Patent Application
20120055569
This invention relates to mining shovels, and more particularly to a hydraulic tank system for a mining shovel.
Mining equipment, such as mining shovels, are a significant capital expenditure. It is important, therefore, to maximize operational time of this equipment. Mining shovels, for example, are operated almost constantly, as much as twenty-four hours a day, three hundred and sixty-five days a year. To minimize down time, it is therefore important that the equipment be suited to the environmental conditions in which the equipment operates.
The environment in which mining equipment is used, however, is extremely dirty, and includes both a significant amount of air borne dust and moisture. Because of these environmental conditions, hydraulic systems and components, which are particularly prone to contamination, are often avoided in mining shovel constructions. Hydraulic systems, however, can be very efficient, and are therefore also desirable in mining shovel applications. Accordingly, a need exists for a hydraulic system which is shielded from the operating environment, and which can therefore increase operational time and minimize the need for maintenance.
In one aspect, the present invention provides a tank system defining a fluid chamber for retaining hydraulic fluid used to control one or more hydraulic cylinder in a mining shovel. The tank system comprises an upper tank, a lower tank, coupled to the upper tank by a transfer tube, and an expansion bladder. The expansion bladder is coupled to the upper tank through an air transfer tube located exterior to the upper tank, such that air can be exchanged between the tank system and the bladder when the cylinder is activated.
In another aspect of the invention, the tank system can include a filtering system. The upper tank can include a filter for filtering hydraulic fluid, also referred to herein as oil, in the upper tank. The upper tank can also include a plurality of baffles partitioning the upper tank into a plurality of compartments, wherein at least one of the baffles includes an aperture to direct a flow of fluid through the tank. The apertures in the baffles can be offset a distance above the bottom surface of the upper tank to filter contaminants from the hydraulic fluids. The aperture in the baffle can also be larger adjacent a top surface of the tank than adjacent a bottom surface of the tank to provide a higher flow rate for the hydraulic fluid at the top of the tank than at the bottom of the tank.
In another aspect of the invention, the lower tank can comprise a plurality of baffles partitioning the lower tank into a plurality of compartments, wherein at least one of the baffles includes an aperture to direct a flow of fluid through the lower tank. The aperture in the baffle can be offset a distance above the bottom surface of the upper tank to filter contaminants from the hydraulic fluid. The aperture in the baffle can also be larger adjacent a top surface of the tank than adjacent a bottom surface of the tank to provide a higher flow rate for the hydraulic fluid at the top of the tank than at the bottom of the tank.
In another aspect of the invention, a tank system defining a fluid chamber for retaining hydraulic fluid used to control one or more hydraulic cylinder in a mining shovel is provided. The tank system includes an upper tank comprising an inlet, an outlet, and a plurality of baffles dividing the tank into compartments between the inlet and the outlet. At least one of the baffles comprises an aperture for directing a flow of hydraulic fluid between the inlet and the outlet. The tank system also includes a lower tank, fluidly coupled to the upper tank. The lower tank includes an inlet, an outlet, and a plurality of baffles dividing the tank into compartments between the inlet and the outlet. At least one of the baffles comprises an aperture for directing a flow of hydraulic fluid between the inlet and the outlet. The tank system also includes an expansion bladder, the expansion bladder coupled to the upper tank, wherein air is exchanged between the tank system and the bladder when the cylinder is activated. In some embodiments, the bladder system is exterior to the upper tank and to the lower tank, and wherein the bladder system is coupled to the upper tank through an air transfer tube.
In still another aspect of the invention, a tank system is provided defining a fluid chamber for retaining hydraulic fluid used to control one or more hydraulic cylinder in a mining shovel. The tank system includes an upper tank, a lower tank, coupled to the upper tank by a transfer tube, and a cooler system connected between the upper and lower tanks, wherein when the hydraulic cylinders are activated, hot oil is returned to the upper tank and is transmitted through the cooler system and to the lower tank.
These and still other advantages of the invention will be apparent from the description which follows. In the detailed description below, the preferred embodiment of the invention will be described in reference to the accompanying drawings. This embodiment does not represent the full scope of the invention. Rather the invention may be employed in other embodiments. Reference should therefore be made to the claims herein for interpreting the breadth of the invention.
Referring to
The A-frame 16 supports a top end 22 of a boom 24, a bottom end 26 of the boom 24 being supported by the turntable 12. A dipper 28 is mounted on the front end 30 of a dipper handle 32 which is slidably supported in a saddle block 34 mounted in the boom 24. The saddle block includes a yoke 36 and a support frame 38 which projects rearwardly from the yoke 36 and encloses the back end of the dipper handle 32. The yoke 36 of the saddle block 34 is pivotally mounted in the boom 24, so as to pivot in a vertical plane. A hoist cable 40 extends upward from a powered hoist drum 42 on the turntable 12, over a sheave 44 at the top end 22 of the boom 24 and down to a padlock 46 on the dipper 28. The hoist cable 40 provides for the vertical, raising and lowering, movement of the dipper 28. A hydraulic crowd mechanism (not shown) is enclosed in the support frame 38, provides the horizontal component, or crowd, of the dipper's movement.
Referring now to
Referring now also to
Referring now to
As shown here, the tank 70 is divided into a plurality of compartments by a series of baffles 100, 102, 104, 106, and 108, where the baffle 108 extends between the opposing end walls 120 and 122, and the baffles 100, 102, 104, and 106 extend between opposing side walls. The baffle 108 is substantially centered in the tank between the side walls and extends along a length of the tank 70, parallel to the side wall 124, dividing the tank 70 into two compartments 103 and 105 between the end walls 120 and 122. The compartment 103, which receives oil from the inlet port 118, is further subdivided by baffles 104 and 106, which extend in a direction substantially perpendicular to side wall 124 and toward the center baffle 108.
