Piston limit sensing for fluid applications

Abstract

The liquid delivery system (106) includes a hydraulic fluid source (502) and a hydraulic cylinder (114) fluidly coupled to the hydraulic fluid source (502) and having a hydraulic piston (224) movable between a first extreme position and a second extreme position. The liquid delivery system (106) includes a rod (210) connected to the piston and extending out of the hydraulic cylinder (114) and a sensor device (204, 206) located outside the hydraulic cylinder (114) and configured to sense a position of the rod (210) and generate a signal indicative of the sensed position. The liquid delivery system (106) includes a liquid cylinder including a liquid piston operably driven by a rod (210) to pump liquid along a flow path to a fluid applicator (518).

Description

[0001] This application is a divisional application of patent application No. 201880057749.6 entitled "Piston Limit Sensing for Fluid Applications" (International Application Date: 2018-09-07, International Application No.: PCT / US2018 / 049866), which entered the Chinese national phase on March 5, 2020. Background Technology

[0002] Liquid delivery systems are used to transport fluids from a source location to a delivery location. In some cases, liquid delivery systems include pump systems configured to deliver the liquid at a desired operating pressure. Liquid delivery systems are useful for a variety of fluids, such as paints, primers, and other exemplary fluids. Summary of the Invention

[0003] The liquid delivery system includes a hydraulic fluid source and a hydraulic cylinder fluidly coupled to the hydraulic fluid source and having a hydraulic piston movable between a first limit position and a second limit position. The liquid delivery system includes a rod connected to the piston and extending out of the hydraulic cylinder, and a sensor device located outside the hydraulic cylinder and configured to sense the position of the rod and generate a signal indicating the sensed position. The liquid delivery system includes a liquid cylinder comprising a liquid piston operably driven by the rod to pump liquid along a flow path to a fluid applicator.

[0004] The above description of the invention is not intended to depict every illustrated embodiment or every implementation of the present disclosure. Attached Figure Description

[0005] Figure 1 This is a perspective view showing an example of a painting system.

[0006] Figure 2A-2C This is a view of the example pump component.

[0007] Figure 3A -B is a diagram illustrating an example hydraulic circuit.

[0008] Figure 4A -C is the view of the example sensor.

[0009] Figure 5 This is a block diagram illustrating an example liquid dispensing system.

[0010] Figure 6 This is a block diagram illustrating the control of an example pump system.

[0011] Figure 7 It is a flowchart illustrating the operation of a pump system with a self-charging and limit sensing system in one example.

[0012] Figure 8A This is a close-up view of a self-charging sensor system used in a pump assembly, as shown in the example.

[0013] Figure 8B This is a graph showing the output of induced current and piston speed over time in an example. Detailed Implementation

[0014] This disclosure relates to hydraulically powered liquid pumps, and more specifically to sensors for use in limit sensing systems for determining, controlling, and filling pistons in liquid delivery systems. While this disclosure is not necessarily limited to such applications, various aspects of this disclosure can be understood by discussing various examples of paint use as background.

[0015] Many fluid applicators, especially paint applicators, suffer significant wear during their use. For hydraulic applicators, which traditionally include cables for charging limit position sensors and communicating with the controller, wear can damage these cables. For example, if the cable is cut or exposed to degrading solvents, the sensor may no longer function properly. A system is desired that wirelessly charges the sensor and facilitates wireless communication between the controller and the sensor system.

[0016] It is also desirable for the system to detect the piston speed, direction, and position in real time during the stroke. While many current systems detect when the piston passes the sensor (or reaches the stroke limit), there is a need for a system capable of detecting the piston position during the mid-stroke. For example, in multi-component systems, the ratio between two different components is important for product quality, so the system should detect and monitor the piston's real-time position during each stroke.

[0017] Additionally, it is desirable for the system to enable wireless communication between the limit sensors and the controller. Wireless communication can also allow detected information to be transmitted to remote devices. For example, if the controller detects abnormal behavior while monitoring piston position and speed, it can report that behavior. In some cases, the controller can also report diagnostics, such as a seal that may be failing, as indicated by a faster-than-normal downward forming or a slower-than-normal upward stroke.

