MTS Series 247 Actuators - Manual (Page 15)

Component Identification
Series 247 Actuators Introduction 15
Component Identification
Component Descriptions (part 1 of 2)
Item Description
Extension port/
Retraction port High-pressure hydraulic fluid is ported into the cylinder through the retraction
port or the extension port. The flow is regulated by a servovalve. As hydraulic
pressure is applied to one port, the other port is opened to a return line causing
the actuator to extend or to retract.
Piston seal
A reinforced Teflon ® seal on the piston provides a positive seal and reduces
friction.
Piston bearing These high-capacity nonmetallic bearings are bonded directly to the end caps.
The nonmetallic bearings are standard due to their high sideload tolerance and
resistance to failure from galling and seizure.
Drainback port The drainback port allows fluid that manages to leak past the seals to be routed
out of the actuator. This prevents pressure pockets from interfering with the
actuator performance.
Piston rod The piston rod is machined from a heat-treated alloy steel, hard-chrome plated,
and precision ground to a fine finish for reliable operation. The piston rod is
hollow to allow for installation and accurate alignment of a displacement
transducer. The piston rod end has an internal thread for mounting force
transducers, swivels, and test fixtures.
Low-pressure seal The low-pressure seal assembly contains a seal to guide excess fluid to the
drain back port and a wiper to prevent external contamination from entering
the actuator.
Extension
Port
Front End
Cap Piston
Seal Piston
Bearing
Front End
Cap
Retraction
Port Drainback
Port (on back) Actuator
Rod
LVDT
Connector O-ring LVDT
Coil LVDT Core
Extension High Pressure
Seal/O-ring Low Pressure
Seal/Wiper O-ring