WO2011037132A1

WO2011037132A1 - Oil rotary vacuum pump

Info

Publication number: WO2011037132A1
Application number: PCT/JP2010/066391
Authority: WO
Inventors: 智成田中; 浩司柴山
Original assignee: 株式会社アルバック
Priority date: 2009-09-25
Filing date: 2010-09-22
Publication date: 2011-03-31
Also published as: TW201135066A

Abstract

A sedimentation section (6) is formed in the lower section of a housing (2). The sedimentation section (6) is an oil tank which is a member integrated with the housing (2) and which is formed to have a predetermined depth in the section below a pump chamber (10), for example. The sedimentation section (6) is provided with a partition wall (42), a discharge port (43) and a convection suppression member (44). A predetermined amount of lubricating oil (vacuum pump oil) (41) is retained (sealed) in the sedimentation section (6).

Description

Oil rotary vacuum pump

The present invention relates to an oil rotary vacuum pump.
This application claims priority based on Japanese Patent Application No. 2009-220968 filed in Japan on September 25, 2009, the contents of which are incorporated herein by reference.

The oil rotary vacuum pump is a positive displacement vacuum pump that uses oil to reduce airtightness and ineffective space between components such as rotors and sliding blades (vanes). Oil rotary vacuum pumps operate effectively from atmospheric pressure to high vacuum, are small and capable of large pumping speeds, and are the most efficient pumps that can operate from atmospheric pressure. It is often used as a representative model.

In such an oil rotary vacuum pump, lubricating oil (vacuum pump oil) is enclosed in a housing that houses a pump chamber for the purpose of internal gas sealing and lubrication of a bearing portion of a rotor rotating shaft. This lubricating oil is supplied to the bearing portion of the rotor rotating shaft and the pump chamber by an oil circulation device including a sub pump, for example. And the lubricating oil provided for lubrication or sealing flows, for example, into an oil tank provided in the lower part of the housing and is stored.

Lubricating oil used in oil rotary vacuum pumps is mixed with foreign matter such as fine particles (powder) insoluble in lubricating oil as it is used. For example, when an oil rotary vacuum pump is used for decompression of a silicon refining device, silicon fine particles contained in the sucked gas adhere to a cylinder or vane of the pump or a bearing portion of a rotor rotating shaft. Since such silicon fine particles may cause damage to the inner wall and vane of the cylinder due to the rotation of the rotor, the attached fine particles are discharged by supplying lubricating oil to these parts by the oil circulation device.

As the lubricating oil circulates, fine particles are dispersed and accumulated in the lubricating oil that has passed through the cylinders, vanes, bearings of the rotor rotating shaft, and the like. If the lubricating oil containing fine particles is supplied again to the bearings of the cylinder, vane, rotor rotating shaft, etc., the fine particles may cause wear and damage to the bearings of the cylinder, vane, rotor rotating shaft and the like.

For this reason, in a conventional oil rotary vacuum pump, for example, circulating lubricating oil is passed through a filter device to capture fine particles and remove fine particles contained in the lubricating oil.

JP 2002-70775 A

However, since the conventional oil rotary vacuum pump as described above requires a filter device for separating foreign matter (fine particles) dispersed in the lubricating oil, the structure becomes complicated and the manufacturing cost increases. was there.
Further, the running cost is increased due to periodic replacement of the consumable filter and the maintenance of the filter device itself, and at the same time, the operation rate of the oil rotary vacuum pump due to the maintenance is also reduced. In particular, when an oil rotary vacuum pump as described above is used to depressurize a device that produces extremely fine foreign matter of a size of several μm, such as a silicon purification device, the filter is clogged in a short time with fine foreign matter. Running costs due to frequent filter changes.

An object of the present invention is to provide an oil rotary vacuum pump capable of easily performing solid-liquid separation of lubricating oil with a simple configuration and capable of reducing manufacturing costs and running costs.

An oil rotary vacuum pump according to an aspect of the present invention includes a pump chamber in which a rotor is rotatably incorporated in a cylinder, a housing that houses the pump chamber, and an oil circulation device that circulates lubricating oil in the housing. And a precipitation section for storing the lubricating oil and precipitating solid matter mixed in the lubricating oil to perform solid-liquid separation.

The said aspect WHEREIN: The discharge port which discharges the settled solid substance out of the said precipitation part can be formed in the bottom part vicinity of the said precipitation part.
In the above aspect, a convection suppressing member that suppresses re-diffusion of the precipitated solid matter can be formed in the settling portion between the liquid level of the stored lubricating oil and the bottom surface of the settling portion.