[0018] According to various examples, a fluid delivery system may include a hydraulic cylinder. A hydraulic cylinder may be a mechanical actuator that distributes force onto the fluid using a reciprocating piston stroke. A piston is attached to a piston rod or other suitable structure, and the movement of the piston causes the piston rod to reciprocate. One end of the cylinder is closed by a cylinder top (hereinafter referred to as the head), and the other end is closed by a cylinder bottom (hereinafter referred to as the base), at which the piston rod extends out of the cylinder. In a hydraulically powered fluid delivery system, the hydraulic cylinder derives its power from pressurized hydraulic fluid. In some examples, an actuator (e.g., a solenoid valve) may direct a flow of hydraulic fluid generated by a hydraulic pump through a first port located on the cylinder (e.g., a port near the head, hereinafter referred to as the head port). As the hydraulic fluid is directed by the actuator to the head port, pressure builds up within the cylinder, forcing the piston to move from the head through the cylinder to the base.

[0019] Figure 1 This is a perspective view showing an example painting system 100. The painting system 100 includes an upper cover 126, a frame 128, wheels 130, a lower cover 132, a motor system 102, and a solenoid valve below 132. Figure 1 (Not shown in the image), pump assembly 106, hydraulic motor 136, and paint reservoir (not shown). The motor system 102 can be electric, pneumatic, etc., and may include a hydraulic pump located below the lower cover 132 and a hydraulic fluid reservoir also located below the lower cover 132. Figure 1 (Not shown in the image). The hydraulic pump delivers hydraulic fluid (e.g., oil) from the hydraulic fluid reservoir to the solenoid valve. The solenoid valve may be an electromechanical device comprising a solenoid, a head port on the valve body, and a rod port on the valve body. The head port and the rod port on the valve body can be controlled by an electric current flowing through the solenoid. For the solenoid valve, the current can cause the flow from the head port and the rod port on the valve body to alternate.

[0020] As shown, the solenoid is coupled to controller 140. Control 140 may include various hardware and / or software components. In one example, the controller includes a MOSFET and flip-flop integrated circuit system. In another example, the solenoid is controlled by a computer processor and integrated software, such as a circuit board. The circuit board may be communicatively coupled directly to the solenoid. The controller may also be coupled to memory, allowing it to report or store information collected from a cycle counter and / or a run-time tracker. This controller can be used to measure the performance of the pump system without manual counting. In some examples, as discussed in more detail below, the controller may also monitor piston speed and determine the instantaneous position of the piston during its stroke. As shown, controller 140 is on pump assembly 106; however, controller 140 may be located elsewhere.

[0021] Pump assembly 106 includes a hydraulic cylinder 114 and a paint pump 116. A solenoid valve directs hydraulic fluid generated by the hydraulic pump through a head port on the valve body to a head port 122 of the hydraulic cylinder 114. As the hydraulic fluid is directed by the solenoid valve through the head port 122 of the hydraulic cylinder 114, pressure accumulates in the cylinder, forcing the hydraulic piston to move. As the hydraulic piston moves through the cylinder, hydraulic fluid is forced through the rod port 124 of the hydraulic cylinder 114, via the rod port on the valve body, into the solenoid valve, and returns to the hydraulic fluid reservoir. Furthermore, a hydraulic piston rod connected to the hydraulic piston (…) Figure 1 (Not shown in the image) can also be connected to the paint piston rod ( Figure 1 (Not shown in the image). As a result, the hydraulic piston moves the paint piston rod through the paint pump 116 to pump paint from the paint reservoir to the paint applicator (not shown in the image). Figure 1 The outlet hose 134 (not shown in the image).

[0022] In one example, a ferrous collar is attached to the hydraulic piston rod. Additionally, at least two sensors are located outside the cylinder, corresponding to two extreme positions of the hydraulic piston at the end of each stroke, hereinafter referred to as stroke limit positions. In some examples, the sensors may be Hall effect sensors.

[0023] In one example, one or more limit sensors are coupled to the controller ( Figure 1(Not shown in the diagram). The controller can use one or more limit sensors to detect the piston rod position. For example, detecting the piston rod position during startup may help initiate a regular operation loop. In some previous systems, uncertainty in the piston position could make initiating a regular operation loop difficult. For example, the piston could be mid-stroke, topped out, bottomed out, etc. A software-controlled controller can be able to detect the piston position and engage the corresponding operation loop.

[0024] The controller can also be configured to track cycles, for example, by updating the cycle rate count (after each completed cycle) and the pump system's uptime. This allows for the calculation of performance parameters without adding additional hardware to the pump system to manually calculate cycles.

