HOUSING MOUNT ASSEMBLY FOR A ROLLER CUTTER

Abstract

A housing mount assembly for supporting a roller cutter is described. The housing mount assembly comprises a housing mount defining an outer surface for attaching to a housing and a profiled inner surface extending away from the outer surface, the profiled inner surface defining a channel extending in a longitudinal direction, and a seat support block extending away from the outer surface and defining a first seat support surface transverse to the channel, and a second seat support surface transverse to the first seat support surface. The housing mount assembly further comprises a removable seat mounted on the seat support surfaces and defining two transverse roller cutter shaft support surfaces whereby the removable seat and the seat support block together provide support for a roller cutter shaft.

Description

BACKGROUND OF THE INVENTION

A tunnel boring machine (“TBM”) is used to create tunnels in soil or rock. A conventional TBM includes a rotatably driven cutting head that supports a plurality of roller cutter assemblies, which are intended to be replaced when worn down.

One type of roller cutter assembly is disclosed in FIG. 1 of US 2018/0258764 to Lenaburg. However, this roller cutter assembly is typically welded onto the TBM, which makes in situ removal time consuming and difficult. Furthermore, the need to weld the roller cutter assembly to the TBM reduces the available options for materials that can be used for the roller cutter assembly.

SUMMARY OF THE DISCLOSURE

According to a first aspect there is provided a housing mount assembly for supporting a roller cutter, the housing mount assembly comprising: (i) a housing mount defining an outer surface for attaching to a housing and a profiled inner surface extending away from the outer surface, the profiled inner surface defining a channel extending in a longitudinal direction, and a seat support block extending away from the outer surface and defining a first seat support surface transverse to the channel, and a second seat support surface transverse to the first seat support surface; (ii) a removable seat mounted on the seat support surfaces and defining two transverse roller cutter shaft support surfaces whereby the removable seat and the seat support block together provide support for a roller cutter shaft; and (iii) an engagement device for releasably holding the removable seat in proximity to the seat support surfaces.

The engagement device may be located between the removable seat and the outer surface.

The housing mount may further define a recess in which the engagement device is mounted. The recess may be located above the seat support block so that it is located behind the removable seat when assembled.

The engagement device may comprise a magnet, a spring clip coupling, a snap fit coupling, a deformable (elastic) material mounted in a perimeter of the recess to provide an interference fit for the removable seat when inserted therein, an adhesive for coupling the removable seat to the recess or other portion of the housing mount, a bolt extending through an aperture defined by the removable seat and engaging with a complementary thread in the profiled inner surface of the housing mount, or any other convenient mechanical coupling.

Where the engagement device comprises a bolt extending through an aperture, the aperture may comprise a slot, for example, extending generally parallel with the channel, to allow some movement of the removable seat during use.

The bolt may initially be located at a lower portion of the slotted aperture to allow the bolt to rise up the slotted aperture as the removable seat wears during use.

In some embodiments, one purpose of the engagement device may hold the removable seat in position during assembly of the parts of a roller cutter assembly, where the roller cutter assembly comprises a roller cutter mounted between opposing complementary housing mounts, and held together by two retaining couplings, optionally in the form of bolt and wedge sets, each bolt being partially located within, or adjacent to, a channel.

The second seat support surface may be obliquely transverse to the first seat support surface. In particular, the second seat support surface and a removable seat sidewall may define complementary surfaces to enable the second seat support surface to assist in retaining the removable seat in place. For example, the second seat support surface may be tapered inwardly (i.e. inclined towards the channel as the seat support surface extends away from the outer surface); and the removable seat may define a tapered sidewall corresponding to the tapered second seat support surface so that the removable seat is retained in place by the mutual interaction of the tapered surfaces.

The housing mount may comprise cast or forged iron or steel to facilitate welding of the housing mount to a housing of a tunnel boring machine.

The housing mount assembly may further comprise a removable insert mounted on an opposite side of the channel to the removable seat, wherein part of the retaining coupling acts against the removable insert and an opposite part of the retaining coupling acts against a shaft of the roller cutter.

The removable seat (and or the removable insert) may comprise a high hardness metal or alloy as there is no requirement to weld the removable seat. This has the advantage of improving the wear resistance, and therefore the useful life, of the housing mount assembly.

According to a second aspect there is provided an assembly for a roller cutter, the assembly comprising: a pair of complementary housing mounts as set forth in the first aspect.

According to a third aspect there is provided a roller cutter assembly comprising a roller cutter mounted in the assembly of the second aspect and held in place by a pair of retaining couplings.

