Improvements in Means for Supporting Electric Motors for Tramway Cars.
Year: 1898

page_text: Date of Application, 13th Dec,, 1898-Accepted, 13th Dec., 1899
COMPLETE SPECIFICATION.
Improvements in Means for Supporting Electric Motors for Tramway
Cars.
I, JOHN MCLEOD MURPHY, of Torrington, in the County of Litchfield and State
of Connecticut, United States of America, Electrician, do hereby declare the
nature of this invention and in what manner the same is to be performed, to
be particularly described and ascertained in and by the following statement:-
-
This invention is an improved ball bearing and supporting means for electric
motors for tramway cars, and seeks to provide means whereby to reduce the
frictional wear on the axle to a minimum, and which has the parts so arranged
that the bearing can be quickly adjusted so that the motor will have a true
bearing on the axle and which parts are capable of being easily manipulated
and adjusted without disconnecting or otherwise affecting any of the parts of
or supports for the motor.
In the drawing;-
Figure 1 is a side elevation of an electric motor having my improvements
applied, parts being in section.
Fig. 2 is a longitudinal section of the axle bearing.
Fig. 3 is a detail perspective view of several of the parts detached.
Fig. 4 is an end view on the line 4-4 of Fig. 2.
Fig. 5 is a detail view of the detent devices hereinafter referred to.
1 indicates the motor casing: 2 the drive gear; 3 the supporting spring
hanger devices; 4 the fixedly held hanger beam, and 5 the rest or spring brace
for the axle-bearing end of the motor frame.
The axle end of the motor frame is horizontally divided into
an upper
section 6, and a lower section 6ª, each having semi-circular opposing seats 7—7",
which encircle the axle 8, but are held from frictional contact therewith as
shown in Fig. 2.
The opposite ends of the section ", have lateral horizontal extensions (;b,
forming guards to protect the under edge of the ball-retaining caps presently
referred to, and the sections 6 and 6ª also have semi-circular seats 9-9 with
internal threads 9b, and semi-circular concaved seats 10-10%, of a smaller
diameter, which form the inner portion of the ball races, as shown in Fig. 2,
by reference to which it will be seen that the outer edges X of the races 12
project beyond the vertical or central bearing line of the ball races so that
each outer edge of the races is out of direct bearing line with the balls 13,
thereby providing a smooth bearing face for the balls and avoiding the danger
of quick wear thereof which would occur were the line X in a plane with the
central or maximum radii of the annular ball race.
It will thus be seen the front end of the motor is supported entirely on the
anti-friction balls 13, which alone bear on the axle.
To hold such bearings in a proper annular relation with each other and to
provide for a ready substitution of new bearings. I provide simple and easily-
adjustable cap-plates 14, loosely fitted on the axles for a limited longitudinal
movement thereon, and such caps have concaved annular portions 14ª, which

page_text: form the outer portions of the ball-races. The cap-plates, which are fitted
just loosely enough on the axle 8 not to turn fixedly therewith, have each a
threaded shank 15, which are adapted to have engagement with the threads
in the ends of the motor when they are adjusted, whereby to be drawn into
their operative position; but such threaded shanks 15, are of -somewhat smaller
diameter than the internal threaded portion which they engage, so that when
properly adjusted they will be held out of a tight frictional contact with the
motor-frame sections, and thereby hold such sections from tight frictional
contact with the cap-plates and leaving the entire bearing-support of the front
end of the motor-frame on the balls 13, such result being attained by making
the space intervening the threads on the motor-frame sections and the cap-
plate shanks slightly greater than the space between the cap-plates 14 and
the axle, such plates being, as it were, loosely supported on the axle, it being
manifest that as the balls 13 are adapted at all times to engage the seats 10"
the members 14 serve merely as cover or cap plates and form practically no
bearing means for supporting the motor-frame on the axle. The outer ends
of the caps terminate in annular enlarged toothed disks 17, the lower ends
of which are protected from being engaged by any obstruction or loose member
of the car or motor frame by the extensions GbGb
To hold the caps from unscrewing while in operation, and thereby loosen
the ball roller-bearings, (which might cause accident) I provide a simple detent
for each cap, each of which consists of a bracket 18, secured to the motor-frame,
in which is fitted a T-headed set-screw 19, which passes through an elongated
slot 20 in a longitudinally-adjustable lock-plate 21, which is so disposed rela-
tively to its coincident cap-plate to be readily moved into and out of engagement
with the toothed disk of the cap, as clearly shown in Fig. 5, it being obvious
that when held in locked engagement with the toothed disk the cap will be
positively held from turning on the axle, and by loosening the T-bolt such
plate 21 can be quickly shifted from engagement with the aforesaid cap-disk.
To hold the upper and lower bearing-sections of the motor in a firm position
on the roller or ball bearings, stay-bolts 22 are passed up through the same
at each side of the axle, the ends of which have lock and jam nuts 23 23", as
shown.
From the foregoing, taken in connection with the accompanying drawings,
it will be readily seen that the motor-frame will have bearing only on the
balls, and the devices for retaining the balls will also be positively held from
frictional engagement with such motor-frame when set to their proper adjust-
ment.
It will be noticed the bearing mechanism and the parts are of such construe-
tion that access thereto can be quickly had and the same adjusted without in
the slightest interfering with or disconnecting any of the other parts of the
motor-frame.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
1. As an improvement in axle-bearings for electric motors, the combination
with the axle and the fixed hanger devices for supporting the motor at one
end; of the motor-frame having its front end constructed to fit over the axle,
and having ball-race portions at the ends; balls fitting such race portions, and
detachable means for holding the balls in place, substantially as described.
2. As an improvement in axle-bearings for electric motors; the combination
with the axle and the fixed hanger devices for supporting the motor at one end:
of the motor-frame having its axle-end sections divided and formed with semi-
circular seats to form an axle-passage, said divided sections having their outer
ends formed with annular concaved seats forming ball-races; the balls held
therein, and the ball-holding caps longitudinally adjustable along the axle, but

page_text: held from frictional engagement with the motor-frame, all being arranged
substantially as described.
3. The combination with the axle, of the motor-frame having its front end
formed of upper and lower sections, said sections having semi-circular seats
to embrace the axle, and having annular ball-race grooves in the ends and
enlarged internally-threaded annular recesses; cap-plates having recesses on
their inner faces, externally-threaded portions to engage the threaded recesses
in the ends of the motor-sections said threaded portions being of a less diameter
than the said threaded recesses, and the bearing-balls, all being arranged
substantially as described.
4. The combination with the axle and the motor-frame having its front end
formed of upper and lower sections said sections having semi-circular seats
forming the axle-aperture and having their ends provided with annular ball-
race portions and internally-threaded annular recesses, and the bearing-balls
seating in the said ball-race portions, of the retaining-caps having internal
grooves, an annular threaded outer portion adapted to engage with the internally-
threaded recesses of the motor ends, but of slightly less diameter than such
recesses whereby the threads will be held out of frictional engagement when
the caps are properly adjusted, said caps having toothed disks, and the adjust-
able lock detent devices for holding the caps from turning in the axle, all
being arranged substantially as described.
Dated this 18th day of December 1898.
BOULT & WADE,
Agents for the Applicant.