Crusher, brake system used in combination with crusher and compact eccentric crusher

Abstract

The utility model discloses a crusher for crushing supplied mineral materials. The crusher comprises a fixed crushing component, a fixed crushing component and a movable crushing component, a crushing gap is formed between the movable crushing component and the fixed crushing component, and the movable crushing component can move towards and away from the fixed crushing component to change the crushing gap and crush mineral materials in the crushing gap; and an induced current braking system operable to generate a magnetic braking force to limit movement of the movable crushing member. A braking system for use in conjunction with a crusher and a compact eccentric crusher are also disclosed. According to the braking system, the eddy current generated by the relative movement of the magnet in the braking yoke and the braking disc is used for generating a magnetic field and braking force, the braking system can be used in different types of crushers so as to restrict or limit the rotation of the movable crushing component, friction braking is not needed, and the service life of the crusher is prolonged. The braking system can be used in conjunction with a compact eccentric crusher to limit rotation of the crusher roller during idle mode.

Description

Technical Field

[0001] The utility model relates to the field of crushers, in particular to an eddy current brake of a crusher. Background Art

[0002] The disclosed system generally relates to a braking system for use in conjunction with a crusher having a stationary crushing member and a movable crushing member. More specifically, the present disclosure relates to a braking system including an eddy current brake for limiting rotation of a movable crushing member of a crusher.

[0003] Currently, different types of crushers are used to reduce the size of mineral material present in the infeed of the crusher. After processing, the size of the mineral material is reduced to produce a feed of mineral material having individual components of smaller size. In these types of crushers, the movable crushing members move towards and away from the fixed crushing members to produce a varying crushing gap, thereby crushing the infeed mineral material.

[0004] One type of crusher used to reduce the size of mineral material is known as a compact eccentric crusher. In a compact eccentric crusher, a freely rotatable crushing roller is mounted to an eccentric shaft by means of a series of roller bearings. The crushing roller is spaced from a fixed crushing jaw. In a compact eccentric crusher, the eccentric arrangement of the crushing roller on the eccentric drive shaft produces a movement of the crushing roller towards and away from the fixed crushing jaw. This movement changes the size of the crushing gap, causing the mineral material fed into the compact eccentric crusher to be crushed in the crushing gap.

[0005] During operation, the freely rotatable mounting of the crushing roller on the eccentric drive shaft causes the crushing roller to slowly rotate about the eccentric drive shaft in a direction opposite to the rotation of the eccentric drive shaft. Although the crushing force is generated by the lateral movement of the crushing roller relative to the fixed crushing jaw, the free rotation of the crushing roller distributes the wear to all parts of the outer circumference of the crushing roller.

[0006] When a compact eccentric crusher is operated in idle mode, with no material to be crushed, internal friction mounting the crushing rollers in the roller bearings of the eccentric drive shaft causes the crushing rollers to rotate with the eccentric drive shaft at the speed of the drive shaft.

[0007] As the crushing roller rotates with the eccentric drive shaft, if a supply of mineral material is fed into the crushing chamber and the crushing gap, the material will contact the outer surface of the crushing roller and immediately brake the rotation of the crushing roller. This instant braking will generate a large impact force in the roller bearings and support structure, which will shorten the service life of these components over time. Therefore, friction-based braking systems have been used to reduce and limit the rotation of the crushing roller. However, these friction-based braking systems tend to wear quickly and must be replaced. Moreover, friction-based braking systems require some type of actuator and control system to provide braking force only when desired.

[0008] Designers have therefore recognised the need for a braking system in a crusher to limit rotation between fixed and movable crushing elements without requiring any actuators or control systems and without requiring replacement due to wear caused by friction. Utility Model Content

[0009] The utility model relates to a braking system used in combination with a crusher, wherein the crusher has a fixed crushing component and a movable crushing component. Further, the utility model relates to a braking system comprising an eddy current brake for limiting the rotation speed of the movable crushing component of the crusher.

[0010] According to one aspect of the utility model, a crusher for crushing a feed of mineral material is provided, the crusher comprising: a fixed crushing member; a movable crushing member separated from the fixed crushing member by a crushing gap, wherein the movable crushing member can move toward and away from the fixed crushing member to change the crushing gap and crush the mineral material in the crushing gap; and an induction current braking system, which can be operated to generate a magnetic braking force to limit the movement of the movable crushing member.

[0011] Preferably, the induction current braking system comprises: a brake disc formed of a conductive material; and at least one brake yoke, wherein rotational movement of the brake disc relative to the brake yoke induces the magnetic braking force that restricts rotational movement of the movable crushing member.

