Note: Descriptions are shown in the official language in which they were submitted.
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RINSING DEVICE IN A DRILL DEVICE FOR ROCK DRILLING
TECHNICAL FIELD
The present invention concerns a rinsing device for a drill for rock drilling,
as well as a
drilling device comprising a rinsing device. In particular, the invention
concerns lubrication
of sealing elements in the rinsing device.
BACKGROUND OF THE INVENTION
A typical example of a rock drill comprises a number of drilling rods which
are joined
together and form a drill string. One end of the drill string culminates in a
drill head which
drills into the stone as it cuts and rotates. The other end of the drill rod
is coupled to a
drive apparatus via a neck adaptor. In use, the drill string cuts and rotates
by means of
the drive apparatus.
In order that drilling can be carried out effectively when drilling stone, it
is necessary that
the bottom of the drill hole is kept clean and that drill cuttings are carried
away from the
drill hole. This is done by a rinsing medium, e.g. water or air, being flushed
from a rinse
adaptor via a rinse head in through, through a central hole in the neck
adaptor, and further
through a central hole in the drill string and out through the drill head to
the bottom of the
drill hole. Drill cuttings mixed with the rinsing medium are then forced out
of the drill hole
between the drilling rod and the walls of the drill hole.
To prevent the rinsing medium from entering the drill, the neck adaptor is
sealed against
the rinse head by means of rinse seals. The neck adaptor has a rotating to-and-
fro
movement, while the rinse head is stationary relative to the drill.
These rinse seals are often doubled both forward and backward and have one or
more
so-called "spyhole" so that the operator is given the chance to notice a leak
and replace
the primary seal before the secondary seal also fails. In this way, the
rinsing medium is
prevented from entering the drill, which prevents damage to the drill.
The current lifetime of rinse seals can be seen as a problem. Damaged rinse
seals are a
common reason why drills need to be serviced.
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Mine environments with damp air, and occasionally saline rinse water are a
particular
problem. The surface of the neck adaptor quickly becomes corroded and the
surface
upon which the rinse seals must glide becomes highly wearing.
Additional problems are that the rinse seals become warm through contact
friction,
especially in high-frequency machines. The primary seals are effectively
cooled by the
rinse water, but the secondary seals are not always cooled, as the separate
lubricating
gas in the drill does not always reach the secondary seals.
The front bearing of the neck adaptor is stationary relative to the drill.
Currently, to
lubricate this contact surface, an air-oil mixture is used, which has been the
tradition since
pneumatic drills. In such drills, oil was added to the pressurized gas which
drove the
striking apparatus and rinsed away drill cuttings. When production and use of
hydraulic
drills began, it was desirable to maintain lubrication, which is why a
separate lubricating
gas flow was introduced.
Lubricating gas in hydraulic drills comprises an entire system which branches
to many
places in the drill. This is partly due to the requirement for lubrication in
many places, but
also ¨ by means of overpressure ¨ to prevent drill cuttings from entering the
drill.
As the lubricating gas system branches off to the entire machine, water and
dirt, as well
as drill cuttings and particles ground from drilling parts and the like, are
effectively spread
to the entire machine, should the lubricating gas system be polluted.
The risk of such pollution, especially water penetration, is large at the
front of the drill.
Here, water can penetrate both from the outside by, e.g. a worn nose bush, or
from the
inside, by rinse water passing through a worn rinse seal.
SUMMARY OF THE INVENTION
One aim of some embodiments of the present invention is therefore to provide a
rinsing
device for a drilling device which improves the lifetime of the rinse seals in
the rinsing device.
In accordance with some embodiments of the present invention, this
aim is achieved by a rinsing device for a
drilling device for rock drilling. The rinsing device comprises a cylindrical
neck adaptor
which comprises a mantle surface, two end surfaces, a central axial passage
which opens
at one end surface, and a radial connection between the central axial passage
and an
opening in the mantle surface. The rinsing device also comprises a rinse head
with a
axially-extending hole. The neck adaptor is slidably arranged in said hole.
