The present application claims priority to German application DE 10 2022 119 153.2 filed Jul. 29, 2022, which is incorporated herein by reference.
The invention relates to a crusher for mineral materials or recycled materials, in particular a rotary impact crusher or a jaw crusher, having a crusher unit, which has a movable first crusher body, in particular a rotor or a crusher jaw, wherein a second crusher body, in particular an impact rocker or a crusher jaw, is assigned to the first crusher body, wherein a crushing gap is formed between the crusher bodies, wherein a movable assembly of an overload triggering device is coupled to the first crusher body or to the second crusher body, wherein the movable assembly has a hydraulic cylinder or a piston guided in a hydraulic cylinder, wherein the movable assembly is designed to permit a motion of the coupled crusher body increasing the width of the crushing gap in an evasive motion, wherein a pressure chamber is formed in the hydraulic cylinder , which pressure chamber is delimited by means of the piston, and wherein the overload triggering device has a valve, which, in its open position, establishes a fluid-conducting connection between the pressure chamber and a compensation area and, in the closed valve position, blocks this connection.
In these crushers according to the invention, a crushing gap is formed between the two crusher bodies. During normal operation (normal mode), the mineral material to be crushed is crushed in the crusher unit until its particle size is sufficiently small to exit the crusher unit through the crushing gap. Below the crushing gap, a conveying device may be provided, which transports the crushed material away from the work area of the crusher unit. The conveyor can be designed as an endless circulating conveyor belt. During operation, an unbreakable object or an object that is difficult to break may enter the crusher unit. This object is too large to be removed through the crushing gap. Then an overload situation occurs at the crusher unit. This overload situation can cause damage to components of the crusher. It is therefore necessary to respond to this overload situation. In the crushers according to the invention, an overload triggering device is used for this purpose. The overload triggering device has a movable assembly connected to one of the two crusher bodies, preferably the second crusher body (e.g., crushing jaw or impact rocker). The overload triggering device has a movable assembly having a hydraulic cylinder. For instance, the cylinder or the piston of the hydraulic cylinder guided in the cylinder can be part of the movable assembly of the overload triggering device. The movable assembly is supported in the hydraulic cylinder against a fluid that is pressurized in a pressure chamber of the hydraulic cylinder. Furthermore, the overload triggering device has a valve that opens as soon as the pressure in the pressure chamber reaches an impermissible threshold value as a result of an overload situation. The fluid then escapes from the pressure chamber and the pressure in the pressure chamber drops abruptly. The moving assembly is then no longer supported against the pressure and can be adjusted to open the crushing gap wide. The non-crushable object can then exit the crusher unit.
A crusher having an overload triggering device is known from EP 2 888 049 B1 (U.S. Pat. No. 10,183,297). To this end, a hydraulic cylinder is used, which has a unit as a movable assembly comprising the piston, the piston rod and a coupling piece. The coupling piece couples the movable assembly to a crushing jaw of the crusher unit. The pressure chamber of the hydraulic cylinder is connected to a hydraulic tank via a hydraulic line. A pressure valve is integrated into the hydraulic line. It opens when the pressure in the pressure chamber reaches a threshold due to an overload situation. Then the fluid is drained from the pressure chamber into the hydraulic tank. It has been shown that this type of overload protection is too sluggish when a fast opening of the crushing gap is required as a result of an overload situation. The pressure valve sometimes does not open sufficiently fast. As a result, a component of the crusher, especially the movable assembly, may be damaged.
From DE 10 2020 114 104 A1 another crusher having a hydraulic system specially designed for overload protection is known.
The invention addresses the problem of providing a crusher of the type mentioned above, which permits an efficient safeguarding of the crusher against overload situations.
This problem is solved in that the valve is formed between two components of the movable assembly that are movable relative to each other.
In an overload situation, the crusher body to which the movable assembly is connected, is deflected. This motion also moves and accelerates the assembly. As now the valve is integrated into the movable assembly according to the invention, this motion can be used to open the valve formed between two components of the assembly that can be moved relative to each other. According to the invention, the opening motion of the valve is therefore motion-controlled, which significantly improves the response behavior and thus the reaction time when an overload situation occurs.
