JP2016075200A - Scroll type fluid machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scroll type fluid machine that prevents deterioration in durability of a casing, deterioration of sealability in a movable scroll, deterioration in volumetric efficiency, increase in friction resistance, increase in noise, and high temperature of working fluid, thereby to prevent increase in power consumption of the scroll type fluid machine, and has high reliability and high efficiency.SOLUTION: A scroll type fluid machine includes: a thrust reception part 4a that receives a load in a thrust direction by revolving motion of a movable scroll to a stationary scroll; a casing 4 that has a bolt fastening part arranged on the outer peripheral side of the thrust reception part, and is fastened to the stationary scroll at a bolt fastening part with a bolt extending in the thrust direction; and a recess part 44 that is formed in the thrust reception part, positioned near the bolt fastening part, and recessed in the thrust direction.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a scroll type fluid machine, and more particularly to a scroll type fluid machine used in a refrigeration circuit of a vehicle air conditioner.

  Patent Document 1 discloses a compressor including an electric motor section and a compression mechanism section. The compression mechanism is configured by superimposing elements of an upper bearing, a cylinder, and a lower bearing, and the upper bearing and the lower bearing are in contact with the cylinder end surface and fastened to the cylinder with several bolts. Further, by providing ribs on the bearing surface contact portion of the bolt, the fastening force by the bolt is dispersed throughout the cylinder, and the distortion of the upper bearing and the lower bearing due to the bolt fastening, and hence the leakage of the working fluid from the compression mechanism portion is reduced. Is planned.

JP 2011-106410 A

  By the way, in the scroll type fluid machine, the spiral wall of the fixed scroll and the spiral wall of the movable scroll are engaged with each other, and the pressure chamber of the working fluid is partitioned by the revolving turning of the movable scroll with respect to the fixed scroll. For this reason, the thrust receiving portion of the scroll type fluid machine has not only the bolt tightening force as in Patent Document 1, but also the internal pressure of the casing and the reaction force of the pressure chamber accompanying the revolution rotation of the movable scroll (of the compressor). In this case, a thrust load based on the compression reaction force is applied.

Therefore, when a casing, a movable scroll, and a thrust plate are disposed between them, the thrust plate or the like may be greatly bent and deformed in the thrust direction. Such bending causes stress concentration on the casing, which reduces the durability of the casing.
Further, as an example of the bending in the thrust direction of the fluid machine, when the back surface of the substrate on which the spiral wall of the movable scroll is erected is convexly deformed, the movable scroll rolls over and the sealing performance of the pressure chamber is deteriorated.

  In addition, an annular belt-shaped pedestal surface is formed on the casing, and the pedestal surface is slid on the back surface of the movable scroll while receiving a load in the thrust direction accompanying the revolution of the movable scroll. When a thrust plate is disposed between the movable scroll and the front casing, the back surface of the movable scroll is slid on the sliding surface of the thrust plate. These deformations of the pedestal surface and the sliding surface impede smooth sliding on the back surface of the movable scroll.

Specifically, in the region where the gap between the above-described pedestal surface or sliding surface and the back surface of the movable scroll is narrowed, the frictional resistance between these surfaces increases, and the power consumption of the fluid machine increases.
In addition, the movable scroll may not be smoothly rotated and revolved by being pulled in a region where the gap is narrow, and noise may be generated.
On the other hand, in the region where the gap becomes large, the gap between the tip of one spiral wall of the fixed and movable scrolls and the other substrate increases, the working fluid leaks from the pressure chamber, and consequently the volume efficiency of the fluid machine Gets worse.

In addition, when the fluid machine is a compressor, the temperature of the discharge gas that is the working fluid rises, which may adversely affect the refrigeration cycle in which the compressor is incorporated.
The present invention has been made in view of such a problem, and the object of the present invention is to reduce the durability of the casing, the deterioration of the sealing performance of the movable scroll, the volume due to the bending in the thrust direction of the scroll type fluid machine. To provide a highly reliable and highly efficient scroll type fluid machine that prevents a decrease in efficiency, an increase in frictional resistance, an increase in noise, and a high temperature of the working fluid, and consequently an increase in power consumption of the scroll type fluid machine. It is in.

