A rotary percussion hydraulic drill provided with a shank equipped with a coupling spline

Abstract

A rotary impact hydraulic drill (2) includes: a main body (3); a handle (13) having a female coupling spline and a male coupling spline; an impact piston (5) configured to strike the handle (13); a rotary drive device (18) configured to drive the handle (13) to rotate; and a front stop surface (23) against which the handle (13) is configured to abut. The handle (13) has an annular support flange (24) provided on an outer surface of the handle (13) and having an annular support surface configured to abut against the front stop surface (23). Each of the female coupling spline and the male coupling spline provided on the handle (13) extends from the annular support flange (24) in the direction of the impact piston (5).

Description

Technical Field

[0001] The present invention relates to a rotary impact hydraulic drill, and more particularly to a rotary impact hydraulic drill used on drilling equipment. Background Art

[0002] In a known manner, drilling equipment comprises a rotary percussion hydraulic drill slidably mounted on a slide and driving one or more drill rods, the last of which carries a tool, known as a cutting edge, that comes into contact with the rock. The purpose of such a drill is generally to drill a hole of varying depths in order to place explosives therein. The drill bit is therefore a key element of the drilling equipment, which, on the one hand, imparts a rotational and percussive setting to the cutting edge via the drill rod in order to penetrate the rock, and, on the other hand, provides for the injection of fluid to extract debris from the drilled hole.

[0003] More specifically, the rotary percussion hydraulic drilling rig comprises, on the one hand, a percussion device driven by one or more hydraulic fluid flow rates from a main hydraulic supply circuit and comprising a percussion piston configured to percuss a shank coupled to a drill rod during each operating cycle of the drilling rig, and, on the other hand, a rotary drive device provided with a hydraulic rotary motor and configured to rotate the shank and the drill rod.

[0004] The rotary drive device particularly includes a coupling member disposed around the handle, the coupling member including a male coupling spline and a female coupling spline, the male coupling spline and the female coupling spline being rotatably coupled to female coupling splines and male coupling splines disposed on an outer surface of the handle, respectively. The male coupling spline and the female coupling spline disposed on the handle extend substantially parallel to an axis of extension of the handle and are angularly offset from each other relative to the axis of extension of the handle.

[0005] When the cutting edge is stuck in the rock, the rotary percussion hydraulic drill is retracted until the front end of the male coupling spline provided on the shank abuts against a front abutment surface provided on a front abutment member fixed to the body of the rotary percussion hydraulic drill.

[0006] Then, when attempting to unlock the tool, the rotary drive and / or the impact device can be activated to drive the handle in rotation and / or impact the handle with the impact piston.

[0007] Such activation of the rotary drive means and / or the impact means results in rotational friction of the male coupling splines provided on the shank against the front abutment surface and / or axial impact of the male coupling splines provided on the shank against the front abutment surface.

[0008] However, such repeated axial collisions and rotational friction may cause the male coupling splines provided on the shank to wear rapidly, requiring frequent replacement of the shank. In addition, such wear of the male coupling splines may generate debris that may become lodged between the various moving parts of the rotary percussion hydraulic drill, thereby damaging the moving parts.

[0009] The present invention aims to remedy all or part of these disadvantages.

[0010] Therefore, the technical problem of the present invention is to provide a rotary percussion hydraulic drilling rig that is simple in structure, economical, reliable and compact. Summary of the Invention

[0011] To this end, the present invention relates to a rotary percussion hydraulic drilling rig, comprising:

[0012] -main body;

[0013] a shank for coupling to at least one drill rod equipped with a tool, the shank comprising a coupling portion including a female coupling spline and a male coupling spline angularly offset from one another relative to an axis of extension of the shank;

[0014] - a striking piston slidably mounted inside the body along a striking axis and configured to strike the handle;

[0015] a rotation drive device configured to drive the handle to rotate about a rotation axis substantially coincident with the striking axis, the rotation drive device comprising a coupling member disposed around the handle, the coupling member comprising a male coupling spline and a female coupling spline rotatably coupled to the female coupling spline and the male coupling spline of the handle, respectively;

[0016] a front abutment surface fixed relative to the body, the front abutment surface being annular and extending around the handle, the handle being configured to abut against the front abutment surface so as to limit the forward displacement travel of the handle;

[0017] The invention is characterized in that the handle includes an annular support flange provided on the outer surface of the handle, and the annular support flange includes an annular support surface configured to abut against the front abutment surface, and each female coupling spline and male coupling spline provided on the handle extends from the annular support flange in the direction of the impact piston, each female coupling spline provided on the handle includes a bottom surface and a connecting surface, which connects the corresponding bottom surface to the annular support flange and extends forward away from the extension axis of the handle, and the connecting surface of each female coupling spline provided on the handle is at least partially formed by a curved concave surface, which extends basically in the extension direction of the corresponding female coupling spline and has a curvature radius smaller than the radial height of each male coupling spline provided on the handle.

