A GYRATORY CRUSHER AND A METHOD FOR ADJUSTING A SETTING OF A GYRATORY CRUSHER

Field of the invention

The invention relates to crushers, particularly gyratory crushers. More precisely, the invention relates to an apparatus and a method for adjusting the setting of a crusher.

Background of the invention

A gyratory crusher comprises a frame provided with an outer crushing blade. An inner crushing blade is fitted by means of a crushing head on a main shaft. The main shaft is arranged to move in such a way that the inner crushing blade is in a kind of a pendulum motion with respect to the outer crushing blade.

The movement of the main shaft is typically produced by means of an eccentric which is rotated by means of a suitable actuator. The main shaft is placed in an eccentric manner with respect to the rotation axis of the eccentric shaft, wherein during the rotation of the eccentric shaft, the position of the main shaft with respect to the frame of the crusher is changed. In other words, the distance between the different points of the outer and inner crushing blades varies during the rotation of the eccentric shaft, or the cycle. In a gyratory crusher, the movement of the main shaft is greater in the lower part than in the upper part. This is because the axial line of the main shaft and the rotation axis line of the eccentric shaft are not parallel, but the lines intersect at a so-called pivot point. The pivot point is typically above the crushing blades.

The main shaft is supported to the frame by means of a thrust bearing above the outer crushing blade. Preferably, the thrust bearing is substantially at the pivot point, at which point the horizontal movement of the main shaft reaches its minimum.

The properties of the crusher are changed, among other things, by changing the distance between the outer and the inner crushing blades. This change in the so-called setting is implemented by changing the position of the inner crushing blade. Because the inner crushing blade is connected to the main shaft, a typical way is to move the main shaft in the height direction. In arrangements of prior art, a adjusting piston is used for this purpose. The adjusting piston is located below the gyratory shaft. A adjusting oil sump is placed in the space limited by the lower part of the frame and the adjusting piston. The quantity of the adjusting oil in the adjusting oil sump can be util- ized to lift up and lower the main shaft. Bearings are found between the adjusting piston and the main shaft. By the effect of the adjustment, the bearings slide in the vertical direction with respect to the frame, simultaneously changing the eccentricity between the adjusting piston of the bearings and the parts on the side of the main shaft . For this reason, the known bearings comprise an intermediate plate, wherein two bearing surfaces are formed. In many cases, the intermediate plate tends to engage the bearing of the gyratory shaft, and when the shaft is lifted away, the intermediate plate may fall onto the lower bearing and damage it.

Brief summary of the invention

It is an aim of the solution according to the invention to eliminate drawbacks and faults of the above-presented solutions of prior art.

It is an aim of the present invention to provide a simpler and steadier arrangement for adjusting the setting of a gyratory crusher.

To achieve this aim, the gyratory crusher according to the invention is primarily characterized in what will be presented in the independent claim 1. The crushing plant according to the invention is primarily characterized in what will be presented in the independent claim 6. The method according to the invention is, in turn, primarily characterized in what will be presented in the independent claim 11. The other, dependent claims will present some preferred embodiments of the invention.

The invention is based on the idea that the adjusting piston is formed inside the main shaft.

The crusher according to the invention comprises at least a frame and a main shaft, as well as at least a first crushing blade fitted in the frame and a second crushing blade fitted on the main shaft. Furthermore, the crusher comprises a first bearing unit fitted in the frame for supporting the main shaft above the second crushing blade, and a adjusting piston for changing the setting of the crusher (the mutual position between the first crushing blade and the second crushing blade). The adjusting piston is fitted at least partly inside the main shaft.

In the method according to the invention, the setting of the crusher is changed at least partly by means of a adjusting piston fitted inside the main shaft, by changing the volume of the space between the adjusting piston and the main shaft.

In one embodiment, the crusher also comprises a adjusting oil sump fitted in the space limited by the main shaft and the adjusting piston.

In one embodiment, the crusher also comprises a second bearing unit fitted to support the adjusting piston to the frame at the lower part of the adjusting piston.

In one embodiment, the second bearing unit comprises a first part with a first slide surface and a second part with a second slide surface. Advantageously, the first part is fitted in the frame and the second part is fitted in the adjusting piston, and the first slide surface is against the second slide surface.

In one embodiment, the second slide surface is fitted above the first slide surface, and the second slide surface is fitted to move along a rotationally symmetrical path in the horizontal direction with respect to the first slide surface.

The different embodiments of the above-described arrangement, taken separately and in various combinations, provide several advantages. A significant

advantage provided by one embodiment lies in that the thrust bearing does not move in the axial direction when the setting is adjusted.

A significant advantage provided by one embodiment lies in that no intermediate plate is needed in the bearing. With the omission of the intermediate plate, the damaging risk of the falling intermediate plate is also eliminated. Moreover, the bearing preferably comprises only one friction surface, wherein the lubrication of the bearing is easier to implement.

