Hydraulic oil tank and crane thereof

Abstract

The invention discloses a hydraulic oil tank and a crane thereof. The hydraulic oil tank comprises a closed oil tank body, and a pressure gauge I, an exhaust valve, a pressure gauge II, a pressure regulating device, a pressure reducing valve, an oil suction filter, an oil return filter, a liquid level meter and an oil discharge port are arranged on the oil tank body; the pressure reducing valve is connected with the air reservoir through a pipeline provided with a one-way valve; the oil return filter is provided with an oil return filter partition plate. The pressure and liquid level height self-adaptive compensation function is achieved, the oil pressure and the liquid level height can be dynamically adjusted in real time, generation of bubbles in the oil return process is effectively restrained, and the phenomena of pump air suction and cavitation are prevented; the vibration and noise level of a hydraulic system can be remarkably reduced, meanwhile, the service life of elements is prolonged, the working efficiency of the system is improved, and therefore reliable guarantee is provided for stable operation of the hydraulic transmission system.

Description

Technical Field

[0001] This invention relates to the field of cranes, and more particularly to a hydraulic oil tank and a crane thereof. Background Technology

[0002] Hydraulic transmission is one of the main transmission methods in engineering machinery. As an important auxiliary unit of the hydraulic system, the oil tank performs multiple functions, including storing the hydraulic oil required for system circulation, dissipating heat generated during system operation, separating gases from the oil, and settling particulate matter. During actual operation, the hydraulic oil level fluctuates due to mechanical movement. When the level drops, air may be introduced into the oil tank during the return flow, causing air bubbles to form. Once these bubbles are sucked into the hydraulic system, they will cause noise, vibration, and cavitation problems, adversely affecting the service life and efficiency of hydraulic components. Furthermore, a drop in the oil level in the tank will lead to a decrease in the absolute pressure at the hydraulic pump's suction port. Especially when the hydraulic pump's self-priming capability is weak, cavitation is likely to occur, further exacerbating cavitation and vibration noise. Therefore, addressing abnormal noise and noise reduction issues in hydraulic pump suction has become a critical problem that engineers urgently need to solve, and a well-designed hydraulic oil tank is an effective way to address these issues.

[0003] Existing technologies, such as patents CN 104454679 A, ​​CN 105134674 B, and CN 107630842 A, provide three types of bladder-type hydraulic oil tanks. The space inside the oil tank is connected to a flexible air bladder, which compensates for pressure changes within the oil tank. However, using an air bladder for pressure compensation can only regulate the oil pressure and cannot dynamically adjust the oil level.

[0004] Existing technologies, such as patents CN 107934784 A, CN 110778543 A, and CN 117869392 A, provide three types of pneumatic pressurization systems for hydraulic oil tanks. These systems utilize compressed air stored in an air tank to pressurize the oil tank and increase the oil pump's suction pressure. However, hydraulic oil tanks using air tanks and accumulators for pressure compensation have slow response times, high costs, complex structures, and can only adjust oil pressure, not dynamically adjust the oil level.

[0005] Existing technology, such as patent CN 113530897 A, provides a hydraulic oil tank anti-cavitation device, which is composed of a cylinder, a movable spring, and an isolation piston, and can effectively prevent cavitation from occurring. However, when using an anti-cavitation device for a hydraulic oil tank, this type of device does not have a pressurization effect and cannot perform pressure compensation. Summary of the Invention

[0006] Purpose of the invention: To address the shortcomings and defects of existing technologies, this invention provides a hydraulic oil tank and its crane, which has adaptive compensation functions for pressure and liquid level. It can dynamically adjust the oil pressure and liquid level in real time, effectively suppress the generation of air bubbles during the oil return process, and prevent pump cavitation and cavitation phenomena. It can significantly reduce the vibration and noise level of the hydraulic system, while extending the service life of components and improving the system's working efficiency, thereby providing a reliable guarantee for the stable operation of the hydraulic transmission system.

[0007] Technical solution: The present invention provides a hydraulic oil tank, characterized in that: it includes a closed tank body, on which are provided a pressure gauge I, an exhaust valve, a pressure gauge II, a pressure regulating device, a pressure reducing valve, an oil suction filter, a return oil filter, a level gauge and an oil drain port; the pressure reducing valve is connected to an air storage tank through a pipe equipped with a check valve; the return oil filter is provided with a return oil filter baffle.

