Hydraulic cylinders

The cylinders of the RR series are intended for heavy-duty industrial applications such as steelworks and other heavy-duty types. They are suitable for severe operating environments, in the presence of strong vibrations, pressure pulsation, high cycle frequency and significant mechanical stresses, including high radial loads. Thanks to the attention paid to the design and choice of materials and seals used, construction with high quality and accuracy standards, combined to a strict final test that reproduces the typical operating conditions of the cylinder, these hydraulic actuators are a valid choice for those applications where sturdy cylinders and long-term reliability are required, also in extreme conditions.

CMI provides its technical and design staff for special executions according to specific requirements. Special anchoring, non-standard boring or stem sizes, alternative sealing systems and non-standard options, such as control (servo-cylinders) and sealing modules (safety solutions in compliance with the machine Directive) installed directly on the actuator, are only some of the customisation options offered by our company.

General characteristics

The building components are assembled by means of threads and high-resistance steel screws, the sleeve inside of which the piston slides is entirely polished in order to minimize friction coefficients, reducing the seals wear and maximizing the sealing performances. The stem is made in steel C45 with high-thickness chrome appliqué and guide components are made in bronze and composite material.

Sealing components

Particular focus is paid to sealing components, all the employed seals are of absolutely cutting-edge with regards to the mixtures, in order to minimize fluid leakage, maximizing static sealing, without compromising the overall performances and dynamics of the actuator. These cylinders withstand a maximum actuating speed of 0.5m/sec. The various combinations include bellows seals, seals in polyurethane + PTFE, PTFE low-friction seals, VITON and Chesterton seals for low-speed, heavy-duty applications. Ad-hoc sealing solutions can be studied upon request, for particular actuating needs of the customer.

Dimensional inter-exchangeability

Cylinders comply with ISO 6022 (1981) and DIN 24333 standard, therefore they can be inter-exchanged with reference standard cylinders.
They can be designed and built upon request, to respond to the customer’s specific dimensional needs.

Size range

• Boring from Ø50mm to Ø320mm
• Stem from Ø32mm to Ø220mm
• Available with any practical operating travel.
• Six different types of standard anchoring and two stem sizes, two male threads and two female threads for boring

Connection inlets

Standard BSPP connection inlets with support surface.
Standard SAE flanges with support surface, that can be ordered upon request.
Possibility to manufacture non-standard connection inlets based on the customer’s needs.
Four possible alternative positions for supply inlets, also applicable to air exhaust vents and damper adjustments.

Operating limits

• Nominal operating pressure (constant operation): 250 Bar (25MPa).
• Nominal operating pressure (intermittent operation): 320 Bar (32MPa).
• Actuating speed up to 0.5 m/sec with standard seals, 15 m/sec with special seals.
• Operating temperature: from -20°C to +80°C according to the fluid and type of seals used.