Axial flow fan moving blade adjusting device

Abstract

The invention is suitable for an axial flow fan, and provides an axial flow fan moving blade adjusting device. The device comprises a valve shell assembly, a mandrel, a hydraulic control switch assembly and a first sealing piece. The control end of the mandrel is contained in a first containing cavity of the valve shell assembly in a sealed mode, and the mandrel is in clearance fit with the valve shell assembly. The hydraulic control switch assembly is contained in a second containing cavity of the mandrel, and a closed control oil cavity is formed between the hydraulic control switch assembly and a first sealing assembly. A first annular pressure oil groove and a second annular pressure oil groove in the mandrel communicate with a first oil way and a second oil way correspondingly, and the hydraulic control switch assembly is used for opening or closing a communicating channel of the second oil way and the second annular pressure oil groove. Almost no internal leakage can be realized through clearance sealing. The machining difficulty is low, and the assembling precision is high. When being matched with a proportional valve for use, the device is insensitive to oil and abrasive wear. And under the condition that hydraulic oil is interrupted, the blade position keeping function is achieved instantly.

Description

technical field [0001] The invention relates to an axial flow fan, in particular to an axial flow fan blade adjustment device. Background technique [0002] Axial fans with adjustable rotor blades can adjust the installation angle of the rotor blades to match different system working conditions, and at the same time make the adjusted fans work in the high-efficiency area, so they are widely used in thermal power, metallurgy, mines, tunnels and other industries. in the smoke system. However, in the prior art, the rotor blade adjustment system of the axial flow fan with adjustable rotor blades makes the structure of the fan complex, and its manufacturing precision and reliability are extremely high. [0003] In the prior art, for the adjustment of the movable blades of the axial flow fan with adjustable movable blades, a mechanical adjustment mechanism is mainly used, that is, a sliding valve type rotary joint is dragged by a mechanical structure. However, due to the poor ad...

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Problems solved by technology

However, due to the poor adjustment accuracy, low reliability and internal leakage of this structure, it is gradually replaced by an electro-hydraulic control system based on a proportional valve, that is, the electromagnets at both ends of the proportional valve drive the movement of the proportional valve spool (that is, the spool valve) Rotary joint mechanism) to complete the position switching of the three-position four-way proportional valve, and finally realize the forward and backward movement of the hydraulic cylinder piston

[0004] But this kind of slide valve rotary joint has the following problems: First, the design requires extremely high radial and axial dimensional accuracy for the cooperation between the valve sleeve and the valve core, and the processing is difficult; second, the valve sleeve and the valve core need to be It can move relative to the axial direction, and is easily affected by oil quality, resulting in abrasive wear, which leads to the failure of the gap seal; third, the structure cannot prevent the reverse flow of oil in the oil circuit, so it does not have the design basis for the function of retaining the rotor blade, which is manifested as Once the hydraulic oil is cut off, the installation angle of the blade will change randomly under the action of the load moment and internal leakage of the working condition

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