Engine braking system
AssigneeDeere & Company
InventorsKyle D. Redfern, Neil S. Erickson, Gregory J. Horton
Life of this patent
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Abstract
An engine braking system includes a camshaft, a follower, an exhaust armature, a lever, and a hydraulically actuated piston. The camshaft includes at least one cam. The cam has a lobe and a brake bump. The follower engages the cam. The exhaust armature is coupled to the follower. The lever is coupled to the exhaust armature. The hydraulically actuated piston moves the lever. Hydraulic actuation of the piston causes a change in lash distance between the cam and the follower. In an engine brake mode, the follower contacts the cam throughout rotation of the cam.
Claims18
An engine braking system comprising:
- a camshaft including a plurality of cams, each cam having a lobe and a brake bump;
- a plurality of followers, each follower configured to engage a respective cam of the plurality of cams;
- a plurality of exhaust armatures, each exhaust armature coupled to a respective follower of the plurality of followers;
- a mount shaft having a longitudinal axis, each exhaust armature rotatably coupled to the mount shaft, the mount shaft being rotationally static about the longitudinal axis;
- a plurality of levers, each lever coupled to a respective exhaust armature of the plurality of exhaust armatures;
- and
- a plurality of hydraulically actuated pistons, each hydraulically actuated piston configured to move a respective lever of the plurality of levers,
- wherein
- actuation of each piston causes a change in lash distance between the respective cam and the respective follower, and
- in an engine brake mode, a balance of forces causes the respective follower to automatically adjust to reduce the lash distance below a threshold value and thereby contact the respective cam throughout rotation of the respective cam, and fluid remains trapped behind each piston throughout the engine brake mode.
A method of operating an engine braking system, the method comprising:
- receiving a signal to engage the engine braking system;
- opening a fluid valve in response to the signal;
- introducing fluid through the valve to hydraulically move a plurality of pistons;
- engaging a lever with each piston of the plurality of pistons due to movement of the respective piston, the lever being one of a plurality of levers, and each lever of the plurality of levers being engageable by the respective piston of the plurality of pistons;
- changing a position of an exhaust armature coupled to the lever due to movement of the lever, the exhaust armature being one of a plurality of exhaust armatures, and each exhaust armature of the plurality of exhaust armatures being statically coupled to a respective eccentric bushing, each eccentric bushing at least partially surrounding a common mount shaft, the eccentric bushing being statically coupled to a respective lever of the plurality of levers;
- reducing a lash distance between a cam and a follower due to movement of the exhaust armature, the follower coupled to the exhaust armature, the cam being one of a plurality of cams on a camshaft, the follower being one of a plurality of followers corresponding to respective cams of the plurality of cams, and each follower of the plurality of followers being coupled to each exhaust armature of the plurality of exhaust armatures;
- contacting the cam with the follower throughout rotation of the cam in an engine brake mode due to a balance of forces causing the follower to automatically adjust to reduce the lash distance below a threshold value;
- and
- trapping fluid behind each piston of the plurality of pistons throughout the engine brake mode.
Dependencies are inferred from the claim text.