JP2010084687A - Fluid machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluid machine capable of sufficiently securing the sealability and wear resistance of a sliding part between a fixed scroll and a movable scroll and improving power efficiency. <P>SOLUTION: The movable scroll 34 of the fluid machine includes a first communication passage 80 communicated with a back pressure chamber 46 via a back pressure adjusting mechanism 70 and opening at a tip 34c of a spiral lap at a first prescribed position on the outermost periphery of the spiral lap 34a of the movable scroll, and a second communication passage 84 communicated with the back pressure 46 and opening at the tip 34c of the spiral lap at a second prescribed position on the inner-most periphery of the spiral lap 34a of the movable scroll. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a fluid machine, and more particularly, to a fluid machine suitable for a refrigeration air conditioner or a heat pump type hot water heater.

This type of fluid machine, for example, a hermetic scroll compressor, performs a series of processes of sucking, compressing and discharging refrigerant including lubricating oil by revolving orbiting the movable scroll with respect to the fixed scroll in the housing. ing.
Specifically, spiral wraps are provided on the end plate surfaces of the movable and fixed scroll end plates, respectively, and these laps cooperate to form a compression chamber, and the volume of the compression chamber is reduced to reduce the volume of the above-described series. The process is implemented.

By the way, in such a fluid machine, the lubricating oil is mixed with the refrigerant and allowed to flow into the suction chamber. However, the sliding portion between the spiral wraps, particularly the compression chamber where the pressure is higher than the suction chamber, is compressed. As the oil advances, the lubricating oil hardly spreads, the lubricating oil reaching the sliding portion becomes insufficient, and there is a problem that the sealing performance of the sliding portion is likely to be lowered or worn.
Therefore, the sliding pressure between the fixed scroll and the movable scroll is received by receiving the refrigerant discharge pressure and is pumped to the back side of the movable scroll, and lubricates the lubricating scroll to apply back pressure to the movable scroll so as to press the movable scroll against the fixed scroll. The structure of supplying to a part is known (refer patent document 1).
JP 2008-106711 A

Lubricating oil flowing on the back side of the movable scroll usually flows so as to diffuse radially from the center of the movable scroll under the refrigerant discharge pressure, so that the back pressure is high on the inner peripheral side but goes to the outer peripheral side. In general, the outer peripheral side is maintained at an intermediate pressure between the suction pressure and the discharge pressure of the refrigerant.
In this regard, in the prior art disclosed in Patent Document 1, a through-hole is provided in the movable scroll where the back pressure becomes the intermediate pressure, and the periphery of the compression chamber where the intermediate pressure is equal to or slightly lower than the intermediate pressure. Thus, lubricating oil is supplied to the sliding portion between the fixed scroll and the movable scroll.

However, in such a configuration, the lubricating oil cannot be sufficiently supplied to the sliding portion of the central portion that is higher than the intermediate pressure in which the refrigerant has been compressed, and sufficient sealing performance and wear resistance performance are ensured. As a result, there is a problem that the power efficiency of the fluid machine cannot be sufficiently improved.
In addition, if the lubricating oil is mixed with the refrigerant and allowed to flow through the suction chamber, the amount of refrigerant sucked will be reduced by the amount of the lubricating oil, and the volumetric efficiency of the refrigerant in the compression chamber will be degraded. There is also a problem that the power efficiency cannot be sufficiently improved.

  The present invention has been made to solve the above-described problems, and the object of the present invention is to sufficiently secure the sealing performance and wear resistance performance of the sliding portion of the fixed scroll and the movable scroll and to improve the power efficiency. It is an object of the present invention to provide a fluid machine capable of achieving the above.

  In order to achieve the above object, a fluid machine according to claim 1 includes a rotating shaft that extends through a container and is rotatably supported by the container, a fixed scroll, and a fixed scroll that is provided in the container. A movable scroll having an orbiting revolving movement around an axis, and suctioning of a working fluid while reducing the volume of a compression chamber formed between the orbiting wrap of the movable scroll and the fixed scroll by the orbiting revolving movement of the movable scroll A scroll unit that performs a series of compression and discharge processes, a spindle frame that is housed in the container and includes a bearing that supports the rotating shaft, and an upper surface of the spindle frame and an end plate surface of the movable scroll And a back pressure chamber filled with the lubricating oil pressurized at a pressure higher than that of the outer peripheral side on the inner peripheral side, and the pressure of the back pressure chamber being the pressure of the compression chamber A back pressure adjusting mechanism that adjusts according to a difference between the back pressure chamber and the back pressure chamber that extends through the movable scroll and communicates with the back pressure chamber via the back pressure adjusting mechanism at a first predetermined position on the outermost periphery of the spiral wrap of the movable scroll. And a first communication path that opens at the tip of the spiral wrap, and extends through the movable scroll, communicates with the back pressure chamber at a second predetermined position on the innermost periphery of the spiral wrap of the movable scroll, and And a second communication passage that opens at the tip of the spiral wrap.

