An internal circulation heating system for an electric actuator

Abstract

The application relates to an internal circulation heating system of an electric actuator and relates to the field of electric actuators; the system comprises a heater arranged at the inlet of a lubricating pump and used for preheating lubricating oil, an outer pumping assembly used for extracting and pushing the preheated lubricating oil into a reduction mechanism to form circulation, and a heating control circuit electrically connected with the heater and the outer pumping assembly respectively to control the working states of the heater and the outer pumping assembly; the outer pumping assembly comprises a plunger pump, an inlet one-way valve and an outlet one-way valve; the system is also provided with an outer cooling assembly for heat dissipation; and the heating control circuit comprises a temperature sensor, a temperature control switch, a time delay relay and the like. The application has the effect of solving the problem that the viscosity of lubricating oil is increased in an extremely cold environment.

Description

Technical Field

[0001] This application relates to the technical field of electric actuators, and in particular to an internal circulation heating system for an electric actuator. Background Technology

[0002] Electric actuators, as key equipment in industrial automation, play an indispensable role in many industrial production processes. With the continuous expansion of industrial applications, the demand for electric actuators in complex and extreme environments is becoming increasingly prominent. Particularly in special fields such as polar scientific expeditions, industrial facilities in high-altitude and cold regions, and aerospace, electric actuators need to operate stably in extremely cold environments. The reduction mechanism of an electric actuator has multiple chambers, which are connected by connecting holes / pipes. Lubricating oil can flow between the chambers, lubricating the reduction mechanism, seals, bearings, and other transmission components within each chamber. This is of great significance for improving industrial production efficiency and ensuring the safe and reliable operation of equipment.

[0003] However, when electric actuators operate in extremely cold environments, the viscosity of the lubricating oil in the reduction mechanism increases significantly; the friction between the shaft end seals and moving parts also increases dramatically; the ball / roller clearance of the bearings decreases, lubrication conditions deteriorate, and the bearing's motion resistance increases significantly. The crystal lattice of mechanical components at low temperatures differs from that at room temperature, resulting in decreased material properties and an inability to meet stiffness and elasticity requirements. Starting the motor at low temperatures carries a risk of stalling, and prolonged stalling can even lead to motor burnout. Utility Model Content

[0004] To address the problem of increased lubricant viscosity in electric actuators under extremely cold environments, this application provides an internal circulation heating system for electric actuators.

[0005] The internal circulation heating system for an electric actuator provided in this application adopts the following technical solution: An internal circulation heating system for an electric actuator includes a heater, an external pumping assembly, and a heating control circuit. The heater is located at the inlet of a lubrication pump inside the electric actuator and is used to preheat lubricating oil. The external pumping assembly is used to draw and push the preheated lubricating oil into the deceleration mechanism. Both the heater and the external pumping assembly are controlled and connected to the heating control circuit.

[0006] By adopting the above technical solution, the heater preheats the lubricating oil to a low viscosity state, and the external pumping component draws and pushes the preheated lubricating oil into the reduction mechanism to form a circulation, so that the electric actuator can start normally under extremely cold conditions. The heating control circuit controls the operation of the heater and the external pumping component to ensure that the electric actuator can operate under low temperature conditions.

[0007] Preferably, the external pumping assembly includes a plunger pump, an inlet check valve, and an outlet check valve. The inlet end of the inlet check valve is connected to the outlet of the electric actuator via a pipeline, and the outlet end of the inlet check valve is connected to the inlet of the plunger pump. The inlet end of the outlet check valve is connected to the outlet of the plunger pump, and the outlet end of the outlet check valve is connected to the inlet of the electric actuator.

[0008] By adopting the above technical solution, the inlet check valve and outlet check valve prevent lubricating oil backflow, ensure unidirectional flow in the circulation path, and improve heating efficiency.

[0009] Preferably, the plunger pump includes a pump cylinder, a plunger movably disposed within the pump cylinder, and a driving component, wherein the output end of the driving component is fixedly connected to the plunger via a connecting rod to drive the plunger to reciprocate.

