Variable cam timing phaser utilizing series-coupled check valves

Patent metadata

Field	Value
Publication number	US-10731520-B2
Application number	US-201716306860-A
Country	US
Kind code	B2
Filing date	May 10, 2017
Priority date	Jun 8, 2016
Publication date	Aug 4, 2020
Grant date	Aug 4, 2020

Abstract

A variable cam timing phaser arrangement is disclosed, comprising: a rotor having at least one vane; a stator co-axially surrounding the rotor, having at least one recess for receiving the at least one vane, wherein the at least one vane divides the at least one recess into a first and second chambers; and a control assembly for regulating hydraulic fluid flow from the first chamber to the second chamber or vice-versa. The control assembly comprises a first check valve, a second check valve and a selective deactivation device. The check valves are arranged in series in a fluid passage between the first chamber and the second chamber. The selective deactivation device is deployable and is configured to selectively deactivate either the first check valve or the second check valve upon deployment. By timing the deployment of the deactivation device, the direction of flow between the first and second chambers can be controlled.

First claim

The invention claimed is:

1. A variable cam timing phaser arrangement for an internal combustion engine comprising:
a rotor having at least one vane, the rotor arranged to be connected to a camshaft;
a stator co-axially surrounding the rotor, having at least one recess for receiving the at least one vane of the rotor and allowing rotational movement of the rotor with respect to the stator, the stator having an outer circumference arranged for accepting drive force,
wherein the at least one vane divides the at least one recess into a first chamber and a second chamber, the first chamber and the second chamber being arranged to receive hydraulic fluid under pressure, wherein the introduction of hydraulic fluid into the first chamber causes the rotor to move in a first rotational direction relative to the stator and the introduction of hydraulic fluid into the second chamber causes the rotor to move in a second rotational direction relative to the stator, the second rotational direction being opposite the first rotational direction; and
a control assembly for regulating hydraulic fluid flow from the first chamber to the second chamber or vice-versa, wherein the control assembly comprises:
a first check valve;
a second check valve; and
a selective deactivation device,
wherein the first check valve and the second check valve are arranged in series in a fluid passage between the first chamber and the second chamber, wherein the first check valve is configured to prevent fluid flow in a first direction from the first chamber to the second chamber and to allow fluid flow in a second direction from the second chamber to the first chamber, and wherein the second check valve is configured to allow fluid flow in the first direction and to prevent fluid flow in the second direction,
wherein the selective deactivation device is deployable and is configured to selectively deactivate either the first check valve or the second check valve upon deployment, depending on the relative fluid pressure between the first chamber and the second chamber, whereby the deactivated first or second check valve allows fluid flow in both the first direction and second direction, and
wherein the first check valve is deactivated upon deployment of the selective deactivation device whenever the second chamber has overpressure, and wherein the second check valve is deactivated upon deployment of the selective deactivation device whenever the first chamber has overpressure.

2. The variable cam timing phaser arrangement according to claim 1 , wherein the hydraulic fluid is hydraulic oil.

3. A variable cam timing phaser arrangement for an internal combustion engine comprising:
a rotor having at least one vane, the rotor arranged to be connected to a camshaft;
a stator co-axially surrounding the rotor, having at least one recess for receiving the at least one vane of the rotor and allowing rotational movement of the rotor with respect to the stator, the stator having an outer circumference arranged for accepting drive force,
wherein the at least one vane divides the at least one recess into a first chamber and a second chamber, the first chamber and the second chamber being arranged to receive hydraulic fluid under pressure, wherein the introduction of hydraulic fluid into the first chamber causes the rotor to move in a first rotational direction relative to the stator and the introduction of hydraulic fluid into the second chamber causes the rotor to move in a second rotational direction relative to the stator, the second rotational direction being opposite the first rotational direction; and
a control assembly for regulating hydraulic fluid flow from the first chamber to the second chamber or vice-versa, wherein the control assembly comprises:
a first check valve;
a second check valve; and
a selective deactivation device,
wherein the first check valve and the second check valve are arranged in series in a fluid passage between the first chamber and the second chamber, wherein the first check valve is configured to prevent fluid flow in a first direction from the first chamber to the second chamber and to allow fluid flow in a second direction from the second chamber to the first chamber, and wherein the second check valve is configured to allow fluid flow in the first direction and to prevent fluid flow in the second direction,
wherein the first check valve comprises a first port in fluid communication with the first chamber, a second port, and a first valve member, wherein the first valve member is configured to allow flow from the second port of the first check valve to the first port of the first check valve, and to prevent flow from the first port of the first check valve to the second port of the first check valve; and wherein the second check valve comprises a first port in fluid communication with the second chamber, a second port in fluid communication with the second port of the first check valve, and a second valve member, wherein the second valve member is configured to allow flow from the second port of the second check valve to the first port of the second check valve, and to prevent flow from the first port of the second check valve to the second port of the second check valve, and
wherein the selective deactivation device is deployable and is configured to selectively deactivate either the first check valve or the second check valve upon deployment, depending on the relative fluid pressure between the first chamber and the second chamber, whereby the deactivated first or second check valve allows fluid flow in both the first direction and second direction.

4. The variable cam timing phaser arrangement according to claim 3 , wherein the selective deactivation device comprises at least one deactivation element that is movable from a disengaged position to an engaged position when the selective deactivation device is deployed, wherein the selective deactivation device when deployed selectively displaces either the first valve member or the second valve member.

5. The variable cam timing phaser arrangement according to claim 4 , wherein the selective deactivation device comprises:
a cylinder having a first end in fluid communication with the first chamber and a second end in fluid communication with the second chamber;
a cylinder member arranged in the cylinder and arranged to be moveable in a direction along a longitudinal axis of the cylinder between a first cylinder position by fluid pressure whenever the first chamber has overpressure, and a second cylinder position by fluid pressure whenever the second chamber has overpressure, wherein the cylinder member is arranged to be moveable in a radial direction relative to the longitudinal axis of the cylinder when in the first cylinder position or second cylinder position whenever the selective deactivation device is deployed;
a first deactivation element arranged to be moveable to an engaged position by the radial motion of the cylinder member whenever the selective deactivation device is deployed with the cylinder member in the second position, wherein the engaged first deactivation element displaces the first valve member; and
a second deactivation element arranged to be moveable to an engaged position by the radial motion of the cylinder member whenever the selective deactivation device is deployed with the cylinder member in the first position, wherein the engaged second deactivation element displaces the second valve member.

6. A variable cam timing phaser arrangement, for an internal combustion engine comprising:
a rotor having at least one vane, the rotor arranged to be connected to a camshaft;
a stator co-axially surrounding the rotor, having at least one recess for receiving the at least one vane of the rotor and allowing rotational movement of the

Assignees

• Scania Cv Ab

Inventors

• Olovsson Daniel
• Eriksson Mikael

Classifications

• F01L1/34409 Primary

  by torque-responsive means · CPC title

• F01L1/3442

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

• F01L2001/34433

  Location oil control valves · CPC title

• F01L1/356

  making the angular relationship oscillate {, e.g. non-homokinetic drive} · CPC title

• F01L2001/34426

  Oil control valves · CPC title