[0018] The presence of such annular bearing flange at the front of the female and male coupling splines provided on the shank makes it possible to avoid contact between the front abutment surface and the male coupling splines provided on the shank and thus maintain the integrity of the male coupling splines.

[0019] Furthermore, the presence of the annular bearing surface on the annular bearing flange ensures a relatively large contact surface between the front abutment surface and the annular bearing flange and thus ensures a better distribution of impact and / or friction forces exerted by the shank against the front abutment surface.

[0020] Therefore, the specific construction of the rotary percussion hydraulic drill according to the present invention significantly increases the service life of the handle, which makes it possible to significantly reduce the period of time during which the drill is out of operation when the handle is replaced, as well as the risk of damage to the drill that may affect the safety of the user.

[0021] Furthermore, by providing the male coupling splines provided on the shank extending directly from the annular support flange, the axial length of the shank is unaffected by the presence of the annular support flange, which enables a compact rotary percussion hydraulic drill. The implementation of each female coupling spline provided on the shank including a connection surface formed at least partially by a curved concave surface having a small radius of curvature further reduces the axial length of the shank, thereby further increasing the compactness of the rotary percussion hydraulic drill.

[0022] The specific configuration of the connection surface of each female coupling spline provided on the shank also makes it possible to avoid the presence of sharp corners that could cause high stresses on the shank during operation of the drilling machine and thus cause it to break.

[0023] The rotary percussion hydraulic drill may also have one or more of the following features, alone or in combination.

[0024] According to one embodiment of the present invention, the female coupling splines and the male coupling splines provided on the handle extend substantially parallel to the extension axis of the handle.

[0025] According to one embodiment of the invention, the connection surface of each female coupling spline provided on the shank is completely formed by a corresponding curved concave surface.

[0026] According to one embodiment of the present invention, the maximum outer diameter of the annular support flange is greater than or equal to the outer diameter of the coupling portion. This configuration of the coupling portion makes it possible to reduce the cross-section of the shank at the coupling portion, and therefore the cross-section of the coupling member, while maintaining a large protective surface. Consequently, this arrangement makes it possible to reduce the footprint of the rotary percussion hydraulic drill according to the present invention.

[0027] According to one embodiment of the present invention, the front end of each female coupling spline provided on the handle is provided on the annular support flange. According to a variation of the present invention, the front end of each female coupling spline provided on the handle may be adjacent to the annular support flange.

[0028] According to one embodiment of the present invention, the front end portion of each male coupling spline provided on the shank is adjacent to the annular supporting flange.

[0029] According to one embodiment of the invention, each male coupling spline provided on the shank comprises a top surface extending from the annular support flange.

[0030] According to one embodiment of the invention, for each male coupling spline provided on the shank, a radial distance between the extension axis of the shank and a top surface of said male coupling spline is substantially constant along said male coupling spline.

[0031] According to one embodiment of the present invention, the radius of curvature of each curved concave surface is less than 15 mm, for example, less than 10 mm. This value of the radius of curvature of the curved concave surface of each female coupling spline provided on the shank makes it possible to reduce the length of the connection between the support flange and the various coupling splines provided on the shank, and thus reduce the length of the shank. Consequently, this arrangement makes it possible to increase the compactness of the rotary percussion hydraulic drill according to the present invention.

[0032] According to one embodiment of the invention, the connection surface of each female coupling spline provided on the shank comprises an inclined surface that is inclined relative to the axis of extension of the shank and offset in the direction of the front abutment surface. Advantageously, the inclined surface extends in the extension of the curved concave surface and in the direction of the front end of the shank.

[0033] According to one embodiment of the invention, the annular bearing flange comprises a substantially cylindrical outer peripheral surface.

[0034] According to one embodiment of the present invention, the front end portion of each female coupling spline provided on the shank opens to the outer surface of the annular supporting flange.

