APPLICATIONS OF LUBRICANT DEVICES

Application of Lubricants

Efficient operation of machinery largely depends not only on the lubricant selected but also on its method

of application. Lubricants formerly were applied by hand, but modern machinery requires exact methods

that can be precisely controlled. For most machinery, different methods of lubrication and types of

lubricants must be employed for different parts. In an automobile, for example, the chassis is lubricated

with grease, the manual transmission and rear-axle housings are filled with heavy oil, the automatic

transmission is lubricated with a special-grade light oil, wheel bearings are packed with a grease that has

a thickener composed of long fibers, and the crankcase oil that lubricates engine parts is a lightweight,

free-flowing oil.

Application of Liquid Lubricants

Mechanical devices to supply lubricants are called lubricators. A simple form of lubricator is a container

mounted over a bearing or other part and provided with a hole or an adjustable valve through which the

lubricant is gravity-fed at the desired rate of flow. Wick-feed oilers are placed under moving parts, and by

pressing against them they feed oil by capillary action. Horizontal bearings are frequently oiled by a

rotating ring or chain that carries oil from a reservoir in the bearing housing and distributes it along the

bearing through grooves or channels. Bath oiling is useful where an oil-tight reservoir can be provided in

which the bearing journal may be submerged; the pool of oil helps to carry away heat from contact

surfaces. Splash-oiling devices are used where gears, bearings, or other parts contained in housings

have moving parts that dip into the lubricant and splash it on the bearings or into distribution channels.

Centralized oiling systems usually consist of a reservoir, pump, and tubes through which oil is circulated,

while heaters or coolers may be introduced to change the viscosity of the lubricant for various parts of the

system. Many oiling operations are automatically synchronized to start and stop with the machinery.

Application of Semisolid and Solid Lubricants

Grease lubricants are semisolid and have several important advantages: They resist being squeezed out,

they are useful under heavy load conditions and in inaccessible parts where the supply of lubricant

cannot easily be renewed, and they tend to form a crust that prevents the entry of dirt or grit between

contact surfaces. Grease is a mixture of a lubricant and a thickener; often it is made from a mineral oil

and a soap. It may be applied in various ways: by packing enclosed parts with it, by pressing it onto

moving parts from an adjacent well, by forcing it through grease cups by a spring device, and by pumping

it through pressure guns. Solid lubricants are especially useful at high and low temperatures, in high

vacuums, and in other applications where oil is not suitable; common solid lubricants are graphite and

molybdenum disulfide.

1. Manual Lubrications

2. Chain Oilers

3. Wick and Felt Type Lubricators

APPLICATIONS:

Bearings

Bearing with a wick type lubricator

4. Air-Oil Lubricator / Oil Mist Lubricator

History Of Oil Mist Lubrication

The Oil Mist principle was developed by a bearing manufacturer in Europe during the 1930s. The problem

that nurtured this development was the inability to satisfactorily lubricate high-speed spindle bearings on

grinders and similar equipment. The speed of these bearing was too high for grease lubrication, and liquid

oil generated too much heat through fluid friction, necessitating an expensive recirculating system.

Continuous thin-film lubrication with Oil Mist provided a solution. The purging and slight cooling effects of the

carrier air gave additional benefits. The Oil Mist generator resulted later from this development and used a

small amount of air to produce a dense concentration of small oil particles. About 97% of these particles

could be transmitted to the bearings without condensing in the piping, regardless of the distance of the

bearings from the Oil Mist generator itself.

In 1958, air heaters were developed because it was discovered that, by heating the air used to generate Oil

Mist, oils of just about any viscosity could be atomized. Many applications, subject to extremes in ambient

temperature, use air heaters to ensure a constant oil/air ratio regardless of the oil viscosity.

