Impact crusher

Abstract

A method of determining wear of a rotary impact crusher includes adjusting the position of an impact rocker relative to an impact rotor with an actuator by a first adjustment value until a crushing section of the impact rocker contacts an impact bar or an impact circle of the impact rotor. The first adjustment value is compared to a first reference value to make a first comparison corresponding to total wear of the impact rocker and the impact bar. The position of the impact rocker is adjusted relative to the impact rotor by a second adjustment value until the impact rocker contacts a reference measurement section. The second adjustment value is compared to a second reference value to make a comparison corresponding to wear of the impact rocker.

Claims

1. A method of determining wear of a rotary impact crusher, the rotary impact crusher including: an impact rotor and at least two impact bars connected to the impact rotor, the impact bars each having a radially outer end, wherein the radially outer end of at least one of the impact bars forms an impact circle during rotation of the impact rotor; at least one impact rocker operably associated with the impact rotor such that in an operating position a crushing gap is formed between the impact circle and a crushing section of the at least one impact rocker; and an actuator configured to adjust a position of the at least one impact rocker relative to the impact rotor; wherein the method comprises steps of: (a) adjusting the position of the at least one impact rocker relative to the impact rotor with the actuator by a first adjustment value until the crushing section of the at least one impact rocker contacts the at least one of the impact bars or the impact circle; (b) comparing the first adjustment value to a first reference value to make a first comparison corresponding to total wear of the at least one impact rocker and the at least one of the impact bars; (c) adjusting the position of the at least one impact rocker relative to the impact rotor by a second adjustment value until the at least one impact rocker contacts a reference measurement section defined on the impact rotor; and (d) comparing the second adjustment value to a second reference value to make a comparison corresponding to wear of the at least one impact rocker.

2. The method of claim 1, wherein step (c) further comprises: rotating the impact rotor to a position wherein the reference measurement section of the impact rotor faces the crushing section of the at least one impact rocker; then stopping or slowing rotational motion of the impact rotor; and then adjusting the position of the at least one impact rocker until the crushing section of the at least one impact rocker rests against the reference measurement section.

3. The method of claim 1, wherein step (c) further comprises: detecting contact of the crushing section of the at least one impact rocker with the reference measurement section with a sensor; and stopping movement of the at least one impact rocker relative to the impact rotor with a controller in response to a contact signal from the sensor.

4. The method of claim 3, wherein step (c) further comprises: when the at least one impact rocker is in contact with the reference measurement section, measuring the second adjustment value as an angular position of the at least one impact rocker.

5. The method of claim 3, wherein step (c) further comprises: when the at least one impact rocker is in contact with the reference measurement section, measuring the second adjustment value as a displacement of the actuator.

6. The method of claim 1, wherein step (c) further comprises: rotating the impact rotor with a rotary actuator to a predetermined angular position wherein the reference measurement section of the impact rotor faces the crushing section of the at least one impact rocker, and stopping the impact rotor at the predetermined angular position.

7. The method of claim 6, the rotary impact crusher including a main drive for rotating the impact rotor during a crushing operation, wherein: the step of rotating the impact rotor with a rotary actuator is further characterized in that the rotary actuator comprises an auxiliary drive in addition to the main drive.

8. The method of claim 7, wherein: the step of rotating the impact rotor with a rotary actuator is further characterized in that the auxiliary drive is manually operated.

9. The method of claim 7, wherein: the step of rotating the impact rotor with a rotary actuator is further characterized in that the auxiliary drive is motorized and the impact rotor is rotated with a motor.

10. The method of claim 1, wherein step (c) is further characterized in that the reference measurement section is defined by one or more surface areas of the impact rotor.

11. The method of claim 10, wherein step (c) further comprises: detecting an angular position of the impact rotor about an axis of rotation of the impact rotor with an angular position sensor; transmitting an angular position signal from the angular position sensor to a controller; and adjusting the angular position of the impact rotor in response to a control signal from the controller until one of the one or more surface areas of the impact rotor faces the crushing section of the at least one impact rocker.

