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| Illustration 1 | g06339617 |
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(1) Generator
(2) Stator (3) Rotor group (4) Stator Exciter (5) Coupler (6) Inverter cabinet (7) Electric retarding grid (8) Wheel traction motors (9) Axle (10) Final drives (11) Steering pump (12) Steering oil filter (13) Priority Valve and Manifold (blower fan motor, final drive lubrication, steering) (15) Blower fan (16) Blower motor (17) Solenoid valve (blower motor) (18) Speed sensor (blower fan) (19) Cooling ductwork (20) Pump and motor (final drive lubrication) (21) Oil filter (final drive lubrication) (22) Bypass switch(final drive lubrication filter) (23) Pressure sensor (final drive lubrication oil) (24) Temperature sensor (final drive lubrication oil) (25) Electronic Control Module (Drive Train) (26) Electronic Control Module (Chassis) (27) Electronic Control Module (Brake) (28) Shift Control Lever (29) Retarding Pedal (30) Automatic Retarding Switch (31) Automatic Retarding Speed Control (32) Excitation Field Regulator (EFR) | |
The 794 AC Off-Highway Truck drive train arrangement uses mechanical energy from the engine to rotate the generator. The power is transmitted to an Inverter Cabinet. Components within the Inverter Cabinet change and control the incoming power. The power is then sent to an electric traction motor coupled to a final drive at each rear wheel station. The rear traction motors convert the electrical energy back to mechanical energy to propel the truck.
The 794 AC Off-Highway Truck power train consists of the following arrangements:
- Electric Drive Train
- Drive Train Cooling System
- Final Drive Lubrication
For additional information on the electric drive train, refer to Systems Operation, UENR2267, "Electric Power Generation" and Systems Operation, UENR2267, "Electric Drive System".
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| Illustration 2 | g03657765 |
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(1) Engine
(2) Coupler (3) Generator (4) Inverter cabinet | |
The power source for the electric drive system is engine (1) that is connected to generator (3) through coupler (2). Generator (3) is then able to use the mechanical energy from the engine to produce electrical energy.
Power from generator (3) is transmitted to inverter cabinet (4). Inverter cabinet (4) controls the torque, direction, and speed of the truck. Generator (3) produces Alternating Current (AC) power that is rectified to Direct Current (DC) power inside inverter cabinet (4). Inverter cabinet (4) then inverts this DC power back to AC power. This AC power is then transmitted to the wheel traction motors in the rear axle.
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| Illustration 3 | g03657766 |
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(4) Inverter cabinet
(5) Wheel traction control motor (6) Rear axle (7) Final drive | |
The AC power that is inverted by inverter cabinet (4) is sent to the rear axle housing to wheel traction control motors (5). Each traction control motor (5) is a three-phase AC induction type. Traction control motors (5) convert the electrical energy from inverter cabinet (4) to rotating mechanical energy.
Traction control motors (5) are connected to rear axles (6). Rear axles (6) are connected to final drives (7).
Drive Train Cooling System and Final Drive Lubrication
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| Illustration 4 | g03657774 |
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(1) Drive cooling fan
(2) Motor for drive cooling fan (3) Inverter cabinet (4) Generator (5) Wheel traction motors (6) Tube (7) Ductwork | |
Drive cooling fan (1) cools the electrical drive train components. Drive train fan motor (2) drives cooling fan (1). Cooling fan (1) circulates air flow through drive train ductwork (7) which routes the air to the electrical drive train components.
Cooling fan (1) pulls air through inverter cabinet (3) which cools inverter cabinet (3) and sends the air flow through ductwork (7). The air through ductwork (7) cools generator (4) and wheel traction motors (5). The air then exits the truck at the rear of the rear axle and at the "Generator".
Tube (6) provides pressurized air for inverter cabinet (3) to keep dirt and debris out of the cabinet.
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| Illustration 5 | g06339786 |
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(1) Drive cooling fan
(2) Motor for drive cooling fan (8) Steering pump (9) Oil filter (10) "Priority Valve and Manifold" (11) "Makeup" valve (blower motor) | |
Drive cooling fan motor (2) is powered by steering hydraulic oil.
Oil from steering pump (8) is sent to oil filter (9). Oil flows from filter (9) to solenoid valve and "Priority Valve and Manifold" (10). The "Priority Valve and Manifold" (10) distribute the hydraulic oil throughout the hydraulic system. Oil from solenoid valve and "Priority Valve and Manifold" (10) goes to the "Makeup" valve (11) and to drive the "Cooling Fan" motor (2). Motor (2) then powers the "Drive Cooling" fan (1).
After powering the "Drive Cooling" fan (1), the hydraulic oil goes back through "Makeup" valve (11) to the manifold on the front axle for the front brake cooling. After cooling the "Front" brakes, the hydraulic oil is returned to the hydraulic tank.
The final drive lubrication system provides oil to the final drives for lubrication and cooling.
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| Illustration 6 | g06341807 |
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(1) Steering pump
(2) Oil filter (3) Priority Valve and Manifold (4) Final drive lubrication pump and motor (5) Oil filter (final drive lubrication) (6) Bypass switch (7) Pressure sensor (8) Temperature sensor | |
When the steering accumulators are charged, solenoid valve and "Priority Valve and Manifold" (3) send hydraulic oil from the steering pump to "Final Drive Lubrication" pump and motor (4).
Final drive lubrication pump and motor (4) powers two gear pumps for lubrication of the two final drives. The two section pump draws oil from both final drives and circulates oil through filters (5).