Patent ID: 7588020
Filing Date: 2009-09-15
Classification: F01M

Abstract:
1. An oil separator for separating oil contained in blow-by gas from the blow-by gas, the oil separator comprising: a casing having an inlet port through which blow-by gas flows into the oil separator, and an outlet port through which the blow-by gas flows out of the oil separator, the casing defining a blow-by gas passage extending to connect the inlet port and the outlet port to each other, wherein the outlet port is formed to pass through a wall of the casing and the blow-by gas passage is surrounded by the wall of the casing; a separation mechanism located in the blow-by gas passage, the separation mechanism trapping oil in blow-by gas, wherein the separating mechanism includes a trapping plate, the trapping plate being configured to allow the blow-by gas flowing in the blow-by gas passage to collide against the trapping plate, thereby separating the oil from the blow-by gas; and a drain port formed in the casing, the drain port draining the separated oil, the outlet port being located in one of side portions of the casing that are located in opposite ends, and the drain port being located in the other one of the side portions, wherein the blow-by gas passage includes a first passage section located upstream of the separation mechanism, a second passage section located downstream of the separation mechanism, and a third passage section located downstream of the second passage section and between the second passage section and the outlet port, wherein the oil separator is provided in a blow-by gas returning device and is arranged such that the third passage section is located higher than the separation mechanism and the second passage section, and wherein the third passage section has a smaller cross-sectional area than the second passage section and a larger cross-sectional area than the outlet port, wherein the blow-by gas passages has a turned section, the second passage section being located downstream of the turned section.