JPS5830494A - Scroll type compressor - Google Patents

Abstract

PURPOSE:To make the intake fluid volume larger without increasing the outside diameter of a compressor and to improve the rigitity of a volute body by constituting the first gas intake volume section with a high wall portion and by forming the central wall low in height. CONSTITUTION:The volute body 222 of a movable scroll member 22 has a wall height H1 from a side plate 221 at its outside section. This height becomes (H1-l2) at an optional point alpha proceeding inward from the outermost end of the volute along the volute since the surface of the side wall 221 is elevated by l2. A stationary scroll member is formed in the same shape as the movable scroll member. The first gas intake volume section is constituted with a high wall section and the central wall is formed low in height, thereby the intake fluid volume to be compressed can be made large without increasing the outside diameter of the compressor and also the rigitity of the volute body can be improved.

Description

[Detailed description of the invention] By meshing and applying a circular orbital motion to one side, the closed space formed between the two spiral bodies is moved toward the center of the spiral body, reducing the volume and drawing compressed fluid from the center. The present invention relates to a scroll type compressor that discharges air, and particularly relates to an improvement in the structure of the scroll in order to increase the compression ratio.

By the way, in a scroll compressor such as
The fluid taken into the sealed space formed on the outermost side is compressed as the volume decreases as the sealed space moves toward the center along with the spiral movement.

Therefore, increasing the number of spiral turns in order to increase the intake amount of fluid to be compressed, and hence the compression capacity, increases the diameter of the compressor. On the other hand, increasing the height of the spiral wall weakens the rigidity of the spiral body against compressed fluid pressure.

In view of the above points, it is an object of the present invention to provide a compressor in which the amount of fluid to be compressed is increased without increasing the outer diameter of the compressor, and the rigidity of the spiral body is increased. .

The present invention provides a first scroll member in which a first spiral body is fixed on one surface of a first plate, and a second scroll member in which a second spiral body is similarly fixed on one surface of a second plate. The second scroll member and the second scroll member are overlapped with each other with the angles of the two spiral bodies being shifted and engaged with each other, and the first scroll member is moved relative to the second scroll member so as to revolve in one circular orbit. The fluid is taken in while forming a closed space between the five spiral bodies.

In a positive displacement fluid compression device, the space is moved toward the center as the first scroll member moves, and the volume is reduced to perform a unidirectional continuous compression action. The surface area between the pitches of the spiral wound body of at least one of the first and second plate bodies is formed to become higher in a stepwise manner from the outer peripheral end to the inner peripheral end along the spiral. This positive displacement fluid compression device is characterized in that the height of the spiral from the surface of the plate becomes stepwise smaller as it approaches the inner peripheral end.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention shown in the drawings will be described in detail below.

Referring to FIG. 1, the illustrated compressor 1 has a compressor housing IO consisting of a front end loop-top portion 12 made of aluminum or an aluminum alloy.

front end play) 1 1ha, Lord'tllll 3
It is formed around a through hole 111 for inserting it, and an annular protrusion 112 concentric with the through hole 111 is formed on the back side. On the other hand, the cup-shaped portion '12 is formed by drawing a steel plate or by aluminum die-casting. The cup-shaped portion 12 has its opening connected to the annular projection 1 of the front end plate. 24 and is fixed. Note that an O-ring 14 is held between the joints to perform sealing.

A disk rotor [5 is fixed inside the main shaft 13, and the disk rotor 15 is rotatably supported within the through hole 111 by a ball bearing 16 and a thrust bearing 17.

Front end plate 11. N,, 1, Lord 111
It has a sleeve 18 that extends forward so as to surround the sleeve 113. The sleeve 18 is a front end block 1/-)1
It may be molded integrally with the front end plate 1, but here, the front end plate (!: it) is formed separately from steel and is attached to the front surface of the front end plate 11 by screws 19. The sealing body 20 is assembled on the main shaft 13 in the sleeve 18.

The outer surface of the sleeve 18 is not shown.

The pulley is rotatably supported by the bearing, and the electromagnet is fixed. on the other hand.

The end portion of the main shaft 13 protruding from the sleeve 18 is curved.

Armature gray 1 (not shown) is elastically supported (5
) ing. That is, the pulley, electromagnet, and armature plate constitute an electromagnetic clutch, which transmits the rotation of an external drive source (for example, an automobile engine) to the pulley via a belt.

By energizing the electromagnet, the armature plate is attracted to the pulley, thereby transmitting rotational force to the main shaft 13.

