| 摘要 |
PURPOSE:To reduce the weight and size of a balancer by providing balancers respectively in parts, corresponding to bearings of the first and the third cylinders, of a balancer shaft rotating in the direction opposite to a crankshaft and also providing balancers which are divided into two parts in positions corresponding to bearings of the second cylinder and further using all these balancers as both balancers and bearings. CONSTITUTION:Counterweights 6a'-1, 6a'-2; 6c'-1, 6c'-2 are provided on crank arms 2a-1, 2a-2; 2c-1, 2c-2 of the first, the third cylinders of a crankshaft 1 in such positions as to make right angles with crank arms of the second cylinder. Further, one balancer shaft 7 is provided which rotates in the opposite direction and at an equal speed in relation to the cranishaft 1. The balancer shaft 7 is provided with balancers 8a, 8c in positions corresponding to bearings 9a, 9d on both sides of the crankshaft as corresponding parts to the first, the third cylinders and also provided with balancers 8b-1, 8b-2 which are divided into two parts in positions corresponding to two bearings 9b, 9c on the inner side as corresponding parts to the second cylinder. The abovementioned balancers 8a- 8c are all supported in the entire periphery-shaped shaft pipe and used as both balancers and bearings 23. |
