JPH0442557Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an oil rotary vacuum pump used in various vacuum equipment fields.

[Prior Art] For the purpose of increasing the compression performance and the ultimate degree of vacuum, oil rotary vacuum pumps are of the dual type, in which pump bodies are connected in two stages in series.
An outline of this dual type oil rotary vacuum pump is shown in FIG. That is, in the case of the illustrated example, the first and second parts have a common internal structure (a rotor R with a vane V is inscribed in a stator S) inside an oil tank case T that stores an appropriate amount of oil O. The pump body is arranged in stages. Here, each pump body of each stage has an intake port a ₁ , a ₂ and an exhaust port b ₁ , b ₂ , and the intake port of the first stage pump body
The intake port A of the pump is communicated with a ₁ through the ventilation system path D, while the exhaust gas intermittently discharged from the exhaust port b ₂ of the second stage pump body via the exhaust valve E is connected to the inside of the oil tank case T. After passing through the space C, it is led out to the exhaust port B of the pump, and then the exhaust port _B1 of the first stage pump body and the intake port of the second stage pump body
_a2 are communicated with each other through an exhaust communication passage G. An intermediate exhaust port b ₃ equipped with a relief valve F is provided near the exhaust port b ₁ of the first stage pump main body to which the exhaust communication passage G is connected. The gas density is high and the first
When it is not possible to introduce all of the gas discharged from the pump chamber of the stage pump main body into the pump chamber of the second stage pump main body, which has a relatively small volume, into the latter stage pump chamber, the gas is directly exhausted from this intermediate exhaust port _b3 . A part of the oil is discharged into the internal space C of the oil tank case T, which communicates with the exhaust port B of the pump.

In addition, as shown in Fig. 5, the conventional assembly structure of this type of oil rotary vacuum pump is that the motor M is sandwiched between the first stage pump body and the second stage pump body on one side of the base body BB. The oil tank case T is attached to the side of the body BB so as to surround these two-stage pump bodies.
I try to keep it connected.

[Problems that the invention attempts to solve] However, with such an existing structure, the first
Intake line (suction pipe) required for stage pump body
In order to connect D, it must be passed through the oil tank case T as shown in Fig. 5;
This may cause other inconveniences. In other words, with this mounting structure, it is difficult to center the suction pipe D and the through hole of the oil tank case T during assembly, and if there is a gap in the through hole, exhaust gas will leak from the case T, especially when using hazardous gas. It becomes a problem.

In addition, oil rotary vacuum pumps perform exhaust operation while supplying oil stored in the oil tank case to the pump chamber, so they generally tend to entrain oil droplets during the exhaust process and also have problems with loud exhaust noise. (Particularly during exhaust relief from the exhaust port of the first stage pump body, the exhaust gas containing oil is vigorously jetted into the oil tank case). To deal with this problem, various types of partition plates have been installed inside the oil tank case to separate oil droplets from the exhaust gas discharged into the internal space, or measures have been taken to obtain a noise reduction effect. However, the situation is still insufficient.

The present invention aims to provide a new oil rotary vacuum pump with an improved structure to eliminate or alleviate these problems.

[Means for Solving the Problems] The present invention provides the following configuration to achieve this object. That is, the first stage pump body is provided inside the base body,
The oil rotary pump is a double oil rotary pump in which a second stage pump main body is housed inside an oil tank case connected to one side of the base body, and the second stage pump main body is housed inside the oil tank case. A partition plate having a chevron-shaped cross section is disposed to cover the exhaust port and guide the exhaust gas discharged from the exhaust port along the inner surface thereof, and a partition plate is provided between the oil tank case and the base body, The exhaust gas discharged from the exhaust port of the first stage pump body is guided through a narrow gas passage provided in the partition plate to an exhaust passage formed by the partition plate in the oil tank case.

