A true grease consists of an oil and/or other fluid lubricant that is mixed with a thickener, typically a soap, to form a solid or semisolid.[1] Greases are usually shear-thinning or pseudo-plastic fluids, which means that the viscosity of the fluid is reduced under shear. After sufficient force to shear the grease has been applied, the viscosity drops and approaches that of the base lubricant, such as the mineral oil. This sudden drop in shear force means that grease is considered a plastic fluid, and the reduction of shear force with time makes it thixotropic. A few greases are rheotropic, meaning they become more viscous when worked.[2] It is often applied using a grease gun, which applies the grease to the part being lubricated under pressure, forcing the solid grease into the spaces in the part.
Soaps are the most common emulsifying agent used, and the selection of the type of soap is determined by the application.[3] Soaps include calcium stearate, sodium stearate, lithium stearate, as well as mixtures of these components. Fatty acids derivatives other than stearates are also used, especially lithium 12-hydroxystearate. The nature of the soaps influences the temperature resistance (relating to the viscosity), water resistance, and chemical stability of the resulting grease. Calcium sulphonates and polyureas are increasingly common grease thickeners not based on metallic soaps.[4][5]
Powdered solids may also be used as thickeners, especially as clays. Fatty oil-based greases have also been prepared with other thickeners, such as tar, graphite, or mica, which also increase the durability of the grease. Silicone greases are generally thickened with silica.
Lithium-based greases are the most commonly used; sodium and lithium-based greases have higher melting point (dropping point) than calcium-based greases but are not resistant to the action of water. Lithium-based grease has a dropping point at 190 to 220 ÂC (350 to 400 ÂF). However the maximum usable temperature for lithium-based grease is 120 ÂC.
Some greases are labeled "EP", which indicates "extreme pressure". Under high pressure or shock loading, normal grease can be compressed to the extent that the greased parts come into physical contact, causing friction and wear. EP greases have increased resistance to film breakdown, form sacrificial coatings on the metal surface to protect if the film does break down, or include solid lubricants such as graphite or molybdenum disulfide to provide protection even without any grease remaining.[3]
Solid additives such as copper or ceramic powder are added to some greases for static high pressure and/or high temperature applications, or where corrosion could prevent dis-assembly of components later in their service life. These compounds are working as a release agent.[7][8] Solid additives cannot be used in bearings because of tight tolerances. Solid additives will cause increased wear in bearings.[citation needed]
Grease from the early Egyptian or Roman eras is thought to have been prepared by combining lime with olive oil. The lime saponifies some of the triglyceride that comprises oil to give a calcium grease. In the middle of the 19th century, soaps were intentionally added as thickeners to oils.[9] Over the centuries, all manner of materials have been employed as greases. For example, black slugs Arion ater were used as axle-grease to lubricate wooden axle-trees or carts in Sweden.[10]
Apiezon, silicone-based, and fluoroether-based greases are all used commonly in laboratories for lubricating stopcocks and ground glass joints. The grease helps to prevent joints from "freezing", as well as ensuring high vacuum systems are properly sealed. Apiezon or similar hydrocarbon based greases are the cheapest, and most suitable for high vacuum applications. However, they dissolve in many organic solvents. This quality makes clean-up with pentane or hexanes trivial, but also easily leads to contamination of reaction mixtures.
Silicone-based greases are cheaper than fluoroether-based greases. They are relatively inert and generally do not affect reactions, though reaction mixtures often get contaminated (detected through NMR near Î 0[13]). Silicone-based greases are not easily removed with solvent, but they are removed efficiently by soaking in a base bath.
