Disc chipper for crushing lumpy feed material, particularly wood

Abstract

A disc chipper for crushing lumpy feed material. The disc chipper has a crushing rotor driven by a drive unit, rotating about an axle, including a rotor shaft and a chipping disc connected in a rotationally fixed manner with the rotor shaft. The chipping disc has chipping knives, which are transversely aligned in the disc plane to the rotational direction and which cooperate with stationary counter knives for the comminution of the feed material. In order to ensure a secure and accurate fastening of the chipping disc on the rotor shaft and to thereby conduct the driving force from the rotor shaft to the chipping disc without damage, the rotor shaft in the region of the bearing seat for the chipping disc has a polygonal cross section and the chipping disc has a centric through-hole form-locking thereto.

Claims

1. A disc chipper for comminution of lumpy feed material, the disc chipper comprising: a crushing rotor driven by a drive unit and rotating about a rotational axis; a rotor shaft; and a chipping disc connected in a rotationally fixed manner with the rotor shaft, a surface of the chipping disc having chipping knives that are transversely aligned in a disc plane to the rotational direction and that cooperate with stationary counter knives for the comminution of the feed material, wherein the rotor shaft has a bearing seat for the chipping disc, the bearing seat having a polygonal cross section, and the surface of the chipping disc having the chipping knives having a centric through-hole extending therethrough, the through-hole having a polygonal cross section that is complementary to and mates with the polygonal cross section of the bearing seat for a form-lock fit, and wherein the chipping disc has a weight of at least 5,000 kg.

2. The disc chipper according to claim 1, wherein the polygonal cross section of the bearing seat for the chipping disc is formed as an equilateral and/or equiangular polygon, a square, a pentagon, a hexagon or an octagon.

3. The disc chipper according to claim 1, wherein the rotor shaft in the region of the bearing seat has a bearing flange radially extending to the rotational axis, wherein a back side of the chipping disk, which faces away from the chipping knives, rests against the bearing flange.

4. The disc chipper according to claim 1, wherein in the region of the chipping disc, a rigid receptacle is provided, the rigid receptacle having a bearing surface and a stop surface, wherein the counter knives each have a blade, a longitudinal edge situated opposite the blade and a flat side connected between the blade and the longitudinal edge, wherein the counter knives are arranged with the flat side against the bearing surface and indirectly abutting, via an adjusting device, against the stop surface with the longitudinal edge situated opposite the blade, wherein the adjusting device has an adjuster for adjusting a relative position of the counter knife in respect of the receptacle.

5. The disc chipper according to claim 4, wherein the adjuster comprises at least one spacer plate which is disposed between the longitudinal edge and the stop surface.

6. The disc chipper according to claim 4, wherein the adjuster comprises at least one screw which can be screwed into a threaded bore that is transverse to the longitudinal edge on the plane of the counter knife, the at least one screw having a head, the head having a first surface that faces the counter knife and a second surface that opposes the first surface and faces away from the counter knife and wherein the second surface of the head of the at least one screw bears against the stop surface.

7. The disc chipper according to claim 4, further comprising a first cover plate, wherein the counter knives each have a second flat side that opposes the flat side, and wherein an angled distal end of the first cover plate bears against the second flat side of the counter knives.

8. The disc chipper according to claim 7, wherein the rigid receptacle further includes a supporting plate, wherein one end of the supporting plate bears against the rigid receptacle and a second end of the supporting plate bears against a lower surface of the first cover plate.

9. The disc chipper according to claim 7, wherein a second distal end of the first cover plate, that opposes the angled distal end, has a rib that extends perpendicularly therefrom.

10. The disc chipper according to claim 1, wherein the drive unit includes a primary drive and a secondary drive, which drive the crushing rotor via a transmission, wherein the primary drive is in active operative connection with the crushing rotor during a crushing operation, and the secondary drive is in active operative connection with the crushing rotor during an acceleration process.

11. The disc chipper according to claim 10, wherein the primary drive is composed of an electric motor and the secondary drive is composed of a hydraulic motor.

12. The disc chipper according to claim 10, wherein the primary drive and the secondary drive are arranged coaxially to a drive shaft of the transmission and are coupled thereto.

13. The disc chipper according to claim 10, wherein the transmission has a gear ratio of between 5:1 and 6:1.

14. The disc chipper according to claim 10, wherein the primary drive has a power P of between 450 kW and 1500 kW, or between 900 kW and 1400 kW.

15. The disc chipper according to claim 10, wherein the secondary drive comprises a power P of between 25 kW and 75 kW, or between 35 kW and 55 kW.