[0012] Preferably, the brake disc is fixed and the brake yoke is mounted to the movable crushing member.

[0013] Preferably, the brake yoke comprises at least one permanent magnet and the brake disc moves past the at least one permanent magnet.

[0014] Preferably, the brake yoke comprises an electromagnet.

[0015] Preferably, the crusher comprises a plurality of brake yokes, and the brake disc moves through each of the plurality of brake yokes.

[0016] According to another aspect of the present invention, there is provided a braking system for use in conjunction with a crusher having a fixed crushing member and a movable crushing member spaced apart from each other to define a crushing gap, wherein the braking system comprises: a brake disc formed of a conductive material; and at least one brake yoke, wherein relative movement between the brake disc and the brake yoke induces a magnetic braking force that resists the rotational movement of the movable crushing member.

[0017] Preferably, the movable crushing member comprises a crushing roller mounted to an eccentric shaft, wherein rotation of the eccentric shaft produces eccentric movement of the crushing roller relative to the crushing gap.

[0018] Preferably, the brake disc is stationary and the at least one brake yoke rotates relative to the brake disc.

[0019] Preferably, the crusher is a compact eccentric crusher having a fixed jaw and a crushing roller mounted to an eccentric shaft such that rotation of the eccentric shaft produces eccentric movement of the crushing roller in and out of the crushing gap.

[0020] Preferably, the crushing roller is mounted to the eccentric shaft by means of a plurality of bearings such that the crushing roller rotates about the eccentric shaft, wherein the braking system limits the rotation of the crushing roller about the eccentric shaft.

[0021] Preferably, said at least one brake yoke is mounted for rotational movement with said crushing roller, whereas said brake disc is fixed with respect to the rotational movement of said crushing roller.

[0022] Preferably, the braking system comprises a plurality of brake yokes spaced around the crushing roller.

[0023] Preferably, each of the brake yokes includes at least one permanent magnet, and the brake disc passes through the brake yokes.

[0024] Preferably, the brake yoke comprises an electromagnet.

[0025] According to another aspect of the utility model, there is provided a compact eccentric crusher having a fixed jaw and a crushing roller mounted to an eccentric shaft, so that rotation of the eccentric shaft produces eccentric movement of the crushing roller into and out of a crushing gap. The crusher comprises: at least one brake yoke mounted to rotate with the crushing roller; a fixed brake disc formed of a conductive material, wherein the at least one brake yoke rotates around the brake disc, wherein the rotation of the at least one brake yoke relative to the brake disc induces a magnetic braking force that resists the rotational movement of the crushing roller.

[0026] Preferably, the compact eccentric crusher comprises a plurality of brake yokes spaced around the crushing roller.

[0027] Preferably, each of the brake yokes comprises at least one permanent magnet, and the brake disc moves past the at least one permanent magnet to induce the braking force.

[0028] Preferably, each of the brake yokes comprises a pair of spaced apart support arms, each support arm supporting a permanent magnet, wherein the brake disc moves between the permanent magnets of the brake yoke.

[0029] Preferably, the at least one brake yoke comprises a magnetic element, wherein relative movement of the brake disc and the brake yoke induces eddy currents in the brake disc.

[0030] Preferably, the crushing roller is mounted to the eccentric shaft via a plurality of bearings such that the crushing roller can rotate about the eccentric shaft, wherein the braking system limits the rotation of the crushing roller about the eccentric shaft.

[0031] According to one embodiment of the present invention, a crusher for crushing a supply of mineral material is provided. The crusher includes a fixed crushing member and a movable crushing member. The movable crushing member is separated from the fixed crushing member by a crushing gap. During operation of the crusher, the movable crushing member can move toward and away from the fixed crushing member to crush the mineral material in the crushing gap. With the operation of the crusher, the movable crushing member can rotate. The crusher also includes an induction current braking system, which is operable to generate a braking force that limits the rotational movement of the movable crushing element.

[0032] In one contemplated embodiment, the induction current braking system includes a brake disc formed of an electrically conductive material such as, but not limited to, copper or aluminum, although other electrically conductive materials are possible. The brake disc is positioned such that the brake disc moves through one or more brake yokes, each brake yoke comprising a magnetic material. As the brake disc moves past or through the brake yokes, a braking force is generated that opposes the rotational movement of the movable crushing member. The brake disc and brake yokes are mounted such that there is relative movement between these components during rotational movement of the movable crushing member.