The said aspect WHEREIN: The said precipitation part is integrally formed with the said housing | casing, and can be distribute | arranged to the lower part of the said pump chamber.
In the above aspect, an oil suction port and an oil discharge port of the oil circulation device extend to the settling portion, and a stored lubricating oil is disposed between the oil suction port forming position and the oil discharge port forming position in the settling portion. The partition which suppresses the flow of can be formed.

The said aspect WHEREIN: The said precipitation part is formed separately from the said housing | casing, and can provide the oil-absorption port and oil drain port of the said oil circulation apparatus.
In the above aspect, the precipitation portion can be formed airtight with respect to the outside air.

According to the oil rotary vacuum pump according to the aspect of the present invention, the fine particles (foreign matter) diffused in the lubricating oil can be easily and reliably retained only in the settling portion for a predetermined time without using a filter device or the like. Can be separated and removed. As a result, an oil rotary vacuum pump with a simple configuration and easy maintenance can be manufactured at low cost.

Moreover, by performing precipitation separation to remove fine particles, it is possible to significantly reduce the running cost of oil rotary vacuum pumps, including that consumables such as filters are unnecessary and that maintenance of the filter device is unnecessary. It becomes possible.

Furthermore, by performing precipitation separation to remove fine particles, the separated precipitate (slurry) can be discharged at any time from the discharge port provided at the bottom of the precipitation portion even during operation of the oil rotary vacuum pump. It becomes possible to increase the operating rate of the pump.

It is the schematic which shows an example of an oil rotary vacuum pump. It is sectional drawing which shows the structure of a pump chamber. It is a principal part perspective view which shows the rotor of a pump chamber. It is the schematic which shows another example of an oil rotary vacuum pump.

Hereinafter, an oil rotary vacuum pump according to an embodiment of the present invention will be described with reference to the drawings. The present embodiment is specifically described for better understanding of the gist of the invention, and does not limit the invention unless otherwise specified. In addition, in the drawings used in the following description, in order to make the features of the present invention easier to understand, there is a case where a main part is shown in an enlarged manner for the sake of convenience. Not necessarily.

(First embodiment)
FIG. 1 is a schematic diagram showing a configuration of an oil rotary vacuum pump according to an embodiment of the present invention. The oil rotary vacuum pump 1 includes a pump chamber 10 and an oil circulation device 3 inside a pressure-resistant housing 2. In addition, the housing 2 is formed with an inlet 4 connected to a chamber for decompressing, for example, a chamber of a silicon purifier, and a lead-out port 5 for exhausting the gas in the housing 2 toward the outside air. A precipitation part (solid-liquid separation part) 6 is formed at the lower part of the housing 2.

FIG. 2 is a sectional view showing an outline of the pump chamber. The pump chamber 10 includes a cylindrical cylinder 12. An intake port 14 and an exhaust port 16 are provided in the upper portion of the cylinder 12. The air inlet 14 is connected to the inlet 4 formed in the housing 2, and the air inlet 14 is connected to the outlet 5. A cylindrical rotor 20 is rotatably disposed inside the cylinder 12. The rotation axis of the rotor 20 is disposed offset upward from the center axis of the cylinder 12.

FIG. 3 is an exploded perspective view of the rotor. A plurality (two in this embodiment) of slots 22 are formed in parallel with the rotation axis from the outer peripheral surface of the rotor 20 toward the rotation axis. A vane 30 is inserted into the slot 22. The vane 30 is formed in a flat plate shape.

In such a pump chamber 10, when the oil rotary vacuum pump 1 is operated, the rotor 20 rotates and the vane 30 is displaced in a direction of jumping out of the slot 22 by centrifugal force. Thereby, the rotor 20 rotates while the tip of the vane 30 is in contact with the inner surface of the cylinder 12. Since the rotational axis of the rotor 20 is offset from the central axis of the cylinder 12, the volume of the space surrounded by the rotor 20, the cylinder 12 and the vane 30 changes as the rotor 20 rotates. Gas transfer is performed by this volume change, and the chamber of the apparatus connected to the inlet 4 (see FIG. 1) is decompressed.

The pump chamber 10 generally has a structure in which a cylinder is immersed in lubricating oil (vacuum pump oil) to prevent intrusion of outside air. For this reason, the lubricating oil necessary for the lubrication and sealing with the oil film is sucked.

Referring again to FIG. 1, the rotor 20 (see FIG. 2) accommodated in the pump chamber 10 is rotatably supported by bearings 7 at both ends. The bearing 7 is also supplied with lubricating oil for lubrication.
An oil mist trap or the like may be formed at the outlet 5. The oil mist trap captures oil contained in the gas exhausted from the exhaust port 16 of the pump chamber 10.

