Independent oil return heat dissipation system of excavator

Abstract

The utility model discloses an independent oil return heat dissipation system of an excavator, and belongs to the technical field of engineering machinery. The excavator cooling system overcomes the defect that a radiator of a traditional excavator cooling system in the prior art is prone to being damaged too early. A main body structure of the device comprises a heat dissipation driving pump, an oil dissipation cooling pump, a heat dissipation motor-pump and a temperature sensor arranged on a hydraulic oil tank, the heat dissipation driving pump is connected with the oil dissipation cooling pump, a signal end on the heat dissipation driving pump is connected with the temperature sensor through a controller, an oil outlet of the oil dissipation cooling pump is connected with an oil dissipation motor, and the oil dissipation motor is connected with the heat dissipation motor-pump. The heat dissipation motor-pump is connected with the hydraulic oil tank, the third one-way valve, the second one-way valve and the heat dissipation driving pump. The utility model is mainly applied to engineering machinery such as excavators and the like.

Description

Technical Field

[0001] The utility model belongs to the technical field of engineering machinery, and in particular relates to an independent oil return and heat dissipation system for an excavator. Background Art

[0002] Ultra-large excavators have become important mechanical equipment in mining. With the increase in the tonnage of the whole machine, the system flow increases, the return oil pressure and impact increase, and the core of the hydraulic oil radiator also increases. Due to the structure of the radiator core, as the volume increases, the pressure resistance decreases, which can easily cause faults such as radiator core cracking.

[0003] The common principles for improving the pressure of the oil return system are as follows: Figure 4 As shown, it mainly includes main control valve C33, main control valve D34, fourth check valve 35, fifth check valve 36, radiator A25, oil radiator motor A26, oil radiator cooling pump A27, plunger pump C28, plunger pump D29, engine A30, hydraulic oil tank A31 and transfer case A32. When the excavator is working normally, the return oil from the main valve merges and then passes through the fourth check valve 35 and the fifth check valve 36 for diversion. When the oil temperature is low, the return oil pressure is high, and the system return oil from the fourth check valve is high. When the oil temperature is high, the return oil pressure is low, and the system return oil passes more through the fifth one-way valve 36 (relatively when the oil temperature is low). This oil is cooled by the radiator A25, which has the effect of lowering the oil temperature. Although the fourth one-way valve 35 and the fifth one-way valve 36 protect the radiator to a certain extent, the return oil pressure increases due to the large changes in the system flow rate, and the pressure changes greatly, and cannot be adjusted to the ideal pressure, resulting in premature damage to the radiator. Utility Model Content

[0004] The technical problem to be solved by the utility model is to overcome the deficiencies of the prior art and provide an independent oil return and heat dissipation system for an excavator.

[0005] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0006] An independent oil return and heat dissipation system for an excavator includes a heat dissipation drive pump, an oil radiator cooling pump, a heat dissipation motor-pump, and a temperature sensor arranged on a hydraulic oil tank. The heat dissipation drive pump is connected to the oil radiator cooling pump, a signal end on the heat dissipation drive pump is connected to the temperature sensor through a controller, an oil outlet of the oil radiator cooling pump is connected to the oil radiator motor, and the heat dissipation motor-pump is respectively connected to the hydraulic oil tank, a third one-way valve, a second one-way valve, and the heat dissipation drive pump.

[0007] Preferably, the heat dissipation motor-pump comprises a pump and a motor, and the pump and the motor are coaxially connected.

[0008] Preferably, the oil suction port of the pump is connected to the hydraulic oil tank, the oil outlet of the pump is connected to the third one-way valve and the second one-way valve respectively, the oil suction port of the motor is connected to the oil outlet of the heat dissipation drive pump, and the oil outlet of the motor is connected to the third one-way valve and the second one-way valve respectively.

[0009] Preferably, the pump is a gear pump or a variable displacement pump.

[0010] Preferably, the oil outlet of the third one-way valve is connected to the hydraulic oil tank, and the oil outlet of the second one-way valve is connected to the hydraulic oil tank through a radiator.

