Hydraulic motor

Abstract

A hydraulic motor for energy conversion and a method for operating the hydraulic motor for energy conversion are provided. The present invention achieves the above objective by a pressure neutralization unit that can selectively neutralize ambient pressure outside the pressure neutralization unit.

Description

[Technical Field]

[0001] The present invention generally relates to mechanical conversion, and more particularly to systems and methods for hydraulic motors. [Background technology]

[0002] The latest technology is being incorporated into conventional hydraulic systems such as hydraulic cylinders.

[0003] From conventional technology, we consider a hydraulic system that applies pressure to a cylinder to displace a piston located inside the cylinder. This pressure acts on the load connected to the piston and also on the ambient pressure. As the depth increases, the ambient pressure increases, and greater pressure is required to supply sufficient excess pressure to overcome the effects of the ambient pressure.

[0004] According to the translation of the abstract, CN115467867A discloses a pressure equalizer, a hydraulic system, and an operating machine, the pressure equalizer comprising a valve body, an oil discharge main pipeline, an opening valve element, and a pressure regulating assembly, the valve body being provided with an oil discharge cavity, a first oil port, and a second oil port, the first and second oil ports communicating with the oil discharge cavity, the first oil port communicating with the oil discharge port of a hydraulic motor, the second oil port communicating with the oil discharge main pipeline, the opening valve element sealing the first oil port, the opening valve element being movably positioned within the oil discharge cavity, and the pressure regulating assembly applying a first pressure to the opening valve element when the pressure in the oil discharge main pipeline is higher than the external atmospheric pressure.

[0005] According to the translation of the abstract, EP3222856A1 discloses a self-contained pressure compensation system and a method for controlling the same, the self-contained pressure compensation system comprising an oil supply device, a pressure compensation device, a power unit associated with the pressure compensation device, and a switch control device, wherein the pressure compensation device supplies oil to the power unit and detects changes in its own chamber pressure in real time, and the switch control device triggers the oil supply device to supply oil to the pressure compensation device when the chamber pressure falls below a predetermined first threshold, and triggers the oil supply device to stop supplying oil to the pressure compensation device when the chamber pressure exceeds a predetermined second threshold.

[0006] CN201520281074U, according to the translation of the abstract, discloses a deep-sea valve actuation mechanism with a bidirectional pressure dynamic balance compensator, comprising an actuation mechanism, a piston pressure balance compensator, and a valve adaptation unit. The piston pressure balance compensator is located outside the actuation mechanism and connected to the actuation mechanism, and the actuation mechanism is connected to a submerged valve through the valve adaptation unit. The actuation mechanism comprises an actuation mechanism casing, a pneumatic cylinder end cover, a piston rod, a drive sleeve, a spring holder, and several springs. The piston pressure balance compensator comprises a pressure balance wear casing, one side of which is provided with a filter end cover, and the opposite side is connected to the actuation mechanism through a connecting shaft. A piston is provided within the pressure balance wear casing, and the piston is divided into a dynamic balance chamber and a seawater compensation cavity with an equalizer casing.

[0007] NO341441B1, according to the abstract, discloses a depth-compensating actuator comprising a minimum of two small cylinders, each including a piston tube, a piston rod, and a tail rod. The piston rods belonging to the minimum of two small cylinders are connected by rod connecting means and comprise a first connecting means. The minimum of one large cylinder comprises a piston tube, a piston rod with a second connecting means, and a tail rod. The cylinders are connected by cylinder connecting means, which form a rigid connection that prevents the cylinder tubes from moving relative to each other.