The oil circulation device 3 includes, for example, an oil pump 40 and a supply pipe P <b> 1 that is connected to the oil pump 40 and extends from the settling portion 6 to the pump chamber 10 and the bearing 7 via the oil pump 40. The oil circulation device 3 sucks the lubricating oil 41 from the precipitation section 6 described later, and supplies the lubricating oil 41 to the pump chamber 10 and the bearing 7 via the supply pipe P1.
Also, the oil circulation device 3 directs the lubricating oil 41 used for lubrication or sealing with an oil film in the pump chamber 10 and the bearing 7 and the lubricating oil 41 accumulated in the oil mist trap of the outlet port 5 toward the settling portion 6. A recovery pipe P2 is provided.

The sedimentation part 6 is an oil tank formed so as to have a predetermined depth at the lower part of the pump chamber 10 by a member integral with the housing 2, for example. The sedimentation section 6 is provided with a partition wall 42, a discharge port 43, and a convection suppressing member 44. A predetermined amount of lubricating oil (vacuum pump oil) 41 is stored (enclosed) in the precipitation portion 6. The oil suction port PI that constitutes one end of the supply pipe P1 of the oil circulation device 3 may be formed so as to be positioned near the surface layer (near the oil surface) of the lubricating oil 41. Further, the oil discharge port PO forming one end of the recovery pipe P2 may be formed at a position extending to the middle of the storage depth of the lubricating oil 41.

The partition wall 42 is a lubricating oil between the formation position of the oil suction port PI that forms one end of the supply pipe P1 of the oil circulation device 3 and the formation position of the oil discharge port PO that forms one end of the recovery pipe P2 in the sedimentation section 6. It is formed with a predetermined length from the oil surface 41 toward the bottom surface of the precipitation portion 6.

The discharge port 43 may be formed in the vicinity of the bottom surface of the precipitation part 6 and provided with a valve that can be freely opened and closed. The discharge port 43 discharges a precipitate (slurry) S in which foreign matter such as fine particles that have flowed in by the operation of the oil rotary vacuum pump 1 is precipitated in the settling unit 6.

The convection suppressing member 44 has a structure (for example, a net structure or a porous structure such as a net or a sponge) that covers (covers) at least a part of the surface of the precipitate (slurry) S. The convection suppressing member 44 partially shields the dynamic pressure action on the surface of the precipitate due to the inflow of the lubricating oil 41 discharged from the oil discharge port PO toward the settling portion 6 or partially blocks the impact. Relax. Therefore, the re-diffusion of the precipitate in the precipitation part 6 can be suppressed, and the re-diffusion of at least a part of the precipitate can be limited to the vicinity of the convection suppressing member 44. In one embodiment, the aperture ratio (porosity, aperture size and density) of at least a part of the convection suppressing member 44 can be changed.

The operation and effect of the oil rotary vacuum pump having such a configuration will be described. When the oil rotary vacuum pump 1 is operated, gas is transported from the inlet 4 to the outlet 5 by the operation of the pump chamber 10 described above, and a device such as a vacuum device connected to the inlet 4 is depressurized and vacuumed. Can be. Simultaneously with the operation of the pump chamber 10, the oil circulation device 3 is operated, and the lubricating oil stored in the settling portion 6 is sucked up from the oil suction port PI by the oil pump 40. Then, the lubricating oil 41 sucked into the pump chamber 10 and the bearing 7 is supplied via the supply pipe P1.

Lubricating oil 41 supplied to the pump chamber 10 and the bearing 7 is used for lubrication and sealing with an oil film, and is discharged from the oil discharge port PO toward the precipitation unit 6 through the recovery pipe P2. Further, the mist-like lubricating oil 41 contained in the gas exhausted from the pump chamber 10 is also recovered by an oil mist trap or the like provided at the outlet port 5 and passes through the recovery pipe P2 and from the oil outlet PO to the precipitation section 6. It is discharged toward

The lubricating oil 41 returned to the sedimentation section 6 through the recovery pipe P2 is mixed with fine particles (foreign matter) contained in the gas sucked in the pump chamber 10. For example, when the oil rotary vacuum pump 1 is used for decompression of the silicon refining device, silicon fine particles having a size of several μm are mixed and diffused in the lubricating oil 41 that has passed through the pump chamber 10. Similarly, fine particles such as silicon fine particles are mixed and diffused in the lubricating oil 41 recovered from the oil mist trap provided at the outlet 5.

