JP2000186684A - Oil rotary vacuum pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oil rotary vacuum pump which can keep low vacuum exhaust function, and attain low noise operation. SOLUTION: In an oil rotary vacuum pump for feeding oil by connecting oil feed passages to a pump chamber, two oil feed passages Y4, Y5 are parallely arranged. An opening/closing valve KV is arranged on one oil feed passage Y5. A minimum amount of oil is fed through the other oil feed passage Y4 on which the opening/closing valve KV is not arranged. The opening/closing valve KV is operated according to a generation state of the noises, for keeping exhaust function while performing low noise operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an oil rotary vacuum pump used in a vacuum application field.

[0002]

2. Description of the Related Art Oil rotary vacuum pumps have improved pumping capacity,
As shown in FIG. 5, two pump mechanisms, a first stage and a second stage, are provided to obtain a high vacuum. A so-called two-stage oil rotary vacuum pump configured to take in air and exhaust by rotation of a rotor in the second-stage pump chamber is often used.

In this two-stage oil rotary vacuum pump, pump chambers P1 and P2 are usually arranged coaxially. The pump chambers P1 and P2 are composed of cylinders C1 and C2 and cylinders C1 and C2. Rotor R1, which is inscribed at the eccentric position of
R2 and the rotors R1 and R2 are housed so as to be able to protrude and retract in the radial direction, and the ends are partitioned by vanes V1 and V2 slidably provided on the inner peripheral surfaces of the cylinders C1 and C2.

The pump bodies constituting the pump chambers P1 and P2 are usually immersed in oil, and the rotors R1 and R2 are driven to rotate while the pump oil is supplied to the pump chambers P1 and P2. The gas sucked in from the intake port S1 by this rotation drive is compressed and exhausted in the first-stage pump chamber P1, and then the second gas is discharged from the exhaust port H1 of the first-stage pump chamber P1 through the intermediate passage M.
It is sent to the stage pump chamber P2. The gas sent to the second-stage pump chamber P2 is sucked into the intake port S2 of the second-stage pump chamber P2, and subsequently compressed and exhausted by the rotation of the rotor R2, and the gas is discharged through the exhaust port H2 of the second-stage pump chamber P2. It will be discharged outside.

[0005] In such a two-stage oil rotary vacuum pump, the oil passage Y1, the hydraulic pump FP, and the filter are inserted into the pump chambers P1 and P2 for the second-stage pump chamber P2 in order to enhance the exhaust characteristics. The fuel is supplied by providing a refueling means including an F, a tank T, and the like. Further, the first-stage pump chamber P1 is configured to be supplied with a necessary oil amount for lubrication and airtightness through a communication oil supply passage RS. In this case, conventionally, as shown in the figure, in order to eliminate the adverse effect caused by the oil supply from the second-stage pump chamber P2 to the first-stage pump chamber P1 by the differential pressure, the oil supply path is provided separately from the communication oil supply path RS. Y
A branch oil supply passage Y3 branching from 2 is provided, and an on-off valve FV that opens and closes the branch oil supply passage Y3 according to the level of the intake pressure of the first-stage pump chamber P1 is provided in the branch oil supply passage Y3. The on-off valve FV is opened during a load operation in which the intake port pressure is high, and the first-stage pump chamber P1 is refueled directly by the refueling means in addition to refueling from the communication refueling passage RS.
The pump function of the stage pump chamber P1 is maintained.

[0006]

In such a conventional technique, refueling by the refueling means often increases the amount of refueling. When the refueling amount is large, an accident such as seizure of the pump can be prevented, which is advantageous. However, when the refueling amount is too large, there is a problem that noise is increased. From the viewpoint of noise prevention, a small refueling amount is desirable. In this regard, in the related art, the oil supply path Y2 is connected to the second-stage pump chamber P2, and the communication oil supply path RS and the branch oil supply path Y3 are provided side-by-side for the first-stage pump chamber P1. Although the opening and closing of the on-off valve FV is adjusted in consideration of the above, the provision of the branch refueling passage Y3 has a long oil passage, and it is difficult to refuel smoothly.
The structure is complicated, and the second-stage pump chamber P2
Since oil is supplied through a single fixed-type oil supply path, the amount of oil cannot be adjusted, and the noise problem has not yet been solved.

