JPH0830469B2 - Oil-free scroll type fluid machinery - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a scroll fluid machine used for a vacuum pump, an air-conditioning compressor, an air and gas compressor, etc., and particularly in a state of no lubrication or low lubricating oil. The present invention relates to a scroll member suitable for driving.

[Background of the Invention]

In the conventional scroll fluid machine, since the scroll member is made of metal, cutting using a cutter is often used to obtain a scroll lap shape. However, with this method, it is quite difficult to reduce the price because a lot of time is required for processing. To solve this problem, a manufacturing method disclosed in Japanese Patent Laid-Open No. 56-2487 has been devised. However, there was a problem due to the obtained dimensional accuracy, and it was difficult to adopt. JP-A-58-214689 is disclosed as another manufacturing method for separating scroll components. However, in this case, no specific consideration has been given to the method of processing the scroll trap portion. In other words, this is a scroll component separated into a metal component and a ceramic component, but with the current processing technology,
There was a big problem in terms of manufacturing at a low price because the processing time was further consumed to obtain the scroll lap which required a considerable dimensional accuracy. Further, since the coefficient of friction of the ceramic material in a non-lubricated state is large,
An oil-free scroll fluid machine directly connected to a general-purpose motor has a practical problem because it rotates at a high speed. Further, there are some scrolls made of resin, but there is a problem that more frictional heat is generated and compression efficiency is lowered as compared with those cooled by oil.

Further, there is a problem that the proper orbiting movement is impaired due to the difference in the expansion coefficient of the scroll member due to heat.

[Object of the Invention]

It is an object of the present invention to provide a scroll fluid machine in which the orbiting motion is not impaired while reducing the compression efficiency as much as possible even when frictional heat is generated.

[Outline of Invention]

In order to achieve the above object, the present invention comprises a fixed scroll, an orbiting scroll and a frame made of a composite resin material mainly containing tetrafluoroethylene resin.
Since the composite resin material mainly composed of tetrafluoroethylene resin has a small coefficient of friction, it is possible to suppress the generation of frictional heat. However, the scroll fluid machine has a heat generation source in addition to frictional heat and compression heat, and most of them are electric motors that orbit the orbiting scroll. When the heat of the electric motor is transferred to the scroll, the heat transfer amount of the gas flowing into the scroll member is increased, and the gas is heated. When the gas is heated, its density is reduced, so that the weight flow rate per unit weight is reduced and the compression efficiency is deteriorated. In the present invention, the frame that is a member that fixes the fixed scroll is a composite resin material that is mainly made of tetrafluoroethylene resin that is the same material as the fixed scroll and the orbiting scroll, so that the heat generated by the electric motor has a thermal conductivity. The amount of transmission to the scroll side is smaller than that of the frame of the metal member because it is blocked by the frame formed of the composite resin material mainly composed of low tetrafluoroethylene resin. For this reason,
Not only is the density of the gas flowing into the compressor increased, but the amount of heat transfer during compression is also reduced, so that the adiabatic compression efficiency is improved and the overall compression efficiency is improved. Further, since the fixed crawl, orbiting scroll and frame are made of a composite resin material mainly composed of tetrafluoroethylene resin, the degree of expansion by heat is made uniform, so that the orbiting movement is not hindered.

