Note: Descriptions are shown in the official language in which they were submitted.
BACKGROUND OF THE INVENTION
The present invention relates to a new and im-
proved construction of a double joint clutch having two
clutch hubs, a clutch socket or sleeve interconnecting the
clutch hubs and transmitting or txansmission elements for
transmitting a torque which are uniformly distributed
over the circumference of the clutch hubs.
For the transmission of large power ~utputs
between rapidly running shafts, it is often necessary to
interconnect two shaft ends so as to be elastically bend-
able by means of a clutch having a compact construction
and, at the same time, to ensure that an axial thrust,
such as for instance can arise during switching~in or
switching~off a drive machine, does not lead to destruc-
tion of the clutch.
In German Patent No. 1,963,755 there are known
to the art double joint or universal joint clutches of
the above-described species, which are constructed as
rotationally rigid double jaw clutches having an internal-
ly toothed clutch socket and two externally toothed `
clutch hubs. According to one constructional embodiment ~-
of such type of prior art clutch there are arranged, in-
stead of individual teeth between the clutch hubs and the
clutch socket, elastically structured engagement elements
in radial direction, which are under a pre-bias or stress
and center the clutch socket or sleeve in relation to the
clutch hubs. According to another embodimen-t the center-
ing action of the clutch socket in relation to the clutch
hubs is realized in that, teet~h individually formed at
the clutch hubs have, in relation to the related teeth of
the clutch socket, an overdimension and the clutch socket
is elastically expandible. In both cases the clutch
socket can be centered due to its radial pre-bias in
relation to the clutch hubs. However, disturbance free
operation can only be maintained if such clutches are not
loaded with any appreciable axial forces. Greater axial
forces and the moments brought about when axially offset-
ting both of the shafts which are to be coupled with one
another, therefore lead rapidly to destruction of the
heretofore known species of clutches. Hence, it is
absolutely mandatory that such state-of-the-art clutch
be load relieved from any appreciable axial force by axial
pressure bearings arranged to both sides of such clutch.
Each bearing arran~ement however means that when
transmitting larger loads at higher rotational speeds,
there arises a loss in efficiency, and it is for this
reason that the number of bearings must be maintained as
low as possible.
SUMMARY OF THE INVENTION
Therefore, with the foregoing in mind it is a
primary object of the present invention to p~vide a new
and improved construction of a double joint clutch of the
character described which is not associated with the afore-
mentioned drawbacks and limitations of the prior art con-
structions.
Another and more specif:ic object of -the present
invention aims at providing a new and improved construction
of clutch of the previously described type which, during
the transmission of large torque or rotational moments be-
tween rapidly running shafts, allows for relatively large
parallel displacement and other axial shifting of such
shafts in relation to one another and is extensively insen-
sitive to axial forces.
Now in order to implement these and still further
objects of the invention, which will become more readily
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5~
apparent as the description proceeds, -the clutch of the
present development is manifested by the features that
both clutch hubs are additionally interconnected with one
another by means of a bending rod arranged within the
clutch socket or sleeve.
On the one hand, the bending rod is rotatably
yielding such that the total torque or rotational moment
can be transmitted, by means of the transmission or trans-
mitting elements and the clutch socket, from one clutch
hub to the other clutch hub. On the other hand, the
bending rod is sufficiently buckling resistant or stiff
in order to take-up axial thrusts. Such axial thrusts can
be periodically and/or surgewise generated, for instance
by means of a drive machine or a driven machine.
The inventive double joint clutch is especially
contemplated to transmit power outputs exceeding 10,000 kW.
In machine assemblies havinga p~wer output of this order
of magnitude it is possible that one machine produces an
axial thrust of, for instance, 10,000 kp in one direction
and another machine an axial thrust of 15,000 kp in the
opposite direction. The in~entive clutch is capable of
absorbing such axial thrusts, so that only a single axial
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~L~25~
pressure bearing is needed, which can take-up the resultant
axial thrust of, in the example given, for instance 5,000
kp. Hence, the total efficiency of the machine assembly
can be appreciably increased in comparison to heretofore
known clutch and bearing arrangements, while retaining
the other conditions the same.
