RU2763334C1 - Scroll compressor range of scroll compressor - Google Patents

Abstract

FIELD: scroll compressors.

SUBSTANCE: invention relates to scroll compressors, scroll vacuum pumps, scroll expanders with one movable and one fixed scroll or with two movable scroll, especially if there are requirements for the purity of the pumped gas. The spiral 2 of the compression mechanism of the scroll compressor is made in the form of an integral connection of a set of flat plates 4 of the same height and different width. The surfaces of adjacent flat plates 4 form equal angles, selected according to a certain formula.

EFFECT: invention is aimed at increasing the rigidity of the structure and reducing internal gas flows.

1 cl, 7 dwg

Description

DESCRIPTION OF THE INVENTION

The invention relates to scroll compressors, scroll vacuum pumps, scroll expanders with one movable and one fixed scroll or two movable scrolls, especially when there are requirements for the purity of the pumped gas [F04C 18/00, F04C 2/00].

The prior art SPIRAL MACHINE [RU 2267652, publ. 01/10/2006] containing a housing with suction and discharge openings, a fixed spiral element located in the housing, engaged with a movable spiral element mounted on an eccentric shaft and having the ability to perform orbital movement with eccentricity relative to the fixed spiral element with the formation of closed compression cavities, and an anti-rotation device having at least one driver placed in the hole of the movable spiral element, characterized in that the movable spiral element is made without a base with the possibility of eliminating the effect of axial force on it during gas compression, through holes are made in the fixed spiral element, and holes are made in the body, coinciding with the through holes of the fixed spiral element with the formation of through channels for the passage of cooling air.

The disadvantages of analog are:

- the complexity of the design due to the presence of through holes in the fixed spiral element and the body of the structure, which requires additional technological operations in the manufacture of the product, and as a result complicates and increases the cost of production;

- low rigidity of the structure due to the fact that the analogue uses smooth spiral elements that do not have stiffeners;

- the need to use a lubricant to seal the gaps between the spirals;

- in case of contact of spirals - increased specific contact pressures during friction of metal surfaces.

The closest in technical essence is the SCROLL COMPRESSOR [RU 2560647, publ. 20.08.2015], containing: a compression mechanism, including a fixed scroll, including a fixed side end plate and a spiral wall-shaped shell of the fixed side mounted on the fixed side end plate, and an orbital spiral, including an end plate of the orbital side and a helical wall shaped orbital side shell mounted on an end plate of the orbital side, wherein the fixed side shell and the orbital side shell engage with each other and form a compression chamber between the coils, the fixed coil has an injection port that is configured to communicate with the chamber ) compression through the communication passage hole located in the end plate of the fixed side, the shell of the orbital side has a thick section, including an increasing section of the thickness of the tooth and located at a location corresponding to the injection channel, the thickness of the tooth of the increasing section the thickness of the tooth increases from the start of the twist to the end of the twist of the orbital side shell, and the thick portion has a thickness greater than or equal to the size of the injection port opening measured along the tooth thickness of the orbital side shell.

The main technical problems of the prototype are:

- low rigidity of the structure, due to the fact that the sides of the fixed and orbital spirals are smooth, which does not provide for the presence of stiffeners that can significantly increase the rigidity of the structure;

- the presence of internal gas leaks in the device due to the fact that when using a fixed and movable smooth-shaped spiral, gas flows from the high-pressure cavity to the low-pressure cavity due to the formation of radial gaps between the spirals, which in turn necessitates the use of a lubricant in the prototype for sealing the gaps between the spirals.

The objective of the invention is to eliminate the disadvantages of the prototype.

The technical result of the claimed invention is to increase the rigidity of the structure and reduce internal gas leakage.

This technical result is achieved due to the fact that the scroll of the scroll compressor compression mechanism, characterized in that it is made in the form of an integral connection of a set of flat plates of the same height and different widths, while the surfaces of adjacent flat plates form equal angles α, while α=2π/ n, where n is an even integer and 24<n<44.

Brief description of the drawings.

In FIG. 1 shows a general view of a fixed scroll scroll compressor.

In FIG. 2 shows a general view of the movable scroll of a scroll compressor.

In FIG. 3 shows an illustration of the calculation procedure for the scroll of the scroll compressor compression mechanism.

In FIG. 4-6 show the successive phases of the relative motion of the inner surface of the first scroll and the outer surface of the second scroll of a scroll compressor.

