brochure metalloids

1

2

3

Idler terminology and types


WHAT IS AN IDLER

The industry accepted nomenclature for conveyor idlers is that a conveyor Idler = Frame + Rollers

This distinction is often overlooked and as a result care must be taken when purchasing replacement components that an idler is not
specified when only a replacement roller is required.












COMMON ROLLER/IDLER TYPES

The three common types of conveyor rollers are as follows:
Plain - this roller can be supplied with a steel, aluminium or plastic shell. It is the most common roller type used for general applications.
Impact - these rollers are used where there is heavy impact from lumps of material. Rubber impact disks cushion the roller and
conveyor from this impact.
Disc - disc rollers are used on the return side of the conveyor. Rubber or polyurethane discs break up the contact between the belt and
the roller and encourage any product that is adheared to the belt to break off and fall away.













IDENTIFICATION PARAMETERS

Metalloids is able to provide replacement rollers for all of our equipment as well as replacement rollers for equipment supplied by
others. In order to correctly identify a roller we need to be supplied with the Metalloids part number to allow the roller to be identified.

In the event that the Metalloids part number is not known we will need the following dimensional information to be supplied. If it is not
possible to determine the diameter of the shaft in the middle of the roller (diameter E), we will need to be supplied with the operating
data to allow a full design check to be carried out.

H SHAFT LENGTH

G BETWEEN FLATS

F ROLL FACE
ØB



ØE
ØA Brg Outside Diameter






4

TROUGH AND CARRY IDLER TYPES






























































5

Idler Mounting Centres
To generally conform with accepted practices, the mounting hole centres listed in the dimensional tables are based on:


Belt Width + 250mm

For belts up to and including 1200mm

Belt Width + 300mm

For belts over 1200 mm up to and including 1500mm

Belt Width + 400mm

For belts 1600mm and above.

Inline Vs OFFSET Idlers

Offset
Offset idlers have slightly overlapping rollers for light duty belts that are susceptible to pinching.
They also have self training properties which means they must be installed in the correct orientation.












Direction Of Belt







The moving belt must contact the centre roller

Inline
Inline idlers are generally used on long conveyors and where thick belts are used.
















Direction Of Belt














6

Type description Type description

01 2 roll trough 49 5 roll trough retractable impact (angle on channel)
02 2 roll trough impact 50 5 roll trough rigid suspended
03 2 roll trough transition 51 5 roll trough rigid suspended impact
04 2 roll trough trainer 52 5 roll picking
05 3 roll trough offset 53 5 roll picking impact
06 3 roll trough offset impact 54 5 roll picking trainer
07 3 roll trough offset transition 55 single roll flat carry
08 3 roll trough offset trainer 56 single roll flat impact
09 3 roll trough offset weigh 57 single roll flat carry trainer
10 3 roll picking offset 58 2 roll flat carry
11 3 roll picking offset impact 59 2 roll flat impact
12 3 roll picking offset trainer 60 2 roll flat carry trainer
13 3 roll trough inline 61 single roll return
14 3 roll trough inline impact 62 single roll disc return
15 3 roll trough inline transition 63 single roll return trainer
16 3 roll trough inline trainer 64 single roll disc return trainer
17 3 roll trough inline weigh 65 2 roll return
18 3 roll trough retractable (angle on angle) 66 2 roll disc return
19 3 roll trough retractable impact (angle on angle) 67 2 roll return trainer
20 3 roll trough retractable (angle on channel) 68 2 roll disc return trainer
21 3 roll trough retractable impact (angle on channel) 69 2 roll vee return
22 3 roll trough rigid suspended 70 2 roll disc vee return
23 3 roll trough rigid suspended impact 71 2 roll vee return trainer
24 3 roll picking inline 72 2 roll disc vee return trainer
25 3 roll picking inline impact 73 2 roll inverted vee
26 3 roll picking inline trainer 74 3 roll suspended trough
27 4 roll trough 75 3 roll suspended trough impact
28 4 roll trough impact 76 5 roll suspended trough
29 4 roll trough transition 77 5 roll suspended trough impact
30 4 roll trough trainer 78 2 roll suspended return
31 4 roll trough weigh 79 2 roll suspended disc return
32 4 roll trough retractable (angle on angle) 80 trough roller - steel & aluminium
33 4 roll trough retractable impact (angle on angle) 81 trough roller - c.r.s.
34 4 roll trough retractable (angle on channel) 82 trough impact roller
35 4 roll trough retractable impact (angle on channel) 83 return roller - steel & aluminium
36 4 roll trough rigid suspended 84 return roller - c.r.s.
37 4 roll trough rigid suspended impact 85 vee return roller - steel & aluminium
38 4 roll picking 86 vee return roller - c.r.s.
39 4 roll picking impact 87 disc return roller
40 4 roll picking trainer 88 disc vee return roller
41 5 roll trough 89 flat carry roller
42 5 roll trough impact 90 flat impact roller
43 5 roll trough transition 91 return roller - spiral
44 5 roll trough trainer 92 suspended trough roller - steel & aluminium
45 5 roll trough weigh 93 suspended trough roller - c.r.s.
46 5 roll trough retractable (angle on angle) 94 suspended trough impact roller
47 5 roll trough retractable impact (angle on angle) 95 suspended vee return roller - steel & aluminium
48 5 roll trough retractable (angle on channel) 96 suspended vee return roller - c.r.s.
97
suspended disc vee return roller
7

