When selecting gear grease, attention should be paid to the base oils used in the manufacture of the grease and its viscosity grade. Most gearboxes tend to be highly loaded and therefore require a lot of lubricant to protect the internal surfaces of the machine. In this case, the viscosity should not be low to ensure a good lubricating film. Another point to be aware of are extreme pressure additives. These additives can be chemically aggressive and can lead to chemical corrosion of machine surfaces. This is why Copmlex Ag 1500 is the most common in equipment parts. For this reason, polyurea greases are commonly used for bearing lubrication. The biggest factor when choosing a lubricating grease is to make sure that all other components of the grease are compatible with the requirements of the machine. Once these are balanced, you can be sure that you have chosen the most suitable lubricant for your application.

Large, slow-moving, open gears are often heavily loaded working equipments. During the working process, the gears are constantly subjected to impact, sliding and rolling forces. This is why the specially developed Complex Ag 1500 must have the best extreme pressure and wear prevention properties. In this way, the lubricant reduces both wear and friction on the gear teeth and ensures lower energy consumption.

The lubricant must be sticky to adhere to the gear teeth. It must not be wiped off by meshing teeth, washed off by rain or centrifuged away. It must also remain sufficiently flexible within the temperature range of the application. Complex Ag 1500 is therefore adhesive and cohesive. It is reinforced with special additives to ensure optimum coverage. It has a balance between adhesion to the tooth surface of the gears and cohesion, and the strips of lubricant fill the film continuously as interlocking tooth pieces.

In some cases this might be true. Certain types of EP additives are designed to react at elevated temperatures to protect metal surfaces under extreme lubrication conditions. Such additives are often called “chemically active” and at high temperatures (higher than 140 to 150 F), they can indeed begin to react with yellow metals. This is why it is so important to be careful when choosing gear oils for worm gears in order for the gears to function properly. A good way to check if an oil is “chemically active” is to look at the specification sheet provided by the oil manufacturer. On the sheet you will typically see a test called “copper strip corrosion” (ASTM D130). It tests how chemically reactive an oil is to copper or copper-containing alloys. For gear oils, a rating of 1a is typically a good indication that the oil is chemically inert; higher ratings (such as 1b or 2a) can indicate possible problems when used in certain gears at high operating temperatures. Often, a lubricant manufacturer will specifically state that “this oil should not be used in gearboxes containing yellow metals”; other times they will state that the oil is only suitable for application on steel, meaning that they should not be used where the ring gear is brass or bronze.