In FIG. Figure 7 shows the calculated graph of the dependence of pressure in two adjacent slot plane-parallel gaps between the working surfaces of the spirals on the angle of rotation of the spirals, where each of curves 1-8 is plotted at different fixed angles of rotation of the spirals.

The figures indicate: 1 - housing; 2 - the first spiral; 3 - the second spiral; 4 - plate, 5 - bottom wall.

Implementation of the invention.

The scroll compressor consists of a housing 1, inside which are placed the details of the scroll compressor compression mechanism, which are the first scroll 2 and the second scroll 3. In this case, the first 2 and second 3 spirals are located eccentrically relative to each other. The inner and outer surface of the first spiral 2 is a set of flat faces (shown in Fig. 1), forming a set of plates 4 of the same height and different widths. The inner and outer surface of the second spiral 3 is also a set of flat faces (shown in Fig. 2), forming a set of plates 4 of the same height and different widths. The angles (α) between adjacent plates 4 of each of the surfaces of the first 2 and second 3 spirals are equal, while α=2π/n, where n is an even integer and 24<n<44, while the nearest plates 4 of adjacent turns of the first 2 and the second 3 spirals are arranged in parallel. Plates 4 of the first 2 and second 3 spirals are made in such a way that when they are mutually plane-parallel moving, their lines of contact (or minimum clearance) remain strictly parallel. In the lower part of the housing 1 there is a bottom wall 5 connected to the side walls of the housing 1.

The scroll compressor also includes an electric motor configured to rotate the first 2 and second 3 scrolls (not shown in the figure).

In an embodiment, the scroll compressor is configured to orbit either the first 2 or the second 3 scroll. In this case, one of the spirals is fixed, and the other is movable.

In embodiments, the scroll compressor may include additional elements that provide power, as well as eccentric and anti-rotation mechanisms (not shown in the figure).

The scroll compressor compression mechanism is used as follows.

Initially, an electric motor is switched on from the power source, which drives the details of the compression mechanism in the form of the first 2 and second 3 spirals. At a certain moment, the walls of the spiral are cut off by two crescent-shaped cavities. Details of the compression mechanism, namely, the first 2 and second 3 spirals rotate at the same speed and in the same direction. As the movement develops, the areas formed by the internal volume of the flat plates 4 of the spirals and filled with gas gradually push towards the center, simultaneously shrinking in volume. At the same time, initially the cavities of high pressure and low pressure are physically separated by adjacent plates 4. When the plates 4 rotate, a transition from a closed position to an open one is realized with the formation of a gap with a reduced gas pressure. At the same time, the adjacent (previous) pair of adjacent plates 4 closes, forming a contracting gap with increased gas pressure in the gap. The presence of zones of low and high gas pressure indicates the formation of a dynamic gas seal. Further, when the regions reach the center of the spiral, the gas, which is now under high pressure, is pushed out of the central part.

An implementation option is possible, when during the gas compression process, the fixed spiral remains stationary, and the movable spiral makes orbital movements around the fixed spiral. As such a movement develops, the areas formed by the internal volume between the flat plates 4 of the fixed and movable spirals and filled with gas gradually push towards the center, simultaneously shrinking in volume. As the regions reach the center of the spiral, the gas, now under high pressure, is forced out of the center.

The technical result of the invention in the form of increased structural rigidity is achieved due to the fact that the scroll of the scroll compressor compression mechanism is formed by an integral joint of a set of plates 4 of the same height and different widths, while the flat plates 4 form stiffeners, due to which the product becomes less susceptible to deformation during use, and can withstand more dynamic force.

The technical result of the invention in the form of a reduction in internal gas leakage is achieved due to the fact that the scroll of the scroll compressor compression mechanism, formed by an integral joint of a set of plates 4 of the same height and different widths, in which the surfaces of adjacent flat plates 4 form equal angles α=2π/n, where n is an even integer and 24<n<44, while the nearest plates 4 of adjacent turns of the spiral are parallel to each other, which, when used in a scroll compressor, ensures the formation of a dynamic gas seal between the planes of the first 2 and second 3 spirals. The dynamic gas seal prevents the flow of gas from the high pressure cavity to the low pressure cavity of the device, thereby reducing internal gas leakage, which in turn leads to a decrease in the need for lubricant supply.

