944364 Volvo.Penta O-ring

GOVERNOR OIL FLOW SCHEMATICThe governor drive shaft is hydraulic valve bushing (7). Pilot valve plunger (5), in the hollow center of the bushing, screws into thrust bearing and spring seat (2). The bushing drives weights (1); the toes of the weights rest against the thrust bearing and spring seat. One of hydraulic pump gears (9) is integral with bushing (7).When the load on the engine increases, the rpm of the engine decreases and the rotating speed of governor weights (1) decreases. Governor weight centrifugal force is less and governor spring (3) pushes spring seat (2) and pilot valve plunger (5) to a position in bushing (7) where an oil passage is opened and oil is directed to power piston (6). The pressure of the oil moves the power piston which moves lever (4). The lever is the part of the governor terminal shaft which is linked to the engine fuel rack. The fuel rack is moved to a more fuel position and the rpm of the engine increases. As the engine rpm increases, governor weights (1) rotate faster, centrifugal force is greater and the toes of the weights move thrust bearing and spring seat (2) connected to pilot valve plunger (5). When the rpm of the engine is again the same as it was before the load increased, the governor weights will have moved the pilot valve plunger to its original position, closing the oil passage to power piston (6) to stop the movement of the power piston and engine fuel rack.When the load on the engine decreases, the rpm of the engine increases and the rotating speed of governor weights (1) increase. The toes on the governor weights move thrust bearing and spring seat (2) and pilot valve plunger (5) to a position in bushing (7) that allows the oil under power piston (6) to drain. When the oil under the power piston can drain, a spring in the governor linkage (not part of the governor) moves the engine fuel rack to a lesser fuel position and the rpm of the engine decreases. The governor weights rotate slower and governor spring (3) pushes on spring seat (2) and pilot valve plunger (5). When the rpm of the engine is again the same as it was before the load decreased, the governor spring will have pushed the pilot valve plunger to a position where oil can no longer drain from under power piston (6) and the movement of the power piston and fuel rack is stopped.
HYDRAULIC GOVERNOR (CROSS SECTION)
1. Weights (two in ball head assembly). 2. Thrust bearing and spring seat. 3. Governor spring. 4. Lever (terminal shaft). 5. Pilot valve plunger. 6. Power piston. 7. Bushing (drive shaft). 8. Buffer piston. 9. Hydraulic pump gears. 10. Buffer springs (two).The sensitivity of governor weights (1) and governor spring (3) to the slightest variations in engine rpm are absorbed by buffer springs (10) that center buffer piston (8) in power piston (6). The oil directed to the power piston must first pass through an opening in the bottom of the power piston and act on the buffer piston to move the power piston.The hydraulic governor is a zero percent speed droop governor (isochronous). Speed droop is the percent difference between the rpm of an engine operating under no load and the rpm of an engine operating under full load. The percent of speed droop is calculated by using the following equation. Pierce Output Shaft Governor
OUTPUT SHAFT GOVERNOR AND HYDRAULIC SERVO MECHANISM
1. Flexible drive cable. 2. Output shaft governor. 3. Terminal lever. 4. Rocker shaft. 5. Rate adjusting screw. 6. Speed change lever. 7. Governor spring. 8. Bumper screw. 9. Link. 10. Lever. 11. Lever. 12. Low speed adjusting screw. 13. High speed adjusting screw. 14. Bracket.The output shaft governor (2) is driven by a flexible cable assembly (1) which connects to the governor drive mechanism on the torque converter. The output shaft governor (2) and hydraulic servo mechanism are connected by means of an adjustable link (9).The output shaft governor acts as an "assistant operator," automatically reducing engine speed, which in turn reduces converter output shaft speed whenever the load on the converter output shaft decreases. Thus, it acts as a speed limiting device by preventing the output shaft and drive equipment from suddenly and perhaps dangerously, overspeeding. This also relieves the operator of making speed adjustments through the engine governor.The torque converter output shaft maximum speed is either a high speed setting or a low speed setting, which is determined by changing the position of speed change lever (6), normally by remote control. High speed screw (13) determines the maximum speed for the high speed setting, and low speed screw (12) determines the maximum low speed setting. In other words, for either setting there is a predetermined maximum speed which the output shaft cannot exceed.The operation of the governor is the same as most rotating weight-type governors. The governor operates only when the torque converter output shaft attempts to exceed a predetermined maximum speed. This speed is determined by the amount of tension placed on governor spring (7). On a variable speed governor, the spring tension is controlled by rate adjusting screw (5) and the position of the speed change lever. Increasing the spring tension increases the maximum speeds.When the output shaft speed approaches the predetermined governed speed setting, weights (15) are forced out moving thrust sleeve (17) and bearing assembly (18) against the rocker yoke (19). As the output shaft speed reaches the predetermined governor speed setting, the force of the weights overcomes the force of the governor spring and the rocker yoke is moved, rotating the rocker shaft (4). Linkage attached to the rocker shaft overrides the diesel engine governor and reduces engine speed which in turn reduces converter output shaft speed. As the rocker yoke moves outward, it contacts small bumper spring (16) in the end of the governor body, which dampens oscillation of the yoke preventing erratic governor control. A bumper screw positions the