According to a preferred embodiment of the invention, provision may be made for the movable assembly to comprise the piston, a piston rod coupled to the piston, and an inertia element, for the inertia element to be coupled to the piston or the piston rod, for the inertia element to form part of the valve, and for the inertia element to be preferably held preloaded in the closed valve position by means of a spring element. This enables a simple design that can be easily integrated into classically constructed crusher units without the need for time-consuming adaptation work. In particular, the piston rod can be moved out of the hydraulic cylinder and connected directly or indirectly to the crusher body to be supported. The motion of the crusher body results in an acceleration of the piston rod or piston. The inertia element does not follow this motion or follows it with a delay. This creates a relative motion between the inertia element and another component, such as the piston rod or piston, of the movable assembly. It can be used for opening the valve.
Alternatively, it is also conceivable that if the movable assembly comprises the cylinder of the hydraulic cylinder the inertia element is coupled to the cylinder.
If provision is made for the inertia element to be held preloaded in the closed valve position by means of a spring element, then a safe operation is possible. The spring element can then also be used to adjust the valve pressure, i.e., the pressure which keeps the components forming the valve together. In particular, the valve can then be reliably held in the closed position under the action of the spring preload. In the event of an overload, a separating force results between the inertia element and the component of the movable assembly that is in contact with the inertia element. It results from the acceleration of the unit moving relative to the inertia element multiplied by its mass and minus the spring preload and possible seal friction. If this force is positive, the valve seat opens and the fluid can escape from the pressure chamber.
For an exact valve function, provision may be made for the inertia element to have one or more guide sections by means of which it is movably guided within the cylinder between the open and the closed position of the valve.
If provision is made for the fluid-conducting connection between the pressure chamber and the compensation area to be routed inside the cylinder, then this results in a simple design that can be installed in a crusher requiring little assembly effort.
If provision is made for the inertia element to be formed by an inertia piston, which is moved in the cylinder in the same way as the piston, the valve can be formed in a simple manner, for instance between the piston and the inertia piston.
If provision is made for the piston rod to be guided through the compensation area into the environment, and for the fluid-conducting connection between the pressure chamber and the compensation area to comprise a discharge channel formed by the piston, and/or for the fluid-conducting connection to comprise a fluid guide formed by the inertia element, then a robust design can be created in a simple manner. Particularly advantageously, the fluid-conducting connection is at least partially protected from mechanical effects within the cylinder.
It has been shown that the overload release safety device is particularly effective if provision is made for the inertia piston to have a sealing piece and the piston to have a valve seat, for the sealing piece and the valve seat to form parts of the valve, and for the sealing piece to be seated on the valve seat to block the connection between the pressure chamber and the compensation area in the closed position of the valve.
A crusher according to the invention may also be characterized in that the inertia piston has a bolt mount, into which a mounting bolt is inserted and bolted into a threaded mount of the piston, wherein the central longitudinal axis of the mounting bolt extends in the direction of the longitudinal axis of the cylinder, in that a/the spring element, which, in the closed position, braces the inertia piston with respect to the piston, acts on the mounting bolt, and in that the inertia piston is mounted in such a way that it can be moved relative to the piston from the closed position into the open position of the valve while increasing the preload of the spring element.
A stable design for transmitting large forces can be implemented in a simple manner in such a way that the piston has a piston crown adjoined by a securing piece, that the piston rod has a mounting neck connected to the securing piece and that between the piston rod and the securing piece an overflow area of the fluid-conducting connection is formed between the pressure chamber and the compensation area.
For discharging the amount of oil that can no longer be held by the compensation area in the event of an overload and for pressure protection of the compensation area during normal operation of the crusher, provision may be made for the compensation area to be connected to a pressure valve via a pressure line. For this purpose, the hydraulic fluid can be discharged in an orderly manner after the occurrence of an overload situation if provision is made for a hydraulic line downstream of the pressure valve to be routed to a tank, and for the pressure valve to open after the valve has been triggered as a result of an overload situation at the crusher unit in order to discharge hydraulic fluid from the compensation area into the tank.
