US 5,961,185 AGranted

Shielded cutterhead with small rolling disc cutters

AssigneeExcavation Engineering Associates, Inc.

InventorsJames E. Friant, Levent Ozdemir

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Abstract

An improved disc type rolling rock cutter, and novel cutterheads employing such cutters. A rock cutter with an improved, simplified structure, with compact bearing, and smooth, rounded blade shape is disclosed. The design incorporates a cutter ring, bearing, and seal into a single cutter ring assembly. The cutter may be assembled and disassembled for rework by a single worker with simple hand tools. Replacement of worn out cutter rings is done quickly and easily by removing the old ring assembly and then sliding a new ring, bearing, and seal assembly on to the cutter shaft. This simplified assembly is achieved by using a comparatively large shaft which is normally in the range of 40-50% of the ring diameter. The shaft design is sufficiently robust to permit a cantilever mount of the cutter. The unique configuration allows 30,000 lbs. or more thrust to be applied to a 5 inch diameter miniature disc. This capacity permits single disc cutter technology to be applied to smaller bits or cutterheads than previously possible. Also, a unique method of shaping and installing hard metal inserts improves cutting efficiency over the life of the cutter, and increases wear life in highly abrasive conditions.

Claims60

Dependent claims

The combination of a shielded face cutterhead and a plurality of small diameter rolling disc cutters, said combination adapted for excavating a tunnel of preselected diameter, said combination comprising:

(a) a shielded cutterhead, said shielded cutterhead adapted for rotary movement about an axis of rotation which extends along a centerline of the tunnel;
(b) two or more rolling disc cutters, said rolling disc cutters configured for use in combination with said shielded cutterhead to exert pressure against substantially solid matter such as rock, compacted earth, or mixtures thereof by acting on a cutting face, said rolling disc cutters, upon rolling as a result of rotary movement of said shielded cutterhead, forming a kerf by penetration into said cutting face so that, when two or more rolling disc cutters are used, solid matter between a proximate pair of said kerfs is fractured to produce chips which separate from said cutting face, and wherein each of said two or more rolling disc cutters comprise
(1) a stiff shaft, said shaft providing an axis for rotation of said rolling disc cutter thereabout, said shaft having
(i) a proximal end directly protruding from said shielded cutterhead at an angle which allows said rolling cutter to address said cutting face, and
(ii) a distal end,
(2) a cutter ring assembly, said cutter ring assembly further comprising
(i) an annular cutter ring having an interior annulus defining portion and an outer ring portion, said outer ring portion including a cutting edge having diameter OD and radius R.sub.1
(ii) a bearing assembly, said bearing assembly adapted
(A) to substantially fit into said annulus of said cutter ring, and
(B) in a close fitting relationship with said shaft, so that said cutter ring may rotate with respect to and be supported by said shaft,
(iii) said bearing assembly comprising
(A) a bearing, and
(B) a seal, said seal providing a lubricant retaining seal for said interior annulus portion of said cutter ring,
(3) a retainer assembly, said retainer assembly adapted to retain said cutter ring assembly on said shaft,
(4) a cap, said cap having an interior surface portion, said cap adapted to seal said interior annular portion of said cutter ring assembly, so that, in cooperation with said seal and said cutter ring, a lubricant retaining chamber is provided.

