Dual-shaft shredder with interchangeable cutting blade set and releasable shaft ends

Abstract

A dual-shaft shredder for comminuting solids or solids in liquids comprises a housing defining an interior comminuting space, an inlet opening, an outlet opening, and a first and second cutting disc block each having a plurality of cutting discs disposed on a hub body such that an intermediate space is present between each two adjacent cutting discs. Some of the first cutting discs each engage in the intermediate space between two adjacent second cutting discs and some of the second cutting discs each engage in the intermediate space between two adjacent first cutting discs. A first shaft stub and a second shaft stub extend into an axial recess of the first and second cutting disc blocks for transmitting torques, and a first clamping device and a second clamping device clamp the shaft stubs against the cutting disc blocks.

Claims

1. A dual-shaft shredder for comminuting solids or solids in liquids comprising: a housing defining an interior comminuting space; an inlet opening in the housing for feeding solids into the comminuting space; an outlet opening in the housing for discharging comminuted solids out of the comminuting space; a first cutting disc block having a plurality of first cutting discs disposed on a first hub body such that an intermediate space is present between each two adjacent first cutting discs and a second cutting disc block having a plurality of second cutting discs disposed on a second hub body such that an intermediate space is present between each two adjacent second cutting discs, the first and second cutting disc blocks being axially offset from each other, such that at least some of the first cutting discs each engage in the intermediate space between two adjacent second cutting discs and at least some of the second cutting discs each engage in an intermediate space between two adjacent first cutting discs, the first and second cutting disc blocks each comprising a first axial recess; a first shaft stub extending into the first axial recess of the first cutting disc block for transmitting torques; a second shaft stub extending into the first axial recess of the second cutting disc block for transmitting torques; a first clamping device clamping the first shaft stub against the first cutting disc block under tension; and a second clamping device clamping the second shaft stub against the second cutting disc block under tension; further comprising a first and a second axle insert, wherein the first and second cutting disc blocks each comprise a second axial recess, respectively, and the first axle insert is received in the second axial recess of the first cutting disc block and the second axle insert is received in the second axial recess of the second cutting disc block; wherein the first and second axial recesses of each of the first and second cutting disc blocks, respectively, are each connected to each other by an axial bore having a smaller diameter than the respective first and second axial recesses so as to form first and second shoulders for each of the first and second cutting disc blocks, and wherein the first and second clamping devices clamp the first axle insert against the first shaft stub and the second axle insert against the second shaft stub, respectively.

2. The dual-shaft shredder according to claim 1, wherein the first cutting disc block is fixedly attached to the first shaft stub and the second cutting disc block is fixedly attached to the second shaft stub.

3. The dual-shaft shredder according to claim 2, wherein the first cutting disc block and the second cutting disc block are each fixedly attached to the first and second shaft stub, respectively, by a positive shaft-hub connection.

4. The dual-shaft shredder according to claim 1, wherein the first and second shaft stub each comprise a truncated cone-shaped segment contacting a corresponding truncated cone-shaped segment of the first axial recesses of the first and second cutting disc blocks, respectively.

5. The dual-shaft shredder according to claim 4, wherein the truncated cone-shaped segment of the cutting disc blocks is formed by a sleeve placed in the first axial recesses.

6. The dual-shaft shredder according to claim 5, wherein the sleeve is pre-tensioned by means of a spring packet.

7. The dual-shaft shredder according to claim 1, wherein the first and second clamping devices comprise a first and second threaded rod, respectively.

8. The dual-shaft shredder according to claim 7, wherein the first threaded rod is received in a threaded hole in the first shaft stub and extends into or through a through hole in the first axle insert, and wherein the second threaded rod is received in a threaded hole in the second shaft stub and extends into or through a through hole in the second axle insert.

9. The dual-shaft shredder according to claim 1, wherein the first and second axle inserts each comprises an axle stub for supporting the first and second cutting disc blocks, respectively.

