HUB 1770012 - Caterpillar

Stick Cylinder
Illustration 1 g06228247
Hydraulic stick cylinder
(1) Stick cylinder
(2) Head end port
(3) Rod end portThe stick cylinder moves the stick in and out. When hydraulic fluids flows into head end port (2) of stick cylinder (1), the cylinder extends. This action moves the stick inwards on the machine. When hydraulic fluid flows into rod end port (3) of stick cylinder (1), the cylinder retracts. This action causes the stick to move outwards on the machine.Cylinder Construction
Illustration 2 g06242855
Cutaway view of stick cylinder (typical example)
(2) Head end port
(3) Rod end port
(4) Cylinder body
(5) Piston
(6) Rod
(7) HeadStick cylinder (1) is constructed of the following components:
Cylinder body (4)
Piston (5)
Rod (6)
Bearings
Seals
SnubbersStick cylinder (1) has various seals to prevent the hydraulic fluid from leaking past piston (5). Stick cylinder (1) also contains a snubber on the head end and a snubber on the rod end.
Illustration 3 g06242847
Cutaway view of stick cylinder (typical example)
(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 ring
(21) 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
Seals (20) and (21) block oil from passing between the rod and the snubber.Extend
When stick cylinder (1) extends and becomes close to the end of the extension stroke, the oil is restricted by snubber. This action causes the rod to slow down before maximum extension is performed.Retract
When stick cylinder (1) retracts and becomes close to the end of the retraction stroke, oil is restricted by snubber (4). This action causes the rod to slow down before maximum retraction is performed.