A pump supplying reservoir oil reservoired in an input case to devices to be supplied with the reservoir oil and a filter for filtering the reservoir oil circulating in the input case are provided in the input case. A pump supplying reservoir oil in each of left and right axle cases to a hydraulic continuously variable transmission provided in each of the axle cases and a filter filtering the reservoir oil circulating in each of the left and right axle cases are provided in each of the left and right axle cases.