10. The dual-shaft shredder according to claim 1, wherein the first and second axle inserts each comprises a truncated cone-shaped segment contacting a corresponding truncated cone-shaped segment of the second axial recesses of the first and second cutting disc blocks.

11. The dual-shaft shredder according to claim 1, wherein the first and second axial recesses in the first and second cutting disc blocks are implemented symmetrical to each other.

12. The dual-shaft shredder according to claim 1, wherein a first and second axle stub for supporting the first and second cutting disc blocks, respectively, are received in a bearing housing forming a unit together with the first and second axle stubs, said unit being reversibly removable from the cutting disc blocks and/or the housing.

13. A dual-shaft shredder for comminuting solids or solids in liquids comprising: a housing defining an interior comminuting space; an inlet opening in the housing for feeding solids into the comminuting space; an outlet opening in the housing for discharging comminuted solids out of the comminuting space; a first cutting disc block having a plurality of first cutting discs disposed on a first hub body such that an intermediate space is present between each two adjacent first cutting discs and a second cutting disc block having a plurality of second cutting discs disposed on a second hub body such that an intermediate space is present between each two adjacent second cutting discs, the first and second cutting disc blocks being axially offset from each other, such that at least some of the first cutting discs each engage in the intermediate space between two adjacent second cutting discs and at least some of the second cutting discs each engage in an intermediate space between two adjacent first cutting discs, the first and second cutting disc blocks each comprising a first axial recess; a first shaft stub extending into the first axial recess of the first cutting disc block for transmitting torques; a second shaft stub extends into the first axial recess of the second cutting disc block for transmitting torques; a first clamping device clamping the first shaft stub against the first cutting disc block under tension; a second clamping device clamping the second shaft stub against the second cutting disc block under tension; and an oil supply device supplying a bearing of the first or second cutting disc block associated with said bearing with oil through an oil channel extending through the first or second cutting disc block; further comprising a first and a second axle insert, wherein the first and second cutting disc blocks each comprise a second axial recess, respectively, and the first axle insert is received in the second axial recess of the first cutting disc block and the second axle insert is received in the second axial recess of the second cutting disc block; wherein the first and second axial recesses of each of the first and second cutting disc blocks, respectively, are each connected to each other by an axial bore having a smaller diameter than the respective first and second axial recesses so as to form first and second shoulders for each of the first and second cutting disc blocks, and wherein the first and second clamping devices clamp the first axle insert against the first shaft stub and the second axle insert against the second shaft stub, respectively.

14. The dual-shaft shredder according to claim 13, further comprising ring seals disposed about the first or second cutting disc block associated with said bearing.

15. The dual-shaft shredder according to claim 13, wherein the oil channel comprises a first oil channel segment running through the first axial bore of the first cutting disc block.

16. The dual-shaft shredder according to claim 15, wherein the oil supply device further comprises a second oil channel segment fluidically connected to the first oil channel segment and providing oil for a bearing of the second cutting disc block.

17. The dual-shaft shredder according to claim 15, wherein the first oil channel segment runs through the first shaft stub or the first axle insert.

18. A dual-shaft shredder for comminuting solids or solids in liquids comprising: a housing defining an interior comminuting space; an inlet opening in the housing for feeding solids into the comminuting space; an outlet opening in the housing for discharging comminuted solids out of the comminuting space; a first cutting disc block having a plurality of first cutting discs disposed on a first hub body such that an intermediate space is present between each two adjacent first cutting discs and a second cutting disc block having a plurality of second cutting discs disposed on a second hub body such that an intermediate space is present between each two adjacent second cutting discs, the first and second cutting disc blocks being axially offset from each other, such that at least some of the first cutting discs each engage in the intermediate space between two adjacent second cutting discs and at least some of the second cutting discs each engage in an intermediate space between two adjacent first cutting discs, the first and second cutting disc blocks each comprising a first axial recess; a first shaft stub extending into the first axial recess of the first cutting disc block for transmitting torques; a second shaft stub extends into the first axial recess of the second cutting disc block for transmitting torques; a first clamping device clamping the first shaft stub against the first cutting disc block under tension; a second clamping device clamping the second shaft stub against the second cutting disc block under tension; an oil supply device supplying a bearing of the first or second cutting disc block associated with said bearing with oil through an oil channel extending through the first or second cutting disc block; and an oil monitoring device detecting a leakage of a seal sealing the bearing, wherein the oil monitoring device monitors an oil level or an oil pressure in the oil channel; wherein the oil channel comprises a first oil channel segment running through the first axial bore of the first cutting disc block; and the first oil channel segment runs through the first shaft stub or the first axle insert.