[Function] With the oil rotary vacuum pump having the above configuration, first,
Since the first stage pump main body is provided inside the base body, the necessary air intake system path can be installed inside the body. Therefore, in the case of a structure in which the suction pipe passes through the oil tank case, assembly is required.
The inconvenience of installation is avoided, and in addition, the installation of the oil tank to the base body and assembly work can be simplified, and the pump as a whole can be made more compact.

Further, in this device, since a partition plate having a chevron-shaped cross section is provided to cover the exhaust port of the second stage pump body, the effect of removing oil droplets from the exhaust gas is improved more reliably. The partition plate temporarily blocks the exhaust gas discharged from the exhaust port of the pump body and reduces its energy.
This system guides the exhaust air along the inner surface of the oil tank and promotes the separation of oil droplets.However, with conventional partition plates, even if oil droplets are trapped, they accumulate on the surface of the partition plate, and the pump There is a problem in that when the exhaust gas is vigorously jetted out from the main body, it scatters again and is emitted from the pump exhaust port along with the exhaust gas.
On the other hand, since the partition plate according to the present invention has a chevron-shaped cross section and sloped surfaces on both sides, the oil droplets adhering to the surface of the partition plate do not flow down one after another and become stagnant.

Furthermore, in this invention, a partition diaphragm is provided between the oil tank case and the base body, and the exhaust gas discharged from the exhaust port of the first stage pump body at the time of relief is transferred to a narrow gas chamber provided with the partition diaphragm. Since the oil is led out through the passage to the exhaust passage formed by the partition plate in the oil tank case, it is more effective in separating and removing oil droplets from the exhaust gas and reducing the exhaust noise. In other words, with this structure, the gas that is vigorously blown out from the exhaust port of the first stage pump body during relief is transferred to a substantially sealed space within the base body above the exhaust port (the five sides of which are connected to the inner wall and the partition plate). This type of pump causes a large amount of noise and oil dispersion, as the oil expands and diffuses once in the oil tank (which is blocked by This alleviates the violent blowing of exhaust gas during relief, which was a factor, and provides a sound-reducing effect and prevents oil from scattering.

[Example] Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 3.

The oil rotary vacuum pump according to the present invention has a first stage pump main body having a large volume and a second stage pump main body having a small volume connected in two stages, as shown in the longitudinal section in Fig. 1. configured. As shown in Fig. 2, the pump body of each stage has an eccentric rotor R with two vanes V retractable from its axis and projecting in opposite directions from the pump frame forming the stator S. It is a well-known mechanism that, under the drive rotation of the rotor R, suction is drawn into the enrichment pump chamber formed at the rear of each vane V, and exhausted from the volume reduction pump chamber formed at the front. It is designed to perform the pump function of the pump.

In this dual type oil rotary vacuum pump, the first
The pump main body of each stage, including the intake system path to be described later, is provided inside the base body 1. That is, the base body 1 is also used as the pump frame of the first stage pump main body, a vaned rotor R is arranged in the space of the stator S formed inside the base body 1, and a rotary shaft 4 is arranged at the axial center of the rotor S. It is penetrated by. Both sides of the pump chamber formed by the stator S and the rotor R are closed by a front wall 5 and an intermediate wall 6, and the intermediate wall 6
Connect the second stage pump body to base body 1 through
is attached to. The second stage pump main body has the same configuration as the first stage pump main body, except that the pump volume is reduced as described above, and the rotary shaft has both rotors R, R mounted on the same axis. A rear wall 7 closes the rear end side of the extended portion 4. In addition, an end plate 8 is further joined to the back surface of this rear wall 7, and a small oil feed pump (rotary pump) operated with the rotating shaft 4 as a drive shaft is installed between the two.
has been established.

