JP5206556B2 - Compound gear and torque transmission mechanism - Google Patents

Description

本発明は、金属等のインサートと樹脂製の表層部材で構成される複合ギヤおよびトルク伝達機構に関する。   The present invention relates to a composite gear and a torque transmission mechanism including metal inserts and resin surface layer members.

ギヤ歯の部分を樹脂で形成した樹脂ギヤは、樹脂の大減衰・低剛性という樹脂の物性により、低振動、低騒音のトルク伝達機構を構成できることに加え、軽量であり、射出成形のみで安価に歯部を形成でき、ＯＡ機器などで広範に使用されているが、上記物性が制約となり、低負荷、低回転且つ常温付近で使用されることが殆どであった。   Resin gears with gear teeth made of resin can be used to form a low-vibration, low-noise torque transmission mechanism due to the resin's physical properties of high damping and low rigidity. The tooth part can be formed in a wide range, and it is widely used in OA equipment and the like. However, the physical properties are limited, and it is almost always used at a low load, a low rotation, and near room temperature.

特許文献１には、金属製芯部材をインサートして射出成形し、ギヤ歯部を樹脂材で被覆した樹脂ギヤが開示されているが、この樹脂ギヤは、ギヤ歯部の樹脂材のみで衝撃を受けるため樹脂部への負担が大きく、高負荷時に樹脂部が損傷または剥離する問題が指摘されている。そこで、特許文献２は、金属製芯部材の中間部に樹脂製の緩衝帯を設けることを開示している。しかし、この樹脂ギヤは、相手ギヤとの噛合部分から入力される荷重により、緩衝帯が周方向に不均衡に弾性変形してギヤ部に偏心を生じるおそれがあり、高負荷での使用は不可能である。   Patent Document 1 discloses a resin gear in which a metal core member is inserted and injection-molded, and a gear tooth portion is covered with a resin material. This resin gear is impacted only by a resin material of the gear tooth portion. Therefore, the burden on the resin part is large, and there is a problem that the resin part is damaged or peeled off under high load. Therefore, Patent Document 2 discloses that a buffer band made of resin is provided in the middle part of the metal core member. However, with this resin gear, there is a possibility that the shock absorber band will elastically deform in an unbalanced manner in the circumferential direction due to the load input from the meshing part with the mating gear, and the gear part may be eccentric. Is possible.

そこで、本発明者は、特許文献３に開示されるように、ギヤ歯を含むギヤ外周部を、高弾性率かつ高強度の樹脂材からなる内芯部と、該内芯部を覆う低弾性率の樹脂材からなる表層部とで構成し、内芯部を金属製インサートの周囲に回動可能に設ける一方、表層部と金属製インサートとの接合部分に、軸回りの回動を阻止する係合部を設けることで、ギヤ部に偏心を生じずに衝撃や振動を吸収可能な樹脂ギヤを開発した。この樹脂ギヤは、静粛性や摺動特性といった樹脂ギヤの一般的な長所を保持しつつ、従来の樹脂ギヤに比べて疲労強度や耐衝撃性に対する顕著な改善が見られた。しかし、内芯部も樹脂材で射出成形されるため、高負荷で使用される金属製ギヤの代替品として見た場合、強度、特に高温強度の点でさらなる改善が望まれることとなった。   Therefore, as disclosed in Patent Document 3, the present inventor has a gear outer peripheral portion including gear teeth, an inner core portion made of a resin material having a high elastic modulus and high strength, and a low elasticity covering the inner core portion. It is composed of a surface layer portion made of a resin material with a ratio, and an inner core portion is rotatably provided around the metal insert, while the joint portion between the surface layer portion and the metal insert is prevented from rotating around the axis. By providing an engaging part, we developed a resin gear that can absorb shock and vibration without causing eccentricity in the gear part. While this resin gear maintained the general advantages of the resin gear, such as quietness and sliding characteristics, the resin gear showed significant improvements in fatigue strength and impact resistance compared to conventional resin gears. However, since the inner core portion is also injection-molded with a resin material, further improvement in strength, particularly high-temperature strength, has been desired when viewed as a substitute for metal gears used at high loads.

特開平１１−１９２９５５号公報JP 11-192955 A 特開２００４−１５０５１８号公報JP 2004-150518 A 特開２００８−１５１２７７号公報JP 2008-151277 A

本発明はこのような実状に鑑みてなされたものであって、その目的は、静粛性や摺動特性などを損なわずに、従来の樹脂ギヤでは得られない高疲労強度、高耐熱性、高耐衝撃性などの特長を有する複合ギヤおよびトルク伝達機構を提供することにある。   The present invention has been made in view of such a situation, and its purpose is to achieve high fatigue strength, high heat resistance, high resistance that cannot be obtained by conventional resin gears without impairing silence and sliding characteristics. The object is to provide a composite gear and a torque transmission mechanism having features such as impact resistance.

上記課題を解決するために、本発明は、軸または軸への取付け部を含む金属製の内周部材（２）と、ギヤ歯に対応する複数の芯歯を有する環状の芯部材（３）と、前記芯歯を包覆する表歯部を含み前記芯部材および前記内周部材の外周部を被覆する樹脂製の表層部材（４）と、を備え、前記芯部材が、金属、合金、または焼結金属で構成され、前記内周部材の前記外周部に周方向に相対変位可能に嵌合され、前記内周部材と前記芯部材との嵌合面が、軸方向に平行なラジアル摺接面（２３，３３）と、軸方向に対して直交または傾斜したスラスト摺接面（２４，３４）とを含む組立体（２，３）をなし、該組立体をインサート材として、その周囲に前記表層部材（４）が射出成形されることで、前記表層部材の側面部と前記内周部材との接合部に、周方向への相対変位を阻止する係合部（２７，４７）が形成されている、複合ギヤにある。 In order to solve the above-mentioned problems, the present invention provides a metal inner peripheral member (2) including a shaft or a mounting portion to the shaft, and an annular core member (3) having a plurality of core teeth corresponding to gear teeth. And a resin surface layer member (4) including a surface tooth portion covering the core teeth and covering the outer peripheral portion of the core member and the inner peripheral member, wherein the core member is made of metal, alloy, Alternatively, it is made of sintered metal, is fitted to the outer peripheral portion of the inner peripheral member so as to be relatively displaceable in the circumferential direction, and the fitting surface between the inner peripheral member and the core member is a radial slide parallel to the axial direction. An assembly (2, 3) including a contact surface (23, 33) and a thrust sliding contact surface (24, 34) orthogonal to or inclined with respect to the axial direction is formed, and the assembly is used as an insert material, The surface layer member (4) is injection-molded to join the side surface portion of the surface layer member and the inner peripheral member. The engaging portion to prevent relative displacement in the circumferential direction (27, 47) are formed, in the composite gear.

