초록 ▼

A crankcase for a motorcycle is divided into an upper half and a lower half. A crankshaft, a main shaft, a counter shaft, and a pivot portion are arranged substantially on a straight line along a parting plane P of the crankcase. An eccentric cam and a pivot collar are disposed in the pivot portion,

A crankcase for a motorcycle is divided into an upper half and a lower half. A crankshaft, a main shaft, a counter shaft, and a pivot portion are arranged substantially on a straight line along a parting plane P of the crankcase. An eccentric cam and a pivot collar are disposed in the pivot portion, and a rear swing arm is connected to the pivot shaft. The upper half and lower half are vertically mated to each other in front of and behind the pivot portion and then vertically fastened to each other. The center of the pivot collar is offset downwardly from the parting plane P.

대표청구항 ▼

[ What is claimed is:] [1.] A body structure of a motorcycle comprising:a head pipe turnably supporting a front fork supporting a front wheel;a body frame extending rearwardly from said head pipe;an engine supported downwardly from said body frame;a rear swing arm having a front end portion rockably

[ What is claimed is:] [1.] A body structure of a motorcycle comprising:a head pipe turnably supporting a front fork supporting a front wheel;a body frame extending rearwardly from said head pipe;an engine supported downwardly from said body frame;a rear swing arm having a front end portion rockably supported on a rear portion of a crankcase of said engine through a pivot shaft; anda rear wheel supported on a rear end portion of said rear swing arm;wherein said crankcase is divided into upper and lower parts, and a pivot portion for supporting said pivot shaft is provided along a parting plane of said upper and lower parts of said crankcase.