Research history and development process of scroll machine Scroll compressor has the characteristics of high efficiency, high reliability, low noise, light weight and small size, which combines the advantages of volumetric and rotary compressors. The scientific community has paid extensive attention. In the early 1980s, scroll machines first achieved commercial applications in the field of air-conditioning compressor technology, used as automotive air-conditioning compressors (Sanden, 1981) and cabinet air-conditioning compressors (Hitachi, China's research on scroll machines) In the late 1900s, the research units were mainly two universities, Gansu University of Technology and Xi'an Jiaotong University. After years of efforts, four series of more than 20 scroll compressor products have been developed, and their small air compressors have been produced on a small scale.

Working principle of scroll machine Scroll machine is a new type of volumetric fluid machine. It is mainly composed of moving scroll, static scroll, anti-rotation mechanism, crankshaft and bracket body. The two scrolls are relatively installed. After rotating at an angle and relatively offset by a distance, the pairs are inserted together, so that the wraps on the two scrolls are multi-pointed to form a plurality of sets of crescent-shaped closed working chamber volumes. With the rotation of the crankshaft, the plurality of meshing points formed continuously move from the outer to the inner along the spiral tooth wall, so that the plurality of sets of crescent-shaped working cavities formed gradually become smaller and smaller, and the periodicity of the closed working chamber volume is realized. The change, in turn, achieves the inhalation, compression and discharge of gases.

The accident prevention and emergency response system will complete the combination of existing resources and resources to be built so that it can meet the needs of accident prevention and emergency response, and achieve the overall functions of prevention and emergency.

(3) Through the GIS system, the collection, comprehensive analysis and storage processing of various geographical environment information parameters of the location/space of the special equipment are formed, and the specific geographical location and environmental conditions (temperature, humidity, precipitation, etc.) of the special equipment are realized. High-level, pollutant concentration, etc., the distribution of special equipment, as well as the distribution, addition, deletion, and invocation of all information related to geographical location, such as the number and type of distribution within a certain area, to achieve various related The overall grasp of external factors provides more information service support and technical support for the monitoring, inspection, monitoring, accident prevention and emergency disposal of special equipment. For example, real-time tracking of movable special equipment; through the system of the spiral tooth profile line, the type of the spiral tooth profile line mainly has a circular involute, a line involute, a regular polygon involute, and a parallelogram involute. Line, Archimedes spiral, algebraic spiral, variable diameter base involute, envelope profile, and general purpose wire. Since the wraps formed by the single base type wire are difficult to achieve complete meshing, the requirements of compression, exhaust, and machining cannot be balanced, and the structural characteristics of the wrap line are such that the wrap at the wrap head is processed. There is a situation in which the tool is involved, so that the profile correction of the wrap is required, so the profile correction is often performed on the wrap tooth head which greatly affects the performance of the compressor, and the profile correction can also be increased. The engagement of the wraps, increasing the compression ratio, enhancing the strength of the wrap head and improving the performance of the scroll compressor.

By studying the basic structure and working principle of the scroll compressor, the multi-scroll tooth and its profile correction problem are analyzed and discussed, which are mainly reflected in two aspects.

(1) Under the same design task conditions, the influence of the difference of the number of teeth of the spiral teeth on the performance of the compressor is studied by comparing the performance parameters of the single and double teeth.

(2) By studying the correction method of the multi-vortex vortex profile, the problem of the small compression ratio of the multi-vortex compressor is solved.

Second, the scroll compressor performance parameters study 1. Circular involute scroll basic geometric parameters design conditions: medium, air. The exhaust gas volume is 200m3/h, and the intake pressure is 0.1MPa (absolute pressure). The exhaust pressure is 0.1MPa, and the basic information such as the variety, technical parameters and danger degree of the accident equipment is quickly determined on the electronic map, and the on-site rescue is quickly implemented; the special equipment monitoring, inspection and maintenance human resources are allocated according to the geographical distribution.

