HELICAL GEAR DRIVE TRANSMISSION DEVICE, AND IMAGE FORMING APPARATUS

PROBLEM TO BE SOLVED: To reduce propagation of vibration in a rotating direction produced in engagement, vibration (vibromotive force) in a translational direction around a gear, and vibration propagation exerting an influence on a peripheral portion, respectively, by setting axial displacement by inclination of a shaft of a driving helical gear, and a tooth surface deflection amount of a driven helical gear to be equal to each other in engagement of the cantilevered driving helical gear and the driven helical gear.SOLUTION: A helical gear drive transmission device includes: a driving helical gear; a driven helical gear driven while being engaged with the driving helical gear; a driving gear bearing portion rotatably and pivotally supporting a shaft portion of the driving helical gear; and a driven gear bearing portion rotatably and pivotally supporting a shaft portion of the driven helical gear. An axial position in starting the engagement of the driving helical gear is set to a side separating from the driving gear bearing portion, and axial displacement by inclination of a rotation shaft of the driving helical gear determined by load torque added to the driving helical gear, and bearing rigidity of the bearing portion of the driving helical gear, and a tooth surface deflection amount of the driven helical gear are made equal to each other.SELECTED DRAWING: Figure 2 【課題】片持ち支持の駆動はすば歯車と被駆動用はすば歯車のかみ合いにおいて、駆動はすば歯車の軸の傾きによる軸変位と被駆動はすば歯車の歯面たわみ量とを同等に設定することで、かみ合い時に発生する回転方向の振動や、歯車周辺の並進方向への振動（起振力）や、周辺部に影響を与える振動伝播を夫々低減する。【解決手段】駆動はすば歯車と、該駆動はすば歯車とかみ合って駆動される被駆動はすば歯車と、駆動はすば歯車の軸部を回転自在に軸支する駆動歯車軸受部と、被駆動はすば歯車の軸部を回転自在に軸支する被駆動歯車軸受部と、を備え、駆動はすば歯車のかみ合い始めの軸方向の位置が駆動歯車軸受部から離れている側とし、かつ、駆動はすば歯車に加わる負荷トルクと駆動はすば歯車の軸受部の軸受け剛性とにより定まる駆動はすば歯車の回転軸の傾きによる軸変位と、被駆動はすば歯車の歯面たわみ量とを同等にした。【選択図】図２