Rotary table system – a new way to assemble and inspect safety valves

Marginal Column

Photo: Osai A.S. S.r.l.

November 2013

 

A rotary table system built by Osai assembles and inspects safety valves with tremendous reliability. In addition, this system is more productive than ever before.

 
 

If for some reason the water in the dishwasher doesn’t drain, it doesn’t necessarily mean that a flood will have to be mopped up in the kitchen. Safety valves in top-of-the-line dishwashers ensure that no water can exit, even following a malfunction. And the Osai company, located in Italy, ensures that these safety valves work properly. The firm, located near Turin, has developed a machine that assembles such valves, in two different versions, and carries out the final inspection.

Simple and trendy

Osai’s expectations for its own products are high. “Our machines naturally have to incorporate the latest technology. But they are also production resources and need to be both versatile and easy to operate,” says sales manager Marco Bernardi. He then adds: “What’s more, our equipment ought to look good, as well. That’s a factor that is becoming ever more important.”

Osai satisfies this self-imposed requirement with a semi-automatic machine for safety valves, taking the form of a rotary table with twelve separate workstations. Rexroth motors are used to examine the threads in the ring nuts carried out here. The ring nuts in compliance are then screwed in place with a device that at the same time measures torque and rotation angle. In the final inspection, a brushless MSK motor is used to examine torque during unhindered rotation. A further MSK motor drives the removal manipulator. Filippo Costan Zovi, Rexroth sales engineer: “We proposed a new combination of our technologies for this system. In addition to the motors for the compact drives, we also used a screw system, linear guides, and parts of our TS2 transfer system.”

“We demand more than quality”

The components can be combined in a number of different ways. Thus the rotary table system can be used to manufacture up to 18 different valve designs, depending on the customer’s needs, and thus doubles the product range. With just a single operator, the machine can assemble up to one thousand valves per hour, around the clock. That is 30 percent more than in the past. Bernardi emphasizes: “Rexroth did not just deliver us its products. More importantly, and especially in the field of electronics, they worked closely with our developers and provided skilled consulting support. That is exactly what we expect from our suppliers.”