CAMSHAFT PHASER WITH COAXIAL CONTROL VALVES

• US 20120234275A1
• Filed: 03/16/2011
• Published: 09/20/2012
• Est. Priority Date: 03/16/2011
• Status: Active Grant

• Current Assignee: Delphi Technologies Ip Limited (BorgWarner Incorporated)
• Original Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Inventors: FISCHER, THOMAS H., LICHTI, THOMAS H.
• Granted Patent: US 8,662,039 B2
• Time in Patent Office: Days
• US Class Current: 123/90.17
• CPC Class Codes: F01L 1/344 changing the angular relationship between crankshaft and camshaft, e.g. using helicoidal gear
• CPC Class Codes: F01L 1/3442 using hydraulic chambers with variable volume to transmit the rotating force
• CPC Class Codes: F01L 2001/34426 Oil control valves
• CPC Class Codes: F01L 2001/3443 Solenoid driven oil control valves
• CPC Class Codes: F01L 2001/34433 Location oil control valves
• CPC Class Codes: F01L 2001/34453 Locking means between driving and driven members
• CPC Class Codes: F01L 2001/34479 Sealing of phaser devices

Abstract

A camshaft phaser is provided for varying the phase relationship between a crankshaft and a camshaft in an engine. The camshaft phaser includes a stator having lobes. A rotor is disposed within the stator includes vanes interspersed with the stator lobes to define alternating advance and retard chambers. A lock pin is provided for selective engagement with a lock pin seat for preventing relative rotation between the rotor and the stator. Pressurized oil disengages the lock pin from the seat while oil is vented for engaging the lock pin with the seat. A phase relationship control valve is coaxial with the rotor and controls the flow of oil into and out of the chambers. A lock pin control valve is coaxial with the phase relationship control valve and controls the flow of oil to and from the lock pin. The control valves are operational independent of each other.

Claims

1. A camshaft phaser for controllably varying the phase relationship between a crankshaft and a camshaft in an internal combustion engine, said camshaft phaser comprising:

a stator having a plurality of lobes and connectable to said crankshaft of said internal combustion engine to provide a fixed ratio of rotation between said stator and said crankshaft;

a rotor coaxially disposed within said stator and having a plurality of vanes interspersed with said stator lobes defining alternating advance chambers and retard chambers, wherein said advance chambers receive pressurized oil in order to change the phase relationship between said crankshaft and said camshaft in the advance direction and said retard chambers receive pressurized oil in order to change the phase relationship between said camshaft and said crankshaft in the retard direction, said rotor being attachable to said camshaft of said internal combustion engine to prevent relative rotation between said rotor and said camshaft;

a lock pin disposed within one of said rotor and said stator for selective engagement with a lock pin seat in the other of said rotor and said stator for substantially preventing relative rotation between said rotor and stator when said lock pin is engaged with said lock pin seat, wherein pressurized oil is selectively supplied to said lock pin in order to disengage said lock pin from said lock pin seat, and wherein oil is selectively vented from said lock pin in order to engage said lock pin with said lock pin seat;

a phase relationship control valve for controlling the flow of oil into and out of said advance and retard chambers, wherein said phase relationship control valve is coaxial with said rotor; and

a lock pin control valve for controlling the flow of oil to and from said lock pin, wherein said lock pin control valve is coaxial with said phase relationship control valve;

wherein said phase relationship control valve is operational independent of said lock pin control valve.

2. A camshaft phaser as in claim 1 further comprising a camshaft phaser attachment bolt extending coaxially through said rotor and said stator and threadably engageable into said camshaft to attach said camshaft phaser to said camshaft, wherein said phase relationship control valve and said lock pin control valve are disposed within a blind bore of said camshaft phaser attachment bolt.

3. A camshaft phaser as in claim 1 further comprising a phase relationship control valve actuator for actuating said phase relationship control valve and a lock pin control valve actuator for actuating said lock pin control valve.