12. The method of claim 10, wherein step (c) is further characterized in that the one or more surface areas of the impact rotor in side view perpendicular to an axis of rotation of the impact rotor have a shape of a circular segment rotating about the axis of rotation of the impact rotor.

13. The method of claim 10, wherein step (c) is further characterized in that the one or more surface areas of the impact rotor in side view perpendicular to an axis of rotation of the impact rotor form a cross-sectional shape of a spiral arc segment, and a radial distance of points on the spiral arc segment from the axis of rotation is stored in a memory of a controller.

14. The method of claim 1, further comprising: repeating steps (a) through (d); and determining with a controller an expected remaining service life of the impact bars and/or the at least one impact rocker.

15. The method of claim 14, further comprising: providing the controller with information relating to a material property of material to be crushed; and wherein the determining with the controller of the expected remaining service life of the impact bars and/or the at least one impact rocker is based at least in part upon the information relating to the material property.

16. The method of claim 1, further comprising: determining wear of the at least one of the impact bars by subtracting the wear of the at least one impact rocker from the total wear.

17. The method of claim 1, wherein: the first reference value is equal to a predetermined crushing gap dimension.

18. The method of claim 1, wherein: steps (b) and (d) are performed by a controller.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is explained in greater detail below based on an exemplary embodiment shown in the drawings. In the Figures:

(2) FIG. 1 shows a side view of a schematic representation of an impact crusher partially in section,

(3) FIG. 2 shows a side view of a detailed representation of a crusher unit of the impact crusher according to FIG. 1 and

(4) FIG. 3 shows the representation of FIG. 2 in a different operating position.

(5) FIG. 4 is a schematic illustration of a controller of the impact crusher and the associated sensors and actuators.

DETAILED DESCRIPTION

(6) FIG. 1 shows a lateral, partially cutaway view of an impact crusher designed as a rotary impact crusher. The impact crusher can be designed as a mobile unit with a chassis 13 and a chain drive 15. It has a feed unit 10, if necessary a pre-screen unit, a crusher unit 20 and at least one crusher discharge conveyor 24.

(7) A hopper 11 can be arranged in the area of the feed unit 10. The hopper 11 has hopper walls. It directs the fed feed material to a conveyor unit 12, which can preferably be designed as a vibratory feed chute.

(8) The conveyor unit 12 conveys the feed material to a screening unit 14, which may be formed by a double-deck prescreen, for instance. In this exemplary embodiment, the screen unit 14 has an upper heavy-duty double-deck screen 14.1, which is designed as a comparatively coarse screen and forms an upper deck. Below, there is a comparatively finer screen forming a lower deck 14.2. A drive causes it to vibrate in a circular motion. The upper deck separates a fine fraction and a medium grain from the material to be crushed. The lower deck separates the fine fraction from the medium grain. The fine fraction can optionally be discharged from the material crusher plant by means of a side discharge belt 14.3 or returned to the medium grain by setting a bypass flap accordingly. The medium grain is routed past the crusher unit 20 to the crusher discharge conveyor 24 via a bypass 23. The material to be crushed is routed to the crusher unit 20 via a crusher inlet 22 at the end of the pre-screen unit.

(9) The crusher unit 20 has a crusher housing 21, in which an impact rotor 30 is rotatably mounted. A main drive 16 of the impact crusher can be used to drive the impact rotor 30. The impact rotor 30 rotates about an axis of rotation 32.

(10) FIGS. 2 and 3 show the structure of the crusher unit 20 more clearly. As these drawings illustrate, the impact rotor 30 has a carrier 31 having several mounts 33 on its outer periphery. In this exemplary embodiment, three mounts 33 are provided. However, it is also conceivable that only two or more than three mounts 33 are used.

(11) Impact bars 35 can be interchangeably inserted into the mounts 33 and a securing section 35.4 can be used to interchangeably secure impact bars in the mounts 33.

