1.19. PUMP DRIVE SYSTEM

TM 5-3895-373-20 1.19. PUMP DRIVE SYSTEM. The hydraulic pump drive system consists of the paving machine engine, pump drive gearbox, and five hydraulic pumps. The Perkins T4.236 turbosupercharged diesel engine flywheel is shaft coupled to the input of the attached pump drive gearbox. The gearbox input drives two output gears at a 1:1 input-to-output ratio. There are five hydraulic pumps attached in a tandem configuration to the oil-filled gearbox. Coupled directly to the gearbox are two hydraulic propulsion pumps. They provide 5000 psi (34 500 kPa) at 2.8 cu in./rev (46,6 cc/rev) to the left and right hydraulic propulsion motors. Attached in tandem to the right propulsion pump is one shaftdriven auxiliary hydraulic pump with two outputs. One output provides 0.7 cu in./rev (11,6 cc/rev) while the second output provides 0.58 cu in./rev (9,67 cc/rev), both at 2500 psi (17 200 kPa). Attached to the left propulsion pump is a hydraulic auxiliary vibration pump that provides 0.24 cu in./rev (4,00 cc/rev) at 2000 psi (13 800 kPa). Connected to the vibration pump is a second auxiliary pump with two outputs, the same as the auxiliary pump on the right side. Both outputs of the left auxiliary pump, and the 0.7 cu in./rev (11,7 cc/rev) output of the right auxiliary pump, are used for the auger/conveyor motor. The 0.58 cu in./rev (9,67 cc/rev) output of the right auxiliary pump is split through a 50/50 flow divider. Half the fluid is used for the stack valve (screed extension, hopper lift, track tensioning, and screed lift cylinders). The other half of the output fluid is used for tow point cylinders and to supplement screed vibration. 1-35