The second stage pump main body etc. that are attached to the rear side of the base body 1 in this way are housed inside the oil tank case 2 which is connected to the outer periphery of one end face of the base body 1. Most of it will be immersed in the oil O that is injected and stored in the tank 2. Note that the oil O in the oil tank case 2 is also introduced into a space recessed around the first stage pump body within the base body 1. Further, oil O required for each stage of the rotary pump is supplied from the oil feed pump through required oil passages and circulated. On the other hand, on the front side of the base body 1, a front cover 3 is attached to the outer periphery of the end face, and a fan 9 for directly cooling the front side wall of the base body 1 is provided on a rotating shaft 4 extending from the front wall 5. At the same time, the rotating shaft 4 is connected to a motor (not shown) via coupling rings 10, 10.

Next, the suction and exhaust systems connected to the first and second stage pump bodies will be explained. The suction and exhaust system in this type of pump is already shown in FIG. They are connected and communicated through the opened intake system path 11A. In addition, the exhaust port 12 of the first stage pump body and the intake port 14 of the second stage pump body
and communicate with each other through an exhaust communication passage 13 bored in the intermediate wall 6. A pair of intermediate exhaust ports 15, 15 are provided in the first stage pump main body so as to pass upward through the stator S to directly release part of the exhaust gas from the pump chamber. This intermediate exhaust port 15,
15 is the inside of the base body 1, and includes an upper wall 16a;
It opens into a space (exhaust chamber) 17 surrounded by the front wall 16b and side walls 16c and 16d, and is opened only when the exhaust pressure of the first stage pump body rises above a certain level. Relief valves 18, 18 are attached. Specifically, a support guide rod 18 is inserted into the exhaust chamber 17 from its upper wall 16a.
c, 18c are hung down, and this and the valve bodies 18a, 18a
Springs 18b, 18b are interposed to urge the valve bodies 18a, 18a toward the valve seat. Note that one of the support guide rods 18c, 18c is provided with a ventilation passage 19, into which a sealing plug 20 is screwed at the upper end thereof, so that the ventilation passage 19 is connected to the exhaust chamber 17 in the base body 1.
We have devised a way to allow charging gas to flow in from 9.

Further, the second stage pump body is provided with an exhaust port 21 for further compressing the exhaust gas sent from the first stage and then discharging it intermittently. The exhaust port 21 passes through the stator S upward and opens into the internal space 22 of the oil tank case 2, and an exhaust valve 23 operates the exhaust port at a predetermined exhaust pressure.
It is equipped with That is, a support plate 25 is installed on the vertical wall 24 provided on the frame of the second stage pump main body, and the support guide rod 23c is installed from the support plate 25.
hangs down, and a spring 23b is interposed between the valve body 23a and the valve body 23a to bias the valve body 23a toward the valve seat. A valve mechanism 26 is attached to the rear end of the support plate 25 to adjust the amount of oil supplied by the oil feed pump. The exhaust gas discharged from the exhaust port 21 of the second stage pump body passes through the internal space 22 of the oil tank case 2 together with the exhaust gas discharged from the intermediate exhaust port 15 of the first stage pump body, and finally ends up in the oil tank. It is discharged to the outside from the exhaust port B of the pump provided on the rear upper wall of the case 2.

Therefore, in the dual oil rotary vacuum pump having such a structure, the internal space 2 of the oil tank case 2 is
2, a partition plate 27 having a chevron-shaped cross section is disposed to cover the exhaust port 23 of the second stage pump body. As shown in FIG. 3, this partition plate 27 has a short oblique side 27a with a steep slope on one side and a long oblique side 27b with a gentle slope on the other side. It is eccentric to the side where the exhaust port 21 is located, and the base body 1 is located inside the oil tank case 2.
It extends from the joint surface with the oil tank case 2 to the vicinity of the rear wall of the oil tank case 2. The partition plate 27 forms an exhaust passage 28 below, and the exhaust gas discharged from the exhaust port 21 of the second stage pump body is guided once along its inner surface and then circulated to the internal space 22 above. . Further, a partition partition plate 29 is interposed between the oil tank case 2 having the partition plate 27 therein and the exhaust chamber 17 of the base body 1.
and each of the aforementioned walls of the base body 1, the first
It surrounds five sides of the exhaust chamber 17 formed inside the base body 1 above the intermediate exhaust port 15 of the stage pump main body. Then, a narrow slit-shaped gas passage 30 is opened at the lower end of this partition plate 29, and the exhaust gas discharged from the intermediate exhaust port 15 is expanded and diffused in a closed type exhaust chamber 17 to reduce its energy. The oil is led out through the oil tank case 2 to the exhaust passage 28 below the partition plate 27 disposed inside the oil tank case 2.