[0008] The pressure regulating device includes a pressure regulating knob, a lead screw, a spring, a base, and a diaphragm piston. The pre-compression of the spring is adjusted by the pressure regulating knob and the lead screw. The spring is a compression spring, with its two ends fixed to the pressure regulating knob and the base, respectively. The spring moves with the diaphragm piston.

[0009] The gas stored inside the air reservoir is supplied by an air compressor, which is driven by an engine. The compressed air inside the air reservoir is regulated by a pressure reducing valve, and the pressure is reduced to the pressure required by the hydraulic oil tank before being input into the diaphragm piston on the left side of the hydraulic oil tank.

[0010] The hydraulic oil level in the tank changes with the movement of the actuator. When the internal pressure and level of the hydraulic oil tank decrease, compressed air from the air reservoir is input into the diaphragm piston inside the hydraulic oil tank through the pressure reducing valve. When the level rises, the internal pressure of the hydraulic oil tank increases. When the pressure rises to the set pressure of the exhaust valve, the exhaust valve opens, releasing the gas, the pressure reducing valve closes, and the air reservoir stops supplying air to the hydraulic oil tank. Furthermore, when the hydraulic oil level drops again, the internal pressure of the hydraulic oil tank decreases, the pressure reducing valve opens, and the air reservoir continues to supply air to the hydraulic oil tank. This cycle repeats continuously.

[0011] The exhaust valve is installed on the oil tank. The spring opening pressure of the exhaust valve is higher than the maximum operating pressure in the hydraulic oil tank. When the oil pressure exceeds the preset value, the exhaust valve works to release the pressure and protect the system safety.

[0012] The oil return filter baffle plate has oil inlets and round holes at its four corners and on its body to connect the oil suction area and the oil return area.

[0013] The oil return zone is equipped with an oil return filter and a level gauge.

[0014] The oil suction filter is installed on the oil suction flange. The oil suction filter is equipped with an oil suction screen, a connecting flange and a rotary valve. A rotary valve is installed at the outlet of the oil suction filter to control the oil suction flow.

[0015] The oil drain port is installed at the bottom of the oil tank.

[0016] A crane according to the present invention is characterized in that it uses the hydraulic oil tank of the present invention.

[0017] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: The present invention uses a spring diaphragm installed inside the oil tank to sense changes in oil pressure in real time, and a compressed air energy storage device configured outside the oil tank to provide a stable air source for the diaphragm piston. By precisely controlling the position of the diaphragm piston, the oil pressure and liquid level can be dynamically adjusted, providing a stable and reliable oil suction environment for the hydraulic pump and significantly improving the reliability of the hydraulic system operation.

[0018] This invention employs a pressure regulating device consisting of a spring and a diaphragm piston, combined with an air reservoir for replenishment, to achieve dynamic adjustment of hydraulic pressure. This ensures that the oil pressure in the tank remains constant, providing a stable oil suction environment for the hydraulic pump and effectively preventing pump cavitation and other cavitation phenomena. Furthermore, this invention dynamically adjusts the oil level, maintaining it within a reasonable range and ensuring that the oil does not come into contact with air during the return process, thus preventing the generation of excess air bubbles. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the present invention;

[0020] Figure 2 This is a side view of the structure of the present invention;

[0021] Figure 3 This is a schematic diagram of the cross-sectional structure of the present invention;

[0022] Figure 4 This is a schematic diagram of the structure of the return oil filter diaphragm of the present invention;

[0023] In the diagram, 1 is the oil tank; 2 is pressure gauge I; 3 is the exhaust valve; 4 is pressure gauge II; 5 is the pressure regulating device; 6 is the pressure reducing valve; 7 is the suction filter; 8 is the return filter; 9 is the level gauge; 10 is the drain port; 11 is the return filter baffle; 51 is the pressure regulating knob; 52 is the lead screw; 53 is the spring; 54 is the base; 55 is the diaphragm piston; 71 is the suction screen; 72 is the suction flange; 73 is the connecting flange; 74 is the rotary valve; 111 is the oil port; 112 is the round hole; 12 is the air tank; and 13 is the check valve. Detailed Implementation

