A series of hydraulic rack and pinion rotary actuators - completely enclosed - offer high levels of strength and torque, with a long, trouble-free operating life.

The latest HTR Series hydraulic rack and pinion rotary actuators from Parker Hannifin offer high levels of strength and torque, with a long, trouble-free operating life. HTR actuators are suitable for use in the most demanding production systems including those used in the mining, off-shore, power generation, automotive, commercial marine and metals processing sectors. HTR actuators convert fluid power into rotary motion by using the piston in a conventional tie rod cylinder to move an output shaft via a through-hardened, chrome-alloy steel rack and pinion.

The entire unit is completely enclosed, avoiding the need for external protection and preventing contamination of moving surfaces.

The pinion and shaft are manufactured as a single piece and are supported in high capacity tapered roller bearings, eliminating the need for additional external bearings for the corresponding machine member.

The gear housing is manufactured from high strength ductile iron and, on larger capacity models, the rack is supported by heavy duty bronze bearings.

This construction results in an extremely robust system which produces uniform torque in both directions of rotation and which is capable of withstanding high radial and thrust loads even in applications with high cycle rates.

In addition, the latest HTR rotary actuators are designed to deliver a long operating life and to be both easy to install and maintain.

For example, the single-piece steel pistons are fitted with self-compensating polyurethane seals and durable PTFE wear rings as standard, which can be inspected and replaced with the actuator in-situ.

HTR rotary actuators are rated for working pressures up to 210 bar, and are available in a range of sizes with output torque ratings of 100 to 68,000Nm.

Shaft rotations of 90 deg, l80 deg and 360 deg are available as standard while up to five full rotations or more are possible.

Options include a choice of port positions, cushioning for progressive deceleration of piston speeds, different seal materials, feedback devices and position sensors.