Two-roll crusher

Abstract

A two-roll crusher (1) with rollers (2, 3) rotatably mounted in a crusher housing and driven in opposite directions by motors, the central longitudinal axes of which are parallel to one another, wherein a first roller (2) as a fixed roller is immovable and a second roller (3) as a loose roller is displaceable relative to the first roller (2) in the crusher housing to change the gap between the rollers (2, 3), wherein the adjustment of the bearings together with the loose roller (3) takes place along a sliding surface formed on the machine frame (4) against the force of at least one return means, for example a hydraulic cylinder (5), wherein a rocker arm (6) is articulated with a first end to bearings or near the bearings of the loose roller (3), the other ends of which are connected to a cross member (7) which is held fixed to the frame and is rotatable about its bearing areas, characterized in thatthat the return means is arranged in the adjustment direction approximately parallel to the installation plane on the side of the bearings of the rollers (2, 3) facing the installation plane, wherein the return means is articulated at a first end of each rocker arm (6) which projects from the cross member (7) in the direction of the installation plane, wherein the second ends of the rocker arms (6) are fixed to the cross member (7) which is arranged above the alignment of the rollers (2, 3) and which projects significantly above the central longitudinal axes of the rollers in height, i.e. at a distance from the installation plane, wherein approximately at the level of the central longitudinal axis of the rollers (2, 3) an articulated lever (8) is articulated on the one hand to the rocker arm (6) and on the other hand to the roller bearing or close to the roller bearing (at 9).

Description

[0001] The invention relates to a two-roll crusher with rollers which are rotatably mounted in a crusher housing and driven in opposite directions by a motor, the central longitudinal axes of which are directed parallel to one another, wherein a first roller is fixed as a fixed roller and a second roller is movable relative to the first roller in the crusher housing in order to change the gap between the rollers, wherein the adjustment of the bearings together with the loose roller takes place along a sliding surface formed on the machine frame against the force of at least one return means, for example a hydraulic cylinder, wherein a rocker arm is articulated with a first end to bearings or near the bearings of the loose roller, the other ends of which are connected to a cross member which is held fixed to the frame and can be rotated about its bearing areas.

[0002] Such two-roll crushers are widely known in the art. They are used, for example, to crush rock or similar materials to a desired grain size and are therefore frequently used in mining and mineral processing.

[0003] Two-roll crushers of a similar type are known, for example, from German patent specification 1073833 and German patent specification 1056909 and DE 3310071 C2.

[0004] Another two-roll crusher is known in the prior art from GB 746308 A.

[0005] The adjustability of the roller spacing and thus the gap between the rollers primarily serves to variably adjust the grain size to be produced. Furthermore, progressive wear on the crushing tools, also called crushing shells, can be compensated for. This is achieved by moving the already worn crushing tools slightly closer together. The gap between the rollers can thus be reduced to compensate for a certain amount of wear on the crushing tools. This also allows for better control of the desired target grain size and its achievement by adjusting the gap spacing accordingly.

[0006] In addition, different grain sizes can be achieved using the same set of crushing shells as a crushing tool, which were actually designed for a different grain size.

[0007] Another function of the adjustability of at least one roller relative to the other is overload protection. If, for example, foreign objects such as metal or the like enter the crushing chamber, it is usually impossible to stop the machine in time to protect it from damage if the rollers are non-adjustable, i.e., fixed. The adjustability of at least one roller protects components such as the drive and bearings from damage by pushing the loose roller outward due to the compressive forces generated between the rollers. Once the foreign object has left the machine chamber, the roller can be returned to its original or working position.

[0008] In the prior art, both hydraulic systems, which are usually adjusted synchronously via two hydraulic cylinders, and systems preloaded with a spring are known for adjusting the loose roller relative to the fixed roller. To ensure synchronization (displacement over the travel), this synchronization is usually achieved mechanically via a rocker arm for each roller side. The rocker arms are firmly connected to the other bearing side by an axis that forms a cross member. The hydraulic cylinders are arranged at a distance from the rocker arms, aligned with the center of the bearing, and are firmly connected to the bearing at a second connection point. The part of this axis consisting of the rocker arm and the synchronization fork that connects the rocker arms, namely the cross member, is usually located close to the ground or the installation level. Here, for example, this hinders the arrangement of a conveyor belt.

