Apparatus and system comprising integrated master-slave pistons for actuating engine valves
View Patent ↗An apparatus for actuating first and second engine valves comprises a rocker arm that receives motion from primary and auxiliary valve actuation motion sources at a motion receiving end of the rocker arm. A master piston residing in a master piston bore in the rocker arm is configured to received motion from the auxiliary valve actuation motion source. A slave piston residing in a slave piston bore in the rocker arm is configured to provide auxiliary valve actuation motion to the first engine valve. A hydraulic circuit is provided in the rocker arm connecting the master piston bore and the slave piston bore, and a check valve is disposed within the rocker arm, configured to supply hydraulic fluid to the hydraulic circuit. The apparatus may be incorporated into a system comprising a rocker arm shaft and the primary and secondary valve actuation motion sources, such as an internal combustion engine.
1. An apparatus for actuating first and second engine valves associated with an engine cylinder, comprising:
a rocker arm configured to be disposed on a rocker arm shaft and to actuate the first and second engine valves, and further configured at a motion receiving end of the rocker arm to receive motion from a primary valve actuation motion source;
a master piston disposed in a master piston bore at a portion of the motion receiving end of the rocker arm separate from that portion of the motion receiving end of the rocker arm configured to receive motion from the primary valve actuation motion source and configured, at an end of the master piston extending out of the master piston bore, to receive motion from an auxiliary valve actuation motion source;
a slave piston disposed in a slave piston bore at a valve actuation end of the rocker arm opposite the motion receiving end of the rocker arm, the slave piston configured to provide auxiliary valve actuation motion to only the first of the first and second engine valves;
an hydraulic circuit within the rocker arm; and
a check valve disposed in the rocker arm and configured to supply hydraulic fluid to the hydraulic circuit,
wherein the hydraulic circuit connects the master piston bore and the slave piston bore.
2. The apparatus of claim 1 , the rocker arm further comprising, at the motion receiving end of the rocker arm, a cam roller configured to receive motion from the primary valve actuation motion source.
3. The apparatus of claim 1 , the rocker arm further comprising, at the motion receiving end of the rocker arm, a flat tappet configured to receive motion from the primary valve actuation motion source.
4. The apparatus of claim 1 , the master piston comprising, at the end of the master piston extending out of the master piston bore, a cam roller configured to receive motion from the auxiliary valve actuation motion source.
5. The apparatus of claim 1 , the master piston comprising, at the end of the master piston extending out of the master piston bore, a flat tappet configured to receive motion from the auxiliary valve actuation motion source.
6. The apparatus of claim 1 , wherein the master piston bore is formed in a master piston boss extending laterally from the rocker arm.
7. The apparatus of claim 1 , the rocker arm further comprising a primary valve actuator at the valve actuation end of the rocker arm.
8. The apparatus of claim 7 , wherein the primary valve actuator is located more distally than the slave piston relative to the motion receiving end of the rocker arm.
9. The apparatus of claim 1 , wherein the check valve is disposed within a control valve, the control valve disposed within a control valve bore of the rocker arm, and wherein the hydraulic circuit connects the master piston bore, the slave piston bore and the control valve bore.
10. The apparatus of claim 1 , the rocker arm comprising a rocker arm shaft bore configured to receive the rocker arm shaft, the rocker arm further comprising an hydraulic fluid supply passage providing fluid communication between the check valve and an hydraulic fluid supply port positioned on a surface of the rocker arm shaft bore.
11. The apparatus of claim 1 , wherein the rocker arm is an exhaust rocker arm.
12. The apparatus of claim 1 , wherein the rocker arm is an intake rocker arm.
13. A system for actuating first and second engine valves associated with an engine cylinder, comprising:
a rocker arm shaft;
a primary valve actuation motion source;
an auxiliary valve actuation motion source;
a rocker arm disposed on the rocker arm shaft, configured to actuate the first and second engine valves and further configured, at a motion receiving end of the rocker arm, to receive motion from the primary valve actuation motion source;
a master piston disposed in a master piston bore at a portion of the motion receiving end of the rocker arm separate from that portion of the motion receiving end of the rocker arm configured to receive motion from the primary valve actuation motion source and configured, at an end of the master piston extending out of the master piston bore, to receive motion from the auxiliary valve actuation motion source;
a slave piston disposed in a slave piston bore at a valve actuation end of the rocker arm opposite the motion receiving end of the rocker arm, the slave piston configured to provide auxiliary valve actuation motion to only the first of the first and second engine valves;
an hydraulic circuit within the rocker arm; and
a check valve disposed in the rocker arm and configured to supply hydraulic fluid to the hydraulic circuit,
wherein the hydraulic circuit connects the master piston bore and the slave piston bore.
14. The system of claim 13 , wherein the primary valve actuation motion source and the secondary valve actuation motion source comprise cams, the rocker arm further comprising, at the motion receiving end of the rocker arm, a primary cam roller configured to receive motion from the primary valve actuation motion source, and the master piston comprising, at the end of the master piston extending out of the master piston bore, an auxiliary cam roller configured to receive motion from the auxiliary valve actuation motion source.
15. The system of claim 13 , wherein the primary valve actuation motion source and the secondary valve actuation motion source comprise pushrods, the rocker arm further comprising, at the motion receiving end of the rocker arm, a primary ball or socket configured to receive motion from the primary valve actuation motion source, and the master piston comprising, at the end of the master piston extending out of the master piston bore, an auxiliary ball or socket configured to receive motion from the auxiliary valve actuation motion source.
16. The system of claim 13 , further comprising:
at least one fluid supply device configured to control supply of the hydraulic fluid to the check valve.
17. The system of claim 13 , wherein the master piston bore is formed in a master piston boss extending laterally from the rocker arm.
18. The system of claim 13 , the rocker arm further comprising a primary valve actuator at the valve actuation end of the rocker arm.
19. The system of claim 18 , wherein the primary valve actuator is located more distally than the slave piston relative to the motion receiving end of the rocker arm.
20. The system of claim 13 , wherein the check valve is disposed within a control valve, the control valve disposed within a control valve bore of the rocker arm, and wherein the hydraulic circuit connects the master piston bore, the slave piston bore and the control valve bore.
21. The system of claim 13 , the rocker arm comprising a rocker arm shaft bore configured to receive the rocker arm shaft, the rocker arm further comprising an hydraulic fluid supply passage providing fluid communication between the check valve and an hydraulic fluid supply port positioned on a surface of the rocker arm shaft bore.
22. The system of claim 13 , wherein the rocker arm is an exhaust rocker arm.
23. The system of claim 13 , wherein the rocker arm is an intake rocker arm.