[0007]

The oil rotary vacuum pump provided by the present invention is an oil rotary vacuum pump for connecting the oil supply passage to a pump chamber to supply oil, in order to solve the above problems. The two oil supply paths are arranged in parallel, and one of the oil supply paths is provided with an on-off valve. Therefore, by configuring the oil supply passage without the on-off valve to function as a system for performing minimum lubrication, the on-off valve can be operated depending on the presence / absence of noise, and a low level can be maintained while maintaining the exhaust function. Noise driving can be realized.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below with reference to an embodiment shown in the drawings. The embodiment of the present invention can be applied to a single-stage oil rotary vacuum pump having one pump chamber in principle, but can also be suitably applied to a two-stage oil rotary vacuum pump having two pump chambers. . First,
FIG. 1 shows an embodiment applied to this two-stage oil rotary vacuum pump.
It will be described based on. In FIG. 1, components and configurations denoted by the same reference numerals as those in FIG. 5 are the same as those in FIG. 1, and detailed description is omitted.

In FIG. 1, a first-stage pump mechanism includes a rotor R inscribed at an eccentric position in a first-stage pump chamber P1.
1 and a vane V accommodated in the rotor R1 so as to be able to appear and disappear.
1 and an intake port S1 and an exhaust port H1. On the other hand, the second-stage pump mechanism includes a rotor R2 inscribed at an eccentric position in the second-stage pump chamber P2, a vane V2 housed in the rotor R2 so as to be retractable, and an intake port S2.
And an exhaust port H2. Both rotors R
Specifically, R1 and R2 have their respective centers disposed on a coaxial core and are rotationally driven by an electric motor (not shown) or the like. First, the first-stage pump mechanism is connected to the intake port S1 by the change in the volume defined by the cylinders C1, C2 and the vanes V1, V2 and the rotors R1, R2 due to the rotation of the rotors R1, R2.
And exhausts the gas to the exhaust port H1. The discharged gas is guided to the intake port S2 of the second-stage pump mechanism via the intermediate communication passage M, and is sucked into the second-stage pump chamber P2. Finally, the exhaust valve HV is pushed up from the exhaust port H2 and is discharged to the outside.

In such a two-stage oil rotary pump, oil is supplied by oil supply means using a hydraulic pump FP. That is, the oil from the oil tank T is configured to be supplied to the pressurized on-off valve mechanism KM via the oil passage Y1. The pressure oil from the pressurized on-off valve mechanism KM is supplied to the oil passage Y
The oil passage Y2 is supplied to the second-stage pump chamber P2 through the oil passage 2, and the oil passage Y2 is branched in the middle, and oil supply passages Y4 and Y5 are provided side by side.
Both oil supply passages are connected to the second-stage pump chamber P2.
Here, the oil supply passage Y4 is set to a hole diameter capable of performing the minimum necessary oil supply when the vacuum pressure is low, and the other oil supply passage Y5 functions as an auxiliary oil supply passage. Open / close valve KV is provided. The on-off valve KV is kept open at all times, and is operated so as to be closed particularly when noise is generated in exhaust near the ultimate pressure.

When the on-off valve KV1 is closed, the oil supply passage Y
When the refueling from the pump 5 is stopped, the pump chambers P2 and P1
Is supplied only from the oil supply path Y4 and the communication oil supply path RS, so that the amount is limited and the noise can be reduced. FIG. 2 shows an embodiment in which an on-off valve KV1 opened and closed by a solenoid SL is interposed instead of the on-off valve KV1 in FIG. 1, and the on-off valve KV1 is operated by the pressure of the intake port S1 of the first-stage pump chamber P1. It is like that. That is, when low pressure (high vacuum) and when lubrication is not necessary much, the pressure sensor VS detects the pressure,
The detection signal is input to the control circuit CD. Then, in response to a signal from the pressure sensor VS, the control circuit CD operates the solenoid SL to close the on-off valve KV1. Other configurations are the same as those in FIG. 1, and detailed description is omitted.

In this manner, lubrication and sealing in the pump chambers P1 and P2 are sufficiently performed by lubricating the second-stage pump mechanism and the first-stage pump mechanism by the lubrication mechanism, and the lubrication amount is minimized and the noise is reduced. Oil rotary vacuum pump having a small size can be provided. In addition, in FIG. 1 and FIG.
Is commonly used as an oil tank for immersing the pump bodies PD of both pump mechanisms. In addition, pressurized on-off valve mechanism KM
, The valve body PL is biased by the spring SP, and the hydraulic pump FP
Is pressurized and supplied through an oil passage Y2,
It will be transferred to Y5. When the pressure is high, such as at the start of operation, there is no output signal from the pressure sensor VS and there is no on-off valve K
V1 is open and the pump chambers P1, P2
A large amount of lubrication is performed so that internal lubrication and sealing can be performed more reliably, and safe driving is guaranteed.

