Weather or not there is a rolling as well as rubbing motion, and the relative speeds of moving parts, also need to be considered.
天气或不存在，以及滚动摩擦运动，和运动部件的相对速度，同时还需要考虑。The balls fill the space between the two races and roll with negligible friction in the grooves.
球装在两套圈之间，且在滚道内滚动，摩擦力很小。is very small, the force couple of resistance is neglected in most engineering problems, hence the rolling friction is neglected.
由于滚阻系数很小，所以在工程中大多数情况下滚阻力偶不计，即滚动摩擦忽略不计。If you ride a bicycle with tires at low pressure, you have to work harder to overcome the increased rolling resistance.
当你骑着装有低风压轮胎的自行车时，你必须更加用力，以克服增加的滚动摩擦力。The rotary wheel can conduct rolling friction with wheel hubs, and can also conduct rolling friction with tyres.
转动轮可与轮毂滚动摩擦，也可与轮胎滚动摩擦。Rolling friction occurs when roller devices are subjected to tremendous stresses which cause the parts to change shape or deform.
滚动摩擦力产生在受到引起部件形变的巨大压力的滚动装置上。Determination of the coefficient of elastic hysteresis in the rolling friction force calculation
滚动摩擦力计算中弹性滞后系数的确定Experimental Study of Planar Bearing Rolling Friction
平面轴承滚动摩擦试验研究A study on the rolling friction coefficient and the horizontal driving-force calculation in building monolithic moving engineering
滚轴滚动摩擦系数研究与建筑物迁移工程水平动力计算