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| Illustration 1 | g01216861 |
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Torque Divider (1) Ring Gear (2) Planetary Carrier (3) Sun Gear (4) Flywheel (5) Turbine (6) Torque Converter Housing (7) Impeller (8) Case (9) Yoke (10) Output Shaft (11) Planetary Gears | |
The torque divider connects the engine to the planetary transmission. The connection is both a hydraulic connection and a mechanical connection. The hydraulic connection is through a torque converter. The mechanical connection is through a planetary gear set.
The planetary gear set multiplies the torque from the engine by making an increase in the mechanical advantage. The torque multiplication also makes an increase as the load on the machine becomes higher.
When the machine works against a low load, the torque multiplication is low. When the machine works against a high load, the torque multiplication is higher. A higher torque can then be sent to the transmission during high load conditions.
During no-load conditions, neither the torque converter nor the planetary gear set can multiply the torque from the engine.
Torque converter housing (6) and sun gear (3) are splined to engine flywheel (4). The torque divider case is installed on the engine flywheel housing. Output shaft (10) is connected to yoke (9). Yoke (9) is connected to the planetary transmission through a drive shaft.
The planetary gear set is composed of the following parts:
- Ring gear (1)
- Planetary carrier (2)
- Sun gear (3)
- Planetary gears (11)
Sun gear (3) is connected to the flywheel by splines. Planetary carrier (2) is connected to output shaft (10) by splines. Planetary gears (11) are held by the planetary carrier. The planetary gears are engaged by sun gear (3) and by ring gear (1).
The torque converter is composed of the following parts:
- Turbine (5)
- Torque converter housing (6)
- Impeller (7)
Torque converter housing (6) is connected to flywheel (4) by splines. Impeller (7) is connected to torque converter housing (6). Turbine (5) is connected to ring gear (1) by splines.
Operation of the Torque Converter
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| Illustration 2 | g01217303 |
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Torque Converter (5) Turbine (6) Torque Converter Housing (7) Impeller (12) Inlet Passage (13) Outlet Passage (14) Support | |
Oil for the operation of the torque converter flows through inlet passage (12) in support (14) to impeller (7). The rotation of the impeller drives the oil. The impeller sends the oil around the inside of torque converter housing (6) to turbine (5).
The force of the oil on the blades of the turbine turns the turbine. The turbine drives ring gear (1). See Illustration 1. The torque that is given to the turbine by the force of the oil cannot be a greater force than the torque output of the engine to the impeller.
Operation of the Torque Divider
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| Illustration 3 | g01217390 |
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Torque Divider (1) Ring Gear (2) Planetary Carrier (3) Sun Gear (6) Torque Converter Housing (10) Output Shaft (11) Planetary Gears | |
Torque converter housing (6) and sun gear (3) are driven by the engine flywheel. The planetary gear set is driven by the engine through sun gear (3). These connections allow the torque output of the engine to go in two separate directions.
Because of the larger radius of ring gear (1), most of the torque is sent by the torque converter through the ring gear to planetary gears (11). The remainder of the torque is sent by sun gear (3) to the planetary gears.
If planetary carrier (2) has no resistance to rotation, then the following components turn at the same speed:
- Ring gear (1)
- Planetary carrier (2)
- Sun gear (3)
- Planetary gears (11)
The torque from the converter and from the planetary gear set is now through the planetary carrier to output shaft (10) and the planetary transmission. Neither the torque converter nor the planetary gear set can multiply the torque from the engine when both these components turn at the same speed.
When the machine has a load, output shaft (10) and planetary carrier (2) have resistance to rotation. Since sun gear (3) is turning at the rpm of the engine, the resistance to rotation turns planetary gears (11). This rotation is the reverse of the rotation of ring gear (1). The speed of the ring gear decreases.
Since the turbine is connected to the ring gear, a decrease in speed will cause the torque converter to multiply the torque from torque converter housing (6). The torque multiplication is sent to planetary carrier (2) and the output shaft.
If the resistance to rotation of planetary carrier (2) increases, the speed of the ring gear decreases more. The slower speed will allow the torque multiplication through both the torque converter and the sun gear to become higher.
If the resistance to rotation of the planetary carrier increases enough, the ring gear stops. During some very high load conditions, the rotation of the planetary carrier and the output shaft also stop. When output shaft (10) is stopped, the ring gear slowly turns in the opposite direction. The torque multiplication of the torque converter and the sun gear is at the maximum.
Oil for the lubrication of the torque divider bearings and for the planetary gear set comes from the supply that is used for the operation of the torque converter. The bearings constantly run in oil. Bearings and gears in the planetary gear set and the pilot bearing get lubrication through passages in the output shaft.
Torque Converter Outlet Relief Valve
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| Illustration 4 | g01215811 |
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Torque Converter Outlet Relief Valve (16) Inlet Passage from Torque Converter (17) Outlet Passage to Power Train Oil Cooler (18) Spring (19) Spool (20) Shims | |
The torque converter outlet relief valve is mounted to the right rear of the torque divider case. The torque converter outlet relief valve maintains a minimum pressure in the torque converter. The pressure setting of the relief valve may be adjusted with shims (20).
Oil flows into the valve from the torque converter through inlet passage (16). The pressure of the oil acts against spool (19). When the pressure of the oil becomes greater than the force of spring (18), spool (19) shifts to the right. Oil is allowed to flow through the holes around the circumference of the spool to outlet passage (17) to the power train oil cooler.
Torque Converter Inlet Relief Valve
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| Illustration 5 | g01215820 |
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Torque Converter Inlet Relief Valve (21) Bottom of Main Case (22) Lubrication Distribution Manifold (23) Passage to Torque Converter Inlet (24) Passage (25) Front of Main Case (26) Spring (27) Torque Converter Inlet Relief Valve (28) Passage to Main Sump (29) Passage from Priority Valve | |
Torque converter inlet relief valve (27) is located in a passage on the left, front of the main case and behind the lubrication distribution manifold.
The torque converter inlet relief valve limits the maximum pressure to the torque converter section of the torque divider. The torque converter inlet relief valve also prevents damage to the torque converter when the engine is started and the oil is cold. The setting of the torque converter relief valve is not adjustable.
Oil enters lubrication distribution manifold (22) from the priority valve through passage (29) in the front of the bevel gear case.
When the pressure in passage (24) is enough to overcome the force of spring (26), the oil will flow through torque converter inlet relief valve (27) to the main sump through passage (28).