Note: Descriptions are shown in the official language in which they were submitted.
CA 02904697 2015-09-16
EagleBurgmann Germany GmbH & Co. KG
BMIXX0002PCA-6/GR
Auflere Sauerlacher Str. 6-10
82515 Wolfratshausen
Drill wash device with pre-mounted exchange insert
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Description
The present invention relates to a drill wash device with a pre-mounted
exchange insert
for connecting a stationary, non-rotating washpipe to a rotating washpipe
which is
inserted into a drill hole.
For drillings in the earth's crust, particularly for raw materials, so-called
washpipe
assemblies are used, in which a drill head is arranged at the end of a
rotating pipe. A
washing or flushing liquid is guided through the pipe from above downwards
into the drill
hole, the liquid then exiting at the drill head and being returned along the
outer
circumference of the rotating pipe to the earth's surface. A problematic issue
in such drill
hole arrangements is a sealing between a stationary washpipe and the rotating
washpipe. To prevent any leaks at this sealing between stationary and rotating
washpipe particularly under environmental aspects, conservative solutions are
used as
much as possible. A sealing solution is e.g. a series connection of a
plurality of
stationary seals, for instance stuffing-box seals or lip seals. In case of
failure of one of
said stationary seals the subsequent stationary seal will then ensure the
sealing
function. Due to the great loads arising during drilling the service life of
the individual
stationary seals is however very short. It is thus necessary to replace the
stationary
seals after a short period of time. This, however, leads to a standstill of
the drilling rig
and thus to considerable costs. Since the stationary seals have to be put
individually
over the pipe parts, the exchange efforts are also very great. Furthermore, EP
1 630 347
B1 discloses a sealing between a rotating and a stationary pipe which uses a
mechanical seal. In principle, mechanical seals have the advantage of a longer
service
life as long as damage to the sliding surfaces can be avoided. To keep the
sliding
surfaces of said mechanical seal always in contact with one another, if
possible, a spring
element is provided that during operation applies a constant preload in axial
direction to
the seal rings. Due to the great loads arising during drilling the mechanical
seal must
however also be replaced after some time. To this end a nut-screw assembly is
then
provided for compressing the spring elements in axial direction so as to
terminate the
preload on the seal rings. It is only then that an exchange of the seal rings
is possible.
This exchange process is complicated and time-consuming. Furthermore, the seal
rings
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are removed or mounted again individually, so that there is the risk of damage
to the
sliding surfaces during mounting. Here, particular attention must be paid that
the sealing
between rotating and stationary washpipe is arranged in a bell of a drilling
tower at a
height of several meters and that particularly external influences, such as
weather and
temperature, cannot have a negative impact on the exchange operation because
drilling
is performed especially at more and more inhospitable places, e.g. on the high
seas and
in cold regions of the earth. That is why the exchange must be carried out
with utmost
care despite possibly very adverse external circumstances so as to avoid
damage to the
sliding surfaces. This also leads to a long and complicated exchange process.
Furthermore, US 4,557,489 discloses a sealing with seal rings which is
pressure-
compensated. For this purpose bores are either provided in the seal rings in
radial
direction, the bores ensuring pressure compensation relative to the outer
circumference
of the seal rings, or bores are provided in seal ring holders and lead to the
outer
circumference of the seal rings to provide pressure compensation. In case of
damage to
the seal, the seal rings must be replaced separately.
It is therefore the object of the present invention to provide a drill wash
device with a
rotating and a stationary washpipe which while being of a simple and
inexpensive
construction particularly permits a fast seal-ring exchange.
This object is achieved with a drill wash device comprising the features of
claim 1. The
sub-claims show preferred developments of the invention.
