JPH0253638B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a scroll compressor that uses a combination of a fixed scroll and an oscillating scroll. [Prior Art] Prior to a detailed explanation of the present invention, the structure and operation of a scroll compressor using a scroll formed by connecting semicircular arcs will be briefly described. FIG. 1 shows a scroll formed by sequentially connecting semicircular arcs. That is, in FIG. 1, the scroll 1 draws a semicircle with radius (a-t)/2 and (a+t)/2 centering on point O, and then draws a semicircle a/2 apart from point O. point
Radius (2a−
Draw each semicircle of t)/2 and (2a+t)/2,
Thereafter, this process is repeated, and in the example shown in FIG. 1, four semicircular arc groups of basic pitch a and tooth thickness t are successively connected in a scroll shape. Hereinafter, such a configuration will be referred to as a two-turn scroll.
Note that the end of the smallest semicircular arc of this scroll 1 is placed in a semicircular arc whose diameter is the tooth thickness t. Further, FIG. 2 shows the principle of operation of a scroll compressor constructed by combining one set of scrolls shown in FIG. 1, and in this FIG. 2, 2 is a fixed scroll; 3 is an oscillating scroll that is symmetrically combined with the fixed scroll 2 . Here, the fixed scroll 2 is stationary and fixed at the arrangement position, and its center O ₁ corresponding to the point O is immovable. Due to the mating arrangement, compression chambers 4 and 5 are formed between the fixed scroll 2 and the closed circular arc spaces. Then, the center O ₂ corresponding to the point O' of the oscillating scroll 3 is moved around the stationary point A corresponding to the point O ' of the stationary scroll ₂ .
-A is held at a distance of a/2-t and rotated, that is, oscillated or revolved without changing its attitude, the angles of 0°, 90°, 180°, and 270° are shown in Fig. 2. As shown at each corner position, the compression chambers 4, 5
Once opened at the outer periphery, the volume gradually decreases toward the center, and if the object to be compressed is fluid, the fluid can be taken out from the discharge port 31 shown by the dotted line. During this operation, the center point B of the outer end of the scroll of the oscillating scroll 3 moves around the fixed point C on the line D-D' connecting the fixed point A and the center _O1 of the fixed scroll 2 . , will perform a circular motion of radius a/2-t. In this way, a compressor can be constructed by symmetrically combining one set of scrolls. By the way, as this type of scroll compressor, U.S. Patent No. 4,065,279 is known, and according to this, a fixed scroll, an oscillating scroll,
The compression part formed by the main body is placed at the top and the motor is placed at the bottom, and these are housed in a sealed shell. Suction gas is introduced from the outside into the space inside the sealed shell, cools the motor, and then compresses the part. After being sucked into and compressed by the fixed scroll, it is discharged to the outside from a discharge port provided in the center of the fixed scroll through a discharge pipe connected to the sealed shell. A so-called low pressure shell type scroll compressor is described. Further, the crankshaft is supported perpendicularly to the main body, is connected to an oscillating scroll at its upper end, and has a motor/rotor as a rotational drive source attached to its lower end, sandwiching the support by the main body. In order to prevent the crankshaft from falling off due to the weight of the crankshaft and the motor rotor, a flange is formed on the upper end of the crankshaft and is supported on the upper end surface of the crankshaft support portion of the main body. By the way, in the case of a low-pressure shell type, the crankshaft only needs to support the weight of the crankshaft and the motor/rotor as described above, but the intake gas is directly sucked into the compression part from the outside, and after being compressed, it is discharged from the space inside the sealed shell. The motor is filled with gas, cooled by the discharged gas, and then discharged to the outside via the discharge pipe. When configured as a so-called high-pressure shell type, the crankshaft has a structure unique to scroll compressors in that it does not penetrate through the compression section, so the lower end of the crankshaft exposed to the high-pressure sealed shell internal space,
A fairly large pressure difference is generated between the oscillating scroll and the upper end of the crankshaft connected to it, and this differential pressure pushes the upper end of the crankshaft toward the oscillating scroll, causing a gap between the upper end of the crankshaft and the oscillating scroll base plate. Since a large thrust is generated between the two, there are problems such as a large frictional force being applied between the two, which may cause wear. [Summary of the Invention] A scroll compressor according to the present invention includes a main body that is installed in a closed shell and has a stepped portion formed by a large-diameter hole at the upper end thereof, through which a shaft hole penetrates upward and downward, and a periphery of the large-diameter hole of the main body. a base plate supported by;
