Patent Publication Number: US-2015059330-A1

Title: Fluid delivery system

Description:
TECHNICAL FIELD  
     The present disclosure relates to a fluid delivery system, and more particularly, to a vehicle including the fluid delivery system for dispensing a pressurized fluid. 
     BACKGROUND 
     Fluid distribution systems, in particular mobile fluid distribution systems, are used in a variety of applications. For example, at mining and construction sites, it is common to use mobile fluid distribution systems to spray water over roads and work areas to minimize the creation of dust during operations. A specific example might include a water truck that sprays water over roads at a mine site. Other applications of mobile fluid distribution systems may include spraying of pesticides and herbicides, e.g., for agricultural use, disbursement of saline solutions on roads for snow and ice control, fire suppression, and the like. 
     Typically, these fluid distribution systems are coupled to an engine directly or through a torque converter of the vehicle. The fluid distribution systems may be configured to vary a fluid output based upon a change in engine speed, a ground speed, or a speed of the torque converter. For example, U.S. Pat. No. 7,896,258 discloses a system and apparatus for controlling the delivery of fluid from a reservoir, in relation to the ground speed of the vehicle delivering the fluid. 
     However, when the size of the fluid dispensing vehicles and the corresponding engine and torque converter sizes increase, installation of the previously mentioned fluid delivery systems onto the engine or the torque converter may become difficult and cumbersome. 
     SUMMARY 
     In one aspect of the present disclosure, a fluid delivery system includes a first hydraulic circuit, and a second hydraulic circuit. The first hydraulic circuit includes a first hydraulic pump, and a first hydraulic motor. The first hydraulic motor is fluidly connected to the first hydraulic pump and is configured to be driven by the first hydraulic pump. The second hydraulic circuit includes a second hydraulic pump, and a second hydraulic motor. The second hydraulic pump is mechanically coupled to the first hydraulic motor and configured to be driven by the first hydraulic motor. The second hydraulic motor is disposed in loop with the second hydraulic pump and configured to be driven by the second hydraulic pump. The fluid delivery system further includes a delivery pump mechanically coupled to the second hydraulic motor and fluidly connected to a fluid source. The delivery pump is configured to deliver a pressurized fluid. 
     In another aspect, the present disclosure provides a vehicle for dispensing pressurized fluid. The vehicle includes a frame, and a fluid delivery system disposed on the frame. The fluid delivery system includes a first hydraulic circuit, and a second hydraulic circuit. The first hydraulic circuit includes a first hydraulic pump, and a first hydraulic motor. The first hydraulic motor is fluidly connected to the first hydraulic pump and is configured to be driven by the first hydraulic pump. The second hydraulic circuit includes a second hydraulic pump, and a second hydraulic motor. The second hydraulic pump is mechanically coupled to the first hydraulic motor and configured to be driven by the first hydraulic motor. The second hydraulic motor is disposed in loop with the second hydraulic pump and configured to be driven by the second hydraulic pump. The fluid delivery system further includes a delivery pump mechanically coupled to the second hydraulic motor and fluidly connected to a fluid source. The delivery pump is configured to deliver a pressurized fluid. 
     Other features and aspects of this disclosure will be apparent from the following description and the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an exemplary vehicle in accordance with an exemplary embodiment of the present disclosure; and 
         FIG. 2  is a schematic representation of a fluid delivery system employed in the exemplary vehicle of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure relates to a fluid delivery system, and more particularly, to a vehicle including the fluid delivery system for dispensing pressurized fluid.  FIG. 1  illustrates an exemplary embodiment of a vehicle  100  according to the present disclosure. The vehicle  100  may be configured for dispensing a pressurized fluid. The vehicle  100  of  FIG. 1  is shown as a truck, typically used in off-highway applications, converted to dispense a pressurized fluid. However, other types of mobile machines may be employed, for example, articulated trucks, on-highway trucks, tractor-scrapers, tractors in combination with trailers, or the like. 
