JPS63246484A - Scroll type hydraulic machine - Google Patents

Abstract

PURPOSE:To improve the airtightness between each scroll so as to obtain greater vacuum by sealing lubricating oil in the other container, and providing the scroll with a lubricator which permits the lubricating oil transferred from a discharge port to return thereto partly. CONSTITUTION:Lubricating oil is sealed in a container 3. A lubricator 26 is provided in such that it has the upper portion of an exhaust path 1d connected with a compressor chamber A so as to feed oil into the compression chamber A. Additionally, the lubricator 26 permits the oil transferred from a discharge port 1c to partly return to the compression chamber A. The cross-sectional area of the lubricator 26 is determined in terms of dimension in such that the volume V of the small chamber A is roughly equal to the oil return quantity q per each rotation of both scrolls 1, 2. Hence the airtightness between each scroll is remarkably improved and greater vacuum can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a scroll vacuum pump that applies the principle of a fully rotating scroll compressor in which a driving scroll and a driven scroll are rotated.

[Conventional technology]

The principle of a scroll compressor has been known for a long time, and it is a type of positive displacement compressor that performs compression by combining a pair of spiral protrusions. Normally, one of the spiral protrusions is fixed and the other is oscillated to perform a compression action, but a so-called whole-system rotation type in which both spiral protrusions rotate around their respective centers also works on this principle. For example, U.S. Pat. No. 3,884.
It is known from No. 599 specification.

A diagram of the principle of this fully rotary scroll compressor is shown in FIG. The drive scroll (100) is an electric motor.

The axis center O is determined by a drive source such as an engine or a turbine.
It rotates around 1. Driven scroll (200
) also has a single drive scroll (1
Rotation movement is performed in synchronization with the rotation of 00).

Due to the rotation of both, the compression chamber (A) moves toward the center, reducing its volume and increasing the pressure of the compressed gas.

It is forced out as high-pressure gas from the discharge port (200C).

In the state of Oo in FIG. 5(a), gas is sucked into the compression chamber (3), and as shown in FIG. 5(b) to (d), 0'
By rotating -90'-180°-270°-360° (0°), the compression chamber (5) gradually moves toward the center and its volume decreases. During this time, both scrolls (100) (2
It can be seen that the radial seal portion S by the spiral protrusion (100a) (200a) of No. 00) is lined up in a straight line in the radial direction and occupies a fixed position in a stationary state.

[Problem that the invention seeks to solve]

In the conventional scroll compressor as described above, it is extremely difficult to maintain a high degree of vacuum between the gas suction chamber and the discharge side. For this reason, there is a problem in that the principle of conventional scroll compressors cannot be applied to many vacuum pumps, and this is an unprecedented situation.

This invention was made to solve these problems, and aims to obtain a scroll vacuum pump with a simple structure and a high degree of vacuum by applying the principle of a scroll compressor.

[Means for solving problems]

In the scroll type fluid machine according to the present invention, lubricating oil is sealed in the other container, and a portion of the lubricating oil is transferred from the discharge port to a small chamber formed by the winding start end of each of the m pair of scrolls. A refueling port for returning lubricating oil is provided on the first scroll, and the cross-sectional area of the refueling port is set to a size such that the capacity V of the small chamber and the return amount 9 of lubricating oil per one rotation of the pair of scrolls are approximately equal. This is what I did.

[Effect]

In the scroll-type fluid machine according to the present invention, an optimal amount of lubricating oil is returned to the small chamber through the oil supply port, and the airtightness of the small chamber is improved and a high vacuum can be obtained.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. In the figure, (1) is a drive scroll disposed in the upper part and constitutes the first scroll, in which a spiral protrusion (1a) is provided on the disk portion (1b), and a discharge port (
IC) is provided, and a drive shaft (11) is protruded upward, either integrally or fixedly. (1d) is valve C4, which will be described later.
(1c) is a plurality of discharge holes drilled in the radial direction; (2) is disposed below.

