Piston four-way reversing valve for refrigerating system

Abstract

The invention discloses a piston four-way reversing valve for a refrigerating system and belongs to a valve which can be used for changing the flow direction of refrigerants. The existing four-way reversing valve in a stopped status has the defect that the piston is easily deadlocked due to lack of the lubricating oil when the oil film is easily washed and moved away by the refrigerating fluid. According to the invention, the piston four-way reversing valve is mainly composed of a main valve and a pilot valve, wherein the pilot valve is communicated with the cavity of the main valve through a gas-guide pipe; the main valve comprises a valve body, a piston which is arranged in the valve body and two end caps which are arranged on the two ends of the valve body; the valve body is provided with four valve ports, a lubricating sleeve is arranged between the inner surface of the valve body and the piston, the lubricating sleeve is fixedly connected with the valve body; a through hole which corresponds to and is communicated with the valve port is arranged on a lubricating sleeve body; the lubricating sleeve is divided into a steel substrate layer, a copper substrate alloy powder layer and a solid lubricating layer in the radial direction from outside to inside; and the first layer and the second layer are sintered into a whole, the third layer is rolled on the surface of the second layer, a solid lubricating material can play a role in lubricating the piston so as to ensure the piston to flexibly move in the valve body without being deadlocked, thus the service life can be prolonged.

Description

technical field [0001] The invention belongs to a valve for changing the flow direction of refrigerant in a refrigeration system, and in particular relates to a piston-type four-way reversing valve for the refrigeration system. Background technique [0002] Large-capacity four-way reversing valves are generally used in heat pump air conditioners. The usual piston type four-way reversing valve for refrigeration system is composed of a pilot valve and a main valve. The valve body, the piston and the end cover form two cavities, the left and the right. The pilot valve communicates with the cavity of the main valve through the air guide tube. There are valves on the air guide tube respectively, and there is a valve that can be closed between the valve and the main valve cavity. Exhaust device; the piston mainly uses the system pressure difference inside the four-way reversing valve to move. When the four-way valve is shut down and the ambient temperature is below zero, the liqu...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to overcome the defects of the aforementioned four-way reversing valve that the oil film is easily washed away by the refrigerant after shutdown, resulting in lack of lubricating oil and causing the piston to be stuck, and to provide a refrigeration system that can ensure the flexible movement of the piston in the valve body. Piston type four-way reversing valve for system

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