Curves

Tapered conveyor rollers convey materials to be transported safely in curves. With tapered conveyor rollers, the conveyor speed increases according to the radius of the curve so that the materials to be transported maintain their alignment between the side profiles. Side guides are recommended but are not imperative.

Horizontal surface of the tube

When designing the curve it is essential to ensure that the tube surface of the tapered elements is horizontal. The shaft of the conveyor roller is inclined by 1.8°.

Series 1700KXO/ 3500KXO with an internal radius of 650 mm
Interroll's Tapered Conveyor Rollers are suitable for use with curve internal radii of 800/850 mm770/820 mm where the drive head is on the internal radius.
Platform 1700 Tapered Conveyor Rollers can also be used for an internal curve radius of 650 mm.

Should the specified internal curve radii not be adhered to then the user has to count on the materials not being conveyed smoothly.

The actual clearance of the conveyor should be approx. 50 mm greater than the calculated width to ensure smooth conveyance of the materials around curves. Please select the next higher standard installation length.

Interroll offers two types of Tapered Conveyor Roller, which are both designated as KXO. The first roller is based on the Series 1700 Universal Conveyor Roller and the second on the Series 3500 Fixed Drive Conveyor Roller.

Tapered Universal Conveyor Roller Series 1700KXO/ 3500KXO

Tapered polymer tube sleeves:
- Abrasion-proof
- Sound reduction
- Impact-resistant
- Weather- and temperature-resistant
Lightweight, hence good running and starting properties
End cap for tapered elements on the side with the largest diameter
Load capacity 500 N

Tapered Conveyor Roller Versions

Tapered conveyor rollers with curved internal radii of 800/850 mm are available in the following versions and materials:

Version
Reference length	From 250 to 900 mm in increments of 50 mm
Shaft	Female threaded shaft (M8 x 15)
Shaft diameter	12 or 14 mm
Bearing	Precision ball bearing 6002 2RZ Precision ball bearing 6002 2RZ stainless steel
Material
Inner tube	Zinc-plated steel or stainless steel
Tapered elements	Polypropylene (grey) on a cylindrical inner tube made of zinc-plated steel / stainless steel with an external diameter of 50 mm
Shaft	Uncoated steel or stainless steel
Bearing	Bearing housing made of polyamide (black) Bearing seal made of polypropylene (yellow) End cap for the side with the largest diameter made of polypropylene (yellow)

Drives Combinable with Tapered Conveyor Rollers

Drives can be combined with an internal curved radius of 800 and 850 mm (or 770/820 mm when the drive head is on the internal radius), providing nothing else is specified. The internal radius of the curve is measured to the internal edge of the internal bearing profile, that is to the beginning of the installation length EL.

Drive elements
The following drive elements are available:

	PolyVee drive head made of high-grade polyamide 6.6 form PJ, ISO 9981, for flexible PolyVee belts
	Round belt head made of high-grade polyamide 6.6 for standard round belts with a diameter of 4, 5 and 6 mm, optional grooving on the extended inner tube on the internal radius of the curve
	Double sprocket head made of high quality polyamide 6.6 with 14 teeth, measuring 1/2'' on the external radius of the curve

Calculating the installation length (PolyVee/ round belt head)
The installation length of curved sections must be longer than that of straight sections to ensure that the material to be transported does do not touch the side profiles in the curve. The following steps are necessary to calculate the
minimum installation length:
1. Calculate the minimum external radius

2. Calculate the minimum installation length ELmin = Ra - Ri
3. Adjust the ELmin to standard length (next higher dimension in increments of 50 mm):

From 286 to 936 mm for curves with PolyVee or round belt heads
From 312 to 962 mm for curves with 2 sprockets
From 250 to 900 mm for non-driven curves4. Calculate the actual Ra = EL + Ri with the standard EL selected

4. Calculate the actual Ra = EL + Ri with the standard EL selected

Calculating the roller pitch on the external diameter
The roller pitch Ta is measured on the internal edge of the external profile and is calculated as follows:

EL	Installation length of the conveyor roller
L	Maximum length of material to be transported
W	Maximum width of the material to be transported
Ra	External radius of the curve
Ri	Internal radius of the curve
Ta	Roller pitch on the external diameter
Ti	Roller pitch on the internal diameter

Internal curve radius
Internal radius of curve for non-driven roller curves
The internal radius of the curve depends on the length of the roller and is:

800 mm with a reference length of 300, 400, 500 mm etc.
850 mm with a reference length of 250, 350, 450 mm etc.

Calculating the internal radius of the curve for driven roller curves (PolyVee/round belt head)
The internal radius of the curve depends on the length of the roller and is:

770 mm with a reference length of 300, 400, 500 mm etc.
820 mm with a reference length of 250, 350, 450 mm etc.

RollerDrive
Using a RollerDrive as the drive for driven roller curves has established itself as the most cost-effective and attractive of all drive solutions. Curves with a RollerDrive combined with the aforementioned tapered conveyor rollers are silent, compact and have a simple design.

The average diameter of the tapered elements must be used to calculate the necessary torque and conveyor speed when RollerDrive is used as the drive.

PolyVee torque transmission
Only flexible PolyVee belts with three ribs combined with Fixed Drive Rollers Series 3500 and PolyVee drive heads can be used as torque transmission.

The projected drive head (RL = EL - 36 mm) produces internal curve radii of 770 and 820 mm.

When PolyVee belts (2-ribbed) are used, the roller pitch on the internal radius is defined as Ti = 73.7 mm. If this roller pitch is not feasible, a drive with a round belt or chain will have to be selected.

Round belt torque transmission
The pitch for round belt drives and for non-driven curves can be selected at will providing the following conditions are adhered to:

Safe conveyance of the material to be transported
No contact between the tapered elements
First and last conveyor roller has approx. half of the roller pitch (internal radius) at the end of the curve
Possible standard belt lengths are taken into account

Torque transmission with chains
Using a chain as a drive medium only allows a limited number of roller pitches, which always have to be a multiple of the chain pitch of ½". Chain drive is only feasible in a curve using the roller-to-roller method. The pitches from conveyor roller to conveyor roller on the internal and external radius must be calculated individually according to the length and pitch of the roller.
The calculation of the pitch spacings always begins at the external radius in order to guarantee the correct chain tension. Please note when doing so that the sprockets in contact change from roller to roller (internal/external sprocket) and that the pitch only repeats on every second roller. The pitch on the internal radius is determined by the respective reference length . Torque transmission with chains

The following theoretical pitches (measured on the sprocket Z14) have proved themselves in practice:

Number of chain links	Pitch measured on the sprocket mm
28	88.9
30	101.6
32	114.3
34	127.0
36	139.7
38	152.4

The number of conveyor rollers changes according to the length and, thereby, the greater radian on the external radius.
The following information on the number of conveyor rollers required relates to a 90° curve on which a projection to the 90° angle of the side profile has been designed in for equalisation.

Reference length in mm	Chain pitch in mm
	88.9	101.6	114.3	127.0	139.7	152.4
250/300	19	16	14	13
350/400	20	18	16	14	13
450/500		19	17	15	14	13
550/600		21	18	17	15	14
650/700			20	18	16	15
750			21	19	17	16
800				19	17	16
850/900				20	18	17

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Curves

Tapered Conveyor Roller Versions

Drives Combinable with Tapered Conveyor Rollers

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