JP6924027B2 - Shaft hole structure of resin rotation transmission member - Google Patents

Description

The present invention relates to a shaft hole structure of a resin rotation transmission member that eliminates rattling of a fitting portion between a shaft hole of the resin rotation transmission member and the rotation transmission shaft.

Conventionally, in a rotation transmission mechanism, in order to rotate a rotation transmission member such as a gear integrally with a rotation transmission shaft (drive shaft or driven shaft), the rotation transmission shaft has a D-cut shaft portion (at the axis of the rotation transmission shaft). A D-shaped shaft portion having an orthogonal cross-sectional shape) is formed, and the rotation transmission member has a D-cut hole that fits with the D-cut shaft portion (a D-shaped hole having a cross-sectional shape orthogonal to the rotation axis of the rotation transmission member). Is formed. Then, the rotation transmission shaft and the rotation transmission member rotate relative to each other on the shaft-side flat surface of the D-cut shaft portion and the hole-side flat surface of the D-cut hole by fitting the D-cut shaft portion and the D-cut hole. The movement is blocked (see Patent Documents 1 and 2).

Jikkenhei 2-80251 (see the description in FIGS. 1 and 2) Japanese Patent No. 5030555 (see paragraph number 0032, paragraph number 0036, and description in FIG. 2)

However, when the rotation transmission shaft and the rotation transmission member have a fitting gap Δ between the D-cut shaft portion and the D-cut hole, the fitting portion between the D-cut shaft portion and the D-cut hole causes rattling, and the rotation transmission occurs. It causes an error. Further, as shown in FIG. 16, when the rotation transmission shaft 100 and the rotation transmission member 101 have a fitting gap Δ in the D-cut shaft portion 102 and the D-cut hole 103, the rotation starts, the rotation stops, and the reverse rotation occurs. Occasionally, the ends 104a and 104b of the shaft-side flat surface 104 of the D-cut shaft portion 102 and the hole-side flat surface 105 of the D-cut hole 103 collide with each other to generate a collision sound.

Therefore, the present invention provides a shaft hole structure of a resin rotation transmission member capable of preventing the occurrence of rotation transmission error and collision noise due to rattling of the fitting portion with the rotation transmission shaft.

The present invention relates to a shaft hole structure of a resin rotation transmission member 1 fitted to a rotation transmission shaft 2. In the present invention, the rotation transmission shaft 2 has a shaft-side flat surface 6 extending along the axial direction formed at a shaft end portion 3 fitted in the shaft hole 4 of the resin rotation transmission member 1. Further, in the shaft hole 4 of the resin rotation transmission member 1, a first shaft hole portion and a second shaft hole portion are formed in order along the fitting direction of the shaft end portion 3 of the rotation transmission shaft 1. ing. Further, the first shaft hole portion is a round hole having a circular cross-sectional shape orthogonal to the axial direction. Further, the second shaft hole portion is formed with a hole-side flat surface 13 facing the shaft-side flat surface 6 of the rotation transmission shaft 2. Further, the hole-side flat surface 13 is smoothly connected to the inner peripheral surface of the round hole by an inclined surface 14, and when the shaft end portion 3 of the rotation transmission shaft 2 is fitted into the shaft hole 4. , The linear protrusion 17 deformed by the shaft end portion 3 is formed so as to extend along the fitting direction of the shaft end portion 3. Further, the linear protrusion 17 gradually increases the height of the protrusion on the side where the shaft end portion 3 is inserted into the shaft hole 4 along the fitting direction of the shaft end portion 3. Further, the resin rotation transmission member is inserted into the second shaft hole portion so that the shaft-side flat surface of the shaft end portion faces the hole-side flat surface of the second shaft hole portion. The relative rotation with the rotation transmission shaft is prevented without causing rattling in the fitting portion with the shaft end portion.