19. A dual-shaft shredder for comminuting solids or solids in liquids comprising: a housing defining an interior comminuting space; an inlet opening in the housing for feeding solids into the comminuting space; an outlet opening in the housing for discharging comminuted solids out of the comminuting space; a first cutting disc block having a plurality of first cutting discs disposed on a first hub body such that an intermediate space is present between each two adjacent first cutting discs and a second cutting disc block having a plurality of second cutting discs disposed on a second hub body such that an intermediate space is present between each two adjacent second cutting discs, the first and second cutting disc blocks being axially offset from each other, such that at least some of the first cutting discs each engage in the intermediate space between two adjacent second cutting discs and at least some of the second cutting discs each engage in an intermediate space between two adjacent first cutting discs, the first and second cutting disc blocks each comprising a first axial recess; a first shaft stub extending into the first axial recess of the first cutting disc block for transmitting torques; a second shaft stub extending into the first axial recess of the second cutting disc block for transmitting torques; a first clamping device clamping the first shaft stub against the first cutting disc block under tension; and a second clamping device clamping the second shaft stub against the second cutting disc block under tension; wherein the first and second shaft stub each comprise a truncated cone-shaped segment contacting a corresponding truncated cone-shaped segment of the first axial recesses of the first and second cutting disc blocks, respectively.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is described in more detail below, using an embodiment example and referencing the attached figures. Shown are:

(2) FIG. 1 is a perspective view of a dual-shaft shredder in an assembled state;

(3) FIG. 2 is another view of the dual-shaft shredder from FIG. 1, wherein the housing is removed;

(4) FIG. 3 is a third view of the dual-shaft shredder from FIGS. 1 and 2, having the cutting disc blocks removed and bearing housing removed;

(5) FIG. 4 is a partial section through the dual-shaft shredder from FIG. 2 with separate details showing a shaft stub and an axle stub;

(6) FIG. 5 is an overview showing a partial section view of a dual-shaft shredder of a second embodiment example having two separate details;

(7) FIG. 6A is an enlarged view of detail A from FIG. 5; and

(8) FIG. 6B is an enlarged view of detail B from FIG. 5.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(9) A dual-shaft shredder 1 according to the present embodiment example comprises a gearbox segment 2 and a comminuting segment 4. A drive motor 6 and a gearbox 8 are provided in the gearbox segment 2, by means of which the two first and second cutting disc blocks 10, 12 are coupled to the drive motor 6. The gearbox 8 comprises two gears having different numbers of teeth (not shown) meshing with each other. Rotary motions of the two cutting disc blocks 10, 12 are thereby produced in opposite directions and at different rotary speeds. Only the corresponding drive shaft (also not shown) of the first cutting disc block 10 is coupled to the drive motor 6, and the second drive shaft (not shown) for the second cutting disc block 12 is driven exclusively by the gearbox 8. The drive motor 6 and the gearbox 8 are altogether implemented as described in DE 20 2010 010 662 U1. In this respect, reference is made in full to said disclosure and the disclosed content thereof is incorporated herein.

(10) The two cutting disc blocks 10, 12 are disposed in a housing 14 of the comminuting segment 4. The housing 14 comprises an inlet opening 16 and an outlet opening 18 each for connecting to a pipeline system or the like of a plant. The inlet opening 16 and the outlet opening 18 are implemented opposite each other and identical in geometry. It should be understood, however, that the inlet and outlet can be different, for example, in what are known as side rails. The housing 14 is coupled to the gearbox 8 by means of a flange 20. The housing 14 can also be removed from the gearbox 8 by means of the flange 20.

