Apparatus for changing capacity of multi-stage rotary compressor

Abstract

A multi-stage compressor with variable capacity comprises: a first cylinder provided with a first suction and a first discharge port, and divided into a first suction chamber and a first compression chamber by a first rolling piston which orbits and a first vane which makes a linear movement in contact with the first rolling piston; a second cylinder provided with a second suction port and a second discharge port, and divided into a second suction chamber and a second compression chamber by a second rolling piston which orbits and a second vane which makes a linear movement in contact with the second rolling piston; a middle bearing inserted between the first cylinder and the second cylinder, having a bypass hole to allow communication between the compression chambers of the first cylinder and the second cylinder, and having a valve hole for communication in the middle of the bypass hole; a sliding valve slidingly coupled to the valve hole of the middle bearing, and selectively opening or closing the bypass hole; and a pressure switching unit for selectively supplying discharge pressure to one side of the sliding valve, thereby changing a capacity using all the plural compression units, and obtaining power saving effect suitable for the saving mode.

Description

technical field [0001] The present invention relates to a rotary compressor performing multi-stage compression, and more particularly to a multi-stage rotary compressor capable of using all compression units to achieve optimum compression efficiency. Background technique [0002] A compressor is a device that receives energy from an energy generator such as an electric motor to compress air, refrigerant gas, or other specialized gas to increase pressure and is widely used in industry. Depending on how compression is performed, compressors can be classified into positive displacement compressors and turbo compressors. Positive displacement compressors perform compression by a compression method in which pressure is increased by volume reduction; and turbo compressors perform compression by converting kinetic energy of gas into pressure energy. [0003] A rotary compressor, which is a type of positive displacement compressor, is generally used in an air conditioning apparatus...

AI Technical Summary

Problems solved by technology

[0017] First of all, in saving mode, the method in which the blades are moved backwards and fixed has the problem that special parts such as parts etc. and the installation space of this part are not ideal and increase the number of manufacturing processes

[0018] Second, due to repeated collisions of parts with the blade, the surface of the blade may be damaged over time, and reliability problems such as abrasion, foreign matter generation, etc. may be caused

[0019] Third, since variable frequency motors are usually expensive, using variable frequency motors as drive units may cause an increase in manufacturing costs

[0020] Fourth, when using an existing constant speed motor, frequently repeat ON / OFF operations to control room temperature

For this reason, since the energy consumption of the starting current is very large, the wear of the compression unit is accelerated, and the reliability of the compression unit is reduced.

Moreover, since the change between the set temperature and the room temperature is also large in the ON / OFF of the constant speed motor, it is difficult to control the room temperature to a satisfactory state

[0021] Fifth, when the compression unit is idling or the refrigerant suction is blocked, some compression units are not used at all, which also reduces the efficiency of the compressor

Images