Load Unit: Component Description - MTS Systems 318 Series Product Information

I C
TEM OMPONENT
4 Control panel
Grip
controls
Crosshea
d lift
control
Emergenc
y Stop
5 Servovalve
6 Isolation pads
7 Accumulators
8 LVDT
9 Manifold
10 Linear actuator
11 Force transducer
12 Lifting rings

318 Load Unit: Component Description

18 Introduction
Component Descriptions
D
ESCRIPTION
The Emergency Stop button is standard; the other controls are optional.
Clamps and unclamps the hydraulically controlled grips during specimen
installation and removal.
Controls the crosshead lifts to raise and lower the crosshead hydraulically.
Removes hydraulic pressure from the load unit and issues an interlock signal
to the controller to stop the test program.
Controls both the flow rate and the direction of fluid entering the actuators. It
determines how fast the actuator extends or retracts.
Dampens the natural frequency to about 20 Hz. Optional air inflated isolators
dampen the frequency to about 2 Hz.
Stores hydraulic fluid under pressure to increase the actuator's response time.
One accumulator connects to the pressure line; the other to the return line.
Measures the displacement of the actuator's travel. The linear variable
displacement transducer (LVDT) is located inside the actuator.
Serves as the junction point between the hydraulic power unit (HPU),
accumulators, servovalve, and actuator. The actuator manifold controls the
hydraulic circuit that connects the hydraulic components.
Applies axial forces to specimens. The actuator is a hydraulically powered
device that provides linear displacement of (or forces into) a specimen. Grips
and fixtures can be mounted to the actuator.
Measures the axial forces applied to specimen.
Allows the load unit to be moved by lifting the entire load unit.
The load unit is a stand alone testing structure. It consists of the following
components:
• Load frame
• Crosshead lifts and locks
• Manifold
– Actuators
– Servovalves
– Accumulators
• Transducers
• Grip controls
318 Load Unit