16. The disc chipper according to claim 1, The disc chipper according to claim 1, wherein the chipping disc has a weight of at least 7,500 kg.

17. The disc chipper according to claim 1, wherein the chipping disc has a weight of a minimum of 10,000 kg.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

(2) FIG. 1a is a side view of an inventive disc chipper with a closed housing,

(3) FIG. 1b illustrates the disc chipper shown in FIG. 1 with an open housing,

(4) FIG. 2 is a section through the disc chipper shown in FIG. 1, along the local line II-II.

(5) FIG. 3 is a plan view of the disc chipper shown in FIG. 1, including the drive unit,

(6) FIG. 4a is a view of the front side of the chipping disc of the disc chipper shown in FIG. 1,

(7) FIG. 4b is a view of the back side of the chipping disc shown in FIG. 4a, and

(8) FIG. 5 is a detailed view of the region marked in FIG. 2 with V.

DETAILED DESCRIPTION

(9) FIGS. 1a, 1b, 2 and 3 show a disc chipper 1 according to the invention in different views and sections. The disc chipper 1 has a housing 2, which is composed of a lower part 3 and a hood-like upper part 4. The housing 2 has a front wall 5 and a rear wall 6 plane-parallel thereto, which are connected via a cylindrical housing shell 7 and in this manner enclose a downwardly open comminuting chamber 9 which extends along an axis 8. The housing upper part 4 is formed of a housing segment 10 via a sector-shaped portion, which, driven by a cylinder-piston assembly 11, can be pivoted about the axis 12 in order to open the housing 2, for example, for maintenance or repair work. The lower housing part 3 is reinforced by a number of rib-shaped stiffening plates 13.

(10) In the transition area between the lower part 3 and the upper part 4, in each case a console 14 is secured on the outside front wall 5 and the rear wall 6, on each of which a pivot bearing 15, 16 is positioned for receiving a crushing rotor 17 that rotates about the axis 8. The crushing rotor 17 has a rotor shaft 18, which shaft end associated with the front wall 5 is supported by the local pivot bearing 16, and which other end is passed through the pivot bearing 15 and attached to a drive described in particular in more detail in FIG. 3.

(11) The shaft section extending within the housing 2 forms a bearing seat 19 for a chipping disc 20 oriented perpendicular to the axis 8, which, for example, may comprise a diameter of about 2.5 m and a weight of about 10,000 kg. The chipping disc 20 has a centric through-hole 21 with which it is mounted on the bearing seat 19. For exact axial positioning of the chipping disc 20, the bearing seat 19 has a bearing flange 22 encircling the shaft circumference, which seat delimits the axial insertion depth of the chipper disc 20. The chipping disc 20 is clamped against the bearing flange 22 by means of the screws 23 (FIGS. 2 and 4a).

(12) To transmit the torque from the rotor shaft 18 to the chipping disc 20, the bearing seat 19 is designed as a hexagon and the through-hole 21 of the chipping disc 20 has an outline complementary thereto. In this way, relatively large force transfer surfaces result that are also capable of transferring great driving forces as they occur especially in chipping discs with large weight and large diameter, without overstressing the material.

(13) The more precise design of the chipping disc 20 is also shown in FIGS. 4a and 4b. The chipping disc 20 has a number of linearly extending passage gaps 24 reaching from the disc front side 25 to the disc back side 26 and which extend star-shaped from the near-axial inner disc portion to the near outer disc portion (FIG. 4b). On the disk front side 25 along each passage gap 24, a chipping knife 27 is arranged which with a predetermined blade projection protrudes from the plane of the chipping disc 20 and guides the freshly obtained chips into the passage gap 24. The blades of all chipping discs 27 thus lie on a common plane, plane-parallel to the disc plane. For producing high-quality wood chips, it is important that the chipping knives rotate in exactly this plane.

(14) For the loading of the disc chipper 1 with feed indicated by arrow 34, a housing opening 28, into which a horizontal feed chute 29 opens extending at an acute angle to the disc plane, is disposed at the front wall 5 of the housing 2 approximately centrally below the pivot bearing 15. Opposite the housing opening 28, the feed chute 29 has an opening 30, which is closable by a pivotable flap 32 about an axis 31. The opening and closing of the flap 32 is carried out by means of a cylinder-piston unit 33, which is hinged both on the housing 2 and on the flap 32.

(15) Counter knives 35 cooperating with the chipper knives 27 extend along the lower horizontal edge and the vertical edge of the housing opening 28 that adjoins in the direction of rotation 45. As shown particularly in FIG. 5, for this purpose receptacles are provided in these areas, which are each welded in the form of a rigid bearing beam 36 with the front wall 5 of the housing 2 and of which the side facing the housing opening 28 is formed by an inclined bearing surface 37. Along the edge of the bearing surface 37 facing away from the housing opening 28, a strip-shaped extension 39 extends to form a stop surface 38.

