Gear oil purification

Gear oil purification is a procedure that takes place in oil-filled gearboxes that do not have fixed filters. Gearboxes are widely used in various industrial machines and mechanisms to increase the torque, as well as to reduce the angular speed of the driven shaft. Lifting machines, fans, conveyors, pumping jacks, wind turbines normally include a gearbox which has to operate in a tough environment characterized by heavy loads and impact stresses, cold starts with differential temperatures, vibrations and friction. This may cause microdamage and cracks on the gears, or other failures that render the gearbox and the entire industrial mechanism inoperable.

Causes of deterioration in gear oil quality

In order for gear systems to operate with maximum efficiency, the mechanism parts should be lubricated with gear oil of proper performance. High-quality gear oil minimizes friction, forming a dense film on the surfaces of parts that come into contact with one another during operation.

However, as time goes by, the condition of gear oils deteriorates which is associated with contamination by particulate matter: both solids and dirt, as well as water. Water contributes to oil oxidation, degrades the lubricating film quality, and causes corrosion. For gear systems with stationary filters, this problem is not critical when the filters are changed on a periodic basis. However, gear systems without stationary filters require more complex maintenance. For the second case, GlobeCore has developed an integrated technology to service the machines and mechanisms that use gear oil, which includes:

• CMM-G oil changer machines for gearboxes, in particular, for those placed at a height, specifically operate as part of wind turbines.
• CMM-F gear oil filtration machines.
• ZP gear oil dehydration machines.

Gearbox oil purification and changing

CMM-G machines help in automating and speeding up the gear systems maintenance process. This includes automatic draining of waste oil, flushing the system and filling it with new or purified oil. The machines can be trailer- or skid-mounted in accordance with the customer preferences.

CMM-F gear oil filtration machines purify gear oils at a processing rate of up to 4,000 liters per hour by means of coarse and fine filters. The filtration fineness for each filter can be selected from a nominal range of 25, 5, 3, 1, or 0.3 microns.

ZP machines are necessary in cases where, for example, due to a differential temperature, the gear oil is moistened and requires dehydrating. In this equipment, oil dehydration occurs through the use of zeolite sorbent. Zeolite has a high absorptive capacity relative to water, absorbs it, and securely retains it in its granules. ZP machines are produced in two versions — with one or two zeolite cartridges, which allows achieving a throughput of 2,000 or 4,000 liters per hour. For convenience, CMM-F and ZP gear oil purification machines can be mounted on one wheeled platform which allows using them for servicing of gear systems as a single unit.

After passing through the CMM-F and ZP gear oil purification machines, the gear oil complies with purity class 14/12 of ISO 4406 and class 6 of NAS 1638.

If industrial oil is used as gear oil, GlobeCore technology allows reclaiming it to as good as a new condition through the use of CMM-R machines.

Conclusions

The use of GlobeCore technologies for the maintenance of gear systems allows:

• extending the service life of a gearbox and bearings;
• avoiding the disposal of waste oils, thereby reducing the adverse environmental impacts;
• extending the service life of gear oils, saving money on the purchase of new and disposal of waste oils;
• cutting back on expenses for maintenance of gear systems;
• reducing the downtime of mechanisms and machines due to the problems associated with gearbox malfunctions.