WO2009065995A1

WO2009065995A1 - Crusher

Info

Publication number: WO2009065995A1
Application number: PCT/FI2007/050622
Authority: WO
Inventors: Pekka Reinikainen
Original assignee: Metso Minerals Inc.
Priority date: 2007-11-20
Filing date: 2007-11-20
Publication date: 2009-05-28
Also published as: WO2009066001A1

Abstract

A crusher comprising a frame (1) provided with a first crushing blade (2), a crushing head (6) provided with a second crushing blade (7), and a main shaft (3) provided with the crushing head (6). A pressurized medium space (10) is provided around the main shaft (3). At least one pressurized medium channel (22) is connected to the pressurized medium space for conveying pressurized medium into the pressurized medium space (10); wherein the setting (s) of the crusher can be changed by the effect of the quantity of the pressurized medium in the pressurized medium space (10).

Description

CRUSHER

Field of the invention

The invention relates to a crusher according toCthe preamble of the appended claim 1.

Background of the invention

When mineral material is crushed, the material is introduced between two hard surfaces pressed against each other, that is crushing blades, in a crusher. The pressing force between the crushing blades makes the material crumble into smaller particles. What is essential for the particle size of the crushed product is the so-called crusher setting, that is, the distance between the crushing blades of the crusher during the cycle of the crusher, which distance should remain constant during the crushing.

The substantially constant setting during the crushing will guarantee that the crushed product is homogenous. However, when the crushing blades are worn, the setting is changed and it has to be adjusted. Furthermore, the setting must be adjusted when the quality and quantity of the material to be crushed vary, in order to produce crushed material that is as homogenous as possible.

There are different types of crushers for different uses and for different mineral and rock types. Typically, cone and gyratory crushers are used for intermediate and fine crushing of mineral material, such as rock. The main shaft of a typical cone crusher is bearing-mounted below the crushing head only. In gyratory crushers, which are normally considered a subtype of the cone crusher, the main shaft of the crusher is further supported at its upper end to the frame by means of an upper thrust bearing.

The cone crushers have a frame consisting of an upper frame and a lower frame, which are fitted to each other. Inside the frame, the main shaft is mounted stationary in the vertical direction. An eccentric shaft is bearing- mounted centrally on the main shaft, the outer jacket of the eccentric shaft being machined obliquely in relation to the main shaft. A crushing head is bearing-mounted on the oblique part of the outer jacket of the eccentric shaft. The crushing head is surrounded by the upper frame of the crusher, and a means called an outer crushing blade or outer blade and functioning as a wearing part is mounted on the inner part of the upper frame. To the crushing head, in turn, is mounted a means called an inner crushing blade or inner blade and used as a wearing part. The inner crushing blade and the outer crushing blade together form a crushing chamber, in which the feed material is crushed. When the eccentric shaft is rotated, the crushing head is entrained in an oscillating motion, wherein the crushing gap between the inner and outer crushing blades varies at each point during the cycle.

The upper frame of a cone crusher consists of an outer part and an inner part which are connected to each other by a thread formed between them. The outer upper frame part is mounted on the lower frame of the crusher. For adjusting the setting of the crusher, the frame parts are rotated with respect to each other around a vertical axis, resulting in a movement of the frame part towards each other in the vertical direction. Thus, the inner upper frame part and the outer crushing blade connected to the same ascend or descend with respect to the inner crushing blade. The rotation of the frame parts is normally effected by hydraulic cylinders or hydraulic engines. The machine elements effecting the crushing movement of such a crusher, that is, the main shaft and the eccentric shaft, remain stationary in the vertical direction when the setting is adjusted. A problem with such a crusher is the large size of the machine, which makes it difficult to place the crusher in a crushing plant. Particularly the fact that the outer dimensions of the crusher are changed when the upper frame is moved during the adjustment of the setting, causes problems. Also, the mechanism for adjusting the setting, a toothed rim remaining outside the upper frame, is large in size.