[0035] According to one embodiment of the present invention, a front end portion of each female coupling spline provided on the shank opens to the outer peripheral surface.

[0036] According to one embodiment of the invention, the outer peripheral surface extends in the extension of the annular bearing surface in the direction of the impact piston.

[0037] According to one embodiment of the invention, the front end portion of each female coupling spline provided on the shank opens into the annular bearing surface of the annular bearing flange.

[0038] According to one embodiment of the present invention, the radial height of the annular support flange at the outlet of the front end of each female coupling spline on the shank is greater than 50% of the maximum radial height of the annular support flange, for example greater than or equal to 60% or 70%.

[0039] According to one embodiment of the invention, each female coupling spline provided on the shank comprises two lateral surfaces extending longitudinally and being substantially parallel.

[0040] According to one embodiment of the invention, the annular bearing surface is inclined relative to the striking axis and is offset in the direction of the striking piston. However, according to a variant of the invention, the annular bearing surface can be perpendicular to the striking axis.

[0041] According to one embodiment of the invention, the front abutment surface is provided on the main body.

[0042] According to another embodiment of the present invention, a rotary percussion hydraulic drill includes an annular abutment ring disposed in the body, the annular abutment ring being disposed around the shank and including a front abutment surface.

[0043] According to one embodiment of the invention, the coupling member comprises peripheral teeth which are rotatably coupled, for example directly or indirectly, to an output shaft of a drive motor belonging to the rotary drive device.

[0044] According to one embodiment of the invention, the coupling member is a coupling pinion.

[0045] According to one embodiment of the invention, the female coupling splines of the handle are evenly distributed around the extension axis.

[0046] According to one embodiment of the invention, the male coupling splines of the coupling member are evenly distributed around the extension axis of the shank.

[0047] According to one embodiment of the invention, the shank comprises a first end portion facing the impact piston and provided with an end face against which the impact piston will impact, and a second end portion opposite the first end portion which will be coupled to at least one drill rod.

[0048] According to one embodiment of the invention, the coupling portion is formed by the first end portion of the handle.

[0049] According to one embodiment of the present invention, the extension axis of the handle is parallel to the striking axis, for example coincides with the striking axis.

[0050] According to one embodiment of the present invention, a rotary percussion hydraulic drill includes a main hydraulic supply circuit configured to control reciprocating sliding of a percussion piston along a percussion axis.

[0051] According to an embodiment of the present invention, each female coupling spline and male coupling spline provided on the handle extends to the rear end of the handle. According to a variation of the present invention, the rear end of each female coupling spline and male coupling spline provided on the handle is spaced apart from the rear end of the handle.

[0052] According to an embodiment of the present invention, each of the female coupling spline and the male coupling spline provided on the handle has an effective length of less than 100 mm.

[0053] According to an embodiment of the invention, the shank has a maximum diameter at the front of the annular supporting flange that is smaller than or equal to 61 mm, and advantageously smaller than 46 mm.

[0054] According to an embodiment of the present invention, the bottom surface of each female coupling spline provided on the shank is substantially flat. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] The invention will be better understood with the aid of the following description made with reference to the accompanying drawing which shows, by way of non-limiting example, an embodiment of such a rotary percussion hydraulic drill.

[0056] Figure 1 is a schematic view of a longitudinal section of a rotary percussion hydraulic drill according to a first embodiment of the present invention.

[0057] Figure 2 Belongs to Figure 1 A side view of the shank of a rotary percussion hydraulic drill.

[0058] Figure 3 yes Figure 2 A cross-sectional view of the handle is shown.

[0059] Figure 4 yes Figure 2 Partial view of a longitudinal section of the handle.

[0060] Figure 5 FIG. 1 is a partial view of a longitudinal section of a shank of a rotary percussion hydraulic drill according to a second embodiment of the present invention. DETAILED DESCRIPTION

[0061] Figures 1 to 4 A rotary percussion hydraulic drill rig 2 is shown, which is used for drilling blast holes.

[0062] The rotary percussion hydraulic drill 2 includes a main body 3 configured to be slidably mounted on a slide.

[0063] The rotary percussion hydraulic drill 2 further comprises a percussion device 4 including a percussion piston 5 mounted to slide alternately in a piston cylinder 6 defined by the body 3 and extending along a percussion axis A. The percussion piston 5 and the percussion cylinder 6 define an annular main control chamber 7 and a secondary control chamber 8 , the secondary control chamber having a larger cross section than the main control chamber 7 and being opposite to the main control chamber 7 .

