JPH0114435B2 - - 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 each having a basic pitch a and a 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 the center O1 corresponding to the point O is immovable, and the oscillating scroll 3 _is fixed relative to the fixed scroll 2. 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 fixed 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 without changing the position, 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 compression chamber can be constructed by symmetrically combining a set of scrolls. By the way, this type of scroll compressor is known as U.S. Patent No. 4,065,279, and according to this, the compression section is placed at the top, the motor is placed at the bottom, and these are housed in a sealed shell. Suction gas is introduced from the outside into the shell internal space, and after cooling the motor, it is sucked into the compression section and compressed, and then is passed through the discharge pipe connected to the sealed shell from the discharge port provided in the center of the fixed scroll. It is discharged to the outside. A so-called low pressure shell type scroll compressor is described. In addition, lubricating oil is stored at the bottom of the shell, and the lower end of the main shaft is immersed in this, and after the lubricating oil is supplied to each sliding surface of the upper compression part through the oil supply hole penetrating the main shaft by the action of a centrifugal pump, the oil is applied to the shell by gravity. It flows down to the bottom. In such a configuration, the lubricating oil flowing down flows against the flow of the suction gas, so the lubricating oil mixed in the suction gas is sucked into the compression part, and is discharged out of the compressor together with the gas. There is a problem of running out of lubricating oil. To prevent this, it is necessary to provide oil separation means or to increase the internal space volume of the sealed shell to reduce the flow rate of the intake gas. In addition, the discharge port of the fixed scroll and the upper part of the sealed shell are connected by a discharge pipe, but in this case, if the discharge pipe is fixed to the fixed scroll and the sealed shell respectively, high temperature discharge gas will flow. When the discharge pipe thermally expands and stretches in the axial direction, the fixed scroll deforms in the axial direction, and the tip of each tooth of the fixed and oscillating scroll is pressed against the bottom of the other tooth, potentially causing seizure. be. Furthermore, there is wasted space between the fixed scroll and the upper part of the hermetic shell, which not only increases the axial dimension, but also requires the addition of a discharge muffler outside the compressor to damp the pulsation of the discharged gas. There were other drawbacks. [Summary of the Invention] The present invention divides the inside of the shell into an upper space and a lower space that are both maintained at a high pressure state for supplying lubricating oil, etc., and discharges high pressure gas from a compression chamber into the upper space. Gas and lubricating oil are separated in this space, and the separated lubricating oil is returned to the oil reservoir along the motor stator disposed in the lower space through an oil return hole that communicates the upper and lower spaces. The present invention is designed to eliminate the above-mentioned drawbacks. [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,
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 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, 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 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 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 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' 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 entire body, with bolts 36 via the flange portion 13a of the main body 13. The space inside the shell is divided into an upper space 47a inside the shell and a lower space 47b inside the shell, and a suction pipe 44 introduced through the shell 42 is connected to the suction port 33. A discharge pipe 45 provided at positions radially shifted from each other is taken out, and an oil return hole 46 is formed in the mounting flange 43 to communicate the upper and lower spaces 47a and 47b inside the shell. Lubricating oil 48 is stored in the oil reservoir 42a. The lead wires 49 of the stator 40 are taken out to the outside of the shell via hermetic terminals 50, and the stator 40 is extended between the inner wall surface of the shell 42 and on both sides of the motor stator 40 in the axial direction. A mounting hole 53 in the center of the rotor 37 is connected to the crankshaft 17 so that the rotor 37 is fixed to the stator 40 through a gap 51 formed therein, and the rotor 37 is opposed to the stator 40 via an air gap 52. 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 is rotated.
As a result, the swing-side scroll 3 is guided by the guide pin 12 with its recess 9 loosely engaged, performs the swing movement shown in FIG. 2, and reaches the suction space 34 from the suction pipe 44. Gas is sucked in, compressed in the compression chambers 4 and 5, and discharged from the discharge port 31 into the upper space 47a inside the shell, where it is separated into gas and lubricating oil, and the gas is led out through the discharge pipe 45. However, since the discharge pipe 45 and the discharge port 31 are misaligned, the above-mentioned separation is further promoted. In other words, the volume of the discharged gas discharged from the discharge port 31 rapidly increases in the upper space 47a inside the shell, so that the discharge pulsation is reduced and the flow velocity is lowered.
2. The oil collides with the upper inner wall and changes its direction two or more times, so the oil is separated by these effects. However, during the compression operation of the lever, the lower space 4 inside the shell
7b, the discharge gas flows through the oil return hole 46, creating a high-pressure atmosphere with a discharge pressure. At this time, the separated lubricating oil falls from the oil return hole 46 and passes through the gap 51, cooling the motor stator 40 and moving it to the oil sump 42.
The oil is returned to a. And the shell inner lower space 47
The lubricating oil 48 stored in the oil reservoir 42a at the inner bottom of the shell is caused to flow through the oil holes 19, 20, 21 and the oil grooves 22, 23, 27 as shown by the single line arrow. It is supplied to each lubricating part from the lubrication area, reducing losses due to wear on sliding surfaces. That is, the lubricating oil that has reached the joint between the orbiting scroll shaft 8 and the eccentric hole 18 through the oil hole 19 and the oil hole 1
The lubricating oil that has reached oil holes 20 and 21 from oil hole 2
3 and the sliding surface of the swinging scroll shaft 8 and the eccentric hole 18 of the crankshaft 17, and the oil groove 27 and the sliding surface 24 of the inner circumferential surface of the shaft hole 16 of the main body 13 and the outer circumferential surface of the crankshaft 17. During the process, 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, space 2
The lubricating oil that has reached No. 5 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. The lubricating oil is then supplied to the fixed and swinging scroll teeth 29 along with the suction gas.
The oil is discharged into the upper space 47a within the shell, separated from the high pressure gas as described above, and returned to the oil reservoir 42a at the bottom of the shell. 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 17 of the crankshaft 17. In addition, as shown in FIG. 19, for pumping, the oil hole 19 is located at the center of the shaft, without making the oil hole eccentric.
A screw 55 may be inserted inside the screw 55, and the lubricating oil may be supplied by the pumping action caused by the rotation of the shaft. In this case, it is possible to obtain the same effect as in the embodiment shown in FIG. 17. can. [Effects of the Invention] As described above, in this invention, the inside of the shell is divided into an upper space and a lower space that are both maintained at a high pressure state for supplying lubricating oil, etc., and high pressure gas from the compression chamber is transferred to the upper space. It is discharged and separated into gas and lubricating oil in this space, and the separated lubricating oil is passed through an oil return hole that communicates the upper and lower spaces into the oil reservoir along the motor stator disposed in the lower space. A compact scroll compressor that can separate the high-pressure gas discharged from the compression chamber into gas and lubricating oil using the upper space inside the shell, and attenuate the pulsation of the discharged high-pressure gas. is obtained. In addition, the separated lubricating oil does not flow against the flow of suction gas with a high flow rate as in conventional devices, so it is reliably returned to the oil reservoir.
The problem of oil depletion will be solved. Furthermore, high pressure gas from the compression chamber is discharged into the upper space inside the shell,
The discharge pipe is fixed only to the shell wall so that the gas is sent outside the shell after being separated.
Unlike conventional devices, the fixed scroll does not deform due to thermal expansion, and it is possible to prevent seizure between the fixed and oscillating scrolls.

