Wire way securement means for dynamoelectric machine

This invention relates to a dynamoelectric machine having a stator and rotor with the latter including a hollow shaft extending from the body of the rotor and with the rotor shaft being journalled by bearings carried by the end shields or bearings supports of the dynamoelectric machine. A tubular wire way extends through the hollow rotor shaft and is stationarily secured to the stator. Specifically, an opening is provided in one of the end shields for threadably receiving the wire way and the end of this wire way protrudes beyond the one end shield. A locking nut is threadably received on the end of the wire way protruding beyond the end shield so as to lock the wire way with respect to the end shield.

BACKGROUND OF THE INVENTION 
This invention relates to a dynamoelectric machine and more particularly to 
a fractional horsepower induction motor such as may be utilized with an 
overhead ceiling fan. 
Overhead ceiling fan motors are oftentimes multi-pole motors, for example, 
an 18 pole permanent split capacitor (PSC) motor, which have a relatively 
slow synchronous speed (e.g., 400 rpm). These motors typically include a 
stator assembly having a core made of a stack of laminations of suitable 
ferromagnetic material having a central bore therethrough and having 
radial slots extending outwardly from the bore for receiving a 
multiplicity of coils of magnet wire so as to constitute the windings of 
the motor. A rotor is positioned within the bore of the core of the stator 
assembly and the rotor includes a hollow rotor shaft extending endwise 
from the rotor body. The stator further includes end shields or bearing 
supports carrying suitable bearings, for example ball bearings, which 
receive and journal the rotor shaft such that the rotor is free to rotate 
within the bore of the stator. Typically, an overhead ceiling fan motor is 
suspended from a support pipe which is attached to a suitable structure on 
the ceiling. The fan blades for the overhead ceiling fan are attached to a 
hub secured to the end of the rotor shaft which extends down below the 
motor such that the hub and the blades rotate with the rotor shaft. 
Oftentimes a switch housing is provided below the fan blade hub which 
encloses a control switch for controlling operation of the motor (i.e., 
energization, de-energization, and speed control of the motor). 
Additionally, the switch housing may be provided so as to support a 
lighting fixture in a combination overhead ceiling fan/lighting fixture 
appliance. With the switch housing located stationarily below the rotating 
fan blade hub, it is conventional to provide a hollow, stationary wire way 
extending through the rotor shaft and to provide a passageway for 
electrical lead wires between the windings of the motor, the speed control 
and on/off switch located in the switch housing, the light fixture carried 
by the switch housing, and the source of electrical power which is 
typically located on the ceiling of the building. 
Heretofore, as shown in FIG. 10 of the present drawings, it was 
conventional in prior art overhead ceiling fans to securely locate the 
wire way relative to the upper end shield of the motor by means of a 
locknut located within a hollow hub formed on the end shield. Then, a 
flanged cap was removably secured to the hub formed on the end shield by a 
plurality of screws with this flanged hub having a receptacle for 
threadably receiving the pipe support suspending the overhead ceiling fan 
from the overhead ceiling structure. However, as shown in FIG. 10, this 
construction required a multiplicity of additional parts to be attached to 
the motor and required additional steps in the manufacture of the motor. 
Still further, such a structure required a considerable increase in 
materials, costs, and overall length (or height) of the motor for the 
overhead ceiling fan. It will be appreciated in many applications for 
overhead ceiling fans in modern day residential dwelling units with 8 foot 
ceilings, even small increases in the overall length of the overhead 
ceiling fan is a substantial disadvantage. 
In another type of prior art overhead ceiling fan, as illustrated in FIG. 
11, a housing structure ws rigidly attached to the stator assembly of the 
motor so as to extend above the motor and to provide a support for a hub 
into which the support pipe for the motor is threadably secured. The wire 
way was fixedly secured relative to the end shields of the motor by press 
fitting a cup-shaped member into a receptacle formed in the end shield of 
the motor so as to stationarily affix the wire way relative to the end 
shield. This arrangement, as shown in FIG. 11, added appreciably to the 
overall length of the overhead ceiling fan motor, required additional 
parts, and was expensive to manufacture and assemble. 