Actively promote the research and application of Internet of Things technology in the field of special equipment security, and strive to improve in detection and monitoring, safety assessment, risk management, life prediction, major hazard monitoring, forecasting and early warning, emergency rescue, risk-based accident prevention, etc. Great breakthrough, the first to establish a demonstration system for smart equipment management, rapid inspection, key equipment health monitoring, remote diagnosis of safety hazards and accident prevention and emergency disposal in Jiangsu Province, providing technical support for special equipment legislation and law enforcement, to ensure safety Promote development and provide technical support.

[Editor Wang Yongzhou] Equipment management and maintenance mm, tooth thickness 4.5mm. Spindle radius 7.5mm, intake air temperature 20 compression index 1.4. 2. Compressor scroll part parameter setting and scroll tooth basic parameters calculation scroll tooth height h=50mm, wrap thickness t=4.5mm, rotation speed n=3600r/min, spindle eccentricity Rr=7.5mm, scroll radius Rw=130mm, scroll number Z=2. Pitch P=2 B compression Ratio s=2.8931, see formula (6 3. Compressor closed working chamber volume calculation at any time, the working chamber volume changes with the spindle rotation angle as shown. It can be seen that as the number of vortex teeth increases, the crankshaft eccentricity decreases. The exhaust gas volume decreases, the compression ratio increases slightly, and the relative sliding speed decreases sharply. As the tooth thickness increases, the exhaust gas volume decreases, the compression ratio increases, and the relative sliding speed decreases.

When the eccentricity of the crankshaft, the tooth thickness and the radius of the circumscribed circle of the wrap are the same, the multi-vortex scroll as shown, the displacement law, the compression ratio and the radius of the base circle vary with the number of teeth as shown in the figure. Draw according to h=50mm, n=3600r/min.Ru mm, Rw=145mm. As the number of wraps increases, the number of wraps decreases, the amount of inspiratory increases significantly, the compression ratio drops sharply, and the radius of the base circle increases. As the tooth thickness increases, the amount of exhaust decreases, the compression ratio decreases, and the radius of the base circle increases.

When the eccentricity and the tooth thickness of the crankshaft are the same, if the intake air volume and the rotational speed are kept constant, the multi-scrolling teeth are beneficial to reduce the radius of the circumscribed circle of the wrap, that is, reduce the diameter of the scroll, but the number of wraps and The compression ratio is significantly reduced, as shown in Table 1. The relevant parameters are calculated as h=50mm, t=4.5mm, R=7.5mm, n=3600r/min, and Qs=3.3m3/min.

If the amount of inhalation and the radius of the circumscribed circle of the wrap are kept the same, the multi-scrolling tooth is advantageous for reducing the relative sliding speed between the rotational speed and the dynamic and static vortex, as shown in Table 2, when the inspiratory volume of the phase table 1 is the same. Performance comparison number of teeth Z / number of loops N / loop compression ratio e scroll teeth circumscribed circle radius Rw / mm scroll diameter.

In the figure, AB is the inhalation process, the working chamber volume is gradually increased, and the gas gradually enters the working chamber. At the end of point B, the inhalation ends, and the corresponding volume at this time is the inspiratory volume, wherein the maximum volume of the working chamber volume is about 5 before the end of inhalation. BC is the compression process, and point C is the end point of the compression process. At this time, the compression chamber is connected to the exhaust port, and the exhaust process begins. At this time, the corresponding spindle rotation angle is the exhaust angle, and CD is the exhaust process, D point. At the end of the exhaust, the exhaust port is completely covered by the passive wrap (only when the wrap is profiled to form a fully engaged wrap, the exhaust port can be completely covered by the passive wrap.

See the working chamber pressure at any time (7. Study on the influence of the number of teeth on the mechanical properties of the vortex). When the radius of the base circle, the thickness of the tooth and the radius of the circumscribed circle of the vortex are the same, the multi-vortex teeth with different numbers of teeth are as It is shown that the inspiratory volume, the compression ratio (calculated as adiabatic compression k = 1.4, the same below) and the relative sliding speed as a function of the number of teeth are as shown, and the multi-scroll teeth 114 are managed with the same base circle radius and tooth thickness. To repair the multi-scroll tooth with the same tooth thickness and pitch (1 multi-scroll double-arc correction tooth profile generation (to establish the coordinate system with the rotation center point O as the origin, and make the feature circle. On the outer and inner circular involutes, the midline angles are respectively less, <5+0. Two points C, respectively, the two points are used as the tangent of the base circle CD, G. Connect CA and pass C, two points Make a circular arc, and make the circumferential angle corresponding to the CA arc 0, the circle and the feature circle intersect at two points. Take the intersection point B adjacent to the C point to connect BC, BA, and make the vertical line, respectively and the tangent CD G is handed over to E and F.

