Valve lifter anti-rotation device and valve lifter assembly in valve actuation system

An anti-rotation device for valve lifters in a valve actuation system comprising:

• a collar including a sleeve portion and a boss portion;
• the sleeve portion including an inner peripheral guide surface forming a lifter bore defining a bore center axis,
• the inner peripheral guide surface including a plurality of inner planar surfaces in an alternating arrangement with a plurality of inner arcuate surfaces;
• the inner peripheral guide surface having a shape that is varied, circumferentially around the bore center axis, to limit rotation of a first valve lifter slidably received in the lifter bore;
• the boss portion including an outer peripheral surface facing a radially outward direction;
• a bridge connector projecting from the outer peripheral surface for engagement with a second valve lifter;
• the outer peripheral surface includes an outer planar surface located opposite to one of the plurality of inner planar surfaces, and a radial thickness of the boss portion is defined between the outer planar surface and the one of the plurality of inner planar surfaces;
• and
• the sleeve portion includes an arcuate band originating and terminating at the boss portion.

An engine valve actuation system comprising:

• a rotatable camshaft including a first cam having a first cam profile about a cam axis of rotation, and a second cam having a second cam profile, different from the first cam profile, about the cam axis of rotation;
• a first valve lifter including a lifting surface structured to actuate a first valve in the engine, and a cam follower in contact with the first cam to reciprocate the first valve lifter in response to rotation of the first cam;
• a second valve lifter including a lifting surface structured to actuate a second valve in the engine, and a cam follower in contact with the second cam to reciprocate the second valve lifter in response to rotation of the second cam;
• an anti-rotation device including, a collar having a sleeve portion with an inner peripheral guide surface forming a lifter bore and a boss portion having an outer peripheral surface, and first and second bridge connectors projecting from the outer peripheral surface;
• the first valve lifter is slidably received in the lifter bore and in contact with the inner peripheral guide surface to inhibit rotation of the first valve lifter;
• and
• the second valve lifter includes a first carrying recess and a second carrying recess formed therein and receiving, respectively, the first bridge connector and the second bridge connector, whereby the second valve lifter is fixedly coupled to the bridge connector, such that the anti-rotation device is moved with the second valve lifter, and relative to the first valve lifter, between a lifted position and a dropped position in response to the rotation of the second cam.