问题
问答题 简答题
牙轮钻头的工作原理是什么？
答案
参考答案：
牙轮钻头是靠施加回转力矩和施加的轴压力来破碎岩石的。当钻头回转带动牙轮转动时，在轴压的静载荷和牙轮滚动时的动载荷的作用下牙轮上的刃齿以凿碎、压入、剪切和刮削等形式破碎岩石成孔的。
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牙轮钻头的工作原理是什么？
参考答案：
牙轮钻头是靠施加回转力矩和施加的轴压力来破碎岩石的。当钻头回转带动牙轮转动时，在轴压的静载荷和牙轮滚动时的动载荷的作用下牙轮上的刃齿以凿碎、压入、剪切和刮削等形式破碎岩石成孔的。
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| When I was about 13, my father would take me on short outings on Saturdays. On the way home, Dad 1 stopped at the Dairy Queen for 10-cent ice creams. I couldn't 2 it, but I could pray from the 3 we started heading home to that corner where we would either go straight for the ice cream or 4 and go home empty-handed. That corner 5 either mouth-watering excitement or 6 . One day, we were heading home, and again I was praying for the 7 sound of his offer. It 8 . "Would you like an ice cream today?" "That sounds great, Dad!" But then he said, "Would you like to 9 today?" "Twenty cents!" I thought to myself, "I can afford it. I got 25 cents' pocket money and some 10 for odd jobs (零活). Well, 11 it is enough, ice cream isn't a good use of it." 12 , I said, "Well, in that case, I guess I'll 13 ." My father just said, "Okay, Son." But as we headed home, I realized how wrong I was and begged him to 14 . But he just said, "That's okay, we don't really need one." I felt 15 for my selfishness and ungratefulness. He didn't mind, or 16 act disappointed. From that I 17 generosity (慷慨) goes two ways and gratefulness (感谢) sometimes costs more than "thank you". On that day gratefulness would have cost 20 cents and it would have been the 18 ice cream I'd ever had. I'll tell you one more thing. We 19 another trip the next week. As we 20 the corner, I said, "Dad, would you like an ice cream today? My treat." | ||||
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