JPH0112951B2 - - 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.
In particular, it relates to improvements in high-pressure shell type scroll compressors. [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 combined arrangement, there is a space between the fixed scroll 2 and the
Compression chambers 4 and 5 consisting of closed circular arc spaces
is formed. 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 .
If the distance of -A is maintained at a/2-t and the position is rotated, that is, oscillated or revolved, 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 swinging scroll 3 is located around the fixed point C on the line D-D' connecting the fixed point A and the center _O1 of the fixed scroll 2 . , a circular motion of radius a/2-t is performed. In this way, a compressor can be constructed by symmetrically combining one set of scrolls. By the way, this type of scroll compressor is known as U.S. Pat. No. 4,065,279, which describes a scroll compressor in which the compression section is driven by an electric motor via the main shaft, and the compression section is placed in the upper part. , the motor is placed at the bottom, these are housed in a sealed shell, suction gas is introduced from the outside into the space inside the sealed shell, and after the motor is cooled, it is sucked into the compression part and compressed in the compression part, and then the gas is passed through the compression part discharge port. It is discharged from a discharge pipe connected to the sealed shell.
A so-called low pressure shul type refrigerant compressor is described. In addition, the lower end of the main shaft is immersed in oil stored at the bottom of the shell, and each sliding part is supplied with oil through an oil supply hole eccentrically provided in the main shaft in the axial direction.
The shaft rotates, resulting in a centrifugal pump action. However, since the upper end of the oil supply hole opens into the oscillating scroll joint, it is not possible to secure an effective gas venting passage, which tends to cause a delay in oil supply at startup, resulting in a problem of reduced bearing reliability. . Furthermore, in the case of centrifugal pump oil supply, the amount of oil supplied decreases as the rotation speed of the shaft decreases, so when controlling the rotation speed, the low speed rotation range is regulated by the diameter of the main shaft. In addition, sufficient lubrication is expected as the thrust bearing that supports the orbiting scroll in the axial direction and the anti-rotation mechanism are supplied only by splashing oil discharged from the joint between the orbiting scroll and the main shaft. Further, since the oil does not actively flow into the compression section, the oil seal is difficult and requires a special sealing device, and the overall structure is complicated. [Summary of the Invention] This invention discharges high-pressure gas discharged from a compression chamber into a shell to create a high-pressure atmosphere inside the shell, and an oil reservoir formed at the bottom of the shell and on the back side of a base plate of an oscillating scroll. In order to eliminate the above-mentioned drawbacks, the compression chamber is configured to supply differential pressure oil to the space between the crankshaft and the oscillating scroll through the joint between the crankshaft and the oscillating scroll, and to supply differential pressure oil from the space to the compression chamber. . [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-mentioned 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 the surface, and 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,
Further, reference numeral 11 is an imaginary extension line of the inner surface of the oscillating scroll tooth 6. In addition, in FIGS. 7 and 8, each guide pin 12 having a shaft end with a smaller diameter 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 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 8 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 crankshaft 1
The oil hole (oil passage) communicates one end of the eccentric hole 18 with the eccentric hole 18 through the center point J of the oil hole 7, and the oil holes 20 and 21 are a plurality of oil holes in the radial direction that communicate the oil hole 19 and the sliding surface 24. , are bored apart from each other in the axial direction on the end side of the protrusion 13b. 22 is the thrust bearing surface 1
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, during this swinging, the distance between the center J of the crankshaft 17 and the center K of the swinging scroll shaft 8 is
It is necessary to hold the guide pin 12 at a/2-t as explained in FIG. 2, and in order to achieve this, as shown in FIG. The diameter of the 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 swinging side scroll 3 is replaced by a balancer 10
If the rocking motion is to be made as described above in a state where there is no This is because the swinging side scroll 3 performs a swinging motion, and in such a case, it is extremely difficult to maintain balance. For this purpose, a balancer 10 is provided in the embodiment,
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 oscillating scroll 3 becomes equal to K. , and can perform balanced eccentric rotation around the center J of the crankshaft. The details of the crankshaft 17 are as follows.
As shown in the figures or FIG. 12, the base end of the shaft is stepped to form a motor mounting part 26, and an oil groove 27 is formed on the outer periphery of the shaft. Falling off from the shaft hole 16 is prevented. Therefore, the flange 28 and the shaft hole 16
Since the crankshaft 17 is rotatable using the joint surface with the flange 28 as a sliding surface, a space 25 is formed around the flange 28 as shown in FIG. 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' connecting 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 as described above. 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 a type of induction motor and which seals the whole body with its bolt 36. 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 driven to rotate by energizing the electric motor,
The oscillating scroll 3 is guided by the guide pin 12 into which the recess 9 is loosely engaged by the shaft 8 rotatably fitted in the eccentric hole 18, thereby performing the oscillating movement shown in FIG. The gas flowing from the suction pipe 44 to the suction space 34 is sucked into the compression chambers 4 and 5.
The compressed air can be compressed and discharged from the discharge port 31 into the shell inner space 47a, and can be led out through the discharge pipe 45. However, during the compression work of the lever, the inner shell 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.
to the sliding surface of the oil groove 27 and the shaft hole 16 of the main body 13.
In the process of reaching the sliding surface between the outer periphery of the crankshaft 17, the pressure is reduced and the pressure in the space 25 becomes lower than the discharge gas pressure, so the lubricating oil flows due to the differential pressure. Furthermore, the lubricating oil that has reached the space 25 is
It is constricted 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. 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, the lubricating oil, the oil seal, and the oil separation function are performed by pumping using differential pressure in this manner. 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. [Effects of the Invention] As described above, in this invention, the high-pressure gas discharged from the compression chamber is discharged into the shell to create a high-pressure atmosphere inside the shell, and the lubricating oil in the oil reservoir at the bottom of the shell is transferred to the base of the oscillating scroll. Since differential pressure oil is supplied to the space formed on the back side of the plate through the oil passage and the joint between the crankshaft and the oscillating scroll, there are no dimensional restrictions and the crankshaft diameter can be reduced. At the same time, stable lubrication can be ensured without being affected by the rotation speed. In addition, it lubricates the joint between the crankshaft and the oscillating scroll shaft and provides sufficient lubrication between the base plate and the tip of each tooth and between each tooth, so the sealing effect is enhanced and the machining accuracy is relatively low. The function can be achieved with .