[0010] By adopting the above technical solutions, the reciprocating motion design of the plunger pump provides a stable lubricating oil delivery pressure, adapting to the pumping requirements of high-viscosity lubricating oil.

[0011] Preferably, the heating control circuit includes a power supply U1, an AC contactor K1, a time delay relay K3, a normally closed temperature control switch S1, and a temperature sensor PT100. The first, second, and third output terminals of the power supply U1 are electrically connected to pins 1, 2, and 3 of the normally open contact K11 of the AC contactor K1, respectively. Pins 4, 5, and 6 of the normally open contact K11 are electrically connected to one end of a plurality of heaters, and the other ends of the plurality of heaters are electrically connected to each other. The second output terminal is electrically connected to pin 12 of the temperature control switch S1, pin 14 of the temperature control switch S1 is left floating, and pin 11 of the temperature control switch S1 is electrically connected to the third output terminal through the AC contactor K1. The second output terminal is connected to the third output terminal in sequence through the normally open contact K12 of the AC contactor K1 and the time delay relay K3. The second output terminal is also connected to the third output terminal in sequence through the normally open contact K12 of the normally open contact K31 of the time delay relay K3 and a driving element.

[0012] By adopting the above technical solution, when no power is supplied in a low-temperature environment, the AC contactor K1 is energized, causing the heater E1 to start working and heating the lubricating oil. At the same time, the time delay relay K3 starts timing, providing sufficient heating time for the lubricating oil. After the delay ends, the drive motor starts, driving the external pumping assembly to begin circulating the preheated lubricating oil.

[0013] As the lubricating oil circulates continuously, when the temperature sensor detects that the oil temperature has reached the set value, the temperature control switch S1 automatically cuts off the circuit. At this time, the AC contactor K1 is de-energized, and the heater E1 stops working; simultaneously, the time-delay relay K3 and the drive motor are also de-energized, and the entire system stops operating. This automatic control mechanism ensures that the electric actuator can obtain proper preheating in low-temperature environments, while automatically stopping after reaching the ideal temperature, thus ensuring normal equipment startup and avoiding energy waste.

[0014] Preferably, the system also includes a transformer T1, with pins 4, 5, and 6 of the normally open contact K11 electrically connected to pins 1, 2, and 3 of the transformer T1, respectively; pins 4, 5, and 6 of the transformer T1 are electrically connected to one end of a plurality of heaters, and the other ends of the plurality of heaters are electrically connected to each other.

[0015] By adopting the above technical solution, transformer T1 can be adapted to heaters of different voltage levels, thus expanding system compatibility.

[0016] Preferably, a three-phase fuse F1 is also included. The first output terminal, the second output terminal, and the third output terminal of the power supply U1 are electrically connected to pins 1, 3, and 5 of the three-phase fuse F1, respectively. Pins 2, 4, and 6 of the three-phase fuse F1 are electrically connected to pins 1, 2, and 3 of the normally open contact K11 of the AC contactor K1, respectively.

[0017] By adopting the above technical solution, the three-phase fuse F1 is used to provide overcurrent protection to prevent short circuits or overloads from damaging key components.

[0018] Preferably, a normally closed contact K21 for temperature detection is also included, and the second output terminal is electrically connected to pin 12 of the temperature control switch S1 through the normally closed contact K21.

[0019] By adopting the above technical solution, the normally closed contact K21 for temperature detection serves as redundant protection, forcibly disconnecting the circuit when the temperature control switch fails, thus providing dual protection for system safety.

[0020] Preferably, the device also includes an external cooling assembly connected to the electric actuator, the external cooling assembly being configured as a cooling circulation pipeline.

[0021] By adopting the above technical solution, the external cooling component actively dissipates heat in high-temperature environments, preventing overheating failure of transmission components and electronic control units, achieving bidirectional temperature regulation, expanding the operating temperature range of the electric actuator, and adapting to extreme environments.

