JP2023090131A - Composite structure rotor - Google Patents

Abstract

To suppress deterioration in strength of a composite structure rotor caused by a crack.SOLUTION: A composite structure gear 1 is a composite structure rotor comprising: a metal annular member 7 having a tooth profile formed on its outer peripheral part; an annular metal bush 3; and a resin annular member 5 that connects the metal annular member 7 and the metal bush 3. The metal annular member 7 has a plurality of convex anti-rotation parts 71 formed on its inner peripheral surface at predetermined intervals in a circumferential direction. In an axial cross section along an axial direction of the metal bush 3, the anti-rotation part 71 has an inner angle of 90 degrees or more between all adjacent two sides forming its outer edge.SELECTED DRAWING: Figure 1

Description

One aspect of the present invention relates to a composite structure of revolution.

For example, a gear disclosed in Patent Literature 1 is known as a technology related to a composite structure rotating body. The gear described in Patent Document 1 includes a metal annular body (metal annular member) having teeth formed on the outer peripheral portion, an annular metal bush, and a resin that connects the metal annular body and the metal bush. and a web (resin annular member).

JP 2017-61059 A

Here, when molding the composite structure rotating body as described above, due to the difference in thermal contraction between the metallic annular member and the metallic bush made of metal and the resin web made of resin, the metal and Cracks may occur at the joints of the resin. A problem is that the strength of the molded composite structure rotating body decreases due to the occurrence of cracks.

Conventionally, techniques for suppressing the cracks described above have been proposed. For example, there is a technique of suppressing the occurrence of cracks by performing annealing treatment or curing treatment on a composite structure rotating body immediately after molding. However, since such treatment must be carried out before the molded product is cooled, it is necessary to change the facility so as to enable such rapid treatment. In addition, curing acceleration and physical property improvement by annealing cannot be expected in the case of using a thermoplastic resin, so the effect of the above treatment is limited. As another technique for suppressing cracks, for example, there is a technique for suppressing the occurrence of cracks by performing R-chamfering on the edge of the joining portion of metal and resin. However, depending on the shape of the joint portion, the R-chamfering process becomes complicated. In addition, the effect of suppressing crack generation by such techniques is limited. As described above, the reduction in strength of the composite structure rotating body due to the influence of cracks cannot be sufficiently suppressed by the conventional crack suppression technology.

One aspect of the present invention has been made in view of the above circumstances, and an object of the present invention is to suppress deterioration in the strength of a composite structure rotor due to the influence of cracks.

A composite structure rotating body according to an aspect of the present invention includes a metal annular member having a tooth profile formed on an outer peripheral portion, an annular metal bush, and a resin annular member connecting the metal annular member and the metal bush. , wherein the metal annular member has a plurality of convex first detent portions formed on the inner peripheral surface thereof at predetermined intervals in the circumferential direction, the first The anti-rotation portion has an internal angle of 90 degrees or more between all adjacent two sides forming the outer edge in an axial cross section, which is a cross section along the axial direction of the metal bush.

In the composite structure rotating body according to one aspect of the present invention, in an axial cross section, all the inner angles of the two adjacent sides that form the outer edge of the first anti-rotation portion formed in plurality on the inner peripheral surface of the metal annular member is 90 degrees or more. Regarding the anti-rotation portion formed on the inner peripheral surface of the metal annular member, from the viewpoint of increasing the bonding force (restraining force) between the resin annular member and the metal annular member, it is usually It has a shape that expands in the axial direction from the surface toward the tip side. In the case of such a shape, on the tip side of the detent part, the inner angle of the two sides forming the outer edge in the axial cross section becomes an acute angle, and stress based on the difference in thermal contraction between members is likely to be applied, resulting in cracks. becomes more likely to occur. In this regard, in the composite structure rotating body according to one aspect of the present invention, since the interior angle of all two adjacent sides that form the outer edge of the first detent portion is 90 degrees or more, the acute angle described above is formed. never As a result, it is possible to prevent stress from being easily concentrated on the distal end side of the first rotation preventing portion, and to prevent cracks from occurring. As a result, it is possible to suppress a decrease in the strength of the composite structure rotating body due to the influence of cracks.