[0033] In one contemplated embodiment, the brake yoke includes a pair of permanent magnets, and the brake disc passes between the pair of spaced permanent magnets. In another contemplated embodiment, the brake yoke may include a pair of electromagnets that may be selectively activated and deactivated to help control the generation of braking force.

[0034] The crusher may be one of several different types of crushers, such as a compact eccentric crusher, which includes a crushing roller and a fixed crushing jaw. In a compact eccentric crusher, the crushing roller is mounted to a rotating eccentric shaft via a series (a set) of bearings. In such an embodiment, the brake disc is preferably fixed and the brake yoke is mounted to the crushing roller and can therefore move with the crushing roller. During the idling mode, the crushing roller rotates with the rotation of the eccentric shaft. When the crushing roller rotates around the fixed brake disc, a braking force is generated to limit the rotation speed of the crushing roller.

[0035] The brake system of the utility model uses eddy currents generated by the relative movement of magnets in the brake yoke and the brake disc to generate magnetic field and braking force. The brake system can be used in different types of crushers to restrict or limit the rotation of the movable crushing member without friction braking.

[0036] Various other features, objects and advantages of the present invention will become apparent from the following description in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The accompanying drawings illustrate the best mode currently contemplated for carrying out the present invention. In the drawings:

[0038] Figure 1 is a schematic diagram of several different types of crushers, each of which is operable to crush a feed of mineral material;

[0039] Figure 2 is a side view of a compact eccentric crusher including a fixed crushing member and a movable crushing member;

[0040] Figure 3 It is along Figure 2 A cross-sectional view taken along line 3-3 showing the crushing roller mounted to the rotating eccentric shaft;

[0041] Figure 4 is an enlarged cross-sectional view showing the position of the brake system of the present invention;

[0042] Figure 5 is a further enlarged view showing the braking system;

[0043] Figure 6 It is along Figure 5 an enlarged view taken along line 6-6;

[0044] Figure 7 is a view of a brake yoke and brake disc; and

[0045] Figure 8 is a graph showing the relationship between braking force and rotational speed for two materials that form the brake disc. DETAILED DESCRIPTION

[0046] Figure 1 A number of different types of crushers are shown that can be used to break and reduce the size of hard rock and stone in mines and quarries. Figure 1 In the present invention, the first type of crusher is called a jaw crusher, which is shown by reference numeral 10. The jaw crusher 10 includes a fixed crushing member 12 and a movable crushing member 14. The movable crushing member 14 can move toward and away from the fixed crushing member 12 to crush a feed of mineral material entering a crushing gap 16, as shown by arrow 18. In the jaw crusher 10, the movable member 14 is a movable jaw having a first wear surface 20 that captures the mineral material between a second wear surface 22 formed on the fixed jaw of the fixed crushing member 12. The first wear surface and the second wear surface can be replaced after prolonged use.

[0047] The second type of crusher is called a gyratory crusher 24, comprising an internal crushing head having an outer wear surface, which moves in a gyratory mode within a stationary bowl comprising an outer wear surface. The gyratory crushing head is mounted to a main shaft 26 that moves by means of an eccentric. The movement of the eccentric causes the gyratory movement of the crushing head within the stationary bowl. The crushing head acts as a movable crushing member, while the stationary bowl acts as a stationary crushing member. A crushing gap is formed between the stationary crushing member and the movable crushing member of the gyratory crusher 24, so that a feed stream of mineral material indicated by arrow 28 is crushed within the crushing gap to produce a product stream 30 that flows out from the lower end of the gyratory crusher. The product stream 30 includes particles of a size smaller than the particle size included in the feed mineral material stream indicated by arrow 28. As is well known, gyratory crushers are designed so that the gyratory movement of the crushing head within the gyratory crusher 24 occurs with little or no spin of the crushing head so that the main movement of the crushing head is towards and away from the fixed crushing member to increase and decrease the size of the crushing gap to process the mineral material.

[0048] Figure 1 A third type of crusher is further shown, which is referred to as a compact eccentric crusher and is indicated by reference numeral 32. The compact eccentric crusher 32 includes a fixed crushing member 34 and a movable crushing member 36. In the compact eccentric crusher 32, the fixed crushing member is a fixed jaw 38, and the movable crushing member is a crushing roller 40. The crushing roller 40 is mounted to an eccentric drive shaft 42 that can be driven for rotation by a drive motor. As the eccentric shaft 42 rotates, the crushing roller 40 moves along an eccentric path toward and away from the fixed jaw 38 to change the size of the internal crushing gap 44. The eccentric movement of the crushing roller is caused by Figure 1The movement of the crushing roller 40 generates a crushing gap 44 of varying size, which serves to crush the flow of mineral material entering the crushing gap 44, as indicated by arrow 48.

