Patent Application
20200276592
Embodiments disclosed herein relate generally to cone crushers and more specifically to a system for preventing the tendency of a cone crusher head to elevated and/or to rotate.
Cone crushers are typically used to crush large rocks into smaller rocks at quarries. They include a conical crushing head that gyrates with a central shaft, the gyration of which is caused by a rotating eccentric surrounding the shaft. A hardened mantle covers the crushing head to crush rocks between it and a hardened liner of the crusher bowl in a crushing zone. The eccentric is driven by a diesel engine or electric motor power drive.
A cone head ball surface is typically mounted to the central shaft. This ball surface carries downward thrust loads, which it passes on to a stationary socket and thrust bearings disposed below the ball surface and socket interface. The thrust forces push the ball surface down on the stationary socket, creating friction that normally holds the shaft from rotating with the rotation of the eccentric. The downward thrust forces are anything but constant as the mantle gyrates and rocks enter and exit the crushing chamber. Without constant and substantial friction between the ball, which is mounted to the central shaft, and the stationary socket, the shaft and the mantle mounted to it may tend to rotate, which may create problems with the operation of the crusher.
Another drawback with some existing cone crushers is that, under particularly cold conditions, some cone crushers will exhibit what is called “cone head lift.” This phenomenon sometimes occurs during warm up of the crusher in cold weather, when the lubricating oil is especially viscous. Under these conditions, high internal fluid pressure may exceed the weight of the shaft and head, causing the head to lift. This can result in oil leakage and oil contamination, as well as damage to the oil seals. This cone head lift can be addressed by keeping a relatively constant downward pressure on the shaft, preventing the lifting even when forces generated by the thickened oil exceed the weight of the shaft and head.
Embodiments will be readily understood by the following detailed description in conjunction with the accompanying drawings and the appended claims. Embodiments are illustrated by way of example and not by way of limitation in the figures of the accompanying drawings.
In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which are shown by way of illustration embodiments that may be practiced. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope. Therefore, the following detailed description is not to be taken in a limiting sense.
Various operations may be described as multiple discrete operations in turn, in a manner that may be helpful in understanding embodiments; however, the order of description should not be construed to imply that these operations are order-dependent.
The description may use perspective-based descriptions such as up/down, back/front, and top/bottom. Such descriptions are merely used to facilitate the discussion and are not intended to restrict the application of disclosed embodiments.
The terms “coupled” and “connected,” along with their derivatives, may be used. It should be understood that these terms are not intended as synonyms for each other. Rather, in particular embodiments, “connected” may be used to indicate that two or more elements are in direct physical or electrical contact with each other. “Coupled” may mean that two or more elements are in direct physical or electrical contact.
However, “coupled” may also mean that two or more elements are not in direct contact with each other, but yet still cooperate or interact with each other.
For the purposes of the description, a phrase in the form “A/B” or in the form “A and/or B” means (A), (B), or (A and B). For the purposes of the description, a phrase in the form “at least one of A, B, and C” means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B and C). For the purposes of the description, a phrase in the form “(A)B” means (B) or (AB) that is, A is an optional element.
The description may use the terms “embodiment” or “embodiments,” which may each refer to one or more of the same or different embodiments. Furthermore, the terms “comprising,” “including,” “having,” and the like, as used with respect to embodiments, are synonymous, and are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.).
With respect to the use of any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.
The disclosed embodiment provides a continuous downward force on the crusher shaft, thus ensuring that there will be adequate friction between the previously-described ball and socket. This ensures that the head of the crusher will not rotate with the eccentric.
Embodiments include a system for maintaining a downward force on a central shaft of a cone crusher having a stationary frame, including a disc fixedly mounted to the frame, the disc having a centrally-disposed aperture with a first diameter. A plate is mounted to an end cap, the plate having a second diameter that is greater than the first diameter. The plate is disposed distally of the disc and the end cap is disposed proximally of the disc. A housing is fixed to the central shaft and biased away from the end cap wherein a downward bias is imparted to the central shaft.
The housing may be slidably mounted to the end cap and/or the plate. The plate may be threadably mounted to the end cap. The bias may be generated by at least one spring disposed between the housing and the end cap. Gyration may be imparted to the central shaft by an eccentric, and the gyration of the central shaft may be passed to the plate, which gyrates with respect to the disc.
