Patent ID: 9534515
Date: 2017-01-03
CPC Classifications: F01L

Claim:
1. A camshaft phaser comprising: a vane-type phaser having a stator connectable to a crankshaft of an internal combustion engine, and a rotor rotatably mounted in the stator and connectable to a camshaft, the stator being provided with a plurality of lobes dividing an annular space between the stator and the rotor into a plurality of pressure chambers, the rotor having a plurality of radially outwardly extending vanes dividing the pressure chambers into two groups of working chambers of different directions of action, said working chambers each being capable of being pressurized with a pressure medium flowing in and out in a pressure medium circuit, and a central-position locking device for locking the rotor in a central locking position relative to the stator, the central-position locking device having at least two spring-loaded locking pins lockable in a locking slot stationary with respect to the stator and which, during a rotation of the rotor from either of an advance stop position or a retard stop position toward the central locking position, lock in the locking slot from different directions, at a first locking pin of the at least two spring-loaded locking pins being provided with a blocking portion and a flow-through pressure medium conduit, by which a fluid connection between two of the working chambers of different directions of action can be established or blocked in the different positions of the first locking pin, the working chambers of the different directions of actions being capable of being short-circuited by a switching device, and at least one pressure medium conduit fluidically connectable to the pressure medium circuit by the flow-through pressure medium conduit of the first locking pin having a check valve therein allowing the pressure medium to flow into one of the working chambers whose volume is increased during a rotation of the rotor from either of the advance or retard stop positions toward the central locking position, while at the same time preventing backflow from the same working chamber.