JPS61138895A - Scroll type fluid machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to improvements in improving the performance of scroll-type fluid machines.

(Prior Art) Conventionally, among scroll type fluid machines, there is a compressor as shown in Japanese Patent Application Laid-open No. 57-181896, for example.

Hereinafter, the schematic structure of this device will be explained based on FIG. 1
01 is a closed container, and a motor section 108 is provided above so that a scroll compressor section 102 is located below. 10
Reference numeral 4 denotes a rotary shaft formed by extending the motor shaft downward, forming a crankshaft portion (eccentric shaft portion) 104a near the lower end, and forming an airtight container 101 below the motor portion 103.
It is rotatably supported on a frame 105 fixed to. 1
06 is an orbiting scroll, which has an end plate 106a and a wrap 106.
b, and the boss portion 106c is connected to the crankshaft portion 104a.
The rotating shaft 104 is rotatably fitted into the frame 105, and a rotating function 108 provided between the rotating shaft 104 and the frame 105 causes a rotating movement in accordance with the rotation of the rotating shaft 104. A fixed scroll 107 has an end plate 1.7a and a wrap 107b, and is fixed to the lowest part of the closed container 101, and the compression is caused by the engagement of the wrap 107b and the wrap 106b of the orbiting scroll 1 (16). The machine part 102 is formed.

Reference numeral 110 denotes an intermediate chamber formed between the frame 105 and the orbiting scroll 106, which is isolated from the interior of the closed container 101 and kept airtight. In addition, the scroll compressor section 1
02 is a passage 118 cut in the fixed scroll 107.
a, a passage 113b cut in the frame 105 and a passage 113c cut in the electric motor part 108 communicate with each other, so that the airtight container 101 is exposed to the outside through the discharge pipe 114.

Therefore, the orbiting scroll 106 is connected to the compressor section 10.
2 and the pressure in the intermediate chamber 110 slightly exceed the pressure in the suction chamber 115 side, so that the lower surface of the end of the blunt root 106a is constantly pressed against the upper surface of the end of the end plate 107a of the fixed scroll to perform sliding rotation, The sealing action on the sliding surface provides airtight isolation between the intermediate chamber 110 and the interior of the closed container 101. When the wraps 106b-107b expand due to heat generation, if the gap between the tips of the wraps 106b and 107b and the opposing end plates 107a and 106a is made very small during assembly, the turning The scroll 106 is pushed up, creating a gap in the sliding portion between the bottom surface of the end plate 106a and the top surface of the end plate 107a, making it impossible to seal the sliding portion. Therefore, the intermediate chamber 110 can maintain a predetermined pressure by communicating with the suction chamber 115, and the orbiting scroll 106 is thereby pushed upward. This does not change the fact that large gaps are created between each of the wraps 106b and the end plate 107a, and between the wraps 107b and the end plate 106a, which significantly deteriorates the compression function.

Therefore, normally the wrap 106b during the above-mentioned operation is
- Considering the thermal expansion of 107b, it is necessary to provide an extra gap for the expansion during assembly. Therefore, the gap between the wrap and the head plate remains large until the specified temperature is reached after startup, so the specified performance is not achieved due to pressure leakage at the core, and it takes 12 hours until the specified performance is reached. This type of scroll compressor has a common drawback of requiring a long time. Particularly in non-lubricated configurations, there is no cooling effect due to oil, which poses a major problem.

(Means for solving the problem) The fixed scroll is clamped and fixed between the end cover and the rotary shaft prime mover side cover, and the rotary shaft is rotatably supported at least on the fixed scroll by a bearing, and the A crankshaft is formed on the prime mover side, the orbiting scroll is rotatably supported on the crankshaft by a bearing, and both sides of the end of the orbiting scroll end plate are provided with a gap between the end cover and the fixed scroll, It is characterized in that the pressure on the back side of the orbiting scroll is maintained at the same pressure as that in the suction chamber.

(Function) The orbiting scroll is supported by bearings on the crankshaft, so it hardly moves in the axial direction, and the rotating shaft, which is provided integrally with the crankshaft, is supported by bearings on the fixed scroll. Therefore, it does not move in the axial direction. Moreover, the end face of the orbiting scroll end plate is provided with a gap between the end cover and the fixed scroll.

Therefore, even if the gap between the ends of both rotating and fixed scroll wraps and the opposing end plate is made very small during assembly, when the wraps expand and expand due to heat generated during operation, the rotating shaft will also expand in the same way. As a result, the orbiting scroll moves toward the crankshaft by an amount corresponding to the extension of the rotating shaft. In this case, since both the lap part and the rotating shaft parallel to it are under the same conditions, the degree of elongation due to thermal expansion is also almost the same, and the gap between the tip of the lap and the end plate is normally the same regardless of the temperature rise. It can be held almost constant.

(Example) Next, an example of the present invention shown in FIG. 1 will be described. 1 is a fixed scroll having a wrap 1a, a suction chamber 1b, and a suction port 1c on the upper surface, and a boss portion 1d on the lower side and a discharge passage 1e above it, and an end cover 2 on the upper surface.
Furthermore, electric motor chambers 3 are connected to the lower surface.