(16) The counter knife 35 rests with its planar side full-surface on the bearing surface 37 and is fixed via a clamping strip 40 and a number of clamping screws 41 on the bearing beam 36. So that the counter knives 35 are arranged at the exact axial distance from the chipping knives 27, an adjusting device is provided on the back side of the counter knives 35 facing the stop surface 38, said adjusting device being supported by the stop surface 38. In the present embodiment, the adjusting device includes two adjusting screws 42 arranged at a lateral distance, each engaging with its threaded portion in threaded holes at the rear side of the counter knives 35, and each being supported by their screw head on the stop surface 38. By a suitably wide screwing-in or unscrewing of the adjustment screws 42, the distance between the counter knives 35 from the stop surface 38 and thus the distance of the blades of the counter knife 35 from the chipping knives 27 can be adjusted. Setting the correct insertion depth of the adjustment screws 42 can be done via a lock nut or a suitable number of spacer plates between the back side of the counter knives 35 and the screw head.

(17) Accessibility to the horizontal counter knives 35 near the bottom 43 of the feed shaft 29 is ensured there by a provided opening, which is filled by a removable first cover plate 44. With its front edge, the first cover plate 44 joins gap-free to the counter knife 35, while the opposite rear edge is supported on the opening edge. To support the first cover plate 44 perpendicular to the display plane, a supporting plate 46 approximately centrally supporting the first cover plate 44 is provided on the support beam 36, and the rear edge of the first cover plate 44 is reinforced by arranging a rib 47.

(18) In the region of the vertical counter knives 35, these are protected by a second removable cover 48 which is integrated in the flap 32 and in the course of opening the flap 32, releases the vertical counter knives 35. The second cover 48 has a plate that is rigidly welded to the outside of the flap 32 along the flap edge facing the hinge region, perpendicular to the flap plane, and that in the course of closing the housing opening 28 covers the vertical counter knives 35.

(19) An inventive drive unit as shown in FIG. 3 in a plan view drives the chipping disc 20. The drive unit comprises an electric motor 49 as a primary drive, which shaft is aligned coaxially to the drive shaft 51 of a transmission 52 and acts directly via a first clutch 50 on the drive shaft 51. The output shaft 53 of the transmission 52 is in turn coupled via a second coupling 54 with the rotor shaft 18 that is driving the chipping disc 20. The two clutches 50 and 54 are each composed of two coaxially opposed clutch discs, at which sides facing each other resilient carriers and openings are alternately arranged. Through a mutual offset of the clutch plates in the circumferential direction, when merging the clutch plates, the carriers of the one clutch disc position themselves in the openings of the other clutch disc. Because of the toothing thereby formed, torques can be transmitted. Within the transmission 52, the rotational speed of the electric motor 49 is decelerated at a ratio of 5:1 to 6:1 into a rotational speed of about 300 rev/min on the output side, which corresponds to the speed of the chipper disc 20. The output of the primary drive thereby amounts to 1400 kW.

(20) On the opposite side of the transmission 52, a hydraulic motor 55 is arranged as a secondary drive, which shaft that is coaxial to the drive shaft 51 is directly coupled to the drive shaft 51. The hydraulic motor 55 is connected via hydraulic lines 56 to a hydraulic unit 57 having pumps and an oil tank. The output of the secondary drive amounts to 45 kW.

(21) In order to bring the inventive disc chipper 1 into the operating state, the chipping disc 20 is accelerated by means of the secondary drive to the rotational speed at which the disc chipper 1 is later operated in the chipping operation. During acceleration, the primary drive is turned off, that is, the rotor of the electric motor 49 remains passive and is only set in rotation by the hydraulic motor 55 together with the chipping disc 20. When the predetermined operating speed is reached, the secondary drive is switched off and the primary drive is switched on. Thus, during the chipping operation, the secondary drive is driven by the primary drive, without participating in driving the chipping disc 20. Only in the braking phase of the chipping disc 20 is the hydraulic motor 55 again turned on, after the primary drive has been previously switched off. The hydraulic oil pumped in the circuit by the hydraulic motor 55 carries out the braking process.

(22) If maintenance or repair work are to be done on the chipping disc 20, for example, when worn chipping knives 27 must be replaced by sharpened ones, the secondary drive can also be used for the gradual readjustment of the chipping disc in the respective blade change position without the need for the primary drive to be enabled.

(23) The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.