(12) For instance, it is conceivable that a bearing piece 34.1 is inserted in the mount 33 in the direction of rotation V at the rear, preferably interchangeably, for securing the impact bars 35. The rear end of the impact bar 35 can be supported against this bearing piece 34.1. Preferably, provision is made that at least one clamping wedge 34.2, 34.3 is installed in front of the impact bar 35 in the direction of rotation V of the impact rotor 30. In this exemplary embodiment, two clamping wedges 34.2, 34.3 are provided for the stable securing of the impact bar 35. Tensioners can be used to adjust the clamping wedges 34.2, 34.3 to press the impact bar 35 against the rear bearing piece 34.1.

(13) The impact bars 35 have one radial end 35.1 each. In this exemplary embodiment, the radially outer ends 35.1 of the impact bars 35 are located on a joint impact circle K.

(14) Free areas 35.2 adjoin the radial ends 35.1 of the impact bars 35. The open spaces 35.2 extend at a distance from the impact circle K.

(15) Adjacent to the radial ends 35.1, the impact bars 35 have front surfaces 35.3 at the front. These front surfaces 35.3 protrude beyond a circumferential rotor surface 36.

(16) The rotor circumferential surface 36 forms reference measurement sections 36.1 between the mounts 33 and thus between the impact bars 35. As FIG. 2 shows, the reference measurement sections 36.1 are formed by arc segments that extend spirally around the axis of rotation 32 of the impact rotor 30. Accordingly, the distance of the circumferential rotor surface 36 from the axis of rotation 32 increases continuously, at least piecewise. In this exemplary embodiment, this distance increases continuously in the circumferential direction. However, it is also conceivable that the distance increases in the direction counter to the circumferential direction.

(17) Preferably, a reference measurement section 36.1 is arranged in each intermediate area between the impact bars 35. However, it is also conceivable that only one reference measurement section 36.1 is provided on the circumferential rotor surface 36.

(18) The crusher unit 20 has two impact rockers 41, 42. These impact rockers 41, 42 are assigned to the impact rotor 30.

(19) The impact rocker 42 has a rocker body 42.1 that is connected in a swiveling manner to the chassis 13 via a swivel bearing 42.2. The oscillating body 42.1 has an impact surface 42.3 at the front, which is assigned to the impact rotor 30. At its end facing away from the swivel bearing 42.2, the impact surface 42.3 ends in a crushing section 42.6.

(20) An actuating unit, which is not shown in FIG. 2, is used to swivel the impact rocker 42 about the swivel bearing 42.2.

(21) The impact rocker 41 has a rocker body 41.1 that is connected in a swiveling manner to the chassis 13 via a swivel bearing 41.2. The oscillating body 41.1 has an impact surface 41.3 at the front, which is assigned to the impact rotor 30. The impact surface 41.3 has a mount 41.4 at its end facing away from the swivel bearing 41.2. A wear insert 41.5 is secured in this mount 41.4, preferably in an interchangeable manner. The wear insert 41.5 is made of a material which has a greater hardness than the impact surface 41.3. Preferably, the wear insert 41.5 is made of a hard material. The wear insert 41.5 has a crushing section 41.6 at its end facing away from the swivel bearing 41.2.

(22) An actuating unit 50 is used to swivel the impact rocker 41 around the swivel bearing 41.2. The actuating unit 50 can also be referred to as an actuator 50 and may be formed by a hydraulic cylinder. The hydraulic cylinder has a cylinder 51, in which a piston is adjustably guided. A piston rod 52 is connected to the cylinder 51. The end of the piston rod 52 bears a coupling piece 53. The coupling piece 53 is swivel coupled to the oscillating body 41.1. The hydraulic cylinder may be a smart cylinder having an integral extension sensor 102 configured to generate an extension signal which is transmitted to the controller 100 shown in FIG. 4 and further described below.

(23) The actuating unit 50 is used to form a resistance against which the impact rocker 41 is arranged to be able to freely oscillate in the crushing chamber to a limited extent.

(24) The actuating unit 50 is further used to adjust the spacing of the crushing section 41.6 and the impact circle K. For this purpose, the piston is moved in the hydraulic cylinder, wherein the piston rod 52 increasingly moves into or out of the cylinder 51 depending on the direction of motion of the piston.