[0008] CN2654920Y, according to the translated abstract, discloses a seawater environmental pressure compensator for underwater hydraulic systems. The utility model has the advantage of sensing the pressure around seawater and transmitting the seawater environmental pressure to the hydraulic system to compensate for the pressure in the hydraulic system, thereby eliminating or reducing the influence of the seawater environmental pressure on the hydraulic system. The utility model comprises a mechanical seawater pressure sensing unit, an automatic discharge unit, and an automatic lubrication unit. A rolling membrane is used to sense the seawater environmental pressure, and the pressure to be compensated is slightly higher than the seawater environmental pressure due to the initial pressure function of a long-term stress spring, thus preventing seawater from entering the hydraulic system. A special triple-seal design ensures that the compensator can operate reliably for a long period of time. An automatic discharge unit is used to ensure the automatic discharge of air from inside the device. An automatic lubrication unit is used to complete the lubrication function of the pressure sensing unit. The pressure compensator overcomes the shortcomings of conventional pressure compensators. [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] Therefore, methods and systems to overcome the above problems are needed.

[0010] Therefore, the main object of the present invention is to provide a system and method for a hydraulic motor. [Means for solving the problem]

[0011] According to the present invention, this objective is achieved by a pressure neutralization unit described in the preamble of claim 1 having the features of the feature part of claim 1, a method for operating the pressure neutralization unit described in the preamble of claim 3 having the features of the feature part of claim 3, a hydraulic motor described in the preamble of claim 4 having the features of the feature part of claim 4, and a method for operating the hydraulic motor described in the preamble of claim 5 having the features of the feature part of claim 5.

[0012] Some non-exclusive embodiments, variations, or alternatives of the present invention are defined by the dependent claims.

[0013] The present invention achieves the above objective by a pressure neutralization unit that can selectively neutralize ambient pressure outside the pressure neutralization unit. [Effects of the Invention]

[0014] The technical difference from conventional hydraulic systems is that the pressure neutralization unit can selectively neutralize ambient pressure outside the unit.

[0015] These effects, in turn, lead to several further advantageous effects: This makes it possible to operate the hydraulic system with lower power. Because ambient pressure is neutralized, it becomes possible to operate the system at lower pressures. Because the pressure difference can be reduced, it becomes possible to use lighter materials.

[0016] The above and further features of the present invention are described in detail in the appended claims, and will become more apparent by considering the following detailed description of (exemplary) embodiments of the present invention with reference to the appended drawings, together with the advantages thereof.

[0017] The present invention will be further described below in connection with exemplary embodiments schematically shown in the drawings.

Brief Description of the Drawings

[0018] [Figure 1] It is a diagram showing an exception to Archimedes' principle of buoyancy. [Figure 2] It is a diagram showing the principle of FIG. 1 applied to a pressure nullifying unit. [Figure 3] It is a diagram showing the nullifying unit in detail. [Figure 4] It is a diagram showing a P-V diagram. [Figure 5] It is a diagram showing the nullifying unit at position A in the P-V diagram. [Figure 6] It is a diagram showing the nullifying unit at position B in the P-V diagram. [Figure 7] It is a diagram showing the nullifying unit at position C in the P-V diagram. [Figure 8] It is a diagram showing the nullifying unit at position D in the P-V diagram. [Figure 8B] It is a diagram showing the force acting on the nullifying unit at position D in the P-V diagram. [Figure 9] It is a diagram showing an application example of the nullifying unit as a heave compensator with a payload.

Embodiments for Carrying Out the Invention

[0019] Detailed Description of the Present Invention Various aspects of this disclosure are described more fully below with reference to the accompanying drawings. However, this disclosure may be embodied in many different forms and should not be construed as being limited to any particular structure or function presented throughout this disclosure. Rather, these aspects are provided so that this disclosure may be thorough and complete and so that the scope of this disclosure may be fully conveyed 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 all aspects of the disclosure disclosed herein, whether implemented independently or in combination with other aspects of the disclosure. For example, an apparatus may be implemented or a method may be carried out using any number of aspects described herein. Furthermore, the scope of this disclosure is intended to cover such apparatus or method carried out using, in addition to or with other structures, functions, or structures and functions, in addition to the various aspects of the disclosure described herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied in one or more elements of the claims.

[0020] The present invention will be further described in relation to exemplary embodiments schematically shown in the drawings.

