问题 问答题 简答题

电动机电流升高,发生异常振动,过热响声等现象的原因?

答案

参考答案:

(1)上煤量过载,电机负荷过大;(2)电压低,电动机动静之间有磨擦;(3)电流表失灵;(4)电机两相运行;(5)通风不良或电机层间绕组短路;(6)轴承故障,地脚螺丝松动;(7)连续启动次数过多。

选择题
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     It was a cold winter's night when I stopped for gas on my way home from work. I was tired and
had a slight   1  .
     I worked in a   2   doctor's office and this was one of those days when the unexpected happened,
making the schedule run   3   than usual. It seemed I was going to be late   4   home and my husband,
being the  5   person, would be ready to pronounce me late once again. Maybe   6   I hurried, I could
still make it home.
     I was heading inside to   7   for my gas when I noticed an older couple at the counter. I heard them
asking for   8   to the local hospital. It was the same hospital that I had just   9   a few minutes ago.
     The young man at the counter was trying to be   10   in explaining how to get there, with two other
people making   11  . One of them was   12   trying to give them a whole different route back. It was
then that I walked over to the couple and said, "Would you like to follow me to the   13 ?"
     A look of   14   crossed the woman's face.
     "I'm going right by there," I said, which wasn't a(an)   15  since I had just made up my mind to do
   16   that.
     I got in my car and began the journey back. I was trying to watch to be sure they were right   17 
me. It took only fifteen minutes to get there as rush hour traffic was beginning to   18  . I felt better
than I had all day and my headache was nearly gone.
     Later, as I arrived home, my husband   19  , "So you aren't ever late any more."
     I said, "Sometimes it's   20  to be late."
( )1. A. break
( )2. A. foreign
( )3. A. earlier
( )4. A. getting
( )5. A. tough
( )6. A. as
( )7. A. pay
( )8. A. opinions
( )9. A. reached
( )10. A. skilled
( )11. A. comments
( )12. A. only
( )13. A. station
( )14. A. panic
( )15. A. duty
( )16. A. partly
( )17. A. across
( )18. A. go up
( )19. A. teased
( )20. A. possible
B. fever
B. common
B. later
B. cooking
B. punctual
B. since
B. change
B. trouble
B. visited
B. helpful
B. promises
B. still
B. office
B. relief
B. fact
B. properly
B. before
B. die down
B. shouted
B. special
C. cold
C. busy
C. easier
C. calling
C. generous
C. while
C. wait
C. directions
C. called
C. experienced
C. jokes
C. even
C. hospital
C. sadness
C. reason
C. exactly
C. beside
C. speed up
C. burst
C. good
D. headache
D. noisy    
D. simpler  
D. working  
D. careful  
D. if      
D. search  
D. money    
D. left    
D. active  
D. offers  
D. ever    
D. hotel    
D. peace    
D. lie    
D. perfectly
D. behind  
D. turn down
D. laughed  
D. safe