Each retaining coupling may comprise: (i) a bolt extending through the longitudinal channel securing (ii) a wedge at one end thereof and (iii) a clamp block abutting a clamping surface defined by the housing mount. The wedge may abut an angled face of the roller cutter shaft to maintain the roller cutter shaft in contact with the transverse roller cutter shaft support surfaces defined by the removable seat.

According to a fourth aspect there is provided a tunnel boring machine comprising a plurality of roller cutter assemblies as set forth in the third aspect.

It should now be appreciated that when a roller cutter assembly has worn down due to the removable seat wearing beyond a usable point, the removable seat can be easily removed and the roller cutter assembly re-assembled without requiring welding joints to be removed; thereby greatly speeding up the process of replacing a worn down seat.

It should now also be appreciated that the removable seat can be made from a very hard material because it does not need to be welded; thereby allowing the useful life of the seat to be increased.

DESCRIPTION OF THE DRAWINGS

These and other aspects will now be described, by way of example only, with reference to the accompanying drawings, in which:

FIG. 1 is a simplified, exploded perspective view of part of a roller cutter assembly according to one embodiment of the present invention;

FIG. 2 is a simplified, front elevation view of the roller cutter assembly parts of FIG. 1 in assembled form (with one part shown partly in broken line);

FIG. 3 is a simplified, side view of the roller cutter assembly parts of FIG. 1 in assembled form;

FIG. 4 is a simplified, plan view of a complete roller cutter assembly comprising the housing mount assembly parts and roller cutter shown in FIG. 1 in assembled form and a complementary housing mount; and

FIG. 5 is a simplified perspective view of an alternative part for use in a roller cutter assembly according to another embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference is made to FIGS. 1 to 3, which show various views of parts of a roller cutter assembly 10 according to one embodiment of the present invention. The roller cutter assembly 10 comprises a pair of complementary housing mounts 12 (only one of which (12a) is shown in FIGS. 1 to 3, the other housing mount is shown in FIG. 4), each of which is a mirror image of the other. For simplicity and clarity of explanation, only one of the housing mounts 12a will be described because the other housing mount 12b is identical (other than being the mirror image of the one being described). The housing mounts 12 are typically permanently fixed to the TBM cutter wheel (not shown), usually by a welding joint but a mechanical coupling may be used. The housing mounts 12 are typically made of steel, but other materials may be used.

Reference is also made to FIG. 4, which is a simplified, plan view of a complete roller cutter assembly comprising the parts of FIG. 1 and the complementary housing mount 12b, all in assembled form.

The housing mount 12a comprises an outer surface 14 (best seen in FIGS. 3 and 4), and a profiled inner surface 16 on an opposite side of the housing mount 12 to the outer surface 14. The purpose of the profiled inner surface 16 is to secure in place various removable parts of the roller cutter assembly 10. These removable parts include: a roller cutter 20, a seat 22, an insert 24, and a retaining coupling 26.

The combination of the housing mount 12a, the seat 22, and the insert 24 are referred to as a housing mount assembly. The combination of two complementary housing mount assemblies having the roller cutter therebetween retained in place by the retaining coupling 26 is a roller cutter assembly 10.

Returning to the housing mount 12a, the profiled inner surface 16 thereof partially defines a channel 30 extending in a longitudinal direction (indicated by broken line 32). In particular, the channel 30 is defined by a seat support block 34 and an insert support block 36 of the profiled inner surface 16, and also by the seat 22 and the insert 24 when installed. FIG. 1 illustrates by broken leader lines where the seat 22 and the insert 24 are located on the housing mount 12a when fully assembled.

The seat 22 and optionally the insert 24 are made from a high hardness alloy and are held, at least temporarily during the assembly process, in place by an engagement device (or mechanism) 40. In this embodiment, the engagement device 40 comprises magnetised portions (shown delineated by broken line 40) of the housing mount 12 that attract the seat 22 and the insert 24. High hardness alloys can be used because there is no requirement to weld the seat 22 or insert 24 to the housing mount 12. In other embodiments, the housing mount 12 may define a recess behind the final location of the seat 22, and a magnet may be located in this recess, or an alternative engagement device, such as a spring clip may be located in this recess.

In other embodiments, the seat 22 and/or insert 24 may include a magnetised portion (optionally in the form of a removable magnet or a local magnetised area) that engages with the housing mount 12 (which includes portions attracted to magnets and located opposite the seat and insert magnetised portions), thereby providing an engagement device.

