ZA200202681B

ZA200202681B - Rotor and rotor tip.

Info

Publication number: ZA200202681B
Application number: ZA200202681A
Authority: ZA
Inventors: Andrew Graham Catto
Original assignee: Milestone Equipment Pty Ltd
Priority date: 1999-09-07
Filing date: 2002-04-05
Publication date: 2002-12-24

Description

ROTOR AND ROTOR TIP

BACKGROUND OF THE INVENTION

THIS invention relates to a rotor for a vertical shaft-type impact crusher, and in particular to a tip for such a rotor.

Vertical shaft-type impact crushers are used for crushing bulk material such as natural rock, for example, into smaller stones, particles or grains. These materials are typically used in aggregate, mining or industrial minerals industries.

Impact crushers of this type use centrifugal forces generated by high-speed rotation of the rotor to accelerate the bulk material into an impact zone in order to crush the material. In the case of anvil-type impact crushers, the material is crushed into smaller sized stones or gravel. In the case of autogenous impact crushers, the surfaces of already crushed stones are . smoothed to provide gravel or the like having a generally uniform size distribution. -

The rotors for use in the vertical shaft-type impact crushers generally have radial wings or blades which accelerate the raw stones towards the impact zone when rotated at high speed.

The blades typically support tips which protect discharge ports associated with the rotor. Rotors typically have three discharge ports, although rotors having five or six discharge ports are also known. In operation, the tips are worn by the accelerated stones. In order to reduce this wear, they typically include a tip insert formed from tungsten carbide or similar wear resistant material. However, these tips are still subjected to wear and damage and need to be replaced relatively frequently.

CONFIRMATION COPY

1 3, N

SUMMARY OF THE INVENTION

According to the invention there is provided a rotor for a vertical shaft-type impact crusher, the rotor comprising: a rotor body defining a central axis of rotation; a plurality of radially or obliquely extending blades or wings for . accelerating bulk material to be crushed towards an impact zone of : the vertical shaft-type impact crusher; and a plurality of corresponding tips radially disposed relative to the central axis of rotation of the rotor body, each tip comprising at least one pair of opposed tip inserts formed of wear resistant material located at or adjacent the periphery of the tip, the tip inserts being oriented so that in use one of the tip inserts, the operative tip insert, is directed towards the accelerated bulk material and the other tip . insert(s), the inoperative tip insert(s), is/are directed in the opposite direction, the arrangement being such that when the operative insert is worn or damaged, the orientation of the tip inserts can be interchanged, thereby to increase the operational life of the tip.

Lo ~The invention extends to a rotor tip for a vertical shaft-type impact crusher, i the tip comprising: a tip body arranged to be mounted on or received by a rotor of a vertical shaft-type impact crusher; and at least one pair of opposed tip inserts located at or adjacent the periphery of the tip body and being operatively oriented so that one of the tip inserts is exposed to wear and the other tip insert(s) is/are sheltered from wear, the orientation of the tip inserts being reversible or interchangeable.

The invention also extends to a vertical shaft-type impact crusher incorporating the rotor and tip of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in more detail, by way of example only, with reference to the accompanying drawings in which:

Figure 1 is a diagrammatic plan view of a vertical shaft-type crusher rotor of the invention;

Figure 2 is a perspective view of a first embodiment of a rotor tip of the invention,

Figure 3 is a plan view of the rotor tip of Figure 2;

Figure 4 is a perspective view of a second embodiment of a rotor tip of the invention;

Figure 5 is a plan view of the rotor tip of Figure 4;

Figure 6 is a perspective view of a third embodiment of a rotor tip of the invention; and

Figure 7 is a plan view of the rotor tip of Figure 6.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to Figure 1 of the drawings, there is shown, diagrammatically, a rotor 10 for a vertical shaft-type impact crusher. The rotor 10 consists of a circular rotor body 12 including three oblique wings or blades 14 supported thereon. Three associated discharge port tips 16 are supported at the respective distal ends 18 of the blades 14 adjacent the periphery 20 of the rotor body 12. Upon rotation of the rotor body 12, the blades 14 accelerate raw material introduced into the vertical shaft-type impact crusher towards an impact zone (not shown) for crushing the bulk material into smaller sized stones or gravel.

