CaseStudy vol.1
Client Profile
Major heavy industry manufacturers, chemical manufacturers, research institutions and many more
Products for this case study
Corrosion Guard Pro Bearing
Application example> High-performance film manufacturing equipment, cleaning equipment, etc.
"Are there any bearings that can be used in water?"
Prior to 1984, various manufacturers were seeking corrosion-resistant bearings.

This was a time without ceramic bearings.
Many manufacturers engaged in tasks that had to be carried out in liquid such as offshore equipment construction, pharmaceutical research and food manufacturing were using devices with built-in stainless bearings underwater.

However, although stainless steel has excellent corrosion-resistance, it is a softer type of material.
As such, it is costly to use due to the high frequency of maintenance and replacement required.
There were expectations from not only specific industries, but the market in general, to commercialize a high strength, corrosion-resistant bearing.

Conceiving the concept of engineering ceramics in an age where metal products where mainstream
Birth of a highly functional bearing that is not merely corrosion-resistant and high strength

JTEKT (Koyo Seiko at the time) came up with the concept of adopting engineering ceramic for the rolling element in order to develop a bearing that had strength and did not rust.

At first we attempted using aluminum oxide (alumina) as the base ingredient, but gave up as we were unable to solve the issue of fragility.
After this, receiving a hint from a report published by NASA, we began working on a technique to machine silicon nitride ceramic in a hot press.
As a joint development project together with Company T, we repeated the process of trial-and-error to create a groundbreaking bearing with high strength, corrosion-resistance and other properties.

Features of a ceramic bearing

The emergence of the ceramic bearing meant that there was now a bearing that could be used in special environments, such as submerged in seawater or solutions, contributing to longer life and high functionality for the machinery it was equipped.
However, at the time, metal was the mainstream material for bearings and many customers were still anxious that ceramic was easy to break.

In response, JTEKT took the bold action of holding a demonstration whereby customers would strike a ceramic ball with a hammer.
By showing then firsthand that rather than the ball breaking, the concrete block that the ball was sitting on broke, thus gradually building up the level of trust towards ceramic.

"The bearing used to break after one week, now it doesn't break even after one month!"
Koyo ceramic bearings achieve stable operation even when submerged in solution

These days, ceramic bearings are widely accepted however at the time, manufacturers were astonished, with many voicing their joy with feedback such as "all the bearings I'd used to date had broken within a week, but now it doesn't break even after a month!" and "It doesn't rust even when I use it under water!".

Moreover, customers were pleased with our ceramic bearings for more reasons than just being able to use them under water. Specifically, our ceramic bearings were highly regarded for their performance in a broad variety of fields, and were adopted in the spindle of machine tools due to their strength and high speed, as well as by semiconductor manufacturers due to being oil free and not producing waste.

Many of the customers who chose to use JTEKT's ceramic bearings back in the 1980s continue to use Koyo brand bearings to this day.

Recipient of several awards

In 1993, JTEKT's predecessor "Koyo Seiko", together with Company T, was awarded the Industry Promotion Award from the Ceramic Society of Japan for their development and commercialization of a ceramic bearing.
This development was also recognized with the Takagi Award in 1991, an award at the STEC International Seminar of 1993 and many more awards.

Comment from person in charge of development
Research & Development Headquarters
Material R&D Dept.
Senior Principal Researcher
Hiroaki Takebayashi
We take pride in the fact that when people think "Ceramic Bearing" they think "Koyo".

Eventually, JTEKT's ceramic bearings began being used in a truly diverse range of fields, including automobile engines, semiconductor equipment and some experimental devices in space shuttles.
We are very happy that we set a new standard for ceramic bearings as having good strength and being resistant to corrosion.

When we were engaging in this research, we kept ourselves constantly inspired by thinking "taking on difficult challenges is the only road for Koyo Seiko's survival".
Even now that our company name has changed to "JTEKT", I feel that we have maintained our spirit of taking on challenges. If you have a difficult issue you need solving, please consult with JTEKT.

Products relevant to this case

Since commercialization in 1984, JTEKT has constantly been improving our ceramic bearing versions and one legitimate successor product is the Corrosion Guard Pro Bearing.
This bearing can be used in corrosive solvent, water, etc. and in a thrust rolling life test conducted in solvent, demonstrated a life 3.5 times that of a conventional bearing (precipitation-hardened stainless steel).
This bearing has high corrosion-resistance against acid, alkaline, dye and pure water and superior load bearing.

Related product type
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