When the seat 22 and insert 24 are temporarily retained in place, the roller cutter 20 (which is a conventional roller cutter) may be mounted on the seat 22 (best seen in FIG. 2). For clarity (to prevent obscuring other parts), the roller cutter 20 is shown in broken line.

The roller cutter 20 is positioned to engage the tunnel face during tunnel boring operations. The roller cutter 20 comprises a cutter ring 50 mounted on a hub 52 rotatable about a shaft 54. The shaft 54 defines a pair of mutually transverse flat surfaces 56a,b and an angled surface 58 opposite an area where the flat surfaces 56a,b are closest.

The seat support block 34 defines a pair of engagement surfaces 60a,b (best seen in FIGS. 1 and 4) for receiving the seat 22. The first engagement surface 60a (also referred to as the horizontal seat support surface) is transverse (generally horizontal in this embodiment) to the longitudinal direction 32; the second engagement surface 60b (also referred to as the vertical seat support surface) is generally parallel to the longitudinal direction 32, but it is angled inwards (best seen in FIG. 4). In other words, the portion of the vertical engagement surface 60b that is nearest the outer surface 14 is further from the channel 30 than the portion of the vertical engagement surface 60b that is furthest from the outer surface 14.

The seat 22 also defines a pair of outer support surfaces 62a,b (also referred to as base 62a and sidewall 62b), and a pair of inner support surfaces 64a,b (also referred to as shaft support surfaces).

The base 62a is complementary, and of similar dimensions, to the horizontal seat support surface 60a, and the sidewall 62b is angled in a complementary manner (and is of similar dimensions) to the vertical seat support surface 60b, thereby providing a closely fitting engagement when the seat 22 is mounted on the seat support block 34. The complementary angles of the sidewall 62b and the vertical seat support surface 60b function as a draft to ensure that the seat 22 is hindered from moving away from the housing mount 12.

The shaft support surfaces 64a,b of the removable seat 22 are mutually transverse (horizontal and vertical in this embodiment) and of similar dimensions to the shaft flat surfaces 56a,b, but are slightly longer (best seen in FIG. 2), thereby ensuring a close-fitting connection.

In a similar way to the seat support block 34, the insert support block 36 defines a pair of insert support surfaces 66a,b for receiving the insert 24. The horizontal surface 66a is flat, and the vertical surface 66b is angled in an opposite (complementary) manner to the vertical seat support surface 60b (best seen in FIG. 4).

The insert 24 defines a pair of outer support surfaces 68a,b (also referred to as base 68a and sidewall 68b), and an inner support surface 70.

The insert base 68a is complementary, and of similar dimensions, to the horizontal insert support surface 66a, and the insert sidewall 68b is angled in a complementary manner (and is of similar dimensions) to the vertical insert support surface 66b, thereby providing a closely fitting engagement when the insert 24 is mounted on the insert support block 36. The complementary angles of the insert sidewall 68b and the vertical insert support surface 66b function as a draft to ensure that the insert 24 is hindered from moving away from the housing mount 12.

The seat support block 34 also defines a clamping surface 72a transverse to the longitudinal direction 32 and at an opposite end of the seat support block 34 to the horizontal seat support surface 60a.

The insert support block 36 also defines a clamping surface 72b transverse to the longitudinal direction 32 and at an opposite end of the insert support block 36 to the horizontal insert support surface 66a.

To assemble the parts, the seat 22 is located on the seat support block 34, the insert 24 is located on the insert support block 36 (both are held in place by the magnetised portions 40), and then the retaining coupling 26 is used to move the roller cutter 20, seat 22 and insert 24 into the correct positions and to hold them in place on a permanent basis.

The retaining coupling 26 comprises a wedge 80 and a clamp block 82 releasably coupled together by a threaded bolt 84 that passes through apertures in the wedge 80 and clamp block 82, and is secured by a pair of nuts 86.

The wedge 80 defines an upright surface 90 parallel to the longitudinal direction 32 and an angled surface 92. The wedge angled surface 92 defines the same angle as the shaft angled surface 58, and the wedge upright surface 90 matches the insert inner support surface 70, to ensure a close-fitting connection.

When the shaft 54 is located on the seat 22 (which is mounted on the seat support block 34) and the insert 24 is located on the insert support block 36, then the wedge 80 can be placed between the shaft 54 and the insert 24, the bolt 84 can be inserted through both the wedge 80 and the clamp block 82 (which abuts the clamping surfaces 72a,b), and then the pair of nuts 86 can be tightened.

