Hydraulic pressure supply system of automatic transmission

Abstract

A hydraulic pressure supply system of an automatic transmission for a vehicle may include a low-pressure hydraulic pump driven by an electric motor, generating low hydraulic pressure using oil stored in an oil pan, and supplying the low hydraulic pressure to a low pressure portion and a cooler, and a high-pressure hydraulic pump driven by the electric motor, increasing a portion of the low hydraulic pressure to high hydraulic pressure, and supplying the high hydraulic pressure to a high pressure portion through a high-pressure line fluid-connecting the high-pressure hydraulic pump to the high pressure portion, wherein a pressure sensor for detecting the low hydraulic pressure supplied to the cooler may be disposed at an input side of the cooler, and a rotation speed of the electric motor may be controlled based on the low hydraulic pressure detected by the pressure sensor.

What is claimed is: 
     
         1 . A hydraulic pressure supply system of an automatic transmission for a vehicle comprising:
 a low-pressure hydraulic pump driven by an electric motor, generating low hydraulic pressure using oil stored in an oil pan, and supplying the low hydraulic pressure to a low pressure portion and a cooler; and   a high-pressure hydraulic pump driven by the electric motor, increasing a portion of the low hydraulic pressure to high hydraulic pressure, and supplying the high hydraulic pressure to a high pressure portion through a high-pressure line fluid-connecting the high-pressure hydraulic pump to the high pressure portion,   wherein a pressure sensor for detecting the low hydraulic pressure supplied to the cooler is disposed at an input side of the cooler, and a rotation speed of the electric motor is controlled based on the low hydraulic pressure detected by the pressure sensor.   
     
     
         2 . The hydraulic pressure supply system of  claim 1 , wherein the low-pressure hydraulic pump and the high-pressure hydraulic pump are connected to each other by one shaft and are driven by the electric motor. 
     
     
         3 . The hydraulic pressure supply system of  claim 1 , wherein the low-pressure hydraulic pump receives the oil stored in the oil pan through an input line fluid-connecting the low-pressure hydraulic pump and the oil pan, generates the low hydraulic pressure, discharges the low hydraulic pressure to a first low-pressure line fluid-connected to the low-pressure hydraulic pump and the high-pressure hydraulic pump. 
     
     
         4 . The hydraulic pressure supply system of  claim 3 , further comprising:
 a low-pressure regulator valve fluid-connected to the first low-pressure line and controlling the low hydraulic pressure supplied from the first low-pressure line to be a stable low hydraulic pressure,   wherein the low-pressure regulator valve supplies the stable low hydraulic pressure to the low pressure portion and the cooler through a second low-pressure line fluid-connecting the low-pressure regulator valve to the low pressure portion and the cooler respectively.   
     
     
         5 . The hydraulic pressure supply system of  claim 4 ,
 wherein the low-pressure regulator valve is controlled by elastic force of an elastic member disposed at a side thereof and the low hydraulic pressure of the first low-pressure line supplied to an opposite side to the elastic member, and   wherein the low-pressure regulator valve recirculates a portion of the low hydraulic pressure supplied through the first low-pressure line to the input line through a first recirculation line fluid-connecting the low-pressure regulator valve and the input line so as to control the low hydraulic pressure.   
     
     
         6 . The hydraulic pressure supply system of  claim 4 , wherein the high-pressure hydraulic pump increases a portion of the low hydraulic pressure supplied through the first low-pressure line to the high hydraulic pressure and discharges the high hydraulic pressure to the high-pressure line. 
     
     
         7 . The hydraulic pressure supply system of  claim 6 , further comprising:
 a high-pressure regulator valve fluid-connected to the high pressure line and controlling the high hydraulic pressure supplied from the high-pressure line to be a stable high pressure,   wherein the high-pressure regulator valve supplies the stable high hydraulic pressure to the high pressure portion.   
     
     
         8 . The hydraulic pressure supply system of  claim 7 ,
 wherein the high-pressure regulator valve is controlled by control pressure of a solenoid valve applying to a side thereof, elastic force of an elastic member disposed at the side thereof, and a portion of the high hydraulic pressure in the high-pressure line applying to the other side thereof, and   wherein the high-pressure regulator valve recirculates a portion of the high hydraulic pressure supplied through the high-pressure line to the second low-pressure line through a second recirculation line fluid-connecting the high-pressure regulator valve and the second low pressure line so as to control the high hydraulic pressure.   
     
     
         9 . The hydraulic pressure supply system of  claim 4 , wherein the pressure sensor is mounted on the second low-pressure line connected to the cooler. 
     
     
         10 . A hydraulic pressure supply system of an automatic transmission for a vehicle which generates low hydraulic pressure and high hydraulic pressure using oil stored in an oil pan and supplies the low hydraulic pressure and the high hydraulic pressure respectively to a low pressure portion and a high pressure portion, the hydraulic pressure supply system comprising:
 a low-pressure hydraulic pump receiving the oil stored in the oil pan through an input line fluid-connecting the low-pressure hydraulic pump to the oil pan, generating the low hydraulic pressure, and discharging the low hydraulic pressure to a first low-pressure line fluid-connected to the low-pressure hydraulic pump;   a low-pressure regulator valve fluid-connected to the first low-pressure line and controlled by elastic force of an elastic member disposed at a side thereof and the low hydraulic pressure of the first low-pressure line supplied to the other side thereof, recirculating a portion of the low hydraulic pressure supplied through the first low-pressure line to the input line through a first recirculation line fluid-connecting to the low-pressure regulator valve to the input line, and supplying a controlled low hydraulic pressure to the low pressure portion and a cooler through a second low-pressure line fluid-connecting the low-pressure regulator valve to the low pressure portion and the cooler;   a high-pressure hydraulic pump fluid-connected to the low-pressure hydraulic pump through the first low-pressure line and increasing a portion of the low hydraulic pressure supplied through the first low-pressure line and discharging the high hydraulic pressure to a high-pressure line fluid-connected to the high-pressure hydraulic pump;   a high-pressure regulator valve fluid-connected to the high-pressure line and controlled by control pressure of a solenoid valve applying to a side thereof, elastic force of an elastic member disposed at the side thereof, and the high hydraulic pressure of the high-pressure line applying to the other side thereof, recirculating a portion of the high hydraulic pressure supplied through the high-pressure line to the second low-pressure line through a second recirculation line fluid-connecting the high-pressure regulator valve and the second low-pressure line so as to control the high hydraulic pressure, and supplying a controlled high hydraulic pressure to the high pressure portion;   a pressure sensor disposed on the second low-pressure line connected to the cooler; and   an electric motor operating the low-pressure hydraulic pump and the high-pressure hydraulic pump based on the stable low hydraulic pressure in the second low-pressure line detected by the pressure sensor.   
     
     
         11 . The hydraulic pressure supply system of  claim 10 , wherein the low-pressure hydraulic pump and the high-pressure hydraulic pump are connected to each other by one shaft and are driven by the electric motor.