AU2015205912A1 - A jaw crusher - Google Patents

Abstract

A JAW CRUSHER Abstract There is disclosed a jaw crusher (10), including: a body (11); a first jaw member (14) mounted to the body (11), the first jaw member (14) having a first crushing surface (16); a second jaw member (15) mounted to the body (11) for movement relative to the first jaw member (14), the second jaw member (15) having a second crushing surface (17), the first and the second crushing surfaces (16, 17) being spaced apart by a distance to define a crushing chamber (18) therebetween for passing material through to be crushed, the distance diminishing downwardly to a minimum distance; a drive mechanism (21) coupled to the second jaw member (15) to reciprocate the second jaw member (15) such that the distance alters to crush the material; and a displacement mechanism (27) coupled to the second jaw member (15) to at least aid in maintaining the minimum distance, wherein the displacement mechanism (27) is configured to allow the second jaw member (15) to move away from the first jaw member (14) to increase the minimum distance when a predetermined force exerted thereon is exceeded.

Description

1 A JAW CRUSHER Field [0001] The present invention relates to a jaw crusher. Background [0002] Jaw crushers are used to break materials into smaller fractional pieces by the utilisation of compressive forces. [0003] A known jaw crusher includes a pair of opposingjaw plates that are spaced apart to define a tapered crushing chamber therebetween for materials to pass through to be crushed. During use, the reciprocating movement of one jaw plate relative to the other applies compressive forces to the materials passing through the crushing chamber. The minimum distance between the jaw plates dictates the maximum size of the crushed material. To adjust the minimum distance, and thereby adjust the maximum size of the crushed material, it is known to insert or remove shims into/from a structure that supports one of the jaw plates. It is also known to utilise adjustable wedges to adjust the minimum distance. [0004] A disadvantage of the known jaw crusher is that, if an uncrushable object is passed through the crushing chamber during use, the known jaw crusher can become jammed or damaged such that it is no longer operable. To unjam or fix the known jaw crusher, the known jaw crusher often needs to be stopped and the uncrushable object manually cleared from the crushing chamber. This is a time consuming and dangerous process. In some instances, if an uncrushable object is passed through the crushing chamber during use, a toggle device can break requiring it to be replaced before the known jaw crusher can properly operate again. Object of Invention [0005] It is the object of the present invention to substantially overcome or at least ameliorate one or more of the above disadvantages, or at least provide a useful alternative. Summary of Invention 2 [0006] There is disclosed herein ajaw crusher, including: a body; a first jaw member mounted to the body, the first jaw member having a first crushing surface; a second jaw member mounted to the body for movement relative to the first jaw member, the second jaw member having a second crushing surface, the first and the second crushing surfaces being spaced apart by a distance to define a crushing chamber therebetween for passing material through to be crushed, the distance diminishing downwardly to a minimum distance; a drive mechanism coupled to the second jaw member to reciprocate the second jaw member such that the distance alters to crush the material; and a displacement mechanism coupled to the second jaw member to at least aid in maintaining the minimum distance, wherein the displacement mechanism is configured to allow the second jaw member to move away from the first jaw member to increase the minimum distance when a predetermined force exerted thereon is exceeded. [0007] Preferably, the displacement mechanism comprises a least one hydraulic-pneumatic cylinder, the hydraulic-pneumatic cylinder having a bore and a piston, the piston being operatively connected to the second jaw member and located within the bore defining first and second chambers, the first chamber being fillable with a gas, the gas being compressed by the piston when the predetermined force is exceeded such that the second jaw member moves away from the first jaw member to increase the minimum distance. [0008] Preferably, the second chamber is configured to receive a hydraulic fluid to move the piston such that the second jaw member moves away from the first jaw member to increase the minimum distance. [0009] Preferably, the bore has a longitudinal axis defining an acute angle with respect to the second crushing surface of the second jaw member. [0010] Preferably, the displacement member comprises a toggle member pivotally connected to the second jaw member and the piston.

