| 主权项 |
1. A vehicle transmission comprising:
an input shaft; a first input gear connected to the input shaft and rotating therewith; a second input gear connected to the input shaft and rotating therewith; a third input gear connected to the input shaft and rotating therewith, the second input gear being disposed between the first and the third input gears; a transmission shaft disposed parallel to the input shaft, the input shaft selectively driving the transmission shaft; a first transmission gear rotatably connected to the transmission shaft such that the transmission shaft can rotate independently of the first transmission gear, the first transmission gear operatively engaging the first input gear; a second transmission gear rotatably connected to the transmission shaft such that the transmission shaft can rotate independently of the second transmission gear, the second transmission gear operatively engaging the second input gear; a third transmission gear rotatably connected to the transmission shaft such that the transmission shaft can rotate independently of the third transmission gear, the third transmission gear operatively engaging the third input gear, the second transmission gear being disposed between the first and the third transmission gears; a first shifting sleeve disposed on the transmission shaft between the first and second transmission gears, the first shifting sleeve being rotatably fixed to the transmission shaft for rotation therewith, the first shifting sleeve being movable axially with respect to the transmission shaft, the first shifting sleeve having a first set of teeth selectively engaging a first set of openings defined in the first transmission gear; a second shifting sleeve disposed on the transmission shaft between the first shifting sleeve and the second transmission gear, the second shifting sleeve being rotatably fixed to the transmission shaft for rotation therewith, the second shifting sleeve being movable axially with respect to the transmission shaft, the second shifting sleeve having a second set of teeth selectively engaging a second set of openings defined in the second transmission gear; a third shifting sleeve disposed on the transmission shaft, the second and third transmission gears being disposed between the second and third shifting sleeves, the third shifting sleeve being rotatably fixed to the transmission shaft for rotation therewith, the third shifting sleeve being movable axially with respect to the transmission shaft, the third shifting sleeve having a third set of teeth for selectively engaging a third set of openings defined in the third transmission gear; a fork rod disposed parallel to the transmission shaft; a first shift fork slidably disposed on the fork rod, the first shift fork extending between the first and second shifting sleeves and being operatively connected to the first and second shifting sleeves; a second shift fork slidably disposed on the fork rod, the second shift fork being operatively connected to the third shifting sleeve; a shift drum shaft disposed parallel to the transmission shaft, the shift drum shaft being rotatable sequentially between a first position, a second position, a third position, and a fourth position; a first shift drum disposed on the shift drum shaft, the first shift drum being rotatably fixed to the shift drum shaft for rotation therewith, the first shift drum being movable axially with respect to the shift drum shaft between a default position and a pre-select position, the first shift drum operatively engaging the first fork; a first spring biasing the first shift drum toward the default position of the first shift drum; a second shift drum disposed on the shift drum shaft, the second shift drum being rotatably fixed to the shift drum shaft for rotation therewith, the second shift drum being movable axially with respect to the shift drum shaft between a default position and a pre-select position, the second shift drum operatively engaging the second fork; a second spring biasing the second shift drum toward the default position of the second shift drum; and an output shaft operatively connected to the transmission shaft, the transmission shaft driving the output shaft. |
