Differential pressure sensor for dynamic high-pressure hydraulic system

Abstract

Examples of a differential pressure sensor designed to operate with a dynamic high pressure hydraulic system are described herein. The sensor has a one-piece sensor housing that is sufficiently durable to withstand strong fluid pressures and associated stresses. Additionally, the sensor uses foil (rather than, for example, piezoelectric) strain gauges, enabling pressure measurements even under unique stresses exerted by the dynamic high pressure hydraulic system. Further, the sensor tube of the sensor helps isolate the strain gauge from some of the arcuate flexural / flexural stresses that the body of the sensor may experience due to strong fluid pressure.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of U.S. Provisional Patent Application No. 63 / 540,198, filed on September 25, 2023, entitled “Differential Pressure Sensors for Dynamic, High Pressure, Hydraulic Systems,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates generally to differential pressure sensors and, more particularly, to differential pressure sensors for dynamic high pressure hydraulic systems. Background Art

[0004] A pressure sensor measures the pressure of a fluid (e.g., air, gas, liquid, etc.). A differential pressure sensor measures the difference between the pressures of two fluids. Such sensors can be used in hydraulic systems to measure hydraulic pressure.

[0005] By comparing such a system with the present disclosure set forth in the remainder of this application with reference to the accompanying drawings, the limitations and disadvantages of conventional and traditional methods will become clear to those skilled in the art. Summary of the invention

[0006] The present disclosure is directed to a differential pressure sensor for a dynamic high pressure hydraulic system, substantially as illustrated in and / or as described in connection with at least one of the accompanying drawings and as more fully set forth in the claims.

[0007] These and other advantages, aspects and novel features of the present disclosure, as well as details of illustrated examples of the disclosure, will be more fully understood from the following description and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 An example hydraulic system according to aspects of the present disclosure is shown.

[0009] Figure 2 It is shown that according to various aspects of the present disclosure, Figure 1 A perspective view of an example differential pressure sensor used in an example hydraulic system.

[0010] Figure 3 The present invention shows various aspects of the present disclosure. Figure 2 A perspective view of the sensor cover of a differential pressure sensor.

[0011] Figures 4a to 4i The present invention shows various aspects of the present disclosure. Figure 2Different views of the sensor housing of a differential pressure sensor.

[0012] Figure 5a to Figure 5d It is shown that according to various aspects of the present disclosure, Figure 2 Different views of an example first alternative sensor housing for use in a differential pressure sensor.

[0013] Figures 6a to 6c It is shown that according to various aspects of the present disclosure, Figure 2 Different views of an example second alternative sensor housing for use in a differential pressure sensor.

[0014] Figures 7a to 7c It is shown that according to various aspects of the present disclosure, Figure 2 Different views of an example third alternative sensor housing for use in a differential pressure sensor.

[0015] Figures 8a to 8c It is shown that according to various aspects of the present disclosure, Figure 2 Different views of an example fourth alternative sensor housing for use in a differential pressure sensor.

[0016] Figure 9a to Figure 9b It is shown that according to various aspects of the present disclosure, Figure 2 An example sensor circuit used in a differential pressure sensor.

[0017] Fig.10 It shows that various aspects of the present disclosure can be used with Figure 2 A perspective view of an example adapter for use with a differential pressure sensor.

[0018] Figures 11a to 11e Attachment to the Figures 4a to 4f The sensor housing Fig.10 Different views of the adapter.

[0019] Fig.12 Attachment to the Fig.10 Sensor cover Figure 2 A perspective view of a differential pressure sensor.

[0020] Figure 13a to Figure 13b It is shown that according to various aspects of the present disclosure, Figure 2 A cross-sectional view of a fifth alternative sensor housing for use in a differential pressure sensor.

[0021] Fig.14 It is shown that according to various aspects of the present disclosure, Figure 1 Examples of alternative differential pressure sensors and alternative adapters for use in an example hydraulic system.

[0022] Fig.15 The present invention shows various aspects of the present disclosure. Fig.14 Examples of alternative covers for alternative differential pressure sensors.

[0023] Figures 16a to 16d The present invention shows various aspects of the present disclosure. Fig.14 Different views of an alternative adapter are shown in FIG.

[0024] Figures 17a to 17d It is shown that according to various aspects of the present disclosure, Fig.14 Different views of an example sixth alternative sensor housing for use in an example alternative differential pressure sensor.

[0025] Fig.18 It is shown that according to various aspects of the present disclosure, Fig.14 An example alternative sensor circuit for use in an example alternative differential pressure sensor.

[0026] The drawings are not necessarily drawn to scale. Where appropriate, the same or similar reference numbers are used in the drawings to refer to similar or identical elements. For example, reference numbers using letters (e.g., diaphragm 424a, diaphragm 424b) refer to instances of the same reference number without those letters (e.g., diaphragm 424). DETAILED DESCRIPTION

[0027] Some examples of the present disclosure relate to differential pressure sensors for use in dynamic high-pressure hydraulic systems. Dynamic high-pressure hydraulic systems may generate a large amount of heat and pressure during normal operation, and may even experience higher pressure peaks at certain points in time. Such heat and pressure may subject components of the hydraulic system to significant stress and / or fatigue, which may cause component failure if the components are not properly designed to withstand these stresses.

[0028] The differential pressure sensors disclosed herein are specifically designed to withstand the higher heat, pressure, stress, and / or fatigue of dynamic high-pressure hydraulic systems. For example, the disclosed differential pressure sensors have a one-piece metal sensor housing that is durable enough to withstand intense fluid pressures and associated stresses. As another example, the disclosed differential pressure sensors use foil strain gauges that can withstand intense stresses, rather than, for example, piezoelectric elements that may be more fragile. In addition, the disclosed differential pressure sensors include sensor tubes that help isolate the diaphragm and strain gauges from some of the bow flexure / bending stresses that the body of the sensor may experience due to intense fluid pressures.

[0029] Some examples of the present disclosure relate to a differential pressure sensor, the differential pressure sensor comprising: a sensor housing, the sensor housing including a first input port and a second input port; a first sensor tube, the first sensor tube connected to the sensor housing at a first tube housing end, the first sensor tube extending from the first tube housing end to a first conduit end isolated from the sensor housing; a second sensor tube, the second sensor tube connected to the sensor housing at a second tube housing end, the second sensor tube extending from the second tube housing end to a second conduit end isolated from the sensor housing; a first fluid conduit extending from the first input port through the sensor housing and the first sensor tube to the first conduit end, the first sensor tube being configured to undergo a first deflection in response to a first fluid pressure within the first fluid conduit; and a second fluid conduit extending from the second fluid conduit to the first conduit end. Two input ports extend through the sensor housing and the second sensor tube to the end of the second tube, the second sensor tube is configured to experience a second deflection in response to a second fluid pressure in the second fluid tube; a first circuit element, the first circuit element is bonded and adhered to the first sensor tube, the first circuit element has a first electrical characteristic that depends on the first deflection of the first sensor tube; a second circuit element, the second circuit element is bonded and adhered to the second sensor tube, the second circuit element has a second electrical characteristic that depends on the second deflection of the second sensor tube; and a sensing circuit, the sensing circuit is electrically connected to the first circuit element and the second circuit element, the sensing circuit is configured to determine a pressure difference between a first fluid pressure in the first fluid conduit and a second fluid pressure in the second fluid conduit based on the first electrical characteristic of the first circuit element and the second electrical characteristic of the second circuit element.

[0030] In some examples, the sensor housing further includes a first housing end and a second housing end opposite the first housing end, the first housing end including a first input port and a second input port, the second housing connected to the first sensor tube or the second sensor tube at the first tube housing end or the second tube housing end. In some examples, the first sensor tube or the second sensor tube is recessed within the sensor housing such that the sensor housing surrounds the first sensor tube or the second sensor tube. In some examples, the sensor housing is constructed of a metal material.

[0031] In some examples, the sensor housing further includes: a first groove surrounding a first portion of the first sensor tube so that the first portion of the first sensor tube is isolated from the sensor housing; and a second groove surrounding a second portion of the second sensor tube so that the second portion of the second sensor tube is isolated from the sensor housing. In some examples, the first circuit element includes a first resistor, the second circuit element includes a second resistor, the first electrical characteristic includes a first resistance, and the second electrical characteristic includes a second resistance. In some examples, the first circuit element includes a first strain gauge, and the second circuit element includes a second strain gauge.

