Working Principle of Cummins Generator MVS Governor

by Starlight Generator dieselgeneratortech

Working principle of Cummins Generator MVS Governor

On Cummins generator set diesel engine, the PT pump of its PT fuel system is equipped with an MVS full-speed governor in addition to the PTG two-pole governor. It can make the diesel engine run stably at any speed selected by the user to meet the needs of the construction machinery.

The structure of the MVS governor is shown in the figure below. The left side of the plunger is subjected to the pressure from the fuel transfer pump and through the fuel filter diesel oil. The oil pressure changes with the change of the diesel engine speed. The right side of the plunger is in contact with the governor spring plunger to withstand the spring force of the speed governing spring (including the idle speed spring and the governor spring).

When the speed regulating handle of PT pump is in a certain position, the double arm lever under it makes MVS balance the elastic force of spring with the oil pressure on the left side of plunger, so that the diesel engine can work stably at this speed. When the load of the diesel engine is reduced and the rotation speed is increased, the oil pressure on the left side of the plunger is increased, so the plunger is moved to the right, the diesel channel from the throttle valve is reduced, and the output oil pressure of the PT pump drops, and the circulating fuel injection pump amount of the fuel injection pump is also decreased accordingly to limit the increase of the diesel engine speed; On the contrary, when the load of the diesel engine increases and the rotation speed decreases, the spring force of the speed regulating spring is greater than the oil pressure on the left side of the plunger, the plunger moves to the left, and the diesel channel from the throttle valve is opened to make the output oil pressure of the PT pump rises, the circulating fuel injection amount of the fuel injection pump also increases to limit the decrease in the diesel engine speed. By changing the position of the speed regulating handle, the pre-tightening force of the speed regulating spring is changed, and the diesel engine runs stably at another speed. At idle speed, the speed-regulating spring is in a free state and does not work, and only the idle speed spring maintains stable operation at idle speed. The MVS governor is equipped with high speed and low speed limit screws to limit the extreme position of the speed regulating handle.

After the PT pump is attached with MVS governor, the throttle valve is fixed by screws during normal operation. If adjustment is required, the throttle valve is turned to change the oil pressure flowing through the throttle valve to the MVS governor, so that the amount of circulating fuel injection is changed.

The above working principle of Cummins generator governor shared by Jiangsu Starlight Power Equipments Co., Ltd., as an OEM manufacturer of Cummins generator, Starlight can provide customers with 20kw to 2500KW Cummins diesel generator sets. Contact us: sales@dieselgeneratortech.com.