EP1592862B1

EP1592862B1 - Rock drill machine and flushing housing

Info

Publication number: EP1592862B1
Application number: EP04703808A
Authority: EP
Inventors: Ari Kotala; Aimo Helin; Jean-Claude Barthomeuf
Original assignee: Sandvik Mining and Construction Oy
Current assignee: Sandvik Mining and Construction Oy
Priority date: 2003-01-22
Filing date: 2004-01-21
Publication date: 2007-08-22
Anticipated expiration: 2024-01-21
Also published as: AU2004206069B2; ATE371090T1; FI20030097A0; AU2004206069A1; ZA200505624B; DE602004008427D1; DE602004008427T2; PL377197A1; FI121026B; EP1592862A1; WO2004065755A1; FI20030097L; PL203202B1

Abstract

The invention relates to a rock drill machine and a flushing housing for a rock drill machine. At least one bearing (19, 20) in the shank (4) is located in the flushing housing (13). Flushing medium is arranged to flow through the bearing (19, 20). This allows the flushing medium to lubricate and cool the bearing.

Description

BACKGROUND OF THE INVENTION

The invention relates to a rock drill machine comprising at least: a body; a percussion element for generating percussion pulses required in rock breaking; a shank arranged in front of the percussion element in the percussion direction and supported to the body with at least one bearing and whose rear end is provided with a percussion surface for receiving percussion pulses; a flushing housing that forms a space around the shank; at least one first flushing duct along which flushing medium is arranged to be led into the flushing housing; and at least one second flushing duct provided in the shank and along which flushing medium is arranged to flow out of the flushing housing.
The invention further relates to a flushing housing through which a shank of a rock drill machine is axially adaptable, the flushing housing comprising: at least one bearing for supporting the shank; and at least one first duct for leading flushing medium into the flushing housing.
A drawback in percussive rock drill machines can be insufficient lubrication and cooling of the bearings in the shank. The problem may result in inadequate service life of the bearings in the shank. Furthermore, in some cases, the excessive axial length of the rock drill machine may cause problems. For example US-4 576 240 discloses a rock drill machine wherein these drawbacks are present.

BRIEF DESCRIPTION OF THE INVENTION

The object of the present invention is to provide a new and improved flushing housing and a rock drill machine provided with such a flushing housing.
The rock drill of the invention is characterized in that the flushing medium is arranged to flow through at least one bearing that supports the shank, whereby the flushing medium is arranged to lubricate and cool the bearing.
The flushing housing of the invention is characterized in that the first duct is arranged at the bearing when viewed axially, whereby the flushing medium is arranged to lubricate and cool the bearing.
An essential idea of the invention is that flushing medium is fed through at least one bearing of the shank. An advantage herein is that the flushing medium is able to efficiently lubricate the bearing. In addition, the flushing medium flowing through the bearing is able to discharge any impurities out of the bearing. A still further advantage is that the flushing medium is able to cool the bearing very efficiently. This may lengthen the service life of the bearing of the shank and reduce malfunction. Furthermore, the invention enables a shorter construction of the flushing housing.
The essential idea of a preferred embodiment of the invention is that the flushing duct from which the flushing medium is fed into the flushing housing is arranged at the bearing that supports the shank. This way the flushing medium is arranged to flow through the bearing substantially radially. Since the bearing and the feed of flushing medium are arranged to overlap, the flushing housing may be particularly short when viewed axially.
The essential idea of a preferred embodiment of the invention is that the flushing housing constitutes the foremost part of the body of the rock drill machine. Accordingly, the rock drill machine does not comprise a separate front cover. This being so, only one sealing surface is provided between the flushing housing and the body, facilitating the manufacture of the flushing housing. The assembly is also easier and the structure is more durable since there are fewer seals. Furthermore, the body of the drill machine may be axially shorter there being no separate front cover.

