RELAY 2434628 - Caterpillar

Table 1
Operation of the Torque Converter For Transmission Speed    
Transmission Speed     Torque Converter Drive     Direct Drive with an Engaged Lockup Clutch    
Reverse     X        
Neutral     X        
First     X     X    
Second         X    
Third         X    
Fourth         X    
Fifth         X    
Sixth         X    Torque Converter Drive
Illustration 1 g00358357
(1) Rotating housing (2) Turbine (3) Impeller (4) Drive gear for torque converter, parking brake release, and brake cooling gear pump (5) Outlet passage for torque converter oil (6) Carrier (7) Output yoke (8) Inlet passage (9) One-way clutch (10) Stator (11) Lockup clutch (12) Hub (25) Output shaftThe engine flywheel turns rotating housing (1) which turns impeller (3). The impeller directs the oil to the blades of turbine (2). This will cause the turbine to turn. The turbine directs the oil to stator (10). This causes the stator to try to turn in the opposite direction of the turbine. The movement of the stator causes the rollers of one-way clutch (9) to move between stator (10) and the carrier for the stator. The action of the one-way clutch keeps the stator from rotation in the opposite direction of the turbine (2). The stator now directs most of the oil back to impeller (3). The remainder of the oil goes out of the torque converter through outlet passage (5). The oil, that goes back to impeller (3) from stator (10), moves in the same direction as the rotation of the impeller. Since this oil is moving in the same direction as the impeller, the torque output from the torque converter is multiplied.Turbine (2) turns hub (12). Hub (12) turns output shaft (25). Power is sent through the output yoke (7) to the drive shaft and the transfer gears of the transmission.One-Way Clutch
Illustration 2 g00358454
(10) Stator (13) Race (14) Cam for the one-way clutch (15) Rollers (16) Cage (17) Springs (18) Slot (19) Cam surfaceThe one-way clutch functions in order to keep the stator stationary up to higher torque converter output speeds. Stator (10) is connected to the cam (14) through splines. As a result, stator (10) rotates with cam (14), and race (13) is stationary. Roller cage (16) is located between cam (14) and race (13). Spring (17) is partially inserted in a tab at the top and at the bottom of cage (16). At lower turbine speeds, spring (17) forces the tab of cage (16) to the right in slot (18). This forces roller cage (16) to rotate clockwise. Then, rollers (15) move against the surfaces (19) of cam (14). The rollers will wedge between cam (14) and race (13). This action locks stator (10) to race (13) which is stationary. The stator then returns oil to the impeller which multiplies the torque output of the torque converter.As the speed of turbine (2) approaches the speed of impeller (3),