Patent ID: 7308876

Claim:
A camshaft adjuster ( 1 , 1 ′) for adjusting and fixing a position of the angle of rotation of a camshaft ( 8 ) relative to a crankshaft of a reciprocating-piston internal-combustion engine comprising: a high transmission and friction-reduced adjusting gear mechanism ( 2 ) comprising a drive shaft rotationally fixed to the crankshaft; a driven shaft rotationally fixed to the camshaft ( 8 ); and an adjusting shaft ( 9 ) connected to an adjusting motor shaft ( 10 ) of an adjusting motor, wherein the adjusting gear mechanism ( 2 ) and the adjusting motor ( 3 ) are formed as separate units and are connected to each other by a rotational backlash-free, disengaging coupling ( 4 , 4 ′, 4 ″; 32 , 32 ′; 46 ; 51 ), the adjusting motor is an electric adjusting motor ( 3 ), the coupling ( 4 , 4 ′, 4 ″; 32 , 32 ′; 46 ; 51 ) has two parts, which can be joined together and of which one is rotationally fixed to the adjusting motor shaft ( 10 ) and the other is rotationally fixed to the adjusting shaft ( 9 ) or are formed integrally with the shafts ( 9 , 10 ), one of the two parts is formed as the outer part ( 19 , 19 ′; 33 , 33 ′) and the other is formed as the inner part ( 18 , 18 ′; 34 , 34 ′), and the two parts can be inserted one into the other in a rotational backlash-free way, and the coupling is formed as a profiled shaft coupling, as a two-side shaft coupling ( 4 , 4 ′, 4 ″), which has two coupling surfaces ( 21 , 21 ′) on the outer part ( 19 , 19 ′) and two coupling surfaces ( 20 , 20 ′) on the inner part ( 18 , 18 ′), and rotational backlash-reducing means are provided on the latter.