Method for determining a torque acting on a rotational device or a force acting on a rotational device

A method for ascertaining a torque and/or a force, which acts on a rotary apparatus and which is directed across an axis of rotation of a rotor of the rotary apparatus, wherein the rotary apparatus comprises a measuring system, the latter comprising:

• a measuring body,
• at least three detection devices for detecting a relative position of detection device and the measuring body and/or for detecting a change in the relative position of a detection device and the measuring body,
• and wherein the method comprises the following steps:
• producing a torque and/or a force, which acts on the rotary apparatus and which is directed across the axis of rotation of the rotor of the rotary apparatus, in a set rotational position, wherein the torque and/or the force brings about a deflection of the rotor,
• ascertaining the deflection of the rotor and/or a position error of the rotor in the one set rotational position of the rotor, from the relative position of the at least three detection devices and of the measuring body,
• ascertaining the torque and/or the force at the one set rotational position of the rotor using a relationship, which is known or ascertained for the rotary apparatus, between
• i) torque and/or force, and
• ii) deflection and/or position error.