maintenance-free and robust: bearing and e-chain® in special electric wheelchairs

• What was needed: linear guide for seat height adjustment, plain bearings for almost all bearing points, energy chain
• Requirements: Resistance to outdoor use and high loads; a maintenance- and lubrication-free profile guide.
• Industry: Medical technology
• Success for the customer: The linear guides and plain bearings made from our high-performance plastics ensure consistently reliable, low-friction movement of the wheelchair components. The incorporated solid lubricants mean that no external lubrication is required, so that the bearing points do not become dirty and require no maintenance. The energy chains also prevent functional restrictions by protecting and safely guiding the moving cables.

Motion Solutions GmbH - "moso" for short - has set itself the task of ensuring and maintaining the mobility of its physically disabled customers. The company develops and manufactures a wide range of aids that are characterised by innovative functions - for example, the special mobility of the seating systems.

Motion Solutions customises and distributes the "EasyStand Evolv" standing trainers for people who are unable to stand independently. They move the user from sitting to the trade show stand at the touch of a button and without any other intervention. This strengthens the active and passive musculature, stabilises the cardiovascular system, treats contractures and brings users to eye level with their standing fellow human beings.
The construction of such a device is anything but simple. The mechanics must be optimally adapted to the body's own joint functions. There must be no shearing movements on the backrest or seat surface during the entire raising process and all system components that touch and guide the body must be in the same position throughout the entire raising and sitting down phase.

In addition, these devices have a so-called de-lordosis function, which brings the pelvis into the correct orthopaedic position in the trade show stand by shifting the seat surface according to the user's needs as an additional movement.

The moso engineers have realised this extension with a drylin® W profile guide, more precisely a drylin® WJ200QM housing bearing with an angular contour, which exerts a leverage effect on the unloading system. It moves on a profile rail guide and is equipped with a clamping system that synchronises the movement radius in relation to the upright position. This is just one of many examples of the use of igus® plain bearings in Motion Solutions' rehab equipment and wheelchairs. The designers have been using the particularly compact plain bearings, which do not require lubrication and are suitable for outdoor use without restriction, for more than ten years. The fact that the bearings are also suitable for high loads has to be proven in other devices from the moso range.

A prime example is the "Leo 350 XXL": a power wheelchair for people with disabilities who weigh up to 350 kilograms and are up to 2.20 metres tall. The wheelchair itself is extremely manoeuvrable and compact. Here z. For example, the longitudinal and (optional) height adjustment of the drylin® W-linear guide seat system ensures manoeuvrability and stability. The seat tilt, which means that the seat can be tilted backwards by up to 45 degrees and forwards as an entry and exit aid, should also be emphasised. Plastic bushings made of iglidur® Q material are used here, as well as in the drive and steering system of the Leo 350. They also prove their worth under high mechanical loads such as impacts caused by driving over kerbs, for example, as well as the twisting that the chassis is subjected to in practical operation.