Drive assembly for a marine dual-propeller drive unit

A drive assembly for a marine dual-propeller drive unit, said drive assembly comprising:

• a housing,
• an outer drive shaft assembly comprising an outer drive shaft comprising an outer end portion for holding a first propeller and an axially opposite inner end portion for connection to a gear or a motor,
• an inner drive shaft assembly comprising an inner drive shaft comprising and outer end portion for holding a second propeller and an axially opposite inner end portion for connection to a gear or a motor, and a lubrication system,
• said outer drive shaft comprising a through central opening extending along a rotational axis of the outer drive shaft,
• said inner drive shaft extending co-axially with the outer drive shaft, through the central opening of the outer drive shaft,
• wherein a plurality of primary bearings are mounted in the central opening for rotationally supporting the inner drive shaft in the outer drive shaft such that the inner drive shaft and the outer drive shaft are rotatable relatively each other about the rotational axis,
• wherein a plurality of secondary bearings are mounted around the outer drive shaft for rotatably supporting the outer drive shaft in the housing such that the outer drive shaft is rotatable relatively the housing about the rotational axis,
• said lubrication system comprising a liquid lubricant pump, and a primary fluid channel comprising a primary inlet fluidly connected to the liquid lubricant pump for receiving pressurized liquid lubricant, and at least one primary outlet emanating in the central opening of the outer drive shaft,
• said outer drive shaft comprising at least one secondary fluid channel extending from a secondary inlet facing the central opening to a secondary outlet facing an outer space between the housing and a radial outside of the outer drive shaft,
• said outer drive shaft being provided with at least one protrusion protruding radially inwards from an inner surface of the outer drive shaft,
• said secondary inlet of the secondary fluid channel being provided in said at least one protrusion at a first radial level offset radially inwards from the inner surface of the outer drive shaft such that liquid lubricant at said first radial level is able to lubricate at least some of the primary bearings.