[0064] The impact device 4 further includes a control valve 9, which is arranged to control the reciprocating motion of the impact piston 5 within the piston cylinder 6, alternatingly during an impact stroke and a return stroke. The control valve 9 is configured to alternately connect the secondary control chamber 8 to a high-pressure fluid supply conduit 11 (e.g., a high-pressure incompressible fluid supply conduit) during the impact stroke of the impact piston 5, and to a low-pressure fluid return conduit 12 (e.g., a low-pressure incompressible fluid return conduit) during the return stroke of the impact piston 5. The primary control chamber 7 is advantageously continuously supplied with high-pressure fluid via a supply channel.

[0065] The high-pressure fluid supply conduit 11 and the low-pressure fluid return conduit 12 belong to a main hydraulic supply circuit with which the percussion device 4 is provided. The main hydraulic supply circuit may advantageously comprise a high-pressure accumulator connected to the high-pressure fluid supply conduit 11 .

[0066] The rotary percussion hydraulic drill 2 further comprises a shank 13, which is intended to be coupled in a known manner to at least one drill rod (not shown) equipped with a tool. The shank 13 extends longitudinally along an axis of extension that advantageously coincides with the percussion axis A and comprises a first end portion 14.1, which faces the percussion piston 5 and is provided with an end face 15 on which the percussion piston 5 strikes during each operating cycle of the rotary percussion hydraulic drill 2, and a second end portion 14.2, which is opposite the first end portion 14.1 and is intended to be coupled to at least one drill rod.

[0067] The shank 13 comprises a coupling portion, for example formed by a first end portion 14.1, which comprises, for example, female coupling splines 16 and male coupling splines 17 extending parallel to the axis of extension of the shank 13 and angularly offset from one another relative to the axis of extension of the shank 13. Advantageously, the female coupling splines 16 and the male coupling splines 17 are evenly distributed around the axis of extension of the shank 13. Advantageously, each male coupling spline 17 is arranged between two adjacent female coupling splines 16.

[0068] Each of the female coupling spline 16 and the male coupling spline 17 includes a rear end portion oriented toward the striking piston 5 and a front end portion opposite to the respective rear end portion. Figures 1 to 4In the illustrated embodiment, each of the female and male coupling splines 16, 17 extends to the rear end of the shank 13. However, according to a variation of the present invention, the rear end of each of the female and male coupling splines 16, 17 may be spaced apart from the rear end of the shank 13.

[0069] The rotary percussion hydraulic drill 2 further comprises a rotary drive device 18 , which is configured to drive the shank 13 to rotate about a rotation axis substantially coinciding with the striking axis A.

[0070] The rotary drive device 18 includes a coupling member 19, such as a coupling pinion, which is tubular and disposed around the handle 13. The coupling member 19 includes male coupling splines and female coupling splines that are rotatably coupled to the female coupling splines 16 and the male coupling splines 17 of the handle 13, respectively. The male coupling splines and the female coupling splines provided on the coupling member 19 are evenly distributed around the extension axis of the handle 13.

[0071] Advantageously, the coupling member 19 comprises peripheral teeth rotatably coupled to the output shaft of a drive motor 21, for example a hydraulic motor hydraulically supplied by an external hydraulic supply circuit, belonging to the rotary drive 18. The rotary drive 18 may, for example, comprise an intermediate pinion 22 coupled on the one hand to the output shaft of the drive motor 21 and on the other hand to the peripheral teeth of the coupling member 19.

[0072] The rotary percussion hydraulic drill 2 further comprises a front abutment surface 23 which is annular and extends around the shank 13. The front abutment surface 23 is located opposite the impact piston 5 relative to the coupling member 19. The front abutment surface 23 may be provided directly on the body 3 or may be provided on an annular abutment ring arranged in the body 3.

[0073] The shank 13 comprises an annular bearing flange 24 provided on the outer surface of the shank 13. The annular bearing flange 24 comprises an annular bearing surface 25 configured to abut against the front abutment surface 23 in order to limit the forward displacement stroke of the shank 13. Advantageously, the annular bearing surface 25 is inclined relative to the impact axis A and offset in the direction of the coupling portion of the shank 13.