In an axial cross section, the first anti-rotation portion includes a first side extending in the axial direction so as to face the inner peripheral surface and a first side extending in the axial direction so as to face the inner peripheral surface as sides constituting an outer edge in an axial cross section. and a plurality of second sides extending continuously from each other, and the interior angle between adjacent second sides and the interior angle between the first side and the second side are both 90 degrees or more. may By forming a plurality of second sides in this way, for example, while forming a portion that suppresses the occurrence of cracks, the joining force (binding force) between the resin annular member and the metal annular member is ensured. Parts can also be configured appropriately.

The plurality of second sides include inclined sides extending outward in the axial direction from the inner peripheral surface toward the direction of the first sides and extending to the first sides while being continuous with the inclined sides. and a vertical side whose interior angle between and is 90 degrees. According to this configuration, the vertical side suppresses concentration of stress on the tip end side of the first detent portion, while the inclined side extending outward in the axial direction is configured. It is possible to ensure the bonding force (binding force) between the resin annular member and the metal annular member.

In an axial cross-section, the first anti-rotation portion includes, as sides forming an outer edge, a first side extending in the axial direction so as to face the inner peripheral surface and a second side extending from the inner peripheral surface to the first side. and two sides, and the interior angle between the first side and the second side may be 90 degrees. According to such a configuration, since only the vertical side is configured as the second side, it is possible to more significantly suppress the concentration of stress on the tip end side of the first anti-rotation portion. .

The metal bush has a plurality of convex second detents formed on its outer peripheral surface at predetermined intervals in the circumferential direction. The interior angles of all adjacent two sides forming the shape may be 90 degrees or more. Cracks are also likely to occur on the tip end side of the second anti-rotation part, though not as much as on the tip end side of the first anti-rotation part. In this regard, stress is concentrated on the tip side of the second anti-rotation portion by setting the inner angle of all adjacent two sides forming the outer edge of the second anti-rotation portion to 90 degrees or more in the axial cross section. It is possible to suppress the occurrence of cracks. As a result, it is possible to suppress a decrease in the strength of the composite structure rotating body due to the influence of cracks.

ADVANTAGE OF THE INVENTION According to one aspect of the present invention, it is possible to suppress a decrease in the strength of a composite structure rotating body due to the influence of cracks.

FIG. 1 is a front view and cross-sectional view of a composite structure gear according to an embodiment. 2 is a perspective view of a metal bush included in the composite structure gear of FIG. 1; FIG. 3 is a perspective view of a metal annular member included in the composite structure gear of FIG. 1; FIG. FIG. 4 is a diagram for explaining the molding process of the composite structure gear of FIGS. 1(a) and 1(b). FIG. 5 is a diagram schematically showing a configuration example of a detent. FIG. 6 is a diagram for explaining a detent portion according to a comparative example.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same or corresponding elements are denoted by the same reference numerals, and overlapping descriptions are omitted.

FIG. 1 is a front view (FIG. 1(a)) and a sectional view (FIG. 1(b)) of a composite structure gear 1 according to an embodiment. FIG. 1(b) is, in detail, a sectional view of a section along the axial direction (axial section) of the metal bush 3, which will be described later. As shown in FIGS. 1(a) and 1(b), the composite structure gear 1 is a so-called hybrid gear made of resin and metal, and is used as a gear for vehicles and industries, for example. The composite structure gear 1 is a composite structure rotating body that includes a metal bush 3 , a resin annular member 5 , and a metal annular member 7 . The composite structure gear 1 is, for example, a helical gear. The composite structure gear 1 may be a spur gear.