The discharge port tips 16 are provided for protecting the rotor discharge ports (not shown). In use, the discharge port tips 16 are worn by accelerated stones. In order to reduce this wear, each discharge port tip 16 is provided with a pair of opposed tip inserts 22 and 24 formed of a wear resistant material such as tungsten carbide, for example. The respective tip inserts 22, the operative tip inserts, are arranged to be directed towards the centre 26 of the rotor body 12 whilst the respective tip inserts 24, the inoperative tip inserts, face the opposite direction and are sheltered from wear.

Referring to Figures 2 and 3, there is shown a first embodiment of a - discharge port tip of the invention. The discharge port tip 30 consists of a tip holder or body 32 formed of a suitable steel, either cast or fabricated, and including a pair of opposed slots 34 and 36, machined therein. A pair of opposed tip inserts 38 and 40 formed of an appropriate wear resistant material, in this case tungsten carbide, are located in the slots 34 and 36, ] respectively. The inserts 38 and 40 may be brazed or welded in place, or they may be glued into the respective slots 34 and 36 using an appropriate | a glue or bonding agent.

In use, the discharge port tip 30 is arranged on a rotor so that the tip insert 38 is directed towards the centre 26 of the rotor body 12 whilst the tip insert 40 is disposed in the opposite direction. As a result, the tip insert 38 is exposed to accelerating stones or other bulk material whilst the tip 40 is sheltered therefrom. When the tip insert 38 is worn to the point that it is no longer effective, the tip 30 is simply removed, rotated through 180°, and remounted or attached to the rotor body 12 or respective wings 14. In this way, the tip insert 40 is now exposed to accelerating stone or bulk material.

In the case of failure of the tip insert 38, for instance due to it wearing through before being interchanged with the tip insert 40, the tip insert 40 acts as a back-up to prevent damage to the discharge port or the rotor.

Referring to Figures 4 and 5, there is shown a second embodiment of a discharge port tip of the invention. This discharge port tip 50 consists of a tip holder or body 52, including a pair of opposed slots 54 and 56, and a pair of opposed tip inserts 58 and 60 formed of wear resistant material, once again tungsten carbide in this case, located in the slots 54 and 56, respectively. The tips 58 and 60 are once again held in place by brazing, welding or using an appropriate glue or bonding agent. In this embodiment, instead of presenting a relatively narrow wear surface as with the tip inserts 38 and 40 of discharge port tip 30, the tip inserts 58 and 60 of discharge port tip 50 present substantially larger wear surfaces 62 and 64, respectively, to accelerated stone and other bulk material. Once again, once tip insert 58, the operative tip insert, is worn to the point where it is no . longer effective, the discharge port tip 50 may be rotated so that the tip insert 60 is now in the path of the accelerated material. The tip insert 60 - again provides a back-up in case of failure of the tip insert 58.

As mentioned above, the tip inserts of the invention are typically held in the relevant discharge port tip by way of brazing, welding or using an appropriate glue or bonding agent. The use of an appropriate glue or bonding agent is preferred because it is generally more cost effective and, additionally, brazing or welding may lead to a change in the physical properties of the rotor body, which may not be desirable. A problem with the use of glue or similar bonding agent, is that the inoperative tip insert may be prone to ejection from the tip body due to strong centrifugal forces in use, which may lead to damage to the rotor and/or injury to an operator.