The said rinse
head surrounds a part of the mantle surface of the neck adaptor and provides a
first
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space which extends around the mantle surface of the neck adaptor in the
region of
the opening in the mantle surface of the neck adaptor. The first space is
connected to
the outside of the rinse head via a feed channel. The rinsing device comprises
at
least one primary sealing element arranged in the axial direction on each side
of the
first space in the rinse head to provide a seal between the neck adaptor and
the first
space. The rinsing device also comprises at least one second space which
extends
about the mantle surface of the neck adaptor. Each of the second spaces
borders
that side of each primary sealing element which faces away from the first
space. The
rinsing device comprises means for supplying lubricant to the second space.
As the rinsing device comprises means for supplying lubricant to the second
space,
lubricant will be able to lubricate the contact between the neck adaptor and
the
sealing element. In this way, friction is lower and wear of the seal is
reduced, which
means that the lifetime of the sealing element is improved.
In accordance with some embodiments of the present invention, there is
provided a
rinsing device in a drill device for rock drilling, said rinsing device
comprising: a
cylindrical neck adaptor which comprises a mantle surface, two end surfaces, a
central axial passage which opens at one end surface, and a radial connection
between the central axial passage and an opening in the mantle surface, a
rinse
head with an axially-extending hole, said neck adaptor being slidably arranged
in said
hole and said rinse head surrounding a part of the mantle surface of the neck
adaptor
and providing a first space which extends around the mantle surface of the
neck
adaptor in the region of the opening in the mantle surface of the neck
adaptor, said
first space being connected to the outside of the rinse head via a feed
channel, at
least one primary sealing element arranged in the axial direction on each side
of the
first space in the rinse head to provide a seal between the neck adaptor and
the first
space, at least one second space which extends about the mantle surface of the
neck adaptor, each of which second spaces borders that side of each primary
sealing
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element which faces away from the first space wherein the rinsing device
comprises
means for supplying lubricant to the second space.
In accordance with some embodiments of the present invention, there is
provided a
drilling device for rock drilling, said drilling device comprising a drill; a
number of
drilling rods joined together to form a drill string, one end of the drill
string culminating
in a drill head and the other end of the drill string coupled to the drill;
and a rinsing
device as described herein.
One advantage of some embodiments of the present invention is that corrosion
of the
mantle surface of the neck adaptor is reduced, as it is not subjected to the
moist air
which can reach the mantle surface through the spyhole, which also contributes
to an
improved lifetime.
Another advantage of some embodiments of the present invention is that water
and
dirt penetration into the drill via the lubricating gas system - and the
damage resulting
therefrom - is avoided. This also means that the drill is more available, as
it does not
have to be taken out of service for repair so often.
Another advantage with some embodiments of the present invention is that
concurrent lubrication of the guide is possible.
Another advantage of some embodiments of the present invention is that - if
simultaneous lubrication of the guide is carried out - power use is reduced in
that a
smaller amount of air is used in the lubrication system.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a schematic side view of a drilling device for rock drilling.
Figure 2 is a schematic view which shows a longitudinal cross-section of a
first
embodiment of a rinsing device.
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Figure 3 is a schematic view which shows a radial cross-section of the rinsing
device
along the line in Figure 2.
Figure 4 is a schematic view which shows a longitudinal cross-section of a
second
embodiment of a rinsing device.
Figure 5 is a schematic view which shows a radial cross-section of the rinsing
device
along the line V-V in Figure 4.
Figure 6 is a schematic view which shows a radial cross-section of the rinsing
device
along the line VI-VI in Figure 4.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
A number of embodiments of the present invention will now be described with
reference to
the figures. The present invention is not limited to these embodiments.
Different
variations, equivalents and modifications can be used. These embodiments
should not
therefore be takes as limiting the scope of the invention, the scope of which
is defined by
appended claims.
Figure 1 shows a device for rock drilling 10. The rock drilling device 10
comprises a drill
20, a number of drilling rods 30 (only one is shown), which are joined
together and form a
drill string 40. One end of the drill string culminates in a drill head 50
which drills into the
stone 52 as it cuts and rotates, thereby forming a drill hole 55. The other
end of the drill
rod is coupled to drill 20 via a neck adaptor 60. In use, the drill string 40
cuts and with to-
and-fro movements, and rotates in use, driven by the drill 20.
