Today Steelhead Composites produces pressure vessels for a wide variety of applications and industries. Steelhead was initially founded with a mission to revolutionize the hydraulics industry with lightweight hydraulic accumulators. Increasingly we are seeing interest in our accumulators for automotive suspension application and hence we decided to investigate how our products are used in this market.
Use of accumulators in hydraulic or hydropneumatics suspension systems traces its history to 1954. Invented by Citroën the system uses the compressibility of gas and the incompressibility of hydraulic fluid in a “Spheres” with a rubber membrane fixed at the equator of the hollow metal ball. The spheres are, in effect, identical to what we sell as diaphragm accumulators. The history of this invention is quite fascinating with quite a bit of success across multiple platforms and millions of vehicles. And it appears that innovation in these systems continues at a rapid pace.
A 10% reduction in vehicle weight can result in a 6%-8% fuel economy improvement. Steelhead Composites has a successful legacy of taking advantage of the strength and weight of carbon fiber in components that help automotive companies decrease the vehicle weight. It appears that one component with both lightweight benefits and significant research are suspension systems. We don’t know how our products are being used since auto makers and Tier 1 auto manufacturers don’t advertise how their systems work. We just manufacture a component. As showed in our quick side-by-side of our 2L diaphragm accumulators, our design weighs 1/7th of traditional steel (and has a greatly reduced part count). Our products are opening up design opportunities deemed too heavy by legacy accumulators for suspension systems. This is even more critical if the design needs significant scale-up in size.
The applications appear to be primarily in active suspensions, some which operate hydraulically. The hydraulics control the vertical movement of the chassis relative to the driving surface using an onboard system which can also allow independent movement of each wheel. In addition, this allows for better traction, improved stability on a greater variety of surfaces and lower probability of vehicle rollover. Additionally, active suspension with hydraulics would allow the vehicle to lean, dive and squat as desired, which is a critical feature being demanded by the defense industry for next generation vehicles.
It is worth commenting that the fluid power industry is not usually associated with anything light weight as main customers of fluid power products – mobile machinery and oil and gas – are usually agnostic to weight. Our first products were bladder accumulators, both high pressure and low pressure, ranging from 5 gallons to 40 gallons, where we were able to shave 100’s of kgs from the product. Our thesis is that the weight savings are so great that we’ll have an attractive opportunity on anything which requires shipping or overhead installation. A couple of years ago, however, we had a series of unexpected requests from the robotics industry and the automotive industry who asked: “how small of an accumulator can you make?“. To meet their needs we engineered, patented, designed, tested and started manufacturing of a line of diaphragm accumulators and have recently improved the design, lowered the weight and increased the performance.
Steelhead now leads the industry in the manufacturing and supply of composite high-pressure vessels for the fluid power across multiple sectors including marine, aerospace and automotive. Our company holds a successful track record in the development of end-to-end solutions with OEMs, becoming integral to the manufacture of the final product.