3 [0011] Preferably, the displacement member comprises a tensioning mechanism connected to the second jaw member and the piston, the tensioning mechanism configured to maintain the connection of the toggle member to the second jaw member and the piston. [0012] Preferably, the piston moves within the bore in a direction having a component normal to the first crushing surface of the first jaw member. [0013] Preferably, the displacement mechanism further comprises a release valve configured to release the gas within the first chamber when a predetermined gas pressure is exceeded. [0014] Preferably, the predetermined force is at least 500kN. [0015] Preferably, the predetermined force is at least 1000kN. [0016] Preferably, the drive mechanism comprises: an eccentric shaft rotatably mounted to the body and coupled to the second jaw member; a drive motor configured to rotate the eccentric shaft around a drive axis; and a flywheel coupled to the eccentric shaft, wherein the eccentric shaft has a central longitudinal axis displaced from the drive axis such that the second jaw member is provided with angular movement upon rotation of the eccentric shaft. Brief Description of Drawings [0017] A preferred embodiment of the invention will be described hereinafter, by way of examples only, with reference to the accompanying drawings, wherein: [0018] Figure 1 is a perspective view of an embodiment of a jaw crusher with a side wall and a fly wheel removed; [0019] Figure 2 is a sectioned side view of the jaw crusher of Figure 1; and [0020] Figure 3 is a schematic view of a hydraulic circuit of the jaw crusher of Figure 1. Description of Embodiments 4 [0021] Figures I to 3 show an embodiment of a jaw crusher 10 for crushing material. The jaw crusher 10 includes a body 11 having a pair of opposing side walls 12, 13 that are spaced apart and substantially parallel in relation to each other. [0022] The jaw crusher 10 further includes a first jaw member 14 and a second jaw member 15. The first jaw member 14 is preferably fixedly mounted between the walls 12, 13 and has a grooved crushing surface 16. The second jaw member 15 is movably mounted between the walls 12, 13 and has a grooved crushing surface 17 facing the crushing surface 16. The crushing surfaces 16, 17 are spaced apart by a distance such that, with the side walls 12, 13, a crushing chamber 18 is defined therebetween. The crushing chamber 18 has an upper opening 37 for receiving material and a lower opening 38 for discharging the crushed material. As shown in Figure 2, the crushing chamber 18 extends downwardly from the upper opening 37 to the lower opening 38 such that the material passes therethrough by gravity. The crushing chamber 18 has a tapered sectional profile with the distance between the crushing surfaces 16, 17 diminishing downwardly to a minimum distance 20 at the lower opening 38. [0023] The jaw crusher 10 further includes a drive mechanism 21 coupled to the second jaw member 15 to reciprocate the second jaw member 15 such that the distance between the crushing surfaces 16, 17 is altered to crush the material within the crushing chamber 18. The drive mechanism 21 reciprocates the second jaw member 15 between a forward crushing position and a backward retracted position. In the forward crushing position, the second jaw member 15 is moved towards the first jaw member 14 such that the distance between the crushing surfaces 16, 17 is reduced engaging (i.e. compressing) the material within the crushing chamber 18. It will be appreciated that the minimum distance 20 is defined between lower ends of the crushing surfaces 16, 17 when the second jaw member 15 is in the forward crushing position. In the backward retracted position, the second jaw member 15 is moved away from the first jaw member 14 such that the distance between the crushing surfaces 16, 17 is increased allowing the material to pass downwardly through the crushing chamber 18. [0024] The drive mechanism 21 comprises an eccentric shaft 22, a drive motor 23 and a pair of fly wheels 25. The shaft 22 is rotatably mounted to the walls 12, 13 and coupled to the upper end of the second jaw member 15. The fly wheels 25 are coupled to respective ends of the shaft 22. The drive motor 23 is connected to the shaft 22 by a belt system 26 and configured to rotate the 5 shaft 22 around a drive axis. The shaft 22 has a central longitudinal axis displaced from the drive axis such that the second jaw member 15 is provided with angular movement upon rotation of the shaft 22 to reciprocate the second jaw member 15 between the forward crushing position and the backward retracted position. [0025] The jaw crusher 10 further includes a displacement mechanism 27 coupled to the second jaw member 15 to at least aid in maintaining the minimum distance 20 and to allow the second jaw member 15 to move away from the first jaw member to increase the minimum distance 20 when a predetermined force exerted thereon is exceeded. The predetermined force is at least 500kN, preferably 1000kN. [0026] The displacement mechanism 27 comprises three linear hydraulic-pneumatic cylinders 28, 29, 30 mounted between the walls 12, 13. Each of the hydraulic-pneumatic cylinders 28, 29, 30 is configured to utilise both hydraulic fluid and gas to provide two-way linear movement. As shown in Figure 2, each of the hydraulic-pneumatic cylinders 28, 29, 30 has a bore 31 and a piston 32. Each bore 31 has a longitudinal axis and is arranged such that the longitudinal axis 39 defines an acute angle with respect to the crushing surface 17 of the second jaw member 15. The acute angle 40 is less than 65 degrees, preferably 45 degrees. The piston 32 is located within the bore 31 defining first 33 and second chambers 34. The first chamber 33 is fillable with a gas, such as nitrogen, and the second chamber 34 is configured to receive a hydraulic fluid. The piston 32 is able to move within the bore 31 in a direction having a component normal to the crushing surface 16 of the first jaw member 14. [0027] The displacement mechanism 27 further comprises a toggle member 35 and a tensioning rod 36. The toggle member 35 is pivotally connected to the lower end of the second jaw member 15 and the pistons 32 of each hydraulic-pneumatic cylinder 28, 29, 30. The tensioning rod 36 is connected to the lower end of the second jaw member 15 and the pistons 32 of each hydraulic pneumatic cylinder 28, 29, 30. The tensioning rod 36 is configured to apply a tension force between the lower end of the second jaw member 15 and the pistons 32 of each hydraulic pneumatic cylinder 28, 29, 30 so as to maintain the pivotable connection of the toggle member 35.

