What is a Ball Transfer?
ISB ball transfer units consist of a large load-ball that sits upon small balls encapsulated in a hemispherical cup. ISB ball transfers falls into two categories, Ball-up type and Ball-down type castor like, also in some applications they are used to support from the side as a guide. Their design creates a multi-directional, material-handling system that enables heavy loads to be moved smoothly along with minimal effort and friction. They are designed to assist in transferring, directing, or facilitating loading of flat products in workplaces such as warehouses, production lines, port cargo handling facilities, semiconductor production systems, FPD production system, PV, Solar glass handling production lines, medical equipments, research laboratories, under-floor facilities of buildings and offices manufacturing or freight transfer. Similar to a roller system, the balls are installed within the table or work surface and the product rolls over the balls and allows for turning, lifting, directing or transferring from one conveyor line to another. People with lifting or carrying restrictions resulting from back, neck, shoulder, heart, and various repetitive strain injuries may benefit from the use of ball transfer technology if lifting or handling flat products on a repetitive basis within the workplace.
Starting friction of Ball Transfers
The data below was obtained by testing the mechanical resistance of four IS-51 ball-up castor type catalog model ball transfers conveying 1000 kg load. To compare and consider various articles, we measured on raw SS steels (mill scale and polished), and hardened (SK steel, hardness HRC60, polished).
As shown in the chart below, the harder the runway surface is the smoother the article conveyed. For not-hardened steel, or black scale applications please contact our sales.
| Material | SS Steel | SK Steel HRC60˚ Polished | |
|---|---|---|---|
| Black Scale | Polished | ||
| Resistance | 0.03~0.05 | 0.02~0.035 | 0.01~0.015 |
Determining the load for a Ball Transfer unit
ISB ball transfers come into two categories, pressed and molded type for light load, and precision-machined type for heavy loads. When considering ball transfers for an application, the border line for light/heavy loads are approx. 500 kg. Equal load distribution over many ball transfers is seldom, if ever achieved. Load distribution is governed by the flatness, hardness and smoothness of the load surface in contact with the balls and the ball transfer installation height variance and system deflection. Absolute flatness of the application design is difficult to insure under field service conditions.
To determine the load rating required per units simply divide the ball transfer load capacity by 2 for pressed and molded products and 2/3 for machine-cut products.