Device for supporting a trolley wire

The invention relates to a device (3', 3'') for supporting a trolley wire (4), which runs in a longitudinal direction (5), for supplying electrical energy to a rail vehicle on a supporting body (11) which is arranged above the trolley wire (4) as viewed in a vertical direction (7) running at a right angle to the longitudinal direction (5), comprising a guide rail (23) which guides a thermal expansion movement of at least the trolley wire (4) and has a first rail body (25) on which the trolley wire (4) is held in a positionally fixed manner, and a second rail body (26) which is held on the supporting body (11) in a positionally fixed manner, wherein the first rail body (25) and the second rail body (26) are guided with respect to one another via rolling elements (32).