12 more elements

(a) a shielded cutterhead, said shielded cutterhead adapted for rotary movement about an axis of rotation which extends along a centerline of the tunnel;
(b) two or more rolling disc cutters, said rolling disc cutters configured for use in combination with said shielded cutterhead to exert pressure against substantially solid matter such as rock, compacted earth, or mixtures thereof by acting on a cutting face, said rolling disc cutters, upon rolling as a result of rotary movement of said shielded cutterhead, forming a kerf by penetration into said cutting face so that, when two or more rolling disc cutters are used, solid matter between a proximate pair of said kerfs is fractured to produce chips which separate from said cutting face, and wherein each of said two or more rolling disc cutters comprise
(1) a stiff shaft, said shaft providing an axis for rotation of said rolling disc cutter thereabout, said shaft having
(i) a proximal end directly protruding from said shielded cutterhead at an angle which allows said rolling cutter to address said cutting face, and
(ii) a distal end,
(2) a cutter ring assembly, said cutter ring assembly further comprising
(i) an annular cutter ring having an interior annulus defining portion and an outer ring portion, said outer ring portion including a cutting edge having diameter OD and radius R.sub.1
(ii) a bearing assembly, said bearing assembly adapted
(A) to substantially fit into said annulus of said cutter ring, and
(B) in a close fitting relationship with said shaft, so that said cutter ring may rotate with respect to and be supported by said shaft,
(iii) said bearing assembly comprising
(A) a bearing, and
(B) a seal, said seal providing a lubricant retaining seal for said interior annulus portion of said cutter ring,
(3) a retainer assembly, said retainer assembly adapted to retain said cutter ring assembly onto said shaft;
(4) a cap, said cap having an interior surface portion, said cap adapted to seal said interior annular portion of said cutter ring assembly, so that, in cooperation with said seal and said cutter ring, a lubricant retaining chamber is provided;
(5) wherein said cutter ring further comprises:
(i) a pair of laterally spaced apart support ridges, said ridges having therebetween a groove forming portion, said groove forming portion including
(A) a pair of interior walls, and
(B) an interior bottom surface interconnecting with said interior walls, and
(ii) wherein said interior walls outwardly extend relative to said interior bottom surface to thereby define a peripheral groove around the outer edge of said outer cutter ring,
(6) two or more hardened, wear-resistant inserts, said inserts substantially aligned within and located in a radially outward relationship from said groove, said inserts further comprising
(i) a substantially continuous engaging contact portion of radius R.sub.1, said contact portion on the outer side of said inserts and adapted to act on said face, and
(ii) a lower groove insert portion, said groove insert portion,
(A) having a bottom surface shaped and sized in complementary matching relationship relative to said bottom surface of said groove, and
(B) having first and second opposing exterior side surfaces, said first and second side surfaces being shaped and sized in a complementary matching relationship relative to said interior walls,
(iii) a rotationwise front and rear portion, wherein said lower groove insert portion of said inserts fit within said groove in a close fitting relationship which defines a slight gap between said inserts and said interior walls, and
(7) wherein a somewhat elastic preselected filler material is placed between and joins said inserts in a spaced apart relationship to said groove bottom and to said interior sidewalls, said preselected filler material having a modulus of elasticity so that said inserts can slightly move elastically relative to said cutter ring so as to tend to relieve stress and strain acting on said insert segments.

24 more elements

(a) a shielded cutterhead, said shielded cutterhead adapted for rotary movement about an axis of rotation which extends along a centerline of the tunnel;
(b) two or more rolling disc cutters, said rolling disc cutters configured for use in combination with said shielded cutterhead to exert pressure against substantially solid matter such as rock, compacted earth, or mixtures thereof by acting on a cutting face, said rolling disc cutters, upon rolling as a result of rotary movement of said shielded cutterhead, forming a kerf by penetration into said cutting face so that, when two or more rolling disc cutters are used, solid matter between a proximate pair of said kerfs is fractured to produce chips which separate from said cutting face, and wherein each of said two or more rolling disc cutters comprise:
(1) an outer cutter ring, said cutter ring further comprising:
(i) a pair of laterally spaced apart support ridges, said ridges having therebetween a groove forming portion, said groove forming portion including
(A) a pair of interior walls, and
(B) an interior bottom surface interconnecting with said interior walls
(ii) wherein said interior walls outwardly extend relative to said interior bottom surface to thereby define a peripheral groove around the outer edge of said outer cutter ring,
(2) two or more hardened, wear-resistant inserts, said inserts substantially aligned within and located in a radially outward relationship from said groove, said inserts further comprising
(i) a substantially continuous engaging contact portion of radius R.sub.1, said contact portion on the outer side of said inserts and adapted to act on said face, and
(ii) a lower groove insert portion, said groove insert portion,
(A) having a bottom surface shaped and sized in complementary matching relationship relative to said bottom surface of said groove, and
(B) having first and second opposing exterior side surfaces, said first and second side surfaces being shaped and sized in a complementary matching relationship relative to said interior walls,
(iii) rotationwise, a rounded leading edge surface portion of reduced curvature relative to contact portion radius R.sub.1, and a rounded trailing edge surface portion of reduced curvature relative to contact portion radius R,
(iv)wherein said lower groove insert portion of said inserts fit within said groove in a close fitting relationship which defines a slight gap between said inserts and said interior walls, and
(3) wherein a somewhat elastic preselected filler material is placed between and joins said inserts in a spaced apart relationship to said pair of interior sidewalls and said interior bottom surface, said preselected filler material having a modulus of elasticity so that said inserts can slightly move elastically relative to said cutter ring so as to tend to relieve stress and strain acting on said insert segments.

12 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/852,003Filed 6 May 1997 · division
Priority: 20 Sep 1993
Granted: 5 Oct 1999
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

E21B 10/25
Characterised by bearing, lubrication or sealing details: characterised by sealing details
E21B 10/12
Roller bits: with discs cutters
E21B 10/22
Roller bits: characterised by bearing, lubrication or sealing details
E21B 10/50
Characterised by wear resisting parts, e.g. diamond inserts: the bit being of roller type