In the present invention, when the shaft end of the rotation transmission shaft is fitted into the shaft hole of the resin rotation transmission member, the linear protrusion formed on the hole-side flat surface of the shaft hole of the resin rotation transmission member rotates. It is deformed at the shaft end of the transmission shaft, and the linear protrusion partially fills the gap between the hole-side flat surface of the shaft hole and the shaft-side flat surface of the shaft end, and the shaft hole and the shaft end are fitted. The rattling of the joint part is prevented. As a result, the present invention can prevent the occurrence of rotation transmission error and the occurrence of collision noise due to the rattling of the fitting portion between the shaft hole and the shaft end portion.

FIG. 1A is a side view of a shaft end portion of a rotation transmission shaft (driving shaft or driven shaft), and FIG. 1B is a front view of the rotation transmission shaft. FIG. 2A is a front view of the resin rotation transmission member, and FIG. 2B is a cross-sectional view taken along the line A1-A1 of FIG. 2A. FIG. 3A is a cross-sectional view of a fitting portion between the shaft end of the rotation transmission shaft and the shaft hole of the resin rotation transmission member, and FIG. 3B is an enlarged portion of FIG. 3A. It is a figure which shows. It is a figure for demonstrating the shaft hole structure of the resin rotation transmission member which concerns on modification 1 of 1st Embodiment, and is the front view of the resin rotation transmission member. It is a figure for demonstrating the shaft hole structure of the resin rotation transmission member which concerns on modification 1 of 1st Embodiment, and is the fitting part of the shaft end portion of the rotation transmission shaft, and the shaft hole of the resin rotation transmission member. It is a cross-sectional view. It is a figure which shows the cross-sectional shape of a linear protrusion. It is a figure for demonstrating the shaft hole structure of the resin rotation transmission member which concerns on modification 2 of 1st Embodiment, FIG. 7A is a front view of the resin rotation transmission member, and FIG. 7B is a figure. It is sectional drawing which shows by cutting along the A2-A2 line of 7 (a). It is a figure for demonstrating the shaft hole structure of the resin rotation transmission member which concerns on modification 3 of 1st Embodiment, FIG. 8A is a front view of the resin rotation transmission member, and FIG. 8B is a figure. It is sectional drawing which shows by cutting along the A3-A3 line of 8 (a). It is a figure for demonstrating the shaft hole structure of the resin rotation transmission member which concerns on modification 4 of 1st Embodiment, FIG. 9A is a front view of the resin rotation transmission member 1, and FIG. 9B is a front view. It is sectional drawing of the fitting part of the shaft end portion of the rotation transmission shaft and the shaft hole of the resin rotation transmission member. It is a figure for demonstrating the shaft hole structure of the resin rotation transmission member which concerns on 2nd Embodiment of this invention, and FIG. 10A is a side view of the shaft end portion of the rotation transmission shaft (drive shaft or driven shaft). 10 (b) is a front view of the rotation transmission shaft. 11 (a) is a front view of the resin rotation transmission member, and FIG. 11 (b) is a cross-sectional view taken along the line A4-A4 of FIG. 11 (a). 12 (a) is a cross-sectional view of a fitting portion between the shaft end of the rotation transmission shaft and the shaft hole of the resin rotation transmission member, and FIG. 12 (b) is an enlarged part of FIG. 12 (a). It is a figure which shows. It is a figure for demonstrating the shaft hole structure of the resin rotation transmission member which concerns on modification 1 of 2nd Embodiment, and is the front view of the resin rotation transmission member. It is a figure for demonstrating the shaft hole structure of the resin rotation transmission member which concerns on modification 1 of 2nd Embodiment, and is the fitting part of the shaft end portion of the rotation transmission shaft, and the shaft hole of the resin rotation transmission member. It is a cross-sectional view. It is a figure for demonstrating the shaft hole structure of the resin rotation transmission member which concerns on modification 2 of 2nd Embodiment, FIG. 15A is a front view of the resin rotation transmission member 1, and FIG. It is sectional drawing of the fitting part of the shaft end portion of the rotation transmission shaft and the shaft hole of the resin rotation transmission member. It is sectional drawing of the fitting part of the shaft end portion of the conventional rotation transmission shaft and the shaft hole of the rotation transmission member.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[First Embodiment]
1 to 3 are views for explaining a shaft hole structure of the resin rotation transmission member 1 according to the first embodiment of the present invention. Note that FIG. 1A is a side view of a shaft end portion 3 of a rotation transmission shaft 2 (drive shaft or driven shaft), and FIG. 1B is a front view of the rotation transmission shaft 2. 2 (a) is a front view of the resin rotation transmitting member 1, and FIG. 2 (b) is a cross-sectional view taken along the line A1-A1 of FIG. 2 (a). Further, FIG. 3A is a cross-sectional view of a fitting portion between the shaft end portion 3 of the rotation transmission shaft 2 and the shaft hole 4 of the resin rotation transmission member 1, and FIG. 3B is FIG. 3A. It is a figure which shows a part of.