Example of Invention

An embodiment of the present invention will be described below with reference to FIG. The fixed scroll 1 made of resin is composed of an end plate 1a and a scroll trap 1b standing upright on the end plate 1a, and has a gas suction port 3 in the outer peripheral portion and a discharge port 4 having a discharge valve body 14 in the central portion. ing. And, this fixed scroll 1 has its outer peripheral portion,
It is fixed to the resin frame 5 by fastening means 6, and the frame 5 is fixed to the casing 7 by fastening means 6 '. The orbiting scroll 2 made of resin is composed of an end plate 2a and a scroll trap 2b, and is engaged with the fixed scroll 1 while keeping a constant rotation angle. In this outer peripheral portion, a plurality of pin cranks 15 are arranged so that the other end is locked to the fixed scroll 1 to prevent the orbiting scroll 2 from rotating. The orbiting scroll 1 is connected via a bearing 8 to a crank portion 9'provided at one end of a drive shaft 9 which is supported by bearings 10 and 10 'fixed to a casing 7. With the rotation of the drive shaft 9, the orbiting scroll 2 is orbitally supported by the frame 5 and the fixed scroll 1 at its outer peripheral portion, and while maintaining a stable movement, the orbiting scroll 2 performs a orbiting movement with a constant orbiting radius. Along with this, the gas is sucked into the inlet 3.
Is discharged from the discharge port 4 after being compressed by the scroll trap. Then, although the resin member undergoes a slight dry heat expansion due to the heat generated during the movement, since the frame 5 is also made of resin, the clearance between the outer periphery of the orbiting scroll 2, that is, (the surface distance between the fixed scroll and the frame) )-(End plate thickness on the outer circumference of the orbiting scroll)
Can be maintained in a substantially constant state to ensure stable movement. By the way, the resinization of the frame 5 is a means for keeping the sun clearance constant. The same applies to the frames described in the following embodiments. Further, even if the laps slide together, the self-lubricating property peculiar to the applied resin material enables the operation even without lubrication. Further, since the orbiting scroll 2 is made of resin, it is possible to reduce the weight, and the centrifugal force accompanying the movement can be reduced and the load acting on the bearing 8 can be reduced, so that the life of the bearing can be extended. Further, the main shaft 9 is provided with shaft sealing means 11 and 11 ', and can be practically used as a vacuum pump. The present invention (including the following examples)
As the resin applicable to, there is a composite material mainly composed of tetrafluoroethylene resin. All of these materials have excellent heat resistance, friction resistance, wear resistance, corrosion resistance, rigidity, creep resistance, and formability. Therefore, by using such a resin, it is possible to handle a wide variety of gases. This has a great effect when this embodiment is used as a vacuum pump. That is, one of the fields in which vacuum pumps are frequently used is the semiconductor manufacturing field. Semiconductor manufacturing is performed in a vacuum, but various gases are used in the process for manufacturing convenience, and many of them are highly corrosive. Therefore, the resin materials shown in the examples are very excellent in corrosion resistance, and are materials that can sufficiently withstand non-lubrication sliding. Furthermore, since the load applied to the scroll member in the vacuum pump is small, sliding Since the PV value indicating the situation is small, clean vacuum exhaust is possible as an oil-free vacuum pump. This is a very important feature in the semiconductor manufacturing field.

Next, differences between the embodiment shown in FIG. 2 and the embodiment shown in FIG. 1 will be described. Fixed scroll 1 made of resin
Is composed of a fixed spiral wrap 1b and an end plate 1a having a size corresponding to the lap meshing diameter, and is fixed to the fixed scroll locking member 17. In addition, the orbiting scroll 2 made of resin
Is also an end plate 2a having a size corresponding to the meshing diameter.
And a swirl spiral loop 2b. The orbiting scroll locking member 16 is connected to the crankshaft 9'at its center and is connected to a plurality of pin cranks 15 at its outer peripheral portion. An orbiting scroll is arranged and fixed inside. The fixing method is to provide a knock pin 19 for determining the relative relationship with the engaging position of the pin crank 15 in the outer peripheral portion (particularly the rotational direction), and to connect the central portion and the outer peripheral portion with fastening means 18, 1.
It is done in 8 '. On the other hand, the fixing method of the fixed scroll 1 is carried out in substantially the same manner, but at the time of assembly, the sealing element 20 is interposed between the fixed scroll 1 and the fixed scroll locking member 17. By configuring as described above and making the scroll locking members 16 and 17 made of metal, the scroll members 1 and 2 are reinforced, and the rigidity of the metal is also exerted around the crankshaft 9'and the pin crank 15. Therefore, not only the oil-free vacuum pump of the above-described embodiment but also the oil-free compressor can be sufficiently applied. The scroll locking members 16 and 17 described above are made of Al having a thermal expansion coefficient similar to that of the resin applied to the scroll members.
Metals such as wood can be used. In the case of this embodiment, the resin portion can be made small, and the moldability can be kept very good. Moreover, since it requires less resin material, it can be provided at a lower price.