     The vehicle  100  may include a variety of piping, hoses, pumps and valves for fluid transmission and/or distribution purposes. In particular, the vehicle  100  in  FIG. 1  is shown as an off-highway truck configured as a water truck for spraying water at a work site. However, the present disclosure may also apply to other types of mobile machines configured to distribute water or other types of fluids in a wide variety of applications. For example, a tractor pulling a trailer may be used to distribute chemicals in agricultural settings, an on-highway truck may be configured to spray a saline solution on roads, runways, or parking lots to melt snow and ice, or other varieties of applications and setups may be used. 
     In an embodiment, the vehicle  100  may include an engine (not shown), such as an internal combustion engine or other power source, which may be supported on a frame  102 . Although different arrangements and setups are contemplated, the vehicle  100  may include among other systems, a fluid delivery system  104  disposed on the frame  102  as shown in  FIG. 1 . The fluid delivery system  104  may be powered by the engine. Further, the engine may be configured to provide power to a number of other systems and devices (not shown) in addition to the fluid delivery system  104 . The fluid delivery system  104  may include a fluid source  126  and one or more spray heads  130  fluidly connected thereto, explaining to which will be made hereinafter. 
     Referring now to  FIG. 2 , details pertaining to the fluid delivery system  104  will be disclosed hereinafter. The fluid delivery system  104  includes a first hydraulic circuit  106 . The first hydraulic circuit  102  includes two first hydraulic pumps  108 , and a first hydraulic motor  110 . The first hydraulic motor  110  is fluidly connected to the first hydraulic pumps  108  and is configured to be driven by the first hydraulic pump  108 . 
     For purposes of illustration, two first hydraulic pumps  108  have been shown in  FIG. 2 . However, it is to be noted that the number of first hydraulic pumps shown in  FIG. 2  is merely exemplary in nature and hence, non-limiting of this disclosure. Any number of hydraulic pumps may be used in the first hydraulic circuit  106  depending on specific requirements of an application. 
     The first hydraulic circuit  106  may further comprise a first tank  112  configured to store a first working fluid. In an embodiment, the first hydraulic circuit  106  may further comprise a control valve  113  disposed in loop with the first hydraulic pumps  108  and the first hydraulic motor  110 . The control valve  113  may be configured to control the first working fluid that circulates from the first hydraulic pumps  108  and the first hydraulic motor  110  to other applications on the vehicle  100 . 
     In an embodiment, the first hydraulic circuit  106  may further include a bypass valve  114  disposed between the control valve  113  and the first hydraulic pumps  108 . Further, the bypass valve  114  may be fluidly connected to the control valve  113  and the first hydraulic pumps  108 . The bypass valve  114  may be configured to allow the first working fluid from the first hydraulic pumps  108  to enter or bypass the first hydraulic motor  110 . In an exemplary embodiment, the bypass valve  114  may be a 2-way, 2-position valve. However, the 2-way, 2-position valve is merely exemplary in nature and hence, non-limiting of this disclosure. Any type of valve commonly known in the art may be used to form the bypass valve  114 . An operational state of the fluid delivery system  104  may be controlled by operating the bypass valve  114 . Explanation pertaining to the functioning and control of the fluid delivery system  104  by operation of the bypass valve  114  will be made later herein. 
     The fluid delivery system  104  further includes a second hydraulic circuit  116  including a second hydraulic pump  118 , and a second hydraulic motor  120 . The second hydraulic pump  118  is mechanically coupled to the first hydraulic motor  110  and is configured to be driven by the first hydraulic motor  110 . The second hydraulic motor  120  is disposed in loop with the second hydraulic pump  118  and configured to be driven by the second hydraulic pump  118 . As shown in  FIG. 2 , the second hydraulic pump  118  is fluidly connected to and disposed in loop with the second hydraulic motor  120  by a primary input line  121  and a drain line  122 . 
     The second hydraulic circuit  116  further includes a second tank  123  disposed in loop with and fluidly connected to the second hydraulic pump  118 , and the second hydraulic motor  120 . The second tank  123  may be configured to store a second working fluid. The second working fluid may be circulated from the second tank  123  to the second hydraulic pump  118 , and the second hydraulic motor  120  via the primary input line  121  and the drain line  122 . 