4. A camshaft phaser as in claim 2 wherein said lock pin control valve comprises:

a hollow cylindrical manifold press fit within said blind bore and defining a manifold central bore; and

a lock pin valve spool within said manifold central bore and axially moveable between a lock pin disengaging position and a lock pin engaging position such that said lock pin disengaging position supplies pressurized oil to said lock pin and said lock pin engaging position vents oil from said lock pin.

5. A camshaft phaser as in claim 4 wherein said manifold defines a first end and a second end and comprises:

a plurality of manifold axial grooves extending only part way axially and radially into the outer circumference of said manifold from said first end for receiving pressurized oil from said internal combustion engine;

a plurality of manifold supply connecting passages extending radially through said manifold to provide fluid communication between each of said axial grooves and said manifold central bore;

a plurality of blind axial grooves extending only part way axially and radially into the outside diameter of said manifold, wherein said plurality of blind axial grooves do not extend to said first end and said second end, and wherein each one of said plurality of said blind axial grooves is located azimuthally between a pair of said manifold axial grooves;

a plurality of lock pin connecting passages extending radially through said manifold to provide fluid communication between each of said blind axial grooves and said manifold central bore;

a plurality of vent grooves extending only part way axially and radially into the outer circumference of said manifold from said second end;

a plurality of vent connecting passages extending radially through said manifold to provide fluid communication between each of said vent grooves and said manifold central bore.

6. A camshaft phaser as in claim 5 further comprising a bushing adaptor coaxially disposable within a pocket of said camshaft and coaxially disposed within said rotor such that said camshaft phaser attachment bolt extends coaxially through said bushing adaptor in a close fitting relationship, wherein said bushing adaptor defines at least in part:

a supply passage for communicating pressurized oil from said internal combustion engine to a phase relationship control valve, said supply passage being defined at least in part by a first annular groove formed on the inside surface defining the inside diameter of said bushing adapter;

an advance passage for selectively communicating pressurized oil from said phase relationship control valve to said advance chambers; and

a retard passage for selectively communicating pressurized oil from said phase relationship control valve to said retard chambers.

7. A camshaft phaser as in claim 6 wherein said supply passage is further defined by an axial groove formed in the inside surface of said rotor, said axial groove being in fluid communication with said first annular groove through a first connecting passage extending radially through said bushing adaptor.

8. A camshaft phaser as in claim 7 wherein said supply passage is further defined by a second annular groove formed on the inside diameter of said bushing adapter, said second annular groove being in fluid communication with said axial groove through a second connecting passage extending radially through said bushing adaptor.

9. A camshaft phaser as in claim 8 wherein said second annular groove is disposable within said pocket of said camshaft.

10. A camshaft phaser as in claim 8 wherein said supply passage is further defined by a third annular groove formed on the outside diameter of said bushing adapter, said third annular groove being in fluid communication with said axial groove and said second connecting passage.

11. A camshaft phaser as in claim 6 wherein one of said advance passage and said retard passage is defined by a fourth annular groove formed on the inside diameter of said bushing adaptor.

12. A camshaft phaser as in claim 11 wherein the other of said advance passage and said retard passage is defined by an axial space formed between an axial end of said bushing adaptor and said camshaft phaser attachment bolt.

13. A camshaft phaser as in claim 5 wherein said camshaft phaser attachment bolt comprises:

a first radial passage therethrough for communicating pressurized oil from said internal combustion engine to said blind bore; and

a second radial passage therethrough for communicating pressurized oil from said blind bore to said manifold axial grooves.

14. A camshaft phaser as in claim 10 wherein said manifold axial grooves are in fluid communication with said third annular groove for supplying pressurized oil to said third annular groove.

15. A camshaft phaser as in claim 6 wherein a fifth annular groove formed on the inside diameter of said bushing adapter defines in part a passage for providing fluid communication between said manifold central bore and said lock pin.