PIN 8T9288 - Caterpillar

Illustration 1 g00472123
Cross Section of the Implement Pump (1) Cover. (2) Head. (3) Port plate. (4) Barrel assembly. (5) Bearing. (6) Retraction plate. (7) Shaft. (8) Retainer assembly. (9) Housing. (10) Cam. (11) Thrust plate or wear plate. (12) Slipper (one of nine). (13) Piston (one of nine). (14) Spring. (15) Spacer. (16) Snap ring. (17) Impeller.
Illustration 2 g00472124
Location of the Implement Pumps (18) Left implement pump. (19) Center implement pump. (20) Right implement pump. (21) Front pump drive.Implement pumps (18), (19), and (20) are fixed displacement pumps. Implement pumps (18), (19), and (20) are axial piston type pumps. Each of the pumps has the same output. Pumps (18) and (20) have a clockwise rotation when the pumps are viewed from the drive end. Center pump (19) has a counterclockwise rotation when the pump is viewed from the drive end.A drive shaft turns pump drive (21) when the engine is running. The pump drive causes shaft (7) to rotate. The following components rotate at the same speed as shaft (7) : Pistons (13), barrel assembly (4), spring (14), impeller (17), slipper (12), retraction plate (6) and bearing (5). Cam (10) is fastened to housing (9). Port plate (3) is fastened to head (2). Cam (10) and port plate (3) do not rotate.One slipper (12) is part of each piston (13). Nine pistons (13) slide in and out of barrel assembly (4). When shaft (7) and barrel (4) rotate, slippers (12) adjust to the slope of cam (10) during movement. This causes each piston (13) in the piston cylinders in barrel (4) to move in and out.As a piston moves in and out of the barrel, the piston will draw oil into the barrel. The oil will be pushed out through port plate (3). Piston (13) is shown at the end of the exhaust stroke and at the beginning of the intake stroke.Oil from the hydraulic tank flows into the inlet port on the top of cover (1). The oil then flows through the inlet to impeller (17) .The force of spring (14) against retainer (15) holds barrel (4) against port plate (3). A retainer in the bottom of the bore in the barrel rests on a shoulder of shaft (7). On the other end of spring (14), snap ring (16) fits into a groove in the barrel.