Patent ID: 8549941
Filing Date: 2013-10-08
Classification: F16H,Y10T

Abstract:
1. A multi-stage transmission wherein a drive gear shaft and a driven gear shaft are disposed in parallel; a plurality of drive gears and a plurality of driven gears are supported on the drive gear shaft and the driven gear shaft, respectively, wherein the drive gears and the driven gears are constantly meshed with each other to constitute meshing gear combinations for different speeds; one of the drive gears and the driven gears are fixed to the gear shaft supporting the same, while the gear shaft supporting the other of the drive gears and the driven gears is a hollow gear shaft; the other gears are supported on the hollow gear shaft individually in an engageable and disengageable manner through engaging means, which are operated by gear shift driving means for gear shift: said engaging means includes: a first engaging device for causing a first gear of the other gears and the hollow gear shaft to abut with each other in a rotational direction of the first gear to thereby cause the first gear and the hollow gear shaft to be rotated synchronously; and a second engaging device for causing a second gear, one step lower in reduction gear ratio than the first gear, of the other gears and the hollow gear shaft to abut with each other in said rotational direction of the gear to thereby cause the second gear and the hollow gear shaft to be rotated synchronously; wherein for making an upshift through changing over the engaging means from the engagement with the first gear to the engagement with the second gear by the gear shift driving means, the gear shift is made by engaging the second gear with the hollow gear shaft through the second engaging device wherein the first gear is in engagement with the hollow gear shaft through the first engaging device; wherein each of said first and second engaging devices comprises: engaging projections provided at an inner peripheral surface of each the gears at circumferentially spaced locations; a plurality of cam rods placed in sliding contact with an inner peripheral surface of an internal hole of the hollow gear shaft to be slidable in an axial direction of the hollow gear shaft and being provided with sliding contact surfaces thereof with a plurality of cam grooves at axially spaced locations; pin members fitted in through-holes radially penetrating portions of the hollow gear shaft for advancement and retractment while alternately making contact with the sliding contact surfaces of the cam rods and the cam grooves; swing pawl members swingably supported in the hollow gear shaft and which are swung by advance/retreat of the pin members to be engaged with and disengaged from the engaging projections; the cam rods being movable by the gear shift driving means to thereby make a gear shift; and a control rod disposed axially slidably in an inner hole of the hollow gear shaft in sliding contact with the cam rods.