Hydraulic motor

Abstract

A hydraulic motor for energy conversion and a method for operating a hydraulic motor 5 for energy conversion are provided. The target is achieved through the pressure eliminating unit, and the pressure eliminating unit can selectively eliminate the environment pressure outside the pressure eliminating unit.

Description

Technical Field

[0001] This invention relates generally to mechanical conversion, and more specifically to systems and methods for use with hydraulic motors. Background Technology

[0002] Existing technologies are embodied in traditional hydraulic systems such as hydraulic cylinders.

[0003] According to existing technology, a hydraulic system should be referenced, in which a cylinder is pressurized to move a piston located within the cylinder. This pressure counteracts the load connected to the piston and ambient pressure. At deeper locations, ambient pressure becomes significant, requiring even greater pressure to provide sufficient overpressure to overcome the effects of ambient pressure.

[0004] According to the translation of the abstract of CN 115467867 A, a pressure balancing device, a hydraulic system, and an operating machine are disclosed. The pressure balancing device includes a valve body, a main drain pipe, an opening valve element, and a pressure regulating assembly. The valve body is provided with a drain chamber, a first oil port, and a second oil port. The first and second oil ports are connected to the drain chamber. The first oil port is connected to the drain port of a hydraulic motor, and the second oil port is connected to the drain port of the hydraulic motor. The second oil port is connected to the main drain pipe. The opening valve element seals the first oil port and is movably disposed within the drain chamber. When the pressure in the main drain pipe is greater than the external atmospheric pressure, the pressure regulating assembly applies a first force to the opening valve element.

[0005] According to the translation of the abstract of EP 3222856 A1, a self-contained pressure compensation system and its control method are disclosed. The self-contained pressure compensation system includes an oil supply device, a pressure compensation device, a power unit associated with the pressure compensation device, and a switch control device. The pressure compensation device supplies oil to the power unit and detects the change of its own cavity pressure in real time. When the cavity pressure is less than a preset first threshold, the switch control device triggers the oil supply device to supply oil to the pressure compensation device. When the cavity pressure is greater than a preset second threshold, the switch control device triggers the oil supply device to stop supplying oil to the pressure compensation device.

[0006] According to the translation of the abstract of CN 201520281074 U, a deep-sea valve actuation mechanism with a bidirectional pressure dynamic balance compensation arrangement is disclosed. This deep-sea valve actuation mechanism includes an actuation mechanism, a piston pressure balance compensator, and a valve adapter unit. The piston pressure balance compensator is located outside the actuation mechanism and connected to it. The actuation mechanism is connected to an underwater valve through the valve adapter unit. The actuation mechanism includes an actuation mechanism housing, a cylinder end cap, a piston rod, a drive sleeve, a spring retainer, and multiple springs. The piston pressure balance compensator includes a pressure balance housing, with a filter end cap on one side of the pressure balance housing and a piston disposed within the pressure balance housing on the other side via a connecting shaft connected to the actuation mechanism. The piston is divided into a dynamic balance chamber and a seawater compensation chamber by the balancer housing.

[0007] Therefore, a method and system are needed to overcome the above problems. Summary of the Invention

[0008] The technical problem to be solved by the present invention Therefore, the main objective of this invention is to provide a system and method for a hydraulic motor.

[0009] Technical solutions to solve technical problems The present invention achieves this objective by means of: a pressure relief unit defined in the preamble of claim 1 having the features of the feature portion of claim 1; a method for operating the pressure relief unit defined in the preamble of claim 3 having the features of the feature portion of claim 3; a hydraulic motor defined in the preamble of claim 4 having the features of the feature portion of claim 4; and an operating method for operating the hydraulic motor defined in the preamble of claim 5 having the features of the feature portion of claim 5.

[0010] Numerous non-exhaustive embodiments, variations, or alternatives of the present invention are defined by the dependent claims.

[0011] The present invention achieves the above objectives through a pressure relief unit, which can selectively relieve environmental pressure outside the pressure relief unit.

[0012] Technical effects of the present invention The technical difference compared to traditional hydraulic systems is that the pressure relief unit can selectively relieve the environmental pressure outside the pressure relief unit.

[0013] These functions, in turn, provide several additional beneficial technical effects: This allows the hydraulic system to operate at lower power. Because environmental stress is eliminated, this allows the system to operate at lower stress levels, and Because the pressure differential can be reduced, it makes it possible to use lighter materials. Attached Figure Description

[0014] The above and other features of the present invention have been described in detail in the appended claims, and these features and advantages will become clearer from the detailed description of exemplary embodiments of the present invention with reference to the accompanying drawings.

