Patent ID: 7040454
Filing Date: 2006-05-09
Classification: F01M

Abstract:
1. A dry-sump lubrication type four-stroke cycle engine comprising: a crankcase in which a crank chamber is formed in its front part and a transmission chamber is formed in its rear part, the crankcase having a pair of end walls positioned at one end and other end along a crank axis direction, respectively; a first cover and a second cover disposed on the end walls of the crankcase, respectively; and a first chamber and a second chamber formed in the first cover and the second cover, respectively, wherein a partition wall of a given height is provided between the crank chamber and the transmission chamber so as to form an oil reservoir chamber in a lower part of the transmission chamber separated from the crank chamber by the partition wall, wherein one of the end walls is provided with a drain passage through which oil drains from the crank chamber into the first chamber, wherein the second chamber has a second oil reservoir chamber which communicates with the oil reservoir chamber so that a level of oil contained in the second oil reservoir chamber is equal to a level of oil in the oil reservoir chamber, and wherein the engine further comprising a scavenging pump pumping up oil from the first chamber and discharges oil into the oil reservoir chamber or the second oil reservoir chamber.