Power wrench with swivelling gear casing

A power tool, comprising:

• a housing;
• a rotation motor;
• a reduction gearing;
• an output shaft;
• and
• a separate gearing casing carried on the housing and supporting the output shaft;
• wherein:
• said reduction gearing comprises a first gearing stage disposed in the housing, a second gearing stage disposed in the gearing casing, and a torque sensing device associated with said first gearing stage and arranged to indicate a torque corresponding to a torque delivered via the output shaft;
• the gearing casing together with said second gearing stage form a separate gearing unit which is detachably connected to the housing;
• said first gearing stage is connected to said second gearing stage via an intermediate spindle;
• said motor is connected to said first gearing stage via a drive shaft;
• said drive shaft is tubular and surrounds co-axially said intermediate spindle, and the motor is coupled to said drive shaft via an angle gear;
• said first gearing stage includes a planetary gearing with a ring gear coupled to the housing;
• and
• said torque sensing device includes a torque transferring element coupling said ring gear to the housing and arranged to be elastically deformable under a reaction torque load applied on said ring gear, and a strain gauge sensor attached to said torque transferring element and arranged to deliver electric signals in response to the reaction torque transferred to the housing via said torque transferring element.