HOW THE UNITS OPERATE
The torque converter portion of the power train enacts an important role in delivering engine power to
the driving wheels. In order to properly maintain and service these units it is important to first understand
their function and how they operate.
The torque converter and transmission function together and operate through a common hydraulic system.
To obtain maximum serviceability they have been designed and built as separate units. It is necessary, however,
to consider both units in the study of their function and operation.
To supplement the text herein, and for reference use therewith, the following illustrations are provided.
Fig.
A
-
Torque Converter
Assembly - Cross Section
Fig,
B
-
Internal Oil Flow
- Torque Converter
Fig.
C
-
Torque Converter
Assembly - Exploded View
Fig.
D
-
External Oil Flow
- Converter and Transmission
The torque converter is composed of four members: The impeller which is the driving member, the drive
Disc or impeller cover, the turbine, which is the driven member and the reaction member. The reaction member
is splined to the converter support and does not rotate in either direction. The impeller and drive disc form
the outer shell. The turbine runs within the outer shell and is connected to the output shaft. The oil is the
only connection between the turbine and impeller members.
Three pump drive gears are bearing mounted in the converter housing and meshed with a gear splined
to the impeller hub. With the engine running the pump drive gears rotate at engine speed. The pumps are
externally mounted on the converter housing and the splined pump shafts are inserted in the pump gear shaft.
With the engine running, the converter charging pump draws oil from the transmission sump and directs it
through oil filters to the pressure regulating valve located in the control cover. The control cover is mounted
on the top of the transmission. From the regulating valve it is then directed through the control cover to the
transmission clutches and to the converter.
The pressure regulating valve remains closed until required pressure is delivered to the transmission for
actuating the direction and speed clutches. This regulator valve consists of a hardened valve spool operating
in a closely fitted bore. The valve spool is backed up by a spring to hold the valve spool against its seat until
the oil pressure overrides the spring force. The valve spool moves toward the spring until a port is exposed in
the side of the bore. The oil can flow through this port into a distributor which directs the oil through a line
to the converter inlet port.
After entering the converter, the oil is directed into the converter support through the impeller bearing and
to the converter cavity.
Three members of the torque converter are composed of a series of blades. The blades are curved in such
a manner as to force the oil to circulate from the impeller to the turbine, through the reaction member and again
into the impeller. This circulation causes the turbine to turn in the same direction as the impeller. Oil enters
the inner diameter of the impeller and exits from the outer diameter into the outer diameter of the turbine, then
exits from the inner diameter of the turbine and through the reaction member. The oil again enters the inner
diameter of the impeller.
The oil exits between the turbine shaft and converter support and through an oil distributor which directs
the oil out of the converter, through a regulating valve and to the oil cooler. After leaving the cooler the oil
is directed to the lubricating oil inlet on the transmission and through a series of tubes to the transmission bear-
ings, and clutches. The oil is internally returned to the transmission sump.
-A-
