A gear unit with fan assembly, wherein the fan assembly has a fan impeller , a cowl and a grille, wherein the fan impeller is connected non-rotatably to the input shaft of the gear unit, wherein the fan cowl is fastened to a holding frame which is fastened to the housing of the gear unit, wherein the grille is formed of two grille parts , wherein the cowl is formed of two cowl parts, wherein each grille part is connected to each of the two cowl parts , characterised in that - the grille parts are each formed as a polygon such that the contacting face between the respective grille part and the respective cowl part in each case is composed of planar face pieces, - or in that between the two grille parts a first parting line is formed as a straight section or as two straight sections which lie flush with each other, with between the two cowl parts a second parting line being formed as a plane curve composed of straight section portions, with the first parting line and the axis of rotation of the input shaft spanning a first plane, with the second parting line and the axis of rotation of the input shaft spanning a second plane, with the second plane being oriented perpendicularly or at least being at an angle of between 30° and 90° to the first plane. wherein the fan assembly has a fan impeller , a cowl and a grille, wherein the fan impeller is connected non-rotatably to the input shaft of the gear unit, wherein the fan cowl is fastened to a holding frame which is fastened to the housing of the gear unit, wherein the grille is formed of two grille parts , wherein the cowl is formed of two cowl parts, wherein each grille part is connected to each of the two cowl parts , characterised in that - the grille parts are each formed as a polygon such that the contacting face between the respective grille part and the respective cowl part in each case is composed of planar face pieces, - or in that between the two grille parts a first parting line is formed as a straight section or as two straight sections which lie flush with each other, with between the two cowl parts a second parting line being formed as a plane curve composed of straight section portions, with the first parting line and the axis of rotation of the input shaft spanning a first plane, with the second parting line and the axis of rotation of the input shaft spanning a second plane, - the grille parts are each formed as a polygon such that the contacting face between the respective grille part and the respective cowl part in each case is composed of planar face pieces, - or in that between the two grille parts a first parting line is formed as a straight section or as two straight sections which lie flush with each other, with between the two cowl parts a second parting line being formed as a plane curve composed of straight section portions, with the first parting line and the axis of rotation of the input shaft spanning a first plane, with the second parting line and the axis of rotation of the input shaft spanning a second plane, with between the two cowl parts a second parting line being formed as a plane curve composed of straight section portions, with the first parting line and the axis of rotation of the input shaft spanning a first plane, with the second parting line and the axis of rotation of the input shaft spanning a second plane, with the second plane being oriented perpendicularly or at least being at an angle of between 30° and 90° to the first plane. <EOS>