Direct Current machines converting mechanical energy inyo electrical one are referred to as d.c. generators . Those , on the other hand , which convert electrical energy into mechanical one , are spoken of as d.c. motors . D.c. machines are reversible and , therefore identical in construction . They are composed of two main parts - the stationary part which is called the frame provided with the main poles and the commutating poles , and the rotating part which is said to be the armature , its windings and commutator being positioned on it .
The frame is made of steel in the form of a closed magnetic conductor . The main poles for the purposes of decreasing the losses are assembled of sheet steel laminations . Mounted on them , the field windings are built of copper isolated conductors . The main poles are intended to produce the main magnetic flux .
The commutating poles are also made of steel and arranged midway between the main poles . Their windings as well as of the main poles are built of copper conductors . The commutating poles with the windings are designed to ensure non-sparking operation of an electric machine .
The armature makes up a cylindrical core made of sheet steel laminations , a two-layer winding being fixed in their slots . The former is built of sections made of isolated copper conductors . The commutator is constructed of separate copper bars isolated from each other and from the frame . The section made of isolated copper conductors .
The commutator is constructed of separate copper bars isolated from each other and from the frame . The section leads of the armature winding are connected to the bars . The commutator is designed for the conversion of an alternating emf induced in the armature winding into a direct one .
The brushgear is an element designed for collecting the current from the armature winging and leading it to the latter . It is composed of brushes , brush-holders , brush-studs , brush-rockers and current collecting bars.
The commutator and brushgear are the most essential parts of a d.c. machine , its reliable operation being dependent on their condition .
The operative principle of a d.c. machine is built upon the laws of electromagnetic induction and electromagnetic force . As the armature is rotated in the magnetic flux of the main poles by a drive motor , the e.m.f. is induced in the armature winding . In the loaded machine , the e.m.f. brings into existince the current with which it coincides in direction . This current interacting with the magnetic flux produces the electromagnetic torque directed in opposition to that produced by a prime mover . As this takes place , the machine operates as a generator . The mechanical power consumed from the drive motor is converted into the electrical one and is given up to the mains .
When a d.c. machine is connected to the electrical source of supply , the current is generated in the armature winding . INteracting with the magnetic flux of the poles , it produces the electromagnetic torque ehich brings into rotation the armature . The e.m.f. directed in opposition to the current direction is induced in the armature winding . in this case the machine works as a motor . The electrical power consumed from the mains is converted into the mechanical one .
The frame is made of steel in the form of a closed magnetic conductor . The main poles for the purposes of decreasing the losses are assembled of sheet steel laminations . Mounted on them , the field windings are built of copper isolated conductors . The main poles are intended to produce the main magnetic flux .
The commutating poles are also made of steel and arranged midway between the main poles . Their windings as well as of the main poles are built of copper conductors . The commutating poles with the windings are designed to ensure non-sparking operation of an electric machine .
The armature makes up a cylindrical core made of sheet steel laminations , a two-layer winding being fixed in their slots . The former is built of sections made of isolated copper conductors . The commutator is constructed of separate copper bars isolated from each other and from the frame . The section made of isolated copper conductors .
The commutator is constructed of separate copper bars isolated from each other and from the frame . The section leads of the armature winding are connected to the bars . The commutator is designed for the conversion of an alternating emf induced in the armature winding into a direct one .
The brushgear is an element designed for collecting the current from the armature winging and leading it to the latter . It is composed of brushes , brush-holders , brush-studs , brush-rockers and current collecting bars.
The commutator and brushgear are the most essential parts of a d.c. machine , its reliable operation being dependent on their condition .
The operative principle of a d.c. machine is built upon the laws of electromagnetic induction and electromagnetic force . As the armature is rotated in the magnetic flux of the main poles by a drive motor , the e.m.f. is induced in the armature winding . In the loaded machine , the e.m.f. brings into existince the current with which it coincides in direction . This current interacting with the magnetic flux produces the electromagnetic torque directed in opposition to that produced by a prime mover . As this takes place , the machine operates as a generator . The mechanical power consumed from the drive motor is converted into the electrical one and is given up to the mains .
When a d.c. machine is connected to the electrical source of supply , the current is generated in the armature winding . INteracting with the magnetic flux of the poles , it produces the electromagnetic torque ehich brings into rotation the armature . The e.m.f. directed in opposition to the current direction is induced in the armature winding . in this case the machine works as a motor . The electrical power consumed from the mains is converted into the mechanical one .
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