an oscillating scroll having a shaft projecting downward from the base plate and scroll-shaped teeth; a scroll that is combined with the teeth of the oscillating scroll to form a compression chamber for discharging high-pressure gas into the space within the shell; A fixed scroll having shaped teeth, a flange formed at an upper end that is rotatably inserted into the shaft hole of the main body and coupled to the shaft of the oscillating scroll, is connected to the base plate through a first gap. A crankshaft supported by the stepped portion and whose lower end is immersed in lubricating oil stored in an oil reservoir at the bottom of the shell; The upper end communicates with the first gap through the joint, and the lower end opens into the lubricating oil, and supplies lubricating oil by the pressure difference between the pressure inside the shell 42 and the pressure acting on the lubricating oil. a rotor fitted to the lower end of the crankshaft, and supplies lubricating oil to the first gap between the base plate of the oscillating scroll and the flange formed at the upper end of the crankshaft. However, this lubricating oil film supports the thrust force acting between the upper end of the crankshaft and the oscillating scroll base plate, thereby reducing the large frictional force exerted between the two and preventing wear. [Embodiments of the Invention] Examples of the scroll compressor of the present invention will be described. 3 to 6 show an embodiment of the above-described swinging scroll 3 , and FIGS. 7 and 8 show an embodiment of the support and swing mechanism for the swinging scroll 3 . It shows. In FIGS. 3 to 6, the swinging scroll 3 has swinging scroll teeth 6, a swinging scroll base plate 7 with the swinging scroll teeth 6 protruding from one surface, and a swinging scroll base plate 7 having the swinging scroll teeth 6 protruding from one surface. an oscillating scroll shaft 8 extending on one surface; oscillating guide recesses 9 similarly formed on the other surface at equal angular intervals on a concentric circle;
It consists of an oscillating scroll balancer 10,
The reference numeral 11 is a virtual extension line of the inner surface of the swinging scroll tooth 6. In addition, in FIGS. 7 and 8, each guide pin 12 having a smaller diameter shaft end loosely fitted into the swing guide recess 9 of the swing side scroll 3 is connected to a flange portion of the main body 13 . The thrust bearing surface 15 at the tip of the guide pin hole 14 is supported by each guide pin hole 14 formed in the guide pin hole 13a corresponding to each of the recesses 9.
The oscillating scroll base plate 7 is in contact with the main body 1
The oscillating scroll shaft is pivotally supported in an eccentric hole 18 of a crankshaft 17, which is rotatably supported in a shaft hole 16 bored in the central protrusion 13b on both sides thereof. Therefore, when the crankshaft rotates, a sliding surface 24 is formed between the inner peripheral surface of the shaft hole 16 and the outer peripheral surface of the crankshaft 17. 19 is the crankshaft 17
An oil hole (oil passage) that communicates one end of the eccentric hole 18 with the eccentric hole 18 through the center point J of
The projecting portions 13b are bored at the end thereof so as to be spaced apart from each other in the axial direction. 22 is an oil groove provided on the thrust bearing surface 15, and 23 is an oil groove provided on the inner surface of the eccentric hole 18. Therefore, according to the embodiments shown in FIGS. 3 to 8, the swing scroll shaft 8 of the swing scroll shaft 8 is connected to the eccentric hole 18 of the crankshaft 17 , and each swing guide recess 9 is connected to each guide pin 12. As the crankshaft 17 rotates from 0° → 90° → 180° → 270° as shown in FIG. 9, the oscillating scroll 3 rotates as shown in FIG. Then, the relative position remains the same and the swing is performed. However, when the lever swings, the distance between the center J of the crankshaft 17 and the center K of the swinging scroll shaft 8 needs to be maintained at a/2-t as explained in FIG. In order to make it happen, the 9th
As shown in the figure, if the diameter of the guide pin 12 is b, then the diameter of the swing guide recess 9 must be a+b-2t. Furthermore, in FIGS. 3 and 5, E~
E', F~F' and G~G' are each the base line, K is the center of the oscillating scroll shaft, h is the oscillating scroll tooth height, I
is the center of gravity of the oscillating scroll tooth portion when there is no balancer. That is, in this way, a desired swing trajectory can be constructed by at least three swing guide recesses 9 and each guide pin 12 that is loosely engaged with the swing guide recesses 9. Now, regarding the balancing of the swinging scroll 3 according to the configurations of the embodiments shown in FIGS. 3 to 6, as is clear from the drawings, the center of gravity of only the swinging scroll teeth 6 is located at the base line G~ It will be located near point (I) on G'. This is due to the fact that the shape of the scroll teeth is not symmetrical.
