Feed rolls

Feeder rollers

The "Feeder rollers" are the idlers installed in a conveyor belt system in the area where the bulk material is fed onto the conveyor belt. 
These idlers are usually highly loaded: they not only support the conveyor belt and the bulk material, but also absorb the forces of the impact of the bulk material on the conveyor belt.

To dampen the impact forces, the feed rollers are usually equipped with buffer rings in a dense configuration. 

If the loads are particularly high, hot vulcanized rubber coating is used instead of the buffer rings. 

In the case of extremely high loads (e.g. individual chunks weighing up to 1t at a feed height >5m), even the highest-quality rubber lining cannot withstand the impact forces for long without additional constructive measures to dampen them. In extreme cases, it is therefore better to dispense with the rubber coating of the idlers and at the same time take other constructive measures to dampen the impact forces (see Forking garlands, Heavy duty feeding garlands).

For detailed information on idler dimensions, see "Dimensions and designs".

Quality classes of feed rolls in comparison

We have three quality classes ("Compact", "Compact Plus" and "Premium") have been defined, which we recommend as the optimum solution depending on the application-specific case. Each quality class corresponds to the type of operating conditions on site and the requirements placed on the idlers, respectively, also the manufacturing effort.

Support roller shell
Pipes	Welded, dimensionally rolled steel pipes according to EN 10305-3	Welded, dimensionally rolled steel pipes according to EN 10305-3; with narrowed tolerances (Küpper standard)	Welded, dimensionally rolled steel pipes according to EN 10305-3; with narrowed tolerances (Küpper standard)
Material	S235JR according to EN 10025-2	S235JR according to EN 10025-2	S235JR according to EN 10025-2
Bearing housing (roller bottoms)
type	Deep-drawn part	forging part	forging part
Materials	steel DD13 according to EN 10111	steel C15 according to EN 10267-2 or S235JR according to EN 10025-2	steel C15 according to EN 10267-2 or S235JR according to EN 10025-2
Bearing seat	IT7	IT7	IT7
axes
type	full axle	full axle or bending hollow axle	Full axle or bending resistant hollow axle
Materials	Round steel according to EN 10277	round steel according to EN 10083-2 / pipe according to EN 10305-3	Round steel according to EN 10083-2 / Pipe according to EN 10305-3
Bearing seat	IT9	IT6	IT6
Bearing
Factory	AKT	AKT	AKT
Bearing type	Deep groove ball bearing	Deep groove ball bearing	Deep groove ball bearings	Spherical roller bearings
Bearing sizes	6204 - 6306	6306 - 6312	6306 - 6312	21312 - 22318
Sealing	2Z	2Z	2Z	-
Storage air	C4	C4	C4H	C3
Tolerance classes	P0	P0	P5	P0
Cage	Plastic cage	Plastic cage	Plastic cage	Sheet steel cage Brass cage
Lubrication	50 - 60% of free bearing volume	50 - 60% of free bearing volume	Application specific design
Gasket
type	QLR Hybrid Seal	QLR Hybrid Seal	QLR Hybrid Seal weather-shield
running characteristics
roundness [mm/m]	-	-	≤ 0.2
Buffer rings / lining
type	Buffer rings or hot-vulcanized rubber lining	Buffer rings or hot-vulcanized rubber lining	-
material	rubber	rubber	-