     The fluid delivery system  104  further includes a delivery pump  124  mechanically coupled to the second hydraulic motor  120  and fluidly connected to the fluid source  126  (as shown in  FIG. 2  and also in  FIG. 1 ). The delivery pump  124  is configured to deliver a pressurized fluid. In an embodiment, the fluid source  126  may be a third tank configured to store a third fluid different from the first working fluid and the second working fluid. For ease in referring to the fluid source  126 , “the fluid source” may hereinafter be referred to as “the third tank”. Further, the numeral  126  designating “the fluid source” may be correspondingly used to designate “the third tank”. Furthermore, with reference to the embodiments disclosed herein, it may be noted that the first tank ( 112 ) associated with the first hydraulic circuit ( 106 ), the second tank ( 123 ) associated with the second hydraulic circuit ( 116 ), and the third tank ( 126 ) connected to the delivery pump ( 124 ) are hydraulically isolated from each other. The first hydraulic circuit ( 106 ), the second hydraulic circuit ( 116 ), and the third tank ( 126 ) may thus operate without any fluid-mixing or exchange therebetween. 
     In an embodiment, as shown in  FIGS. 1-2 , the fluid delivery system  104  further includes a fluid manifold  128 , and the spray heads  130  mounted onto the fluid manifold  128  (four spray heads  130  shown in  FIGS. 1-2 ). The fluid manifold  128  (as shown in  FIGS. 1-2 ) may be fluidly coupled to the delivery pump  124  and configured to receive the pressurized fluid from the delivery pump  124 . The spray heads  130  may be configured to dispense the pressurized fluid. Although four spray heads  130  are shown in  FIG. 2 , it is to be noted that a number of spray heads mounted onto the fluid manifold  128  is merely exemplary in nature and hence, non-limiting of this disclosure. Any number of spray heads may be employed in the fluid delivery system  104  depending on specific requirements of an application. 
     In an embodiment, as shown in  FIG. 2 , the second hydraulic motor  120  may be a variable displacement hydraulic motor (as indicated by a slant arrow on circle representing the second hydraulic motor  120 ). The second hydraulic circuit  116  may further include a control pump  132  mechanically coupled to the second hydraulic pump  118 . The control pump  132  is disposed in loop with the second hydraulic motor  120  and is configured to provide a control pressure to the second hydraulic motor  120 . The control pump  132  may be further configured to provide flow to a cooler  138  thereby cooling the second working fluid in the second tank  123 . 
     In another embodiment as shown in  FIGS. 1-2 , the fluid delivery system  104  may further include an electronic control module (ECM)  134  electrically connected to the second hydraulic motor  120 . In an embodiment, the ECM  134  may control one or more actuators (not shown) associated with the second hydraulic motor  120  using the control pressure from the control pump  132  as a reference. Further, the ECM  134  may be electrically connected to a pressure sensor (not shown) located at the fluid manifold  128  and spray heads  130  via one or more solenoids  136 . 
     The ECM  134  may be configured to modulate a speed of the second hydraulic motor  120  such that a fluid output from the delivery pump  124  is varied, i.e., a flow rate and/or pressure of the third fluid from the delivery pump  124  are varied. Varying the fluid output from the delivery pump  124  may increase or decrease a pressure of the third fluid in the fluid manifold  128  such that the spray heads  130  may dispense the third fluid at an increased or decreased flow rate and/or pressure. 
     In one exemplary embodiment, the variation in the flow rate or pressure of the third fluid may be based on the speed of the vehicle  100 . In another exemplary embodiment, the variation in the flow rate or pressure of the third fluid may be based on one or more operator inputs, wherein an operator may command the ECM  134  with the required input signals. 
     In an embodiment as shown in  FIG. 2 , the second hydraulic circuit  116  may further include the cooler  138  disposed downstream of the control pump  132 . The cooler  138  may be configured to cool the second working fluid returning from the second hydraulic motor  120 . 
     The second hydraulic circuit  116  may further include a relief valve  142  disposed between the cooler  138 , the control pump  132 , and the second hydraulic motor  120 . The relief valve  142  may be fluidly connected to the cooler  138 , the control pump  132 , and the second hydraulic motor  120 . As shown in  FIG. 2 , the relief valve  142  may be disposed in a control input line  144  of the second hydraulic motor  120 . The relief valve  142  may be configured to maintain a control pressure of the second working fluid in the control input line  144 . 
