US 5,492,027 A · Rotary shift control valving mechanism for a power transmission

Abstract

An automatic transmission drive ratio control for operating a five speed automatic transmission is provided. The control is particularly adapted for use with a twin countershaft automatic transmission that requires only one torque transfer device for each drive ratio. A system of valves is employed to direct the flow of pressurized fluid necessary for the on-going actuation of each drive ratio and the simultaneous off-going actuation of the previously actuated drive ratio. The flow control for actuating and deactuating the torque control devices is directly effected by a two-position spool valve operating in concert with a rotary valve, pressurized hydraulic fluid used to position the spool valve and the rotary valve is primarily provided by three on/off solenoid shift control valves. A failure of the electrical supply to the solenoid valves will effect a shift to the third drive ratio when the transmission is operating in the first through fourth drive ratios, but will effect a shift to the fifth drive ratio should the electrical failure occur while operating in the fifth drive ratio.

Claims17

Dependent claims

In a shifting system for a power transmission having a source of pressurized fluid and a two-position valve for directing the pressurized fluid to at least one torque transfer device for actuating a selected drive ratio and for directing the pressurized fluid to a rotary control valve mechanism for actuating a plurality of selected drive ratios, said rotary control valve mechanism comprising:

a housing with a cylindrical bore therein;
a rotor received within said cylindrical bore and selectively sequenceable through a plurality of angular dispositions;
a pressure feed passage in said rotor;
control means selectively to rotate said rotor to each of said plurality of angular dispositions;
said feed passage communicating with a selected torque transfer device at each of said angular dispositions of said rotor to apply on-going hydraulic pressure thereto;
exhaust passageways in said rotor;
said exhaust passageways communicating with at least an off-going torque transfer device at each said angular disposition of said rotor.

4 more elements

An automatic power transmission drive ratio control comprising:

a source of fluid pressure;
a two-position spool valve;
a control chamber incorporated in said spool valve;
a first on/off solenoid valve connected with said source of fluid pressure;
a control conduit means for directing fluid from said first on/off solenoid valve to said control chamber in said spool valve to effect a pressure-set state for said two-position spool valve when said first on/off solenoid valve is on;
spring means for biasing said spool valve means to effect a spring-set position when said first on/off solenoid valve is off;
a rotary valve;
a feed conduit;
a rotor disposed within said rotary valve in communication with said feed conduit;
a supply passage disposed within said rotor;
a plurality of exhaust passages disposed within said rotor;
a torque transfer device supply conduit connected to said source of fluid pressure and to said rotary valve through said spool valve;
a second on/off solenoid valve connected with said source of fluid pressure;
a first rotary valve control conduit connecting said second on/off solenoid valve with said rotary valve;
a third on/off solenoid valve connected with said source of fluid pressure;
a second rotary valve control conduit connecting said third on/off solenoid valve with said rotary valve;
a plurality of torque transfer devices;
each torque transfer device effecting a selected drive ratio;
and,
a modulating solenoid valve connected to said source of fluid pressure and to said spool valve for directing fluid flow to selected torque transfer devices.

17 more elements

An automatic power transmission drive ratio control comprising:

a source of fluid pressure;
a two-position spool valve;
a control chamber incorporated in said spool valve;
a first on/off solenoid valve connected with said source of fluid pressure;
a control conduit means for directing fluid from said first on/off solenoid valve to said control chamber in said spool valve to effect a pressure-set state for said two-position spool valve when said first on/off solenoid valve is on;
spring means for biasing said spool valve means to effect a spring-set state when said first on/off solenoid valve is off;
a rotary valve;
said rotary valve having a housing with a cylindrical bore therein;
a rotor received within said cylindrical bore and selectively sequenceable through a plurality of angular dispositions;
a pressure feed passage in said rotor;
control means selectively to rotate said rotor to each of said plurality of angular dispositions;
a plurality of torque transfer devices, each torque transfer device being selected to actuate a predetermined drive ratio;
said feed passage communicating with a selected torque transfer device at each of said angular dispositions of said rotor to apply on-going hydraulic pressure thereto;
exhaust passageways in said rotor;
said exhaust passageways communicating with at least an off-going torque transfer device at each said angular disposition of said rotor;
a second on/off solenoid valve connected with said source of fluid pressure;
a first rotary valve control conduit connecting said second on/off solenoid valve with said rotary valve;
a third on/off solenoid valve connected with said source of fluid pressure;
a second rotary valve control conduit connecting said third on/off solenoid valve with said rotary valve;
and,
a modulating solenoid valve connected to said source of fluid pressure and to said spool valve for directing fluid flow to selected torque transfer devices.

18 more elements

Dependencies are inferred from the claim text.

Rotary shift control valving mechanism for a power transmission

Life of this patent

Rotary shift control valving mechanism for a power transmission

Life of this patent

Abstract

Claims17