[0024] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0025] The hydraulic oil tank of the present invention includes a closed tank body 1. The tank body 1 is equipped with a pressure gauge I2, an exhaust valve 3, a pressure gauge II4, a pressure regulating device 5, a pressure reducing valve 6, an oil suction filter 7, a return oil filter 8, a level gauge 9, and an oil drain port 10. The pressure reducing valve 6 is connected to an air reservoir 12 via a pipe equipped with a one-way valve 13. The return oil filter 8 is equipped with a return oil filter baffle 11. The pressure regulating device 5 includes a pressure regulating knob 51, a lead screw 52, ​​a spring 53, a base 54, and a diaphragm piston 55. The pre-compression of the spring 53 is adjusted by the pressure regulating knob 51 and the lead screw 52. The spring 53 is a compression spring, with its two ends fixed to the pressure regulating knob 51 and the base 54 respectively. The spring 53 moves with the diaphragm piston 55. The gas stored inside the air reservoir 12 is supplied by an air compressor driven by an engine. The compressed air inside the air reservoir 12 is regulated by the pressure reducing valve 6, reducing the pressure to the pressure required by the hydraulic oil tank, and then inputting it into the diaphragm piston 55 on the left side of the hydraulic oil tank. The hydraulic oil level in the tank changes with the movement of the actuator. When the internal pressure and level of the hydraulic oil tank decrease, compressed air inside the air reservoir 12 is input into the diaphragm piston 55 inside the hydraulic oil tank through the pressure reducing valve 6. When the level rises, the internal pressure of the hydraulic oil tank increases. When the pressure rises to the set pressure of the exhaust valve 3, the exhaust valve 3 opens, releasing the gas, the pressure reducing valve 6 closes, and the air reservoir 12 stops supplying air to the hydraulic oil tank. Furthermore, when the hydraulic oil level drops again, the internal pressure of the hydraulic oil tank decreases, the pressure reducing valve 6 opens, and the air reservoir 12 continues to supply air to the hydraulic oil tank; this cycle repeats continuously. The exhaust valve 3 is installed on the oil tank body 1. The spring opening pressure of the exhaust valve 3 is higher than the maximum operating pressure inside the hydraulic oil tank. When the oil pressure exceeds the preset value, the exhaust valve works to release the pressure and protect the system safety.

[0026] The return oil filter baffle 11 of the present invention has oil ports 111 and round holes 112 at its four corners and on its body for connecting the oil suction zone and the oil return zone. The oil return zone is equipped with an oil return filter 8 and a level gauge 9. The oil suction filter 7 is installed on the oil suction flange 72 and includes an oil suction screen 71, a connecting flange 73, and a rotary valve 74. A rotary valve is installed at the outlet of the oil suction filter 7 to control the oil suction flow rate. The oil drain port 10 is installed at the bottom of the oil tank 1.

[0027] The hydraulic oil tank of the present invention, which has adaptive compensation functions for pressure and liquid level, includes a pressure regulating mechanism, a gas supply mechanism, and a tank body. The pressure regulating mechanism achieves dynamic pressure regulation through elastic drive elements and seals, while the gas supply mechanism achieves intelligent gas supply through a gas storage tank and a pressure control element. When the operation of the actuator causes changes in the pressure and liquid level inside the tank, the pressure regulating mechanism and the gas supply mechanism work together to maintain the stability of the system pressure and liquid level.

[0028] The hydraulic oil tank pressure and level adaptive compensation method of the present invention involves the following steps: when the pressure and level in the oil tank decrease, a gas source device supplies compressed gas to the oil tank for pressure compensation; when the pressure in the tank rises to a preset threshold, a pressure release device opens to release the gas; when the pressure decreases again, the gas source device restarts gas supply; through the repeated cycle of the above pressure compensation and pressure release processes, the pressure and level in the tank are adaptively adjusted.

[0029] The oil tank of this invention is equipped with a pressure relief device. The opening threshold of the pressure relief device is higher than the maximum operating pressure of the oil tank. When the pressure inside the tank exceeds the threshold, the pressure relief device operates to release the overpressure and ensure the safe operation of the system. This invention achieves dynamic compensation of oil pressure and liquid level through purely mechanical control, but it can also be controlled by an electrical system.

[0030] This invention uses a spring diaphragm installed inside the oil tank to sense changes in oil pressure in real time. A compressed air energy storage device is configured outside the oil tank to provide a stable air source for the diaphragm piston. By precisely controlling the position of the diaphragm piston, the oil pressure and level can be dynamically adjusted, providing a stable and reliable oil suction environment for the hydraulic pump and significantly improving the reliability of the hydraulic system.

