Trigger wheel arrangement for concentrically arranged camshafts

A camshaft phaser assembly, comprising:

• an axis of rotation;
• a first hydraulic camshaft phaser including:
• a first stator arranged to receive rotational torque;
• a first rotor;
• and,
• a first plurality of phaser chambers circumferentially bounded by the first stator and the first rotor;
• a plurality of first through-bores in the first rotor connected to a plurality of first phaser chambers included in the first plurality of phaser chambers;
• and,
• a plurality of second through-bores in the first rotor:
• connected to a plurality of second phaser chambers, the plurality of second phaser chambers included in the first plurality of phaser chambers and circumferentially interleaved with the plurality of first phaser chambers;
• a second hydraulic camshaft phaser including:
• a second stator non-rotatably connected to the first stator;
• a second rotor;
• and,
• a second plurality of phaser chambers circumferentially bounded by the second stator and the second rotor;
• a first trigger wheel:
• non-rotatably connected to the first rotor;
• arranged to identify a rotational position of the first rotor;
• and, including:
• a plurality of third through-bores connected to the plurality of first through-bores;
• and,
• a plurality of fourth through-bores connected to the plurality of second through-bores;
• and,
• a second trigger wheel:
• non-rotatably connected to the second rotor;
• and,
• arranged to identify a rotational position of the second rotor, wherein at least a portion of the plurality of fourth through-bores is radially inward of the plurality of third through-bores.

A method of using a camshaft phaser assembly, the camshaft phaser assembly including:

• a first hydraulic camshaft phaser with a stator, a rotor and a plurality of phaser chambers bounded by the stator and the rotor;
• a second hydraulic camshaft phaser;
• a first trigger wheel non-rotatably connected to the rotor;
• and a second trigger wheel connected to the second hydraulic camshaft phaser, the method comprising:
• non-rotatably connecting the rotor to a first camshaft of an internal combustion engine of a vehicle;
• starting the internal combustion engine;
• transmitting rotational torque from the internal combustion engine to the stator;
• rotating, with the rotational torque, the stator and the rotor;
• creating, with the rotation of the stator and the rotor, a thrust force;
• urging, with the thrust force, the first hydraulic camshaft phaser toward an engine block of the internal combustion engine;
• contacting the engine block with a surface of the first trigger wheel;
• identifying, using the first trigger wheel, a rotational position of the rotor;
• flowing oil to the plurality of phaser chambers:
• through a first plurality of through-bores in the first trigger wheel connected to a second plurality of through-bores in the rotor;
• and,
• through a third plurality of through-bores in the first trigger wheel connected to a fourth plurality of through-bores in the rotor;
• and,
• rotating the rotor with respect to the stator.