Switched cushion stop

Patent metadata

Field	Value
Publication number	US-10487701-B2
Application number	US-201815937905-A
Country	US
Kind code	B2
Filing date	Mar 28, 2018
Priority date	Mar 28, 2017
Publication date	Nov 26, 2019
Grant date	Nov 26, 2019

Abstract

A switched cushion stop for a variable cam timing phaser of a variable cam timing system is disclosed. The cushion stop may be actively controlled by the spool valve or passively controlled.

First claim

What is claimed is:

1. A variable cam timing phaser comprising:
a housing assembly having an outer circumference which accepts a drive force;
a rotor assembly connected to a camshaft, the rotor assembly coaxially located within the housing assembly, the rotor assembly having a rotor body with at least one vane extending from the rotor body, the at least one vane having a vane body with at least one protrusion extending laterally from the vane body, wherein the housing assembly and the rotor assembly define at least one chamber separated by the at least one vane into an advance chamber and a retard chamber, the at least one chamber defined by an advance wall and a retard wall, the at least one vane within the at least one chamber shifting relative angular position of the housing assembly and the rotor assembly and the at least one vane;
a control valve which directs fluid from a fluid input to and from the advance chamber and the retard chamber;
an advance line in fluid communication with the control valve and the advance chamber;
a retard line in fluid communication with the control valve and the retard chamber;
a cushion stop line in fluid communication with at least one of the advance chamber or the retard chamber;
a lock pin slidably located in the rotor assembly or the housing assembly in fluid communication with the control valve, the lock pin being moveable by the fluid from a locked position in which an end portion engages a recess, locking the relative angular position of the housing assembly and the rotor assembly, to an unlocked position, in which the end portion does not engage the recess;
wherein when the control valve is moved such that the fluid from the fluid input flows to the advance chamber or the retard chamber, and exhausts from a remaining chamber of the retard chamber or the advance chamber, the fluid exhausting from the remaining chamber is captured between the at least one vane, the cushion stop line, and the housing assembly, such that at least one cushion pocket is defined between the at least one protrusion of the at least one vane, the housing assembly, the cushion stop line and one of the retard wall or the advance wall, the at least one cushion pocket cushioning impact of the at least one vane with the one of the retard wall or the advance wall;
wherein when the fluid in the at least one cushion pocket exhausts to the control valve through an interface between the at least one protrusion of the at least one vane and the housing assembly, the lock pin is moved to the locked position; and
wherein when the fluid is provided to one of the advance chamber or the retard chamber through the cushion stop line and through a corresponding one of the advance line or the retard line from the control valve, the lock pin is moved to the unlocked position.

2. The phaser of claim 1 , wherein the cushion stop line further comprises a one-way valve.

3. The phaser of claim 1 , wherein the retard line further comprises a one-way valve.

4. The phaser of claim 1 , wherein the lock pin further comprises a body with a first land and a second land, the body being received within a sleeve having a port, wherein when the lock pin is in the unlocked position, the fluid flows between the first land and the second land through the port of the sleeve and when the lock pin is in the locked position, the fluid is blocked from flowing through the port by one of the first land or the second land of the body of the lock pin.

5. The phaser of claim 4 , wherein the lock pin is in further fluid communication with the advance chamber or the retard chamber through the cushion stop line.

6. The phaser of claim 1 , wherein the lock pin is in fluid communication with the retard chamber through the retard line.

7. The phaser of claim 1 , wherein the retard wall further comprises a recess which receives the at least one protrusion.

8. The phaser of claim 1 , wherein the advance wall further comprises a recess which receives the at least one protrusion.

9. The phaser of claim 1 , wherein the at least one cushion pocket exhausts the fluid through the interface to the control valve through the retard line.

10. The phaser of claim 1 , wherein the at least one cushion pocket exhausts the fluid to the cushion stop line and through the control valve to a tank.

11. A variable cam timing phaser comprising:
a housing assembly having an outer circumference which accepts a drive force;
a rotor assembly connected to a camshaft, the rotor assembly coaxially located within the housing assembly, the rotor assembly having a rotor body with at least one vane extending from the rotor body, the at least one vane having a vane body with at least one protrusion extending laterally from the vane body, wherein the housing assembly and the rotor assembly define at least one chamber separated by the at least one vane into an advance chamber and a retard chamber, the at least one chamber defined by an advance wall and a retard wall, the at least one vane within the at least one chamber shifting relative angular position of the housing assembly and the rotor assembly and the at least one vane;
a control valve which directs fluid from a fluid input to and from the advance chamber and the retard chamber;
an advance line in fluid communication with the control valve and the advance chamber;
a retard line in fluid communication with the control valve and the retard chamber;
a cushion stop line in fluid communication with at least one of the advance chamber or the retard chamber;
a lock pin slidably located in the rotor assembly or the housing assembly and in fluid communication with the control valve, the lock pin being moveable by the fluid from a locked position in which an end portion engages a recess, locking the relative angular position of the housing assembly and the rotor assembly, to an unlocked position, in which the end portion does not engage the recess;
wherein when the control valve is moved such that the fluid from the fluid input flows to the advance chamber and exhausts from the retard chamber, the fluid exhausting from the retard chamber is captured between the at least one vane, the retard line, a one-way valve, the retard wall and the at least one chamber of the housing assembly, such that at least one cushion pocket is defined between the at least one protrusion of the at least one vane, the housing assembly, the retard line and the retard wall, the at least one cushion pocket cushioning impact of the at least one vane with the retard wall;
wherein when the fluid in the at least one cushion pocket exhausts to the control valve through an interface between the rotor assembly and the housing assembly, and the control valve blocks the fluid from the fluid input from communicating with the lock pin, the lock pin is moved to the locked position; and
wherein when the fluid is provided to the retard chamber through the cushion stop line and through the retard line from the control valve, and the fluid from the fluid input is in communication with the lock pin, the lock pin is moved to the unlocked position.

12. A variable cam timing phaser comprising:
a housing assembly having an outer circumference which accepts a drive force;
a rotor assembly connected to a camshaft, the rotor assembly coaxially located within the housing assembly, the rotor assembly having a rotor body with a first vane and a second vane extending from the rotor body, the first vane having a vane body with at least one protrusion extending laterally from the vane body, wherein the housing assembly and the rotor assembly define a first chamber separated by the first vane into a first advance chamber and a first retard chamber, the

Assignees

• Borgwarner Inc

Inventors

• Mccloy Chad
• Kenyon Brian

Classifications

• F01L2001/34456

  Locking in only one position · CPC title

• F01L2001/3445

  Details relating to the hydraulic means for changing the angular relationship · CPC title

• F01L2001/34426

  Oil control valves · CPC title

• F01L1/3442 Primary

  using hydraulic chambers with variable volume to transmit the rotating force · CPC title

• F01L2001/34496

  Two phasers on different camshafts · CPC title