Note: Descriptions are shown in the official language in which they were submitted.
G13~L
A-2753 ~:
SHAFT COUPLING
BACKGROUND OF THE INVENTION:
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This invention relates generally to shaft couplings and
more particularly to an improved coupling for transmitting
torque between two connected shaft flanges and for maintaining
the associated shafts in alignment.
It is particularly important in shaft couplings such as
those between crusher rolls and drive shafts that an effective
means of transferring torque be provided and also that means be
provided for achieving and maintaining a high degree of
alignment between the axes of rotation of these members. In :
many of the early shaft couplings, the associated shafts were
provided with end flanges which had interfitting tongue and
groove elements provided to transfer torque between the shafts
and circumferentially spaced clamping bolts and nuts to connect
the flanges together. The multiplicity of parts presented a
distinct disadvantage in this type of coupling and made
assembly and disassembly time consuming and difficult.
A prior patent of particular interest in this field is
U.S. Patent No. 3,328,058 which is an earlier invention made by
the present inventor. This patent discloses a shaft coupling
or flanged shafts which utilizes circumferentially spaced
shoulder bolts to transfer torque and maintain alignment and
ciccumferentially spaced clamping bolts, intermediate the
shoulder bolts, to clamp the flanges together. While this
structural arrangement of parts is effective it is still
necessary to remove a relatively large number of parts in order
to disassemble the coupling.
Although shaft couplings are known which utilize
segmental coupling sleeves overfitting and accommodating a
longitudinal key extending between associated shafts, the
primary was on transmitting the torque and achieving and
maintaining shaft concentricity was secondary. -~
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The present shaft coupler solves these and other problems
in a manner not revealed by ~he known prior art.
SUMMARY OF THE INVENTION~
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This coupling for flanged shafts provides an improved
keying system to transmit torque between the shafts and an
enclosing housing system to align and connect the shafts which
requires only a small number of parts to effectuate coupling.
The coupling comprises a first shaft including a flange
having an end face; a second shaft including a flange having an
end face disposed in face-to-face relation with the end face of
the first shaft flange; key means between said flanges to
transfer torque between said shafts, and housing means
including a plurality of housing segments enclosing said
flanges and fastening means between said housing segments
connecting said segments together, said housing means tending
to align said shafts in the connected condition.
It is an aspect of this invention to provide that the
housing segments consist of a pair of generally semi-circular
segments and to further provide that the housing segments are
generally U-shaped in cross section and formed to closely
interfit the flanges.
~ nother aspect of this invention is to provide that the
flanges each include an annular inner face, and a
circumferentially extending outer face, and to provide that the
housing segments include opposed sidewalls and an intermediate
wall, said intermediate wall including an arcuate inner face
disposed adjacent the outer faces of said flanges and said
sidewalls including annular inner faces disposed adjacent
associated annular inner faces of said flanges.
Still another aspect of this invention is to provide that
the annular inner faces of the flanges and the adjacent annular
faces of the housing segments are compatibly tapered tending to
draw said flanges into engagement when said segments are
connected.
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Yet another aspect of this invention is to provide that
the flanges of the first and second shafts are of substantially
th~ same diameter, and the arcuate inner faces of the segments
are substantially the same outer diameter as the outer faces of
said flanges tending to automatically align said shafts when
said arcuate inner faces of said housing segments are drawn
into close juxtaposition with said outer faces of said flanges.
A further aspect of this invention is to provide that the
key means includes a keyway provided in each flange and a key
closely interfitting said keyways and extending between said
flanges.
It is another aspect of the invention to provide that
each keyway is a peripherally accessible notch formed in the
flange and the key is a compatibly shaped element received by
said keyways and still another aspect of the invention to
provide that said keyways are generally U-shaped and said key
is generally rectangular.
It is yet another aspect of the invention to provide that
the fastening means includes toggle bolt means having one end
pivotal_y attached to one of said housing segments and the
other end engageable with an adjacent housing segment.
It is a further aspect of the invention to provide that
the housing seg~ents are substantially identical, and the
fastening means includes opposed pairs of toggle bolt means
each having one end pivotally attached to one of said segments
and having the other end threaded to receive a nut engageable
with the adjacent segment.
It is another aspect of the invention to provide that the
housing segment annular sidewalls each include a remote end
disposed adjacent an associated shaft portion, said housing
segments being sized so that said annular wall ends are spaced
from said shaft portions when said housing segment intermediate
wall inner faces are engaged with the outer ~aces of said
flanges.