To transport drill cuttings from the bottom of the drill hole 55, the drill
comprises a rinsing
device 70. A rinsing medium, e.g. water or air, is flushed by a device 80 for
supply of
rinsing medium in via rinsing device 70 in a central hole in the neck adaptor
60, and
further through a central hole in the drill string 40 and out through the
drill head 50 to the
bottom of the drill hole 55. Drill cuttings mixed with the rinsing medium are
then forced
out of the drill hole 55 between the drill string 40 and the walls of the
drill hole.
Figure 2 shows a side-view of a first example of the rinsing device 70 and
Figure 3 shows
a cross-section along the line in Figure 2 of the first example of the
rinsing device 70.
The rinsing device 70 comprises a neck adaptor 60, said neck adaptor 60 being
cylindrical
and comprising a mantle surface 90, two end surfaces, a central axial passage
100 which
opens at one end surface. The neck adaptor 60 also comprises a radial
connection 110
between the central axial passage 100 and an opening 120 in the mantle surface
90.
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The rinsing medium is intended to be flushed into the neck adaptor 60 through
opening
120, further through the radial connection 110 and into the central axial
passage 100 for
futher passage through the drill string 40 and drill head 50, and out through
the drill head
to the drill hole (as shown in Figure 1).
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The rinsing device 70 comprises a rinse head 130. An aim of the rinse head 130
is that it
provides a replaceable holder for the sealing element (said sealing element is
described
in more detail below). The rinse head 130 comprises an axially extending hole
140, in
which hole the neck adaptor 60 is slidably arranged, so that ¨ during drilling
¨ the neck
adaptor can rotate and move forwards and backwards in the rinse head which is
stationary relative to the drill 20.
The rinse head 130 surrounds a part of the mantle surface 90 of the neck
adaptor and
provides a first space 150. The first space 150 extends around the mantle
surface 90 of
the neck adaptor in the region of the opening 120 in the mantle surface 90 of
the neck
adaptor. The first space 150 is connected to the outside of the rinse head 130
via a feed
channel 160. This can for example be via a rinse adaptor 170. The first space
150 is
preferably arranged so that the opening 120 of the neck adaptor is always
located within
the first space 150 upon rotating to-and-fro movement, which means that the
rinsing
medium always has free access to opening 120 in the mantle surface 90 of the
neck
adaptor.
The rinsing device 70 comprises at least one primary sealing element 180. The
primary
sealing element 180 is arranged in the axial direction on each side of the
first space 150
in the rinse head 130 to provide a seal between the neck adaptor 60 and the
first space
150, to prevent rinse medium leaking from the first space 150 along the gap
between the
mantle surface 90 of the neck adaptor 60 and the rinse head 130. Should such a
leakage
for instance reach the drill, damage can occur. Certain embodiments, such as
the
example in Figure 2, comprise two primary sealing elements 180, wherein one is
arranged
on one side of the opening 120 in the neck adaptor, and the other is arranged
on the other
side of the neck adaptor's opening 120.
In certain embodiments, the rinsing device 170 comprises at least one
secondary sealing
element 190 arranged in the axial direction on each side of the first space
150 in the rinse
head 130 and on that side of each primary sealing element 180 which faces away
from
the first space 150, for a further seal between the neck adaptor 60 and the
first space 150.
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This means that, should any rinse medium leak past any of the primary sealing
elements
180, the rinse medium is prevented from leaking further along the gap between
the mantle
surface 90 of the neck adaptor 60 and the rinse head 130. Certain embodiments,
such as
the example in Figure 2, comprise two secondary sealing elements 190, whereby
one is
arranged on that side of one primary sealing element 180 which faces away from
the first
space 150, and the other is arranged on that side of the other primary sealing
element
180 which faces away from the first space 150.
The primary sealing elements 180 and the secondary sealing elements 190 can
e.g. be
unidirectional, such as e.g. so-called U-sleeves, i.e. in this case these
should seal in the
direction from the first space 150.
The rinsing device 70 also comprises at least one second space 200 which
extends about
the mantle surface 90 of the neck adaptor, which second space 200 borders that
face of
each primary sealing element 180 which faces away from the first space. In
certain
embodiments, such as e.g. that shown in Figure 2 (and also in Figure 4), the
rinsing
device comprises two second spaces 200, each of said two second spaces 200
being
arranged on each side of the first space 150.
The rinsing device 70 comprises means for supplying lubricant to the second
space 200.