Lubricating oil 41 mixed and diffused with fine particles (foreign matter) discharged from the oil discharge port PO to the precipitation part 6 is stored in the precipitation part 6. In the precipitation unit 6, the fine particles (foreign matter) contained in the discharged lubricating oil 41 are solid-liquid separated by precipitation, and are deposited as fine particle precipitates (slurry) S on the bottom of the precipitation unit 6. Even when the oil rotary vacuum pump 1 is in operation, the precipitate (slurry) S is discharged from the discharge port 43 formed in the vicinity of the bottom surface of the precipitation portion 6 as needed, and the precipitate (slurry) S is discharged from the precipitation portion 6. Can be removed.

Moreover, since the convection produced by the flow of the lubricating oil 41 flowing into the precipitation part 6 from the oil outlet PO is relaxed and suppressed by the convection suppression member 44 formed in the middle of the precipitation part 6, the convection is suppressed at the bottom of the precipitation part 6. The deposited sediment S is not substantially re-diffused by convection.

Further, by forming the partition wall 42 that separates the formation position of the oil suction port PI and the formation position of the oil discharge port PO, the flow of oil from the vicinity of the oil discharge port PO toward the vicinity of the oil suction port PI is achieved. It is suppressed. As a result, it is possible to prevent the lubricating oil 41 including the fine particles flowing from the oil discharge port PO from flowing (circulating) near the surface layer without being precipitated, and being sucked up from the oil suction port PI as it is.

Although depending on the specific gravity of the fine particles mixed in the lubricating oil 41, the lubricating oil 41 discharged from the middle of the depth of the lubricating oil 41 is sucked up from the oil suction port PI formed near the surface layer of the lubricating oil 41. By adjusting the shape of the precipitation part 6 and the flow rate (circulation amount) of the lubricating oil 41 so as to stay on the precipitation part 6 on average for 15 minutes or more by the time, the fine particles (foreign matter) diffused in the lubricating oil 41 Can be reliably precipitated and separated.

As described above, according to the oil rotary vacuum pump 1 according to the aspect of the present invention, the fine particles (foreign matter) diffused in the lubricating oil 41 are retained in the precipitation unit 6 for a predetermined time without using a filter device or the like. It can be easily and reliably separated and removed. Thereby, the oil rotary vacuum pump 1 having a simple configuration and easy maintenance can be manufactured at low cost.

Furthermore, by performing precipitation separation to remove fine particles, the separated precipitate (slurry) can be discharged from the discharge port 43 provided at the bottom of the precipitation portion 6 at any time even during operation of the oil rotary vacuum pump 1, The operating rate of the oil rotary vacuum pump 1 can be increased.

In the above-described embodiment, the lubricating oil 41 supplied to the pump chamber 10 and the bearing 7 is discharged from the oil discharge port PO toward the settling portion 6 via the recovery pipe P2. However, the present invention is not limited to this, and the configuration may be such that the lubricating oil 41 is recovered directly from the pump chamber 10 or the bearing 7 to the precipitation portion 6 by natural fall.

(Second embodiment)
FIG. 4 is a schematic diagram showing a configuration of an oil rotary vacuum pump according to another embodiment of the present invention.
The oil rotary vacuum pump 51 includes a pump chamber 50 and an oil circulation device 53 inside a pressure-resistant housing 52. In addition, the casing 52 is formed with an inlet 54 connected to a chamber for decompressing, for example, a chamber of a silicon purification apparatus, and an outlet 55 for exhausting the gas in the casing 52 toward the outside air. In addition, an oil tank 59 for temporarily storing the lubricating oil 61 circulated by the oil circulation device 53 is formed integrally with the housing 52 near the bottom of the housing 52. In addition, adjacent to the casing 52, a precipitation portion 56 is provided that is separate from the casing 52.

The oil circulation device 53 includes, for example, an oil pump 60 and a supply pipe P <b> 1 extending toward the pump chamber 50 and the bearing 57. The oil circulation device 53 has a recovery pipe P2 for recovering the lubricating oil 61 used for lubrication and sealing with an oil film in the pump chamber 50 and the bearing 57, and the lubricating oil 46 collected in the oil mist trap of the outlet 55. Prepare.

The supply pipe P1 is extended to the outside of the casing 52 and connected to the settling portion 56 so that the oil inlet PI that constitutes one end thereof is located near the surface layer of the lubricating oil 61 stored in the settling portion 56. Further, the recovery pipe P2 is further extended toward the settling portion 56 via an oil tank 59 formed integrally with the bottom of the casing 52, and the recovery pipe P2 is extended to a position where the lubricating oil 61 is stored to the middle. An oil discharge port PO that forms one end of the oil is formed.