[0022] In summary, this application includes at least one of the following beneficial technical effects: 1. The heater preheats the lubricating oil to a low viscosity state, and the external pumping component pushes the heated lubricating oil back into the reduction mechanism and makes it flow as quickly as possible. This solves the problem of the lubricating grease viscosity increasing significantly and the lubricating oil flow poorly in extremely cold environments to the greatest extent, so that the electric actuator can start normally in extremely cold conditions. 2. The inlet and outlet check valves ensure unidirectional flow of lubricating oil, prevent backflow, and guarantee the normal operation of lubricating oil circulation heating. Attached Figure Description

[0023] Fig. 1 This is a schematic diagram of an embodiment of this application; Fig. 2 This is a circuit diagram of the heating control circuit in an embodiment of this application.

[0024] Reference numerals: 1. Electric actuator; 11. Heater; 2. External pumping assembly; 21. Piston pump; 211. Piston; 212. Pump cylinder; 213. Drive unit; 22. Outlet check valve; 23. Inlet check valve. Detailed Implementation

[0025] The following combination Figs. 1-2 This application will be described in further detail.

[0026] This application discloses an internal circulation heating system for an electric actuator.

[0027] Reference Fig. 1 An internal circulation heating system for an electric actuator 1 includes an external pumping assembly 2, a heater 11 disposed within the electric actuator 1, and a heating control circuit. The heater 11 is located at the inlet of the lubrication pump, and its electric heating portion can employ an electric heating tube or a PTC heating material to preheat the lubricating oil to a low viscosity state. The external pumping assembly 2 is connected to the electric actuator 1, and the heating control circuit is electrically connected to both the heater 11 and the external pumping assembly 2. The external pumping assembly 2 is used to draw the preheated lubricating oil and push it back into the reduction mechanism, allowing the heated lubricating oil to circulate rapidly within the reduction mechanism, enabling the electric actuator 1 to start normally even in extremely cold environmental conditions.

[0028] The external pumping assembly 2 includes a plunger pump 21, an outlet check valve 22, and an inlet check valve 23. The plunger pump 21 includes a plunger 211, a pump cylinder 212, and a drive component 213. In this embodiment, the drive component 213 is a motor. The drive component 213 is located outside the pump cylinder 212, and the plunger 211 is movably located inside the pump cylinder 212. The output end of the drive component 213 is connected to the plunger 211 via a connecting rod, enabling the drive component 213 to drive the plunger 211 to reciprocate within the pump cylinder 212. The inlet and outlet of the pump cylinder 212 are both located on the side of the plunger 211 away from the drive component 213, which facilitates the intake and discharge of lubricating oil. The inlet of the inlet check valve 23 is connected to the outlet of the electric actuator 1 via a pipeline, and the outlet of the inlet check valve 23 is connected to the inlet of the pump cylinder 212 via a pipeline. The inlet of the outlet check valve 22 is connected to the outlet of the pump cylinder 212 via a pipeline, and the outlet of the outlet check valve 22 is connected to the inlet of the electric actuator 1 via a pipeline. The inlet check valve 23 and the outlet check valve 22 are used to ensure that the lubricating oil flows in only one direction, preventing backflow.

[0029] After the control circuit controls the heater 11 to heat the oil, the drive component 213 moves the plunger 211 away from the inlet of the pump cylinder 212. At this time, the heated lubricating oil enters the pump cylinder 212 from the electric actuator 1 through the inlet check valve 23. Then, the drive component 213 moves the plunger 211 closer to the outlet of the pump cylinder 212, allowing the heated lubricating oil to re-enter the electric actuator 1 through the outlet check valve 22. By repeating the above process, the lubricating oil in each chamber of the electric actuator 1 is heated, thus achieving the heating effect on the electric actuator 1.

