Perkins develops tilt table test capability
| March 30, 2012 |
“Our lives would be much easier if the world was flat and level, but it isn’t and we have to deal with the consequences of that fact.”
Mike Looney deals with those consequences every day. As Operations Manager of Perkins Engine’s Global Engine Development Center (GED) in Peterborough, England, Looney’s responsibilities include determining just how the company’s products react to the ups and downs of real-world operation.
The company has invested $31 million in GED over the last three years, including 12 new validation cells and upgrades to five existing cells. Along with this expanded ability to test and validate their new Tier 4 engines, Perkins has also added a tilt cell that allows them to check performance while simulating the typical and extreme attitudes, an engine would see in customer applications.
“A conventional test cell can tell you many things about an engine,” Looney said, “but it won’t give you any information about how it responds to being tipped up and down, or rolled from side to side, or even turned upside down while it’s running. All of those things happen in the real world, and we need to know how our engines react.”
Perkins’ tilt cell has a hydraulically-actuated table that can rotate a fully-instrumented engine through 180 degrees on the crankshaft axis, and it tilt up or down 45 degrees off horizontal while it’s running. A typical test includes a battery of tilts and rotations that mirror actual conditions the engine is likely to meet in use.
What the engineers are most commonly looking for is a loss of oil pressure as the pump loses suction. To monitor this, they equip the test engines with sensors that read the oil pressure from the “full” and “add” marks on the dipstick gauge while tilting and rotating the engine at various fixed and dynamic throttle settings.
“This kind of a test accurately simulates what happens to an engine when it’s going up a steep incline,” Looney explained. “With the 180-degree rotational capability we can simulate what happens when a boat or a ship lists, or even rolls over with the engine running. Our customers who build land-based vehicles may not want to think about that, but it’s really important to the marine industry.
“After the test, we often will completely tear the engine down and examine all of the moving parts to see how much wear or damage we’ve been able to produce. With that information, and the data from the test runs, product engineers can make accurate assessments of engine performance under real world conditions to make more accurate estimates of engine life and overhaul intervals.”
Perkins’ GED has approximately 50 standard test cells and several specialized cells like the tilt unit to support a variety of complex validation tests, including performance and emissions, mechanical development, endurance and transient development.
“We wanted to create a highly flexible testing center able to support our long-term needs,” Looney said. “The new cells will have a significant additional capability and will enable us to develop and test our engines so that they are truly customer and application specific.