An auxiliary transmission section (14) shift control system (230)/method is provided which includes a control member (234) to prevent auxiliary section synchronized clutch (92, 128) damage if the main transmission section (12) is engaged during an auxiliary section shift. Upon sensing main section engagement during a shift into the auxiliary section high-speed ratio, the force used to engage the high speed ratio is reduced from a first to a considerably lower second level by reducing the pressurization of the actuating pressurized fluid. To accomplish this, a dual pressure pressure regulator assembly (234) is utilized.
A vehicle transmission assembly includes a main gear box and an auxiliary or range gear box. An electrical actuation device for effecting changes in the range gear box preferably includes a solenoid actuator associated with each of the range gear members. A switch, which is preferably provided on the shift lever handle, allows the driver of the vehicle to indicate a desire to make a change in the range gear box. The solenoid actuators are responsive to the electrical switch to effect the range shift. The electrical components replace pneumatic components and associated fittings and airlines used with some prior systems. A further feature of this invention is to include a synchronizer protection circuit that disables the solenoid actuators unless prescribed transmission conditions are met.
A vehicle transmission assembly includes a main gear box and an auxiliary or range gear box. An electrical actuation device for effecting changes in the range gear box preferably includes a solenoid actuator associated with each of the range gear members. A switch, which is preferably provided on the shift lever handle, allows the driver of the vehicle to indicate a desire to make a change in the range gear box. The solenoid actuators are responsive to the electrical switch to effect the range shift. The electrical components replace pneumatic components and associated fittings and airlines used with some prior systems. A further feature of this invention is to include a synchronizer protection circuit that disables the solenoid actuators unless prescribed transmission conditions are met.
A control system for controlling splitter jaw clutch (88) engagement and disengagement forces during a splitter section (16B) shift. The splitter section is shifted by a variable force splitter actuator (142) and is preferably capable of asserting at least a low, medium and high force to the splitter jaw clutch members.
An embodiment provides a shift inhibitor apparatus. At least a portion of the range actuating assembly is moveable between a range first ratio and a range second ratio. The portion of the range actuating assembly is moveable, at least in part, in response to a fluid pressure. The range chamber is selectively in fluid communication with a vent. The shift inhibitor includes a main section neutral interlock having an interlock chamber. At least a portion of the main section neutral interlock is moveable between a first condition and a second condition. The interlock chamber is selectively in fluid communication with the vent. The range chamber can be exhausted such that the range section is selectively switched from the first ratio to the second ratio. The interlock chamber can be exhausted such that the main section neutral interlock is selectively switched from the first condition to the second condition.
A control system for auxiliary section range and/or splitter control includes a direct ported control valve assembly having a spool disposed within a bore of a cover housing, the spool having a differential area to bias the valve and two sealing members radially biased by a spring to direct pressurized air or hydraulic fluid to an appropriate side of a piston to effect the splitter and/or range shift of the transmission. The control valve assembly includes components, such as the valve spool, which may be used in various transmission applications in addition to components, such as the pilot cap and seal plate, which may be selected to control the logic (normally open or normally closed) of the valve assembly and the apply rate of the range and/or splitter cylinder depending upon the particular application. A filter/regulator is mounted to the valve cover assembly to provide direct porting of the pressurized fluid supply to eliminate connecting hoses.