[0049] pass Figure 1 From the description of the three different types of crushers shown in , it will be appreciated that each crusher comprises fixed crushing members and movable crushing members which combine to open and close a crushing gap to crush a feed of mineral material supplied to the particular crusher.

[0050] Figure 2 A specific configuration of a compact eccentric crusher 32 is further shown. Figure 2 , the compact eccentric crusher 32 receives a supply of mineral material 50 from a feed conveyor 52. In the illustrated embodiment, the supply of mineral material 50 may fall onto a feed screen 54 that includes slots or other openings that allow particles of sufficiently small size to bypass the primary crushing operation. The feed screen 54 directs larger particles in the supply of mineral material to a crushing chamber 56. In another contemplated embodiment, the feed screen 54 may be omitted such that the entire supply of material is directed to the crushing chamber 56.

[0051] A crushing chamber 56 is generally formed between the fixed jaw 38 and an outer surface 58 of the crushing roller 40. As will be described in more detail below, the crushing roller 40 is mounted to an eccentric drive shaft 42 that produces eccentric motion of the outer surface 58 along an eccentric path, including motion toward and away from the fixed jaw 38, as indicated by arrow 46. The motion of the entire crushing roller 40 increases and decreases the size of the crushing gap 44. The increase and decrease in the size of the crushing gap 44 causes larger particles of the feed stream to be crushed, thereby producing an outlet product stream 60.

[0052] In addition to the movement of the entire crushing roller 40, the position of the crushing jaw 38 can be changed by movement of the support arm 62. However, during crushing operation, the movement of the crushing roller 40 relative to the fixed jaw 38 generates a crushing force to convert the inlet product flow to the outlet product flow 60.

[0053] During operation of the compact eccentric crusher 32 with a feed of mineral material to be crushed, the crushing forces generated at the crushing gap cause the crushing rollers 40 to rotate at very low RPM in a direction opposite to the rotation of the eccentric shaft. Figure 2, the eccentric shaft 42 will rotate in a clockwise direction, while the crushing force generated in the crushing gap 44 will cause the crushing roller 40 to rotate in a counterclockwise direction. When no material is present and the compact crusher 32 is in an idle mode, the crushing roller 40 will eventually rotate in conjunction with the rotation of the eccentric shaft 42 at the same rotational speed and in the same rotational direction. In some embodiments, the crushing roller is thus capable of rotating between 100 RPM and 200 RPM in the idle mode.

[0054] Figure 3 It shows that the structure is Figure 2 2 is a cross-sectional view of a movable crushing member 36 of a portion of a compact eccentric crusher 32 shown in FIG. The movable crushing member comprises a crushing roller 40 rotatably mounted to an eccentric shaft 42. Figure 3 As shown in FIG. 1 , the eccentric shaft 42 includes a variable radial thickness around its periphery, so that the rotation of the eccentric shaft 42 causes the eccentric movement of the crushing roller 40, as shown in FIG. Figure 2 As shown by arrow 46 in FIG. Figure 3 In the cross-sectional view of FIG. 6 , the increased radial thickness of the eccentric shaft is shown in the region 64 .

[0055] exist Figure 3 In the illustrated embodiment, the crushing roller 40 includes a series of roller linings 65, each of which is mounted to a roller support hub 83. The roller linings 65 are replaceable wear parts mounted to the roller support hub 83 for easy replacement when worn. When the roller linings 65 are mounted to the roller support hub 83, the roller linings 65 define the outer contact surface 58 of the crushing roller 40. As shown, this outer surface 58 is defined by a series of extended ridges 66, each of which is separated by a series of grooves 68. These ridges 66 and grooves 68 provide a stronger outer crushing surface 58 for the crushing roller 40.

[0056] like Figure 3 As shown, the eccentric shaft 42 includes a pair of stub ends 70, which are connected to a drive wheel (not shown), which in turn is connected to a drive motor, which is operable to generate rotational movement of the entire eccentric shaft 42. The eccentric shaft 42 includes a pair of outer bearings 72 and a pair of inner bearings 74. The outer bearings 72 provide rotational support for the eccentric shaft 42 on a support frame (not shown), while the inner bearings 74 provide rotational support for the crushing roller 40. During operation of the compact eccentric crusher, the crushing roller 40 can freely rotate around the eccentric drive shaft 42.

