# US 8,464,851 B2 · Electro-hydraulic control system for an automatic transmission > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,464,851 B2 - Document ID: US8464851B2 - Status: Granted - Kind: B2 - Application number: 13/079,108 - Filed: 2011-04-04 - Published: 2012-10-04 - Granted: 2013-06-18 - Earliest claimed: 2011-04-04 - Assignees: GM Global Technology Operations LLC - Applicants: Steven P. Moorman - Inventors: Steven P. Moorman - Web page: https://patentgrep.com/patent/US8464851B2 ## CPC - F16H 61/0206: {Layout of electro-hydraulic control circuits, e.g. arrangement of valves} - F16H 61/0031: {using auxiliary pumps, e.g. pump driven by a different power source than the engine} - F16H 61/684: without interruption of drive - F16H 2061/0209: {with independent solenoid valves modulating the pressure individually for each clutch or brake} - Y10T 74/20024: Fluid actuator - F16H: GEARING - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract An electro-hydraulic control system for a multiple speed automatic motor vehicle transmission includes main and auxiliary hydraulic pumps, a line pressure regulator, a lubrication pressure regulator, a lubrication override control valve and a torque converter control valve which is controlled by a variable force solenoid (VFS). Driver commands are provided to the system through a manual logic or spool valve which functions in conjunction with a spool or logic default valve and a default solenoid. Five solenoid valves receive various flows of hydraulic fluid and supply them to hydraulic actuators that engage and disengage four friction clutches and a selectable one-way clutch. ## Claims ### Claim 1 A control system for an automatic transmission comprising, in combination, a first hydraulic pump having an output, a second hydraulic pump having an output, a feed limit valve in fluid communication with said output of said second hydraulic pump and having an output, a torque converter control valve in fluid communication with said output of said first hydraulic pump and having a control port and an output, a torque converter apply solenoid valve having a first output in fluid communication with said control port of said torque converter control valve and a second output adapted to engage a lockup clutch of a torque converter, a lubrication flow regulator valve having a first control port in fluid communication with said output of said first hydraulic pump and a second control port, an oil cooler operably disposed between an outlet port of said torque converter control valve and an inlet port of said lubrication flow regulator valve, a lubrication override enable valve having an outlet in fluid communication with said second control port of said lubrication flow regulator valve, a manually operated spool valve having a first output enabling reverse and a second output enabling forward gears of such transmission, a default control valve having inlet ports in fluid communication with said second output of said manually operated spool valve, a first default valve control port in fluid communication with said first output of said manually operated valve and a second default valve control port, a default solenoid valve having an output in fluid communication with said second default valve control port of said default control valve, and a plurality of solenoid valves, each of said solenoid valves having an inlet in fluid communication with said output of said second hydraulic pump and an output in fluid communication with a hydraulic clutch actuator. ### Claim 2 (depends on 1) The control system of claim 1 wherein said manually operated valve includes a gear shift selector moveable by a vehicle operator and said default control valve is a two position valve. ### Claim 3 (depends on 1) The control system of claim 1 further including a clutch solenoid valve having an output, a clutch enable valve having an inlet in fluid communication with said output of said clutch solenoid valve, an outlet and a control port in fluid communication with said output of said default solenoid and said output of said clutch enable valve through a three way check valve, and a double acting hydraulic piston and cylinder assembly having a first inlet in fluid communication with said output of said clutch enable valve and said first default valve control port through a three way check valve. ### Claim 4 (depends on 3) The control system of claim 3 further including a selectable one-way clutch acted upon by said double acting hydraulic piston and cylinder assembly. ### Claim 5 (depends on 1) The control system of claim 1 further including a variable bleed solenoid valve having an output in fluid communication with a control port of said pressure regulator valve. ### Claim 6 (depends on 1) The control system of claim 1 wherein second hydraulic pump is electrically driven. ### Claim 7 (depends on 1) The control system of claim 1 further including a hydraulic line from a port of said lubrication flow regulator valve for providing hydraulic fluid to a plurality of clutches. ### Claim 8 An electro-hydraulic control system for an automatic transmission comprising, in combination, a source of pressurized hydraulic fluid, a feed limit valve in fluid communication with said source of hydraulic fluid and having an output, a torque converter control valve in fluid communication with said source of pressurized hydraulic fluid and having a control port and an output, a torque converter apply solenoid valve having a first output in fluid communication with said control port of said torque converter control valve and a second output adapted to engage a lockup clutch of a torque converter, a lubrication flow regulator valve having a first control port in fluid communication with said source of hydraulic fluid and a second control port, a lubrication override enable valve having an outlet in fluid communication with said second control port of said lubrication flow regulator valve, a manually operated valve