The present disclosure generally relates to a spider bushing for use within a gyratory crusher. More specifically, the present disclosure relates to a system and method for adjusting the position of a spider bushing within a spider of a gyratory crusher to selectively modify the interference fit between the spider bushing and an internal receiving bore within the central hub of the spider.
Presently, gyratory crushers exist that include a cast iron spider bushing that is installed within the internal bore formed in the central hub of the spider with an interference fit. The internal bore of the spider hub is machined with a tapered inside diameter (ID) and the spider bushing is machined with a tapered outside diameter (OD). The spider bushing is formed with an outer flange having a series of spaced through holes such that bolts can be used to pull the tapered spider bushing down tightly into the internal bore of the spider hub to create an interference fit between the spider bushing and the spider hub.
The spider bushing must be rigidly installed in the central spider hub for the crusher to operate properly, which requires very precise machining of both the tapered OD on the spider bushing and the tapered ID within the spider hub. This precise machining increases the production costs of both components.
Over time, it is not uncommon for the tapered inner surface within the spider hub to wear, which results in the loss of the interference fit between the spider bushing and the spider hub. As a result of the loss of interference fit, the spider bushing will move within the hub, resulting in breakage of the retaining bolts that hold the spider bushing in place. If the spider bushing is not held rigidly in place, seizure of the eccentric bushing in the lower end of the crusher will eventually occur because of the misalignment that is created within the lower eccentric bushing. In order to prevent this problem, the spider bushing must be removed and either replaced with an oversized spider bushing to recreate the interference fit or the inner bore formed within the spider hub must be re-machined. In either case, a significant expense and extended downtime of the gyratory crusher result.
The present disclosure relates to a gyratory crusher for use in breaking rock, stone or other materials in a crushing cavity. The gyratory crusher includes a spider positioned near the top end of the gyratory crusher. The spider includes a central hub having an internal bore and a bushing support shoulder. A mainshaft of the gyratory crusher is mounted such that an upper end of the mainshaft is supported within the central hub of the spider. Specifically, a spider bushing surrounds the upper end of the main shaft to support the upper end of the main shaft. The spider bushing is positioned within the internal bore of the central hub of the spider. The spider bushing includes a main body and an outer flange that extends radially from the main body.
The main body of the spider bushing includes an outer surface that decreases in outer diameter from an upper end to a lower end. The internal bore formed within the central hub of the spider includes a tapered inner surface that has a decreasing inner diameter from an upper end to a lower end of the internal bore. The tapered outer surface of the spider bushing and the tapered inner surface of the internal bore formed within the spider create an interference fit between the spider bushing and the internal bore of the spider.
In accordance with the present disclosure, an adjustment means is used to adjust the spacing between a bushing support shoulder of the spider and the outer flange of the spider bushing. The use of the adjustment means allows the interference fit created between the spider and the spider bushing to be modified upon wear to either the spider bushing or the spider.
In one embodiment of the disclosure, the adjustment means is one or more shims that are positioned between the bushing support shoulder of the spider and the outer flange of the spider bushing. The one or more shims are positioned between the bushing support shoulder and the outer flange of the spider bushing to create a desired gap between the bushing support shoulder and the outer flange of the spider bushing. Once the shims are in position, the spider and the spider bushing can be connected to each other utilizing a series of spaced connectors.
Upon wear to either the spider or the spider bushing, one or more of the shims can be removed such that the spider bushing can move further downward into the spider. The movement of the spider bushing into the spider improves the interference fit between the spider bushing and the spider upon wear to either of the components.
In another embodiment of the disclosure, the adjustment means is either a series of individual washers or support bolts that can be adjusted to define the desired gap between the spider and the spider bushing.
Various other features, objects and advantages of the invention will be made apparent from the following description taken together with the drawings.
The drawings illustrate the best mode presently contemplated of carrying out the disclosure. In the drawings:
The upper end 28 of the mainshaft 26 is supported in a spider bushing 30 contained within a central hub 32 of a spider 34. The spider 34 is mounted to the upper top shell 16 by a series of bolts 36. The spider 34 includes a plurality of spider arms 38 that support the central hub 32 in the position as shown. In the embodiment illustrated, spider arm shields 40 are mounted to each of the spider arms 38 to provide wear protection. A spider cap 42 mounts over the central hub 32 to provide additional wear protection for the central hub 32.
An access area 54 is positioned slightly above the internal bore 44. The access area 54 allows tooling and other components to access the upper end 28 of the mainshaft 26 when the spider bushing 30 is installed, as can be understood in
Referring again to
The upper end 64 is located below an outer flange 66 that protrudes radially outward from the outer surface 60 of the annular wall 58. The flange 66 has a lower contact surface 68 and an annular top surface 70. As illustrated in
In the embodiment shown in
Since both the outer surface 60 of the spider bushing 30 and the inner surface 46 of the bore 44 wear during operation of the gyratory crusher and the cost and effort to maintain the tight machining tolerances is high, the present disclosure includes a means for adjusting the interference fit between the spider bushing 30 and the internal bore 44. The use of the adjustment means allows for a slight relaxation of the machining tolerances on the tapered surfaces, which simplifies the manufacturing process and may lead to a reduction in the cost of the parts.
In order to accommodate the interference fit adjustment means, the spider bushing 30 is machined such that the tapered outer diameter defined by the outer surface 60 is slightly greater than the inner diameter of the internal bore 44 defined by the inner surface 46. When the spider bushing is initially installed in the internal bore, the interference fit between the two components creates a gap A-A shown in
In one embodiment of the disclosure, the means for adjusting the interference fit between the bushing support shoulder 52 and the outer flange 66 of the spider bushing 30 takes the form of one or more annular shims 78, which is shown in
Referring now to
In a first embodiment of the disclosure, the adjustment means is comprised of one or more annular shims 78, which are illustrated in
As illustrated in
Referring back to
Once the shims have been positioned as shown in
As the gyratory crusher operates and the outer surface of the spider bushing and the inner surface of the internal bore formed within the central hub begin to wear, the interference fit between the two components will begin to it will begin to lessen. When this happens, it will become necessary to modify the adjustment means to improve the interference fit. This can be done by first removing the spider bushing 30 from the spider. Once the spider bushing 30 is removed, one or more of the individual shims can be removed from between the spider bushing and the central hub. Once the shims are removed, the spider bushing 30 is again lowered into the internal bore. Since the shims 78 shown in
As described above, in one embodiment of the disclosure, the means for adjusting the interference fit between the bushing support shoulder and the outer flange of the spider bushing is created through the use of one or more individual shims. However, it is contemplated that other types of devices or components could be utilized while operating within the scope of the present disclosure.
As the spider bushing 30 and central hub 32 begin to wear, the set screw 90 can be rotated to adjust the amount the bottom 94 extends past the lower contact surface 68, as illustrated by the arrow in
As the spider bushing 30 and central hub 32 begin to wear, the adjustment nut 102 can be rotated to adjust the vertical position of the adjustment nut 102 along the spider bushing. In this manner, the adjustment nut 102 can improve the interference fit between the spider bushing and the inner bore of the spider.
In yet another contemplated alternative, individual washers could be utilized surrounding each of the connectors 74 rather than the annular shim shown in
Various other different types of devices and mechanisms could also be utilized while operating within the scope of the present disclosure. In each case, the adjustment device would create the desired spacing between the outer flange 66 of the spider bushing and the bushing support shoulder formed within the central hub. During wear, this adjustment device could be modified to begin to decrease the spacing between the outer flange of the spider bushing and the bushing support shoulder.