초록 ▼

A driveshaft housing structure adapted for interposition between the powerhead and the gearcase of an outboard marine propulsion system. The driveshaft housing structure is integrally formed, and provides a driveshaft passage, a cooling water intake conduit arrangement, an exhaust discharge passage,

A driveshaft housing structure adapted for interposition between the powerhead and the gearcase of an outboard marine propulsion system. The driveshaft housing structure is integrally formed, and provides a driveshaft passage, a cooling water intake conduit arrangement, an exhaust discharge passage, a cooling water discharge passage, and an exhaust idler relief system. The listed components are formed of a series of walls which comprise a part of the integrally formed driveshaft housing structure, to provide a unitary one-piece cast structure eliminating the need to assemble an adaptor plate to the upper end of a driveshaft housing, as in the prior art. The unitary one-piece structure is constructed from lost foam casting of an assembled pattern which allows the various components to be integrally formed with each other.

대표청구항 ▼

In a marine propulsion system including a powerhead and a lower unit, wherein the powerhead includes an internal combustion engine having a rotatable output member, a cooling water inlet, and an exhaust discharge, and wherein the lower unit includes a housing, a propeller rotatably mounted to the ho

In a marine propulsion system including a powerhead and a lower unit, wherein the powerhead includes an internal combustion engine having a rotatable output member, a cooling water inlet, and an exhaust discharge, and wherein the lower unit includes a housing, a propeller rotatably mounted to the housing, and a rotatable power transfer arrangement disposed within the housing and interconnected with the propeller, and further comprising a driveshaft interposed between the rotatable engine output member and the lower unit power transfer arrangement for rotatably driving the propeller in response to operation of the engine, the improvement comprising an integral unitary structure adapted for interposition between the powerhead and the lower unit, comprising: an upper substantially horizontal mounting surface to which the powerhead is mounted, and including an exhaust opening in communication with the engine exhaust discharge; a lower substantially horizontal mounting surface to which the lower unit is mounted; an external housing extending between the upper and lower surfaces and including walls defining a longitudinally extending internal cavity; first closed wall structure located within the internal cavity and defining a downwardly extending exhaust passage in communication with the upper surface exhaust opening; second closed wall structure located within the internal cavity and defining a substantially vertical driveshaft passage extending between the upper surface and the lower surface to accommodate the driveshaft; an exhaust idle relief system, including at least one exhaust idle relief chamber, located within the internal cavity below the upper horizontal mounting surface, wherein the upper extent of the exhaust idle relief chamber is defined in part by at least one walls extending transverse to the longitudinal axis of the internal cavity; an exhaust idle discharge outlet formed in one of the housing walls in communication with the exhaust idle relief chamber; and an exhaust idle passage formed in the first closed wall structure for discharging exhaust into the exhaust idle relief chamber during idle operation of the marine propulsion system; wherein the upper surface, the lower surface, the housing, the first and second closed wall structures and the transverse walls defining the upper extent of the exhaust idle relief chamber comprise a unitary integrally formed structure.