Abstract: A drive unit (54) for an electric motor-operated vehicle is provided with a planetary gear mechanism (58) having; a sun gear (58a) rotating together with a motor output shaft (57a), a planetary gear (58b) meshing the sun gear (58a), and a ring gear (58c) meshing the planetary gear (58b); and constituted that an arm plate (58d) supporting the planetary gear (58b) is rotated with the rotation of the motor (57) at a specified speed reduction ratio. The ring gear (58c) is supported for rotation relative to a housing and a switching mechanism (65) is provided to hold or release the relative rotation of the ring gear (58c).

Abstract: A number of embodiments of acoustical devices for improving either or both the intake and exhaust sounds emanated from an internal combustion engine. This is achieved by employing acoustical devices which are configured so as to discharge the desired sound waves to the atmosphere rather than by attempting to dampen the undesired sound waves generated in the system.