[0032] In some examples, the first strain gauge and the second strain gauge are formed of foil. In some examples, the sensor housing, the first sensor tube, and the second sensor tube include a single continuously machined metal piece. In some examples, the first sensor tube includes a first sensor tube inner wall within the first fluid conduit and a first sensor outer tube portion outside the first fluid conduit, the second sensor tube includes a second sensor inner tube portion within the second fluid conduit and a second sensor outer tube portion outside the first fluid conduit, the first circuit element is coupled to the first sensor outer tube portion, and the second circuit element is coupled to the second sensor outer tube portion.

[0033] Some examples of the present disclosure relate to a hydraulic system, including: a hydraulic device, the hydraulic device including a device housing, the device housing enclosing a first fluid volume and a second fluid volume separated from each other; and a differential pressure sensor, the differential pressure sensor including: a sensor housing, the sensor housing being formed of a metal material, the sensor housing including a first input port in fluid communication with the first fluid volume and a second input port in fluid communication with the second fluid volume; a first sensor tube, the first sensor tube being connected to the sensor housing at a first tube housing end, the first sensor tube extending from the first tube housing end to a first conduit end isolated from the sensor housing; a second sensor tube, the second sensor tube being connected to the sensor housing at a second tube housing end, the second sensor tube extending from the second tube housing end to a second conduit end isolated from the sensor housing; a first fluid conduit extending from the first input port through the sensor housing and the first sensor tube to the first conduit end, the first sensor tube The sensor tube is configured to experience a first deflection in response to a first fluid pressure within the first fluid conduit; a second fluid conduit extending from the second input port through the sensor housing and the second sensor tube to the second conduit end, the second sensor tube being configured to experience a second deflection in response to a second fluid pressure within the second fluid conduit; a first circuit element coupled to the first sensor tube, the first circuit element having a first electrical characteristic that depends on the first deflection of the first sensor tube; a second circuit element coupled to the second sensor tube, the second circuit element having a second electrical characteristic that depends on the second deflection of the second sensor tube; and a sensing circuit electrically connected to the first circuit element and the second circuit element, the sensing circuit being configured to determine a pressure difference between a fluid in a first fluid volume of the hydraulic device and a fluid in a second fluid volume of the hydraulic device based on the first electrical characteristic of the first circuit element and the second electrical characteristic of the second circuit element.

[0034] In some examples, the sensor housing further includes a first housing end and a second housing end opposite the first housing end, the first housing end including a first input port and a second input port, the second housing connected to the first sensor tube or the second sensor tube at the first tube housing end or the second tube housing end. In some examples, the first sensor tube or the second sensor tube is recessed within the sensor housing such that the sensor housing surrounds the first sensor tube or the second sensor tube. In some examples, the sensor housing is constructed of a metal material.

[0035] In some examples, the sensor housing further includes: a first groove surrounding a first portion of the first sensor tube so that the first portion of the first sensor tube is isolated from the sensor housing; and a second groove surrounding a second portion of the second sensor tube so that the second portion of the second sensor tube is isolated from the sensor housing. In some examples, the first circuit element includes a first resistor, the second circuit element includes a second resistor, the first electrical characteristic includes a first resistance, and the second electrical characteristic includes a second resistance. In some examples, the first circuit element includes a first strain gauge, and the second circuit element includes a second strain gauge.

[0036] In some examples, the first strain gauge and the second strain gauge are formed of foil. In some examples, the sensor housing, the first sensor tube, and the second sensor tube comprise a single continuously machined metal piece. In some examples, the first sensor tube comprises a first sensor inner tube portion within the first fluid conduit and a first sensor outer tube portion outside the first fluid conduit, the second sensor tube comprises a second sensor inner tube portion within the second fluid conduit and a second sensor outer tube portion outside the second fluid conduit, the first circuit element is coupled to the first sensor outer tube portion, and the second circuit element is coupled to the second sensor outer tube portion.

[0037] Figure 1 An example of a hydraulic system 100 is shown. Figure 1 In some examples, the hydraulic system 100 includes a hydraulic actuator 102 and a hydraulic fluid supply 104 in fluid communication with the hydraulic actuator 102. In some examples, the hydraulic fluid supply 104 may include one or more hydraulic pumps and / or fluid tanks configured to circulate hydraulic fluid through the hydraulic actuator 102 of the hydraulic system 100.

[0038] exist Figure 1 In the example of , the hydraulic actuator 102 includes an actuator housing 106. A hydraulic piston 108 is disposed within the actuator housing 106. A piston seal 110 of the hydraulic piston 108 forms an enclosure within the actuator housing 106 at the end of the hydraulic piston 108.

[0039] As shown, the piston seal 108 divides the interior volume of the actuator housing 106 into two sections 112. The hydraulic fluid pressure within the interior volume of the actuator housing 106 can act on the piston seal 110, thereby moving (e.g., moving back and forth) the hydraulic piston 108. More specifically, the pressure differential across the piston seal 110 (and / or the pressure differential between section 112a and section 112b) can move the hydraulic piston 108.

[0040] Thus, for example, if the hydraulic pressure in the interior volume of the first section 112a of the actuator housing 106 is greater or less than the hydraulic pressure in the second section 112b of the actuator housing 106, the hydraulic pressure difference may move the piston 108. On the other hand, if the hydraulic pressure in the first section 112a is equal to the hydraulic pressure in the second section 112b, the piston 108 may remain stationary.

[0041] exist Figure 1 In the example of FIG. 1 , the actuator housing 106 includes a fluid port 114 in fluid communication with the interior volume section 112 of the actuator housing 106. The fluid port 114 is in turn shown in fluid communication with the manifold 150 via a fluid line 118. The fluid line inside the manifold 150 is connected to the differential pressure sensor 200, thereby placing the differential pressure sensor 200 in fluid communication with the interior volume section 112 of the actuator housing 106.

[0042] The differential pressure sensor 200 is connected to the manifold fastener 250 (see, e.g. Figure 2 ) is fixed to the manifold 150. Figure 1 In some examples, the differential pressure sensor 200 is electrically connected to the actuator controller 120 of the hydraulic actuator 102. In some examples, the differential pressure sensor 200 can output one or more electrical signals that represent the pressure difference between the internal volume sections 112 of the hydraulic actuator 102. In some examples, the actuator controller 120 can use the signal from the differential pressure sensor 200 (and / or the pressure difference measured by the differential pressure sensor 200) to control the hydraulic actuator 102 (and / or other parts of the hydraulic system 100).

[0043] Although it is theoretically possible to use two separate pressure sensors and connecting circuitry in place of the differential pressure sensor 200, there are many advantages to using the differential pressure sensor 200 instead of two separate pressure sensors. For example, the differential pressure sensor 200 is generally smaller and more compact than two separate pressure sensors and connecting circuitry. In addition, the differential pressure sensor 200 does not need to be as sensitive and / or responsive as the separate pressure sensors (e.g., because the differential pressure sensor 200 only measures the pressure differential and not the actual pressure). Furthermore, many legacy (e.g., hydraulic) systems have historically used differential pressure sensors, and continuing to use the differential pressure sensor 200 in the system is much simpler, more cost-effective, and / or more efficient than modifying or retrofitting the system to work with separate pressure sensors.

[0044] Although in Figure 1 100 is shown as including a hydraulic actuator 102 in the example of , but in some examples, the hydraulic system 100 may include one or more additional and / or alternative hydraulic devices. In some examples, the hydraulic system 100 may be part of a larger system for testing various structures and / or machines (e.g., buildings, bridges, airplanes, trains, automobiles, ships, turbines, oil rigs, etc.). For example, the hydraulic system 100 may be used to test the reliability, durability, flexibility, balance, strength, and / or other aspects of various structures and / or machines. In doing so, the hydraulic actuator 102 and / or the differential pressure sensor 200 may be subjected to dynamic hydraulic pressures of up to 5,000 pounds per square inch (psi), with possible pressure peaks of up to 15,000 psi.

