Kitz FBS - Actuator Driving Mechanism; Output Torques

Document No.:KE-4011-03 Page: 4/27
8. Actuator Driving Mechanism
Type FBS spring return actuator
(1) The Air pressure supplied into the chamber A through the inlet ① pushes the piston-gear
rack assembly toward the left, compresses the spring and discharges the air residue left in
the chamber B through the outlet ② (Fig 1).
(2) At the same time the gear rack rotates the pinion gear and the shaft counter-clockwise, to
drive the valve.
(3) At the moment the air in A is discharged through the solenoid valve, the spring force
pushes the piston and the gear rack to the reverse direction, and the gear rack activates
rotation of the shaft clockwise to reversely operate the valve.
Fig1
9. Output Torques
Type FBS spring-return actuator Unit: N-m
Actuator
type-size
Spring
rating
Operating pressure (air)
Operating force
(spring)
0.3 MPa 0.4 MPa 0.5 MPa
0°
* 1
90°
* 2
0°
* 1
90°
* 2
0°
* 1
90°
* 2
0°
* 3
90°
* 4
FBS-1
3
8.8 6.0 13.7 10.9 18.6 15.8 5.9 8.7
4
－ －
12.1 8.0 17.0 12.9 7.6 11.7
5
－ － － －
15.1 10.0 9.4 14.5
*1. For starting an actuator travel to open a fully closed valve:
*2. For ending an actuator travel to open a fully closed valve.
*3. For ending an actuator travel to close a fully open valve.
*4. For starting an actuator travel to close a fully open valve.
Spring
Drive shaft
Gear rack
Piston
Pinion gear