As described above, the present invention is characterized in that two oil supply paths by the oil supply means are connected in parallel and connected to the pump chamber, and the oil supply can be adjusted by interposing an open / close valve in one of the oil supply paths. The present invention is applicable to not only a two-stage oil rotary vacuum pump but also a so-called ordinary oil rotary vacuum pump having one pump mechanism, that is, one pump chamber, in principle. 3 and 4 show an embodiment in which the present invention is applied to this ordinary oil rotary vacuum pump. That is, the embodiment of FIG. 3 corresponds to FIG. 1, and is an example in which a manual on-off valve KV is interposed in the auxiliary oil supply passage Y5, only the number of pump mechanisms is different, and the embodiment of FIG. This corresponds to FIG. 2 and is an example in which an on-off valve KV1 operated by a solenoid SL is interposed in an oil supply path Y5, and is an example in which only the number of pump mechanisms is different.
Components and mechanisms in FIGS. 3 and 4 that are the same as those in FIGS. 1 and 2 are the same as those in FIGS. 1 and 2, and detailed descriptions of operations and functions are omitted.

Although the features of the oil rotary vacuum pump provided by the present invention are as described above, other modified embodiments utilizing the features are included. For example, an on / off valve, a shutoff valve, a gate valve, or the like can be applied as the opening / closing valve, but an adjusting valve that can adjust the opening degree according to the pressure condition can also be used. Further, in the illustrated example, an example of a forced oil supply means is shown, and the hydraulic pump PL and the pressurized on-off valve mechanism KM are provided. However, such a forced oil supply means is not always necessary. And a configuration in which the pump chambers P1 and P2 are refueled by the head of the oil tank T. Further, even when the hydraulic pump FP is used, it is not always necessary to interpose the pressurized on-off valve mechanism KM, and various modifications can be given. The present invention covers all of these modifications.

[0015]

The oil rotary vacuum pump provided by the present invention is as described above in detail, and at the time of high pressure, lubrication necessary for lubrication and airtightness is performed in the pump chamber to ensure safe operation. In addition, it is possible to provide a vacuum pump in which the amount of lubrication is minimized during low pressure (high vacuum) and noise is reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an oil rotary vacuum pump of the present invention.

FIG. 2 is a diagram showing a configuration of an oil rotary vacuum pump of the present invention.

FIG. 3 is a diagram showing a configuration of an oil rotary vacuum pump of the present invention.

FIG. 4 is a diagram showing a configuration of an oil rotary vacuum pump of the present invention.

FIG. 5 is a diagram showing a configuration of a conventional oil rotary vacuum pump.

[Explanation of symbols]

 C1, C2: Cylinder CD: Control circuit F: Filter FP: Hydraulic pump H1, H2: Exhaust port HP: Hydraulic pump HV: Exhaust valve K1: Oil supply path KM: Pressurized on-off valve Mechanism Y3 Branch oil supply passage KV, KV1 On-off valve KV2 Electromagnetic on-off valve M Intermediate passage P1 First-stage pump chamber P2 Second-stage pump room PL Valve element FP Hydraulic pressure Pump R1, R2 ... Rotor RS ... Communication oil supply path S1, S2 ... Inlet SL ... Solenoid SP ... Spring T ... Tank V1, V2 ... Vane VS ... Pressure sensor Y1 ... Oil path Y2, Y4, Y5 ... Refueling path

Claims (2)

[Claims] An oil rotary type vacuum pump configured to discharge gas from an intake port to an exhaust port by rotation of a rotor in a pump chamber and to connect an oil supply path to the pump chamber to supply oil. An oil rotary vacuum pump characterized in that two oil supply passages are juxtaposed, and an open / close valve is interposed in one of the oil supply passages. 2. A two-stage pump chamber having a first stage and a second stage, wherein the second-stage pump chamber takes in exhaust gas generated by rotation of the rotor in the first-stage pump chamber. In an oil rotary type vacuum pump configured to exhaust by rotation and connecting the two pump chambers through a communication oil supply path and performing oil supply through an oil supply path connected to the second-stage pump chamber, An oil rotary vacuum pump characterized in that two oil supply passages are juxtaposed, and an open / close valve is interposed in one of the oil supply passages.