Number of teeth Z/strip speed n/Multi-vortex vortex disc has significant advantages in applications with large displacement and small compression ratio. The conditions of the tooth height, tooth thickness and rotation speed of the wrap are the same. The multi-vortex has a larger inspiratory capacity than the single-scrolling tooth, and the outer radius of the spiral tooth is small, that is, the outer diameter of the scroll is small, and the performance of the two scrolls is the same as that of the two scrolls. The relative sliding speed between the two is small, and the wear is small, the number of wraps is small, and the compression ratio is reduced.

Positive research and correction equipment management and maintenance are based on E and F points respectively. The EC and A are used as the radius of the small arc CB, and the large circular multi-vortex tooth can be used for the correction of the profile: there can be no meshing type within the feature circle. The line, that is, the joint point C on the outer profile line cannot be selected within the feature circle. According to this, the range of the modified spread angle can be determined. When the feature circle is within the base circle, the minimum value of the modified spread angle is exempted from =-a. When the feature circle is outside the base circle, the minimum value of the modified spread angle is corrected. (8 The minimum value of the visible correction angle f can be less than zero, and the maximum value is often not more than 360° in practice.

The double arc modified tooth profile of the multi-scroll (including single wrap) has three common features. 1 The inner and outer involutes and the large and small arcs smoothly transition at the joint point C. 2 The size arc and the feature circle only intersect at the point, and this point is the final mesh point of the modified wrap. 3 The line connecting the two points A and C at the two ends of the arc or the circle passing through the two points must intersect the feature circle at two points, wherein the point adjacent to the point C on the outer profile line is the final meshing point.

The fixed scroll without correction is the corrected fixed scroll. The double-vortex-shaped double-arc correction has some advantages. The four wraps of the double-swollen teeth can fully mesh with each other, and there are two dynamic and static wraps. Therefore, the degree of meshing of the wraps is enhanced, the utilization ratio of the center of the double scroll wrap is improved, the compression process becomes longer, the compression time becomes longer, the exhaust volume is reduced, and the compression ratio is increased. The projected area of ​​the vortex tooth head is increased, and the strength rigidity at the tooth head is increased, which avoids the involvement of the vortex tooth wall and the machining tool, avoids the knife in the machining process, and improves the processing characteristics of the double scroll tooth.

2. The multi-scroll double-arc correction tooth profile is the meshing diagram of the final meshing point B of the multi-scutter double-arc modified tooth profile when it is engaged, because the pair of large and small arcs on the arc satisfy the arc The multi-scrolling teeth mesh the condition of the profile, and thus the multi-scroll correction tooth profile enables full engagement.

With the development of scroll machinery to large displacement, large compression ratio, etc., the traditional single-tooth scroll machine can not meet the requirements, and can meet the requirements by correcting the scroll line and increasing the number of teeth.

The use of a multi-vortex structure is an effective way to increase the displacement. The multi-vortex vortex machine has a significant advantage in increasing displacement, reducing the size of the scroll and improving the force characteristics of the scroll. .

The modified double scroll tooth type line can fully mesh with each other, the compression process becomes longer, the compression ratio is improved, the strength and rigidity at the tooth head are increased, and the wrap of the scroll tooth wall and the machining tool is avoided, and the improvement is avoided. The processing characteristics of the double scroll teeth.

Control Arm For Nissan

Rear Control Arm Nissan Altima,Upper Control Arm Nissan Frontier,Rear Lower Control Arm Nissan Altima,Upper Control Arm Nissan Titan

Saga Trading (Zhoushan) Co., Ltd. , https://www.sagatd.com