An advantage offered by one embodiment, in turn, lies in that the crusher can be made lower. One embodiment, in turn, makes it possible to reduce the diameter of the toothed rim. In an advantageous embodiment, the lower part of the crusher becomes lighter in weight, wherein the total mass of the crusher is reduced, which, in turn, has an advantageous effect in movable crushing plants.

In one embodiment, the number of components is reduced with respect to the solutions of prior art. For example, the bearing unit can be implemented with fewer components.

One embodiment makes it possible to improve the function of an overload valve, because the valve can be placed in connection with the piston. This has an advantageous effect on, for example, the response rate of the overload protection system.

Brief description of the drawings

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

Fig. 1 shows an advantageous embodiment,

Fig. 1 b shows a detail in an advantageous embodiment,

Fig. 2 shows a crusher in the upper position,

Fig. 3 shows a crusher in the lower position,

Fig. 4 shows a movable crushing plant.

For the sake of clarity, the drawings only show the details necessary for understanding the invention. The structures and details that are not necessary for understanding the invention but are obvious for anyone skilled in the art have been omitted from the figures in order to emphasize the characteristics of the invention.

Detailed description of the invention

In this description, 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.

Figure 1 a shows a very advantageous assembly according to the basic idea of the present invention. The apparatus according to the example comprises at least a frame 1 and a main shaft 2. Furthermore, the crusher comprises a first crushing blade 3 fitted in the frame 1 , and a second crushing blade 4 fitted on the main shaft 2. The inner conical crushing blade, i.e. the second crushing blade 4, is movable on the main shaft 2 with respect to the outer crushing blade, i.e. the first crushing blade 3, in such a way that a forced stroke is produced in the crushing chamber between the crushing blades. The movement of the main shaft 2 and thereby also of the second crushing blade 4 is greater in the lower part than in the upper part.

The movement of the main shaft 2 is produced by means of an eccentric 5. During a cycle, the eccentric 3, to which the main shaft 2 is fitted, causes a forced swinging movement of the second crushing blade 4, which reduces and increases the gap between the first crushing blade 3 and the second crushing blade 4, effecting the crushing of the material to be crushed. The rotation force is transmitted to the eccentric 3 from a suitable actuator by means of a drive shaft 6.

The main shaft 2 is supported to the frame 1 by means of a first bearing unit 7 above the second crushing blade 4. The point of intersection between the central line of the main shaft 2 and the central line of the first crushing blade 3, called the pivot point P, is placed above the second crushing blade 4, preferably at the first bearing unit 7.

Furthermore, the crusher comprises a adjusting piston 8 for changing the mutual position between the first crushing blade 3 and the second crushing blade 4, i.e. for changing the setting of the crusher. The adjusting piston 8 is fitted at least partly inside the main shaft 2.

In the example, the crusher also comprises a adjusting oil sump 9 and a second bearing unit 10. The adjusting oil sump 9 is fitted in the space limited by the main shaft 2 and the adjusting piston 8. The adjusting oil is guided via a suitable inlet 11 into and from the adjusting oil sump 9. In the example, the supply is effected via an inlet 11 on the axial line. In connection with the inlet 11 of adjusting oil, it is advantageous to provide an anti-overload device, such as an overload valve. The overload valve allows adjusting oil to exit the adjusting oil sump 9 in an overload situation. An overload situation may occur, for example, when such material that cannot be crushed by the crushing blades 3, 4 enters the crushing chamber. In crushers intended for the crushing of mineral materials, the situation typically occurs when there are metal pieces among rock to be crushed.

The second bearing unit 10 is provided to support the adjusting piston 8 to the frame 1 at the lower part of the adjusting piston. In the example, the second bearing unit 10 is a thrust bearing. The thrust bearing 10 placed between the adjusting piston 8 and the frame 1 does not move in the axial direction when the setting is adjusted. However, the thrust bearing 10 allows the movement of the adjusting piston 8 in the radial direction. In an advantageous embodiment, the lower part 10a of the second bearing unit 10 (the first part of the bearing unit) is connected to the frame 1 of the crusher in a substantially stationary manner. The upper part 10b of the second bearing unit 10 (the second part of the bearing unit), in turn, is connected to the adjusting piston 8, and the upper part 10b and the lower part 10a of the bearing unit may move in relation to each other in the horizontal direction. The upper part

10b and the lower part 10a of the second bearing unit 10 comprise slide surfaces which are arranged to face each other. The second bearing unit 10 makes it possible that the adjusting piston 8 and the main shaft 2 connected to it (as well as the upper part 10b of the bearing unit) may move along a rotational path produced by the eccentric 5.