BRIEF DESCRIPTION OF THE FIGURES

The invention will be described in more detail in the attached drawings, wherein

Figure 1 is a schematic side view of a rock drill machine,
Figure 2 is a schematic sectional view of the front end and flushing housing of a rock drill machine of the invention, and
Figure 3 is a schematic sectional view of the front end and flushing housing of another rock drill machine of the invention.

For the sake of clarity, the figures show the invention in a simplified manner. In the figures, like parts are designated with like reference numerals.

DETAILED DESCRIPTION OF THE INVENTION

Figure 1 shows a rock drill machine 1 comprising a body 2, a percussion device 3 and a shank 4. In addition, the rock drill machine 1 may comprise a rotation device 5 for rotating the shank 4 and a tool 6 connected thereto around its axis. The rock drill machine 1 may be arranged on a feed beam 7 relative to which it can be moved with feed means 8 during drilling. Furthermore, flushing medium is led to the rock drill machine 1 along a feed duct 9, the medium being led further to a drill hole by means of the shank 4 and the tool 6.
Figure 2 shows that the percussion device 3 comprises a percussion element 10 for generating percussion pulses to a percussion surface 11 of the shank 4 located in front of it. The percussion element 10 may be an axially back and forth movable percussion piston that is movable for instance by means of pressure medium or electricity. Alternatively, the percussion element 10 may generate percussion pulses required in rock breaking in some other manner, for instance based on the magnetostrictive effect. The shank 4 transfers the percussion pulses to the tool 6 and further to a rock 12. The shank 4 may comprise joints, such as threads, for example, for fastening the tools 6. Alternatively, the shank 4 and the tool 6 may constitute an integrated entity. Furthermore, the tool 6 may comprise several detachable pieces, for instance a plurality of extension rods and a drill bit. The front end of the body 2 of the drill machine 1 comprises a flushing housing 13, which is a space provided around the shank 4. The flushing housing 13 is in communication via a first flushing duct 14 with the feed duct 9 for leading flushing medium to the flushing housing 13. A front cover 21 may be provided with a first seal 15 or, alternatively, the front end of the flushing housing 13 may be provided with a first seal 15 and farther back at a distance a second seal 16 may be provided, the flushing housing 13 being sealed with said seals 15, 16 to the shank 4. In some cases, the back seal 16 may be arranged in a piece separate from the flushing housing 13 or elsewhere in the body 2. The shank 4 may comprise a second flushing duct 17, which is in communication with the flushing housing 13, allowing the flushing medium fed into the flushing housing 13 to flow into the second flushing duct 17 and further along a third flushing duct 18 in the tool 6 into the drill hole. The shank 4 may be mounted in bearings from the front part with a front bearing 19 and from the rear part with a rear bearing 20. In some cases, only one bearing may suffice. On the other hand, there may be more than two bearings. Furthermore, the front bearing 19 may be arranged in a section between the first flushing duct 14 and the second flushing duct 17. This being so, at least part of the flushing medium is arranged to flow through the front bearing 19 substantially axially. Accordingly, the flushing medium is able to lubricate and cool the bearing 19. In the construction according to Figure 2, the foremost section of the body 2 is formed by the front cover 21, which may be fastened to the flushing housing 13. Alternatively, the front cover 21 may be an integrated part of the flushing housing 13, in which case there are fewer mating surfaces. In addition, this being so, the body 2 can be made axially shorter.
Figure 3 shows a section of an alternative structure of the flushing housing 13. In this case, the flushing housing 13 can constitute the foremost part of the body 2. The front part of the body 2 of the drill machine 1 has no front cover. This being so, only one mating surface is sufficient between the flushing housing 13 and the other parts of the body 2, facilitating the manufacture of the flushing housing. Such a flushing housing is also fast and simple to open when required and to replace with a new one for instance when the bearings are damaged. Not only the front cover, but also the seals 15, 16, the front bearing 19 and the flushing duct 14 may be integrated into the flushing housing 13. On the other hand, the back seal 16 may be adapted in another body piece than the flushing housing 13. The first flushing duct 14 may be arranged at the front bearing 19, allowing the flushing medium from the flushing duct 14 to flow radially through the bearing 19. The advantage of this structure is that the body 2 can be made shorter since no front cover exists and, further, since the flushing duct 14 and the bearing 19 are arranged to overlap and not to be in succession. In addition, the rear end of the shank 4 is cup-shaped, the percussion element 10 being partly nested within the shank 4. This is another fact that enables the construction of a short rock drill machine 1.
Let it be mentioned that the flushing medium may be gas or fluid. Typically, the flushing medium is water or a mixture of water and one or more additives.
The bearings 15, 16 of the shank 4 may be roller bearings, slide bearings or other bearings suitable for the purpose. For example, in the solution according to Figure 3, the shank 4 may be supported with slide bearings 15 and 16. In addition, the front bearing 15 is provided with one or more substantially radial ducts in a manner allowing the flushing medium to flow radially through the bearing 15. On the other hand, in the construction according to Figure 2, the flushing medium may flow substantially axially through clearances in the bearing 15 and/or through one or more ducts passing through the bearing 15.
In some cases, the flushing medium may be arranged to flow through the rear bearing 20. Furthermore, both bearings 19, 20 may be located in the flushing housing 13, and the feed of flushing medium may even be arranged to enable the flow of flushing medium through both bearings 19, 20.
A separate flushing housing 13 may also be arranged in front of the actual body 2 of the rock drill machine 1.
The drawings and the related description are only intended to illustrate the inventive idea. The details of the invention may vary within the scope of the claims.

