Fan cooling device without electrical control

Abstract

The technical scheme of the utility model discloses a fan cooling device without electrical control, which comprises a load-sensitive variable pump, a temperature control proportional overflow valve and a fan motor, the load-sensitive variable pump comprises an output port and a load feedback port, the output port is connected with the fan motor, the load feedback port is connected with the temperature control proportional overflow valve, and the load feedback port is connected with the fan motor. An output port of the load-sensitive variable pump is used for controlling the rotating speed of the fan motor; the temperature control proportional overflow valve is used for controlling the output pressure of the temperature control proportional overflow valve according to the temperature change and transmitting the output pressure of the temperature control proportional overflow valve to the load-sensitive variable pump, so that the output pressure of the load-sensitive variable pump is controlled; and the rotating speed of the fan motor is automatically adjusted according to the medium temperature change, so that inorganic variable adjustment of the fan is realized, and the fan is suitable for being used in an explosion-proof environment.

Description

Technical Field

[0001] The utility model belongs to the technical field of engineering machinery, and in particular relates to a fan cooling device which does not require electrical control. Background Art

[0002] The heat dissipation of hydraulic systems and engine systems in construction machinery is mostly achieved by hydraulic pumps driving fans. Initially, the fans were driven by gear pumps + relief valves + motors. With the increasing demand for advanced equipment and intelligentization, most of them now use electric proportional variable pumps to drive fan motors (such as the attached Figure 1 As shown in the figure, the electric proportional variable pump 9 needs to cooperate with the temperature sensor and the controller to realize the stepless variable of the fan system. This solution can better realize the stepless variable function of the fan, but it also has the following problems: (1) The cost is high. This solution must be implemented with the temperature sensor and the controller, and the price of the electric proportional variable pump is also high; (2) The solenoid valve coil in the electric proportional variable pump is easily damaged when it is powered for a long time; (3) Since the controller must be involved in the electrical system, it cannot be used in an explosion-proof environment.

[0003] Patent CN103527537B discloses a load-sensitive control system, method and engineering machinery; the load-sensitive control system includes: a load-sensitive pump, including an output port and a load feedback port; a valve group, including a load feedback port; an actuator, the output port of the load-sensitive pump is connected to the actuator through the valve group; a first damping unit, whose input end is connected to the output port of the load-sensitive pump; a second damping unit, whose input end is connected to the load feedback port of the valve group, and the output end of the first damping unit and the output end of the second damping unit are both connected to the load feedback port of the load-sensitive pump; when the pressure difference between the input end and the output end of the first damping unit is less than a preset value, the first damping unit is cut off, otherwise the first damping unit is turned on, thereby controlling the output of the load-sensitive pump, but multiple valve groups and damping units are required to realize the output of the load-sensitive pump, the structure is still relatively complex, and can only be sensed according to the needs of the operator to control the output of the load-sensitive pump, which is not suitable for automatic stepless variable adjustment of the fan system. Therefore, it is necessary to develop a fan cooling device that can be used in an explosion-proof environment without using electrical control and can automatically steplessly adjust the variable. Utility Model Content

[0004] In order to solve the existing technical problems, the utility model provides a fan cooling device that does not require electrical control. Through the cooperation of a load-sensitive variable pump and a temperature-controlled proportional relief valve, the speed of the fan motor is automatically adjusted according to changes in the medium temperature, thereby realizing stepless variable adjustment of the fan, and is suitable for use in explosion-proof environments.

[0005] The technical solution of the utility model is: a fan cooling device without electrical control, comprising a load-sensitive variable pump, a temperature-controlled proportional relief valve and a fan motor, the load-sensitive variable pump comprising an output port and a load feedback port, the output port being connected to the fan motor, the load feedback port being connected to the temperature-controlled proportional relief valve, the output port of the load-sensitive variable pump being used to control the rotation speed of the fan motor; the temperature-controlled proportional relief valve controlling the output pressure of the temperature-controlled proportional relief valve according to temperature changes and transmitting the output pressure of the temperature-controlled proportional relief valve to the load-sensitive variable pump, thereby controlling the output pressure of the load-sensitive variable pump.