Gyratory crushers also comprise a frame consisting of an upper frame and a lower frame fitted to each other. A vertical eccentric shaft with an oblique inner hole is fitted inside the frame. A main shaft, to which a crushing head is fastened, is fitted in the hole. The crushing head is surrounded by the upper frame of the crusher, to which the outer blade is fastened. The inner blade is fastened to the crushing head. Also in this crusher type, the inner and outer crushing blades together form a crushing chamber, in which the feed material is crushed. When the crusher is in operation, the eccentric shaft is rotated, wherein the supporting cone is entrained in an oscillating motion and effects variation in the size of the crushing gap and the crushing of the material in the crushing gap.

The setting of the gyratory crusher is normally adjusted by means of a hydraulic system in such a way that the main shaft is moved in the vertical direction with respect to the frame of the crusher. The main shaft of the crusher is placed above the hydraulic control piston of the control system of the crusher by means of a thrust bearing assembly. The control piston is placed in a control cylinder formed in the frame of the crusher, and by controlling the quantity of control oil supplied into the control cylinder it is possible to effect a vertical movement of the main shaft of the crusher to change the setting of the crusher. Thus, for adjusting the setting, both the main shaft and the supporting cone are moved in the vertical direction with : respect to the frame of the crusher. One such system for adjusting the setting is disclosed in patent publication WO 99/22869.

Another alternative for adjusting the setting in a gyratory crusher is disclosed in Fl-patent 82393 (corresponding to US 5,152,468). In the publication, a cup-like control piston is arranged to surround the eccentric shaft and the main shaft partly at their lower end. For adjusting the setting, both the main shaft and the crushing head mounted on it move in the vertical direction with respect to the frame of the crusher. As an advantage of this structure to the structure of the above-presented WO 99/22869, the height of the crusher is reduced, because the control cylinder and the control piston are arranged to surround the main shaft. However, both of these gyratory crusher types have the problem that when adjusting the setting, the main shaft and the parts mounted on it move, wherein, due to the kinematics of the machine, it is difficult to form tight lubrication and control oil sealings. Furthermore, the crusher is large in its outer dimensions, because space must be left in the frames for a vertical adjustment movement in several different locations: for the control piston, for the inner blade, and above the upper thrust bearing. Finnish patent publications 117044 and 1 17325 (corresponding to WO publications 2005/102530 and 2006/067277) disclose an alternative solution for adjusting the setting of a cone crusher. In this solution, the setting is adjusted by moving only the crushing head and the inner crushing blade mounted on it with respect to the outer crushing blade. The adjustment is made hydraulically. The control piston and the control cylinder of the hydraulic control system are formed in the space limited by the main shaft and the crushing head. The control cylinder, to which the control oil is supplied, is placed as an extention to the main shaft. By the effect of the pressure caused by the control oil, the crushing head and the inner crushing blade can be placed in a desired position. The main shaft is stationary.

Publication US 3,801 ,026 discloses a solution for adjusting the setting of a crusher, in which the main shaft is formed cylindrical. The main shaft and a supporting shaft mounted inside the same constitute a cylinder-piston assembly, which is moved in the vertical direction with respect to the frame of the crusher when the setting is adjusted. A control oil space is provided inside the main shaft, underneath the supporting shaft. The crushing head is mounted on bearings on the eccentric shaft surrounding the main shaft, and the supporting shaft supports the crushing head at its lower end. For adjusting the setting, control oil to be supplied into the control oil space is used to adjust the position of the crushing head and the inner crushing blade mounted on the same with respect to the outer crushing blade. The crusher according to the publication is high and takes a lot of space in its use. Furthermore, even this solution involves the problem of difficulties in adjusting the setting when the crushing blades have been worn in use and the adjustment distance is long.

Publication US 4,895,311 discloses a crusher, in which a cylindrical sleeve shaft is arranged around an eccentric shaft. The sleeve shaft supports the crushing head at its lower part. For adjusting the setting, the sleeve shaft is moved by introducing control oil into the sleeve shaft and into a control oil space connected to its sliding surfaces. The control oil space is provided at the upper end of the sleeve shaft and the eccentric shaft. A problem with this arrangement is that the structure of the crusher is complex and comprises a number of sliding parts. Furthermore, a substantial amount of force is required for adjusting the setting, because the pressure effect produced by the control oil is used to move not only the eccentric and the crushing head connected to it but also the sleeve shaft and the main shaft.