(11) The dual-shaft shredder 1 is shown in FIG. 2 in the removed state of the housing 14.

(12) The first and second cutting disc blocks 10, 12 are clamped against the flange 20. A bearing housing 24 is provided at the distal end from the gearbox 8 and is described in more detail below. The bearing housing 24 can be removed from the cutting disc blocks 10, 12 as a unit.

(13) FIG. 3 shows the removed state of the bearing housing 24. Two axle stubs 26, 28 protrude out of the bearing housing 24. Corresponding shaft stubs 30, 32 having geometry corresponding to the axle stubs 26, 28 extend out of the gearbox 8. While the shaft stubs 30, 32 protrude into first axial recesses 34, 36 of the cutting disc blocks 10, 12, the axle stubs 26, 28 are received in second axial recesses 38, 40 of the cutting disc blocks 10, 12. The first axial recesses 34, 36 and the second axial recesses 38, 40 are implemented symmetrical to each other, that is, particularly identical or largely identical in internal geometry. Complete mirror symmetry is not required, but rather the recesses 34, 36, 38, 40 are implemented such that the orientation of the cutting disc blocks 10, 12 can be rotated 180° relative to the longitudinal axis A1 thereof (as shown in FIG. 3).

(14) With reference to FIG. 4 and particularly to the two details shown, the attachment of the cutting disc blocks 10, 12 in the dual-shaft shredder 1 is now described. FIG. 4 shows only the first cutting disc block 10 in section, while the second cutting disc block 12 is shown in plan view. It should be understood, however, that the second cutting disc block 12 is identical in section to the first cutting disc block 10. Altogether, the cutting disc blocks 10, 12 are implemented identical to each other, which also applies to the first and second shaft stubs 30, 32 and the first and second axle stubs 26, 28.

(15) It can initially be seen in FIG. 4 that the shaft stub 30 extends for a length LW in the axial direction and the two cutting disc blocks 10, 12 extend over a length LM. The axial length LW is about 10% of the axial length LM. It is thus evident from FIG. 4 that the dual-shaft shredder 1 according to the present invention can be operated having different lengths of cutting disc blocks 10, 12. Only one axially adapted housing 14 is thus provided, in which the corresponding cutting disc blocks 10, 12 are received. The shaft stubs 30, 32 and the drive 6 and the gearbox 8 are not thereby changed.

(16) The shaft stub 30 comprises a truncated cone-shaped segment 42 at the free end thereof. A sleeve 44 is provided in the interior of the recess 34 and correspondingly comprises a truncated cone-shaped segment at the inner diameter. Said segment corresponds to the truncated cone-shaped segment 42. The sleeve 44 contacts a transmitting element 46 in turn contacting a spring packet 48, comprising a plurality of spring washers in the present embodiment example. The spring washers of the spring packet 48 are then supported on a ring shoulder 50 in the cutting disc block 10. Depending on the embodiment, the spring packet 48 can also comprise only one single spring, particularly a spring washer.

(17) A key 52 is provided for transmitting torque from the shaft stub 30 to the cutting disc block 10. As an alternative, a spline shaft connection or transmitting torque by frictional fit in the conical connection are also conceivable and preferable.

(18) A second axial recess 38 is made in the opposite side of the cutting disc block 10. An axle insert in the form of an axle stub 26 is received in said axial recess 38. The external geometry of the axle stub 26 is altogether identical to that of the shaft stub 30 and also has a truncated cone-shaped segment 54. A sleeve 56 having a truncated cone-shaped inner segment, a transmitting element 58, and a spring packet 60 are provided correspondingly in the recess 38. The spring packet 60 is supported against a second ring shoulder 62.