This is to lubricate the contact surfaces between the neck adaptor 60 (and in
certain
cases also the guide which is described in more detail below) and the primary
sealing
elements 180 and in certain cases, the secondary sealing elements 190, so that
contact
friction between the neck adaptor 60 and the primary and secondary sealing
elements
180, 190 is reduced. This reduces wear on the primary and secondary sealing
elements
180, 190. Preferably, grease or another lubricant with high viscosity can be
used as
lubricant. The lubricant should not comprise lubricating gas. Grease can be
defined as a
solid, semi-liquid or hard product, which is obtained by introducing a
thickening agent to a
liquid lubricant. To determine consistency, a special method is used according
to EN-ISO
2137. The values measured are the depth in mm to which a special cone
penetrates
homogenized grease under 5 seconds at 25 C. The consistency is specified as
penetration in 1/10mm. It is preferable for the present invention to use
grease in class 00
¨ class 4, classified according to the National Lubrication Grease Institute
(NGLI) in the
USA, i.e. "hard" to "semi-liquid" grease with a penetration of 205-400,
preferably a
"normal" grease classed in class 2 with a penetration from 265 to 295 or a
"relatively hard"
grease classed in class 3 with a penetration from 220 to 250.
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In certain embodiments, the means for supplying lubricant to the second space
200
comprises one or more inlets 210, said inlets 210 extending from the outside
of the rinsing
device 70 to the second space 200. The inlets 210 allow lubricant to be
transferred from
the outside of the rinsing device, e.g. via a grease nipple 215 to the second
space 200. In
certain embodiments, such as e.g. that shown in Figure 3, (and also in Figure
5), the inlet
210 extends radially to the mantle surface 90 of the neck adaptor in the
second space
200. The inlet 210 can e.g. extend through the rinse head 130 from an opening
220 on a
mantle surface 230 of the rinse head 130 to the second space 200, such as e.g.
that
shown in Figure 3. The inlet 210 can e.g. be formed as two or more channels
240, such
as e.g. shown in Figure 3, in which the inlet 210 is formed as two channels
240. In certain
embodiments, such as e.g. that shown in Figure 3, the opening 220 of the inlet
in the rinse
head 130 is comprised in a recess 250 in the mantle surface 230 of the rinse
head. This
has the advantage that lubricant can more easily be distributed in the inlet
210 or
channels 240 where these pass through the rinse head 130. The recess prevents
lubricant from taking short-cuts along the outer mantle surface of the rinse
head from the
inlet 210 to the outlet 260 (as described below), without passing the neck
adapter 60 and
the second space 200.
In certain embodiments, the means for supplying lubricant to the second space
200
comprises one or more outlets 260. The outlets extend from the second space
200 to the
outside of the rinse head, and allow excess lubricant to pass out of the
rinsing device 70,
e.g. through so-called spyhole 265 in an outer cover 267 of the rinsing device
70. This
also allows rinse medium to flow out if it has leaked past the primary and in
certain cases
secondary sealing elements 180, 190, which means that a user can see from the
outside
of the rinsing device 70 whether such a leak has occurred, so that the
primary, and in
certain cases, the secondary sealing elements 180, 190 can be replaced if they
have
worn out. The supply of lubricant increases the lifetime of the primary and in
certain
cases, secondary, sealing elements 180, 190. The lubricant does not prevent
the
passage of rinse medium through the spyhole 265, as the rinse medium has a
certain
pressure, and pushes out the lubricant. However, any lubricant present in the
spyhole
does prevent water and dirt entering from outside and penetrating the neck
adaptor 60
and the primary and secondary sealing elements 180 and 190, where they would
cause
wear and corrosion.
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In certain embodiments, such as e.g. that shown in Figure 3 (and also in
Figures 5 and 6
described below), the outlet 260 extends radially from the mantle surface 90
of the neck
adaptor in the second space 200. The outlet 260 can e.g. extend from the
second space
200, through the rinse head 130 and to a vent 270 on the mantle surface 230 of
the rinse
head, such as e.g. shown in Figures 3, 5 and 6. In certain embodiments, such
as e.g. that
shown in Figure 3, each outlet 260 through the rinse head 130 comprises two or
more
channels 280 through the rinse head 130. In certain embodiments, such as e.g.
that
shown in Figure 3, the vent 270 of the outlet in the rinse head is comprised
in a recess
290 in the mantle surface 90 of the rinse head.