As shown in FIG. 1, in the rotation transmission shaft 2, the shaft end portion 3 is fitted into the shaft hole 4 of the resin rotation transmission member 1. The shaft end portion 3 of the rotation transmission shaft 2 has a D shape in cross section orthogonal to the axial direction (the direction in which the axial center 5 extends), so that the axial flat surface 6 extending along the axial direction cuts out a round bar. It is formed in.

As shown in FIG. 2, in the resin rotation transmission member 1, a worm 8 is formed on the outer peripheral side of the boss 7 in which the bottomed shaft hole 4 is formed, and the worm 8 meshes with a worm wheel (not shown). It has become. The resin rotation transmission member 1 is formed by injecting a molten synthetic resin material (polyacetal (POM), polyamide (PA), etc.) into a cavity of a mold. The shaft hole 4 is formed along the rotation shaft center 10, and an opening end side shaft hole portion (first shaft hole portion) 11 and a hole bottom side shaft hole portion (second shaft hole portion) 12 are formed. ing. The end-side shaft hole portion 11 is a round hole having a circular cross-sectional shape orthogonal to the rotation axis 10. The hole bottom side shaft hole portion 12 is a hole having a D-shaped cross section orthogonal to the rotation axis 10 (hereinafter, abbreviated as D-shaped hole), and the shaft of the shaft end portion 3 fitted in the shaft hole 4. A hole-side flat surface 13 facing the side flat surface 6 is formed. Then, the hole-side flat surface 13 is smoothly connected to the inner peripheral surface of the opening end-side shaft hole portion (round hole) 11 by an inclined surface 14. As a result, the shaft end portion 3 of the rotation transmission shaft 2 inserted into the shaft hole portion 11 on the open end side of the shaft hole 4 is guided by the inclined surface 14 and smoothly fits into the D-shaped hole 12 on the hole bottom 15 side. It fits. Further, the hole-side flat surface 13 of the D-shaped hole 12 has a longitudinal direction in the direction along the rotation axis 10 (direction along the fitting direction of the shaft end portion 3), and a width in a direction orthogonal to the longitudinal direction. As for the direction, the line is located at a position deviated from the inclined surface 14 in the longitudinal direction by a predetermined dimension and at a position deviated from the center in the width direction (the intersection of the A1-A1 line and the flat surface 13 on the hole side) 16 toward one end in the width direction. The shape protrusion 17 is formed. The linear protrusion 17 is formed up to the hole bottom 15 along the longitudinal direction, has a substantially semicircular cross-sectional shape orthogonal to the longitudinal direction (see FIG. 6A), and the tip portion has a protrusion height. It is an inclined surface 18 that gradually increases along the longitudinal direction (toward the hole bottom 15). Then, when the shaft end portion 3 of the rotation transmission shaft 2 is fitted into the D-shaped hole 12 of the shaft hole 4, the linear protrusion 17 is formed from the inclined surface 18 on the shaft side flat surface 6 of the shaft end portion 3. Since it is designed to be gradually deformed, it can be deformed without difficulty. Further, since the linear protrusion 17 is located slightly deviated from one end in the width direction of the flat surface 13 on the hole side toward the center 16 in the width direction, a space for allowing deformation is secured on both sides in the width direction, and the shaft end is provided. The flat surface 6 on the shaft side of the portion 3 is smoothly deformed, and a large fitting resistance that does not hinder the fitting operation of the shaft end portion 3 into the shaft hole 4 is not generated. The linear protrusion 17 is not limited to the substantially semicircular cross-sectional shape shown in FIG. 6 (a), and may be a substantially isosceles triangular cross-sectional shape as shown in FIG. 6 (b). Further, it may have a cross-sectional shape of a substantially right triangle as shown in FIG. 6 (c). Further, the linear protrusion 17 is not limited to the one having the cross-sectional shape of FIGS. 6 (a) to 6 (c) as long as the same effect as that of the one having a substantially semicircular cross-sectional shape can be obtained.