[0025] For example, as the hydraulic piston moves from the head port 122 through the cylinder to the rod port 124, the ferrous metal on the hydraulic piston rod moves closer to the first Hall effect sensor at the stroke limit position. When the hydraulic piston reaches the stroke limit position in the cylinder, the ferrous metal will be detected by the first Hall effect sensor (…). Figure 1 (Not shown) is detected. In response to the detection of the ferrous metal, the Hall effect sensor sends a sensor signal to the controller 140. In an example using a MOSFET and trigger integrated circuit control system as a component of the controller 140, the controller 140 may provide a voltage or other suitable indication that activates a set of metal-oxide-semiconductor field-effect transistors (MOSFETs) and trigger integrated circuits or other suitable switching devices to change the solenoid state. In another example, the controller 140 includes integrated software configured to change the solenoid state.

[0026] Once the solenoid state changes, hydraulic fluid can now flow into the cylinder through the rod port 124 of the hydraulic cylinder 114. Additionally, hydraulic fluid can be pushed back into the solenoid valve through the head port 122 of the hydraulic cylinder 114, and then back to the hydraulic fluid reservoir. When the hydraulic piston moves through the cylinder in the opposite direction (e.g., from the rod port 124 towards the head port 122), the magnetic field strength relative to the first Hall effect sensor decreases, and the first Hall effect sensor detects this change. When the hydraulic piston reaches its stroke limit position, the ferrous metal on the hydraulic piston rod causes the second Hall effect sensor to detect the position of the piston rod. The controller 140 receives a signal from the second Hall effect sensor and then reverses the flow of hydraulic fluid from the solenoid valve.

[0027] Figure 2A-2CA view of an example pump assembly is shown. Figure 2A This is a front view of the pump assembly, showing paint inlet 116 and cover 105. Figure 2B This is a perspective view showing the cover 105 removed. Figure 2C This is a cross-sectional view of pump assembly 106.

[0028] As in Figure 2C As can be seen, the pump assembly 106 includes a head port 122 of a hydraulic cylinder 114, a rod port 124 of the hydraulic cylinder 114, a paint piston rod 212, a hydraulic piston rod 210, a hydraulic piston 224, a paint inlet 216, a hydraulic cylinder chamber 218, a minimum sensor 204, a maximum sensor 206, and a sleeve 208. An actuator (e.g., a solenoid valve) directs hydraulic fluid through the head port 122 of the hydraulic cylinder 114 into the hydraulic cylinder chamber 218. The hydraulic fluid forces the hydraulic piston 224 downward through the hydraulic cylinder chamber 218. As the hydraulic piston 224 moves downward through the hydraulic cylinder chamber 218, the paint piston rod 212 moves downward through the paint pump chamber and pushes paint out of the hose outlet (e.g., through the hose to the paint applicator). Additionally, the hydraulic fluid is forced back through the rod port 124 of the hydraulic cylinder 114, into the solenoid valve, and back to the hydraulic fluid reservoir.

[0029] In one example, when the hydraulic piston 224 is at its stroke limit, the sleeve 208 approaches the maximum sensor 206, and the maximum sensor 206 generates a sensor signal indicating that the sleeve 208 has reached its maximum position. In response to receiving this sensor signal, the controller 140 reverses the state of the solenoid valve and allows hydraulic fluid to flow into the hydraulic cylinder chamber 218 through the rod port 124 of the hydraulic cylinder 114, thereby reversing the direction of the piston 224. As the piston 224 moves upward, the hydraulic fluid is forced out of the head port 122 of the hydraulic cylinder 114, into the solenoid valve, and back to the hydraulic fluid reservoir. The paint piston rod 212 also moves upward through the paint pump chamber and through the paint inlet 216 (… Figure 2A (As shown) the paint is drawn in. When the hydraulic piston reaches its upper stroke limit position, the minimum sensor 204 senses the sleeve 208, and the hydraulic fluid is reversed and flows into the hydraulic cylinder chamber 218 through the head port 122 of the hydraulic cylinder 114.

[0030] The sleeve 208 may include some type of ferrous metal or other material that can be detected by the minimum sensor 204 or the maximum sensor 206 to sense the stroke position of the hydraulic rod 210 and the paint pump rod 212. However, the sleeve 208 may also be used for other purposes.

