Lubricants

Eco-Friendly Energy-Saving Grease

Photo - Grease

Greases are used on automotive parts and in many types of industrial equipment, and are key to the smooth operation of bearings. It's no exaggeration to say that without grease, our machines would stop moving.
People's growing concern over energy use has created a need for greases with energy-saving effects.

Concept behind Energy-Saving Grease

Holds oil like a sponge
Fig. 1 - Electron micrograph of thickener

A grease differs from a regular lubricating oil in that it typically consists of three components: a base oil, additives, and a thickener that holds the other components together.
If we look at a thickener with an electron microscope, we see a network of entangled fibers, which holds the oil like a sponge. To make a grease with energy-saving properties, we need to find the optimal combination of base oil, additives, and thickener.

Fig. 2 - Designing an energy-saving grease (Stribeck curve)

Here's what goes into designing an energy-saving grease.
A grease helps save energy by reducing the friction coefficient. This figure shows the Stribeck curve, which shows friction coefficient as a function of the lubrication conditions. In hydrodynamic lubrication regimes, in which the metal parts are separated by an oil film, reducing drag torque is key. This can be achieved by using a low-viscosity, low-friction base oil. Meanwhile, in boundary and mixed lubrication regimes, in which the oil film breaks to allow metal-to-metal contact, it is critical to reduce friction and wear. This is done by optimizing the thickener and additive package.

Another thing to remember is that the way the grease is distributed inside a bearing also affects drag. As shown below, as the rolling elements move through a bearing, the grease is pushed out of the way to create an open path. In a condition known as churning, the grease will close down the path after the rolling element moves through, and the next rolling element must push the grease aside to move forward. This results in increased rotational drag. By contrast, in conditions known as channeling, the path is not blocked and there is less rotational drag. For an energy-saving grease, this channeling is what is desired. For this to occur, the grease must have the right hardness at start-up, must not be too fluid, and must stay where it is put.


The unique flow properties of a grease (Fluidity inside rolling bearing)

Fig. 3 - Behavior of grease inside a bearing (Churning, channeling)

Development of the energy-saving TOUGHLIX GREASE MP2

We optimized the three primary components of a grease to develop TOUGHLIX MP2, a grease with energy-saving properties.
We start with a low viscosity base oil to reduce sliding drag. For the thickener, we use a lithium complex, which reduces rolling drag by minimizing fluidity. We then add a molybdenum friction modifier, which also reduces sliding drag.

Fluid Properties of TOUGHLIX MP2

TOUGHLIX MP2 has outstanding stickiness, so it tends to stay in place. In a bearing, this means that the grease will be channeling quickly and a path is cleared for the bearing balls, which helps to keep down drag.

Measured amounts of grease were placed on a disk, which was spun at 400 rpm for 30 min. at room temperature to see if they would fly off.
Left: Competitor's product, Right: TOUGHLIX MP2

Energy-Saving Properties of TOUGHLIX MP2

Fig. 4 - Test rig for measuring energy-saving properties of grease

Using a test rig like that shown in the figure, we measured the electricity consumed by the motor and the temperature inside the bearings. The test showed that with TOUGHLIX MP2, power consumption was reduced by up to 11% and the bearings stayed cooler by up to 10°C, thereby showing the exceptional energy-saving properties of the grease.

Applications for Energy-Saving Grease

TOUGHLIX MP2 is suitable for use in all types of equipment. The table below lists some of the types of equipment and lubrication points where TOUGHLIX MP2 could help save energy and keep temperatures lower in bearings, which could mean higher efficiency and reduced maintenance for vehicles and equipment.
With a lithium complex as a thickener, which is little affected by changes in temperature or the presence of water, and its extreme-pressure performance, heat resistance, moisture resistance, and long-life properties, TOUGHLIX MP2 grease is truly an all-around performer.

Equipment Lubrication points
Applied location Construction machinery
Agricultural machinery
Engine surroundings, wheels, propeller shafts, dampers, rotating mechanisms, pedals, etc.
Railways Axles, main motors, etc.
Industrial machinery Mill rolls, continuous casting equipment, sintering equipment, dollies, cranes, lifting equipment, etc.
Machine tools, electric motors, direct drive units, reduction gears, vacuum pumps, compressors, chains, robots, fans, etc.
Home electronics Vacuum cleaners, washing machines, air conditioners, ventilators, copiers, etc.

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