[0021] Principles forming the basis of this invention Figure 1 illustrates an exception to the well-known Archimedes' principle of buoyancy (ABP), which forms the basis of this invention. This exception occurs when an object in water is not completely surrounded by a continuous fluid. This exception can occur when an object in water is in the fluid except in contact with a container holding the fluid, for example, when a cube is placed at the bottom of a swimming pool. At this point, as in the normal case of ABP, the forces acting horizontally still cancel each other out in general. However, the forces acting vertically are different. The downward force is the area integral of the pressure acting on the top surface at the height of the cube. This can be written as follows:

number

[0022] This is in contrast to the usual ABP condition where the force can be written as follows: [Number] Here, ρ f is the density of the fluid, V disp,f is the displaced volume of the fluid, g is the acceleration due to gravity, [Number] is the unit vector directed upward along the z-axis, m f,disp is the total mass of the fluid displaced volume (V disp,f ).

[0023] The inventor recognized that using the above, a system can be devised in which forces act on both sides of the central unit, operate in opposite directions, and thereby cancel each other out.

[0024] FIG. 2 shows the principle of FIG. 1 applied to a pressure nullification unit in which forces are canceled by forces acting in opposite directions. The water columns shown are related to Pascal's law and indicate how much force is applied to each piston. The opposing pistons cancel each other's forces, and the wire also applies a force that cancels the force applied to the third piston. As a result, a force remains on the fourth piston provided on the opposite side of the third piston.

[0025] Figure 3 shows the deactivation unit 200 in detail. This unit is a hollow deactivation body 202 having a cavity provided with multiple cylinders for receiving one or more pistons.

[0026] In one embodiment, the cavity is divided into the following three chambers: A lower chamber 210 is provided inside the vertical cylinder 212 and includes a lower vertical piston 214. An intermediate chamber 220 comprising a first horizontal piston 224A and a second horizontal piston 224B, which are movably provided inside the corresponding first horizontal cylinder 222A and second horizontal cylinder 222B and are arranged opposite to each other so as to cancel out the hydrostatic pressure from either of them, An upper chamber 230 comprising an upper vertical piston 234 located inside a vertical cylinder 232.

[0027] The first and second pistons 224A and 224B are operatively connected to the upper vertical piston 234 using wires and pulleys such that the inward movement of the first and second pistons causes the outward movement of the upper piston.

[0028] The lower chamber 210 is equipped with an air hose and an attached air vent to supply air to the chamber when needed. The air vent can also be opened and closed. All of this is operated from above sea level, from land. The intermediate chamber 220 is equipped with an air vent, which is closed before the deactivation unit is submerged in water. In other words, no air is supplied to this chamber.

[0029] The piston has an outer surface exposed to the fluid surrounding the deactivation unit and an inner surface exposed to the respective volume of each chamber.

[0030] The lower, upper, and intermediate chambers are provided with means for adding or removing fluid sealed within the chambers.

[0031] Typically, an air hose that is always open is attached to the upper chamber 230, and therefore, if the volume of the intermediate chamber 220 changes, air can freely enter and exit this chamber. In this case, the upper chamber 230 has a constant pressure of P = 1 bar (atmospheric pressure).

[0032] A first horizontal piston is movably mounted inside a corresponding first horizontal cylinder and is operatively connected to an upper vertical piston, which is movably mounted inside a corresponding upper vertical cylinder. Similarly, a second horizontal piston is movably mounted inside a corresponding second horizontal cylinder and is operatively connected to an upper vertical piston. The first and second pistons are positioned so as to cancel out the hydrostatic pressure from either of them.

[0033] The first and second horizontal pistons are operatively connected to the upper vertical piston such that the inward movement of the first and second pistons causes the outward movement of the upper piston. This can be achieved using a mechanical linkage mechanism such as a rod or wire and pulley.

[0034] Typically, the cavity is filled with a compressible fluid, while the surrounding fluid may be an incompressible fluid such as a liquid. Such a liquid could be water, for example.

