Positive pressure oil tank for fan hydraulic system

Abstract

The utility model relates to a positive pressure oil tank for a fan hydraulic system, which belongs to the technical field of fan hydraulic systems, and comprises a tank body, a positive pressure oil tank and a positive pressure oil tank, the cylinder barrel is arranged on the end face of one side of the box body, and a cylinder barrel piston abutting against the inner wall face of the cylinder barrel is arranged in the cylinder barrel; one end of the piston rod is connected with the box body piston, and the other end is inserted into the cylinder barrel and connected with the cylinder barrel piston; an area defined by the box body, the end face, where the cylinder barrel is located, of the box body and the outer wall face, between the box body and the cylinder barrel, of the box body is a low-pressure cavity, and hydraulic oil is filled in the low-pressure cavity. An area defined by the cylinder barrel piston, the cylinder barrel end face where the piston rod is inserted and the outer wall face of the cylinder barrel between the cylinder barrel piston and the cylinder barrel end face is a high-pressure cavity and filled with hydraulic oil. Compared with the prior art, hydraulic oil in the low-pressure cavity is pressurized through the high-pressure cavity, and pressurization through compressed gas or a spring is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of fan hydraulic systems, in particular to a positive pressure oil tank for a fan hydraulic system. Background Art

[0002] There are two main types of positive pressure oil tanks on the market: one is to use compressed gas to pressurize the oil tank, and the other is to use springs to pressurize the oil tank. If compressed gas is used for pressurization, once the compressed gas leaks, the pressurization function will fail, and the gas pressure is affected by temperature; if springs are used for pressurization, the change in the force of the spring during the tension and compression process will cause unstable pressurization. If used on high fatigue working equipment, the reliability and service life of the spring will be a shortcoming, and spring failure may cause serious damage to the equipment. Utility Model Content

[0003] The purpose of the present utility model is to provide a positive pressure oil tank for a fan hydraulic system in order to overcome at least one of the defects of the above-mentioned prior art. The oil tank introduces high-pressure oil from the outside into the high-pressure cavity, thereby pressurizing the hydraulic oil in the low-pressure cavity, avoiding the use of compressed gas or springs for pressurization.

[0004] The purpose of the utility model can be achieved through the following technical solutions:

[0005] A positive pressure oil tank for a fan hydraulic system, comprising:

[0006] A box body, in which a box body piston is arranged to abut against the inner wall surface of the box body;

[0007] A cylinder barrel is arranged on one end surface of the box body, and a cylinder barrel piston is arranged therein and abuts against the inner wall surface of the cylinder barrel;

[0008] A piston rod, one end of which is connected to the box piston and the other end of which is inserted into the cylinder and connected to the cylinder piston;

[0009] Among them, the area surrounded by the box body, the box end surface where the cylinder is located, and the outer wall surface of the box body between the two is a low-pressure cavity filled with hydraulic oil; the area surrounded by the cylinder piston, the cylinder end surface where the piston rod is inserted, and the outer wall surface of the cylinder between the two is a high-pressure cavity filled with hydraulic oil.

[0010] Furthermore, the box body includes a box body cylinder and sealing end covers arranged on both sides of the box body cylinder; a first flange ring is arranged at both ends of the cylinder body, and a spring retaining ring is arranged on the inner ring side of the first flange ring; the sealing end cover includes an end cover and a second flange ring arranged concentrically with the end cover, and the first flange ring and the second flange ring are connected by bolts.

[0011] Furthermore, an oil return port and a first oil outlet are arranged on the sealing end cover of the box body on the side facing the cylinder barrel; and an air vent and an oil drain port are arranged on the sealing end cover of the box body on the side facing away from the cylinder barrel.

[0012] Furthermore, a second oil outlet is provided on a side of the cylinder barrel facing the box body, which is used for the hydraulic oil in the high-pressure cavity to enter and exit.

[0013] Furthermore, one end of the cylinder barrel extends into the box body, and a cylinder piston rod sealing portion is provided at the abutment between the end and the piston rod; and a cylinder piston sealing portion is provided at the cylinder barrel piston.

[0014] Furthermore, a one-way valve or a low-pressure relief valve is also provided on the box piston to avoid overpressure of the box.

[0015] Furthermore, the box body and the cylinder barrel are both cylindrical.

