U.S. patent application number 09/779945 was filed with the patent office on 2001-06-28 for drive coupler.
Invention is credited to Korus, Thomas J..
Application Number | 20010005693 09/779945 |
Document ID | / |
Family ID | 22506547 |
Filed Date | 2001-06-28 |
United States Patent
Application |
20010005693 |
Kind Code |
A1 |
Korus, Thomas J. |
June 28, 2001 |
Drive coupler
Abstract
A coupler for connecting first and second shafts has a male
cross member pinned to the first shaft and a female body member
clamped onto the second shaft. The female body member has a housing
with internal splines interlocking with mating external splines on
the cross member. A longitudinally split clamp has a sill portion
integral with the female body member and a half clamp member
engageable with the sill portion. The split clamp has a single
locking bolt which reduces the time required for installation. The
external splines are relieved at one end to allow the coupler to
tolerate some misalignment between the shafts.
Inventors: |
Korus, Thomas J.; (Lindsay,
NE) |
Correspondence
Address: |
COOK, ALEX, McFARRON, MANZO,
CUMMINGS & MEHLER, LTD.
Suite 2850
200 West Adams Street
Chicago
IL
60606
US
|
Family ID: |
22506547 |
Appl. No.: |
09/779945 |
Filed: |
February 9, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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09779945 |
Feb 9, 2001 |
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09143981 |
Aug 31, 1998 |
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Current U.S.
Class: |
464/74 |
Current CPC
Class: |
F16D 1/0847 20130101;
Y10S 464/901 20130101; F16B 2200/40 20180801; F16D 3/185
20130101 |
Class at
Publication: |
464/74 |
International
Class: |
F16D 003/52; F16D
003/56; F16D 003/64; F16D 003/72; F16D 003/76; F16D 003/78 |
Claims
1. A coupler for connecting first and second shafts such that
rotational motion of the first shaft is transferred to the second
shaft, comprising: a first connector element engageable with an end
of the first shaft; a second connector element interengaging with
the first connector element in rotationally-driving relation and
having a sill defining a pocket into which an end portion of the
second shaft can be placed by non-axial relative movement between
the sill and second shaft; and a clamp member being radially and
axially split from the second connector element and being
engageable with the sill to enclose the end portion of the second
shaft and fix it in rotationally-driving relation with the second
connector element.
2. The coupler of claim 1 wherein each of the first and second
connector elements includes a plurality of splines defining grooves
therebetween with the splines of one connector element being
received in the grooves of the other connector element.
3. The coupler of claim 2 wherein each connector element has a body
and the splines each extend from a root connected to the body to a
free end.
4. The coupler of claim 3 wherein on one connector element the
spline roots are closer to its shaft than the free ends while on
the other connector element the spline free ends are closer to its
shaft than the roots.
5. The coupler of claim 2 wherein sufficient clearance is provided
between the splines and grooves to permit the shafts to rotate even
if misaligned by about three to five degrees angularity.
6. The coupler of claim 1 wherein one of the connector elements
comprises a generally cylindrical female body disposed about the
shafts and defining a cavity with radially-directed splines
extending from the body into the cavity.
7. The coupler of claim 6 wherein the body further comprises a wall
enclosing one end of the body with the sill connected to the
wall.
8. The coupler of claim 7 wherein the clamp has a lug extending
therefrom and the wall has an aperture for receiving the lug.
9. The coupler of claim 1 further comprising a fastener for
retaining the clamp on the sill.
10. A coupler for connecting first and second shafts, comprising: a
first connector element having a body engageable with an end of the
first shaft; a second connector element having a generally
cylindrical housing at least partially surrounding the body, the
housing defining a unitary radial opening to interengage with the
first connector element in rotationally-driving relation; a sill
attached to the housing and defining a pocket into which an end
portion of the second shaft can be placed by non-axial relative
movement between the sill and second shaft; and a clamp member
being radially and axially split from the second connector element
and being engageable with the sill to enclose the end portion of
the second shaft and fix it in rotationally-driving relation with
the second connector element.
11. The coupler of claim 10 wherein each of the first and second
connector elements includes a plurality of splines defining grooves
therebetween with the splines of one connector element being
received in the grooves of the other connector element.
12. The coupler of claim 10 wherein each connector element has a
body and the splines each extend from a root connected to the body
to a free end.
13. The coupler of claim 12 wherein on one connector element the
spline roots are closer to its shaft than the free ends while on
the other connector element the spline free ends are closer to its
shaft than the roots.
