A liquid cooling device with a main body has a planar surface for the arrangement of a power semiconductor device. This main body has a first end face and a second end face opposite said first one, and a plurality of tubular cooling recesses extending from the first to the second end face. A first swirling element arranged in an associated cooling recess, wherein the swirling element has an operative section arranged within the associated cooling recess and a locking section, wherein the locking section interacts with a locking abutment and/or with a further swirling element, and therefore prevents rotation of the operative section in the associated recess.