What is the working principle of an engine oil pump?
2 Answers
The principle of the oil pump is that when the engine is running, the drive gear on the camshaft drives the transmission gear of the oil pump, causing the drive gear fixed on the drive gear shaft to rotate, thereby driving the driven gear to rotate in the opposite direction, sending the oil from the inlet chamber along the tooth gap and pump wall to the outlet chamber. In this way, a low pressure is formed at the inlet chamber, creating suction to draw oil from the oil pan into the oil chamber. The specific introduction is as follows: 1. The function of the oil pump is to raise the oil to a certain pressure and then forcibly deliver it to the moving surfaces of various engine components. The structural forms of oil pumps can be divided into two types: gear-type and rotor-type. Gear-type oil pumps are further divided into internal gear-type and external gear-type, with the latter generally referred to as gear-type oil pumps. 2. It is used to increase oil pressure and ensure a certain oil volume, serving as a component that forcibly supplies oil to various friction surfaces. Internal combustion engines widely use gear-type oil pumps and rotor-type oil pumps. Gear-type oil pumps have a simple structure, are easy to manufacture, reliable in operation, have a long service life, and provide high oil pressure, making them widely used.
With years of experience in automotive research, I can say the oil pump works like the heart of an engine. When the engine runs, the crankshaft directly or indirectly drives the oil pump—typically a gear-type design with two meshing gears. As the gears rotate, the changing space between their teeth creates suction, drawing oil from the oil pan. The oil is then pressurized and pushed out, flowing through a filter to remove impurities before entering the main oil gallery. From there, it’s distributed to critical components like crankshaft bearings, camshafts, and piston pins, forming an oil film to prevent dry friction while also carrying away heat to cool the engine. If oil pressure drops too low, a warning light will trigger—prompt inspection is crucial to avoid engine seizure. Regular maintenance, including timely oil and filter changes, ensures a longer oil pump lifespan and worry-free driving.
