Rodeye Ends For PG Series LVDTs

Rod eye ends (also called swivel rod eyes or clevis ends) provide a pin-joint connection between the LVDT core rod and the measured object, allowing rotation about the pin axis without transmitting bending loads to the core rod. In steam turbine valve linkages, where the valve stem and the sensor mounting point may not be in perfect linear alignment, pin-joint connections at the sensor core rod end prevent the actuator's angular motion from applying side loads to the core rod that would cause premature seal wear and measurement hysteresis.

PG Series Linkage Requirements

The PG Series core rod must remain aligned with the sensor bore throughout its full travel range. Any angular deviation between the core rod axis and the sensor axis produces a side load on the shaft seal — the dual double-contact seals that keep contaminants out of the bore. While these seals are designed for robustness, sustained off-axis loading accelerates wear and can eventually cause seal leakage that allows contamination into the bore. The rod eye end eliminates this problem by absorbing the angular component of the linkage motion in the pin joint.

Available Configurations

Rod eye ends for the PG Series are available in the thread sizes matching the 3/8-inch core rod assembly (3/8-24 UNF and M10 x 1.25 metric) and in bore diameters to match standard clevis pin sizes. Stainless steel construction is standard for the corrosion resistance required in steam plant environments. All rod eye ends thread onto the core rod tip and are retained by a jam nut that prevents loosening under vibration — critical in turbine environments where continuous vibration could unscrew an inadequately locked connection over time.