Connection system of a transmission rod for solar trackers

A connection system of a transmission rod (1) for solar trackers with at least two rows of solar panels (2) the transmission rod (1) of which connects a main rotation shaft (3) with a motorised rotation module (4) to a driven shaft (3′) with a rotation module (4′) without a motor, said transmission rod (1) being connectable to the rotation modules (4, 4′) by means of universal joints (5, 5′) that are fastened to the connection output (4.1, 4.1′) of the rotation module (4, 4′), wherein the universal joint (5, 5′) has at one connection end (5.1, 5.1′) corresponding to the connection output (4.1, 4.1′) of the rotation module (4, 4′), and at the other end of the universal joint (5, 5′) corresponding to a tubular connection output (5.2, 5.2′) with a polygonal cross section for connection to the transmission rod (1), the transmission rod (1) correspondingly having a polygonal configuration, and with a first end (1.1) of the transmission rod (1) longitudinally slidably connectable to the connection output (5.2) of a first universal joint (5) and with a second end (1.1′) of the transmission rod (1) fixedly connectable to the connection output (5.2′) of a second universal joint (5′).