Idlers & Pulleys
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Idlers & Pulleys
IDLERS
Macmet supplies all types of 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.
|
Idler Range |
|
Belt Width (mm) |
Three Roll Troughing Idler Length (mm) |
Single Roll Return Idler Length (mm) |
Roller Diameter (mm) |
Bearing size (mm) |
Shaft Diameter at Bearing (mm) |
|
500 |
200 |
600 |
76.1-88.9-101.6 |
20 |
20 |
|
650 |
250 |
750 |
88.9-101.6-114.3 |
20 |
20 |
|
800 |
315 |
950 |
101.6-114.3-127 |
20 |
20 |
|
1000 |
380 |
1150 |
114.3-127-139.7 |
20-25 |
20-25 |
|
1200 |
465 |
1400 |
127-139.7-152.4 |
20-35-30 |
20-35-30 |
|
1400 |
530 |
1600 |
127-139.7-152.4 |
20-35-30 |
20-35-30 |
|
1600 |
600 |
1800 |
139.7-152.4-168.3 |
25-30-40 |
25-30-40 |
|
1800 |
670 |
2000 |
139.7-152.4-168.3 |
25-30-40 |
25-30-40 |
|
2000 |
Garland Idlers |
139.7-152.4-168.3 |
25-30-40 |
25-30-40 |
PULLEYS
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.
List of satisfied customers:
Neyveli Lignite Corporation Limited
Andhra Pradesh State Electricity Board
South Eastern Coalfields Limited
Renusagar Power Corporation
Ferro Alloy Corporation Limited
Visakhapatnam Port Trust
Paradeep Port Trust
Gujarat Ambuja Cements Limited
The Associated Cement Companies Limited
MECON
Singareni Collieries Limited.
