However, the mixer encounters high
contamination (flour, sugar, and other baking materials), which could work
its way into the latch and cause it to stick. Initial testing showed that
the locking pin in the bowl latch could seize. This not only halts production
but increases maintenance time and, therefore, costs.
The problem was discovered during the advanced design stages, so any significant
design changes would require additional tooling, added lead times for parts,
and more testing. These were three issues the company wanted to avoid.
The search for a compatible alternative ensued. The solution needed to
be lubrication-free since any grease or oil needed by a metal bearing would
contaminate the food. It also needed to be maintenance-free to ensure the
machine will perform as expected.
Maintenance-free translates into less labor for the user. Also, in situations
where any regular maintenance is required, the performance of the part
hinges on the assumption that the users will indeed perform the necessary
adjustments and that they will perform them correctly.
Hobart finally discovered iglide J from igus (East Providence, RI, U.S.).
The iglide J is a self-lubricated, maintenance-free, plastic-based plain
bearing. It is also contamination- and chemical-resistant. The iglide plastic
bearings are available in more than 16 high-performance material blends,
and customers can choose from more than 6,000 imperial and metric bearing
sizes from stock. The plastic bearings are an alternative to bronze, metal-back,
and custom injection-molded bearings.
The bearing Hobart used also diverts food ingredients that might work
their way into the latch and cause it to stick or seize. The bearing is
slotted to accommodate material flow and any residual dough or ingredients
that will pass through the slots tooled into the bearing.
Not only did the supplier offer the features Hobart needed to suit its
mixer, but it also worked closely with the OEM to meet every aspect of
the application. Hobart decided to use two other iglide bearings on the
The iglide L250 is installed on the handle on the side that actuates the
lever for the pin to be lifted and lowered, and the iglide T500 is used
on the pin on the rear of the mixer. Both prevent the cast-iron parts from
rubbing together, eliminating the potential of early failure and premature
The iglide plastic bearings are ideal for the application, confirms Brian Brunswick,
design engineer for Hobart. “We first contemplated using a bronze bearing,
but quickly realized plastic was the way to go,” he explains. “The
excellent chemical resistance of the bearings was also a large contributing
factor in our decision.”
With the new plastic bearings, Hobart says it has averted warranty calls
and service problems and can deliver a high-quality product to its customers.