Roll Balance Plungers and Liquid Springs

Roll Balance Plungers for Rolling Mills

SELF CONTAINED – NO EXTERNAL CONNECTION TO HYDRAULIC SYSTEM

ALL STAINLESS STEEL CONSTRUCTION

CAN BE USED TO ELIMINATE THE HYDRAULIC ROLL BALANCE SYSTEM

Diemx Roll Balancers are used to balance the upper rolls and chocks of rolling mills. They have application in Hot Mills, Cold Mills and Rod & Bar Mills.

The BALANCERS are characterized by customer specified preloads and spring constants.

BALANCERS are designed to meet the specific application requirements.

A pre-load can be applied to the BALANCER which will not allow movement until a predetermined force is applied.

Roll Balance plungers support the weight of of the top roll assembly without the assistance of external hydraulic systems.

When used for roll balancing, the plungers can usually be installed in existing hydraulic cavities in the bottom roll chock. Normally the hydraulic system can be eliminated although in some cases the hydraulics are maintained to extend the stroke or to be used with roll bending.

Four plungers (two per chock) supply sufficient force to separate the top roll assembly from the bottom roll assembly so that at rest (zero screw-down force) the plungers are fully extended to provide repeatable roll separation for spindle engagement at roll change.

During the mill operation, when screw-down forces the top roll down to produce the required roll gap with the bottom roll, the BALANCERS compress and follow the motion of the screw-down.

When the screw-down force is relieved, the plungers force the top work roll assembly upwards and away from the bottom work roll assembly, resulting in a fixed center-to-center separation of the rolls.

Design Features

Roll balance plungers utilize a compressible fluid to supply the force required in the smallest possible envelope.
All roll balance plungers are manufactured using the highest quality materials. Construction features include a heavy walled high alloy stainless steel cylinder machined from solid bar stock.
Plungers can be used in combination with hydraulic pressure when additional stroke is required and for application of roll bending force.

Advantage and Benefits

Plungers are self-contained -active hydraulic systems can be eliminated.
Reduce time required for roll change
Prevents damage to roll surfaces by preventing rolls from contacting each other.
No adjustment required
Easy installation - chock modification is not usually required.
One moving part - one dynamic seal.

The following information is required to order a Roll Balance Plunger

Preload force for plunger (F)
Stroke required (S)
Cylinder maximum allowable diameter (OD)
Overall length of assembly including end caps and strikers (OAL)

The preload force per balancer is evaluated as follows:

F=Total Weight of top roll assembly

The plunger stroke can be evaluated in one of two ways:

Method 1:

S=maximum roll diameter - minimum roll diameter + maximum opening with max rolls + clearance

Method 2:

S=maximum centre to center distance - minimum roll diameter + clearance

The OD and OAL are determined from the geometry of the mill and chocks. If you would like us to review your requirements or evaluate your mill for use with roll balance plungers please contact us at sales@diemx.com.