The tension roller device provides a support shaft, a securing plate that is fixed on the support shaft, an eccentric hub that is free to rotate relative to the shaft, and a spring that is arranged axially between the eccentric hub and the securing plate. The support shaft includes a stop surface, against which the securing plate is axially supported, and which is delimited radially on the outer side by a circular outer edge. At least one opening is formed in the securing plate, in order to delimit a tongue for radial centering of the spring. The opening is situated radially on the outer side relative to the circular outer edge of the stop surface of the support shaft.