| 摘要 |
<p>Step gear box having an input shaft (1) which is connected to a drive unit, an output shaft (2) from which a gear changed rotation can be received, clutches (8-11) between said input and output shafts (1, 2), one or more reverse and forward drive gears (4-7), one displaceable gear shift sleeve (14) which is connected to the output shaft (2) for rotation therewith and adapted for shifting of gear between the different gear stages (4-7), and a gear shift bar (21) for providing such gear shifting, and in which the gear box is formed with a reverse drive gear (4) comprising two cog wheels (8) which are directly co-operating with each other for providing a reversing of the direction of rotation from the input shaft (1) to the output shaft (2), and one or more forward drive gear stages comprising freely rotatable cog wheels (9-11) which are connected in pairs to each other over a cog belt or a chain (12, 13), and in which each reverse and forward drive stage (4-7) is connected to the output shaft (2) over a free wheel clutch (18, 19), and in which the displaceable sleeve (14), at one end thereof, is formed with a grip ring (20) for acting on each respective free wheel clutch (18, 19) for providing a force transmittance in one direction of rotation and a free wheel function in the opposite direction of rotation.</p> |
