This week our department carried out a training course on ceramic bearings. After the training our manager told us a joke about ceramic bearings, but we didn't laugh because didn't understand. Now I tell the story to you, test your ability to understand, it means you are very clever if you laugh after reading it. A brief introduction of our training content.
First: the material of ceramic bearings.
(1)ZrO2 resistance to high temperature 270-450 degrees.
(2)Si3N4 resistance to high temperature 400-700 degrees.
(3)SiC resistance to high temperature 700-1200 degrees.
Second: the characteristics of ceramic bearings.
(1)Resistance to high temperature 180-1200 degrees, compared with general steel (-20-120 degrees) .
(2) High hardness.
(3) Corrosion resistant .
(4) Natural lubrication, don't need oil to lubricate .
(5) Full ball bearing speed relative .
(6) Because the bearing cage can't work under the temperature of 270 degrees, so the ceramic bearing is designed for full bearings (cage in above 270 degrees will melt and can lead to bearing lock)
Let's enter our joke:
A customer wants to buy our bearings, requirements are as follow:
(1) resistance to high temperature of 350 degrees.
(2) don't require high speed.
(3) need self-aligning ball bearings.
A new salesman answers:
(1) choose CrO2 material, it can meet the requirement of high temperature and the price will be reasonable.
(2) design for the full ball bearings, because we can't use bearing cage under high temperature, and can meet the required speed.
You laugh? Ha-ha.
tip: if you are just starting on bearing like me, please look at ''self-aligning ball bearing'' I believe you will like me, in hindsight, laughed!