14. The coupler of claim 10 wherein sufficient clearance is
provided between the splines and grooves to permit the shafts to
rotate even if misaligned by about three to five degrees
angularity.
15. The coupler of claim 13 wherein said other of the connector
elements comprises the generally cylindrical housing disposed about
the shafts and defining the unitary radial opening with
radially-directed splines extending from the housing into the
unitary radial opening.
16. The coupler of claim 10 wherein the generally cylindrical
housing further comprises a wall enclosing one end of the
housing.
17. The coupler of claim 16 wherein the clamp has a lug extending
therefrom and the wall has an aperture for receiving the lug.
18. A coupler for connecting first and second shafts in
rotationally-driving relation, comprising: first and second
connector elements engageable with facing ends of the first and
second shafts, one of the connector elements being axially slidable
onto its shaft and the other connector element being transversely
movable onto its shaft, the first and second connector elements
being matingly engageable with each other to form a yieldable
interlock therebetween which allows the coupler to operate under
conditions having slight misalignments between the shafts; and a
clamp engageable with said other connector element to retain it on
its shaft.
19. The coupler of claim 18 wherein one of the first and second
connector elements has a generally cylindrical housing defining a
unitary radial opening.
20. The coupler of claim 19 wherein the generally cylindrical
housing further comprises a wall enclosing one end of the
housing.
21. The coupler of claim 20 wherein the clamp has a lug extending
therefrom and the wall has an aperture for receiving the lug.
Description
[0001] This application is a continuation of copending application
Ser. No. 09/143,981.
BACKGROUND OF THE INVENTION
[0002] This invention relates to couplers for connecting two shafts
together for the purpose of transferring rotational motion from one
shaft to the other. The coupler has particular application in the
agricultural irrigation field where irrigation pipeline support
towers have centrally located drive motors for propelling wheels
located at the ends of the towers. The motor's gear box is
connected to worm drives at the wheels by drive shafts. Drive
couplers are used to connect the drive shaft to both the motor gear
box and the worm drives. Of course couplers could also be used in
other applications where two generally aligned but spaced shafts
have to be connected such that rotational motion of one shaft is
transferred to the other. Additionally, it is quite often desirable
that the coupler be able to tolerate some degree of misalignment
between the shafts. Misalignment usually takes the form of the
shafts not being parallel to one another.
[0003] The invention is particularly concerned with situations
where the ends of the shafts remote from the coupler have to be
fixed in position prior to installing the coupler. Accordingly, the
shafts have no axial movement and perhaps little or no transverse
movement available with the result that the coupler has to be
installed generally between and/or around the pre-installed
shafts.
[0004] Prior art couplers of the above type are known as split
couplers and have what might be described as a built-up
construction wherein a plurality of arms are placed about the end
of a shaft and bolted together. The arms extend beyond the end of
the shaft where they intersect with the arms of the opposite shaft
or some intervening third part in some sort of engagement.
Sometimes a rubber connecting block is involved to accommodate
misalignment but this leads to problems with the rubber block
adding lots of torsional movement called wind-up, with attendant
backlash problems. In addition to wind-up, a major problem with the
built-up construction is the high number of components and the
large number of fasteners required. The high part count adds to
cost and installation time.
SUMMARY OF THE INVENTION
[0005] The present invention concerns a coupler for transmitting
rotational motion from one shaft to an adjacent but spaced shaft. A
primary object of the invention is a coupler whose installation can
be completed after that of the shafts and with a minimal number of
parts.
[0006] Another object of the invention is a coupler of the type
described which can accommodate misalignment of the shafts.
[0007] A further object of the invention is a coupler that reduces
lost torsional movement or wind-up.
[0008] These and other objects which may become apparent in the
following specification are realized by a coupler for connecting
first and second shafts. The coupler has first and second connector
elements attached to the ends of the respective shafts. The
connector elements each include a plurality of splines defining
grooves therebetween. One set of splines is internal and the other
external such that the splines of one connector element fit into
the grooves of the other connector element to interlock the
connector elements in rotationally-driving relation. A sill is
attached to the second connector element and defines a pocket into
which an end portion of the second shaft can be placed by means of
a non-axial relative movement between the sill and second shaft. A
clamp member is engageable with the sill to enclose the end portion
of the second shaft and fix the shaft in rotationally-driving
relation with the second connector element. The clamp has a lug
which fits into a slot formed in an end wall of the second
connector element.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a side elevation view of a portion of the drive
system of an agricultural irrigation machine, showing three of the
couplers of the present invention.