(25) As mentioned above, the material to be crushed is routed to the impact rotor 30 during operation. The impact rotor 30 rotates at a high speed about the axis of rotation 32. In so doing, the front surfaces 35.3 of the impact bars 35 come into engagement with the material to be crushed and accelerate it. The material to be crushed is hurled against the impact surfaces 42.3 and 41.3 of the impact rockers 42 and 41. In so doing, the material to be crushed is broken. If it has a grain size that permits the material to fall between the crushing section 42.6 and the impact circle K, the crushed material is further crushed at the impact rocker 41. When a grain size is reached that permits the crushed material to fall through the crushing gap formed between the crushing section 41.6 and the impact circle K, the crushed material passes onto the crusher discharge conveyor 24.

(26) During operation, both the impact rocker 41 and the impact bars 35 are subject to a high degree of wear. In this way, the size of the crushing gap is increased. If the crushing gap has an impermissible width, it has to be readjusted. The actuating unit 50 is used for this purpose.

(27) According to the invention, the wear of the impact bars 35 and, separately, the wear of the impact rocker 41 can be determined. The material feed is stopped to determine wear and to perform a measurement process. The impact rotor 30 continues to operate until there is no more crushed material in the crusher unit 20. Now the impact rotor 30 runs freely without being influenced by crushed material. The impact rotor 30 is then stopped. The impact rotor 30 is then rotated until the crushing section 41.6 of the impact rocker 41 faces a reference measurement section 36.1 of the impact rotor 30.

(28) Rotation of the impact rotor 30 can be achieved, for instance, using an auxiliary drive 104 which may be either a manually driven auxiliary drive or an auxiliary drive driven by an electric motor 106 as schematically shown in FIG. 4.

(29) When one of the reference measurement sections 36.1 faces the crushing section 41.6, the actuating unit 50 moves the impact rocker 41, starting from a defined home position, in the direction of the reference measurement section 36.1 until the crushing section 41.6 rests against the reference measurement section 36.1 (see FIG. 2). A force gauge 108 schematically shown in FIG. 4, for instance in the hydraulic cylinder or using another suitable sensor 108, can be used to determine the contact with the reference measurement section 36.1. The deflection of the impact rocker 41 from the home position is measured as the second adjustment value. It can, for instance, be determined by measuring the angle at the swivel bearing 41.2 of the impact rocker 41 with an angular position sensor 110 as schematically shown in FIG. 4 or based on the travel motion of the hydraulic cylinder (for instance, the piston rod 52 or the piston) as detected by the internal extension sensor 102 of the actuator 50. The reference measurement sections 36.1 are arranged between the impact bars 35 in an area which is not subject to wear or at most only to slight wear.

(30) The distance of the circumferential rotor surface 36 from the axis of rotation 32 in the area of the reference measurement sections 36.1 can be stored in a memory unit 116 of the controller 100 of the impact crusher as a functional relationship depending on the angular location on the impact rotor 30 relative to a reference location on the rotor. The reference location on the impact rotor 30 can be any identifiable feature on the impact rotor 30 the angular position of which relative to the impact rocker 41 can be input to the controller 100. It is also conceivable that pairs of values are stored in the memory unit 116 of the controller 100, wherein certain angular locations on the impact rotor 30 are assigned to distances of the circumferential rotor surface 36 from the axis of rotation 32. The movement of the angular locations on the impact rotor 30 about its axis of rotation 32 relative to the impact rocker 41 can be detected by an angular position sensor 111 such as schematically shown in FIG. 4 and the controller 100 can keep track of the angular position of those angular locations relative to the impact rocker 41.

(31) The second adjustment value is compared to a second reference value in a computing unit 114 of the controller. The computing unit 114 may also be referred to as a processor 114. The matching deflection of a non-worn impact rocker 41 in contact with the same area of the reference measurement section 36.1 against which the crushing section 41.6 rests is used as the second reference value. Here, too, a functional relationship or value pairs for the second reference value can be stored in the memory unit 116 of the controller.