本発明に係る複合ギヤは、上記構成により、芯歯の表面が樹脂製の表層部材（表歯部）で包覆されることで、良好な摺動特性や静粛性を得つつも、芯歯を有する芯部材に、製造法や材料選択に関する制約がなく、金属、合金、焼結金属など、疲労強度や耐熱性を優先した材料選択が可能であり、このような芯部材が、内周部材に対して周方向に相対変位可能に嵌合されることで、表層部材側面部の粘弾性的挙動による衝撃吸収が誘導され、良好な耐衝撃性が得られる。しかも、芯部材と内周部材との組立体は、それらの嵌合公差を含めて高精度に加工でき、かつ、このような組立体をインサート材として１回の射出成形で複合ギヤを製造可能であるため、成形工程が簡素化される利点もある。   In the composite gear according to the present invention, the surface of the core tooth is covered with a resin surface layer member (surface tooth portion) with the above configuration, so that the core tooth is obtained while obtaining good sliding characteristics and quietness. There is no restriction on the manufacturing method and material selection for the core member having a material, and it is possible to select materials giving priority to fatigue strength and heat resistance, such as metals, alloys, sintered metals, etc. By being fitted so as to be relatively displaceable in the circumferential direction, shock absorption due to the viscoelastic behavior of the side surface portion of the surface layer member is induced, and good impact resistance is obtained. Moreover, the assembly of the core member and the inner peripheral member can be processed with high accuracy including their fitting tolerances, and a composite gear can be manufactured by one injection molding using such an assembly as an insert material. Therefore, there is an advantage that the molding process is simplified.

また、本発明に係る複合ギヤは、前記内周部材と前記芯部材との相対変位可能な嵌合面が、軸方向に平行なラジアル摺接面（２３，３３）を含むので、高負荷でも芯部材に偏心を生じず安定的な動作が行え、樹脂製の表層部材による耐衝撃性を最大限に得ることができる。 The composite gear according to the present invention, the relative displaceable mating surfaces of the core member and the inner peripheral member, because it includes parallel radial sliding contact surface in the axial direction (23, 33), even at high loads Stable operation can be performed without causing eccentricity of the core member, and the impact resistance of the resin surface layer member can be maximized.

さらに、本発明に係る複合ギヤは、前記内周部材と前記芯部材との相対変位可能な嵌合面が、軸方向に対して直交または傾斜したスラスト摺接面（２４，３４）をも含むので、スラスト摺接面によって芯部材の軸方向位置が規定され、表層部材側面部のスラスト荷重に対する負担が軽減され、ヘリカルギヤやベベルギヤ等、スラスト荷重を恒常的に受けるギヤへの実施に好適である。また、芯部材を内周部材に嵌合した組立体を金型内にインサートして射出成形する際に、スラスト摺接面の支持方向に対向してゲートを設置することで、樹脂材料の流入圧をスラスト摺接面で受圧可能となり、支持が不要となるとともに、樹脂材料の流入圧で芯部材が内周部材のスラスト摺接面に圧接され、嵌合面への樹脂の侵入が抑制され、表層部材の内側に隠れた芯部材の安定動作を確保するうえで有利である。 Further, the composite gear according to the present invention, the relative displaceable mating surfaces of the core member and the inner peripheral member, also includes a thrust sliding surface perpendicular or inclined to the axial direction (24, 34) Therefore , the axial position of the core member is defined by the thrust sliding contact surface, and the burden on the thrust load on the side surface portion of the surface layer member is reduced. . In addition, when an assembly in which the core member is fitted to the inner peripheral member is inserted into the mold and injection molded, a gate is installed facing the support direction of the thrust sliding contact surface, so that the inflow of the resin material Pressure can be received at the thrust sliding contact surface, and support is not required, and the core member is pressed against the thrust sliding contact surface of the inner peripheral member by the inflow pressure of the resin material, and the penetration of the resin into the fitting surface is suppressed. This is advantageous in ensuring stable operation of the core member hidden inside the surface layer member.

本発明において、前記表層部材が、熱可塑性樹脂のナチュラル材で射出成形され、かつ、電子線照射によって高分子鎖間に架橋構造を生じている態様では、強化繊維を含有しないことで、相手ギヤに対する攻撃性が低減されるとともに、強化繊維の端部が起点となって表層部材が損傷するのが防止される一方、架橋構造により強度および耐熱性が向上し、高疲労強度および高耐熱性を有する複合ギヤを構成するうえで有利である。   In the present invention, in a mode in which the surface layer member is injection-molded with a natural material of thermoplastic resin and a cross-linked structure is formed between the polymer chains by electron beam irradiation, the mating gear is not contained by containing no reinforcing fiber. As well as preventing the damage of the surface layer starting from the end of the reinforcing fiber, the cross-linked structure improves the strength and heat resistance, resulting in high fatigue strength and high heat resistance. This is advantageous in constructing a composite gear.

また、上記特徴を備えた複合ギヤと、それに噛合する駆動側相手ギヤとを含むトルク伝達機構において、前記相手ギヤの歯先が、チップリリーフとＲ形状により修整されていることが好適である。この構成により、複合ギヤ歯面への相手ギヤの歯当たりが緩和され、歯面における圧力分布が分散的になり、表層部材の損傷や劣化が抑制され、良好な摺動特性および静粛性を有するトルク伝達機構としての耐久性を向上するうえで有利である。   In the torque transmission mechanism including the composite gear having the above characteristics and the driving-side mating gear meshing with the composite gear, it is preferable that the tooth tip of the mating gear is modified with a tip relief and an R shape. With this configuration, the contact of the mating gear with the tooth surface of the composite gear is relaxed, the pressure distribution on the tooth surface is distributed, damage and deterioration of the surface layer member are suppressed, and good sliding characteristics and quietness are achieved. This is advantageous in improving durability as a torque transmission mechanism.

前記歯先修整の大きさは、前記複合ギヤに定格トルクに相当する静荷重を負荷した場合におけるギヤ歯の作用線方向の弾性変位の３０％以上であることが好ましく、特に、５０％以上の場合に顕著な耐久性の向上効果が得られる。また、相手ギヤの歯先修整量を上記のような静荷重負荷時の弾性変位（たわみ量）から設定することで、数多くの耐久試験を行う時間と労力を節減するうえでも有利である。   The magnitude of the tooth tip modification is preferably 30% or more of the elastic displacement in the action line direction of the gear teeth when a static load corresponding to a rated torque is applied to the composite gear, and particularly 50% or more. In some cases, a remarkable durability improvement effect is obtained. In addition, setting the tooth tip modification amount of the mating gear from the elastic displacement (deflection amount) when the static load is applied as described above is advantageous in saving time and labor for performing many durability tests.

