Large Bore Hydraulic Cylinders Manufacturer

Maximum bore size up to 500 mm, stroke up to 6000 mm.
MOQ starts from only 1 piece.
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Brands We Serve in Hydraulic Industry

Large Bore Hydraulic Cylinders

Large bore hydraulic cylinders mainly consist of large-diameter pistons and matching cylinder tubes. They deliver high thrust and strong impact resistance. 14 MPa to 35 Mpa is the pressure range that they can bear while operating. They are widely used for heavy-duty applications such as metallurgical and water-conservancy equipment.

The cylinder tube is the key pressure-bearing part of a large bore hydraulic cylinder, so we make cylinder tubes from alloy steels like 40Cr or 42CrMo to meet high-pressure working conditions. Our cylinder bores reach H7 or H8 tolerance, which ensures proper fitting clearance for pistons. Besides, their inner-surface roughness is controlled between Ra 0.16 μm and 0.32 μm to reduce seal wear.

We machine inner bores of large bore cylinder tubes via rough-boring, finish-boring and honing. Fully custom cylinders are available to your drawings and specifications.

Your Reliable Supplier of Large Bore Hydraulic Cylinders

Large bore hydraulic cylinders are large-sized. When operating, even minor component machining errors can cause issues like cylinder tube scoring, so they require much higher machining precision.

With over ten years of experience in large bore hydraulic cylinder manufacturing, we have strict requirements for cylinder tube straightness and bore surface finish. During deep-hole boring, the longer the cylinder tube, the more the boring bar sticks out. When cutting forces act on it, the boring bar may bend and cause the tube to deform. To avoid this, we mount supports on deep-hole boring machines to stabilize the boring bar and minimize bending. We also fully inspect boring-bar guide parts before each production run and replace worn components as needed. This ensures reliable cylinder-tube straightness and inner-surface finish.

We provide highly flexible custom services for large bore hydraulic cylinders, offering alternative material and process options according to your equipment type and working conditions.

Large Bore Hydraulic Cylinders

Applications of Large Bore Hydraulic Cylinders

Tunneling Equipment

Large bore hydraulic cylinders are widely used in tunneling equipment, powering tunnel boring machines to perform tunneling and steering. These applications require high thrust output and good control accuracy. Large bore cylinders can produce strong thrust even in compact mounting spaces. They can also change pressure and flow right away to adjust the machine’s direction, so the machine can bore through curved tunnels.

Offshore and Port Heavy Equipment

Large bore hydraulic cylinders are widely used in port and offshore operations. They power heavy-duty equipment such as portal cranes to lift heavy loads. At sea, heavy wind and waves demand strong shock and side-load resistance. These large bore cylinders come with thick pistons and cylinder bottoms for excellent rigidity. Together with extended guide bands, they can handle cyclic shock loads caused by wind and waves. They can also resist side loads and prevent scuffing on the cylinder barrel.

Oil Drilling Equipment

Large bore hydraulic cylinders are widely used in oil drilling equipment, powering rig substructures to perform operations such as heavy-load jacking and rig movement. Downhole mud is abrasive and corrosive, so equipment demands strong abrasion and corrosion resistance.These large bore cylinders come with quenched-and-tempered 42CrMo piston rods. With thick hard-chrome plating and super-fine polishing, they stand up to particle-induced scratching from mud and resist corrosion.

Bridge Construction Equipment

Large bore hydraulic cylinders are widely used in bridge construction machinery, powering launching gantries for jacking, shifting, tensioning and positioning tasks. These applications demand high thrust. Construction sites are dusty, and debris can easily get inside the cylinders. Large bore hydraulic cylinders come with thicker chrome plating and dust-proof seals. Three-layer anti-corrosion coating is also applied to the outer barrel surface, preventing rod movement from scratching the seals.

Metallurgical Machinery

Large bore hydraulic cylinders are widely used in metallurgical machinery. They power metallurgical equipment for heavy-duty operations such as material pushing and steel straightening in ironmaking and rolling. These applications require high load-bearing capacity. Large bore hydraulic cylinders feature piston diameters of 400-500 mm and above. If multiple cylinders work in parallel, they can carry the total rolling force from rolling mills.

Water Conservancy Equipment

Large bore hydraulic cylinders power various sluice gates to open and close, regulating water flow. These applications demand extremely stable operation. Hydraulic cylinders deliver smooth low-speed performance. Equipped with counterbalance valves, they maintain consistent speed for gate opening and closing throughout the full stroke.

Mining Machinery

Large bore hydraulic cylinders power mining equipment such as excavators and crushers for lifting and discharge-gap adjustment. These applications demand excellent shock-resistance and overload tolerance. Large bore hydraulic cylinders have thick-walled barrels and ample pressure capacity. They resist deformation and damage even under sudden high-pressure shocks from hard rock.

Environmental and Recycling Equipment

Large bore hydraulic cylinders power recycling-industry equipment such as scrap shears and balers for shearing, compressing and baling work. These applications demand cylinders to withstand continuous operation at high workshop temperatures. Compared with other hydraulic cylinders, large-bore cylinders hold more oil, so their oil temperature rises more slowly in hot conditions, which eases system overheating caused by continuous running.

High Repair Costs on Large Bore Hydraulic Cylinders

Large bore hydraulic cylinders come with high repair costs. The main reason is their large size, which leads to high shipping fees. Besides, most of their seal components are custom-made or non-standard imported parts with high unit costs. Even minor assembly errors can make seals leak, and frequent seal replacements add significantly to repair costs.

To solve this problem, we properly control the fitting clearances for the guide sleeve and piston and keep the surface finish of piston seal grooves within Ra0.4, helping prevent seal distortion during installation and cuts down seal replacement frequency. Meanwhile, we deburr and add smooth chamfers to the connecting threads between piston rod and piston. This avoids damage during assembly and disassembly, so you won’t face extra repair costs.

Guide Bearing Failure on Large Bore Hydraulic Cylinders

Large bore hydraulic cylinders feature heavy piston rods. The guide sleeve must carry the full weight of the piston rod and side-loading forces during operation, so it wears easily. Once the guide sleeve gets damaged, the piston rod will tilt, which puts uneven side pressure on the seals, eventually causing seal failure and cylinder oil leaks.

To solve this problem, we pay close attention to guide-sleeve material selection first. We offer suitable options such as cast tin bronze or high-strength ductile iron according to customers’ actual working conditions. Next, we control the assembly clearance between piston rod and guide sleeve. A proper clearance builds up an oil-lubrication film, which reduces wear on contact surfaces and avoids piston rod tilting.

Thermal Shock on Large Bore Hydraulic Cylinders

Large bore hydraulic cylinders come with long piston rods. When heated, uneven thermal expansion can make the piston rod tend to bend. Since the guide sleeve fits deep into the cylinder head, it restricts this bending movement. This puts heavy side loads on the guide sleeve and wears it out quicker. That then harms the seals and can even cause oil leaks.

To solve this problem, we first optimize the piston-rod chrome-plating process. We apply section-by-section pre-heating for uniform rod temperatures during plating, and then closely regulate plating current and keep coating-thickness variation within 0.02 mm. This improves coating adhesion, so the piston rod can stand up to repeated hot-and-cold shocks. After assembly, We simulate rapid temperature-change conditions with heat guns and cooling equipment. We check cylinder performance to make sure thermal shock will not cause problems.