Figure 4 shows a side-view of an embodiment of the rinsing device 70. Figure 5
shows a
cross-section along the line V-V of the embodiment of Figure 4, e.g. the cross-
sections
runs through a cylindrical guide 300. Figure 6 shows a cross-section along the
line VI-VI
of the embodiment of Figure 4.
In certain embodiments, such as e.g. that shown in Figures 4 and 5, the
rinsing device
comprises a guide 300, said guide 300 comprising an axially extending hole
310, the neck
adaptor 60 being slidably arranged in said hole. The guide can e.g. be a so-
called nose
bush. The guide 300 surrounds a portion of the mantle surface 90 of the neck
adaptor.
The guide 300 borders the rinse head 130 and the second space 200. In certain
embodiments, such as e.g. that shown in Figures 4 and 5, the inlet 210 extends
through
the guide 300 from an opening 320 on a mantle surface 330 of the guide 300 to
the
second space 200. The inlets 210 of certain embodiments can comprise two or
more
channels (not shown), to obtain an even better flow of lubricant to the second
space 200.
In one embodiment, the inlet 210 runs through the guide 300 and the outlet 260
through
the rinse head 130, this is shown in Figures 4, 5 and 6.
The lubricant is squirted in via channels 240 through, e.g. the outer cover
267 of the
rinsing device 70. The lubricant is carried further in through the inlet 210
to the second
space 200, where it is allowed to spread.
The second space 200 can e.g. be contained between the primary sealing
elements 180
and the secondary sealing elements 190, as shown in Figure 2. In this way, the
lubricant
can be supplied between the primary sealing element 180 and the secondary
sealing
element 190 to the second space 200.
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The second space 200 can also be contained on that face of each primary
sealing
element 180 which faces away from the first space 150, as shown in Figure 4.
Lubricant
can therefore be supplied to the second space 200, on that face of each second
sealing
element which faces away from the first space 150. This requires that, when
the lubricant
reaches the secondary sealing element 190, and the secondary sealing element
190 is
unidirectional, such as e.g. so-called U-sleeves, the secondary sealing
element 190
releases and allows lubricant to enter into the space between the primary 180
and
secondary 190 sealing elements. In this embodiment, lubrication of the guide
300 is also
made possible; in this case, the second space extends along the mantle surface
of the
neck adaptor 60 both in the region where it is surrounded by the rinse head
130 and
where the neck adaptor 660 is surrounded by the guide 300. (This requires that
the
lubricant spreads both to the left and right in Figure 4, when it is squirted
in through the
left grease nipple 215). This embodiment is very advantageous, as water and
drill
cuttings are prevented from entering via the lubricating gas pipes in the
guide 300, as no
lubricating gas pipes are required.
Alternatively, if only the primary sealing elements 180 are present (and no
secondary
sealing elements), lubricant is squirted in on that face of each primary
sealing element
180 which faces away from the first space 150. The lubricant can e.g. be
squirted in via
inlet 210 in the rinse head 130 or via inlet 210 in the guide 300.
The lubricant is then carried further out through the oulet 260. When
lubricant is seen e.g.
in some of the spyholes 265 coupled to the outlet 206, filling with lubricant
is complete.
The variously described embodiments of the rinse head 130 and guide 300 are
formed so
that grease is forced all the way to the neck adaptor 60 before it can spread
further out via
the outlet 260 and the spyholes.
The lubricant lubricates the contact between the neck adaptor 60 and the
sealing
elements 180, 190 and in certain embodiments, also between the neck adaptor 60
and
the guide 300. In this way, friction is lowered and wear and heat production
is lowered.
The lubricant also reduces corrosion by preventing air from making contact
with the neck
adaptor 60. External water which enters via the rear entrance through the
spyholes 265 is
also prevented from reaching the neck adaptor 60 and in certain cases, the
guide 300.
The lubricant can e.g. be squirted in continuously or at close intervals, e.g.
by manual
injection through the grease nipple, by a central lubrication system from e.g.
a drill rig in
which the drill 20 is arranged, by a lubricant container on a sled on which
the drill 20 is
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arranged, said lubricant container in turn may be pressurised by lubricating
gas via a
branched tube from a lubricating gas intake on the drill 20, or by an
automated grease
cartridge which is exchanged at regular intervals.
5