[0009] A disadvantage of such a solution is that the synchronization levers are arranged off-center, i.e., at a greater or smaller distance from the mounting surface than the alignment of the bearing center. This connection of the synchronization rocker arms, also known as an off-center connection, results in tilting moments acting on the bearings, and in particular the bearing guides, when a peak load is introduced, which can occur, for example, due to a foreign object getting caught between the rollers. This tilting moment is caused by the restoring force of the hydraulic cylinder. This places additional stress on the bearing guides and, if applicable, the bearings, potentially severely limiting their service life.The overload function for releasing the loose roller is often effected by a load holding valve integrated into the hydraulic system, which is preset to a certain maximum pressure in order to release the movable roller (loose roller) from the crushing chamber due to the internal forces, i.e. the forces that arise, for example, due to the effect of a foreign body on the rollers, in order to avoid damage.

[0010] For this purpose, guides are known in the prior art which are arranged below the bearings, i.e. between the installation surface and the bearing, and which enable horizontal displacement of at least the loose roller.

[0011] In the solutions known in the state of the art, the hydraulic cylinders are also arranged at the height of the central longitudinal axes of the rollers, thus resulting in a particularly long design of the entire machine.

[0012] Based on the prior art mentioned at the outset, the object of the invention is to improve a two-roll crusher of the type mentioned at the outset in such a way that in the event of load introduction, for example by foreign bodies, the bearing guides and possibly the bearings are only slightly loaded in order to increase their service life, which also enables a particularly compact and thus only short design and which is inexpensive and easy to manufacture while having a long service life.

[0013] To achieve this object, the invention proposes that the return means is arranged in the adjustment direction approximately parallel to the installation plane on the side of the roller bearings facing the installation plane, wherein the return means is articulated in each case to a first end of each rocker arm which projects from the cross member in the direction of the installation plane, wherein the second ends of the rocker arms are fixed to the cross member which is arranged above the alignment of the rollers and which projects significantly above the central longitudinal axes of the rollers in height, i.e. in distance from the installation plane, wherein approximately at the level of the central longitudinal axis of the rollers an articulated lever is articulated on the one hand to the rocker arm and on the other hand to the roller bearing or close to the roller bearing.

[0014] Such an arrangement of the return means, in particular hydraulic cylinders, enables, on the one hand, a particularly compact design of a two-roll crusher according to the invention with only a short length.

[0015] Furthermore, both the load application in the event of an overload and the return movement by the return mechanism take place at the level of the rollers' central longitudinal axis. This means minimal wear occurs on the bearing guides and roller bearings, as they do not have to compensate for additional tilting moments caused by off-center force application.

[0016] The additional articulated lever allows hydraulic cylinders to be arranged as a return device parallel to the installation plane between the installation plane and the roller bearings. The rocker arm, which is articulated at the end of the hydraulic cylinder's piston rod, and the articulated lever, which is articulated on the one hand to the rocker arm and on the other hand to or close to the respective bearing, allow the forces resulting from the overload and the subsequent return to be absorbed in a linear manner. This means that the force generated in the event of an overload, which is caused by the rollers suddenly moving apart and thus increasing the roller gap, can be introduced linearly into the articulated lever and reversed by it. This largely avoids tilting moments that place excessive strain on the bearing guides and bearings and lead to excessive wear.

[0017] A further advantage of such a compact design is that there is sufficient space along the longitudinal axis, approximately midway between the hydraulic cylinders, to position a conveyor belt for transporting the crushed material. The entire area below the crusher rollers is free, allowing a conveyor belt to be installed here to transport the crushed material.

[0018] The conveyor belt can be positioned protruding from both ends of the machine, as the crosshead, particularly in the area of ​​the idler roller, is positioned at a height that does not interfere with the conveyor belt. Furthermore, all other synchronization devices, namely the two articulated levers and the two rocker arms, are located on or near the outer sides of the two-roll crusher and do not protrude into the working area or the area where a conveyor belt is positioned to transport the crushed material.