The metal bush 3 is a member attached to, for example, a rotating shaft (not shown). FIG. 2 is a perspective view of a metal bushing 3 included in the composite structure gear 1 of FIG. As shown in FIGS. 1(a), 1(b) and 2, the metal bushing 3 is annular. The metal bush 3 is made of metal such as stainless steel. The metal bush 3 is provided with a through hole 3h. The through hole 3h penetrates the metal bush 3 in the axial direction. A rotary shaft is inserted into the through hole 3h. The metal bush 3 has a plurality of convex anti-rotation portions 31 (second anti-rotation portions) formed on its outer peripheral surface at predetermined intervals in the circumferential direction. The anti-rotation portion 31 is inserted into the resin annular member 5 . The anti-rotation portion 31 functions to prevent the resin annular member 5 from rotating with respect to the metal bush 3 and to prevent it from coming off.

The resin annular member 5 is provided between the metal bush 3 and the metal annular member 7 and connects the metal bush 3 and the metal annular member 7 . The resin annular member 5 is, for example, a member that dampens vibrations propagating between the metal annular member 7 and the metal bush 3 . Vibration includes impact caused by meshing of the composite structure gear 1 with other gears. The resin annular member 5 absorbs and attenuates vibration through its elastic deformation. The resin annular member 5 is annular and coaxial with the metal bush 3 . The resin annular member 5 is provided around the metal bush 3 . The resin annular member 5 here is provided so as to be in contact with the outer peripheral surface of the metal bush 3 . In addition, being provided around the metal bush 3 includes not only being provided so as to be in contact with the periphery of the metal bush 3 but also being provided around the metal bush 3 via other members. .

The resin annular member 5 is manufactured by resin molding. The resin 80 (first resin) constituting the resin annular member 5 is, for example, a thermoplastic resin such as acrylonitrile butadiene styrene, acrylonitrile styrene acrylate, cycloolefin copolymer, cycloolefin polymer, ethylene acrylic acid resin, or ethylene vinyl acetate. , liquid crystal polymer, polyamide, polybutylene terephthalate, polycarbonate, polyethylene, polyetheretherketone, polyetherimide, polyethersulfone, polyethyleneterephthalate, perfluoroalkoxyalkane, polymethylmethacrylate, polyoxymethylene, polypropylene, polyphenylene ether, Polyphenylene sulfide, polyphenylsulfone, polystyrene, polysulfone, polyvinyl chloride, polyvinylidene fluoride, styrene acrylonitrile, styrene-butadiene, styrene-butadiene-styrene, styrene-ethylene-butadiene-styrene, or the like may be used. Alternatively, the resin 80 may be, for example, a thermosetting resin such as an unsaturated polyester resin, an epoxy resin, a liquid silicone rubber, a phenolic resin, or a polyurethane. Moreover, the resin 80 (first resin) forming the resin annular member 5 may be a fiber-reinforced resin. The end surface of the resin annular member 5 continues to the end surface of the metal bush 3 without a step.

The metal annular member 7 is a member that meshes with other gears. FIG. 3 is a perspective view of the metal annular member 7 included in the composite structure gear 1 of FIG. As shown in FIGS. 1( a ), 1 ( b ) and 3 , the metallic annular member 7 is annular and coaxial with the metallic bushing 3 . The metal annular member 7 is made of metal such as stainless steel, for example. The metal annular member 7 is provided around the metal bush 3 and further around the resin annular member 5 . The metal annular member 7 here is provided so as to be in contact with the outer peripheral surface of the resin annular member 5 . It should be noted that the provision around the resin annular member 5 includes not only being provided so as to be in direct contact with the circumference of the resin annular member 5, but also being provided around the resin annular member 5 via another member. including being A tooth profile 7 a is formed on the outer peripheral portion of the metal annular member 7 . A plurality of tooth profiles 7a are formed at predetermined intervals in the circumferential direction of the metal annular member 7 . The tooth profile 7a is obliquely formed with respect to the rotation axis.

The metal annular member 7 has a plurality of convex anti-rotation portions 71 (first anti-rotation portions) formed on the inner peripheral surface thereof at predetermined intervals in the circumferential direction. The anti-rotation portion 71 is inserted into the resin annular member 5 . The anti-rotation portion 71 functions to prevent the resin annular member 5 from rotating with respect to the metal annular member 7 and to prevent the resin annular member 5 from coming off. Details of the shape of the anti-rotation portion 71 will be described later. The end surface of the metal annular member 7 is connected to the end surface of the resin annular member 5 without a step.

