The armature, for instance, must not give way to the centrifugal forces
imposed upon it, nor should the field magnets be so flexible as to yield
to the statical pull of the magnetic poles. The compass of this paper
does not permit of a detailed discussion of the essential points to be
observed in the construction of electro-motors; a reference to the main
points, may, however, be useful. The designer has, first of all, to
determine the most effective positions of the purely electrical and
magnetic parts; secondly, compactness and simplicity in details;
thirdly, easy access to such parts as are subject to wear and
adjustment; and, fourthly, the cost of materials and labor. The internal
resistance of the motor should be proportioned to the resistances of the
generator and the conductors leading from the generator to the receiver.
The insulation resistances must be as high as possible; the insulation
can never be too good. The motor should he made to run at that speed
at which it gives the greatest power with a high efficiency, without
heating to a degree which would damage the insulating material.
Pages:
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49