Corrosion-Resistant Bearings That Can Withstand a Wider Range of Extreme Environments

Problems

• There are corrosive environments that cannot be handled by current corrosion-resistant bearings.
• In these corrosive environments, the bearings quickly get damaged and have short service lives, and we need bearings that will last a long time.

Solutions

• Producing bearings that can withstand corrosive environments?that conventional bearings could not handle, through the use of zirconia and silicon carbide, and selecting the appropriate material for the application.
• Achieving longer service life through the distinction between different corrosive environments and the use of different materials?that are suited to different corrosive environments

Achievements

• Improved corrosion resistance?by using materials suited to different types and levels of corrosiveness

Standard bearings are made with high carbon chromium bearing steel such as JIS G 4805 SUJ2 or 52100.

However, such steel materials have poor corrosion resistance, and cannot be used in corrosive environments.

JTEKT, in order to meet the needs of our customers, developed the world’s first bearings made with ceramic materials, which can withstand these corrosive environments. In this way, we became an industry pioneer and achieved tremendous results in various fields and environments such as semiconductor and food manufacturers.

• Various corrosive environments

Here at JTEKT, we have provided ceramic bearings primarily made with silicon nitride to handle environments where high corrosion resistance is required. Silicon nitride is a material that has a higher level of corrosion resistance than normal bearing steel or stainless steel.

However, even though the phrase “corrosive environments” is used, there is actually a difference in qualities such as acidity and alkalinity, as well as variability in the level of corrosiveness. For this reason, even silicon nitride has its limits: depending on the environment in which it is used, it could get damaged quickly, its service life could be shortened, and it could therefore be insufficient for certain environments (see Figure 1).

Fig.?1: An illustration of the applicable range of conventional bearing materials

Table 1: The characteristics of various materials

In addition, by conducting corrosion tests with various corrosive solutions, we obtained the corrosion resistance results of different ceramic materials shown in Table 2.

Table?2: Corrosion resistance of ceramic materials

△ May have Slight Corrosion ○ Slight Corrosion ◎ No Corrosion × Maybe Corroded

Using these corrosion test results, we are able to break down what kinds of bearing materials are best used for various types of environments, and to achieve greater corrosion resistance than ever before.

A Video Explaining the Wafer Cleaning Process

(Water flows from above, and an acrylic board simulating a wafer moves side-to-side)

• A Message from JTEKT

As more and more bearings are used in an ever-growing variety of fields, corrosion resistance has become even more important.

There is a growing need for bearings that, even while maintaining the same load performance and service life as before, can be used over a long period of time in corrosive solutions.

Here at JTEKT, we have been applying a variety of ceramic materials to bearings, thus allowing them to withstand a greater ranger of corrosive environments. If you have any problems dealing with corrosive environments, please feel free to give us a call.

• Product

At JTEKT, we have prepared the EXSEV (Extreme Special Environment) Series of special-environment, a lineup of corrosion-resistant bearings, including bearings that use stainless steels such as precipitation hardening stainless steel (SUS630), which has better corrosion resistance than SUS440, and full ceramic bearings with silicon nitride and silicon carbide, in order to achieve resistance to more and more different corrosive environments.

These contribute to longer service life and reduced maintenance cost for equipment used in the production of things like semiconductors, high-performance film, and food products, resolving a wide range of customer concerns and contributing to greater productivity.

Corrosion-resistant Exsev and ceramic bearings

More information on JTEKT Exsev Bearings:

Link to the original article from JTEKT:

* EXSEV? is a registered trademark of JTEKT.