SUMMARY OF THE INVENTION 
Among the several objects and features of the present invention may be 
noted the provision of a dynamoelectric machine such as described above, 
particularly adapted for use in an overhead ceiling fan application, which 
eliminates the necessity of additional parts to be attached to the end 
shield of the dynamoelectric machine for attachment of the wire way and 
for attachment of the overhead support pipe; 
The provision of such a dynamoelectric machine which permits the minimum 
length of electric lead wires to be provided for connecting the windings 
and control switch of the dynamoelectric machine to the source of 
electrical power; 
The provision of such a dynamoelectric machine in which the overall length 
or height of the motor is minimized; 
The provision of such a dynamoelectric machine in which the materials 
utilized to form the end shield and support pipe securement member is 
minimized; and 
The provision of such a dynamoelectric machine which is of economical 
construction, which is relatively easy to assemble, and which requires no 
field assembly. 
Other objects and features will be in part apparent and in part pointed out 
hereinafter. 
Briefly stated, this invention relates to a dynamoelectric machine having a 
stator assembly including a core, the core having a bore extending 
longitudinally therethrough. The stator assembly further includes a 
bearing support or end shield carried by the core. Still further, the 
dynamoelectric machine includes a rotor assembly having a rotor body 
rotatable within the bore of the stator core. A shaft extends from the 
rotor body, this shaft being hollow and being journalled by bearings 
carried by the bearing support. A wire way extends through the hollow 
rotor shaft and is stationarily secured relative to the stator assembly. 
Specifically, the improvement of this invention comprises an opening 
within the bearing support for threadably receiving the wire way. An end 
of the wire way protrudes beyond the bearing support and a locking nut is 
threadably received on the end of the wire way protruding beyond the 
bearing support thereby to lock the wire way with respect to the bearing 
support. 
More specifically, the bearing support has a hub integral thereon generally 
coaxial with respect to the wire way and the wire way opening with the hub 
having a blind opening therein facinhg away from the rotor, this blind 
opening being substantially coaxial with the opening threadably receiving 
the wire way. Further, this blind opening is of only slightly larger 
diameter than the diameter of the locking nut securing the wire way 
relative to the bearing support. The locking nut has means in its outer 
end for engagement by a tool for tightening the locking nut on the wire 
way and on the base of the blind opening surrounding the opening on the 
bearing support which threadably receives the wire way.

Corresponding reference characters indicate corresponding parts throughout 
the several views of the drawings. 
DESCRIPTION OF PREFERRED EMBODIMENTS 
Referring now to the drawings, a dynamoelectric machine of the present 
invention is indicated in its entirety by reference character 1. More 
specifically, the dynamoelectric machine is shown to be an induction motor 
particularly adapted for use with an overhead ceiling fan. For example, a 
typical overhead ceiling fan motor may be an 18 pole permanent split 
capacitor (PSC) motor. The motor typically includes a stator assembly, as 
generally indicated at 3, and a rotor assembly 5. The stator assembly 
includes a shell 7 enclosing the stator assembly and a core 9 comprised of 
a stack of plate-like laminations of suitable ferromagnetic material. As 
is conventional, the core has a central bore B extending longitudinally 
therethrough and a plurality of notches or slots (not shown) extending 
generally radially outwardly from bore B for receiving a plurality of 
coils of magnet wire to constitute the windings W (shown in phantom in 
FIG. 2) of the motor. The stator assembly further includes a plurality of 
bearing supports or end shields at each end of the stator assembly, as 
indicated by references characters 11a, 11b. Typically, the end shields 
are fixedly secured in place on the shell 7 by means of through bolts 12 
extending through the motor. 