[0015] The present invention will be further described below with reference to exemplary embodiments schematically illustrated in the figures, in which: Figure 1 An exception to Archimedes' principle of buoyancy is shown. Figure 2 This shows an application to the pressure relief unit. Figure 1 The principle, Figure 3 The elimination unit is shown in detail. Figure 4 The PV diagram is shown. Figure 5 The elimination unit at position A in the PV diagram is shown. Figure 6 The elimination unit at position B in the PV diagram is shown. Figure 7 The elimination unit at position C in the PV diagram is shown. Figure 8 The elimination unit at position D in the PV diagram is shown. Figure 8B The force acting on the elimination element located at position D in the PV diagram is shown. Figure 9 The application of the elimination unit as a heave compensator with a payload is shown.

[0016] Explanation of reference numerals in the attached figures The following reference numerals and figure labels correspond to the figures: Detailed Implementation

[0017] The various aspects of this disclosure will now be described in more detail with reference to the accompanying drawings. However, this disclosure may be implemented in many different forms and should not be construed as being limited to any particular structure or function presented herein. Rather, these aspects are provided to make this disclosure comprehensive and complete, and to fully communicate the scope of this disclosure to those skilled in the art. Based on the teachings herein, those skilled in the art will understand that the scope of this disclosure is intended to cover any aspect disclosed herein, whether implemented independently or in combination with any other aspect of this disclosure. For example, any number of the aspects described herein may be used to implement an apparatus or method. Furthermore, the scope of this disclosure is intended to cover apparatus or methods implemented using structures, functions, or structures and functions other than those described herein. It should be understood that any aspect of this disclosure disclosed herein may be embodied by one or more elements of the claims.

[0018] The invention will be further described in conjunction with exemplary embodiments schematically illustrated in the figures, wherein: The principles that form the basis of this invention Figure 1 An exception to the well-known Archimedes' principle of buoyancy (ABP) is illustrated, which forms the basis of this invention. This exception occurs when the submerged object is not completely surrounded by a continuous fluid. For example, this exception occurs when the submerged object is in a fluid but not in contact with the container holding the fluid, such as a cube resting at the bottom of a pool. In this case, the resultant forces acting horizontally still cancel each other out, as is the usual case with ABP. However, the forces acting vertically are different. The downward force is the area integral of the pressure acting on the top surface of the cube's height. This can be expressed as:

[0019] in This indicates that the force is downward along the z-axis (along...) Figure 1 (the negative direction of the z-axis in the equation).

[0020] item It is the pressure acting on the top surface of the submerged cube, and the item It increases linearly with depth.

[0021] This is contrary to the conventional ABP condition, under which the force can be expressed as:

[0022] in, ρ f It is the density of the fluid. V disp,f It is the volume of fluid displaced. g It is gravitational acceleration. It is a unit vector pointing in the positive direction of the z-axis, and m f,disp It is the displaced volume of the fluid ( V disp,f (total mass).

[0023] The inventors have realized that the above can be used to design systems in which forces are located on opposite sides of the central unit and act in opposite directions, thereby canceling each other out.

[0024] Figure 2 This shows the application in the pressure relief unit. Figure 1 The principle is that forces are canceled out by forces acting in opposite directions. The water column shown involves Pascal's law, which states the magnitude of the forces applied to each piston. The forces on opposite pistons cancel each other out, and the wire exerts a force on the third piston, which similarly cancels out the force applied to that piston. This causes a force to act on the fourth piston, which is positioned opposite the third piston.

[0025] Figure 3 The elimination unit 200 is shown in detail. This unit is a hollow elimination body 202, which has a cavity provided with multiple cylinders to receive one or more pistons.

[0026] In one implementation, the cavity is subdivided into three chambers: The lower chamber 210 includes a lower vertical piston 214 disposed inside the vertical cylinder 212; Intermediate chamber 220 includes a first horizontal piston 224A and a second horizontal piston 224B, which are movably disposed within corresponding first horizontal cylinders 222A and 222B, wherein the first pistons and the second pistons are positioned opposite each other such that the hydrostatic pressure from each piston cancels out. The upper chamber 230 includes an upper vertical piston 234 disposed within a vertical cylinder 232.

[0027] The first piston 224A and the second piston 224B are operatively connected to the upper vertical piston 234 by means of wires and pulleys, such that inward movement of the first piston and the second piston will cause outward movement of the upper piston.