If this swing-side scroll 3 is to be caused to swing as described above without the balancer 10, the crankshaft 1 shown in FIGS. 7 and 8 will be
Instead of being rotated at a fixed eccentric position around the center J of 7, it performs an eccentric rotational movement around another center, and this is because the swinging side scroll 3 performs a swinging motion. Therefore, it is very difficult to achieve balance in such a case. For this purpose, the embodiment is provided with a halter 10,
The center of gravity of these scroll teeth 6 and the balancer 10 is made to coincide with the center K of the oscillating scroll shaft, and in order not to impede the operation, it is placed outside the virtual extension line 11, It is sufficient to select a shape that has the same height as the scroll tooth height h and the center of gravity in the height direction, and also selects its mass, so that the entire center of gravity of the swinging scroll 3 is equal to K. and the center of the crankshaft J
It is possible to perform balanced eccentric rotation around the . The details of the crankshaft 17 are as follows.
As shown in the figures through FIG. 12, the base end side of the shaft portion becomes a motor mounting portion 26 by stepping. That is, this attachment part 26 has a 17th
As shown in the figure, a portion of the upper end surface of the rotor 37 is attached to the stepped portion. Therefore, a second gap is formed between the upper end surface of the rotor 37 and the lower end surface of the main body protrusion 13b, which is longer in the axial direction than the first gap described later. Further, an oil groove 27 is formed on the outer periphery of the shaft portion of the crankshaft 17, and a flange portion 28 at the tip end of the shaft is formed in the shaft hole 16.
Prevents it from falling off. That is, Fig. 7,
As shown in FIGS. 15 and 17, a stepped portion 13c is provided on the swinging scroll 3 side of the main body 13 by a large diameter hole connected to the shaft hole 16. By providing this step 13c, the swinging scroll 3 is A space 25 is formed between the bottom surface of the base plate 7 and the crankshaft 1.
The lower surface of the flange 28 is disposed on the step 13c with a first gap 25a in between so that the flange 28 of No. 7 can move in the axial direction within the space 25. Therefore, when the crankshaft rotates, the lower surface of the flange 28 and the step 13
A sliding surface 28a is formed between the sliding surface 28c and the sliding surface 28a. Next, an embodiment of the fixed scroll 2 combined with the swinging scroll 3 is shown in FIGS. 13 and 14, and the position and size of its discharge port will be described in particular. In these FIGS. 13 and 14, the fixed scroll 2 has fixed scroll teeth 29,
This fixed scroll tooth 29 is made up of a fixed scroll base plate 30 which is protruded from one surface corresponding to the oscillating scroll tooth 6, and is located at the following positions:
A discharge port 31 having a certain shape and size is formed. Here, the fixed scroll teeth 29 have a tooth height h equal to that of the oscillating scroll teeth 6, and the discharge port 31 is eccentric from the center point by a distance c and has a diameter d. In this configuration of the fixed scroll 2 , as is clear from FIG. 2, the diameter d of the discharge port 31 is made smaller than at least the scroll tooth thickness t, and is large enough to seal the discharged fluid. In order to completely discharge the fluid in the compression chamber 4 (FIG. 2), its center must be on the base line N to N', and the point p on the inner circumference must be in contact with the innermost edge of the fixed scroll tooth 29. In other words, the requirements for the specifications of the discharge port 31 are as follows:
It is eccentric by (a/2-t≦c<a-t/2), and its center is on the base line N~N' that connects the center of the base plate and the innermost edge of the scroll tooth, and the point p on the inner circumference of the opening is It occupies a position adjacent to the innermost edge of the scroll teeth, and
It is nothing but a circular shape with a diameter d (d=a-t-2c or 0<d≦t). One embodiment of a scroll compression mechanism formed by assembling each of the above-mentioned components is shown in FIGS. 15 and 1.
