HYTEC – Hybrid rolling bearings

What are hybrid bearings

Hybrid bearings are manufactured with rings made of normal bearing steels (e.g. 100Cr6, AISI440C) and rolling elements made of silicon nitride Si₃N₄. All dimensions and tolerances remain the same. HYTEC hybrid bearings can therefore replace standard rolling bearings without any changes to the adjacent construction. Si₃N₄ rolling elements offer a whole range of advantages in many applications, especially in critical and difficult environmental conditions.

Silicon nitride in rolling bearing quality, as used in HYTEC rolling elements, is characterized by a uniform and extremely fine microstructure and high purity. It combines extremely high strength with toughness, is chemically inert and an excellent insulator.

Advantages of HYTEC hybrid bearings

Excellent current insulation

Silicon nitride is an excellent insulator and can be used as a rolling element instead of oxide-ceramic coated inner or outer rings. Hybrid bearings are often the economical solution for small and medium sizes. The dielectric strength of Si₃N₄ balls is 15,000 V/mm, compared to a maximum layer thickness of 0.5 mm applied to rings

Low friction

Silicon nitride has low friction compared to steel. At the same speed, hybrid rolling bearings have a lower operating temperature. This extends the service life of the bearing and the lubricant.

Higher speeds / acceleration / rigidity

Si₃N₄ balls have a 59 % lower density than steel balls and therefore reduce centrifugal forces and mass-induced forces when accelerating or decelerating the bearing. Due to the lower friction and lower operating temperature, hybrid bearings can be operated at higher speeds. Typical examples are speed limits increased by 20 % for deep groove ball bearings, up to ndm_max 3 million for high-performance spindle bearings

Due to the 50 % higher modulus of elasticity, hybrid bearings become stiffer

Tolerance to temperature changes and high operating temperatures

Thanks to the 76 % reduction in the coefficient of thermal expansion, HYTEC hybrid bearings are significantly less sensitive to temperature fluctuations in the application. The operating bearing air can be adjusted more precisely. Silicon nitride has almost the same hardness up to 800 °C. In combination with heat-resistant rings and adapted dry lubrication, hybrid bearings can be used at operating temperatures of up to 400 °C

Longer service life of the bearing and lubrication in critical applications

The friction between steel and silicon nitride is very low, so the operating temperature and wear are low. This results in longer service lives. The required lubricant film thickness is significantly lower for hybrid bearings, which is why they also function in the event of insufficient lubrication or mixed and boundary friction conditions. Even when running dry, hybrid bearings do not tend to seize; in emergency operation without any lubrication, they run considerably longer.

High resistance to dirt particles in the bearing

Si3N4 rolling elements are usually harder than typical dirt particles in the bearing. When rolling over, these are crushed or pressed into the raceway and flattened by the following rolling elements

High resistance to vibration

HYTEC hybrid bearings are relatively insensitive to standstill vibrations. Damage such as false brinelling can therefore be largely avoided

Production of HYTEC hybrid bearings

The rolling bearing rings and cages are manufactured by renowned European and Japanese manufacturers. Our _Si3N4 balls, in rolling bearing quality, with optimized microstructure and porosity, are installed in these rings in Austria.

Our high-performance lubricants come from well-known German manufacturers, although we are also happy to use customized lubricants. For the food industry, lubricants in accordance with NSF H1 are used, usually in combination with bearings made of low-rust material.

The smallest batch size is 1 piece. Our customers can therefore also test hybrid bearings in very small quantities.

The production of small quantities is usually possible in 2–4 days.

Manufacturing partners in Europe and Asia are available for series solutions. An extensive portfolio of high-performance materials such as PEEK, FKM and high-performance steels is available even for medium quantities

Which bearing types can be manufactured as hybrid

Hybrid bearings are always significantly more expensive to purchase than all-steel bearings. Ball bearings up to medium size can be produced “economically” today. However, the larger the balls used, the higher the manufacturing costs.

Ceramic castors are extremely expensive and are only installed by us on customer request. The delivery time for standard castors is 3–5 weeks

Labelling / Packaging / Marking

The bearing itself is not labelled. The labelling on the bearing is genuine and unchanged.

We pack in the original packaging of the bearing manufacturer and mark with a sticker