问题 问答题 简答题

在管理维修叶片泵时主要应注意些什么?

答案

参考答案:

1.注意转向,不可反向旋转;

2.保持油液清洁及合适的油温与粘度;

3.叶片与滑槽之间的间隙及端面间隙应在规定范围内;

4.配油盘与定子应正确定位,转子、叶片、配油盘不能装反;

5.转子与配油盘有擦伤时,可重新研磨,但叶片也要研磨,以保证轴向间隙,另外应注意叶片的轴向宽度应比转子略小(0.005~0.01mm)。

单项选择题
单项选择题

The United States government publishes guidelines for appropriate nutrient intakes. These are known as the Recommended Dietary Allowances (RDAs) and are updated regularly based on new research in nutrition. RDAs are suggested amounts of calories, protein, and some minerals and vitamins for an adequate diet. For other dietary substances, specific goals must await further research. However, for the U.S. population as a whole, increasing starch and fiber in one’’s diet and reducing calories (primarily from fats, sugar, and alcohol) is sensible. These suggestions are especially appropriate for people who have other factors for chronic diseases due to family history of obesity, premature heart disease, diabetes, high blood pressure, and high blood cholesterol, or for those who use tobacco.Snacks can furnish about one-fourth of the calorie requirements among teenagers. Those snacks should also provide much of the day’’s allowances for protein, minerals, and vitamins. Sandwiches, fruit, and milk make good snacks for active teenagers. Food from the food pyramid may be part of any meal. A grilled cheese sandwich or a bowl of whole-grain cereal is just as nutritious in the morning as it is at noon. In addition, a good breakfast consists of any foods that supply about one-fourth of the necessary nutrients for the day.

One implication in this passage is that________.

A.all RDAs have been established

B.not all RDAs have been established yet

C.it’s not important to know RDAs

D.RDAs are necessary only for sick people