Hydraulic variable camshaft timing with a temperature based hydraulic switch

Patent metadata

Field	Value
Publication number	US-12392265-B2
Application number	US-202318197997-A
Country	US
Kind code	B2
Filing date	May 16, 2023
Priority date	May 16, 2022
Publication date	Aug 19, 2025
Grant date	Aug 19, 2025

Abstract

A hydraulic variable camshaft timing (VCT) assembly including a stator having at least one fluid chamber; and a rotor, received by and angularly displaceable relative to the stator, having at least one vane positioned within the fluid chamber extending radially outwardly from a hub, and a hydraulic switch assembly positioned in the rotor to regulate a flow of fluid between an advancing chamber and a retarding chamber through the vane.

First claim

What is claimed is:

1. A hydraulic variable camshaft timing (VCT) assembly, comprising:
a stator having at least one fluid chamber; and
a rotor, received by and angularly displaceable relative to the stator, having at least one vane positioned within the at least one fluid chamber extending radially outwardly from a hub, and a contorted fluid path positioned in the rotor to regulate a flow of fluid between an advancing chamber and a retarding chamber, further comprising a chamber logic valve that controls a flow of fluid to the advancing chamber or the retarding chamber based on a rate of fluid flow through the contorted fluid path and a short logic valve that controls a flow of fluid through a shorting fluid path, wherein the contorted fluid path selectively impedes the flow of fluid through the contorted fluid path depending on temperature.

2. The hydraulic VCT assembly recited in claim 1 , wherein the contorted fluid path impedes the flow of fluid within the at least one fluid chamber at lower temperatures.

3. The hydraulic VCT assembly recited in claim 2 , wherein the contorted fluid path comprises a rod or plug having fluid channels formed on an outer radial surface.

4. The hydraulic VCT assembly recited in claim 1 , wherein the short logic valve and the chamber logic valve comprise spool valves.

5. The hydraulic VCT assembly recited in claim 4 , wherein the spool valves are biased by springs in a position that permits fluid flow.

6. The hydraulic VCT assembly recited in claim 4 , wherein the short logic valve and the chamber logic valve move linearly parallel with an axis of camshaft rotation.

7. The hydraulic VCT assembly recited in claim 1 , further comprising no more than one fluid logic valve.

8. A hydraulic variable camshaft timing (VCT) assembly, comprising:
a stator having at least one fluid chamber;
a rotor, received by and angularly displaceable relative to the stator, having at least one vane positioned within the at least one fluid chamber extending radially outwardly from a hub, and a contorted fluid path positioned in the rotor further comprising a dual logic valve that controls a flow of fluid through a shorting fluid path between advancing and retarding chambers based on a rate of fluid flow through the contorted fluid path as well as a flow of fluid from a control valve to either the advancing chamber or retarding chamber to prevent a flow of fluid between the advancing chamber and the retarding chamber at or below a predetermined temperature and permit the flow of fluid between the advancing chamber and the retarding chamber above the predetermined temperature.

9. The hydraulic VCT assembly recited in claim 8 , wherein the contorted fluid path comprises a rod or plug having fluid channels formed on an outer radial surface.

10. The hydraulic VCT assembly recited in claim 8 , further comprising a short logic valve and a chamber logic valve.

11. The hydraulic VCT assembly recited in claim 10 , wherein the short logic valve and the chamber logic valve comprise spool valves.

12. The hydraulic VCT assembly recited in claim 11 , wherein the spool valves are biased by springs in a position that permits fluid flow.

13. The hydraulic VCT assembly recited in claim 8 , further comprising no more than one fluid logic valve.

Assignees

• Borgwarner Inc

Inventors

• Bruce Adam
• Feldt Keith
• Wing Braman

Classifications

• F01L2001/34426

  Oil control valves · CPC title

• F01L2001/34423

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• F01L2001/34453

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• F01L2001/34433

  Location oil control valves · CPC title

• F01L1/3442 Primary

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