CoNSTRUCTIoN

ball transfer units are composed of a large precision ball rolling on a bed of small precision balls seated in

a hardened hemispheric cup.

All balls are ground and heat treated; they start moving when the main big ball (which is made of hardened

steel, stainless steel or plastic) rolls, to let it move with the lowest possible friction and guarantee a regular

movement. This kind of construction allows moving with small effort any kind of heavy material, whose surface

is plain, smooth and rigid enough.

Friction is extremely reduced and a smooth movement is provided at a speed of 2m / sec. In this way, very heavy

loads can be easily moved.

Our production range includes different kinds of ball transfer units, starting from a main supporting ball's

dimension of 8 mm up to a maximum of 90 mm in steel, stainless steel or polyacetal plastic material, and loading

capacities from 15 kg to 2000 kg. Basically there are two kinds of products: Machined Heavy Duty units (studied

for heavy shock loads and long life applications), and Pressed Light Duty units (suitable for light loads). The

housings of the units are bright metal zinc plated or completely stainless steel made and they incorporate self

cleaning bottom holes and oiled felt sealing system (except SP8-12-15-25). This is available on request on SP

15 and 25 series only. We can also provide ball transfer units with main balls made of AISI 440C, AISI 304, AISI

316, teflon, glass, with various coupling between big and small balls.

The ball transfer units can be assembled horizontally, vertically or ball down, they do not need hard maintenance

and are provided with a felt sealing (or a plastic one if they have to be exposed to high temperature).

Under particular conditions (high humidity, dyes, soaking baths, sea water) the usual correct activity can be

damaged; in order to repair these inconveniences, some kinds of ball transfer units have a dirt exit hole in the

bottom.

HoW To DETERMINE THE TYPE,

NUMBER AND DISTANCE

Ball size loading capacity and the effective load placed on each ball transfer unit are normally provided by the

weight of charge divided by 3. The result gives the highest load which any individual ball transfer unit may

support. It is important that the load is supported through the centre line of the unit; the load carrying capacity

is much affected by downwards and sidewards applications, so a suitable security charge margin is suggested.

In order to determine the distance between the ball transfer units, divide the shortest horizontal distance of

the load by 2,50. For example, for a weight measuring across the base 500 mm x 1.000 mm the recommended

distance will be 200 mm (500 : 2,50). This is the distance among the units that guarantees enough ball transfer

units on the shortest side of the load.

The units can be usually placed in three different ways: