Automated lubricators achieve rapid pay-back

Amal Grow, one of the largest vegetable growers in the Channel Islands, has achieved a 75 per cent reduction in maintenance times on its potato grading and washing machines simply by upgrading the bearing units and fitting SKF System 24 single-point automatic lubricators.

The new bearing units and lubricators are manufactured by SKF and were supplied by Antifriction Components, an SKF Authorised Distributor, via its agent in Jersey, CAF Engineering.

Ewan Pervis, of Amal Grow, explains: "We specialise in vegetables grown outdoors, with the sale of potatoes accounting for a large volume of our business. These are harvested and then graded and washed before being packed for delivery to our customers around Jersey. Machinery is generally running seven days a week and is exposed to the elements, with the operating environment for both the grading and washing machines being especially tough, ranging from dry dust, dirt and grit in the summer, to wet liquid mud in the winter months. As a result, we found that these machines needed constant maintenance; in particular, bearings fitted to the rotating drive, agitator and idler shafts needed regular lubrication and frequent replacement.

"Bearings had to be lubricated manually via grease nipples. These were often located behind machine guarding or were hard to reach safely. Additionally, it was difficult to apply the correct volume of lubricant and easy to miss lubrication points, so bearings could run dry or be over-lubricated; in each case their operating life was dramatically shortened, resulting in considerable downtime. It was not uncommon for us to have a machine offline for several days and for two engineers to be tied up carrying out repairs."

Stainless steel bearings

CAF Engineering supplied replacement stainless steel bearings, which are fitted when each existing unit needs replacement, plus a dedicated SKF System 24 single-point automatic lubricator for each bearing.

Once set up, the SKF System 24 lubricator is fully automatic, eliminating the need for manual lubrication. Each device is constructed from a tough polyamide plastic cartridge that is filled with lubricant and hermetically sealed to prevent the ingress of dust or moisture; it is also transparent so that lubricant levels can easily be checked.

Integrated into the head of the cartridge is a hydrogen cell that releases gas at controlled intervals to pressurise an internal piston; in turn, this forces lubricant through the neck of the cartridge, which is connected to the bearing unit.

The piston and internal cartridge surfaces are shaped to ensure that all the lubricant is dispensed, while the rate at which lubricant is distributed is accurately controlled by an integrated timer. This can be adjusted on-site, so oil or grease can be dispensed at intervals of between one and 12 months and at rates that can be as low as 4.5g/month.

Pervis comments: "SKF System 24 has revolutionised our maintenance procedures. The devices are tough, so they withstand the operating conditions, are simple to fit and setup, and are available with a range of different lubricants, including food-safe greases. We have fitted them where they can easily be seen on the machines, so a quick visual check of reservoir levels is all that is required during a routine monthly maintenance check. Typically, each device operates for around 12 months before needing replenishment.

"Since we switched to the SKF System 24 technology, we estimate that we have cut the maintenance time required for lubrication by over 75 per cent. This represents a significant cost saving; it also frees up our engineers to concentrate on more critical tasks elsewhere in the business and has dramatically increased bearing life, from one or two years to over four years. All in all, SKF System 24 has proven to be an excellent investment, with a particularly fast pay-back."