Facing tightening emissions regulations and fuel economy expectations, a commercial vehicle manufacturer approached JVS Engineering to develop a cost-efficient Variable Valve Actuation (VVA) system for their new engine. JVS Engineering leveraged lost motion VVA, their existing proprietary technology, developing proof of concept, targeting cost reduction and durability improvements for the final system. Durability expectations for the VVA system were high, and needed to be proven through the successful completion of a 2,000 hour engine test with less than 0.25% reduction in timing accuracy.
The customer chose JVS Engineering because of their ability to deliver the entire project, including concept design, prototypes, proof-of-concept hardware and extensive endurance testing that simulated real-world use of the system. Everything the customer needed was under one roof allowing the teams to stay closely integrated and aligned.
In order to achieve the cost target, the team adopted the mantra of “simple is better.” They invested time and effort in design and development and leveraged a TRIZ-like thought process to find the most streamlined solution to achieve the product specification. The work paid off with a system that achieved the objectives through a 68% part count reduction which resulted in a 52% cost reduction compared to previous designs.
To prove that the system could meet the reliability and durability needs, an extensive test matrix was developed for the system from the FMEA, ensuring that the tests focused on the critical failure modes early in the project. This test schedule took more than two years and included individual component testing, fatigue testing, debris ingestion, oil temperature and sensitivity to viscosity, system performance optimization, and finally a 2,000-hour endurance test.
The aggressive testing allowed the team to identify and fix issues early in the development of the technology. For instance, at 2,000 hours, a wear issue was identified on a critical component which resulted in the performance of the system failing to meet the specification. The team subsequently worked with the supplier of the component to improve the wear issue and validated it through focused testing.
The rigorous testing developed for this project was designed to simulate extreme situations anticipated in real world conditions, thus providing confidence in the robustness and durability of the VVA system. The five-year partnership between the JVS Engineering team and the customer resulted in a collaborative group which worked to test the system, share ideas, discuss conclusions, overcome roadblocks and collaborate on findings and possible improvements. This ultimately provided the customer with a viable technology to help achieve emissions and fuel economy reduction for their vehicles.
During the five-year partnership between the JVS Engineering team and the customer, the collaborative group worked to test the system, share ideas, discuss conclusions, overcome roadblocks and collaborate on findings and possible improvements. The rigorous testing developed for this project was designed to simulate extreme situations anticipated in real world conditions, thus proving the robustness and durability of the VVA system. Through testing, the customer gained the confidence needed to move into production and achieve emissions and reduce fuel consumption.