(19) The first and second axial recesses 34, 38 are connected to each other by means of a through hole 64. A threaded rod 66 extends through the through hole 64. A first end 68 of the threaded rod 66 is received in a corresponding threaded bore 70 of the shaft stub 30. From there, the threaded rod 66 extends through a through hole 72 in the axle insert implemented as an axle stub 26 and is coupled to a nut 74 at the outer end. By tightening the nut 74, the axle stub 26 can be clamped against the shaft stub 30 by means of the threaded rod 66. The conical segments 54, 56 and 42, 44 thereby ensure self-centering of the axle stub 26 and the shaft stub 30 in the recesses 38, 34. Additional pretensioning of the sleeves 56, 44 is provided by means of the spring packets 48, 60 via the transmitting element 46, 58, so that tensioning without clearance is achieved.

(20) The outer end of the axle stub 26 is further received in a rolling bearing 76 supported correspondingly in the bearing housing 24. Access to the nut 74 is closed off by means of a cover 78 comprising a bayonet joint 80 having an internal hex drive 82, so that a user can remove the cover 78. After the cover 78 is removed, the nut 74 can be tightened or loosened. If the nut 74 is loosened, the clamping of the axle stub 26 against the shaft stub 30 is relieved, and when the nut 74 is removed, it is possible to remove the entire bearing housing 24 including the two axle stubs 26, 28, as shown in FIG. 3.

(21) Because the clamping is relieved in this state, the two cutting disc blocks 10, 12 can be removed (see FIG. 3) and replaced with a second pair of cutting disc blocks 10, 12, or only the orientation thereof is modified. It has been demonstrated that, particularly in vertically oriented dual-shaft shredders 1, wherein the axis A1 (FIG. 3) is aligned vertically, wear on the cutting discs near the ground is greater, as heavy and hard objects tend to fall downward. By changing the orientation of the cutting disc blocks, the potentially worn lower ends can be placed in the upper region having lesser loading.

(22) As can further be seen particularly in FIG. 4, the individual cutting discs are integrally connected to the inner hub body. Each cutting disc block 10, 12 is altogether made from a solid material by means of machining, particularly using turning and milling. Stress peaks are thereby prevented and service life is further increased.

(23) Each cutting disc block 10, 12 comprises a plurality of individual cutting discs 101, 102, 103, 104 (only two of the cutting discs in the block 10, 12 have reference numerals). The number of cutting discs 101, 102, 103, 104 depends on the overall size of the dual-shaft shredder 1 and the comminuting task to be performed.

(24) A plurality, particularly six, cutting edge elements 105 (see FIGS. 1 and 4) are further implemented at the circumference of each cutting disc 101, 102, 103, 104 and evenly distributed in the circumferential direction. The cutting edge elements form helical curves 106 of a six-start thread (a higher or lower number of thread starts is also possible) having a steep pitch along the circumference of each cutting disc block 10, 12. The cutting edge elements 105 of the cutting disc block 10 here form a left-handed thread (whereby a right-handed thread is also possible and preferable), and the cutting edge elements 105 of the cutting disc block 12 do the same. The two cutting disc blocks 10, 12 are thereby implemented identically.

(25) FIGS. 5, 6A, and 6B illustrate a second embodiment example of a dual-shaft shredder 1. Identical and similar elements have the same reference numeral as the first embodiment example (FIGS. 1 through 4), so that reference is made thereto in full. The differences from the first embodiment example are particularly emphasized below.

(26) In addition to the first embodiment example (FIGS. 1 through 4), the dual-shaft shredder 1 of the second embodiment example (FIGS. 5, 6A, 6B) comprises an oil supply device 200 for lubricating the first and second cutting disc blocks 10, 12 As seen in FIGS. 5 and 6A, the first and second cutting disc blocks 10, 12 are supported on the housing 14 by means of the first and second shaft stubs 30, 32. To this end, the first shaft stub 30 is supported in a first bearing, implemented here as a rolling bearing, more specifically as a first spherical rolling bearing 202, and the second shaft stub 32 is supported in second bearing, implemented here as a rolling bearing, more specifically as a second spherical rolling bearing 204, of which only part is visible in FIG. 6A but implemented correspondingly to the first spherical rolling bearing 202.