本発明実施形態の複合ギヤを示す一部切除した側面図である。It is the side view partly excised showing the compound gear of the embodiment of the present invention. 図１のＡ−Ａ断面図である。It is AA sectional drawing of FIG. 内周部材を示す一部切除した斜視図である。It is the perspective view which partially cut away which shows an inner peripheral member. 芯部材を示す一部切除した斜視図である。It is the perspective view which partially cut off which shows a core member. 表層部材を示す一部切除した斜視図である。It is the perspective view which partially cut off which shows a surface layer member. （ａ）は相手ギヤのギヤ歯部を示す要部概略側面図、（ｂ）はその歯先部分を示す拡大図である。(A) is a principal part schematic side view which shows the gear tooth part of the other party gear, (b) is an enlarged view which shows the tooth tip part. 本発明実施例１および比較例１，２の耐久試験結果を示すグラフである。It is a graph which shows the durability test result of this invention Example 1 and Comparative Examples 1 and 2. FIG. 本発明実施例１〜３の耐久試験結果を示すグラフである。It is a graph which shows the endurance test result of this invention Examples 1-3. 本発明実施例２，４，５の複合ギヤおよび比較例１のギヤの伝達トルク−たわみ曲線である。6 is a transmission torque-deflection curve of the composite gears of Examples 2, 4 and 5 of the present invention and the gear of Comparative Example 1; 本発明実施例４，５の各複合ギヤに噛合する相手ギヤへの歯先修整の有無各場合における耐久試験結果を示すグラフである。It is a graph which shows the endurance test result in each case of the presence or absence of tooth-tip modification to the other gear meshing with each compound gear of the present invention Examples 4 and 5.

以下、本発明の実施の形態について図面と共に詳細に説明する。
図１〜図３において、本発明に係る複合ギヤ１は、ギヤ内周部材２とその外周側の芯部材３、芯部材３および前記内周部材２の外周部２２を被覆する樹脂製の表層部材４から構成されている。 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 to 3, a composite gear 1 according to the present invention includes a gear inner peripheral member 2, a core member 3 on the outer peripheral side thereof, a core member 3, and a resin surface layer covering the outer peripheral portion 22 of the inner peripheral member 2. It is comprised from the member 4.

内周部材２は、図２および図３に示すように、中央に軸孔２０が貫通したハブ２１と、その周囲にフランジ状に延在する外周部２２とを有し、全体としては円盤状に形成されている。外周部２２は、ハブ２１の幅方向中央部から延出しており、その基部の幅方向両側にハブ２１の外周面を画成する肩部２６，２６が形成され、各肩部２６，２６には、周方向に所定の間隔で複数の係止溝２７（切欠部）が形成されている。図示例では、係止溝２７は円溝として形成されているが、台形溝など、他の形状であっても良い。   As shown in FIGS. 2 and 3, the inner peripheral member 2 has a hub 21 through which a shaft hole 20 penetrates in the center and an outer peripheral portion 22 extending in the form of a flange around the hub 21. Is formed. The outer peripheral portion 22 extends from the central portion in the width direction of the hub 21, and shoulder portions 26 and 26 that define the outer peripheral surface of the hub 21 are formed on both sides of the base portion in the width direction. A plurality of locking grooves 27 (notches) are formed at predetermined intervals in the circumferential direction. In the illustrated example, the locking groove 27 is formed as a circular groove, but may have other shapes such as a trapezoidal groove.

外周部２２は、最外周部に軸方向に対して平行なラジアル摺接面２３を有し、該ラジアル摺接面２３と一方の肩部２６との中間には段部２５が設けられ、該段部２５とラジアル摺接面２３との間の側面部にスラスト摺接面２４が画成されている。外周部２２は、全周に亘り一様な断面形状を成し、図２に示されるように、ラジアル摺接面２３は、外周部２２の基部とほぼ同じ幅を有しているが、幅方向に対して段部２５の分だけオフセットされ、それに伴い、外周部２２の段部２５と反対側の側面には逆段部または逆傾斜部が形成されている。   The outer peripheral portion 22 has a radial sliding contact surface 23 parallel to the axial direction at the outermost peripheral portion, and a step portion 25 is provided between the radial sliding contact surface 23 and one shoulder portion 26, A thrust slidable contact surface 24 is defined at a side surface portion between the step portion 25 and the radial slidable contact surface 23. The outer peripheral portion 22 has a uniform cross-sectional shape over the entire periphery, and the radial sliding contact surface 23 has substantially the same width as the base portion of the outer peripheral portion 22 as shown in FIG. The direction is offset by the amount of the step portion 25, and accordingly, a reverse step portion or a reverse inclined portion is formed on the side surface of the outer peripheral portion 22 opposite to the step portion 25.

芯部材３は、図２および図４に示されるように、複合ギヤ１の各ギヤ歯１１に対応した複数の芯歯３１、および各芯歯を周方向に結合する環状部３２から構成されている。環状部３２の内周側には、軸方向に略平行な最内周面３５と、該最内周面３５の一側に隣接して軸方向に直交する方向に配向されたスラスト摺接面３４と、該スラスト摺接面３４の大径側に隣接する軸方向に平行なラジアル摺接面３３とが画成されており、該ラジアル摺接面３３が、前記内周部材２のラジアル摺接面２３に嵌合されることで、芯部材３の内周部材２に対する周方向の相対変位すなわち回動が許容され、かつ、スラスト摺接面３４が、前記内周部材２のスラスト摺接面２４に当接することで、前記内周部材外周部２２に対する芯部材３の軸方向位置が規制されるように構成されている。また、図２に示すように、環状部３２の一方の側面には、周方向に１乃至数箇所の位置決め穴３８が設けられている。   As shown in FIGS. 2 and 4, the core member 3 includes a plurality of core teeth 31 corresponding to the gear teeth 11 of the composite gear 1 and an annular portion 32 that couples the core teeth in the circumferential direction. Yes. On the inner peripheral side of the annular portion 32, an innermost peripheral surface 35 that is substantially parallel to the axial direction, and a thrust sliding contact surface that is adjacent to one side of the innermost peripheral surface 35 and is oriented in a direction orthogonal to the axial direction. 34 and a radial sliding contact surface 33 parallel to the axial direction adjacent to the large diameter side of the thrust sliding contact surface 34 are defined, and the radial sliding contact surface 33 is a radial sliding contact of the inner peripheral member 2. By being fitted to the contact surface 23, the relative displacement, that is, the rotation of the core member 3 in the circumferential direction with respect to the inner peripheral member 2 is allowed, and the thrust slide contact surface 34 is the thrust slide contact of the inner peripheral member 2. By abutting on the surface 24, the axial position of the core member 3 with respect to the inner peripheral member outer peripheral portion 22 is restricted. As shown in FIG. 2, one or several positioning holes 38 are provided on one side surface of the annular portion 32 in the circumferential direction.

