US 12,421,877 B2
Variable cam timing phaser and system including the same
Braman C. Wing, Ithaca, NY (US); Keith Feldt, Ithaca, NY (US); Adam Bruce, Ithaca, NY (US); and Chris Thomas, Dryden, NY (US)
Assigned to BorgWarner Inc., Auburn Hills, MI (US)
Filed by BorgWarner Inc., Auburn Hills, MI (US)
Filed on Apr. 16, 2024, as Appl. No. 18/636,424.
Application 18/636,424 is a continuation of application No. 17/842,898, filed on Jun. 17, 2022, granted, now 12,000,315.
Claims priority of provisional application 63/220,079, filed on Jul. 9, 2021.
Prior Publication US 2024/0263570 A1, Aug. 8, 2024
Int. Cl. F01L 1/344 (2006.01); F01L 1/02 (2006.01)
CPC F01L 1/3442 (2013.01) [F01L 1/022 (2013.01); F01L 2001/34426 (2013.01); F01L 2001/34433 (2013.01); F01L 2001/34446 (2013.01); F01L 2001/3445 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A variable cam timing phaser of a variable cam timing system, with the variable cam timing system including a camshaft, said variable cam timing phaser comprising:
a housing having a housing wall disposed about an axis and defining a housing interior;
a rotor at least partially disposed within said housing interior and moveable with respect to said housing, with said rotor having a hub and a plurality of vanes extending from said hub away from said axis toward said housing wall, and with said rotor and said housing defining an advance chamber and a retard chamber; and
a control valve assembly comprising,
a valve housing extending along an axis of said valve housing and defining a valve housing interior, with said valve housing also defining a supply port for supplying hydraulic fluid to said valve housing interior, a first working port, a second working port, and an exhaust port, with said first working port being fluidly connectable with one of said advance chamber and said retard chamber, and with said second working port being fluidly connectable with the other of said advance chamber and said retard chamber, and
a piston disposed in said valve housing interior and moveable along said axis of said valve housing for controlling flow of the hydraulic fluid through said valve housing interior;
wherein said exhaust port is fluidly connectable with a sump through a vent path that is defined by at least one of said valve housing and said rotor;
wherein during a torque reversal of the camshaft said vent path is fluidly connectable with one of said advance and retard chambers and is configured to prevent air from being sucked into said variable cam timing phaser through said vent path;
wherein said variable cam timing phaser is free of a check valve in said vent path;
wherein said vent path defines a reservoir having a reservoir volume;
wherein said variable cam timing phaser further comprises an outer plate coupled to said housing; and
wherein said reservoir is collectively defined by said rotor and said outer plate.