The drill wash device according to the invention has the advantage that a seal
ring
exchange can be performed very rapidly and easily. According to the invention
a pre-
mounted, replaceable exchange insert is provided for connecting a stationary
washpipe
to a rotating washpipe, the pre-mounted exchange insert comprising a
mechanical seal
assembly with a stationary seal ring and a rotating seal ring. A first adapter
is provided
which is arranged between the stationary washpipe and the pre-mounted exchange
insert. The first adapter is fixed to the stationary washpipe and comprises a
first
adjusting mechanism operative in axial direction. The pre-mounted exchange
insert itself
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comprises a second adjusting mechanism operative in axial direction for
changing an
axial length of the exchange insert. Hence, two separate adjusting mechanisms
are
provided according to the invention, with one of the two adjusting mechanisms
being
arranged on the stationary washpipe and the other one of the two adjusting
mechanisms
being integrated into the pre-mounted exchange insert. It is thereby possible
to first
extend the first adjusting mechanism on the first adapter after insertion of
the pre-
mounted exchange insert into a region between the stationary and the rotating
washpipe, so that the exchange insert is firmly fixed to the first adapter,
and then to
activate the second adjusting mechanism, so that the pre-mounted exchange
insert is
connected to the rotating washpipe. Hence, although two adjusting mechanisms
have to
be provided according to the invention, these can be operated rapidly and
easily one
after the other, so that a fast exchange of the pre-mounted exchange insert is
possible.
Moreover, since mechanical seals are used in the pre-mounted exchange insert,
a very
long service life of the exchange insert can be achieved in comparison with
series-
connected stuffing boxes. Moreover, the pre-mounted exchange insert can be pre-
mounted in a workshop, or the like, so that all secondary sealing elements and
possibly
existing spring elements can also be replaced. This also leads to a longer
service life of
the exchange insert.
Preferably, the first adjusting mechanism comprises a first screw connection
with an
outer ring and an inner ring between which a thread is formed. The axial
length between
the first adapter and the pre-mounted exchange insert can thereby be adapted
by
relative rotation of the outer ring with respect to the inner ring of the
first adapter.
The outer ring of the first screw connection preferably comprises first tool
recesses on
an outer circumferential surface which is configured to receive a tool for
rotating the
outer ring relative to the inner ring. The recesses are preferably bores.
Further preferably, the second adjusting mechanism comprises a second screw
connection with an external sleeve with an internal thread, and an internal
sleeve with
an external thread. Hence, a threaded connection which can be extended by
relative
rotation between external sleeve and internal sleeve in axial direction is
here also
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provided between the external sleeve and the internal sleeve. The pitches of
the first
and second screw connection are here preferably identical, but may also be
different.
Further preferably, an axial length of the internal sleeve is greater than an
axial length of
5 the external sleeve. Hence, the internal sleeve always protrudes beyond the
external
sleeve by a predetermined length.
Further preferably, on a portion which is not covered by the external sleeve
the internal
sleeve is provided on its outer circumference with second tool recesses for
receiving a
tool for rotating the internal sleeve relative to the external sleeve. The
second tool
recesses are also preferably bores. Particularly preferably, the second tool
recesses
have the same geometrical dimensions as the first tool recesses. As a
consequence, a
mechanic can adjust both the first adjusting mechanism on the first adapter
and the
second adjusting mechanism on the exchange insert with the same tool.
To enable a torque transmission from the rotating washpipe to the exchange
insert, the
exchange insert comprises a projection protruding in axial direction of the
washpipe,
preferably at an end directed towards the rotating washpipe.
Further preferably, the exchange insert further comprises an aligning ring
which aligns
the protruding projection on the exchange insert for torque transmission from
the
rotating washpipe in circumferential direction. A reliable mounting and form-
fit
connection between the projection of the exchange insert and the rotating
washpipe can
thereby be achieved.
According to a further preferred configuration of the present invention the
drill wash
device further comprises a second adapter between the rotating washpipe and
the
exchange insert. Especially the mounting on the rotating washpipe can thereby
be
simplified significantly.
To even further simplify a mounting operation, a mounting aid is preferably
provided
which is arranged on the stationary washpipe. The mounting aid supports
assembly and
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disassembly of the pre-mounted exchange insert in the area between the
stationary and
the rotating washpipe.
The mounting aid preferably comprises a first and a second guide arm which are
arranged on the first adapter. The two guide arms are provided preferably in
parallel with
each other and further preferably comprise supporting surfaces for supporting
the pre-
mounted exchange insert. Further preferably, the pre-mounted exchange insert
comprises a circumferential groove for a form-fit engagement with the guide
arms.
Further preferably, the second adjusting mechanism of the exchange insert
comprises
an anti-rotation device. The anti-rotation device is preferably a threaded
bolt, or the like.