Depending upon the desired axial rigidity the
bending rod can be connected to be buckling resistant and/
or also rotationally fixed with the clutch hubs.
Depending upon the desired torsional rigidity the
engagement elements which transmit the torque or rotational
moment can be structured as membrane bending rods, lamellae,
sleeves, teeth or the like.
With a direct attachment of the bending rod at
both Glutch hubs there is realized the possibility of
assembling and disassembling the entire inventive double
joint clutch, without having to take the same apart, be-
tween both of the shaft ends which are to becoupled with
one another.
,
BRIEF DESCR_PTION OF THE DRAWI:NGS
The invention will be better understood and ob-
jects other than those set forth above will become apparent
when consideration is given to the following detailed des-
cription thereof. Such description makes reference to the
annexed drawings wherein:
Figure 1 is an axial sectional view of a first
embodiment of double joint clutch showing the same in its
normal position:
Figure la is an enlarged partial sectional view
of the clutch arrangement of Figu:re 1, the section being
taken along the line A-A thereof;
Figure 2 is an axial sectional view of the clutch
shown in Figure 1 illustrating the same in strongly exag-
gerated deflected position,
Figure 3 is an axial sectional view of a second
embodiment of double joint clutch in its normal position;
and
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Figure 4 is an axial sectional view of the clutch
shown inFigure 3, with markedly exaggerated deElection of
the clutch.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Describing now the drawings, both of the exem-
plary embodiments of double joint or universal joint clutch-
es shown in Figures 1, la and 2 on the one hand and in
Figures 3 and 4 on the other hand, will be initially col-
lectively described hereinafter to the extent that the
structure of both embodiments coincides with one another.
In both instances the double joint clutch serves to inter-
connect two shaft ends 10 and 12 with one another, the
axes of which normally are in alignment with one another,
but equally also oould be inclined with respect to one
another, or, as shown in Figures 2 and 4 in extremely
exaggerated illustration, could be offset parallelly with
respect to one another. Both shaft ends 10 and 12 each ;
have a respective flange 14 for the double joint clutch. ;
The shaft end 12 arran~ed to the right of the double
joint clutch, as shown in Figure 1, is mounted in a bear-
ing 16.
Each of the illustrated double joint elutches has
as its primary components two elutch hubs 18, a clutch
socket or sleeve 20 and a bending rod 22.
Formed at each clutch hub 18 is a radial outer
flange 24 whieh is threadably eonneeted, for instanee
bolted bymeans of the threaded bolts with the flange 14 at
the neighboring shaft end 10 and 12, respeetively.
Additionally, at each eluteh hub 18 there is formed a radial
inner flange 26 which is threadably eonneeted, again for
instanee by means of the threaded bolts, with a flange 28
at the neighboring end of the bending rod 220 This bending
rod 22 is eentered in the flanges 26 of both eluteh hubs 18
and furthermore extends, with radial intermediate play or
spaee, through the clutch hubs 18 and the elutch socket 20.
Each of both eluteh hubs 18 has teeth or teeth
means 30, which aecording to the embodiment of Figures 1,
la and 2, are strue-tured as external teeth, whereas in the
embodiment of Figures 3 and 4 they are eonstructed as inter~ ;
nal teeth~ The teeth 30 of the clutch hubs 18 have opera-
tively associated therewi~h the respeetive teeth 32 provided
at the eluteh soeket 20, which according to the embodiment
of Figures 1, la and 2 are eonstrueted as internal teeth~
while in the embodiment of Figures 3 and 4 on the other
hand they are constructed as external teeth. -
Now since however the torque or rotational moment
which is to be transmitted by the double joint clutch is
exclusively taken-up by the clutch hubs, the clutch sockets
interconnecting the same and the transmission elements ;
arranged between both of these components, these teeth 30
and 32, with both of the exemplary embodiments, fulfill
quite different functions.