[0031] This invention employs a pressure regulating device consisting of a spring and a diaphragm piston, combined with an air reservoir for replenishment, to achieve dynamic adjustment of hydraulic pressure. This ensures that the oil pressure in the tank remains constant, providing a stable oil suction environment for the hydraulic pump and effectively preventing pump cavitation and other cavitation phenomena. Furthermore, this invention dynamically adjusts the oil level, maintaining it within a reasonable range and ensuring that the oil does not come into contact with air during the return process, thus preventing the generation of excess air bubbles.

Claims

1. A hydraulic oil tank characterized by: The hydraulic oil tank comprises a closed oil tank body (1), and the oil tank body (1) is provided with a pressure gauge I (2), an exhaust valve (3), a pressure gauge II (4), a pressure regulating device (5), a pressure reducing valve (6), an oil suction filter (7), an oil return filter (8), a liquid level gauge (9) and a oil drain port (10); the pressure reducing valve (6) is connected with an air reservoir (12) through a pipeline provided with a one-way valve (13); and the oil return filter (8) is provided with an oil return filter partition plate (11).

2. The hydraulic oil tank according to claim 1, characterized by: The pressure regulating device (5) comprises a pressure regulating knob (51), a lead screw (52), a spring (53), a base (54) and a diaphragm piston (55); the pre-compression amount of the spring (53) is adjusted through the pressure regulating knob (51) and the lead screw (52); the spring (53) is a compression spring, and the two ends of the spring (53) are fixed on the pressure regulating knob (51) and the base (54) respectively; and the spring (53) moves along with the diaphragm piston (55).

3. The hydraulic oil tank according to claim 2, characterized by: The gas stored in the air reservoir (12) is provided by an air compressor, and the air compressor is driven by an engine; the compressed air in the air reservoir (12) is adjusted through the pressure reducing valve (6), and the pressure is reduced to the pressure required by the hydraulic oil tank, and then the compressed air is input into the diaphragm piston (55) on the left side of the hydraulic oil tank.

4. The hydraulic oil tank according to claim 3, characterized by: The liquid level of the hydraulic oil tank changes along with the movement of an actuator; when the internal pressure and the liquid level height of the hydraulic oil tank decrease, the compressed air in the air reservoir (12) is input into the diaphragm piston (55) in the hydraulic oil tank through the pressure reducing valve (6); when the liquid level rises, the internal pressure of the hydraulic oil tank rises; when the pressure rises to the set pressure of the exhaust valve (3), the exhaust valve (3) is opened, the gas is discharged, the pressure reducing valve (6) is closed, and the air reservoir (12) stops supplying air to the hydraulic oil tank; further, when the liquid level of the hydraulic oil tank decreases again, the internal pressure of the hydraulic oil tank decreases, the pressure reducing valve (6) is opened, and the air reservoir (12) continues to supply air to the hydraulic oil tank; and the above-mentioned process is repeated.

5. The hydraulic oil tank according to claim 4, characterized in that: The exhaust valve (3) is installed on the oil tank body (1), the spring opening pressure of the exhaust valve (3) is higher than the maximum operating pressure in the hydraulic oil tank, the exhaust valve works to release pressure when the oil pressure exceeds the preset value, and the system safety is protected.

6. The hydraulic oil tank according to claim 1, characterized by: The oil return filter partition plate (11) is provided with oil ports (111) and circular holes (112) on the four corners and the plate body, and is used for connecting the oil suction area and the oil return area.

7. The hydraulic oil tank according to claim 6, characterized in that: The oil return filter (8) and the liquid level gauge (9) are installed in the oil return area.

8. The hydraulic oil tank according to claim 1, characterized by: The oil suction filter (7) is installed on the oil suction flange (72), and is provided with an oil suction filter screen (71), a connecting flange (73) and a rotary valve (74); the rotary valve is installed at the outlet of the oil suction filter (7), and is used for controlling the oil suction flow.

9. The hydraulic oil tank according to claim 1, characterized by: The oil drain port (10) is installed at the bottom of the oil tank body (1).

10. A crane, characterized by: The hydraulic oil tank of any one of claims 1-9 is used.

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