The anti-rotation device thereby ensures that a relative position between the
external
sleeve and the internal sleeve is reliably held during operation. In other
words, after
adjustment of the axial length of the exchange insert, which is carried out by
rotation
between external sleeve and internal sleeve, the position is secured by the
anti-rotation
device. Prior to disassembly the anti-rotation device must of course be
released, so that
a rotation between external sleeve and internal sleeve is possible again to
permit a
shortening of the axial length of the exchange insert.
The anti-rotation device is particularly preferably a threaded bolt with a
spring-biased
locking element, particularly a spring-biased ball, which is arranged on the
tip of the
threaded bolt. At a start position in which the exchange insert is not axially
extended yet,
the locking element engages into a first recess on the external sleeve. This
defines a
basic position of the pre-mounted exchange insert. During preassembly a
mechanic can
thus easily discern when the pre-mounted position has been reached.
Furthermore, a
second recess is provided on the external sleeve, in which the locking element
locks in
place when the exchange insert has reached the axially extended end state,
i.e. the end
assembly state, during assembly. Hence, there is also an indicator indicating
a correct
position for the achievement of the end position of the exchange insert in the
mounted
state. These measures considerably facilitate the assembly which, as has been
mentioned, must be carried out partly under extremely difficult conditions
because of
external influences. Due to the spring-biased locking element, the locking in
place during
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assembly and the locking out of place during disassembly take place
automatically
owing to the rotating operation between external sleeve and internal sleeve of
the screw
connection.
The anti-rotation device is preferably arranged on an arm connected to the
internal
sleeve, the external sleeve being arranged between the arm and the internal
sleeve.
Further preferably, the rotating and the stationary seal ring are each
provided with a
bandage. The seal rings can thereby withstand high pressure loads.
To avoid damage to the pre-mounted exchange insert during assembly or during
transportation of the exchange insert, the exchange insert preferably
comprises a
transportation lock. The transportation lock comprises at least one spring
element to
exert a bias or preload on the mechanical seal assembly prior to a final
assembly of the
exchange insert. The preload is here exerted on the seal rings such that the
sliding
surfaces of the seal rings reliably abut on one another so as to avoid damage
to the
sliding surfaces. The transportation lock is here arranged between a
connection
component to the stationary washpipe and a first seal ring carrier for holding
the
stationary seal ring. The transportation lock is further configured such that
in the end-
mounted state of the exchange insert no preload is exerted on the mechanical
seal
during operation. This is e.g. achieved by providing spring elements which no
longer
exert a preload in the mounted state of the exchange insert, in which an axial
length of
the exchange insert has been increased by the second adjusting mechanism. The
spring elements can e.g. have a correspondingly short length so that in the
end-
mounted, axially extended state of the exchange insert no preload is exerted
on the seal
rings. Thanks to the dead weight of the seal ring and the weight of the first
seal ring
carrier the stationary seal ring nevertheless reliably lies on the rotating
seal ring.
To avoid a situation where the pressure on the seal rings during operation
gets
excessively strong, the rotating and the stationary seal ring are preferably
provided with
a respective bevel on the inner circumference. The bevel extends preferably
from an
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inner circumference of the seal rings up to half a seal ring width.
Particularly preferably,
the bevels are equally provided on both seal rings.
A preferred embodiment of the invention shall be described hereinafter in
detail with
reference to the accompanying drawing, in which:
Fig. 1 is a schematic illustration of a drill wash device according
to the invention
with a pre-mounted exchange insert,
Fig. 2 is a schematic, perspective illustration of an exchange operation of
the
exchange insert,
Fig. 3 is a schematic partial sectional view of the exchange insert
during a first
mounting step in which the exchange insert is slid into the drill wash
device;
Fig. 4 is a schematic partial sectional view of the exchange insert
in which the
exchange insert is connected to a stationary washpipe,
Fig. 5 is a schematic partial sectional view of the exchange insert while
being
connected to a rotating washpipe,
Fig. 6 is a schematic perspective view of an adjusting ring for
aligning the
exchange insert with respect to the rotating washpipe,
Fig. 7 is a schematic partial sectional view of the exchange insert
in the mounted
state, and
Fig. 8 is a schematic sectional view of the exchange insert in the
mounted state,
the stationary and the rotating washpipe being not shown for the sake of
clarity.
