How to dynamically adjust the flow rate of a variable displacement oil pump based on engine load to reduce pumping losses?

Variable displacement oil pump is an important technology in modern engine lubrication systems. It can dynamically adjust the oil flow according to different loads of the engine, thereby significantly reducing pumping losses and improving the overall efficiency of the engine.

Working principle

Variable displacement oil pump mainly achieves flow regulation by changing the working volume of the pump. Its core components usually include pump body, rotor, control mechanism, etc. Common variable displacement oil pumps include blade type and gear type. Taking the blade type variable displacement oil pump as an example, its blades move in a circular motion under the drive of the rotor, and by changing the extension length of the blades or the geometric shape of the pump chamber, the pumping amount of oil can be changed.

Load perception and regulation mechanism

Low load operating conditions

When the engine is running at low load, such as idle or constant speed, the required oil pressure and flow rate are relatively low. At this time, the control mechanism of the variable displacement oil pump will receive a signal from the engine control unit (ECU), which is comprehensively judged based on multiple parameters such as engine speed, throttle opening, oil temperature, etc. The control mechanism adjusts the working volume of the pump according to signal instructions, reducing the extension length of the blades or changing the shape of the pump chamber, thereby reducing the pumping amount of oil. In this way, the driving power required for the oil pump is correspondingly reduced, effectively reducing pumping losses. At the same time, the lower oil flow rate also reduces the internal oil mixing loss of the engine, further improving fuel economy.

High load operating conditions

During high load operation of the engine, such as rapid acceleration, climbing, etc., the friction and heat of various engine components increase, requiring more oil for lubrication and cooling. The ECU will determine the need to increase the oil flow rate based on the feedback information from the sensors. After receiving the command, the control mechanism adjusts the working volume of the pump, increases the extension length of the blade or changes the shape of the pump chamber to increase the pumping volume, so as to ensure that all parts of the engine are supplied with sufficient oil and ensure the normal operation of the engine.

Advantages and application prospects

The variable displacement oil pump can achieve optimal lubrication under different engine loads by dynamically adjusting the oil flow rate, while reducing pumping losses and improving engine efficiency and fuel economy. According to statistics, using a variable displacement oil pump can reduce the fuel consumption of the engine by 2% -5%. In addition, it can reduce internal wear of the engine and extend its service life. With the increasing demand for energy conservation, emission reduction, and improved engine performance in the automotive industry, the application prospects of variable displacement oil pumps are very broad. They are not only widely used in traditional fuel engines, but also have potential application value in the lubrication systems of hybrid and electric engines.

In summary, variable displacement oil pumps play an important role in reducing pumping losses and improving engine efficiency through precise load sensing and flexible flow regulation mechanisms, and are an important direction for the future development of engine lubrication systems.