GRAPHALLOY Replaces Ball Bearings In High Temperature Application

GRAPHALLOY® self-lubricating bearings keep the wheels rolling for a manufacturer of specialty powders

When a major manufacturer of alumina powders contacted us because of a high rate of sealed ball bearing failures in their oven carts, we knew GRAPHALLOY bearings would solve the problem.

Sudden stops ruin equipment and material

Our customer manufactures high purity alumina powders and specialty powders designed for a wide range of markets including lighting, watches & jewelry, health & medicine, plasma TV and microelectronics. The manufacturing process for the powders consists of loading pans of  powder mixture onto a train of carts which are then driven by an electric motor through a series of ovens. Each cart has four casters, with bushings, that ride on rails into the ovens. It is critical that the carts move through the heating process in a smooth manner, at a constant speed so that the blocks of powder do not break.

The sealed ball bearings on the carts were losing lubrication and sticking due to the high oven temperatures. This was causing the wheels to lock and the carts to come to a sudden stop. The electric motor would continue trying to drag the carts through the oven.  As a result, the powder blocks would break and the cart wheels developed flat spots from sliding rather than spinning.  Since the carts would not move freely, the electric motor would overload and fail.  The carts would then have to be manually pulled through the ovens.

Greaseless GRAPHALLOY Solution
Our engineers reviewed the application and recommended one of our self-lubricating GRAPHALLOY grades to replace the sealed ball bearings. Our customer tested the GRAPHALLOY bearings on two carts. During the test, the customer told us they randomly pushed carts by hand and only two carts moved smoothly when pushed: the carts with the GRAPHALLOY bearings installed. Since the customer changed all his cart bearings to GRAPHALLOY, he estimates saving thousands of dollars annually in replacement parts, maintenance costs, product waste and downtime.

Consider the advantages of GRAPHALLOY for your next application:
- Self-lubricating
- Temperature extremes
  (-400° F to +1000° F/-240° C to 535° C)
- Extended operation
- No downtime

High Heat May Cause Problems for Traditional Bearings

Steel and metals production creates problems for tradtional bearings because of the high heat and heavy loads. GRAPHALLOY® bearings provide a solution to these problems. Here is a really tough application:

The annealing furnace at a Pennsylvania metal manufacturer had an interior temperature in the range of 1200°F (650°C). Bearings supporting the pinch rolls were located outside the furnace walls and reached temperatures up to 750°F (400°C) due to heat transmitted through the furnace wall by the shaft.

The heat transmitted by the shaft through the oven wall to the bearing was causing lubrication failure. In addition, the movement (linear expansion) of the shaft caused problems well beyond the capability of any standard ball or roller bearing arrangement.

GRAPHALLOY high temperature bearings were installed in a metal adapter designed to fit the original bearing housings and solved the problem without a major redesign. With minimal investment, bearings failures and associated maintenance costs were reduced.

Even if your application isn't this tough, GRAPHALLOY bearings can solve your high temperature bearing problems.