In order to address the above problem, a third embodiment of a discharge port tip 70 has a tip body 72 having opposed, tapered or dove tailed slots

~ 74 and 76 for receiving correspondingly shaped tip inserts 78 and 80, respectively, as shown in Figures 6 and 7. Although this arrangement is preferred, any appropriately shaped slot and tip insert may be used to provide a physical barrier to ejection of the tip insert from the tip body under the centrifugal forces caused by rotation of the rotor. in the above embodiments, the tip inserts are formed of single layers or portions of tungsten carbide or other appropriate wear resistant material. If desirable, a second layer or portion of tungsten carbide or other material may be positioned directly behind the relevant tip insert. These additional layers or portions of tungsten carbide or the like provide additional back up should the tip inserts be broken, damaged or worn through. In such an arrangement, the inserts are reversed once both layers of the first insert are no longer effective.

By providing discharge port tips having at least one pair of opposed tip inserts as described above, the effective life of the tip is substantially ] increased. Accordingly, there is a reduction in the number of tip changes : that need to take place during the operation of a vertical shaft-type impact - crusher. As a result, there is an increase in the productivity of a particular vertical shaft-type impact crusher utilising the tip inserts of the invention, which is also more cost effective than conventional machines. Although the above embodiments describe the use of a single pair of opposed tip inserts, it is possible to include more than one such pair. However, this will lead to an increase in the costs of the tip and the tip body may be worn out before oC all the tip inserts have been used, resulting in wasted costs. ) oo

Claims

1. A rotor for a vertical shaft-type impact crusher, the rotor comprising: a rotor body defining a central axis of rotation; a plurality of radially or obliquely extending blades or wings for accelerating bulk material to be crushed towards an impact zone of the vertical shaft-type impact crusher; and a plurality of corresponding tips radially disposed relative to the central axis of rotation of the rotor body, each tip comprising at least one pair of opposed tip inserts formed of wear resistant material located at or adjacent the periphery of the tip, the tip inserts being oriented so that in use one of the tip inserts, the operative tip.insert, is directed towards the accelerated bulk material and the other tip insert(s), the inoperative tip insert(s), is/are directed in the opposite direction, the arrangement being such that when the operative insert is worn or damaged, the orientation of the tip inserts can be interchanged, thereby to increase the operational life of the tip.

2. A rotor according to claim 1, wherein each tip comprises a tip body So oo © including at least one pair of opposed slots machined therein for receiving the respective tip inserts.

3. A rotor according to claim 2, wherein the slots are dove tailed or of similar shape so that the tip inserts, which are similarly shaped, when located in the slots are prevented from being ejected from the tip body by centrifugal forces generated by the rotor in use.

4. A rotor according to claim 2 or claim 3, wherein the tip inserts are secured in their respective slots by brazing, welding or glueing.

5. A rotor according to any one of the preceding claims, wherein each tip comprises a single pair of opposed tip inserts.

6. A rotor tip for a vertical shaft-type impact crusher, the tip comprising: a tip body arranged to be mounted on or received by a rotor of a vertical shaft-type impact crusher; and at least one pair of opposed tip inserts located at or adjacent the periphery of the tip body and being operatively oriented so that one of the tip inserts is exposed to wear and the other tip insert(s) is/are sheltered from wear, the orientation of the tip inserts being reversible or interchangeable.

7. A rotor tip according to claim 6, wherein the tip body includes at least one pair of opposed slots machined therein for receiving the respective tip inserts.

8. A rotor tip according to claim 7, wherein the slots are dove tailed or of similar shape so that the tip inserts, which are similarly shaped, when located in the slots are prevented from being ejected from the tip body by centrifugal forces generated by the rotor in use.

9. A rotor tip according to claim 7 or claim 8, wherein the tip inserts are secured in their respective slots by brazing, welding or glueing.

10. A rotor tip according to any one of claims 6 to 9, comprising a single pair of opposed tip inserts.

11. A vertical shaft-type impact crusher incorporating a rotor according to any one of claims 1 to 5 or a rotor tip according to any one of claims 6 to 10.