JPH07208359A - Scroll oilless fluid machine - Google Patents

Abstract

PURPOSE:To improve the strength of a frame and a bearing, and improve sliding performance of an Oldham's ring by forming the frame of aluminum, forming an oxide film such as anodic oxide coating in which solid lubricant such as molybudenum disulfide is charged on the surface of the frame, and forming the Oldham's ring of synthetic resin. CONSTITUTION:An oxide film made of hard anodized aluminum in which solid lubricant such as molybdenum disulfide is charged is formed on total surfaces of fixed and oscillating scrolls 6, 7. The surface of a frame 5 is also hardened, and strength of the frame 5 and a bearing 4 is improved. Dropping of a ball bearing 24 caused by deformation of the frame 5 is avoided. It is possible to improve lubricating performance of a sliding groove 41 of the frame 5 as a sliding surface of an Oldham's ring 33 for suppressing abrasion by the solid lubricant charged in the oxide film, to reduce input to a compressor. Weight of the compressor is reduced because the Oldham's ring is formed of synthetic resin, and sliding performans of the Oldham's ring 33 is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll type oilless type fluid machine having a drive device for transmitting the rotational force of an electric element to an orbiting scroll.

[0002]

2. Description of the Related Art A conventional scroll type oil-free fluid machine,
In particular, an air compressor is provided with a scroll compression element and an electric element, for example, as disclosed in Japanese Patent Laid-Open No. 262186/1987, and the scroll compression element is fixed to this frame with a frame having a bearing in the center. A fixed scroll having a mirror plate and a spiral wrap standing on the mirror plate; a mirror plate, a spiral wrap standing on one surface of the mirror plate, and a boss standing on the other surface; An ordinal scroll having an orbiting scroll and an Oldham coupling revolving the orbiting scroll on a circular orbit so that the orbiting scroll does not rotate with respect to the fixed scroll, and a compression space formed between the both scrolls is directed from the outside to the inside. It is configured to gradually reduce and compress gas such as air.

In the scroll compressor having the above structure, in order to prevent the gas compressed between the scrolls from leaking and to prevent the compressed gas from entering the suction side, the side surface of the wrap and the end plate surface are minute. It is designed to have a wide sliding gap.

In the scroll type oil-free fluid machine of this structure, since it is oil-free, the surface where the fixed scroll and the orbiting scroll are in sliding contact is subject to gas leakage due to wear or abrasion. Careful consideration must be given to the materials and processing accuracy of both scrolls and Oldham's joints.

On the other hand, the fixed and oscillating scrolls are usually made of an iron material or an aluminum material in terms of durability and processing accuracy. Further, the frame or the bearing is made of an iron material such as a casting or an aluminum material.

[0006]

However, according to the above structure, since both the fixed and swing scrolls are made of a metal material such as iron or aluminum, both scrolls are partially formed due to operating conditions such as overload. In the case of contact with the, there was a problem that the sliding surfaces of both scrolls were worn or worn due to scoring and galling, the sliding gap became large and the gas leaked, and the performance deteriorated. .

On the other hand, in order to deal with this problem, it was considered to coat the sliding surface of the fixed or oscillating scroll with a synthetic resin material. However, when the scroll is made of aluminum, the resin film on the sliding surface peels off. In addition, the poor tribological characteristics of aluminum itself add to the speed of wear. This problem becomes a particularly serious defect when the compressor is an oil-free type.

The frame is usually made of a ferrous material such as a casting, but when aluminum is used to promote weight reduction, the frame is deformed by stress or heat, and the ball bearing comes off or the Oldham ring slides. There is a problem that deformation of the sliding groove of the frame as a surface causes sliding failure of the Oldham ring, which causes wear and increases the input of the compressor.

The present invention solves the above problems,
Even if the frame is made of aluminum, the strength of the frame can be improved, the deformation of the sliding groove of the Oldham ring is also prevented, and the entire surface is hardened by the oxide film to improve the strength of the frame and the bearing and the deformation of the frame An object of the present invention is to provide a fluid machine which can prevent the ball bearing from falling off due to the above, improve the sliding characteristics of the Oldham ring, and have a small input and a good performance.

[0010]

According to the present invention, there is provided a fixed scroll having a frame having a bearing and a sliding groove of an Oldham ring, an end plate fixed to the frame, and a spiral wrap standing on the end plate. , An orbiting scroll having an end plate and a spiral wrap erected on one surface of the end plate, and an Oldham coupling for revolving the orbiting scroll on a circular orbit so as not to rotate with respect to the fixed scroll. In a scroll type oil-free fluid machine that compresses a gas such as air by gradually reducing the compression space formed between the scrolls from the outside to the inside,
The frame is formed of an aluminum material, an oxide film such as an alumite film filled with a solid lubricant such as molybdenum disulfide is formed on the surface of the frame, and the Oldham ring is formed of a synthetic resin. .

