JP2002115690A - Cooling structure in vacuum pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently cool oil cooling a material to be cooled in a vacuum pump. SOLUTION: Gears 34, 35 are fixed while they mesh each other in protruding end parts of rotary shafts 19, 20 protruding into a gear housing 33. The rotary shafts 19, 20 are rotated in synchronization by the gears 34, 35. A hole 473 for heat radiation is provided on a bottom wall 472 of a peripheral wall 47 of the gear housing 33 storing the gears 34, 35 by passing through the bottom wall. The hole 473 for heat radiation is covered with a cooling device 50. A fin 503 for heat transfer is integrally provided in the cooling device 50. The fin 503 for heat transfer enters the hole 473 for heat radiation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling structure for a vacuum pump which moves a gas transfer member in a pump chamber based on rotation of a rotating shaft and transfers gas by the operation of the gas transfer member to provide a suction effect. It is.

[0002]

2. Description of the Related Art In a vacuum pump disclosed in JP-A-2-157490 and JP-A-6-101677,
Two adjacent rotors are rotated in a meshed state. The rotating operation of the two rotors rotating while meshing transfers gas. One of the rotation axes of the rotor is
The driving force is obtained from the motor, and the other rotating shaft receives the driving force from the one rotating shaft via a gear mechanism.

[0003] Lubricating oil is stored in a housing that houses the gear mechanism, and the stored oil lubricates the gear mechanism. In order to prevent this lubricating oil from leaking into the pump chamber, a lip seal is provided between the housing wall and a portion of the rotary shaft that penetrates the housing wall separating the housing chamber of the gear mechanism and the pump chamber. .

[0004] In a vacuum pump, heat is generated during the process of compressing exhaust gas, and the generated heat raises the temperature of the main body of the vacuum pump. The lip seal deteriorates when exposed to a high-temperature environment, and the sealing function of the lip seal deteriorates. Therefore, measures are taken to directly cool the lip seal with oil for lubricating the gear mechanism, or to indirectly cool the lip seal by cooling the rotating shaft with the oil.

[0005]

In order to continuously cool an object to be cooled such as a lip seal or a rotating shaft, it is necessary to take heat from oil which has taken heat from the object to be cooled and discharge it to the outside of the main body of the vacuum pump. There is. That is, it is necessary to cool the oil that has cooled the object to be cooled. This heat release is achieved by transferring heat from the oil to the outer wall of the housing containing the gear mechanism. However, the outer wall of the housing that houses the gear mechanism is thick, and the heat transfer efficiency at the outer wall is not good. Therefore, the efficiency of cooling the oil is low, and the cooling target cannot be efficiently cooled. Such poor cooling efficiency leads to early deterioration of the lip seal.

An object of the present invention is to efficiently cool oil for cooling an object to be cooled in a vacuum pump.

[0007]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a vacuum pump which moves a gas transfer body in a pump chamber based on rotation of a rotating shaft and transfers gas by the operation of the gas transfer body to provide a suction action. According to the invention of claim 1, the rotating shaft is protruded from an oil-existing area in an oil housing that forms an area where oil for cooling is present, and a heat-transfer fin is provided on an outer wall of the oil housing that is exposed to the outside. Provided.

[0008] The heat of the oil in the oil housing is transferred from the inner surface to the outer surface of the outer wall of the oil housing and transferred to the outside. By increasing the area of the outer wall of the oil housing,
The heat transfer performance on the outer wall of the oil housing is improved,
The efficiency of cooling the oil in the oil housing is improved. The heat transfer fins increase the area of the wall surface of the oil housing, and the oil in the oil housing is efficiently cooled.

According to the invention of claim 2, in claim 1,
The heat transfer fin is provided on a bottom wall at a bottom of the oil housing for storing the oil. Oil in the oil housing tends to go to the bottom wall. Therefore, the configuration in which the heat transfer fins are provided on the bottom wall is optimal for improving the efficiency of cooling oil.

