A marine drive unit with a bi-directional integrated oil channel

Abstract

A drive unit for a marine vessel has an elongated drive unit body arranged to support a propeller shaft at a lower end and a motor interface at an upper end of the drive unit body, where the propeller shaft extends in a center plane of the drive unit. A drive shaft is arranged extending from the motor interface through the drive unit body to a bevel gear arrangement arranged to rotatably connect the drive shaft to the propeller shaft. The bevel gear arrangement has a first bevel gear arranged on the drive shaft and a second bevel gear arranged on the propeller shaft to cooperate with the first bevel gear. The drive unit has an oil channel with an aperture arranged to steer a flow of oil to flow away from the propeller shaft upwards through the drive unit body.

1 . A drive unit for a marine vessel,
 the drive unit comprising an elongated drive unit body arranged to support a propeller shaft at a lower end and a motor interface at an upper end of the drive unit body, where the propeller shaft extends in a center plane of the drive unit,   where a drive shaft is arranged extending from the motor interface through the drive unit body to a bevel gear arrangement arranged to rotatably connect the drive shaft to the propeller shaft,   the bevel gear arrangement comprising a first bevel gear arranged on the drive shaft and a second bevel gear arranged on the propeller shaft to cooperate with the first bevel gear,   the drive unit further comprising an oil channel arranged to allow a flow of oil to flow away from the propeller shaft through the drive unit body in direction of the motor interface,   the oil channel having an input aperture comprising a first aperture part and a second aperture part arranged separated by the center plane and facing the second bevel gear,   where when the second bevel gear rotates, the second bevel gear pushes oil up into one of the first aperture part and second aperture part,   where the input aperture is arranged in connection to the second bevel gear such that an upwards flow of oil is generated through the first aperture part if the propeller shaft is rotated in a clockwise direction, and an upwards flow of oil is generated through the second aperture part if the propeller shaft is rotated in a counter-clockwise direction.   
     
     
         2 . The drive unit according to  claim 1 , where the oil channel is separated into first and second oil conduits by a separating wall, where the first aperture part opens up into the first oil conduit and the second aperture part opens up into the second oil conduit. 
     
     
         3 . The drive unit according to  claim 2 , where the separating wall is aligned with the center plane. 
     
     
         4 . The drive unit according to  claim 1 , where the oil channel has an output aperture arranged to eject the flow of oil in connection to the motor interface. 
     
     
         5 . The drive unit according to  claim 1 , where the motor interface comprises a planetary gear arrangement. 
     
     
         6 . The drive unit according to  claim 1 , comprising an oil return channel extending from the motor interface to a port arranged facing the drive shaft. 
     
     
         7 . The drive unit according to  claim 1 , where an oil reservoir is formed in the drive unit body in connection to the second bevel gear. 
     
     
         8 . The drive unit according to  claim 1 , where ribs, protruding buttons, or a chevron pattern is formed on an internal wall of the oil channel. 
     
     
         9 . The drive unit according to  claim 1 , where the drive unit body is at least partly formed in a Manganese bronze alloy or NiBrAl. 
     
     
         10 . The drive unit according to  claim 1 , where the outer surface of the drive unit is uncoated such that the material of the drive unit body makes direct contact with the surrounding water. 
     
     
         11 . The drive unit according to  claim 1 , where the oil channel extends in a back part of the drive unit body, to the rear of the drive shaft in a travelling direction of the marine vessel. 
     
     
         12 . The drive unit according to  claim 1 , where the input aperture is positioned adjacent and radially outside the second bevel gear. 
     
     
         13 . The drive unit according to  claim 1 , where the oil is pushed up into one of the first aperture part and second aperture part by the teeth of the second bevel gear. 
     
     
         14 . A marine vessel comprising a drive unit according to  claim 1 .