BONNA MENS. EL CAMINO HACIA UNA NUEVA MANERA DE PENSAR
5. Aproximación a una teoría del conocimiento
The boom dual rod telescope cylinder (upper telescope cylinder) (Figure 2-39) has a 235 mm (9.25 in) bore. The cylinder is internally ported (rod ported). Oil from the telescope control valve is routed to the cylinder by external lines. Foreign material is prevented from entering the cylinder rod during retraction by a wiper seal in the head. O-ring seals prevent internal and external leakage.
The retracted length of the telescope cylinder is 11005 mm (433.25 in). The cylinder incorporates two cylinder rods, therefore each rod has a separate stroke. Each rod has a stroke of 8966 mm (353 in) which provides a combined overall stroke of 17932 mm (706 in). This gives the cylinder an overall extended length of 28931 mm (1139 in) from the end of the cylinder barrel to the center of the attachment fittings on the cylinder rod.
The cylinder weighs approximately 1971 kg (4345 pounds) wet.
Maintenance
Disassembly
NOTE: Any maintenance requiring disassembly of the cylinder should include replacement of all cylinder seals and o-rings.
1. Using a spanner wrench, unscrew the outer cylinder head from the cylinder barrel.
2. Remove the cylinder rod assembly from the cylinder barrel and cover the barrel to avoid contamination.
NOTE: Aligning discarded seals and rings in the order of disassembly will facilitate installation of new seals and rings.
3. Remove the hydrolock piston seal to gain access to the setscrew securing the piston to the outer cylinder rod.
4. Remove the setscrew and unscrew the piston from the cylinder rod.
5. Remove the remaining hydrolock seal from the outside of the piston and the o-ring and two backup rings from the inside of the piston.
6. Remove the spacer from the rod and remove the wear ring from the spacer.
7. Remove the cylinder head from the outer rod.
8. Remove the o-ring and backup ring from the outside of the head and the wear rings, buffer seal, deep Z rod seal, and the wiper ring from the inside of the head.
9. Using a spanner wrench, unscrew the inner cylinder head from the outer cylinder rod.
10. Remove the inner cylinder rod assembly from the outer cylinder rod and cover the opening to avoid contamination.
11. Remove the hydrolock piston seal to gain access to the setscrew securing the piston to the inner cylinder rod.
12. Remove the setscrew and unscrew the piston from the cylinder rod.
13. Remove the remaining hydrolock seal from the outside of the piston and the o-ring and two backup rings from the cylinder rod
14. Remove the spacer from the rod and remove the wear ring from the spacer.
15. Remove the cylinder head from the inner rod.
CAUTION
Do not retract the cylinder completely if it is not attached to the boom. Maintain a spacer that is split or hinged 6.88”
long to prevent cylinder from retracting completely.
DANGER
Do not use air pressure to remove the rod. Use only a source of controlled hydraulic oil pressure if the rod is hard to move.
CAUTION
Exercise extreme care when handling or setting down the cylinder rod. Do not damage the chrome surface.
CAUTION
When removing seals and rings, avoid scratching grooved and gland surfaces.
DANGER
Do not use air pressure to remove the cylinder rod assembly. Use only a source of controlled hydraulic oil pressure if the rod is hard to move.
CAUTION
Exercise extreme care when handling or setting down the cylinder rod. Do not damage the chrome surface.
16. Remove the o-ring and backup ring from the outside of the head and the wear rings, buffer seal, deep Z rod seal, and the wiper ring from the inside of the head.
17. If necessary, remove the holding valve from the inner cylinder rod and from the cylinder barrel.
Inspection
1. Clean all parts with solvent and dry with compressed air.
Inspect for damaged or worn parts and replace as required.
2. Stone out minor blemishes and polish with fine crocus cloth.
3. Clean all with solvent and dry with compressed air any parts that have been stoned and polished.
4. Inspect the barrel for scoring.
Assembly
1. If removed, install the holding valves. Refer to HOLDING VALVES in this section.
NOTE: Lubricate new seals and rings with clean hydraulic oil.
