JPH04365901A - Scroll type fluid machine - Google Patents

Abstract

PURPOSE:To provide a scroll type fluid machine capable of being used in an oil free manner. CONSTITUTION:A plural number of cams 19 provided with axes 19a, 19b which have specified eccentric quantities arranged between an oscillating scroll 2 and a housing 13, and the axis 19a is supported by a bearing 20 provided at the oscillating scroll 2, and then the axis 19b is supported by a bearing 21 provided at the housing 13. Consequently, since an autorotation preventing mechanism of the oscillating scroll is composed of the cams and the bearings, oscillation resistance, heat generation, abrasion and seizure, etc., are decreased, so that usage in an oil free state can be achieved.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll-type fluid machine used, for example, in compressors for refrigeration or air conditioning, pump blowers for industrial use, and the like.

0002

2. Description of the Related Art FIG. 9 is a cross-sectional side view showing a conventional general scroll-type fluid machine disclosed in, for example, Japanese Patent Application Laid-Open No. 64-77779, and FIG. 10 is a plan cross-sectional view of the main parts showing its operation. be. In FIG. 9, a fixed scroll 1 has a spiral body 1a as shown in FIG. Reference numeral 2 denotes an oscillating scroll, which has a spiral body 2a as shown in FIG. 3 is a compression chamber forming a substantially crescent shape formed by the spiral bodies 1a and 2a, 4 is a discharge port for discharging the fluid compressed in the compression chamber 3, and 5 is a distal end of the spiral bodies 1a and 2a. Provided compression chamber 3
6 is an oscillating scroll shaft, and 7 is an oscillating scroll bearing that supports the oscillating scroll shaft 6.

Reference numeral 8 denotes a crankshaft eccentrically connected to the oscillating scroll shaft 6; 9 a balancer for compensating the balance against the centrifugal force of the oscillating motion due to the eccentricity; 1;
0 is the crank bearing, 11 is the electric motor, 12 is the crankshaft 8
A motor shaft 13 is a housing that houses the entire motor shaft, and the fixed scroll 1, the crank bearing 10, the motor 11, etc. are fixed therein. Reference numeral 14 denotes an Oldham ring that is slidably engaged with the swinging scroll 2 and the housing 13 in directions orthogonal to each other, and is configured to prevent the swinging scroll 2 from rotating on its axis.

Next, the operation will be explained. Electric motor shaft 12
The electric motor 11 is driven with the oscillating scroll shaft 6 eccentrically held on the crankshaft 8 connected to the crankshaft 8 . The swinging scroll 2 has an Oldham ring 1 provided to prevent rotation.
4 allows for rocking motion without rotation. The spiral body 2a of the oscillating scroll 2 and the spiral body 1a of the fixed scroll 1 are eccentrically engaged with each other, and one or more compression chambers 3
form.

As shown in FIG. 10, when the oscillating scroll 2 oscillates in the range of 0° to 360°, the compression chamber 3 formed at the periphery moves toward the center of the spiral bodies 1a, 2a. , thereby compressing the fluid. At this time, in the orbiting scroll 2, a centrifugal force is generated in the radial direction due to the eccentric movement, and a thrust force is generated in the axial direction as a reaction force of the fluid compression force. Note that, as a conventional scroll compressor, there is one disclosed in Japanese Patent Publication No. 1-35195, for example.

The above-mentioned scroll-type fluid machine can achieve higher efficiency and lower noise than other types of fluid machines, such as reciprocating type and rotary type, and is less likely to cause mechanical failure, so it is widely used in air conditioners. It is increasingly being used as a commercial compressor or an industrial pump. Such a scroll-type fluid machine requires a mechanism for preventing rotation of the orbiting scroll 2 by rotation of the driving crankshaft 8, that is, a swing mechanism. As this rotation prevention mechanism, an Oldham ring 14 is generally used as in the conventional example shown in FIG. 9 mentioned above. Further, as another rotation prevention mechanism, a retainer having a plurality of storage holes for storing a plurality of steel balls is provided between the orbiting scroll and the housing. Note that the above-mentioned conventional rotation prevention mechanisms are all used in a wet type in which the intervention of lubricating oil is allowed.

[0007]

[Problems to be Solved by the Invention] Since the conventional scroll type fluid machine is constructed as described above, when the Oldham ring 14 is used as the rotation prevention mechanism of the oscillating scroll 2, the lower surface of the oscillating scroll 2 and housing 13
Since the Oridum ring 14 is connected in a mutually slidable manner, the sliding movement is basically the main movement. Therefore, lubricating oil is essential, and it can be used in an oil-free manner without using lubricating oil. In this case, sliding wear becomes significant, and in the worst case, the Oldham ring 14 may seize and become locked, and there are other problems such as premature wear of parts and noise.

Furthermore, when a retainer containing a plurality of steel balls is used as the rotation prevention mechanism, the retainer operates in the same manner as an axial ball bearing, and the collision of the steel balls within the retainer causes abnormal noise. In addition, since the steel balls are supported by point contact, the surface pressure is high, which tends to cause premature wear and deformation of the parts, making it difficult to use them in an oil-free environment. Ta.