[0031] For example, collar 214 couples hydraulic rod 210 to paint pump rod 212. As shown, collar 214 includes two semi-circular parts that engage with hydraulic rod 210 at interface 219 and with paint pump rod 212 at interface 217. To keep the two parts of collar 214 in contact with hydraulic rod 210 and paint pump rod 212, sleeve 208 may engage on the outer surface of collar 214 to prevent lateral movement of collar 214 relative to the stroke direction of hydraulic rod 210 and paint pump rod 212. In some examples, collar 214 may have more or fewer parts.

[0032] The integrated software controller can allow for parameter tracking of the performance metrics of the pump assembly 106. For example, the integrated software controller may include a cycle counter configured to track the total cycles and run-time of the pump assembly 106 over its entire service life.

[0033] Figure 2B This is a perspective view of an open pump coupling assembly. Figure 2B In this configuration, cover 105 has been removed to expose minimum sensor 204, maximum sensor 206, sleeve 208, hydraulic rod 210, and paint pump rod 212. Minimum sensor 204 and maximum sensor 206 sense the position of sleeve 208. Sleeve 208 is coupled to hydraulic rod 210 and paint pump rod 212, thus the position of sleeve 208 indicates the position of hydraulic rod 210 and paint pump rod 212. Therefore, when minimum sensor 204 or maximum sensor 206 detects sleeve 208, the sensor output also indicates that hydraulic rod 210 and paint pump rod 212 have reached their stroke limits.

[0034] As shown, the minimum sensor 204 and the maximum sensor 206 are Hall effect sensors capable of detecting changes in the electromagnetic field. For example, both the minimum sensor 204 and the maximum sensor 206 include a magnet that generates a magnetic field. When the sleeve 208 is very close to the magnet, the magnetic field changes in a detectable manner. This change indicates that the sleeve is located at either the minimum sensor 204 or the maximum sensor 206. The positions of the minimum sensor 204 and the maximum sensor 206 relative to the sleeve 208 can be set such that when the sleeve 208 reaches either sensor, the hydraulic rod 210 and / or the paint pump rod 212 are either at their maximum stroke position or their minimum stroke position.

[0035] Figure 3AFigure 3 illustrates an example of a hydraulic circuit. The hydraulic circuit 500 may include a hydraulic reservoir 502, a hydraulic pump 504, a solenoid 506, a head port 508, a rod port 510, a hydraulic cylinder 512, a paint cylinder 514, a paint reservoir 516, and a spray gun 518. The hydraulic pump 504 pumps hydraulic fluid from the hydraulic reservoir 502 to the solenoid 506. In Figure 3, the solenoid 506 is shown as a directional control valve. Directional control valves allow fluid to flow from one or more sources along different paths. They may include a spool within a cylinder and may be mechanically, electrically, and / or hydraulically controlled. Furthermore, movement of the spool can restrict or allow the flow of hydraulic fluid from the hydraulic reservoir 502.

[0036] An electromechanical solenoid can operate a 4-way, 2-position valve because it has two spool positions and four ports. However, other position valves can also be used. A 4-way, 2-position valve combined with a Hall effect sensor (not shown in Figure 4) allows for rapid switching between the downward and upward strokes of the hydraulic cylinder 512. This allows the hydraulic circuit 500 to achieve constant paint pressure. In this example, initially, the head port 508 is a pressure port connected to the hydraulic pump 504, while the rod port is connected to the hydraulic reservoir 502. When hydraulic fluid is introduced into the head port 508, the pressure within the hydraulic cylinder 512 forces the hydraulic piston downward through the cylinder, and the hydraulic fluid is pushed out of the rod port 510 and returned to the hydraulic reservoir 502. Since the hydraulic piston is connected to the paint piston, the paint piston also moves downward through the paint cylinder 514, and the paint located in the paint cylinder is pushed into the spray gun 518.

[0037] In one example, when the hydraulic piston has reached its stroke limit, a Hall effect sensor can signal the controller, activating a set of MOSFETs and trigger integrated circuits (not shown in Figure 3). This causes the solenoid 506 to slide the valve spool to its second position. Thus, the rod port 510 is a pressure port connected to the hydraulic pump 504, while the head port is connected to the hydraulic reservoir 502. When hydraulic fluid is introduced into the rod port 510, the pressure within the hydraulic cylinder 512 forces the hydraulic piston upward through the cylinder, and the hydraulic fluid is expelled from the head port and returned to the hydraulic reservoir 502. Furthermore, the paint piston also moves upward through the paint cylinder 514, and paint from the paint reservoir 516 can be drawn into the paint cylinder 517.