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It is another aspect of this invention to provide that
the first and second shafts are of unequal diameter and the
housing segment sidewalls are of unequal length; and still
another aspect to provide that the first shaft includes an
enlarged portion adjacent said associated sidewall.
It is an aspect of this invention to provide a shaft
coupling which is relatively simple and inexpensive to
manufacture and easy to assemble and disassemble.
BRIEF DESCRIPTION OF THE DRAWINGS:
FIG. 1 is a side elevational view of the shaft coupling;
FIG. 2 is a cross sectional view through the housing
segments taken on line 2-2 of FIG. l;
FIG. 3 is a cross sectional view through the toggle bolt
assembly taken on line 3-3 if FIG. l;
FIG. 4 is a cross sectional view through the shaft
coupling taken on line 4-4 of FIG. 2;
FIG. 5 iS a fragmentary cross sectional view of the
toggle bolt assembly taken on line 5-5 of FIG. 3;
FIG. 6 is a fragmentary cross sectional view of the
toggle bolt assembly taken on line 6-6 of FIG. 3;
FIG. 7 is an exploded perspective view of the respective
flanges nothced keyways and key; and
FIG. 8 is a perspective view of the seal between the
housing segments.
DESCRIPTION OF THE PREFERRED EMBODIMENT:
Referring now by reference numerals to the drawings and
firs' to FIGS. 1 and 4, it will be understood that the shaft
coupling generally indicated by nu~eral 10 interconnects a pair
of shafts such as a drive shaft 12 and a roll hub shaft 14.
The drive shaft 12, which constitutes a first shaft, is
supported by a bearing 11 and includes a concentric end flange
16 and the roll hub shaft 14, which constitutes a second shaft,
includes a concentric end flange 18. The flanges 16 and 18
include annular end faces 20 and 22 respectively which are
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disposed in face-to-face abutting relation. In the embodiment
shown, the drive shaft 12 is smaller in diameter than the hub
roll shaft 14 and includes an enlarged diameter portion 23
adjacent the flange 16. The shaft coupling 10 further includes
a key assembly between the flanges 16 and 18, which is
generally indicated by numeral 24, and transfers torque between
the drive shaft 12 and the roll hub shaft 14; and a housing
assembly 26 consisting of a pair of substantially identical
semi-circular housing segments 28 and 30 and toggle bolt
assemblies 32 providing means for fastening said housing
segments together.
More particularly, and as best shown in FIGS. 2, 4 and 7,
the key assembly 24 includes a key block 34 and opposed keyways
36 and 38 in the form of U-shaped notches or recesses in each
respective flange 16 and 18. As shown in Fig. 2 the key block
34 closely interfits within the keyways 36 and 38 and extends
between said flanges, said keyways being of substantially
identical size and peripherally accessible in the embodiment
shown to simplify the shape of the key block 34 and facilitate
insertion thereof into said keyways.
The flanges 16 and 18 include annular inner faces 40 and
42, respectively, and circumferentially extending outer faces
44 and 46, respectively. The outer faces 44 and 46 are of
substantially the same diameter and width and the annular faces
40 and 42, although of different inside diameters, are inclined
at substantially the same angle to the planar outer faces 20
and 22 of the flanges 16 and 18, respectively. The housing
segments 28 and 30 enclose the flanges 16 and 18 and, in the
embodiment shown, are generally U-shaped in cross section, as
best shown in FIG. 4, to include opposed sidewalls 48 and 50
and an intermediate wall 52. The sidewalls 48 and 50 are
defined by inclined annular faces 54 and 56 and
circumferentially extending sidewall remote end faces 58 and
60, respectively. The intermediate wall 52 is defined by an
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arcuate face 62. Each of the sidewall end faces 58 and 60 is
grcoved to receive O-ring seals 64 and 66 respectively, and
said faces 58 and 60 are spaced from the associated adjacent
portions of shafts 12 and 14, respectively.
