【基本额定动载荷】是一个轴承的载荷术语，它指的是一个持续的载荷加在轴承上，轴承的寿命可以达到100万转的额定寿命。[Basic Dynamic Load Rating] is a bearing term that represents an applicable constant load (in direction and magnitude) where a bearing will achieve 10 6 (1,000,000) rotations of Rated Life.

轴承的额定寿命是这样定义的：样品中的90%的轴承可以达到额定的转数，没有因为滚动压力而产生的任何脱落损伤。这些，对于滚珠丝杠来讲，就是：一个轴向的载荷施加在一批同样的滚珠丝杠中，其中90%可以达到100万转，没有表面剥离损伤。The Rated Life of a bearing is defined as: Total number of rotations reached by 90% of a specimen group of bearings, without sustaining any material damages due to rolling stress.  This in a Ball Screw perspective, will mean: An axial load applied to a group of same ball screws where 90% of them will reach 1,000,000 rotations without suffering any Flaking.

把以上内容总结成更实用的描述：To put all the above in a more practical terms:

例如，我们的样本中载明10mm的直径的丝杠，单螺母，1x1.5回路，其基本额定动载荷是440daN.这意味着给100个这样的丝杠施加 440daN的轴向载荷，90个或者更多的丝杠可以无损伤的工作100万转。（如果丝杠的转速为33.3rpm的话，100万转相当与工作500小时。）For instance, our catalog shows that a ball screw, 10mm shaft diameter with a single ball nut with 1-ball-row x 1.5 turns, has a Dynamic Load Rating of 440daN.  This means that when we apply 440daN of axial load on 100 specimens of this type, 90 specimens or more will reach 1,000,000 rotations without any damages.  (One million rotations will equate to 500 hours if the ball screw is operated at 33.3 rpm)

换句话说，基本额定动载荷提供了一个基于丝杠类型和尺寸来计算寿命的基础。对于该数据，不同的螺母形式只要丝杠的直径，导程，回路数以及钢球的直径相同就会相同。In other words, the Basic Dynamic Load Rating provides a basis of Life Calculations based on the size and type of ball screws.  This rating will be the same for different ball nut types such as Single Nut, Integral Nut and Double Nut, as long as the shaft diameter, lead, number of recirculating circuits, and ball diameter are the same.