A suitable solution ... brushless motors

Jon Lawson

Stefan Roschi presents a protective suit that relies on brushless motors

TB Safety is a small Swiss company that specialises in high-quality protective suits with ventilation. The wearers enjoy a maximum degree of safety with freedom of movement. For ventilation, the blower units use Maxon's fast brushless DC motors.

At first glance, the yellow protection suits look a little strange and slightly bloated. The bloating effect is caused by the blower unit filling the entire suit with clean air. Nik Keel, founder and owner of TB Safety, is an expert in protective suits. He states that the benefits of his system are, “greater freedom of movement for the wearer, comfortable suit climate and most importantly, safety.”

One of the highest risks inherent to protective suits is the process of taking them off. The wearer must avoid any contact with the outside of the suit to prevent contamination. The VenION single-piece suit can be easily peeled off and is therefore extremely safe. Another advantage is the placement of the blower unit. It is inside the suit itself; only the filters are on the outside. The air is distributed by ducts that are cleverly sewn into the suit so there is no need for heavy straps or for air supply hoses on the back.

TB Safety mainly provides its quality suits to the pharmaceutical and nuclear industries – selling over 30,000 units per year in Switzerland alone. The suits may also be used in areas affected by epidemics, such as the Ebola virus. However, this could prove to be very costly, as each suit costs between CHF 80  (€72) and CHF 150 (€134) and can be used only once. However, the blower unit, the ‘heart’ of the suit, is reusable.

Its Li-ion battery is good for more than four hours of operation. The blower unit is capable of providing an air supply flow of up to 600 litres per minute. It is driven by a Maxon DC motor, the brushless EC 22. With its ironless winding and strong magnet, the EC 22 is efficient, fast and very durable. Keel selected the motor especially for its compact and lightweight design. He says: “Low vibrations and noise were also key requirements.” Additionally, the drive needed to be electronically commutated. This was mandatory because a brushed motor poses a risk of spark formation and would not have passed the strict approval process.

Keel has great plans for his company. He wants to expand production in Italy and Poland and sell up to 2,000 blower units annually. At the same time, he is developing a new type of suit, equipped with magnetic connections for the blower unit. This would allow the blower and filter to be attached to the magnetic connections inside the suit. As a result, the filters would also be protected against contamination and could be reused repeatedly.

Another challenging project has already been completed successfully. TB Safety built an isolation unit for the air transport of Ebola patients. In only four months, the company developed a small chamber with space for one person. The pressure was high, and time was tight, but the developers succeeded. The customer, the Swiss air rescue unit Rega, immediately used the chamber in a real emergency. “The secret of our success,” says Keel, “is that instead of mass production, we make products that fit the specific needs of our customers.”

Stefan Roschi is with Maxon Motor.