[0035] Therefore, when unit 200 is lowered into the pool, the pressure in the cavity will reflect the pressure difference, as described in the exception of ABP. This difference can be applied to perform work in a different manner than a single cylinder with a piston sealed with a closed working medium.

[0036] Figure 4 shows a PV diagram with four corner positions. The principle of the present invention is to use a neutralizing unit to reduce the effective pressure experienced by at least one of the chambers, and thus reduce the effective work performed to move at least one piston. In the following example, the lower piston performs the effective work, and the other three pistons operate to neutralize at least a portion of the effective external pressure acting on the lower piston.

[0037] The transitions shown in the PV diagram are caused by the movement of fluid inside and outside the chamber. The line returning to the beginning of the cycle in the PV diagram does not enclose a region and therefore does no work. The transition from step 2 to step 3 follows a path where the integral is non-zero. This transition occurs by stopping the deactivation effect, which is then restarted in the transition from step 4 back to step 1.

[0038] Figures 5 to 8 show typical cycle examples in the form of pressure-volume (PV) diagrams illustrating energy transfer. In this configuration, chamber 1 corresponds to the upper chamber 230, chamber 2 corresponds to the intermediate chamber 220, and chamber 3 corresponds to the lower chamber 210.

[0039] Chamber 1: This chamber is equipped with an air hose and an attached air vent to supply air to the chamber when needed. The air vent can also be opened and closed. All of this is operated from above sea level, on land. Chamber 2: This chamber is equipped with an air vent, which is closed before the pressure neutralization unit is submerged in water. In other words, no air is supplied to this chamber. Chamber 3: This chamber is fitted with an air hose that is always open, allowing air to freely enter and exit this chamber when the volume of Chamber 2 changes. Furthermore, Chamber 3 maintains a constant pressure of P = 1 bar (atmospheric pressure).

[0040] Figure 5 shows the system in state 1, which is the starting position, as shown in Figure 4.

[0041] In state 1, the pressure neutralization unit is separated 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 that fixes and holds the lower piston. That is, in state 1, there is no contact between the fixed piston and the end of chamber 1.

[0042] State 1 → State 2: The piston in chamber 1 is kept in a fixed position as shown in Figure 5. Pressurized air is then supplied to chamber 1, and as the volume in chamber 1 increases, the pressure neutralization unit transitions from state 1 to state 2. Typically, the pressure does not increase instantaneously, especially if the valve is on the surface and it takes time for the air hose to pressurize before supplying air to chamber 1, so the pressure increases as the volume increases.

[0043] Figure 5 also shows the pulley forces acting on the pressure neutralization unit as the volume of chamber 1 increases and approaches maximum expansion. Note how the equilibrium of the pressure neutralization unit is when the fixed piston is no longer in contact with the end of chamber 1. The fixed piston is no longer in contact with the end of chamber 1, and therefore the piston in chamber 2 and the piston in chamber 3 are in a new equilibrium state.

[0044] Figure 6 shows the system in state 2 of Figure 4, which is the end position of the expansion. The pressure neutralization unit is in equilibrium, and the fixed piston is away from the end of chamber 1.

[0045] State 2 → State 3: The piston corresponding to chamber 1 is released from its fixed position here, and the air vent of chamber 1 is opened. This means that ambient pressure is now applied directly and fully to chamber 1, and therefore the pressure increases as quickly as the release is completed. The pressure neutralization unit then transitions from state 2 to state 3 as the piston in chamber 1 is released from its fixed position.

[0046] Figure 7 shows the system in state 3 of Figure 4, which is the starting position of the transition where the piston in chamber 1 is pushed in by ambient pressure and the volume V decreases.

[0047] State 3 → State 4: After the piston corresponding to chamber 1 is released, the piston moves inside chamber 1, thus reducing the volume of chamber 1. Due to the water pressure acting on the piston, the piston is pushed inside chamber 1 at a water pressure of P = 1.2 bar, and the moving piston pushes the air inside chamber 1 through the air hose.

