Note: Descriptions are shown in the official language in which they were submitted.
105~496
This invention relates generally to dynamoelectric
mac'hines and more specifically to the construction of large
electric motors and generators.
In the past, the cost of manufacturing large dynamo-
electric machines was extremely high because of the difficulty
in assembling the stator and the rotor of the machine with an
accurate air gap. Expensive and time consuming machining and
assembly were required on the large stator supports and other
members to properly align the motor rotor and the stator. In
addition, the machines frequently had to be disassembled and
adjusted to retain the desired air gap.
To overcome this, machines have been designed which
provide a standard type of base having mounting means connected
thereto which are accurately located relative to one another so
as to accurately position the rotor and stator of the machine.
Examples of such prior art are U.S. 2,274,351 issued to
A. P. Wood, February 24,-1942;'U.S. 3,064,152 issued to
A. S. DePaul--e~ al,-November 13,--1962; and U.S. 3,375,382
issued-to-R; H-. Barber-et al,-March--26~--196~. While these
prior art patents did provide improvements over the then known
prior art, the invention of this patent takes an additional
step by locating all mounting surfaces in horizontally disposed
parallel planes and in the preferred embodiment axially aligned
to simplify the machining process.
It is, therefore, the purpose and general object of
this invention to provide an improved construction of a dynamo-
electric machine.
Another object of this invention is to provide a
support frame for large dynamoelectric machines in which the
air gap alignment can be easily and accurately formed prior to
assembly so that no adjustments are required during and after
assembly.
- 1 -
~05~
A furt,her object of this invention is to provide a
support frame for a dynamoelectric machine of the hereinbefore
des,cribed type wherein all mounting surfaces are horizontally
disposed and are located in parallel planes.
A more specific object of this invention is to pro-
vide a support frame for a dynamoelectric machine of the
hereinbefore described type wherein all mounting surfaces on
each lateral side of the support frame are axially aligned.
These and other objects of the subject invention will
become more fully apparent when the following description is
read in light of the attached drawings wherein:
Fig. 1 is an exploded side view of a dynamoelectric
machine constructed in accordance with this invention; and
Fig. 2 is an exploded front view of Fig. 1.
Referring to the drawings in more detail, the inven-
tion is illustrated in a large electric motor. The motor is
made up generally of a base member 6, a stator 7 and a rotor
8. The rotor 8 is constructed of any conventional type and is
provided with oppositely extending shaft~ends 9. The rotor-is
constructed for positioning within the stator bore and for
rotation therein with a predetermined uniform air gap 11.
The stator 7 is constructed of a plurality of annular
steel laminations 12 stacked and clamped together in the con-
ventional manner such as by axially extending bars 13 and end
plates 14 to form the stator core having a cylindrical bore
within which the rotor 8 rotates. The preferred form of stator
is provided with two sets 16 and 17 of mounting pads. These
mounting pads are accurately machined and located relative to
one another and the center of the cylindrical bore of the
stator.
105~496
~ In the preferred embodiment shown herein for purposes
of illustration, the base member is &onstructed of a bottom
plat:e 18 and two laterally spaced upstanding side walls 19 and
21. A first and second pair of stator mounting surfaces 22
and 23 are rigidly connected to the base member. All points
on all of the stator mounting surfaces 22 and 23 lie in a
common horizontally disposed plane. ~urthermore, the stator
mounting surfaces on each lateral side of the base member 6
are axially aligned.
lQ The base member 6 is also provided with a first and
second pair of axially-spaced rotor bearing bracket mounting
surfaces 24 and 26. The stator mounting surfaces are located
intermediate the bearing bracket mounting surfaces. All points
on all of the rotor bearing bracket mounting surfaces lie in a
common horizontal plane which is parallel to the plane of the
stator mounting surfaces. Furthermore, the rotor bracket
mountin~ surfaces on each lateral side of the base member are
also axially aligned. In the preferred embodiment shown herein,
the rotor bearing bracket mounting surfaces and the stator
mounting surfaces on each lateral side of the base member are
also axially aligned.
A rotor bearing bracket is provided at each end of
the base member 6. ~ach rotor bearing bracket is composed of
a lower portion 27 and;28 having spaced mounting surfaces 29
and 3I whlch are accurately machined and located relative to
the'centerline o~ the ~earing bracket. Aligned bolt holes are
provided through'the ~earing brackets and into the bearing
bracket supp4rts 24 and 26. ~ ~earing hracket cap 32 having
a complementar~ h~lf sha'ft opening therethrough is constructed
3~ for'a~tachment to e~ch'lower bxacket mounting sur~ace 24 and
2~ in any conventlonal manner such'as by bolts Cnot shown~.
~QS14~6
In order to insure proper air gap 11 between the
rolor 8 and stator 7, the moun~ing surfaces on the base member
6 rnust be accurately located. To this end, the base member
is located on a milling machine and since each of the stator
mounting surfaces are in a common plane, all four of these
surfaces 22 and 23 can be accurately machined by merely chang-
ing the lateral setting of the milling head. The same is true
of the bearing bracket mounting surfaces since they also are
in a common plane. Additionally, as shown herein the preferred
embodiment has all mounting surfaces both for the stator and
the bearing bracket on each lateral side of the base member
axially aligned. Therefore, all of these mounting surfaces can
be machined by merely changing the height of the milling cutter
but without requiring a separate setting to locate these surfaces
relative to the centerline of the base member. With this
arrangement, a very accurate alignment can be obtained between
both the stator mounting surfaces and the bearing bracket mount-
ing surfaces. It is then possible to accurately machine the
mounting surfaces of the lower bearing bracket half 28-and -- -
the stator mounting pads 16 and 17 each relative to their own
centerline. With this arrangement, a uniform air gap can be
obtained without extensive adjustment during assembly.
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