With the first-mentioned embodiment of Figures l,
la and 2, the teeth 30 and 32, and as particularly well
seen by referring to Figure la, have an appreciable play ;
in radial direction with respect to one another and also a `
certain play in the circumferential direction. This means
that in normal operation they do not participate in the
transmission of the torque, quite in contrast to the
second exemplary embodiment of Figures 3 and 4. Both of
the clutch hubs 18, in the first exemplary embodiment, as
best seen by referring to Figures 1 and 2, have membrane-
like arranged bending rods 34, whose radial outer ends are
clamped between one of the end pieces or members 36 of -the ~
clutch socket 20 operativeIy associated with the related ~;
clutch hub 18 and a protective ring 38 which is -threadably
connected therewith. The membrane-like hending rods 34
are extremely elastic~ so that any axial shifting of both
shaft ends lO and 12 can be taken-up by such bending rods
34.
With the embodiment of Figures 3 and 4 such axial
shifting is taken-up by the crown configuration of the
teeth 32.
In the critical case, that is to say upon exceed-
ing the permissible torque, with the embodiment of Figures
l and 2 the membrane-like bending rods 34 rupture. Hence,
the teeth 30 and 32 of Figure la come into play, which in
that case enables shutdown of the machine assembly. With
the same critical situation for the embodiment of Figures
3 and 4, only one or a number of teeth of the teeth 30 and
32 will become defective.
The bending r¢d 22 is so slim and correspondingly
soft or yieldable that it does not participate in the torque
transmission. However, it is sufficiently bending or
buckling resistant that it is capable of transmitting all
of the arising axial forces directly from one clutch hub 18
to the other clutch hub 18, and specifically, also even
then when both shaft ends 10 and 12, as shown in Figures 2
and 4, are offset parallelly with respect to one another.
In the event that the bending rod 22 should rupture, then
with the exemplary embodiment of Figures 1, la and 2,
there is formed at the inner surface of each end piece 36
of the clutch socket or sleeve 20 a substantially ring-
shaped or annular stop or impact member 40 which engages
into an intermediate space between the teeth 30 of the re-
lated clutch hub 18 and a likewise ring-shaped counterstop
42 attached at such clutch hub 18.
In the event of fracture of the bending rod 22
these stops 40 and counterstops 42, together with the ring-
shaped constructed ends of the related teeth 30, limit the
axial relative shifting of both shaft ends 10 and 12, so
that the double joint clutch can still run, without
suffering any additional damage, until the machine assembly,
of which the shaft ends 10 and 12 are a part, can be
turned-off and shut down. With the embodiment of Figures
3 and 4, in the event of rupture of the bending rod 22 the
teeth 30 and 32 assume the function of the stops 40, and
the counterstops 42 on the one hand, or the clutch hubs r on
the other hand, prevent the axial relative displacement or
shifting of both shaft ends 10 and 12.
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The substantially ring-shaped constructed stops
(Figures 1 and 2), and the corresponding counterstops 42
and the end of the teeth 32 protruding against the stops 40
are provided with a convex end surface. For reasons of
simplicity in illustration such end surface has not been
particularly shown in the drawings.
For the exact functionally equivalent purpose
there-lsprovided with the second exemplary embodiment of
Figures 3 and 4 a conve~ end surface at the end of the
teeth 32 directed towards the counterstops or impact ~
members 42. ~;
With the embodiment of Figures~`l,la and 2 both
of the end pieces or members 36 oE the clutch socket 20
are interconnected by a tubular-shaped intermediate piece
or element 44. In this case the clutch socket 20 is con-
structed as a three-part unit or, if there are considered
the protective rings 38, then as a five-part unit.
On the other hand, with the embodiment of
Figures 3 and 4, the clutch socket or sleeve 20 is con-
structed as a one-part unit, however is provided at both
of its ends with a respective lubricant chamber or space 46
~2~
which is formed within its teeth 3Z. From such chamber
46 it is possible to directly impinge with a suitable
lubricant the teeth by means of a type of spray nozzle
which consists of small bores at the tooth root or base
of the teeth. The teeth 3~ are crowned and engage with
radial pre-bias or stress into the teeth 30 of the clutch
hubs 18, so that in this case there is ensured for center-
ing of both ends of the cltuch socket 20 in relation to
the clutch hubs 18.