[0019] It can be particularly preferably provided that each articulated lever is arranged in an approximately horizontal position, almost parallel to the installation plane.

[0020] The approximately horizontal arrangement of the articulated levers, almost parallel to the installation plane, enables the linear introduction of the forces resulting from an overload into the load-balancing synchronization devices. This prevents the occurrence of wear-promoting tilting moments.

[0021] In particular, it can be particularly preferably provided that the return means is formed by a hydraulic cylinder, the piston rod of which is articulated at the end of the rocker arm and is subjected to tensile stress when the loose roller moves from the working position into a gap-enlarging position.

[0022] In such an arrangement, the hydraulic cylinders are used in such a way that the target roller spacing, which can be adjusted by the user according to the desired grain size, is held in tension by the hydraulic cylinders. In the event of an overload, which moves the idler roller further from the target position away from the fixed roller, the piston rod of the hydraulic cylinder is thus retracted from the hydraulic cylinder. The hydraulic cylinder can be preset to a specific maximum tension in order to release the idler roller in the event of a load when this force is exceeded, allowing it to move away from the fixed roller, for example, to prevent increased wear on the roller or damage to the roller due to foreign matter.

[0023] After the foreign material has been removed, the hydraulic cylinder uses the piston rod to pull the loose roller back into the preset position.

[0024] Alternatively, it may be particularly preferred that the return means is formed by a tension spring.

[0025] The use of one or more tension springs as a return device is also possible, whereby with this solution the target position of the loose roller can be adjusted to tension and in the case of a load the loose roller acts indirectly by means of the synchronization on the tension spring in order to increase the gap distance between the loose roller and the fixed roller in order to avoid possible damage to the rollers.

[0026] Furthermore, it can be particularly preferably provided that the bearings of the loose roller have sliding surfaces forming a guide both on their side facing the installation plane and on their side facing away from the installation plane.

[0027] In particular, the guides arranged on both the side facing the installation plane and the side facing away from the installation plane, or the sliding surfaces forming a guide, ensure the horizontal, in particular parallel to the installation plane, course of the loose roller in the load case, i.e. in the case in which the gap is increased by removing the loose roller from the fixed roller, so that any tilting moments that may occur are largely compensated for.

[0028] Finally, it can be particularly preferably provided that the return means is formed by a hydraulic cylinder, wherein the piston rod of the hydraulic cylinder is connected to the rocker arm by pressure or the return means is formed by a compression spring, wherein a deflection lever is arranged parallel to the return means and is arranged between the return means and the roller bearing, one end of which is articulated to the first end of the return means and the other end of which is articulated to the rocker arm end.

[0029] In such an embodiment of the invention, a hydraulic cylinder can be used that is pressure-connected to the synchronization. An additional reversing lever is arranged between the piston rod of the hydraulic cylinder and the end of the rocker arm closest to the ground. This lever runs approximately parallel to the hydraulic cylinder with piston rod and is located between the hydraulic cylinder and the roller bearings.

[0030] The hydraulic cylinder used here under pressure can also be replaced by a compression spring as a return device.

[0031] Even with such a solution, the force is introduced linearly by means of the articulated lever into the rocker arm, which is hinged or connected at one end to the bell crank and at its other end to the cross member.

[0032] This also largely prevents the effect of tilting moments on the bearings and in particular the bearing guides, so that wear on these parts is significantly reduced and service life is increased.

[0033] Furthermore, such an arrangement according to the invention of return means, rocker arm, articulated lever and cross member connecting the rocker arm is also possible in two-roll crushers in which both rollers are designed as loose rollers and are displaceably adjustable relative to the other roller in the crusher housing.

[0034] In this case, the so-called synchronization, consisting of a cross member, articulated lever, rocker arm and hydraulic cylinder, would be arranged on the side of the two-roll crusher opposite the first synchronization.

[0035] Embodiments of the invention are illustrated in the figures and described in more detail below.

[0036] It shows: Fig. 1 essential parts of a two-roll crusher according to the invention in perspective view; Fig. 2 likewise without drive of the idler roller; Fig. 3 likewise from Fig. 1 without frame parts; Fig. 4 likewise without frames and without drives; Fig. 5 likewise without frame and without drives in side view in a first position; Fig. 6 likewise in another position.