[0010] FIG. 2 is an enlarged side elevation view of the coupler
assembly, showing the clamp both in phantom and solid lines to
illustrate its installation procedure.
[0011] FIG. 3 is a section taken along line 3-3 of FIG. 2.
[0012] FIG. 4 is a side elevation view of a wear pad.
[0013] FIG. 5 is a side elevation view of a connector element in
the form of a male cross piece.
[0014] FIG. 6 is an end elevation view of the cross piece of FIG.
5.
[0015] FIG. 7 is a top plan view of a connector element in the form
of a female body.
[0016] FIG. 8 is an end elevation view of the female body.
[0017] FIG. 9 is a side elevation view of a clamp.
[0018] FIG. 10 is an end elevation view of the clamp.
DETAILED DESCRIPTION OF THE INVENTION
[0019] FIG. 1 illustrates the drive coupler 10 of the present
invention as applied to the propulsion system of a support tower
for an agricultural irrigation machine. That system includes an
electric motor 12 mounted near the center of the tower and coupled
to a gear box 14. The gear box has two output shafts 16, one on
each side of the box. Each output shaft 16 is connected by a
coupler 10 to a square drive shaft 18. The drive shafts 18 extend
to the ends of the tower where they are connected by a coupler 10
to an input shaft 20 of a wheel box 22 (only one of a tower's two
wheel boxes in seen in FIG. 1). The wheel box 22 includes a worm
gear 24 driving a hub 26 to which a wheel (not shown) is
attached.
[0020] FIGS. 2 and 3 show the assembly of the coupler 10.
Generally, the coupler comprises first and second connector
elements 28 and 30 in the form of a male cross piece and a female
body member. The first connector element 28 fits on the end of the
square drive shall 18 while the second connector element 30 is
fastened to the input shaft 20. The cross piece fits within the
body member in interlocking engagement as will be explained below.
The first and second connector elements are preferably die-cast
aluminum, although other materials and fabrication methods are
possible.
[0021] Turning now to FIGS. 5 and 6, details of the first connector
element 28 will be described. Element 28 has a body 32 including
four walls 34 and a circular stop or flange 36 at one end. As seen
in FIG. 6, the stop 36 has a diameter larger than the outside
perimeter of the walls 34. The walls 34 define a central socket 38.
The socket extends through the stop 35 but is closed off at the
opposite end by an end wall 39. The socket is sized and shaped to
receive the drive shaft 18 therein. Thus, in the illustrated
embodiment the socket matches the square cross section of the drive
shaft. The body 32 is retained on the shaft by a cross pin 40 (FIG.
3) which extends through aligned holes 42 in two of the walls 34
and an aligned opening in the end of the shaft 18. Alternately the
body 32 could be fixed to the shaft by staking, swaging, set screw
or other suitable method.
[0022] Extending from the body 32 are four splines 44. Each spline
has a root 46 located at a corner of the intersecting walls 34. The
spline extends radially to a distal or free end 48, giving the
element a cross shape when viewed endwise as in FIG. 6. FIG. 5
illustrates that each spline extends axially from the stop 36 to a
taper or relief 50 at the opposite end of the body. The clearances
between the mating parts of the coupler, together with the taper
50, permit the coupler to run with a slight misalignment between
the shafts. The design shown has been found to tolerate between
three and five degrees angularity between the shafts. The splines
44 define a groove or channel 52 between them.
[0023] Details of the second connector element 30 can be seen in
FIGS. 7 and 8. This connector element includes a cylindrical
housing 54 having an open end at 56 and a closed end at wall 58.
The wall has an aperture 60 therethrough with a semi-circular
bottom edge 62 and an angled top edge 64. The housing 54 defines a
cavity into which four internal splines 66 (FIG. 3) extend. The
splines 66 have an anchor portion 68 and a wear pad or cushion 70.
The splines include a root 72 at the anchor and a free end 74 on
the pad. Details of the wear pad 70 will be described below.
[0024] The second connector element 30 further includes a sill 76
integrally formed on the wall 58 on the side opposite the housing
54. The sill terminates at a ledge 78 which has a central
depression forming a pocket 80. The pocket aligns with and conforms
to the shape of the bottom edge 62 of the aperture 60. A bore 82
extends through the ledge 78 at the base of the pocket 80.