According to a third aspect of the present invention, in any one of the first and second aspects, the heat transfer fin is provided on an inner surface of the outer wall. The heat transfer fins are exposed to the oil existing area in the oil housing to increase the area of the inner surface of the outer wall of the oil housing. The heat of the oil in the oil housing transfers to the outside of the outer wall of the oil housing via the surface of the heat transfer fins directly.

According to a fourth aspect of the present invention, in any one of the first to third aspects, a heat radiation hole is provided through the outer wall of the oil housing, and the heat radiation hole is covered with a cooler. Thus, the cooler in which the cooler is a part of the outer wall and the cooler is provided with the heat transfer fins is exposed to the oil existing area, so that the efficiency of cooling the oil in the oil housing increases.

According to a fifth aspect of the present invention, in the fourth aspect,
The cooler was formed of a material having higher heat transfer performance than the material of the oil housing. Usually, the oil housing is made of an iron-based material. The configuration using a material having higher heat transfer performance than the iron-based material as the material of the cooler is effective for improving the efficiency of cooling the oil in the oil housing.

According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the oil-existing region is separated from the pump chamber by a partition, and the rotary shaft passes through the partition. A contact-type sealing means for shaft sealing is interposed between the rotary shaft and the partition wall so as to protrude into the oil existing area.

The deterioration of the contact-type sealing means due to heat is suppressed by directly cooling the contact-type sealing means with oil, or indirectly cooling the contact-type sealing means by cooling the rotating shaft with the oil. .

According to a seventh aspect of the present invention, in any one of the first to sixth aspects, the vacuum pump arranges a plurality of the rotating shafts in parallel and arranges a rotor on each of the rotating shafts. A multistage vacuum pump in which rotors on adjacent rotary shafts are meshed with each other and a plurality of pump chambers accommodating a plurality of meshed rotors as a set are arranged in the axial direction of the rotary shaft. The volume of the pump chamber becomes smaller in the order of approaching the partition wall along the axial direction of the rotary shaft, and the gas is transferred through the plurality of pump chambers in the order of the smaller volume. The pump chamber adjacent to the oil existing area was a pump chamber having a minimum volume.

Such a vacuum pump is suitable as an object to which the present invention is applied. In the invention of claim 8, in claim 7, the plurality of rotation shafts are synchronously rotated by using a gear mechanism, and the oil presence area is an area for accommodating the gear mechanism, and the oil presence area is The oil for lubricating the gear mechanism is stored, and oil scraping means for scraping the stored oil so as to lubricate the gear mechanism is provided in the oil existing area.

Oil for lubricating the gear mechanism is used for cooling.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment in which the present invention is embodied in a roots pump will be described below with reference to FIGS.

As shown in FIG. 1A, a front housing 13 is joined to a front end of a rotor housing 12 of the multi-stage roots pump 11, and a front housing 13 is provided.
The sealing body 36 is joined to the. Rotor housing 1
A rear housing 14 as a partition is joined to the rear end of 2. The rotor housing 12, the front housing 13, and the rear housing 14 are all made of an iron-based material. The rotor housing 12 includes the cylinder block 1
5 and a plurality of chamber forming walls 16. As shown in FIG. 2B, the cylinder block 15 includes a pair of block pieces 1.
7 and 18, and the chamber forming wall 16 has a pair of wall pieces 161,
162. As shown in FIG. 1A, the space between the front housing 13 and the room forming wall 16, the space between the adjacent room forming walls 16, and the space between the rear housing 14 and the room forming wall 16 are: , Pump chambers 39, 40, respectively
41, 42 and 43.

A pair of rotating shafts 19, 20 are rotatably supported by the front housing 13 and the rear housing 14 via radial bearings 21, 37, 22, 38 as bearings. Both rotating shafts 19 and 20 are arranged parallel to each other. The rotation shafts 19 and 20 are passed through the chamber forming wall 16.

