System having a screening body and an unbalance drive for screening bodies, which exert vibrations, of a screening machine having a conveying direction of the screening material, in particular mineral crushing materials, such as, for example, oil sand, wherein - a drive motor and a synchronous gear mechanism in operative connection therewith having output shafts (4, 5) which rotate oppositely to one another in pairs with the same speed of rotation are provided, - the drive motor and the synchronous gear mechanism are mounted in a stationary manner separately from the screening body, laterally next to the screening body, and do not co-vibrate therewith, - shafts (19, 20), which are arranged on the screening body horizontally, parallel to one another, and transversally to the conveying direction of the screening material, are connected to the output shafts (4, 5) in each case by means of rotationally fixed articulated shafts (4' 5') and have unbalanced elements (15, 16, 17) directly fastened thereto in the horizontal direction between the side walls of the screening body, - the shafts (19, 20) are supported between the unbalance elements (15, 16, 17) by means of bearing elements (18, 18') on crossmembers connected to the side walls, - the shafts (19, 20) are formed from shaft portions and compensating couplings connecting the latter in a rotationally fixed manner, and - a shaft portion forms, together with the unbalance elements (15, 16, 17) and bearing elements (18, 18') arranged thereon, an unbalance module, characterized in that - the unbalance module includes three unbalance elements (15, 16, 17) which are fastened on a shaft portion, wherein the bearing elements (18, 18') are positioned between the unbalance elements (15, 16, 17), wherein two unbalance elements (15, 17) are arranged outside a housing of the unbalance elements. - a drive motor and a synchronous gear mechanism in operative connection therewith having output shafts (4, 5) which rotate oppositely to one another in pairs with the same speed of rotation are provided, - the drive motor and the synchronous gear mechanism are mounted in a stationary manner separately from the screening body, laterally next to the screening body, and do not co-vibrate therewith, - shafts (19, 20), which are arranged on the screening body horizontally, parallel to one another, and transversally to the conveying direction of the screening material, are connected to the output shafts (4, 5) in each case by means of rotationally fixed articulated shafts (4' 5') and have unbalanced elements (15, 16, 17) directly fastened thereto in the horizontal direction between the side walls of the screening body, - the shafts (19, 20) are supported between the unbalance elements (15, 16, 17) by means of bearing elements (18, 18') on crossmembers connected to the side walls, - the shafts (19, 20) are formed from shaft portions and compensating couplings connecting the latter in a rotationally fixed manner, and - a shaft portion forms, together with the unbalance elements (15, 16, 17) and bearing elements (18, 18') arranged thereon, an unbalance module, - the unbalance module includes three unbalance elements (15, 16, 17) which are fastened on a shaft portion, wherein the bearing elements (18, 18') are positioned between the unbalance elements (15, 16, 17), wherein two unbalance elements (15, 17) are arranged outside a housing of the unbalance elements.