  In order to achieve the above object, a scroll type fluid machine according to the present invention includes a thrust receiving portion that receives a load in a thrust direction when the movable scroll revolves with respect to a fixed scroll, and a bolt that is disposed on an outer peripheral side of the thrust receiving portion. A casing having a fastening portion and fastened to the fixed scroll at the bolt fastening portion by a bolt extending in the thrust direction; and a recess formed in the thrust receiving portion and positioned near the bolt fastening portion and recessed in the thrust direction. It is characterized by.

Preferably, the recess has a depth, a size, and a depth that allow deflection in at least one of the movable scroll, the thrust receiving portion, and the casing due to the load in the thrust direction and the tightening force of the bolt. Has a shape.
Preferably, the rotation receiving mechanism is further provided between the thrust receiving portion and the movable scroll, and further includes a rotation prevention mechanism that allows the revolving turning of the movable scroll while preventing the rotation of the movable scroll, and the recess is formed on the outer peripheral side of the rotation prevention mechanism. The

Preferably, the casing is a front casing that sandwiches the fixed scroll together with a rear casing disposed on the back side of the substrate on which the spiral wall of the fixed scroll is erected, and the bolts are the rear casing, the fixed scroll, and the front casing. Each of the outer peripheries are fastened through a consistent bolt hole.
Preferably, the apparatus further includes a thrust plate disposed between the back surface of the substrate on which the spiral wall of the movable scroll is erected and the casing, and the thrust plate is slid on the back surface of the movable scroll as the movable scroll revolves. A ring-shaped sliding surface.

Preferably, the casing has an annular belt-shaped pedestal surface disposed on the back side of the substrate on which the spiral wall of the movable scroll is erected, and the recess is formed on the pedestal surface.
Preferably, the concave portion is formed on a surface opposite to the sliding surface of the thrust plate.
Preferably, a plurality of bolts are provided, and the number of recesses is equal to or less than the number of bolts.

  According to the scroll type fluid machine of the present invention, the durability of the casing is lowered, the sealing performance is deteriorated in the movable scroll, the volume efficiency is lowered, the frictional resistance is increased, and the noise is increased due to the bending in the thrust direction of the scroll type fluid machine. In addition, it is possible to provide a highly reliable and highly efficient scroll type fluid machine that prevents the working fluid from increasing in temperature and consequently increases the power consumption of the scroll type fluid machine.

It is a longitudinal section of a scroll compressor concerning one embodiment of the present invention. It is the perspective view which looked at the front casing of FIG. 1 from the end wall side. FIG. 3 is a partial cross-sectional view of the compressor of FIG. 1 when viewed in the AA direction cross section of the front casing of FIG. It is a partial cross section figure of the compressor used as the modification of FIG. It is a partial cross section figure of the compressor used as another modification of FIG.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a longitudinal sectional view of a scroll compressor according to an embodiment of the present invention. The compressor 1 is incorporated in, for example, a refrigeration circuit of a vehicle air conditioner mounted on a vehicle (not shown). The refrigeration circuit has a refrigerant circulation path for the refrigerant that is the working fluid of the compressor 1, and the compressor 1 sucks the refrigerant from the return path of the refrigerant circulation path, compresses the refrigerant, and discharges the refrigerant toward the forward path of the refrigerant circulation path. .

  As shown in FIG. 1, the compressor 1 includes a rear casing 2 and a front casing (casing) 4. A scroll unit 6 is disposed between the rear casing 2 and the front casing 4. A drive shaft 8 extends into the front casing 4, and the drive shaft 8 is rotatably supported by the front casing 4 via a bearing. Further, a pedestal portion (thrust receiving portion) 4a projects from the front casing 4 toward the inside thereof.