[0006] Furthermore, the temperature-controlled proportional relief valve includes a thermal element, an upper spring, a lower spring and a pressure chamber, the thermal element is connected above the upper spring, the lower spring is connected to the lower side of the upper spring, a pressure chamber is arranged at the connection between the upper spring and the lower spring, and an output port P of the pressure chamber is connected to a load feedback port of a load-sensitive variable pump.

[0007] Furthermore, the thermal element is a bimetallic spring sheet.

[0008] Furthermore, the load feedback port of the load-sensitive variable displacement pump is a load-sensitive valve, and the output port P of the pressure chamber of the temperature-controlled proportional relief valve is connected to the load-sensitive valve.

[0009] The working principle of the utility model is: when the fan cooling device is working, the speed of the fan motor is controlled by controlling the output pressure of the load-sensitive variable pump. The output pressure P1 of the load-sensitive variable pump = P2 + P3, wherein the value of P3 is determined by the spring setting value of the load-sensitive valve and is a constant, so the value of P1 is positively correlated with the value of P2, and the value of P2 is the output pressure value of the temperature-controlled proportional relief valve, that is, the output pressure value of the output port P of the pressure chamber, and the output pressure value of the temperature-controlled proportional relief valve = the pressure setting value of the thermal element + the pressure setting value of the upper spring - the pressure setting value of the lower spring, wherein the pressure of the upper spring is The force setting value and the pressure setting value of the lower spring are constants, so the output pressure value of the temperature-controlled proportional relief valve is only related to the pressure setting value of the thermal element, that is, the value of P2 is only related to the pressure setting value of the thermal element. Therefore, the value of the output pressure P1 of the load-sensitive variable pump is only related to the pressure setting value of the thermal element. Therefore, when the fan cooling device is working, the thermal element of the temperature-controlled proportional relief valve senses the temperature change of the medium, causing the output pressure of the temperature-controlled proportional relief valve to change, and then automatically adjusts the output pressure of the load-sensitive variable pump, thereby automatically adjusting the speed change of the fan motor, and realizing stepless adjustment of the fan.

[0010] By adopting the above technical solution, the beneficial effects achieved by the utility model are as follows:

[0011] (1) The utility model automatically adjusts the speed of the fan motor according to the change of the medium temperature through the cooperation of the load-sensitive variable pump and the temperature-controlled proportional relief valve, thereby realizing stepless variable adjustment of the fan. It does not use an electrical system and is suitable for use in explosion-proof environments, especially in underground mines.

[0012] (2) The load-sensitive variable pump and temperature-controlled proportional relief valve do not need to be powered on and are not prone to damage.

[0013] (3) Low cost, simple structure, easy to install and maintain. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of a technical solution of using an electric proportional variable pump to drive a fan motor in the prior art;

[0015] Figure 2 It is a structural schematic diagram of the utility model;

[0016] Figure 3 It is a structural schematic diagram of the temperature-controlled proportional relief valve of the utility model.

[0017] In the figure, a load-sensing variable displacement pump 1, a temperature-controlled proportional relief valve 2, a fan motor 3, a thermal element 4, an upper spring 5, a lower spring 6, a pressure chamber 7, a load-sensing valve 8, and an electric proportional variable displacement pump 9 are provided. DETAILED DESCRIPTION

[0018] The utility model is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. Example

[0019] Reference Figure 2-3 A fan cooling device without electrical control includes a load-sensitive variable pump 1, a temperature-controlled proportional relief valve 2 and a fan motor 3. The load-sensitive variable pump 1 includes an output port and a load feedback port. The output port is connected to the fan motor 3, and the load feedback port is connected to the temperature-controlled proportional relief valve 2. The output port of the load-sensitive variable pump 1 is used to control the speed of the fan motor 3; the temperature-controlled proportional relief valve 2 controls the output pressure of the temperature-controlled proportional relief valve 2 according to temperature changes and transmits the output pressure of the temperature-controlled proportional relief valve 2 to the load-sensitive variable pump 1, thereby controlling the output pressure of the load-sensitive variable pump 1.

[0020] The temperature change of the medium is sensed by the temperature-controlled proportional relief valve 2, thereby causing the change of the output pressure of the temperature-controlled proportional relief valve 2, and then automatically adjusting the output pressure of the load-sensitive variable pump 1. The output pressure of the load-sensitive variable pump 1 is the pressure of the fan motor 3, which controls the speed of the fan motor 3.