In the driven scroll constituting the second scroll, a spiral protrusion (2a) provided on a disc portion (2b) is combined with a spiral protrusion (1a), and a boss portion (2c) is provided at the bottom. . (3) is a cylindrical container constituting a first container that communicates with the inside of a vacuum container (not shown) which is evacuated through an intake port (3a); (3b) is its suction chamber; (3C)
is a bearing housing provided at the lower end of this container (3), which is connected to the driven scroll (2) via bearings (51, (61).
) supports the boss part (2C). (7) is a container (3
) The upper housing is airtightly attached to the upper end of the housing by a bolt (8) via an O-ring CIG in an O-ring groove (3d), and a cylindrical bearing support part (7a) is provided at one central part of the upper housing.

(7b) is an annular atmospheric pressure chamber formed in the housing (7), ■ is oil sealed in this chamber (7b), (1
2 is a bearing that is fitted into the bearing support part (7K) and supports the drive shaft (1f), 1 is a seal backed up by a spring α, and α9 is a flange fixed to the upper housing (7) with bolts (1e). It has a communication port (151) that communicates the atmospheric chamber (7b) with the atmosphere.The α force is a bearing that supports the drive shaft (1f), the hammer is a baffle plate fixed to the flange C151, and a9 is a presser foot. The board is fixed to the upper housing (7) by bolts ω, and supports the seal Q3 and the bearing α force. (21b) is the rotating shaft of the electric motor Q1), which is connected to the drive shaft (1f) by a shaft coupling. r
2 is a valve installed at the discharge port (IC).
) is reverse checked. (to) is the oil sealed in the container (3), and (support) is the exhaust path (1) provided on the drive shaft (1f).
A part of the oil transferred from the above-mentioned discharge port (IC) at the oil supply port which communicates the upper part of d) with the compression chamber (A) near the discharge port (IC) and supplies oil into the compression chamber (A). is returned to the compression chamber (N).

Note that the compression chamber (A) constitutes a small chamber. Here, the cross-sectional area of the oil filler port ω is set to such a size that the volume ■ of the small chamber < A) and the amount of oil returned per rotation of both scrolls + 1) (21) are approximately equal. When the port (A) has a circular cross section, the relationship between the radius r and the volume V of the fuel filler port d is as follows.

First, the oil return amount q per second is expressed by equation (1).

Here, r2 oil hole radius (m) μ: Static viscosity coefficient = Pν (I/In-1e C) P: Specific weight (Kf/m3) C: Kinematic viscosity coefficient (m3/5ec) j: Total oil filled length (m) ΔP: Differential pressure (N 7m'') From equation (1), the oil return area per revolution is expressed as equation (2).

Here, N: rotational speed (Hz) Oil return amount q (m3/rev,) obtained by this formula (2)
The relationship between and the volume of the compression chamber (A) is that if V<q, too much oil will return, and if V>q, there will be insufficient oil; in either case, a high degree of vacuum cannot be obtained. Therefore, Vsq is optimal.

Here, the relationship between the volume V and the radius r of the fuel filler port is as shown in equation (3).

The operation of the pump in the above embodiment is as follows. When the motor rotates, the driving scroll (1) rotates around the shaft center O1, and the driven scroll (2), whose spiral projection (1λ) is in contact with the spiral projection (2a), rotates around the shaft center O! It follows and rotates around the center.

Both scroll ill, by +21 rotation, the 4th
As shown in the figure, only gas is inhaled, compressed, and expelled.

Therefore, by the rotation of the scroll fil, +21, the gas of the body to be evacuated (not shown) is sucked from the suction port (section 3), is sucked into the suction chamber (3b), and is sucked into the compression chamber (A
)to go into. The gas that entered the compression chamber (5) is transferred to the compression chamber (A).
By moving toward the center, the gas is compressed and is discharged from the discharge port (IC). On the other hand, the container (
3) The oil (to) in both spiral protrusions (la), (2a
) and the contact parts of the corresponding side walls to ensure airtightness and lubricate the bearings (51+61).In addition, the compressed gas flows from the discharge port (1c) to the incompressible oil Utilizes the property of the valve to push up the exhaust path (
ld), and reaches the atmospheric pressure chamber (7b) via the discharge hole (1e).