Tightening the nuts 86 urges the wedge 80 downwards, which urges the shaft 54 against the removable seat 22. The first draft provided by the sidewall 62b and the vertical seat support surface 60b, and the second draft provided by insert sidewall 68b and the vertical insert support surface 66b, assist in maintaining the roller cutter 20, seat 22, insert 24, and retaining coupling 26 in position.

A complementary housing mount 12 can then be coupled to the other side of the shaft 54 in a similar manner to provide a complete roller cutter assembly ready for installation in a TBM.

A roller cutter assembly is subjected to very high forces during tunnel boring operations. One typical failure mechanism is the point at which the shaft of a roller cutter is supported on a housing mount. This embodiment has the advantage that the roller cutter assembly 10 can be easily disassembled and the worn seat 22 easily removed and replaced with a new seat 22.

Reference is now made to FIG. 5, which is a perspective view of an alternative removable seat 122. The removable seat 122 couples to a housing mount 112a (similar to housing mount 12a) defining a screw threaded aperture therein (shown as broken line 123, which is in a similar location to the engagement device 40 location in FIG. 1). The removable seat 122 defines an aperture 125 in the form of a slot extending generally parallel to the channel 30 (i.e. in the longitudinal direction indicated by broken line 32 in FIG. 1). A bolt 127, having a complementary thread to screw threaded aperture 123, extends through the slot 125 (along axis 129) to secure the removable seat 122 in place against the housing mount 112a. The bolt 127 and screw threaded aperture 123 provide an engagement device to retain the removable seat 122 in position.

A base 162a of the removable seat 122 rests on a first engagement surface 160a (also referred to as the horizontal seat support surface 160a). The slot 125 is configured such that the bolt 127 is initially near the lower end of the slot 125. As the removable seat 122 wears during use, the wear primarily occurs at the base 162a, which results in the removable seat 122 moving downwards, and the bolt 127 effectively rising upwards in the slot 125. The slot 125 therefore allows the removable seat 122 to have a degree of movement during operation of the roller cutter assembly.

In the foregoing description of certain embodiments, specific terminology has been used for the sake of clarity. However, the disclosure is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes other technical equivalents which operate in a similar manner to accomplish a similar technical purpose. Terms such as “upper” and “lower”, “above” and “below”, “vertical” and “horizontal” and the like are used as words of convenience to provide reference points with respect to the Figures, and are not to be construed as limiting terms, nor to imply a required orientation of the assembly.

In this specification, the word “comprising” is to be understood in its “open” sense, that is, in the sense of “including”, and thus not limited to its “closed” sense, that is the sense of “consisting only of”. A corresponding meaning is to be attributed to the corresponding words “comprise”, “comprised” and “comprises” where they appear.

The preceding description is provided in relation to several embodiments which may share common characteristics and features. It is to be understood that one or more features of any one embodiment may be combined with one or more features of the other embodiments. In addition, any single feature or combination of features in any of the embodiments may constitute additional embodiments.

In addition, the foregoing describes only some embodiments of the inventions, and alterations, modifications, additions and/or changes can be made thereto without departing from the scope of the disclosed embodiments, the embodiments being illustrative and not restrictive.

List of Numerals
Roller cutter assembly 10  Vertical seat support
                           surface 60b
Housing mount 12, 112      Seat base 62a, 162a
Outer surface 14           Seat sidewall 62b
Profiled inner surface 16  Seat shaft support
                           surfaces 64a, b
Roller cutter 20           Horizontal insert support
                           surface 66a
Seat 22, 122               Vertical insert support
                           surface 66b
Insert 24                  Insert base 68a
Retaining coupling 26      Insert sidewall 68b
Channel 30                 Inner support surface 70
Longitudinal direction 32  Clamping surface 72a, b
Seat support block 34      Wedge 80
Insert support block 36    Clamp block 82
Engagement device 40       Threaded bolt 84
Cutter ring 50             Pair of nuts 86.
Hub 52                     Wedge upright surface 90
Shaft 54                   Wedge angled surface 92
Shaft flat surfaces 56a, b Insert upright surface 94
Angled surface 58          Screw threaded aperture 123
Horizontal seat support    Aperture (slot) 125
surface 60a, 160a          Bolt 127
                           Bolt axis 129

Claims

1. A housing mount assembly for supporting a roller cutter, the housing mount assembly comprising: (i) a housing mount defining an outer surface for attaching to a housing and a profiled inner surface extending away from the outer surface, the profiled inner surface defining a channel extending in a longitudinal direction, and a seat support block extending away from the outer surface and defining a first seat support surface transverse to the channel, and a second seat support surface transverse to the first seat support surface;(ii) a removable seat mounted on the seat support surfaces and defining two transverse roller cutter shaft support surfaces having an internal corner therebetween whereby the removable seat transverse roller cutter shaft support surfaces provide support for a pair of mutually transverse flat surfaces of a roller cutter shaft; and(iii) an engagement device for releasably holding the removable seat in proximity to the seat support surfaces.