FIG. 3 is an enlarged view showing a fitting portion between the D-shaped shaft end portion 3 and the D-shaped hole 12. As shown in FIG. 3, the linear protrusion 17 located on the one end side in the width direction of the hole-side flat surface 13 has a gap Δ between the D-shaped shaft end portion 3 and the D-shaped hole 12. , When the D-shaped shaft end portion 3 is fitted into the D-shaped hole 12, the hole-side flat surface 13 is deformed at one end side in the width direction of the shaft-side flat surface 6 of the shaft end portion 3. The other end of the shaft-side flat surface 6 in the width direction is brought into contact with the other end in the width direction (the gap is partially filled), and the D-shaped shaft end 3 and the D-shaped hole 12 are fitted. Prevents rattling of the joint part. As a result, according to the shaft hole structure of the resin rotation transmission member 1 according to the present embodiment, the rotation transmission error and the collision sound due to the rattling of the fitting portion between the shaft hole 4 and the shaft end portion 3 occur. Can be prevented.

(Modification 1 of the first embodiment)
4 and 5 are views for explaining the shaft hole structure of the resin rotation transmission member 1 according to the first modification of the first embodiment. Note that FIG. 4 is a front view of the resin rotation transmission member 1 according to the present modification 1. Further, FIG. 5 is a cross-sectional view of a fitting portion between the shaft end portion 3 of the rotation transmission shaft 2 and the shaft hole 4 of the resin rotation transmission member 1, and is a view corresponding to FIG. 3A.

In the shaft hole structure of the resin rotation transmission member 1 according to the first modification, a pair of linear protrusions 17 and 17 are arranged symmetrically with respect to the center 16 in the width direction of the hole-side flat surface 13. According to the shaft hole structure of the resin rotation transmission member 1 according to the present modification 1, the pair of linear protrusions 17 and 17 are uniformly deformed on the shaft-side flat surface 6 of the shaft end portion 3. A pair of deformed linear protrusions 17 and 17 fill the gap (Δ) between both end sides of the shaft side flat surface 6 in the width direction and the hole side flat surface 13, so that the shaft end portion 3 and the shaft hole 4 are formed. It is possible to prevent rattling of the fitting portion. As a result, according to the shaft hole structure of the resin rotation transmission member 1 according to the first modification, the shaft hole 4 and the shaft end portion are the same as the shaft hole structure of the resin rotation transmission member 1 according to the first embodiment. It is possible to prevent the occurrence of rotation transmission error and the occurrence of collision noise due to the rattling of the fitting portion with 3.

(Modification 2 of the first embodiment)
FIG. 7 is a diagram for explaining a shaft hole structure of the resin rotation transmission member 1 according to the second modification. 7 (a) is a front view of the resin rotation transmitting member 1, and FIG. 7 (b) is a cross-sectional view taken along the line A2-A2 of FIG. 7 (a).

In the resin rotation transmission member 1 according to the second modification, the shaft hole 4 penetrates the boss 7 along the rotation axis 10, and the bottomed shaft hole 4 is formed in the boss 7. Although it is different from the resin rotation transmission member 1 according to the above, other configurations are the same as those of the resin rotation transmission member 1 according to the first embodiment. In the second modification, as shown in FIG. 7B, the linear protrusion 17 is formed together with the hole-side flat surface 13 of the second shaft hole portion up to the opening end on the right side of the shaft hole 4. According to the shaft hole structure of the resin rotation transmission member 1 according to the second modification, the same effect as the shaft hole structure of the resin rotation transmission member 1 according to the first embodiment can be obtained.