[0057] Now refer to Figure 4, the details of each of the pair of inner bearings 74 will now be described. Each inner bearing 74 includes an inner race 76 that is securely mounted to the outer surface 78 of the eccentric shaft 42. The inner race 76 supports a series of individual rollers 80 that are positioned between the inner race 76 and a corresponding outer race 82. The outer race 82 is securely mounted to an inner support wall 84 of a roller support hub 83. The support hub 83 includes a support wall extending between the inner support wall 84 and the outer support wall 86. In the illustrated embodiment, the entire roller support hub 83 is an integrally cast component that provides the required structural stability for the series of roller liners 65. As shown in FIG. Figure 4 As shown in the figure, the individual roller linings 65 are firmly attached to the outer support wall 86, so that the combination of the support hub 83 and the series of roller linings 65 defines the crushing roller 40. The crushing roller 40 also includes a pair of annular end walls 88, which are also mounted to the ends of the support hub 83 through a series of connecting pieces passing through the connecting openings 85. The end walls 88 rotate as part of the entire crushing roller 40 with the rotation of the outer race 82 of the inner bearing 74.

[0058] Figure 2 During operation of the compact eccentric crusher 32 shown in FIG. 3 without any (processed) material present, which is referred to as idle mode, the rotation of the eccentric shaft 42 is transferred to the rotation of the crushing roller 40 by the bearing friction in each internal bearing 74. After a sufficient period of idle mode, the crushing roller 40 will rotate synchronously with the rotation of the eccentric shaft 42. When the feed of mineral material is initially fed into the crushing chamber 56, larger diameter stones will enter the crushing gap, which will cause the rotation of the crushing roller 40 to brake almost instantaneously. This near instantaneous termination of the rotation of the crushing roller will cause extreme impact forces to be induced in the internal bearings 74 and in the support structure including the roller support hub 83. Such extreme impact forces generated during the interruption of the rotation of the crushing roller 40 in the case of the introduction of the feed flow of mineral material after a longer period of idle mode increase the wear and failure of the internal components. Therefore, a braking system is designed and included in the compact eccentric crusher.

[0059] Return to reference Figure 3, the outer race 90 of each outer bearing 72 is isolated from the rotation of the eccentric shaft 42 by a series of rollers 91 located between the outer race 90 and the inner race 93. In this way, the outer race 90 can remain fixed while the inner race 93 rotates with the eccentric shaft. As shown, the outer race 90 is coupled to a support frame 92. The support frame 92 is designed to be securely mounted to the outer race 90 and is therefore fixed during the rotational movement of the eccentric shaft 42. The support frame 92 is mounted to a support plate 94 which is also fixed relative to the rotating eccentric shaft 42. The support plate 94 is connected to the brake disc 96 by a series of connecting support columns 98 (standoffs, sheet metal copper columns), as shown in Figure 4 The brake disc 96 (through its connection to the mounting plate 94 and the support bracket 92) is a stationary component even during the rotational operation of the eccentric shaft 42. Figure 4 In the illustrated embodiment, the brake disc 96 has an annular configuration and includes a body 100 defined by an inner edge 102 and an outer edge 104, as shown in FIG. Figure 5 Although the brake disc 96 has an annular shape in the illustrated embodiment, the brake disc 96 may also be a plate or other flat shape having other configurations, such as a circular plate, an annular segment, or other similar shapes.

[0060] Return to reference Figure 4 , includes a pair of brake discs 96, wherein each brake disc 96 is mounted into the end wall 88 at each end of the crushing roller 40. The brake discs 96 are included to form a part of the braking system of the present disclosure. As described above, each brake disc 96 is fixed (stationary) relative to the rotational movement of the crushing roller 40. The brake discs 96 form part of an eddy current braking system designed to be used in conjunction with the eccentric roll crusher 32 of the present disclosure.

[0061] The second component that forms part of the eddy current braking system of the present disclosure along with the fixed brake disc 96 is a series of brake yokes 106. Figure 4 In the embodiment shown in FIG, two brake yokes 106 are positioned at each end of the crushing roller 40. However, it is contemplated that a fewer or greater number of brake yokes 106 may be used at each end of the crushing roller 40 while operating within the scope of the present disclosure.

[0062] Now refer to Figures 5 to 7 , the details of each individual brake yoke 106 will be described. Figure 6As shown in , the brake yoke 106 includes a mounting block 108 that is securely attached to the outer support wall 86 that forms part of the roller support hub 83. The mounting block 108 provides an attachment point for a pair of support arms 110. Each support arm 110 is mounted to the mounting block 108 by a connector 112. The support arms 110 extend radially inwardly from the outer support wall 86 and are spaced apart from each other so as to define a receiving recess 114 therebetween. The receiving recess 114 is sized so that it can receive the brake disc 96. As shown in Figure 6 As shown in FIG. 8 , the outer edge 104 of the brake disc 96 is spaced radially inward from the mounting block 108 such that the brake yoke 106 can freely rotate relative to the fixed brake disc 96 .

