Power tool and method

A power tool comprising:

• a support structure,
• a pivot bearing arranged on the support structure,
• a shaft mounted on the support structure via the pivot bearing,
• a rotatable tool coupled to the shaft,
• a strain gauge arrangement for detecting a mechanical vector quantity which depends on a force emanating from the tool, and
• a control device adapted to recognize an event and/or a state of the power tool according to the detected mechanical vector quantity,
• wherein the strain gauge arrangement is arranged on a stationary structure section coupled in a force-transmitting manner to the pivot bearing and is not arranged on the pivot bearing, wherein the stationary structure section is part of the support structure and/or is arranged directly on the support structure, wherein the strain gauge arrangement comprises a plurality of strain gauges which are distributed on a path running around the shaft, and wherein the strain gauge arrangement is adapted to detect the mechanical vector quantity as an at least two-dimensional vector by measuring a mechanical quantity underlying the mechanical vector quantity in at least two different spatial directions,
• wherein the support structure is part of a gearbox housing of the power tool, wherein the pivot bearing comprises an outer ring and an inner ring which is mounted so as to be rotatable relative to the outer ring, wherein the shaft is mounted on the inner ring and the pivot bearing abuts with the outer ring against an radially inward facing surface of the gearbox housing, wherein the strain gauge arrangement is located on a radially outward facing surface of the gearbox housing.

A method for retrofitting a power tool with a retrofit arrangement, wherein the power tool comprises a pivot bearing, a shaft mounted via the pivot bearing, the pivot bearing having an outer ring and an inner ring which is mounted so as to be rotatable relative to the outer ring, wherein the shaft is mounted on the inner ring, and the power tool further comprises a rotatable tool coupled to the shaft, and wherein the retrofit arrangement comprises a bearing flange having a pivot bearing receptacle section for receiving the pivot bearing of the power tool, a collar section adjoining the pivot bearing receptacle section, and a strain gauge arrangement arranged on an radially outward facing outer surface of the collar section, the strain gauge arrangement comprising a plurality of strain gauges which are distributed on a path running around the collar section, and wherein the strain gauge arrangement is adapted to detect a mechanical vector quantity as an at least two-dimensional vector by measuring a mechanical quantity underlying the mechanical vector quantity in at least two different spatial directions, the method comprising the step of:

• installing the retrofit arrangement in the power tool so that the pivot bearing is inserted into the pivot bearing receptacle section, the pivot bearing abuts with the outer ring against an radially inward facing surface of the bearing flange, the bearing flange is coupled in a force-transmitting manner to the pivot bearing, the mechanical vector quantity detected by the strain gauge arrangement depends on a force emanating from the tool, and a control device of the power tool is adapted to recognize an event and/or a state of the power tool according to the mechanical vector quantity.