Actual exposure of the surface of the journal and the sliding bearing

Both to make the journal even and close contact with the sliding bearing, but also a certain fit clearance.
The contact angle refers to a central angle of the contact surface of the journal and bearing right. The contact angle is not too large nor too small. The contact angle is too small to make the sliding bearing pressure increase, serious cause sliding bearings have a greater deformation, accelerated wear and shorten life; the contact angle is too large, it will affect the formation of the film, not a good liquid lubrication.
Experimental studies have shown that the limit bearing contact angle is 120 °. When the slide bearing wear to the contact angle of liquid lubricant will destroy. So do not compromising bearing pressure conditions, the contact angle of the smaller the better. Theoretical analysis of distance from the friction, when the contact angle of 60 °, the friction torque minimum, it is recommended for higher speed 500r / min sliding bearings, the contact angle using 60 °, speed is lower than 500r / min sliding bearings, The contact angle can 90 °, can also be used 60 °.
Contact point
Journal actual contact with the sliding bearing surface, the actual number of contact points available per unit area to represent. The more points of contact, more detailed, more uniform, indicating that the sliding bearing scraping the better, on the contrary, it means bearing scraping bad. Generally the more detailed the more points of contact, the greater the difficulty scraping.