Further, in the above structure, a dry bearing made of synthetic resin is interposed in the sliding portion between the frame and the orbiting scroll.

[0012]

The present invention is constructed as described above,
The entire surface of the frame is hardened by the oxide film to improve the strength of the frame and the bearing, and it is possible to prevent the ball bearing from falling off due to the deformation of the frame, and the sliding surface of the Oldham ring is covered by the solid lubricant filled in the oxide film. The lubrication characteristics of the sliding groove of the frame can be improved to suppress wear and reduce the input of the compressor.

Further, since the Oldham ring is formed of a synthetic resin material, not only can the weight of the compressor be reduced and the input can be reduced, but the material must also have excellent heat resistance and wear resistance. For example, polytetrafluoroethylene (PT
By using FE), the wear coefficient between the swing scroll and the frame made of aluminum can be greatly reduced, and the sliding characteristics of the Oldham ring can be improved.

Further, since the dry bearing made of synthetic resin is interposed on the sliding surface between the frame and the orbiting scroll, the sliding resistance of the orbiting scroll can be reduced.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the embodiments shown in the drawings.

Reference numeral 1 is a scroll type air compressor, which is composed of an upper scroll compression element 2 and a lower electric element 3. Scroll compression element 2
Is composed of a frame 5 having a main bearing 4 in the center, a fixed scroll 6 fixed to the frame, and an orbiting scroll 7 sandwiched between the fixed scroll and the frame 5.

The fixed scroll 6 has a disk-shaped end plate 8, an annular wall 9 projecting from the peripheral edge of one surface of the end plate, and a spiral wrap 1 erected on the end plate 8 surrounded by the annular wall.
It is composed of 0 and. The fixed scroll 6 has the annular wall 9 and the wrap 10 protruding downward.

The orbiting scroll 7 has a disk-shaped end plate 11,
A spiral wrap 12 erected on one surface of this end plate
And the boss portion 13 protruding in the center of the other surface of the end plate 11.
It consists of and. The orbiting scroll 7 has the wrap 12 projecting upward.

The fixed scroll 6 and the orbiting scroll 7 are formed so that the wraps 10 and 12 face each other and engage with each other to form a plurality of compression spaces 14. The electric element 3 includes a motor cover 15 fixed to the frame 5 and a stator 16 fixed in the motor cover.
And a rotor 17 arranged inside the stator and a rotary shaft 18 inserted in the center of the rotor. The motor cover 15 has an auxiliary bearing 1 that supports a rotating shaft.
9 is provided. The main bearing 4 is fixed to the frame 5 with bolts 40. This main bearing has a rotating shaft 18
The ball bearing 24 fitted to the stepped portion 20 of the above is attached, and the upper surface thereof is provided with the sliding groove 41 on which the Oldham ring 33 slides and the thrust surface 42 for pivotally supporting the orbiting scroll 7. ing. In addition, a material having excellent heat resistance and abrasion resistance, for example, a synthetic resin material of polytetrafluoroethylene (PTFE), is provided between the sliding portion of the thrust surface 42 of the bearing 4 and the thrust surface 43 of the orbiting scroll. The dry bearing 44 is made up of.

Reference numeral 25 is a drive unit for transmitting the rotational force of the electric element 3 to the orbiting scroll 7, and this drive unit balances the unbalanced force of the orbiting scroll 7 with a balance weight 26.
And an eccentric bush 28 that inserts into the boss hole of the boss portion 13 of the orbiting scroll to revolve the orbiting scroll 7.
And a pin 29 for positioning the eccentric bush and the balance weight, and a bolt 30 for fixing the eccentric bush 28 to the rotating shaft 18.

The fixed scroll 6 has a suction hole 31 communicating with the outer compression space 14 in the annular wall 9 and a discharge hole 32 communicating with the compression space 14 in the center of the end plate 8.

Here, the end plate 11 of the orbiting scroll 7 is described.
An annular groove 22 is formed in the abutting surface 21 of the fixed scroll 6 that faces the fixed scroll 6, and a seamless annular seal member 23 made of a synthetic resin material or the like is formed in the annular groove 22.
An elastic body 27 made of a rubber material (which may be a leaf spring) that presses the seal member toward the orbiting scroll 7 is housed.