[0011] Preferably, the opening pressure of the third one-way valve is greater than the opening pressure of the second one-way valve.

[0012] Preferably, the heat dissipation drive pump includes a heat dissipation drive pump body, a displacement adjusting piston connected to the swash plate swing angle of the heat dissipation drive pump body, a control valve and a solenoid valve, the control valve is connected to the solenoid valve and the displacement adjusting piston respectively, and the signal end of the solenoid valve is connected to the controller, and the oil outlet of the heat dissipation drive pump body is connected to the oil suction port of the motor.

[0013] Preferably, the independent oil return and cooling system of the excavator also includes a main control valve A, a main control valve B, a plunger pump A and a plunger pump B. The oil outlet of the plunger pump A is connected to the main control valve A, and the oil outlet of the plunger pump B is connected to the main control valve B. The oil outlets of the main control valve A and the main control valve B are both connected to the hydraulic oil tank through a first one-way valve.

[0014] Compared with the prior art, the beneficial effects of the present invention are:

[0015] 1. The heat dissipation drive pump drives the heat dissipation motor-the pump speed is adjustable. By running the pump at a high speed, a wide range of heat dissipation flow can be adjusted, so that the system return oil pressure remains at a low and stable state;

[0016] 2. Through the application and displacement control of the heat dissipation drive pump and the heat dissipation motor-pump, flexible pipeline layout and adjustable heat dissipation flow are achieved to ensure that the pressure of the heat dissipation system does not exceed the limit value. At the same time, it can avoid the system return oil pipeline returning to the radiator from being too complicated and can be flexibly arranged. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is the hydraulic principle diagram of the utility model;

[0018] Figure 2 It is a linear diagram of temperature and current of the solenoid valve in the present invention;

[0019] Figure 3 This is a hydraulic principle diagram of the heat dissipation drive pump in the utility model;

[0020] Figure 4This is the existing hydraulic principle diagram.

[0021] In the figure: 1. Main control valve A; 2. Main control valve B; 3. First check valve; 4. Second check valve; 5. Radiator; 6. Oil radiator motor; 7. Oil radiator cooling pump; 8. Piston pump A; 9. Piston pump B; 10. Engine; 11. Hydraulic oil tank; 12. Transfer case; 13. Radiator drive pump; 14. Pump; 15. Third check valve; 16. Motor; 17. Temperature sensor; 18. Controller; 19. Radiator drive 1. Hydraulic pump body; 20. Displacement adjusting piston; 21. Control valve; 22. Solenoid valve; 23. Cooling motor-pump; 25. Radiator A; 26. Oil radiator motor A; 27. Oil radiator cooling pump A; 28. Plunger pump C; 29. Plunger pump D; 30. Engine A; 31. Hydraulic oil tank A; 32. Transfer case A; 33. Main control valve C; 34. Main control valve D; 35. Fourth one-way valve; 36. Fifth one-way valve. DETAILED DESCRIPTION

[0022] The present invention will be further described below through specific embodiments in conjunction with the accompanying drawings.

[0023] Example 1:

[0024] like Figure 1 As shown, an independent oil return and heat dissipation system for an excavator includes a heat dissipation drive pump 13, an oil radiator cooling pump 7, a heat dissipation motor-pump 23, and a temperature sensor 17 disposed on the hydraulic oil tank 11. The heat dissipation drive pump 13 is connected to the oil radiator cooling pump 7. The signal terminal on the heat dissipation drive pump 13 is connected to the temperature sensor 17 via a controller 18. The oil outlet of the oil radiator cooling pump 7 is connected to the oil radiator motor 6. The heat dissipation motor-pump 23 is connected to the hydraulic oil tank 11, the third check valve 15, the second check valve 4, and the heat dissipation drive pump 13, respectively. In this embodiment, the temperature sensor 17 detects the temperature of the hydraulic oil in the hydraulic oil tank 11. The controller 18 receives the current input from the temperature sensor 17 and outputs a control current to the heat dissipation drive pump 13.