[0063] exist Figures 5 to 7 In the embodiment shown in FIG. 1 , each brake yoke 106 includes a pair of permanent magnets 116 mounted to an interior surface 118 of a support arm 110. These permanent magnets 116 each include an outer surface 120 that are spaced apart from one another by a distance greater than the thickness of the brake disc 96. The pair of permanent magnets 116 are oriented so that the north pole of one permanent magnet 116 faces the south pole of the other permanent magnet 116. In this orientation, the pair of magnets 116 generates a toroidal magnetic field.

[0064] As shown, the brake disc 96 is perpendicular to the pair of support arms 110 and is capable of passing between the pair of spaced apart permanent magnets 116 during operation of the crusher and rotational movement of the crushing roller 40. The brake disc 96 is oriented perpendicular to the annular magnetic field generated by the magnets 116 so that movement of the brake yoke 106 causes the brake disc 96 to move perpendicularly through the annular magnetic field, which induces eddy currents in the brake disc 96.

[0065] When the brake disc 96 is located between the pair of permanent magnets 116, an air gap 117 is defined on each side of the brake disc 96 and one of the permanent magnets 116. The size of the air gap 117 is selected to help define the braking force generated by the brake system, as will be described in more detail below. Although the permanent magnets 116 are mounted to each support arm 110, it is conceivable that the permanent magnets 116 may also be replaced by electromagnets connected to an electrical power supply. One of the advantages of using an electromagnet is that the brake system can be selectively activated and deactivated (deactivated) by turning the electromagnet on and off. Moreover, the power of the magnetic field can be varied and controlled by using an electromagnet.

[0066] Return to reference Figure 4, as shown in this embodiment, a pair of brake yokes 106 are spaced 180° apart from each other. However, it should be understood that in embodiments where four brake yokes 106 are used at each end of the crushing roller 40, the brake yokes 106 are equally spaced at a rotation angle of 90° from each other. In embodiments where three brake yokes 106 are used, the brake yokes 106 are spaced at an angular position of 120° from each other. Increasing or decreasing the number of brake yokes 106 will increase or decrease the braking force generated, in a manner that will be described in detail below.

[0067] According to the present disclosure, the braking system will function as an eddy current braking system as follows. In the illustrated embodiment, the brake disc 96 is formed of an electrically conductive material and is designed to be stationary during operation of the crusher including the rotating eccentric shaft 42 and the drive roller 40. As previously described, each brake yoke 106 includes a pair of permanent magnets 116 that are spaced apart from each other and are located on opposite sides of the brake disc 96, such as Figure 6 and Figure 7 Best shown.

[0068] During the idle mode when no mineral material is fed into the crushing gap, the crushing roller 40 will begin to rotate with the rotation of the eccentric shaft 42 due to the internal friction forces generated in the internal bearings 74. As the brake yokes 106 begin to rotate with the crushing roller 40, the permanent magnets 116 included in each brake yoke 106 will move around the fixed conductive material of the brake disc 96. The relative movement of the conductive material of the brake disc 96 through the magnetic field generated by the pair of spaced apart permanent magnets 116 will induce eddy currents in the conductive material forming the brake disc 96. Such induced eddy currents will begin to generate an additional magnetic field that interacts with the magnetic field generated by the permanent magnets 116. The induced magnetic field formed in the brake disc will generate a force that resists the rotation of the brake yoke 106 relative to the fixed brake disc 96. As the rotational speed of the crushing roller 40 and the brake yoke 106 mounted thereto increases, the magnetic field induced in the fixed brake disc 96 increases, further resisting the rotation of the crushing roller. As such, use of the braking system of the present disclosure generates a braking force between the fixed brake disc 96 and the rotating brake yoke 106, thereby limiting the rotational speed of the crushing roller 40, such as during an idle mode.

[0069] Although the present disclosure shows a fixed brake disc 96 and a movable brake yoke 106, it should be understood that the brake disc 96 can be movable and the brake yoke 106 can be fixed. As described, it is the relative movement between the brake disc 96 and the brake yoke 106 that generates eddy currents and opposing magnetic fields.