  A drive pulley 12 incorporating an electromagnetic clutch 10 is attached to the projecting end of the drive shaft 8 from the front casing 4. The drive pulley 12 is rotatably supported by the front casing 4 via a bearing. The power of the vehicle engine is transmitted to the drive pulley 12 via a drive belt (not shown), and the rotation of the drive pulley 12 can be transmitted to the drive shaft 8 via the electromagnetic clutch 10. Therefore, when the electromagnetic clutch 10 is turned on during driving of the engine, the drive shaft 8 rotates integrally with the drive pulley 12.

  The scroll unit 6 includes a fixed scroll 14 and a movable scroll 16. The movable scroll 16 is assembled so as to mesh with the fixed scroll 14. The fixed scroll 14 is positioned between the rear casing 2 and the front casing 4, and is clamped and fastened between the rear casing 2 and the front casing 4 by four bolts 17 extending in the axial direction of the drive shaft 8, that is, in the thrust direction. .

The movable scroll 16 includes a substrate 16 a, and a spiral wall 16 b is erected on the substrate 16 a toward the fixed scroll 14. The back surface 16c of the substrate 16a of the movable scroll 16 is positioned to face the pedestal 4a of the front casing.
A spiral wall 14 b is also erected on the substrate 14 a of the fixed scroll 14 toward the substrate 16 a of the movable scroll 16. Then, the spiral walls 14 b and 16 b of the fixed scroll 14 and the movable scroll 16 are engaged with each other, and the movable scroll 16 revolves with respect to the fixed scroll 14, so that the compression chamber of the refrigerant that is the working fluid of the compressor 1 ( The pressure chamber 18 is partitioned, and the volume of the compression chamber 18 is increased or decreased with the revolution of the movable scroll 16.

  An end wall (bolt fastening portion) 4 b is positioned on the outer peripheral side of the pedestal surface 4 c of the front casing 4. The end wall 4b is in contact with the end face 14c of the outer peripheral portion of the spiral wall 14b of the fixed scroll 14, and the substrate 16a of the movable scroll 16 is positioned in the front casing 4. A refrigerant suction chamber 20 is secured between the end wall 4b of the front casing 4 and the substrate 16a. The suction chamber 20 communicates with the return path of the refrigerant circulation path described above.

  A rear surface 14 d of the substrate 14 a of the fixed scroll 14 is in contact with the end wall 2 a of the rear casing 2. A refrigerant discharge chamber 22 partitioned from the substrate 14 a is formed in the rear casing 2, and the discharge chamber 22 communicates with the aforementioned refrigerant circulation path. Further, the discharge chamber 22 communicates with the compression chamber 18 through a discharge hole 24 drilled in the substrate 14 a of the fixed scroll 14. A discharge valve 26 for opening and closing the discharge hole 24 is disposed in the discharge chamber 22, and the opening degree of the discharge valve 26 is regulated by a stopper plate 28.

  A boss 30 projects from the back surface 16c of the substrate 16a of the movable scroll 16, and a bush 32 is rotatably inserted into the boss 30 through a bearing. An eccentric shaft portion 8 a of the drive shaft 8 is eccentrically supported on the bush 32, and a revolving orbiting motion is imparted to the movable scroll 16 by the rotation of the drive shaft 8. An annular plate-shaped thrust plate 34 is disposed between the back surface 16 c of the substrate 16 a of the movable scroll 16 and the pedestal portion 4 a of the front casing 4.

The thrust plate 34 has an annular belt-like sliding surface 34a. The sliding surface 34a receives a load in the thrust direction on the drive shaft 8 as the movable scroll 16 revolves, and the rear surface 16c of the movable scroll 16 slides. Moved.
Further, as will be described in detail later, a rotation prevention mechanism 36 is disposed between the back surface 16c of the substrate 16a of the movable scroll 16 and the base portion 4a of the front casing 4 (see FIG. 3). The rotation prevention mechanism 36 prevents the rotation of the movable scroll 16 without hindering the revolving turning motion of the movable scroll 16 relative to the fixed scroll 14.