6 [0028] As shown in Figure 3, the displacement mechanism 27 further comprises three nitrogen bottles 41, 42, 43. Each nitrogen bottle 41, 42, 43 is directly connected to a respective first chamber 33 of the hydraulic-pneumatic cylinders 28, 29, 30 to supply nitrogen thereto. The displacement mechanism 27 further comprises a release valve (not shown) connected to the first chambers 33 of each hydraulic-pneumatic cylinder 28, 29, 30. The release valve is configured to release the gas within the first chambers 33 of hydraulic-pneumatic cylinders 28, 29, 30 when the pressure therein exceeds a safe amount. The first chambers 33 of each hydraulic-pneumatic cylinder 28, 29, 30 are connected by a balance line 50. The displacement mechanism 27 further comprises a monometer 51 and a pressure transducer 52 that are both located on the balance line 50 and used to measure the pressure within the first chambers 33 of the hydraulic-pneumatic cylinders 28, 29, 30. [0029] The displacement mechanism 27 further comprises a hydraulic circuit 44 that connects to the second chambers 34 of the hydraulic-pneumatic cylinders 28, 29, 30 to supply hydraulic fluid. The hydraulic circuit 44 comprises a reservoir 45 of the hydraulic fluid, a hydraulic pump 46 configured to supply the hydraulic fluid from the reservoir 45 to the second chambers 34 and a hydraulic accumulator 46 configured to maintain a positive pressure within the hydraulic circuit 44. The hydraulic circuit 44 further comprises a filter 47 connected to the reservoir 45 and a pressure relief 48 configured to control or limit the pressure in the hydraulic circuit 44. The hydraulic circuit 44 further comprises a hydraulic valve 49 configured to control the flow of the hydraulic fluid such that the hydraulic fluid can be either supplied or removed from the second chambers 34 of each hydraulic-pneumatic cylinder 28, 29, 30. [0030] A typical operation of thejaw crusher 10 will now be described. [0031] Material to be crushed is fed through the top of the crushing chamber 18. The drive mechanism 21 reciprocates the second jaw member 15 between the forward crushing position and the backward retracted position such that the material within the crushing chamber 18 is crushed and passed therethrough. In the event that an uncrushable object is present within the crushing chamber 18, a force exceeding 1OOOkN will be exerted on the second jaw member 15 as it attempts to move towards the forward crushing position. The force will then translate to the pistons 32 of each hydraulic-pneumatic cylinder 28, 29, 30 via the toggle member 35. The pistons 32 of each hydraulic-pneumatic cylinder 28, 29, 30 will then be forced into respective 7 first chambers 33 by compressing the nitrogen contained therein. The movement of the pistons 32 of each hydraulic-pneumatic cylinder 28, 29, 30 will in turn move the second jaw member 15 away from the first jaw member 14 such that the minimum distance 20 is increased allowing the uncrushable object to pass through the crushing chamber 18. Once the uncrushable object is passed through, the pressure of the compressed nitrogen will force the pistons 32 of hydraulic pneumatic cylinder 28, 29, 30 to move out such that the second jaw member 15 moves towards the first jaw member 14 and thereby returns the minimum distance 20 to its original value. [0032] In the event a force exerted on the pistons 32 of each hydraulic-pneumatic cylinder 28, 29, 30 causes the pressure within the first chambers 33 to exceed a safety limit, the nitrogen will be released through the release valve. [0033] To increase the minimum distance 20, and thereby increase the maximum size of the crushed material, hydraulic fluid is pumped into the second chambers 34 of each hydraulic pneumatic cylinder 28, 29, 30 causing the pistons 32 to move into the first chambers 33 and compress the nitrogen contained therein. This causes the second jaw member 15 to move away from the first jaw member 14 and thereby increase the minimum distance 20. Similarly, to decrease the minimum distance 20, and thereby decrease the maximum size of the crushed material, hydraulic fluid is removed from the second chambers 34 of each hydraulic-pneumatic cylinder 28, 29, 30 causing the pistons 32 to move into the second chambers 34. This causes the second jaw member 15 to move towards the first jaw member 14 and thereby decrease the minimum distance 20. [0034] In the event that the uncrushable object becomes stuck within the crushing chamber 18 and the drive motor 23 stalls, the minimum distance 20 can be increased and decreased as described above to clear the uncrushable object. It will be appreciated that, as the minimum distance 20 is increased, the nitrogen within the first chambers 33 of each hydraulic-pneumatic cylinder 28, 29, 30 can be released via the release valve and thereby allow the minimum distance 20 to be increased to its maximum value. [0035] Advantageously, the jaw crusher 10 allows an uncrushable object to be automatically passed through the crushing chamber 18 reducing the risk of becoming jammed or damaged.