A plurality of rotors 23, 24, 25, 26, 27 serving as gas transfer bodies are integrally formed on the rotating shaft 19, and the same number of rotors 28, 29, 30, are formed on the rotating shaft 20.
31 and 32 are integrally formed. Rotors 23-32
Have the same shape and the same size when viewed in the direction of the axes 191 and 201 of the rotating shafts 19 and 20. Rotors 23, 24, 2
The thicknesses of the rotors 5, 26, 27 decrease in this order, and the thicknesses of the rotors 28, 29, 30, 31, 32 also decrease in this order.
The rotors 23 and 28 are housed in the pump chamber 39 in a state of being engaged with each other with a slight gap therebetween.
Similarly, the pumps 9 are housed in the pump chamber 40 in a mutually meshed state. Similarly, the rotors 25 and 30 are in the pump chamber 41, the rotors 26 and 31 are in the pump chamber 42,
7, 32 are housed in the pump chamber 43, respectively.

A gear housing 33 as an oil housing made of an iron-based material is joined to the rear housing 14 by tightening a screw 46 (shown in FIG. 3). The end face of the rear housing 14 and the gear housing 3
3 between the peripheral wall 47 and the edge 471 of the peripheral wall 47.
Is interposed. The rotating shafts 19 and 20 penetrate the rear housing 14 and protrude into the gear housing 33, and the protruding ends of the rotating shafts 19 and 20 are provided with gears 34 and 35, respectively.
Are fixedly engaged with each other. An electric motor M is mounted on an end wall 49 of the gear housing 33. The driving force of the electric motor M is transmitted to the rotating shaft 19 via the shaft joint 10, and the rotating shaft 19 is rotated by the electric motor M in the direction of arrow R <b> 1 in FIGS. 2A, 2 </ b> B, and 2 </ b> C. Is done. The rotating shaft 20 obtains the driving force from the electric motor M via the gears 34 and 35,
As shown by the arrow R2 in (a), (b), and (c), the rotating shaft 19 rotates in the opposite direction.

As shown in FIG. 3, lubricating oil Y is stored at the bottom of a gear housing chamber 331 that houses a gear mechanism composed of gears 34 and 35, and the lower part of the gears 34 and 35 is immersed. The lubricating oil Y is swept up by the rotation of the gears 34 and 35. The gear mechanism composed of the gears 34 and 35
It serves as oil scraping means for scraping the stored oil. The lubricating oil Y is supplied to the gears 34 and 35 and the radial bearings 37 and 3
Lubricate 8. The rear housing 14 serves as a partition wall that separates the pump chamber 43 from the gear housing chamber 331 which is an oil existing area. The lubricating oil Y cools the protruding ends 192 and 202 of the rotating shafts 19 and 20.

As shown in FIG. 2B, a passage 163 is formed in the chamber forming wall 16. An inlet 164 and an outlet 165 of the passage 163 are formed in the chamber forming wall 16. The adjacent pump chambers 39, 40, 41, 42, 43
It communicates via a passage 163.

As shown in FIG. 2A, the block piece 18
Is formed so that an inlet 181 communicates with the pump chamber 39. As shown in FIG.
Is formed so that a discharge port 171 communicates with the pump chamber 43. The gas introduced into the pump chamber 39 from the inlet 181 is rotated by the rotation of the rotors 23 and 28 to form the chamber forming wall 1.
6 from the inlet 164 via the passage 163 to the adjacent pump chamber 40 from the outlet 165. Hereinafter, similarly, the gas flows in the order of decreasing the volume of the pump chamber, that is, the pump chamber 4
The transport is performed in the order of 0, 41, 42, 43. Pump room 43
The gas transferred to the discharge port is discharged from the discharge port 171 to the outside. The rotors 23 to 32 are gas transfer bodies that transfer gas.

As shown in FIGS. 1A and 1B, rubber lip seals 44 and 45 serving as contact-type sealing means are arranged near the protruding ends of the rotating shafts 19 and 20. The lip seals 44 and 45 are brought into sliding contact with the peripheral surfaces near the protruding ends, which are the protruding portions of the rotating shafts 19 and 20, to provide a sealing action. The lubricating oil Y scraped up by the gears 34, 35 reaches the lip seals 44, 45 via the gap between the inner ring and the outer ring of the radial bearings 37, 38. The lip seals 44 and 45 are lubricated by the lubricating oil Y and cooled.