Next, the molding process (manufacturing method) of the composite structure gear 1 will be described with reference to FIG. FIG. 4 is a diagram for explaining the molding process of the composite structure gear of FIGS. 1(a) and 1(b). FIG. 4(a) shows the flow of the molding process. FIG. 4(b) shows the injection molding machine 100 before injection injection. An example of molding the composite structure gear 1 by injection molding will be described below, but the composite structure gear 1 may be molded by compression molding, transfer molding, injection compression molding, RTM molding, autoclave molding, or the like.

Molding of the composite structure gear 1 is performed by injection molding. As shown in FIG. 4(b), the injection molding machine 100 has a mold 101 in which the metal bushing 3 and the metal annular member 7 are set, and a resin 80 that forms the resin annular member 5. A hopper 102 , a cylinder 103 for heating and melting the resin 80 put into the hopper 102 , and a nozzle 104 for injecting the melted resin 80 are provided.

In such an injection molding machine 100, as shown in FIG. 4(a), the mold 101 is first preheated (step S1) and molded (step S2). In this state, as shown in FIG. 4(b), the metal bush 3 is set in the mold 101, and the metal annular ring is positioned outside the position where the metal bush 3 is set in the mold 101. Member 7 is set. When the metal bush 3 and the metal ring member 7 are set, the rotation stop portion 31 of the metal bush 3 extends toward the metal ring member 7, and the rotation stop portion 71 of the metal ring member 7 extends toward the metal ring member 7. extends towards the metal bush 3.

Then, as shown in FIG. 4A, the resin 80 forming the resin annular member 5 is put into the hopper 102 (step S11), the resin 80 is heated and melted in the cylinder 103 (step S12), and the resin 80 is is weighed (step S13). In this state, the resin 80 can be injected from the nozzle 104 as shown in FIG. 4(b).

Then, in a state in which the metal bush 3 and the metal annular member 7 are set in the mold 101 of the injection molding machine 100, the resin 80 is poured between the metal bush 3 and the metal annular member 7, and injection molding is performed. , the metal bush 3, the metal annular member 7, and the resin annular member 5 are integrally molded. More specifically, as shown in FIG. 4A, an injection process for pouring the resin 80 (step S21), a pressure holding process (step S22), and a curing or solidification process (step S23) are sequentially performed. In step S23, if the resin 80 is a thermosetting resin, a curing process is performed, and if it is a thermoplastic resin, a solidification process is performed.

FIG. 4(c) shows the injection molding machine 100 during injection molding. FIG. 4(d) shows a partially enlarged view of FIG. 4(c). As shown in FIG. 4C, the resin 80 injected from the nozzle 104 passes through the flow path 101a inside the mold 101. As shown in FIG. Then, as shown in FIG. 4(d), the resin 80 flows from the disk gate 101b on the circumference into the area between the metal bush 3 and the metal annular member 7, and The area between the members 7 is filled. The resin 80 is applied, for example, to the entire outer peripheral surface of the metal bush 3 (including the area of the anti-rotation portion 31) and the entire inner peripheral surface of the metal annular member 7 (including the area of the anti-rotation portion 71). Filled to touch.

When integral molding by injection molding is completed, as shown in FIG. The annular member 5 is taken out and naturally cooled (step S31, third step). Finally, annealing treatment or curing treatment is performed as required. For example, if the resin 80 is a thermosetting resin, annealing is performed (step S41).

Here, in the above-described molding process, due to the difference in thermal contraction between the metal bush 3 and the metal annular member 7 made of metal and the resin annular member 5 shaped by resin, the metal and resin Cracks may occur at the joints. That is, cracks may occur at the joint between the metal bush 3 and the resin annular member 5 and the joint between the metal annular member 7 and the resin annular member 5 . Cracks are particularly conspicuous at the junction between the metal annular member 7 and the resin annular member 5 . The occurrence of cracks may reduce the strength of the molded composite structure gear 1 .