[0045] Figure 2 An enlarged perspective view of an example differential pressure sensor 200 is shown. Figure 2 In the example of FIG. 1 , the differential pressure sensor 200 includes a sensor cover 300 attached to the top of a sensor housing 400, thereby enclosing a sensing circuit 900 (discussed further below with reference to FIG. 9 ) between the sensor cover 300 and the sensor housing 400. As shown, the sensor cover 300 is attached to the sensor housing 400 using a cover fastener 202 that passes through aligned cover fastener holes 302 / 402 in the sensor cover 300 and the sensor housing 400 (see also, for example, FIG. 1 ). Figure 3 and Figure 4a ) is inserted. Manifold fastener 250 is shown extending through sensor cover 300 and sensor housing 400 for fastening differential pressure sensor 200 to manifold 150. Sensor cover 300 further includes manifold fastener passage 350 (e.g., sealed from the interior of sensor cover 300) through which manifold fastener 250 can be inserted into sensor housing 400 and / or manifold 150.

[0046] exist Figure 24, the sensor cover 300 further includes a sensor input / output (I / O) connector 304. Although not clearly visible due to the perspective of the drawing, the sensor I / O connector 304 includes a number of conductive pins, and the sensor I / O connector 304 can be electrically connected to other devices (e.g., actuator controller 120) through these conductive pins. In some examples, the differential pressure sensor 200 can output a signal representing the measured pressure difference via the sensing I / O connector 304 (e.g., its pins). In some examples, the differential pressure sensor 200 can receive power (e.g., for powering its circuit system) via the sensing I / O connector 304 (e.g., its pins).

[0047] Figures 4a to 4f An example view of the sensor housing 400 of the differential pressure sensor 200 is shown with the sensor cover 300 and the manifold fastener 250 removed. As shown, the sensor housing 400 includes a cubic body 404 having a front wall 406, a rear wall 408, a top wall 410, a bottom wall 412, and side walls 414. The manifold fastener conduit 450 extends from the top wall 410 through the sensor housing 400 to the bottom wall 412 (see, e.g., Fig.11c and Fig.11e ).

[0048] exist Figure 4c and Figure 4e to Figure 4f In the example of FIG. 4 , the bottom wall 412 of the sensor housing 400 has two circular input ports 416. In some examples, one or more input ports 416 may alternatively or additionally be positioned in, on, and / or at the front wall 406, the rear wall 408, and / or the side walls 414. As shown, the input ports 416 lead to fluid conduits 418 that extend through the sensor housing 400 from the bottom wall 412 to the top wall 410. As shown, each fluid conduit 418 is generally cylindrical (e.g., where all points on the wall of the fluid conduit 418 are equidistant from the central axis of the fluid conduit 418 along a plane generally perpendicular to the central axis of the fluid conduit 418, within 5% of the mean, mode, or average distance from the central axis along the perpendicular plane).

[0049] In some examples, when the differential pressure sensor 200 is in Figure 1 When used in the hydraulic system 100 shown in FIG. 1 , each input port 416 of the sensor housing 400 can be connected to a different fluid line 118 within the manifold 150. Thus, when the differential pressure sensor 200 is in Figure 1 When used in the hydraulic system 100 shown in FIG. 1 , each input port 416 and / or fluid conduit 418 of the sensor housing 400 may be in fluid communication with a different interior volume section 112 of the actuator housing 106 .

[0050] exist Figure 4c and Figure 4e In the example of the embodiment of the present invention, each input port 416 includes an annular groove in which an O-ring 420 is mounted. In some examples, the O-ring 420 can be used to seal the input port 416 and / or the fluid conduit 418 when connected to the manifold 150. In examples where one or more input ports 416 can be alternatively or additionally disposed in, on, and / or at the front wall 406, rear wall 408, and / or side wall 414, a threaded fitting connection can be alternatively or additionally used. In examples where two input ports 416 lead to and / or are connected to the same fluid conduit 418, a port seal can be used to seal and isolate one of the input ports 416 when it is not in use.

[0051] exist Figure 4e to Figure 4f In the example of FIG. 4 , the fluid conduit 418 extends through the sensor housing 400 into two generally cylindrical sensor tubes 422 that are connected to the top wall 410 of the sensor housing 400. In some examples, the cylindrical shape of the sensor tubes 422 may be more durable than a polygonal shape because the cylindrical shape has a reduced number of sides and / or corners that may rupture under pressure. Additionally, polygons (and / or square holes) may be more difficult and / or expensive to machine.

[0052] As shown, each sensor tube 422 extends generally perpendicular to (e.g., within 5 degrees of 90 degrees) the top wall 410, with two sensor tubes 422 extending generally parallel to each other (e.g., within 5 degrees of 0 / 180 degrees). The height (e.g., on the y-axis) of each sensor tube 422 (e.g., starting at the top wall 410) is shown to be approximately one-third (e.g., within 5% of) the height (e.g., on the y-axis) of the body 404 of the sensor housing 400. Each sensor tube 422 (and / or fluid conduit 418) is shown to terminate at a sensor diaphragm 424.

[0053] exist Figures 4a to 4fIn the example of FIG. 4 , each sensor diaphragm 424 closes an end of a sensor tube 422 (and / or fluid conduit 418). As shown, each sensor diaphragm 424 is generally circular (e.g., wherein all points on the periphery of the diaphragm 424 are equidistant from a center point, within 5% of a mean, mode, or average distance from the center point). Each sensor diaphragm 424 is further shown to have a width (e.g., in the y-direction) that is approximately as thick as the width of the sidewall of the sensor tube 422 to which the diaphragm is attached. In some examples, the relatively thin width of the diaphragm 424 allows the fluid pressure of the hydraulic fluid in the fluid conduit 418 to push the diaphragm 424 (e.g., a middle portion thereof) to deflect, expand, deform, and / or bend outward (e.g., in the y-direction).

[0054] exist Figure 4a and Figure 4d In the example of FIG. 4 , the differential pressure sensor 200 further includes a strain gauge 426 attached, fastened, adhered and / or otherwise coupled to the diaphragm 424. Figure 4d As shown, four strain gauges 426 are shown bonded to each diaphragm 424. Each strain gauge 426 is shown bonded to an outer surface of the diaphragm 424, which is outside the fluid conduit 418 and / or the sensor tube 422 and opposite the inner surface of the diaphragm 424 disposed inside the fluid conduit 418 and / or the sensor tube 422. In some examples, when so disposed on the diaphragm 434, the inner / middle strain gauges 426a1, 426a2, 426b1, and 426b2 can respond to and / or measure circumferential and / or hoop strains, while the outer strain gauges 426a3, 426a4, 426b3, and 426b4 can respond to and / or measure radial strains. In some examples, the differential pressure sensor 200 can primarily use the strain gauges 426a1, 426a2, 426b1, and 426b2 bonded to the middle portion of the diaphragm 400 for pressure sensing.

[0055] In some examples, strain gauge 426 may additionally or alternatively be bonded to an outer surface of sensor tube 422 (e.g., near diaphragm 424). Figure 4a 426c and 426d are shown as dashed lines on the outer surface of the sensor tube 422. In some examples, when the strain gauge 426 is disposed on the outer surface of the sensor tube 422, the differential pressure sensor 400 can rely more on the outer (rather than the inner) strain gauge 426. In some examples, when the strain gauge 426 is positioned on the outer surface of the sensor tube 422, the strain gauges 426c and 426d can respond to the hoop stress applied to the sensor tube 422.

[0056] In some examples, each strain gauge 426 can include a foil material whose resistance (and / or impedance) changes with the applied force. For example, the resistance of the strain gauge 426 can increase as the strain gauge 426 is stretched. Since each strain gauge 426 is coupled to the diaphragm 424, the strain gauge 426 will stretch as the diaphragm 424 stretches (and / or deflects, deforms, expands, etc.), such as can occur in response to fluid pressure from the fluid within the fluid conduit 418. Specifically, the strain gauges 426a1, 426a2, 426b1, and 426b2 coupled to the middle portion of the diaphragm 400 will stretch as the diaphragm 424 stretches. In this configuration, the resistance (and / or impedance) of each strain gauge 426 depends on the degree to which its diaphragm 424 stretches (and / or deflects, deforms, expands, etc.).

[0057] In some examples, foil strain gauge 426 is used in differential pressure sensor 200 because foil strain gauge 426 is more resilient and / or able to withstand higher stresses. This is in contrast to, for example, piezoelectric elements, which are more fragile and therefore more likely to break under the higher temperatures and / or stresses of hydraulic system 100. Strain gauge 426 is further bonded to the outer surface of diaphragm 424, thereby preventing strain gauge 426 from directly contacting hot pressurized hydraulic fluid.

