Material Engineering

Various materials are used to make our products, including metals, plastics, and ceramics.

The appropriate selection of these materials to suit the environment in which the products will be used is extremely important to prevent major damage (e.g., fracture, corrosion, and wear) being caused to the materials and to continuously supply highly reliable products.

For our products to operate steadily without problems over the long term, EBARA uses a variety of measures for the appropriate evaluation and selection of the materials to be used, such as experiments and numerical analysis. If necessary, we also develop new high-performance materials.

The sliding bearings in pumps are critical components that support the rotor.

When sliding bearings use low viscosity fluids such as water as a lubricant or are in an unlubricated state for a short time, the environment becomes harsh, with contact occurring between the material of the rotor and the material of the stator. This can cause problems such as abnormal abrasion unless appropriate materials are selected or developed.

To achieve stable operation without lubrication, EBARA develops materials by adding additives to heat-resisting plastics to lower their friction factor. We also develop materials with high corrosion resistance even under harsh environments by optimizing the composition of the materials. These newly developed materials are then applied to our products.

Depending on the shape of the structure, large stresses may occur in certain sections, increasing the risk of damage. It is therefore necessary to evaluate the stresses appropriately and design the optimal shapes.

For example, many fluid machines such as pumps have structures in which the stepped surface of the shaft is subjected to a load in the axial direction, so inappropriate design may increase the risk of cracks in the base. Therefore, it is necessary to evaluate the strength of the shaft’s stepped surface.

With the latest FEM*1 analysis technology, EBARA derives the relationships between the stress concentration factor and the stress intensity factor*2 for the shaft diameter, level difference, radius of the base, and crack depth, and applies them to shaft design.

*1 FEM: Finite Element Method
*2 Stress concentration factor, Stress intensity factor: Parameters for evaluation of stress