PUMP GP-GEAR 1249390 - Caterpillar

Operation
MARINE TRANSMISSION CUTAWAY 1. Oil pump.2. Top shaft (input).3. Pinion gears.4. A head clutch (discs and plates).5. Dump valve (for astern clutch).6. Flexible connector (to engine flywheel).7. Astern clutch (discs and plates).8. Output shaft.9. Bottom shaft.10. Driven gears.11. Dump valve (for ahead clutch).The Marine transmission has a flexible connector (6) on top (input) shaft (2). Drive pinions (3) and driven gears (10) make a reduction in speed (rpm) so output shaft (8) from the transmission, turns slower than the speed (rpm) of the engine.The flexible connector (6) has a spider with gear teeth on the diameter of the spider. The spider is on the top (input) shaft of the transmission. Another part of the flexible connector is a ring with gear teeth in the bore of the ring. The ring is on the engine flywheel. The flexible parts are the rubber blocks between the teeth on the spider and the teeth in the ring. The engine turns the flywheel and ring, the teeth in the ring push on the rubber blocks. The rubber blocks push the teeth on the spider which turns the spider and the top shaft of the transmission.Back to back hydraulically activated clutches (4) and (7) operate the forward and reverse drives. A control valve directs the flow of oil to either of the clutches for forward or reverse operation. The valve is operated by a lever which can be manually or remotely controlled.The oil pump (1) is connected to the end of top shaft (2) and turns at the same speed (rpm) as the engine. The oil for the pump is in the sump of the transmission. The oil from the pump is both for lubrication and is the supply of pressure oil that can activate either the ahead or the astern clutch. The reference to the clutches, is the astern clutch (reverse motion) and the ahead clutch (forward motion of the vessel when the propeller has a right hand pitch).The astern clutch (front) section engages the three gear drive section in the marine gear which rotates the propeller shaft in the same direction of rotation as the engine. The ahead clutch (rear) section engages the two gear section which reverses the direction of propeller shaft rotation.The direction of flywheel rotation for a standard engine is counterclockwise, when viewed from the flywheel end of the engine. With a right hand propeller, the ahead clutch (rear) section is engaged to produce ahead motion.
MARINE GEAR SCHEMATIC (Ahead Clutch Section Engaged)
4. Ahead clutch. 7. Astern clutch.Hydraulic System
In the information that follows the clutch rear section will be referred to as the "ahead clutch" and the clutch front section will be referred to as the "astern clutch."Oil pump (1) supplies the hydraulic oil to the control valve. The control valve positions, AHEAD and REVERSE, direct the pressure oil to engage eithr ahead clutch (4) or astern clutch (7). Moving the control valve to the AHEAD position directs the hydraulic pressure oil through the oil passage around the tube