The plate may be indirectly mounted to the central shaft such that any gyration of the central shaft is passed on to the plate, which gyrates with respect to the disc and is in contact with an underside of the disc at least part of the time.
The disclosed embodiments also include a pressure plate apparatus for mounting to a central shaft that gyrates in a cone crusher, the pressure plate maintaining a downward force on the central shaft during crushing operations. The apparatus may include a housing fixed to an underside of the central shaft, the housing slidably receiving an end cap and a raised portion of a plate. At least one spring may be mounted between the end cap and the housing to bias the plate toward the central shaft. A disc may be fixed to a stationary frame of the crusher, the disc having an aperture with a first diameter and being disposed between the plate and the housing, the plate having a second diameter that is greater than the first diameter. The plate may gyrate with the central shaft on the disc for some of the crushing operations and, in other crushing operations, the at least one spring may push the plate away from the disc to maintain a downward force on the central shaft.
Other embodiments may include a process for maintaining downward pressure on the cone of a cone crusher having a stationary frame, a central shaft, a first and a second thrust bearing surface mounted to the central shaft that absorb at least some downward thrust during crushing operations, and a rotating eccentric that gyrates the central shaft with respect to the frame. The process includes the following steps, not necessarily in the order recited: positioning at least one spring adjacent a housing; mounting an end cap to the housing such that the at least one spring is disposed between the housing and the end cap; fixing the housing to the central shaft and in doing so, compressing the at least one spring; fixing a disc to a lower portion of the frame, the disc having a centrally-disposed aperture having a first diameter; selecting a plate having a second diameter that is greater than the first diameter; and mounting the plate to the end cap such that the disc is disposed between the plate and the end cap so that when crushing operations are initiated, the plate will gyrate with the central shaft and with respect to the disc. The process may also include the step of maintaining spring tension on the central shaft, thus maintaining pressure between the first and second thrust bearing surfaces.
Crusher 10 is largely conventional, except for the pressure plate apparatus, generally indicated at 12, at the bottom of the crusher.
When rocks are fed into a crushing chamber 24, a crushing force acts on mantle 14, pushing the mantle downward and pressing central shaft 16 against a radial bearing 28. But most of the downward force is transmitted from central shaft 16 to ball surface 14 and stationary socket 16 and to a pair of flat, ring-type thrust bearings 30. As described above, this downward thrust of central shaft ball surface against stationary socket 16 creates friction between the ball surface and the socket, tending to prevent central shaft 18 and mantle 20 mounted to it from rotating. However, given the substantial and widely varying thrust forces generating during crushing operations, this force and therefore the amount of friction will vary greatly, providing for the possibility that cone head ball surface 14, central shaft 16 and mantle 20 may from time to time, rotate.
To counter this possibility and to provide a relatively constant amount of pressure between cone head ball surface 14 and stationary socket 18, pressure plate apparatus 12 is provided. This relatively constant pressure is effected by providing a constant downward force on central shaft 16 using a series of springs, the operation of which will be explained as this discussion continues.
A housing 60 may also be included, which is designed to retain at least one spring. It is possible that a single spring may extend around the housing but the preferred, design includes a plurality of springs 62. The housing is shown best in
Also included in housing 60 are a plurality of bolt holes 70 evenly positioned around the periphery of the housing, provided with shoulders 72 to support the heads of bolts 74 that extend therethrough. As seen in
As seen best in
The lubrication between the upper surface of pressure plate 38 and the lower surface of thrust washer disc 40 is further facilitated by the fact that the pressure plate may from time to time during crushing operations be moving slightly up and down with respect to the thrust washer disc, as shown by the arrows in
Although certain embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a wide variety of alternate and/or equivalent embodiments or implementations calculated to achieve the same purposes may be substituted for the embodiments shown and described without departing from the scope. Those with skill in the art will readily appreciate that embodiments may be implemented in a very wide variety of ways. This application is intended to cover any adaptations or variations of the embodiments discussed herein. Therefore, it is manifestly intended that embodiments be limited only by the claims and the equivalents thereof.