[0048] The piston corresponding to chamber 1 now empties the volume of chamber 1, and the pressure neutralization unit enters state 4. In state 4, the pressure neutralization unit is in equilibrium, similar to a normal piston and cylinder system. This is illustrated in Figure 8B. The pressure on the pressure neutralization unit shown in Figure 7 arises from the fact that the pressure neutralization unit is submerged.

[0049] Figure 8 shows the system in state 4 of Figure 4, where the piston in chamber 1 is again in full contact with the end of the cylinder. Only in state 4 is the piston in direct contact with the end of the cylinder, and no deactivation effect occurs.

[0050] State 4 → State 1: The piston corresponding to chamber 1 returns to its fixed position. Furthermore, as shown in Figure 8, it moves slightly away from the edge of chamber 1 and no longer contacts the edge of chamber 1. Thus, because the air hose is open in chamber 1, the air pressure in chamber 1 returns to 1 bar, and the pressure neutralization unit returns to state 1. Here, the volume is almost equal to 0, with little increase in volume, only increasing to separate the fixed piston from the pressure neutralization unit.

[0051] Therefore, returning to Figure 4, it is demonstrated that the work performed in this cycle is the region enclosed by the lines between the four states.

[0052] The pressure neutralization unit in this embodiment can be turned on or off. When switched off, the equilibrium state of the pressure neutralization unit corresponds to a normal / conventional / standard piston being fully compressed into a normal / conventional / standard cylinder. The pressure neutralization unit is switched off only in state 4. When switched on, the fixed piston no longer comes into contact with the pressure neutralization unit, except for a seal that creates friction between the fixed piston and chamber 1 during expansion. Furthermore, the piston in chamber 2 and the piston in chamber 3 become equilibrium with each other. Thus, it becomes possible to isolate the fixed piston from the system while maintaining equilibrium. The pressure neutralization unit is switched on in states 1, 2, and 3, as well as in the path from states 1, 2, and 3 to state 4.

[0053] In an exemplary execution of one embodiment, 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 V = 0.00199 m 3 It corresponds to the maximum volume.

[0054] In State 1, the pressure neutralization unit is submerged 12m below sea level, meaning it is subjected to a water pressure (gauge pressure) of 1.2 bar. Furthermore, the pressure neutralization unit has a total weight of 49.5 kg and requires the following minimum air pressure to overcome gravity.

number

[0055] Note that the radius of the piston in chamber 1 is r = 6.5 cm. Therefore, the total resistance of the pressure neutralization unit is P water +P weight This can be expressed as =1.2 bar + 0.366 bar = 1.566 bar. However, the required pressure to be supplied to chamber 1 is only 0.5 bar. Note that the water pressure acting on the upper piston (corresponding to chamber 3) is canceled out by the pressure acting on the piston corresponding to chamber 2. Therefore, the supplied air is at water pressure P water It does not need to exceed 1.2 bar.

[0056] As the volume of chamber 1 increases, air at a constant pressure of 0.5 bar is continuously supplied to chamber 1.

[0057] When transitioning from state 3 to state 4, the water pressure acting on the fixed piston pushes the piston inward into chamber 1 at a water pressure of P=1.2 bar, and the moving piston pushes the air inside chamber 1 through the air hose.

[0058] When transitioning from state 2 to state 3, the effective pressure increases from 0.5 to 1.2 bar. This results in a stronger force during the transition from state 3 to state 4, causing the volume to contract.

[0059] Best mode for carrying out the invention The embodiments of the apparatus according to the present invention shown in Figures 4 to 8 include a deactivation unit suitable for use in a submerged state.

[0060] Alternative Embodiments Several variations are possible for the above.

[0061] Figure 9 shows one embodiment of a deactivation unit in which the lower vertical shaft 216 is connected to the payload 105 to perform its work.