As shown in FIGS. 3 and 4, the rotating shaft 19,
The bottom wall 4 of the peripheral wall 47 surrounding the 20 axes 191 and 201
A heat radiation hole 473 is provided through 72. The bottom wall 472 becomes a part of an outer wall exposed outside the main body of the multi-stage roots pump 11. The heat dissipation hole 473 is provided near the edge 471 of the peripheral wall 47 and so as to remove the end wall 49.

On the outer surface of the bottom wall 472, a cooler 50 is provided with a screw 5.
1 is fixed by tightening. The cooler 50 is
The heat dissipation hole 473 is covered, and the cooler 50 and the bottom wall 47 are covered.
A seal ring 52 is interposed between the outer ring 2 and the outer surface. The seal ring 52 surrounds the heat dissipation hole 473. The seal ring 52 prevents the lubricating oil Y in the gear housing 33 from leaking from between the cooler 50 and the outer surface of the bottom wall 472. Cooler 50 covering heat dissipation hole 473
Is a part of the outer wall of the gear housing 33.

The cooler 50 is made of an aluminum or brass material. The supply pipe 50 is connected to the cooler 50.
1 and the discharge pipe 502 are connected. Supply pipe 501
Sends the coolant from a coolant supply source (not shown) to the cooler 50, and the discharge pipe 502 returns the coolant passing through the cooler 50 to the coolant supply source. The cooling liquid passing through the cooler 50 cools a contact object that contacts the surface of the cooler 50.

On the upper surface of the cooler 50, a plurality of heat transfer fins 503 (three in this embodiment) are integrally formed. The heat transfer fins 503 project into the gear housing 331 through the heat dissipation holes 473. Each heat transfer fin 503 has a long plate shape along a direction orthogonal to the axes 191 and 201 of the rotating shafts 19 and 20.

In the first embodiment, the following effects can be obtained. (1-1) The heat of the lubricating oil Y in the gear housing 33, which is an oil housing, is transferred from the inner surface of the outer wall of the gear housing 33 to the outer surface and transferred to the outside. If the area of the inner surface of the outer wall of the gear housing 33 is increased, the heat transfer performance on the outer wall of the gear housing 33 is improved, and the cooling efficiency of the lubricating oil Y in the gear housing 33 is improved. Heat transfer fins 5
03 increases the area of the inner surface of the outer wall of the gear housing 33, and the lubricating oil Y in the gear housing 33 is efficiently cooled. The improvement in the efficiency of cooling the oil in the gear housing 33 results in efficient cooling of the lip seals 44 and 45, which are contact-type sealing means for the shaft seal, and extends the life of the lip seals 44 and 45.

(1-2) A part of the surface of the cooler 50 on which the heat transfer fins 503 are erected is exposed to the gear accommodating chamber 331 which is an oil existing area. Becomes Cooler 5 with heat transfer fins 503 installed
The surface of 0 is the inner surface of the bottom wall 472 of the gear housing 33. The configuration in which a part of the surface of the cooler 50 on which the heat transfer fins 503 are erected is exposed to the gear housing chamber 331 has a higher heat than the structure in which a wall is interposed between the cooler 50 and the gear housing chamber 331. Excellent in transmission efficiency. Therefore, the heat transfer efficiency at the portion of the cooler 50 that covers the heat dissipation hole 473 is higher than the heat transfer efficiency at the other portion of the peripheral wall 47 where the heat dissipation hole 473 is not provided. The improvement of the heat transfer efficiency in a part of the peripheral wall 47 increases the efficiency of cooling the oil in the gear housing 33 serving as the oil housing.