8

The engineering



concept




Any conveyor idler roller requires a bearing and shaft assembly to operate under
deflection
conditions. The relatively thin shaft is supported only at its extremities. It must accept
the load from the shell through the bearings located 40 mm to 75 mm in from each end.
This results in shaft bending and angular deflection at the bearings.

Metalloids rollers are engineered to satisfy this simple requirement. Bearings must
accept angular deflection within specified limits and shafts must be sized so limits are
not exceeded.
There is a wide bearing selection to choose from: parallel roller bearings, taper roller
bearings or single row deep groove precision ball bearings. Parallel and taper roller
bearings will tolerate 2 to 5 minutes of angular deflection, while single row deep groove
precision ball bearings with C3 C4 clearances allow 12 to 16 minutes. All roller bearings
have a grease pumping action which
throws lubricant away from the roller track where it is required while ball bearings
churn the grease, but retain it within the ball track area.


Metalloids chose single row deep groove precision ball bearings because they:

• Satisfy deflection criteria without unreasonable increases in shaft diameters
between the bearings.
• Adequately accept the axial thrust component of the load generated by
conveyor belt movement across the roller face or where rollers are inclined in wing
positions.
• Permit practical shaft diameters which satisfy bearing deflection criteria and
allow manufacturers normal dynamic capacity ratings to assess B10 bearing life.
• Retain grease at the bearing faces permitting an extended period of operation
without relubrication.
• Have much lower friction or “drag” resistance, thus minimizing the power
required to drive the rollers.
• If the angular deflection limits are exceeded, the effect on ball bearings is less
critical than for roller bearings.
• Are readily available in commercial quantities at a competitive cost.
































9

Welded idler


manufacturing concept




Automatic circumferential welding ensures uniform
quality and repeatability. The 3mm radius provides a
safe edge in the event that it contacts the conveyor belt.










A minimum of 80% weld penetration between end cap
and shell. The weld has a higher strength than the shell
or end cap material.










Metalloids flexibility in manufacturing can match
most spindle ends and slot sizes. The shaft
bearing journals are manufactured to bearing
manufacturers’ tolerances.








Metalloids flexibility in manufacturing can match

most spindle ends and slot sizes. The shaft
bearing journals are manufactured to bearing
manufacturers’ tolerances.









Rollers are checked at an equivalent belt speed of
9 m/s. Metalloids can manufacture
competitors’ dimensions for interchangeability with
existing frames.










10

Recommended location


Head & Tail Pulleys





It is critical that the transition lengths between the pulley and the fully troughed idlers are of sufficient length
to prevent damage to the conveyor belt or components.
If the transition length is too short then this will result in excess tensions in the conveyor belt edges which
can cause the following problems:
• Splice failure – at belt edges.
• Premature roller failure due to high deviation loads on the wing rollers.
• Excessive and accelerated pulley lagging wear.
The level of stress induced at the belt edges is dependent on a number of factors being:
• The transition length.
• The vertical distance the belt edges raises or lowers in the transition.
• The idler trough angle.
• The elastic modulus of the belt at the edges under tension.
• The induced belt edge stress in the transition.
The location of the belt line in relation with the top of the pulley therefore has a significant effect on the
transition length required.
It is common practice to locate the head or discharge pulleys at ½ of the trough depth to minimise the
stresses induced in the belt and on the wing rollers. In the case of tail pulleys the full trough depth is often
used to avoid an unloaded belt from being lifted up into the skirts which can result in mechanical damage.








Head or high tension pulley Tail or low tension pulley









Transition length Transition length




















11

Top face of head pulley Top face of head pulley

-- ---------- -- --------- -- ------- --- H H

------------ -- --------- -- ----------




The following tables detail the distance from the belt line to the top of the pulley (H)
to achieve a ½ trough depth.