AS best shown in FIGS. 1 and 3, each of the housing
segments 28 and 30 include recessed portions 70 and 72, which
define web portions 74 and 76, respectively, and base portions
78 and 80 provided with slots 82 and 84 respectively. As shown
in Figs. 3 and 5 each toggle bolt assembly 32 includes a pair
of toggle bolts 86 having a ring 88 at one end and being
provided with a flanged nut 90 on the other end. Each toggle
bolt assembly 32 also includes a transverse pivot pin 92, each
I received within a bore 94 extending through each web 74. The
pins have opposed reduced ends each and being received by a
bolt ring 88 and each having a snap ring 96 holding said bolt
in place. As shown in Figs 5 and 6, the base portion 80
includes a recessed circular portion 98 for holding the flanged
nut 90, and therefor the associated toggle bolt 86, against
lateral movement out of the associated slots. As will be
readily understood the pivotal connection of the toggle bolts
86 to the associated housing segments and the provision of
slots 82 and 84 provides that said bolts can be swung
outwardly, as shown in phantom outline in Fig. 3, when the
flanged nuts 90 are backed off sufficiently. Also, the threads
at the ends of the bolts 86 are crushed or the bolt ends are
peened to provide a means of retaining said nuts on said bolts.
In the embodiment shown, the diameters of the
circumferentially extending flange outer faces 44 and 46 are
substantially the same as the diameter of the circumferentially
extending arcuate faces 62 of the housing segments 28 and 30.
Similarly, the combined width of the said outer faces 44 and 46
is substantially the same as the width of said arcuate faces
62. The result of this close tolerance fit and the
corresponding inclination of flange annular faces 40 and 42 and
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associated sidewall annular faces 54 and 56, respectively,
provides that when the semi-circular housing segments 28 and 30
are brought into engagement with the flanges 16 and 18, said
flanges and shafts are automatically brought into axial
alignment and into abutting face-to-face engagement. It will
be understood that the provision of a substant:ial spaced
relationship between the housing segment sidewalls end faces 58
and 60 and the adjacent shaft portions ensures that engagement
of the housing segments and the flanges occurs before
engagement between the housing segments and adjacent shaft
portions. As an example, the diametrical difference between
the annular housing segment sidewalls and the adjacent shaft
portions could be of the order of thirty thousandths of one
inch (0.030W) for a shaft of four to five and one-half inches
(4~ to 5-1/2~) in diameter.
~ gasket shown in Fig. 8 is provided between the housing
segments 28 and 30 on each side thereof which is configurated
to substantially seal the space between said segments.
It is thought that the structural features and functional
advantages of this coupling 10 have become fully apparent from
the foregoing description of parts not for completeness of
disclosure the assembly and disassembly of the shaft coupling
10 will be briefly described.
To assemble the coupling 10/ the flanges 16 and 18 are
disposed in face-to-face relation, with the annular faces 20
and 22 in register and the keyways 36 and 38 in direct
alignment. In this position, the key block 34 can be readily
inserted into the keyway notches 36 and 38 as will be apparent
from Fig. 7. Following this, the housing segments 28 and 30,
with the gaskets 100 in place and the toggle bolts 86 in the
outwardly pivoted position, are emplaced about the flanges 16
and 18. It will be understood that this emplacement is
considerably facilitated by the tapered walls 48 and 50 of said
housing segments which readily fit over the compatibily tapered
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combined flanges as is illustrated by reference to Fi9. 4.
When this is accomplished the toggle bolts 86 can be swung into
position within associated slots 82 and 84 and the flanged nuts
9o tightened so that they are seated within the recesses 98.
When the tightening is completed the flange end faces 20 and 22
are drawn together and the flanges accurately and automatically
rendered concentric by virtue of the engagement between the
arcuate faces 62 of the two housing segments 28 and 30 and the
circumferentially extending outer faces 44 and 46 of said
flanges.
As will be also readily understood uncoupling of the
shafts for replacement or repair, for example, of the roll hub
is simply a matter of backing off the flanged nuts 90 a short
distance to unseat them from the associated recesses 98, so
that the bolts 86 can be swung clear at which time the housing
segments 28 and 30 can readily be removed, it being understood
that the flanged nuts 90 do not have to be removed and are
retained by peening or by crushing the end threads thereby
avoiding accidental loss of such nuts. The uncoupling is
completed by removal of the key block 34 from the keyways 36
and 38 by simply tapping it with an appropriate tool such as a
non-metallic hammer. It will be particularly understood from
Fig. 3 that the provision of toggle bolts 86 which are
pivotally connected at diametrically opposite points on each of
the housing sections 28 and 30 permits these sections to be
identical thereby avoiding the need for two dissimilar sections.
In view of the above it will be seen that various aspects
and features of the invention are achieved and other
advantageous results attained. While a preferred embodiment of
the invention has been shown and described, it will be clear to
those skilled in the art that changes and modifications may be
made therein without departing from the invention in its
broader aspect. -~
I claim as my invention:
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