Abstract:
An oil filtration system includes three separate tanks. A first of these tanks is to receive oil from a wheel motor of the mining or construction vehicle. A second of these tanks is to receive the oil from the first tank after the oil in the first tank has been sufficiently heated so as to remove moisture therefrom. And, a third of these tanks is to receive the oil from the second tank after the oil has been sufficiently filtered so as to remove particles and debris therefrom. The third tank can hold the filtered oil therein until it is ready to be supplied back to the wheel motor.

Description:
This application claims the benefit of U.S. Provisional Application No. 60/528,185, filed Dec. 10, 2003. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The instant invention pertains to an oil filtration system that is to filter oil supplied from a mining or construction vehicle. To prolong life of components of the vehicle and to limit downtime of the vehicle in a cost effective manner, oil used in conjunction with these components is filtered, by the oil filtration system, for re-use with the vehicle. 
     2. Description of Related Art 
     A conventional oil filtration system for filtering oil used in a wheel motor is shown in  FIG. 1 . As shown in  FIG. 1 , oil is removed from wheel motor  51  through lines  52  and  53 , passes through oil tank  54  in which the oil is heated. The oil then passes through a filter  55  and back into the wheel motor  51  through supply line  56 . This conventional oil filtration system suffers from a drawback in that the wheel itself forms part of a circuit through which the oil is passed, such that the vehicle to which this wheel belongs cannot be operated until the oil has been sufficiently filtered. Thus, vehicle downtime associated with the conventional oil filtration system is great. 
     OBJECT OF THE INVENTION 
     An object of the invention is to provide an oil filtration system that limits downtime associated with mining or construction vehicles by having a wheel from which oil is to be removed not form part of an oil filtration circuit. 
     To meet this object, the oil filtration system includes three separate tanks. A first of these tanks is to receive oil from a wheel motor of the mining or construction vehicle. A second of these tanks is to receive the oil from the first tank after the oil in the first tank has been sufficiently heated so as to remove moisture therefrom. And, a third of these tanks is to receive the oil from the second tank after the oil has been sufficiently filtered so as to remove particles and debris therefrom. The third tank can hold the filtered oil therein until it is ready to be supplied back to the wheel motor. 
     Accordingly, because all of the oil is removed from the wheel motor and then passed through a filtration circuit, while this oil is being filtered new oil can be supplied into the wheel motor such that downtime of the mining or construction vehicle is limited to a minimum. 
     SUMMARY OF THE INVENTION 
     Provided is an oil filtration system that comprises a first tank, a second tank and a third tank in fluid communication with one another. A heater is provided in the first tank, and a filter is provided between the second tank and the third tank. A first pump is proved for pumping oil from the first tank to the second tank, and a second pump is provided for pumping oil from the second tank through the first filter and to the third tank. A first valve is positioned downstream of the first filter an upstream of the third tank such that when the first valve is in an open positioned and oil is pumped by the second pump, the oil flows through the first filter and then to the third tank, and when the first valve is in a closed position and oil is pumped by the second pump, the oil is re-circulated through the first filter. 
     A particle counter is provided for determining an amount of particles in the oil after the oil has passed through the first filter. A second valve is positioned downstream of the first filter and upstream of the particle counter such that when the second valve is in an open position and the first valve is in a closed positioned, and oil is pumped by the second pump, the oil flows through the first filter and to the particle counter. Heaters can also be provided in each of the second tank and third tank. 
     Additionally, a second filter can be provided between the second tank and the third tank. Associated with this second filter is a third pump for pumping oil from the second tank through the second filter and to the third tank. A third valve is positioned downstream of the second filter and upstream of the third tank such that when the third valve is in an open position and oil is pumped by the third pump, the oil flows through the second filter and then to the third tank, and when the third valve is in a closed position and oil is pumped by the third pump the oil is re-circulated through the second filter. Oil passing through the second filter can also be passed to the particle counter by providing a fourth valve that is positioned downstream of the second filter and upstream of the particle counter such that when the fourth valve is in an open positioned and the third valve is in a closed position, and oil is pumped by the third pump, the oil flows through the second filter and to particle counter. 
     The second filter can have a greater filtration capacity than that of the first filter, and the second pump and the third pump can be operated in series so as to first pump oil from the second tank through the first filter and then pump the oil through the second filter. Alternatively, the second filter and the third filter can have equal filtration capacities, and the second pump and the third pump can be operated in parallel so as to simultaneously pump oil from the second tank through the first filter and the second filter. 