As shown in FIG. 2, rotor assembly 5 includes a rotor body 13, the rotor 
body being of squirrel-cage construction. A hollow rotor shaft 15 is 
fixedly secured to the rotor body and the rotor body and the rotor shaft 
are rotatable together. Each of the end shields 11a, 11b is provided with 
a respective bearing hub 16a, 16b which receives respective bearings, 
preferably ball bearings, as indicated at 17a, 17b, which receive and 
journal rotor shaft 15 thereby to accurately locate and to maintain rotor 
body 13 centered within bore B of stator core 9. As shown in FIG. 1, a 
plurality of mounting brackets 19 are rigidly affixed to shell 7 of the 
stator assembly and these mounting brackets may support an outer 
decorative shell (not shown) for the overhead ceiling fan. 
As best shown in FIG. 2, a hollow wire way tube, as indicated at 21, is 
coaxial within hollow rotor shaft 15. Wire way tube 21 has threads 23 at 
its upper end. End shield 11a is provided with a hub 25 integrally die 
cast with the end shield. The hub has a blind opening 27 therein which 
faces outwardly away from the motor and is generally coaxial with the 
longitudinal centerline of rotor shaft 15 and with wire way 21. A 
so-called wire way opening 29 is provided in the base 31 of opening 27 and 
the wire way opening 29 is threaded so as to threadably receive threads 23 
on wire way tube 21. As further shown in FIG. 2, the upper end of opening 
27 is threaded, as indicated at 33, so as to receive a support pipe 35 
(see FIG. 4). A set screw 37 is threadably received in the upper end of 
hub 25 so when tightened to securely affix the support pipe 35 relative to 
the hub and to prevent rotation of the motor relative to the support pipe. 
In accordance with this invention, a locking nut, as generally indicated at 
39, is threadably received on the upper portion of wire way tube 21 (see 
FIG. 2) so as to securely affix or lock the wire way relative to end 
shield 11a. More specifically, locking nut 39 engages and bears against 
base 31 of blind opening 27 so as to positively prevent rotation of wire 
way tube 21 relative to the end shield. 
Referring now to FIGS. 8 and 9, wire way nut 39 is shown to include a nut 
body 41 having a threaded opening 43 extending therethrough and being 
adapted to be threadably received on threads 23 of wire way tube 21. 
Opposed openings 45a, 45b are provided on the upper end face of nut body 
41. An alternative embodiment for locking nut is shown in FIGS. 6 and 7 
with the "primed" reference characters indicating parts corresponding in 
construction and in function to the parts heretofore described in regard 
to locking nut 39 illustrated in FIGS. 8 and 9. However, in place of the 
opposed openings 45a, 45b of locking nut 39, locking nut 39' includes a 
pair of opposed lugs 47a, 47b on opposite sides of the nut and as are best 
shown in FIG. 7. It will be understood that lugs 45a, 45b and openings 
47a, 47b are provided for the purpose of allowing an insertion tool, as 
will be hereinafter described, to positively engage nut 39 or 39' and to 
tightly secure the locking nut relative to base 31 of end shield 11a 
thereby to fixably lock wire way tube 21 relative to the end shield. 
Upon assembling of the motor generally as shown in FIG. 2, wire way tube 21 
is inserted longitudinally through hollow rotor shaft 15 from the bottom 
of the motor and the upper end of the wire way tube is threaded into 
threaded opening 29 in end shield 11a such that the upper end of the wire 
way tube extends above the base 31 of blind opening 27 in hub 25 a 
distance generally similar to that shown in FIGS. 2-4. Then, a locking nut 
39 or 39' is inserted down into blind opening 27 and is threadably engaged 
on the threads 23 provided on the upper end of wire way tube 21. A tool, 
as indicated generally at 49, is inserted into blind opening 27 in hub 25 
so as to engage the upper end face of locking nut body 41 and so as to 
permit the locking nut to be forceably, threadably driven into firm 
locking engagement with wire way tube 21 and with the base 31 of end 
shield 11a. 
