LaunchPoint Technologies has been awarded a National Science Foundation Phase II Small Business Innovation Research (SBIR) Grant (No. IIP-1058556) to continue the development of a novel magnetic valve actuator. The actuator, once fully developed, will enable implementation of electronically-controlled variable valve timing in camless internal combustion engines.
Despite the introduction of hybrid-electric and electric cars, the vast majority of vehicles driven worldwide will continue to use internal combustion engines for several decades. To meet stringent emissions regulations and improve fuel-efficiency, new engine technologies are necessary. Variable valve timing technology, while demonstrating significant improvements in fuel-efficiency, torque, and emissions reductions, has remained either too costly to implement on conventional vehicles or far less effective and robust than desired.
Phase I Results
The goal of the Phase I development effort (NSF SBIR Award No. IIP-0945595)1 was to demonstrate a compact, linear-motion actuator capable of driving a typical engine valve. LaunchPoint designed and tested a prototype actuator using the magnetic spring technology originally developed for a high-speed switching mechanism in a space application.
The very first prototype demonstrated outstanding performance characteristics. The figure below illustrates several superimposed switching curves collected during the experiments with the valve actuator traversing an 8 millimeter trajectory in 3 milliseconds. The data reveal consistent switching trajectories and very smooth landings with speeds less than 0.3 m/sec and almost no oscillations.
Magnetic Actuator Performance Curve
The Phase II Effort
The Phase II development effort, led by Principal Investigator Mike Ricci, VP of Engineering, will be aimed at reducing the switching interval even further while improving robustness of the design. During this phase LaunchPoint engineers will design, construct, and test on an experimental engine, a second generation of the magnetic valve actuator integrated into a complete engine subsystem. This Magnetic Valve System (MVS) will be comprised of the magnetic valve actuator, an integrated sensor, a control unit, and a power amplifier, which together provide electronic control of the valve timing.
"Variable valve timing is the Holy Grail of internal combustion control," explains Dr. Maksim Subbotin, Systems Engineer and Principal Investigator for the Phase I effort. "The advantages of our technology stem from the inherent nature of the nonlinear magnetic spring used as the primary valve actuator. The nonlinear spring provides most of the energy required to open or close the valve while also ensuring a soft landing. The low-power electromagnetic actuator is used only to 'throw' or 'catch' the valve at the beginning or the end of the stroke."
Variable valve timing technology has demonstrated a fuel efficiency improvement of up to 20 percent, torque improvement of 5 to 13 percent, emission reductions of up to 10 percent in hydrocarbons, and 40 to 60 percent in NOx for conventional spark ignition (SI) and compression ignition engines. The demonstrated improvements are even more dramatic for innovative Homogeneous Charge Compression Ignition (HCCI) engines. For example, the NOx reduction is predicted to be two orders of magnitude lower in comparison to a conventional SI engine with almost zero particulate matter emissions.
Magnetic valve actuators can be applied to a wide variety of internal combustion engines. Actuators of this type would eliminate the numerous engine components required for a typical camshaft drive, in turn, decreasing manufacturing and maintenance costs and increasing reliability. Magnetic actuators could be designed into new engines and retrofitted to existing engines. The widespread adoption of these actuators would substantially decrease petroleum usage, the associated production of greenhouse gases, and air pollution, while promoting the country's energy independence.
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1Research results are based upon work supported by the National Science Foundation Small Business Innovation Research (SBIR) Program under Grant No. IIP-0945595. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.