Patent ID: 9297371
Filing Date: 2016-03-29
CPC Classification: F04B,F16H

Claim Text:
1. 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 a first input line, generating hydraulic pressure, and discharging the hydraulic pressure to a first low-pressure line; a first switch valve selectively opening or closing a hydraulic line connected to the first low-pressure line; a low-pressure regulator valve controlling hydraulic pressure supplied from the first switch valve through a second low-pressure line connected to the first switch valve to be a stable hydraulic pressure and supplying the stable hydraulic pressure to the low pressure portion through a third low-pressure line connected to the low pressure portion; a high-pressure hydraulic pump raising the hydraulic pressure supplied from the low-pressure hydraulic pump through the first low-pressure line and discharging a raised hydraulic pressure to a high-pressure line connected to the high-pressure hydraulic pump and the high pressure portion; a second switch valve disposed between the first low-pressure line and the high-pressure line and selectively opening or closing a hydraulic line branched from the first low-pressure line and connected to the high-pressure line; a high-pressure regulator valve controlling the raised hydraulic pressure supplied from the high-pressure hydraulic pump through the high-pressure line or the hydraulic pressure of the low-pressure hydraulic pump selectively supplied through the second switch valve to be a stable high hydraulic pressure and supplying the stable high hydraulic pressure to the high pressure portion; a bypass line bypassing the first switch valve and connecting the first low-pressure line with the second low-pressure line; and a second input line connecting the oil pan with the first low-pressure line between the low-pressure hydraulic pump and the high-pressure hydraulic pump so as for the oil to flow in only one direction from the oil pan to the first low-pressure line, wherein the high-pressure regulator valve is selectively fluidically connected to the first low-pressure line through the second switch valve and is directly fluidically connected to the high-pressure line so as to supply a portion of the hydraulic pressure from the first low-pressure line and the high-pressure line to a second supply line, thereby controlling stability of the hydraulic pressure, and wherein the second supply line is connected to the second low-pressure line.