A boom luffing cylinder changes the angle of a construction-machine boom around its pivot. As the cylinder extends or retracts, the boom rises or lowers and the machine's working radius changes. The required force and cylinder position vary through that arc, so a bore-and-stroke match alone does not confirm the configuration.
We review your cylinder with the boom and linkage. Send us the machine model, pivot geometry, operating angles, load data, reference lengths and hydraulic schematic so we can check the interfaces that control travel, alignment and load holding.
The boom linkage changes cylinder leverage as it moves. Provide the mechanism and circuit data for the full working range, not only one static position.
| Item | What you should provide | What it establishes |
|---|---|---|
| Machine and boom function | Machine model, boom type, cylinder quantity, installed orientation and intended movement | Confirms that the inquiry is for boom luffing rather than telescopic extension, mast tilt or chassis stabilization. |
| Pivot and load geometry | Boom and cylinder pivot coordinates, working-angle range, load cases and centre-of-gravity information | Shows how the required cylinder force and direction change through the boom arc. |
| Stroke and reference lengths | Stroke plus pin-centre lengths at the lowest, highest and any critical intermediate position | Defines travel and helps prevent the cylinder from becoming the mechanism's unintended stop. |
| Mounting interfaces | Eye, clevis, trunnion or flange details; pin diameters, widths, offsets and alignment | Allows both ends to be checked against the boom and base structures for fit and axial loading. |
| Hydraulic and holding circuit | Working and peak pressure, port thread and position, flow, hose clearance, valve block and circuit schematic | Confirms connection details and whether a machine-specified load-holding arrangement must be integrated. |
| Duty and environment | Cycle pattern, speed, shock conditions, fluid, temperature, dust, water, salt and outdoor exposure | Guides review of seals, rod finish, wipers and external protection for your operating conditions. |
Share the boom and cylinder drawings, working angles, load cases, available pressure and hydraulic schematic. We can review the envelope, stroke, reference lengths, mounts, ports and valve interface as one configuration.
If the approved drawing is unavailable, send the existing part number, clear installation photos and complete measurements from the removed cylinder. We will identify any missing geometry or circuit information before quotation.
Inspect pins, bushings, brackets, boom pivots, hoses and the load-holding components. Wear, bent structure or misalignment outside the cylinder can alter the motion path and introduce side load.
On some translated equipment documents, “amplitude cylinder” refers to the cylinder that changes boom angle and working radius. Confirm the actual machine function and linkage; “boom luffing cylinder” is the clearer English term for this page.
Provide stroke, pin-centre lengths at known boom positions, both mounting interfaces, pin sizes, bore and rod diameters, port details, valve-block arrangement and installed photos.
The linkage leverage and cylinder angle change throughout travel. Lowest, highest and critical intermediate positions help define stroke, installed lengths and the load cases your engineering review must cover.
Browse the construction machinery cylinder range. For chassis stabilization rather than boom movement, use the construction equipment support-leg cylinder page.