(32) The wear of the impact rocker 41 in the area of the crushing section 41.6 can be determined by subtraction, wherein the second reference value is subtracted from the second adjustment value.

(33) It is also conceivable that only an average value of the spacing of the rotor circumferential surface 36 in the area of the reference measurement section 36.1 is stored in the memory unit of the controller as the second reference value. Furthermore, it is conceivable that the circumferential rotor surface 36 as the reference measurement section 36.1 forms an arc of a circle or approximately an arc of a circle that revolves at a radius around the axis of rotation 32. In this case, for instance, the radius of the arc can be used as the second reference value.

(34) The actuating unit 50 then returns the impact rocker 41 to a home position. Then the impact rotor 30 can be rotated, for instance by means of the main drive 16 or by means of an auxiliary drive.

(35) While the impact rotor 30 is rotating, the actuating unit 50 adjusts the impact rocker 41 from a predefined home position until the crushing section 41.6 touches the impact circle K. While the impact rotor 30 is rotating, contact is then made between the impact rocker 41 and the radial end 35.1 of the impact bar 35, which can be determined acoustically, for instance using a microphone 112 as schematically shown in FIG. 4 or by an operator.

(36) In the context of the invention, the contact of the impact rocker 41 with the radial end 35.1 of the impact bar 35 can be determined acoustically with a microphone, as mentioned above. In addition or alternatively, this contact can also be determined using a suitable signal transducer, for instance a contact sensor, in particular an acceleration sensor.

(37) The deflection of the impact rocker 41 from the home position to contact the impact circle K is determined as the first adjustment value. This first adjustment value can be determined, for example, by angular measurement at the pivot bearing 41.2 of the impact rocker 41 with angular position sensor 110 or as a deflection of the hydraulic cylinder (for example, travel of the piston rod 52 or of the piston of the hydraulic cylinder) measured with extension sensor 102. In other words, the zero position of the impact rocker 41 is set and determined.

(38) The first adjustment value can also be determined alternatively when the impact rotor 30 is stationary. In this case, the crushing section 41.6 is moved against the radial end 35.1 of the impact bar 35, as shown in FIG. 3. The measured deflection from the predefined home position of the impact rocker 41 is then used as the first adjustment value. The assignment of the impact rotor 30 to the crushing section 41.6 can again be achieved by a manual or motorized auxiliary drive.

(39) The first adjustment value is compared to a first reference value. The first reference value is the matching deflection of a non-worn impact rocker 41 and a non-worn impact bar 35 when the crushing section 41.6 contacts the impact circle K or a contact point of the impact bar 35.

(40) By computing the difference, wherein the first reference value is subtracted from the first adjustment value, the total wear can be determined, which results from the wear of the crushing section 41.6 and the wear of the impact bar 35.

(41) If the total wear and the wear of the impact rocker 41 are now known, the wear of the impact bar 35 can be determined by computing the difference.

(42) In this way, the wear of the impact bar 35 and, separately, the wear of the impact rocker 41 can be easily determined individually, without the operator having to enter the crushing chamber with measurement equipment and/or without having to use complex optical measurement devices.

(43) In the example described above, first the second adjustment value and then the first adjustment value were determined. Of course, the first adjustment value and then the second adjustment value can also be determined in reverse order.

(44) After the measurement process has been completed, the actuating unit 50 can be used to swivel the impact rocker 41 again until the desired width of the crushing gap is set. For instance, from the zero crushing gap position, the impact rocker 41 can be moved back to the desired distance dimension in the crushing gap, as is common in the prior art.

(45) With the knowledge of the wear of the impact rocker 41 and the impact bars 35, a wear prediction can be made. For instance, a determination can be made whether the condition of the impact rocker 41 and/or the impact bars 35 is sufficient for a planned material processing job.

(46) For continuous wear prediction, provision may be made in the context of the invention that every time the crushing gap is adjusted or at regular intervals (for instance, once per shift, always at the beginning or end of work, etc.), the operation described above is also performed to determine the wear on the impact rocker 41 and the impact bars 35. In this way, wear can be monitored and a forecast can be used to compute when the impact bars 35 or the wear inserts 41.5 have to be replaced.

