The present invention relates to lubrication systems, and more particularly to lubrication systems with automatically-controlled valves.
Lubrication systems are known and typically contain a reservoir containing lubricant, one or more fluid supply lines for transporting the lubricant to a location to be lubricated, such as a machine component (e.g., a bearing) and a pump or other means to initiate flow from the reservoir, through the fluid lines and to the component to be lubricated. In certain systems, a valve controls flow from the supply line to the machine component and a controller is provided to operate the pump and open the valve(s). Typically, the controller will start the pump at a set time interval, open the one or more valves and then close the valves and stop the pump when all machine components have received re-lubrication.
Particularly when the lubricant is grease, the lubricant will degrade over time and become ineffective to prevent metal-to-metal contact between the lubricated components. Grease tends to lose consistency, such that oil in the grease bleeds out, and/or oxidizes and breaks down, so as to be generally incapable of providing a film thickness. Such degradation increases at elevated temperatures and higher speeds of the lubricated components, so as to decrease the effective “life” of the grease.
In a first aspect, the present invention is a lubrication system for lubricating at least one movable machine component, the system comprising a lubricant reservoir containing a lubricant and a fluid line fluidly coupled with the reservoir and having an outlet for dispensing the lubricant on or within the machine component. A valve is configured to selectively permit lubricant flow through the fluid line so as to dispense a quantity of lubricant through the fluid line outlet. A sensor is configured to sense a property of one of the machine component and the quantity of lubricant. Further, a control is coupled with the sensor and with the valve, the control being configured to receive information from the sensor, to determine an estimated period of effectiveness of the quantity of lubricant using the sensor information, and to operate the valve based on the estimated lubricant effectiveness period so as to dispense another quantity of lubricant on or within the machine component.
In another aspect, the present invention is a lubrication system for lubricating first and second machine components. The lubrication system comprises a lubricant reservoir containing a lubricant, a first dispenser line fluidly coupled with the reservoir and having an outlet for dispensing lubricant on or within the first machine component, and a first dispenser valve for selectively permitting lubricant flow through the first dispenser line so as to dispense a first quantity of lubricant through the first fluid line outlet. A second dispenser line is fluidly coupled with the reservoir and has an outlet for dispensing lubricant on or within the second machine component, and a second dispenser valve selectively permits lubricant flow through the second dispenser line so as to dispense a second quantity of lubricant through the second fluid line outlet. Further, a control is coupled with each one the first and second valves, the control being configured to determine a first estimated period of effectiveness of the first quantity of lubricant, to determine a second estimated period of effectiveness of the second quantity of lubricant, to operate the first valve based on the first estimated lubricant effectiveness period so as to dispense another first quantity of lubricant on or within the first machine component, and to operate the second valve based on the second estimated lubricant effectiveness period so as to dispense another second quantity of lubricant on or within the second machine component. The second estimated lubricant effectiveness period is greater than the first estimated lubricant effectiveness period such that the control operates the first valve more frequently than the control operates the second valve.
In a further aspect, the present invention is a method of operating a lubrication system for lubricating a machine component, the lubrication system including a lubricant reservoir, a fluid line fluidly coupled with the reservoir and having an outlet for dispensing a quantity of lubricant on or within the machine component, a valve for selectively permitting lubricant flow through the fluid line, and a sensor for sensing a property of the machine component or the lubricant quantity. The method comprises the steps of: determining an estimated period of effectiveness of the quantity of lubricant using the sensor information, and operating the valve based on the estimated lubricant effectiveness period so as to dispense another quantity of lubricant on or within the machine component.