  According to the compressor 1 described above, as the drive shaft 8 rotates, the movable scroll 16 revolves without rotating while sliding the back surface 16 c on the thrust plate 34. Thereby, the refrigerant sucked into the suction chamber 20 from the return path of the refrigerant circulation path forms the compression chamber 18, and the refrigerant in the compression chamber 18 is compressed while being moved toward the center of the scroll unit 6, and then discharged. It is discharged into the discharge chamber 22 through the hole 24 and sent out from the discharge chamber 22 to the forward path of the refrigerant circulation path.

  FIG. 2 is a perspective view of the front casing 4 as viewed from the end wall 4b side. As shown in FIG. 2, the base portion 4 a of the front casing 4 is formed with an annular belt-like base surface 4 c. In the case of this embodiment, the thrust plate 34 shown in FIG. 1 is arranged on the pedestal surface 4c, and the pedestal surface 4c is loaded with the thrust plate 34 through the thrust plate 34 in the thrust direction along with the revolution rotation of the movable scroll 16. Receive. The back surface 16 c of the movable scroll 16 is slid on the sliding surface 34 a of the thrust plate 34.

A fastening surface 4d is formed on the end surface of the end wall 4b of the front casing. The bolt holes 38 and the fastening surface 4d are formed at four locations facing each other across the boss 30 on the end surface of the end wall 4b, and the four bolts 17 described above are inserted into the respective bolt holes 38.
Further, four press-fitting holes 42 for press-fitting and fixing a pin 40 (see FIG. 3), which will be described later, of the rotation preventing mechanism 36 are opened in the vicinity of the line connecting the opposing bolt holes 38 on the pedestal surface 4c.

  Then, in the vicinity of each bolt hole 38 on the pedestal surface 4c, a concave portion 44 that is recessed in the thrust direction is formed. In the case of the present embodiment, each recess 44 has a substantially oval shape in plan view that is recessed from the press-fitting hole 42 of the pedestal surface 4c in the thrust direction that is recessed toward the pedestal surface 4c.

FIG. 3 is a partial view of the compressor 1 as seen in the AA cross section of the front casing 4 of FIG. 2 in order to show the fastening state of the rear casing 2, the fixed scroll 14 and the front casing 4 with bolts 17 in an enlarged manner. It is sectional drawing.
As shown in FIG. 3, the bolts 17 are through bolts that are fastened through the bolt holes 38 that are consistent with the outer peripheral portions of the rear casing 2, the fixed scroll 14, and the front casing 4.

  The rotation prevention mechanism 36 is a pin-and-ring mechanism composed of four pairs of pins 40 and a ring 46. The pin 40 is press-fitted and fixed in a press-fitting hole 42 opened in the pedestal surface 4 c of the front casing 4. The ring 46 is press-fitted and fixed in a hole 48 opened in the back surface 16 c of the movable scroll 16. Then, the pin 40 is loosely fitted in the hole 48 and is slid on the inner peripheral surface of the ring 46, thereby preventing the movable scroll 16 from rotating while allowing the movable scroll 16 to revolve around the fixed scroll 14.

The recess 44 is formed on the outer peripheral side of the rotation prevention mechanism 36, specifically, on the outer peripheral side of the press-fit hole 42 of the pin 40. In this embodiment, the wall surface of the end wall 4 b of the front casing 4 is the inner peripheral surface of the recess 44. Is part of.
As described above, in the present embodiment, the pedestal surface 4c of the pedestal portion 4a of the front casing 4 is formed with the recess 44 that is located in the vicinity of the fastening surface 4d of the bolt 17 of the end wall 4b of the front casing 4 and is recessed in the thrust direction. Is done.

  Thereby, the recessed part 44 can be functioned as a relief area of the bending in the thrust direction of the compressor 1. Therefore, the stress concentration on the front casing 4 due to the deflection in the thrust direction of the compressor 1, the resulting decrease in the durability of the front casing 4, the deterioration of the sealing performance in the movable scroll 16, the decrease in volume efficiency, the increase in frictional resistance, In addition, it is possible to prevent the increase in noise and the temperature of the working fluid, and consequently the increase in power consumption of the compressor 1, and to realize a highly reliable and highly efficient compressor 1.

