问题 问答题 简答题

离心压缩机轴向力的危害是什么?

答案

参考答案:高速运行的转子,始终作用着由高压端指向低压端的轴向力,转子在轴向力的作用下,将沿轴向力的方向产生轴向位移。转子的轴向位移,将使轴颈与轴瓦间产生相对滑动,因此,有可能将轴瓦或轴颈拉伤,更严重的是,由于转子位移,将导致转子组件与定子组件的摩擦、碰撞乃至机器损坏。由于转子轴向力,有导致机件摩擦、磨损、碰撞乃至破坏机器的危害,因此应采用有效的技术措施予以平衡,以提高机器运行的可靠性。

阅读理解

Chinese are very generous in educating their children. Not caring about the money, parents often send their children to the best schools or even abroad to England, the United States and Australia. They also want their children to take extra-course activities such as musical instrument learning or ballet classes, or other classes. They think these will give them a good future. The Chinese believe that the more expensive an education is, the better it is. So parents will spend much unreasonable money on education. Even poor parents will buy a computer for their son or daughter.

However, most parents don’t understand that the best early education they can give their children is usually very cheap.

Parents can see that their children are very good in some areas while poor in others. Parents can also see some children are good at these skills and others do well in others. Most parents don’t realize that today’s children lack self-respect and self-confidence.

The problem is that parents are only educating their children on how to take tests and how to study well, but parents are not teaching them the most important skills that they need are to be confident, happy and clever.

Parents can achieve this by teaching skills like cooking, sewing and doing other housework. Teaching a child to cook will improve many of the skills that he will need later in life. Cooking needs patience and time. It is an enjoyable but difficult experience. A good cook always tries to improve his cooking, so he will learn to work hard and finish his job successfully. His result, a well-cooked dinner, will give him much satisfaction and lots of self-confidence. 

Some old machines, such as a broken radio or TV set that you give your child to play with, will make him curious(好奇的) and improve his interest. He will spend hours looking at them, trying to fix them. Your child might become an engineer when he grows up. These activities are not only teaching a child to read a book, but rather to think, to use his mind. And that is more important.

小题1:We know from this passage parents in China         .

A.are too strict with their children

B.are too rich to educate their children

C.are too poor to educate their children

D.have some problems in educating their children correctly小题2:We learn from the passage that        .

A.the cheaper an education is, the better it is

B.children today should learn difficult skills

C.practical skills are helpful to children’s growth

D.school education can’t meet parents’ expectations小题3:Doing some cooking at home helps children        .

A.benefit (有益于) from it and prepare themselves for the future

B.learn how to serve their parents

C.learn how to become strong and fat

D.make their parents believe that they are clever小题4:What is the main idea of the last paragraph?

A.Broken things are useful for children

B.Interest is necessary for everything

C.Learning to think is very important.

D.Using hands helps improve thinking ability

填空题