[0058] Also advantageous is bonding the strain gauge 426 to the outer surface of the diaphragm 424, coupled with a direct connection between the input port 416 and the diaphragm 424 to which the strain gauge 426 is bonded (e.g., without an intervening oil layer or intermediate diaphragm). For example, this configuration means that even after the strain gauge 426 is bonded to the diaphragm 424, a mechanical tool can be inserted through the input port 416 and the fluid conduit 418 to mechanically modify the width of the diaphragm 424. In some examples, modifying the width of the diaphragm 424 can make the diaphragm 424 more easily deflectable (and / or expand, deform, etc.) in response to fluid pressure.

[0059] In some examples, it may be desirable for a particular diaphragm 424 to be more susceptible to deflection (and / or expansion, deformation, etc.) in response to fluid pressure. For example, it may be desirable to make one diaphragm 424 more sensitive and / or more responsive than another diaphragm, such as in a hydraulic system where some of the pressure differentials are steady-state conditions. In such an example, one diaphragm 424 may be made thinner (and therefore, more sensitive / responsive and / or more susceptible to deflection) than another diaphragm, such that when a certain pressure imbalance (e.g., a steady-state pressure imbalance) exists, the sensor 200 outputs a pressure differential (and / or a representative signal value) of zero.

[0060] In some examples, the sensor tube 422 can be considered part of the sensor housing 400. In some examples, the body 404 of the sensor housing 400, the sensor tube 422, and the diaphragm 424 can include one solid and continuous piece of machined material (e.g., steel and / or other metal) without welded connections. In some examples, this one-piece design can help the sensor 200 better withstand the higher pressures and / or stresses of the hydraulic system 100, as opposed to welded designs that may be more susceptible to failure along welds under higher pressures and / or stresses.

[0061] Although the one-piece design of the sensor housing 400 may prevent tearing, rupture, and / or failure of welds along the sensor housing 400, the body 404 of the sensor housing 400 may still be subject to bending and / or bulging stresses due to the higher pressure of the hydraulic fluid. Specifically, when within the fluid conduit 418 of the sensor housing 400, the pressurized hydraulic fluid may exert upward (e.g., in the y-direction) and / or outward (e.g., in the x and / or z-directions) forces on the sensor housing 400. Since the sensor housing 400 will be secured to the manifold 150 while experiencing the upward and outward forces, the sensor housing 400 may experience some upward bending and / or outward bulging.

[0062] In some examples, positioning the diaphragm 424 and / or strain gauge 426 at the end of the sensor tube 422 that extends away from the body 404 of the sensor housing 400 can isolate the diaphragm 424 and / or strain gauge 426 from the effects of much of the outward bulging experienced by the sensor housing 400. This can be important because such bulging of the sensor tube 422 near the diaphragm 424 can affect the strain gauge 426 (e.g., its resistance) in a manner that distorts the measurements and / or outputs of the sensor 200.

[0063] Figure 5a to Figure 5c An example of a first alternative sensor housing 500 that can be used with the differential pressure sensor 200 is shown. The first alternative sensor housing 500 and Figures 4a to 4f 424, except that the first alternative sensor housing 500 does not have a sensor tube 422. Instead of positioning the diaphragm 424 at the end of the sensor tube 422 (and / or the fluid conduit 418) extending beyond the top wall 410, the fluid conduit 418 extends only to the top wall 410, and the diaphragm 424 forms a portion of and / or is substantially coplanar with the top wall 410. As discussed above, the configuration of the first alternative sensor housing 500 may cause the sensor housing 400 to bulge in a portion proximate the diaphragm 424, which may affect the strain gauge 426 (e.g., its resistance) in a manner that distorts the measurement and / or output of the sensor 200.

[0064] Figure 4g and Figure 5d An exaggerated example of how sensor housing 400 and first alternative sensor housing 500 may experience fluid pressure stress that bends upward (e.g., in the y direction) and / or outward (e.g., in the x and / or z directions) is shown. As shown, the body 404 / 504 of each of sensor housing 400 and first alternative sensor housing 500 experiences some bending in the y direction, causing each body 404 / 504 to flex slightly in a bow shape. Because diaphragm 424 is in Figure 5d In the first alternative sensor housing 500 that is part of the body 504, the diaphragm 424 also experiences this bending, which may distort the measurement of the associated strain gauge 426. Figure 4g The use of a sensor tube 422 in the sensor housing 400 allows the diaphragm 424 to be isolated from the body 404 so that the diaphragm 424 experiences much less bending stress.

[0065] Figure 4h and Figure 4i are top-down perspective views of the sensor body 400. These views are simplified and semi-transparent, showing additional exaggerated examples of the effects of fluid pressure stresses that bulge upward (e.g., in the y-direction) and / or outward (e.g., in the z-direction) on the sensor housing 400. As shown, the fluid pressure stresses on the body 404 cause the fluid conduit 418 and / or sensor tube 422 to become expanded into more shapes such as an oval shape, an egg shape, and / or an elliptical (rather than a circular) shape, wherein the sensor tube 422 is connected to the top wall 410 of the body 404 of the sensor housing 400 (e.g., at a sensor tube housing connection point 423). However, the use of the sensor tube 422 allows the diaphragm 424 to extend away from and / or be isolated from the body 404 of the sensor housing 400, so that the diaphragm 424 experiences much less bending and / or bulging stresses and remains generally circular. The shape of one diaphragm 424 and one sensor tube housing connection point 423 is generally described as follows: Figure 4h and Figure 4i The dashed line is drawn to illustrate this situation.

[0066] Figures 6a to 6c An example of a second alternative sensor housing 600 that can be used with the differential pressure sensor 200 is shown. The second alternative sensor housing 600 is similar to Figure 5a to Figure 5c The first alternative sensor housing 500 is shown in FIG. 5 , wherein the fluid conduit 418 extends only to the top wall 410 and the diaphragm 424 is substantially coplanar with the top wall 410. The second alternative sensor housing 600 is similar to FIG. Figures 4a to 4f The sensor housing 400 of FIG. 1 , wherein the second alternative sensor housing 600 includes a second alternative sensor tube 622 .

[0067] picture Figure 4a to Figure 4g Like the sensor tube 422 of the first embodiment, the second alternative sensor tube 622 is separate from the second alternative body 604 of the second alternative sensor housing 600. Figure 4a to Figure 4g As with the sensor tube 422 of the second alternative sensor tube 622 , such separation and / or isolation of the second alternative sensor tube 622 may help isolate the diaphragm 424 and / or strain gauge 426 from much of the effects of bending and / or bulging felt by the second alternative body 604 .

[0068] However, the second alternative sensor tube 622 is separated from the second alternative body 604 by the perforated annular groove 630 surrounding the second alternative sensor tube 622 rather than the extension of the second alternative sensor tube 622 above the top wall 410. Figures 6a to 6c In the example of FIG. 6 , the annular groove 630 is between the second alternative body 604 and the second alternative sensor tube 622, so that the second alternative body 604 surrounds both the annular groove 630 and the second alternative sensor tube 622. In other aspects, the second alternative sensor housing 600 can be connected to the second alternative sensor housing 600. Figure 4a to Figure 4g The sensor housing 400 is similar (and / or identical) to that of FIG.

[0069] Figures 7a to 7c An example of a third alternative sensor housing 700 that can be used with the differential pressure sensor 200 is shown. As shown, the third alternative sensor housing 700 is similar (and / or identical) to the second alternative sensor housing 600. However, unlike the third alternative sensor housing 700, the third alternative sensor housing 700 is similar (and / or identical) to the second alternative sensor housing 600. Figures 6a to 6c Unlike the second alternative sensor housing 600, which is coplanar with the top wall 410, the third alternative sensor tube 722 extends above the top wall 410 of the third alternative sensor housing 700, similar to Figure 4a to Figure 4g In this configuration, the annular groove 730 (and / or the third alternative sensor housing 700) surrounds only the portion of the third alternative sensor tube 722 below the top wall 410 of the third alternative sensor housing 700.

