Patent ID: 8425374

Claim:
A planetary gear unit ( 20 ) comprising: a planet carrier ( 11 ) comprising a backplate ( 13 ) and being provided with planet shafts ( 14 ) distributed uniformly around the planet carrier's axis and extending through bores ( 28 ) in the backplate ( 13 ), each planet shaft ( 14 ) rotatably supporting a pair of planet gears ( 17 , 18 ) by means of planet bearings ( 15 , 16 ), the planet gears ( 17 , 18 ) being mounted between a ring gear ( 19 ) and a sun gear ( 21 ) for mutual interaction, and a key ( 26 ) provided in a keyway ( 27 ) in the planet shaft ( 14 ) and extending to the backplate ( 13 ) for preventing the at least one planet shaft ( 14 ) from rotating around its own axis, characterized in that the key ( 26 ) and keyway ( 27 ) are provided at a location positioned between 45° and 270° in a clockwise direction around the circumference of the planet shaft ( 14 ), with 0° being defined as a point at the planet shaft circumference corresponding with the largest distance from the centre (BC) of the back plate ( 13 ) seen from a rotor side onwards.