[0025] An independent oil return and cooling system for an excavator also includes a main control valve A1, a main control valve B2, a first one-way valve 3, a plunger pump A8, a plunger pump B9, an engine 10, a hydraulic oil tank 11 and a transfer case 12. The plunger pump A8 and the plunger pump B9 are both connected to the engine 10 through the transfer case 12. The oil outlet of the plunger pump A8 is connected to the main control valve A1, and the oil outlet of the plunger pump B9 is connected to the main control valve B2. The oil outlets of the main control valve A1 and the main control valve B2 are both connected to the first one-way valve 3, and the first one-way valve 3 is connected to the hydraulic oil tank 11. Through the first one-way valve 3, the oil of the main system is directly returned to the hydraulic oil tank 11, which can solve the problem of failure of the radiator 5 caused by high return oil pressure.

[0026] Example 2:

[0027] An independent oil return and heat dissipation system for an excavator is different from Example 1 in that the heat dissipation motor-pump 23 includes a pump 14 and a motor 16, and the pump 14 and the motor 16 are connected; the oil suction port of the pump 14 is connected to the hydraulic oil tank 11, and the oil outlet of the pump 14 is respectively connected to the third one-way valve 15 and the second one-way valve 4, the oil suction port of the motor 16 is connected to the oil outlet of the heat dissipation drive pump 13, and the oil outlet of the motor 16 is respectively connected to the third one-way valve 15 and the second one-way valve 4.

[0028] Furthermore, the pump 14 is a gear pump or a variable displacement pump. In this embodiment, the pump 14 and the motor 16 are preferably quantitative because the displacement of the motor 16 is smaller than that of the heat dissipation drive pump 13. According to the formula n m =n P *(V P / V m ), so that the pump 14 can obtain a speed far exceeding that of the engine 10, and realize a wide range of adjustment of the heat dissipation flow. Among them, the pump 14 and the motor 16 are coaxial, and the heat dissipation drive pump 13 is at the same speed as the engine 10, n m is the speed of the motor 16, n P is the speed of the heat dissipation drive pump 13, V P is the displacement of the heat dissipation drive pump 13, V m is the displacement of the motor 16.

[0029] Furthermore, the oil outlet of the third one-way valve 15 is connected to the hydraulic oil tank 11 , and the oil outlet of the second one-way valve 4 is connected to the hydraulic oil tank 11 through the radiator 5 .

[0030] Furthermore, the opening pressure of the third one-way valve 15 is greater than the opening pressure of the second one-way valve 4. The first one-way valve 3 and the third one-way valve 15 are generally set at (6±1) bar, mainly to protect the radiator 5; the second one-way valve 4 is generally set at (3±0.5) bar.

[0031] like Figure 3 As shown, the heat dissipation drive pump 13 includes a heat dissipation drive pump body 19, a displacement adjustment piston 20 connected to the swash plate of the heat dissipation drive pump body 19, a control valve 21, and a solenoid valve 22. The control valve 21 is connected to the solenoid valve 22 and the displacement adjustment piston 20, respectively. The signal end of the solenoid valve 22 is connected to the controller 18. The oil outlet of the heat dissipation drive pump body 19 is connected to the oil intake of the motor 16. In addition, the heat dissipation drive pump 13 is a variable displacement pump, and the displacement changes with temperature.

[0032] The working principle of this utility model is:

[0033] 1. When the oil temperature is low (T≤T1), the controller 18 does not output current to the solenoid valve 22 of the heat dissipation drive pump 13. At this time, the displacement of the heat dissipation drive pump 13 is the smallest, the speed of the pump 14 is the lowest, and the flow rate of the heat dissipation system is the smallest, ensuring that the hydraulic oil heats up quickly;

[0034] 2. When the oil temperature is normal (T1<T≤T2), the controller 18 outputs current to the electromagnetic valve 22 of the heat dissipation drive pump 13. The temperature T1-T2 linearly corresponds to the current Imin→Imax of the electromagnetic valve 22 of the heat dissipation drive pump 13. Figure 2 As shown, the displacement of the heat dissipation drive pump 13 corresponds to Vmin→Vmax, ensuring that the hydraulic oil is at an optimal working temperature;