As shown in FIG. 6, a cylinder 32 is disposed on the outer edge of the flange of the main body 13 , a suction port 33 is formed in the cylinder 32 to communicate with a suction space 34, and the fixed scroll 2 is aligned with the cylinder 32 . They are connected by bolts 36 through bolt holes 35, and this cylinder 32 also plays the role of adjusting and setting the axial height and clearance between the fixed and swinging scrolls 2 and 3 . P-P′,
Q-Q' is the baseline. Further, FIG. 17 shows a scroll compressor of a closed type in which an electric motor is incorporated into the scroll compression mechanism constructed in this manner. FIG. 17 shows a scroll compressor according to an embodiment of the so-called high-pressure shell type in which the inside of the closed shell is maintained at the discharge side pressure.
In FIG. 7, the rotor 37 constituting the electric motor has an end ring 38 and a balance weight 39, as is clear from FIG. The above-mentioned scroll compression mechanism is attached to the mounting flange 43 provided around the upper inner side of the shell 42, which forms an induction motor and seals the whole, with its bolt 36, and the suction introduced through the shell 42. A pipe 44 is connected to the suction port 33, and a discharge pipe 45 is taken out from the shell 42. Furthermore, a communication port 46 is formed in the mounting flange 43 to communicate the inner spaces 47a and 47b of the shell. Lubricating oil 48 is stored in the oil reservoir. The lead wire 49 of the stator 40 is connected to a hermetic terminal 50.
This stator 40 is taken out to the outside of the shell through
is fixed to the inner surface of the shell 42 through a gap 51, and a mounting hole 53 in the center of the rotor 37 is connected to the crankshaft 17 so that the rotor 37 is opposed to the stator 40 with an air gap 52 interposed therebetween. It is fixed to the mounting portion 26 by, for example, shrink fitting. Therefore, in the embodiment shown in FIG. 17, when the crankshaft 17 is rotationally driven by energizing the electric motor, the shaft 8 rotatably fitted in the eccentric hole 18 causes the crankshaft 17 to rotate.
The oscillating scroll 3 is guided by the guide pin 12 whose recess 9 is loosely engaged, and performs the oscillating movement shown in FIG.
4 is sucked in, compressed in the compression chambers 4 and 5, and discharged from the discharge port 31 into the shell internal space 47a, and can be led out through the discharge pipe 45. However, during the compression operation of the lever, the shell internal space 47b
The discharge gas flows through the communication port 46 to create a high-pressure atmosphere with a discharge pressure. Therefore, the shell internal space 47
Due to the discharge pressure acting on b, the lubricating oil 48 stored in the oil reservoir at the inner bottom of the shell is discharged from each oil hole 19, 20, 21 and oil groove 22, 23, 27 as shown by the single line arrow. It is supplied to each lubricating part, reducing loss due to wear on sliding surfaces. That is,
The oscillating scroll shaft 8 and the eccentric hole 1 are connected through the oil hole 19.
The lubricating oil that has reached the connection part with 8 and the lubricating oil that has reached the oil holes 20 and 21 from the oil hole 19 is transferred to the oil hole 23 and the eccentric hole 18 of the swinging scroll shaft 8 and the crankshaft 17.
