∅ **18mm Actuator:**


### ∅ **36mm Actuator:**


#### **Single Chamber Actuator:**


be compressed and thus the range of motion depends on the applied torque. Except for the extreme angular ranges, the torque over angle is fairly linear. Figure 19 shows the torque-angle plot for different pressure values.


**Figure 18.** The three GPA generations

16 Will-be-set-by-IN-TECH

Torque [Nm]

0,0 0,2 0,4 0,6 0,8 1,0 1,2 1,4 1,6 1,8 2,0

> 0,0 0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,0 4,5 5,0

be compressed and thus the range of motion depends on the applied torque. Except for the extreme angular ranges, the torque over angle is fairly linear. Figure 19 shows the torque-angle

Torque [Nm]

Torque [Nm]

Torque [Nm]


Angle [°]


Angle [°]


Angle [°]

0 10 20 30

Angle [°]

2,2 0 bar

 1 bar 2 bar 3 bar 4 bar 5 bar 6 bar 7 bar 8 bar 9 bar 10 bar 11 bar 12 bar 13 bar 14 bar 15 bar 16 bar 17 bar 18 bar 19 bar 20 bar

(Pressure Tolerance +/-0,1bar)

(Pressure Tolerance +/-0,1bar)

(Pressure Tolerance +/-0,1bar)

(Pressure Tolerance +/-0,1bar)

 0bar 1bar 2bar 3bar 4bar 5bar 6bar 7bar 8bar 9bar 10bar

 0bar 1bar 2bar 3bar 4bar 5bar 6bar 7bar 8bar 9bar 10bar

 0bar 1bar 2bar 3bar 4bar 5bar 6bar 7bar 8bar 9bar 10bar 11bar 12bar 13bar 14bar 15bar 16bar 17bar 18bar 19bar 20bar

∅ **11mm Actuator:**

∅ **18mm Actuator:**

∅ **36mm Actuator:**

• 6 Pleats

• 1 Pleat

• Range of Motion 90◦ • Symmetric Shape

• Burst Pressure > 40 *bar*

• Effective Diameter of 36 *mm*

• Range of Motion ±90◦ • Asymmetric Shape

**Single Chamber Actuator:** • Effective Diameter of 40 *mm*

Linear Motion • Symmetric Shape

• Range of Motion ±12◦ or 19*mm*

plot for different pressure values.

• 5 Pleats

• Range of Motion 90◦ • Symmetric Shape

• 5 Pleats

• Effective Diameter of 11 *mm*

• Effective Diameter of 18 *mm*

**Figure 19.** Torque-Angle Plot for GPA-3 module with a 10 chamber actuator

Of course table 1 does not reflect all the important parameters. For example, the lifespan of actuators has grown dramatically from a view thousand up to more than 350, 000 stress cycles (full range motion with 4 *bar* forth and back in 3.6 *s*) for GPA3.2 joint modules. Lifespan depends very much on the maximum applied pressure and the valves to be used. The value of 4 *bar* is a good compromise between maximal torque and lifespan. Most GPA types may be operated using higher pressure (up to 6 *bar*), but the lifespan of actuators will decrease dramatically at this pressure. In many cases repair welding is possible.