[0028] The lower chamber 210 is equipped with an air pipe and a vent attached to the air pipe, allowing air to be supplied to the chamber when necessary. The vent can also be closed and opened. All of the above operations are performed from above sea level, on land. The intermediate chamber 220 is equipped with a vent attached to it, which is closed before the elimination unit is submerged in water. That is, no air is supplied to this chamber.

[0029] The piston has an outer surface and an inner surface. The outer surface is exposed to the fluid around the elimination unit, and the inner surface is exposed within the corresponding volume of each chamber.

[0030] The lower chamber, upper chamber, and intermediate chamber are all equipped with devices for adding fluid to the chamber or removing fluid that will be contained within the chamber.

[0031] Typically, the upper chamber 230 is provided with an air pipe attached to it, which is always open, allowing air to freely flow into and out of the upper chamber 230 when the volume of the intermediate chamber 220 changes. In this case, the upper chamber 230 has a constant pressure of P = 1 bar (atmospheres).

[0032] A first horizontal piston is movably disposed within a corresponding first horizontal cylinder, wherein the first horizontal piston is operatively connected to an upper vertical piston, which is movably disposed within a corresponding upper vertical cylinder. Similarly, a second horizontal piston is movably disposed within a corresponding second horizontal cylinder, wherein the second horizontal piston is operatively connected to the upper vertical piston. The first and second pistons are positioned such that the hydrostatic pressure from each piston cancels out.

[0033] The first and second horizontal pistons are operably connected to the upper vertical piston such that inward movement of the first and second pistons causes outward movement of the upper piston. This can be achieved using, for example, a mechanical link between a rod or wire and a pulley.

[0034] Typically, the cavity is filled with a compressible fluid, but the surrounding fluid can be incompressible, such as water.

[0035] Therefore, when unit 200 is lowered into the pool, the pressure inside the chamber will reflect the pressure differential as explained in the exceptions of ABP. This pressure differential can be applied to perform work in a manner different from that of a single cylinder with a piston that seals off the enclosed working medium.

[0036] Figure 4A PV diagram is shown, with four corner positions. The principle of the invention is to reduce the effective pressure on at least one chamber by using elimination units, thereby reducing the effective work done to move at least one piston. In the following example, the lower piston is the piston that does the effective work, while the other three pistons are used to eliminate at least part of the effective external pressure acting on the lower piston.

[0037] The transition shown in the PV diagram is achieved by moving fluid into and out of the chamber. The lines folding back to themselves in the PV diagram's loops do not enclose any area and therefore do no work. The transition from step 2 to step 3 opens up the trajectory, making the integral non-zero. This opening is achieved by stopping the elimination effect, which then reappears in the transition from step 4 back to step 1.

[0038] Figures 5 to 8 A typical cycle example is illustrated in the form of a pressure-volume (PV) diagram, demonstrating energy transfer. In this configuration, the chambers are constructed as follows: chamber 1 corresponds to the upper chamber 230, chamber 2 corresponds to the middle chamber 220, and chamber 3 corresponds to the lower chamber 210. Chamber 1: This chamber is equipped with an air pipe and a vent connected to the air pipe, allowing air to be supplied to the chamber when necessary. The vent can also be closed and opened. All of the above operations are carried out above sea level, on land.

[0039] Chamber 2: This chamber is provided with a vent attached to it, which is closed before the pressure relief unit is submerged in water. That is, no air is supplied to this chamber.

[0040] Chamber 3: This chamber is equipped with an air pipe attached to it, which is always open, allowing air to flow freely into and out of the chamber as the volume of chamber 2 changes. Furthermore, chamber 3 has a constant pressure of P = 1 bar (atmospheres).

[0041] Figure 5 It shows in Figure 4 The system is in state 1, which is the starting position.

[0042] In state 1, the pressure relief unit is divided into two systems. System 1 includes chamber 2 and its corresponding piston, and chamber 3 and its corresponding piston. System 2 includes only a fixed lower piston and a lower vertical shaft, with the lower vertical shaft holding the lower piston in place. Therefore, in state 1, there is no contact between the fixed piston and the end of chamber 1.

[0043] State 1 State 2: like Figure 5As shown, the piston in chamber 1 is held in a fixed position. Pressurized air is supplied to chamber 1 at this time, so as the volume in chamber 1 increases, the pressure relief unit will leave state 1 and transition to state 2. Typically, the pressure will increase as the volume increases. Since the pressure does not increase instantaneously, especially since the valve is located on the surface and the air pipe requires a certain amount of time to pressurize before air can be delivered into chamber 1.