(Modification 3 of the first embodiment)
FIG. 8 is a diagram for explaining a shaft hole structure of the resin rotation transmission member 1 according to the third modification. 8 (a) is a front view of the resin rotation transmitting member 1, and FIG. 8 (b) is a cross-sectional view taken along the line A3-A3 of FIG. 8 (a).

The resin rotation transmission member 1 according to the third modification is a spur gear having teeth 20 formed on the outer peripheral side of the boss 7, and the shaft hole 4 penetrates the boss 7 along the rotation axis 10. The shaft end portion 3 can be fitted from any side of both open ends of the shaft hole 4. Then, as shown in FIG. 8B, in the resin rotation transmission member 1 according to the third modification, the shape of the hole-side flat surface 13 and the linear protrusion 17 of the second shaft hole portion in the shaft hole 4 is a boss. It is formed so as to be symmetrical with respect to the center line 21 that divides 7 into two in the direction along the rotation axis 10. As shown in FIG. 8A, in the resin rotation transmission member 1 according to the third modification, the shape of the front side of the shaft hole 4 is the shaft hole of the resin rotation transmission member 1 according to the first embodiment. It is the same as the shape on the front side of No. 4 (see FIG. 2A). According to the shaft hole structure of the resin rotation transmission member 1 according to the third modification, the same effect as the shaft hole structure of the resin rotation transmission member 1 according to the first embodiment can be obtained.

(Modification 4 of the first embodiment)
9A and 9B are views for explaining the shaft hole structure of the resin rotation transmission member 1 according to the present modification 4, FIG. 9A is a front view of the resin rotation transmission member 1, and FIG. 9A is a front view. b) is a cross-sectional view of a fitting portion between the shaft end portion of the rotation transmission shaft and the shaft hole of the resin rotation transmission member. The resin rotation transmitting member 1 shown in FIG. 9 has the same configuration as the resin rotation transmitting member 1 according to the first embodiment except for the position where the linear protrusion 17 is formed (FIG. 2A). reference).

In the resin rotation transmission member 1 according to this modification, the linear protrusion 17 is formed at the center 16 in the width direction of the hole-side flat surface 13 of the D-shaped hole 12. According to the shaft hole structure of the resin rotation transmission member 1 according to the present modification, the linear protrusion 17 formed on the hole-side flat surface 13 of the shaft hole 4 of the resin rotation transmission member 1 is the rotation transmission shaft. The shaft end portion 3 is deformed, and the linear protrusion 17 partially fills the gap (Δ) between the hole-side flat surface 13 of the shaft hole 4 and the shaft-side flat surface 6 of the shaft end portion 3, and the shaft. The rattling of the fitting portion between the hole 4 and the shaft end portion 3 is prevented.

[Second Embodiment]
10 to 12 are views for explaining the shaft hole structure of the resin rotation transmission member 1 according to the second embodiment of the present invention. 10 (a) is a side view of the shaft end 3 of the rotation transmission shaft 2 (drive shaft or driven shaft), and FIG. 10 (b) is a front view of the rotation transmission shaft 2. 11 (a) is a front view of the resin rotation transmitting member 1, and FIG. 11 (b) is a cross-sectional view taken along the line A4-A4 of FIG. 11 (a). Further, FIG. 12 (a) is a cross-sectional view of a fitting portion between the shaft end portion of the rotation transmission shaft and the shaft hole of the resin rotation transmission member, and FIG. 12 (b) shows a part of FIG. 12 (a). It is an enlarged figure.

As shown in FIG. 10, the shaft end portion 3 of the rotation transmission shaft 2 has an oval cross-sectional shape orthogonal to the axial direction (the direction in which the axial center 5 extends), and a pair of axial sides extending along the axial direction. The flat surfaces 6 and 6 are formed so as to cut out a round bar in parallel along the axial direction.

