PURPOSE: To enlarge work machine containing space at a middle part, and restrict fuel consumption by installing pipings to connect a hydraulic motor to an axle case supporting a steered wheel, and a hydraulic pump connected to a shaft of a driving wheel speed changing transmission mechanism to a center section of a continuously variable transmission respectively.

CONSTITUTION: A hydraulic motor M to drive a front wheel 15 is installed on an axle case 1 supporting the freely steered front wheel 15, and an oil pressure type continuously variable transmission H to drive rear wheels is disposed at the front of an axle case 2 supporting rear wheels 14. A variable displacement hydraulic pump 3, a fixed capacity hydraulic motor 4, and a variable displacement hydraulic pump P for driving the front wheel 15 are provided at a center section of the oil pressure type continuously variable transmission H, and these are connected to each other by piping members 32 by fluid. Rotation of an engine E is inputted from a crank shaft 12 through a joint shaft 13 to an input shaft 11 of the oil pressure type continuously variable transmission H, and a mid mower R is disposed in space at a middle part, thereby work machine containing space can be secured at the middle part, and fuel consumption can be restricted in simple constitution.