Ogura permanent magnet hysteresis brake used to control tension of wire for a coil winding machine.
Ogura's new PHT permanent magnet brake.
Will depend upon wire tension and pulley diameter.
Description of Operation
The wire is set on a spool located on the ground. The normal tendency for the wire coming off of the spool is to uncoil, so there is a slight slack in the line. The wire goes up to a pulley which is mounted on a shaft going through the Ogura PHT brake. The wire is normally wrapped around the pulley twice to give a good tight connection. The wire then goes across an idler pulley and then down to the coil winder. As the wire is drawn from the Ogura PHT brake to the coil winder, it is being drawn at a constant tension regardless of the speed of the coil winder.
Reason for Selection of the Ogura PHT Brake
The PHT brake is ideal for this type of application. Since many small coils do not change that much in diameter, a constant torque brake is ideal because it allows for a slight tapper tension on the end of the coil wind. Since the PHT brake will deliver constant torque regardless of the slip speed the wire tension is constant even at the high speed of the coil winder. Since the Ogura PHT brakes are adjustable many different wire sizes can be accommodated. (All a customer needs to do is set the marks on the PHT unit to the individual wire tension required.)
Besides tensioning for wire, magnetic film tensioning is another popular application for hysteresis tensioners. A film application would be handled in a similar fashion accept instead of the film being wrapped around a pulley, it is usually compressed between two pinch rollers which use the friction of film to transfer the drag. In other installations such as the medical industry, small thin walled tubing is critical in certain applications. Since many friction devices on the market have a substantial difference between static and dynamic coefficients, there are problems in using them on these types of applications. Since the Ogura PHT hysteresis brake almost eliminates differences in "stick slip" they are ideal for these installations.