[0070] Figures 8a to 8c An example of a fourth alternative sensor housing 800 that can be used with the differential pressure sensor 200 is shown. As shown, the fourth alternative sensor housing 800 is similar (and / or identical) to the second alternative sensor housing 600 and / or the third alternative sensor housing 700, except that the fourth alternative sensor tube 822 is recessed below the top wall 410 of the third alternative sensor housing 700 (and / or within the third alternative sensor housing 700). In this configuration, an annular groove 830 (and / or the fourth alternative sensor housing 800) surrounds the entire fourth alternative sensor tube 822, as well as the diaphragm 424, and some of the space above the diaphragm 424 (e.g., in the direction of the positive y-axis).

[0071] exist Figures 4a to 4f In the example of FIG. 4 , the differential pressure sensor 200 includes a total of eight strain gauges 426, of which four strain gauges 426 are bonded to each of the two diaphragms 424. However, as discussed above, the differential pressure sensor 200 may mainly use the strain gauges 426a1, 426a2, 426b1, and 426b2 bonded to the middle portion of the diaphragm 400 for pressure detection. Figure 9a Four strain gauges are shown connected together in sensing circuit 900a, namely, strain gauges 426a1, 426a2, 426b1, and 426b2.

[0072] In some examples, the sensing circuit 900a is configured to generate an output signal 904 that represents a resistance difference between the strain gauge 426a1 and / or the strain gauge 426a2 coupled to the first diaphragm 424a and the strain gauge 426b1 and / or the strain gauge 426b2 coupled to the second diaphragm 424b. Since the resistance of the central strain gauge 426 coupled to a particular diaphragm 242 should be approximately equal, the resistance difference between the strain gauges 426 of different diaphragms 424 may be the result of a difference in the misalignment (and / or distortion, deformation, etc.) of the diaphragms 424. And since the misalignment (and / or distortion, deformation, etc.) of the diaphragms 424 is due to the fluid pressure within the fluid conduit 418, the output signal can represent the difference in fluid pressure within the corresponding fluid conduits 418.

[0073] exist Figure 9a In the example of , the sensing circuit 900a is further shown to include a terminal 434. Figures 4a to 4f In the example of , the terminal 434 is attached to the top wall 410 of the sensing housing. Figure 9a In the example of FIG. 9 , the sensing circuit 900 a is further shown as potentially including two conventional resistors 430 and / or two wearable resistors 432 . Figures 4a to 4f In the example of FIG. 4 , a conventional resistor 430 and a wearable resistor 432 are also shown attached to the top wall 410 of the sensor housing 400 .

[0074] Although not included in the Figures 5a to 8c , but conventional resistors 430, wearable resistors 432, and / or terminals 434 may be similarly attached to the top wall 410 of the first alternative sensor housing 500, the second alternative sensor housing 600, the third alternative sensor housing 700, and / or the fourth alternative sensor housing 800. Additionally, strain gauges 426 may be attached to the diaphragm 424 of the first alternative sensor housing 500, the second alternative sensor housing 600, the third alternative sensor housing 700, and / or the fourth alternative sensor housing 800.

[0075] exist Figure 9a In the example of FIG. 9 , the sensing circuit 900a is a modified Wheatstone bridge, wherein the strain gauge 426 forms the main resistance element of the Wheatstone bridge. As shown, the strain gauges 426a1 and 426b1 are wired together in series, the strain gauges 426a2 and 426b2 are wired together in series, and the two pairs of strain gauges in series are wired in parallel with each other relative to the power input 902 (and / or power input pin) of the sensor I / O connector 304. In some examples, the power input 902 (and / or power input pin) of the sensor I / O connector 304 can be connected to a power source of the hydraulic system 100 (e.g., via the actuator controller 120).

[0076] exist Figure 9a In the example of FIG. 1 , terminal 434b and terminal 434d of sensing circuit 900a are connected to output 904 (and / or output signal pin) of sensor I / O connector 304. In some examples, when the voltage between terminal 434b and terminal 434d (and / or the current flowing from terminal 434b to terminal 434d) is zero, output 904 of sensor I / O connector 304 will be zero.

[0077] In some examples, the zero output 904 of the sensor I / O connector 304 can be the result of the resistance of the strain gauge 426a1 and / or the strain gauge 426a2 being approximately equal to the resistance of the strain gauge 426b1 and / or the strain gauge 426b2. In some examples, the resistance of the strain gauge 426a1 and / or the strain gauge 426a2 being approximately equal to the resistance of the strain gauge 426b1 and / or the strain gauge 426b2 can occur when the deflection of the diaphragm 424a is approximately equal to the deflection of the diaphragm 424b. In some examples, the deflection of the diaphragm 424a is approximately equal to the deflection of the diaphragm 424b when the fluid pressure within the fluid conduit 418a is approximately the same as the fluid pressure within the fluid conduit 418b. Therefore, in some examples, the zero output 904 of the sensor I / O connector 304 can indicate that the fluid pressure within the fluid conduit 418a is approximately the same as the fluid pressure within the fluid conduit 418b.

[0078] exist Figure 9aIn the example of , conventional resistors 430 are depicted in dashed lines, showing how they can potentially be arranged in series or in parallel (e.g., as a shunt resistor) with strain gauge 426a1. In some examples, conventional resistors 430 can be arranged in series and / or in parallel with strain gauge 426a1 to balance the resistance in two parallel branches of sensing circuit 900a. Although shown as being applied to sensing circuit 900a in series or in parallel with strain gauge 426a1 for clarity, one of ordinary skill in the art will understand that conventional resistors 430 can alternatively be arranged in series and / or in parallel with strain gauge 426a2, strain gauge 426b1, or strain gauge 426b2.

[0079] For example, if the diaphragm 424a to which the strain gauge 426a1 is attached is (e.g., accidentally) machined to be less sensitive / less responsive (and / or thicker) than the other diaphragm 424b, a conventional resistor 430 may be arranged in series with the strain gauge 426a to balance the sensing circuit 900. As another example, if the diaphragm 424b to which the strain gauges 426b1 and 426b2 are attached is (e.g., accidentally) machined to be more sensitive / more responsive (and / or thinner) than the other diaphragm 424a, a conventional resistor 430 may be arranged in parallel with the strain gauges 426b1 and 426b2.

[0080] exist Figure 9a In the example of , each wearable resistor 432 is depicted in dotted lines, showing how they can potentially be arranged in the sensing circuit 900 if necessary. As shown, each wearable resistor 432 can be used to replace the terminal 434 (and / or itself includes the internal terminal 434). Each wearable resistor 432 basically includes two resistors 432a and 432b positioned on both sides of the terminal 434. In some examples, the resistance of each resistor 432a / 432b in the wearable resistor 432 can be modified by wear. In some examples, one wearable resistor (e.g., replacing terminal 434c) in the plurality of wearable resistors 432 can be used to balance the Wheatstone bridge, while another wearable resistor 432 (e.g., replacing terminal 434d) can be used for temperature compensation. Although shown as replacing terminals 434c and 434d, in some examples, the wearable resistor can replace terminals 434a and / or 434b instead.

[0081] Although Figure 9a The sensing circuit 900a is shown as a bridge including four strain gauges 426a1, 426a2, 426b1 and 426b2, but Figure 9b A sensing circuit 900b is shown that includes all eight strain gauges 426 and two bridges. However, this configuration may be more complex and / or require more power.

[0082] Although shown in a specific configuration Figure 9a to Figure 9b 426). However, in some examples, the sensing circuit 900 can be configured differently. In some examples, the sensing circuit 900 can use different sensing elements (e.g., instead of and / or in addition to the strain gauge 426). For example, the differential pressure sensor 400 can include a sensor 299 that detects and / or measures the displacement of the diaphragm 424 (and / or the sensor tube 422) using different means (e.g., optical, ultrasonic, etc.). For example, Figure 2 Sensors 299 are shown connected to sensing circuitry 900 and enclosed between sensor cap 300 and sensor housing 400. In some examples, sensors 299 can be connected to or disconnected from sensor housing 400. In some examples, sensors 299 can alternatively be connected to sensor cap 300. In some examples, sensing circuitry 900 can alternatively or additionally use electrical signals and / or characteristics of sensors 299 to determine differential pressure.

[0083] Although Figure 9a to Figure 9b The sensing circuit 900 is shown as an analog circuit, but in some examples, the sensing circuit 900 can be digital and / or include one or more digital components (e.g., an analog-to-digital converter). In some examples, one or more strain gauges 426 can be connected to a processing chip (such as a digital signal processor), and the processing chip can implement one or more functions of the sensing circuit 900. In some examples, one or more amplifiers can be included in the sensing circuit 900 to amplify the output of the sensing circuit 900.