Food-grade greases are those greases that come in contact with food. Food-grade lubricant base oil are generally low sulfur petrochemical, less easily oxidized and emulsified. Another commonly used poly-Î olefin base oil as well The United States Department of Agriculture (USDA) has three food-grade designations: H1, H2 and H3. H1 lubricants are food-grade lubricants used in food-processing environments where there is the possibility of incidental food contact. H2 lubricants are industrial lubricants used on equipment and machine parts in locations with no possibility of contact. H3 lubricants are food-grade lubricants, typically edible oils, used to prevent rust on hooks, trolleys and similar equipment.[citation needed]
In some cases, the lubrication and high viscosity of a grease are desired in situations where non-toxic, non-oil based materials are required. Carboxymethyl cellulose, or CMC, is one popular material used to create a water-based analog of greases. CMC serves to both thicken the solution and add a lubricating effect, and often silicone-based lubricants are added for additional lubrication. The most familiar example of this type of lubricant, used as a surgical and personal lubricant, is K-Y Jelly.
The E-Z Lube system consists of axle spindles that have been specially drilled and assembled with grease fittings. When grease is pumped into the fittings, it is channeled to the inner bearing, then to the outer bearing, and eventually back out the grease cap hole for a complete bearing repack. The protection and maintenance features of the E-Z Lube system make it ideal for most towable axles. E-Z Lube is designed to allow for immersion in water.
At ambient temperature, the hybrid oil lubrication is thick with a viscosity approaching grease. As the bearing temperature rises during towing, the lubricant thins out, replenishing the bearing, reducing friction and dissipating heat. No inspection, no maintenance and no service required.
The hub/spindle is equipped with the Dexter VortexTM Lubrication System. Vortex is designed to be maintenance-free. However, there may be an instance when it is necessary to change or add new grease. Bearings can be lubricated without removing the hubs from the axle. Unlike systems that just push new grease on top of old grease, Vortex uses new grease to saturate the inner and outer bearings while pushing out the existing grease. This ensures that the hub cavity is completely filled with new grease if ever required.
Axle bearings on the wagons and carts used on the emigrant trails in 1800s needed regular lubrication. Most wagons carried the grease in a hanging bucket. Dusty conditions or excessive use could deplete the carried grease. This created a demand for axle grease among the travelers. The resulting grease trade is thought to be the first commercial petroleum business in Wyoming.
Seeps and pools of oil on the surface were the source of the grease. When fur trader Capt. B. L. E. Bonneville traveled to the Wind River Valley in 1832, he found oil springs southeast of present Lander near Dallas Dome. And an oil spring near Hilliard in present Uinta County was well known by the time Fort Bridger was established nearby in 1842.
Although no diaries have yet been found that record a purchase of grease by pioneers near Oil Mountain, numerous geologic documents, all written at least three decades after the fact, mention petroleum commerce with emigrants near the Oil Mountain seep.
Natrona County Road 319, the Oregon Trail Road, passes through the Iron Creek Oil Field, which is the only oil field along the road. Oil Mountain is the prominent anticline on the west side of the road. The grease trade was in this general area. The oil seep is some miles to the northwest, and is inaccessible without crossing private land.
Speaking of oiled machines, the trail name derives from the buckets of grease that hung from horse-drawn wagons that rumbled through the area in the 1800s. The grease was used to lubricate wheels and axles to keep the rickety vehicles running smoothly.
A calculated combination of Lithium extreme pressure (EP) complex grease, PAO full synthetic ISO 460 gear lube, and a sophisticated additive package delivers maximum protection to prevent premature wear, rust and corrosion, and damage in shock loading applications that:
A quick, easy option for greasing your buggy or wagon axle, this grease is a direct descendant of the Original Schaeffer Black Beauty Wagon Axle Grease. Grease comes in a tube that is compatable with grease guns. It is extra tacky and waterproof for good adhesion and tolerates extreme pressure and heat up to 350 degrees F.
Answer: Greasing the axles of your wagon about every 40 miles of use is recommended for wagons with skeins and boxings or buggies with "old-style" axles. It is also a good idea to check the axles prior to using your horse-drawn vehicle after having it stored for a long period of time.
MAG 1Â High Temp/Wheel Bearing Grease isdesigned and formulated for bearings operating under conditions of extremepressure and high temperature. Can also be used for general purpose lubricationand as a replacement for several conventional greases, resulting in smallerinventory and less chance of misapplication.
38c6e68cf9