| 摘要 |
PURPOSE:To prevent water from submarging into a crankcase by a method wherein a crankshaft is supported by a supporting pipe provided between a crankcase and an impeller casing and the supporting pipe is provided with a hole for releasing the pressure on the rear of the impeller, in a system having an engine provided at a rear part of a surfboard. CONSTITUTION:An engine chamber 12 is formed at a ridge part 6 of the rear part of the surfboard 1, a square engine mount box 13 is placed a the bottom of the chamber 12, and the engine 14 is mounted on the box 13. The crankshaft 21 for the engine 14 is disposed vertically and it is connected to an impeller 46 by passing through the supporting pipe 52 provided between the crankcase 17 and the impeller casing 45. The cranckshaft 21 is supported by a self-lubricating plane bearing 55 in the pipe 52, and the pipe 52 is provided with the hole 57 for releasing the pressure on the rear of the impeller 46. Numerals 53, 54 represent seals. |