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A drill wash device 100 according to a preferred embodiment of the invention
will now be
described in detail with reference to Figs. 1 to 8.
As can be seen in Fig. 1, a pre-mounted exchange insert 1 is used in the drill
wash
device 100. The drill wash device 100 comprises a drilling tower 101 and is
configured
to introduce a flushing or washing medium from above into a drill hole 106
(arrow A).
The drill wash device 100 comprises a stationary washpipe 102 and a rotating
washpipe
103 having a free end on which a drill head 104 is arranged. A washing medium
is
introduced by means of a pump 105 via the stationary washpipe 102 into the
rotating
washpipe 103 and exits on the drill head 104. The washing medium then flows on
the
outer circumference of the rotating washpipe 103 back to the surface into a
separating
device 107. In the separating device 107, rocks, or the like, that have been
washed out
of the drill hole 106 are separated from the washing medium which can then be
recirculated.
According to the invention a drill wash device 100 with pre-mounted exchange
insert 1 is
provided, which can be exchanged completely. This is schematically indicated
in Fig. 2
by the double-headed arrow B. The pre-mounted exchange insert is here mounted
in a
space 112 between the stationary washpipe 102 and the rotating washpipe 103. A
first
adapter 108 is provided at the free end of the stationary washpipe 102, and a
second
adapter 109 is provided at the opposite free end of the rotating washpipe 103.
Furthermore, the first adapter 108 has formed thereon first and second guide
arms 110,
111 which allow an easy insertion of the pre-mounted exchange insert 1. To
this end two
guide elements 10, 11 are provided on the exchange insert 1 on a connection
component 5. The guide elements 10, 11 are here lying with their bottom side
on the
rail-like guide arms 110, 111, so that the weight of the exchange insert 1
after the latter
has been slid onto the guide arms 110, 111 is carried by said arms, and the
mounting
operation is facilitated. The connection component 5 further comprises a
circumferential
groove 50 for engagement with the guide arms 110, 111.
As is particularly apparent from Figs. 3 and 8, the pre-mounted exchange
insert 1
according to the invention comprises a mechanical seal assembly 2 with a
stationary
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seal ring 20 and a rotating seal ring 26. A sealing gap 26 is formed between
the two seal
rings. The stationary seal ring 20 is enclosed by a first bandage 22 and the
rotating seal
ring 21 is enclosed by a second bandage 23.
5 Furthermore, a first bevel 24 is provided on the stationary seal ring 20
on the inner
circumferential side thereof, and a second bevel 25 is provided on the
rotating seal ring
21 in mirror-inverted fashion with respect to the sealing gap. The two bevels
24, 25
extend in radial direction of the exchange insert.
10 The first adapter 108 of the drill wash device 100 comprises a first
adjusting mechanism
116 which is operative in axial direction. The first adjusting mechanism 116
comprises a
first screw connection 117 with an outer ring 118 and an inner ring 128
between which a
thread 129 is provided. Hence, an axial length of the first adapter 108 can be
increased
or decreased by way of a relative rotation between the outer ring 118 and the
inner ring
119.
The exchange insert 1 further comprises a first seal ring carrier 3 which
holds the
stationary seal ring 20, and a second seal ring carrier 4 which holds the
rotating seal
ring 21. The first seal ring carrier 3 is configured in two parts, consisting
of a first carrier
part 31 and a second carrier part 32. Furthermore, a shoulder 33 is provided
on the
inner circumference of the first seal ring carrier 3.
The second seal ring carrier 4 is also configured in two parts comprising a
first carrier
part 41 and a second carrier part, which is an adjusting ring 42, and further
comprises a
plurality of projections 43 extending in axial direction X-X of the exchange
insert 1. The
projections 43 serve to transmit a torque from the driven rotating washpipe
103 via the
second adapter 109 and the second seal ring carrier 4 to the rotating seal
ring 21.
Furthermore, the pre-mounted exchange insert 1 comprises a second adjusting
mechanism 6 with a second screw connection 60. The second adjusting mechanism
6
comprises an external sleeve 61 with an internal thread 63 and an internal
sleeve 62
with an external thread 64. The internal thread 63 and the external thread 64
engage
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one another and upon a relative rotation between the external sleeve 61 and
the internal
sleeve 62 the pre-mounted exchange insert is elongated in axial direction X-X
of the
second adjusting mechanism 6. Fig. 2 shows a start length L1 of the pre-
mounted
exchange insert 1 in axial direction. Fig. 8 shows the fully extended axial
length L2
which is longer by a length L3 than the start length L1.
