KR100739373B1 - Scroll compressor - Google Patents

Abstract

This invention makes it a subject to reduce the loss accompanying a leak in the hard plate sliding surface of a turning scroll and a fixed scroll.

A back pressure introduction space is provided on the hard plate surface of the fixed scroll or the revolving scroll, and the pressure loss in the large leakage area on the hard plate surface is increased to reduce the leakage loss.

Fixed Scroll, Swivel Scroll, Suction Chamber, Compression Chamber, Suction Port

Description

Scroll Compressor {SCROLL COMPRESSOR}

1 is a longitudinal sectional view of a scroll compressor in one embodiment of the present invention;

2 (a) to 2 (d) are plan views showing the compression chamber constituted by the turning scroll and the fixed scroll in FIG.

3 is a plan view of the fixed scroll in FIG. 1;

4 is a diagram schematically showing a pressure distribution on a hard plate surface.

Fig. 5 is a diagram schematically showing the pressure distribution on the hard plate surface.

Fig. 6 is a plan view of a fixed scroll in another embodiment of the present invention.

Fig. 7 is a plan view of a swing scroll in still another embodiment of the present invention.

8 is a cross-sectional view taken along line A-A of FIG.

<Explanation of symbols for the main parts of the drawings>

1: groove provided in a fixed scroll

7: fixed scroll

8: turning scroll

[Document 1] Japanese Unexamined Patent Application Publication No. 7-208356

The present invention relates to a scroll compressor.

The scroll compressor has a fixed scroll formed by mounting a spiral wrap on a die plate, and a swing scroll formed by installing a spiral wrap on a hard plate. The scroll compressor compresses the fluid by engaging the wraps of both scrolls so as to face each other, and turning the swing scrolls to sequentially reduce the volumes of the plurality of compression chambers formed between the wraps.

By this compression action, an axial force (hereinafter, referred to as a separation force) is generated to separate the fixed scroll and the swing scroll from each other. When both scrolls are spaced apart, a gap is created between the tooth line and the tooth bottom of the wrap, and the sealability of the compression chamber is deteriorated, and the efficiency of the compressor is lowered.

Thus, a back pressure chamber is formed on the rear surface of the rotating plate of the swing scroll to become a pressure between the discharge pressure and the suction pressure, and the swing scroll is pressed against the fixed scroll side by the back pressure to negate the separation force, and the swing scroll is fixed to the fixed scroll. It is generating a pressing force.

However, due to this pressing force, sliding friction occurs on the hard plate surface of the fixed scroll and the revolving scroll, and when the pressing force is excessive, the baking occurs on the hard plate surface, thereby losing the reliability of the compressor.

In the scroll compressor described in Patent Literature 1 in order to reduce the sliding movement loss on the hard plate surface and to improve the reliability of the compressor, it is slid by arranging a plurality of oil grooves having an arc shape or a straight line shape on the hard plate surface at approximately pitch or the like. The lubricating oil is reliably supplied to the moving part.

[Patent Document 1] Japanese Patent Application Laid-Open No. 7-208356

The technique disclosed in Patent Literature 1 provides a plurality of oil grooves on the hard plate surface at approximately pitch or the like, and the lubrication state of the hard plate surface is good. However, no particular consideration has been given to the leakage of fluid from the back pressure chamber on the hard plate surface to the suction chamber or the compression chamber.

This invention makes it a subject to reduce the loss accompanying a leak in a hard board surface.

In order to solve the above-mentioned problems, the scroll compressor of the present invention is a fixed scroll having a spiral-shaped lap mounted on a die plate, a hard plate surface disposed around the lap in succession with the front end surface of the lap, and the fixed scroll. Spiral-shaped wraps forming a plurality of compression chambers between the wraps, a swinging scroll having a hard plate on which the wraps are placed, and a gas compressed in the compression chamber for pressing the hard plate of the swinging scroll against the hard plate surface of the fixed scroll. A back pressure chamber having a pressure between the pressure of the gas and the pressure of the gas sucked into the compression chamber, and a hard plate surface of at least one of the hard plate surface of the pivoting scroll plate and the hard plate surface of the fixed scroll. It is provided with the back pressure space in which the pressure of a back pressure chamber is introduce | transduced.