(27) The first axle insert 26 is supported in the rolling bearing 76 supported at the bearing housing 24 at the axially opposite side of the cutting disc blocks 10, 12 (see FIG. 6B). The rolling bearing 76 is implemented as a first taper rolling bearing for better receiving axial forces. The second axle insert 28 is supported in a corresponding rolling bearing 206 implemented as a second taper rolling bearing and also supported on the bearing housing 24.

(28) In order to supply oil to said bearings 76, 206, an oil connection 208 is provided at the housing 14. In the present embodiment example, the oil connection 208 is connected to a hose 209 by means of which oil can be provided at the oil connection 208, preferably at a predefined oil pressure. In addition to the bearings 76, 206, corresponding face seals 77, 207 associated therewith are also preferably supplied with oil. There can also be embodiments in which only the face seals 77, 207 are supplied with oil.

(29) The oil connection 208 opens within the housing 14 into a sealed oil coupling 210, in turn fluidically connected to a first axial channel 212 running through the first shaft stub 30. Said first axial channel 212 is connected to a first radial channel 214, in turn fluidically connected to a second axial channel 216. The first radial channel 214 is substantially closed off radially externally by means of the key 52. It can occur that a small amount of oil escapes, and then collects in the region of the key or under the same, but this does not further inhibit operation. Production is thereby facilitated. The first radial channel 214 can be bored radially in the first shaft stub 30 in the region of the groove for the key 52 and an additional closure is not required.

(30) The second axial channel 216 then exits from the first shaft stub 30 at the end face (with reference to FIG. 6A, left). A diagonal channel 218 is cut in the transmitting element 46 receiving the spring packet 48 and opens into the first axial bore 64 in the first cutting disc block 10. In this manner, the first axial bore 64 is connected to the oil connection 208. The first axial channel 212, the first radial channel 214, the second axial channel 216, the diagonal channel 218, and the bore 64 together form segments of a first oil channel 219 running through the bore 64.

(31) As a result, oil flows from the oil connection 208 into the first axial bore 64 of the first cutting disc block 10. Because the inner diameter of the bore 64 is selected to be correspondingly greater than the outer diameter of the threaded rod 66, the flow is also not impeded.

(32) The through hole 72 is implemented in the first axle insert 26 at the opposite end of the first cutting disc block 10 (FIG. 6B), deviating from the first embodiment example (FIG. 4): in a first segment 220, the through hole 72 has an enlarged inner diameter, particularly greater than the outer diameter of the first threaded rod 66. The corresponding thread 224 is made only in a second segment 222, distal with respect to the first cutting disc block, and engages with the first threaded rod 66. A second radial channel 226 is made in the first axle insert 26 and opens radially into a first bearing space 228 and can thus supply the bearing 76 and preferably the face seal 77 with oil. The through hole 72 and the second radial channel 226 also form a segment of the first oil channel 219.

(33) Instead of a simple cover 78, as in the first embodiment example (FIGS. 1 through 4), in the present embodiment example (FIGS. 5, 6A, 6B), a connecting unit 230 having a second oil channel 232 is provided. Said second oil channel 232 connects the first bearing space 228 with a second bearing space 234 associated with the second cutting disc block 12, more precisely the rolling bearing 206. In this manner, the second oil channel 232 provides oil for the second cutting disc block 12.

(34) Leak-tightness can be tested in that a predefined pressure is applied at the oil connection 208 and said pressure or the oil level is monitored. If a change in the oil level or the pressure is detected, then there is a leak to be closed off in the oil supply device 200, that is, in a seal sealing the oil circuit against the surrounding area or against the interior space of the dual-shaft shredder.

(35) Said oil supply device 200 is then particularly advantageous if the end of the dual-shaft shredder 1 in which the axle inserts 26, 28 are provided is installed in a drain or the like, so that the bearings 76, 206 are not easily accessible for lubricating. The present consideration makes particular use of the bore 64 and uses the same as a segment of the first oil channel 219. A particularly advantageous design is thereby achieved.