Seals and Orings

Sealing solutions for machine tools spindles

Contaminants and moisture can negatively affect bearing service life and performance. This is particularly important for machine tool applications where coolant and swarf are an integral part of the operating environment. Therefore, an effective sealing arrangement is essential if a spindle is to operate reliably. To protect the bearings, GTI offers a wide assortment of external and integral seals. 

External seals

For bearing arrangements where the effectiveness of the seal under specific operating conditions is more important than space considerations or cost, there are two types of external seals available: non-contact seals, and contact seals.

Non-contact seals

Non-contact seals are almost always used in high-speed precision applications. Their effectiveness depends, in principle, on the sealing action of the narrow gap between the shaft and housing. Because there is no contact, these seals generate almost no friction and do not, in practice, limit speeds, making them an excellent solution for machine tool applications.

Seal variants range from simple gap-type seals to multi-stage labyrinth seals. Compared to gap-type seals, multi-stage labyrinth seals are considerably more effective as their series of axially and radially intersecting components make it more difficult for contaminants and cutting fluid to enter the bearing.

In highly contaminated environments, a complex labyrinth seal design is often required. Labyrinth seals can have three or more stages to keep lubricant in and contaminants out of the bearing arrangement.

Contact seals

Contact seals are generally very reliable. Their effectiveness, however, depends on a number of factors. Friction between the seal lip and counterface can generate a significant amount of heat at higher speeds. As a result, these seals can only be used in lower speed spindles and/or in applications where the additional heat does not significantly affect spindle performance.

Integral seals

Sealed bearings are generally used for arrangements where a sufficiently effective external sealing solution cannot be provided for cost reasons or because of space limitations.

GTI supplies a wide assortment of super precision bearings fitted with a seal on each side. For details, refer to Sealing solutions in the relevant product section.

Standard as well as customized sealing solutions in Machine tools applications

Decades of experience with cutting and forming machines, combined with advanced materials expertise, has made GTI a leading supplier of standard and custom-engineered sealing solutions. 

These include integrated solutions consisting of seals and advanced engineered plastic parts, as well as moulded seals for higher volume orders and high-performance machined seals or hydraulic and pneumatic applications like press-cylinders, valves or clamping devices as well as for rotary applications like rotary distributors, joints or indexing tables.

Due to the flexible production process, you can benefit from short delivery times and just-in-time delivery for standard and special seals in customized dimensions and high performance one-piece sealing materials up to 4 000 mm in diameter as one piece. 

A wide variety of high performance sealing materials – provides high wear resistance, long service-life and chemical compatibility with various machine tool liquids. In addition, GTI supports customers with on-site solution analysis and application engineering. Located close to our customers, GTI’s machined seals competence centers provide global availability with truly local service.