  Moreover, the shape of the recessed part 44 is not restricted to planar view substantially elliptical shape as shown in FIG. 2, and the recessed direction of the recessed part 44 is not restricted to the base surface 4c side. That is, a depth that allows bending in at least one of the movable scroll 16, the pedestal portion 4a, the thrust plate 34, and the front casing 4 due to the load in the thrust direction and the tightening force of the bolt 17 described above. As long as it has a size, size, and shape, it is possible to more reliably prevent the above-described adverse effects caused by the deflection of the compressor 1 in the thrust direction.

  Further, when the compressor 1 includes the rotation prevention mechanism 36 as in the present embodiment, in the thrust receiving portion including the pedestal surface 4c and the sliding surface 34a, between the rotation prevention mechanism 36 and the fastening surface 4d of the bolt 17. It has been found that the deflection in the thrust direction is increased. Therefore, by providing the recess 44 on the outer peripheral side of the rotation prevention mechanism 36, each of the above-described adverse effects caused by the deflection of the compressor 1 in the thrust direction can be more effectively prevented.

  Further, as in this embodiment, when the bolt 17 is a through bolt that fastens the outer peripheral portions of the rear casing 2, the fixed scroll 14, and the front casing 4 through a consistent bolt hole 38, one bolt is used. The number of members fastened by one bolt 17 is larger than when only the front casing 4 and the fixed scroll 14 are fastened (see FIG. 4). When the number of members fastened by one bolt 17 is increased, there is a risk that the deflection of the compressor 1 in the thrust direction increases accordingly. Therefore, when the bolt 17 is a through-bolt that fastens the three members, the above-described adverse effects caused by the deflection of the compressor 1 in the thrust direction can be more effectively prevented.

  However, as shown in FIG. 4, the bolt hole 38 is consistent only in the outer peripheral portion of the front casing 4 and a part of the outer peripheral portion of the fixed scroll 14, and the bolt 17 is inserted into the bolt hole 38 and fixed to the front casing 4. The scroll 14 may be fastened. In this case, a consistent bolt hole 50 is formed only in the outer peripheral portion of the rear casing 2 and a part of the outer peripheral portion of the fixed scroll 14, and a bolt 52 different from the bolt 17 is inserted into the bolt hole 50 to insert the rear casing. 2 and the fixed scroll 14 are fastened separately. Even in this case, as long as the bolt 17 is inserted to fasten the front casing 4 and the fixed scroll 14 and a plurality of members serving as thrust receiving portions are overlapped and bolted together, the compressor 1 in the thrust direction Since there exists a possibility that bending may generate | occur | produce, each evil mentioned above resulting from the bending in the thrust direction of the compressor 1 can be prevented reliably.

  In the present embodiment, the number of the recesses 44 is four, which is the same as the bolt 17, that is, the bolt hole 38. However, depending on the occurrence of bending in the thrust direction of any one of the movable scroll 16, the pedestal 4 a, the thrust plate 34, and the front casing 4, the number of the recesses 44 may be less than the number of the bolt holes 38. There may be cases where the deflection in the thrust direction is sufficiently acceptable.

The present invention is not limited to the above embodiment, and various modifications are possible.
For example, as shown in FIG. 5, a recess 54 that is recessed in the thrust direction is formed on the back surface 34b of the thrust plate 34 that is the surface opposite to the sliding surface 34a of the thrust plate (thrust receiving portion) 34. good. The recess 54 is recessed in the thrust direction that is recessed toward the sliding surface 34a, and is on the outer peripheral side of the press-fitting hole 42 of the pin 40 of the rotation prevention mechanism 36, and in the vicinity of the end wall 4b of the front casing 4, that is, the sliding surface 34a. It is positioned near the outer periphery of.