(1-3) The gear housing 33 is made of an iron-based material, and the cooler 50 is made of an aluminum-based or brass material. Aluminum and brass materials have better heat transfer performance than iron-based materials. The structure using an aluminum-based material or the like having a higher heat transfer performance than the iron-based material as the material of the cooler 50 can reduce the heat of the lubricating oil Y
It is very suitable for improving the efficiency of transmission to the cooling liquid inside.
The configuration using a material having higher heat transfer performance than the iron-based material as the material of the cooler 50 is effective for improving the efficiency of cooling the lubricating oil Y in the gear housing 33. In particular, an aluminum-based material is optimal as a material for the cooler 50 in consideration of weight reduction and cost.

(1-4) The heat dissipation hole 473 is provided only on the bottom wall 472 which is a part of the peripheral wall 47. Heat dissipation hole 4
Since 73 is limited to a part of the entire gear housing 33, it is easy to secure necessary strength of the gear housing 33.

(1-5) Lubricating oil Y in gear housing 33
Are located at the bottom of the gear housing chamber 331, that is, in the heat dissipation hole 473;
And accumulate on the inner surface of the bottom wall 472 around the heat dissipation hole 473. The lubricating oil Y accumulated in the heat dissipation holes 473 contacts the heat transfer fins 503, and the heat of the stored oil is directly transmitted to the cooler 50. Therefore, the configuration in which the heat radiation holes 473 in which the stored oil is present is covered with the cooler 50 and the heat transfer fins 503 are arranged at the bottom of the gear housing chamber 331 is optimal for improving the efficiency of cooling the lubricating oil Y. is there.

(1-6) The lip seal 4 interposed between the rear housing 14 as a partition and the rotating shafts 19 and 20
The deterioration of the lip seals 44 and 46 due to the heat can be performed by directly cooling the lip seals 44 and 46 with the lubricating oil Y or indirectly cooling the protruding ends of the rotating shafts 19 and 20 with the lubricating oil Y. It is suppressed by cooling.

(1-7) Rubber lip seals 44 and 45
Is extremely excellent in close contact with the peripheral surfaces of the rotating shafts 19 and 20, but the durability is extremely reduced without lubrication with the lubricating oil Y. The rubber lip seals 44 and 45 which are lubricated by the lubricating oil Y and subjected to a cooling action are contact-type sealing means capable of securing high durability and high sealing performance.

(1-8) The pump chamber 43 is a pump chamber having a minimum volume adjacent to the gear housing chamber 331 via the rear housing 14 serving as a partition. The pump chamber 43 having the minimum volume is a place where the temperature is highest. Therefore, the rear housing 1
The temperatures near the protruding ends of the rotary shaft 4 and the rotating shafts 19 and 20 are also likely to increase, and the lip seals 44 and 45 are exposed to a severe high-temperature environment. Therefore, cooling of the lip seals 44 and 45 is extremely important, and the present invention provides a multi-stage roots pump 1 having the lip seals 44 and 45 that are important cooling targets.
Particularly suitable for application to 1.

Next, a second embodiment shown in FIGS. 5A and 5B will be described. The same components as those in the first embodiment are denoted by the same reference numerals. A plurality of heat transfer fins 474 (three in this embodiment) are integrally provided on the inner surface of the bottom wall 472 of the peripheral wall 47 of the gear housing 33. Bottom wall 4
A cooler 50A made of aluminum or brass material is attached to the outer surface of 72.

In the third embodiment, items (1-1), (1-3), (1-6) to (1-) in the first embodiment are used.
8) The same effect as in the item is obtained. Next, a third embodiment of FIG. 6 will be described. The same components as those in the first embodiment are denoted by the same reference numerals.

Heat transfer fins 504 are provided upright on the cooler 50B. A cooling passage 505 is formed in the heat transfer fin 504, and the coolant flows through the cooling passage 505. The heat transfer fins 503 are connected to the gear housing 33.
It is located at the bottom.