As shown in FIG. 11, in the resin rotation transmission member 1, a worm 8 is formed on the outer peripheral side of the boss 7 in which the bottomed shaft hole 4 is formed, and the worm 8 meshes with a worm wheel (not shown). It has become. The resin rotation transmission member 1 is formed by injecting a molten synthetic resin material (polyacetal (POM), polyamide (PA), etc.) into a cavity of a mold. The shaft hole 4 is formed along the rotation shaft center 10, and an opening end side shaft hole portion (first shaft hole portion) 11 and a hole bottom side shaft hole portion (second shaft hole portion) 22 are formed. ing. The end-side shaft hole portion 11 is a round hole having a circular cross-sectional shape orthogonal to the rotation axis 10. The hole bottom side shaft hole portion 22 is a hole having an oval shape (hereinafter, abbreviated as an oval shape hole) having a cross-sectional shape orthogonal to the rotation axis 10 and is fitted to the shaft hole 4. A pair of hole-side flat surfaces 13 and 13 facing the pair of shaft-side flat surfaces 6 and 6 are formed. Then, the hole-side flat surfaces 13 and 13 are smoothly connected to the inner peripheral surface of the opening end-side shaft hole portion (round hole) 11 by an inclined surface 14. As a result, the oval-shaped shaft end portion 3 of the rotation transmission shaft 2 inserted into the opening end side shaft hole portion 11 located on the opening end side of the shaft hole 4 is guided by the inclined surface 14, and the hole bottom 15 It fits smoothly into the oval-shaped hole 22 on the side. Further, the hole-side flat surfaces 13 and 13 of the oval-shaped hole 22 have a longitudinal direction in the direction along the rotation axis 10 (direction along the fitting direction of the shaft end portion 3), and are orthogonal to the longitudinal direction. Assuming that the direction is the width direction, the linear protrusions 17 and 17 are formed at positions deviated from the inclined surface 14 in the longitudinal direction by a predetermined dimension and at positions deviated from the center 16 in the width direction toward one end in the width direction. The pair of linear protrusions 17 and 17 are formed at positions such that the virtual straight line connecting one linear protrusion 17 and the other linear protrusion 17 passes through the center of the shaft hole 4 (rotational axis 10). It is located at a position symmetrically twice with the rotation axis 10 of the shaft hole 4 as the center of rotation. Further, the pair of linear protrusions 17 and 17 are formed up to the hole bottom 15 along the longitudinal direction, and the cross-sectional shape orthogonal to the longitudinal direction is a substantially semicircular shape (see FIG. 6A), and the tip thereof. The portion is an inclined surface 18 that gradually increases the height of the protrusion along the longitudinal direction (toward the bottom of the hole). Then, when the shaft end portion 3 of the rotation transmission shaft 2 is fitted into the oval-shaped hole 22 of the shaft hole 4, the linear protrusion 17 is an inclined surface 18 on the shaft side flat surface 6 of the shaft end portion 3. Since it can be gradually deformed from, it can be deformed without difficulty. Further, since the linear protrusion 17 is located slightly deviated from one end of the hole-side flat surfaces 13 and 13 in the width direction toward the center 16 in the width direction, a space for allowing deformation is secured on both sides in the width direction. The flat surface 6 on the shaft side of the shaft end portion 3 is smoothly deformed, and a large fitting resistance that hinders the fitting operation of the shaft end portion 3 into the shaft hole 4 is not generated. The linear protrusion 17 is not limited to the substantially semicircular cross-sectional shape shown in FIG. 6 (a), and may be a substantially isosceles triangular cross-sectional shape as shown in FIG. 6 (b). Further, it may have a cross-sectional shape of a substantially right triangle as shown in FIG. 6 (c). Further, the linear protrusion 17 is not limited to the one having the cross-sectional shape of FIGS. 6 (a) to 6 (c) as long as the same effect as that of the one having a substantially semicircular cross-sectional shape can be obtained.

