The invention relates to a downwardly conveying conveyor installation, in particular belt-conveyor installation, having a circulating web-like, chain-like or circular conveying means for receiving conveyable articles and transporting the conveyable articles along a conveying path from a geodetically higher location to a geodetically lower location; having a motor drive which causes the conveying means to circulate; having a hydrodynamic coupling comprising a drive-side pump wheel and an output-side turbine wheel, which together form a toroidal operating space which is filled, or can be filled, with operating medium; the pump wheel and the turbine wheel each have a blade arrangement with a multiplicity of blades which are arranged opposite one another such that the blades of the pump wheel are flush with the blades of the turbine wheel.; The invention is characterized in that the blades of the pump wheel, as seen in a circumferentially directed section through the operating space, are positioned obliquely, in the direction from the rotor base to the blade tip, counter to the driving direction of rotation of the pump wheel, and the blades of the turbine wheel are positioned obliquely, in the direction from the rotor base to the blade tip, in the driving direction of rotation of the turbine wheel.