[0038] In another example, solenoid 506 is controlled by an integrated software controller (not shown in Figure 3) that is communicatively coupled to solenoid 506. The integrated software controller is useful for locating the position of the piston, which is detectable before the pump assembly starts.

[0039] Figure 3B This is a diagram illustrating an example of a hydraulic circuit. Figure 3B Similar to Figure 3A And similar parts are numbered similarly. However, in Figure 3B In the middle, the rod end side of cylinder 512 has direct pump pressure. Additionally, as shown in Figure 2, Figure 3B As shown, solenoid 506 includes a two-way valve that alternately transmits pump pressure to the head side of cylinder 512.

[0040] During the downward stroke (e.g., when solenoid 506 is in the open position), both the rod and head sides of cylinder 512 are pressurized, and piston 513 moves downward because the annual area on the head side is larger than that on the rod side. During the retraction stroke (e.g., when solenoid 506 is in the closed position), pump pressure is present only on the rod side, while the head side returns to the reservoir and is at low pressure. In one example, the difference in annual area between the head side and the rod side of piston 513 is approximately a 2:1 ratio. This results in equal extension and retraction forces. Maintaining equal extension and retraction forces is important for keeping the fluid pressure equal during the extension and retraction strokes to maintain a consistent spray pattern.

[0041] Figure 4A This is a perspective view of sensor 400 (e.g., minimum sensor 204 and maximum sensor 206). Sensor 400 includes a potting body 402 that protects the electronic components (e.g., circuitry 404) therein. Potting body 402 may include different types of fasteners 406 to allow sensor 400 to be mounted to a surface (e.g., the inner surface of a pump housing, as shown in...). Figure 2B As shown in the image). Figure 4B This is a cross-sectional view showing an example of sensor 400. Circuitry 404 can be seen in this view. Circuitry 404 may include a Hall effect sensor, a magnet, communication circuitry, signal conditioning circuitry, etc.

[0042] Figure 4C It shows from Figure 4A and Figure 4BA circuit diagram of an example of circuit 404 is provided. Circuit 450 is powered by power supply 452 and grounded by ground wire 454. Power supply 452 and ground wire 454 are functionally coupled to Hall effect sensor 456. Hall effect sensor 456 may include a transducer and a magnet. The transducer measures the electromagnetic field generated by the magnet. When a ferrous metal is brought very close to the magnet, the magnetic field changes and is measured. Circuit 450 may optionally include microcontroller 458. Microcontroller 458 may modify or process the signal generated by Hall effect sensor 456 in some way before it is sent to comparator 460. Comparator 460 compares two voltages and generates an output voltage (typically in digital form).

[0043] Circuit 450 generates an output at output 462, which can be read by another computing system. For example, output 462 is used by pump controller 140 to determine whether the pump piston is in its maximum or minimum position (depending on which sensor generated the output). Based on output 462, controller 140 can actuate the solenoid to the opposite position. Output 462 may include some form of communication circuitry (e.g., wireless or wired communication components).

[0044] Figure 5 This is a block diagram illustrating one example of a liquid distribution system. The fluid distribution system 800 can be used, for example, to distribute paint or other exemplary fluids, such as primers, coatings, multi-component fluids, etc. System 800 may include a fluid source 810 operatively coupled to a pump 820 within the fluid distribution system 800. Pump 820 is operatively coupled to a pump controller 830. Pump 820 may be configured to pressurize or otherwise deliver fluid from fluid source 810 to outlet 802. In one example, controller 830 may be configured to provide an output 804. In one example, output 804 includes storing detected parameters related to the operation of pump 820 in the memory of controller 830. In another example, output 804 includes transmitting the detected parameters to a separate unit, such as downloading the detected parameter information to a separate computing unit. In yet another example, output 804 includes audio or visual output, such as an audible alarm or visual indication, such as a separate display unit. In some examples, the fluid distribution system 800 includes additional features 840 integrated into the delivery of fluid from a fluid source 810 to an outlet 802. For example, in an example where fluid is delivered at a set temperature, the additional feature 840 includes a heater. Additionally, in some examples, fluid can be transferred a long distance from a pump 820 to an outlet 802. In such examples, the additional feature 840 may include a conveying mechanism.

