Governor in diesel engine

⬅Engine construction and Operation 

Theory of Governor
Variable speed Hydraulic Governor
Governor Characteristics
Speed Droop
Governor Maintenance

Electronic Governor➡

Theory of Governor.

Theory of gov

Variable speed Hydraulic Governor.

hyd gov

Governor Characteristics.

gov char

Speed Droop.

speed droop

Governor maintenance.

In addition to problems inside the Governor, the following external conditions can also affect it
a. Tension of the chain drive (in case of engines having chain drive).
b. Oil pressure fluctuation (in case of separate lube oil supply).
c. Drop in control air pressure ( in case of pneumatic type).
d. Sluggishness in the regulating gear.
It is most important to keep the Governor oil absolutely clean, since the complex moving parts inside can seize with dirt in the oil. Change the oil at the specified intervals, with the correct grade, as given in the manual. The oil usually has anti-foam and detergent additives. The viscosity index must be high and the viscosity is normally in the range of 22 to 63 Cst at 40°C, In case of mechanical governors it is important to lubricate all linkages to keep from seizing and rusting. The pin holding the flyweights tends to wear and requires renewal. The compensating needle valve setting needs to  be checked, if any hunting is observed, or if the governor operation has become excessively sluggish.
Overspeed trip
An over-speed trip is required to be separate from the Governor, and needs to be periodically tested, to ensure that it is functioning correctly and that the engine has been brought to a stop.
The electronic Overspeed Protection System monitors three individual magnetic pickups to provide Overspeed protection. This system replaces mechanical over-speed devices, especially in high-speed applications when a mechanical over-speed device becomes unreliable.
Ease of calibration and testing, accuracy, and repeatability are the benefits of this system. It uses digital speed-sensing technology to change the setpoint by programming the value from the touch panel on the front.
To ensure its accuracy and functionality, each of the three speed-sensing units can be individually tested while the prime mover is running, using the integral frequency generator.
A key lock prevents programming and testing by unauthorized personnel. Accuracy is achieved through the three digital units which sense and indicate speed to within 0.1 %.
No mechanical over-speed device can match this accuracy level. The system's two-out-of-three voting scheme assures that the device will not shut down the prime mover because of transient conditions or conditions affecting only one of the three isolated units.


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Electronic Governor