EDGE-CUTTING 6Y0478 - Caterpillar

Bucket Cylinder Operation
Illustration 1 g06199058
Hydraulic bucket cylinder
(1) Bucket cylinder
(2) Head end port
(3) Rod end portThe bucket cylinder opens and closes the bucket. When hydraulic fluids flows into head end port (2) of bucket cylinder (1), the cylinder extends. This action causes the bucket to close on the machine. When hydraulic fluid flows into rod end port (3) of bucket cylinder (1), the cylinder retracts. This action causes the bucket to open on the machine.Cylinder Construction
Illustration 2 g06200481
Cutaway view of bucket cylinder
(3) Rod end port
(4) Cylinder housing
(5) Piston
(6) Rod
(7) Head
Illustration 3 g06199289
Cutaway view of bucket cylinder
(8) Wiper seal
(9) Backup ring
(10) U-cup seal
(11) Buffer seal
(12) Bearing sleeve
(13) Retaining ring
(14) Backup ring
(15) O-ring
(16) Wear ring
(17) Wear ring
(18) Backup ring
(19) Piston sealThe bucket cylinder is constructed of the following components:
Cylinder housing (4)
Piston (5)
Rod (6)
Head (7)
Seals, wear rings, bearing sleeves (8) - (19)Piston Seals
Wear rings (16) and (17) provide a bearing surface for the piston and prevent the piston from touching the inner diameter of the cylinder housing. Wear rings (16) also function as a spark arrestor.Piston seal (19) blocks oil from passing between the cylinder housing and the piston. Two backup rings (18) help hold the seal in position.Rod Seals
Bearing sleeve (12) provides a bearing surface for the rod and prevents wear on the cylinder head. Retaining ring (13) holds the bearing sleeve in place.Buffer seal (11) is the first seal that receives pressure. The purpose of the buffer seal is to reduce the pressure spikes on U-cup seal (10) and backup ring (9) for increased longevity.U-cup seal (10) blocks oil from passing externally through the cylinder head. The seal also blocks external liquid from entering the cylinder.Wiper seal (8) has a lip seal that is pointed outward to wipe off debris of the rod during retraction. The purpose of the wiper seal is to prevent particles from entering the cylinder.Head Seals
O-ring (15) prevents oil leakage between cylinder housing (4) and head (7).Backup ring (14) holds the O-ring in place.