output side case member 11, so that the external force in the axis L direction is applied to the shaft portion 6 (projecting portion 7) of the output member 5. Work. Further, when removing the pointer 3 from the projecting portion 7, the projecting portion 83 of the gear portion 35 abuts on the end surface 95 a of the cylindrical portion 95 of the output side case member 12, so that the shaft portion 6 (projecting portion) of the output member 5. The external force in the direction of the axis L acts on 7). Further, when attaching the pointer 3 to the protruding portion 7 or when removing the pointer 3 from the protruding portion 7, the gear-side protrusion 85 of the gear portion 35 and the case-side protrusion 97 of the output-side case member 12 Due to the contact, an external force in the circumferential direction around the axis L may be applied to the shaft portion 6 (projecting portion 7) of the output member 5.

  On the other hand, in this example, the shaft portion 6 of the output member 5 includes the first recess 73 and the second recess 74, and the gear portion 35 is formed on the inner peripheral surface of the shaft hole 71 with the first recess 73 and the second recess. 74 are provided with protrusions 86 and 87 that fit into 74. Thereby, the pull-out strength with respect to the gear portion 35 of the shaft portion 6 is increased, and the detent strength with respect to the gear portion 35 of the shaft portion 6 is increased. Therefore, when attaching the pointer 3 to the shaft portion 6 or when a situation occurs in which the pointer 3 attached to the shaft portion 6 is pulled out, the shaft portion 6 is moved relative to the gear portion 35 in the axis L direction. Even when an external force to be applied is applied, even when an external force is applied to rotate the shaft portion 6 around the axis L with respect to the gear portion 35, the joint state between the gear portion 35 and the shaft portion 6 is prevented from being broken. Or it can be suppressed.

(Modification)
In addition, the recessed part provided in the outer peripheral surface part 6b of the axial part 6 may be three or more places. Also in this case, if the output member 5 is manufactured by insert molding, the gear portion 35 includes a plurality of protrusions fitted in the plurality of recesses on the inner peripheral surface of the shaft hole 71. Therefore, it is easy to prevent the joint state between the gear portion 35 and the shaft portion 6 from being broken when an external force is applied.

  Further, when viewed from the direction orthogonal to the axis L, the entire first recess 73 or second recess 74 formed in the shaft portion 6 may overlap the gear portion 76 of the gear portion 35.

Furthermore, in the above example, each of the recesses 73 and 74 is a notch, but each recess may be a recess that is recessed inward in the radial direction in a part of the circumferential direction of the shaft portion 6. Even in this case, it is easy to make such a depression deeper than the depth of the knurled groove formed on the surface of the shaft portion 6 by rolling.

DESCRIPTION OF SYMBOLS 1 ... Pointer type display apparatus, 2 ... Geared motor, 3 ... Pointer, 4 ... Case, 5 ... Output member, 6 ... Shaft part, 6a ... Outer peripheral surface, 6b ... Outer peripheral surface part, 6c ... Annular outer peripheral surface part (Part not provided), 7 ... projecting part, 8 ... pointer cylinder part, 8a ... fitting hole, 9 ... needle part, 11 ... counter-output side case member (second case), 12 ... output side case member (first) 1 case), 14 ... end plate part, 15 ... side plate part, 16 ... hook, 17 ... first support part, 18 ... second support part, 21 ... end plate part, 21a ... hole, 22 ... side plate part, 23 ... Engaging protrusion, 31 ... motor part, 32 ... gear train, 35 ... gear part, 41 ... rotor, 42 ... stator, 43 ... support shaft, 44 ... shaft hole, 45 ... shaft hole, 47 ... pinion, 48 ... magnet , 51 ... Stator core, 52 ... Coil bobbin, 53 ... Coil, 55 ... Terminal pin, 61 ... Compound gear, 6 ... support shaft, 63 ... hole, 65 ... large diameter gear, 66 ... small diameter gear, 67 ... shaft hole, 68 ... cylindrical portion, 69 ... shaft hole, 70 ... tooth portion, 71 ... shaft hole (shaft hole of gear portion) 73 ... first recess (notch), 73a ... bottom surface of the recess, 74 ... second recess (notch), 74a ... bottom surface of the recess, 76 ... gear part, 77 ... protruding part on the output side (second projecting part), 78 ... Output-side protruding portion (first protruding portion), 81 ... groove, 82 ... plate spring, 83 ... projection, 85 ... gear-side projection, 86 ... first projection (projection of the inner peripheral surface of the shaft hole) Part), 87 ... second protrusion (protrusion part of the inner peripheral surface of the shaft hole), 90 ... stopper mechanism, 91 ... cylindrical part, 92 ... shaft hole, 94 ... through hole, 95 ... cylindrical part, 95a ... end face, 96a to 96d ... rib, 97 ... case side protrusion, L ... axis, L0 ... axis, L1 ... first direction, L2 ... second direction

Claims (7)

A motor section;
An output member;
A gear train,
The output member includes a resin gear portion having a shaft hole and a metal shaft portion fixed to the gear portion in a state of passing through the shaft hole,
The gear train transmits the rotation of the motor unit to the gear unit,
The inner peripheral surface of the shaft hole of the gear portion and the outer peripheral surface portion located on the inner peripheral side of the shaft hole in the outer peripheral surface of the shaft portion are in close contact with each other,
The shaft portion includes concave portions at a plurality of positions spaced apart in the axial direction of the outer peripheral surface portion,
The geared motor is provided with a plurality of protrusions fitted in the recesses on the inner peripheral surface of the shaft hole.   The geared motor according to claim 1, wherein each recess is a notch having a recess bottom surface parallel to the axis.   The geared motor according to claim 2, wherein the bottom surface of the recess is rectangular, and the height dimension in the axial direction is longer than the width dimension in the circumferential direction.   The geared motor according to claim 2 or 3, wherein the plurality of notches are provided at the same angular position around the axis. The gear portion includes a disc-shaped gear portion having teeth provided on an outer peripheral surface, a first protruding portion protruding from the gear portion in a first axial direction, and the axial direction from the gear portion in the first direction. A second projecting portion projecting in a second direction opposite to the direction,
The shaft hole passes through the gear portion, the first protruding portion, and the second protruding portion,
The shaft portion includes a first recess and a second recess as the plurality of recesses,
When viewed from a direction orthogonal to the axis, the first recess overlaps the first protrusion, the second recess overlaps the second protrusion, and the first recess on the outer peripheral surface of the shaft The geared motor according to any one of claims 1 to 4, wherein a portion where the concave portion is not provided between the second concave portion and the gear portion overlaps with the second concave portion. Have a case,
The case includes a support portion that accommodates the motor portion, the gear portion of the output member, and the gear train, and rotatably supports the shaft portion of the output member,
The support portion includes a through hole,
The geared motor according to any one of claims 1 to 5, wherein the shaft portion includes a protruding portion that protrudes to the outside of the case from the through hole. A geared motor according to claim 6,
A pointer attached to the protruding portion of the shaft portion of the output member,
The pointer type display device, wherein the pointer includes a fitting hole into which the protruding portion is fitted.

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