Oil groove 27 to the sliding surface and first gap 25a
and the inner peripheral surface of the shaft hole 16 of the main body 13 and the crankshaft 1
7 and the sliding surface 28a between the lower surface of the collar 28 and the step 13c, the pressure is reduced and the pressure in the space 25 becomes lower than the discharge gas pressure. The lubricating oil flows due to the differential pressure. Furthermore, the lubricating oil that has reached the space 25 is squeezed by the oil groove 22 and the thrust bearing surface 7, and reaches the suction space where the pressure is lowest with some pressure loss. In addition, the above-mentioned differential pressure and oil hole 2 are connected to the sliding surface 24.
The lubricating oil is supplied by the centrifugal force acting on the lubricating oil in the oil holes 20 and 21, and the lubricating oil is sufficiently supplied to the sliding surface 24 between the oil holes 20 and 21. Therefore, the oil holes 20, 21
The sliding surface 24 between them is filled with lubricating oil to form an oil seal film, and even if the high-pressure gas in the shell inner space 47b attempts to enter through the gap in the sliding surface 24 on the end side of the protrusion 13b, it is blocked. On the other hand, when the crankshaft 17 is started, the discharge gas pressure from the compression chambers 4 and 5 is low, so the pressure acting on the lubricating oil in the oil reservoir is small, and the flange 28 is located on the sliding surface 28a. Rotate. As the discharge pressure increases, the pressure acting on the lubricating oil also increases, and the crankshaft 17 is lifted upward, causing the flange 2
The upper surface of the rocking scroll rotates with its upper surface in contact with the lower surface of the base plate 7 and receives thrust force, but as mentioned above, the differential pressure forces the first gap 25
Lubricating oil is supplied to part a to provide a lubricating effect. At this time, the first gap 25a is the second gap 3 mentioned above.
Since the rotor 3 is formed smaller than 7a,
The upper end surface of the rotor 37 does not come into contact with the lower end surface of the protrusion 13b, and the rotor 37 is smoothly driven to operate the compressor. The lubricating oil is then discharged into the shell inner space 47a together with the intake gas forming a seal between the fixed and swinging scroll teeth 29 and 6, separated from the compressed gas, and returned to the shell inner bottom again. That is, in this way, oil lubrication, oil sealing, and oil separation effects are performed by pumping using differential pressure. In particular, during compression operation, a thrust load is generated on the swinging scroll 3 between its base plate 7 and the thrust bearing surface 15 of the main body 13 due to the compression action in the compression chambers 4 and 5. The load can be reduced by applying oil pressure to the groove 22. The balance weight 39 balances the swinging scroll 3 that performs an eccentric movement around the rotation center J of the crankshaft 17. As shown in Fig. 19, for pumping, in addition to oil supply using the differential pressure, a screw 55 is inserted into the oil hole 19 at the center of the crank, and the pumping action accompanying the rotation of the shaft lubricates the oil. Oil may be supplied; in this case, the 17th
It is possible to obtain exactly the same effect as in the embodiment shown in the figure. [Effects of the Invention] As described above, the scroll compressor of the present invention has a main body that is installed in a hermetic shell and has a stepped portion formed by a large-diameter hole at the upper end thereof, through which the shaft hole passes upward and downward; an oscillating scroll having a base plate supported by the peripheral edge of the diameter hole, a shaft projecting downward from the base plate, and scroll-shaped teeth; a fixed scroll having scroll-shaped teeth forming a compression chamber for discharging high-pressure gas; a flange formed at an upper end portion rotatably inserted into the shaft hole of the main body and coupled to the shaft of the oscillating scroll; a crankshaft whose portion is supported by the stepped portion through a first gap between the base plate and the crankshaft, and whose lower end is immersed in lubricating oil stored in an oil reservoir at the bottom of the shell; The upper end portion communicates with the first gap through a joint between the shaft of the oscillating scroll and the crankshaft, and the lower end portion is formed to open into the lubricating oil and acts on the lubricating oil. An oil passage that supplies lubricating oil based on the pressure difference with the pressure inside the shell, and a rotor fitted to the lower end of the crankshaft, are formed on the base plate of the oscillating scroll and the upper end of the crankshaft. 1st between Tsubabe
The oil film of lubricating oil supplied to the gap supports the thrust force unique to high-pressure shell types that acts between the upper end of the crankshaft and the oscillating scroll base plate, so the upper end of the crankshaft and the oscillating scroll base plate This has the effect of reducing the frictional force between the parts and preventing wear.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of a scroll formed by sequentially connecting semicircular arcs with different radii in a scroll shape, Fig. 2 is an operational diagram of a scroll compression mechanism constructed by mutually combining a set of scrolls as described above, and Fig. 3 and Fig. 4 are plan and bottom views of the swinging side scroll, Figs. 5 and 6 are Fig. 3 E-E' and F-H-
Each sectional view of the G' section, FIG. 7 is a longitudinally sectional front view of the main parts showing the support and swing mechanism of the swinging side scroll, FIG. 8 is a plan view of the same supporting part, and FIG. 9 is the swing mechanism. 10, 11 and 1
Figure 2 is a side cross-sectional view and an end view of the crankshaft.