[0044] Figure 5 The pulley force acting on the pressure relief unit is also shown, with the volume of chamber 1 increasing and gradually approaching its maximum expansion. Note the equilibrium state of the pressure relief unit when the stationary piston is no longer in contact with the end of chamber 1. Since the stationary piston is no longer in contact with the end of chamber 1, a new equilibrium will be formed between the pistons in chamber 2 and chamber 3.

[0045] Figure 6 It shows in Figure 4 The system is in state 2, which is the end position of expansion. The pressure relief unit is in equilibrium, and the fixed piston is separated from the end of chamber 1.

[0046] State 2 State 3: The piston corresponding to chamber 1 is now released from its fixed position, and the vent in chamber 1 is opened. This means that the entire ambient pressure is now applied directly to chamber 1, and the pressure increases as quickly as it would have been during the release. As the piston in chamber 1 is released from its fixed position, the pressure relief unit now leaves state 2 and enters state 3.

[0047] Figure 7 It shows Figure 4 The system is in state 3, which is the starting position for the transition, in which the piston in chamber 1 is pressed inward by the surrounding pressure, thereby reducing the volume V.

[0048] State 3 State 4: After the piston corresponding to chamber 1 is released, the volume of chamber 1 will decrease as the piston moves into the interior of chamber 1. The water pressure acting on the piston, at a pressure of P = 1.2 bar, forces the piston into the interior of chamber 1, and the moving piston pushes the air in chamber 1 out through the air pipe.

[0049] The piston corresponding to chamber 1 has now emptied the volume of chamber 1, and the pressure relief unit has entered state 4. In state 4, the pressure relief unit is in equilibrium, like a conventional piston and cylinder system. This is... Figure 8B It is shown in the middle. Figure 7 The pressure on the pressure relief unit shown is caused by the submerged pressure relief unit.

[0050] Figure 8 It shows Figure 4 The system is in state 4, where the piston in chamber 1 is now in full contact with the end of the cylinder again. Only in state 4 is the piston in direct contact with the cylinder end and the elimination effect does not occur.

[0051] State 4 State 1: The piston corresponding to chamber 1 is returned to its fixed position. Furthermore, as in... Figure 8 As shown, the piston is moved slightly away from the end of chamber 1 and is no longer in contact with the end of chamber 1. Therefore, since the air pipe in chamber 1 is open, the air pressure in chamber 1 will return to 1 bar, and the pressure relief unit will return to state 1. Here, the volume is approximately zero and hardly increases further; any increase is only for separating the stationary piston from the pressure relief unit.

[0052] Return to Figure 4 Therefore, it can be seen that the work done in this cycle is the area enclosed by the lines between the four states.

[0053] The pressure relief unit in this embodiment can be turned on or off.

[0054] When closed, the pressure relief unit balances the system as if the conventional / classic / standard piston were fully compressed into the conventional / classic / standard cylinder. The pressure relief unit is only closed in state 4.

[0055] When activated, the stationary piston does not contact the pressure relief unit, except for the seal that generates friction between the stationary piston and chamber 1 during expansion. Furthermore, the pistons in chamber 2 and chamber 3 are self-balancing. This allows the stationary piston to separate from the system while maintaining balance. The pressure relief unit is activated in states 1, 2, and 3, and along the path from state 1, 2, 3 up to state 4.

[0056] In the example operation of the implementation, the radius of the piston in chamber 210 is r = 6.5 cm, and the total depth of chamber 1 is d = 15 cm, which corresponds to a maximum volume V = 0.00199 m³. 3 .

[0057] In State 1, the pressure relief unit is submerged 12 m below sea level, meaning the water pressure exerted on it is 1.2 bar (gauge pressure). Furthermore, the total weight of the pressure relief unit is 49.5 kg, and to overcome gravity, air must be supplied at the following minimum pressure:

[0058] It should be noted that the radius of the piston in chamber 1 is r = 6.5 cm.

[0059] Therefore, the total resistance acting on the pressure relief unit can be expressed as: P 水 +P 重量 = 1.2 bar + 0.366 bar = 1.566 bar. However, the necessary pressure to be supplied to chamber 1 is only 0.5 bar. It should be noted that the water pressure acting on the top piston (corresponding to chamber 3) is offset by the pressure acting on the piston corresponding to chamber 2. Therefore, the supplied air does not need to overcome P. 水 =1.2 bar water pressure.

[0060] As the volume of chamber 1 increases, air is continuously supplied to chamber 1 at a constant pressure of 0.5 bar.

