Mike Krzyzewski is really a famous coach of Dream Team. She has coached north america men's basketball team for some time, that's clinched numerous medals for his country. Following London Olympic was over, Krzyzewski told The Associated Press that this game will be his final one as national coach, a job he's held for seven years. He had left open the possibility of staying with the team beyond the London Games, when practice on Saturday said these will be his last Olympics.When asked if he was sure, Krzyzewski didn't hesitate before again saying, "yes," this will be his last game "If we could win it, then it might be three major championships in a row, i always do not know when that has been done because we haven't usually won the globe championships," Krzyzewski said. "It becomes an enormous thing for the program." Whatever, he's an awesome coach. His achievement are going to be remembered by the country.

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接触器的故障处理方法

2019/9/4 8:53:42      点击:

接触器的触头接触不牢靠会使动静触头间接触电阻增大,导致接触面温度过高,使面接触变成点接触,甚至出现不导通现象。
    一、故障的处理方法有:
    1、对于触头上的油污、花毛或异物,可以用棉布蘸酒精或汽油擦洗即可。
    2、如果是银或银基合金触头,其接触表面生成氧化层或在电弧作用下形成轻微烧伤及发黑时,一般不影响工作,.可用酒精和汽油或四氯化碳溶液擦洗。即使触头表面被烧得凸凹不平,也只能用细锉清除四周溅珠或毛刺,切勿锉修过多,以免影响触头寿命。对于铜质触头,若烧伤程度较轻,只需用细锉把凸凹不平处修理平整即可,但不允许用细砂布打磨,以免石英砂粒留在触头间,而不能保持良好的接触;若烧伤严重,接触面低落,则必须更换新触头。
    3、运动部分有卡阻现象,可拆开检修。
     三、接触器触头粘连是一种比较严重的故障。因为触头粘连会造成机器失控,甚至还会造成机械事故和人身伤害事故。造成此故障的原因有:
    1、负荷过重,触头容量过小。
    2、操作频率过高。
    3、电源电压太低,导致磁系统吸力不足而造成触头反复振动,发生电弧熔焊。
    4、触头初压力过小,在闭合感性负载时跳动很厉害,发生了电弧熔焊
    5、火花过大。
    6、安装不妥。
     四、运行中的交流接触器的噪声很大,可作以下处理:
    1、电源电压不足,电磁铁的吸力不够而产生噪声,应设法提高操作回路的电压。
    2、磁系统装配不当或受震动而歪斜或者机件卡住,是铁芯不能吸平,因而产生噪声。处理时应调整此系统,查明并消除机件不灵活的原因。
    3、极面生锈或有异物(如油垢、粉尘、花毛等)侵入铁芯极面,此时应当清理铁芯极面。
    4、由于触头弹簧压力过大而产生电磁铁噪声,通常调整触头弹簧压力即可。
    5、由于短路环断裂而产生噪声,应更换铁芯或短路环。
    6、铁芯极面磨损过度而不平,应更换铁芯。
    7、线圈匝间短路,通常更换线圈即可。

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