[0030] Preferably, for some electric actuators 1 that cannot operate in high-temperature environments, an external cooling component connected to the electric actuator 1 is also included. The external cooling component can be configured as a cooling circulation pipeline, using methods such as condensate water or air cooling to dissipate heat from the electric actuator 1, preventing the transmission components, motor, and electronic control unit inside the electric actuator 1 from failing due to high temperatures.

[0031] Reference Fig. 2The heating control circuit includes a power supply U1, a three-phase fuse F1, a transformer T1, an AC contactor K1, a time-delay relay K3, a normally closed temperature control switch S1, a normally closed temperature detection contact K21, and a temperature sensor PT100. The first, second, and third output terminals of the power supply U1 are electrically connected to pins 1, 3, and 5 of the three-phase fuse F1, respectively. The three-phase fuse F1 protects the circuit from overload. Pins 2, 4, and 6 of the three-phase fuse F1 are electrically connected to pins 1, 2, and 3 of the normally open contact K11 of the AC contactor K1, respectively. Pins 4, 5, and 6 of the normally open contact K11 are electrically connected to pins 1, 2, and 3 of the transformer T1, and pins 4, 5, and 6 of the transformer T1 are electrically connected to one end of each of the multiple heaters E1. The other ends of the multiple heaters E1 are interconnected. The multiple heaters are connected in parallel, ensuring that each heater can operate independently without interference, while also facilitating unified control. When one heater fails, it will not affect the normal operation of other heaters, thus improving the reliability and stability of the heating system.

[0032] Transformer T1 is used to convert the output voltage of power supply U1 to a voltage suitable for the heater. If the voltage and power rating of the heater match the output voltage of power supply U1, the transformer can be omitted and power supply U1 can be used directly to power the heating element.

[0033] Pin 4 of the three-phase fuse F1 is electrically connected to pin 12 of the temperature control switch S1 via normally closed contact K21. Pin 14 of the temperature control switch S1 is left floating, and pin 11 of the temperature control switch S1 is electrically connected to pin 6 of the three-phase fuse F1 via AC contactor K1. Pin 4 of the three-phase fuse F1 is connected to pin 6 of the three-phase fuse F1 in sequence via normally open contact K12 of AC contactor K1 and time delay relay K3. Pin 4 of the three-phase fuse F1 is also connected to pin 6 of the three-phase fuse F1 in sequence via normally open contact K12 of normally open contact K31 of time delay relay K3 and drive element Y1.

[0034] In low-temperature environments and when not powered on, the normally closed contact K21 is closed, the temperature control switch S1 is closed, the AC contactor K1 is energized, causing the normally open contact K11 to close, energizing the transformer T1, which in turn energizes the heater E1 and initiates heating. Simultaneously, the normally open contact K12 closes, energizing the time-delay relay K3, causing it to close after a delay. This delay allows time for the heater to heat the lubricating oil, reducing its viscosity. After the normally open contact K3 is fully closed, the drive unit Y1 is energized, causing the external pumping assembly to start operating, thus achieving circulating heating of the lubricating oil. After a period of cyclic heating, when the temperature of the motor actuator reaches the switching temperature of the temperature control switch S1, pins 11 and 14 of the temperature control switch S1 are electrically connected, the temperature control switch S1 is disconnected, the AC relay K1 is de-energized, and at this time the normally open contact K11 is open, causing the heater to be de-energized and stop heating; at the same time, the normally open contact K12 is open, causing the time delay relay K3 to be de-energized, the normally open contact K13 is open, and the drive Y1 stops working.

[0035] The implementation principle of the internal circulation heating system of an electric actuator 1 in this application embodiment is as follows: the lubricating oil is preheated by the heater 11 to reduce its viscosity, and then the heated lubricating oil is circulated within the reduction mechanism by the external pumping component 2. This reduces the motion resistance of the mechanical parts, avoids motor stalling and burnout, and ensures the normal start-up and operation of the electric actuator 1. The heating control circuit can automatically control the working state of the heater 11 and the external pumping component 2 according to the internal temperature of the electric actuator 1, realizing intelligent temperature regulation, improving the reliability and stability of the system, and solving the working problem of the electric actuator 1 in extremely cold environments as much as possible compared with traditional measures to deal with low temperatures.