By the above configuration, the back pressure applied to the swing scroll is applied to the hard plate sliding surface between the fixed scroll and the swing scroll, and the center of the scroll wrap is started to press the desired range of the swing scroll deck to the hard plate surface of the fixed scroll. This makes it possible to reduce the gas leakage on the hard plate surface.

In addition to the above configuration, a back pressure space may be provided on the suction pressure region provided near the winding completion of the fixed scroll wrap and the hard plate surface of the fixed scroll that is symmetrical with respect to the spiral center of the fixed scroll wrap.

In addition, the length of the circumferential direction of a back pressure space may be at least the same length or more than the length of the circumferential direction of a suction pressure area | region.

In addition to the above configuration, the back pressure space may be a stepped portion formed on at least one of the hard plate surface of the swing scroll plate and the hard plate surface of the fixed scroll which are slid to face each other.

Further, a ring-shaped groove portion may be provided outside the hard plate surface of the fixed scroll, and the back pressure space may be a stepped portion extending from the ring-shaped groove portion in the spiral center direction.

In addition to the above configuration, the radial length of the hard plate surface of the fixed scroll in the radially outer side of the suction pressure region provided near the winding completion of the fixed scroll wrap is the hard plate surface from the back pressure space to the compression chamber or the suction chamber of the fixed scroll. You may make it larger than the hard-plate sliding distance which slides together.

Moreover, in order to solve the said subject, the scroll compressor of this invention is a fixed scroll which has a spiral-shaped wrap | ramp standing up on a die plate, the hard-plate surface provided around the said wrap in series with the front end surface of this wrap, and the said fixed scroll A spiral-shaped wrap forming a plurality of compression chambers between the wraps, a swinging scroll having a stiff plate provided with the wrap, and a compression plate for pressing the hard plate of the swivel scroll against the hard plate surface of the fixed scroll. A back pressure chamber having a pressure between a pressure of a gas and a pressure of a gas sucked into the compression chamber, and a sliding plate sliding surface of the two scrolls which slides between the back pressure chamber and the suction chamber where the compression chamber or the gas for compression is sucked. On the basis of the spiral center of the fixed scroll wrap for the portion of the seal length of The turning length of the seal length of the seal length from the outermost part of the inner wall surface of the fixed scroll wrap to the outer circumference part of the pivoting scroll slab is longer than the seal length of the part becoming the minimum part. It will have a configuration shorter than the minimum length for the turning movement of the athlete.

In addition to the above configuration, the length from the outermost circumference of the fixed scroll extension to the ring-shaped groove provided on the fixed scroll hardplate surface may be shorter than any shorter one.

In addition to the above configuration, the minimum portion may be the plate sliding surface of the two scrolls in the radially outer side of the suction pressure region provided near the winding completion of the fixed scroll wrap.

EMBODIMENT OF THE INVENTION Hereinafter, 1st Embodiment of this invention is described with reference to drawings. Fig. 1 is a sectional view showing the whole of the scroll compressor of the present embodiment. As shown in Fig. 1, the fixed scroll 7 includes a disc-shaped die plate 7a, a wrap 7b provided upright in a spiral shape on the die plate 7a, and an outer periphery of the die plate 7a. It is located in the side, and has a cylindrical support part 7d which has a hard plate surface continuous with the front end surface of the wrap 7b, and surrounds the wrap 7b.

Since the surface of the die plate 7a in which the wrap 7b is standing up is between the wraps 7b, it is called the jingle 7c. In addition, the surface which contact | connects the hard plate 8a of the turning scroll 8 of the support part 7d is the hard plate surface 7e of the fixed scroll 7.

The fixed scroll 7 is fixed to the frame 17 by bolts or the like at the support 7d, and the frame 17 integrated with the fixed scroll 7 is fixed to the casing 9 by fixing means such as welding. It is.

