Outboard motor

Abstract

A power transmitting portion of an outboard motor has a power transmitting shaft connected to an output shaft of an engine to rotate together therewith, an oil pump disposed on the power transmitting shaft, and a driving force acquisition mechanism arranged to acquire driving force from the power transmitting shaft. The power transmitting portion is able to provide an outboard motor capable of ensuring a pump discharge amount without incurring an increase in the pump size and the oil amount.

1 . An outboard motor comprising:
 an engine arranged to generate power including a vertically oriented crankshaft; and   a transmission device connected to the crankshaft and arranged to change a speed of rotation of the engine and transmit the rotation to a propeller; wherein   the transmission device includes a power transmitting portion connected to the crankshaft and a speed changing portion connected to the power transmitting portion; and   the power transmitting portion includes a power transmitting shaft connected to an output shaft of the engine to rotate together therewith, and an oil pump disposed on the power transmitting shaft.   
     
     
         2 . The outboard motor according to  claim 1 , wherein the power transmitting portion includes:
 a driving force acquisition mechanism arranged to acquire driving force from the power transmitting shaft;   a first housing;   a second housing housed arranged in the first housing and arranged to house the oil pump; and   a third housing connected to the first housing and arranged to house the driving force acquisition mechanism.   
     
     
         3 . The outboard motor according to  claim 2 , wherein a relief passage arranged to fluidly connect an oil discharge passage and an oil drawing passage together is defined in the second housing, and a relief valve which opens when pressure in the relief passage exceeds a predetermined value is interposed in the relief passage. 
     
     
         4 . The outboard motor according to  claim 3 , wherein the oil discharge passage and the oil drawing passage are provided on one side in a watercraft width direction of a straight line extending in a traveling direction through the power transmitting shaft.