5-min guide to oil-impregnated bearings
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- 5-min guide to oil-impregnated bearings
What are sintered oil-impregnated bearings?
How are they made? Do they have advantages?
We answer questions like these in an easy 5-min guide.
1 What are sintered oil-impregnated bearings?
Sintered oil-impregnated bearings are bearings that employ material which has many minute oil-containing pores on the surface that comes in contact with the spindle, and by lubricating, the bearing smoothly supports spindle rotation. The bearings are made by compacting powdered metal which has many pores and then firing it at high temperatures. Impregnating the pores with oil forms a lubricating oil film on the surface, which comes in contact with the spindle, and maintains good sliding conditions.
2 How are they made?
They are manufactured using a method called powder metallurgy. In this method, metal powder is compacted to give it a desired form, then fired at high temperatures to increase its density. This enables improvement of durability and friction properties.
- Mixing
- Molding
- Sintering
- Sizing
- Impregnation
- Final inspection
- Product complete
If we compare it to making a rice ball…
If we compare it to making a rice ball…
3 What are the advantages? How are they used?
Sintered oil-impregnated bearings have the following advantages:
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① Excellent abrasion resistance
The impregnated lubrication oil is used effectively, so excellent abrasion resistance is maintained.
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② Low coefficient of friction
Thanks to the reduced frictional force, abrasion can be reduced and long service life can be achieved.
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③ Excellent durability
The bearings have excellent abrasion and corrosion resistance and display superior performance in high temperatures, so they have excellent durability and a long life span.
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④ Low cost
The bearings are made from iron powder. This means the raw materials are relatively cheap and the cost of manufacture is low, meaning they can be provided at a low price.
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⑤ Self-lubricating
The impregnated lubricating oil is constantly supplied to the contact surface to maintain good lubrication, so there is no need for applying separate lubrication such as oil and grease.
4 Resin gears vs. cutting gears - What’s the difference?
Each of the gear materials has their own strengths and drawbacks.
In the end, it is necessary to select the right gear based on what it will be used for and what properties it needs.
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Resin gear
Gears made using resin material◎Advantages
Light weight, low noise
▲Disadvantages
Heat resistance and durability are limited, strength is low
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Cutting gear
Gears cut from metal material◎Advantages
High precision & high strength
▲Disadvantages
Manufacturing cost is high, a lot of material is wasted
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Sintered gear
Gears made using powder metallurgy technology◎Advantages
Suited to mass production, complex shapes can be manufactured, not much material is wasted
▲Disadvantages
Sometimes they may have low strength, sometimes surface processing is necessary