On the other hand, the revolving scroll 8 is arrange | positioned facing the fixed scroll 7, and is provided in the frame 17 so that rotation is possible. Swivel scroll 8 is a spiral wrap 8b and a rigid plate (8b), which are erected from a chamfer 8c, which is the surface of the hard plate 8a, similarly to the wrap 7b of the disc-shaped hard plate 8a and the fixed scroll 7. It has the boss | hub part 8d provided in the back center of 8a). Moreover, the surface which contact | connects the fixed scroll 7 of the outer peripheral part of the hard board 8a becomes the hard board surface 8e of the revolving scroll 8. As shown in FIG.

The casing 9 accommodates the scroll part which consists of the fixed scroll 7 and the revolving scroll 8, the motor 16, and lubricating oil inside, and forms a sealed structure. The shaft 10 provided with the rotor 16a of the motor 16 is rotatably attached to the frame 17 and coaxial with the axis of the fixed scroll 7.

The crank 10a is provided in the front-end | tip part of the shaft 10, the crank 10a is attached to the turning bearing 11 provided in the boss | hub part 8d of the turning scroll 8, and the turning scroll 8 is a shaft It is attached to 10 in a rotatable manner. At this time, the turning scroll 8 is in a state where the axis is eccentric with respect to the axis of the fixed scroll 7 by a predetermined distance σ. Further, the wrap 8b of the swing scroll 8 is polymerized by being shifted by a predetermined angle in the circumferential direction to the wrap 7b of the fixed scroll 7.

Then, the Oldham ring 12 is attached as a mechanism for relatively swinging movement while restraining the swinging scroll 8 from rotating relative to the fixed scroll 7.

Moreover, the ring-shaped groove 19 provided in the outer peripheral part of the hard board surface 7e has a surface from which the predetermined height differs from the hard board surface 7e, and the edge of the hard board surface 8e of the revolving scroll 8 is over it. It passes with the revolving motion of the revolving scroll 8. Since the ring-shaped groove 19 faces the back pressure space, the end of the hard plate surface 8e of the swing scroll 8 may overlap the ring-shaped groove 19 with the orbiting motion of the swing scroll 8. The hard plate surface 8e is opened in the back pressure space.

When the swing scroll 8 is pivoted in this state, a plurality of crescent shaped compression chambers 13 are formed in which the volume is continuously reduced as the center portion moves between the wraps 7b and 8b. For example, as shown in Figs. 2A to 2D, the turning inner compression chamber 13a and the turning outer compression chamber are respectively located on the inner and outer sides of the turning scroll wrap 8b. 13b is formed. In addition, the suction chamber 23 is a space in which fluid is being sucked. This suction chamber 23 becomes the compression chamber 13 from the time when the phase of the rotational movement of the revolving scroll 8 progresses, and closing of fluid is completed.

The suction port 14 is provided in the fixed scroll 7. This suction port 14 is provided in the outer peripheral side of the die plate 7a so as to communicate with the suction chamber 23. The fluid flowing from the suction port 14 is closed by the suction chamber 23 and exists at suction pressure until it newly communicates with the suction chamber 23. The region in which the fluid is at suction pressure is the suction pressure region. Usually this suction pressure region is located near the winding-up portion of the fixed scroll wrap 7b. Therefore, the fixed scroll hard plate surface 7e near this suction pressure area | region is a part where the length of radial direction is short and it is hard to fully take a seal distance. In addition, the discharge port 15 is provided in the vicinity of the spiral center of the die plate 7a of the fixed scroll 7 so as to communicate with the compression chamber 13 on the innermost circumferential side.

Next, the operation will be described. First, when the shaft 10 is driven to rotate by the motor 16, this rotation is transmitted from the crank 10a of the shaft 10 to the swing scroll 8 through the swing bearing 11. As a result, the swinging scroll 8 pivots about a turning radius of a predetermined distance σ around the axis of the fixed scroll 7. During the swing movement, the swing scroll 8 is constrained by the Oldham ring 12 so as not to rotate.

And the compression chamber 13 which arises between each wrap 7b, 8b by the turning movement of the turning scroll 8 continuously moves to the center, and the volume of the compression chamber 13 continuously shrinks according to the movement. do. Thereby, the fluid sucked from the suction port 14 is sequentially compressed in each compression chamber 13, and the fluid so compressed is discharged from the discharge port 15. FIG. The fluid thus discharged is supplied from the discharge pipe 6 through the case 9 to, for example, a refrigeration cycle.