  According to a second aspect of the present invention, in the fluid machine according to the first aspect, the back pressure chamber further extends through the movable scroll, and on both sides of the first predetermined position of the spiral wrap via the back pressure adjusting mechanism. A third communication passage that communicates with and opens to face the compression chamber, and extends through the movable scroll, communicates with the back pressure chamber on both sides of the second predetermined position of the spiral wrap, and the compression chamber And a fourth communication passage opening toward the front.

  The fluid machine according to claim 3 is characterized in that, in claim 1 or 2, the back pressure adjusting mechanism is disposed in the movable scroll.

  According to the fluid machine of claim 1, the movable scroll communicates with the back pressure chamber via the back pressure adjusting mechanism at the first predetermined position on the outermost periphery of the spiral wrap of the movable scroll and at the tip of the spiral wrap. Since the first communication path that opens and the second communication path that communicates with the back pressure chamber at the second predetermined position on the innermost circumference of the spiral wrap of the movable scroll and opens at the tip of the spiral wrap are formed, Lubricating oil is not only supplied to the tip of the scroll of the movable scroll at the outermost periphery of the spiral wrap, but also the lubricant is supplied to the tip of the scroll of the movable scroll at the innermost periphery of the spiral wrap. The

As a result, the minute gap between the spiral scroll of the movable scroll and the end plate surface of the fixed scroll is sealed well overall, so that the sealing performance of the compression chamber formed by the spiral wrap of the movable scroll and the fixed scroll is improved, and the compression is performed. It is possible to increase efficiency.
Moreover, since the oil film of a sliding part becomes thick by supplying lubricating oil to the front-end | tip of a movable scroll, abrasion of a sliding part can be prevented.

  According to the fluid machine of claim 2, the movable scroll communicates with the back pressure chamber via the back pressure adjusting mechanism on both side surfaces of the first predetermined position of the spiral wrap and opens toward the compression chamber. Since the third communication path and the fourth communication path that opens to the compression chamber and open to the compression chamber are formed on both side surfaces of the second predetermined position of the spiral wrap, the end face of the movable scroll is formed on the end plate surface of the movable scroll. Since the lubricating oil is supplied, the minute gap between the end plate surface of the movable scroll and the spiral wrap of the fixed scroll is sealed as a whole. Further, the orbiting scroll makes a revolving orbiting motion, so that the space between the side surface of the spiral wrap of the movable scroll and the side surface of the spiral wrap of the fixed scroll is sealed as a whole.

Accordingly, the sealing performance of the compression chamber formed by the spiral scroll of the movable scroll and the fixed scroll is improved, and the compression efficiency can be further improved.
According to the fluid machine of the third aspect, since the back pressure adjusting mechanism is built in the movable scroll, the pressure in the back pressure chamber becomes relatively large, and the back pressure shortage can be eliminated.
Further, even when the pressure in the compression chamber may become larger than the pressure in the back pressure chamber, the back pressure adjustment mechanism has the effect of a check valve that prevents the back flow of the working fluid.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a sectional view of a hermetic scroll compressor which is one of fluid machines according to the present invention.
A scroll compressor (hereinafter referred to as a compressor) 1 is incorporated in a refrigeration circuit such as a refrigeration air conditioner or a heat pump water heater. The circuit includes a path through which carbon dioxide refrigerant (hereinafter referred to as refrigerant), which is an example of a working fluid, circulates, and the compressor 1 sucks the refrigerant from the path, compresses it, and discharges it toward the path.

  As shown in the figure, the compressor 1 includes a housing 2, and the body 4 of the housing 2 is hermetically fitted on the upper and lower sides by an upper lid 6 and a lower lid 8, respectively. The inside is sealed and a high discharge pressure is acting. Further, a suction pipe 10 for sucking refrigerant taken in from the circuit is connected to the body 4, and a discharge pipe 12 for sending compressed refrigerant in the housing 2 to the circuit is connected to an appropriate position of the upper lid 6. Yes.

