High-performance bearing in lifting chair

Profile

• What was needed: iglidur plastic plain bearings
• Requirements: The bearings must be able to withstand high loads when the chair is slowly raised
• Industry: Medical technology, mobility and rehab
• Success for the customer: Today, the iglidur bearings offer three concrete advantages in the application: they are robust and withstand the high forces in the long term, are lightweight and cost-effective compared to conventional ball bearings.

Problem

The Raizer is a medical chair from the Danish manufacturer Liftup, which is designed to help elderly and physically disabled people to get up without help from others in emergency situations.
The appliance can be easily set up and operated by just one person. The built-in mechanism can lift people who have fallen within a few minutes safely and effortlessly. As the Raizer is as flat as a couch in its starting position, the person can be quickly transferred to the device. Then it's the chair's turn: the mechanism pulls the flat chair legs towards each other and the Raizer slowly and safely stands up. Naturally, very high forces act on the chair and especially on the bearing supports of the chair legs, as these not only bear the weight of the person, but also have to reliably perform the very slow straightening. Standard bearings were therefore out of the question for the manufacturer.

Solution

As extremely high forces act on all components in the medical chair, especially the central bearings at the upper end of the chair legs, a particularly robust solution was required.
The manufacturer ultimately opted for iglidur plastic bearings, which are used in three different types at a total of six points in the device.
Compared to the originally planned ball bearings, the iglidur bearings have three specific advantages that were decisive here:
The bearings are designed for very high loads and work reliably and safely under these circumstances.
They are also exceptionally lightweight. In order to ensure the easiest possible handling, great attention is often paid to the weight of medical equipment. The lightweight plastic bearings make a decisive contribution to this goal.
Last but not least, Liftup was also able to save on purchasing costs compared to conventional ball bearings.