Material Handling Systems

Idlers & Pulleys from Macmet

Idlers from Macmet

Macmet supplies idlers for trouble free conveyor operations. A wide range of 'sealed for life' type idlers, either with seize resistant or deep groove ball bearings, are manufactured and supplied to suit specific requirements and applications.

Both fixed bracket type (in-line & staggered) idlers and garland type idlers with roll diameters from 76.1 mm to 219.1 mm are manufactured by MACMET. All fixed bracket idlers will be drop in slot type. Slotted holes will be provided at the base of the idlers bracket to permit adjustment up to 5 mm on each side of the true center for training of the belt. All idlers conform strictly to IS:8598.

The idlers are provided with sufficient quantity of servo grade grease and sealed for life. Special type bearing housing are made out of deep drawn quality steel sheets, idler rollers are made with ERW black tubes conforming to IS:9295. The out of roundness of the rollers will be within +/- 0.5mm. Tubes are cut into required lengths and both ends are bored to required accuracy and to achieve concentricity. The bearing housings are made out of deep drawn quality steel sheets.


The pressed steel bearing housings are made in precisely manufactured dies in hydraulic press to precise tolerances having a minimum thickness as indicated at the bearing seats. These housings are then accurately machined to tolerance for correct seating of bearings and fitment at the roller ends. The idler spindles are made from EN-8 or C-40 conforming to BS:970 or IS:1570 respectively. The spindles are precision machined to the specific tolerances. The inner seal, labyrinth seal comprising of inner and outer rings and inner dust seal are of Nylong 6 material whereas outer dust seal are pressed from CRCA sheets.

The machined housings and the roller tube are placed on a mandrel and the collars are inserted inside the housings over the mandrel to hold the total assembly together. The welding of the machined roller tubes with the housings are carried out simultaneously on both sides with CO2 welding in a special purpose machine, thereby ensuring a total mono block construction and a rigid roller with two axes of the bearings in line.

Subsequently, the idler spindle, inner seals, bearings, labyrinth rings, dust seals, and circlips are assembled in sequence. After the rollers are fully assembled, random sampling and testing are carried out for free rotation, friction factor and water and dust ingress. Idler selection is guided by the type of material handled, belt speed and service requirement.

Pulleys from Macmet

Macmet pulleys are time tested drive components for all types of belt conveyor systems. They are safe, robust and reliable with long service life. Basic pulley diameters are 250, 315, 400, 500, 630, 800, 1000, 1250, 1400 & 1600 mm. All pulleys are made conforming to IS:8531. The pulleys, unless otherwise agreed with the customer, are rolled and fabricated from low carbon steel plates with end/center disc welded to the shell. For specific requirements and applications, turbo diaphragm type cast steel end discs are also used. All pulley shafts are made from C-40/EN-8 grade steel. The outer surface of the pulley shells are machined to specific tolerances.


All pulley shafts are generally keyed with the hub. Pulleys with tapered locking assembly arrangement are also made for special applications and/or as per specific requirement of the customer. All pulleys are statically balanced. The lagging for drive pulleys are provided by hot vulcanizing natural rubber with herringbone groove as per customer requirement. Apex of the grooves will be in the belt travel direction. Non drive pulleys are provided with plain lagging unless agreed otherwise with the customer. The shore hardiness of rubber lagging are 55 to 65 (durometer) Shore Scale A.

All pulleys are provided with self-aligning spherical roller bearings to suit the loading conditions. Plummer Blocks are provided with grease nipples for lubricating purposes. All lubricating nipples are readily accessible. Bearings are protected against ingress of dust and moisture by providing of suitable seals on both sides. The bearing housing (Plummer blocks) are horizontally split type and provided with removable caps and grease seals for operating in dust laden atmosphere. Bearings are protected against ingress of dust and moisture by providing of suitable labyrinth/rubber seals on both sides. Plummer block are made of cast steel.

Material Handling Systems:

Corporate Office
10-B O. C. Ganguly Sarani, Kolkata- 700 020, West Bengal, India
Phone: +91 33 2281 6000, Fax: +91 33 2281 5566
E-mail: macmet@vsnl.com

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