An electric motor 14 is accommodated in the body 4, and a rotating shaft 16 is disposed in the motor 14. The rotating shaft 16 is driven by energization of the motor 14. Further, the upper end side of the rotating shaft 16 is rotatably supported by the spindle frame 18 via a bearing 17.
On the other hand, the lower end side of the rotating shaft 16 is rotatably supported by the countershaft frame 22 via the bearing 20. An oil pump 24 is attached to the lower end side of the rotating shaft 16, and the pump 24 sucks the lubricating oil in the oil storage chamber 26 formed inside the lower lid 8, that is, at the bottom of the housing 2. The lubricating oil functions as a lubricant for each sliding portion and a bearing and a seal for the sliding surface through an oil supply passage 28 formed along the axis inside the rotating shaft 16.

Note that the discharge pressure of the refrigerant acts on the oil surface of the lubricating oil in the oil storage chamber 26, and the fact that the discharge pressure of the refrigerant acts on the oil surface of the lubricating oil also contributes to the increase of the lubricating oil in the oil supply passage 28. . As a result, the outlet of the oil supply passage 28 becomes a high pressure environment substantially equal to the refrigerant discharge pressure.
A lubricating oil introduction port 32 is formed at an appropriate position of the countershaft frame 22, and the lubricating oil supplied to each sliding portion in the compressor 1 enters the oil storage chamber 26 via the introduction port 32. Stored.

The scroll unit 30 is disposed above the motor 14 in the body 4 and performs a series of processes of refrigerant suction, compression, and discharge.
Specifically, the scroll unit 30 is composed of a movable scroll 34 and a fixed scroll 36, and spiral wraps 34a, 36a are integrally provided on the opposing surfaces of the scrolls 34, 36, respectively. A compression chamber 39 is formed between 34a and 36a. As a result, when the movable scroll 34 orbits with respect to the fixed scroll 36, the spiral wraps 34 a and 36 a mesh with each other and cooperate with each other through the suction pipe 10 from the suction chamber 37 formed on the outer peripheral side of the movable scroll 34. The refrigerant is sucked into the compression chamber 39, and the volume of the compression chamber 39 is reduced while the compression chamber 39 moves toward the centers of the spiral wraps 34a and 36a, and the refrigerant is compressed.

  Specifically, when the orbiting scroll 34 pivots, the side surfaces of the spiral wraps 34a and 36a are engaged with each other with a minute gap, and the tooth tip (tip) 34c of the spiral wrap 34a, the end plate surface of the fixed scroll 36, and the teeth of the spiral wrap 36a. The volume of the compression chamber is reduced while the tip and the end plate surface 34d of the movable scroll 34 are engaged with each other with a minute gap, and a series of processes of refrigerant suction, compression and discharge are performed.

  In order to impart a turning motion to the movable scroll 34 described above, a boss portion 38 is formed on the rear surface 34 b of the movable scroll 34 so as to protrude, and this boss portion 38 is connected to the crank pin 42 via a bearing 44. . The crank pin 42 is integrally formed on the upper end side of the rotating shaft 16, and causes the movable scroll 34 to make a revolving orbiting motion on the spindle frame 18 as the rotating shaft 16 rotates.

  On the other hand, the rotation of the movable scroll 34 is blocked by a rotation blocking pin 62. The pin 62 protrudes from the back surface 34 b of the movable scroll 34 and is loosely fitted in a hole 64 on the bottom formed in the spindle frame 18. That is, a so-called pin-hole type rotation prevention mechanism 60 is formed in the gap 45 between the back surface 34 b of the movable scroll 34 and the spindle frame 18. Specifically, the rotation prevention mechanism 60 includes, for example, four sets of pins 62 and holes 64.

  As shown in the enlarged view of the scroll unit 30 in FIG. 2, the movable scroll 34 has a built-in back pressure adjusting mechanism 70 including a valve body 72 and a spring 74 inserted so as to contact the tapered surface. . The movable scroll 34 is connected to a communication path (first communication path) 80 that penetrates from the back surface of the back pressure adjustment mechanism 70 to the tooth tip 34c of the outermost spiral wrap 34a located above the back pressure adjustment mechanism 70. A pair of communication passages (third communication passages) 82, 82 located on both sides of the passage 80 and penetrating from the back surface of the back pressure adjusting mechanism 70 to the end plate surface 34 d of the movable scroll 34 located on the side surface side of the spiral wrap 34 a. Have.