[0016] Furthermore, a displacement sensor is provided at one end of the cylinder away from the box body, preferably a non-contact magnetostrictive displacement sensor.

[0017] Furthermore, an oil return filter and / or an overflow valve and / or a temperature sensor is provided on the end cover of the box body facing the cylinder barrel.

[0018] Furthermore, a heating element is provided on the outer wall of the box.

[0019] Compared with the prior art, the utility model has the following advantages:

[0020] (1) The utility model provides a positive pressure oil tank for a fan hydraulic system, which introduces high-pressure oil from the outside into a high-pressure cavity, thereby pressurizing the hydraulic oil in the low-pressure cavity, avoiding the use of compressed gas or springs for pressurization; compared with an oil tank pressurized by compressed gas, the utility model eliminates the failure of the positive pressure function of the oil tank due to leakage of compressed gas, reduces the operation and maintenance requirements, and regular operation and maintenance does not require inspection and replenishment of compressed gas; compared with an oil tank pressurized by a spring, the utility model avoids significant fluctuations in the oil tank pressure caused by changes in the reaction force of the spring during the tension and compression process;

[0021] (2) The utility model provides a positive pressure oil tank for a fan hydraulic system, in which the oil cylinder piston rod seal is immersed in the oil tank, and the oil cylinder piston seal is connected to the oil tank. Even if the high pressure seal fails, the high pressure oil will only leak into the oil tank, and the oil will not leak out of the oil tank, thereby avoiding environmental pollution;

[0022] (3) The utility model provides a positive pressure oil tank for a fan hydraulic system, the tank body and cylinder barrel of which are both cylindrical, and the cylindrical design has equal circumferential pressure, uniform stress distribution, and fatigue resistance;

[0023] (4) The utility model provides a positive pressure oil tank for a fan hydraulic system. The flanges on both sides of the oil tank adopt a spring retaining ring design. Compared with the traditional welded flange connection, the welding process is omitted, the risk of cylinder deformation caused by welding is avoided, and the non-destructive testing of the weld is omitted, so the reliability is high and the cost is low;

[0024] (5) The utility model provides a positive pressure oil tank for a fan hydraulic system, which also integrates a displacement sensor to monitor the position of the oil tank piston in real time to determine whether the oil tank is leaking;

[0025] (6) The utility model provides a positive pressure oil tank for a fan hydraulic system, which also integrates an oil temperature sensor to detect the oil temperature in real time;

[0026] (7) The utility model provides a positive pressure oil tank for a fan hydraulic system, which also integrates a high pressure relief valve to avoid overpressure on the high pressure side;

[0027] (8) The utility model provides a positive pressure oil tank for a fan hydraulic system, which also integrates a low-pressure relief valve or a one-way valve to avoid overpressure in the oil tank;

[0028] (9) The utility model provides a positive pressure oil tank for a fan hydraulic system, wherein a heating element is provided on the outer wall of the oil tank to preheat the oil tank in a low temperature environment;

[0029] (10) The utility model provides a positive pressure oil tank for a fan hydraulic system, and the oil tank is also integrated with a return oil filter to filter out impurities in the return oil. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic diagram of a positive pressure oil tank in an embodiment;

[0031] Figure 2 A schematic diagram of a positive pressure oil tank in an embodiment;

[0032] Figure 3 is a cross-sectional view of a positive pressure oil tank in an embodiment;

[0033] Figure 4 A diagram showing the connection relationship between the piston rod and the cylinder of the positive pressure oil tank in the embodiment;

[0034] Figure 5 is a connection relationship diagram of the first flange ring and the second flange ring of the positive pressure oil tank in the embodiment;

[0035] Figure 6 It is a cross-sectional view of a positive pressure oil tank integrated with a one-way valve, a heating element, an oil return filter, a displacement sensor, a temperature sensor and a relief valve in an embodiment;

[0036] As shown in the figure, the numbers are as follows: 1-box body; 2-box body piston; 3-check valve; 4-piston rod; 5-cylinder piston; 6-cylinder; 7-heating element; 8-first oil outlet; 9-second oil outlet; 10-return oil outlet; 11-drain oil outlet; 12-vent; 13-cylinder piston rod sealing part; 14-cylinder piston sealing part; 15-first flange ring; 16-second flange ring; 17-spring retaining ring; 18-end cover; 19-box body; 20-return oil filter; 21-displacement sensor; 22-temperature sensor; 23-overflow valve. DETAILED DESCRIPTION

