Abstract:
An outboard motor includes a transmission device disposed on a middle portion of a drive shaft driven by an engine. The transmission device includes a forward-reverse switching device housed in a transmission case. Lubricating oil for lubricating the forward-reverse switching device is stored in the transmission case. The transmission case has a drain hole arranged to discharge lubricating oil in the transmission case that is provided in a lower portion of a side wall and in a position in front of the drive shaft, and a drain bolt for opening or closing the drain hole. An exposed opening for exposing the drain hole is provided in an upper case that covers the transmission case. As a result, work efficiency in discharging or draining of lubricating oil is greatly improved without requiring dismantling of a main body of the outboard motor.
Abstract:
In an outboard motor, a speed reduction mechanism includes an inner gear connected with an input shaft (i.e., second output shaft), a planetary gear that meshes with the inner gear and that rolls inside the inner gear, and a sun gear that meshes with the planetary gear and that is not rotatable. A shaft portion of a carrier that supports the planetary gear, and a shaft core portion of the sun gear, preferably have a cylindrical or substantially cylindrical shape. The shaft portion of the carrier is inserted and arranged to overlap with the shaft core portion of the sun gear in a direction perpendicular or substantially perpendicular to the shaft. The output shaft (i.e., drive shaft) is inserted and coupled to the shaft portion of the carrier. Accordingly, this provides an outboard motor that makes it possible to prevent the size of a speed change device from increasing in size when a speed reduction mechanism is added.
Abstract:
A water cooling apparatus in a power transmission system of a boat propulsion system includes a transmission unit that changes the speed of an output from an engine and then transmits the output to a propeller shaft. The transmission unit includes a cylindrical transmission case with an axis extending vertically, a transmission device housed in the transmission case and arranged to change the speed of an input, and a cooling water passage formed in the transmission case for flowing cooling water. In the plan sectional view of the transmission unit, the cooling water passage is formed in at least one of a side portion or a rear portion of the transmission case. As a result, strain on a rear portion of a hull that supports a boat propulsion unit is prevented and minimized, while a transmission unit is sufficiently cooled with cooling water.
Abstract:
A power transmission system for a marine propulsion unit includes a case arranged to be supported on a hull; a propeller supported at the lower end portion of the case for rotation about an axis extending in a fore-and-aft direction; a transmission housed in the case and having an axis with planetary gear trains extending vertically to receive an output from an engine, and change the speed of the output prior to transmission thereof; and an interlocking device arranged to receive the output from the transmission and transmit the output to the propeller. A speed reduction device is arranged such that it is interposed between the transmission and the interlocking device, receives the output from the transmission, and decelerates the output to transmit it to the interlocking device. This arrangement reduces the weight of a transmission unit in a power transmission system of a marine propulsion unit and decreases an external size of the transmission unit.
Abstract:
A transmission device includes hydraulic type transmission mechanisms arranged to change the speed or the direction of rotation of an engine, and hydraulic pressure control valves arranged to control hydraulic pressure supplied to the hydraulic type transmission mechanisms. The hydraulic pressure control valves are disposed on one side or the other side in the watercraft width direction. The transmission device provides an outboard motor capable of securing cooling characteristics of a hydraulic pressure control valve without incurring complexity in structure and increase in cost.
Abstract:
An outboard motor includes an engine that generates power and a transmission device arranged to change the speed of rotation of the engine and to transmit the rotation to a propeller. The transmission device includes a planetary gear type transmission mechanism arranged to shift to any of a plurality of speed positions, and the planetary gear type transmission mechanism is controlled to shift such that a sun gear and planetary gears unitarily rotate when a speed position is a normally used speed position. The outboard motor achieves a reduction in load normally caused by engagements between gears in a normally used speed position and also achieves significant improvement in durability of the gears.
Abstract:
A power transmission system of a marine propulsion system includes a transmission arranged to change the speed of an output from an engine and then to transmit the output to a propeller shaft. Wet-type multi-plate clutches provided in the transmission include a plurality of clutch plates fitted to a clutch rotating body for axial movement with the clutch rotating body. The clutch rotating body includes an oil reservoir in its inner bottom portion and arranged to hold lubricating oil and a peripheral wall arranged to cover the oil reservoir from the radial outside and fit to each of the clutch plates to permit axial movement of the clutch plates. Communicating holes are arranged on the peripheral wall such that they communicate the oil reservoir side to the outside of the clutch rotating body in the radial direction. The above arrangement provides an engine wherein, even at startup of the engine in the marine propulsion system, each clutch plate of the wet-type multi-plate clutch in the power transmission system is sufficiently lubricated.
Abstract:
A boat propulsion unit minimizes a shock upon switching of an engagement state of a clutch mechanism. The boat propulsion unit includes an upper clutch mechanism that is arranged on an axis of a lower drive shaft and that can be switched between an engagement state (first engagement state) in which driving force of an engine is transmitted to a downstream side, and a half clutch state in which the driving force of the engine is reduced and then is transmitted; and an advance-reverse drive that is disposed on an axis of a front propeller drive shaft and a rear propeller drive shaft and that can be switched between a forward travel engagement state and a reverse travel engagement state (second disengagement state) in which the driving force of the engine is transmitted to a front propeller and a rear propeller in order to propel a boat, and a disengagement state (second disengagement state) in which the driving force of the engine is disengaged.
Abstract:
A marine vessel propulsion unit includes an engine, a drive shaft, a single propeller shaft, a single propeller, and a planetary gear mechanism. The drive shaft is arranged to extend vertically. The propeller shaft is arranged to extend in a direction intersecting the drive shaft. The rotation of the engine is transmitted to the propeller shaft via the drive shaft. The propeller is arranged to rotate together with the propeller shaft. The planetary gear mechanism is arranged at the front relative to the drive shaft and coaxial to a central rotation axis of the propeller shaft. The planetary gear mechanism is arranged to decelerate the rotation from the drive shaft and transmit the decelerated rotation toward the propeller shaft.
Abstract:
An outboard motor includes a drive shaft including a pinion gear arranged at one end of the drive shaft, a first driven gear engaged with the pinion gear, a second driven gear engaged with the pinion gear, a first propeller shaft connected to a second propeller, a second propeller shaft connected to a first propeller, and a shift change mechanism arranged to selectively engage the first driven gear with the second propeller shaft, and to selectively engage the second driven gear with the first propeller shaft and with the second propeller shaft.