The fixed and swinging scrolls 6 and 7 are also provided.
Oxide films 50 and 51 made of hard alumite filled with a solid lubricant such as molybdenum disulfide are formed on the entire surface of, and the sliding surface of the orbiting scroll 7, that is, the oxide film 51 is formed. A resin layer 52 is formed by applying a tetrafluororesin-based synthetic resin material to the sliding surface of the end plate 11 and the end surface of the wrap 12.

That is, as shown in FIG. 3, oxide films 50 and 51 filled with a solid lubricant such as molybdenum disulfide are formed on the entire surfaces of both fixed and oscillating scrolls 6 and 7.
Further, the sliding surface of the orbiting scroll 7 on which the oxide film 51 is formed, that is, the sliding surface of the end plate 11 and the end surface of the wrap 12 are coated with a synthetic resin material of a tetrafluororesin type to form a resin layer 52. Has been formed. Here, the above-mentioned oxide film 5
Nos. 0 and 51 are formed by subjecting an aluminum base material to anodizing treatment and sufficiently depositing molybdenum disulfide from the bottom in a porous layer specific to the hard coating.

On the other hand, a lower cover 63 is attached to the lower portion of the motor cover 15, and a hermetic terminal 60 for supplying power to the electric element 3, a starting capacitor 61, and an operating capacitor 62 are housed in this cover.

In the scroll type air compressor constructed as above, when the electric element 3 is rotated, the rotational force is transmitted to the orbiting scroll 7 through the rotary shaft 18.
That is, the orbiting scroll 7 is driven by the eccentric bush 28 of the drive device 25 attached to the rotary shaft 18 inserted in the boss hole 27 of the boss portion 13 of the scroll, and does not rotate with respect to the fixed scroll 6 by the Oldham coupling 33. Can be revolved in a circular orbit. Then, the fixed scroll 6 and the orbiting scroll 7 gradually reduce the compression space 14 formed by these scrolls from the outside to the inside, and compress the air flowing in from the suction hole 31.
The compressed air is discharged from the discharge hole 32 of the end plate 8 of the fixed scroll 6.

The order of assembling the driving device 25 will be described. First, the frame 4 is fixed to the motor cover 15 in which the electric element 3 is incorporated. At this time, a ball bearing 24 is incorporated in the main bearing 4 of the frame 4. In this state, the balance weight 26 is inserted into the rotating shaft 18 so as to contact the inner ring of the ball bearing 24. A pin 29 is set on the balance weight 26 inserted on the rotary shaft. Then, the eccentric bush 28 is inserted into the rotary shaft 18 so as to fit into the pin 29. Finally, the eccentric bush 28 is fixed to the rotary shaft 18 with the bolt 30. At this time, the needle bearing 33 is set between the boss portion 13 of the orbiting scroll 7 and the eccentric bush 28. The inner ring of the ball bearing 24 and the balance weight 26 are pressed and fixed to the step portion 20 of the rotary shaft by the tightening force of the bolt 30 that fixes the eccentric bush 28 to the rotary shaft 18. As a result, the drive device 25 is securely fixed by the single bolt 30.

Balance weight 26 and eccentric bush 28
By positioning with the pin 29, the unbalanced force generated by the orbiting of the orbiting scroll 7 during operation is reliably canceled by the balance weight 26.

Further, the drive device 25 is fixed to the rotary shaft 18 with a single bolt 30, so that the work of attaching each component is eliminated, and the assembling process can be simplified.

Oxide films 50 and 51 made of hard alumite film filled with a solid lubricant such as molybdenum disulfide are formed on the entire surfaces of the fixed and oscillating scrolls 6 and 7, and these films are formed. Since the resin layer 52 coated with a synthetic resin material of a tetrafluoride resin is formed on each sliding surface of the orbiting scroll 7 having 51, the entire surface of both the fixed and orbiting scrolls 6 and 7 is Anodized film 40,
41 makes it hard to improve the strength of the scroll and suppress sliding wear, and the oxide films 50, 51
The solid lubricant filled in improves the lubrication characteristics of the sliding surface to further suppress abrasion, and the layer 52 of the synthetic resin material makes it possible to secure an optimum gap of the sliding surface while sliding. Even if the layer 52 of the tetrafluororesin-based synthetic resin material is peeled off, the oxide layers 50 and 51 having high hardness and excellent adhesion to aluminum are formed in the lower layer, so that the layer 52 is formed of the aluminum material. Even if the scrolls 6 and 7 are not worn, the scrolls 6 and 7 are not worn.
Even if it partially touches, the sliding surfaces of both scrolls 6 and 7 almost never cause scoring or galling, wear is reduced and the sliding gap is properly maintained to prevent gas leakage. The performance of the compressor can be improved.