In the second embodiment, the same effect as in the first embodiment can be obtained. Further, since the coolant flows through the heat transfer fins 504 that have entered the gear housing chamber 331, the efficiency of cooling the lubricating oil Y in the gear housing 33 is further improved as compared with the case of the first embodiment. I do.

Next, a fourth embodiment shown in FIG. 7 will be described. The same components as those in the first embodiment are denoted by the same reference numerals. The heat dissipation hole 473 is covered with a cover 53 made of an aluminum-based material. Heat transfer fins 531 and 532 are integrally provided on both surfaces of the cover 53. The heat transfer fins 531 are arranged at the bottom of the gear housing 33. The heat of the lubricating oil Y in the gear housing chamber 331 is radiated to the outside of the gear housing 33 through the heat transfer fins 531, the plate portion of the cover 53, and the heat transfer fins 532.

Although the cooling efficiency of the fourth embodiment is not as high as that of the cooling system using a cooling liquid, the heat transfer through the heat transfer fins 531 and 532 is performed through the flat wall of the gear housing. It is better than when heat is transferred in the thickness direction.

Next, a fifth embodiment shown in FIGS. 8A and 8B will be described. The same components as those in the first embodiment are denoted by the same reference numerals. The bottom wall 472 of the gear housing 33
A plurality of heat transfer fins 475 are integrally provided on the inner surface of the bottom wall 472, and a plurality of heat transfer fins 476 are provided integrally on the outer surface of the bottom wall 472. A cooler 50C made of an aluminum or brass material is attached to the outer surface of the bottom wall 472. A plurality of recesses 506 are provided on the upper surface of cooler 50C, and heat transfer fins 476 are fitted into recesses 506. The recess 506 and the heat transfer fins 476 are in close contact with each other.

The heat of the lubricating oil Y in the gear storage chamber 331 is transferred to the heat transfer fins 475, the bottom wall 472, and the heat transfer fins 47.
6 to the cooler 50C. In the fifth embodiment, the terms (1-1) and (1-3) in the first embodiment
The same effects as those of the items (1-6) to (1-8) can be obtained.
Also, a plurality of heat transfer fins 476 and a plurality of recesses 506 are provided.
The contact area for transferring heat from the outer surface of the outer wall of the gear housing 33 to the cooler 50C increases. Such an increase in the contact area contributes to an improvement in the heat transfer efficiency.

In the present invention, the following embodiments are also possible. (1) A heat-dissipating hole is provided on the side wall of the peripheral wall 47 of the gear housing 33, and the heat-dissipating hole is covered with a cooler, and a heat transfer fin that enters the heat-dissipating hole is provided on the cooler. (2) A heat-dissipating hole is provided on the upper wall of the peripheral wall 47 of the gear housing 33, and the heat-dissipating hole is covered with a cooler, and a heat transfer fin that enters the heat-dissipating hole is provided on the cooler. (3) A plurality of heat dissipation holes are provided on the outer wall of the gear housing 33, and each heat dissipation hole is covered with a single cooler or a separate cooler.

[0048]

As described above in detail, according to the present invention, the rotating shaft is protruded from the oil existing area in the oil housing forming the oil existing area, so that the outer wall of the oil housing is exposed to the outside. Since the heat transfer fins are provided, there is an excellent effect that the oil for cooling the object to be cooled in the vacuum pump can be efficiently cooled.

[Brief description of the drawings]

FIG. 1 shows a first embodiment, in which (a) is a plan sectional view of the whole multi-stage roots pump 11; (B) Lip seal 4
4 and 45 are enlarged plan sectional views.

FIG. 2A is a sectional view taken along line AA of FIG. (B) is FIG.
BB sectional drawing of FIG. (C) is a sectional view taken along line CC of FIG. 1.

FIG. 3 is a sectional view taken along line DD of FIG. 1;

FIG. 4 is a sectional view taken along line EE of FIG. 3;

5A and 5B show a second embodiment, and FIG. (B) is a sectional view taken along line FF of (a).

FIG. 6 is a sectional side view of a main part showing a third embodiment.

FIG. 7 is a sectional side view of a main part showing a fourth embodiment.

