| 摘要 |
PROBLEM TO BE SOLVED: To suppress energy loss due to friction, while suppressing vibration of a crank shaft.SOLUTION: A bearing structure 2 of a crank shaft 1 has four crank pins 3 connected to a connecting rod 5, and a main journal 4 supported by a plurality of bearing parts 7 arranged in both neighborhoods of each crank pin; and is provided with a power transmission unit 9 configured to transmit rotational power to a cam shaft, on one end side. Among the plurality of bearing parts, a third bearing part 7c from the power transmission unit side has a smaller clearance than a second bearing part 7b (reference bearing part) from the power transmission unit side.SELECTED DRAWING: Figure 1 |