[Brief explanation of drawings]

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 4 is a plan view and a bottom view of the swinging scroll, and FIGS. 5 and 6 are EE' and FH-
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 sectional view and end view of the crankshaft, Figure 13 is a plan view of the stationary scroll, Figure 14 is a sectional view taken along line N-N' in Figure 13, and Figures 15 and 16 are scroll compression. FIG. 17 is a side cross-sectional view and a plane cross-sectional view of the P-P' and Q-Q' portions according to an embodiment of the mechanism; FIG. 17 is a vertical cross-sectional view showing a scroll compressor according to an embodiment of the high-pressure shell type; FIG.
The figure is a perspective view showing an electric motor rotor combined with a crankshaft. 1 ...Scroll, 2 and 3 ...Fixed side and swing side scroll, 4, 5...Compression chamber, 6...
Oscillating scroll tooth, 7...Occillating scroll base plate,
8... Oscillating scroll shaft, 13 ... Main body, 15...
... Thrust bearing surface, 16 ... Shaft hole, 17 ... Crankshaft, 18 ... Eccentric hole, 19 ... Oil hole (oil passage),
20, 21... Oil hole, 22, 23, 27... Oil groove, 25... Space, 28... Flange, 29... Fixed scroll tooth, 30... Fixed scroll base plate, 3
1... 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, 47b...Space inside the shell,
48...Lubricating oil.

Claims (1)

[Claims] 1. A sealed shell 42, a main body 13 which is attached to partition the inside of this shell 42 into upper and lower parts and has a shaft hole 16 that penetrates in the vertical direction, and a main body 13 that is rotatably inserted into the shaft hole 16 of this main body 13. A supported crankshaft 17, an oscillating scroll 3 having a base plate 7 coupled to the upper end of the crankshaft 17 and scroll-shaped teeth 6 and disposed within the shell 42, and the oscillating scroll 3 disposed within the shell 42; A scroll that is combined with a base plate 30 opposite to the base plate 7 of the scroll 3 and the teeth 6 of the oscillating scroll 3 to form compression chambers 4 and 5 whose volumes change while moving in a scroll-like manner with the oscillating motion. a fixed scroll 2 having shaped teeth 29 and disposed within the shell 42; 4
It is located at a higher position than the oil level of 8, and
A communication passage 46 is provided for introducing the high-pressure gas discharged from the compression chambers 4 and 5 into the inner space of the shell 42 above the oil level of the lubricating oil 48. The crankshaft 17 is placed in a space 25 formed on the lower surface side of the base plate 7.
An oil passage 19 is provided, one end of which communicates with the above-mentioned oscillating scroll 3 and the other end of which opens into the lubricating oil 48 in the oil reservoir.
The lubricating oil 5 is communicated with the compression chambers 4 and 5 via a thrust bearing 15 that supports the lower surface of the base plate 7 of the rocking scroll 3 on the main body 13, and is introduced into the oil passage 19 from the other end. 48 is supplied into the space 25 via the coupling part due to a pressure difference with the space 25, and further, the pressure difference is supplied from this space 25 to the compression chambers 4 and 5. scroll compressor.