A fixed scroll member 21 is contained within the cup-shaped portion whose opening is closed by the front end plates 1 and 11.
, movable scroll member 22, movable scroll drive mechanism 2
3 and a movable scroll rotation prevention mechanism 24 are provided.

The fixed scroll part 21 generally consists of a side plate 211 and a spiral body 212 fixed to one side of the side plate 211. A cylindrical partition wall 213 is formed on the back side of the side plate 211 to protrude in the axial direction. The wall thickness becomes thicker at five positions at equal angular intervals, and the fixed scroll foot 214
Configure.

Each leg 214 is screwed into the leg 214 from the outside of the end plate part (6) 121 with its tip surface in contact with the inner surface of the end plate part 121 of the cup-shaped part 12.
is fixed to the cup-shaped portion 12 by. In addition,
A seal ring 26 is sandwiched between the head of the screw 25 and the end plate portion 12 to prevent fluid leakage along the screw 25. There are grooves 2 on the outer peripheral surface of the side plate 211.
15 is formed +? A seal ring 27 is disposed in the groove c, and seals between the outer peripheral surface of the side plates 21, 1 and the inner surface of the cup-shaped portion 12. Therefore, by the side plate 211 of the fixed scroll member 21, the inside of the cup-shaped portion is divided into a force extraction chamber 28 where the partition wall 213 exists and a spiral body 2.
The oil pressure chamber 29 is divided into 12 parts.

In the chamber 29, a movable scroll part old 22 is arranged. Movable scroll member 22 kl: From the side plate 221 and the spiral body 222 fixed to one side thereof, the spiral body 222 is engaged with the spiral body 212 with an angular deviation of 180°, so that fluid is generated between the two spiral bodies. forming a pocket. The movable scroll member 22 has a drive wheel 231 eccentrically connected to the inner end surface of the disc rotor I5.
It is installed on the top via a radial bearing 232 so that it can rotate once. On the other hand, a fixed ring 241 fixedly connected to the front end plate 11, a movable ring 242 fixed to the III plate 221 of the movable scroll 22 so as to face the recess, and a ball receiving hole 2 formed in the nine rings.
The rotation prevention mechanism 24 is constituted by the balls 245 arranged in 43 and 244.

The compressor housing 10 has a cup-shaped portion 12.

A suction port 30 and a discharge port 31 are provided for connection to an external fluid circuit. The fluid introduced from the suction port 30 into the chamber 29 inside the housing.

The fluid is drawn into the fluid pocket between both scroll members 21 and 22, compressed by the circular orbital movement of the movable scroll 22, and then moved to the center, and from the discharge hole 216 provided in the center of the side plate 211 of the fixed scroll member 21. 032 is blown out into the chamber 28 and from there flows out through the communication hole 217 formed in the partition wall 213, through the discharge port 31, and into the fluid circuit.
is the discharge valve.

In the above configuration, when the main shaft 13 is rotated by an external drive source (not shown) through the operation of the two electromagnetic clutches, the movable scroll member 22 is rotated via the movable scroll drive mechanism 23 and the rotation blocking mechanism 24. Perform circular orbital motion. For this reason, the fluid formed between the old scroll parts 21 and 22, the IPket, is the suction yl? The fluid introduced from -1-30 is taken in and moved toward the center without decreasing the volume and capacity, and the compressed fluid is then transferred from the discharge hole 21G to the center of the discharge chamber 28. It is discharged into the chamber 281 and reaches the surrounding chamber 282 through the communication hole 217.

By the way, in this type of compressor, conventionally.

The wall height of both the fixed and movable scroll parts was constant, and the bottom plate surface was flat. Therefore, the fluid intake volume is proportional to the total wall height.

Also, the volume is determined by line a in Figure 2 as the crank angle changes.

As shown in b, it had a tendency to decrease linearly. In addition, in the same figure, the wall height of a is 1-1.

b is the case of H2 (111>■-■2).

(9) However, if you think about it basically, the intake volume of the whirlpool is determined by the confined space formed at the outermost periphery.
It has nothing to do with the middle or central part.

Further, the gas reaction force received during compression is proportional to the cross-sectional area of the compression chamber (compression direction), but the pressure in the intermediate and central chambers is high. Therefore, it is desirable that the wall height in this area be low. Furthermore, it is desirable that the minimum volume of the central chamber, which is the final point of compression, be as small as possible in consideration of re-expansion loss.

A low wall height is also advantageous for this purpose.

