JPH07332269A - Oilless scroll type vacuum pump - Google Patents

Abstract

PURPOSE:To provide a vacuum pump which is constituted to drain a moisture content generated by compression gas and prevent the generation of noise. CONSTITUTION:Gas inputted through a gas suction port 16 is inputted in a closed space, formed by using a revolving scroll 20 and a fixed scroll 10, through drive of the revolving scroll 20. The gas is compressed as it is transferred, in order, to a central closed space and compressed gas is discharged through a delivery port 17 to the outside and a moisture content generated from the compressed gas is drained through a drain hole 15 to the outside.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oilless scroll type vacuum pump.

2. Description of the Related Art Conventionally, a technique of vacuuming a container is to put food in a polyvinyl bag and evacuate the air to prevent bacteria floating in the air from adhering to prevent food from spoiling. From ordinary life to low temperature technology such as vacuum car, blood collection tube, thermos, or outer wall of container for storing cooling refrigerant for medical, industrial, or experimental purposes to prevent heat conduction due to air convection. Is widely used. The inside of the closed container is evacuated by connecting a vacuum pump to the suction port of the closed container and sucking out air and other gases by the vacuum pump.

Recently, an oilless scroll type vacuum pump has attracted attention as a vacuum pump. The scrolling action of an oilless scroll vacuum pump is shown in FIG. 2 and 4, the peripheral wall 11 will be described.
An orbiting scroll 20 having a fixed scroll 10 in which a first wrap 13 is formed in a concave space surrounded by and a second wrap 21 that can be fitted into the first wrap 13.
The revolving scroll 20 is revolved with respect to the fixed scroll 10 without rotating, thereby forming a closed space 2 formed between the wraps 13 and 21.
The volume of 2 is variable. Therefore, the orbiting scroll 20 is moved around the center of the wrap 2 of the fixed scroll 10 at a constant radius so that the contact point between the both wraps forming the closed space 22 functioning as a compression chamber gradually moves toward the center. The gas taken in through the suction port by the orbital movement is drawn into the closed space 22 formed by the two wraps 13 and 21 while wrapping around the winding end of the second wrap 21, and the orbiting scroll 2
With the revolution movement of 0, the volume is gradually reduced and the pressure is increased while moving toward the center, and the closed space 2
2 is discharged to the outside when conducting with the discharge port 17.

Therefore, in the case of this embodiment, it is extremely important to secure the sealed state of the space 22 formed between the both laps 13 and 21 in order to improve the compression efficiency and the vacuum degree. Therefore, as shown in FIG. 3, chip seals 31A and 31B made of a self-lubricating resin material are interposed between the facing sliding surfaces on the axial end surface of the wrap. That is, as shown in FIG. 3, an involute-shaped wrap 13 (21) is provided on the front side of the disk-shaped end plate of the scroll member 10 (20) that functions as a fixed scroll or an orbiting scroll, and Lap groove 13a communicating from the center to the peripheral side on the end face side
(21a) is provided as a recess, and the tip seal 31
A and 31B are connected in series and fitted. Further, a dust seal 32 is attached in an annular shape to the outer peripheral end surface portion of the disk-shaped end plate of the scroll member 10 (20) in order to prevent air from entering the inside.

[0004]

The oilless scroll type vacuum pump thus constructed sucks the gas in the hermetically sealed container and pressurizes and compresses it, so that heat generated causes liquefaction of water vapor contained in the gas. Then, only the compressed gas is discharged from the discharge port, and the remaining water is accumulated below the discharge port in the final space formed by the swirl scroll and the fixed scroll. Every time the compressed gas is fed into the final space from the closed space in the previous stage, the compressed gas collides with the accumulated water, and the water is deposited on the wrap walls of the swirl scroll and the fixed scroll forming the final space. collide. At that time, an abnormal sound is likely to occur. For that purpose, a method of providing a gas ballast, introducing atmospheric pressure into the closed container, lowering the partial pressure of water vapor, and exhausting without liquefying is used, but the degree of vacuum becomes worse and more power is required. There was a problem. SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks of the prior art, and an object thereof is to provide a vacuum pump capable of efficiently draining water. Another object of the present invention is to provide a vacuum pump having a water draining device which has a simple structure and is inexpensive.

[0005]

SUMMARY OF THE INVENTION According to the present invention, a closed space formed between both scrolls is provided from the suction port provided on the outer peripheral side to the center side while revolving the orbiting scroll which is opposed to the fixed scroll and revolves. Oil-less that exhausts while gradually contracting to the discharge port
In the scroll type vacuum pump, a drain hole communicating with the atmosphere is provided in the final spot volume of the fixed scroll at least near the lower side of the discharge port. In addition, it is preferable that the water drain hole is configured so as to be inclined downward from the final spot volume portion toward an external opening portion. Further, it is preferable that the opening position of the discharge port is deviated downward from the center so as to be close to the lower wrap peripheral surface side of the fixed scroll forming the final spot volume. Further, it is preferable that the discharge port is configured so as to be inclined downward from the final spot volume portion toward the external opening.