     To remove oil from the wheel motor, a first conduit is provided which is connectable to the wheel driven by the wheel motor, and to supply filtered oil back into the wheel motor, a second conduit is provided which is also connectable to the wheel. 
     When 680 viscosity oil is to be filtered by the system, the oil is heated in the first tank to a temperature of 130° F. prior to being passed through the remainder of the oil filtration system. When oil to be treated is 1,000 viscosity oil, this oil is heated in the first tank to a temperature of 160° F. prior to being passed through the remainder of the oil filtration system. In either case, the oil is continually passed through the filter(s) until the oil corresponds to ISO specification of 18/13. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a conventional oil filtration system used in connection with a wheel motor. 
         FIG. 2  is a schematic diagram showing an oil filtration system of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     As shown in  FIG. 1 , the oil filtration system comprises a dirty oil tank  1 , a circulation oil tank  2  and a clean oil tank  3 . The dirty oil tank  1  is designed to hold up to fifty gallons of oil and is in fluid communication with the circulation oil tank  2  via conduit sections T 1 , T 7 . To control the flow of oil from the dirty oil tank  1  to the circulation oil tank  2 , provided in the conduit section T 1  are valves V 1 , V 3  and pump P 1 , and provided in conduit section T 7  is valve V 4 . Associated with pump P 1  is a pressure gauge to measure a pressure of the oil pumped by this pump. 
     The circulation oil tank  2  is in fluid communication with the clean oil tank  3  via conduit sections T 11 , T 1 , T 2  and also via conduit sections T 3 , T 4 . To control the flow of oil from the circulation oil tank  2  to the clean oil tank  3  via conduit sections T 11 , T 1 , T 2  provided in the conduit section T 1  is pump P 2  and provided in the conduit section T 2  is valve V 6 . And, to control the flow of oil from the circulation oil tank  2  to the clean oil tank  3  via conduit sections T 3 , T 4  provided in the conduit section T 3  is pump P 3  and provided in the conduit section T 4  is valve V 9 . Associated with pumps P 2  and P 3  are respective pressure gauges to measure a pressure of the oil pumped by these pumps. Even though conduit sections T 11 , T 1 , T 2  and conduit sections T 3 , T 4  are shown for fluidly interconnecting the circulation oil tank  2  and the clean oil tank  3 , only conduit sections T 11 , T 1 , T 2 , along with valve V 6  and pump P 2 , are absolutely necessary for fluidly interconnecting the circulation oil tank  2  with the clean oil tank  3 . To place the dirty oil tank  1  in fluid communication with a vehicle or other apparatus from which oil is to be received so as to be filtered, there is provided conduit section T 5  and valve V 2  in this conduit section. A fill port  10  is associated with conduit section T 1 , to which fill port a recovery hose is to be connected, and through which recovery hose and fill port oil is to be supplied to the dirty oil tank  1  via conduit section T 5 . A pressure gauge, e.g. a vacuum gauge, is provided to measure pressure within the fill port  10 . As will be described subsequently, valves V 1 , V 2  and V 3  are operated so as to allow oil to either flow from the vehicle or other apparatus into the dirty oil tank  1 , or flow from the dirty oil tank  1  into the circulation oil tank  2 . 
     To place the clean oil tank  3  in fluid communication with a vehicle or other apparatus to which filtered oil is to be supplied, there is provided conduit section T 6  and pump P 4  in this conduit section. Associated with pump P 4  is a pressure gauge to measure a pressure of the oil pumped by this pump. A supply port  11  is associated with conduit section T 6 , to which supply port a recovery hose is to be connected, and through which supply port and recovery hose oil is to flow from the clean supply tank  3  to the vehicle or other apparatus. 
     Within the dirty oil tank  1  there is provided a heater  7 , which is to heat oil in the dirty oil tank  1  so as to remove moisture therefrom and so as to ensure that a viscosity of the oil is sufficiently low such that the oil can be adequately and efficiently pumped from this tank. Within circulation oil tank  2  a heater  8  is provided, and within clean oil tank  3  a heater  9  is provided, which heaters are to heat oil in these tanks to ensure that a viscosity of oil in these tanks is sufficiently low for allowing the oil to be adequately and efficiently pumped from these tanks. 
     Each of heaters  7 ,  8  and  9  includes an adjustable thermostat within a housing. When an oil temperature within any of the tanks  1 ,  2  or  3  is below a point set by the thermostat of its respective heater, then the heater will automatically be activated. Similarly, when an oil temperature within any of the tanks  1 ,  2  or  3  is approximately 5 F above the point set by the thermostat of its respective heater, then the heater will automatically be de-activated. 