In the case of this embodiment, the partition plate 27 that defines the internal space 22 of the oil tank case 2 and the partition plate 29 that separates this from the space (exhaust chamber) 17 of the base body 1 are assembled integrally. Base body 1
A fixture 31 is installed at the contact area between the side walls 16c, 16d of the pump body and the support plate 25 on the second stage pump body.
It is fixed by attaching it.

In the dual oil rotary vacuum pump according to the present invention described above, as mentioned above, the first stage pump body is installed inside the base body 1, so there is no need to connect a suction pipe, etc. This simplifies assembly of the pump as a whole and contributes to miniaturization. and,
This structure maintains the airtightness inside the oil tank case 2,
Furthermore, since the exhaust chamber 17 of the base body 1 is equipped with a charging gas inflow mechanism, safety in exhausting hazardous gas is also ensured. The exhaust port 21 of the second stage pump main body is located inside the oil tank case 2.
A partition plate 27 having a chevron-shaped cross section is disposed to cover the base body 1, and a partition plate 29 is interposed between the exhaust chamber 17 in the base body 1 and the oil tank case 2, thereby preventing exhaust from the first stage pump body. By directing the narrow gas passage 30 provided in the partition plate 29 to the rear exhaust passage 28 formed by the partition plate 27, the exhaust gas from both pump bodies can be well calmed down internally. Since oil droplets do not accumulate on the plate 27, the discharge of exhaust gas carrying oil droplets from the exhaust port B of the pump is reduced, and the noise reduction effect is further improved.

[Effects of the Invention] As described above, according to the present invention, it is possible to provide an oil rotary vacuum pump that is easy to assemble, has little oil dissipation from the pump exhaust port, and has characteristics of quiet exhaust noise.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view of a double oil rotary vacuum pump showing an embodiment of the present invention, Fig. 2 is a cross-sectional view taken along the line X--X of Fig. 1, and Fig. 3 is a cross-sectional view taken along the line Y-Y. FIG. FIG. 4 is a schematic cross-sectional view showing an example of the configuration of a double oil rotary vacuum pump, and FIG. 5 is a schematic cross-sectional view showing the assembled structure. ...1st stage pump main body, ...2nd stage pump main body, 1...Base body, 2...Oil tank case,
3... Front cover, 4... Rotating shaft, 15... Intermediate exhaust port of the first stage pump body, 17... Space in the base body (exhaust chamber), 21... Exhaust port of the second stage pump body, 22... Internal space of oil tank case, 27
... Partition plate, 28 ... Exhaust passage, 29 ... Partition partition plate, 30 ... Gas passage, A ... Pump intake port,
B...Pump exhaust port, O...Oil.

Claims (1)

[Scope of utility model registration request] A first stage pump main body is provided inside a base body, and a second stage pump main body is housed inside an oil tank case connected to one side of the base body.
In the continuous oil rotary pump, a partition plate having a chevron-shaped cross section is provided inside the oil tank case and covers the exhaust port of the second stage pump body and guides the exhaust gas discharged from the exhaust port along the inner surface thereof. In addition to arranging
A partition diaphragm is provided between the oil tank case and the base body, and the exhaust gas discharged from the exhaust port of the first stage pump body is passed through the narrow gas passage provided in the partition diaphragm to the partition plate inside the oil tank case. An oil rotary vacuum pump characterized in that the pump is led out to an exhaust passage formed by.