[0037] The figures show essential parts of a two-roller crusher 1. Such a two-roller crusher 1 has two rollers 2, 3 which are rotatably mounted in a crusher housing and driven in counter-rotating directions by motors. The central longitudinal axes of the rollers 2, 3 are aligned parallel to one another. In the exemplary embodiment, a first roller 2 is designed as a fixed roller and is immovable, and a second roller 3 is designed as a loose roller and is movable relative to the roller 2. The second roller 3 is adjustable within the crusher housing to change the gap between the rollers 2, 3 and is movable relative to the first roller 2. The adjustment of the second roller 3 takes place together with the bearings of the loose roller 3 along a sliding surface 11 formed on the machine frame 4. The adjustment takes place against the force of a return means which, in the exemplary embodiments, is formed by hydraulic cylinders 5.To synchronize and thus prevent the roller 3 from tilting due to the movement when adjusting the roller 3 to a position that increases the gap relative to the roller 2, a rocker arm 6 is pivoted at a first end near the bearing of the idler roller 3. The other end of each rocker arm 6 is connected to a cross member 7, which is fixed to the frame and rotatable about its bearing areas.

[0038] According to the invention, the return means is arranged in the adjustment direction, approximately parallel to the installation plane, on the side of the bearings of the rollers 2, 3 facing the installation plane. This allows, for example, the discharge for shredded material to be freely accessible and offers sufficient space to install a suitable conveying means, such as a conveyor belt.

[0039] In the exemplary embodiments shown in the figures, the return means is formed by a hydraulic cylinder 5, which is hinged to a first end of each rocking lever 6. The rocking lever 6 projects from the cross member 7 in the direction of the installation plane. The second ends of the rocking levers 6 are fixed to the cross member 7. The cross member 7 lies above the alignment of the rollers 2, 3. Thus, the cross member 7 is arranged in a plane spanned above the rollers 2, 3 and also enables the arrangement of a conveyor belt for transporting the shredded material in this area below the cross member 7.

[0040] In addition, at the level of the central longitudinal axis of the rollers 2, 3, an articulated lever 8 is arranged on the one hand on the rocker arm 6 and on the other hand on the roller bearing or a fastening point on the roller bearing at 9, and is hinged to the latter. This enables a central introduction of force into the bearings of the floating roller 3. As soon as a foreign body penetrates the working area of ​​the rollers 2, 3, the roller 3 can be displaced by the foreign body in a direction parallel to the installation plane, i.e. horizontally. The forces transmitted to the rocker arms 6 by the articulated levers 8 are transmitted almost exclusively in a horizontal direction. This largely avoids tilting moments that could act on the bearing guides and possibly the bearings of the floating roller 3 and damage them or limit their service life.

[0041] In addition, such an arrangement of the articulated lever 8, the rocker arm 6 and the cross member 7 in combination with the hydraulic cylinder 5, which forms the return means, results in a particularly short, compact design, which additionally enables the mobile transport of such a two-roll crusher 1.

[0042] This is also advantageous for the peripheral components, as support elements of a steel structure, etc., can be installed closer to the crusher.

[0043] As can be seen in particular from the Fig. 5 and Fig. 6, each articulated lever 8 is arranged in a horizontal position, approximately parallel to the installation plane. Fig. In the load case shown in Figure 6, the articulated lever 8 is still arranged in a position almost parallel to the installation plane, so that the described tipping moments are largely avoided.

[0044] As can be seen from the figures, the return means is formed by a hydraulic cylinder 5, to whose piston rod 10 the end of the rocker arm 6 opposite the cross member 7 is pivoted. When the idler roller 3 moves from the working position to a gap-increasing position, the hydraulic cylinder 5 is subjected to tensile stress. The hydraulic cylinder 5 can be preset to a specific maximum tension and, if this tension is exceeded, for example, under load, can release the idler roller 3 in order to enlarge the gap between the rollers 2, 3 and to prevent or avoid destruction or damage to the crusher rollers 2, 3.

[0045] Alternatively, and not shown in the figures, the return means can also be formed by a tension spring.