More specifically, as shown in FIG. 5, locking nut installation tool 49 
comprises a tool body 51 of generally cylindrical construction having a 
diameter slightly less than the inside diameter of blind opening 27. Tool 
body 51 is provided with a counterbore in its lower end which is of 
somewhat larger diameter than the outer diameter of wire way tube 21 such 
that the upper end of the wire way comfortably fits within counterbore 53, 
as shown in FIG. 3. Additionally, means is provided on the lower end face 
of tool body 51 for engagement with either lugs 47a, 47b or with opposed 
openings 45a, 45b of locking nuts 39' or 39, respectively, so as to permit 
the locking nut to be forceably driven by tool 49. As shown in FIGS. 3 and 
5, locking nut 39 having slots 45a, 45b therein is utilized to affix wire 
way tube 21 relative to end shield 11a. Accordingly, the driving means on 
tool 41 is shown to comprise a pair of opposed lugs 59a, 59b which fit 
within and which engage opposed slots 45a, 45b on locking nut body 41'. 
Further, tool 49 includes a socket opening 55 in its end opposite 
counterbore 53 thereby to permit a driving tool (not shown) to engage and 
to forceably turn tool 49 thereby to torque locking nut 39 to a desired 
torque level and so as to positively fix wire way tube 21 relative to end 
shield 11a. It will be understood that if locking nut 39', as shown in 
FIG. 6 and 7, were used in place of locking nut 39 shown in FIGS. 8 and 9, 
tool 49 could be provided with respective slots in its end base for 
receiving lugs 47a, 47b in place of the protruding lugs 59a, 59b as 
heretofore described. As indicated at 61, an optional pilot pin may be 
provided in tool body 51 to extend outwardly beyond the end face of tool 
body 51 so as to be received within the hollow opening of wire way tube 21 
thereby to align the driving tool relative to the wire way tube and to 
hold the driving tube in generally coaxial relationship with both locking 
nut 39 and with respect to the wire way tube. However, because of the 
relatively close tolerances between the outer cylindric surfaces of tool 
body 51 and blind opening 27 in hub 25, pilot pin 61 may be omitted from 
the tool in many applications. 
After insertion of wire way tube 21 and locking nut 39 or 39', as 
heretofore described, it will be appreciated that wire way tube 21 is 
fixably secured and is held stationary with respect to end shield 11a. 
Then, the various lead wires for the electric motor may be inserted into 
hollow wire way tube 21 so as to extend down to the switch housing carried 
by the lower end of the wire way tube (generally as shown in FIG. 11, as 
will be hereinafter explained). It will be further noted that hub 25 on 
end shield 11a is provided with a slot 63 at one side thereof so as to 
permit lead wires exiting end shield 11a from a lead wire opening 65 at 
one side of the end shield to enter the hub and to pass downwardly through 
the wire way 21 and likewise to permit lead wires from the wire way tube 
and from slot 65 to be inserted up through support pipe 35 after the 
support pipe has been screwed in place into opening 27 and has been 
securely affixed by means of set screw 37. 
Referring now to FIG. 10, a prior art system for securing a wire way tube 
to an end shield and for securing a pipe support for an overhead ceiling 
fan to the end shield is illustrated. It will be understood that the 
"primed" reference characters in FIG. 10 illustrate parts of the prior art 
motor construction having a similar construction and operation to the 
parts heretofore described in regard to FIGS. 1-4. As shown, the prior art 
end shield 11a' includes a circular flange 101 die cast-in-place with the 
end shield which extends axially outwardly beyond the end face of the end 
shield. A so-called mounting hub, as generally indicated at 103, includes 
a cup-shaped counterbore which fits over and extends downwardly around the 
outside of circular flange 101. The end faces 107 of flange 101 bear 
against a plate 109 provided between mounting hub 103 and flange 101. 