The internal sleeve 62 covers the mechanical seal 2 in radial direction and it
provides a
guide surface 66 for the rotating seal ring 21 on a radial outside of the
bandage 23.
Furthermore, the internal sleeve 62 also holds the second seal ring carrier 4
via the
adjusting ring 42 of the second seal ring carrier 4.
Furthermore, the exchange insert 1 according to the invention comprises a
plurality of
spring elements 7 which are arranged between the connection component 5 for a
connection to the stationary washpipe 102 and the first seal ring carrier 3.
Each spring
element 7 is arranged around a pin 70 for guiding and positioning the spring
elements.
The spring elements 7 are arranged in pockets 51 in the connection component
5.
The spring elements 7 ensure that in the state in which the exchange insert is
not end-
mounted (Figs. 2, 3 and 4) a force F is exerted via the first seal ring
carrier 3 on the
stationary seal ring 20, so that the stationary seal ring 20 reliably abuts on
the rotating
seal ring 21 and the sliding surfaces touch each other (cf. Fig. 4). In the
end-mounted
state which is shown in Figs. 7 and 8, the spring elements 7 do however not
exert any
spring force on the mechanical seal 2. This is e.g. achieved by way of a
corresponding
design of a length of the springs 7, so that in the end-mounted state of the
exchange
insert 1 in the drill wash device 100 a spring distance 71 exists between an
end of the
spring elements 7 and the connection component 5, as shown in Fig. 8.
Hence, the spring elements 7 form a transportation lock which prior to a final
end
mounting of the exchange insert 1 exerts a constant preload in axial direction
X-X on the
mechanical seal.
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Furthermore, a sealing element 8 is arranged between the connection component
5 and
the first seal ring carrier 3. Furthermore, the exchange insert 1 comprises a
first, second,
third and fourth secondary sealing element 12, 13, 14, 15. The first secondary
sealing
element 12 seals between the connection component 5 and the stationary
washpipe
102, the second secondary sealing element 13 seals between the first seal ring
carrier 3
and the stationary seal ring 20, the third secondary sealing element 14 seals
between
the rotating seal ring 20 and the second seal ring carrier 4, and the fourth
secondary
sealing element 15 seals between the second seal ring carrier 4 and the second
adapter
109 relative to the rotating washpipe 103.
The adjusting ring 42 of the second seal ring carrier which is rotatable from
outside of
the pre-mounted exchange insert 1 by means of a tool on openings 9 permits an
alignment of the second seal ring carrier 4 in circumferential direction. This
is necessary
for allowing a torque transmission via the projections 53, which are
protruding in axial
direction X-X, from the second adapter 109 via the second seal ring carrier 4
to the
rotating seal ring 21. This process can be seen in Figs. 5 and 6.
The first and second tool recesses 119 and 65 as well as the openings 9 on the
adjusting ring preferably have an identical geometric shape, e.g. a bore, so
that they are
adjustable by means of the same tool.
The second adapter 109 comprises recesses 44 formed to conform to the
projections
43, so that a form-fit connection is possible between the second adapter 109
and the
adjusting ring 42.
Furthermore, an anti-rotation device 16 is provided for fixing a relative
position of the
second adjusting mechanism 6 between the external sleeve 61 and the internal
sleeve
62. The anti-rotation device 16 of this embodiment is a threaded bolt which
fixes a
relative position between the external sleeve 61 and the internal sleeve 62.
The
threaded bolt comprises a spring-biased ball which in the not yet end-mounted
position
locks into a first recess 67 on the outer circumference of the external sleeve
61 (Fig. 3).
The anti-rotation device is here arranged on an arm 69 which is connected to
the
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internal sleeve, so that the external sleeve 61 is arranged between the arm 69
and the
internal sleeve (cf. Fig. 3 and 4). In the fully end-mounted position (Fig.
7), the ball is
locked into a second recess 68 on the external sleeve 61, which serves as an
indicator
which indicates that the end position of the axially elongated exchange insert
is reached.
