41. /30 мин./ На следующем отрывке из инструкции проверьтеп свои навыки работы с английским текстом по специальности, а) Ознакомьтесь с текстом с целью понять его общее содержание /Зафиксируйте время начала и окончания выполнения всего задания./
Slip-Ring Equipment with Brush Lifting
In these machines the function of the brush lifting & short-circuit device' must be checked from time to time, e.g. during maintenance of the machine. When moving from position “Start” to position “Run”, the short-circuit contacts must reach their final position before the brush lifting is effected. If necessary, the brush-lifting bars shall be adjusted.
The short-circuit contacts must be in good condition. If necessary, the contacts shall be adjusted & the worn-out ones renewed. Also the new contacts Should be checked after installation.
Maintenance instructions are also included in the separate operating instructions of a remote controller delivered with the machine provided with a remote controlled slip-ring device.
б) Для каждого из трех предложений выберите правильное продолжение, мысленно обращаясь к тексту данного задания.
1. In these machines the function of the brush lifting & short-circuit device must be checked from time to time ... .
a) before the brush lifting is affected; b) after installation; c) during maintenance of the machine.
2. If necessary ... shall be adjusted.
a) the short-circuit contacts; b) the brush-lifting bars; c) a remote controlled slip-ring device. .y
3. The worn-out contacts shall be ....
a) renewed; b) adjusted; c>checked. j;.
p) Учитывая контекст, восстановите в памяти пропущенни^е слова, затем запишите их на прозрачной пленке, наложенной на текст. Проверьте себя. Укажите количество правильно записанных слов.
In these machines the ... of the brush lifting ... short-circuit device must be ... from time to time,... during maintenance of the ... 'When moving from position ... to position “Run”, the ... contacts must reach their... position before the brush ... is effected. If necessary, the brush-lifting ... shall be adjusted. The short-circuit contacts... be in good condition. If necessary, the contacts ... be adjusted & the ... ones renewed. Also the new ... should be checked after ....
Результаты этой работы запишите в свою тетрадь и сравните
их с предыдущими. ...
42. /25 мин./ Прочтите отрывок из инструкции п ишетьте на вопросы.
1. How do you know the degree down to which the brushes/ may be worn? 2. How would you Hmedy worn brushes? 3. What'>1 factors govern the choice of new brushes? 4. How would you go about new brushes? 5. What should you do to make the brushes move freely on their holders? г ?;i; ,
Replacing Brushes >1>{■ .
The degree down to which the brushes may be worn, isusu&ify shown in the dimension print of the brushes or by a mark engraved• on. the brush. ' >iJr
In general, the brushes should be replaced after they have been worn down to approximately half of their original size. New brushes^ must be of the same quality as the original ones. As there generally' is reason to doubt whether the quality of the new brush set is. exactly the same as that of the old ones, all the brushes on the same slip ring have to be replaced at the same time. When fitting the new brushes, they have to be carefully ground to fit the curvature of the slip rings.
- The brushes can be ground with e.g. a grinding band which is a little broader than the brush. The band is placed below the brush fitted to the brush holder. The grinding is done by pressing the brush with one hand against the grinding band & by pulling the band,with one hand to the rotation direction of the machine, & by simultaneously pressing the end of the band the whole time against the slip ring. The grinding is finished when the working surface of the brush has perfect fit to the curvature of the slip ring. The grinding time can be shortened” by first using a coarse grinding band & by finishing with a fine granular one.
After grinding, the slip-ring device must be carefully cleaned from dust & it is checked that the brushes move freely on their holders. When replacing the brushes, the surface of the slip rings should be also cleaned.
