UAV Engine Lubrication via Electric Solenoid Pump Control
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Solution Overview
Problem
Conventional lubrication systems in two-stroke UAV engines, particularly those with direct injection, face challenges in delivering the exact amount of lubricant required based on altitude, temperature, and power output, leading to inefficient lubrication, poor engine reliability, and increased oil consumption, which affects range and duration.
Innovation Solution
An electric solenoid actuated oil pump system that controls lubrication oil delivery and heating, using a controller to vary the energization period of the solenoid based on engine speed and temperature, ensuring precise oil delivery and heating strategies to meet the engine's lubricant requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a mechanical oil pump driven by the crankshaft is used, then the pump operates at engine speed, but it under-delivers or over-delivers lubrication oil for a given engine speed, resulting in poor engine reliability or poor oil economy
Solution Approach 1:
The patent replaces the mechanical oil pump driven by the crankshaft with an electric oil pump that can be independently controlled. This substitution allows the system to decouple oil delivery from engine speed, enabling precise control of lubrication oil flow rate based on actual engine needs rather than mechanical coupling, thus resolving the contradiction between reliable lubrication delivery and oil consumption efficiency
2Reliability
If pre-mixed oil and fuel is used for two stroke engines, then lubrication is provided in the cylinder, but the injection system cannot efficiently inject the lubrication oil and fuel pre-mix to achieve acceptable combustion and fuel economy
Solution Approach 1:
The patent separates the lubrication oil injection from the fuel injection, using independent injection systems for each. This segmentation allows the fuel injection system to optimize combustion efficiency while the separate lubrication oil injection ensures proper lubrication delivery, resolving the contradiction between combustion efficiency and fuel economy that arises from pre-mixed injection
3Reliability
If the solenoid is continuously energized to deliver lubrication oil, then the engine receives adequate lubrication, but the oil cannot be heated to address low viscosity issues in cold temperatures
Solution Approach 1:
The patent uses periodic energization of the solenoid instead of continuous energization. The solenoid is energized in cycles that allow both oil delivery and heating functions to be performed alternately, resolving the contradiction between maintaining adequate lubrication and heating the oil to address viscosity issues in cold temperatures
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution provides improved oil economy, reduced oil consumption, enhanced engine durability, and accurate lubrication, enabling increased range and duration for UAVs by ensuring the right amount of lubricant is delivered under varying conditions, while also addressing issues of low viscosity and cold temperatures.
Implementation Method 1
an electric solenoid actuated oil pump system that controls lubrication oil delivery
Implementation Method 2
An electric solenoid actuated oil pump system that controls lubrication oil delivery
Implementation Method 3
lubrication oil heating capability
Data Source
AI summary
An unmanned aerial vehicle (UAV) engine (40) lubrication system and lubrication oil heating strategy uses a solenoid actuated electric oil pump (10,42) to deliver lubrication oil to the engine from a lubrication oil reservoir (12,44) by energizing and de-energizing the solenoid (18) to operate a pump mechanism of the electric oil pump. A controller (ECU) (100) can control operation of the electric oil pump, the solenoid maintained energized for a required period of time to cause heating of the oil without continuously pumping the oil. An electric oil pump control strategy can maintain engine speed dependent minimum oil delivery rates, can heat the electric oil pump and oil through extended energized (ON) time of the solenoid, and, by varying the turn on time of the electronic oil pump based on sensed ambient temperature, long time periods can be used to ensure oil delivery for cold temperatures, and shorter times are permitted when necessary in order to reach maximum oil flow rate.