The present invention was made to solve the above-mentioned problems, and its object is to provide a scroll-type fluid machine that can be used completely without oil.

0010

[Means for Solving the Problem] A scroll type fluid machine according to the invention of claim 1 has two shafts at both ends arranged with an eccentricity approximately equal to the swing radius of the swing scroll. This cam is arranged between the swinging scroll and the housing, and the shafts at both ends are supported by bearings provided on the swinging scroll and the housing, respectively.

[0011] In the scroll type fluid machine according to the second aspect of the invention, the outer diameter of the shaft of the cam inserted into the bearing is smaller within a predetermined range than the inner diameter of the bearing provided on the oscillating scroll side.

The scroll type fluid machine according to the third aspect of the present invention uses two bearings provided on the housing side.

[0013]

In the scroll type fluid machine according to the first aspect of the invention, since the cam is provided, rotational movement of the oscillating scroll due to the drive eccentric shaft transmission force is prevented, and only oscillating movement is possible. Additionally, by connecting both shafts of the cam to the oscillating scroll and housing via bearings, the sliding resistance of the oscillating mechanism is small, and wear and noise are prevented, allowing for oil-free use. becomes possible.

[0014] The scroll type fluid machine according to the second aspect of the invention improves the swinging state while suppressing current consumption, absorbs variations in machining accuracy, and improves assemblability.

[0015] In the scroll type fluid machine according to the third aspect of the invention, bearing loss is reduced and smooth operation can be obtained.

[0016]

【Example】

Example 1. An embodiment of the invention according to claims 1 and 2 will be described below with reference to the drawings. In FIGS. 1 and 2, parts substantially equivalent to those in FIG. 9 will be described using the same reference numerals. In Fig. 1, 1 is a fixed scroll that also serves as a part of the housing.
It has a spiral body 1a. Reference numeral 2 denotes an oscillating scroll, which has a spiral body 2a that meshes with the spiral body 1a. 3 is a compression chamber formed by the spiral bodies 1a and 2a, 4 is a discharge port for compressed fluid, 5 is a sealing member, 15 is a valve provided in the discharge port 4, and 16 is a discharge port communicating with the discharge port 4 It's a tube. Figure 1
, In FIG. 2, 6 is an oscillating scroll shaft, 7 is an oscillating scroll bearing, 8 is a crankshaft as a rotating shaft connected eccentrically to the oscillating scroll shaft 6, 9 is a balancer provided on the crankshaft, 17 is a thrust bearing of the swinging scroll shaft 6, 10 and 18 are crank bearings, and 11 is an electric motor that rotationally drives the crankshaft 8, and has an armature 11a. 13 is a housing.

Reference numeral 19 denotes three cams, and as shown in FIG.
19b is integrally provided and is disposed between the swinging scroll 2 and the housing 13 as shown in the figure. Further, the outer diameter of the shaft 19a is D1. Reference numeral 20 designates a bearing having an inner diameter D2 which is provided on the swinging scroll 2 and supports the shaft 19a of the cam 19, and 21 is a bearing provided in the housing 13 and supports the shaft 19b of the cam 19. The cam 19 and bearings 20 and 21 constitute a rotation prevention mechanism for the orbiting scroll 2.

Next, the operation will be explained. In the scroll fluid machine configured as described above, the swinging scroll 2 eccentrically mounted on the balancer 9 is driven by the rotation of the armature 11a, so the swinging scroll 2 has rotational motion and swinging motion. Occur. However, the cam 19 provided between the swinging scroll 2 and the housing 13
This prevents the swinging scroll 2 from rotating and restricts it to perform only swinging motion.

FIG. 4 shows the movement of the swinging scroll 2 through the intervention of a cam. In the figure, when the oscillating scroll 2 indicated by a solid line circle centered at O11 is driven to rotate and rotates to O21, the oscillating scroll 2 indicated by a solid line circle rotates due to the sliding resistance of the oscillating scroll bearing 7. occurs and revolves around the origin 0. However, by interposing the cam 19 whose eccentric radius γ is set equal to the revolution radius of the swinging scroll 2, the centers P11, P21, and P31 of the shaft 19a of the cam 19 on the swinging scroll 2 side swing. Due to the driving force of scroll 2, P1
, P2 and P3 as centers, and P12 and P2, respectively.
2, and revolves up to P32. The center O11 of the oscillating scroll 2 and P11, P21, and P31 regulated by the cam 19 only revolve around the locus of the arrow in the figure, all synchronously.

FIG. 5 shows the shaft 19 inserted into the bearing 20.
It is a graph showing the results of measuring changes in current consumption and changes in vibration level using the outer diameter D1 of a as a parameter. In the figure,
The horizontal axis is from the inner diameter D2 of the bearing 20 to the outer diameter D1 of the shaft 19a.
The solid line a shows the change in current consumption, and the dotted line b shows the change in vibration level. In FIG. 5, the current consumption changes as the clearance of the shaft diameter difference D2 - D1 approaches 0. The direct cause of this is that the positional regulation of the three-point cam 19 becomes stricter. On the other hand, if the shaft diameter 19a is made too small, there is a tendency for the swinging movement of the swinging scroll 2 to become unstable and vibrations to increase. From the above measurement results, 50
It has been found that by making the outer diameter D1 of the shaft 19a smaller than the inner diameter D2 of the bearing 20 by about 100 μm, a balanced operation can be obtained in terms of current consumption, vibration, and ease of assembly.

