Back-up rollers with pivot are mainly used when the sheet to be levelled has a limited thickness.
1 - Outer ring
2 - Washer
3 - Spacer
4 - O-Ring
5 - Seeger
6 - Spring cup
7 - Pin
8 - Radial needle roller cage
9 - Thrust bearing
10 - V-ring
They have a protruding pin at both ends. The hardness and shape of the outer ring are adaptable to the customer's needs; the radial part can be made with a roller / needle cage or full complement to increase the load capacity, which can be combined with axial contrasts with rollers / rollers or balls, the sealing and lubrication systems are adaptable according to the needs expressed by the customer.
The back-up rollers with pivot for sheet tension levellers and straightening machines have the following technical features:
Outer ring made of 100Cr6 (UNI 3097) hardened steel, steel with the best resistance to wear due to fatigue. The surface hardness that can be achieved for these parts is 60 + 2 HRc If requested, the hardness of the outer ring can be reduced to 53 HRc for those bearings used for very thin sheets levelling. The outer ring usually has a crowning radius (which changes depending on the size) that allows a better distribution of loads. For the outer rings of large thicknesses, 100CrMo7.3 (UNI 3097) hardened steel is used.
On request, special hardening treatments are performed, such as bainitic hardening, which is necessary in those applications in which impacts make the application too burdensome for the structure of the traditionally treated outer ring.
The pin (or pivot or stud) is usually built in 18NiCrMo5 case-hardening steel and in particular cases in 100Cr6 steel subjected to adequate heat treatments; in both cases the hardness can reach 60 ± 2 HRc.
For this type of back-up roller, the sealing and protection system can be studied and executed in various ways, with protection plates and sliding seals all suitable to prevent external agents such as dust and scale from penetrating inside, but allowing periodic internal relubrication. . The dimensional and running accuracy of these bearings is generally according to class P0 (DIN 620) but can be brought up to P6 or P5. Stainless steel executions are available on request.
Due to hight requests and different executions and to the specificity of these products, Distitec prefers not to provide a list of products that could be defined as standard, as each request may require a modification that would imply a different code and design. Therefore, if you are searching for backup rollers we suggest you to contact our sales and technical department. We will be glad to give you a prompt feedback, to collect all necessary technical details and required specifics in order to provide you the best and most accurate solution, both in terms of technical as in economic terms.