Hydraulic Motor - Kubota u15-3 Workshop Manual

WSM U15-3

(3) Hydraulic motor

1) Function of motor
The hydraulic motor, which is an axial piston motor (rotating cylinder and swash plate type), converts
the hydraulic energy supplied from the pump to revolving movement.
2) Structure of motor and operating principle (See the figure below.)
(4) Cylinder barrel
(5) Valve plate
(6) Piston
(7) Swash plate
(8) Shaft
The pressure oil flowing in through the hydraulic valve is supplied to the valve plate (5). When the
pressure oil is supplied to the port A, the oil flows into the cylinder port, which corresponds to the port
A, in the cylinder barrel (4) and presses the piston (6). This pressing force is converted to turning
force through the swash plate (7) and the resulting turning force is transmitted to the shaft (3) spline-
coupled with the cylinder barrel (4). The return oil in the cylinder port flows out through the port B of
the valve plate (5).
In the case of reverse rotation, the pressure oil flows in through the port B and flows out through the
port A.
(a) The motor shaft and gear S2 are combined or coupled through splines
(b) Port A
(c) Port B
II-80