Switched cushion stop

Patent metadata

Field	Value
Publication number	US-2018283232-A1
Application number	US-201815937905-A
Country	US
Kind code	A1
Filing date	Mar 28, 2018
Priority date	Mar 28, 2017
Publication date	Oct 4, 2018
Grant date	—

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 for accepting drive force; a rotor assembly for connection to a camshaft, coaxially located within the housing assembly, the rotor assembly having a rotor body with at least one vane extending therefrom, 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 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 chamber acting to shift relative angular position of the housing assembly and the rotor assembly and the at least one vane; a control valve for directing fluid from a fluid input to and from the advance chamber and the retard chamber through an advance line, a retard line, a cushion stop line, an inlet line coupled to the fluid input and at least one exhaust line; 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 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 fluid from the fluid input flows to the advance chamber or the retard chamber, and exhausts from the other of the retard chamber or the advance chamber, fluid input exhausting from the retard chamber or the advance chamber is captured between the vane, the cushion stop line, and the housing assembly, such that at least one cushion pocket is defined between the protrusion of the at least one vane, the housing assembly, the cushion stop line and the retard wall or the advance wall, the at least one cushion pocket cushioning impact of the at least one vane with the retard wall or the advance wall; wherein when fluid in the at least one cushion pocket exhausts to the control valve through an interface between the protrusion of the vane and the housing assembly, the lock pin is moved to the locked position; and wherein when fluid is provided to the advance chamber or the retard chamber through the cushion stop line, and 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 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 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 for receiving the protrusion.

8 . The phaser of claim 1 , wherein the advance wall further comprises a recess for receiving the protrusion.

9 . The phaser of claim 1 , wherein the at least one cushion pocket exhausts 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 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 for accepting drive force; a rotor assembly for connection to a camshaft, coaxially located within the housing assembly, the rotor assembly having a rotor body with at least one vane extending therefrom, 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 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 chamber acting to shift relative angular position of the housing assembly and the rotor assembly and the at least one vane; a control valve for directing fluid from a fluid input to and from the advance chamber and the retard chamber through an advance line, a retard line having a one-way valve, a cushion stop line, an inlet line coupled to the fluid input and at least one exhaust line; 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 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 fluid from the fluid input flows to the advance chamber and exhausts from the retard chamber, fluid input flowing from the retard chamber is captured between the vane, the retard line, the one-way valve, the retard wall and the chamber of the housing assembly, such that at least one cushion pocket is defined between the 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 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 fluid from the fluid input from communicating with the lock pin, the lock pin is moved to the locked position; and wherein when fluid is provided to the retard chamber through the cushion stop line, and the retard line, through the one-way valve from the control valve, and 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 for accepting drive force; a rotor assembly for connection to a camshaft, coaxially located within the housing assembly, the rotor assembly having a rotor body with at least a first vane and a second vane extending therefrom, 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 first chamber defined by a first advance wall and a first retard wall, and wherein the housing assembly and rotor assembly define a second chamber separated by the second vane into a second advance chamber and a second retard chamber, the second chamber defined by a second advance wall and a second retard wall, the first vane and the second vane acting to shift relative angular position of the housing assembly and the rotor assembly; a control valve for directing fluid from a fluid input to and from the first advance chamber, the second advance chamber,

Assignees

• Borgwarner Inc

Inventors

• Mccloy Chad
• Kenyon Brian

Classifications

• F01L1/3442 Primary

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

• F01L2250/02

  the camshaft being driven by chains · CPC title

• F01L2001/34456

  Locking in only one position · CPC title

• F01L2250/06

  the camshaft being driven by gear wheels · CPC title

• F01L2001/34483

  Phaser return springs · CPC title