Pressure is expressed as force per unit area. In the SI system units of pressure are Pascals (N/m2) or Bar (=10 mPa). In Imperial Units, pound per square inch (psi) or lb/ft2.

Actuator force ratings are commonly based on 3,000 psi (207 bar = 20.7 mPa).
You can approximate the actuator area by dividing the force rating of the actuator by the pressure.

A = F/P

Imperial Units
A = square inches
F = lbf
P = lbf/square inches

SI Units
A = square cm
F = kN
P = .1kN/cm2 = 1 mPa

For dynamic applications some of the total system pressure needs to be available to move oil through the valve. Typically, for those applications force calculations (F = PA) are based on 2,000 psi (138 bar = 13.8 mPa)

Actuator Accessories
Swivel Bases and Swivel Rod Ends are actuator accessories which have a semi-spherical bearing with an adjustable preload mechanism. They reduces backlash in a test setup while maintaining the freedom to pivot.  Proper preload reduces friction, minimizes impact noise, and during load reversals encountered in high-frequency testing improves the waveform.

An actuator equipped with both a swivel base and a swivel rod end has the freedom to pivot at both ends. That minimizes moment loads on the piston rod bearings and load cell.

Spiral washers are easy to use devices, Spiral Washers preload elements of the load train to provide backlash-free connections. Placed over threaded studs, each half is rotated in opposite directions, placing a steady state preload on the stud. Typically they are used for attaching swivels and force transducers to an actuator..

92 Series Actuators

The Shore Western 92 Series Linear Actuator is designed for structural testing applications. They are fatigue rated, double acting, single ended linear actuators that come standard with either 10 inch (250 mm), 20 inch (500 mm), 30 inch (750 mm) or 40 inch (1000 mm) stroke lengths and force ratings from 7.5 KIP tension/14 KIP compression (33.4/62.3 kN) to 1000 KIP tension/1350 KIP compression (4448/6005 kN). Typical applications include

  • Aviation and aerospace component static testing
  • Civil engineering low frequency cyclic testing of structures
  • Vehicle quasi-static durability tests

92 Series actuators are designed for low frequency and static test applications. They are a heavy duty, cost effective solution for high-force, quasi-static applications and unlike the MTS Series 243 actuators, they are fatigue rated.

  

Features

  • Bonded polymer bearings — Shore Western utilizes non metallic bearing surfaces for all bearings to provide long life and resist bearing-to-rod galling failures.

  • Ease of service — Innovative design permits the piston rod bearings and cylinder seals to be replaced easily. The bearing retainer assembly acts as a bearing puller when removing the gland assembly.

  • High performance and long stroke — Aviation, aerospace and civil engineering customer’s testing requirements for precision control of large loads through long displacements are easily met. 

  • Displacement transducer— All actuators have an internally mounted Temposonics® transducer that provides repeatable and accurate displacement measurements.

Options

  • Compression side relief valve — Applying a relief valve to the compression side of the actuator enables you to equalizes the tensile and compressive forces. This gives you the equal force performance of a double ended actuator with the compact size of a single-ended, double-acting model.

  • Swivels and base ends — The 99 Series Base Ends and 98 Series Rod End Swivels or Shore Western’s Ball Swivels can help reduce side loads and force alignment problems and eliminate backlash in test setups.

  • Load washers — Load washers preload force train element connections to avoid backlash and fatigue failure between attached components. Available in varying thickness load washers let you quickly preload attached components.

  • Stroke lengths — Custom stroke lengths are available upon request, adapting the 92 Series Actuators to test requirements not served by the standard strokes of 10, 20, 30 or 40 inches (250,500,750 and 1,000 mm).

  • Special manifolds — A variety of servo-valves, manifolds and close-coupled accumulator options can help customize an actuator for various applications.