New Holland 8160-856
Hydraulic Pump Report
Hydraulics is the study of fluid in motion and under pressure. Hydraulic power is usually generated from mechanical power. A pump is what converts mechanical energy to fluid energy. In other words the pump is what creates flow in a hydraulic system. Hydraulic pumps are classified under the principle in which they operate. This is called displacement. Displacement is how much fluid the pump pumps in one revolution of the drive shaft. Several different kinds of pumps have different displacement for different reasons. In this discussion I will focus on a fixed gear style pump and a variable displacement radial piston pump from a New Holland tractor. The hydraulic pump assembly that is used on New Holland tractors is a variable displacement, load sensing, closed center system. This pump is driven from the tractor by a live drive gear train that is directly connected to the PTO clutch input drive shaft. The PTO clutch input drive shaft is driven by the engine flywheel. This pump set up is only used on the 60 series tractors (8160-8560). It is located on the right side of the rear axle housing. What is unique about this system is that there are three pumps linked together. This includes the steering and low pressure system pump, charge pump, and piston pump (refer to fig 8-2-1).
The steering and low pressure system pump (1 on figure 8-2-1) is a fixed displacement external gear pump. This pump operates the steering system, independent power take off, differential lock, front wheel drive axle, transmission clutches, and some minor lubrication. The steering pump puts out 16 gallons per minute at 2200 rpms. There is also a flow control valve located on the end of the steering pumps housing. The flow control valve ensures that 6.6 gallons of hydraulic oil are supplied to the steering pump assembly at all times. All additional