[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 cross-sectional view and an end view of the crankshaft.
Figure 3 is a plan view of the fixed scroll, Figure 14 is a sectional view taken along line N-N' in Figure 13, Figure 15 and Figure 1.
Fig. 6 is a side sectional view and a plane sectional view of the P-P' and Q-Q' portions of an embodiment of the scroll compression mechanism, and Fig. 17 is a longitudinal 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 part, 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, 28...
Flange portion, 29...Fixed scroll tooth, 30...Fixed scroll base plate, 31...Discharge port, 32...Cylinder, 3
3... Suction port, 34... Suction space, 37... Rotor, 4
0...Stator, 42...Ciel, 42a...Oil sump,
43...Mounting flange, 44...Suction pipe, 45...Discharge pipe, 46...Communication port, 47a, 47b...Upper and lower spaces within the shell, 48...Lubricating oil.

Claims (1)

[Claims] 1. A sealed shell 42, a main body 13 having a shaft hole 16 and an oil return hole 46 which are provided so as to divide the interior of the shell 42 into upper and lower spaces 47a and 47b and which pass through the upper and lower spaces. The crank 17 is rotatably inserted and supported in the shaft hole 16 of the main body 13, the base plate 7 is connected to the upper end of the crankshaft 17, and the scroll teeth 6 are arranged in the space 47a. The oscillating scroll 3 and the base plate 3 facing the oscillating scroll base plate 7 from above.
0 and scroll-shaped teeth 29 that are combined with the teeth 6 of the oscillating scroll 3 and form compression chambers 4 and 5 whose volume changes with oscillating motion, and are disposed in the upper space 47a. A scroll 2, a rotor 37 and a stator 40 that are provided on the crankshaft 17 and shell 42 sides in the lower space 47b and constitute an electric motor, and a lubricating oil 48 that is formed at the bottom of the shell 42 below the electric motor.
and lubricating oil 48 in this oil reservoir.
An oil hole 19 for supplying lubricating oil is formed along the axial direction in the crankshaft 17 whose lower end faces inside, and whose upper end communicates with the joint between the swinging scroll base plate 7 and the crankshaft 17. Upper and lower spaces 47
a, 47b are communicated with each other by an oil return hole 46 and maintained in a high pressure atmosphere by high pressure gas discharged from the compression chambers 4, 5. . A scroll compressor characterized in that the scroll compressor is configured such that oil is returned to the oil sump through an oil sump 51 extending across both sides in the axial direction between the scroll compressor and the oil reservoir.