Gerotors by powder metallurgy for Orbital Valves

Powder Metallurgy Gerotors for Orbital and Steering Valves

Gerotors used in orbital and steering valves for low-pressure applications are predominantly manufactured through the powder metallurgy process. This method is ideal for producing these components in high volumes, primarily for oil lubrication and cooling purposes. However, traditional powder metal gerotors typically operate at low pressures—usually below 50 bars—due to the interconnected porosities that prevent effective oil sealing at higher pressures.

We have developed a new powder material that enables the production of high-density sintered parts with a density of up to 7.6 g/cm³—approaching the density of solid steel blanks at 7.8 g/cm³.

At this advanced density, sintered components exhibit mechanical properties comparable to or even superior to those produced through conventional melted iron or steel processes. Notably, their strength exceeds that of metal injection molding (MIM), which is renowned for achieving high density and mechanical integrity.

Currently, most gerotors are manufactured through labor-intensive processes such as machining, honing, and grinding, resulting in high production costs. However, by utilizing the compaction and sintering processes for both the inner and outer rotors, these components can be finished using a cost-effective, high-production-rate method known as sizing. This approach significantly reduces manufacturing costs while maintaining the required precision and performance standards.

This is a new idea derived from my manufacturing experience, with the aim of finding a lower-cost process while taking advantage of the benefits offered by powder metallurgy. This innovative approach leverages advanced materials and processes to reduce costs without compromising quality or performance.