Woodward UG-10 Dial, Installation And Operation Manual, Page: 16 / 62

UG Dial Governor Manual 03040
10 Woodward
Chapter 3.
Principles of Operation
Introduction
Basic UG operation is similar for all types. The only difference is in the method of
setting the speed. Auxiliary devices provide different functions but do not alter the
basic operation of the governor.
Along with the text, a schematic diagram (Figure 3-1) is provided for visual
means of understanding the operation of the UG Dial governor. This schematic
shows a basic design and does not include any auxiliary equipment.
Component Description
Before getting into the operation of the UG, a brief description of the components
will facilitate understanding the operation.
Oil Pump
The purpose of the oil pump (14) is to provide oil pressure for the governor.
The pump gets its oil from the self-contained sump (15). The oil pump is a
positive displacement gear pump with four check valves (13) for either direction
of rotation. One pump gear is part of the rotating bushing, and the other is part of
the laminated drive. The rotating bushing is driven by the governor drive shaft
which is driven by the prime mover. As the bushing rotates, it rotates the
laminated drive. The oil pump gears can be driven either clockwise or
counterclockwise.
Oil flow is directed through the check valve system into the accumulator system
(11).
Accumulator
The purpose of the accumulator (11) is to store oil under pressure for the
operation of the UG governor. The accumulator (two cylinders) also acts as a
pressure relief valve if oil pressure increases above 827 kPa/120 psi (UG-5.7 and
UG-8) or 1034 kPa/150 psi (UG-10).
The accumulator (11) consists of two spring loaded pistons. Oil is pumped into
the cylinders and pressure is increased as the accumulator springs are
compressed. When the oil pressure exceeds 827 kPa/120 psi (UG-5.7 and
UG-8), or 1034 kPa/150 psi (UG-10), oil is released back to sump through a relief
port (12) in each cylinder.
Oil flows from the accumulator through passages to the top of the power piston
and to the pilot valve system.