HARNESS AS-CHASSIS 1725964 - Caterpillar

Boom Cylinder
Illustration 1 g06228338
Hydraulic boom cylinder
(1) Boom cylinder
(2) Head end port
(3) Rod end portThe boom cylinder raises and lowers the boom. When hydraulic fluids flows into head end port (2) of boom cylinder (1), the cylinder extends. This action raises to boom on the machine. When hydraulic fluid flows into rod end port (3) of boom cylinder (1), the cylinder retracts. This action causes the boom to lower.Cylinder Construction
Illustration 2 g06238190
Cutaway view of boom cylinder (typical example)
(2) Head end port
(3) Rod end port
(4) Cylinder body
(5) Piston
(6) Rod
(7) Head
(21) SnubberBoom cylinder (1) is constructed of the following components:
Cylinder body (4)
Piston (5)
Rod (6)
Bearings
Seals
Snubber (21)Boom cylinder (1) has various seals to prevent the hydraulic fluid from leaking past piston (5). Boom cylinder (1) also contains a snubber on the rod end.
Illustration 3 g06238179
Cutaway view of boom 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 seal
(20) Seal ringPiston 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.Snubber Operation
Seal (20) blocks oil from passing between the rod and the snubber (21).When boom cylinder (1) extends and becomes close to the end of the extension stroke, the oil is restricted by the snubber (21). This action causes rod (6) to slow down before maximum extension is performed.