TRANSMISSION AR 4954245 - Caterpillar

Illustration 1 g00854624
HH500 Harvester Head (1) Upper knife. (2) Left delimbing knife. (3) Right delimbing knife. (4) Measuring wheel. (5) Right feed roller. (6) Left feed roller. (7) Saw motor. (8) Saw bar and saw chain. (9) Holding arm. (10) Frame.Note: The harvester heads are equipped with a rotator and a felling link. The rotator and the felling link are not shown in the above illustration.The harvester head can fell a tree. The tree is then delimbed. The tree is then cut to a preset length. The harvester head is made up of the following main systems: felling, holding, feeding, delimbing, measuring, cross cut and lubrication.The harvester head operates on an electrohydraulic system. Pressure oil flows from a hydraulic oil pump on the machine to the main control valve and the pressure reducing valves. The valves are located on the harvester head. The following functions are controlled by the valves:
the left feed roller motor
the right feed roller motor
the cutting system (saw motor and saw bar cylinder)
the delimbing knife cylinders
the feed roller arm cylinders
the holding arm cylinder
the felling link cylinder
the measuring arm cylinderNote: The HH700 Harvester Head can be equipped with a top saw as part of the processing arrangement. The top saw includes a control valve, a saw bar cylinder and a saw motor.Reference: For more information on the operation of these components, refer to the Systems Operation section in this manual.The rotator controls the rotation of the harvester head. The rotator rotates the harvester head in the clockwise direction or the counterclockwise direction. The rotator is controlled by a joystick control in the cab of the machine. The operation of the rotator is similar to a hydraulic motor. Hydraulic oil flows to the rotator from the machine.Feed rollers (5) and (6) are opened and closed by the feed roller arm cylinders. The feed roller arm cylinders keep the feed rollers against the tree.The rotation of feed rollers (5) and (6) is controlled by the feed roller motors. The feed roller motors are bidirectional hydraulic motors. The computerized controller controls the speed of the feed rollers at high speed and slow speed. The motors operate at a slow speed and a high speed when the tree is fed in a forward direction or in a reverse direction. The feed rollers always line up with the tree. The feed rollers move in or the feed rollers move out as the diameter of the tree changes.The saw chain is driven by saw motor (7). The saw motor is single directional. The movement of the saw bar is controlled by the saw cylinder. When the speed of the saw motor increases, the saw swings to the OUT position. The movement of the saw is determined by the diameter of the tree. The saw chain does not cut while the saw bar is retracted.Note: The top saw is similar to the main saw.The harvester head is equipped with a chain tension adjuster. The chain tension adjuster keeps a constant tension on the saw