Connect the contact point along the channel and through the center of the sphere normal

The ball bearing, the ball contacts the inner and outer ring channel, power transformers point. Normal contact points along the channel connections and through the ball center. The external loads along the line by a circuit breakers to another ring, therefore, known as the bearing pressure line and the pressure line and the dihedral angle between the radial plane is called pressure angle.
The sliding bearing, the sliding bearing is the journal and the contact surface of the central angle. Contact angle is not too large nor too small. The contact angle is too small pressure increase will slide bearing, Circuit breaker cause greater deformation, accelerated wear, shorten the service life; touch too, will affect the film formation, not good liquid lubrication. Experimental studies show that the sliding bearing is the limit of the contact angle 120 °.