On the other hand, the lubricating oil is stored in the bottom of the case 9, and the pressure around it is discharge pressure. Since the pressure in the back pressure chamber 18 formed of the frame 17, the shaft 10, the fixed scroll 7, and the swing scroll 8 is lower than the discharge pressure, the lubricant stored in the bottom of the case 9 is a shaft. It flows into the back pressure chamber 18 through the through hole 3 provided in (10). Specifically, a part of the lubricating oil reaches the back pressure chamber 18 while lubricating the main bearing 5 via the horizontal hole 4 provided in the shaft 10.

Further, the other lubricant oil reaches the upper part of the crank 10a of the shaft 10 through the through hole 3, lubricates the swing bearing 11 and enters the back pressure chamber 18. Here, when the lubricating oil passes through the main bearing 5 and the slewing bearing 11, the lubricating oil is throttled and enters the back pressure chamber 18 at a pressure lower than the discharge pressure because the bearing clearance is small. When the back pressure rises, the lubricating oil which entered the back pressure chamber 18 opens the back pressure regulating valve 2 provided in the communication path to the suction chamber 23, and enters the suction chamber 23. As shown in FIG. The lubricant oil discharged from the discharge port 15 through the compression chamber 13 is partially discharged from the discharge pipe 6 in a refrigeration cycle, and the remainder is separated from the refrigerant in the case 9 and stored at the bottom.

Next, the leakage of the fluid on the hard plate surface of both scrolls will be described. In the scroll compressor, an axial force is generated in which the fixed scroll 7 and the swinging scroll 8 are spaced apart from each other by the compression action. If both scrolls are spaced apart, the sealability of the compression chamber deteriorates and the efficiency of the compressor decreases.

Therefore, the back pressure chamber 18 which makes the back side of the hard plate of the turning scroll 8 into the pressure which becomes a pressure between discharge pressure and suction pressure is provided, and negates the separation force by the back pressure, and turns scroll 8 Is pressed against the fixed scroll 7. At this time, the hard plate surface 8e of the revolving scroll 8 and the hard plate surface 7e of the fixed scroll 7 slide together.

The sliding surfaces in this hard plate face each other with a small gap, and serve to sandwich the back pressure chamber 18 and the suction chamber 23 or the compression chamber 13 as shown in FIG. The size of the gap of this sliding surface changes with time and position on the hard plate surface. The reason is described below.

In the turning scroll 8 during operation, not only the axial force but also the tangential direction and the radial direction force are generated by the compression action, and the centrifugal force is also generated. This force results in a so-called rollover moment, which attempts to incline the swinging scroll 8. As a result, the swinging scroll 8 is oscillating, the two hard plates are not always parallel, and the size of the gap is not always constant. The smaller this gap, the smaller the leakage on the hard plate surface.

In addition, the leakage on the hard plate surface is also affected by the seal lengths shown in FIGS. 2A to 2D and 4. The seal length is the length of the radial direction of the hard plate sliding surface of the fixed scroll 7 and the revolving scroll 8, and is the length which sandwiches the back pressure chamber 18, the compression chamber 13, or the suction chamber 23 between them.

For example, the seal length near the suction port 14 is the length between the point 24 and the point 25 in FIG. 2A, and the point 24 and the point 26 in FIG. 2C. ) Is the length between Here, the point 24 is the point on the outermost circumference of the fixed scroll inner line, the point 25 is the point on the inner circumference of the ring-shaped groove 19 provided on the fixed scroll hardboard surface 7e, and the point 26 is the turning scroll. It is a point on the outer circumference of the hard board

The seal length varies depending on the phase of the swing movement of the swing scroll, and the seal length in each phase is either the length between the points 24 and 25 or the length between the points 24 and 26. It becomes the length of either short side. Incidentally, in the case where there is no ring-shaped groove 19, the length is between the point 24 and the point 26, and is increased or decreased by twice the length of the turning radius during one rotation. The subsequent seal length is assumed to represent the minimum value of the seal length in one revolution.