[0074] according to Figures 1 to 4 In the embodiment shown, the annular support flange 24 further comprises an outer peripheral surface 26 which is substantially cylindrical and extends in the extension of the annular support surface 25 in the direction of the rear end of the shank 13. Advantageously, the outer diameter of the outer peripheral surface 26 is greater than or equal to the outer diameter of the coupling portion.

[0075] Advantageously, each female coupling spline 16 and male coupling spline 17 extends from the annular support flange 24 in the direction of the rear end of the shank 13. Figures 1 to 4 In the illustrated embodiment, the front end portion of each female coupling spline 16 is disposed on the annular support flange 24 and opens to the outer surface of the annular support flange 24 , for example, to the outer peripheral surface 26 .

[0076] according to Figures 1 to 4 In the embodiment shown, each female coupling spline 16 comprises a bottom surface 27 which is substantially planar and extends in the direction of extension of said female coupling spline, and a connecting surface 28 which connects the corresponding bottom surface 27 to the annular support flange 24 and extends forwardly away from the extension axis of the shank 13. Figures 1 to 4 In the embodiment shown, the connecting surface 28 of each female coupling spline 16 is completely formed by a curved concave surface 28.1, which extends in the extension direction of the corresponding female coupling spline 16 and has a curvature radius R that is smaller than the radial height Hr of each male coupling spline 17 provided on the shank 13. The curvature radius R of each curved concave surface 28.1 is advantageously smaller than 15 mm, for example smaller than 10 mm.

[0077] Each female coupling spline 16 may, for example, have a rectangular cross section, thus having two longitudinally extending and substantially parallel side surfaces.However, each female coupling spline 16 may have a generally V-shaped cross section.

[0078] according to Figures 1 to 4 In the embodiment shown, for each male coupling spline 17 , the radial distance DR between the axis of extension of the shank 13 and the top surface 29 of said male coupling spline 17 is substantially constant along said male coupling spline.

[0079] When the cutting edge is stuck in the rock, the rotary percussion hydraulic drill 2 is retracted until the annular bearing surface 25 of the annular bearing flange 24 abuts against the front abutment surface 23 .

[0080] Then, in order to unlock the cutting edge, the rotary drive 18 is activated to drive the shank 13 in rotation. The impact device 4 can also be activated simultaneously with the rotary drive 18, thereby also impacting the shank 13 with the impact piston 5.

[0081] Such activation of the rotary drive 18 and possibly the impact device 4 results in rotational friction of the annular bearing surface 25 of the annular bearing flange 24 against the front abutment surface 23 and possibly an axial impact of the annular bearing surface 25 against the front abutment surface 23 .

[0082] The presence of the annular support flange 24 provided at the front of the female coupling splines 16 and the male coupling splines 17 provided on the shank 13 makes it possible to avoid contact between the front abutment surface 23 and the male coupling splines 17 provided on the shank 13, thereby maintaining the integrity of the male coupling splines. In addition, the fact that the annular support surface 25 is annular ensures a relatively large contact surface between the front abutment surface 23 and the annular support flange 24, thereby ensuring a better distribution of the impact force exerted by the shank 13 on the front abutment surface 23.

[0083] Therefore, the specific construction of the rotary percussion hydraulic drill 2 according to the present invention significantly increases the service life of the shank 13, which makes it possible to significantly reduce the period of time during which the rotary percussion hydraulic drill 2 is not in operation when the shank 13 is replaced, and the risk of damage to the rotary percussion hydraulic drill 2 by wear particles from the shank 13.

[0084] Furthermore, given that the male coupling splines 17 provided on the shank 13 extend directly from the annular support flange 24 , the axial length of the shank 13 is not affected by the presence of the annular support flange 24 , which makes it possible to obtain a compact rotary percussion hydraulic drill 2 .

[0085] Figure 5 The shank 13 of the rotary percussion hydraulic drill 2 according to the second embodiment of the present invention is shown. Figures 1 to 4 The first embodiment shown differs primarily in that the front end of each female coupling spline 16 opens into an annular bearing surface 25 of an annular bearing flange 24. According to this embodiment of the invention, the radial height of the annular bearing flange 24 at the outlet of the front end of each female coupling spline 16 is greater than 50% of the maximum radial height of the annular bearing flange 24, for example greater than or equal to 60% or 70%.

[0086] It goes without saying that the invention is not limited to the single embodiment of a rotary percussion hydraulic drill of the type described above by way of example, but rather encompasses all its variants.