Since an oxide film 70 filled with a solid lubricant such as molybdenum disulfide is formed on the entire surface of the main bearing 4 and the Oldham ring 33 is formed of synthetic resin, the strength of the main bearing 4 is increased. Of the ball bearings 24 due to the deformation of the bearings, and the lubrication characteristics of the sliding groove 41 of the main bearing 4 which becomes the sliding surface of the Oldham ring 33 by the solid lubricant filled in the oxide film 70. To reduce wear and reduce compressor input.

Further, since the Oldham ring 33 is formed of a synthetic resin material, not only can the weight of the compressor be promoted and the input can be reduced, but also the material should be excellent in heat resistance and abrasion resistance. , The wear coefficient between the oscillating scroll 7 and the main bearing 4 made of aluminum can be greatly reduced by forming it from polytetrafluoroethylene (PTFE), and the sliding characteristics of the Oldham ring 33 can be reduced. Can be improved.

Further, a dry bearing 4 made of synthetic resin is provided between the main bearing 4 and the sliding surfaces 42, 43 of the orbiting scroll 7.
4 is interposed, the sliding resistance of the orbiting scroll 7 can be reduced.

[0034]

As described above, according to the present invention, the entire surface of the frame is hardened by the oxide film, the strength of the frame and the bearing is improved, and the ball bearing can be prevented from coming off due to the deformation of the frame. The solid lubricant filled in the coating improves the lubrication characteristics of the sliding groove of the frame that becomes the sliding surface of the Oldham ring, suppresses wear, and reduces the input of the compressor.

Further, since the Oldham ring is made of a synthetic resin material, not only can the weight of the compressor be reduced and the input can be reduced, but the material can be made of a material excellent in heat resistance and wear resistance. For example, polytetrafluoroethylene (PT
By using FE), the wear coefficient between the aluminum bearing and the bearing can be greatly reduced,
The sliding characteristics of the Oldham ring can be improved.

Further, since the dry bearing made of synthetic resin is interposed on the sliding surface between the frame and the orbiting scroll, the sliding resistance of the orbiting scroll can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view of a scroll type air compressor showing an embodiment of the present invention.

FIG. 2 is an exploded perspective view showing the orbiting scrolls and bearings of the present invention.

FIG. 3 is an exploded cross-sectional view showing both fixed and oscillating scrolls of the present invention.

[Explanation of symbols]

 2 Scroll compression element 3 Electric element 6 Fixed scroll 7 Swing scroll 8, 11 End plate 10, 12 Wrap 25 Drive device 33 Oldham coupling 40 Bolt 41 Sliding groove 42, 43 Sliding surface 44 Dry bearing 50, 51, 70 Oxidized film 52 resin layer

Claims (2)

[Claims] 1. A fixed scroll having a frame having a bearing and a sliding groove of an Oldham ring, an end plate fixed to the end plate and a spiral wrap standing on the end plate, and an end plate and one of the end plates. An oscillating scroll having a spiral wrap erected on its surface, and an Oldham coupling that revolves the oscillating scroll on a circular orbit so as not to rotate with respect to the fixed scroll. In a scroll type oil-free fluid machine for compressing gas such as air by gradually reducing the compressed space from the outside to the inside, the frame is formed of an aluminum material, and molybdenum disulfide is formed on the surface of the frame. It is characterized by forming an oxide film such as an alumite film filled with a solid lubricant such as, and forming the Oldham ring with a synthetic resin. Scroll type oilless fluid machine. 2. A fixed scroll having a frame having a bearing and a sliding groove of an Oldham ring, an end plate fixed to the end plate and a spiral wrap standing on the end plate, and an end plate and one of the end plates. An oscillating scroll having a spiral wrap erected on its surface, and an Oldham coupling that revolves the oscillating scroll on a circular orbit so as not to rotate with respect to the fixed scroll. In a scroll type oilless fluid machine that compresses gas such as air by gradually reducing the compressed space from the outside to the inside, the frame is formed of aluminum material, and molybdenum disulfide is formed on the surface of the frame. An oxide film such as an alumite film filled with a solid lubricant such as the above is formed, and the Oldham ring is formed of a synthetic resin. A scroll-type oil-free fluid machine characterized in that a dry bearing made of synthetic resin is interposed in the sliding portion between the ram and the orbiting scroll.