Drive roller assembly for a conveyor system, the drive roller assembly comprising: a drive roller having a longitudinal axis, the drive roller comprising a roller body and a shaft, the shaft having first and second axial end portions (14a, 14b), the drive roller being rotatable around the longitudinal axis; a support structure for rotatably supporting the drive roller, the support structure comprising support means for rotatably supporting the second axial end portion of the shaft, wherein the support means is adapted to be detachably attached to an attachment portion of said support structure to maintain said drive roller rotatably supported on said support structure when attached and to allow said drive roller to be removed from said support structure when detached; drive means for rotatably driving said drive roller; and comprising coupling means for rotatably coupling said first axial end portion of the shaft and said drive means in an axially engaged condition of said coupling means in which said drive roller is in rotatable engagement with said drive means and for axially releasing the engagement of said first axial end portion of the shaft and the drive means in an axially disengaged condition of said coupling means, wherein the coupling means comprises a first coupling member rotatably connectable to said drive means and a second coupling member provided on said first axial end portion of the shaft; characterized in that said second coupling member is integrally provided with said first axial end portion of the shaft of the drive roller and comprises a recess that is recessed in the direction of the longitudinal axis and wherein said first coupling member comprises a first axial end portion in the direction of its longitudinal axis, wherein said first axial end portion of the first coupling member comprises a protrusion that is complementary to said recess, and said recess and said protrusion are adapted to be engaged with each other, thereby enabling rotational coupling of said first axial end portion of the shaft of the drive roller and said drive means. a drive roller having a longitudinal axis, the drive roller comprising a roller body and a shaft, the shaft having first and second axial end portions (14a, 14b), the drive roller being rotatable around the longitudinal axis; a support structure for rotatably supporting the drive roller, the support structure comprising support means for rotatably supporting the second axial end portion of the shaft, wherein the support means is adapted to be detachably attached to an attachment portion of said support structure to maintain said drive roller rotatably supported on said support structure when attached and to allow said drive roller to be removed from said support structure when detached; drive means for rotatably driving said drive roller; and comprising coupling means for rotatably coupling said first axial end portion of the shaft and said drive means in an axially engaged condition of said coupling means in which said drive roller is in rotatable engagement with said drive means and for axially releasing the engagement of said first axial end portion of the shaft and the drive means in an axially disengaged condition of said coupling means, wherein the coupling means comprises a first coupling member rotatably connectable to said drive means and a second coupling member provided on said first axial end portion of the shaft; characterized in that said second coupling member is integrally provided with said first axial end portion of the shaft of the drive roller and comprises a recess that is recessed in the direction of the longitudinal axis and wherein said first coupling member comprises a first axial end portion in the direction of its longitudinal axis, wherein said first axial end portion of the first coupling member comprises a protrusion that is complementary to said recess, and said recess and said protrusion are adapted to be engaged with each other, thereby enabling rotational coupling of said first axial end portion of the shaft of the drive roller and said drive means.