How to Size Garbage Truck Hydraulic Cylinders: Bore, Rod, Stroke, and Working Pressure

Sizing a garbage-truck or sanitation-machinery hydraulic cylinder begins with the mechanism and load, not with a catalogue bore. Engineers must define the cylinder function, linkage geometry, required force through the full motion, pressure limits, stroke, retracted length, rod stability, speed, duty cycle, mounting and environment. A cylinder that matches only bore and stroke can still bind, drift, overload pins or fail to fit the machine.

Zhenqiang’s verified product record covers sanitation cylinders used on garbage trucks, road sweepers and waste compactors. The published range below is a manufacturing envelope rather than a machine-specific selection. The product record does not confirm a thrust value for this row, so the required extension force must be calculated from the buyer’s load case and verified during engineering review.

Published product range

Published field	Verified product-library value
Bore	25 – 300 mm
Diámetro de la varilla	12 – 260 mm
Accidente cerebrovascular	21 – 4000 mm
Presión de trabajo	2.5 – 33 MPa
Published pull-force limit	≤ 580 KN
Operating temperature	-40 – 100 ℃
Published application range	Camiones recolectores de residuos con brazo hidráulico (hook lift) de 1 a 31 toneladas Camiones compactadores de basura de 3 a 12 toneladas

1. Identify the cylinder function and linkage

State whether the cylinder lifts a hook, tips a body, operates a compactor, opens a tailgate, controls a scraper or performs another function. Provide a side-view drawing with pivot locations and the cylinder pin centers at the start, middle and end of travel. Linkage leverage changes during motion, so the maximum required cylinder force may occur away from the visible maximum load position.

2. Calculate required extension and retraction force

Convert the machine load and linkage geometry into required cylinder force at the worst operating position. Then apply the OEM’s approved allowance for friction, dynamic impact and uncertainty. Extension force is related to piston area and effective pressure; retraction force uses the annular area after subtracting rod area. System relief pressure is not automatically the permissible continuous working pressure at the cylinder.

3. Select bore from force and available pressure

Use the required force and the minimum available pressure at the cylinder, accounting for line and valve losses. Check normal duty and peak events separately. The published working-pressure range is 2.5–33 MPa, but the final design pressure must be tied to the actual circuit and acceptance test. Do not choose the top of the range by default.

4. Size the rod for tension, compression and buckling

Rod diameter affects retraction force, stiffness and stability. Long-stroke cylinders in compression require a buckling review using the unsupported length, mounting condition, load eccentricity and material properties. Side load from misaligned pivots or distorted structures must be corrected at the mechanism rather than hidden by increasing rod diameter alone.

5. Set stroke and installation lengths

Define effective stroke from the required mechanism travel, then specify retracted pin-to-pin length and extended length. Include clevis gaps, lug widths, pin diameters, bearing types, barrel clearance and hose routing. Avoid adding unverified extra stroke, because it can move the mechanism into interference or hard-stop conditions.

6. Check speed, flow and cycle temperature

Required travel time determines flow after bore is selected. Excess speed can increase impact at the end of stroke, while a larger bore may demand more pump flow and slow the cycle. Record cycles per hour, working hours per shift, dwell time under load and whether the cylinder must hold position. Repeated compactor or tailgate operation can create a different thermal duty from occasional body tipping.

7. Match seals and protection to the environment

Sanitation equipment sees water, road dirt, refuse contamination, outdoor temperature changes and cleaning chemicals. Confirm hydraulic fluid, ambient and oil temperature, rod exposure, corrosion requirement, wiper arrangement and coating. The published temperature range is −40 to 100 °C, but the selected seal and fluid system must be validated for the buyer’s actual conditions.

8. Define ports, valves and load holding

Specify port thread, size, position and orientation, plus any manifold or integrated valve. A cylinder holding a raised body, hook or tailgate may require circuit-level load-control measures. Define acceptable drift and leakage, emergency lowering behavior and how the machine prevents uncontrolled movement during hose or valve failure.

Sizing data to send with an RFQ

• Machine model, gross load and cylinder function.
• Linkage drawing with pivots and force directions.
• Required push and pull force throughout the motion.
• Retracted length, extended length, stroke and installation envelope.
• Normal pressure, peak pressure, pump flow and cycle time.
• Mounting ends, pins, bearings, ports and valve arrangement.
• Fluid, temperature, contamination, corrosion and washdown conditions.
• Test pressure, hold time, leakage limit, documents, quantity and delivery target.

Common sizing mistakes

• Copying bore and stroke from a visually similar truck without checking linkage leverage.
• Using relief pressure as the continuous design pressure.
• Ignoring rod buckling and side load on long compression strokes.
• Leaving retracted length, port orientation or clevis width until production.
• Selecting seals without fluid, temperature and contamination data.

Frequently asked questions

Can the supplier calculate the cylinder from truck tonnage alone?

No. Vehicle or payload tonnage does not define linkage leverage, cylinder angle, pressure, stroke, speed or mounting. A drawing and load case are required.

What if extension force is missing from the product record?

Keep the value open. Provide the load, geometry and pressure so engineering can calculate and validate the required force. Do not borrow a thrust figure from another product row.

Visit Zhenqiang Hydraulic and review the sanitation machinery hydraulic cylinder range before submitting the machine data.