In order to solve the above-described problems, in the composite structure gear 1 according to the present embodiment, the shape of the anti-rotation portion 71, which is the joint portion of the metal annular member 7 and the resin annular member 5, is a shape suitable for suppressing cracks. It is FIG. 5 is a diagram schematically showing a configuration example of the detent part, and is an axial cross-sectional view along the axial direction of the metal bush 3. As shown in FIG. FIGS. 5(a) to 5(c) show a configuration example of the anti-rotation portion of the metal annular member 7 suitable for suppressing cracks, as an anti-rotation portion 71 (see FIG. 5(a)) and an anti-rotation portion 171 (see FIG. 5(b)), and a detent 271 (see FIG. 5(c)). FIG. 5D shows a detent portion 171 of the metal annular member 7 as a configuration example of the detent portion of the metal annular member 7 suitable for suppressing cracks and the detent portion of the metal bush 3. and the detent 131 of the metal bush 3 are shown.

5(a) to 5(d), the anti-rotation portions 71, 171, and 271 of the metal annular member 7 are all , the interior angle of all two adjacent sides forming the outer edge is 90 degrees or more.

The anti-rotation portion 71 shown in FIG. 5( a ) extends in the axial direction of the metal bush 3 so as to face the inner peripheral surface of the metal annular member 7 as a side forming the outer edge in an axial cross section. It has one side 71x and a plurality of second sides 71y extending continuously from the inner peripheral surface toward the first side. The plurality of second sides 71y includes an inclined side 71b that extends outward in the axial direction from the inner peripheral surface toward the first side 71x and continues to the inclined side 71b and extends to the first side 71x. and a vertical side 71a. The interior angle between the inclined side 71b and the vertical side 71a, which are adjacent second sides 71y, is an obtuse angle larger than 90 degrees. The interior angle between the vertical side 71a and the first side 71x is 90 degrees. That is, the vertical side 71a extends perpendicularly to the first side 71x. The anti-rotation portion 71 has a pair of vertical sides 71a, 71a extending facing each other. One vertical side 71a extends vertically from one end side of the first side 71x, and the other vertical side 71a It extends vertically from the other end side of side 71x of 1. The anti-rotation portion 71 has a pair of inclined sides 71b, 71b extending in opposition to each other. One inclined side 71b is continuous with one vertical side 71a, and the other inclined side 71b is continuous with the vertical side 71a of the .

The anti-rotation portion 271 shown in FIG. 5( c ) extends in the axial direction of the metal bush 3 so as to face the inner peripheral surface of the metal annular member 7 as a side forming the outer edge in an axial cross section. It has one side 271x and a plurality of second sides 271y continuously extending from the inner peripheral surface toward the first side. The plurality of second sides 271y includes a vertical side 271b extending perpendicularly to the inner peripheral surface from the inner peripheral surface toward the first side 271x, and a vertical side 271b continuous to the first side 71x. and an inclined side 271a extending while narrowing inward in the axial direction. The interior angle between the vertical side 271b and the inclined side 271a, which are adjacent second sides 271y, is an obtuse angle larger than 90 degrees. Also, the interior angle between the inclined side 271a and the first side 71x is an obtuse angle larger than 90 degrees. The anti-rotation portion 271 has a pair of inclined sides 271a, 271a extending opposite to each other. One inclined side 271a extends from one end side of the first side 271x, and the other inclined side 271a It extends from the other end side of the side 271x. The anti-rotation portion 71 has a pair of vertical sides 271b, 271b extending in opposition to each other, one vertical side 271b continuing to one inclined side 271a, and the other vertical side 271b is continuous with the inclined side 271a.

The anti-rotation portion 171 shown in FIG. 5(b) has a first side 171x extending axially so as to face the inner peripheral surface of the metal annular member 7 and a first side 171x as sides forming an outer edge in an axial cross section. , and a second side 171a extending from the inner peripheral surface to the first side 171x. The interior angle between the first side 171x and the second side 171a is 90 degrees. That is, the second side 171a extends perpendicularly to the first side 171x. The anti-rotation portion 71 has a pair of second sides 171a extending in opposition to each other, one of the second sides 171a extending vertically from one end of the first side 171x, The side 171a extends vertically from the other end side of the first side 171x.