Claims

1. A rotary percussion hydraulic drilling rig (2), comprising: Subject (3); A shank (13) for coupling to at least one drill rod equipped with a tool, said shank (13) comprising a coupling portion comprising a female coupling spline (16) and a male coupling spline (17) angularly offset from one another relative to an axis of extension of said shank (13); a striking piston (5) slidably mounted inside the body (3) along a striking axis (A) and configured to strike the handle (13); a rotation drive device (18) configured to drive the handle (13) to rotate about a rotation axis substantially coincident with the impact axis, the rotation drive device (18) comprising a coupling member (19) disposed around the handle (13), the coupling member (19) comprising a male coupling spline and a female coupling spline capable of rotationally coupling with the female coupling spline and the male coupling spline (16, 17) of the handle (13), respectively; a front abutment surface (23) fixed relative to the body (3), the front abutment surface (23) being annular and extending around the handle (13), the handle (13) being configured to abut against the front abutment surface (23) so as to limit the forward displacement travel of the handle (13), The invention is characterized in that the shank (13) comprises an annular supporting flange (24) which is provided on an outer surface of the shank (13) and comprises an annular supporting surface (25) configured to abut against the front abutment surface (23), and each of the female coupling splines and the male coupling splines (16, 17) provided on the shank (13) extends from the annular supporting flange (24) in the direction of the impact piston (5), and each female coupling spline (16) provided on the shank (13) comprises a bottom surface (27) and A connecting surface (28) connects the corresponding bottom surface (27) to the annular support flange (24) and extends forward away from the extension axis of the shank (13), the connecting surface (28) of each female coupling spline (16) provided on the shank (13) being at least partially formed by a curved concave surface (28.1) extending substantially in the extension direction of the corresponding female coupling spline and having a curvature radius (R) that is smaller than the radial height (Hr) of each male coupling spline provided on the shank (13).

2. The rotary percussion hydraulic drilling rig (2) according to claim 1, wherein: The maximum outer diameter of the annular supporting flange (24) is greater than or equal to the outer diameter of the coupling portion.

3. The rotary percussion hydraulic drilling rig (2) according to claim 1 or 2, wherein: The front end portion of each female coupling spline (16) provided on the shank (13) is provided on the annular supporting flange (24).

4. The rotary percussion hydraulic drill (2) according to any one of claims 1 to 3, wherein: Each male coupling spline (17) provided on the shank (13) includes a top surface (29) extending from the annular support flange (24).

5. The rotary percussion hydraulic drill (2) according to any one of claims 1 to 4, wherein: The connecting surface (28) of each female coupling spline (16) provided on the shank (13) is formed entirely by a corresponding curved concave surface (28.1).

6. The rotary percussion hydraulic drill (2) according to any one of claims 1 to 5, wherein: Each of the female coupling spline and the male coupling spline (16, 17) provided on the handle (13) extends to the rear end portion of the handle (13).

7. The rotary percussion hydraulic drill (2) according to any one of claims 1 to 6, wherein: The radius of curvature (R) of each curved concave surface (28.1) is less than 15 mm.

8. The rotary percussion hydraulic drill (2) according to any one of claims 1 to 7, wherein: The annular support flange (24) includes a generally cylindrical outer peripheral surface (26).

9. The rotary percussion hydraulic drilling rig (2) according to claim 8, wherein: A front end portion of each female coupling spline (16) provided on the shank (13) opens to the outer peripheral surface (26).

10. The rotary percussion hydraulic drill (2) according to any one of claims 1 to 8, wherein: The front end of each female coupling spline (16) provided on the shank (13) opens into an annular support surface (25) of the annular support flange (24).

11. The rotary percussion hydraulic drilling rig (2) according to claim 10, wherein: The radial height of the annular support flange (24) at the outlet of the front end of each female coupling spline (16) provided on the shank (13) is greater than 50% of the maximum radial height of the annular support flange (24).

12. The rotary percussion hydraulic drill (2) according to any one of claims 1 to 11, wherein: The annular bearing surface (25) is inclined relative to the impact axis and is offset in the direction of the impact piston (5).

13. A rotary percussion hydraulic drill (2) according to any one of claims 1 to 12, comprising an annular abutment ring provided in the body (3), said annular abutment ring being arranged around the shank (13) and comprising the front abutment surface (23).

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