Papers by Keyword: Rotary Compressor

Abstract: A novel four-chamber rotary compressor (FCRC) is being developed for a refrigerator and an air-conditioning system. The novelty lies in the usage of three rotating sleeves and two oppositely installed vanes each has one end fixed to an outer sleeve and the other end to a rotor, respectively. In this paper, the swept volume, the delivered pressure, the work and the power of the FCRC are formulated and analyzed. The compressor configuration and thermodynamic analysis are based on the 174 cc swept volume with R134a as the compressed gas. Considering the encouraging results, added by design simplicity of mainly cylindrical shaped components, the proposed FCRC is reckoned to be very suitable to be used for air-conditioning and refrigeration applications.

Abstract: This paper introduces a novel two-sleeve rotary compressor (TSRC) concept. The compressor mechanism is basically that of a rotary motion whereby the novelty lies in the usage of two rotating sleeves and a secured vane that has one end fixed to an outer sleeve and the other end to a rotor, respectively. The paper introduces the working principle and thermodynamic model of the TSRC compressor. The swept volume, the delivered pressure, the work and the power of the TSRC are formulated and analyzed. The compressor configuration and thermodynamic analysis are based on the 174 cm³.rev^-1 swept volume with R134a as the compressed gas. The thermodynamic analysis reveals that the TSRC will perform well as refrigerant compressor and can be reliably adopted for refrigeration and air-conditioning applications.

Abstract: The internal-meshing rotary mechanism is widely used in the oil pumps and cyclonical pin wheels application. The working principle of the internal meshing rotary compressor is very different with the current institutions applications. while, the mechanical property method of the internal meshing rotary pump can’t be entirely and directly used in the rotary compressor because of the different working principles. In order to simplify the study of the internal-meshing rotary compressors, the forces acted on the inner and outer gears are computed. The gas force and torque related to the rotating angle are derived, and then compared with other rotary compressors. The result shows that the internal meshing rotary compressor’s mechanical parameters vary periodically and the period is 2π/Z₂and this type of compressor has perfect mechanical property compared with other compressors.

Abstract: This paper presents results of a frictional analysis on a new rotating sleeve multi-vane rotary (RSMVR) compressor. The new five-vane rotary compressor is adapted from the existing concept of a rotating sleeve single-vane rotary (RSSVR) compressor, in which the extended rounded end of one vane is embedded into the inner surface of the sleeve which allows the vane to swing within a certain small angle. As the rotor rotates, this vane drives the sleeve which in turn pushes and pulls the vane into and out of the slot in the rotor, respectively. The other four vanes are similarly pushed into the respective slots in the rotor but slide out only when a sufficient centrifugal force is developed. The driving vane ensures that suction, compression and discharge of the gas occur at all speeds of rotation. Although the sleeve rotates along, due to eccentricity between the rotor and the sleeve, each tip of the four vanes still rubs against the inner surface of the sleeve. The focus of the present study limits its analysis on to only frictions between the vane tip and the inner surface of the sleeve and between the vane sides and the respective slot walls. The frictional analysis is carried out by first determining the instantaneous pressure inside the compression cell and all the associated forces that exist. This involves an analysis on the dynamics of each vane when it reciprocates and at the same time rotates eccentrically with the sleeve. The kinematics of the vane are modelled using cosine and sine rules taking the cell leading vane as a reference to the angle of rotation. In the operation the model estimates a dramatic reduction in friction which is up to 82% lower than that occurs in an existing design of an equivalent conventional multi-vane rotary compressor (MVR). A friction between the rotating sleeve and the two opposite end plates exists in the RSMVR compressor but does not in that of the MVR. This will be included in a later study but on a new integrated brushless DC motor RSMVR compressor concept and on that of the existing shaft driven MVR, to see the overall difference in the frictions exerted.

Abstract: The structure and working principle of a new translational piston rotary compressor was introduced and made theoretical analysis in this paper. It was pointed out that the translational piston rotary compressor had not only fine practical, which with less friction loss and leak loss than the traditionally rotary compressor, but also the advantage of simply structure and technics and low manufacturing cost. The rotary compressor was practical and promising.