[0006]

According to the present invention, the closed space formed between both scrolls is revolved from the suction port provided on the outer peripheral side to the discharge port provided on the central side while revolving the orbiting scroll that is engaged with the fixed scroll. In an oilless scroll type vacuum pump that exhausts gas while gradually reducing and moving it, a drain hole that communicates with the atmosphere is provided at least near the lower side of the discharge port in the final spot volume of the fixed scroll. Water does not accumulate below the discharge port, and no abnormal sound is emitted due to the water. Further, since the opening position of the discharge port is deviated downward from the center so as to be close to the lower wrap peripheral surface side of the fixed scroll forming the final spot volume, moisture is accumulated in the final space. It is not made, and the water does not make an abnormal sound.
Further, when the water drain hole is configured to be inclined downward from the final spot volume portion toward the external opening portion, it is possible to drain water well. Further, the opening position of the discharge port is deviated downward from the center so as to be close to the lower wrap peripheral surface side of the fixed scroll forming the final spot volume, and the discharge port is moved downward toward the external opening. When it is configured to be inclined, it can be drained well together with the exhaust of the compressed gas.

[0007]

The present invention will be described in detail below with reference to the embodiments shown in the drawings. However, the dimensions, materials, shapes, relative positions, etc. of the components described in this embodiment are merely illustrative examples, not the intention to limit the scope of the present invention thereto, unless otherwise specified. Absent.

FIG. 1 is a basic configuration diagram according to the present invention. In the figure, the vacuum pump main body 1 is connected to the rotary shaft of the motor 5 via a pulley 42 and a belt 34, and the rotation of the motor 5 drives the orbiting scroll in the vacuum pump main body 1 through the pipe 4. The gas in the closed container 7 is sucked out and the closed container 7 is evacuated. FIG. 2 shows a scroll type vacuum pump according to an embodiment of the present invention.
As described above, the fixed scroll 10 and the swivel scroll 2
0, and a frame 40 that supports these in a predetermined position or in a rotatable manner. The fixed scroll 10 is fixed to the end surface of the frame 40, and a spiral wrap 13 is formed upright in a concave space surrounded by a peripheral wall 11 having a port 16 functioning as an inlet. , A discharge port 17 for discharging compressed gas almost in the center thereof
And the drain hole 15 is opened. Swivel scroll 20
Is housed in a recessed space in the frame 40 and fixed scroll
A spiral wrap 21 having substantially the same shape as the wrap 13 of the rule 10 is formed upright on one surface of the end plate that abuts the peripheral wall 11, and the laps 13 and 21 are formed as one piece.
It is fitted with a shift of 80 degrees.

Cooling fins 33 and 23 are formed on the back side of the scrolls 10 and 20, respectively, so that the inside of the scroll can be cooled by air cooling. The wraps 13 and 21 of each scroll are self-lubricating seals composed of the tip seals 31A and 31B described in FIG. And a ring-shaped self-lubricating sealing member 32 is inserted into a groove formed in the end face of the swivel scroll 20 which comes into contact with the end plate. The airtightness with the outside in the concave space 12 is maintained. On the other hand, in the frame 40, a main drive crankshaft 41 having a pulley 42 attached to one end is pivotally supported along the central axis, and the main drive crankshaft 41 is also supported.
The driven crankshafts are pivotally supported at positions (three locations) offset by 120 degrees with respect to each other. The crankshafts 41 and 43 are both swivel scrolls 2.
The housing 25, which is integrated with 0, is rotatably supported, and the rotation of the main drive crankshaft 41 prevents the orbiting scroll 20 from rotating, and the fixed scroll 10 has a fixed radius. It is configured to be able to revolve around the center of the lap. The intake port 16 has a pipe 4
Are connected in series, and the tip thereof is connected to the closed container 7 shown in FIG.

FIG. 6 is a view showing the relationship between the fixed scroll and the drainage hole of the vacuum pump according to the first embodiment of the present invention. In the figure, a discharge port 17 is provided at the center of the fixed scroll 10, and a wrap 13 spirally stands up from a sliding surface 14 so as to surround the discharge port 17 from below. The drain hole 15 is provided below the discharge port 17 so that its opening diameter is in contact with the inner wall of the wrap 13 and is inclined downward from the opening of the sliding surface 14 toward the outside as shown in FIG. Has been. FIG. 4 shows the drain hole 15
It is a figure which shows the effect | action of a scroll using the fixed scroll provided with, and is the figure seen from the back side of FIG.

