Blog Entries - December 2016

FREQUENTLY ASKED QUESTIONS ABOUT DENTAL BEARINGS

Posted on: December 20, 2016

1.What are the design differences between radial and angular

contact ball bearings?

The main difference between radial ball bearings and angular

contact ball bearings  is the retainer type: radial bearings include

a crown retainer whereas angular contact bearings include a full

retainer.

2. What are the benefits of radial and angular contact ball bearings?

Which design offers better performance and longer life?

Radial ball bearings are more convenient to use because they

may be installed and axially loaded from either side.

Angular contact ball bearings perform better at higher speeds

and operate longer, on average, than radial bearings. Angular contact

bearings can only be axially loaded from one side.

Keep in mind that bearing life can be significantly impacted by other

factors, like whether or not your customers follow appropriate maintenance

protocols, use a quality cleaner/lubricant, or avoid immersing

their handpieces in aggressive or corrosive cleaning chemicals.

3. What is the difference between a ball bearing manufactured with

a phenolic retainer and one manufactured with a Torlon® retainer?

Phenolic is a porous material that may be impregnated with oil

at the factory. During operation, a phenolic retainer provides continuous

bearing lubrication by releasing micro-droplets of oil contained within

its body.

Torlon is not porous and cannot be impregnated with oil.

However, it contains solid lubricating additives, like graphite and

Teflon®, which help to lubricate a dental bearing during conditions of

conventional-lube starvation. Torlon® handles autoclave sterilization

much better than phenolic, which has a tendency to develop micro-cracks

during repeated sterilization.

4. What is the advantage of using a hybrid ceramic ball bearing

 which includes hardened steel rings and silicon nitride

(ceramic) balls, instead of a typical bearing with steel rings and

steel balls?

Ultimately, a hybrid ceramic ball bearing runs cooler and extends

bearing life.

A ceramic ball is approximately 60% lighter than the same size steel

ball. As a result, the lighter ceramic ball-set generates less centrifugal

force when operating at super-high speeds, which minimizes wear on

the raceway of the outer ring.

Surface wear is further reduced because ceramic and steel are such

different materials. Ceramic balls are harder than heat-treated steel

balls, so it’s less likely that external contaminants or bearing wear debris

will damage them and cause the bearing to fail. Also, a hybrid ceramic

bearing operates better than an all-steel ball bearing in low-lubrication

conditions.

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