Abstract: A new type of stationary blade rotary compressor is developed to overcome the rolling piston compressor’s weaknesses such as severe leaking loss and friction waste. The new compressor has unique sealing structures and friction-reducing techniques, featuring in that the compressor adopts a stationary blade whose out-end is hermetically fastened to the cylinder’s inner wall and the blade’s two side-ends are hermetically fastened to the end-covers which respectively set in both ends of the cylinder. Due to that the cylinder, the blade and the end-covers all are closely fitted to each other, the leakage and friction occurred from these parts are completely eliminated. This paper introduces the compressor’s working principle and structure characteristics, deduces the calculation formulas for displacement volume, chamber pressure and thermodynamic properties, and discusses the design principles of compressor structure parameters and what effects these parameters have on leakage and friction. The research result shows that the stationary blade compressor, in comparison with the conventional rolling piston compressor, has displayed some unique advantages in seal property, friction reduction, manufacturing and assembling techniques.

Abstract: Due to the environmental concerns, especially the greenhouse effect and GWP (Global Warming Potential), the carbon dioxide was investigated as an alternative natural refrigerant to replace HFCs (HydroFluoroCarbons) in refrigerator or air conditioning systems. To develop new compressor, especially rotary type, the friction and wear characteristics of sliding surfaces between vane and flange in the rotary compressor were evaluated in this paper. Several hard coatings, such as TiN, CrN and WC/C, were applied on vane surfaces in order to improve the tribological characteristics, and their performances were evaluated experimentally. The vane-on-flange type lubricated sliding tests were performed with a high pressure wear tester using HFC (R410A) and carbon dioxide. From the tests, wear volumes of vane surfaces applied with various coatings were compared each other.

Abstract: In order to protect the global environment, especially on the point of the greenhouse effect, carbon dioxide should be used as a natural refrigerant. Because new compressors with CO2 are going to be operated under the high pressure, the interaction between sliding surfaces in the compressor becomes very important. To develop new compressor, especially rotary type, the friction and wear characteristics of sliding surfaces were very important. In this paper, the surface interactions between a shaft and a flange, which were one of the contacting parts in compressor, were evaluated. The frictional forces and wear amounts in boundary lubricated sliding condition were measured using the pin-on-disk tester. Two types of refrigerants were used, namely R410A and CO2 to compare the tribological characteristics of conventionally used one with new natural refrigerant. It was found that CO2 lead to a bad lubricity as compared with R410A or pure oil due to the formation of relatively thin protective layer on the sliding surface. Smooth surface of shaft produced lower values of friction and wear than rough surfaces. The smooth surfaces represented much more spheroidal graphite, which had very favorable tribological characteristics, on the sliding surfaces.

Abstract: The CO2 was investigated as an alternative refrigerant to replace HFC (hydrofluorocarbons) refrigerant in air conditioning systems due to the environmental concerns. Because new compressors with CO2 are going to be operated under the high pressure, the tribology of sliding surfaces in the compressor becomes very important. To develop new compressor, especially rotary type, the friction and wear characteristics of sliding surfaces between a vane and a roller in the rotary compressor were evaluated in this paper. Several hard coatings, such as TiN, CrN and WC/C, were applied on vane surfaces in order to improve the tribological characteristics, and their performances were evaluated experimentally. Two types of lubricants were used, namely POE (polyol ester) oil and PAG (polyalkylene glycol) oil. The vane-on-disk type sliding tests were performed with an exclusive high pressure wear tester. From the tests, wear volumes of vane surfaces applied various coatings were compared. Test results showed that WC/C and CrN coatings showed good tribological properties. Also, the results of the sliding tests showed that using PAG oil has an advantage over POE oil in CO2 environment.

Abstract: The carbon dioxide (CO2) is investigated as an alternative refrigerant to replace HFC (hydro fluorocarbon) refrigerants in refrigerators and air conditioning systems due to the environmental concerns. Because new compressors with the carbon dioxide are going to be operated under the high pressure, the tribology of sliding surfaces in the compressor becomes very important. To develop new compressors, especially rotary type, the friction and wear characteristics of sliding surfaces between a vane and a roller in the rotary compressor were evaluated in this paper. Several hard coatings, such as TiN, CrN, and WC/C, were applied on vane surfaces in order to improve the tribological characteristics, and their performances were evaluated experimentally. The vane-on-disk type sliding tests were carried out under the various sliding speeds, normal loads, and carbon dioxide pressures with an exclusive high pressure wear tester. From the tests wear volume of vane surfaces applied various coatings were compared. During the tests coefficients of friction and surface temperatures were monitored. Test results showed that WC/C coatings showed good tribological properties. TiN and CrN coated vanes showed good wear resistance properties but produced high friction.