# US 2014/0190429 A1 · Systems and methods for variable valve actuation

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- Number: US 2014/0190429 A1
- Document ID: US20140190429A1
- Status: Published application
- Kind: A1
- Application number: 14/234,433
- Filed: 2012-08-09
- Published: 2014-07-10
- Earliest claimed: 2011-08-09
- Inventors: Amir Khajepour; Mohammad Pournazeri
- Web page: https://patentgrep.com/patent/US20140190429A1

## CPC

- F01L 9/11: in which the action of a cam is being transmitted to a valve by a liquid column
- F01L 1/344: changing the angular relationship between crankshaft and camshaft, e.g. using helicoidal gear
- F01L 9/10: by fluid means, e.g. hydraulic
- F01L 25/02: by fluid means
- F01L 2820/032: Electric motors
- F01L: CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES

## Abstract

The disclosure is directed at a valvetrain actuation (VA) system for an engine comprising at least two hydraulic rotary valves connected to an engine crankshaft, at least one hydraulic actuator driven by the at least two hydraulic rotary valves, and a high pressure hydraulic fluid source for supplying hydraulic fluid to one of the at least two hydraulic rotary valves, wherein movement of the at least two hydraulic rotary valves by the engine crankshaft allows hydraulic fluid to flow to the at least one hydraulic actuator to actuate an engine valve.

## Claims

### Claim 1

A valvetrain actuation (VA) system for an engine comprising:
at least two hydraulic rotary valves connected to an engine crankshaft;
at least one hydraulic actuator driven by the at least two hydraulic rotary valves; and
a high pressure hydraulic fluid source for supplying hydraulic fluid to one of the at least two hydraulic rotary valves;
wherein movement of the at least two hydraulic rotary valves by the engine crankshaft allows hydraulic fluid to flow to the at least one hydraulic actuator to actuate an engine valve.

### Claim 2 (depends on 1)

The VA system of claim 1 wherein a second of the at least two hydraulic rotary valves receives hydraulic fluid from the at least one hydraulic actuator.

### Claim 3 (depends on 2)

The VA system of claim 2 wherein the hydraulic rotary valves are rotary spool valves.

### Claim 4 (depends on 2)

The VA system of claim 2 further comprising an oil reservoir for receiving the hydraulic fluid from the second hydraulic rotary valve.

### Claim 5 (depends on 4)

The VA system of claim 4 wherein the oil reservoir is connected with the high pressure hydraulic fluid source via a hydraulic pump.

### Claim 6 (depends on 1)

The VA system of claim 1 further comprising individual phase shifters between the engine and the at least two hydraulic rotary valves.

### Claim 7 (depends on 6)

The VA system of claim 6 wherein the phase shifter is a differential gearbox.

### Claim 8 (depends on 7)

The VA system of claim 7 wherein the differential gearbox is driven by an electronic motor.

### Claim 9 (depends on 1)

The VA system of claim 1 further comprising a lift controller for controlling hydraulic pressure of the hydraulic fluid source to adjust a lift of the engine valve.

### Claim 10

A method of hydraulically controlling an engine valve comprising:
supplying pressurized hydraulic fluid to one of at least two hydraulic rotary valves;
driving the at least two hydraulic rotary valves with an engine crankshaft;
wherein the driving of the at least two hydraulic rotary valves causes the one of the at least two hydraulic rotary valves to supply the hydraulic fluid to at least one hydraulic actuator to actuate an engine valve in a first direction.

### Claim 11 (depends on 10)

The method of claim 10 further comprising:
receiving the hydraulic fluid from the at least one hydraulic actuator at a second of the at least two hydraulic rotary valves allowing the at least one hydraulic actuator to actuate the engine valve in a direction opposite the first direction; and
transmitting the hydraulic fluid from the second hydraulic rotary valve to an oil reservoir.

### Claim 12 (depends on 11)

The method of claim 11 further comprising:
phase shifting the at least two hydraulic rotary valves.

### Claim 13 (depends on 10)

The method of claim 10 further comprising, before supplying pressurized hydraulic fluid, controlling a pressure level of the pressurized hydraulic fluid.

### Claim 14 (depends on 10)

The method of claim 10 further comprising, after supplying the hydraulic fluid to the at least one hydraulic actuator, stopping the flow of hydraulic fluid via movement of the engine crankshaft.

### Claim 15 (depends on 14)

The method of claim 14 further comprising:
driving a second of the at least two hydraulic rotary valves, in a low pressure environment, to receive hydraulic fluid from the at least one hydraulic actuator.

### Claim 16 (depends on 15)

The method of claim 15 wherein driving the second of the at least two hydraulic rotary valves occurs concurrently with stopping the flow of hydraulic fluid.

### Claim 17 (depends on 15)

The method of claim 15 wherein driving the second of the at least two hydraulic rotary valves occurs after stopping the flow of hydraulic fluid.