The shorter seal length deteriorates the sealability and increases leakage loss. The seal length depends on the position on the hardboard surface, and in conventional scroll compressors, the seal length near the suction port 14 is the shortest, so that the leakage loss at the hardboard surface near the suction port 14 is different from the hardboard surface. Will be larger than.

In the vicinity of the suction port 14, the pressure difference before and after the seal is a difference between the back pressure and the suction pressure, and the leakage is greater than that of other parts on the hard plate surface that are the difference between the back pressure and the pressure in the compression chamber. In the present invention, in the vicinity of the suction port 14 where the leakage is large, the force for pressing the swing scroll 8 against the fixed scroll 7 is increased, and the gap between the hard plate surfaces is reduced to reduce leakage.

The structure of this embodiment is demonstrated in more detail. As shown in Fig. 3, a groove 1 serving as a back pressure space is provided in the hard plate surface 7e of the fixed scroll 7. The groove 1 is opened in the ring-shaped groove 19 and becomes a space in which fluid is communicated with almost no throttling with the back pressure chamber 18. The groove 1 is formed so as to pass through a position that is approximately point symmetrical with respect to the spiral center 20 with respect to the vicinity of the shortest suction port 14 of the seal length. When the groove 1 is photographed on the opposite side in point symmetry in the circumferential direction, a length covering the suction port 14, for example, at least the suction pressure region, is provided in the circumferential direction.

The fixed scroll 7 shown in this way has a support portion 7d to which fasteners such as bolts for fastening to the frame 17 are sequentially attached from the outside, a ring-shaped groove 19, a hard plate surface 7e and a hard plate surface. As a part of the inner wall of 7e, the wrap 7b wound in a spiral shape with respect to the spiral center 20 is listed. In the groove 1, the groove width of the ring-shaped groove is enlarged in a shape in which a part of the ring-shaped groove 19 is enlarged with respect to the hard plate surface 7e or the center 20 direction. In addition, the groove 1 is a step formed in the hard plate surface 7e of the fixed scroll 7. For example, even if it does not have the ring-shaped groove 19, the back pressure is introduce | transduced by the groove | channel 1 which is a step formed in the hard board surface 7e.

Next, the effect | action of the characteristic structure of this embodiment is demonstrated. FIG. 4 schematically shows the pressure distribution occurring on the hard plate surface 8e of the revolving scroll 8. 4 is a pressure distribution when the groove 1 is provided, and FIG. 5 is a pressure distribution when the groove 1 is not provided.

In the case where the groove 1 is provided, since the pressure in the groove 1 becomes the back pressure, the hard plate surface of the turning scroll 8 by the portion of the region 22 indicated by the triangle as compared with the case where the groove 1 is not provided. The force to press 8e) from above increases. That is, the moment in the direction of pressing down the area corresponding to the groove 1 of the hard plate surface 8e of the turning scroll 8 from top to bottom is newly generated in addition to the rollover moment.

At this time, the area | region on the opposite side which becomes substantially point symmetry with the position corresponding to the groove | channel 1 with respect to the spiral center 20 of the turning scroll hard board surface 8e is made to the hard board surface 7e of the fixed scroll 7 You will be pressed. By adjusting the position of the groove 1 so that the pressed portion becomes the portion with the shortest seal length of the hard plate surface, the pressing force in the portion with the shorter seal length can be increased, and leakage loss can be reduced.

In addition, it is good to finish the connection part 21 of the groove | channel 1 and the ring-shaped groove | channel 19 smoothly so that it may not become as sharp as possible by the method of forming in circular arcs. This is because if there is a pointed portion at the end of the groove provided on the hard plate surface, there is a possibility that the turning scroll 8 may be contacted when the swinging scroll 8 is inclined due to the rocking motion, which may damage the hard plate surface.

In the above embodiment, an example in which the groove 1 is provided in the hard plate surface 7e of the fixed scroll 7 has been described. However, the groove 1 may have a shape as shown in FIG. That is, the groove 1 shown in Fig. 6 is literally a groove drawn from the back pressure space, and the inside becomes a pressure space such as back pressure. Thus, a ring shape which is a wrap 7b and a hard plate surface 7e near the suction pressure space communicating with the suction port 14 on the opposite side with respect to the space of the groove 1, in particular the back pressure space, in particular a back pressure space. This causes an action of pressing the hard plate surface 8e of the revolving scroll 8 against the hard plate surface 7e close to the groove 19.

