Scroll-type vacuum pump with oil seal between suction and discharge chambers

摘要

An upper housing for rotatably supporting a driving scroll in a sealing container is provided with an annular chamber to be maintained at the atmospheric pressure. The annular chamber is communicated with a compression chamber formed between the driving and driven scrolls through a discharge conduit which is formed in the driving shaft of the driving scroll. The annular chamber is communicated with the inside of the container through a throttling path. An oil stored in the lower part of the container is induced with the compression chamber during the revolution of the both scrolls to be introduced into the annular chamber. Owing to the throttling path, the oil is stored in the annular chamber to separate the inside of the container and the annular chamber kept at the atmospheric pressure.