APPLICATIONS

Today Oil Mist is still used to lubricate high speed spindles in grinders. Included in the increasing range of

Oil Mist applications are systems applied to all types of other machine tools, web and sheet processing

equipment, belt and chain conveyors rolling mills, vibrators, crushers, centrifuges, kilns, pulverizers, ball

mills, dryers and liquid processing pumps. Mist Generator Systems Oil Mist is a centralized system in which

the energy of compressed gas, usually air taken from the plant supply, is used to atomize oil. Oil is then

conveyed by the air in a low pressure distribution system to multiple points of lubricant application. - See

more at: http://www.usmotors.com/TechDocs/ProFacts/Oil-Mist-Lubrication.aspx#sthash.BqYUSamW.dpuf

Figure 2. Components of a Typical Oil Mist System

Mist Delivery

Orifice fittings to meter mist supply to individual machine elements involve one of the three

types of classifiers in Figure 3.

Figure 3. Classifier Fittings to Agglomerate Fine

Oil Particles in Dry Mist to Larger Droplets in

Wet Mist at Lubrication Points

A mist fitting consists of a simple metering orifice for delivering a fine wet spray with

minimum condensation. As this fine spray then encounters rolling-motion elements such

as in ball or roller bearings, gears, chain or cams the fine oil particles are agglomerated by

the turbulence action and the larger wet droplets deposit as lubricating films. The mist is

commonly fed into the bearing housing on one side of the row of balls or rollers and is

discharged from the opposite side (Figure 4).

Figure 4. Representative Mist Flow Pattern for

Ball and Roller Bearings

Spray and condensing fittings are used for sliding-motion elements. The major difference

between the two types is how long mist particles are maintained at high velocity under

turbulent flow conditions to promote agglomeration of the fine oil particles in the dry mist

feed. To lubricate sliding surfaces, journal bearings and the like, the resulting wet spray

then runs down adjacent surfaces in arrangements such as those shown in Figure 5.

Figure 5. Mist Lubrication of Plain Bearings

Machine

Element

(fitting type)

Oil Mist

cubic feet/minute

Ball and roller

bearings

(spray and

mist)

DR/40

D=shaft diameter,

inches;

R=number of rows of

balls or rollers

Plain bearings

(condensing

and

spray)

LD/100 L=axial length, inches;

D=shaft diameter, inches

Gears (spray)

Spur

Worm

F(D1+D2+Dn)/160

F(D1+0.5D2)/80

F=face width, inches;

D1=pitch

diameter of small gear or

worm gear,

inches; D2=pitch

diameter of large gear,

inches; Dn=pitch

diameter of additional

gears, inches

Cams (spray) FD/400

F=face width, inches;

D=max. diameter of

cam, inches

Chain (spray)

Power

Silent

Conveyor

PDRS0.5/31,000

WDS0.5/600,000

W(D+0.033L)/170

P=pitch of chain or

sprocket, inches;

D=pitch diameter of

small sprocket or

drive sprocket, inches;

R=number of rows

of chain rollers; W=chain

width, inches;

S=rpm of small sprocket;

L=chain length,

inches

Slides and gibs

(condensing) A/800

A=max. contact area,

square inches

Ways

(condensing) A/400

A=max. contact area,

square inches

For mist feed with a standard density of about 0.4 in3 of oil per

hour/cubic feet of air per minute.

Table 1. Oil Mist Requirements for

Moderate Operating Conditions

5. Built in Lubricant Devices

REFERENCE

http://machinedesign.com/motion-control/central-lubrication-protects-large-mill-equipment-and-

transfer-lines

http://www.dropco.com/air-oil-mist-lubrication-system.html

http://www.machinerylubrication.com/Read/799/oil-mist-lubrication

http://www.usmotors.com/TechDocs/ProFacts/Oil-Mist-Lubrication.aspx

http://www.infoplease.com/encyclopedia/science/lubrication-application-lubricants.html

http://www.infoplease.com/encyclopedia/science/lubrication-application-lubricants.html#ixzz398jcOYoA