This atmospheric pressure chamber (7b) has a considerably large volume, and gas and oil are separated here, and the oil is reliably separated by the baffle ae, and the gas is released into the atmosphere from the communication port (15λ). be discharged. The separated oil αD is stored in the atmospheric pressure chamber (7b)
The oil is stored in the bearing α2 and lubricates the bearing α2.

Furthermore, the seal u3 is located between the atmospheric pressure chamber (7b) and the suction chamber (3b).
is being sealed. In addition, the valve (2) serves to prevent gas and oil compressed and discharged from the compression chamber (N) from returning to the compression chamber (N) from the atmospheric pressure chamber (7b), and to improve the degree of vacuum. The position of this valve (2) is the discharge port (
It is desirable to provide it in the IC).

By the way, the oil filler port (to) provided on the drive shaft (1f).

The upper part of the exhaust path (1d) and the compression chamber (A) near the discharge port (IC) are communicated with each other to supply oil into the compression chamber (A).
Since an appropriate amount of oil Ill is supplied into the compression chamber (A) through the oil supply port ■, this oil flows into the spiral protrusion (la) (2a
) and the compression chamber (A).
The residual gas is absorbed into the compression chamber (5).
This means that the vacuum can be efficiently discharged, and the degree of vacuum can be significantly improved.

Here, when the radius of the optimal fuel filler port ■ is found from equation (3), p = 883 Kip/m3 (20°C) e ) 'near,
lX10-5m3//secμ-Pcy6.3 X 1
0 ”Kip/m-secΔP=1 atm”
1.033 X9.8 X 10' Kp/m-sec
”! = 0.045m N -33Hz (1800rpm) V -Q, 47 cc /rer.

It becomes r-0,001m.

It has been confirmed through experiments that when the ultimate degree of vacuum (Torr) is measured, it matches the radius determined by equation (3), as shown in FIG.

Furthermore, in the above explanation, a single fuel filler port (■) was provided, but a large number may be provided as shown in FIG. This arrangement allows oil to be evenly supplied to the symmetrically formed compression chambers (5).

In this case, for example, as shown in Fig. 4, a pair of oil filler ports in the axial direction, a pair of oil filler ports in the radial direction, and a pair of fuel filler ports that branch from the pair of filler ports, respectively. ■ and a stopper ■ to close unnecessary openings are provided.

〔Effect of the invention〕

As described above, in the present invention, lubricating oil is sealed in the other container, and a portion of the lubricating oil transferred from the discharge port is returned to the small chamber formed by the winding start end of each of the pair of scrolls. A refueling port is provided on the first scroll,
The cross-sectional area of the oil supply port is set to such a size that the volume V of the small chamber and the return amount q of lubricating oil per revolution of the pair of scrolls are approximately equal, so the airtightness between each scroll is significantly improved. This has the effect of increasing the degree of vacuum to an extremely high degree.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing one embodiment of the present invention, FIG. 2 is a characteristic diagram thereof, and FIG. 3 is a plan view of main parts showing still another embodiment.
FIG. 4 is a sectional view thereof, and FIG. 5 is a partial sectional view of the conventional device. In the figure, (1) is a driving scroll, (la) (2a
) is a spiral protrusion, and (1c) is a discharge port. (1d) is the exhaust path, (1e) is the discharge hole, (2) is the driven scroll, (3) is the container - (3a) is the intake port, (7)
is the upper housing, aa is the seal, 211 is the electric motor, (
24) is the valve, and (to) so■ is the fuel filler port. Note that the same reference numerals in each figure indicate the same or equivalent parts.

Claims (1)

[Claims] In a scroll-type fluid machine in which fluid is transferred from one container to the other container through a discharge port configured in a first scroll of one of the pair of scrolls by rotation of a pair of scrolls, the other container is A lubricating oil is sealed in the first scroll, and an oil supply port is provided in the first scroll for returning a part of the lubricating oil transferred from the discharge port to a small chamber formed by the winding start end of each of the pair of scrolls. The cross-sectional area of the fuel filler port is equal to the volume of the small chamber V.
A scroll-type fluid machine characterized in that dimensions are set such that the return amount q of lubricating oil per rotation of the pair of scrolls is approximately equal.