[0070] In one embodiment of the present disclosure, the brake disc 96 is formed of an electrically conductive material, such as (but not limited to) aluminum, copper, gold or silver, and is formed into a disc shape. It is contemplated that the preferred choice of electrically conductive material is a non-ferromagnetic material, but any electrically conductive material may be used. The choice of the type of electrically conductive material will increase or decrease the magnetic braking force generated during the rotation of the crushing roller. In addition, the braking force may be adjusted by increasing or decreasing the number of brake yokes 106 used, increasing or decreasing the air gap 117 between the permanent magnets 116 and the brake disc, increasing or decreasing the strength of the permanent magnets 116, increasing or decreasing the radial height of the permanent magnets 116, or by increasing or decreasing the radial position of the brake yoke 106 relative to the outer edge 104 of the brake disc 96. By varying any or all of these various adjustment parameters, the brake system of the present disclosure may be modified to increase or decrease the braking force applied to limit the rotational motion of the crushing roller.

[0071] Figure 8 One embodiment of the relationship between braking force 122 shown along the vertical line and rotational speed 124 shown along the horizontal line is illustrated. Solid line 126 represents a brake disc formed of copper, while dashed line 128 represents a brake disc formed of aluminum. Figure 8 As can be appreciated from the above, as the rotational speed 124 increases, the braking force (which is the opposing magnetic field induced in the brake disc) also increases. The braking force in a brake disc formed of copper is greater than the braking force in a brake disc formed of aluminum. It should be appreciated that, except for Figure 8 Besides copper and aluminum shown in the graph, other conductive materials can also be used for brake discs.

[0072] The present disclosure also relates to a method for limiting the rotation of a movable crushing member during operation of a crusher, the crusher comprising a fixed crushing member and a movable crushing member. According to the method of the present disclosure, the crusher is provided with an induction current braking system operable to generate a magnetic braking force to limit the rotational movement of the movable crushing machine component. The induction current braking system is installed at a suitable position so that the induction current braking system can generate a magnetic braking force on the movable crushing member.

[0073] In an exemplary embodiment, the induction current braking system includes a brake disc formed of a conductive material and at least one brake yoke including a magnet or an electromagnet. According to the method of the present disclosure, one of the brake disc and the brake yoke is mounted to a movable crushing member, while the other is fixed. The relative movement between the brake disc and the brake yoke generates a magnetic braking force.

[0074] In an embodiment where the crusher is a compact eccentric crusher, the movable crusher comprises a crushing roller mounted to an eccentric shaft. In this embodiment, the method of the present disclosure comprises: mounting a brake disc in a fixed position, and mounting one or more brake yokes to the crushing roller so as to rotate with the crushing roller. During the rotational movement of the crushing roller, the induction current brake system generates a magnetic braking force to limit the rotation of the crushing roller.

[0075] In an embodiment where the brake yoke includes an electromagnet, the method of the present disclosure includes the step of activating the electromagnet. When the electromagnet is activated, the brake disc generates a braking force relative to the rotation of the brake yoke. The method also includes the step of selecting the characteristics of the brake disc and the brake yoke to control the braking force. These characteristics may include the size of the magnet in the brake yoke, the material used to form the brake disc, the spacing between the brake disc and the brake yoke, the depth of overlap between the brake disc and the brake yoke, and other characteristics.

[0076] As can be understood from the above description, the brake system of the present disclosure includes a brake disc and a brake yoke, and has a significant advantage, namely, no frictional interaction is required between the rotating crushing roller and the brake system to limit the rotation speed of the crushing roller. Moreover, because the braking force is generated based on the induced magnetic field generated during the rotation of the crushing roller relative to the fixed brake disc, no external control is required to apply the braking force. In addition, at low operating speeds such as 0.5 RPM to about 5 RPM, almost no braking force is generated, which has the advantage of eliminating any undesirable energy dissipation during normal crushing operation.

[0077] Although the braking system of the present disclosure is primarily shown for use in a compact eccentric crusher, it will be appreciated that the braking system may be used in any type of crusher requiring braking of a rotating component. As an example, in a cone crusher, the braking system of the present disclosure may be positioned between the crushing head and the fixed component to prevent undesired head spin during maneuvering. In cone crushers, head spin has proven to be a problem that must be limited during idling operation. It is possible and considered to be within the scope of the present disclosure to use a braking system that includes a fixed component and a rotating component to induce an opposing magnetic field to limit rotation.

[0078] This written description uses multiple examples to disclose the utility model, including the best mode, and also enables those skilled in the art to make and use the utility model. The patentable scope of the utility model is defined by the claims and may include other examples that occur to those skilled in the art. If these other examples have structural elements that are not different from the literal description of the claims, or if they include equivalent structural elements that are not substantially different from the literal description of the claims, these other examples should fall within the scope of the claims.