A significant advantage provided by one embodiment lies in that no intermediate plate will be needed between the upper part 10b and the lower part 10a of the bearing unit in the second bearing unit 10. With the omission of the intermediate plate, also the damaging risk of the falling intermediate plate is eliminated. Furthermore, the second bearing unit 10 preferably comprises only one friction surface (between the slide surface of the upper part 10b and the slide surface of the lower part 10a of the bearing unit), wherein the lubrication of the bearing is easier to implement. In the example, for the lubrication of the thrust bearing 10, a lubrication inlet 12 is provided, from which the suitable lubricant is supplied to the bearing.

Figure 1b shows a detail in an advantageous embodiment. The apparatus according to the example comprises at least a frame 1 , a main shaft 2, a adjusting piston 8, a adjusting oil sump 9, and a second bearing unit 10. The upper part 10b and the lower part 10a of the second bearing unit 10 comprise slide surfaces which are arranged to face each other. In this embodiment, a first ring seal 13 is provided between the upper part 10b and the lower part 10a of the bearing unit. In the example, the first ring seal 13 is fitted in a groove formed on the slide surface of the lower part 10a of the bearing unit. One function of the first ring seal 13 is to enable the supply of adjusting oil or another corresponding substance from the adjusting oil inlet 11 through the bearing unit 10 into the adjusting oil sump 9. Another function of the first ring seal 13 is to enable the supply of lubrication oil or another corresponding substance from the lubrication inlet 12 through the lower part 10a of the bearing unit into the space between the lower part and the upper part 10b of the bearing unit, to lubricate the slide surfaces. It is advantageous to separate the adjusting oil sump 9 and the adjusting oil inlet system 11 from the lubrication inlet 12 and the lubrication circuit. However, it is advantageous to use the same medium in both circuits.

Furthermore, the example comprises a second ring seal 14. The second ring seal 14 is fitted between the adjusting piston 8 and the main shaft 2. In the example, the adjusting piston 8 comprises a horizontal groove that encircles the adjusting piston and in which the second ring seal 14 is fitted. One func- tion of the second ring seal 14 is to seal the gap between the main shaft 2 and the adjusting piston 8 and thereby also to seal the adjusting oil sump 9.

The first ring seal 13 and the second ring seal 14 can be made of metal, such as, for example, bronze or another corresponding material. Polyurethane (PUR), carbon fibre PTFE or bronze PTFE are also suitable materials for the first ring seal 13 and the second ring seal 14.

Figures 2 and 3 show principle views of the crusher in two different positions. The Figs. 2 and 3 do not show the frame 1 of the crusher, to illustrate the different positions more clearly. In Fig. 2, the second crushing blade 4 has been driven to the upper position, wherein the setting of the crusher is small. Thus, the volume of the adjusting oil space 9 is large.

In Fig. 3, the adjusting piston 8 is in the lower position, wherein the setting of the crusher is large. In this operating position, the volume of the adjusting oil space 9, in turn, is small. A similar operating position may result from an overload situation. In an overload situation, a sufficient quantity of adjusting oil is released from the adjusting oil sump 9 to unload the overload situation.

The different operating positions between the Figs. 2 and 3 may be arrived at by providing the adjusting oil sump 9 with a suitable quantity of oil. To reduce the setting, more oil is supplied. In a corresponding manner, to increase the setting, the quantity of oil is reduced. The adjustment can be made in various ways. In an advantageous embodiment, the setting of the crusher is moni- tored by suitable measuring devices. The measured value is compared with the set values, after which, if necessary, the setting is changed by adjusting the volume of the adjusting oil sump 9 by means of the quantity of the adjusting oil, and thereby the mutual position between the adjusting piston 8 and the main shaft 2.

The placement of the adjusting piston 8 inside the main shaft 2 makes it possible to make the crusher lower than in a solution where the adjusting piston is outside the main shaft. The structure also makes it possible to reduce the diameter of the toothed rim, because the internal adjusting piston 8 does not substantially increase the width of the structure. Furthermore, it is possible to make the lower part of the crusher light in weight (compared with known solutions), wherein the total mass of the crusher is reduced, which, in turn, has an advantageous effect in movable crushing plants.

Figure 4 shows a crushing plant 100 which is suitable for the processing of mineral material, such as for the crushing of rock or the recirculation of construction material, such as for the processing of reinforced concrete. The crushing plant comprises a feeder 110 for feeding material to be crushed further to a screen 120, and to a crusher 130. The crushing plant further comprises a side conveyor 140 and a main conveyor 150 as well as a power source 160 for driving the actuators, and a caterpillar drive 170 for moving the crushing plant. In the example, the crushing plant is a movable plant with a crusher mounted on a caterpillar drive. The crushing plant can also be moved by other means, such as wheels or legs, or it may be stationary.

By combining, in various ways, the modes and structures disclosed in connection with the different embodiments of the invention presented above, it is possible to produce various embodiments of the invention in accordance with the spirit of the invention. Therefore, the above-presented examples must not be interpreted as restrictive to the invention, but the embodiments of the invention may be freely varied within the scope of the inventive features presented in the claims hereinbelow.