A device for feeding oil to a seat of a bearing (5) that supports a rotatable shaft (3) includes an annular oil reservoir (14) surrounding a seat of the bearing (5), an oil pump (8) having two spindles (10, 11) with oppositely extending, respectively feeding channels, oil delivery conduit means (20); and oil return conduit (24, 25, 26, 27) provided on axially opposite sides of the bearing seat.