[0061] When transitioning from state 3 to state 4, the water pressure acting on the stationary piston, at a pressure of P = 1.2 bar, forces the piston into the interior of chamber 1, while the moving piston pushes the air in chamber 1 out through the air pipe.

[0062] When transitioning from state 2 to state 3, the effective pressure increases from 0.5 bar to 1.2 bar. This causes the volume to contract during the transition from state 3 to state 4, providing a greater force.

[0063] Best way to carry out the invention According to embodiments of the device of the present invention Figures 4 to 8 As shown, the device includes an elimination unit suitable for immersion use.

[0064] Alternative implementation methods Various variations of the above can be envisioned.

[0065] Figure 9 An embodiment of the elimination unit is shown, wherein the lower vertical shaft 216 is connected to the payload 105 to perform work.

[0066] One application of the pressure relief unit is as a heave compensator. In this embodiment, the pressure relief unit 200 is connected to the surface vessel by a body 202, while the vertical shaft 216 is connected to the payload 105 directly or via, for example, a connecting body with a wire. By controlling the pressure inside the chamber, the payload can be held in a fixed position relative to the seabed.

[0067] Industrial applicability The invention according to this application is applied in hydraulic systems such as hydraulic motors and heave compensators.

Claims

1. A pressure relief unit (200), the pressure relief unit (200) comprising a hollow relief body (202), the hollow relief body (202) having a cavity, in, The elimination body (202) is provided with multiple cylinders (212, 222A, 222B, 232) to respectively receive pistons (214, 224A, 224B, 234), wherein: A first horizontal piston (224A) is movably disposed inside a corresponding first horizontal cylinder (222A), wherein the first horizontal piston is operatively connected to an upper vertical piston (234), which is movably disposed inside a corresponding upper vertical cylinder (232). The second horizontal piston (224B) is movably disposed inside the corresponding second horizontal cylinder (222B), wherein the second horizontal piston is operatively connected to the upper vertical piston (234). The first horizontal cylinder (222A) and the second horizontal cylinder (224B) are fluidly connected to each other inside the hollow elimination body (202), and The first horizontal piston (224A) and the second horizontal piston (224B) are positioned opposite each other so that the hydrostatic pressure from each horizontal piston cancels out. The pressure relief unit (200) further includes a lower vertical piston (214), which is movably disposed inside a corresponding lower vertical cylinder (212). When the pressure relief unit is submerged in fluid, the outer surfaces of the four pistons are connected to the surrounding fluid.

2. A pressure relief unit (200), wherein, The first horizontal cylinder (222A) and the second horizontal cylinder (224B) are in the form of a continuous cylinder.

3. A method for operating a pressure relief unit (200) according to claim 1, the method beginning in stage 1, in which there is no contact between a fixed piston and the end of chamber 1, the method comprising the following steps: A: Supplying pressurized fluid to the lower vertical cylinder (212) such that: as the volume in chamber 1 increases, the pressure relief unit will move away from state 1 and toward state 2 until the lower vertical piston (214) is in a position such that the lower vertical piston (214) is no longer in contact with the end of the lower vertical cylinder (212) 1; B: Release the lower vertical piston (214) from its fixed position and open the outlet fluidly connected to the lower vertical cylinder (212), so that the pressure relief unit leaves state 2 and enters state 3; C: The ambient pressure acting on the lower vertical piston (214) is allowed to press the lower vertical piston (214) into the interior of the lower vertical cylinder (212), such that the moving piston pushes the fluid in the lower vertical cylinder (212) out through the outlet fluidly connected to the lower vertical cylinder (212) until the lower vertical piston (214) empties the lower vertical cylinder (212) and the pressure relief unit enters state 4, in which the pressure relief unit is in a balanced state; D: The lower vertical piston (214) is at least partially disengaged from the end of the lower vertical cylinder (212), such that: when the outlet operatively connected to the lower vertical cylinder (212) is opened, the pressure of the fluid in the lower vertical cylinder (212) returns to the ambient pressure, wherein, The pressure relief unit will return to state 1.

4. A hydraulic motor (100) for converting energy, the hydraulic motor (100) comprising: The pressure relief unit (200) according to any one of claims 1 to 2, wherein the lower vertical piston (214) is operatively connected to an actuator to perform work.

5. A method of operating a hydraulic motor (100) according to claim 4, comprising the steps of: a. Change the depth of the pressure relief unit (200), b. To make the lower vertical piston do work, wherein the work done (W) is the distance (d) moved by the lower piston multiplied by the force (F), and the force (F) is the pressure difference (ΔP) between the cavity pressure and the external fluid pressure multiplied by the area (A) of the lower piston.

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