Section XV. HYDRAULIC SYSTEM
The steering roll of the road roller is hydraulically operated. Hydraulic oil is stored in the hydraulic tank attached to the
right side of the roller frame. A hydraulic pump is mounted on the cross-member of the roller frame, on the left side of the
engine. The pump is driven by a V-belt from the crankshaft pulley. The hydraulic pump pressure is regulated by the
regulator valve, which reduces the pressure to zero when the valve is closed. When the operating valve is opened, the
pump immediately pumps the required pressure to the hydraulic cylinder. The hydraulic steering cylinder is connected with
the king pin on the steering roll yoke and operates the movement of the steering roll to the right or left.
a. General. The hydraulic pump (9) is of vane type and delivers a given amount of oil per minute to the hydraulic
system as demanded by any working pressure up to 1,000 pound per square inch. The pump is mounted on the adjusting
base (11) and attached to the cross-member (1) of the roller frame. The belt (14) connects the hydraulic pump pulley (13)
with the crankshaft pulley (2) and drives the pump. The pump does not require any lubrication and there are no
adjustments required on the pump. The belt tension is adjusted by means of the adjusting screw (3).
Adjusting screw bracket
Mounting bracket screw
Figure 64. Hydraulic pump drive.