     Before oil is pumped from the circulation tank  2  to the clean oil tank  3 , the oil is passed through a filter  4  so as to remove particles and contaminants from the oil. The oil is passed through filter  4  as many times as is necessary to sufficiently remove the particles and contaminants therefrom. The filter  4  is in conduit section T 1 , which conduit section is in fluid communication with the circulation oil tank  2  via conduit section T 11 , and is also in fluid communication with conduit section T 7 . Within conduit T 7  is provided valve V 4 . Operation of valve V 4  allows the oil to be either re-circulated through the filter  4 , or supplied to the clean oil tank  3 . 
     In a similar manner, oil in the circulation tank  2  can also be passed through a second filter  5 . Filter  5  is in conduit section T 3 , and conduit section T 3  is in fluid communication with the circulation oil tank  2  and conduit section T 8 . A valve V 7  is in conduit section T 8  so as to enable the oil to be re-circulated through filter  5  or to be conveyed from the circulation oil tank  2  to the clean oil tank  3 . Filters  4  and  5  can be used in series or parallel relative to one another. When used in series, filter  5  is designed to remove smaller particles than those removed by filter  4 , and when used in parallel, filters  4  and  5  have the same filtration capacity. The oil filtration system can operate with only filter  4 , such that filter  5  and the conduit sections, valves and pump associated therewith can be omitted. 
     To periodically check whether oil has been sufficiently filtered by filters  4  and  5 , a particle counter  6  is provided, which particle counter is an HIAC model PM 4000 manufactured by Pacific Scientific Instruments. The particle counter  6  is in fluid communication with pump  4  via conduit section T 9 , and is in fluid communication with pump  5  via conduit section T 10 . A valve V 5  is in conduit section T 9 , which valve is operated to allow a sample of oil to be removed from conduit section T 1  after passing through filter  4 . In a similar manner, a valve V 8  is in conduit section T 10 , which valve is operated to allow a sample of oil to removed from conduit section T 3  after passing through filter  5 . 
     The valves, pumps and heaters are electrically controlled via a control panel (not shown). 
     Operation 
     Using only Filter  4   
     Operation of the oil filtration system will now be described with reference to 680 Viscosity oil. 
     One end of a recovery hose is connected to a wheel drain of a vehicle, and another end of the recovery hose is connected to the fill port  10 . With valves V 1  and V 3  closed, and valve V 2  opened, pump P 1  is activated such that oil is pumped from the wheel drain and into the dirty oil tank  1  via conduit T 5 . At this time, a reading from the vacuum gauge associated with the fill port  10  is taken, and if this reading indicates excessive pressure (e.g. more than 25 inches of water), then either the oil needs to be heated to reduce its viscosity or a shorter recovery hose is needed. The recovery hose preferably is not more than eight feet in length. When flow of the oil into the dirty oil tank  1  begins, heater  7  is activated to ensure that the oil is heated to at least 130° F. so as to remove moisture from the oil as well as to ensure that viscosity of the oil is sufficiently low to allow the oil to be efficiently pumped from the dirty oil tank  1 . Once the oil has been pumped into the dirty oil tank  1 , pump P 1  is de-activated. 
     After the oil has been pumped into the dirty oil tank  1  and is at a temperature of at least 130° F., with sufficient moisture being removed from the oil, the heater  7  is de-activated and valves V 1 , V 3  and V 4  are opened while valves V 2 , V 5  and V 6  are closed. Then, pump P 1  is activated so as to pump the oil from the dirty oil tank  1  to the circulation oil tank  2  via conduit sections T 1  and T 7 . At this time, a reading from the pressure gauge associated with pump P 1  is taken, and if this reading indicates excessive pressure (e.g. more than 140 psi), then the oil needs to be further heated so as to reduce its viscosity. When the oil begins to flow into the circulation oil tank  2 , heater  8  is activated so as to maintain the oil in the circulation oil tank  2  at a temperature of at least 130° F. so as maintain the oil at a desired viscosity. 
     After the oil has been received within circulation oil tank  2  and when the oil is only to be passed through filter  4 , valves V 3 , V 5  and V 7  are closed while valve V 4  remains opened. When the oil in circulation oil tank  2  is at a temperature of at least 130° F., pump P 2  is activated such that the oil passes through filter  4  at a flow rate of thirty five gallons per minute. At this time, a reading from the pressure gauge associated with pump P 2  is taken, and if this reading indicates excessive pressure (e.g. more than 140 psi), then the oil needs to be further heated so as to reduce its viscosity. Also at this time, or at a subsequent time, a reading of a pressure differential across filter  4  is taken, and a pressure differential of greater than 30 psi at an oil temperature of 130° F. is an indication that a filter element of the filter must be changed. 