(47) As FIG. 1 further shows, the crushed material received from the impact rotor 30 enters the crusher discharge conveyor 24 in conjunction with the material guided in the bypass 23. A magnetic separator 17 can be located above the crusher discharge conveyor 24. This magnetic separator 24 singles out any ferrous particles that may be present in the crushed material. Accordingly, it attracts these iron parts and conveys them laterally out of the transport area of the crusher discharge conveyor 24.

(48) At the end of the crusher discharge conveyor 24, for instance, another screen unit 24.1 having a screen deck may be provided. The screen deck 24.1 screens out a fine material fraction 24.2. It falls onto another conveyor belt 25. The further conveyor belt 25 conveys the fine material fraction 24.2 to a crushed material pile 14.4.

(49) The material not screened out by the screening unit 24.1 passes onto a return belt 26. By means of the return belt 26, this rock fraction is returned and again passed through the crusher unit 20.

(50) As schematically illustrated in FIG. 4, the impact crusher includes a control system including a controller 100. The controller 100 may be part of the machine control system of the impact crusher, or it may be a separate control module. The controller 100 may be mounted in the operator's cab of the impact crusher. The controller 100 is configured to receive as input signals an extension signal from extension sensor 102, a contact signal or force signal from force sensor 108, an angular position signal for impact rocker 41 from angular position sensor 110, an angular position sensor for the impact rotor 30 from angular position sensor 111, and a sound signal from microphone 112. The signals transmitted from the various sensors to the controller 100 are schematically indicated in FIG. 4 by phantom lines connecting the sensors to the controller with an arrowhead indicating the flow of the signal from the sensor to the controller 100.

(51) Similarly, the controller 100 will generate control signals for controlling the operation of the various actuators, which control signals are indicated schematically in FIG. 4 by phantom lines connecting the controller 100 to the various actuators, such as hydraulic cylinder actuator 50 with the arrow indicating the flow of the command signal from the controller 100 to the respective actuator. It will be understood that the various actuators as disclosed herein may be hydraulic motors or may be hydraulic piston-cylinder units and that the electronic control signals from the controller 100 will actually be received by electro-hydraulic control valves associated with the actuators and the electro-hydraulic control valves will control the flow of hydraulic fluid to and from the respective hydraulic actuators to control the actuation thereof in response to the control signal from the controller 100. The control signals are generated at least in part in response to one or more of the input signals.

(52) Alternatively, the actuators may be electric actuators such as the electric motor 106. In such an embodiment the control signals from the controller 100 may activate relays and switches to direct electrical power to the electric motors to drive the motors in a desired direction at a desired speed.

(53) Controller 100 includes or may be associated with a processor 114, a computer readable medium 116, a data base 118 and an input/output module or control panel 120 having a display 122. An input/output device 124, such as a keyboard, joystick or other user interface, is provided so that the human operator may input instructions to the controller. It is understood that the controller 100 described herein may be a single controller having all of the described functionality, or it may include multiple controllers wherein the described functionality is distributed among the multiple controllers.

(54) Various operations, steps or algorithms as described in connection with the controller 100 can be embodied directly in hardware, in a computer program product 126 such as a software module executed by the processor 114, or in a combination of the two. The computer program product 126 can reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, or any other form of computer-readable medium 116 known in the art. An exemplary computer-readable medium 116 can be coupled to the processor 114 such that the processor can read information from, and write information to, the memory/storage medium. In the alternative, the medium can be integral to the processor. The processor and the medium can reside in an application specific integrated circuit (ASIC). The ASIC can reside in a user terminal. In the alternative, the processor and the medium can reside as discrete components in a user terminal.

(55) The term processor as used herein may refer to at least general-purpose or specific-purpose processing devices and/or logic as may be understood by one of skill in the art, including but not limited to a microprocessor, a microcontroller, a state machine, and the like. A processor can also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.