For wheelchair users, the feeling of uneven ground can seem all too familiar. Determined to make ride discomfort a thing of the past, Israel-based SoftWheel has completely reinvented the wheel for a float-like experience.
With the SoftWheel technology, the wheels are built with three suspension arms that absorb vibrations and bumps instead of forcing them onto the rider’s body. Traditional shock absorbers exert forces that cause vibration to the frame and the user, decreasing forward momentum. With the suspension system of a rigid rim centered around the wheel hub, a more stable ride is secured.
Wheelchair users are finding more comfort with the SoftWheel, including Allaina Humphreys of Chicago, IL. Humphreys was paralyzed in a gymnastics accident in 1994 and regularly had difficulty getting out of bed because of the severe aches from riding a conventional wheelchair.
Superior Shock Absorption
Developing a wheel with optimal shock absorption was met with trial and error. Two main obstacles for engineers was connecting the suspension to the rim and designing a new hub with optimized features. Objectives were met with a four-piece original structure.
The In-wheel Suspension™ technology lets the wheel act rigid over flat surfaces and conserves rider energy. Adaptive Rigidity™ enables the suspension arms to automatically compress and absorb shocks. The wheels reset quickly and absorb nearly almost all of the force — called Rapid Shock-Reset™ — and the arms are ready to go after one-third of a turn. In typical wheels, return to a stable position can take more than three times as long. Single-piece Rigid Rims™ offer stability and as fast a ride as the highest-quality regular rims on the market.
igus® plastic bearings help SoftWheel achieve superior shock absorption. iglide® L280 bushings from igus (East Providence, RI) provide wear resistance in harsh environments or when used with rough shafts. The L280 is often used when low wear, low coefficients of friction, and extended service life are required.
The iglide bearings are installed in the triangular component of the wheels, which connect to the cylinders. With a compressive strength of 8,847 psi and tensile strength of 18,130 at 68 °F, the bushings promote stability.
All igus plastics are engineered with base polymers, solid lubricants, fibers, and filaments. Base polymers promote wear resistance, fibers and filaments act as reinforcing materials to endure high forces and edge loads, and solid lubricants independently lubricate the system when movement occurs for the bearing’s entire service life.
Unlike metal bearings, iglide composite plastic bearings are maintenance-free, self-lubricating, lightweight, vibration-dampening, and dirt-resistant. They can also be paired with any shaft material and remain corrosion-free. “Using slide bearings based on non-metal material has many advantages,” said Yoav Satz, product manager for SoftWheel. “Engineers tried several types of bushings and decided to proceed with igus since it provided the best solution.”
The collection of components in the SoftWheel makes it work because it focuses on the rim and suspension of the wheel instead of the chair. Carefully designed elements significantly reduce bounce on surfaces. With double-digit sales growth in the U.S. over the past year, applications for bicycles, automobiles, and even planes are on the horizon.
A Moving Success
Humphreys is among many wheelchair users who have found comfort with SoftWheel. Before discovering the technology, she found difficulty just moving about her home; the changes in her flooring surfaces were enough to send pain to her spine. Now, there are no limits to where she can go — and there is no fear of pain. “I was barely moving around my house,” she said. “I needed some way to do more with my children, and this is a great solution.”
Back discomfort is completely gone for Humphreys. “Having SoftWheel makes me feel like I’m an active member of the family relationship instead of an observer. It’s life-changing.”
For more information on the igus plastic bearings used in this application, visit here.