US 12,031,462 B2
Self-contained compression brake control module for integrated rocker arm engine braking and methods
Kody Taylor, Surrey (CA); and Peter Stec, Vancouver (CA)
Assigned to Pacbrake Company, Blaine, WA (US)
Filed by Pacbrake Company, Blaine, WA (US)
Filed on Jun. 20, 2023, as Appl. No. 18/211,890.
Claims priority of provisional application 63/353,890, filed on Jun. 21, 2022.
Prior Publication US 2023/0407773 A1, Dec. 21, 2023
Int. Cl. F01L 13/06 (2006.01); F01L 1/18 (2006.01); F01L 1/24 (2006.01); F01L 1/26 (2006.01); F01L 1/46 (2006.01)
CPC F01L 13/06 (2013.01) [F01L 1/181 (2013.01); F01L 1/2411 (2013.01); F01L 1/267 (2013.01); F01L 1/46 (2013.01); F01L 13/065 (2013.01)] 17 Claims
OG exemplary drawing
 
1. An exhaust rocker assembly for operating at least one exhaust valve of an internal combustion engine during a compression-release engine braking operation, the exhaust rocker assembly comprising:
an exhaust rocker arm; and
a self-contained compression brake control module mounted to the exhaust rocker arm and operatively coupled to the at least one exhaust valve so as to control a lift and a phase angle of the at least one exhaust valve, the compression brake control module maintaining the at least one exhaust valve open during a compression stroke of the internal combustion engine when in the compression-release engine braking operation, the compression brake control module comprising:
a hollow casing including a single-piece body mounted in the exhaust rocker arm, the casing defining an internal actuator cavity, and a hollow inner portion extending away from the internal actuator cavity;
a hollow actuation piston disposed outside the casing and in the exhaust rocker arm so as to receive the inner portion, the actuation piston defining a variable volume hydraulic actuation piston cavity between the casing and the actuation piston, the actuation piston reciprocating relative to the inner portion between an extended position and a collapsed position, the actuation piston configured to engage the at least one exhaust valve when in the extended position;
a connecting passage arranged in the casing so as to fluidly connect the actuation piston cavity to the internal actuator cavity;
a reset check valve arranged between the connecting passage and the actuation piston cavity, the reset check valve configured to hydraulically lock the actuation piston cavity when a pressure of hydraulic fluid within the actuation piston cavity exceeds a pressure of hydraulic fluid in a supply port formed in the casing, the reset check valve biased closed via a biasing spring;
a compression brake actuator slidably arranged in the internal actuator cavity so as to control the reset check valve, the compression brake actuator including a control piston exposed to atmospheric pressure, the control piston configured to reciprocate between an extended position and a retracted position; and
a control piston spring biasing the control piston toward the extended position in which the control piston engages and opens the reset check valve solely via a biasing force of the control piston spring so as to unlock the actuation piston cavity and fluidly connect the actuation piston cavity to the supply port;
wherein the actuation piston includes an inner peripheral surface defining a groove, and a retaining ring mounted to the groove,
wherein the inner portion includes an outer peripheral surface defining an inner stopping surface, and
wherein the retaining ring is configured to engage the inner stopping surface so as to stop movement of the actuation piston relative to the casing when the actuation piston reaches the extended position when the retaining ring engages the inner stopping surface.