Automatic retractable hydraulic device for unmanned aerial vehicle undercarriage

Abstract

The invention relates to the technical field of aircraft hydraulic system design, in particular relates to an automatic retractable hydraulic device for an unmanned aerial vehicle undercarriage. The automatic retractable hydraulic device for unmanned aerial vehicle undercarriage comprises an oil tank (1), a quantitative hydraulic pump (2), a variable frequency motor (3), an oil filter (4), an undercarriage retracting electromagnetic valve (5), an overflow valve (6), a first pressure sensor (7), an undercarriage retracting actuator cylinder (8) and a second pressure sensor (9). The undercarriage retracting system with the structure has the advantages of simple structure, unrestricted installation location and low requirements on oil precision, omits a valve controlled throttle governing servo hydraulic system, avoids the system temperature rise and low efficiency caused by the throttling loss and overflow loss, and at the same time abandons the electro-hydraulic servo valve with high cost to realize low cost.

Description

technical field [0001] The invention relates to the technical field of aircraft hydraulic system design, in particular to an automatic retractable hydraulic device for landing gear of an unmanned aerial vehicle. Background technique [0002] In the existing automatic retractable hydraulic device of UAV landing gear, a valve-controlled throttling and speed-adjusting servo hydraulic system is generally used to control the flow and pressure of the system through a throttle valve or by controlling the opening of an electro-hydraulic servo valve. Retractable and retractable landing gear, this type of system has high requirements on the transmission medium, heavy structure, complex structure, and unavoidable throttling loss and overflow loss, resulting in system temperature rise, difficult heat dissipation, and low efficiency. In addition, in some systems, when the landing gear is not retracted, the hydraulic pump is idling, and the hydraulic pump is unloaded through the neutral p...

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Problems solved by technology

[0005] (1) The system has a large loss of capacity and a lot of heat: generally, a valve-controlled throttling and speed-adjusting servo hydraulic system is used, and the flow and pressure of the system are controlled by controlling the opening of the throttle valve to realize the retraction and retraction of the landing gear. This type of system cannot avoid throttling. System temperature rise caused by flow loss and overflow loss, difficult heat dissipation, and low efficiency

[0006] (2) The installation position is limited: the hydraulic pump shaft must be connected to the engine shaft, there is no choice for the position of the hydraulic pump, and the connection process between the hydraulic pump shaft and the engine shaft requires high requirements

[0007] (3) Long idling time of the hydraulic pump: When the landing gear is not retracted, the hydraulic pump is idling, unloaded through the electro-hydraulic servo valve, and the hydraulic pump works for a long time, which affects the life of the hydraulic pump

[0008] (4) The electro-hydraulic servo valve has high requirements on oil precision, high failure rate of the system, and high cost

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