外文翻譯---電動機(jī)的結(jié)構(gòu)特點-其他專業(yè)-文庫吧資料
2025-01-27 09:40本頁面
【正文】 around which coils are wrapped. The flow of direct current through the coils establishes a magic field distribution along the periphery of the air gap in much the same manner as occurs in the rotor of the synchronous machine. Hence in the DC machine the field winding is located on the stator. It follows then that the armature winding is on the rotor. The rotor is posed of a laminated core, which is slotted to acmodate the armature winding. It also contains the mutator—a series of copper segments insulted from one another and arranged in cylindrical fashion. Riding on the mutator are appropriately placed carbon brushes while serve to conduct direct current to or from the armature winding depending upon whether motor or generator action is taking place. In the armature winding is depicted as a coil wrapped around a toroid. This is merely a schematic convenience. In an actual winding, no conductors are wasted by placing them on the inner surface of the rotor core where no flux perates. In the those parts of the armature winding which lie directly below the brush width are assumed to have the insulation removed, ., the copper is 英文翻譯 第 5 頁 共 8 頁 exposed. This allows current to be conducted to and from the armature winding through the brush as the rotor revolves. In a practical winding each coil is made accessible to the brushes by connecting the coils to individual mutator segments and then placing the brushes on the mutator. For motor action direct current is made to flow through the field winding as well as the armature winding. If current is assumed to flow into brush B1 in , then mote that on the left side of the rotor for the outside conductors current flows into the paper while the opposite occurs for the conductors located on the outside surface of the right side of the rotor. A force is produced on each conductor, thereby producing a torque causing clockwise rotation. Now the function of the mutator is to assure that as a conductor such as 1 in revolves and thus goes from the left side of brush B1 to the right side, the current flowing though it reverses, thus yielding a continuous unidirectional torque for the entire armature winding. Recall that a reversed conductor current in a flux field of reversed polarity keeps the torque unidirectional. The reversal of current es about because the mutator always allows current to be conducted in the same directions in either side of the armature winding whether or not it is rotating. Another point of interest in concerns the location of the brushes. By placing the brushes on a line perpendicular to the field axis all conductors contribute in producing a unidirectional
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