     In order to determine when the oil has been sufficiently filtered by filter  4 , a sample of the oil is taken by opening valve V 5  and closing valve V 4  such that a sample of oil flows to the particle counter  6  via conduit section T 9 . If a reading of the particle counter  6  indicates that the oil has not been sufficiently filtered, then valve V 5  is closed while valve V 4  is opened, and the oil is re-circulated through filter  4  via conduit sections T 7 , T 11 . If a reading of the particle counter  6  indicates that the oil has been sufficiently filtered, i.e. a reading corresponding to ISO Specification of 18/13, then pump P 2  is de-activated and the oil is ready to be conveyed to the clean oil tank  3 . 
     To convey the oil from the circulation oil tank  2  to the clean oil tank  3 , the heater  8  is de-activated, and valve V 6  is opened while the valves V 4  and V 5  are closed, such that the oil is pumped by pump P 2  from the circulation oil tank  2  to the clean oil tank  3  via conduit sections T 11 , T 1 , T 2 . 
     Upon flowing of oil into the clean oil tank  3 , heater  9  is activated to ensure that the oil in the clean oil tank is maintained at a temperature of at least 130° F. After the oil has been pumped into clean oil tank  3  and is at a temperature of at least 130° F., the oil is ready to be transferred from the clean oil tank  3  back to the wheel of the vehicle. 
     To convey the oil from the clean oil tank  3  to the wheel, the heater  9  is de-activated, a supply hose is used to interconnect the supply port  11  and the wheel, and pump P 4  is activated. Pump P 4  automatically de-activates after the oil has been pumped from the clean oil tank  3  back to the wheel and the clean oil tank is nearly empty. At this time, a reading from the pressure gauge associated with pump P 4  is taken, and if this reading indicates excessive pressure (e.g. more than 140 psi), then the oil needs to be further heated so as to reduce its viscosity. 
     Using Filter  5  in Series with Filter  4   
     In addition to filtering the oil via filter  4 , the oil in the circulation oil tank  2  can also be filtered via filter  5  after having been filtered by filter  4 . In this case, filter  5  has a greater filtration capacity than does filter  4 , e.g. filter  4  is designed to remove all particles having a particle size of at least 10 microns while filter  5  is designed to remove all particles having a particle size of at least 6 microns. After the oil has been received within circulation oil tank  2  and filtered by filter  4 , valves V 4  and V 8  are closed while valve V 7  is opened, and pump P 2  is de-activated. When the oil in circulation oil tank  2  is at a temperature of at least 130° F., pump P 3  is activated such that the oil passes through filter  5 . At this time, a reading from the pressure gauge associated with pump P 3  is taken, and if this reading indicates excessive pressure (e.g. more than 140 psi), then the oil needs to be further heated so as to reduce its viscosity. Also at this time, or at a subsequent time, a reading of a pressure differential across filter  5  is taken, and a pressure differential of greater than 30 psi at an oil temperature of 130° F. is an indication that a filter element of the filter must be changed. 
     In order to determine when the oil has been sufficiently filtered by filter  5  a sample of the oil is taken by opening valve V 8  and closing valve V 7  such that a sample of oil flows to the particle counter  6  via conduit section T 10 . If a reading of the particle counter  6  indicates that the oil has not been sufficiently filtered, then valve V 8  is closed while valve V 7  is opened, and the oil is re-circulated through filter  5  via conduit sections T 3  and T 8 . If a reading of the particle counter  6  indicates that the oil has been sufficiently filtered, i.e. a reading corresponding to ISO Specification of 18/13, then pump P 3  is de-activated and the oil is ready to be conveyed to the clean oil tank  3 . 
     To convey the oil from the circulation oil tank  2  to the clean oil tank  3 , the heater  8  is de-activated, and valve V 9  is opened while the valves V 7  and V 8  are closed, such that the oil is pumped by pump P 3  from the circulation oil tank  2  to the clean oil tank  3  via conduit sections T 3 , T 4 . 
     Upon flowing of oil into the clean oil tank  3 , heater  9  is activated to ensure that the oil in the clean oil tank is maintained at a temperature of at least 130° F. After the oil has been pumped into clean oil tank  3  and is at a temperature of at least 130° F., the oil is ready to be transferred from the clean oil tank  3  back to the wheel of the vehicle. 