Claims

A rock drill machine comprising at least:
a body (2);

a percussion element (10) for generating percussion pulses required in rock breaking;

a shank (4) arranged in front of the percussion element (10) in the percussion direction (A) and supported to the body (2) with at least one bearing (19, 20) and whose rear end is provided with a percussion surface (11) for receiving percussion pulses;

a flushing housing (13) that forms a space around the shank (4);

at least one first flushing duct (14) along which flushing medium is arranged to be led into the flushing housing (13); and

at least one second flushing duct (17) provided in the shank (4) and along which flushing medium is arranged to flow out of the flushing housing (13), characterized in that

the flushing medium is arranged to flow through at least one bearing (19, 20) that supports the shank (4), whereby the flushing medium is arranged to lubricate and cool the bearing (19, 20).
A rock drill machine as claimed in claim 1, characterized in
that the first flushing medium duct (14) is arranged axially at the bearing (19, 20), and
that the flushing medium is arranged to flow substantially radially through the bearing (19, 20).
A rock drill machine as claimed in claim 1, characterized in
that the bearing (19, 20) is arranged axially in a section between the first flushing medium duct (14) and the second flushing duct (17), and
that the flushing medium is arranged to flow substantially axially through the bearing (19, 20).
A rock drill machine as claimed in any one of the preceding claims, characterized in that at least one bearing (19, 20) is provided with at least one duct for leading the flushing medium through the bearing (19, 20).
A rock drill machine as claimed in any one of the preceding claims, characterized in that the flushing housing (13) constitutes the foremost part of the body (2).
A flushing housing through which a shank (4) of a rock drill machine (1) is axially adaptable, the flushing housing (13) comprising:
at least one bearing (19, 20) for supporting the shank (4); and

at least one first duct (14) for leading flushing medium into the flushing housing (13), characterized in

that the first duct (14) is arranged at the bearing (19, 20) when viewed axially, whereby the flushing medium is arranged to lubricate and cool the bearing (19, 20).
A flushing housing as claimed in claim 6, characterized in that the flushing housing (13) is attachable as part of the body (2) of the rock drill machine (1).
A flushing housing as claimed in claim 7, characterized in that the flushing housing (13) is arranged to constitute the foremost part of the body (2).