[0036] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. An internal circulation heating system for an electric actuator, characterized in that: It includes a heater (11), an external pumping assembly (2), and a heating control circuit. The heater (11) is located at the lubrication pump inlet in the electric actuator (1) and is used to preheat the lubricating oil. The external pumping assembly (2) is used to draw and push the preheated lubricating oil into the deceleration mechanism. Both the heater (11) and the external pumping assembly (2) are controlled and connected to the heating control circuit. The heating control circuit includes a power supply U1, an AC contactor K1, a time delay relay K3, a normally closed temperature control switch S1, and a temperature sensor PT100. The first output terminal, the second output terminal and the third output terminal of the power supply U1 are respectively electrically connected to pins 1, 2 and 3 of the normally open contact K11 of the AC contactor K1. Pins 4, 5 and 6 of the normally open contact K11 are respectively electrically connected to one end of the plurality of heaters (11). The other ends of the plurality of heaters (11) are electrically connected to each other. The second output terminal is electrically connected to pin 12 of the temperature control switch S1, pin 14 of the temperature control switch S1 is left floating, and pin 11 of the temperature control switch S1 is electrically connected to the third output terminal through the AC contactor K1. The second output terminal is electrically connected to the third output terminal in sequence through the normally open contact K12 of the AC contactor K1 and the time delay relay K3; The second output terminal is also electrically connected to the third output terminal in sequence through the normally open contact K31 of the time delay relay K3, the normally open contact K12 of the AC contactor K1 and the driving unit (213).

2. The internal circulation heating system for an electric actuator according to claim 1, characterized in that: The external pumping assembly (2) includes a plunger pump (21), an inlet check valve (23), and an outlet check valve (22). The inlet end of the inlet check valve (23) is connected to the outlet of the electric actuator (1) through a pipeline, and the outlet end of the inlet check valve (23) is connected to the inlet of the plunger pump (21). The inlet end of the outlet check valve (22) is connected to the outlet of the plunger pump (21), and the outlet end of the outlet check valve (22) is connected to the inlet of the electric actuator (1).

3. The internal circulation heating system for an electric actuator according to claim 2, characterized in that: The plunger pump (21) includes a pump cylinder (212), a plunger (211) movably disposed in the pump cylinder (212), and a drive member (213). The output end of the drive member (213) is fixedly connected to the plunger (211) through a connecting rod to drive the plunger (211) to reciprocate.

4. The internal circulation heating system for an electric actuator according to claim 1, characterized in that: It also includes a transformer T1, and the 4th, 5th and 6th pins of the normally open contact K11 are electrically connected to the 1st, 2nd and 3rd pins of the transformer T1, respectively; the 4th, 5th and 6th pins of the transformer T1 are electrically connected to one end of a plurality of heaters (11), and the other ends of the plurality of heaters (11) are electrically connected to each other.

5. The internal circulation heating system for an electric actuator according to claim 1, characterized in that: It also includes a three-phase fuse F1, with the first, second, and third output terminals of the power supply U1 electrically connected to pins 1, 3, and 5 of the three-phase fuse F1, respectively; and pins 2, 4, and 6 of the three-phase fuse F1 electrically connected to pins 1, 2, and 3 of the normally open contact K11 of the AC contactor K1, respectively.

6. The internal circulation heating system for an electric actuator according to claim 1, characterized in that: It also includes a normally closed temperature detection contact K21, and the second output terminal is electrically connected to pin 12 of the temperature control switch S1 through the normally closed temperature detection contact K21.

7. The internal circulation heating system for an electric actuator according to claim 1, characterized in that: It also includes an external cooling assembly, which is connected to the electric actuator (1), and the external cooling assembly is configured as a cooling circulation pipeline.

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