In addition, as shown in FIG. 7 and FIG. 8, which is a cross-sectional view thereof, even if the groove 1 serving as a back pressure space is provided in the hard plate surface 8e of the revolving scroll 8, an equivalent function can be realized. In this case, it is structurally a step part with respect to the hard board surface 8e of the revolving scroll 8. The groove 1 extending from the ring-shaped groove with respect to the hard plate surface 7e is also a stepped portion when viewed with respect to the hard plate surface 7e, and is a back pressure introduction space.

According to the present invention, leakage loss from the back pressure chamber on the hard plate surface of the fixed scroll and the swing scroll to the suction chamber or the compression chamber can be reduced.

Claims (9)

A fixed scroll having a spiral wrap erected on a die plate, a hard plate face provided around the lap in series with the tip end face of the lap; A spiral-shaped wrap that forms a plurality of compression chambers between the wraps of the fixed scroll, a swing scroll having a hard plate provided with the wrap, A back pressure chamber having a pressure between the pressure of the gas compressed in the compression chamber and the pressure of the gas sucked into the compression chamber, for pressing the hard plate of the swing scroll against the hard plate surface of the fixed scroll; The pressure of the back pressure chamber is introduced into at least one of the hard plate surface of the swing scroll hard plate and the hard plate surface of the fixed scroll to slide the hard plate surface of the swing scroll away from the fixed scroll. A scroll compressor having a back pressure space for exerting a force in the direction. The scroll compressor according to claim 1, wherein the back pressure space is provided on a suction pressure region provided near the winding completion of the fixed scroll wrap and a hard plate surface of the fixed scroll that is symmetrical with respect to a spiral center of the fixed scroll wrap. The scroll compressor according to claim 2, wherein the length in the circumferential direction of the back pressure space is at least equal to or greater than the length in the circumferential direction of the suction pressure region. The scroll compressor according to claim 1, wherein the back pressure space is a stepped portion provided on at least one of a hard plate surface of the pivoting scroll plate and a hard plate surface of the fixed scroll which slides against each other. The scroll compressor according to claim 1, further comprising a ring-shaped groove portion on an outer side of the hard plate surface of the fixed scroll, wherein the back pressure space is a step portion extending in a spiral center direction from the ring-shaped groove portion. The compression chamber or the suction chamber of the fixed scroll according to claim 1, wherein the radial length of the hard plate surface of the fixed scroll in the radially outer side of the suction pressure region provided near the winding completion of the fixed scroll wrap is set from the back pressure space. A scroll compressor having a larger than the sliding plate sliding distance at which the above sliding plates are slid. A fixed scroll having a spiral wrap erected on a die plate, a hard plate face provided around the lap in series with the tip end face of the lap; A spiral-shaped wrap that forms a plurality of compression chambers between the wraps of the fixed scroll, a swing scroll having a hard plate provided with the wrap, A back pressure chamber having a pressure between the pressure of the gas compressed in the compression chamber and the pressure of the gas sucked into the compression chamber, for pressing the hard plate of the swing scroll against the hard plate surface of the fixed scroll; The spiral center of the fixed scroll wrap is positioned with respect to a portion where the seal length of the sliding plate sliding surface of the two scrolls which slides between the back pressure chamber and the compression chamber or the suction chamber where the gas for compression is sucked is minimized. Of the seal lengths from the outermost part of the inner wall surface of the fixed scroll wrap to the outer circumferential part of the pivoting scroll slab, the seal length of the side which is symmetrical with the minimum part as a reference is longer than the seal length of the minimum part. And a scroll compressor shorter than the minimum length during the swinging movement of the swinging scroll. The scroll compressor according to claim 7, wherein the scroll compressor is shorter than any of the lengths from the outermost circumference of the fixed scroll inner line to the ring-shaped groove provided on the fixed scroll hardboard surface. The scroll compressor according to claim 7, wherein the minimum portion is a hard plate sliding surface of the two scrolls in the radially outer side of the suction pressure region provided near the winding completion of the fixed scroll wrap.

Images