FIG. 12 is an enlarged view showing a fitting portion between the oval-shaped shaft end portion 3 and the oval-shaped hole 22. As shown in FIG. 11, the linear protrusion 17 located on the one end side in the width direction of the hole-side flat surface 13 is the shaft-side flat surface 6 of the oval-shaped shaft end portion 3 and the oval-shaped hole 22. When there is a gap Δ with the hole-side flat surface 13, when the oval-shaped shaft end portion 3 is fitted into the oval-shaped hole 22, the width direction of the shaft-side flat surface 6 of the shaft end portion 3 The other end of the flat surface 6 on the shaft side in the width direction is brought into contact with the other end of the flat surface 13 on the hole side in the width direction while being deformed on the one end side of the oval shape. And the oval-shaped hole 22 are prevented from rattling at the fitting portion. As a result, according to the shaft hole structure of the resin rotation transmission member 1 according to the present embodiment, the rotation transmission error and the collision sound due to the rattling of the fitting portion between the shaft hole 4 and the shaft end portion 3 occur. Can be prevented.

(Modification 1 of the second embodiment)
13 and 14 are views for explaining the shaft hole structure of the resin rotation transmission member 1 according to the first modification of the second embodiment. Note that FIG. 13 is a front view of the resin rotation transmission member 1 according to the present modification 1. Further, FIG. 14 is a cross-sectional view of a fitting portion between the shaft end portion 3 of the rotation transmission shaft 2 and the shaft hole 4 of the resin rotation transmission member 1, and is a view corresponding to FIG. 12A.

In the shaft hole structure of the resin rotation transmission member 1 according to the first modification, the pair of linear protrusions 17 and 17 are arranged symmetrically with respect to the center 16 in the width direction of one of the pair of hole-side flat surfaces 13 and 13. In addition, a pair of linear protrusions 17, 17 are arranged symmetrically with respect to the center 16 in the width direction of the other pair of hole-shaped flat surfaces 13, 13. According to the shaft hole structure of the resin rotation transmission member 1 according to the present modification 1, the pair of linear protrusions 17 and 17 formed on one of the pair of hole-side flat surfaces 13 and 13 are the shaft end portions. One of the pair of shaft-side flat surfaces 6 and 6 of 3 is uniformly deformed, and the pair of linear protrusions 17 and 17 formed on the other of the pair of hole-side flat surfaces 13 and 13 are formed on the shaft end portion 3. A pair of linear protrusions 17 and 17 formed on one of the pair of hole-side flat surfaces 13 and 13 by being uniformly deformed on the other side of the pair of shaft-side flat surfaces 6 and 6 form a pair of shaft-side flat surfaces 6 and 6. A pair of linear protrusions formed on the other side of the pair of hole-side flat surfaces 13 and 13 by filling the gap (Δ) between one of the widthwise both ends sides of 6 and one of the pair of hole-side flat surfaces 13 and 13. 17 and 17 fill the gap (Δ) between the other end side of the pair of shaft-side flat surfaces 6 and 6 in the width direction and the other of the pair of hole-side flat surfaces 13 and 13, and the shaft end portion 3 and the shaft hole. It is possible to prevent rattling of the fitting portion with 4. As a result, according to the shaft hole structure of the resin rotation transmission member 1 according to the first modification, the shaft hole 4 and the shaft end portion are the same as the shaft hole structure of the resin rotation transmission member 1 according to the second embodiment. It is possible to prevent the occurrence of rotation transmission error and the occurrence of collision noise due to the rattling of the fitting portion with 3.

(Modification 2 of the second embodiment)
15 is a view for explaining the shaft hole structure of the resin rotation transmission member 1 according to the second modification, FIG. 15A is a front view of the resin rotation transmission member 1, and FIG. 15 (a) is a front view of the resin rotation transmission member 1. b) is a cross-sectional view of a fitting portion between the shaft end portion 3 of the rotation transmission shaft 2 and the shaft hole 4 of the resin rotation transmission member 1. The resin rotation transmitting member 1 shown in FIG. 15 has the same configuration as the resin rotation transmitting member 1 according to the second embodiment except for the position where the linear protrusion 17 is formed (FIG. 11A). reference).