[0062] One application is to use the pressure neutralization unit as a heave compensator. In this embodiment, the pressure neutralization unit 200 is connected to a surface vessel by a body 202, and the vertical shaft 216 is connected to the payload 105 directly or via a connector such as a wire. By controlling the pressure in the chamber, it is possible to hold the payload in a stable position relative to the seabed.

[0063] Industrial applicability The invention described in this application is used in hydraulic devices such as hydraulic motors and heave compensators. [Explanation of Symbols]

[0064] The following reference numbers and symbols refer to drawings: 100 Systems 105 payload 200 Disable Units 202 Disabled main unit 210 Lower Chamber 212 Lower vertical cylinder 214 Lower vertical piston 216 Lower vertical shaft 220 Intermediate Chamber 222A First horizontal cylinder 222B Second horizontal cylinder 224A First horizontal piston 224B Second horizontal piston 230 Upper Chamber 232 Upper vertical cylinder 234 Upper vertical piston

Claims

1. A pressure neutralization unit (200) comprising a hollow neutralization body (202) having a cavity, The deactivating body (202) is provided with a plurality of cylinders (212, 222A, 222B, 232) to receive pistons (214, 224A, 224B, 234), respectively. A first horizontal piston (224A) is movably mounted inside a corresponding first horizontal cylinder (222A), and the first horizontal piston is operably connected to an upper vertical piston (234) which is movably mounted inside a corresponding upper vertical cylinder (232). The second horizontal piston (224B) is movably mounted inside the corresponding second horizontal cylinder (222B), and the second horizontal piston is operably connected to the upper vertical piston (234). The first and second horizontal cylinders (222A, 224B) are in fluid communication with each other within the hollow neutralized body (202), The first and second horizontal pistons (224A, 224B) are arranged facing each other such that the hydrostatic pressure from either of the horizontal pistons cancels out. The system further comprises a lower vertical piston (214) movably provided inside the corresponding lower vertical cylinder (212), The four pistons each have an outer surface that is exposed to the surrounding fluid when the pressure neutralization unit is submerged in the fluid. Pressure neutralization unit (200).

2. The first horizontal cylinder (222A) and the second horizontal cylinder (224B) form a single continuous cylinder, which constitutes a pressure neutralization unit (200).

3. A method for operating the pressure neutralization unit (200) according to claim 1, starting from stage 1 where there is no contact between the fixed piston and the end of chamber 1, A: A step in which pressurized fluid is supplied to the lower vertical cylinder (212) until the lower vertical piston (214) no longer contacts the end of the lower vertical cylinder (212) 1, thereby causing the pressure neutralization unit to transition from state 1 to state 2 as the volume in the chamber 1 increases. B: The lower vertical piston (214) is released from its fixed position, and the vent fluid-connected to the lower vertical cylinder (212) is opened, thereby causing the pressure neutralization unit to transition from state 2 to state 3. C: The ambient pressure acting on the lower vertical piston (214) pushes the lower vertical piston (214) inward toward the lower vertical cylinder (212), the moving piston pushes the fluid inside the lower vertical cylinder (212) through the vent which is fluid-connected to the lower vertical cylinder (212), the lower vertical piston (214) empties the lower vertical cylinder (212), and thereby the pressure neutralization unit enters state 4, which is the equilibrium state of the pressure neutralization unit. D: The lower vertical piston (214) is moved at least partially away from the end of the lower vertical cylinder (212), so that when the vent operatively connected to the lower vertical cylinder (212) opens, the fluid pressure inside the lower vertical cylinder (212) returns to ambient pressure, and the pressure neutralization unit returns to state 1. A method that includes this.

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

5. A method for operating the hydraulic motor (100) described in claim 4, a. A step of changing the depth of the pressure neutralization unit (200), b. The step of causing the lower vertical piston to perform work, The work (W) is the product of the distance (d) traveled by the lower piston and the force (F), and the force (F) is the product of the pressure difference (ΔP) between the pressure in the cavity and the pressure of the external fluid and the area (A) of the lower piston. method.

Images