Brief summary of the invention

It is thus an aim of the present invention to provide a crusher which eliminates the above-presented problems and which is smaller in size than the crushers of prior art.

To achieve this aim, the crusher according to the invention is primarily characterized in what will be presented in the characterizing part of the independent claim 1.

The other, dependent claims will present some preferred embodiments of the invention.

The invention is based on the idea that for adjusting the setting of the crusher, an annular space for pressurized medium is provided around the main shaft. By the effect of the pressurized medium to be supplied into the pressurized medium space, it is possible to change the distance between the first and the second crushing blades, that is, the setting of the crusher. When adjusting the setting, the crushing head is moved hydraulically, in the way of a piston, on the outer surface of the main shaft. The vertical crushing forces effected by the crushing on the crushing head are transmitted from the crushing head to the frame of the crusher by means of the pressurized medium in the pressurized medium space.

The pressurized medium space is arranged inside the crushing head. It is formed in such a way that it is limited at least to the outer surface of the main shaft. Elsewhere, it is limited at least by the inner surface of the crushing head.

The pressurized medium needed for adjusting the setting is led into the pressurized medium space via a pressurized medium channel formed in the main shaft. The pressurized medium channel is in the form of, for example, a borehole in the main shaft, and the pressurized medium flows inside it. Thus, separate hoses or tubes for conveying pressurized medium will not be needed. Because no space needs to be reserved for separate hoses or tubes in the pressurized medium channel, the borehole can be made small in diameter, wherein it does not substantially reduce the load-bearing capacity of the main shaft.

It is another advantage of the invention that the crusher can be made smaller in size than before. The overall height of the crusher is reduced, because no space needs to be reserved for the adjustment of the setting above and underneath the main shaft. Furthermore, the diameter of the crusher is reduced at its lower part. With the invention, the material costs of the crusher can also be reduced, because less cast material is consumed, thanks to the reduction in the size of the castings. Thanks to the smaller size and the reduction in cast material, the crusher also becomes lighter in weight than before, wherein it is easier to move, for example when it is mounted in place.

The invention also has a less complex structure than the solutions of prior art. For example, no separate control cylinder and piston need to be provided inside the crushing head. In eventual situations of damage or maintenance, the replacement of parts is easy and simple.

Brief description of the drawings

In the following, the invention will be described in more detail with reference to the appended drawings, in which

Fig. 1 is a cross-sectional view of a gyratory crusher, in which the system for adjusting the setting is arranged in the crushing head, and

Fig. 2 shows the crushing head of the gyratory crusher according to

Fig. 1. In Figs. 1 to 2, the same numerals refer to corresponding parts and they will not be explained separately, unless required for the illustration of the subject matter.

Detailed description of the invention

In this description and in the claims, the term "setting of the crusher" refers to the distance between the outer and inner crushing blades of the crusher during the cycle of the crusher. Thus, for example a millimetre (mm) can be used as the unit of measurement. In the figures, the setting is indicated with the symbol s.

Figure 1 shows a gyratory crusher with a frame 1 consisting of an upper frame 1a and a lower frame 1b connected to each other. A first or outer crushing blade 2 is mounted on the upper frame 1a of the crusher, inside the same. The frame 1 surrounds a main shaft 3 which is bearing-mounted eccentrically on an eccentric shaft 4. As seen in the figure, the eccentric shaft 4 is arranged around the main shaft 3, in its lower part. Thus, the eccentric shaft 4 does not extend to the inside of the crushing head. The main shaft 3 is arranged in the form of an elongated piece that is rotationally symmetrical with respect to an axis A. The main shaft 3 is bearing-mounted at its lower end to the lower frame 1 b by means of an axial bearing assembly 24 which transmits the crushing forces parallel to the main shaft 3 to the lower frame. At its upper end, the main shaft 3 is bearing-mounted to an upper supporting arm 5, which is mounted at its other end by securing means to the upper frame 1 a. A conical supporting cone with a downwards expanding cross- section, that is, the crushing head 6, is mounted on the main shaft, spaced downwards from the upper supporting arm 5. A second or inner crushing blade 7 is fastened to the outer surface of the crushing head 6. The outer crushing blade 2 surrounds the inner crushing blade 7 so that a crushing chamber 8 is formed between them. When the crusher is in operation, the eccentric shaft 4 is rotated, wherein the crushing head 6 fastened to the main shaft 3 and the inner crushing blade 7 fastened to the crushing head 6 are entrained in an eccentric movement which results in variation in the size of the crushing chamber 8 and the crushing of the material in the crushing chamber. The eccentric shaft 4 is rotated by means of an electrical or hydraulic actuator (not shown in the figures). The drive shaft 9 of the actuator is arranged in the lower frame 1 b in such a way that it extends through the lower frame 1 b. The structure and the primary operation of the crusher are known as such by a person skilled in the art and, therefore, they will not be described in more detail in this context.

