DRIVING DEVICE AND OPENING/CLOSING UNIT

To improve easiness of assembly work when assembling by covering a case over a motor and a gear train mechanism.SOLUTION: In a case 10 of an opening/closing member driving device 3, a first case 61 for storing a motor 12, a second case 62 in which a partition wall part 55 is provided, and a third case 63 in which an output shaft 11 is arranged are laminated and combined. A first peripheral wall part 66 of the first case 61 includes a cutout part 54 in which an end part in a second direction X2 is cut out in a first direction X1 is provided at a plurality of positions. An end part in the first direction X1 of a second peripheral wall part 74 of the second case 62 includes an impeller part 53 extending in the first direction X1 in a plurality of positions. When the first case 61 is put over the second case 62 from the first direction X1 to assemble, a place where the first case 61 and the second case 62 are fitted first are a tip of the impeller part 53 and the cutout part 54.SELECTED DRAWING: Figure 14 【課題】モータおよび輪列機構にケースを被せて組み立てる際の組立作業の容易性を向上させる。【解決手段】開閉部材駆動装置３のケース１０は、モータ１２を収容する第１ケース６１と、隔壁部５５が設けられた第２ケース６２と、出力軸１１が配置される第３ケース６３を積層して結合する。第１ケース６１の第１周壁部６６は、第２方向Ｘ２の端部を第１方向Ｘ１に切り欠いた切欠き部５４を複数位置に備える。第２ケース６２の第２周壁部７４の第１方向Ｘ１の端部は、第１方向Ｘ１に延びる羽根部５３を複数位置に備える。第１ケース６１を第２ケース６２に第１方向Ｘ１から被せて組み立てる際、第１ケース６１と第２ケース６２が最初に嵌合する箇所は、羽根部５３の先端と切欠き部５４である。【選択図】図１４