[0035] 3. When the oil temperature is high (T>T2), in order to ensure maximum heat dissipation capacity, the controller 18 outputs the maximum current to the solenoid valve 22 of the heat dissipation drive pump 13. At this time, the heat dissipation drive pump 13 has the largest displacement, the pump 14 has the highest speed, and the heat dissipation system flow is the largest. At this time, the return oil flow through the radiator 5 is the largest, which can exert the maximum heat dissipation capacity and cool the oil temperature to the optimal temperature faster.

[0036] Note: T1 is the lower limit of the optimal working oil temperature set by the system, generally (50±5)℃; T2 is the upper limit of the optimal working oil temperature set by the system, generally (70±5)℃.

Claims

1. An independent oil return and cooling system for an excavator, characterized by: The invention comprises a heat dissipation drive pump (13), an oil radiator cooling pump (7), a heat dissipation motor-pump (23), and a temperature sensor (17) arranged on a hydraulic oil tank (11). The heat dissipation drive pump (13) is connected to the oil radiator cooling pump (7). A signal end on the heat dissipation drive pump (13) is connected to the temperature sensor (17) via a controller (18). The oil outlet of the oil radiator cooling pump (7) is connected to the oil radiator motor (6). The heat dissipation motor-pump (23) is respectively connected to the hydraulic oil tank (11), a third one-way valve (15), a second one-way valve (4), and the heat dissipation drive pump (13).

2. The independent oil return and cooling system for excavators according to claim 1, characterized in that: The heat dissipation motor-pump (23) comprises a pump (14) and a motor (16), and the pump (14) and the motor (16) are coaxially connected.

3. The independent oil return and heat dissipation system for excavators according to claim 2, characterized in that: The oil suction port of the pump (14) is connected to the hydraulic oil tank (11), the oil outlet of the pump (14) is connected to the third one-way valve (15) and the second one-way valve (4) respectively, the oil suction port of the motor (16) is connected to the oil outlet of the heat dissipation drive pump (13), and the oil outlet of the motor (16) is connected to the third one-way valve (15) and the second one-way valve (4) respectively.

4. The independent oil return and heat dissipation system for excavators according to claim 2, characterized in that: The pump (14) is a gear pump or a variable displacement pump.

5. The independent oil return and cooling system for an excavator according to any one of claims 1 to 4, characterized in that: The oil outlet of the third one-way valve (15) is connected to the hydraulic oil tank (11), and the oil outlet of the second one-way valve (4) is connected to the hydraulic oil tank (11) through the radiator (5).

6. The independent oil return and cooling system for an excavator according to any one of claims 1 to 4, characterized in that: The opening pressure of the third one-way valve (15) is greater than the opening pressure of the second one-way valve (4).

7. The independent oil return and cooling system for an excavator according to any one of claims 2 to 4, characterized in that: The heat dissipation drive pump (13) comprises a heat dissipation drive pump body (19), a displacement adjustment piston (20) connected to the swash plate swing angle of the heat dissipation drive pump body (19), a control valve (21) and a solenoid valve (22); the control valve (21) is connected to the solenoid valve (22) and the displacement adjustment piston (20) respectively, and the signal end of the solenoid valve (22) is connected to the controller (18); the oil outlet of the heat dissipation drive pump body (19) is connected to the oil suction port of the motor (16).

8. The independent oil return and cooling system for an excavator according to any one of claims 1 to 4, characterized in that: The independent oil return and heat dissipation system for the excavator further comprises a main control valve A (1), a main control valve B (2), a plunger pump A (8) and a plunger pump B (9), wherein the oil outlet of the plunger pump A (8) is connected to the main control valve A (1), the oil outlet of the plunger pump B (9) is connected to the main control valve B (2), and the oil outlets of the main control valve A (1) and the main control valve B (2) are both connected to the hydraulic oil tank (11) via a first one-way valve (3).

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