提升机制动力矩过小或过大有什么危害？
参考答案：
制动力矩过小有下列危害：⑪各种因素偏离规定条件时容易造成制动不住而发生跑车事故。⑫在安全制动时，虽能制动停车，但制动距离延长，可能发生事故。制动力矩过大有下列危害：⑪下放重载时，特别是速度高、惯性大的提升机，会使设备、钢丝绳、连接装置等承受过大的惯性冲击力，有可能造成事故；⑫上提重载时，特别是倾角较小的斜井，会使提升机的制动减速度大于提升容器的自然减速度，因而带来送绳现象所引起的危害。⑬多绳提升时容易造成打滑跑车事故。
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| I have a friend named Monty Roberts who owns a horse ranch(牧场). He has let me use his 1 to raise money for poor students. 2 I was there he introduced me by saying,"I want to tell you why I let Jack use my house. It all goes back to a story about a boy who was the son of a 3 horse trainer. " One day the boy was 4 to write a paper about what he wanted to do when he grew up. He wrote a paper describing his 5 of someday owning a horse ranch. Two days later he 6 his paper back. On the front page was a large red "F" with a note 7 ,"See me after class. " The boy went to see the 8 after class and asked,"Why did I receive an F?"The teacher said,"This is a(n) 9 dream for a young boy like you. You have no coins. 10 a horse ranch requires a lot of 11 . "Then the teacher added,"lf you 12 rewrite this paper with a more realistic goal,I will 13 your grade. "The boy went home and 14 about it long and hard. Finally,the boy 15 the same paper,making no 16 at all. He said,"You can keep the F and I'll keep my 17 ." Having told the story,Monty said,"l tell you this story 18 you are sitting on my 200-acre horse ranch. I still have that school paper 19 ; over the fireplace. " He added, "The best part of the story is that the same teacher brought 30 kids to camp out on my ranch for a week. " When the teacher was leaving,he said, " Look,Monty,I can tell you this now. When I was your teacher,I was something of a dream 20 . Fortunately you had enough determination not to give up. " Don't let anyone steal your dreams. Follow your heart,no matter what happens. | ||||
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