Power transmission system for an inboard/outboard motor
AssigneeYamaha Hatsudoki Kabushiki Kaisha
InventorKenichi Hayasaka
Life of this patent
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Abstract
A marine outboard drive having an outboard drive unit that includes a bevel gear forward, reverse transmission having hydraulicly operated clutches. A hydraulic pump for actuating the clutches and for lubricating the transmission is driven off the rear end of the input shaft and control valve means selectively communicates the fluid from the hydraulic pump with the hydraulic clutches. The valve means is a rotary plug type valve but is constructed so as to minimize axial and radial forces acting that would tend to bind its movement. The construction of the outboard drive unit is such that the bevel gear transmission and hydraulically operated clutches can conveniently be inserted through like diameter oppositely facing openings formed in the upper end of the housing assembly of the outboard drive unit.
Claims18
An outboard drive unit for marine propulsion comprised of a housing assembly for mounting on the stern of an associated watercraft for tilting movement about a generally horizontally extending transverse axis and steering movement about a generally vertically extending steering axis, an input shaft journalled for rotation about a generally horizontally longitudinally extending axis in an upper portion of said housing assembly, universal joint means at the forward end of said input shaft for driving said input shaft from a watercraft mounted engine and accommodating the trim and steering movement of said housing assembly, a drive shaft journalled for rotation about a generally vertically extending axis by said housing assembly and intersecting the axis of said input shaft, propulsion means at the lower portion of said housing assembly driven by said drive shaft for propelling the associated watercraft, a driven bevel gear affixed for rotation with said drive shaft at the upper end thereof, a pair of driving bevel gears journalled on said input shaft and enmeshed with diametrically opposed sides of said driven bevel gear, hydraulically operated clutch means for selectively coupling one of said driving bevel gears for rotation with said input shaft for driving said drive shaft in selected forward and reverse directions, hydraulic pump means contained in the upper portion of said housing and driven by the rear end of said input shaft, and valve means within the rear of said upper portion of said housing assembly for selectively pressurizing set hydraulically operated clutch means from said hydraulic pump means.
A stern drive unit for a marine propulsion comprised of a housing assembly mounted on the stern of an associated watercraft for tilting movement about a generally horizontally extending transverse axis and for steering movement about a generally vertically extending steering axis, an input shaft journalled for rotation about a generally horizontal longitudinal axis in an upper portion of said housing assembly, universal joint means at the forward end of said input shaft for driving said input shaft from a watercraft mounted engine and accommodating the trim and steering movement of said housing assembly, a drive shaft journalled in said housing assembly for rotation about a generally vertically extending axis, propulsion means at the lower portion of said housing assembly for propelling an associated watercraft, transmission means for driving said drive shaft from said input shaft and said propulsion means from said drive shaft, said transmission means including at least a pair of intermeshing gears and a hydraulicly operated clutch, a hydraulic pump driven by said input shaft for circulating hydraulic fluid, and valve means within said housing assembly for selectively communicating the fluid circulated by said pump with said hydraulic clutch for actuating said clutch and with said gears for lubricating said gears.
Dependencies are inferred from the claim text.