Dual-redundancy electro hydraulic servo actuator

Abstract

The invention relates to a dual-redundancy electro hydraulic servo actuator which comprises a double-outlet rod hydraulic cylinder and a single-outlet rod hydraulic cylinder which are connected in series, wherein one end of the double-outlet rod hydraulic cylinder extends outward, and is connected with load; the rodless cavity side of the single-outlet rod hydraulic cylinder is connected with a displacement sensor; and one end of the double-outlet rod hydraulic cylinder and the rodless cavity side of the single-outlet rod hydraulic cylinder are respectively controlled by a hydraulic control system. According to the invention, the double-outlet rod hydraulic cylinder and the single-outlet rod hydraulic cylinder are adopted to form the dual-redundancy electro hydraulic servo actuator, so that the defect of large occupied space for a dual-redundancy electro hydraulic servo actuator which is composed of two double-outlet rod hydraulic cylinders in series is overcome, thus the structure is more compact, because the control on a single-outlet rod return circuit has a cold and hot oil exchange process, the system working temperature is reduced, and the system works more stably.

Description

technical field [0001] The present invention is related to an electro-hydraulic servo actuator, more specifically a double-redundant electro-hydraulic servo actuator including a double-outlet hydraulic cylinder, a single-outlet hydraulic cylinder and a hydraulic control system thereof. technical background [0002] When the hydraulic device is used in some important occasions, the hydraulic device is required to have a certain amount of redundancy, such as the hydraulic actuator used in the main flight surface of the aircraft. When one hydraulic device fails, another hydraulic device can replace it. run to make the plane fly normally. In the existing electro-hydraulic servo circuit device, the double-redundant hydraulic actuator used is a hydraulic actuator composed of two double-rod hydraulic cylinders connected in series. can work simultaneously. The two hydraulic cylinders in the hydraulic actuator are controlled by their own power sources, control elements and control ...

AI Technical Summary

Problems solved by technology

[0003] However, this kind of double-rod hydraulic cylinder, because the piston rod protrudes in both directions, takes up a lot of space, especially when the stroke of the hydraulic cylinder is large, this shortcoming is even more serious. This is very undesirable for equipment that requires a small footprint, such as aircraft. In this closed circuit, due to the small amount of hydraulic oil exchange, the temperature of the system will be high for a long time, and the oil The high temperature rise will have an adverse effect on the stable operation of the hydraulic system

[0004] In the hydraulic system, more than 90% of the hydraulic actuators use single-rod differential hydraulic cylinders. Since the flow rates of the two chambers of the single-rod hydraulic cylinders are not equal, it is impossible to use the existing double-outlet hydraulic pumps to directly form a closed type hydraulic cylinder. For the circuit, some auxiliary measures are needed, or the structure of the hydraulic pump is redesigned to match the area difference of the single-rod hydraulic cylinder. There is an invention patent of a "closed electro-hydraulic control system" with the publication number CN1818382A , provides such a method, the invention discloses a hydraulic pump with three oil ports, the oil suction port of the pump is connected with the low-pressure oil source, and the other two working oil ports are respectively connected with the two chambers of the single-rod hydraulic cylinder It solves the problem that the two chambers of the pump-controlled differential hydraulic cylinder are not equal in area, and can reduce the axial size of the hydraulic cylinder. However, the current redundant hydraulic actuator composed of two double-rod hydraulic cylinders connected in series does not Suitable for use with this triple port hydraulic pump

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