[0045] Figure 6This is a block diagram illustrating an example of a pump control system. Pump 910 includes a fluid section piston 912 coupled to a hydraulic piston 914. The movement of the hydraulic piston 914 is limited by one or more switching mechanisms 918. The switching mechanism 918 may include, for example, a Hall effect sensor. However, other switching mechanisms 918 may also be used. For example, an integrated software controller 920 may be configured to control a solenoid. Pump 910 may also include one or more limit sensors 916. Limit sensors 916 can set stroke limits for the fluid section piston 912. Fluid section piston 912 may also include a magnet 913. The magnet 913 can induce a current when passing through an induction coil 915, which can charge or power the limit sensors 916. Pump 910 may also include other components 928.

[0046] Illustratively, controller 920 is configured to operatively control and monitor pump 910. Controller 920 may include an induced current detector 922 configured to detect the position of fluid section piston 912 prior to operation of pump 910. Induced current detector 922 may receive a signal indicating a detected current correlated with magnet 913 passing through induction coil 915. Controller 920 also includes a position calculator 921 configured to calculate the real-time position of piston 912 based on the integral / derivative of a calculated velocity (e.g., as shown in the figure). Figure 8B (As shown) and known stroke limits. The controller 920 also includes a communication component 925 configured to communicate the detected induced current, piston speed, and calculated position to a remote device 941. The controller 920 may also include other functions 924.

[0047] During normal operating cycles, controller 920 can control the movement of the fluid section piston 912 within the cylinder. For example, as the fluid section piston 912 moves toward the end of its stroke, limit sensor 916 can send an indication to detector 922, causing the controller to switch the direction of piston movement, for example, using switching mechanism 918. Switching mechanism 918 may include a solenoid coupled to the controller. In another example, switching mechanism 918 includes a solenoid coupled to a MOSFET and trigger integrated circuit system.

[0048] The limiting sensor 916 described above, with reference to other figures, includes a Hall effect sensor. In another example, the limiting sensor 916 includes a mechanical sensor. In another example, the limiting sensor 916 includes a base active transducer sensor. In another example, the limiting sensor 916 includes an eddy current sensor. In another example, the limiting sensor 916 includes an inductive position sensor. In another example, the limiting sensor 916 includes a proximity sensor. However, other suitable limiting sensors 916 have also been contemplated. For example, in one example, the limiting sensor 916 includes anisotropic magnetoresistive (AMR). In another example, the limiting sensor 916 includes a giant magnetoresistive (GRM) magnetic sensor.

[0049] Traditionally, power is supplied to sensor 916, and communication between sensor 916 and controller 920 is accomplished via a wired connection. With the advent of wireless communication, the ability to send wireless signals between controller 920 and sensor 916 has become much easier. However, a wireless charging mechanism is still needed to eliminate the wired connection. To reduce the risk of system damage, completely removing the wired connection may be desirable. Power can be supplied to sensor 916 by a magnet 913 passing through induction coil 915 and inducing current. In one example, induction coil 915 comprises copper wire. However, other suitable materials have also been envisioned.

[0050] In one example, controller 920 may be coupled to memory 930. Memory 930 is schematically shown as part of pump system 900. However, in another example, at least some portions of memory 930 are stored remotely from pump system 900. For example, a start sequence 932 may be stored in an integrated memory coupled to controller 920, allowing controller 920 to read sequence 932 and engage pump 910. Additionally, real-time piston data 936 may be transferred by controller 920 to onboard memory 930 and / or remote device memory 943. Current operating information 938 may be downloaded and compared with historical piston data 936 to track operating parameters related to the operation of pump 910 over time. Onboard memory 930 may also include diagnostic thresholds for detecting and identifying operational problems of the pump system. Figure 8B As shown, abnormal piston behavior may include irregular speed patterns, as well as the detection of abnormal speeds—for example, traveling too fast during the downward stroke or too slow during the upward stroke. Memory 930 may also include other functions 942.

[0051] Pump system 900 can communicate with remote device 941, which may include user interface 940, computing unit 950, memory 943, and other functions. Remote device 941 may include a display associated with pump system 900 or the remote device, such as motion controls that communicate with controller 920 via communication component 925. User interface 940 allows an operator to interact with controller 920. User interface 940 may include input / output mechanisms, such as a set of buttons, keys, etc. Remote device 941 may also include a separate computing unit 950.

