Hand-held power tool

A hand-held power tool comprising:

• a motor;
• a tool holder;
• and
• a percussion mechanism connected in a drive train between the motor and the tool holder, the percussion mechanism including:
• a first shaft,
• a second shaft,
• a hollow wheel connected to the first shaft and whose inside wall is not rotation-symmetrical with respect to an axis of the second shaft,
• an impeller connected to a second shaft and rotatably situated within the hollow wheel,
• a magnet situated coaxially to the second shaft, and
• a magnetorheological fluid filling a cavity between the hollow wheel and the impeller,
• in a first position, the impeller being spaced apart from the hollow wheel by a first air gap, and in a second position, the impeller being spaced apart from the hollow wheel by a second air gap, the first air gap being smaller than the second air gap, and
• the impeller and the hollow wheel being made of a magnetically conductive material.