2. A housing mount assembly according to claim 1, wherein the engagement device is located between the removable seat and the outer surface, and the housing mount further defines a recess in which the engagement device is mounted.

3. A housing mount assembly according to claim 2, wherein the recess is located above the seat support block so that the engagement device is located behind the removable seat when assembled.

4. A housing mount assembly according to claim 3, wherein the engagement device comprises: a magnet or a magnetised portion of the housing mount or the removable seat, a spring clip coupling, a snap fit coupling, a deformable material mounted in a perimeter of the recess to provide an interference fit for the removable seat when inserted therein, a bolt extending through an aperture defined by the removable seat and engaging with a complementary thread in the profiled inner surface of the housing mount, or an adhesive for coupling the removable seat to the recess or other portion of the housing mount.

5. A housing mount assembly according to claim 4, wherein the bolt extends through a slot-shaped aperture defined by the removable seat, with the slot extending in the longitudinal direction, and engaging with the complementary thread defined by the profiled inner surface, thereby allowing the bolt to move within the slot-shaped aperture during use of the housing mount assembly.

6. A housing mount assembly according to claim 1, wherein the second seat support surface is obliquely transverse to the first seat support surface, and the second seat support surface and a removable seat sidewall define complementary surfaces to enable the second seat support surface to assist in retaining the removable seat in place.

7. A housing mount assembly according to claim 1, wherein the housing mount assembly further comprises a removable insert mounted on an opposite side of the channel to the removable seat.

8. A housing mount assembly according to claim 7, wherein the removable insert comprises a high hardness metal.

9. A housing mount assembly according to claim 1, wherein the removable seat comprises a high hardness metal.

10. A housing mount assembly according to claim 1, wherein the removable seat comprises less than 50% of the height of the part of the seat support block on which the removable seat is supported.

11. A roller cutter assembly, the assembly comprising: (i) a first housing mount defining an outer surface for attaching to a housing and a profiled inner surface extending away from the outer surface, the profiled inner surface defining a channel extending in a longitudinal direction, and a seat support block extending away from the outer surface and defining a first seat support surface transverse to the channel, and a second seat support surface transverse to the first seat support surface;(ii) second housing mount comprising a mirror image of the first housing mount;(iii) a pair of removable seats, each removable seat (a) being mounted on the seat support surfaces of the housing mounts, and (b) defining two transverse roller cutter shaft support surfaces whereby the removable seat and the seat support block together provide support for a roller cutter shaft;(iv) a pair of engagement devices for releasably holding the removable seat in proximity to the seat support surfaces;(v) a roller cutter mounted on the pair of removable seats and including a shaft defining a pair of mutually transverse flat surfaces at each end thereof, and an angled surface opposite an area where the flat surfaces are closest; and(vi) a pair of longitudinal couplings;wherein each of the pair of removable seats has a first roller cutter shaft support surface transverse to a second roller cutter shaft support surface such that the first and second roller cutter shaft support surfaces provide an internal corner for the pair of mutually transverse flat surfaces of the roller cutter shaft.

12. A roller cutter assembly according to claim 11, wherein each longitudinal coupling comprises: a bolt extending through the longitudinal channel and securing a wedge at one end thereof and a clamp block abutting a clamping surface defined by the housing mount.

13. A roller cutter assembly according to claim 12, wherein the wedge abuts an angled face of a roller cutter shaft to maintain the roller cutter shaft in contact with the removable seat.

14. A roller cutter assembly according to claim 13, wherein the roller cutter assembly comprises a pair of removable inserts.

15. A roller cutter assembly according to claim 14, wherein the wedge abuts the removable insert and an opposite part of the wedge acts against the roller cutter shaft.

16. A roller cutter assembly according to claim 15, wherein each pair of inserts defines an inner support surface mounted opposite the corresponding removable seat.

17. A tunnel boring machine comprising a plurality of roller cutter assemblies according to claim 11.