[0052] The pump system 900 may also include other functions 960, such as a heating mechanism to heat the fluid before it is delivered to the outlet, or a conveying mechanism configured to deliver pressurized fluid to the outlet.

[0053] Figure 7 It is a flowchart that shows an example operation of the pump control system.

[0054] In block 710, the pump system is engaged. The pump system may include starting an associated motor (e.g., motor 136), priming operations, and / or other appropriate start-up operations.

[0055] In block 720, the piston position is located within the operating stroke cycle. Knowing the piston position, the controller can begin a regular operating cycle from the current position without having to estimate the position. Furthermore, once the piston is positioned, knowing the stroke limits 722 allows the controller to determine the real-time piston position throughout the entire operating cycle. Other information 724 can also be detected at startup, such as the charging status of the limit sensors.

[0056] In block 730, the operating cycle begins. Operation of the pump system can provide a power source for the limit sensor, for example, when a magnet coupled to the fluid piston passes through the induction coil and induces a current, this current will directly or indirectly charge the sensor (e.g., charge a battery coupled to the sensor), as indicated in block 732. Another example of charging a battery could be a thermoelectric cooler (e.g., a Peltier cooler), which can use heat generated by the hydraulic system to charge the sensor. As shown in block 734, the operating cycle may also include wireless control of the limit sensor by a controller. The start of the operating cycle may also include detecting and tracking the piston speed, as shown in block 736, based on the detected induced current. Using the piston speed profile, the real-time position of the piston can be derived, as shown in block 738.

[0057] In block 740, data regarding the operation cycle is communicated. Communication of the operation cycle data may include storing the data in on-board memory 742 or sending it to a remote device 744. In one example, the data is communicated wirelessly 746. Other information may also be communicated and stored.

[0058] The data communicated may include the real-time piston position throughout the operation, as indicated in block 752. Furthermore, as indicated in block 754, the real-time piston speed may be communicated, either in conjunction with or as a substitute for the detected induced current. Diagnostic information may also be transmitted, for example, when abnormal behavior is detected, as shown in block 756.

[0059] While various examples based on inductive charging have been described, other self-charging systems are also envisioned. For example, in one example, the system's hydraulic components generate heat, which is converted back into electrical energy using a thermoelectric generator, and this electrical energy then charges the sensor's battery.

[0060] Figure 8A This is a close-up image illustrating an example of a self-charging sensor. In one example, the pump system may have the sensor system 800 at the coupling between the hydraulic piston 800 and the fluid piston 820. A magnet 822 is attached to the fluid piston 820 in a recess 824. In one example, the magnet 822 has a smaller diameter than the fluid piston. The system described herein may allow the use of even more smaller magnets.

[0061] Magnet 822 is configured to generate a magnetic field 826, which induces a current as piston 820 passes through induction coil 832. The generated current can be used to charge sensor 830. In one example, sensor 830 is a Hall effect sensor. In another example, sensor 830 is a giant magnetoresistive (GMR) sensor. Sensor 830 can be initially powered by battery 834 while being continuously charged, the continuous charging being provided throughout operation by magnet 822 passing through induction coil 832 during each stroke.

[0062] System 800 also includes a communication module 836. In one example, communication module 836 is a wireless communication module with a computer processing unit (CPU). In one example, communication module 836 can be configured to communicate directly with the pump controller. In another example, communication module 836 is configured to communicate directly with a remote device. For example, a user can receive reports on the health status of the pump via a mobile application or other display.

[0063] Figure 8BThis is a graph showing an example of a sample output of the induced current and piston speed over time according to an embodiment of the present invention. As shown, output 850 is a line graph of the induced current 856 and the piston speed 858 over time. As shown, the speed is proportional to the induced current. Calculating the integral of the speed curve 858, and combining it with the known stroke limits, allows for instantaneous calculation of the piston position.

[0064] Output 850 is also useful for detecting potential problems in pump operation. A mechanism to detect pump problems before potential failure occurs prevents damage to the pump or components. Additionally, in cases where the pump is part of a multi-component system, it is important to detect when the pump is moving faster or slower than expected to maintain an ideal ratio between the two components. As shown by output 850, normal piston behavior 860 can be clearly identified from abnormal piston behavior 870. In one example, the controller is configured to detect changes between normal and abnormal behavior and generate an alarm. The alarm can be a visual alarm (e.g., displayed on a display of a system, mobile device, etc.), an audio alarm (e.g., a bell), a physical alarm (e.g., vibration), or other suitable alarm.