It is also worth noting that the use of scrolls of the scroll compressor compression mechanism leads to a more accurate positioning of the relative position of the scrolls in the device.

In 2021, the applicant manufactured a prototype of the claimed device, the trial operation of which confirmed the claimed technical result. The increase in structural rigidity over the period of operation of the device was about 20%, compared with the use of devices with smooth or piecewise circular spirals.

Also, pilot operation showed a decrease in internal gas leakage of the scroll compressor by 60-90% compared to the use of devices with smooth or piecewise circular spirals.

An example of achieving a technical result.

Let us consider the procedure for constructing a scroll of the scroll compressor compression mechanism, consisting of a set of flat plates 4. The construction procedure will be carried out in the application software package for solving problems of technical calculations MatLab.

- Initially, a smooth spiral of Archimedes is built with the center at point O and the radius of the initial circle OA (shown in Fig. 3).

- Points B(i) on a smooth spiral are marked through equal angles α. Angles α are chosen according to the formula α=2π/n, where n is an even integer and 24<n<44. For example, at n=26, α≈13.85°; at n=30, α≈12°, etc. The ratio for calculating α was obtained empirically, during the implementation of the procedure for constructing the details of the scroll compressor compression mechanism. In particular, it was found that for any other values of n, the formation of a dynamic gas seal does not occur.

At the same time, based on experimental data, it is preferable that

- Tangents to the smooth spiral are drawn through the marked points B(i) until they intersect with the tangents from neighboring points B(i-1) and B(i+1).

The procedure for constructing both the inner and outer surfaces of the compressor scrolls is similar, the only significant difference is that the outer surface of the spiral is equidistant to the inner one at a distance equal to the thickness of the rib of the first 2nd spiral. Through the intersection points of the tangents in the direction perpendicular to the XY plane, the edges of the spiral surface are drawn. Thus, we obtain a spiral of the scroll compressor compression mechanism, which is a set of flat plates 4 that form stiffeners, due to which the first claimed technical result is achieved, namely, the rigidity of the structure increases and, accordingly, the resistance to deformation increases during use.

Next, consider the successive phases of the relative movement of the spirals of the compression mechanism, namely the inner surface of the spiral 2 and the outer surface of the spiral 3 (shown in Fig. 4-6). In the position in FIG. The 4 high pressure (HP) and low pressure (LP) cavities are physically separated by touching plates 4. This touch occurs for a short period of time, equal to approximately 1/100000 s, or is absent. With further rotation of the plate 4, which, in the position shown in FIG. 4 were closed, they begin to open (shown in Fig. 5), then due to the fact that between adjacent plates 4 the same angles, an opening gap is formed with a reduced gas pressure in the gap. Simultaneously with the opening of the plates 4 adjacent plates 4 are closed, forming a contracting gap with increased gas pressure in the gap. The process of closing the plates 4 and at the same time the formation of a gap between adjacent plates 4 becomes possible due to the fact that the nearest plates 4 of adjacent turns of the spiral are parallel, which is confirmed by the illustrations (Fig. 4-6), where it can be seen that with mutual plane-parallel movement of the spirals , the lines of their contact (minimum gap) remain parallel. The calculation of the Reynolds equation for a compressible gas in these two gaps and the trial operation of the product shows that when the spirals move, a dynamic gas seal is formed that prevents the gas from flowing from the high pressure region to the low pressure region. Graphs of the dependence of the distribution of the generated pressure on the angle of rotation of the spirals from are shown in Fig. 7. On the left of the graph is the area of low pressure, on the right - high pressure. The lines show the distribution of pressures in two adjacent slotted gaps at various successive angles of rotation of the spirals. The presence of a gas seal is indicated by the presence of sections of graphs with a decrease in pressure from left to right. The presence of a dynamic gas seal during operation of the device leads to the achievement of the second claimed technical result of reducing internal gas leakage.

Additionally, it should be noted that the tightness of the spirals can be increased by rounding the inner edges of both spirals with arcs with a radius equal to the eccentricity of the spirals.

In addition, the inner and outer surfaces of each helix can be built with a shift relative to each other by half the angular step. This results in a halving of the maximum radial loads on the bearings.

Claims (1)

The scroll of the scroll compressor compression mechanism, characterized in that it is made in the form of an integral connection of a set of flat plates of the same height and different widths, while the surfaces of adjacent flat plates form equal angles α, while α=2π/n, where n is an even integer and 24<n<44.

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