US 9,810,108 B2
Engine variable camshaft timing phaser with planetary gear assembly
Larry A. Pritchard, Macomb, MI (US); Thomas R. Benner, Lansing, NY (US); and Christopher J. Pluta, Lansing, NY (US)
Assigned to BorgWarner Inc., Auburn Hills, MI (US)
Appl. No. 15/507,526
Filed by BorgWarner Inc., Auburn Hills, MI (US)
PCT Filed Aug. 24, 2015, PCT No. PCT/US2015/046470
§ 371(c)(1), (2) Date Feb. 28, 2017,
PCT Pub. No. WO2016/036529, PCT Pub. Date Mar. 10, 2016.
Claims priority of provisional application 62/045,731, filed on Sep. 4, 2014.
Prior Publication US 2017/0248045 A1, Aug. 31, 2017
Int. Cl. F01L 1/344 (2006.01); F01L 1/348 (2006.01); F01L 1/047 (2006.01); F01L 1/34 (2006.01); F01L 1/08 (2006.01); F01L 1/352 (2006.01)
CPC F01L 1/348 (2013.01) [F01L 1/047 (2013.01); F01L 1/34413 (2013.01); F01L 1/08 (2013.01); F01L 1/34 (2013.01); F01L 1/3442 (2013.01); F01L 1/34403 (2013.01); F01L 1/34409 (2013.01); F01L 1/352 (2013.01); F01L 2001/34459 (2013.01); F01L 2250/04 (2013.01); F01L 2820/01 (2013.01); F01L 2820/032 (2013.01)] 15 Claims
OG exemplary drawing
 
1. An engine variable camshaft timing phaser (10), comprising:
a sprocket (12) receiving rotational drive input from an engine crankshaft;
a planetary gear assembly (14) comprising:
at least two ring gears (26, 28), one of said at least two ring gears (26, 28) receiving rotational drive input from said sprocket (12) and one of said at least two ring gears (26, 28) transmitting rotational drive output to an engine camshaft;
a plurality of planet gears (24) engaged with said at least two ring gears (26, 28);
a sun gear (22) engaged with said plurality of planet gears (24); and
a wrap spring (76) having a pair of ends (82, 84), said wrap spring (76) interrelated with said sun gear (22) for causing abutment with one of said pair of ends (82, 84) and expansion or contraction exertions of said wrap spring (76);
wherein, when said planetary gear assembly (14) is driven by an electric motor (32), abutment with one of said pair of ends (82, 84) permits relative rotation between said sprocket (12) and the engine camshaft for advancing or retarding engine valve opening and closing, and when said planetary gear assembly (14) is back-driven by the engine camshaft, abutment with one of said pair of ends (82, 84) prevents relative rotation between said sprocket (12) and the engine camshaft to preclude advancing or retarding engine valve opening and closing.