[0021] The operation of the temperature-controlled proportional relief valve 2 and the load-sensitive variable pump 1 does not require the participation of the electrical system, thus meeting the explosion-proof requirements.

[0022] Furthermore, the temperature-controlled proportional relief valve 2 includes a thermal element 4, an upper spring 5, a lower spring 6 and a pressure chamber 7, wherein the thermal element 4 is connected above the upper spring 5, the lower spring 6 is connected to the lower side of the upper spring 5, and the pressure chamber 7 is arranged at the connection between the upper spring 5 and the lower spring 6, and the output port P of the pressure chamber 7 is connected to the load feedback port of the load-sensitive variable pump 1.

[0023] Furthermore, the thermal element 4 is a bimetallic spring sheet, which senses the temperature change of the medium through the different thermal deformation characteristics of the two metals, thereby causing the change of pressure.

[0024] Furthermore, the load feedback port of the load-sensitive variable displacement pump 1 is a load-sensitive valve 8 , and the output port P of the pressure chamber 7 of the temperature-controlled proportional relief valve 2 is connected to the load-sensitive valve 8 .

[0025] The working principle of the utility model is as follows: when the fan cooling device is working, the speed of the fan motor 3 is controlled by controlling the output pressure of the load-sensitive variable pump 1. The output pressure P1 of the load-sensitive variable pump 1 = P2 + P3, wherein the value of P3 is determined by the spring setting value of the load-sensitive valve 8 and is a constant, so the value of P1 is positively correlated with the value of P2. The value of P2 is the output pressure value of the temperature-controlled proportional relief valve 2, i.e., the output pressure value of the output port P of the pressure chamber 7. The output pressure value of the temperature-controlled proportional relief valve 2 = the pressure setting value of the thermal element 4 + the pressure setting value of the upper spring 5 - the pressure setting value of the lower spring 6, wherein the pressure setting value of the upper spring 5 The force setting value and the pressure setting value of the lower spring 6 are constants, so the output pressure value of the temperature-controlled proportional relief valve 2 is only related to the pressure setting value of the thermal element 4, that is, the value of P2 is only related to the pressure setting value of the thermal element 4. Therefore, the value of the output pressure P1 of the load-sensitive variable pump 1 is only related to the pressure setting value of the thermal element 4. Therefore, when the fan cooling device is working, the thermal element 4 of the temperature-controlled proportional relief valve 2 senses the temperature change of the medium, causing the output pressure of the temperature-controlled proportional relief valve 2 to change, and then automatically adjusts the output pressure of the load-sensitive variable pump 1, thereby automatically adjusting the speed change of the fan motor 3, and realizing stepless change regulation of the fan.

Claims

1. A fan cooling device without electrical control, characterized in that: The invention comprises a load-sensitive variable pump (1), a temperature-controlled proportional relief valve (2) and a fan motor (3), wherein the load-sensitive variable pump (1) comprises an output port and a load feedback port, wherein the output port is connected to the fan motor (3), and the load feedback port is connected to the temperature-controlled proportional relief valve (2), and the output port of the load-sensitive variable pump (1) is used to control the rotation speed of the fan motor (3); the temperature-controlled proportional relief valve (2) controls the output pressure of the temperature-controlled proportional relief valve (2) according to temperature changes and transmits the output pressure of the temperature-controlled proportional relief valve (2) to the load-sensitive variable pump (1), thereby controlling the output pressure of the load-sensitive variable pump (1).

2. A fan cooling device without electrical control according to claim 1, characterized in that: The temperature-controlled proportional relief valve (2) comprises a thermal element (4), an upper spring (5), a lower spring (6) and a pressure chamber (7), wherein the thermal element (4) is connected to the upper side of the upper spring (5), the lower spring (6) is connected to the lower side of the upper spring (5), and a pressure chamber (7) is provided at the connection between the upper spring (5) and the lower spring (6), and an output port P of the pressure chamber (7) is connected to a load feedback port of a load-sensitive variable pump (1).

3. A fan cooling device without electrical control according to claim 2, characterized in that: The thermal element (4) is a bimetallic spring sheet.

4. A fan cooling device without electrical control according to claim 1, characterized in that: The load feedback port of the load-sensitive variable pump (1) is a load-sensitive valve (8), and the output port P of the pressure chamber (7) of the temperature-controlled proportional relief valve (2) is connected to the load-sensitive valve (8).

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