Values of H for 1/2 Trough Depth (mm)

3 Roll 5 Roll Trough
Trough
Trough Angle 30° 35° 45° 45° 55°
Belt Width
350 29 33 41
400 33 38 47
450 38 43 53
500 42 48 59
600 50 57 71
650 54 62 77
750 63 72 88
800 67 76 94
900 75 86 106
1000 83 96 118
1050 88 100 124
1200 100 115 141 131 154
1350 113 129 159 147 173
1400 117 134 165 153 179
1500 125 143 177 163 192
1600 133 153 189 174 205
1800 150 172 212 196 231
2000 167 191 236 218 256
2200 183 210 259 240 282
2500 208 239 295 272 320
3000 250 287 354 327 384
3500 292 335 412 381 448

















12

It is recommended that transition lengths are obtained directly from the belt manufacture or from
an appropriate standard such as IOS5293 Conveyor Belts – Determination of minimum transition
distance on three idler rollers.
Alternatively the following tables can be used as a guide.

Half Trough depth - recommended minimum transition distances


Recommended Transition Distance Distance = Factor x Belt
Width

Transition Length

Idler Trough % Rated Belt Fabric Belts Steel Cord
Angle Tension 1.4 Belts
3.2
> 90%
30 60% to 90% 1.1 2.4
< 60% 0.8 1.6
> 90% 1.6 3.4
35 60% to 90% 1.3 2.6
< 60% 1.0 1.8
> 90% 2.0 4.0
45 60% to 90% 1.6 3.2
< 60% 1.3 2.3

full Trough depth - recommended minimum transition distances






Transition Length Recommended Transition Distance Distance = Factor x Belt Width

Idler Trough % Rated Belt Fabric Belts Steel Cord
Angle Tension 3.0 Belts
> 90%
6.6
30 60% to 90% 2.2 5.0
< 60% 1.6 3.4
> 90% 3.2 6.8
35 60% to 90% 2.4 5.2
< 60% 1.8 3.6
> 90% 4.0 8.0
45 60% to 90% 3.2 6.4
< 60% 2.4 4.4
Recommended Idler arrangement at Tail Loading Locations
.
Transition idlers should have plain or rubber covered wing rollers to minimise damage to the belt edge















13

Idler

load charts



Chart 1 3 Roll - 35° trough idlers
Static Load Selection















3 Roll trough set (kg) (rollers Only) Select base from chart 3 on page 36.)

Belt Roller
widt Series
h 01 05 10 11 12 15 20 25 30 35 45 50 54 55 59 60
(mm) 250 248
350
400 266 264
450 281 279
500 295 374 293 373 387 387
600 321 407 320 406 421 421
650 335 424 334 423 425 439
750 358 453 356 360 359 468 745
800 368 466 336 335 335 482 752
900 390 494 290 289 411 511 648
1000 406 514 375 374 373 531 588 531 844 847
1050 420 531 345 344 343 545 541 549 776 876
1200 448 466 294 293 292 465 460 586 661 860 931 1678 933
1350 253 405 400 579 574 747 984 1460 986
1400 249 399 394 570 566 735 990 1438 992
1500 222 356 351 652 749 940 1036 1286 1038
1600 211 340 335 664 716 898 1054 1229 1056 1056 164 206
4
4
1800 632 626 785 1085 1075 1114 1114 144 215
0
0
2000 680 943 932 1178 1178 166 186
6
6
2200 592 824 811 1106 1242 146 163
0
0
2400 1290 1327 1481
2500 1308 1692
2600 1332 1219 1614
2800 1389 1090 1445
3000 1340 995 1323











14

Chart 2 3 Roll - 35° trough idlers
Dynamic Load Selection














3 Roll trough set (kg) (Rollers Only) Select base from chart 3 on page 36.)

Belt Roller
widt Series
h 01 05 10 11 12 15 20 25 30 35 45 50 54 55 59 60
(mm) 282 256
350
400 282 256
450 282 256
500 282 292 256 265 274 302
600 282 292 255 264 274 302
650 281 291 255 264 273 302
750 281 291 255 264 273 301 317
800 281 291 255 264 273 301 317
900 281 290 254 263 272 301 316
1000 280 290 254 263 272 300 315 485 513 642
1050 280 290 254 263 272 300 315 485 512 642
1200 280 289 253 262 271 299 314 484 511 640 759 793 939
1350 253 299 313 484 510 639 757 791 937
1400 249 298 313 484 510 639 757 791 937
1500 222 298 312 483 509 638 756 789 936
1600 211 298 311 483 508 638 756 788 936 1207 978 126
4
1800 482 507 637 755 786 935 1206 976 126
1
2000 635 753 783 933 1204 973 125
8
2200 592 751 780 931 1202 970 125
6
2400 1201 968 1253
2500 1201 1252
2600 1200 966 1251
2800 1198 963 1248
3000 1197 960 1246




















15