Next, FIG. 3 will be described. The fixed scroll 1 made of resin is fixed to a frame 5 made of resin, and the orbiting scroll 2 made of resin is supported by the fixed scroll 1 and the frame 5 at the outer peripheral portion of the end plate 2a thereof, and The scroll traps 1b and 2b are arranged so as to engage with each other. Then, on the back surface of the orbiting scroll 2, an Oldham member 21 for preventing rotation is arranged with the other fixed to the frame 5. The frame 5 is further fixed to a casing 7 around which the bearing element 10 is fixed. And
The compression mechanism section including the above components and the electric element 22 are integrated and housed in the closed container 24 together with the non-oiled oil 25.
Therefore, the rotation of the drive shaft 9 causes the gas to flow from the suction port 3, is compressed, and is discharged from the central discharge port 4. Thereafter, the compressed gas passes through the flow passage 26 provided on the outer circumference of the fixed scroll 1, the frame 5, and the casing 7, and finally flows out of the machine through the discharge port 23. The lubricating oil 25 is provided with an eccentric oil supply hole 27 provided therein as the drive shaft 9 rotates.
And is supplied to each bearing portion 8 and 10 through the. This embodiment can be applied as a compressor for a refrigeration air conditioner. In this case, the suction port 3 and the discharge port 23 are connected to the cycle in which the refrigerant gas is sealed. For this reason, the refrigerant gas enters from the suction port, but the amount of oil entering is small, and the inside of the scroll trap is likely to be in a non-lubricated state. Not only that, the refrigerant gas has an oil cleaning function, which promotes non-lubrication. However, due to the application effect of the resin material described above, high reliability can be obtained even without lubrication. Moreover, since these resin materials have good dimensional stability even in a refrigerant gas, it is possible to maintain an appropriate gear gap and provide a high-performance compressor. Moreover, since the heat conductivity of the material is lower than that of the metal material, overheating due to the heat transfer of the suction gas is reduced, so that the fluid performance is further improved, and a compressor with higher performance can be obtained. Furthermore, when used as an air conditioner, especially in the case of heating, the ratio of heat received by the compression mechanism is worse than that of metal, so hot discharge gas quickly emerges from the exhaust port 23, so heating rises quickly. It is possible to provide an air conditioner that is functionally superior.

〔The invention's effect〕

As described above, according to the present invention, it is possible to provide a scroll fluid machine that improves the compression efficiency and does not impair the orbiting motion.

[Brief description of drawings]

1, 2, and 3 are vertical sectional views showing an embodiment of the present invention. 1 ... Fixed scroll, 2 ... Orbiting scroll, 3 ...
Suction port, 4 ... Discharge port, 5 ... Frame, 7 ... Casing, 9 ... Drive shaft, 10 ... Bearing, 11 ... Shaft sealing means, 12
...... Balance weight, 15 ...... pin crank, 21 …… Oldham member, 22 …… electric element, 24 …… closed container, 25 ……
Lubricating oil, 26 ... Gas flow path, 27 ... Eccentric oil supply hole.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Naoki Maeda 502 Jinritsu-cho, Tsuchiura-shi, Ibaraki Machinery Research Institute, Hiritsu Seisakusho Co., Ltd. (56) Reference JP 59-79090 (JP, A) JP 59-218382 (JP, A) JP 59-192883 (JP, A) JP 58-23516 (JP, B2)

Claims (1)

[Claims] 1. A fixed scroll having a spiral scroll wrap and fixed to a frame, and an orbiting scroll provided between the frame and the fixed scroll so that the scroll wrap meshes with the wrap of the fixed scroll. An oil-free scroll type fluid machine comprising an orbiting scroll and an electric motor for generating an orbiting motion force, and compressing gas by reducing the enclosed space by the orbiting motion. Oil-free scroll type fluid machine composed of composite resin material mainly made of ethylene oxide resin.