Claims

1. A crusher for crushing a feed of mineral material, characterized in that: The crusher comprises: Fixing broken components; a movable crushing member separated from the fixed crushing member by a crushing gap, wherein the movable crushing member is movable toward and away from the fixed crushing member to change the crushing gap and crush the mineral material in the crushing gap; and An induction current braking system is operable to generate a magnetic braking force to restrict movement of the movable crushing member.

2. The crusher according to claim 1, characterized in that: The induction current braking system comprises: a brake disc formed of an electrically conductive material; and at least one brake yoke, wherein rotational movement of the brake disc relative to the brake yoke induces the magnetic braking force that limits rotational movement of the movable crushing member.

3. The crusher according to claim 2, characterized in that: The brake disc is fixed, and the brake yoke is mounted to the movable crushing member.

4. The crusher according to claim 2, characterized in that: The brake yoke includes at least one permanent magnet, and the brake disc moves past the at least one permanent magnet.

5. The crusher according to claim 2, characterized in that: The brake yoke includes an electromagnet.

6. The crusher according to claim 2, characterized in that: The crusher includes a plurality of brake yokes, and the brake disc moves through each of the plurality of brake yokes.

7. A braking system for use in conjunction with a crusher having a fixed crushing member and a movable crushing member spaced apart from each other to define a crushing gap, characterized in that: The braking system comprises: a brake disc formed of an electrically conductive material; and At least one brake yoke, wherein relative movement between the brake disc and the brake yoke induces a magnetic braking force that resists rotational movement of the movable crushing member.

8. The braking system according to claim 7, characterized in that: The movable crushing member comprises a crushing roller mounted to an eccentric shaft, wherein rotation of the eccentric shaft produces an eccentric movement of the crushing roller relative to the crushing gap.

9. The braking system according to claim 8, characterized in that: The brake disk is stationary and the at least one brake yoke rotates relative to the brake disk.

10. The braking system according to claim 7, characterized in that: The crusher is a compact eccentric crusher having a fixed jaw and a crushing roller mounted to an eccentric shaft such that rotation of the eccentric shaft produces an eccentric movement of the crushing roller in and out of the crushing gap.

11. The brake system according to claim 10, characterized in that: The crushing roller is mounted to the eccentric shaft by means of a plurality of bearings such that the crushing roller rotates about the eccentric shaft, wherein the braking system limits the rotation of the crushing roller about the eccentric shaft.

12. The braking system according to claim 11, characterized in that: The at least one brake yoke is mounted for rotational movement together with the crushing roller, whereas the brake disc is fixed with respect to the rotational movement of the crushing roller.

13. The braking system according to claim 12, characterized in that: A plurality of brake yokes are included which are spaced apart around the crushing roller.

14. The braking system according to claim 13, characterized in that: Each of the brake yokes includes at least one permanent magnet, and the brake disc passes through the brake yokes.

15. The braking system according to claim 12, characterized in that: The brake yoke includes an electromagnet.

16. A compact eccentric crusher having a fixed jaw and a crushing roller mounted to an eccentric shaft so that rotation of the eccentric shaft produces an eccentric movement of the crushing roller into and out of a crushing gap, characterized in that The crusher comprises a braking system, the braking system comprising: at least one brake yoke mounted for rotational movement with the crushing roller; and a fixed brake disc formed of an electrically conductive material, wherein the at least one brake yoke rotates about the brake disc, A rotation of the at least one brake yoke relative to the brake disk induces a magnetic braking force that opposes the rotational movement of the crushing roller.

17. The compact eccentric crusher according to claim 16, characterized in that A plurality of brake yokes are included which are spaced apart around the crushing roller.

18. The compact eccentric crusher according to claim 17, characterized in that Each of the brake yokes includes at least one permanent magnet, and the brake disc moves past the at least one permanent magnet to induce the braking force.

19. The compact eccentric crusher according to claim 18, characterized in that Each of the brake yokes includes a pair of spaced apart support arms, each support arm supporting a permanent magnet, wherein the brake disc moves between the permanent magnets of the brake yoke.

20. The compact eccentric crusher according to claim 16, characterized in that The at least one brake yoke comprises a magnetic element, wherein relative movement of the brake disc and the brake yoke induces eddy currents in the brake disc.

21. The compact eccentric crusher according to claim 16, characterized in that The crushing roller is mounted to the eccentric shaft through a plurality of bearings such that the crushing roller can rotate about the eccentric shaft, wherein the braking system limits the rotation of the crushing roller about the eccentric shaft.

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