[0084] Fig.10 An example of an adapter 1000 for a differential pressure sensor 200 is shown. Figures 11a to 11e Adapter 1000 is shown attached to sensor housing 400 . Fig.12 Adapter 1000 is shown attached to sensor housing 400 and sensing cover 300 .

[0085] exist Fig.10 In some examples, the adapter 1000 includes manifold fastener passages 1050 that are configured to align with the manifold fastener passages 350 of the sensor cover 300 and / or the manifold fastener conduits 450 of the sensor housing 400. In some examples, the manifold fastener passages 1050 of the adapter 1000 are configured to receive the manifold fasteners 250 to attach the cover 300 and / or the sensor housing 400 to the adapter 1000. In some examples, the cover 300 and / or the sensor housing 400 can be attached to the adapter 1000 via the manifold fasteners 250 in substantially the same manner as the cover 300 and / or the sensor housing 400 can be attached to the manifold 150. Fig.11c and Fig.11e Manifold fasteners 250 are shown attaching sensor housing 400 to adapter 1000 via manifold fastener passages 1050 .

[0086] exist Fig.10 In the example of the adapter 1000, the adapter 1000 further includes an adapter fastener passage 1052. In some examples, the adapter fastener passage 1052 can be aligned with a complementary passage of the manifold 150. Thereafter, the adapter fastener 1054 can be inserted through the adapter fastener passage 1052 and / or the complementary passage of the manifold 150 to attach the adapter 1000 to the manifold 150. Fig.11d An example of an adapter fastener 1054 inserted through adapter fastener passage 1052 of adapter 1000 is shown.

[0087] In some examples, the adapter 1000 can be attached to the sensor cover 300, the sensor housing 400, and / or the manifold 150 to retrofit the differential pressure sensor 200 for use with an existing hydraulic system 100. For example, the differential pressure sensor 200 can be used as a replacement for a differential pressure sensor of a different design, so that an existing hydraulic system 100 can be configured for a differential pressure sensor of a different design.

[0088] exist Fig.10 and Fig.11d In the example of FIG. 1 , the retrofit functionality of the adapter 1000 is illustrated by the adapter input port 1016 and the adapter fluid conduit 1018 of the adapter 1000, which are shown as being smaller than the input port 416 and the fluid conduit 418 of the sensor housing 400. In some examples, the size of the adapter input port 1016 and the adapter fluid conduit 1018 of the adapter 1000 can correspond to the size of the fluid line of the manifold 150 (and / or the port / conduit of the replaced sensor) on the existing hydraulic system 100. Although the adapter input port 1016 and / or the adapter fluid conduit 1018 of the adapter 1000 are shown as examples in FIG. Fig.10 and Fig.11d 4. Although shown as being smaller, in some examples, it may alternatively be larger than input port 416 and / or fluid conduit 418 of sensor housing 400.

[0089] Figure 13a to Figure 13bAn example of a fifth alternative sensor housing 1300 that can be used with the differential pressure sensor 200 is shown. As shown, the fifth alternative sensor housing 1300 is similar to the sensor housing 400. However, the fifth alternative sensor housing 1300 also includes a plug 1302 that fits within its fluid conduit 418. In some examples, the plug 1302 can also be included in the sensor housing 400 (and / or alternative sensor housings 500, 600, 700, 800, etc.).

[0090] exist Figure 13a to Figure 13b In some examples, plug 1302 is connected to fifth alternative sensor housing 1300 within fluid conduit 418. In some examples, plug 1302 can include engagement features (e.g., threads) that engage complementary engagement features formed within fluid conduit 418. In some examples, plug 1302 can be friction fit within fluid conduit 418 of fifth alternative sensor housing 1300.

[0091] Within each plug 1302 is a hollow plug shaft 1304 extending through the body of each plug 1302. As shown, the plug shaft 1304 is composed of a wide shaft 1304a near the input port 416 and a thin shaft 1304b away from the input port 416. The wide shaft 1304a is hexagonal to accommodate, for example, a hexagonal wrench. In some examples, the hexagonal wrench can use the wide shaft 1304a to help connect the plug 1302 to the fifth alternative sensor housing 1300. The diameter of both the wide shaft 1304a and the thin shaft 1304b is smaller than the diameter of each input port 416. In some examples, the fluid can enter the fluid conduit 418 via the input port 416 and then move through the plug shaft 1304 into the fluid conduit 418.

[0092] In some examples, in the absence of plug 1302, fluid flowing into, out of, and / or through input port 416 may generate Helmholtz resonance. The Helmholtz resonance may in turn cause vibrations that negatively affect the measurements of differential pressure sensor 200 (e.g., via strain gauge 426). Because the diameter of plug shaft 1304 is small, the positioning of plug 1302 within fluid conduit 418 just past input port 416 can be used to reduce and / or minimize the Helmholtz resonance, thereby helping to maintain efficient and / or effective operation of differential pressure sensor 200.

[0093] Fig.14 Examples of an alternative differential pressure sensor 1400 and an alternative adapter 1600 are shown. Fig.14 The alternative differential pressure sensor 1400 shown in FIG. Figure 2 The differential pressure sensor 200 shown in FIG. Figure 2 Where the differential pressure sensor 200 includes a sensor cover 300 , a sensor housing 400 , and a sensing circuit 900 , the alternative differential pressure sensor 1400 similarly includes an alternative sensor cover 1500 , a sixth alternative sensor housing 1700 , and an alternative sensing circuit 1800 .

[0094] Figure 14 to Figure 15 An example of an alternative sensor cover 1500 is shown. As shown, the alternative sensor cover 1500 is similar to the sensor cover 1500 except for a few elements. Figure 3 The sensor cover 300 shown in FIG. 1 is similar (and / or identical) to the sensor cover 300 shown in FIG. Figure 14 to Figure 15 In the example of FIG. 1 , the sensor I / O connector 304 is attached to the top of the alternative sensor cover 1500 (rather than to the top of the sensor cover 1500 as in FIG. Figures 2 to 3 The alternative sensor cover 1500 is also shown as being attached to the front face via screw fasteners 1402 inserted through aligned cover fastener holes 1502 / 1702 on the sides of the alternative sensor cover 1500 and the sixth alternative sensor housing 1700 (rather than via screw fasteners inserted through aligned cover fastener holes 1502 / 1702 on the sides of the alternative sensor cover 1500 and the sixth alternative sensor housing 1700). Figure 2 The sixth alternative sensor housing 1700 is attached to the sensor housing 1700 by inserting cover fasteners 202 into aligned holes 302 / 402 on the front / back sides of the sensor cover 300 and sensor housing 400 shown in FIG. 4 .

[0095] exist Fig.14 In the example of , alternative differential pressure sensor 1400 and sixth alternative sensor housing 1700 are shown attached to alternative adapter 1600 . Figures 16a to 16d 1 shows different views of an alternative adapter 1600. As shown, the alternative adapter 1600 is similar to the Figures 10 to 12 Adapter 1000 is similar to (and / or identical to) that shown in .

[0096] For example, although Figures 10 to 12 10 has an adapter fluid conduit 1018 extending generally parallel to the y-axis along its entire length, but the alternative adapter 1600 includes an alternative adapter fluid conduit 1618 extending generally parallel to the y-axis at some portions and generally parallel to the z-direction at other portions. Plug 1602 is shown sealing (e.g., with an O-ring) an opening of the z-extending portion of the alternative adapter fluid conduit 1618. In some examples, the opening is formed when at least the z-directing portion of the alternative adapter fluid conduit 1618 is machined.

[0097] As another example, although Figures 10 to 12 The adapter 1000 shown in FIG. 1 is shown as being sized to match the profile of the sensor housing 400, but Fig.14 and Figures 16a to 16d 1700 has a larger profile than the sixth alternative sensor housing 1700. The larger profile of the alternative adapter 1600 (e.g., compared to the sixth alternative sensor housing 1700) allows the adapter fastener passage 1052 to be positioned out of alignment with the sixth alternative sensor housing 1700. This allows the adapter fastener passage 1052 (and / or adapter fastener 1054) to be more easily accessible (e.g., when the alternative adapter 1600 is attached to the sixth alternative sensor housing 1700).

