Patent ID: 8449767

Claim:
An oil reservoir for a hydraulic system comprising: a substantially cylindrical reservoir housing ( 1 ) having a lower housing part ( 3 ) and a housing cover ( 4 ) which is connected to the lower housing part ( 3 ) by one of a bonded or a form-locking manner, a substantially cylindrical oil filter ( 2 ) being disposed in the reservoir housing ( 1 ), the reservoir housing ( 1 ) having an oil inlet fitting ( 6 ) and at least one oil outlet fitting ( 7 ) for connecting the oil reservoir to at least one circuit of the hydraulic system, an oil filler neck ( 8 ), closed by a cap ( 9 ), being configured on the reservoir housing ( 1 ), wherein at least one spiraling guide element ( 10 ) being disposed in the reservoir housing ( 1 ) on at least one inside wall of the reservoir housing ( 1 ), the guide element is concentrically arranged within the reservoir housing, the oil filter is concentrically arranged within the guide element and the oil inlet fitting is concentrically arranged within the oil filter such that oil is initially directed from the inlet radially outward through the oil filter, the guide element forming a circular guidance track ( 11 ) for the oil which forces the oil to perform a rotational movement, after passing through the oil filter ( 2 ) but before exiting the oil reservoir by way of the at least one oil outlet fitting ( 7 ), so as to separate air present within the oil, and the separated air exiting the oil reservoir via an air outlet opening disposed in one of a wall of the reservoir cover ( 4 ) or the cap ( 9 ) of the oil filler neck ( 8 ).