The foregoing summary, as well as the detailed description of the preferred embodiments of the present invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings, which are diagrammatic, embodiments that are presently preferred. It should be understood, however, that the present invention is not limited to the precise arrangements and instrumentalities shown. In the drawings:
Referring now to the drawings in detail, wherein like numbers are used to indicate like elements throughout, there is shown in
As used herein, the terms “period of effectiveness PE” and “lubricant effectiveness period PE” each mean a period of time during which a particular quantity of lubricant LQ remains at least generally capable of effectively lubricating a particular machine component 1. In other words, the “period of effectiveness PE” and “lubricant effectiveness period PE” each mean an estimated time interval from the point in time at which a “fresh” quantity of lubricant LQ has been dispensed into or onto a machine component 1 to a point in time at which the particular lubricant quantity LQ will have degraded to the extent of becoming generally ineffective to lubricate the machine component 1. As discussed below, the period of effectiveness PE is determined from empirical data and varies due to structural characteristics of the machine component 1 being lubricated, the material properties (e.g., rheological, chemical, etc.) of the particular lubricant, and the particular operating conditions (e.g., temperature, speed, etc.) of the machinery component 1 and/or the lubricant quantity LQ. Also as used herein, the words “connected” and “coupled” are each intended to include direct connections between two members without any other members interposed therebetween, indirect connections between members in which one or more other members are interposed therebetween, and operative connections without any direct or indirect physical connections between the two members
Preferably, the lubrication system 10 further comprises one or more sensors 22 each coupled with the control 20 and each configured to sense a speed of an associated one of the first machine components 1 (e.g., shaft speed, bearing rotational speed, etc.), a temperature of the associated machine component 1, or a temperature of the lubricant quantity LQ on or within the associated machine component 1. The system 10 may include two or more sensors 22 for sensing different properties of each particular machine component 1 or/and the quantity of lubricant LQ on or within the component 1, such as for example, one sensor 22 for sensing machine component speed and another sensing temperature of the lubricant quantity LQ on/within that component 1, etc.
With such sensors 22, the lubrication control 20 is configured to receive information from each one of the sensors 22 and to determine the estimated period of effectiveness PE of the each lubricant quantity LQ using information from the associated sensor 22 (i.e., the particular sensor 22 monitoring the specific component 1 or lubricant quantity LQ on or within the component 1). The sensors 22 provide information considered to affect lubrication effective life and may also include sensors 22 for sensing other properties or operating conditions of the machine component 1 or lubricant quantity LQ, such as lubricant pressure within the component 1, lubrication volume, or any other relevant property/condition. Further, the control 20 preferably also uses constant or non-variable information to determine or calculate lubricant effectiveness period PE, such as total available space or volume for the lubricant, fixed loading on a machine component 1, rheological properties of the lubricant, etc.
Most preferably, the control 20 is configured to determine or calculate the lubricant effectiveness period PE using both information from the sensors 22 and empirically-derived data stored within memory of the control 20. Such data may be generated by measuring the time period between the point in time at which a quantity of “fresh” (i.e., unused) lubricant is applied or injected into/on a particular machine component 1 until the point at which the particular quantity of lubricant has degraded to the extent of being generally ineffective to lubricate, or at least the lubrication effectiveness has diminished significantly. Preferably, the data is generated for each one of a plurality of different sets or combinations of operating conditions, such as different temperatures of the machine component 1 and/or lubricant quantity, different machine operating speeds, and for any other relevant variable operating condition or parameter. Using such empirically-derived data stored within electronic memory, the control 20 is configured (i.e., by means of stored software, wiring, etc.) to determine the lubricant effectiveness period PE based upon information from the sensor(s) 12 at the time the quantity of lubricant LQ is applied or injected into/on the machine component 1. However, the lubricant effectiveness period PE may be determined by any other appropriate means.