[0037] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0038] Example

[0039] See also Figure 1-6 A positive pressure oil tank for a fan hydraulic system, comprising: a box body 1, in which a box body piston 2 is arranged to abut against the inner wall surface of the box body 1; a cylinder barrel 6 is arranged on one end surface of the box body 1, in which a cylinder barrel piston 5 is arranged to abut against the inner wall surface of the cylinder barrel 6; a piston rod 4, one end of which is connected to the box body piston 2, and the other end is inserted into the cylinder barrel 6 and connected to the cylinder barrel piston 5;

[0040] Among them, the area surrounded by the box body 1, the end face of the box body 1 where the cylinder 6 is located, and the outer wall of the box body 1 between the two is a low-pressure cavity filled with hydraulic oil; the area surrounded by the cylinder piston 5, the end face of the cylinder 6 inserted by the piston rod 4, and the outer wall of the cylinder 6 between the two is a high-pressure cavity filled with hydraulic oil.

[0041] Please refer to Figure 5 In this embodiment, the box body 1 includes a box body 19 and sealing end covers arranged on both sides of the box body 19; both ends of the body are provided with a first flange ring 15, and the inner ring side of the first flange ring 15 is provided with a spring retaining ring 17; the sealing end cover includes an end cover 18 and a second flange ring 16 arranged concentrically with the end cover 18, and the first flange ring 15 and the second flange ring 16 are connected by bolts. Compared with the traditional welded flange connection, this embodiment omits the welding process, avoids the risk of cylinder deformation caused by welding, and also omits the non-destructive testing of the weld, so it has high reliability and low cost.

[0042] Please refer to Figure 1In this embodiment, the sealing end cover of the housing 1 facing the cylinder 6 is provided with an oil return port 10 and a first oil outlet 8; the sealing end cover of the housing 1 facing away from the cylinder 6 is provided with an air vent 12 and an oil drain port 11. The cylinder 6 is provided with a second oil outlet 9 on the side facing the housing 1.

[0043] Please refer to Figure 4 In this embodiment, one end of the cylinder 6 extends into the box body 1, and a cylinder piston rod seal 13 is provided at the abutment between the end and the piston rod 4; and a cylinder piston seal 14 is provided at the cylinder piston 5. The cylinder piston rod seal 13 of the oil tank of this embodiment is immersed in the oil tank, and the cylinder piston seal 13 is connected to the box body 1. Even if the high-pressure seal fails, the high-pressure oil will only leak into the box body 1, and the oil will not leak outside the box body 1, thereby avoiding environmental pollution.

[0044] Please refer to Figure 1 , Figure 6 In this embodiment, a one-way valve 3 or a low-pressure relief valve is also provided on the box piston 2 to prevent the box 1 from being over-pressurized.

[0045] In this embodiment, the box body 1 and the cylinder 6 are both cylindrical. The cylindrical design has equal circumferential pressure, uniform stress distribution, and fatigue resistance.

[0046] Please refer to Figure 6 In this embodiment, a displacement sensor 21 is provided at one end of the cylinder 6 which faces away from the box body 1 .

[0047] Please refer to Figure 6 In this embodiment, an oil return filter 20, a relief valve 23 and a temperature sensor 22 are provided on the end cover of the housing 1 facing the cylinder 6.

[0048] Please refer to Figure 6 In this embodiment, a heating element 7 is provided on the outer wall of the box body 1, and the heating element 7 is preferably a heating blanket.

[0049] Working principle:

[0050] See also Figure 1 The positive pressure oil tank of this embodiment uses the pressure of the external hydraulic system to pressurize the oil tank. The cylinder piston 5 and the box piston 2 are connected together by the piston rod 4. The high-pressure oil acts on the left side of the cylinder piston 5, and the oil pressure of the oil tank acts on the box piston 2. Without considering the friction and gravity, according to the balance of force, the oil pressure of the oil tank is equivalent to the high-pressure pressure divided by the area ratio of the two pistons.

[0051] When the hydraulic system supplies oil to the outside, the cylinder piston 5 and the box piston 2 both move to the right; when the outside returns oil to the positive pressure oil tank of this embodiment, the cylinder piston 5 and the box piston 2 both move to the left.