The baffles 104 and 106 include apertures which direct oil from the inlet 118 in end wall 120 to the opposing end of the tank 70 at wall 122. Baffle 104, which is positioned adjacent the inlet 118, includes an opening 114 which is substantially rectangular in shape, and which extends across a substantial portion of the baffle 104, allowing oil flow through the baffle 104, and also allowing access to the compartments for maintenance. The baffle 106 includes a series of circular apertures 140, 142, 144, and 146 which extend in a linear succession from a position adjacent a top of the baffle 106 to a position adjacent a bottom of the baffle 106, and which are located adjacent the side wall 124. The center baffle 108, similarly, includes a series of apertures extending from a position adjacent the top of the tank 70 to a position adjacent the bottom surface 126. These apertures, 130, 132, 134, and 136, are positioned adjacent the end wall 122, and provide a conduit for oil to move from the compartment 103 to the compartment 105, and provide a filtering function. Although the apertures are shown here as substantially equivalent in size, in some applications, the apertures can be arranged with a larger aperture adjacent the top of the baffle, and smaller apertures adjacent the bottom of the baffle. Here, a higher rate of flow is provided at the top of the tank 70, and a slower rate of flow at the bottom of the tank, which can improve the settlement of particles in the bottom of the tank 70.
The compartment 105, similarly, is subdivided by baffles 100 and 102, where baffle 102, similar to the baffle 106, includes a series of circular apertures 112, 113, 115, and 117, extending from a position adjacent the top of the baffle 102 to a position adjacent the bottom of the baffle 102, and at a side of the baffle 102 that is adjacent the center baffle 108. The baffle 100 is similar to the baffle 104, and includes a relatively large rectangular opening 105. Oil that enters the compartment 105 through the apertures 130, 132, 134, and 136 is directed by the baffles 102 and 104 to the outlet 116. Because the apertures provided in all of the baffles 100, 102, 104, 106, and 108 are positioned above the bottom surface 126 of the tank 70, large contaminants are trapped within the compartments 103 and 105 as oil flows, settling contaminants in the tank. Further, because the oil is directed through the tank 70 in a relatively large flow path, the oil has sufficient time to de-aerate while in the tank 70. As described above, the rectangular opening allows for greater access to the compartments for maintenance, while the smaller circular apertures provide an improved filtering function. These apertures, as described above, can be shaped to be larger at the top and smaller at the bottom, which provides for a higher rate of flow at the top than at the bottom of the tank, and improved filtering. The rectangular apertures, similarly, can be constructed to be larger at the top than at the bottom, varying the rate of flow through the tank.
Referring now to
Referring still to
Upon entry of oil into the tank 68 through inlet ports 156, the oil is filtered by filters 94, and moves into the input compartment 165. Input compartment 165 is further divided by baffle 170, extending perpendicular to baffle 168, between baffle 168 and end wall 154. The baffle 170 includes a rectangular recess that is offset above the floor 150 of the tank 68 to settle contaminants in the tank, as described above. Oil directed through the recess in the baffle 170, and then through a recess in the baffle 166, which causes the oil to turn substantially ninety degrees as it enters the middle compartment 169. Oil exits the middle compartment 169 through a recess formed in the baffle 164, which is formed in a surface adjacent the side wall 152, on the opposite side of the tank 68 from the recess formed in baffle 166, again causing the oil to turn. From the recess in baffle 164, oil is directed toward baffle 162, which extends substantially perpendicular to baffle 164 and toward the end opposite end wall 154. The baffle 162, again, includes a recess that is offset above the bottom surface 150 to settle additional contaminants. On the opposing side of the baffle 162, oil is directed through the outlet port 158, and out of the upper tank 68. The oil, therefore, is directed through a serpentine path that filters contaminants in the tank 68, and allows the oil to de-aerate. As shown here, the opening formed in baffle 164 can be larger at the top and taper downward, to provide a higher rate of flow along the top of the tank 68, and a lower rate of flow along the bottom surface of the tank 68, as discussed above with reference to tank 70. Similar constructions can be provided in other baffles.
Referring now to
In operation, the reservoir system described above ensures cleanliness of the hydraulic system by minimizing the ingestion of air borne dust and moisture, and by maximizing settling and de-aeration time in the tank system. Oil returned to the upper tank 68 enters a filtration chamber including filtration elements 94, and then through a serpentine flow path as established by baffles 162, 164, 166, 168, 170, and 172. Each of these baffles include openings which are raised above the bottom surface of the tank, and which therefore provide a settling chamber for larger particles, limiting transmission of these particles through the remaining compartments in the tank. The lower tank 70 is similarly divided into compartments by a series of baffles, which provide a relatively long flow path of oil from the inlet 118 to the outlet 116, allowing the oil to de-aerate. The baffles, like in the upper tank 68, include apertures which both direct the flow, and allow contaminants to settle in the lower tank 70.
Cooling efficiency is improved by removing oil from the hottest location in the upper return tank, and running the hot oil through the oil cooler. After passing through the oil cooler, the oil passes through the primary oil filter and then returns it to the final baffled compartment of lower reservoir near the pump suction header. Thus, clean and cool oil is introduced to the oil flow going directly into the pumps.
Although specific embodiments have been shown and described, it will be apparent that a number of variations could be made within the scope of the invention. It should be understood therefore that the methods and apparatuses described above are only exemplary and do not limit the scope of the invention, and that various modifications could be made by those skilled in the art that would fall under the scope of the invention. To apprise the public of the scope of this invention, the following claims are made:
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/US09/03328 | 6/1/2009 | WO | 00 | 11/15/2011 |