[0046] As can be seen in particular from the Fig. 3 and Fig.As can be seen in Figure 4, the bearings of the floating roller 3 have sliding surfaces 11 that form a guide on both the side facing the installation plane and the side facing away from the installation plane. These guide means (sliding surfaces 11), which are formed on both the top and bottom sides, provide additional protection against damage in the event of tilting moments, since the approximately horizontal sliding surfaces 11, which form a guide, allow movement exclusively in a horizontal direction. Such tilting moments can also occur if the crushing process generates axial forces that tend to tilt the fixed bearing transversely out of the installation plane.

[0047] In an alternative embodiment not shown in the figures, the return means can also be formed by a hydraulic cylinder 5, whose piston rod 10 is connected to the rocker arm 6 by pressure. For this purpose, a reversing lever is provided between the hydraulic cylinder 5 and the roller bearing, one end of which is connected to the first end of the hydraulic cylinder 5 and the other end to the rocker arm end.

[0048] The invention is not limited to the embodiment, but is variable in many ways within the scope of the disclosure.

[0049] All individual and combination features disclosed in the description and / or drawing are considered essential to the invention. List of reference symbols 1 two-roll crusher 2 rollers (fixed rollers) 3 roller (loose roller) 4 Machine frame 5 hydraulic cylinders 6 rocker arms 7 Traverse 8 articulated levers 9 Pivot point roller bearing 10 Piston rod 11 sliding surfaces

Claims

[1] Two-roll crusher (1) with rollers (2, 3) rotatably mounted in a crusher housing and driven in opposite directions by motors, the central longitudinal axes of which are parallel to one another, wherein a first roller (2) as a fixed roller is immovable and a second roller (3) as a loose roller is displaceable relative to the first roller (2) in the crusher housing to change the gap between the rollers (2, 3), wherein the adjustment of the bearings together with the loose roller (3) takes place along a sliding surface formed on the machine frame (4) against the force of at least one return means, for example a hydraulic cylinder (5), wherein a rocker arm (6) is articulated with a first end to bearings or near the bearings of the loose roller (3), the other ends of which are connected to a cross member (7) which is held fixed to the frame and is rotatable about its bearing areas, characterized byin that the return means is arranged in the adjustment direction approximately parallel to the installation plane on the side of the bearings of the rollers (2, 3) facing the installation plane, wherein the return means is articulated in each case to a first end of each rocking lever (6) which projects from the cross member (7) in the direction of the installation plane, wherein the second ends of the rocking levers (6) are fixed to the cross member (7) which is arranged above the alignment of the rollers (2, 3) and which projects significantly above the central longitudinal axes of the rollers in height, i.e. in distance from the installation plane, wherein approximately at the level of the central longitudinal axis of the rollers (2, 3) an articulated lever (8) is articulated on the one hand to the rocking lever (6) and on the other hand to the roller bearing or close to the roller bearing (at 9). [2] Two-roll crusher (1) according to claim 1, characterized by that each articulated lever (8) is arranged in an approximately horizontal position, almost parallel to the installation plane. [3] Two-roll crusher (1) according to claim 1 or 2, characterized by that the return means is formed by a hydraulic cylinder (5), the piston rod (10) of which is articulated at the end of the rocker arm (6) and is subjected to tensile stress when the loose roller (3) moves from the working position into a gap-enlarging position. [4] Two-roll crusher (1) according to claim 1 or 2, characterized by that the return means is formed by a tension spring. [5] Two-roll crusher (1) according to one of claims 1 to 4, characterized by that the bearings of the loose roller (3) have sliding surfaces (11) forming a guide both on their side facing the installation plane and on their side facing away from the installation plane. [6] Two-roll crusher (1) according to claim 1 or 2 or claim 5, characterized bythat the return means is formed by a hydraulic cylinder (5), wherein the piston rod (10) of the hydraulic cylinder (5) is connected to the rocker arm (6) under pressure or the return means is formed by a compression spring, wherein a deflection lever is arranged parallel to the return means and is arranged between the return means and the roller bearing, one end of which is articulated to the first end of the return means and the other end of which is articulated to the rocker arm end.

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