Furthermore, in the composite structure gear 1 according to the present embodiment, the shape of the anti-rotation portion, which is the joint portion of the metal bushing 3 with the resin annular member 5, may be a shape suitable for crack suppression. In the configuration shown in FIG. 5(d), the above-described detent portion 171 (see FIG. 5(b)) is adopted as the detent portion of the metal annular member 7, and the detent portion of the metal bush 3 is A detent 131 is employed. The anti-rotation portion 131 has an inner angle of 90 degrees or more between all adjacent two sides forming the outer edge in an axial cross section. The anti-rotation portion 131 has a first side 131x extending in the axial direction so as to face the inner peripheral surface of the metal bush 3 and a first side extending from the inner peripheral surface as sides forming an outer edge in an axial cross section. and a second side 131a extending to 131x. The interior angle between the first side 131x and the second side 131a is 90 degrees. That is, the second side 131a extends perpendicularly to the first side 131x. The anti-rotation portion 131 has a pair of second sides 131a extending in opposition to each other, one of the second sides 131a extending vertically from one end of the first side 131x and The side 131a extends vertically from the other end side of the first side 131x.

Next, the effects of the composite structure gear 1 according to this embodiment will be described.

The composite structure gear 1 according to this embodiment includes a metal annular member 7 having a tooth profile formed on the outer peripheral portion, an annular metal bush 3 , and a resin annular member connecting the metal annular member 7 and the metal bush 3 . The metal annular member 7 has a plurality of convex anti-rotation portions 71 formed on the inner peripheral surface thereof at predetermined intervals in the circumferential direction, In the axial cross-section along the axial direction of the metal bushing 3 , the anti-rotation portion 71 has an inner angle of 90 degrees or more between all adjacent two sides forming the outer edge.

In the composite structure gear 1 according to the present embodiment, in the axial cross section, the interior angle of all two adjacent sides forming the outer edge of the plurality of anti-rotation portions 71 formed on the inner peripheral surface of the metal annular member 7 is 90 degrees. That's it. Regarding the anti-rotation portion formed on the inner peripheral surface of the metal annular member, from the viewpoint of increasing the bonding force (restraining force) between the resin annular member and the metal annular member, it is usually It has a shape that expands in the axial direction from the surface toward the tip side. FIG. 6 is a diagram illustrating a detent portion 571 of a metal annular member according to a comparative example. The anti-rotation portion 571 according to the comparative example shown in FIG. 6 has a first side 571x extending in the axial direction and a second side 571a extending from the inner peripheral surface while expanding in the axial direction toward the first side 571x. ,have. When such a detent portion 571 is employed, although the joining force (restraint force) between the resin annular member and the metal annular member is increased, the distal end side of the detent portion 571 constitutes the outer edge in the axial cross section. The inner angles of the two sides become acute angles, stress is likely to be applied due to the difference in thermal contraction between members, and cracks 300 are likely to occur. In this regard, in the composite structure gear 1 according to the present embodiment, since the inner angles of all adjacent two sides forming the outer edge of the anti-rotation portion 71 are 90 degrees or more, the above-described acute angle is not formed. . As a result, it is possible to prevent stress from being easily concentrated on the distal end side of the anti-rotation portion 71 , thereby suppressing the occurrence of cracks. As a result, the reduction in strength of the composite structure gear 1 due to cracks can be suppressed.

As shown in FIG. 5( a ), the anti-rotation portion 71 has a first side 71 x extending axially so as to face the inner peripheral surface and an inner peripheral side 71 x as sides forming an outer edge in an axial cross section. and a plurality of second sides 71y extending continuously from the surface toward the first side 71x. 2 may have an interior angle of 90 degrees or more with the side 71y. By forming the plurality of second sides 71y, 71y in this manner, the bonding force (restraining force) between the resin annular member 5 and the metal annular member 7 is increased while forming a portion that suppresses the occurrence of cracks. It is also possible to appropriately configure the part that guarantees

As shown in FIG. 5(a), the plurality of second sides 71y, 71y includes an inclined side 71b extending outward in the axial direction from the inner peripheral surface toward the first side 71x, and an inclined side 71b. and a vertical side 71a that is continuous with the side 71b and extends to the first side 71x and has an internal angle of 90 degrees with the first side 71x. According to such a configuration, the vertical side 71a suppresses the concentration of stress on the tip end side of the anti-rotation portion 71, while the inclined side 71b extending while expanding in the axial direction is formed of resin. The joining force (binding force) between the annular member 5 and the metal annular member 7 can be ensured.

As shown in FIG. 5(b), the anti-rotation portion 171 of the metal annular member 7 is a first axially extending side facing the inner peripheral surface as a side forming the outer edge in an axial cross section. It may have a side 171x and a second side 171a extending from the inner peripheral surface to the first side 171x, and the interior angle between the first side 171x and the second side 171a may be 90 degrees. According to such a configuration, only the vertical side is formed as the second side 171a, so that the concentration of stress on the tip end side of the anti-rotation portion 171 can be suppressed more remarkably.

As shown in FIG. 5(d), the metal bush 3 has a plurality of convex anti-rotation portions 131 formed on its outer peripheral surface at predetermined intervals in the circumferential direction. In an axial cross-section, all two adjacent sides forming the outer edge may have an internal angle of 90 degrees or more. Cracks are also likely to occur on the tip side of the rotation preventing portion 131 , although not as much as on the tip side of the rotation preventing portion 171 . In this respect, in the axial cross section, by setting the internal angle of all adjacent two sides forming the outer edge of the anti-rotation portion 131 to be 90 degrees or more, the stress tends to concentrate on the tip side of the anti-rotation portion 131. can be suppressed and the occurrence of cracks can be suppressed. As a result, the reduction in strength of the composite structure gear 1 due to cracks can be suppressed.

DESCRIPTION OF SYMBOLS 1... Composite structure gear (composite structure rotating body), 3... Metal bush, 5... Resin ring member, 7... Metal ring member, 7a... Tooth profile, 31, 131... Detent part (second detent part ), 71, 171, 271... Detent part (first detent part), 71a... Vertical side, 71b... Inclined side, 71x... First side, 71y... Second side.

Claims (5)

A composite structure rotating body comprising a metal annular member having a tooth profile formed on an outer peripheral portion thereof, an annular metal bush, and a resin annular member connecting the metal annular member and the metal bush,
The metal annular member has a plurality of convex first detent portions formed on its inner peripheral surface at predetermined intervals in the circumferential direction,
The first anti-rotation part is a composite structure rotating body in which the inner angle of all adjacent two sides forming the outer edge is 90 degrees or more in an axial cross section that is a cross section along the axial direction of the metal bush. . In the axial cross-section, the first anti-rotation portion includes, as sides forming an outer edge, a first side extending in the axial direction so as to face the inner peripheral surface, and a first side extending from the inner peripheral surface to the first side. a plurality of second sides extending continuously toward the sides of
2. The composite structure rotating body according to claim 1, wherein an interior angle between said adjacent second sides and an interior angle between said first side and said second side are both 90 degrees or more. The plurality of second sides include inclined sides extending from the inner peripheral surface toward the first side while expanding outward in the axial direction, and continuous sides extending from the inclined sides to the first side. 3. The composite structure rotor of claim 2, further comprising a vertical side extending at an internal angle of 90 degrees with said first side. In the axial cross-section, the first anti-rotation portion includes, as sides forming an outer edge, a first side extending in the axial direction so as to face the inner peripheral surface, and a first side extending from the inner peripheral surface to the first side. a second side extending to the side of
2. The composite structure rotor according to claim 1, wherein the interior angle between said first side and said second side is 90 degrees. The metal bush has a plurality of convex second anti-rotation portions formed on its outer peripheral surface at predetermined intervals in the circumferential direction,
The composite structure rotating body according to any one of claims 1 to 4, wherein the second anti-rotation portion has an inner angle of 90 degrees or more between all two adjacent sides forming an outer edge in the axial cross section. .

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