having a first output enabling reverse and a second output enabling forward gears of such transmission, a default control valve having inlet ports in fluid communication with said second output of said manually operated spool valve, a first default valve control port in fluid communication with said first output of said manually operated valve and a second default valve control port, a default solenoid valve having an output in fluid communication with said second default valve control port, a clutch solenoid valve having an output, a clutch enable valve having an inlet in fluid communication with said output of said clutch solenoid valve, an outlet and a control port in fluid communication with said output of said default solenoid and said output of said clutch enable valve through a three way check valve, a double acting hydraulic piston and cylinder assembly having a first inlet in fluid communication with said output of said clutch enable valve and said first default valve control port through a three way check valve, and a plurality of solenoid valves, each of said solenoid valves having an inlet in fluid communication with said source of hydraulic fluid and an output in fluid communication with a hydraulic clutch actuator. ### Claim 9 (depends on 8) The electro-hydraulic control system for an automatic transmission of claim 8 wherein said source of hydraulic fluid includes a first mechanically driven pump and a second electrically driven pump. ### Claim 10 (depends on 8) The electro-hydraulic control system for an automatic transmission of claim 8 wherein said default control valve is a two position valve. ### Claim 11 (depends on 8) The electro-hydraulic control system for an automatic transmission of claim 8 further including a selectable one-way clutch acted upon by said double acting hydraulic piston and cylinder assembly. ### Claim 12 (depends on 8) The electro-hydraulic control system for an automatic transmission of claim 8 further including a variable bleed solenoid valve having an output in fluid communication with a control port of said pressure regulator valve. ### Claim 13 (depends on 8) The electro-hydraulic control system for an automatic transmission of claim 8 further including a sump for receiving and storing hydraulic fluid. ### Claim 14 (depends on 8) The electro-hydraulic control system for an automatic transmission of claim 8 further including a hydraulic fluid cooler disposed in fluid communication between an outlet of said torque converter control valve and an inlet of said lubrication flow regulator valve. ### Claim 15 An electro-hydraulic control system for an automatic transmission comprising, in combination, a source of pressurized hydraulic fluid, a feed limit valve in fluid communication with said source of hydraulic fluid and having an output, a torque converter control valve in fluid communication with said source of hydraulic fluid and having a control port and an output, a torque converter apply solenoid valve having a first output in fluid communication with said control port of said torque converter control valve and a second output adapted to engage a lockup clutch of a torque converter, a lubrication flow regulator valve having a first control port in fluid communication with said source of hydraulic fluid and a second control port, a lubrication override enable valve having an outlet in fluid communication with said second control port of said lubrication flow regulator valve, a manually operated valve having a first output enabling reverse and a second output enabling forward gears of such transmission, a default control valve having inlet ports in fluid communication with said second output of said manually operated spool valve, a first default valve control port in fluid communication with said first output of said manually operated valve and a second default valve control port, a default solenoid valve having an output in fluid communication with said second control port and a plurality of solenoid valves, each of said solenoid valves having an inlet in fluid communication with said source of hydraulic fluid and an output in fluid communication with a hydraulic clutch actuator. ### Claim 16 (depends on 15) The electro-hydraulic control system for an automatic transmission of claim 15 wherein said source of hydraulic fluid includes a first mechanically driven pump and a second electrically driven pump. ### Claim 17 (depends on 15) The electro-hydraulic control system for an automatic transmission of claim 15 wherein said manually operated valve includes a gear shift selector moveable by a vehicle operator and said default control valve is a two position valve. ### Claim 18 (depends on 15) The electro-hydraulic control system for an automatic transmission of claim 15 further including a pressure regulator valve operably disposed between said source of pressurized hydraulic fluid and said torque converter control valve. ### Claim 19 (depends on 15) The electro-hydraulic control system for an automatic transmission of claim 15 further including a hydraulic fluid cooler disposed in fluid communication between an outlet of said torque converter control valve and an inlet of said lubrication flow regulator valve. ### Claim 20 (depends on 15) The electro-hydraulic control system for an automatic transmission of claim 15 further including a clutch solenoid valve having an output, a clutch enable valve having an inlet in fluid communication with said output of said clutch solenoid valve, an outlet and a control port in fluid communication with said output of said default solenoid and said output of said clutch enable valve through a three way check valve, a double acting hydraulic piston and cylinder assembly having a first inlet in fluid communication with said output of said clutch enable valve and said first default valve control port through a three way check valve and a selectable one-way clutch acted upon by said double acting hydraulic piston and cylinder assembly.