Ball screw using ball movement, so the starting torque is very small, does not appear sliding movement crawling phenomenon, so can ensure accurate micro feed.
There is no internal scale product of dry screw pump owing to the late research starting, so like products are all depend on importing and the price is very expensive.
由于国内螺杆干泵的研究起步较晚，目前还没有规模化的产品，同类产品全部依靠进口，价格十分昂贵。
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Starting with the current situations of the screw pump lifting, this paper analyzes the adaptability of the screw pump lifting in alkali-surfactant-polymer flooding and poi...