Ceramic linear bearings from PM Bearings - now available from exclusive agent Micromech - are non-magnetic, have reduced friction, retain their stiffness and operate at higher temperatures. On top of that they have an exceptional life span but require little or no lubrication. The non-magnetic properties make the bearings ideal for use in ultra-high vacuum environments.
The bearings are very lightweight as the ceramic's density is about 40-60 percent of traditional bearing steel DIN 1.3505. Because force is directly proportional to mass, the low-density silicon nitride used significantly reduces the starting force, which is required to move the slide/stage. This enhances operations in high dynamic applications where the reduction of the mass-moment of inertia is an ongoing issue.
High Rigidity is achieved because ceramic ways and balls (Silicon Nitride and Alumina) have a Youngs Modulus which is about 50 percent higher than steel, making them an ideal linear bearing material.
The lifespan of linear bearings is directly related to hardness, the most critical mechanical property of a bearing material. With an impressive Rockwell C 78 hardness, this is twice as hard as many bearing steels. They also have a high compressive strength, about five to seven times that of steel therefore silicon nitride improves wear resistance, minimising the damaging effects of repeated surface contacts.
Other characteristics such as vacuum compatibility show they exhibit less particle generation compared with stainless steel - about a third less in both air and vacuum. And they are chemically inert, corrosion resistant and electrically non-conductive, further enhancing linear bearing performance in special applications.
Ceramic linear bearings and slides are manufactured on a made-to-order basis. In this way the ceramic bearing specifications can be matched with the customers system to meet their exacting requirements of speed, operating temperature and accuracy.