The sedimentation part 56 is formed separately from the housing 2 and the inside thereof has an airtight structure against the outside air. Further, a discharge port 63 is formed in the vicinity of the bottom surface of the precipitation portion 56. The discharge port 63 discharges a precipitate (slurry) S in which foreign matters such as fine particles that have flowed in by the operation of the oil rotary vacuum pump 51 are precipitated by the settling portion 56. Further, a convection suppressing member 64 that suppresses re-diffusion of the precipitate (slurry) S in the settling portion 56 by the lubricating oil 61 flowing from the oil outlet PO is provided in the middle of the settling portion 56. ing.

According to the oil rotary vacuum pump 51 having such a configuration, the sedimentation portion 56 is formed separately from the housing 52, thereby preventing the influence of vibration generated in the pump chamber 50 or the like from reaching the sedimentation portion 56. Thus, the precipitation effect of the precipitate (slurry) S in the precipitation portion 56 can be further enhanced. Moreover, if the sedimentation part 56 is made airtight with respect to the outside air and the lubricating oil 61 is caused to flow into the sedimentation part 56 from the oil tank 59 of the housing 52 via the recovery pipe P2, the internal pressure of the sedimentation part 56 increases and the supply pipe Since the lubricating oil 61 is supplied from the P1 to the oil pump 60, the circulation of the lubricating oil 61 can be smoothly started even when using an oil pump of a type that cannot perform the suction operation without the lubricating oil 61 at the start of operation. .

In the above-described embodiment, fine particles contained in the lubricating oil 41 flowing in from the oil outlet PO (foreign matter contained in the gas sucked in the pump chamber 10) are substances (precipitation) having a specific gravity greater than the specific gravity of the lubricating oil 41. Therefore, the oil suction port PI is set near the liquid level of the lubricating oil 41, but the present invention is not limited to this.

For example, referring to FIG. 1, when the fine particles (foreign matter) are a substance having a specific gravity smaller than the specific gravity of the lubricating oil 41, the fine particles float near the liquid surface of the lubricating oil 41, so the lubricating oil 41 containing the fine particles is sucked up. The oil suction port PI is set in the vicinity of the bottom of the lubricating oil 41 so as not to exist. Further, the discharge port 43 is set at a height in the vicinity of the lubricating oil 41 liquid surface (floating matter).
In addition, when the fine particles (foreign matter) are mixed with a substance having a specific gravity larger than the specific gravity of the lubricating oil 41 and a substance having a specific gravity smaller than the specific gravity of the lubricating oil 41, the fine particles are near the liquid surface of the lubricating oil 41. Since the oil is agglomerated in the vicinity of the bottom portion, the oil suction port PI is set at the liquid layer intermediate position of the lubricating oil 41 so as not to suck up the lubricating oil 41 containing fine particles. Further, the discharge port 43 is also arranged at a height near the liquid surface (floating matter) of the lubricating oil 41.

1 Oil rotary vacuum pump, 2 housing, 3 oil circulation device, 6 sedimentation part (solid-liquid separation part), 10 pump room, 41 lubricating oil, 43 discharge port, 44 convection suppression member, PI oil absorption port, PO oil discharge port

Claims

A pump chamber in which a rotor is rotatably incorporated in a cylinder;
A housing for housing the pump chamber;
An oil circulation device that circulates lubricating oil in the housing; a precipitation unit that stores the lubricating oil and precipitates solid matter mixed in the lubricating oil to perform solid-liquid separation;
An oil rotary vacuum pump characterized by comprising:
The oil rotary vacuum pump according to claim 1, wherein a discharge port for discharging the precipitated solid matter to the outside of the settling portion is formed near the bottom of the settling portion.
A convection suppressing member that suppresses re-diffusion of the precipitated solid matter is formed between the liquid surface of the stored lubricating oil and the bottom surface of the precipitation portion in the precipitation portion. The oil rotary vacuum pump according to claim 1 or 2.
The oil rotary vacuum pump according to any one of claims 1 to 3, wherein the settling portion is formed integrally with the casing and is disposed in a lower portion of the pump chamber.
An oil suction port and an oil discharge port of the oil circulation device extend to the settling portion, and the flow of stored lubricating oil is suppressed between the oil suction port forming position and the oil discharge port forming position in the settling portion. The oil rotary vacuum pump according to claim 4, wherein a partition wall is formed.
4. The oil rotation according to claim 1, wherein the settling portion is formed separately from the housing, and is provided with an oil suction port and an oil discharge port of the oil circulation device. Vacuum pump.
The oil rotary vacuum pump according to claim 6, wherein the settling portion is formed airtight with respect to outside air.