• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.11 no.5
• /
• pp.605-614
• /
• 1999

Orbiting scroll mass center is different from the basic circle's for the normal involute profile. As for the orbiting scroll balanced conditions, the dynamic modeling are set up. The influences on sealing, reaction forces between the moving elements and forces from the moving elements to the compressor frame are analyzed in this paper. The simulation and experiment results are presented.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 1996.05a
• /
• pp.41-46
• /
• 1996

For a vertical type crankshaft-journal bearing system used in scroll compressor, nonlinear transient response analysis is applied includung nonlinear fluid film reaction forces of journal beatings. By a connected behavior analysis of crankshaft and orbiting scroll, the radial clearance of scroll wraps is calculated. Considering tangential leakage for this clearance, a coupled analysis model for leakage and dynamic behavior of the orbiting scroll is made, and analyzed by iterative calculation. By regarding clearances of main, sub bearing of crankshaft and orbiting scroll shaft bearing clearance as design parameters, the radial clearance of scroll wraps is analyzed.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.11 no.6
• /
• pp.716-724
• /
• 1999

In co-orbiting scroll compressor, the two scroll members are to orbit with independent radii, producing a relative orbit motion between them. One scroll member is driven by the crank mechanism while the motion of the other member is determined by geometrical constraints and reacting forces. This paper presents an analytical study on the performance of a co-orbiting scroll compressor. The following results have been obtained: Radial contact force between the scroll wraps is virtually free from the centrifugal force of the orbiting scroll member. The frictional losses are somewhat increased due to the complicated drive mechanism, yielding to a little lower EER compared to conventional radially compliant scroll compressors .

• Proceedings of the SAREK Conference
• /
• 2008.06a
• /
• pp.177-183
• /
• 2008

For 10 kW-class Stirling engine using scroll expander and scroll compressor, considerations on thermal expansion of the fixed and orbiting scroll members of the scroll expander due to high gas temperature at the expander inlet has resulted in adopting of the keys between the fixed scroll and main frame for the fixed scroll side and spring type insertion between the orbiting scroll base plate and supporting holders for orbiting scroll side. Dynamic analysis on the fixed and orbiting scroll members and the shafts of the scroll expander showed that using of these devices for complying thermal expansion caused large variations of the forces acting on the fixed scroll keys and on the power transmitting shafts and also on the shaft bearings.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.9
• /
• pp.718-723
• /
• 2016

The use of the scroll compressor in the air conditioning of medium-sized vehicles has increased because of its low torque fluctuation, high energy efficiency and low noise. In addition, the main components of the compressor have been changed from steel to aluminum to reduce its weight, following studies on the constituent materials. The processing precision of the fixed scroll and orbiting involute scroll wrap of the scroll compressor must be below $10{\mu}m$. To ensure this, the surface roughness and contour tolerance are measured. To improve the hardness of the orbiting scrolls using aluminum subjected to anodizing treatment and as the base material, we used a sealing treatment and measured the resulting characteristics. The aluminum materials were made of an Al-Mg-Cu based alloy including small amounts of Ni, Fe, and Zn. The surface roughness was less than $3{\mu}m$ and the processing accuracy was within $10{\mu}m$. Also, the hardness of the nanodiamonds with CNTs used in the sealing treatment was more than 450. This was found to improve the hardness of the material by 50% or more compared to the water sealing treatment and there was little difference between the use of carbon nanotubes and nanodiamonds as sealing materials.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.17 no.8
• /
• pp.1940-1950
• /
• 1993

The theoretical investigation is done on the dynamic behavior of a crank shaft used in a scroll compressor. The compression performance of a scroll compressor is directly influenced by the sealing characteristics between fixed and orbiting scrolls, which is related with the dynamic behavior of a scroll compressor. Analyzing the constrained power transmitting system is came to be of importance, accordingly. The equations of motion and interacting forces of a scroll compressor are derived and solved numerically in this paper. The locus of the crank shaft is also obtained by employing the reaction force caused by the oil film of journal bearing. The results show that the crank shaft of a scroll compressor has considerably stable rotating locus.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.9 no.2
• /
• pp.93-103
• /
• 1997

This study presents a way of improving the stability of fixed scroll in scroll compressors. For the scroll compressor whose fixed scroll is designed to move in the axial direction for the axial compliance, the fixed scroll is under the influence of the overturning moment produced by internal gas forces. Unless the overturning moment is properly compensated by the moments of reaction forces at the suspension of the fixed scroll to the compressor frame, the fixed scroll would exhibit wobbling motion, increasing gas leakage through the gap induced by the wobbling of the fixed scroll between the two scroll members. The conditions on which the wobbling motion can be suppressed have been found analytically; The axial position of the fixed scroll suspension should be made within a certain range. The upper limit of this range is the axial location for the o-rings which are inserted between the fixed scroll and the back pressure chamber to promote sealing for the gas in the back pressure chamber. And the lower limit is mainly determined by the magnitude of the axial sealing force. As long as the axial sealing force is not negative over all crank angles, the lower limit is not above the mid-height of the scroll wrap. Larger axial sealing force lower the lower limit.

• 유체기계공업학회:학술대회논문집
• /
• 2003.12a
• /
• pp.251-256
• /
• 2003

The detailed flow characteristics inside a compression chamber due to the orbiting motion of a scroll is studied numerically. The orbiting motion of a scroll is modelled at 7 orbiting angles. At each orbit angle, the central compression chamber is modelled. All computations are carried by using an in-house code. It is based on the SIMPLE algorithm. Computation results show that the flow structure inside the compression chamber is dependent on the orbit angle. The pressure variation inside the compression chamber also shows great dependence on the orbit angle. The pressure variation shows local maxima when the orbiting motion of a scroll directs toward the center of the compression chamber.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.20 no.2
• /
• pp.113-120
• /
• 2008

Potential application of the scroll type machine to air compressor for fuel cell has been studied. Among the seven configuration factors which determine scroll wrap profile, the wrap thickness and the orbiting radius were chosen as two independent variables to generate various scroll wrap profiles. A conceptual design practice was conducted for scroll air compressor for SOFC with power output of 2 kW. With larger wrap thickness and orbiting radius, base plate area of the orbiting scroll becomes smaller, so is the axial gas force acting on the base plate, resulting in reduced thrust loss in spite of larger friction velocity. Performance analysis on the designed model showed that its total efficiency was 64.4% with the mass flow rate per unit compressor input of 0.00905 kg/(s kW) for the wrap thickness of 3.5 mm and the orbiting radius of 3.0 mm.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.21 no.10
• /
• pp.1339-1349
• /
• 1997

A numerical method of calculating the performance of a scroll compressor for refrigerant R-22 and R-134a is presented in this paper. A series of involute curves are employed for the scroll wrap design and the compression volume is investigated geometrically. The radial leakage flow rate through tip clearance is calculated by the two-dimensional compressible flow. On the basis of the results, quasi one-dimensional leakage modeling can be applied to the performance analysis of a scroll compressor, more effectively. Furthermore, the heat transfer effect between scroll wrap and working fluid in compression chamber is considered for the performance analysis. As the results of this study, the effects of the radial and tangential leakage flow rate and heat transfer on the scroll compressor performance are derived precisely. These results may provide the guideline for the design and development of a real scroll compressor.