The two recesses 67, 68 are arranged by about a quarter turn between internal
sleeve
and external sleeve on the circumference of the external sleeve 61. By locking
the ball
into the recesses 67, 68, a mechanic has - during the respective pre-mounting
of the
exchange insert - an indicator indicating the correct position of the
components internal
sleeve and external sleeve relative to each other and also in the end-mounted
position
by locking into the second recess 68. This permits a reliable mounting also
under the
most severe environmental conditions.
Since the exchange insert is pre-mounted according to the invention, the
exchange
insert can be fully pre-mounted without any problems in a workshop. All
secondary
sealing elements 12, 13, 14, 15 can here also be exchanged in a simple way.
The
transportation lock by means of the spring elements 7 ensures that during
transportation
and installation shortly before an end installation position is reached a
preload is always
exerted on the seal rings 20, 21, so that the sliding surfaces of the seal
rings closely
abut on one another, and damage to the sliding surfaces can be avoided.
According to
the invention a complete exchange of the exchange insert with mechanical seal
assembly can thereby be provided in a simple and fast way. Hence, during each
exchange of the exchange insert new secondary sealing elements can be used,
resulting in reduced maintenance and a respectively longer useful life of the
exchange
insert. In the case of a new exchange insert each of the spring elements 7 can
also be
replaced, if necessary. Since the spring elements 7 are arranged in the
pockets 51, they
are very well protected from the pumped medium, so that an exchange of the
spring
elements 7 is often not required.
The exchange operation will now be described in detail. After the exchange
insert to be
exchanged has been removed from the drill wash device 100, a new pre-mounted
exchange insert 1 is inserted into the drill wash device 100, as outlined in
Fig. 2. The
new pre-mounted exchange insert 1 is pushed on the circumferential groove 50
and the
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guide elements 10, 11 onto the two guide arms 110, 111, so that after a short
push path
the complete weight of the exchange insert 1 is carried by the guide arms 110,
111. This
considerably facilitates an assembly of the exchange insert which is normally
carried out
at a certain height in the drilling tower 101 and must also be executed under
very
extreme weather conditions. Now, a mechanic must just push the pre-mounted
exchange insert 1 along the guide arms 110, 111 into the assembly position.
This
inserted position is illustrated in Fig. 3. A first distance 80 is arranged
between a face of
the connection component 5 and a face of the first adapter 108, which is
arranged on
the stationary washpipe 102 (cf. Fig. 3).
In a next step, this first distance 80 is eliminated in that a length of the
first adapter 108
is changed in axial direction X-X of the exchange insert by means of the first
adjusting
mechanism 116 (Fig. 3). Here, the first adapter 108 comprises an outer ring
118 and an
inner ring 128 between which a thread 129 exists, so that the inner ring 128
gets into
contact with the connection component 5 by rotating at least one of the rings.
This
position is shown in Fig. 4. In this embodiment, the outer ring 118 comprises
first tool
recesses 119 in the form of cylindrical bores to permit a relative rotation
between the
outer ring 118 and the inner ring 128. A connection is thereby established
between the
pre-mounted exchange insert 1 and the stationary washpipe 102 via the first
adapter
108. Since the connection is static, the first secondary sealing element 12 is
adequate
for sealing. The axial length L1 of the pre-mounted exchange insert has not
been
changed yet.
In a next step a connection is now established between the pre-mounted
exchange
insert 1 and the rotating washpipe 103. To this end the second adjusting
mechanism 6 is
operated in that the internal sleeve 62 is rotated relative to the external
sleeve 61. The
internal sleeve 62 also comprises a portion which is exposed to the outside
and in which
plural second tool recesses 65 are provided for the attachment of a tool. The
internal
sleeve 62 is here rotated relative to the external sleeve 61 until the
position shown in
Fig. 5 is reached. In this position a final connection has not been
established yet
between the pre-mounted exchange insert 1 and the second adapter 109 on the
rotating
washpipe 103, but an alignment of the torque transmitting mechanism must still
be
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carried out between the second adapter 109 and the second seal ring carrier 4.
To this
end the adjusting ring 42 is rotated in circumferential direction, which is
also made
possible by way of a tool which can be attached from the outside to the
adjusting ring
42. The alignment is of such a type that the projections 43 of the second seal
ring carrier
5 4 are arranged over the corresponding recesses 44 of the second adapter 109,
as
shown in Fig. 6.
