Rotary actuator, converting actuator and method for producing rotation

Method for producing rotation with a rotary actuator, comprising:

• using a rotary actuator provided with at least two individually operable rotation units, wherein each of the rotation units is provided with a pressure medium operated cylinder and a converting arrangement;
• producing axial movement (L) in selected pressure medium cylinders by feeding and discharging pressure medium to and away from at least one pressure space of the selected pressure medium cylinders;
• converting the produced axial movements (L) of the selected pressure medium cylinders to stepped angular displacements (Rs);
• transmitting the produced angular displacements to an output shaft;
• and
• controlling operation of one or more rotation units individually for producing desired rotation (R) of the output shaft.

A converting actuator for converting linear movement to rotation movement and vice versa, the actuator comprising:

• a frame;
• at least one output shaft;
• and
• at least one pressure medium operated rotation unit;
• at least a first rotation unit and a second rotation unit, which are series connected regarding their movements, and which are individually operable;
• the first rotation unit having a first pressure medium device for providing first axial movement (L) and a first converting arrangement for converting the first axial movement (L) to first angular displacement (Rs) and vice versa;
• the second rotation unit having a second pressure medium device for providing second axial movement (L) and a second converting arrangement for converting the second axial movement (L) to second angular displacement (Rs) and vice versa;
• transmission means for transmitting rotation movements between the at least two rotation units and also between the output shaft and the rotation units;
• and wherein the stepped angular displacements (Rs) produced by the at least two rotation units are configured to generate a rotation outcome (R) for the output shaft, and correspondingly an input torque directed to the output shaft is configured to produce rotation of the output shaft and is configured to be converted into axial movements (L) in the at least two rotation units.