Rotators, Rotary Actuators

Rotators and rotary actuators are mechanical components that enable controlled rotational movement of attachments such as grapples, buckets, or tools. They are essential in many industries:

• Forestry (e.g. log grapples, felling heads)
• Construction (e.g. excavator buckets, tiltrotators)
• Material handling (e.g. for cranes and excavators)
• Agriculture (e.g. round bale grapples)

They are designed to withstand high axial and radial loads and can allow unlimited rotation.

Robust and wear-resistant materials are used to ensure durability and reliability:

• Output shafts: Heat-treated steel, e.g. C45 (UNI EN 10083)
• Housings and load-bearing components: Spheroidal graphite cast iron (EN-GJS-500-7, UNI EN 1563)
• Worm gears: Bronze alloys with good sliding and running properties

Rotators are available in a wide range of sizes and performance classes:

• Small rotators: from approx. 3 tons load capacity, few kg dead weight
• Large slewing drives: over 20 tons load capacity, several hundred kg dead weight
• Housing widths: typically from 112 mm to over 400 mm
• Torque: from a few hundred up to several tens of thousands of Nm

• High load capacity due to axial and radial load resistance
• Robust materials & modular design = long maintenance intervals
• Unlimited rotation with hydraulic continuous rotators
• Long service life thanks to precise manufacturing
• Compact design for protected installation in harsh environments

Important selection criteria include:

• Application and working environment: Load types, operating conditions (indoor/outdoor, temperature, contamination)
• Load capacity & sizing: Bearing capacity, torque, service life
• Movement requirements: Continuous rotation or swing range, speed
• Connection type: Hydraulic (pressure/flow) or electric
• Installation space: Height, width, mechanical integration
• Materials: Corrosion-resistant designs, stainless steel, special steels
• Maintenance & service: Intervals, spare parts, accessibility
• Standards & customization: Machinery directive, modular options
• Cost efficiency: Costs, spare parts availability, supplier reliability

Rotators are maintenance-friendly thanks to modular design and precise manufacturing:

• Wear parts (bearings, seals) easily accessible and replaceable
• Few moving parts simplify maintenance
• Service life: 5 to over 20 years (depending on use and care)
• Regular maintenance significantly extends service life

Hydraulic rotators for log grapples are specifically designed for excavators, cranes, and loaders:

• 1-ton rotator: 350 Nm torque, 250 bar, 10 l/min oil flow, static 10 kN, dynamic 5 kN
• 3-ton rotator: 900 Nm torque, 250 bar, 20 l/min oil flow, static 30 kN, dynamic 15 kN
• 2.5-ton rotator: 760 Nm torque, 250 bar, flange mounting, static 25 kN, dynamic 12 kN

Typically manufactured in OEM quality, often “Made in Italy”.

Cost efficiency and availability are crucial factors:

• Acquisition and spare parts costs
• Reliability of manufacturer and supplier
• Long-term operating costs vs. initial investment
• Fast spare parts supply minimizes downtime
• Technical support ensures smooth operation