8 [0036] Advantageously, the jaw crusher 10 allows the minimum distance 20 to be adjusted without the addition of shims. [0037] Although the invention has been described with reference to a preferred embodiment, it will be appreciated by a person skilled in the art that the invention may be embodied in many other forms.

Claims (11)

1. A jaw crusher, including: a body; a first jaw member mounted to the body, the first jaw member having a first crushing surface; a second jaw member mounted to the body for movement relative to the first jaw member, the second jaw member having a second crushing surface, the first and the second crushing surfaces being spaced apart by a distance to define a crushing chamber therebetween for passing material through to be crushed, the distance diminishing downwardly to a minimum distance; a drive mechanism coupled to the second jaw member to reciprocate the second jaw member such that the distance alters to crush the material; and a displacement mechanism coupled to the second jaw member to at least aid in maintaining the minimum distance, wherein the displacement mechanism is configured to allow the second jaw member to move away from the first jaw member to increase the minimum distance when a predetermined force exerted thereon is exceeded.

2. The jaw crusher according to claim 1, wherein the displacement mechanism comprises a least one hydraulic-pneumatic cylinder, the hydraulic-pneumatic cylinder having a bore and a piston, the piston being operatively connected to the second jaw member and located within the bore defining first and second chambers, the first chamber being fillable with a gas, the gas being compressed by the piston when the predetermined force is exceeded such that the second jaw member moves away from the first jaw member to increase the minimum distance.

3. The jaw crusher according to claim 2, wherein the second chamber is configured to receive a hydraulic fluid to move the piston such that the second jaw member moves away from the first jaw member to increase the minimum distance.

4. The jaw crusher according to claim 2 or 3, wherein the bore has a longitudinal axis defining an acute angle with respect to the second crushing surface of the second jaw member. 10

5. The jaw crusher according to any one of claim 2 to 4, wherein the displacement member comprises a toggle member pivotally connected to the second jaw member and the piston.

6. The jaw crusher according to claim 5, wherein the displacement member comprises a tensioning mechanism connected to the second jaw member and the piston, the tensioning mechanism configured to maintain the connection of the toggle member to the second jaw member and the piston.

7. The jaw crusher according to any one of claims 2 to 6, wherein the piston moves within the bore in a direction having a component normal to the first crushing surface of the first jaw member.

8. The jaw crusher according to any one of claims 2 to 7, wherein the displacement mechanism further comprises a release valve configured to release the gas within the first chamber when a predetermined gas pressure is exceeded.

9. The jaw crusher according to any one of claims 1 to 8, wherein the predetermined force is at least 500kN.

10. The jaw crusher according to any one of claims 1 to 8, wherein the predetermined force is at least 1OOOkN.

11. The jaw crusher according to any one of the preceding claims, wherein the drive mechanism comprises: an eccentric shaft rotatably mounted to the body and coupled to the second jaw member; a drive motor configured to rotate the eccentric shaft around a drive axis; and a flywheel coupled to the eccentric shaft, wherein the eccentric shaft has a central longitudinal axis displaced from the drive axis such that the second jaw member is provided with angular movement upon rotation of the eccentric shaft. CITIC HIC Australia Pty Ltd Patent Attorneys for the Applicant SPRUSON & FERGUSON