In the resin rotation transmission member 1 according to the second modification, the linear protrusion 17 is formed at the center 16 in the width direction of the hole-side flat surfaces 13 and 13 of the oval-shaped hole 22. According to the shaft hole structure of the resin rotation transmission member 1 according to the present modification 2, the linear protrusions 17 formed on the hole-side flat surfaces 13 and 13 of the shaft hole 4 of the resin rotation transmission member 1 are formed. The linear protrusion 17 is deformed at the shaft end 3 of the rotation transmission shaft 2 to form a gap (Δ) between the hole-side flat surfaces 13 and 13 of the shaft hole 4 and the shaft-side flat surfaces 6 and 6 of the shaft end 3. Is partially filled, and rattling of the fitting portion between the shaft hole 4 and the shaft end portion 3 is prevented.

In the present invention, the resin rotation transmission member 1 is not limited to gears such as worms and spur gears, and is widely applied to objects that transmit rotation such as toothed belt pulleys, cams, and rollers.

1 ... Resin rotation transmission member, 2 ... Rotation transmission shaft, 3 ... Shaft end, 4 ... Shaft hole, 6 ... Shaft side flat surface, 13 ... Hole side flat surface, 16 ... Width direction Center, 17 …… Linear protrusion

Claims (5)

In the shaft hole structure of the resin rotation transmission member fitted to the rotation transmission shaft,
The rotation transmission shaft has a shaft-side flat surface extending along the axial direction formed at a shaft end portion fitted in a shaft hole of the resin rotation transmission member.
In the shaft hole of the resin rotation transmission member, the first shaft hole portion (open end side shaft hole portion) and the second shaft hole portion are sequentially arranged along the fitting direction of the shaft end portion of the rotation transmission shaft. Formed,
The first shaft hole portion is a round hole having a circular cross-sectional shape orthogonal to the axial direction.
The second shaft hole portion is formed with a hole-side flat surface facing the shaft-side flat surface of the rotation transmission shaft.
The hole-side flat surface, the is connected by the inclined surface on the inner peripheral surface of the round hole, when the shaft end of the rotation transmission shaft is fitted into the shaft hole, is deformed by the shaft end The linear protrusion to be formed is formed so as to extend along the fitting direction of the shaft end portion.
The linear protrusion gradually increases the height of the protrusion on the side where the shaft end is inserted into the shaft hole along the fitting direction of the shaft end .
The resin rotation transmission member is inserted into the second shaft hole portion so that the shaft-side flat surface of the shaft end portion faces the hole-side flat surface of the second shaft hole portion. Relative rotation with the rotation transmission shaft is prevented without causing rattling in the fitting portion with the shaft end.
A shaft hole structure of a resin rotation transmission member. Assuming that the direction along the fitting direction of the shaft end portion is the longitudinal direction of the hole-side flat surface and the direction orthogonal to the longitudinal direction is the width direction of the hole-side flat surface, the linear protrusion is the hole. The side flat surface is located offset in the width direction from the center in the width direction.
The shaft hole structure of the resin rotation transmitting member according to claim 1. The shaft end portion of the rotation transmission shaft has a D shape in a cross section orthogonal to the axial direction.
The shaft hole of the resin rotation transmission member has a D shape in a cross section orthogonal to the fitting direction of the shaft end portion.
The shaft hole structure of the resin rotation transmitting member according to claim 1 or 2. The shaft end portion of the rotation transmission shaft has an oval shape in a cross section orthogonal to the axial direction.
The shaft hole of the resin rotation transmission member has an oval shape in a cross section orthogonal to the fitting direction of the shaft end portion.
The shaft hole structure of the resin rotation transmitting member according to claim 1 or 2. The linear protrusion is formed at a position where the tip portion is separated from the opening end of the shaft hole.
The shaft hole structure of the resin rotation transmitting member according to any one of claims 1 to 4.

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