[0025] A clamp 84 is shown in FIGS. 9 and 10. The clamp has a body
86 with flat bottom surfaces 88 engageable with the ledge 78 of
sill 76. One edge of surfaces 88 is beveled as at 90 to facilitate
installation of the clamp. A central, semi-circular groove 92
extends through the body. Just above the groove, on one side of the
body is an upwardly angled lug 94. The lug has a semi-circular
cutout on its underside. The cutout is aligned with the groove 92.
The angle of the lug matches the angled top edge 64 of the aperture
60. A bore 96 extends through the body of the clamp for receiving a
retention bolt 98 (FIG. 2). Bolt 98 also extends through a hole in
the input shaft 20 and through the bore 82 in the sill. It is held
in place by a nut 104.
[0026] The wear pads or cushions 70 are shown in FIGS. 3 and 4.
Each pad has a pair of legs 100 which define a channel 102 in the
shape of the anchor 68. Thus, the pads 70 slide lengthwise onto an
anchor 68 as best seen in FIG. 3. The pads are preferably made of
urethane having a Shore D 75 durometer. The pads leave a space
between them which is just wide enough to accept a spline 44 of the
cross piece 28 in a snug fit. Similarly, the channels 52 have a
size and shape that receives the splines 66 in interlocking
engagement.
[0027] The use, operation and function of the coupler are as
follows. A common situation encountered in assembly of drive
couplers is the need to assemble a portion of the drive train in
between two components of the drive train which are already fixed
in position. In terms of the drive system of FIG. 1, such a
situation would arise when the gear box 14 and wheel box 22 are
mounted first and the drive shaft 18 has to be inserted between
them. The drive coupler 10 permits this to be done through the
following assembly sequence. Two of the first connector elements 28
are attached to the ends of the drive shaft 18 by inserting the
shaft into the socket 38 and placing the cross pin 40 through holes
42. This locks the cross pieces 28 on the shaft 18.
[0028] Two of the second connector elements 30 are prepared by
sliding a wear pad 70 onto each of the anchors 68. The second
connector elements are then placed over the first connector
elements such that the cross piece 28 fits into the housing 54 with
the splines of one element engaging the grooves of the other as
best seen in FIG. 3. That is, splines 66 of housing 54 fit into the
grooves 52 of the cross piece 28 and the splines 44 of the cross
piece fit into the spaces between the pads 70. The stop 36 of the
cross piece 28 will engage the pads 70 to prevent them from working
off of the anchors 68.
[0029] With the first and second connector elements 28 and 30
interlocking with one another and attached to the ends of the drive
shaft 18, the assembly can be placed between the gear box 14 and
wheel box 22. Considering the coupler near the wheel box, the shaft
18 is lifted transversely to shaft 20 so that shaft 20 settles into
the pocket 80 of the sill 76. Then the shaft 20 is rotated so its
bore aligns with the bore 82 in sill 76. Next the clamp 84 is
placed over shaft 20. This is done by first tipping the clamp as
shown in phantom in FIG. 2. Tipping the clamp allows the lug 94 to
clear the top edge 64 of aperture 60. The clamp is then rotated as
indicated by the arrow in FIG. 2. As the clamp rotates it can also
slide (to the right in FIG. 2) to fully seat the lug 94 in the
aperture 60 in an interference fit. Bevel 90 provides clearance
from the ledge 78 as this movement proceeds. Once the groove 92 of
the clamp engages the shaft 20, the retention bolt 98 is placed
through bore 82, shaft 20 and bore 96. Tightening the nut 104 locks
the second connector element 30 onto shaft 20. The clamp and sill
fit tightly about shaft 20. The clearance for the bolt 98 in bores
82 and 96 is minimized so that the bolt is not subjected to
backlash that could otherwise lead to premature fatigue failure of
the bolt.
[0030] It will be understood that in cases where shaft 18 has
sufficient flexibility it may be possible to connect a coupler at
one end of the shaft 18 first and then finish the connection at the
other end. Alternately, both ends of the shaft 18 could be lifted
into place and clamped onto their respective adjoining shafts
simultaneously. The important point is the couplers 10 allow the
shaft 18 to be lifted into position even though the axial position
of shafts, 16 and 20 is essentially fixed. Some axial adjustment of
the length of the drive train is afforded by varying the depth to
which the cross piece 28 extends into the housing 54.
[0031] One of the advantages of the coupler of the present
invention is the single bolt locking method. Only bolt 98 is
required to lock the clamp 84 on the sill. This reduces the number
of parts and allows for relatively quick installation of the
coupler.
[0032] While a preferred form of the invention has been shown and
described, it will be realized that alterations and modifications
may be made thereto without departing from the scope of the
following claims.
* * * * *