FIG. 8 shows the fifth embodiment, and FIG. (B) is an exploded perspective view.

[Explanation of symbols]

11 Multi-stage roots pump which is a vacuum pump. 14. Rear housing serving as a partition. 19, 20 ... rotating shaft. 191,
201 ... axis. 192, 202: Protruding ends of the rotating shaft. 2
3 to 32: rotors serving as gas transfer bodies. Reference numeral 33 denotes a gear housing serving as an oil housing. Reference numeral 331 denotes a gear storage chamber serving as an oil existing area. 34, 35 ... gears constituting a gear mechanism.
39-43 ... Pump room. 44, 45: Lip seals serving as contact-type sealing means. 47 ... A peripheral wall which is a part of the outer wall. 4
72 ... Bottom wall. 473: holes for heat radiation. 474,475,47
6,503,504 ... fins for heat transfer. 50, 50A,
50B, 50C ... coolers. Y: Lubricating oil.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme court ゛ (Reference) F04C 27/02 F04C 27/02 29/02 29/02 D (72) Inventor Jin Masaji Toyota, Kariya City, Aichi Prefecture 2 chome, cho-cho F-term in Toyota Industries Corporation (reference) 3H029 AA06 AA18 AA21 AB02 BB01 BB12 BB16 CC02 CC09 CC16 CC19 CC47 CC48

Claims (8)

[Claims] 1. A vacuum pump for moving a gas transfer body in a pump chamber based on rotation of a rotating shaft and transferring a gas by an operation of the gas transfer body to provide a suction action, wherein a region where a cooling oil exists is formed. A cooling structure in a vacuum pump in which the rotary shaft projects from an oil existing region in an oil housing to be provided and heat transfer fins are provided on an outer wall of the oil housing exposed to the outside. 2. The heat transfer fin is provided on a bottom wall of a bottom portion of the oil housing for storing the oil.
A cooling structure in the vacuum pump according to 1. 3. The cooling structure for a vacuum pump according to claim 1, wherein said heat transfer fins are provided on an inner surface of said outer wall. 4. A heat dissipation hole is provided through the outer wall of the oil housing, and the heat dissipation hole is covered with a cooler to make the cooler a part of the outer wall, and the heat transfer is provided to the cooler. The fin according to any one of claims 1 to 3, wherein the fin is provided.
A cooling structure in the vacuum pump described in the paragraph. 5. The cooling structure for a vacuum pump according to claim 4, wherein said cooler is formed of a material having a higher heat transfer performance than a material of said oil housing. 6. The oil-existing region is separated from the pump chamber by a partition, the rotary shaft penetrates the partition and protrudes into the oil-existing region, and a shaft is provided between the rotary shaft and the partition. 2. A method according to claim 1, further comprising contact type sealing means for sealing.
A cooling structure in the vacuum pump according to claim 5. 7. The vacuum pump according to claim 1, wherein a plurality of said rotating shafts are arranged in parallel, a rotor is arranged on each of said rotating shafts, rotors on adjacent rotating shafts are engaged with each other, and said vacuum pump is in a state of being engaged with each other. A multi-stage vacuum pump in which a plurality of pump chambers accommodating a plurality of rotors as one set are arranged in the axial direction of the rotating shaft, and the volumes of the plurality of pump chambers are formed in the partition along the axial direction of the rotating shaft. The gas is transferred through the plurality of pump chambers in the order of decreasing volume, and the pump chamber adjacent to the oil existing area is a pump chamber having a minimum volume. A cooling structure in the vacuum pump according to any one of claims 1 to 6. 8. A plurality of the rotating shafts are synchronously rotated by using a gear mechanism, the oil-existing area is an area for accommodating the gear mechanism, and the oil-existing area lubricates the gear mechanism. 8. A cooling structure in a vacuum pump according to claim 7, wherein oil for storing the oil is stored in the oil-existing area, and oil for scraping the stored oil so as to lubricate the gear mechanism is provided.