[0052] For the hydraulic pitch system integrated in the wind turbine hub, the oil tank will continue to rotate with the hub. If there is air in the oil tank, it will be continuously stirred into the hydraulic oil, causing the hydraulic oil to contain gas. The hydraulic oil containing gas will be sucked into the hydraulic system by the pump, causing abnormal vibration, noise, cavitation of the pump and valve, and other damage.

[0053] If a gas-pressurized oil tank is used, the gas pressure will change during the gas compression and expansion process. According to the requirements of the hydraulic system, the absolute pressure of the oil tank is 0.8 bar to 2 bar. According to this pressure range, the maximum volume of the gas shall not be less than 233L if a gas-pressurized solution is used. If 30L standard gas cylinders are used, 8 are required, which takes up equipment space and increases the total weight of the equipment. The positive pressure oil tank of this embodiment can solve the above two problems.

[0054] The above is only the preferred embodiment of the utility model, and does not limit the utility model in other forms. Any technician familiar with the profession may use the technical content disclosed above to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the utility model without departing from the technical solution of the utility model still belongs to the protection scope of the technical solution of the utility model.

Claims

1. A positive pressure oil tank for a fan hydraulic system, characterized in that: include: A box body (1) is provided with a box body piston (2) which abuts against an inner wall surface of the box body (1); A cylinder barrel (6) is arranged on one end surface of the housing (1), and a cylinder barrel piston (5) is arranged therein and abuts against the inner wall surface of the cylinder barrel (6); A piston rod (4), one end of which is connected to the box piston (2), and the other end of which is inserted into the cylinder (6) and connected to the cylinder piston (5); The area enclosed by the box body (1), the end surface of the box body (1) where the cylinder (6) is located, and the outer wall surface of the box body (1) between the two is a low-pressure cavity filled with hydraulic oil; the area enclosed by the cylinder piston (5), the end surface of the cylinder (6) into which the piston rod (4) is inserted, and the outer wall surface of the cylinder (6) between the two is a high-pressure cavity filled with hydraulic oil.

2. A positive pressure oil tank for a fan hydraulic system according to claim 1, characterized in that: The box body (1) comprises a box body barrel (19) and sealing end covers arranged on both sides of the box body barrel (19); Both ends of the barrel are provided with a first flange ring (15), and the inner ring side of the first flange ring (15) is provided with a spring retaining ring (17); The sealing end cover comprises an end cover (18) and a second flange ring (16) arranged concentrically with the end cover (18); the first flange ring (15) and the second flange ring (16) are connected by bolts.

3. A positive pressure oil tank for a fan hydraulic system according to claim 2, characterized in that: An oil return port (10) and a first oil outlet (8) are provided on the sealing end cover on the side of the box body (1) facing the cylinder barrel (6); and an air vent (12) and an oil drain port (11) are provided on the sealing end cover on the side of the box body (1) facing away from the cylinder barrel (6).

4. A positive pressure oil tank for a fan hydraulic system according to claim 1, characterized in that: A second oil outlet (9) is provided on the side of the cylinder barrel (6) facing the box body (1).

5. A positive pressure oil tank for a fan hydraulic system according to claim 1, characterized in that: One end of the cylinder barrel (6) extends into the box body (1), and a cylinder piston rod sealing portion (13) is provided at the abutment between the end and the piston rod (4); and a cylinder piston sealing portion (14) is provided at the cylinder barrel piston (5).

6. A positive pressure oil tank for a fan hydraulic system according to claim 1, characterized in that: The box piston (2) is also provided with a one-way valve (3) or a low-pressure relief valve to prevent the box (1) from being over-pressurized.

7. A positive pressure oil tank for a fan hydraulic system according to claim 1, characterized in that: The box body (1) and the cylinder barrel (6) are both cylindrical.

8. A positive pressure oil tank for a fan hydraulic system according to claim 1, characterized in that: A displacement sensor (21) is provided at one end of the cylinder (6) facing away from the box body (1).

9. A positive pressure oil tank for a fan hydraulic system according to claim 1, characterized in that: An oil return filter (20) and / or an overflow valve (23) and / or a temperature sensor (22) are provided on the end cover of the box body (1) facing the cylinder barrel (6).

10. A positive pressure oil tank for a fan hydraulic system according to claim 1, characterized in that: The outer wall surface of the box body (1) is provided with a heating element (7).

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