The present invention relates to a system (S) for supporting and tensioning chains or other transmission and/or conveyance elements installed on a machine (M). The system (S) includes a guide device (D) for the gripper and conveyor chain (M1), in which the movement of the guide device (D) corresponds to the movement of the bearings (M2). The guide device (D) includes an element (D1) for supporting and protecting a longitudinal contact element (D2), in which the support and protection element (D1) is coupled to the bearings (M2), while the longitudinal contact element (D2) is used to guide and constantly pressurize an appropriate segment of the gripper and conveyor chain (M1). The system (S) also includes an automatic tensioning unit (C) provided with a pressure element (C1).