Further, the movable scroll 34 has a communication path (second communication path) 84 penetrating from the boss portion 38 to a predetermined position of the tooth tip 34c of the innermost spiral wrap 34a located above the boss portion 38, and a communication path 84. And a communicating path (fourth communicating path) 86 penetrating from the boss portion 38 to the end plate surface 34d of the movable scroll 34 located on the side surface side of the spiral wrap 34a.
That is, as shown in FIG. 3 which is a cross-sectional view taken along the line AA in FIG. The communication passages 82, 82 are formed from the end plate surfaces 34 d on both sides of the communication passage 80 toward the back pressure adjusting mechanism 70. The communication path 84 is formed in the tooth tip 34c of the spiral wrap 34a at a predetermined position on the innermost circumference toward the boss portion 38, and the communication path 86 is an end plate surface 34d on both sides of the communication path 84. To the boss 38.

As shown in FIG. 1, the fixed scroll 36 is fixed to the spindle frame 18 and partitions the discharge chamber 54 side and the compression chamber 39 side formed in the upper lid 6. Specifically, a cylindrical outer peripheral wall 19 concentrically with the rotary shaft 16 extends toward the fixed scroll 36 on the main spindle frame 18, and the fixed scroll 36 is joined to the upper edge of the outer peripheral wall 19.
As described above, the fixed scroll 36 is joined to the upper edge of the outer peripheral wall 19, so that a swivel sliding region in which the movable scroll 34 slides is formed between the fixed scroll 36 and the spindle frame 18. Yes. A back pressure chamber 46 is formed between the upper surface of the spindle frame 18, the end plate surface of the fixed scroll 36, the movable scroll 34 and the outer peripheral wall 19 in the orbiting / sliding region. The back pressure chamber 46 is filled with high-pressure lubricating oil discharged from the outlet of the oil supply passage 28 in a pressurized state. Specifically, the back pressure chamber 46 is filled with lubricating oil so that the inner peripheral side becomes a high pressure and becomes lower as it goes to the outer peripheral side. Thus, in the back pressure chamber 46, the back pressure is generally maintained at an intermediate pressure between the refrigerant suction pressure and the discharge pressure on the outer peripheral side.

A discharge hole 56 communicating with the compression chamber side is formed at an appropriate position in the central portion of the fixed scroll 36, and the discharge hole 56 is disposed on the back surface 36 b side of the fixed scroll 36. It is opened and closed by. Further, the discharge valve 58 is covered with the discharge head 50, and the sound when the discharge valve 58 is opened is suppressed by the discharge head 50.
The fixed scroll 36 and the spindle frame 18 have a refrigerant passage (not shown) located in the outer peripheral portion and extending in the axial direction. Thus, although the description is omitted in detail, the refrigerant discharged from the discharge hole 56 can circulate in the housing 2 through the refrigerant passage.

Hereinafter, an operation of the fluid machine according to the present invention configured as described above will be described.
According to the compressor 1 described above, when the rotating shaft 16 is rotated by the electric motor 14, the movable scroll 34 starts a revolving orbiting motion. The revolving orbiting motion of the movable scroll 34 sucks the refrigerant from the suction pipe 10 toward the inside of the scroll unit 30 and compresses the refrigerant while reducing the volume of the compression chamber. The high-pressure refrigerant compressed in this way is discharged from the discharge hole 56 and circulates while separating the lubricating oil in the housing 2, and is then sent out of the compressor through the discharge pipe 12 from the discharge chamber 54.

  At this time, when the pressure in the back pressure chamber 46 becomes higher than that in the compression chamber 39, the valve body 72 is pushed upward in the back pressure adjusting mechanism 70 to open the valve, and the lubricating oil passes through the communication passages 80 and 82 and swirls. It is supplied to the tooth tip 34 c of the wrap 34 a and the end plate surface 34 d of the movable scroll 34. In the communication paths 84 and 86 provided at predetermined positions on the innermost periphery of the movable scroll 34, the lubricating oil is supplied from the boss portion 38 to the tooth tips 34 c and the end plate surface 34 d through the communication paths 84 and 86.

  Since lubricating oil is supplied to the tooth tip 34c of the spiral wrap 34a through the communication passages 80 and 84, the oil film at the sliding portion between the tooth tip 34c and the end plate surface of the fixed scroll 36 becomes thick. The minute gap between the spiral wrap 34a and the end plate surface of the fixed scroll 36 is well sealed. Accordingly, the sealing performance of the compression chamber 39 is also improved, so that the compression efficiency can be increased. Moreover, since the oil film of a sliding part becomes thick, abrasion of a sliding part can be prevented.