Considering the above, the volume at the time of gas intake is large;
It can be said that it is ideal to reduce the wall height as the compression pressure increases. However, since a scroll compressor performs compression by rotating two spirals in a plane, it is impossible to imagine a structure in which the height of the wall can be changed while maintaining a closed space. Ta. The present invention realizes this ideal state, which has not been considered in the past, through a clever combination of the spiral wall height and the bottom height between the spiral pitches.

r18) Below, 4.1.(f) of scrolling according to the present invention will be explained in detail.

An example of the spiral shape of the present invention is shown in cross-section in FIG. In the illustrated example, the wall height is changed to two levels, but it may be changed to any number of levels. Here, we can say that the basic 2
The case of step change will be explained. Figure 3(a), (
Referring to b), the spiral rest 222 of the movable scroll member 22 has a wall height H from the surface of the side plate 221 at its outer side. From the end, proceeding inward along the spiral, at an arbitrary point α, the surface of the side plate is raised by tl.
The height will be relatively (H+Az). From this point, at point β, which is further inward by π radians at the expansion and opening angle of the spiral, the height of the wall is lowered by tl.

That is, the height of the wall from the side plate surface at that point is H, -tl-t, -H2.

From this point onward, both the height of the side panels and the height of the walls are kept constant on the inside.

Referring to FIGS. 4(a) and 4(b), the fixed scroll member 21 also has the same shape as the movable scroll member 22, and has a mirror-symmetrical shape, but the main points are t and t in both figures, respectively. , /-2, H, , l-12 correspond to each other with the same dimensions.

Note that it is not necessary that the height change point of the side plate surface and the spiral wall height change point have a phase difference of only πrad, and as will be described later, the stepped shape of the fixed movable side scroll part 4 is not necessarily required. Sushi can also be symmetrical and thick. Here t1=
A special case in which the fixed movable cylinder scroll member is completely mirror-image symmetrical will be described as t2.

Figure 5 (a) to (d) shows the state of compression when both scroll members 21 and 22 are combined, with the crank angle at 90°.
This will be explained with reference to the diagram when changing it in increments.

FIG. 5(a) shows the completion of fluid or gas intake. In the figure, since the α point in Figure 3 is set at a point that is about π radians inward from the outermost end of the spiral, half of the -expansion angle is the wall height I-T. The second half is in a state where the wall height is H, -tl-t2=H, and -2t=H2.

FIG. 5(b) shows a state in which the crank has advanced 90 degrees.

As can be seen from the part in the figure, the side edge of the high part of the wall and the curved end surface M part of the low part of the opposite plate surface are separated and are tightly sealed. However, since the chambers on both sides of the tiger's opening section form pairs of chambers with the same pressure, there is no problem with one chamber being open. In addition, this section has the advantageous effect of equalizing the pressure in the paired compartments. As is known, a scroll compressor forms a pair of two symmetrical chambers, and it is desirable from the viewpoint of force balance that the two compartments have the same pressure. However, due to slight differences in the suction route and errors in shape, achieving equal pressure was a considerable challenge.

In the structure of the present invention, the pressure in the compartment is forcibly adjusted to be uniform, as shown in FIG. 5(b). Furthermore, in Figure 5 (1),
A seal is maintained between the suction chamber and the inner chamber. Figure 5(b) (Figure 5(c) shows the state in which the crank angle is further advanced by 90° from the / state. At this point, the seal of the wall film difference is reestablished, and the gas is further
3) Compressed into .

Figure 5 shows the state in which the crank angle has been further advanced by 90° (
d). Here, most of the wall heights are H,−t,
-/=2=H1-2 is 2H2, that is, the closed space is formed with a reduced wall height. If the crank angle increases further, compression will occur only at the lower wall height.

The characteristics of the crank angle versus volume change of the present invention are shown in FIG.

The characteristic of the embodiment of the present invention is a curved line change like the dotted line C in the same figure, and from the middle, the force changes to a linear force change. Four points on the curve, point A, point B, and point C.

Point D is shown, which corresponds to each of the states shown in FIGS. 5(a) to 5(d). As you can see from Figure 2,
Since the initial volume A for gas intake is occupied by the part with a high wall height, the change in volume V with respect to the crank rotation angle θ has a steep slope, p, B, C.

As we move from D, the proportion occupied by the lower wall height becomes ΔV As it increases, the slope down the slope gradually increases.

The structure and operation of the two embodiments of the present invention have been outlined in (14) above, and the advantages of the two present inventions can be expressed in Clause V1 as follows.

(1) Gas intake partial chamber at the end of the spiral outer path,
(2) Because the height of the wall in the center of the curvature is low, it exhibits semi-rigidity in areas of high pressure.

(3) Since the height of the center wall of the spiral becomes lower, it becomes easier to process the spiral.

Since 7 is small in the small part, the compressive load can be made smooth with respect to the crank angle. That is, torque fluctuation becomes smaller.

(5) Since the paired chambers communicate with each other during the compression process, the pressure in the compartments can be balanced. Therefore, various problems associated with the occurrence of uneven loads are eliminated.

(6) The final compression part of the spiral, that is, the sealed space in front of the discharge valve is made smaller, so residual gas can be reduced, and power loss due to gas re-expansion can be reduced.

(7) Since the wall height of the center part of the spiral is low and off, the axial position of the drive bearing provided on the movable spiral body can be moved closer to the spiral wall, which reduces the difference in the points of action of the driving force and the compressed gas reaction force. The generation of moments associated with this can be reduced.

Therefore, the load on each bearing portion can be reduced.

(8) When capacity control is normally performed with this type of compressor.

A practical method is to provide an opening in the middle of the spiral and use a valve mechanism to substantially reduce the number of turns of the spiral, and this method has already been considered, but if this method is applied to the present invention, Since the capacity control ratio can be increased and it basically has pressure equalization characteristics, only one hole is required for the paired chambers instead of two, and the opening/closing mechanism of this valve is also simplified. can.

The present invention has many advantages as described below.

The geometric relationship of the change in the height of the spiral wall will be explained for one example with reference to FIG. Radius rQ + - (rO: radius of the orbit of the movable sphere, j
: A step with a depth t is provided on the side plate surface so as to draw a semicircle of n, '4 thickness). On the other hand, if we change the wall height to a depth t in a semicircle with a radius Σ from the center of the spiral wall at a point where the expansion angle is returned by π radians from this point. This is a two-stage type in which the fixed and movable cylindrical scroll members move symmetrically. From the standpoint of mechanical balance, this is the best. However, an asymmetric type is basically possible if unbalance is tolerated. An example thereof is shown in FIG. This is an example in which the side plate surface 221 of the movable scroll member 22 is made flat. In this case, 1 scroll section profit 21
, 22, the volumes of the paired chambers will be unbalanced when gas is taken in. However, by changing the number of spiral turns of the other chamber, the intake volumes can be balanced. Basically, the present invention is formed by matching the height of the wall protrusion of the other spiral body to the level difference in the side plate surface of one spiral body and the expansion loss. Furthermore, although it has been stated that the height of the thin wall can be changed in multiple stages, it is also possible to change the height in multiple stages as described in (17) above. An example thereof is shown in FIG.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of the present invention, Fig. 2 is a graph showing a change curve of the compression chamber internal volume of the present invention and the conventional one, and Fig. 3 is a diagram showing a movable scroll member according to the invention. (a) is a perspective view, (b) is a sectional view taken along line A-A', and FIG. 4 is a diagram showing a fixed scroll member according to the present invention, (a) is a perspective view, (b) is A, -A' sectional view, and FIG. 5 is a diagram explaining the compressed state. (a'l to (d) are diagrams showing the states at different crank angles, Figure 6 is a diagram showing the positional relationship of 9 steps, and Figure 7 is an example of the scroll member in the case of 3 steps. (a) is a front view, and (b) is a sectional view taken along line A-A. Fig. 8 is a sectional view of another embodiment. ■... Compressor, 13... Main shaft, 21 ...Fixed scroll member, 211... Side plate, 212... Spiral body. 22... Movable scroll member, 221... Side plate. 222... Spiral body, T(,, H',... ...Wirling wall height + t1.t2...Step. (18) (α9 Fig. 5<b) Fig. 5 (G) Fig. 5 (d)

Claims (1)

[Claims] 1. A first scroll member having a first spiral body fixed to one surface of the first plate, and a second scroll member fixed to one surface of the second plate. The first scroll part 4g is formed by overlapping the second scroll member to which the spiral wound body is fixed, while meshing the two spiral bodies at an angle of -14-. The second suf r + −
The first scroll member is moved relative to the first scroll member to form a closed space between the first scroll member and take in fluid, and as the first scroll member moves, the space is moved toward the center and the volume is reduced. In a positive displacement fluid compression device that performs a unidirectional continuous compression action with It is formed so that the height increases in a stepwise manner from the outer peripheral end to the inner peripheral end along the spiral, so that the height of the spiral from the surface of the plate is close to the inner peripheral end. A positive displacement fluid compression device characterized by being progressively smaller.