Silent-running internal combustion motor power unit

Claim 1

A sound absorption chamber device for a silent-running motor power unit, comprising a casing having at least one inlet and one outlet for cooling air and/or air of combustion for a motor unit, said casing containing labyrinthine air passages formed by side, top and bottom walls lined with acoustic absorption material, at least one side wall comprising an inner side wall and outer side wall, said inner side wall being situated inside said, outer side wall, each of said inner and outer side walls limiting a part of an air passage and having at least one portion in the form of a panel or door which is horizontally movable in relation to said portion of the other one of the inner and outer side walls and other moving portions of the casing so as to form side wall portions which are horizontally movable inside one another, said inner and outer side wall portions being displaceable without obstructing one another and being operable to expose an opening from the space outside the power unit through the side walls into the motor unit to make it accessible for servicing, said inner and outer side wall portions being pivotable about a joint at a side edge thereof, said inner side wall portion having vertical pivoting axis being displaced from a vertical pivoting axis of said outer side wall portion in a direction perpendicular to said axes, such that the inner side wall portion is unobstructed when displaced, and a fan being arranged to create an airflow through the inlet passage, a motor power compartment, a radiator of the motor power unit and the outlet passage, respectively, wherein an air intake of the motor unit is arranged in said airflow upstream of said radiator.