[0098] Figures 17a to 17d Shown with Fig.14 An example of a sixth alternative sensor housing 1700 for use with the alternative differential pressure sensor 1400 of FIG. As shown, except for a few elements, the sixth alternative sensor housing 1700 is similar to Figures 4a to 4f For example, the sixth alternative sensor housing 1700 includes a sixth alternative sensor tube 1722 that is similar to the sensor tube 400 of the sensor housing 400 .

[0099] picture Figure 4a to Figure 4g Like the sensor tube 422 of the sixth alternative sensor tube 1722, the sixth alternative sensor tube 1722 is separate from the second alternative body 1704 of the sixth alternative sensor housing 1700. Figure 4a to Figure 4g As with the sensor tube 422 of the sixth alternative sensor tube 1704 , such separation and / or isolation of the sixth alternative sensor tube 1722 may help isolate the strain gauge 426 from much of the bending and / or bulging effects felt by the sixth alternative body 1704 .

[0100] However, unlike the sensor tube 400 of the sensor housing 400, the sixth alternative sensor tube 1722 (and / or the fluid conduit 418) of the sixth alternative sensor housing 1700 terminates at a sensor tube top wall 1799 instead of the diaphragm 424. In some examples, the body 1704 of the sixth alternative sensor housing 1700, the sixth alternative sensor tube 1722, and the sensor tube top wall 1799 can include one solid and continuous piece of machined material (e.g., steel and / or other metal) without welded connections.

[0101] exist Figures 17a to 17d In the example of the sixth alternative sensor housing 1700, the strain gauges 426 are attached, fastened, adhered and / or otherwise bonded to the opposite outer side of the cylindrical sidewall of the sixth alternative sensor tube 1722 (rather than being attached to the diaphragm 424, for example). Figures 17a to 17dIn the example of FIG. 1 , the cylindrical sidewall of the sixth alternative sensor tube 1722 is also shown as being much thinner than the sensor tube top wall 1799. In some examples, the relatively thin width of the sidewall of the sixth alternative sensor tube 1722 allows the fluid pressure of the hydraulic fluid in the fluid conduit 418 to force the sidewall of the sixth alternative sensor tube 1722 to deflect, expand, deform, and / or bend outward (e.g., in the x-direction and / or z-direction). As the sidewall of the sixth alternative sensor tube 1722 expands / deforms, the strain gauge 426 will also expand / deform.

[0102] In some examples, the resistance (and / or impedance) of each strain gauge 426 depends on the degree to which its sensor tube sidewall stretches (and / or deflects, deforms, expands, etc.). In some examples, this arrangement allows the strain gauges 426 to measure the hoop stress applied to (and / or experienced by) the sixth alternative sensor tube 1722. In some examples, positioning the strain gauges 426 on opposite sides of each sixth alternative sensor tube 1722 helps ensure accurate and / or valid measurements, and / or useful pressure differential determinations.

[0103] In some examples, the sixth alternative sensor tube 1722 of the sixth alternative sensor housing 1700 may be surrounded by an open annular groove, for example Figures 6a to 8c As shown. Figures 17a to 17d In the example shown as extending away from the sixth alternative body 1704, however, in some examples, the sixth alternative sensor tube 1722 of the sixth alternative sensor housing 1700 may alternatively be flush with or recessed within the sixth alternative body 1704, for example Figures 6a to 6c and Figures 8a to 8c shown.

[0104] Fig.18 An alternative sensing circuit 1800 is shown that may be used with the alternative differential pressure sensor 1400. As shown, the alternative sensing circuit 1800 is similar (and / or identical) to the sensing circuit 900a of FIG. 9 , except that strain gauges 426c1, 426c2, 426d1, 426d2 are used instead of strain gauges 426a1, 426a2, 426b1, 426b2, and an output signal 1804 is generated instead of output signal 904.

[0105] In some examples, alternative sensing circuit 1800 is configured to generate output signal 1804 (eg, output via an output signal pin of sensor I / O connector 304 ). In some examples, output signal 1804 represents a resistance difference between strain gauges 426 coupled to different sixth alternative sensor tubes 1722 .

[0106] In some examples, the output signal 1804 of the alternative sensing circuit 1800 is similar (and / or identical) to the output signal 904 of the sensing circuit 900a of FIG. 9 , except that the output signal 1804 represents the resistance difference between the strain gauges 426c1 and / or the strain gauges 426c2 and the strain gauges 426d1 and / or the strain gauges 426d2 (rather than the strain gauges 426a1, 426a2, 426b1, 426b2). Since the resistance of the strain gauges 426 coupled to a particular sixth alternative sensor tube 1722 should be approximately equal, the resistance difference between the strain gauges 426 of different diaphragms 424 can be the result of a difference in the misalignment (and / or distortion, deformation, etc.) of the sixth alternative sensor tube 1722. And since the misalignment (and / or distortion, deformation, etc.) of the sixth alternative sensor tube 1722 is due to the fluid pressure within the fluid conduit 418, the output signal can represent the fluid pressure difference within the corresponding fluid conduit 418.

[0107] The differential pressure sensor 200 / 1400 disclosed herein has a unique design that makes it particularly suitable for dynamic high-pressure hydraulic systems 100. For example, the one-piece design of its sensor housing 400 (and / or alternative sensor housings 500, 600, 700, 800, 1300, 1700) increases the durability of the sensor 200 / 1400. Additionally, the use of foil (rather than, for example, piezoelectric) strain gauges 426 ensures continued functionality even under the unique stresses imposed by the dynamic high-pressure hydraulic system 100. Furthermore, the sensor tube 422 helps isolate the diaphragm 424 and strain gauges 426 from some of the bowing / bending stresses that the body 404 of the sensor housing 400 may experience due to intense fluid pressure.

[0108] Although the present method and / or system has been described with reference to certain embodiments, it will be appreciated by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the present method and / or system. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the present disclosure without departing from the scope of the present disclosure. Therefore, the present method and / or system is not intended to be limited to the specific embodiments disclosed, but rather the present method and / or system will include all embodiments falling within the scope of the appended claims.

[0109] As used herein, "and / or" refers to any one or more of the items connected by "and / or" in the list. As an example, "x and / or y" refers to any element in the three-element set {(x), (y), (x, y)}. In other words, "x and / or y" means "one or both of x and y". As another example, "x, y and / or z" refers to any element in the seven-element set {(x), (y), (z), (x, y), (x, z), (y, z), (x, y, z)}. In other words, "x, y and / or z" means "one or more of x, y and z".

[0110] As used herein, the terms "such as" and "for example" introduce a list of one or more non-limiting examples, instances, or illustrations.

[0111] As used herein, the terms "coupled," "coupled to," and "coupled with" refer to structural and / or electrical connections, whether attached, attached, connected, linked, fastened, associated, and / or otherwise secured, respectively. As used herein, the term "attach" refers to attaching, linking, connecting, linking, fastening, associated, and / or otherwise secured. As used herein, the term "connect" refers to attaching, attaching, linking, linking, fastening, associated, and / or otherwise secured.

[0112] As used herein, the terms "circuit" and "circuitry" refer to physical electronic components (i.e., hardware) and any software and / or firmware ("code") that may configure, be executed by, and / or otherwise be associated with the hardware. As used herein, for example, a particular processor and memory may constitute a first "circuit" when executing a first one or more lines of code, and may constitute a second "circuit" when executing a second one or more lines of code. As used herein, a circuitry is "operable" and / or "configured" to perform a function when the circuitry includes the necessary hardware and / or code (if necessary) to perform the function, regardless of whether performance of the function is disabled or enabled (e.g., by a user-configurable setting, a factory adjustment, etc.).

[0113] As used herein, control circuitry may include digital circuit systems and / or analog circuit systems, discrete circuit systems and / or integrated circuit systems, microprocessors, DSPs, etc., located on one or more circuit boards forming part or all of a controller and / or software, hardware and / or firmware for controlling a welding process and / or devices such as a power supply or a wire feeder.

