| 摘要 |
A landing gear for semitrailers includes a two-speed single reduction gear assembly for conversion of crank-handle input turns into vertical travel of the landing gear leg (13). Shifting from a low speed ratio to a high speed ratio is achieved by axial displacement of the input shaft (75). With the input shaft (75) in its low speed position, rotary motion of the shaft (75) is transmitted via a pinion gear (83) formed on the input shaft (75) to a first gear (72) attached to a second shaft (60). Rotation of the second shaft (60) is converted into vertical movement of the leg (13) via a bevel gear assembly (74,34) and a nut-and-screw assembly (25,26). With the input shaft in its high-speed position, the pinion (83) engages interior teeth (84) formed on a high-speed drive gear (90). The exterior teeth (85) of said high-speed drive gear (90) engage a second gear (73), of smaller diameter than the first gear (72), attached to the second shaft (60), resulting in higher speed ratio transmitted to the landing gear leg (13). A simple, compact reduction gear assembly is hereby achieved. <IMAGE> <IMAGE> |
