和志同道合的人在一起:帮我翻译一小段英文。多谢了。

solid metal rings glued to it. Sliding brushes made of carbon and graphite ride on

the metal rings and permit application or extraction of electrical energy from the
rings during rotation. The spilt-ring commutator is similar to the silp ring except
a solid metal ring is cut into two or more separate sections.As a general rule, slip
rings are used in AC motors and generators, while DC machines employ the split-ring
commrtating device .The gap or split in the commutator is kept at a minimum to reduce
sparking of the brushes.
There are several other parts used in the construction of rotating machines.
Among these are the rotor shaft,while rotates between a set of bearings.
Bearings may be either the ball, roller, or sleeve type.Bearing seal,
often made of felt material,are used to keep lubricant around the bearing
and keep dirt out.A rotorcore is usually constructed of laminated steel to
provide a low-reluctance magnetic path between the field poles of a machine
and to reduce eddy currtens. Internal and external electrical connections provide
a means of delivering or extracting electrical energy .