[0114] As used herein, the term "processor" refers to a processing device, apparatus, program, circuit, component, system and subsystem, whether implemented in hardware, software in tangible form or both, and whether or not it is programmable. As used herein, the term "processor" includes, but is not limited to, one or more computing devices, hard-wired circuits, signal modification devices and systems, devices and machines for controlling systems, central processing units, programmable devices and systems, field programmable gate arrays, application-specific integrated circuits, systems on chip, systems including discrete components and / or circuits, state machines, virtual machines, data processors, processing facilities, and any combination of the above components. The processor may be, for example, any type of general-purpose microprocessor or microcontroller, a digital signal processing (DSP) processor, an application-specific integrated circuit (ASIC), a graphics processing unit (GPU), a reduced instruction set computer (RISC) processor with an advanced RISC machine (ARM) core, etc. The processor may be coupled to a memory device and / or integrated with the memory device.

[0115] As used herein, the terms "memory" and / or "memory device" refer to computer hardware or circuitry for storing information for use by a processor and / or other digital device. The memory and / or memory device may be any suitable type of computer memory or any other type of electronic storage medium, such as read-only memory (ROM), random access memory (RAM), cache memory, compact disk read-only memory (CDROM), electro-optical memory, magneto-optical memory, programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), computer-readable media, etc. The memory may include, for example, non-transitory memory, non-transitory processor-readable medium, non-transitory computer-readable medium, non-volatile memory, dynamic RAM (DRAM), volatile memory, ferroelectric RAM (FRAM), first-in-first-out (FIFO) memory, last-in-first-out (LIFO) memory, stack memory, non-volatile RAM (NVRAM), static RAM (SRAM), cache, buffer, semiconductor memory, magnetic memory, optical memory, flash memory, flash memory card, compact flash memory card, memory card, secure digital memory card, micro card, mini card, expansion card, smart card, memory stick, multimedia card, picture card, flash memory device, subscriber identity module (SIM) card, hardware drive (HDD), solid state drive (SSD), etc. The memory may be configured to store code, instructions, applications, software, firmware and / or data, and may be external to the processor, internal to the processor, or both internal and external to the processor.

Claims

1. A differential pressure sensor, comprising: a sensor housing comprising a first input port and a second input port; a first sensor tube connected to the sensor housing at a first tube housing end, the first sensor tube extending from the first tube housing end to a first conduit end isolated from the sensor housing; a second sensor tube connected to the sensor housing at a second tube housing end, the second sensor tube extending from the second tube housing end to a second conduit end isolated from the sensor housing; a first fluid conduit extending from the first input port through the sensor housing and the first sensor tube to the first conduit end, the first sensor tube being configured to undergo a first deflection in response to a first fluid pressure within the first fluid conduit; a second fluid conduit extending from the second input port through the sensor housing and the second sensor tube to the second conduit end, the second sensor tube being configured to undergo a second deflection in response to a second fluid pressure within the second fluid conduit; a first circuit element coupled to the first sensor tube, the first circuit element having a first electrical characteristic dependent on a first offset of the first sensor tube; a second circuit element coupled to the second sensor tube, the second circuit element having a second electrical characteristic dependent on a second offset of the second sensor tube; as well as a sensing circuit electrically connected to the first circuit element and the second circuit element, the sensing circuit being configured to determine a pressure difference between a first fluid pressure in the first fluid conduit and a second fluid pressure in the second fluid conduit based on a first electrical characteristic of the first circuit element and a second electrical characteristic of the second circuit element.

2. The differential pressure sensor according to claim 1, wherein: The sensor housing further includes a first housing end including the first input port and the second input port and a second housing end opposite the first housing end, the second housing end connected to the first sensor tube or the second sensor tube at the first tube housing end or the second tube housing end.

3. The differential pressure sensor according to claim 1, wherein: The first sensor tube or the second sensor tube is recessed into the sensor housing such that the sensor housing surrounds the first sensor tube or the second sensor tube.

4. The differential pressure sensor according to claim 1, wherein: The sensor housing is made of metal material.

5. The differential pressure sensor according to claim 1, wherein: The sensor housing further comprises: a first groove surrounding a first portion of the first sensor tube so that the first portion of the first sensor tube is isolated from the sensor housing, and A second groove surrounds a second portion of the second sensor tube so that the second portion of the second sensor tube is isolated from the sensor housing.

6. The differential pressure sensor according to claim 1, wherein: The first circuit element includes a first resistor, the second circuit element includes a second resistor, the first electrical characteristic includes a first resistance, and the second electrical characteristic includes a second resistance.

7. The differential pressure sensor according to claim 6, wherein: The first circuit element includes a first strain gauge, and the second circuit element includes a second strain gauge.

8. The differential pressure sensor according to claim 7, wherein: The first strain gauge and the second strain gauge are formed of foil.

9. The differential pressure sensor according to claim 1, wherein: The sensor housing, the first sensor tube, and the second sensor tube comprise a single continuously machined piece of metal.

10. The differential pressure sensor of claim 1, wherein: The first sensor tube includes a first sensor inner tube portion inside the first fluid conduit and a first sensor outer tube portion outside the first fluid conduit, The second sensor tube includes a second sensor tube inner wall inside the second conduit and a second sensor outer tube portion outside the second fluid conduit, The first circuit element is coupled to the first sensor outer tube, and The second circuit element is coupled to the second sensor outer tube portion.

11. A hydraulic system comprising: A hydraulic device, the hydraulic device comprising a device housing, the device housing enclosing a first fluid volume and a second fluid volume separated from each other; as well as A differential pressure sensor, the differential pressure sensor comprising: a sensor housing comprising a first input port in fluid communication with the first fluid volume and a second input port in fluid communication with the second fluid volume, a first sensor tube connected to the sensor housing at a first tube housing end, the first sensor tube extending from the first tube housing end to a first conduit end isolated from the sensor housing, a second sensor tube connected to the sensor housing at a second tube housing end, the second sensor tube extending from the second tube housing end to a second conduit end isolated from the sensor housing, a first fluid conduit extending from the first input port through the sensor housing and the first sensor tube to the first conduit end, the first sensor tube being configured to undergo a first deflection in response to a first fluid pressure within the first fluid conduit, a second fluid conduit extending from the second input port through the sensor housing and the second sensor tube to the second conduit end, the second sensor tube being configured to undergo a second deflection in response to a second fluid pressure within the second fluid conduit, a first circuit element coupled to the first sensor tube, the first circuit element having a first electrical characteristic dependent on a first deflection of the first sensor tube, a second circuit element coupled to the second sensor tube, the second circuit element having a second electrical characteristic dependent on a second offset of the second sensor tube, and A sensing circuit is electrically connected to the first circuit element and the second circuit element, the sensing circuit being configured to determine a pressure differential between a fluid in a first fluid volume of the hydraulic device and a fluid in a second fluid volume of the hydraulic device based on a first electrical characteristic of the first circuit element and a second electrical characteristic of the second circuit element.

12. The hydraulic system of claim 11, wherein: The sensor housing further includes a first housing end including the first input port and the second input port and a second housing end opposite the first housing end, the second housing end connected to the first sensor tube or the second sensor tube at the first tube housing end or the second tube housing end.

13. The hydraulic system of claim 11, wherein: The first sensor tube or the second sensor tube is recessed into the sensor housing such that the sensor housing surrounds the first sensor tube or the second sensor tube.

14. The hydraulic system of claim 11, wherein: The sensor housing is made of metal material.

15. The hydraulic system of claim 11, wherein: The sensor housing further comprises: a first groove surrounding a first portion of the first sensor tube so that the first portion of the first sensor tube is isolated from the sensor housing, and A second groove surrounds a second portion of the second sensor tube so that the second portion of the second sensor tube is isolated from the sensor housing.

16. The hydraulic system of claim 11, wherein: The first circuit element includes a first resistor, the second circuit element includes a second resistor, the first electrical characteristic includes a first resistance, and the second electrical characteristic includes a second resistance.

17. The hydraulic system of claim 16, wherein: The first circuit element includes a first strain gauge, and the second circuit element includes a second strain gauge.

18. The hydraulic system of claim 17, wherein: The first strain gauge and the second strain gauge are formed of foil.

19. The hydraulic system of claim 11, wherein: The sensor housing, the first sensor tube, and the second sensor tube comprise a single continuously machined piece of metal.

20. The hydraulic system of claim 11, wherein: The first sensor tube includes a first sensor inner tube portion inside the first fluid conduit and a first sensor outer tube portion outside the first fluid conduit, The second sensor tube includes a second sensor inner tube portion inside the second fluid conduit and a second sensor outer tube portion outside the second fluid conduit, The first circuit element is coupled to the first sensor outer tube, and The second circuit element is coupled to the second sensor outer tube portion.

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