Woodward UG 8 Governor

  Woodward UG 8 Governor

Description

The Pneumatic Speed Adjustment device makes it possible to adjust speed pneumatically from a location remote from the prime mover. It is mounted on top of the UG-8 Lever governor in a separate housing. The housing also accepts Woodward’s standard shutdown devices such as solenoid, pneumatic, or low lube units. The Manual Speed Setting Screw allows for on-site setting of the governor should the pneumatic pressure be lost.

Operation

Two styles of plumbing are available to carry governor pressure oil to the pneumatic head.

Internally plumbed units carry pressure oil from the controlet inside the governor to the speed-setting head. The internally plumbed units require a special pilotvalve bushing to regulate the amount of oil supplied to the head and a specially machined controlet to accept the plumbing connection. The governor is normally returned to the factory for installation of the internally plumbed speed-setting head. Externally plumbed units receive pressure oil from the governor base through an external pipe. An orifice in the cover regulates the amount of oil available to the speed-setting head. The externally plumbed unit may be installed on a lever governor in the field. Installation instructions are included with a conversion kit.

The speed setting air signal is connected to the bellows (5). Lever (16) balances between the force of the bellows and the force of spring (13) under the speed setting piston (11). When the bellows force is more than the spring force, the lever rotates about pin (15). The left end of the lever moves up to close nozzle (25). Oil pressure increases on the speed setting piston, moving it down and increasing the spring load on the lever. When the spring force exceeds the value required to balance the lever against the bellows force the lever rotates counterclockwise, releasing oil through the nozzle. Oil pressure stops increasing and piston movement stops. 

The governor will go to minimum fuel or shutdown in case of failure or interruption of the pneumatic signal. The Manual Speed Setting Screw will act as a minimum speed stop if it is not backed out of the way during normal operation. Should the pneumatic pressure fail, the manual speed setting screw may be used to set the speed of the governor mechanically. Speed setting increases when the screw is turned clockwise and decreases when it is turned counterclockwise. The screw is normally locked with the wing nut at minimum speed setting position with visible clearance between the speed setting screw and the speed setting lever. The wing nut provides positive lock of the speed setting screw. When the pneumatic signal is used for setting the speed, the screw adjustment must be in the minimum speed setting position. Failure to follow this instruction increases the pneumatic speed setting by the amount of the manual setting. The speed setting shaft must be free to rotate between high and low speed stops during pneumatic operation.