After the alignment has been made, the internal sleeve 62 of the adjusting
mechanism 6
is further rotated relative to the external sleeve 61, so that a further
elongation of the
10 exchange insert 1 is carried out in axial direction X-X until the
connecting end position,
which is shown in Figs. 7 and 8, is reached (axial length L2).
Fig. 8 also shows the pre-mounted exchange insert in the connecting end
position
without showing the first and second adapter 108, 109 of the stationary and
rotating
15 washpipe for reasons of clarity.
Owing to the axial elongation of the exchange insert 1 the spring elements 7
can relax
completely, so that the spring distance 71 plotted in Fig. 8 exists between
the free end of
the spring element 7 and the connection component 5. During operation the
pressure on
the seal rings is then built up via the shoulder 33. The spring elements may
also be
designed such that there is no spring distance from the connection component
5, but
that a spring force is no longer exerted between connection component 5 and
first seal
ring carrier 4.
The spring elements 7 are here arranged in correspondingly formed pockets 51
in the
connection component 5.
As a last step, the anti-rotation device 16 is then activated for fixing a
relative position
between the external sleeve 61 and the internal sleeve 62 of the adjusting
mechanism 6.
Here, the ball of the anti-rotation device locks in place in the second recess
68. Hence,
the mechanic possesses an indicator which indicates that the exchange insert
has been
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extended to the correct axial length L2. Subsequently, the drill wash device
100 is again
ready for use.
During operation a pressure is then exerted via the shoulder 33 at the first
seal ring
carrier 3 on the seal rings, so that a reliable sealing is possible at the
sealing gap 26. In
the end-mounted position, the exchange insert 1 thereby has an axial length
which is
extended by length L3, starting from the axial length L1 (Fig. 2) to the axial
length L2
(Fig. 8).
Owing to the inventive idea of providing a drill wash device 100 with a first
and second
adjusting mechanism 116, 6, which respectively permit an elongation in axial
direction, it
is possible to provide a fast and reliable exchange of a mechanical seal. The
mechanical
seal is here integrated into a pre-mounted replaceable exchange insert 1. Upon
exchange of the mechanical seals the complete exchange insert 1 is replaced.
This can
prevent the risk of damage to the seal rings 20, 21 in case of replacement.
When the
first and second adjusting mechanisms comprise a respective screw connection,
a
particularly fast and simple exchange is made possible by way of a relative
rotation
between the two components forming the screw connection. The relative rotation
is here
carried out by means of the same tool. A handling with individual seal rings
at the drilling
tower is not required. The pitches of the two screw connections of the
adjusting
mechanisms are here particularly preferably provided in the same way.
Furthermore, it
should be noted that the tool receiving means on the adjusting ring 42 is also
configured
in the same way as on the first and second adjusting mechanism. Thus, only one
single
tool is needed for the complete assembly of the replaceable exchange insert 1.
The
exchange can here be carried out by only one mechanic.
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List of reference numerals
1 exchange insert
2 mechanical seal assembly
3 first seal ring carrier
4 second seal ring carrier
5 connection component
6 second adjusting mechanism
7 spring element
8 sealing element
9 opening
10, 11 guide elements
12-15 secondary sealing elements
16 anti-rotation device
17 preloaded locking element
stationary seal ring
21 rotating seal ring
22 first bandage
20 23 second bandage
24 first bevel
second bevel
26 sealing gap
31 first carrier part
2 5 32 second carrier part
33 shoulder
41 first carrier part
42 adjusting ring
43 projection
44 recess
50 circumferential groove
51 pocket
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60 second screw connection
61 external sleeve
62 internal sleeve
63 internal thread
64 external thread
65 second tool recess
66 guide surface
67 first recess
68 second recess
69 arm
70 pin for positioning
71 spring distance
80 first distance
100 drill wash device
101 drilling tower
102 stationary washpipe
103 rotating washpipe
104 drill head
105 pump
106 drill hole
107 separating device
108 first adapter
109 second adapter
110 first guide arm
111 second guide arm
112 space
116 first adjusting mechanism
117 first screw connection
118 outer ring
119 first tool recess
128 inner ring
129 thread