According to the invention, for adjusting the setting of the crusher, the crushing head is moved in a substantially vertical direction. For producing a vertical movement around the main shaft 3, a centrally placed annular pressurized medium space 10 is provided around the main shaft 3, inside the crushing head 6. The volume of the pressurized medium space 10 varies as the quantity of the pressurized medium supplied there varies, which effects a reciprocating movement of the crushing head 6 with respect to the height of the main shaft 3. Thus, the crushing head 6 is used as a kind of a cylinder and the main shaft 3 as a kind of a piston.

Figure 2 shows the crushing head of the gyratory crusher of Fig. 1 in an enlarged view. The pressurized medium space 10 has been formed by fitting a circumferential, radially directed cylindrical first front surface 12 on the axially directed inner surface 11 of the crushing head 6. A second circumferential, radially directed, piston-like front surface 14 is fitted on the outer surface 13 of the main shaft 3 as well. The front surfaces 12 and 14 face each other. The pressurized medium space 10 is also limited by the outer surface 13 of the main shaft and the inner surface 17 of the sliding surface, also facing each other. By the effect of a force exerted on the front surface 12, the crushing head 6 is moved in the direction of the axis A. The force is effected by supplying pressurized medium into the pressurized medium space 10, to produce a pressure effect on the area of the surface 12. As the force increases, the crushing head 6 moves upwards, and as the force decreases, the crushing head 6 moves downwards. When the force effect remains unchanged, the crushing head 6 will remain stationary in the axial direction.

Sliding surfaces 15 and 16 are provided on the inner surface 11 of the crushing head 6, on both sides of the front surface 12. The sliding surfaces provide a bearing between the crushing head 6 and the main shaft 3. As the bearing, slide bearing is preferably used. The sliding surfaces extend around the main shaft 3. The first sliding surface 15 is fitted above the pressurized medium space 10. The second sliding surface 16 is provided to extend from the front surface 12 to the lower surface 6a of the crushing head 6. The inner surface 17 of the second sliding surface is fitted against the axially directed outer surface 13 of the main shaft 3.

To prevent that pressurized medium is not discharged to a significant degree from the pressurized medium space 10 onto the sliding surfaces 15 and 16 and that, as a result, the control pressure of the crusher is not dropped in the pressurized medium space 10 and that the setting of the crusher is not increased accordingly, at least one cylindrical sealing is provided on the crushing head and/or the main shaft. The outer surface 13 of the main shaft is sealed against the inner surface 11 of the crushing head 6, by means of a first sealing 18 placed in a groove formed in the inner surface 11. The sealing 18 is placed between the pressurized medium space 10 and the sliding surface 15 in the height direction of the main shaft. A second sealing 19 is arranged to seal the inner surface 11 of the crushing head 6 against the outer surface 20 of the second sliding surface 16. A groove for the sealing 19 is provided on the outer surface 20 of the second sliding surface. The second sealing 19 is placed in the upper part of the second sliding surface 16, spaced apart from the front surface 12. A third sealing 21 is arranged to seal the outer surface 13 of the main shaft against the inner surface 17 of the second sliding surface. A groove for the sealing 21 is provided on the outer surface 13 of the main shaft. The third sealing 21 is placed in the upper part of the second sliding surface 16, but spaced downwards apart from the second sealing 19.