After an overload event, the crushing gap can be easily readjusted if provision is made for the pressure chamber to have a connecting piece with a hydraulic connection, for the pressure chamber to be connected to a pressure generator via the hydraulic connection, and for the hydraulic fluid to be fed into the pressure chamber via the hydraulic connection by means of the pressure generator in order to increase the volume of the pressure chamber.
The invention is explained in greater detail below based on an exemplary embodiment shown in the drawings. In the figures,
An upper impact rocker 13 is disposed inside the crusher housing. Furthermore, another crusher body 14 is also disposed in the crusher housing, which in this case forms a lower impact rocker.
A crushing gap 15 is formed between the rotor (movable crusher body 11) and the lower impact rocker (crusher body 14). When the rotor rotates, the radially outer ends of the impact bars 12 form an outer crushing circle. This crushing circle, in conjunction with a facing surface of the lower impact rocker, forms the crushing gap 15. A swivel bearing 14.1 is used to swivel mount the lower impact rocker 14. The width of the crushing gap 15 can be adjusted via the selected swivel position of the lower impact rocker.
As
This is shown in more detail in
As
As shown in
As
Depending on the crushing task at hand, the operating position of the crushing gap 15 has to be adjusted accordingly. The crusher has a control device for this purpose. If, starting from the position shown in
As shown in
The overload triggering device 30 includes a hydraulic cylinder 20 as shown in
The pressure chamber 24 is partially delimited by a connection piece 29, which has a hydraulic port 27. The hydraulic port 27 of the connector 29 may be integrally connected to the cylinder 25.
The pressure chamber 24 may further be delimited by a piston crown 23.1 of the piston 23, as
A simple design then results for the piston 23 when a securing piece 23.2 adjoins the piston crown 23.1. For instance, the securing piece 23.2 may be used to secure a piston rod 22, which is firmly connected to the piston 23. The piston rod 22 is guided through the compensation area 28 into the environment in a sealed manner.
For the axial support of the piston rod 22 relative to the piston 23, provision may be made for the piston rod 22 and the piston 23, which is provided in addition or as an alternative to the threaded connection mentioned above, to be connected in a form-fitting manner. In the exemplary embodiment shown in
According to one conceivable embodiment, the piston 23 may have a sealing section 23.5, which, on its circumference facing away from the piston rod 22, is equipped with one or more piston seals 23.6, which seal the piston 23 circumferentially against the inner wall of the cylinder 25. In this regard the sealing section 23.5 is integrally secured at the end of the securing piece 23.2 facing away from the piston crown 23.1.
As
Additionally or alternatively, provision may also be made for the inertia piston to have a cylindrical outer contour forming a guide section 47. This guide section 47 can be used to guide the inertia piston on the cylindrical inner contour of the cylinder
The inertia element 40 can be moved against the preload of the spring element 43 in the axial direction of the piston rod 22 to lift the sealing piece 41 off the circumferential valve seat 23.9 and to move the valve 23.8 to the open position.
Preferably, a plurality of mounting bolts 44 having spring elements 43 may be provided for mounting the inertia element 40 to the piston 23, wherein these mounting bolts 44 or the spring elements 43 are disposed uniformly distributed in the circumferential direction of the inertia element 40.
In the assembled state, the cylinder 25 is preferably mounted in such a way that it is held fixed in the axial direction of the piston rod 22. It is conceivable, however, that the cylinder 25 is swivel mounted.
The piston rod 22, the inertia element 40, in particular the inertia piston, and the piston 23 form a movable assembly. As explained above, the coupling piece 21 can be used to couple this movable assembly to the crusher body 14, for instance an impact rocker or crushing jaw.
