**4.2. HF-welded actuators**

HF-welded actuators and the corresponding joint modules have been called GPA (Gelenkmodul fuer Pneumatische Aktoren). GPAs have already a fairly long and successful history as can be seen from the different generations shown in figure 18. The emphasis of continuing developments is improving the lifespan of actuators, the welding process, the maintainability, and some economic aspects.


**Table 1.** Properties of different GPA versions

In table 1, the actuator designators define the number of chambers and the material. The range of motion depends on the applied pressure because the antagonistic actuator needs to

### ∅ **11mm Actuator:**


#### -10 0 10 20 30 40 50 60 70 80 90 0,0 0,2 0,4 0,6 0,8 1,0 1,2 1,4 1,6 1,8 2,0 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 Torque [Nm] Angle [°] (Pressure Tolerance +/-0,1bar) -10 0 10 20 30 40 50 60 70 80 90 0,0 0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,0 4,5 5,0 0bar 1bar 2bar 3bar 4bar 5bar 6bar 7bar 8bar 9bar 10bar 11bar 12bar 13bar 14bar 15bar 16bar 17bar 18bar 19bar 20bar Torque [Nm] Angle [°] (Pressure Tolerance +/-0,1bar) -90 -80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 0 5 10 15 20 25 30 35 40 Torque [Nm] Angle [°] 0bar 1bar 2bar 3bar 4bar 5bar 6bar 7bar 8bar 9bar 10bar (Pressure Tolerance +/-0,1bar) 0 5 10 15 20 25 30 Torque [Nm] 0bar 1bar 2bar 3bar 4bar 5bar 6bar 7bar 8bar 9bar 10bar

0 10 20 30

Angle [°]

(Pressure Tolerance +/-0,1bar)

2,2 0 bar