  The thrust plate 34 and its rear surface 34b are also one of the thrust receiving portions of the compressor 1, and the concave portion 54 functions as a deflection escape region in the thrust direction. The recess 54 may be formed so that the thrust plate 34 is recessed in the thrust direction in the vicinity of the end wall 4b in a region where the sliding of the back surface 16c of the movable scroll 16 with respect to the sliding surface 34a of the thrust plate 34 is not hindered. . Specifically, the recess 54 may be formed in addition to the back surface 34b of the thrust plate 34 as long as it is a portion excluding the sliding surface 34a and receiving a load in the thrust direction.

  Moreover, in the said embodiment and modification, the case where the compressor 1 was provided with both the thrust plate 34 and the rotation prevention mechanism 36 was demonstrated. However, even if the compressor does not include the thrust plate 34, it is possible to secure a relief area for the deflection in the thrust direction generated in the compressor by forming the recess 44 in FIG. Further, the present invention can be applied even to a compressor that does not include the rotation prevention mechanism 36.

  Moreover, in the said embodiment and modification, the engine-driven scroll compressor 1 incorporated in the vehicle air conditioner was demonstrated. However, the present invention can be applied to scroll-type fluid machines in general such as electric motor-driven scroll compressors and compressors or expanders in various fields using various working fluids.

1 Scroll type fluid machine (scroll compressor)
2 Rear casing 4 Front casing (casing)
4a Pedestal part (thrust receiving part)
4b End wall (bolt fastening part)
4c Pedestal surface 14 Fixed scroll 14a Substrate 14b Swirl wall 14d Back surface 16 Movable scroll 16a Substrate (thrust receiving portion)
16b Spiral wall 16c Back 17 Bolt 34 Thrust plate (Thrust receiving part)
34a Sliding surface 34b Back surface (surface opposite to sliding surface)
36 Rotation prevention mechanism 38 Bolt hole 44 Recess 54 Recess

Claims (8)

A thrust receiving portion that receives a load in a thrust direction by revolving and turning the movable scroll with respect to the fixed scroll;
A casing having a bolt fastening portion disposed on an outer peripheral side of the thrust receiving portion, and fastened to the fixed scroll at the bolt fastening portion by a bolt extending in the thrust direction;
A scroll type fluid machine comprising: a recess formed in the thrust receiving portion, positioned near the bolt fastening portion, and recessed in the thrust direction.   The concave portion has a depth that allows bending in the thrust direction of at least one of the movable scroll, the thrust receiving portion, and the casing due to the load in the thrust direction and the tightening force of the bolt. The scroll type fluid machine according to claim 1, having a size and a shape. A rotation preventing mechanism that is disposed between the thrust receiving portion and the movable scroll and that allows the orbiting of the movable scroll while preventing rotation of the movable scroll;
The scroll fluid machine according to claim 2, wherein the recess is formed on an outer peripheral side of the rotation prevention mechanism. The casing is a front casing that sandwiches the fixed scroll together with a rear casing disposed on the back side of the substrate on which the spiral wall of the fixed scroll is erected,
4. The scroll fluid machine according to claim 2, wherein the bolt is fastened through a consistent bolt hole on the outer periphery of each of the rear casing, the fixed scroll, and the front casing. A thrust plate disposed between a back surface of the substrate on which the spiral wall of the movable scroll is erected and the casing;
The scroll type fluid machine according to any one of claims 2 to 4, wherein the thrust plate has an annular belt-like sliding surface on which the back surface of the movable scroll is slid as the movable scroll revolves. . The casing has an annular belt-shaped pedestal surface disposed on the back side of the substrate on which the spiral wall of the movable scroll is erected,
The scroll fluid machine according to any one of claims 2 to 5, wherein the recess is formed in the pedestal surface.   The scroll type fluid machine according to claim 5, wherein the recess is formed on a surface of the thrust plate opposite to the sliding surface. A plurality of the bolts are provided,
The scroll type fluid machine according to any one of claims 1 to 7, wherein the number of the recesses is equal to or less than the number of the bolts.

Images