4 is an electric motor fixed in the electric motor room 8, coupled to the electric motor,
The rotating shaft 5 that passes through extends upward to form a crankshaft portion 5a near the upper end, and the upper end further forms an axle shaft portion 5b.
This is provided.

The rotating shaft 5 has an intermediate portion passing through the fixed scroll 1 and is fixed to a bearing 6 provided at the boss portion 1d with a nut 7, and the central shaft portion 5b is attached to a bearing provided at the center of the end cover 2. 8 for axial movement, and its lower end is supported on a bearing 9 provided at the center of the lower end of the motor chamber 3.

Reference numeral 10 denotes an orbiting scroll fitted onto the rotary shaft 5 so that the wrap 10a engages with the fixed scroll 10 lug la from above, and a boss portion 10c formed on the end plate 10b.
The bearing 11 is rotatably mounted around the crankshaft 5a by a nut 12, and rotation is prevented by a plurality of pin cranks 18 provided between the end cover 2 and the bearing 11.

14 is a bearing retainer, 15 is a shaft seal member, 16 is a balance weight, and 2 is a compressor section.

Therefore, when assembling, the tip of the wrap 1a and the end plate 10
The gaps between the b surface, the tip of the wrap 10a, and the end plate 1f surface are minute, and a slight gap is provided between the upper and lower surfaces of the end plate 10b and the upper surfaces of the ends of the end cover 2 and the end plate 1f of the fixed scroll 1.

Due to the rotation of the rotating shaft 5, the fluid sucked from the suction port 1c through the suction chamber 1b is compressed by the compression action of each of the wraps 1a and 10a, and is discharged to the outside through the compressor section 2 and the discharge passage 1e. In this case, the pressure on the back side of the orbiting scroll 10 is the suction chamber 1b and t! The pressure is almost the same. As the operation continues, each part expands slightly due to temperature rise, and the wraps 1g-141a expand together to form the opposing mirror plates 10b and 1.
Trying to hit the first side. However, the rotating shaft 5 also extends upward under the same conditions, and the orbiting scroll 10 itself also moves slightly upward, thereby reducing the gap between the wraps 1a and 10a and the end plate 10b and the fist 1f surface. The gap is kept almost the same as when assembled.

Of course, in order to make the degree of elongation of the rotating shaft 5 and the degree of elongation of the wraps 1a and 10a almost the same, the degree of elongation of the rotating shaft 5 and the wraps 1 must be
It is necessary to take into consideration in advance various conditions such as the length of the rotating shaft 5 and the temperature rise distribution.

Although the above-mentioned embodiment has been described in terms of a vertical type in which the electric motor is placed below, the present invention is not limited to this; it is also possible to implement a type in which the electric motor is placed in the upper part or a horizontal type. The same effect can be obtained by implementing this method in any type of vacuum pump. The effect is particularly great when configured as a non-lubricated type.

(Effects of the Invention) In the scroll fluid machine according to the present invention, the rotating shaft is rotatably attached to the fixed scroll by a bearing, the orbiting scroll is rotatably attached to the shift flank shaft part by a bearing, and the rear part is at the same pressure as the suction chamber. Therefore, as the wrap expands when the temperature rises, the rotating shaft also expands and moves the orbiting scroll,
As a result, the gap between the wrap tip and the opposing mirror plate surface can be kept almost constant regardless of the rate of temperature rise. In addition, there is no need to provide a slightly larger gap at the tip of the wrap during assembly at room temperature to allow for the wrap to expand due to temperature rise, unlike conventional products, so it is possible to obtain the desired performance from the initial stage of operation. It is possible.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view showing one embodiment of the present invention, and FIG. 2 is a vertical cross-sectional view showing an example of the conventional one. In the figure, 1 is a fixed scroll, 1b is a suction chamber, 2 is an end cover, 8 is a motor chamber, 5 is a rotating shaft, 5a is a crankshaft, 10 is an orbiting scroll, and 10b is an end plate.

Claims (2)

[Claims] (1) In a device in which an orbiting scroll that performs an orbiting motion is arranged opposite to a fixed scroll and their laps are engaged, the fixed scroll is clamped and fixed between an end cover and a rotary shaft prime mover side cover, and the rotary shaft is At least the fixed scroll is rotatably supported by a bearing, and a crankshaft is formed on the side opposite to the prime mover of the wrap engaging part, and the orbiting scroll is rotatably supported by a bearing on the crankshaft, and the orbiting scroll end plate is rotatably supported by a bearing. A scroll-type fluid machine, characterized in that a gap is provided between the end cover and the fixed scroll on both sides of the part, so that the pressure on the back side of the orbiting scroll is maintained at the same pressure as that in the suction chamber. (2) The scroll according to claim 1, wherein the rotating shaft further includes an axial center shaft portion at an end portion on the crankshaft side, and the axial center shaft portion is supported by a bearing on the end cover. Shape fluid machine.