GF27.60-D-5141HA Shift Valve, Component Description

GF27.60-D-5141HA Shift Valve, Component Description
- TRANSMISSION 722.6


Holding pressure shift valve





2a Valve body of shift plate
2b Valve body of shift plate
28a 1-2/4-5 holding pressure shift valve
28b 2-3 holding pressure shift valve
28c 3-4 holding pressure shift valve

Location

A holding pressure shift valve belongs to each shift group.

The 1-2/4-5 holding pressure shift valve and 2-3 holding pressure shift valve 2-3 are installed in the shift plate valve housing, the 3-4 holding pressure shift valve is installed in the shift plate valve body.

Task

Each holding pressure holding pressure shift valve assigns the working pressure to an actuator of a shift group.





Basic condition (one actuator engaged)

0 Oil sump drain
28 Holding pressure shift valve

p-A Working pressure





Switch status

0 Oil sump drain
28 Holding pressure shift valve

p-A Working pressure
p-S Shift pressure
p-U Overlap pressure

Function

The holding pressure shift valve is engaged by the pressures applied to the end face in the actuators and by spring force. It assigns the working pressure to the actuator with the higher pressure (taking into account the spring force and the effective area).

The other element of the shift group is then unpressurized. A changeover of the holding pressure shift valve only takes place during the shift phase and only at a particular pressure ratio of overlap pressure to shift pressure.