# US 9,435,326 B2 · Hydraulic pressure supply system of automatic transmission

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- Number: US 9,435,326 B2
- Document ID: US9435326B2
- Status: Granted
- Kind: B2
- Application number: 14/081,781
- Filed: 2013-11-15
- Published: 2014-10-02
- Granted: 2016-09-06
- Earliest claimed: 2013-04-02
- Assignees: Hyundai Motor Company
- Applicants: Hyundai Motor Company
- Inventors: Se Hwan Jo; Jin Young Hwang; Taehwan Wi
- Web page: https://patentgrep.com/patent/US9435326B2

## CPC

- F04B 23/04: Combinations of two or more pumps
- F04B 49/002: {Hydraulic systems to change the pump delivery}
- F04B 49/022: {by means of pressure}
- F04B 49/035: Bypassing
- F04B 49/08: Regulating by delivery pressure
- F16H 61/0021: {Generation or control of line pressure}
- F16H 61/0267: {Layout of hydraulic control circuits, e.g. arrangement of valves}
- F04B 2205/06: Pressure in a (hydraulic) circuit
- F04B: POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS (machines for liquids, or pumps, of rotary-piston or oscillating-piston type F04C; non-positive-displacement pumps F04D; pumping of fluid by direct contact of another fluid or by using inertia of fluid to be pumped F04F)
- F16H: GEARING

## Abstract

An automatic-transmission hydraulic pressure supply system includes a low-pressure hydraulic pump supplying low hydraulic pressure to a first low-pressure line, a low-pressure regulator valve recirculating through a first recirculation line a portion of the hydraulic pressure supplied through the first low-pressure line to regulate the hydraulic pressure of the first low-pressure line, and supplying the regulated hydraulic pressure to a low pressure portion through a second low-pressure line, a high-pressure hydraulic pump receiving a portion of the hydraulic pressure of the first low-pressure line, increasing and supplying the increased hydraulic pressure to a high pressure portion through a high-pressure line, and a high-pressure regulator valve recirculating a portion of the hydraulic pressure supplied through the high-pressure line through second and/or third recirculation lines, and supplying the regulated hydraulic pressure to the high pressure portion.

## Claims

### Claim 1

A hydraulic pressure supply system of an automatic transmission for a vehicle, comprising:
a low-pressure hydraulic pump receiving oil from an oil pan through an input line, generating a low hydraulic pressure to the oil and supplying the oil of the low hydraulic pressure to a first low-pressure line;
a low-pressure regulator valve connected to the first low-pressure line, recirculating through a first recirculation line a portion of the oil of the low hydraulic pressure supplied through the first low-pressure line directly to the input line to regulate the low hydraulic pressure of the first low-pressure line, and supplying the regulated low hydraulic pressure to a low pressure portion through a second low-pressure line;
a high-pressure hydraulic pump connected to the first low-pressure line, receiving a portion of the oil of the low hydraulic pressure in the first low-pressure line, increasing the low hydraulic pressure to a high hydraulic pressure, and supplying the oil of the increased hydraulic pressure to a high pressure portion through a high-pressure line; and
a high-pressure regulator valve connected to the high-pressure line, recirculating a portion of the oil of the high hydraulic pressure supplied through the high-pressure line directly to the first low-pressure line through a second recirculation line, selectively recirculating a portion of the oil of the high hydraulic pressure supplied through the high-pressure line to the second recirculation line through a third recirculation line, and supplying the oil of the high hydraulic pressure regulated through the high-pressure regulator valve to the high pressure portion,
wherein the third recirculation line is selectively connected to the second recirculation line according to a strength of the high hydraulic pressure of the oil in the high-pressure line.

### Claim 2 (depends on 1)

The hydraulic pressure supply system of claim 1, wherein the low-pressure hydraulic pump is driven by a low-pressure motor and the high-pressure hydraulic pump is driven by a high-pressure motor.

### Claim 3 (depends on 1)

The hydraulic pressure supply system of claim 1, wherein the high-pressure regulator valve recirculates the oil of the high hydraulic pressure through the second recirculation line if the high hydraulic pressure of the high-pressure line is lower than a predetermined value, and recirculates the oil of the high hydraulic pressure through the second and third recirculation lines if the high hydraulic pressure of the high-pressure line is higher than or equal to the predetermined value.

### Claim 4 (depends on 3)

The hydraulic pressure supply system of claim 3, wherein the second recirculation line is provided with an orifice and a pressure sensor is mounted between the orifice and the high-pressure regulator valve.

### Claim 5 (depends on 1)

The hydraulic pressure supply system of claim 1, wherein the high-pressure regulator valve comprises:
a valve body having a first port receiving the high hydraulic pressure of the high-pressure line, a second port receiving the high hydraulic pressure of the high-pressure line as a control pressure, a third port selectively supplying a portion of the oil of the high hydraulic pressure supplied to the first port to the second recirculation line, a fourth port selectively supplying a portion of the oil of the high hydraulic pressure supplied to the first port to the third recirculation line, and a fifth port disposed at an opposite side to the second port and receiving a control pressure of a solenoid valve; and
a valve spool having a first land operated by the high hydraulic pressure supplied to the second port and controlling an opening area of the third port, a second land dividing the first port to supply the high hydraulic pressure supplied to the first port to the third port and the fourth port, and a third land selectively opening or closing the fourth port.

### Claim 6 (depends on 5)

The hydraulic pressure supply system of claim 5, wherein the high-pressure regulator valve further comprises an elastic member disposed between the third land and the valve body.