     To convey the oil from the clean oil tank  3  to the wheel, the heater  9  is de-activated, a supply hose is used to interconnect the supply port  11  and the wheel, and pump P 4  is activated. Pump P 4  automatically de-activates after the oil has been pumped from the clean oil tank  3  back to the wheel and the clean oil tank is nearly empty. At this time, a reading from the pressure gauge associated with pump P 4  is taken, and if this reading indicates excessive pressure (e.g. more than 140 psi), then the oil needs to be further heated so as to reduce its viscosity. 
     Using Filter  5  in Parallel with Filter  4   
     Filters  4  and  5  can also be used simultaneously to filter oil pumped from the circulation oil tank  2 . In this case, filters  4  and  5  are of the same filtration capacity, e.g. both being designed to remove particles having a particle size of at least 10 microns. To operate filters  4  and  5  in parallel, after the oil has been received within circulation oil tank  2 , valves V 3 , V 5 , V 6 , V 8  and V 9  are closed while valves V 4  and V 7  are opened. When the oil in circulation oil tank  2  is at a temperature of at least 130° F., pumps P 2  and P 3  are activated such that the oil passes through filters  4  and  5  via conduit sections T 11  and T 3 , respectively. At this time, a reading from the pressure gauge associated with pump P 3  and a reading from the pressure gauge associated with pump P 2  are taken, and if either of these readings indicates excessive pressure (e.g. more than 140 psi), then the oil needs to be further heated so as to reduce its viscosity. Also at this time, or at a subsequent time, a reading of a pressure differential across filter  5  and a reading of a pressure differential across filter  4  is taken, and a pressure differential of greater than 30 psi at an oil temperature of 130° F. is an indication that a filter element of its corresponding filter must be changed. 
     In order to determine when the oil has been sufficiently filtered by filters  4  and  5 , a sample of the oil is taken by opening valves V 5  and V 8  and closing valves V 4  and V 7  such that a sample of oil flows to the particle counter  6  via conduit sections T 9  and T 10 . If a reading of the particle counter  6  indicates that the oil has not been sufficiently filtered, then valves V 5  and V 8  are closed while valves V 4  and V 7  are opened, and the oil is re-circulated through filter  5  via conduit sections T 3  and T 8  and through filter  4  via conduit sections T 11 , T 1  and T 7 . If a reading of the particle counter  6  indicates that the oil has been sufficiently filtered, i.e. a reading corresponding to ISO Specification of 18/13, then pumps P 2  and P 3  are de-activated and the oil is ready to be conveyed to the clean oil tank  3 . 
     To convey the oil from the circulation oil tank  2  to the clean oil tank  3 , the heater  8  is de-activated, and valves V 6  and V 9  are opened while valves V 4 , V 5 , V 7  and V 8  are closed, such that the oil is pumped by pumps P 3  and P 2  from the circulation oil tank  2  to the clean oil tank  3  via conduit sections T 3 , T 4  and via conduit sections T 11 , T 1 , T 2 , respectively. 
     Upon flowing of oil into the clean oil tank  3 , heater  9  is activated to ensure that the oil in the clean oil tank is maintained at a temperature of at least 130° F. After the oil has been pumped into clean oil tank  3  and is at a temperature of at least 130° F., the oil is ready to be transferred from the clean oil tank  3  back to the wheel of the vehicle. 
     To convey the oil from the clean oil tank  3  to the wheel, the heater  9  is de-activated, a supply hose is used to interconnect the supply port  11  and the wheel, and pump P 4  is activated. Pump P 4  automatically de-activates after the oil has been pumped from the clean oil tank  3  back to the wheel and the clean oil tank is nearly empty. At this time, a reading from the pressure gauge associated with pump P 4  is taken, and if this reading indicates excessive pressure (e.g. more than 140 psi), then the oil needs to be further heated so as to reduce its viscosity. 
     As described above, 680 Viscosity oil is filtered; however, other types of fluid, e.g. engine oil, transmission oil, hydraulic fluid, gear lubrication oil, and the like can be filtered by the filtration system. The specific fluid to be filtered would dictate operating parameters of the system, e.g. temperatures, pressures, flow rates, pressure differentials, filtration capacity, and the like. For example, if a 1000 Viscosity oil were to be filtered, then this oil would be heated by the heaters  7 ,  8  and  9  to a temperature of 160° F. Additionally, for 1000 Viscosity oil a heated filter system could be employed.