From left: Keisuke Hosokuni, Kazuo Bando, Shuntaro Sugimoto, Satoshi Nakagawa (Mechanical Engineering Department, omni-wheel Development Group)
|Both Model A and Model Ci are equipped with special omni (omni-directional) wheels. The omni-wheel combines cutting edge technology, developed exclusively at WHILL. The revolutionary wheel garnered attention during the Model A release. Today, the omni-wheel is a symbol of WHILL.|
Tackling tough terrain and offering a tight turning radius.
Standard power mobility devices have about an inch of ground clearance; therefore making it difficult for users to maneuver curbs or gaps at store entrances, sidewalks, roads, and beyond. One typical solution is to make the front wheels bigger to increase the ground clearance. However, by making the front wheels larger, the turning radius is drastically increased. We set out to overcome this problem–enter the omni-wheel! The revolutionary omni-wheel can navigate across rough terrain while maneuvering within close quarters with large front wheels, as the 24 individual rollers allow the wheels to glide sideways.
By integrating high powered in-wheel motors for the rear wheels, the Model Ci can effortlessly handle 2” obstacles, and has an impressive 29” turning radius. In addition, omni-wheels eliminate problems that casters on traditional wheelchairs cause when changing direction, such as catching corners or hitting users’ legs.
Applying the omni-wheel on WHILL personal EVs
Omni-wheels are typically used for transporting containers, or electric dollies and for robots’ driving wheels. It was a huge task to reduce vibrations in order to enable omni-wheel technology to be used on a personal mobility device. The structure of several rollers creates small vibrations in the gaps of the wheel.
Bando, the oldest member of the development team, retired from the Toyota Motor group in 2007, and had been making improvements on the omni-wheel before WHILL was founded. Over the course of five years, he developed a wheel configuration that suppressed vibration. By combining large and small rollers, narrowing the gap between the wheels, a smooth ride with minimal vibration became possible.
Cooperation of NSK Ltd.
The major advancement of the Model Ci’s omni-wheels was made possible by the provision of bearings from NSK Ltd. Each omni-wheel has 48 bearings, 96 bearings total per personal EV. They are an indispensable component to ensure a smooth ride.
Our partnership with NSK brought access to high quality bearings at low cost from a reliable and long-standing company in the automotive industry. We are continually pushing to increase ride comfort and improve durability, along with support of NSK.
Omni-wheel Development Group, Mechanical Engineering Dept.
Shuntaro Sugimoto, Group Leader
Kazuo Bando, Mechanical Engineer
Satoshi Nakagawa, Mechanical Engineer
Keisuke Hosokuni, Mechanical Engineer