Figure 3 is a plan view of the fixed side scroll, Figure 14 is a cross-sectional view of the section N-N' in Figure 13, Figure 15 and Figure 1.
Fig. 6 is a side cross-sectional view and a plane cross-sectional view of the P-P' and Q-Q' portions of an embodiment of the scroll compression mechanism, and Fig. 17 is a longitudinal cross-sectional view of the scroll compressor of an embodiment of the high-pressure shell type. FIG. 18 is a perspective view showing the motor rotor combined with the crankshaft, and FIG. 19 is a partial sectional view illustrating the oil supply system using a screw. 1 ... Scroll, 2 and 3 ... Fixed side and swinging side scroll, 4, 5... Compression chamber, 6... Rocking scroll tooth, 7... Rocking scroll base plate, 8... Rocking scroll shaft, 13... Main body, 13a ...flange part,
13b...Protrusion, 13c...Step, 15...Thrust bearing surface, 16...Shaft hole, 17 ...Crankshaft, 18...
Eccentric hole, 19... oil hole (oil path), 20, 21... oil hole,
22, 23, 27...Oil groove, 24...Sliding surface, 25...
Space, 25a...first gap, 26...motor attachment part, 28...flange part, 28a...sliding surface, 29...fixed scroll tooth, 30...fixed scroll base plate, 31...
Discharge port, 32...Cylinder, 33...Suction port, 34...
Suction space, 37... Rotor, 40... Stator, 42
...Shell, 43...Mounting flange, 44...Suction pipe, 45...Discharge pipe, 46...Communication port, 47a, 47
b... Shell inner space, 48... Lubricating oil.

Claims (1)

[Claims] 1. The shaft hole 16 is installed in the sealed shell 42 and has a stepped portion 13c formed by a large diameter hole at the upper end.
A main body 13 penetrating downward, a base plate 7 supported by the peripheral edge of the large diameter hole of this main body 13, and a shaft 8 projecting downward from this base plate 7.
an oscillating scroll 3 having a scroll-shaped tooth 6; A fixed scroll 2 having teeth 29 is rotatably inserted into the shaft hole 16 of the main body 13, and a flange 28 formed at the upper end to be coupled to the shaft 8 of the oscillating scroll 3 is connected to the base plate 7. The crankshaft 17 is supported by the stepped portion 13c through the first gap 25a and has its lower end immersed in the lubricating oil 48 stored in the oil reservoir at the bottom of the shell 42; The upper end portion communicates with the first gap 25a through a joint between the shaft 8 of the oscillating scroll 3 and the crankshaft 17, and the lower end portion opens into the lubricating oil 48. Shell 42 acting on lubricating oil 48
an oil passage 19 that supplies lubricating oil based on the pressure difference with the internal pressure;
A scroll compressor comprising a rotor 37 fitted to the lower end of the crankshaft 17.