The operating principle of the hydraulic cylinder 20 is explained in more detail below. To adjust the crushing gap 15 between the two crusher bodies 11 and 14, the hydraulic fluid held in the pressure chamber 24 is pressurized until the desired crushing gap width is set. At the same time, the hydraulic fluid held in the compensation area 28, which is also pressurized, is drained until the desired crushing gap width is reached and the piston 23 has assumed a corresponding position.
Once the crushing gap 15 is set, the crusher can operate in normal mode and crush the supplied material to be crushed 19.1 to obtain the desired crushed material 19.2.
If an overload occurs, for instance because a non-crushable object 19.3 or an object that is difficult to crush enters the work area between the two crusher bodies 11,14, a high force is suddenly applied to the crusher body 14. As a result of this force, the crusher body 14 gives way, for instance it swivels around the axis of the swivel bearing 14.1.
The movable assembly transfers this motion to the hydraulic cylinder 30. In this example, the piston rod 22 transfers this motion to the piston 23. In the process, the hydraulic medium is compressed in the pressure chamber 24.
Because the piston rod 23 is now accelerated as a result of this motion, a relative motion occurs between the piston 23 and the inertia element 40 due to the inertia force acting on the inertia element 40. This relative motion causes the preload of the spring element(s) 43 to increase and the valve 23.8 to open. In detail, the sealing piece 41 is then lifted off the valve seat 23.9.
In this way, a fluid-conducting connection is established from the pressure chamber 24 via the discharge channel 23.10 and the overflow area 23.3 and the fluid guide 45 of the inertia element 40 to the compensation area 28. Accordingly, the pressure in the pressure chamber 24 can abruptly drop toward the compensation area 28 via this fluid conducting connection. As a result, the crushing gap 15 opens rapidly, as the piston rod 22 can now move further towards the pressure chamber 24 using little force. Now the unbreakable object 13.3 can fall through the crushing gap
After the overload situation has ended, the desired width of the crushing gap 15 can be reset as described above.
According to the invention, the valve 23.8 is now controlled by the motion of the movable assembly, for instance, as in this case, by the motion of the piston rod 22, which results in a relative motion of the piston with respect to the inertia element 40.
After the overload situation has ended, the spring element(s) 43 move the inertia element 40 and the piston 23 together again to effect the closed position of the valve 23.8.
The pressure valve 32 is designed in such a way that during normal operation it safeguards the pressure in the compensation area 28 and additionally discharges the quantity of oil that can no longer be held during overload to the tank.
If the piston 23 is now moved in the event of an overload and the fluid is forced from the pressure chamber 24 into the compensation area 28, the pressure valve 32 can be used to discharge excess hydraulic medium from the compensation area 28 through the pressure valve 32. Specifically, this involves an increase in pressure in the compensation area 28, which causes the pressure valve 32 to open and the hydraulic medium to be discharged into the tank 34.
As the above discussion illustrates, the invention relates to a crusher for mineral materials or recycled materials, in particular a rotary impact crusher or a jaw crusher, comprising a crusher unit 10. The crusher unit 10 has a movable first crusher body 11, in particular a rotor or a crushing jaw, and a second crusher body 14, in particular an impact rocker or a crushing jaw, is assigned to the first crusher body 11. The crushing gap 15 is formed between the crusher bodies 11, 14, wherein the movable assembly of the overload triggering device 30 is coupled to the second crusher body 14. The movable assembly comprises the cylinder 25 of the hydraulic cylinder 20 or, as in the exemplary embodiment shown, a piston 23 guided in the cylinder 25, wherein the movable assembly is designed to permit, in an evasive motion, a motion of the coupled crusher body 14, which increases the width of the crushing gap 15. The overload triggering device 30 comprises the valve 23.8, which in its open position establishes a fluid-conducting connection between the pressure chamber 24 and the compensation area 28 and in the closed valve position blocks this connection. According to the invention, the valve 28.8 is formed between two relatively movable components of the movable assembly, in this case between the inertia element 40 and the piston 23.
Number | Date | Country | Kind |
---|---|---|---|
10 2022 119 153.2 | Jul 2022 | DE | national |