NOTE: Locate the gap of wear ring 180 degrees with respect to each other.
2. Install the wiper ring into the cylinder head.
3. Install the wear rings into the head.
4. Install the buffer seal and deep Z rod seal inside the head ensuring the seals are assembled properly and installed in the correct direction.
5. Install the o-ring and backup ring onto the outside of the head.
6. Install the inner cylinder head onto the inner cylinder rod.
7. Install the wear ring onto the spacer and install the spacer onto the rod.
8. Install the o-ring and backup rings onto the rod and install the piston onto the inner cylinder rod. Secure the piston in place with the setscrew.
9. Install the hydrolock seals onto the piston. Refer to (Figure 2-38) for proper seal orientation.
10. Lubricate the inner cylinder rod assembly with clean hydraulic oil and install the rod assembly into the outer cylinder rod with a slight twisting motion.
11. Using a spanner wrench, secure the inner cylinder head to the outer cylinder rod.
12. Install the wiper ring into the outer cylinder head.
13. Install the wear rings into the head.
CAUTION
Clean all surfaces and remove all burrs and nicks before installing new seals and rings. Replace all damaged or worn parts.
CAUTION
When installing new seals and rings, clean all surfaces and carefully remove burrs and nicks. Parts displaying excessive wear or damage should be replaced.
Wiper Ring
Deep Z Seal Buffer Seal
Back-Up Ring
FIGURE 2-37
CAUTION
Improper seal installation can cause faulty cylinder operation.
CAUTION
Avoid scratching or damaging the grooved and gland surfaces or the seals and rings.
Hydrolock Piston Seals
FIGURE 2-38
2
FIGURE 2-39
7279 33
4 9
10
18
18
23 25
27 28
14 31
33
36
32 36
29
19 16
1213 11 9
7
5 6 4
3, 8
2, 3
1
15
11 20
17 21
18 22
24 30 26 26
26
14. Install the buffer seal and deep Z rod seal inside the head ensuring the seals are assembled properly and installed in the correct direction.
15. Install the o-ring and backup ring onto the outside of the outer cylinder head.
16. Install the outer cylinder head onto the outer cylinder rod.
17. Install the wear ring onto the spacer and install the spacer onto the rod.
18. Install the o-ring and backup rings into the piston and install the piston onto the outer cylinder rod. Secure the piston in place with the setscrew.
19. Install the hydrolock seals onto the piston. Refer to (Figure 2-40) for proper seal orientation.
20. Lubricate the outer cylinder rod assembly with clean hydraulic oil and install the rod assembly into the cylinder barrel with a slight twisting motion.
21. Using a spanner wrench, secure the outer cylinder head to the cylinder barrel.
22. Pressurize and cycle the cylinder with hydraulic oil pressure. Test pressure should be 36197.4 kPa/361.9 bar (5250 psi) (rod side pressure) and 24131.6 kPa/
241.3 bar (3500 psi) extended (piston side pressure).
Check for proper operation and any leakage.
Item Description
1 Barrel
2 Piston
3 Setscrew
4 Seal
5 Backup Ring
6 O-ring
7 Spacer
8 Piston
9 Plug
10 Wear Ring
11 Seal
12 O-ring
13 Backup Ring
14 Outer Rod
15 Spacer
16 Inner Rod
17 Outer Cylinder head
18 Wear Ring
19 O-ring
20 Backup Ring
21 Buffer Seal
22 Rod Seal
23 Backup Ring
24 Wiper Ring
25 Inner Cylinder Head
26 Wear Ring
27 O-ring
28 Backup Ring
29 Buffer Seal
30 Rod Seal
31 Backup RIng
32 Wiper Ring
33 Counterbalance Valve
34 Adapter
CAUTION
Improper installation of seals could cause faulty cylinder operation.
CAUTION
Avoid scratching or damaging the grooved or gland surfaces or the ring and seals.
DANGER
Do not use air pressure to cycle or pressurize the cylinder.
Hydrolock Piston Seals
FIGURE 2-40