| 摘要 |
PROBLEM TO BE SOLVED: To reduce a weight of a transmission case while securing rigidity of the transmission case and reducing noise, and to create smooth flow of cooling air in the transmission case.SOLUTION: A side wall portion 27 of a transmission case body 22 of a transmission case 21 is provided with a waveform portion 41 repeatedly curved in a vehicle width direction so that the side wall portion 27 itself draws a wave advancing upward and downward. Further peaks and troughs in the waveform portion 41 are linearly extended in a longitudinal direction of a saddle-type vehicle. Further a waveform portion 42 is provided on a part of a peripheral wall portion 32 of a crank case formation portion 31 disposed on a front part of the transmission case body 22 and forming a part of a crank case, and the peaks and troughs of the wave on the waveform portion 41 formed on the side wall portion 27 of the transmission case body 22, and peaks and troughs of the waveform portion 42 formed on the peripheral wall portion 32 of the crank case formation portion 31 are connected to each other and continued.SELECTED DRAWING: Figure 5 |
