Debugging Method for PT Oil Pump of Cummins Generator Set 1

The Cummins N series and NH series diesel engines adopt PT diesel engines, including PT-G pump system governor, PT-R pump pressure regulator, etc.

The main characteristics of the Cummins generator PT pump diesel system are: in the Cummins PT diesel system, the production pressure, timing distribution, and fuel regulation of diesel are all carried out in the fuel pump and injector; In the diesel system of the fuel pump and injector, diesel generates high pressure, time distribution, and diesel control in the fuel pump and injector. Only 20% of diesel enters the combustion chamber, while the rest is cooled and lubricated into the fuel tank. In the diesel engine system, the PT fuel pump outputs low-pressure oil without high-pressure fuel pipes and high-speed downpressure waves. In addition, the fuel injector piston has a fast deceleration, a large nozzle size, and a maximum injection pressure of up to 100 millipascals, which is conducive to diesel atomization, high combustion efficiency, and low sewage discharge. When the diesel engine stops, use a shut-off valve to close the oil circuit and cut off the oil flow.

We need to perform on-site calibration based on the condition of the engine, body load, and instrument accuracy. The specific methods are as follows:

1. Idling.

When the Cummins diesel engine is running, exhaust all the air in the oil circuit and bring the diesel engine to operating temperature; Tighten the plug under the spring assembly of the PT-G two-stage governor; Adjust the idle speed, increase the idle speed by adjusting the screws, and decrease the idle speed by adjusting the screws; After adjusting the idle speed, return the plug. The PT oil pump equipped with MVS full speed adjustable PT oil pump has its maximum speed and idle correction screw located on the speed control cover. After repair, tighten the screw immediately to prevent indoor air from entering the fuel pump.

For each series of diesel engines, the factory recommends idling and allows for reasonable changes. If it is too large, it is difficult to register, and if it is too low, it is easy to stall. If the idling is unstable and related to the governor plunger, the extension of the piston of the flying hammer booster should be checked.

2. Maximum speed.

The maximum speed is usually calibrated on the PT fuel pump test bench and is typically used to increase or decrease the speed of the high-speed spring washer of the governor. If installed on the test bench, there is no need to replace it. The maximum external no-load speed is: put the transmission in neutral or clutch disengaged state, open the throttle valve, and maintain the fully open position. At this time, the maximum speed of the diesel engine should be 10% -12% higher than the breakpoint of the governor. When the speed exceeds the specified value, check the components of the governor assembly.

3. Governor start-up speed.

When the throttle valve is fully open, increase the load until the speed decreases by at least 100r/rpm, and then slowly reduce the load. Pay attention to the pressure gauge at the diesel outlet (when the load decreases, the pressure at the diesel outlet increases, the governor restricts supply, and as the load decreases, the pressure at the diesel outlet begins to decrease). In other words, before the governor speed reaches 2100 RPM, when the breakpoint speed is higher or lower than the specified value, if the governor correspondingly reduces or increases the adjustment of the high-speed spring at the rear of the governor, until the breakpoint of the governor meets the requirements.

Dingbo Power was founded in 1974 and is one of the earliest manufacturers of generators and diesel generator sets in China. If you want get more information, please feel free to send email to sales@dieselgeneratortech.com we will pay highly attention on your question.