     The relief valve  142  may be preset with a threshold pressure. Based on a pressure of the second working fluid in relation to the threshold pressure of the relief valve  142 , the relief valve  142  may be forced open or closed to maintain the threshold pressure in the control input line  144  of the second hydraulic motor  120 . Hence, the relief valve  142  may bleed off excess pressure build-up from prolonged or constant pumping of the second working fluid within the control input line  144  of the second hydraulic circuit  116  through the cooler  138 . 
     In an embodiment, the second hydraulic circuit  116  may further include a back-pressure valve  146  disposed in the primary output line  140 . The back-pressure valve  146  may be located between the second hydraulic motor  120  and the second tank  123 . The back-pressure valve  146  may be configured to maintain a threshold pressure in the primary output line  140 . This threshold pressure in the primary output line  140  may help to send a small portion of the second working fluid to the drain line  122  through the second hydraulic motor  120  thereby cooling the second hydraulic motor  120 . 
     INDUSTRIAL APPLICABILITY 
     Fluid delivery systems may be used in a number of different applications to deliver, and distribute, various fluids. For example, in mobile applications, a fluid delivery machine, or truck, may use a fluid delivery system to distribute a liquid, such as water, at construction or mining sites to reduce dust. In particular, for example, a fluid delivery machine may distribute water along haul roads at a work site to minimize the creation of dust during work operations. A working of the present fluid delivery system  104  will be disclosed hereinafter. 
     To initiate operation of the fluid delivery system  104 , the bypass valve  114  may be set into a first position such that the bypass valve  114  is configured to allow the first working fluid from the first hydraulic pumps  108  to enter the first hydraulic motor  110 . Therefore, the first working fluid, supplied to the first hydraulic pumps  108  by the first tank  112 , may be pressurized to drive the first hydraulic motor  110 . 
     Rotation of the first hydraulic motor  110  may rotate the second hydraulic pump  118  and the control pump  132 . The second hydraulic pump  118  and the control pump  132  may be supplied with the second working fluid from the second tank  123 . The second hydraulic pump  118  pressurizes the second working fluid to drive the second hydraulic motor  120 . The control pump  132  pressurizes the second working fluid to provide a control pressure to the second hydraulic motor  120  via the control input line  144  and flow to the cooler  138  to cool the second fluid in the tank  123 . 
     Rotation of the second hydraulic motor  120  drives the delivery pump  124 . Therefore, the third fluid supplied to the delivery pump  124  by the third tank  126  is pressurized and sent to the fluid manifold  128 . Thereafter, the spray heads  130  mounted on the fluid manifold  128  may dispense fluid at a pressure and/or flow rate corresponding to the speed of the second hydraulic motor  120 . 
     When a pressure of the third fluid dispensed from the spray heads  130  is to be varied, the ECM  134  may modulate a speed of the second hydraulic motor  120  based upon various input signals from one or more sensors and vehicle operator. For example, based upon input signals from vehicle speed sensors (not shown) and input signals from various pressure and/or position sensors (not shown) associated with the spray heads  130 , the ECM  134  may command movement of the solenoids  136  in a desired position and/or the second hydraulic motor  120  at a desired speed to maintain a certain flow rate out of the spray heads  130 . 
     The ECM  134  may embody a single microprocessor or multiple microprocessors that include components for controlling operation of the fluid delivery system  104  based on an input signals from an operator and/or based on sensed or other known operational parameters. Numerous commercially available microprocessors can be configured to perform the functions of the ECM  134 . It should be appreciated that the ECM  134  could readily be embodied in a general machine microprocessor capable of controlling numerous machine functions. The ECM  134  may include a memory, a secondary storage device, a processor, and any other components for running an application. Various other circuits may be associated with the ECM  134  such as power supply circuitry, signal conditioning circuitry, solenoid driver circuitry, and other types of circuitry. Further, various routines, algorithms, and/or programs may be programmed within the ECM  134  for execution thereof to perform the functions of controlling the solenoids  136  and/or the second hydraulic motor  120 . 
     In order to stop an operation of the fluid delivery system  104 , the bypass valve  114  may be set into a second position such that the bypass valve  114  is configured to allow the first working fluid from the first hydraulic pumps  108  to directly flow to the control valve  113  thereby causing the first working fluid to bypass the first hydraulic motor  110 . Therefore, the first hydraulic motor  110 , the second hydraulic pump  118 , the second hydraulic motor  120 , and the delivery pump  124  may not be driven by the first hydraulic pump  108 . Consequently, the spray heads  130  may not dispense fluid, thus rendering the fluid delivery system  104  in a non-operational state. 