Further, the control 20 is preferably also configured to recalculate the estimated lubricant effectiveness period PE after each lapse of a sampling time period PS and to adjust the value of the estimated lubricant effectiveness period PE when sensor information varies during the sampling period PS. For example, if a sensor 22 determines that the speed (e.g., rotational) of the machine component 1 increases, or/and the temperature of the component 1 or/and lubricant quantity LQ increases, during the sampling period PS, the control 20 will reduce the lubricant effectiveness period PE, and vice-versa. More specifically, the control 20 is preferably configured to continuously track or record a time period TP after each operation (e.g., opening and closing) of each valve 18 and to compare the time period TP to a value of the estimated lubrication effectiveness period PE, as indicated in
Furthermore, lubrication may be dispensed either in a single operation of each dispenser valve 18 (i.e., valve remains open until the entire lubricant quantity LQ flows onto or within the machine component) or in multiple valve operations. Specifically, the control 20 can be configured to operate each valve 18 such that the valve 18 is opened and remains open to dispense an amount of lubricant of about the desired quantity of lubricant LQ in a single operation (i.e., when TP<=PE), as indicated in
Referring to
Preferably, the control 20 includes an electronic controller 28 having electronic memory with stored software for operating the one or more valves 18 and the pump 24. Specifically, the controller software preferably calculates the lubrication effectiveness periods and performs all control functions described above or discussed below, such as opening and closing the valves 18, operating the pump 24, etc. Preferably, the memory of the control 20 also includes stored information concerning each particular machine component 1, such as volume to be lubricated, dimensions of and loading conditions on the component 1, properties of the specific type of lubricant (preferably a type of grease), such as rheological properties of the lubricant, empirically derived lubricant effectiveness periods PE for various conditions, and any other information that the control 20 utilizes to determine or calculate lubricant effectiveness period PE, as discussed above. Further, the control 20 is preferably either a separate master controller or a controller integral with the pump 24. Although preferably being a digital electronic controller with stored software, the control 20 may alternatively be an analog electronic controller or any other appropriate type of control.
Referring particularly to
Referring now to
The volume of the lubricant within the measuring chamber 52 is adjustably variable to provide a specific, predetermined quantity of lubricant LQ or a specific, predetermined lubricant dose lD through the associated valve 18. Although a detailed description of each injector 41 is beyond the scope of the present disclosure, each injector 41 and the one or more manifolds 40 are preferably formed as generally disclosed in U.S. Pat. Nos. 6,705,432 and 6,810,998, the entire contents of each being incorporated by reference herein. However, the valves 18, the manifold(s) 40 and/or the injectors 41 may be formed in any other appropriate manner, such as for example, as separate valves 18 without any manifold or injector, as valves, manifolds and/or injectors having structures differing from those disclosed in two cited patents, etc. Further, the valves 18 themselves may be constructed or configured to provide a predetermined quantity or amount of lubricant, the quantity/amount being adjustable for differing lubrication requirements, such that the lubrication system 10 may be formed without any injectors. Thus, the scope of the present invention is in no manner limited to any particular structure of the one or more valves 18 or the associated fluid components.
Referring now to
Referring to
Referring particularly to
The control 20 is coupled with each one the first and second valves 19A, 19B and is configured to determine a first estimated period of effectiveness PE1 of the first quantity of lubricant LQ1 and to determine a second estimated period of effectiveness PE2 of the second quantity of lubricant LQ2. The control 20 is also configured to operate the first dispenser valve 19A based on the first estimated lubricant effectiveness period PE1 so as to dispense another first quantity of lubricant LQ1 on or within the first machine component 3A and to operate the second dispenser valve 19B based on the second estimated lubricant effectiveness period PE2 so as to dispense another second quantity of lubricant LQ2 on or within the second machine component 3B. When the second estimated lubricant effectiveness period PE2 is greater than the first estimated period of effectiveness PE1, the control 20 operates the first valve 19A more frequently than the control 20 operates the second valve 19B, and vice-versa.
Thus, the control 20 will operate each valve 19A, 19B independently of the other valve 19B, 19A, such that only the machine component 3A, 3B requiring lubrication due to a particular quantity of lubricant LQ1, LQ2 reaching the end of its effective life. That is, the control 20 is configured to separately operate the first valve 19A, such that the first valve 19A opens while the second valve 19B remains closed, and to alternatively operate the second valve 19B, such that the second valve 19B opens while the second valve 19A remains closed. However, the control 20 may operate both the first and second valves 19A, 19B, respectively, at the same time, such that both valves 19A, 19B are open at the same time, but only at instances when both the first and second lubricant quantities LQ1, LQ2 of require replenishment or replacement.
Although the above-described example describes only first and second valves 19A, 19B controlling lubrication to first and second machine components 3A, 3B, the present lubrication system 10 may be used with any number of valves 18 and dispenser lines 14 for lubricating a like number of machine components 1.
It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as generally defined herein and in the appended claims.
Filing Document | Filing Date | Country | Kind |
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PCT/US15/26469 | 4/17/2015 | WO | 00 |
Number | Date | Country | |
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61981046 | Apr 2014 | US |