Patent ID: 8100105

Claim:
A balance unit mass balancing for an internal combustion engine of a motor vehicle, comprising: a housing part having at least one assembly opening which communicates with an introduction passage extending perpendicular to a longitudinal axis of the balancing shaft; at least one balance shaft journaled in the housing part, the balance shaft having at least one balance weight; and a first gear meshingly engaged with a second gear, at least one of the first and second gears introduced into an interior portion of the housing part through the assembly opening and the introduction passage such that the first and second gears are arranged sequentially within the introduction passage; wherein the housing part continuously surrounds the periphery of the assembly opening in one piece, with a length of the assembly opening at an outer side of the housing part in a plane normal to the longitudinal axis of the balance shaft being larger than a diameter of the at least one of the first and second gears, but being smaller than a sum of the diameters of the first and second gears.