Next, the operation of this embodiment will be described with reference to FIGS.
Will be explained. In FIG. 1, when the vacuum pump 1 (not shown) is turned on, the orbiting scroll 20 starts driving. Now, the gas in the space a of FIG. 4A is driven by the wrap 21 of the orbiting scroll 20 to b of FIG. 4B.
, And alternately, as shown in (A) and (B) below, they are taken into the closed space indicated by c, d, e, f, g and compressed, and finally the discharge port 17 is opened. The compressed gas is discharged from the discharge port 17 to the outside of the space h.

On the other hand, the gas taken in from the closed container is
The water droplets are liquefied by being compressed. Therefore, the water generated from the compressed gas is accumulated on the lap 13 below the discharge port 17 as shown by the diagonal lines in FIG. 6 unless drainage treatment is performed, but since the drain hole 15 is provided as shown in the figure. , Is discharged along the slope. In this way, the water is discharged to the outside of the vacuum pump 1 through the water drain hole 15 provided below the final space i, and no abnormal noise as a water hammer occurs.

FIG. 7 is a diagram showing the relationship between another fixed scroll and the drainage hole. This embodiment is a discharge port in which a hole for discharging compressed gas and a water drain hole are integrated with each other, having an opening center which is deviated from the center of the fixed scroll 10 at an angle of 40 degrees to the lower left, and an inner wall of the wrap 13. And a discharge port 24 having an opening that is in contact with the outer diameter of the opening. As shown in FIG. 8, the discharge port 24 is provided so as to be inclined downward from the sliding surface 14 toward the outside. Therefore, the water generated from the compressed gas is discharged from the discharge port 24 along with the discharge of the compressed gas along the inclination thereof.

Next, the operation of the other embodiment will be described with reference to FIG. Note that FIG. 5 is a diagram viewed from the back surface of FIG. 7. Now, the gas in the space a of FIG. 5A is taken into b of FIG. 5B by driving the wrap 21 of the orbiting scroll 20, and as shown in FIG. 5A and FIG. In addition, the gas is taken into the closed space indicated by c, d, e, f, and g and is compressed, and finally reaches the space h in which the discharge port 24 is opened, and the compressed gas is discharged from the discharge port 24 to the outside. It is a thing. On the other hand, the gas taken in from the closed container liquefies the water droplets, but is discharged together with the compressed gas to the outside of the vacuum pump by the discharge port 24 opened below the final space i. Discharge port 24
Has a downward slope toward the outside, and water is discharged along the slope.

According to the present invention, as described above, the drainage hole is provided below the discharge port, or the compressed gas discharge hole and the drainage hole are also provided so as to be offset downward from the center of the fixed scroll. No abnormal noise is generated due to water generated from gas.

[0016]

[Effect] As described above, in the present invention, since water generated from the compressed gas is discharged through the water drain hole or the discharge port that also serves as the water drain hole, an oil with high durability without generating abnormal noise is produced. It is possible to provide a less scroll type vacuum pump.

[Brief description of drawings]

FIG. 1 is a basic configuration diagram of the present invention.

FIG. 2 is an embodiment of a scroll type vacuum pump according to the present invention.

FIG. 3 is a perspective view showing a scroll member and a sealing element.

FIG. 4 is a schematic view showing the action of scroll.

FIG. 5 is a schematic view showing the action of another scroll.

FIG. 6 is a diagram showing a relationship between a fixed scroll and a drainage hole.

FIG. 7 is a diagram showing a relationship between another fixed scroll and a drainage hole.

8 is a view showing a cross section of the fixed scroll shown in FIG.

[Explanation of symbols]

1 Oilless scroll type vacuum pump main body 4 Piping 5 Motor 7 Airtight container 10 Fixed scroll 15 Drain hole 16 Suction port 17 Discharge port 20 Swivel scroll 24 Discharge port 31 Self-lubricating seal Member 32 dust seal

Claims (4)

[Claims] 1. A closed space formed between both scrolls is gradually rotated from an intake port provided on an outer peripheral side toward a discharge port provided on a central side while orbiting a revolving scroll that is engaged with a fixed scroll. An oilless scroll type vacuum pump that exhausts air while reducing and moving, wherein an oilless hole communicating with the atmosphere is provided at least near the lower side of the discharge port of the final spot volume of the fixed scroll. -Scroll type vacuum pump. 2. The oilless scroll type vacuum pump according to claim 1, wherein the water drain hole is formed so as to be inclined downward from the final spot volume portion toward an external opening portion. 3. A closed space formed between both scrolls is gradually rotated from an intake port provided on the outer peripheral side toward a discharge port provided on the central side while revolving the orbiting scroll that is engaged with the fixed scroll. In an oilless scroll type vacuum pump that performs exhaust while reducing and moving, displacing the opening position of the discharge port below the center,
An oilless type characterized by being placed close to the peripheral surface of the lower wrap of the fixed scroll that forms the final spot volume.
Scroll type vacuum pump. 4. The oilless scroll according to claim 3, wherein the discharge port is formed so as to be inclined downward from the final spot volume portion toward the external opening.
Vacuum pump.