     The back-pressure valve  146 , the cooler  138 , and the relief valve  142  disclosed herein may be employed in the fluid delivery system  104  to regulate parameters such as pressure, temperature, and/or flow rate of the second working fluid in the second hydraulic circuit  116 . Control and regulation of the second working fluid may allow smooth operation and facilitate prolonged operation cycles of the fluid delivery system  104 . 
     Previously known fluid distribution systems were coupled to an engine or a torque converter of a water tanker. However, with increase in size of the water tanker, a size of the engine and the torque converter may increase, and consequently the space available in and around the engine or the torque converter for installation of the previously known fluid distribution systems may reduce. The reduced space may make installation of the previously known fluid distribution systems onto the engine or the torque converter difficult and cumbersome. 
     In one aspect of the present disclosure, the first hydraulic pump  108  may be a pump that existed as a part of the vehicle  100  prior to the vehicle  100  being configured for dispensing pressurized fluid. For example, the vehicle  100  may have previously been used as a dump truck employing one or more hoist/brake cooling pumps therein. The hoist/brake cooling pumps may have been associated with a hoisting implement or were used for cooling the brakes of the dump truck. With implementation of the fluid delivery system  104  of the present disclosure, the hoist/brake cooling pumps may be used to form the first hydraulic pumps  108 , and the first hydraulic pumps  108  formed from the hoist/brake cooling pumps may be disposed in connection with the remaining components of the fluid delivery system  104  disclosed herein. In this manner, the fluid delivery system  104  may be configured to have indirect association with the engine or the torque converter of the vehicle  100 . Further, the construction of the fluid delivery system  104  disclosed herein may dispose the fluid delivery system  104  substantially away from the engine or the torque converter. 
     In another aspect of the preceding embodiment, the first working fluid, the second working fluid, and the third fluid associated with the first hydraulic circuit  106 , the second hydraulic circuit  116 , and the delivery pump  124 , respectively, may be distinct from each other. The first hydraulic circuit  106  employing the hoist/brake cooling pumps as the first hydraulic pumps  108  may use a fluid, for example, an oil previously associated with a hoisting/brake cooling arrangement circuit of the vehicle  100 . The second working fluid may be, for example, oil associated with a steering equipment of the vehicle  100 . The third fluid may be, for example, water, or a pesticide liquid that is to be dispensed onto a ground surface (not shown). 
     Oil associated with a circuit, such as the hoisting/brake cooling arrangement circuit of the vehicle  100  is typically known to get contaminated or dirty over a prolonged period of time. Components used in the second hydraulic circuit  116  such as the hydraulic motor  120  for example, may be sensitive to oil contaminants and a life of the components may reduce with an increase in amount of oil contaminants. 
     However, with use of the first, second, and third tanks  112 ,  123 ,  126 , and the distinct fluids circulated therefrom, it is envisioned that the first hydraulic circuit  106 , the second hydraulic circuit  116 , and the delivery pump  124  may operate individually without mixing of the first working fluid, the second working fluid, and the third fluid therebetween. Therefore, the distinct tanks  112 ,  123 ,  126  and the distinct fluids circulated therefrom may help to keep contaminants of each fluid within the respective hydraulic circuits  106 ,  116 , and to the delivery pump  124  respectively. As a result, a service life of the components used in the hydraulic circuits may be prolonged. Further, it may be easier to circulate the fluids of the respective hydraulic circuits  106 ,  116  and the delivery pump  124  and accomplish smooth operation of the fluid delivery system  104 . 
     The construction of the fluid delivery system  104  disclosed herein and the configuration of various components therein may allow a manufacturer to overcome the space demands encountered with implementation of previously known fluid distribution systems onto engines and torque converters. The present fluid delivery system  104  may allow the manufacturer to do away with installing the fluid delivery system  104  onto the engines and torque converters. 
     While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by the modification of the disclosed machine, systems and methods without departing from the spirit and scope of what is disclosed. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof.