Electric bypass valve, radiator, cooling system and lubricating oil temperature control method

Abstract

The invention provides an electric bypass valve, a radiator, a cooling system and a lubricating oil temperature control method, and the electric bypass valve comprises a valve seat which is installed on a radiator shell through threaded connection; the valve assembly is composed of a sliding valve rod, a spring, a valve and a guide piece. Wherein an internal thread is designed on the sliding valve rod and used for being connected with an external thread of the motor; the valve is matched with the sealing surface in the end cover of the radiator for sealing, and the sealing state is correspondingly a non-bypass state, that is, most lubricating oil flows through the core body of the radiator, and the lubricating oil in the non-sealing state is directly bypassed without passing through the core body of the radiator; spring force generated by compression of the spring can enable the valve to be matched with a sealing surface in the radiator more tightly, and bypass leakage is prevented; the guide piece provides movement guide for the valve, and clamping stagnation is prevented; the spring, the valve and the guide piece are mounted on the sliding valve rod through threads; the motor assembly is composed of a hybrid stepping motor and a sliding lead screw.

Description

Technical Field

[0001] The present application belongs to the technical field of helicopter reducers and engine oil cooling systems, and specifically relates to an electric bypass valve, a radiator, a cooling system and an oil temperature control method. Background Art

[0002] In order to ensure that the helicopter reducer and engine always work normally, the internal lubricating oil temperature should always be kept within a certain range, so as to provide lubrication, cooling and cleaning functions for the reducer and engine. Existing helicopters mainly use radiators in conjunction with cooling fans to dissipate heat and cool the lubricating oil. In order to avoid the lubricating oil temperature being too low in a low-temperature environment, the radiator is usually equipped with a bypass valve. When the temperature is below a certain level, the lubricating oil is completely bypassed; when the lubricating oil temperature reaches a certain range, the temperature sensing structure begins to extend, and the bypass cross-sectional area gradually decreases until the bypass branch is completely closed. Generally, when designing a radiator, it is ensured that under the most stringent conditions (maximum ambient temperature, maximum power), the lubricating oil temperature is stabilized within the green zone when the bypass valve is fully closed.

[0003] The CCAR29.923(p) clause of the Airworthiness Regulations for Transport Category Rotorcraft stipulates that the transmission and gearbox must be operated for at least three 10-hour cycles required by this section, with the lubricating oil temperature at the specified measurement position not lower than the maximum operating temperature for which approval is sought. However, as mentioned above, the radiator temperature will be limited to the green zone, and the "not lower than the maximum operating temperature for which approval is sought" stated in the airworthiness clause has exceeded the green zone, which means that the original lubricating oil cooling system design method cannot meet the test requirements. Therefore, this paper provides a new lubricating oil temperature control method to control the lubricating oil temperature within the expected range. Summary of the invention

[0004] Purpose of the invention: The present application provides a method for controlling the lubricating oil temperature of a helicopter reducer or engine, replacing the original mechanical bypass valve of the radiator with an electric bypass valve that can effectively adjust the opening / closing amount in real time, so as to achieve the desired lubricating oil temperature value under any ambient temperature and any power state.

[0005] In a first aspect, the present application provides an electric bypass valve, the electric bypass valve comprising:

[0006] The valve seat is mounted on the radiator housing through threaded connection;

[0007] The valve assembly is composed of a sliding valve rod, a spring, a valve, and a guide member; wherein the sliding valve rod is designed with an internal thread for connecting with an external thread of a motor; the valve cooperates with an internal sealing surface of a radiator end cover for sealing, and the sealing state corresponds to a non-bypass state, that is, most of the lubricating oil flows through the radiator core, and the lubricating oil in the non-sealed state bypasses directly without passing through the radiator core; the spring force generated by the compression of the spring can make the valve cooperate more closely with the internal sealing surface of the radiator to prevent bypass leakage; the guide member provides movement guidance for the valve to prevent jamming; the spring, valve, and guide member are installed on the sliding valve rod through threads;

[0008] The motor assembly consists of two parts: a hybrid stepper motor and a sliding screw.

[0009] Preferably, the sliding seal between the sliding valve rod and the valve seat adopts a double-redundant internal movable sealing structure of a T-ring and a guide ring.

[0010] Preferably, the hybrid stepping motor is composed of a stator, a rotor, and a bearing; the sliding screw is composed of a nut and a screw;

[0011] The thread of the sliding screw is trapezoidal; the hybrid stepping motor and the sliding screw are connected through a screw nut and a motor shaft, which converts rotary motion into linear motion or converts linear motion into rotary motion, thereby realizing linear motion of the motor extension shaft.

[0012] Preferably, the hybrid stepping motor further comprises a driver and a controller;

[0013] Among them, the driver converts electrical pulses into angular displacement to achieve rotational motion; the controller has forward and reverse buttons and inching operations, which can control the motor to extend the shaft for bidirectional linear motion and specific stroke.

[0014] Preferably, the controller is provided with an LED digital display for displaying the current extension and contraction amount of the screw rod; and the controller is provided with a reset button for resetting the extension and contraction amount of the screw rod displayed by the LED digital display.

[0015] In a second aspect, the present application also provides a radiator, which includes the electric bypass valve as described above.

[0016] In a third aspect, the present application also provides a cooling system, which includes the radiator as described above.

[0017] In a fourth aspect, the present application also provides a lubricating oil temperature control method, the method comprising:

[0018] In the initial state, the controller adjusts the screw extension to the minimum, so that the motor extension shaft is in a fully retracted state, and the valve does not contact the internal sealing surface of the radiator end cover. At this time, since the bypass branch resistance is much smaller than the radiator core resistance, most of the lubricating oil will bypass the radiator directly, and the lubricating oil temperature will rise rapidly.

[0019] As the lubricating oil temperature rises, if the bypass branch is still in a fully open state, the lubricating oil temperature is likely to continue to rise and be difficult to stabilize. At this time, the controller needs to be operated to increase the extension of the screw to make the motor extension shaft extend slowly, reduce the bypass cross-sectional area, thereby reducing the bypass flow, and increase the lubricating oil flow through the radiator, so that the lubricating oil temperature rise rate slows down until it stabilizes at a certain value;

[0020] If the current lubricating oil temperature value is higher than the expected range, the controller is operated to increase the screw extension amount so that the motor extension shaft continues to extend, and the bypass flow rate is reduced until the lubricating oil temperature is stabilized within the expected range;

[0021] If the current lubricating oil temperature value is lower than the expected range, the controller is operated to reduce the extension amount of the screw so that the motor extension shaft is slowly retracted, and the bypass flow is increased until the lubricating oil temperature is stabilized within the expected range;

[0022] If the screw extension reaches the maximum and the motor extension shaft is fully extended, the valve will contact the internal sealing surface of the radiator end cover, and the valve will fit tightly with the sealing surface under the action of the spring force. At this time, the bypass branch is closed, most of the lubricating oil will flow through the radiator, and the lubricating oil temperature will be kept within the green zone.

[0023] Preferably, the method further comprises:

[0024] During the entire test process, the ambient temperature and reducer / engine power change. The motor output shaft extension and contraction amount needs to be adaptively adjusted according to the changes in the lubricating oil temperature so that the lubricating oil temperature is within the expected range during the entire test process.

[0025] This application has the following technical effects:

[0026] The present invention involves an electric bypass valve, a radiator, a cooling system and a lubricating oil temperature control method, with an electric bypass valve as the core. Applying it to the radiator and the cooling system can increase the upper limit of the lubricating oil temperature and adjust the lubricating oil temperature to a wider range, thereby providing conditions for the verification test of CCAR29.923(p) clause, and can also be used in other scenarios where the lubricating oil temperature range needs to be widened.

[0027] Since the controller needs to be operated manually, it is generally suitable for test benches. If the lubricating oil temperature and the control logic of the motor are subsequently combined into the software, it can be extended beyond the scope of the test bench to helicopter ground driving and flight use. This invention lays a technical foundation for further development and improvement. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the external structure of an electric bypass valve provided in an embodiment of the present application;

[0029] Figure 2 This is a schematic diagram of the internal structure of an electric bypass valve provided in an embodiment of the present application;

[0030] Figure 3 is a schematic diagram of the internal structure of a motor assembly provided in an embodiment of the present application;

[0031] Figure 4 This is a schematic diagram of a heat sink structure provided in an embodiment of the present application;

[0032] Figure 5 This is a schematic diagram of a radiator core structure provided in an embodiment of the present application;

[0033] Figure 6 is a schematic diagram of a lubricating oil cooling system provided in an embodiment of the present application;

[0034] Figure 7 is a schematic diagram of a motor extension shaft in a fully retracted state provided by an embodiment of the present application;

[0035] Figure 8 is a schematic diagram of a motor extension shaft provided in an embodiment of the present application in a fully extended state;

[0036] Among them: 1. Motor; 2. First sealing ring; 3. Valve seat; 4. Second sealing ring; 5. T-ring; 6. Guide ring; 7. Sliding valve rod; 8. Spring; 9. Valve; 10. Guide; 11. Screw; 12. Front cover; 13. Bearing; 14. Nut; 15. Stator; 16. Rotor; 17. Rear cover; 18. Core; 19. Double-ear floating support plate self-locking nut; 20. Single-ear floating support plate self-locking nut; 21. First end cover; 22. Motor 1. Lubricating oil pump; 2. Lubricating oil filter; 3. Lubricating oil filter bypass valve; 3. Lubricating oil temperature sensor; 3. Lubricating oil pressure sensor; 3. Lubricating oil pressure signal; 3. Lubricating oil temperature signal; 3. Reducer; 3. Oil return pump; 3. Lubricating oil sump; 39. Oil outlet filter. DETAILED DESCRIPTION

[0037] See also Figure 1-Figure 8 The present invention relates to a method for controlling the lubricating oil temperature of a helicopter reducer or engine. The core technology is to replace the original mechanical bypass valve of the radiator with an electric bypass valve that can effectively adjust the opening / closing amount in real time to achieve the desired lubricating oil temperature value under any ambient temperature and any power state.

[0038] 1) Electric bypass valve

[0039] Electric bypass valve appearance Figure 1 .

[0040] The internal structure of the electric bypass valve is shown in Figure 2 ,include:

[0041] The valve seat is installed on the radiator housing through a threaded connection and is sealed using a sealing structure of a HB 4-59 threaded connector; at the same time, four Φ3.3 mounting holes are designed on the valve mounting seat for mounting the motor assembly.

[0042] The valve assembly is composed of a sliding valve rod, a spring, a valve, and a guide. The sliding valve rod is designed with an internal thread for connecting the external thread of the motor; the valve cooperates with the internal sealing surface of the radiator end cover to seal, and the sealing state corresponds to the non-bypass state, that is, most of the lubricating oil flows through the radiator core, and the non-sealed state lubricating oil does not pass through the radiator core but bypasses directly; the spring force generated by the compression of the spring can make the valve and the internal sealing surface of the radiator fit more closely to prevent bypass leakage; the guide provides movement guidance for the valve to prevent jamming. The spring, valve, and guide are installed on the sliding valve rod through threads.

[0043] The sliding seal between the sliding valve rod and the valve seat adopts the double-redundant internal active seal structure of T-ring and guide ring designed by Guangyan Institute. After testing similar products and under more stringent data comparison, the active seal of this structure can achieve zero leakage of lubricating oil, fully ensuring the sealing performance during electric adjustment. At the same time, the guide ring plays the role of axial sliding support for the sliding valve rod.

[0044] The motor assembly consists of two parts: a hybrid stepper motor and a sliding screw. The stepper motor is mainly composed of a stator, a rotor, a bearing, etc., and the sliding screw is composed of a nut and a screw. Figure 3. The thread of the sliding screw adopts the most widely used trapezoidal shape, which has the advantages of high transmission efficiency, strong load capacity, easy installation and long life. The stepper motor and the sliding screw are connected through the screw nut and the motor shaft to convert the rotary motion into linear motion or convert the linear motion into rotary motion, thereby realizing the linear motion of the motor extension shaft. The motor extension shaft is connected to the internal thread of the sliding valve rod through the external thread, driving the sliding valve rod to move linearly, with a maximum stroke of not less than 9mm and a travel speed of 1.6mm / s. The motor assembly is installed on the valve seat through 4 Φ3.3 mounting holes.

[0045] In addition, the stepper motor also includes a stepper motor driver and a controller. The driver converts electrical pulses into angular displacement to achieve rotational motion; the controller has forward and reverse buttons and inching operations, which can control the motor extension shaft to perform bidirectional linear motion and specific stroke; the controller has an LED digital display of the current screw extension and retraction amount; the controller has a reset button that can reset the screw extension and retraction amount displayed on the LED digital display.

[0046] 2) Radiator

[0047] The radiator is used in conjunction with a cooling fan. The cooling fan provides pressurized cold air to the radiator, and the radiator realizes energy exchange between the cold air and the hot lubricating oil of the reducer or engine, ensuring that lubricating oil of a certain temperature and pressure is provided to the reducer or engine.

[0048] The radiator is mainly composed of the core, end cover, electric bypass valve, oil drain nozzle, support plate nut, etc. Figure 4 .

[0049] The core is the place where the heat exchange between hot and cold fluids occurs. The high-temperature fluid is separated from the low-temperature fluid by a partition. Figure 5 .

[0050] The end cover and the oil inlet and outlet nozzle joints are integrated into one design to reduce the argon arc welding seams of the product. There are four mounting holes around the lower edge of the end cover to connect with the machine structure.

[0051] Once the traditional mechanical bypass valve is designed and manufactured, the sensing action point cannot be changed. When the lubricating oil is at high temperature, it must be forced to flow through the radiator and almost never pass through the bypass branch. Under the condition that other conditions remain unchanged, the upper limit of the lubricating oil temperature cannot be increased. The electric bypass valve is located on the radiator end cover and is installed to the corresponding interface of the radiator through threaded matching and grease. It can replace the traditional mechanical bypass valve in situ to minimize maintenance work. By properly controlling the electric bypass valve, the lubricating oil can be heated up quickly when it is at low temperature and the lubricating oil can be fully dissipated when it is at high temperature. In addition, part of the radiator bypass volume can be retained when the lubricating oil is at high temperature, thereby increasing the upper limit of the lubricating oil temperature and widening the lubricating oil temperature range, thereby meeting specific needs in certain situations.

[0052] The oil drain nozzle is located at a lower position of the entire radiator, so that when the oil drain is required, the oil drain nozzle is opened and the lubricating oil flows out from the oil drain nozzle by gravity.

[0053] A mounting edge extends out from each end of the core body, and a double-ear movable support plate self-locking nut and a single-ear movable support plate self-locking nut are designed on the inner side of the mounting edge. The screws are installed on the support plate nuts from the outside to the inside, so as to achieve the installation and fixation of the radiator and the air inlet and exhaust ducts. Moreover, since the nuts are movable, there is a certain amount of movable space during installation, which can reduce the installation stress during installation and improve the installation reliability.

[0054] 3) Cooling system

[0055] The radiator is located at the outlet of the reducer hot lubricating oil in the entire lubricating oil cooling system. Figure 6 . When the rotor rotates, the gear transmission mechanism of the reducer drives the oil pump to rotate, and the hot oil in the reducer oil pool is sucked into the pump, and after being pressurized, it is sent to the radiator through the pipeline and oil filter, and cooled by the mechanical fan driven by the reducer; the cooled oil returns to the reducer through the pipeline, and is distributed to various lubrication points through the internal channel of the reducer casing; the hot oil after lubrication flows into each cavity by its own weight, and finally returns to the oil pool to start a new cycle; in addition, the system is equipped with a lubricating oil temperature sensor, a temperature signal device, a pressure sensor and a pressure signal device to provide the helicopter's electromechanical management system with the lubricating oil temperature and pressure signals of the reducer, so as to monitor and judge the state of the reducer lubricating oil in real time, and ensure that the reducer can operate normally after being fully lubricated and cooled. Since the radiator of the cooling system adopts an electric bypass valve, part of the radiator bypass volume can be retained when the lubricating oil is at high temperature, thereby increasing the upper limit of the lubricating oil temperature and widening the lubricating oil temperature range, thereby meeting specific needs in certain situations.

[0056] 4) Lubricating oil temperature control method

[0057] The method of using an electric bypass valve to control the temperature of the helicopter reduction gear or engine oil is as follows:

[0058] Replace the original mechanical bypass valve on the reducer or engine radiator with an electric bypass valve in situ, extend the cable of the motor assembly controller until the controller can be operated in the cockpit, and the changes in the lubricating oil temperature on the cockpit panel can be observed in real time.

[0059] In the initial state, the controller adjusts the screw extension to the minimum, so that the motor extension shaft is in a fully retracted state. Figure 7 , the valve does not contact the internal sealing surface of the radiator end cover. At this time, since the bypass branch resistance is much smaller than the radiator core resistance, most of the lubricating oil will bypass the radiator directly, and the lubricating oil temperature will rise rapidly;

[0060] As the lubricating oil temperature rises, if the bypass branch is still in a fully open state, the lubricating oil temperature is likely to continue to rise and be difficult to stabilize. At this time, the controller needs to be operated to increase the extension of the screw to make the motor extension shaft extend slowly, reduce the bypass cross-sectional area, thereby reducing the bypass flow, and increase the lubricating oil flow through the radiator, so that the lubricating oil temperature rise rate slows down until it stabilizes at a certain value;

[0061] If the current lubricating oil temperature value is higher than the expected range, the controller is operated to increase the screw extension amount so that the motor extension shaft continues to extend, and the bypass flow rate is reduced until the lubricating oil temperature is stabilized within the expected range;

[0062] If the current lubricating oil temperature value is lower than the expected range, the controller is operated to reduce the extension amount of the screw so that the motor extension shaft is slowly retracted, and the bypass flow is increased until the lubricating oil temperature is stabilized within the expected range;

[0063] If the screw reaches the maximum extension, the motor extension shaft is fully extended, and the valve contacts the inner sealing surface of the radiator end cover. Figure 8 , and the valve will fit tightly with the sealing surface under the action of spring force. At this time, the bypass branch is closed, most of the lubricating oil will flow through the radiator, and the lubricating oil temperature will be kept within the green zone.

[0064] During the entire test process, various internal and external factors such as ambient temperature and reducer / engine power may change. The motor output shaft extension and contraction amount needs to be adaptively adjusted according to the changes in lubricating oil temperature so that the lubricating oil temperature is within the expected range during the entire test process.

[0065] It should be noted that:

[0066] 1) The valve seat can be installed on the radiator housing through threads, and a mounting hole is designed for the installation of the motor;

[0067] 2) The valve assembly is designed with internal threads for connecting the motor to electrically adjust the opening of the valve;

[0068] 3) A double-redundant internal movable sealing structure of a T-ring and a guide ring structure is used between the valve seat and the sliding valve rod in the valve assembly to ensure sealing during electric adjustment;

[0069] 4) The motor can flexibly control the bypass valve to perform bidirectional linear motion, and the controller has an LED digital display of the current extension and contraction amount of the screw;

[0070] 5) After the radiator of the lubricating oil cooling system is installed with an electric bypass valve, the motor can drive the sliding valve rod to control the lubricating oil bypass volume, thereby widening the temperature range of the lubricating oil and controlling the lubricating oil temperature within the expected range.

[0071] The present invention involves an electric bypass valve, a radiator, a cooling system and a lubricating oil temperature control method, with an electric bypass valve as the core. Applying it to the radiator and the cooling system can increase the upper limit of the lubricating oil temperature and adjust the lubricating oil temperature to a wider range, thereby providing conditions for the verification test of CCAR29.923(p) clause, and can also be used in other scenarios where the lubricating oil temperature range needs to be widened.

[0072] Since the controller needs to be operated manually, it is generally suitable for test benches. If the lubricating oil temperature and the control logic of the motor are subsequently combined into the software, it can be extended beyond the scope of the test bench to helicopter ground driving and flight use. This invention lays a technical foundation for further development and improvement.

Claims

1. An electric bypass valve, characterized in that: The electric bypass valve comprises: The valve seat is mounted on the radiator housing through threaded connection; The valve assembly is composed of a sliding valve rod, a spring, a valve, and a guide member; wherein the sliding valve rod is designed with an internal thread for connecting with an external thread of a motor; the valve cooperates with an internal sealing surface of a radiator end cover for sealing, and the sealing state corresponds to a non-bypass state, that is, most of the lubricating oil flows through the radiator core, and the lubricating oil in the non-sealed state bypasses directly without passing through the radiator core; the spring force generated by the compression of the spring can make the valve cooperate more closely with the internal sealing surface of the radiator to prevent bypass leakage; the guide member provides movement guidance for the valve to prevent jamming; the spring, valve, and guide member are installed on the sliding valve rod through threads; The motor assembly consists of two parts: a hybrid stepper motor and a sliding screw.

2. The electric bypass valve according to claim 1, characterized in that: The sliding seal between the sliding valve rod and the valve seat adopts a double-redundant internal movable sealing structure of a T-ring and a guide ring.

3. The electric bypass valve according to claim 1, characterized in that: The hybrid stepping motor is composed of a stator, a rotor, and a bearing; the sliding screw is composed of a nut and a screw; The thread of the sliding screw is trapezoidal; the hybrid stepping motor and the sliding screw are connected through a screw nut and a motor shaft, which converts rotary motion into linear motion or converts linear motion into rotary motion, thereby realizing linear motion of the motor extension shaft.

4. The electric bypass valve according to claim 3, characterized in that: The hybrid stepping motor also includes a driver and a controller; Among them, the driver converts electrical pulses into angular displacement to achieve rotational motion; the controller has forward and reverse buttons and inching operations, which can control the motor to extend the shaft for bidirectional linear motion and specific stroke.

5. The electric bypass valve according to claim 4, characterized in that: The controller has an LED digital display to show the current extension and contraction amount of the screw rod; the controller has a reset button to reset the extension and contraction amount of the screw rod shown in the LED digital display.

6. A radiator, characterized in that: The radiator comprises an electric bypass valve as described in any one of claims 1-5.

7. A cooling system, characterized in that: The cooling system includes the radiator of claim 6.

8. A lubricating oil temperature control method, characterized in that: The method comprises: In the initial state, the controller adjusts the screw extension to the minimum, so that the motor extension shaft is in a fully retracted state, and the valve does not contact the internal sealing surface of the radiator end cover. At this time, since the bypass branch resistance is much smaller than the radiator core resistance, most of the lubricating oil will bypass the radiator directly, and the lubricating oil temperature will rise rapidly. As the lubricating oil temperature rises, if the bypass branch is still in a fully open state, the lubricating oil temperature is likely to continue to rise and be difficult to stabilize. At this time, the controller needs to be operated to increase the extension of the screw to make the motor extension shaft extend slowly, reduce the bypass cross-sectional area, thereby reducing the bypass flow, and increase the lubricating oil flow through the radiator, so that the lubricating oil temperature rise rate slows down until it stabilizes at a certain value; If the current lubricating oil temperature value is higher than the expected range, the controller is operated to increase the screw extension amount so that the motor extension shaft continues to extend, and the bypass flow rate is reduced until the lubricating oil temperature is stabilized within the expected range; If the current lubricating oil temperature value is lower than the expected range, the controller is operated to reduce the extension amount of the screw so that the motor extension shaft is slowly retracted, and the bypass flow is increased until the lubricating oil temperature is stabilized within the expected range; If the screw extension reaches the maximum and the motor extension shaft is fully extended, the valve will contact the internal sealing surface of the radiator end cover, and the valve will fit tightly with the sealing surface under the action of the spring force. At this time, the bypass branch is closed, most of the lubricating oil will flow through the radiator, and the lubricating oil temperature will be kept within the green zone.

9. The method according to claim 8, characterized in that The method further comprises: During the entire test process, the ambient temperature and reducer / engine power change. The motor output shaft extension and contraction amount needs to be adaptively adjusted according to the changes in the lubricating oil temperature so that the lubricating oil temperature is within the expected range during the entire test process.

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