Example 2. In the first embodiment, ball bearings are used as the bearings 20 and 21 as shown in FIG. 3, but as shown in FIG.
Or sleeve bearings 20, 2 made of tetrafluoroethylene resin, etc.
1 may be used.

Example 3. Further, as shown in FIG. 7, bearings 20 and 21 may be used in which materials 20b and 21b having excellent lubricity, such as tetrafluoroethylene resin, are baked or adhered to the inner surfaces of bushes 20a and 21a.

In the above embodiments 2 and 3, the outer diameter D1 of the shaft 19a is set to 50 to 100 mm with respect to the inner diameter D2 of the bearing 20.
It is set as small as μ. This makes it possible to absorb minute positional deviations due to poor machining accuracy when a plurality of cams 19 are used, and also significantly improves assembly efficiency.

Example 4. FIG. 8 shows an embodiment of the invention according to claim 3, in which two bearings 21 on the side of the housing 13 that support the shaft 19b of the cam 19 are used, and as shown in the figure, the upper and lower
It is arranged in stages. According to the above configuration, the cam 1 is generated by the moment during the swing rotation of the swing scroll 2.
Since the inclination of the shaft 19b of No. 9 is corrected, the rocking motion is performed smoothly and bearing loss can be reduced.

[0025]

[Effect of the invention] As described above, according to the invention of claim 1,
A cam having two shafts at both ends arranged with an eccentricity approximately equal to the swing radius is provided between the swinging scroll and the housing, and each shaft is connected to the swinging scroll by a bearing provided in the swinging scroll and the housing. Since it is configured to be supported, the rotation of the oscillating scroll is effectively prevented and only oscillating motion can be performed, and the noise and wear are low, making it possible to use it in an oil-free environment. can get.

Further, according to the second aspect of the invention, since the outer shape of the shaft on the oscillating scroll side of the cam is made thinner within a predetermined range than the inner diameter of its bearing, good oscillation can be achieved while reducing current consumption. At the same time, positional deviations due to poor machining accuracy are absorbed, and furthermore, the ease of assembly is significantly improved.

Furthermore, according to the third aspect of the invention, since two bearings are provided on the housing side to support the shaft of the cam, bearing loss can be reduced and smooth rocking can be achieved. is obtained.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional side view of a scroll-type fluid machine according to an embodiment of the invention.

FIG. 2 is an exploded perspective view of the same machine.

FIG. 3 is a cross-sectional side view of the main parts of the machine.

FIG. 4 is an explanatory diagram of the operation of the machine.

FIG. 5 is a characteristic diagram based on measurement results of the same machine.

FIG. 6 is a cross-sectional side view of the main parts of a scroll-type fluid machine according to another embodiment of the invention.

FIG. 7 is a cross-sectional side view of a main part of a scroll-type fluid machine according to still another embodiment of the present invention.

FIG. 8 is a cross-sectional side view of a main part of a scroll-type fluid machine according to an embodiment of the invention of claim 3;

FIG. 9 is a cross-sectional side view of a conventional scroll-type fluid machine.

FIG. 10 is a cross-sectional plan view showing the operation of the machine.

[Explanation of symbols]

1 Fixed scroll 1a Spiral body 2. Oscillating scroll 2a Spiral body 3 Compression chamber 4 Discharge port 6. Oscillating scroll axis 8 Crankshaft 13 Housing 19 Cam 19a, 19b axis 20, 21 Bearing

Claims (3)

[Claims] Claim 1: A fixed scroll having a spiral body; and an oscillating scroll having a spiral body that forms a fluid compression chamber by meshing with the spiral body; An oscillating scroll shaft connected eccentrically is provided, and the oscillating scroll is prevented from rotating and is attached to a housing, and fluid compressed in the compression chamber is discharged from the discharge port by oscillating the oscillating scroll. In the scroll type fluid machine constructed as above, shafts are provided at both ends of the oscillating scroll and the housing to prevent rotation of the oscillating scroll, and these shafts are connected to the oscillating scroll. a cam arranged with an eccentricity substantially equal to the swing radius of the cam; a bearing provided on the oscillating scroll for supporting a shaft at one end of the cam; and a bearing provided on the housing and supporting the shaft at the other end of the cam. A scroll-type fluid machine equipped with a bearing that supports the side shaft. 2. The scroll fluid machine according to claim 1, wherein the outer diameter of the shaft of the cam supported by the bearing is smaller than the inner diameter of the bearing provided on the orbiting scroll within a predetermined range. Claim 3: Two bearings provided in the housing.
The scroll type fluid machine according to claim 1, wherein the scroll type fluid machine is used individually.