Mounting hub 103 further includes a central boss 111 which extends 
generally coaxially outwardly away from flange 101 and has an opening 113 
therein for threadably receiving a pipe support 35'. Further, mounting hub 
103 includes a plurality of openings 115 therearound generally in register 
with corresponding threaded openings 117 in flange 101 for receiving 
screws 119 which fixedly secure mounting hub on the end face of flange 
101. It will be noted that this prior art arrangement requires the 
provision of a number of separate parts to secure the support pipe 35' to 
the end shield so as to be in generally coaxial relation with wire way 
tube 21' and further it will be noted that this wire way hub must be 
installed on the end shield by the person installing the overhead ceiling 
fan on the ceiling so as to insure that the various lead wires (not shown) 
extend axially through the pipe support 35'. 
Referring now to FIG. 11, another embodiment of a prior art dynamoelectric 
machine for application with an overhead ceiling fan is shown. In FIG. 11, 
parts corresponding to the dynamoelectric machine of the present invention 
heretofore described are indicated by "double primed" reference characters 
and thus a detailed description of these "double primed" parts would be 
repetitive and, for the sake of brevity, is not herein repeated. In many 
dynamoelectric machine overhead ceiling fan applications, a so-called fan 
blade assembly hub 121 is fixably secured to rotor shaft 15" and is 
rotatable with the rotor shaft at a location below the lower end shield 
11b". Further, it will be noted that wire way tube 21' extends coaxially 
through hollow rotor shaft 15" to a location below the lower end of the 
rotor shaft. A so-called switch housing 123 is secured to the lower end of 
wire way tube 21" by means of a nut 125. As is conventional, switch 
housing 123 may include a multi-position speed selector switch S for 
controlling operation of the motor. As indicated by reference character L, 
a plurality of lead wires extends axially through wire way tube 21" and 
are electrically connected to respective terminals on switch S. This is 
conventional in overhead ceiling fan applications and it will be 
understood that a similar fan blade hub and switch housing arrangement may 
be provided with the motor of the present invention, as shown in FIGS. 1 
and 2. 
However, in FIG. 11, it will be noted that wire way tube 21" is affixed to 
end shield 11a" in a manner significantly different from the apparatus and 
system of the present invention. More particularly, end shield 11a" is 
provided with an enlarged diameter counterbore 127 in its upper end face 
and wire way tube 21' has a cup-shaped member 129 swaged or otherwise 
fixably secured to the upper end of the wire way tube. This cup-shaped 
member is press fit into counterbore 127 and thus the pressed in place 
cup-shaped member 129 positively prevents rotation of wire way tube 21' 
relative to hollow rotor shaft 15'. However, the requirement of the 
counterbore 127 in end shield 11a" and the requirement of the cup-shaped 
member 129 fixably secured to wire way tube 21" is significantly more 
complex and costly than the method of securement of the present invention, 
as heretofore described in regard to FIGS. 1-9. 
Further, in FIG. 11, it will be noted that a housing 131 is provided which 
is rigidly secured or bolted to the upper face of end shield 11a. This 
housing 131 extends a considerable distance above the end of wire way tube 
21" and above the upper face of end shield 11a. A bushing 133 is secured 
in place to the upper end of housing 131 and this bushing or socket 
includes a threaded opening 135 for threadably receiving a pipe support 
(not shown in FIG. 11). Thus, it will be appreciated that the structure of 
the instant invention eliminates the necessity of housing 131 and bushing 
135 and thus substantially reduces the overall length or height of the 
overhead ceiling fan motor 1". 
In view of the above, it will be seen that the other objects of this 
invention are achieved and other advantageous results obtained. 
As various changes could be made in the above constructions without 
departing from the scope of the invention, it is intended that all matter 
contained in the above description or shown in the accompanying drawing 
shall be interpreted as illustrative and not in a limiting sense.