The oil leakage of the cycloidal pinwheel reducer is one of the common faults of the cycloidal pinwheel reducer, and it is a headache problem. How to effectively control the oil leakage is of concern to people.Whether the oil return of the cycloidal pinwheel reducer is smooth is also an important factor for the oil leakage of the cycloidal pinwheel reducer.
回油畅流就是要使可能外渗漏的油能够比较通畅地流回箱内去。例如，飞溅在箱内壁上的油，需要使它尽快地流回箱内的油池，因而将摆线针轮减速机箱盖内壁制成圆弧形，为了不让油在轴头密封装置处停留，以防油沿轴头逐渐往箱体外渗漏，轴头处采用油沟式密封装置，油沟下端开有回油精，可使积聚在油沟处的油流回到箱体内，防止泄漏。
摆线针轮减速机箱座绪合面上长方形断面的回油槽，可使飞溅在箱盖内壁上的油沿内壁滴下，汇集到回油槽内，再流回油池。回流槽的尺寸大小可以根据设计需要而定，有些摆线针轮减速机的箱座的个别回油槽偏小，不能真正地起到回流杨流作用。
