When the chips are down, know-how matters

During regular weekly meetings with the customer, ERIKS engineers noticed that the motors used to power knife peeler machines were repeatedly being listed for repair. Closer examination of the figures revealed that each of the 24 knife peeler motors was failing on average every three months.

Necessary repairs generally included rewinds and bearing replacements, at a cost the customer clearly considered sustainable. ERIKS’ engineers thought otherwise.

Getting to the root

With the customer’s permission to look deeper into the issue, ERIKS’ first step was to undertake a Root Cause Analysis to identify the reason for the motors’ failure.

The motors in question play a part in one of the earliest stages of the customer’s production process: powering the knife peelers used to peel thousands of potatoes a day. They operate in arduous conditions in an environment where water is widely present at all times. Built to hygienic food standards from stainless steel, the motors are vertically positioned, with the output shaft at the top.

The failure mode was quickly identified by ERIKS as water ingress, and on-site inspection revealed several factors which were allowing this to happen.

Even at first glance, ERIKS’ engineers could see that the motor bodies were poorly assembled, with rough-and-ready seams where water could potentially find a way in. In addition, cabling and glands were a basic specification, unsuitable for the wet operating environment. 

Lastly, the motors vertical installation presented a flat horizontal top surface where water could collect. With only a basic seal around the shaft drive this meant that, as the shaft turned, any water which had pooled on the top of the motor would sooner or later work its way into the motor.

Sorting the leaks from the potatoes

With a proper understanding of the root cause of the problem, ERIKS could begin to solve it. This meant ensuring water ingress to the motor was eliminated through a number of design improvement measures.

The customer has now installed two of the redesigned motors for a trial period, and ERIKS is confident the results will lead to further replacements, as the remaining motors inevitably fail in the coming months. Meanwhile, ERIKS has been involved in discussions with the original equipment manufacturer, to identify how the benefits of the improved motor designed for this specific case can have wider implications for other applications. 

Small potatoes?

One of the main reasons the customer had never taken action over the frequently failing motors was the low cost of repairs. However ERIKS engineers’ figures showed that the cost of each new motor could be recouped by savings on just three rounds of repairs over the space of around nine months.

With a potential life expectancy of several times that, the new motors will more than pay for themselves, even before taking into account cost savings on maintenance and repeated installation after repair, compared with the previous design.

Now the value of looking deeper into asset failures has been clearly demonstrated, the customer has given the go-ahead for ERIKS’ engineers to monitor downtime in relation to asset failure. Anywhere that 70% or more downtime can be attributed to 30% of assets, ERIKS will look for the root causes, and identify cost-effective solutions.

Clearly it’s not just in the potato field where a bit of digging can yield impressive results. And even if you’re not involved with potatoes, you can rely on ERIKS’ engineers’ expertise when the chips are down.