Introduction

Robust drive technology for cooling tunnels and pasteurizers

Robust drive technology for cooling tunnels and pasteurizers
  • Client

    NORD Drivesystems

  • Services

    Motors, Gearmotors, Drive Systems

  • Technologies

    Drive technologies

  • Dates

    20/08/2017

Description

A manufacturer of bespoke machines for the food and beverage industry, US-based mechanical engineering company G C Evans has come to appreciate the dedicated and capable support provided by their drive supplier, Nord Drivesystems. NORD configures reliable, low-maintenance drive units featuring application-specific options.

Standstill is a word that smacks of bitter losses to the beverage industry. For drive technology in this sector, high availability and easy maintenance are therefore absolutely essential. David McNamer, manufacturing manager at G C Evans Sales & Mfg Inc., a US-American manufacturer of cooling and heating equipment for the food and beverage industry, explains: "If a beverage pasteurizer were to have a drive failure, you are not only talking about lost product in the unit, but stopping a production line to the tune of potentially hundreds of thousands of dollars per hour. I do not want to worry about our drives and I do not want our customers to either. That is why we choose NORD. In 2008, we decided to give NORD drives a chance, and were in for some very pleasant surprises: Not only were the units less costly than comparable competitors', but they were really high-quality and well-engineered units. What impressed us the most was the level of service we received from NORD. We are always dealing with a single engineering contact within their company." Today, NORD drives are used in all G C Evans machines. NORD is one of the world's most experienced gearbox manufacturers with an industry-leading product range featuring variable gear ratios, flexible installation options, and wear-free gearing. NORD configures low-maintenance, sturdy drives for G C Evans, implementing application-specific feature options ranging from special gear lubricants to vent plugs that help prevent leakage.

Fail-proof and efficient in various machines

For two major recent orders, NORD has configured two conveyor drives with very high gear ratios for G.C. Evans. One of these systems, a parallel shaft geared motor, moves 20,000 jam jars, each weighing more than 1 kg, through a cooling tunnel. Its gearbox is configured with a 2,500:1 ratio to achieve an output speed of 0.6 revolutions per minute. This drive system features various special options to meet the hygiene requirements of food processes: a very durable stainless steel finish, a food-grade gear lubricant, a vent plug, and an oil sight glass. The pressure relief vent plug from NORD regulates the air pressure in the gearbox when it heats up and cools down. It prevents the ingress of dust or liquids, which could contaminate the oil and compromise its lubricating properties. This measure enables an extension of the oil change interval. Gaskets, gears, and bearings suffer less wear and tear.

Hard-wearing special coating

Gear units and motors from NORD are generally designed to withstand harsh environmental conditions. They are effectively sealed against an ingress of moisture and are fitted with corrosion-resistant components. The NSD-x3 severe-duty coating, which NORD only offers in the United States, provides extra hard-wearing, long-lasting external corrosion protection for the drives supplied to G.C. Evans. It consists of two primers and a stainless steel (316) saturated silver-gray polyurethane finish. The solvent-based paint ensures increased durability. Completed by a clear top coat, the coating achieves a very high overall resistance to blows, scratches, heat, moisture, and also to industrial solvents such as lacquer thinner, acetone, gasoline, lubricants, and cutting oils.

Sturdy, low-maintenance shaft mounting

The second recent project for which NORD supplied a special drive system was a fruit juice pasteurizer with a slow-running conveyor belt: one bottle takes 45 min to pass through the 25 m long machine. The hollow-shaft parallel shaft geared motor is mounted on the machine shaft with a Gripmaxx bushing. The bushings developed by NORD are mounted on the drive shaft simply by means of a few screws, with no need to make any changes to the machine design. A tutorial on the NORD YouTube channel demonstrates how a Gripmaxx bushing is properly attached. Jason Jones, director of engineering at G.C. Evans, explains why this was the optimal mounting method for the pasteurizer: "This roller is removed every few years to service the bearings and for maintenance. A more traditional keyway-secured bushing may be quite problematic, since fretting and corrosion make it very difficult and sometimes expensive to remove. With the Gripmaxx solution from NORD, the hollow bore simply collapses on to the shaft. Removal of the shaft is then grab-a-wrench simple." While load fluctuations and start/stop or reverse mode operation put strain on keys and can loosen conventional bushings over time, FEM-engineered Gripmaxx bushings spread the forces evenly over the entire contact surface. In contrast to standard shrink discs, NORD's Gripmaxx bushings are available for many different combinations of inner and outer diameter, and therefore require no expensive custom designs.

Company background

NORD Drivesystems develops, produces and sells drive technologies with around 3.400 employees, and is one of the international leaders in the industry. In addition to standard drives, NORD supplies application-specific concepts and solutions, even for special applications, for example with energy-saving drives or explosion-protected systems. Gross sales amounted to approx. EUR 540 mn in the 2015 business year. The company founded in 1965 now has over 36 subsidiaries worldwide. The closely meshed sales and service network ensures optimum availability for short delivery times and customer-oriented services. NORD produces a wide variety of drive units for torques from 10 to 200,000 Nm, electric motors with powers from 0.12 kW to 1,000 kW as well as the necessary power electronics in the form of frequency inverters and servo controllers. Inverter solutions are available for classical installations in the switch cabinet and for decentralised and fully integrated drive units.

Captions:

Illustration 1: No bottlenecks in bottle separation – a resilient worm geared motor prevents gridlocks

Illustrations 2, 3: The parallel shaft geared motor with an input stage (left) driving the conveyor in the cooling tunnel (right) features a low-maintenance Gripmaxx bushing

Illustration 4: A severe-duty coating with four layers of paint ensures scratch-resistant corrosion protection

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