  Further, since the lubricating oil is also supplied to the end plate surface 34d of the movable scroll 34 through the communication passages 82 and 86, the oil film at the sliding portion between the end plate surface 34d and the spiral scroll 36a of the fixed scroll becomes thicker. A minute gap between the spiral wrap 36a of the fixed scroll 36 and the end plate surface 34d of the movable scroll 34 is well sealed. Further, as the movable scroll 34 revolves, the lubricating oil is supplied between the side surface of the spiral wrap 34 a of the movable scroll 34 and the side surface of the spiral wrap 36 a of the fixed scroll 36, and the side surface of the spiral wrap 34 a of the movable scroll 34. Between the side surfaces of the spiral wrap 36a of the fixed scroll 36 is well sealed. Thereby, since the sealing performance of the compression chamber 39 is improved, the compression efficiency can be increased.

  As described above, the communication path 80, 82 provided at a predetermined position on the tip 34c and the end plate surface 34d of the outermost spiral wrap 34a serving as an intermediate pressure region, and the innermost spiral wrap of the movable scroll 34 serving as a high pressure region. Lubricating oil is satisfactorily supplied to the entire spiral wrap 34a by including the communication passages 84 and 86 provided at predetermined positions on the tip 34c of the end plate 34c and the end plate surface 34d. That is, by providing communication passages for oil supply in the intermediate pressure region and the high pressure region respectively, the entire tooth tip 34c and end plate surface 34d of the movable scroll 34 are sealed with lubricating oil, and the compression efficiency can be further improved. is there.

In addition, since the back pressure adjusting mechanism 70 is built in the movable scroll 34, the pressure in the back pressure chamber 46 is adjusted with respect to the compression chamber 39 that has advanced to the extent that compression occurs, and the pressure in the back pressure chamber 46 is relatively high. It becomes larger and the back pressure shortage can be eliminated. Further, when the pressure in the compression chamber 39 becomes higher than that in the back pressure chamber 46, there is also an effect as a check valve that prevents the refrigerant from flowing backward.
Although the description of the embodiment has been completed above, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

For example, in the above-described embodiment, the back pressure adjusting mechanism 70 is configured to press the valve body 72 against the tapered surface with the spring 74. However, if the back pressure adjusting mechanism 70 has a similar function, the back pressure adjusting mechanism 70 is configured as described above. It is not limited to.
Moreover, although the said embodiment demonstrated the sealed scroll compressor, it is applicable not only to this but fluid machines, such as various compressors or an expander.

It is a longitudinal section of a fluid machine concerning an embodiment of the present invention. It is the figure which expanded and showed the scroll unit shown in FIG. FIG. 3 is a transverse sectional view taken along line AA in FIG. 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Scroll compressor 2 Housing 30 Scroll unit 34 Movable scroll 34a Spiral wrap 34c Tooth tip 34d End plate surface 36 Fixed scroll 36a Spiral wrap 38 Boss part 39 Compression chamber 70 Back pressure adjustment mechanism 80, 82, 84, 86 Communication path

Claims (3)

A rotating shaft extending through the container and rotatably supported by the container;
A fixed scroll, and a movable scroll that revolves around the axis of the fixed scroll, and is provided between the movable scroll and the spiral scroll of the fixed scroll by the revolving orbiting movement of the movable scroll. A scroll unit for performing a series of processes of suction, compression and discharge of the working fluid while reducing the volume of the compression chamber formed in
A main shaft frame including a bearing housed in the container and supporting the rotating shaft;
A back pressure chamber formed between the upper surface of the spindle frame and the end plate surface of the movable scroll, and filled with a lubricating oil pressurized at a pressure higher than the outer peripheral side on the inner peripheral side;
A back pressure adjusting mechanism for adjusting the pressure of the back pressure chamber according to the difference from the pressure of the compression chamber;
A first link that extends through the movable scroll and communicates with the back pressure chamber via the back pressure adjusting mechanism at a first predetermined position on the outermost periphery of the spiral wrap of the movable scroll and opens at the tip of the spiral wrap. A passage,
A second communication path extending through the movable scroll and communicating with the back pressure chamber at a second predetermined position on the innermost circumference of the spiral wrap of the movable scroll and opening at the tip of the spiral wrap;
A fluid machine comprising:   Further, a third portion that extends through the movable scroll and communicates with the back pressure chamber via the back pressure adjusting mechanism on both sides of the first predetermined position of the spiral wrap and opens toward the compression chamber. A communication path, and a fourth communication path that extends through the movable scroll and communicates with the back pressure chamber on both sides of the second predetermined position of the spiral wrap and opens toward the compression chamber. The fluid machine according to claim 1.   The fluid machine according to claim 1, wherein the back pressure adjusting mechanism is disposed in the movable scroll.

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