For introducing pressurized medium into the pressurized medium space 10, a pressurized medium channel 22 is provided inside the main shaft 3. The pressurized medium channel 22 is formed in a suitable way, for example as a borehole in the main shaft 3, and it extends from the lower end of the main shaft 3 to the pressurized medium space 10. The pressurized medium is supplied into the pressurized medium channel 22 via a through-hole 23 formed in the lower frame 1 b of the crusher. The supply of the pressurized medium through the axial bearing assembly 24 can be implemented for example in the way disclosed in Finnish patent 117325. The pressurized medium can also be supplied into the pressurized medium space 10 via a pressurized medium channel (not shown in the figure) arranged suitably at the upper end of the main shaft 3, or, for example, through a dust seal (not shown in the figure) arranged in the supporting cone.

The setting of the crusher is adjusted as follows:

To adjust the setting s smaller, pressurized medium is pumped into the pressurized medium space 10. In a corresponding manner, to adjust the setting s larger, pressurized medium is discharged from the pressurized medium space 10. The pressure source is a commonly known combined pressurizing and lubricating device (not shown in the figure) for a crusher.

The pressurized medium and the lubricant used can be any substances suitable for the purpose. Preferably, they consist of one and the same substance, for example commercially available hydraulic oil.

The hydraulic setting adjustment system according to the invention is particularly applicable in gyratory crushers, in which the main shaft remains stationary in the vertical position when the setting is adjusted, and no pressurized medium circulation, including sealing, needs to be provided in the lower part of the main shaft. This means that it is easy to provide the lubricating and control oil sealings. Also, no separate control piston will be needed around the main shaft and the eccentric shaft.

The invention is not intended to be limited to the embodiments presented as examples above, but the invention is intended to be applied widely within the scope of the inventive idea as defined in the appended claims.

Claims

1. A crusher comprising at least

- a frame (1), in which a first crushing blade (2) is fitted, - a crushing head (6), in which a second crushing blade (7) is fitted,

- a main shaft (3), in which the crushing head (6) is fitted,

- a pressurized medium space (10) provided in the crushing head (6), at least one pressurized medium channel (22) being connected to the pressurized medium space (10) for conveying pressurized medium into the pressurized medium space (10); wherein the setting (s) of the crusher can be changed by the effect of the quantity of the pressurized medium in the pressurized medium space (10), characterized in that the pressurized medium space (10) is provided around the main shaft (3).

2. The crusher according to claim 1 , characterized in that the outer surface (13) of the main shaft (3) is arranged to limit the pressurized medium space (10).

3. The crusher according to claim 1 or 2, characterized in that a circumferential, radially directed second front surface (14) is provided on the outer surface (13) of the main shaft (3), arranged to limit the pressurized medium space (10).

4. The crusher according to any of the preceding claims 1 to 3, characterized in that a circumferential, radially directed first front surface (12) is provided on the inner surface (11) of the crushing head, arranged to limit the pressurized medium space (10).

5. The crusher according to claim 3 or 4, characterized in that the first front surface (12) and the second front surface (14) are arranged to face each other.

6. The crusher according to any of the preceding claims 1 to 4, characterized in that the inner surface (11 ) of the crushing head (6) is provided with at least a first and a second sliding surface (15, 16).

7. The crusher according to any of the preceding claims 1 to 4 and 6, characterized in that the inner surface (17) of the second sliding surface is arranged to limit the pressurized medium space (10).

8. The crusher according to claim 2 or 6, characterized in that the outer surface (13) of the main shaft (3) and the inner surface (17) of the second sliding surface are arranged to face each other.

9. The crusher according to any of the preceding claims 1 , characterized in that at least one sealing (18, 19, 21) is arranged in connection with at least one of the following: the main shaft (3), the crushing head (6), and the second sliding surface (16).

10. The crusher according to claim 1 , characterized in that the pressurized medium space (10) is annular and placed centrally around the main shaft (3).

11. The crusher according to claim 1 , characterized in that the crusher is a gyratory crusher.