Oilite

Oilite® is a brand of self-lubricating metal bearings manufactured by Beemer Precision, Inc. Beemer's Oilite® trademark is registered in the United States, the European Union, the United Kingdom and numerous other countries. [1]

Types

Beemer manufactures a variety of Oilite® bearings including Oilite® Plus, Super Oilite® and Oilite Polymer bearings™. Oilite® bearing are made from sintered bronze and impregnated with oil. Oilite® Plus bearings are made from sintered bronze and impregnated with oil and Polytetrafluoroethylene, providing approximately 17% reduced friction. Super Oilite® bearings are made from sintered iron and copper and impregnated with oil. Super Oilite® 16 bearings hold additional strength and are manufactured to a hardness of HRC 50. Oilite® Ultra CX bearings are Oilite® bearings machined to very fine tolerances. Oilite Polymer™ bearings are made with acetal, glass filled polytetrafluoroethylene, nylon, polyether ether ketone, ultra high molecular weight polyethylene, or Dupont Vespel. [2]

Military Grade

Oilite® and Super Oilite® bearings are available from Beemer that meet military lubrication standards MIL -B-5687D type 1 Grade1 and MIL-B-5687D Type 2 Grade 4.

Composition

Beemer manufactures Oilite®, Oilite® Plus and Super Oilite® bearings using powdered metal vacuum impregnated with different types of oils depending on the application. For example, Oilite® non-tox uses a USDA H-1 approved lubricant. Oilite® food contact uses an oil that is approved for contact with food. Various Oilite® bearings meet or exceed ASTM B-438-95A Grade 1 Type II and CT-1000-K26. Super Oilite® bearings meet or exceed ASTM B-439-95 Grade 4. Super Oilite® 16 bearings meet or exceed ASTM B-426Grade 4 Type 2.

Users may purchase Oilite® bearings machined to their specifications by Beemer or purchase stock Oilite® bearings and machine them themselves. Diamond inserts are used in the machining process. Due to the porous structure, machining Oilite® poses a special situation. To machine Oilite® bearings, the cutting tool must be—and stay—sharp; therefore, tungsten carbide is often used. The sharp tool preserves the open-pore structure, because a dull tool would smear the bearing material and close up the pores that are on the surface adjacent to the journal, which is where the lubrication needs to be. Oilite® bearings should not be reamed. If adjustments must be made to the bearing, the user should use a line boring process. Honing and grinding should not be performed on any surface that is in contact with the journal as these processes always smear the pores.[3]

Chemical composition of various Oilite® grades[3]
	Copper [%]	Iron [%]	Graphite [%]	Tin [%]	Other elements (max.) [%]
Oilite®	87.2–90.5	1 max.	0–0.3	9.5–10.5	1.0
Super Oilite®	18–22	Balance	-	-	2.0
Super Oilite® 16	18–22	Balance	0.6–1.0	-	2.0

The different types of Oilite vary by the metal alloy, not by the type of oil with which they are impregnated. Many types of oil can be impregnated to facilitate various applications, such as high and low speed, high and low load, various temperature ranges, food-grade applications, and plastic compatibility.[3]

Oilite®

Oilite® is the most widely used of all the types of Oilite® bearings. Standards that encompass Oilite® bearings are: ASTM B-438-95A Grade 1 Type II, MIL-B-5687D Type 1 Grade 1, CT-1000-K26, SAE 841, and old SAE standard Type 1 Class A.[3]

Oilite® Plus

Oilite® Plus bearings are manufactured using the same bronze alloy as an Oilite® bearings, impregnated with turbine oil and fine particles of polytetrafluoroethylene (PTFE). This reduces the friction by approximately 17% versus standard Oilite® bearing. These bearings are usually used in applications that exhibit mixed-film or boundary condition lubrication. Situations where this type of lubrication is encountered commonly include oscillating motions, slow speeds, intermittent use, pulsating loads, and uneven loads.[3]

Super Oilite®

Super Oilite® bearings use an iron based material that is harder, stronger, and cheaper than the bronze used in Oilite® bearings. Super Oilite® bearings are rated for slower speeds, but they can handle higher loads. Common applications include farm equipment, winches, sheaves, conveyors, and pulleys. Applicable standards are: ASTM B-439-95 Grade 4, MIL-B-5687D Type 2 Grade 4, SAE 863, and old SAE standard Type 3.[3]

Super Oilite® 16 bearings have been heat treated to a hardness greater than HRC 50. These bearings are used for extreme loads and slow oscillating motions. Common applications include cranes, hoists, machine presses, and conveyors. The applicable standard is ASTM B-426 Grade 4 Type 2.[3]

Comparison

Physical and mechanical properties[3]
	Oilite®	Super Oilite®	Super Oilite® 16
Density [g/cm³]	6.4–6.8	5.8–6.2	6.0–6.4
Minimum porosity [% oil by vol.]	19	19	15
Strength constant (K)	26,500	40,000	60,000
Tensile strength [psi]	14,000	22,000	32,000
Elongation [% in 1"]	1	1	0.5
Yield strength in compression [psi]	11,000	22,000	40,000

Maximum bearing limits[3]
Material	PV	Static P [psi]	Dynamic P [psi]	V [sfm]
Oilite®	50,000	8,000	2,000	1,200
Super Oilite®	35,000	20,000	4,000	225
Super Oilite® 16	75,000	50,000	8,000	35

Chrysler Motors Corporation utilized the Oilite® mark starting in 1931 for their brand of oil impregnated bearings. From October 1992 to the present, Beemer Precision has owned the mark and is the sole manufacturer of Oilite® bearings. Chrysler no longer manufactures Oilite® bearings.

References

"USPTO search page". USPTO.
"Beemer Precision Oilite bearings". Beemer Precision, Inc.
Oilite (PDF), archived from the original (PDF) on 2009-12-16, retrieved 2009-12-17.

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[1] "USPTO search page". USPTO.

[2] "Beemer Precision Oilite bearings". Beemer Precision, Inc.

[mct-3] Oilite (PDF), archived from the original (PDF) on 2009-12-16, retrieved 2009-12-17.