Marine Lubricating Oil Pump

Introduction 

The lubricating oil pump is suitable for the transportation of lubricating fluid without solid particles (non-corrosive and liquid with wide viscosity range). The flow rate of the pump can reach 300m/h and the pressure may reach 3 × 10⁷Pa. It is usually used as a hydraulic pump to transport all kinds of petroleum products. The lubricating oil pump (gear oil pump) has the advantages of simple structure, compact structure, easy manufacture, easy maintenance, self-priming and so on. The lubricating oil pump (gear pump) must be equipped with a safety valve to prevent the pump or prime mover from damaging the pump or prime mover because the outlet pressure of the pump exceeds the allowable value due to blockage of the discharge pipe.

According to the purpose, it is divided into: the main lubricating oil pump that provides lubricating oil to the main engine, the supercharger lubricating oil pump that provides lubricating oil to the supercharger, and the stern tube lubricating oil pump that provides lubricating oil to the stern tube bearing. The oil transfer pump that transfers the oil from the oil tank to the daily oil tank, etc. Two main lubricating oil pumps shall be provided, one of which shall be reserved. Large diesel engines generally use vertical electric screw pumps; medium-sized diesel engines and steam turbines commonly use vertical electric gear pumps; medium and small diesel engines use lubricating oil pumps that are often driven by the main engine.

There are usually two lubricating oil pumps, one of which is a spare. If the main engine has its own lubricating oil pump, one can be provided. In order to ensure stable oil pressure and uniform flow, screw pump is often used, and a vacuum gauge is generally installed on the suction end pipe of the pump. In order to ensure normal oil suction, the vacuum degree should not exceed 0.03MPa. The discharge pipe of the pump is equipped with a safety valve and a bypass valve for regulating pressure and flow. The set pressure is 1.1 times the normal oil supply pressure of the pipeline.

Working Principle of Marine Oil Pump

When the meshing gear rotates in the main body of the pump, the gear goes in and out of meshing continuously.In the suction chamber, the teeth of the gear gradually break away from the meshing state, the volume of the suction chamber gradually increases, the pressure decreases, and enters the suction chamber under the action of liquid surface pressure, and enters the discharge chamber with the gear teeth. In the discharge chamber, the teeth of the gear gradually become meshing again, the teeth of the gear are gradually occupied by the teeth of the gear, the volume of the discharge chamber is reduced, and the hydraulic pressure of the discharge chamber increases, so the liquid is discharged from the pump outlet. The gear continues to rotate, and the above process continues to form a continuous oil supply process.

Picture of Marine Lubricating Oil Pump