[0065] Various examples of this disclosure have been described for illustrative purposes, but these descriptions are not intended to be exhaustive or limited to the disclosed examples. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described examples. The terminology chosen herein is for the purpose of explaining the principles of the examples, their practical application, or improvements to existing technologies on the market, or to enable those skilled in the art to understand the examples disclosed herein.

Claims

1. A liquid delivery system, comprising: Hydraulic fluid source; A hydraulic cylinder fluidly coupled to the hydraulic fluid source and having a hydraulic piston capable of moving between a first limit position and a second limit position; A rod, which is connected to the hydraulic piston and extends into the hydraulic cylinder; A liquid cylinder, comprising a liquid piston operably driven by the rod to pump liquid along a flow path to a fluid applicator. A housing assembly is disposed between the hydraulic cylinder and the liquid cylinder, the housing assembly having a wall defining an opening; A removable cover, configured to attach to the wall and cover the opening; A collar assembly having a sleeve and a collar, wherein the collar assembly is disposed within the housing assembly, and the liquid piston is coupled to the rod by the collar, the collar comprising ferrous metal; and A sensor device, integrally disposed within the housing assembly on the inner side of the wall and outside the hydraulic cylinder, includes a package that seals a magnet within it and is configured to sense the position of the ferrous metal collar and generate a signal indicating the sensed position of the ferrous metal collar. The sensor device is configured to detect the position of the hydraulic piston based on the position of the ferrous metal collar. The removable cover is configured to be moved to access the sensor device through the opening; and The hydraulic piston includes a piston head, and the annular area between the piston head and the rod is substantially in a 2:1 ratio.

2. The liquid delivery system according to claim 1, wherein, in, The sensor device includes an encapsulated sensor body that houses the Hall effect sensor and a magnet.

3. The liquid delivery system according to claim 1, wherein, The sensor device includes a first sensor device configured to generate a first signal indicating that the hydraulic piston has reached the first limit position, and the sensor device further includes a second sensor device located outside the cylinder and configured to generate a second signal indicating that the hydraulic piston has reached the second limit position.

4. The liquid delivery system according to claim 3, further comprising: Solenoid valve, which sends hydraulic fluid to and receives hydraulic fluid from the hydraulic cylinder; as well as A controller configured to control the solenoid valve based on the first signal and the second signal.

5. The liquid delivery system according to claim 1, wherein, The sensor device includes a wireless communication component configured to wirelessly transmit signal indications.

6. The liquid delivery system according to claim 5, wherein, The sensor device is coupled to a battery power source.

7. The liquid delivery system of claim 6 further includes an induction coil disposed along at least a portion of the rod, the induction coil being configured to charge the battery power source.

8. The liquid delivery system according to claim 2, wherein, The liquid includes paint.

9. A paint conveying system, comprising: Piston pump assembly, the piston pump assembly comprising: Hydraulic fluid source; A hydraulic cylinder coupled to the hydraulic fluid source and having a hydraulic piston capable of moving between a first limit position and a second limit position, the hydraulic piston including a piston head; A rod, which is connected to the piston head and extends out of the hydraulic cylinder, wherein the annular area between the piston head and the rod is substantially in a 2:1 ratio; A solenoid valve that sends fluid to and receives fluid from the piston pump assembly; A housing assembly is connected to the hydraulic cylinder, the hydraulic cylinder including a wall having an outer side and an inner side; A collar assembly having a sleeve and a collar, wherein the collar assembly is disposed within the housing assembly, and wherein the collar comprises a ferrous metal material; A paint pump, which is coupled to the piston by the collar to move paint from the paint reservoir to the paint applicator; A first sensor device, integrally disposed within the housing assembly on the inner side of the wall of the housing assembly and outside the hydraulic cylinder, is configured to sense the ferrous metal collar and generate a first signal indicating that the hydraulic piston has reached a first limit position. A second sensor device is integrally disposed within the housing assembly on the inner side of the wall of the housing assembly and outside the hydraulic cylinder. The second sensor device is configured to sense the ferrous metal collar and generate a second signal indicating that the hydraulic piston has reached a second limit position. The first sensor device includes a package, and a magnet is sealed inside the package; and The second sensor device includes an encapsulation in which a magnet is sealed.

10. The paint delivery system of claim 9, further comprising a controller configured to receive the first signal and control the solenoid valve based on the first signal.

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