表層部材４は、図２および図５に示されるように、複合ギヤ１の各ギヤ歯１１に対応し、芯部材３の各芯歯３１を被覆する複数の表歯部４１、および芯部材３の環状部３２から内周部材２の外周部２２にかけての側面部分を被覆する側面部４２，４２から構成され、前記芯部材３を内周部材２の外周部２２に嵌合した組立体（２，３）をインサート材として金型内に挿入して樹脂材により射出成形することで、側面部４２，４２の内周縁４６，４６に、内周部材２（ハブ２１）の肩部２６の係止溝２７に係合する突起４７が一体に形成され、これら突起４７と係止溝２７との係合によって、表層部材４の内周縁４６，４６と、内周部材２（ハブ２１）の肩部２６とは、周方向への相対変位が不可能になっている。   As shown in FIGS. 2 and 5, the surface layer member 4 corresponds to each gear tooth 11 of the composite gear 1, and includes a plurality of surface tooth portions 41 covering the core teeth 31 of the core member 3, and the core member 3. An assembly (2) comprising side portions 42, 42 covering side portions from the annular portion 32 to the outer peripheral portion 22 of the inner peripheral member 2 and fitting the core member 3 to the outer peripheral portion 22 of the inner peripheral member 2. 3) is inserted into the mold as an insert material and injection molded with a resin material, so that the inner peripheral edge 46, 46 of the side surface portion 42, 42 is engaged with the shoulder portion 26 of the inner peripheral member 2 (hub 21). Protrusions 47 that engage with the retaining grooves 27 are integrally formed, and by engagement between these protrusions 47 and the locking grooves 27, the inner peripheral edges 46, 46 of the surface layer member 4 and the shoulders of the inner peripheral member 2 (hub 21). The relative displacement in the circumferential direction is impossible with the part 26.

複合ギヤ１の射出成形には、例えば竪型射出成形機を用い、図２における左側が上になるように、金型内に組立体（２，３）をセットする。この際、予め、芯部材３を内周部材２に嵌合して組立体（２，３）を構成した状態で金型内にセットしても良いし、金型内に内周部材２をセットした後、該内周部材２に芯部材３を嵌合しても良い。その際、金型内に突設したピン（図２に３８，４８で示される部分に対応）を、芯部材３の位置決め穴３８に係合し、芯歯３１が、金型の各表歯部４１に対応した凹部に位置決めする。   For injection molding of the composite gear 1, for example, a vertical injection molding machine is used, and the assembly (2, 3) is set in the mold so that the left side in FIG. At this time, the core member 3 may be set in the mold in advance in a state in which the core member 3 is fitted to the inner peripheral member 2 to form the assembly (2, 3), or the inner peripheral member 2 is placed in the mold. After setting, the core member 3 may be fitted to the inner peripheral member 2. At that time, the pins (corresponding to the portions indicated by 38 and 48 in FIG. 2) projecting in the mold are engaged with the positioning holes 38 of the core member 3, and the core teeth 31 are the front teeth of the mold. Position in the recess corresponding to the portion 41.

そして、表層部材４の一方の内周縁４６に沿って設定されたディスクゲート（図示せず）を通じて金型キャビティ内に樹脂を射出することで、各表歯部４１におけるウエルドラインの発生が防止されるとともに、樹脂材料の流入圧が芯部材３に一側から作用することで、芯部材３がスラスト摺接面３４，２４を介して内周部材２に圧接され、その先の嵌合面（２４，３４および２３，３３）内への樹脂の侵入が抑制される。   Then, by injecting resin into the mold cavity through a disk gate (not shown) set along one inner peripheral edge 46 of the surface layer member 4, generation of weld lines in each surface tooth portion 41 is prevented. In addition, when the inflow pressure of the resin material acts on the core member 3 from one side, the core member 3 is pressed against the inner peripheral member 2 via the thrust sliding contact surfaces 34 and 24, and the mating surface ( 24, 34 and 23, 33) are prevented from entering the resin.

上記内周部材２および芯部材３に使用される金属は、特に限定されるものではなく、鉄、アルミニウム、銅などの各種金属および各種合金材を使用できるが、製造コスト面からは焼結金属材が特に好適である。また、表層部材４に使用する樹脂材料としては、各種熱可塑性樹脂を使用可能であり、必要に応じて、熱可塑性樹脂に強化繊維などの補強材を含有することもできるが、後述する実験結果から、補強材を含まない熱可塑性樹脂のナチュラル材、特に、差出成形後の電子線照射によって高分子鎖間に架橋構造を生じるナイロンのナチュラル材が好適である。 The metal used for the inner peripheral member 2 and the core member 3 is not particularly limited, and various metals such as iron, aluminum, and copper, and various alloy materials can be used. A material is particularly suitable. Moreover, as a resin material used for the surface layer member 4, various thermoplastic resins can be used, and if necessary, the thermoplastic resin can contain a reinforcing material such as a reinforcing fiber. Therefore, a natural material of a thermoplastic resin that does not include a reinforcing material, particularly a natural material of nylon that generates a cross-linked structure between polymer chains by electron beam irradiation after extrusion molding is preferable.

［耐久試験１］
次に、本発明に係る複合ギヤ１の耐久性を評価するため、内周部材２および芯部材３が焼結金属で構成され、表層部材４には、補強材として炭素繊維３０ｗｔ％が複合され、常温における曲げ弾性率が１８ＧＰａに強化されているポリアミド係樹脂（ＰＡ４６−ＣＦ３０）を用いた複合ギヤ（実施例１）を作製し、さらに、同じ焼結金属で内周部材（２）と芯部材（３）とを一体に構成して同じ樹脂でインサート成形した樹脂被覆ギヤ（比較例１）と、芯部材３を用いずに内周部材２のみを用いて同じ樹脂でインサート成形した樹脂ギヤ（比較例２）を作製して、耐久試験を行った。 [Durability test 1]
Next, in order to evaluate the durability of the composite gear 1 according to the present invention, the inner peripheral member 2 and the core member 3 are made of sintered metal, and the surface layer member 4 is composited with 30 wt% carbon fiber as a reinforcing material. A composite gear (Example 1) using a polyamide-based resin (PA46-CF30) whose flexural modulus at room temperature is reinforced to 18 GPa is manufactured, and the inner peripheral member (2) and the core are made of the same sintered metal. A resin-coated gear (Comparative Example 1) in which the member (3) is integrally formed and insert-molded with the same resin, and a resin gear that is insert-molded with the same resin using only the inner peripheral member 2 without using the core member 3 (Comparative Example 2) was prepared and subjected to a durability test.

なお、実施例１および比較例１、２の各ギヤは、何れも、モジュール２．５ｍｍ、圧力角２０度、歯数３５、基準円直径８７．５ｍｍ、歯先円直径９２．９ｍｍ、歯幅１１ｍｍ、転位係数０．１４５の平歯車であり、各ギヤに噛合する相手ギヤとして、モジュール２．５ｍｍ、圧力角２０度、歯数３５、基準円直径８７．５ｍｍ、歯先円直径９２．１７５ｍｍ、歯幅１２ｍｍ、転位係数０の鋼製平歯車（歯先修整なし）を用いてトルク伝達機構を構成し、インバーターモータにより相手ギヤを駆動する一方で、被試験ギヤにサーボモータを接続して負荷を与えた。試験条件は、伝達トルク２０Ｎｍ、回転数５０００ｒｐｍ、１００℃とし、グリース潤滑を施した。   The gears of Example 1 and Comparative Examples 1 and 2 are all modules 2.5 mm, pressure angle 20 degrees, number of teeth 35, reference circle diameter 87.5 mm, tooth tip circle diameter 92.9 mm, tooth width. A spur gear of 11 mm and a dislocation coefficient of 0.145. As a mating gear meshing with each gear, the module is 2.5 mm, the pressure angle is 20 degrees, the number of teeth is 35, the reference circle diameter is 87.5 mm, and the tip circle diameter is 92.175 mm. A torque transmission mechanism is constructed using a steel spur gear (with no tooth tip modification) with a tooth width of 12 mm and a shift coefficient of 0, and the mating gear is driven by the inverter motor, while the servo motor is connected to the gear under test. Gave a load. The test conditions were a transmission torque of 20 Nm, a rotation speed of 5000 rpm, 100 ° C., and grease lubrication.

また、芯歯３１の先端の直径（以下「芯歯歯先円直径」という）については、相手ギヤと複合ギヤ１の作用線と、相手ギヤ歯先円との交点をＡ１、複合ギヤ歯先円との交点をＡ２とした場合に、作用線上においてＡ１からＡ２方向に、かみあい率の整数値×基礎円ピッチｐｂだけ離れた点をＳとすると、芯歯歯先円直径が、複合ギヤの中心からＳまでの距離ｒｓ（半径に対応）の２倍以上であることが、噛合に参加している歯数が最小の場合でも、芯歯３１（芯部材３）で伝達荷重を受ける条件（表歯４１に曲げ／剪断応力が生じない条件）となる。また、芯歯３１が表歯４１を貫通しない点で、芯歯歯先円直径は、表歯４１を含めた複合ギヤ１の歯先円直径以下である。本実施例では、複合ギヤと相手ギヤとの中心間距離が８８．０ｍｍ、かみあい率１．５の整数値が1であることから、２ｒｓは８９．６８６ｍｍと計算され、また、複合ギヤ１の歯先円直径が９２．９ｍｍであることを考慮して、芯歯歯先円直径は、８９．９ｍｍとした。   Further, regarding the diameter of the tip of the core tooth 31 (hereinafter referred to as “core tooth tip circle diameter”), the intersection point between the line of action of the mating gear and the composite gear 1 and the mating gear tip circle is A1, and the compound gear tooth tip. Assuming that the intersection point with the circle is A2, assuming that the point separated from the A1 to A2 direction on the action line by an integer value of the meshing rate × the basic circle pitch pb is S, the diameter of the core tooth tip circle is equal to that of the compound gear. Even if the number of teeth participating in meshing is the smallest that the distance rs (corresponding to the radius) from the center to S is twice or more, the condition of receiving the transmission load on the core teeth 31 (core member 3) ( The condition that no bending / shear stress is generated in the front teeth 41). In addition, the core tooth tip circle diameter is equal to or smaller than the tip circle diameter of the composite gear 1 including the front teeth 41 in that the core teeth 31 do not penetrate the front teeth 41. In the present embodiment, since the center distance between the composite gear and the counterpart gear is 88.0 mm and the integer value of the meshing ratio is 1, 2rs is calculated as 89.686 mm. Considering that the diameter of the tooth tip circle is 92.9 mm, the diameter of the core tooth tip circle was set to 89.9 mm.

図７は、本発明に係る実施例１および比較例１、２の各ギヤの耐久試験結果を示している。比較例１の樹脂被覆ギヤ、および比較例２の樹脂ギヤでは、それぞれ、累積回転２．０×１０^５回転、１．５×１０^５回転にて歯面に損傷が発生したのに対し、本発明に係る実施例１の複合ギヤでは、累積回転数４．０×１０^５回転にて歯面に損傷が発生しており、この実験結果は、本発明に係る実施例１の複合ギヤが、比較例１の樹脂被覆ギヤに対して２倍、比較例２の樹脂ギヤに対して２．７倍の耐久性を有することを示している。 FIG. 7 shows the durability test results of the gears of Example 1 and Comparative Examples 1 and 2 according to the present invention. In the resin-coated gear of Comparative Example 1 and the resin gear of Comparative Example 2, the tooth surfaces were damaged at cumulative rotations of 2.0 × 10 ⁵ and 1.5 × 10 ⁵ , respectively. In the compound gear of Example 1 according to the invention, the tooth surface is damaged at a cumulative rotational speed of 4.0 × 10 ⁵ rotations. The experimental results show that the compound gear of Example 1 according to the present invention is It shows that the resin-coated gear of Comparative Example 1 has twice the durability, and the resin gear of Comparative Example 2 has 2.7 times the durability.

［耐久試験２］
次に、上記実施例１の複合ギヤに対して、表層部材４の樹脂材に、補強材を含まず常温における曲げ弾性率が３．３ＧＰａと低弾性率のナイロン６６であって、電子線の照射により高分子鎖間に架橋を生じる材料を使用し、射出成形後に電子線照射を施した複合ギヤ（実施例２）を作製し、前記同様に相手ギヤと組合せて耐久試験を行った。 [Durability test 2]
Next, with respect to the composite gear of the first embodiment, the resin material of the surface layer member 4 is nylon 66 having a bending elastic modulus of 3.3 GPa and a low elastic modulus at room temperature without including a reinforcing material, Using a material that crosslinks between polymer chains upon irradiation, a composite gear (Example 2) that was irradiated with an electron beam after injection molding was prepared, and a durability test was performed in combination with the mating gear as described above.

その結果、図８に示すように、実施例２の複合ギヤでは、累積回転数２．９×１０^６回転に至るまで歯面に損傷が発生しなかった。したがって、実施例２の複合ギヤは、表層部材４に低弾性率の樹脂材料を使用したにも拘わらず、高弾性率の樹脂材料を使用した実施例１の複合ギヤに対して耐久性が約７．３倍向上したことを示している。 As a result, as shown in FIG. 8, in the compound gear of Example 2, the tooth surface was not damaged until the cumulative rotation speed reached 2.9 × 10 ⁶ rotations. Therefore, although the composite gear of Example 2 uses a resin material having a low elastic modulus for the surface layer member 4, the durability of the composite gear of Example 1 using a resin material having a high elastic modulus is approximately the same. This shows an improvement of 7.3 times.

この要因としては次の点が挙げられる。すなわち、表層部材４に低弾性率の樹脂材料を使用した実施例２では、噛合いが進行する際に歯面に発生する動的な負荷がギヤ全体に分散される効果が高まる点、歯面を含む表層部材４の樹脂材料に強化繊維が複合されている実施例１では、圧縮荷重に対して繊維の端部などが起点となり損傷が発生するのに対し、強化繊維などが複合されていないナチュラル材でありかつ高分子鎖間に架橋構造が生成されている実施例２では、表層部材４を構成する樹脂材の分子間の結合が圧縮負荷に対してより強固であることに加えて、高分子鎖間の架橋構造によって樹脂の溶融温度が上昇し、摩擦熱で高温になる歯面においても表層部材４が溶融し難い点である。   This is because of the following points. That is, in Example 2 in which a low elastic modulus resin material is used for the surface layer member 4, the effect that the dynamic load generated on the tooth surface when meshing progresses is distributed over the entire gear is enhanced. In Example 1 in which the reinforcing fiber is composited with the resin material of the surface layer member 4 containing the fiber, the end of the fiber is caused as a starting point with respect to the compressive load and damage occurs, but the reinforcing fiber is not composited. In Example 2 which is a natural material and a cross-linked structure is generated between polymer chains, in addition to the fact that the bonds between the molecules of the resin material constituting the surface layer member 4 are stronger against compression load, The melting temperature of the resin rises due to the cross-linked structure between the polymer chains, and the surface layer member 4 is difficult to melt even on the tooth surface that becomes high due to frictional heat.

［耐久試験３］
次に、本発明に係る複合ギヤに組合せる相手ギヤの歯先修整の効果を検証するために、上記実施例２の複合ギヤに、図６に示すように、チップリリーフによる作用線方向の逃がし量ｔ１が０．１０ｍｍ、歯先Ｒ０．２２７による作用線方向の逃がし量ｔ２が０．０４ｍｍ、それらの合計０．１４ｍｍの歯先修整Ｔを施した相手ギヤ５を組合せて前記同様の耐久試験を行った。 [Durability test 3]
Next, in order to verify the effect of the tooth tip modification of the mating gear to be combined with the composite gear according to the present invention, the composite gear of the second embodiment has a relief in the direction of the action line by tip relief as shown in FIG. Endurance test similar to the above by combining the mating gear 5 with the tooth tip modification T of the amount t1 of 0.10 mm, the amount of relief t2 in the action line direction by the tooth tip R0.227 of 0.04 mm, and a total of 0.14 mm thereof. Went.

その結果、図８に示すように、相手ギヤに歯先修整を施さなかった実施例２に対して、相手ギヤに歯先修整を施した実施例３では、同じ複合ギヤを組合せたにも拘わらず、累積回転数１．０×１０^７回転においても損傷が発生せず、耐久性がさらに３．４倍以上に向上しており、相手ギヤの歯先修整が、複合ギヤの耐久性を向上するうえで有効であることが確認された。 As a result, as shown in FIG. 8, in Example 3 in which the other gear was not subjected to tooth tip modification, in Example 3 in which the other gear was subjected to tooth tip modification, the same composite gear was combined. does not even damage occurs in the rotation accumulated rotation number 1.0 × 10 ^7, has been improved to further 3.4 times or more durable, the addendum modification of the mating gear, improving the durability of the composite gear It was confirmed that this is effective.

相手ギヤ５への歯先修整Ｔにより複合ギヤ１の歯面の損傷発生が遅れ、耐久性が向上するメカニズムについては、次のように推察される。耐久試験における歯面の損傷発生状況を観察すると、歯先修整を施していない相手ギヤを組み合わせた実施例２では、歯面の歯元付近に損傷が発生することが認められた。すなわち、本発明に係る複合ギヤ１の耐衝撃性は、芯部材３が内周部材２に対して周方向に相対変位可能に嵌合され、表層部材４の粘弾性的挙動が誘導される構造的特徴に起因するが、その過程で、相手ギヤの歯当たりが歯先側にシフトする。そのため、歯先修整を施していない相手ギヤの場合には、その歯先角部により、複合ギヤ１の歯面（表層部材４）の歯元付近に凹み痕が発生し、この凹み痕により、歯面に発生する動的負荷の分散効果が減衰する結果、樹脂部の歯面中央付近の応力が高まり、そこを起点として亀裂が発生する。これに対して、歯先修整を行った相手ギヤを組合せた実施例３では、相手ギヤ歯先の当たりが緩和され、複合ギヤの歯面に凹み痕を生じず、歯面の動的負荷のギヤ全体への分散効果が持続するため、歯面の損傷発生が抑制されるものと考えられる。   About the mechanism which the damage generation | occurrence | production of the tooth surface of the composite gear 1 delays by the tooth-tip modification T to the other party gear 5, and durability improves, it is guessed as follows. When observing the occurrence of damage to the tooth surface in the endurance test, it was found that in Example 2 in which the other gear that had not undergone tooth tip modification was combined, damage occurred near the tooth root of the tooth surface. That is, the impact resistance of the composite gear 1 according to the present invention is such that the core member 3 is fitted to the inner circumferential member 2 so as to be relatively displaceable in the circumferential direction, and the viscoelastic behavior of the surface layer member 4 is induced. This is due to the characteristic characteristics, but in the process, the tooth contact of the mating gear shifts to the tip side. Therefore, in the case of a mating gear that has not undergone tooth tip modification, a dent mark is generated near the tooth root of the tooth surface (surface layer member 4) of the composite gear 1 due to the tooth tip corner, As a result of the damping effect of the dynamic load generated on the tooth surface being attenuated, the stress near the center of the tooth surface of the resin portion is increased, and cracks are generated starting from the stress. On the other hand, in Example 3 in which the mating gear having undergone tooth tip modification was combined, the contact of the mating gear tooth tip was alleviated, no dent marks were formed on the tooth surface of the composite gear, and the dynamic load on the tooth surface was reduced. Since the dispersion effect on the entire gear is sustained, it is considered that the occurrence of tooth surface damage is suppressed.

本発明に係る複合ギヤ１では、従来の樹脂ギヤのようなギヤ歯の撓曲や樹脂層の圧縮よりも、表層部材４（側面部）の弾性変形による芯部材３の周方向への相対変位を伴ったギヤ歯のたわみ（周方向の弾性変位）が主体的である。この特徴により、良好な耐衝撃性がもたらされる一方で、たわみ量に比例して、上述した相手ギヤ歯当たりの歯先側へのシフトが大きくなる。したがって、たわみ量に基づいて歯先修整の大きさを設定すれば、本発明に係る複合ギヤ１の耐久性を高い確度で向上でき、数多くの耐久試験を行う時間と労力を節約できる。   In the composite gear 1 according to the present invention, relative displacement in the circumferential direction of the core member 3 due to elastic deformation of the surface layer member 4 (side surface portion) rather than bending of gear teeth and compression of the resin layer as in a conventional resin gear. Deflection of gear teeth (elastic displacement in the circumferential direction) accompanied with the main is mainly. While this feature provides good impact resistance, the shift to the tip side of the above-mentioned counter gear teeth increases in proportion to the amount of deflection. Therefore, if the magnitude of the tooth tip modification is set based on the amount of deflection, the durability of the composite gear 1 according to the present invention can be improved with high accuracy, and the time and labor for performing a number of durability tests can be saved.

［耐久試験４］
そこで、ギヤ歯の剛性が異なる複合ギヤを作製し、それらに、伝達トルク（定格トルク）に相当する静的負荷を与えてたわみ量を測定したうえで、歯先修整を施した相手ギヤ、歯先修整を施していない相手ギヤを組み合わせた各場合について耐久試験を行い、複合ギヤのたわみ量と相手ギヤへの歯先修整による耐久性向上効果との関係を検証した。 [Durability test 4]
Therefore, composite gears with different gear teeth rigidity were prepared, and the amount of deflection was measured by applying a static load equivalent to the transmission torque (rated torque) to the gears. Durability tests were conducted for each case where the mating gears that had not been pre-modified were combined, and the relationship between the amount of deflection of the composite gear and the durability improvement effect of the gear tip modification to the mating gear was verified.

図９は、樹脂部材４にアラミド繊維５ｗｔ％複合のＰＡ４６−ＡＦ５を使用した歯幅１１ｍｍの複合ギヤ（実施例４）、および、同材料を使用した歯幅９ｍｍの複合ギヤ（実施例５）に対して、静的な負荷を与えてギヤ歯のたわみ量（作用線方向の弾性変位）を測定して得られた伝達トルク−たわみ曲線を示すグラフである。なお、比較のため、電子線架橋樹脂を使用した実施例２の複合ギヤと、先述した比較例１の樹脂被覆ギヤ（ともに歯幅１１ｍｍ）についても同様の測定を行った。   FIG. 9 shows a composite gear (Example 4) having a tooth width of 11 mm using PA46-AF5 having 5 wt% aramid fiber composite for the resin member 4 and a composite gear having a tooth width of 9 mm using the same material (Example 5). FIG. 6 is a graph showing a transmission torque-deflection curve obtained by applying a static load and measuring the amount of gear tooth deflection (elastic displacement in the direction of action). For comparison, the same measurement was performed on the composite gear of Example 2 using an electron beam cross-linked resin and the above-described resin-coated gear of Comparative Example 1 (both teeth width 11 mm).

このグラフにおいて、伝達トルク２０Ｎｍの場合のたわみ量は、実施例３が約０．２２ｍｍ、実施例４が約０．２７ｍｍであり、同じ歯幅の比較例１の樹脂被覆ギヤの約０．１０ｍｍに対して２倍以上大きくなっている。比較例１の樹脂被覆ギヤのたわみ量は、樹脂部の圧縮変形分に芯歯のたわみ分が加算されたものであるのに対し、各実施例の複合ギヤでは、芯部材３の周方向変位が許容されているため、芯歯３１のたわみ分はより少ないと言え、これらの差以上に、樹脂製の表層部材４の弾性変形、特に側面部４２の弾性変形が主体的であると言える。実施例５の歯幅９ｍｍの複合ギヤでは、樹脂部分の断面積の減少に伴い、伝達トルク２０Ｎｍの場合のたわみ量が約０．４４ｍｍに増大している。   In this graph, the deflection amount when the transmission torque is 20 Nm is about 0.22 mm in Example 3 and about 0.27 mm in Example 4, and is about 0.10 mm of the resin-coated gear of Comparative Example 1 having the same tooth width. Is more than twice as large. The amount of deflection of the resin-coated gear of Comparative Example 1 is obtained by adding the amount of deflection of the core teeth to the amount of compression deformation of the resin portion, whereas in the composite gear of each example, the circumferential displacement of the core member 3 Therefore, it can be said that the deflection of the core teeth 31 is smaller, and more than these differences, it can be said that the elastic deformation of the resin surface layer member 4, particularly the elastic deformation of the side surface portion 42 is dominant. In the composite gear of Example 5 with a tooth width of 9 mm, the amount of deflection in the case of a transmission torque of 20 Nm increases to about 0.44 mm as the cross-sectional area of the resin portion decreases.

次に、実施例４および５の各複合ギヤに対して、それぞれ、歯先修整を施していない相手ギヤと、先述した耐久試験３と同様に０．１４ｍｍの歯先修整Ｔを施した相手ギヤとを組合せた各場合について、上記伝達トルク２０Ｎｍを負荷して耐久試験を行った。その結果、図１０に示すように、実施例４の複合ギヤでは、約２．５倍という顕著な耐久性向上効果が見られた。また、実施例５の複合ギヤにおいても、約７％ではあるが、耐久性の向上が確認された。しかし、その後、伝達トルクをさらに大きくして追加試験を行ったが、歯先修整による耐久性の向上は認められなかった。   Next, with respect to each of the compound gears of Examples 4 and 5, a mating gear that is not subjected to tooth tip modification and a mating gear that is subjected to a tooth tip modification T of 0.14 mm as in the durability test 3 described above. In each case, the durability test was conducted with the transmission torque of 20 Nm applied. As a result, as shown in FIG. 10, the compound gear of Example 4 showed a remarkable durability improvement effect of about 2.5 times. Further, in the compound gear of Example 5, although it was about 7%, an improvement in durability was confirmed. However, after that, an additional test was conducted with a further increase in transmission torque, but no improvement in durability due to tooth tip modification was observed.

この試験結果から、複合ギヤの耐久性を向上する相手ギヤの歯先修整量について検討すると、各相手ギヤに対する歯先修整量０．１４ｍｍは、実施例４の複合ギヤのたわみ量０．２７ｍｍの約５０％に相当し、実施例５の複合ギヤのたわみ量０．４４ｍｍの約３０％に相当する。また、先に行った耐久試験３における実施例３の複合ギヤの、同条件でのたわみ量０．２２ｍｍの約６５％に相当する。   From this test result, when the amount of tooth tip modification of the mating gear that improves the durability of the composite gear is examined, the amount of tooth tip modification 0.14 mm for each mating gear is 0.27 mm of deflection of the compound gear of Example 4. This corresponds to about 50% and corresponds to about 30% of the deflection amount of 0.44 mm of the composite gear of the fifth embodiment. Further, this corresponds to about 65% of the deflection amount of 0.22 mm under the same conditions of the composite gear of Example 3 in the durability test 3 performed earlier.

したがって、本発明に係る複合ギヤに組み合わせる相手ギヤの歯先修整が、耐久性向上に有効となるためには、当該複合ギヤに定格トルクに相当する静的荷重を負荷した場合のたわみ量の少なくとも３０％以上の歯先修整量が必要であり、前記たわみ量の５０％以上の歯先修整を行えば、一層顕著な耐久性向上が見込めると言える。   Therefore, in order for the tooth tip modification of the mating gear to be combined with the composite gear according to the present invention to be effective in improving durability, at least the amount of deflection when a static load corresponding to the rated torque is applied to the composite gear. A tooth tip modification amount of 30% or more is necessary, and it can be said that a remarkable improvement in durability can be expected if the tooth tip modification is performed by 50% or more of the deflection amount.

なお、過大な歯先修整は、噛み合いに悪影響を及ぼすことになるため、歯形誤差とならないような範囲で行う必要がある。歯先修整を行う場合のチップリリーフによる逃がし量ｔ１と、歯先Ｒによる逃がし量ｔ２の配分は任意に設定できるが、チップリリーフと歯先Ｒの両方を併用することが好ましい。また、歯先修整量Ｔを設定する際の伝達トルク（定格トルク）は、連続運転されることを前提に設定される連続定格トルクであって、絶対最大定格ではなく、本発明に係る複合ギヤには、瞬間的なトルク変動によって相手ギヤから定格以上の衝撃トルクが入力され得ることは勿論である。   In addition, since excessive tooth tip modification will adversely affect the meshing, it must be performed within a range that does not cause a tooth profile error. The distribution of the relief amount t1 due to the tip relief and the relief amount t2 due to the tooth tip R when performing the tooth tip modification can be arbitrarily set, but it is preferable to use both the tip relief and the tooth tip R in combination. Further, the transmission torque (rated torque) when setting the tooth tip modification amount T is a continuous rated torque set on the assumption that continuous operation is performed, and is not an absolute maximum rating, but a composite gear according to the present invention. Needless to say, an impact torque exceeding the rating can be input from the counterpart gear by instantaneous torque fluctuation.

以上、本発明のいくつかの実施形態について述べたが、本発明は上記実施形態に限定されるものではなく、本発明の技術的思想に基づいて各種の変形および変更が可能である。   As mentioned above, although several embodiment of this invention was described, this invention is not limited to the said embodiment, Based on the technical idea of this invention, a various deformation | transformation and change are possible.

例えば、上記実施形態においては、係合部として、内周部材２に係止溝２７を、表層部材４に突起４７を設ける場合を示したが、溝（切欠部）と突起の関係が逆であっても良く、また、相互の回動を阻止できる他の形状をなしていても良い。   For example, in the above-described embodiment, the engaging groove 27 is provided in the inner peripheral member 2 and the protrusion 47 is provided in the surface layer member 4 as the engaging portion, but the relationship between the groove (notch portion) and the protrusion is reversed. There may be other shapes which can prevent mutual rotation.

また、上記実施形態においては、本発明を平歯車として実施する場合について述べたが、本発明はこれに限定されるものではなく、ヘリカルギヤ、ベベルギヤなど、他の形態のギヤとして実施することも本発明の範囲内において可能である。また、内周部材２に軸孔２０を形成する代わりに、回転軸や他の回転体が一体に形成されていても良い。   In the above embodiment, the case where the present invention is implemented as a spur gear has been described. However, the present invention is not limited to this, and the present invention may be implemented as a gear of another form such as a helical gear or a bevel gear. It is possible within the scope of the invention. Further, instead of forming the shaft hole 20 in the inner peripheral member 2, a rotating shaft or another rotating body may be integrally formed.

１ 複合ギヤ
２ 内周部材
３ 芯部材
４ 表層部材
５ 相手ギヤ
１１ ギヤ歯
２１ ハブ
２２ 外周部
２３，３３ ラジアル摺接面
２４，３４ スラスト摺接面
２５ 段部
２６ 肩部（接合部）
２７ 係止溝（切欠部、係合部）
３１ 芯歯
３２ 環状部
３５ 最内周面
３８ 位置決め穴
４１ 表歯部
４２ 側面部
４６ 内周縁（接合部）
４７ 突起（係合部） DESCRIPTION OF SYMBOLS 1 Composite gear 2 Inner peripheral member 3 Core member 4 Surface layer member 5 Opposite gear 11 Gear tooth 21 Hub 22 Outer peripheral part 23, 33 Radial sliding contact surface 24, 34 Thrust sliding contact surface 25 Step part 26 Shoulder part (joint part)
27 Locking groove (notch, engaging part)
31 Core teeth 32 Annular portion 35 Innermost peripheral surface 38 Positioning hole 41 Front tooth portion 42 Side surface portion 46 Inner peripheral edge (joint portion)
47 Protrusion (engagement part)

Claims (4)

軸または軸への取付け部を含む金属製の内周部材と、ギヤ歯に対応する複数の芯歯を有する環状の芯部材と、前記芯歯を包覆する表歯部を含み前記芯部材および前記内周部材の外周部を被覆する樹脂製の表層部材と、を備え、
前記芯部材が、金属、合金、または焼結金属で構成され、前記内周部材の前記外周部に周方向に相対変位可能に嵌合され、前記内周部材と前記芯部材との嵌合面が、軸方向に平行なラジアル摺接面と、軸方向に対して直交または傾斜したスラスト摺接面とを含む組立体をなし、該組立体をインサート材として、その周囲に前記表層部材が射出成形されることで、前記表層部材の側面部と前記内周部材との接合部に、周方向への相対変位を阻止する係合部が形成されている、複合ギヤ。 A metal inner peripheral member including a shaft or an attachment portion to the shaft, an annular core member having a plurality of core teeth corresponding to gear teeth, and a surface tooth portion covering the core teeth; A resin surface layer member that covers the outer peripheral portion of the inner peripheral member,
The core member is made of a metal, an alloy, or a sintered metal, and is fitted to the outer peripheral portion of the inner peripheral member so as to be relatively displaceable in the circumferential direction, and the fitting surface between the inner peripheral member and the core member Is an assembly including a radial sliding contact surface parallel to the axial direction and a thrust sliding contact surface orthogonal to or inclined with respect to the axial direction, and the surface layer member is injected around the assembly as an insert material. The composite gear by which the engaging part which prevents the relative displacement to the circumferential direction is formed in the junction part of the side part of the said surface layer member, and the said inner peripheral member by shape | molding. 前記表層部材が、熱可塑性樹脂のナチュラル材で射出成形され、かつ、電子線照射によって高分子鎖間に架橋構造を生じている、請求項１に記載の複合ギヤ。 2. The composite gear according to claim 1 , wherein the surface layer member is injection-molded with a natural material of a thermoplastic resin and has a crosslinked structure between polymer chains by electron beam irradiation. 請求項１または２に記載の複合ギヤと、前記複合ギヤに噛合する駆動側相手ギヤとを含むトルク伝達機構において、前記相手ギヤの歯先が、チップリリーフとＲ形状により修整されていることを特徴とするトルク伝達機構。 The composite gear according to claim 1 or 2, in the torque transmission mechanism including a driving-side mating gear which meshes with said composite gear, that tooth tips of the mating gear, are modification by the chip relief and R shape A feature torque transmission mechanism. 前記歯先修整の大きさが、前記複合ギヤに定格トルクを負荷した場合におけるギヤ歯の作用線方向の弾性変位の３０％以上であることを特徴とする請求項３に記載のトルク伝達機構。 4. The torque transmission mechanism according to claim 3 , wherein the magnitude of the tooth tip modification is 30% or more of the elastic displacement in the action line direction of the gear teeth when a rated torque is applied to the composite gear.

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