TWI510715B - Vacuum dry pump - Google Patents

Description

Vacuum dry pump

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a mechanical vacuum dry pump that does not use oil or liquid in a vacuum chamber, and more particularly to a vacuum dry pump that is superior in its ability to prevent oil from leaking from the oil chamber to the pump chamber.

Previously, for example, in a vacuum apparatus or the like, a vacuum pump having a pump chamber having an exhaust gas was used, and as a vacuum pump, a dry pump (DRP) or a mechanical booster pump (MBP), etc., are known. .

In such dry pumping (DRP) and mechanical booster pumping (MBP), it is necessary to avoid lubricating oil used in bearings or gears into the pumping chamber. There are the following reasons: First, in order to prevent the oil from flowing back from the oil chamber to the vacuum vessel in the dry pump in the dry pump; second, to prevent the reactive gas from being dissolved in the oil to promote the dry pumping of the base material and the like.

The phenomenon that oil enters from the oil chamber toward the pumping chamber is caused by the pressure of the pumping chamber and the oil chamber due to the fluctuation of the suction pressure due to the vapor pressure of the oil when the pressure in the vacuum pump reaches a certain pressure. The difference produces a gas flow such that oil molecules or oil particles enter the pumping chamber.

Previously, in order to prevent oil from flowing from the oil chamber to the pump chamber, for example, a contact type oil seal or a labyrinth seal or the like was used.

If the air conduction of the oil chamber and the pumping chamber is reduced, the amount of movement of the gas is reduced, and the oil is prevented from flowing from the oil chamber to the pumping chamber, so this configuration is effective. Therefore, in the prior vacuum dry pumping, a contact type oil seal or a contact type seal ring (maze type seal) was used.

However, since this structure is a contact type, there is a concern that mechanical wear occurs due to friction. In recent years, attention has been paid to energy conservation, and a structure that prevents the occurrence of mechanical wear is a demand.

On the other hand, a structure for preventing oil leakage by an annular shaft seal ring attached to a rotating shaft has been known from the prior art. This configuration can prevent oil leakage by the shape or clearance of the shaft seal ring body, and is basically one of the labyrinth seal configurations. Such a configuration is disclosed in, for example, Japanese Laid-Open Patent Publication No. 2002-332963.

Further, as disclosed in Japanese Laid-Open Patent Publication No. 2008-51116, a structure constituting a labyrinth seal is complicated. It is conceivable that the structure constituting the elements constituting the labyrinth seal is effective as a structure for preventing oil leakage, but the shaft seal ring body and the pump body structure supporting the shaft seal ring body are reapplied. Therefore, the manufacturing cost of the vacuum dry pump increases this problem. In particular, it is not easy to cut a plurality of annular grooves having a narrow width in a part of the pump body.

Further, as disclosed in Japanese Laid-Open Patent Publication No. 2002-257070, there is also proposed a structure for preventing oil leakage by a shaft sealing ring body having a pumping action, but it is difficult to rectify the structure in this case. Reduce the manufacturing cost of vacuum dry pumping.

The present invention has been made to solve the above-mentioned problems, and an object thereof is to provide a vacuum dry pump which can have a simple configuration and prevent oil leakage.

The vacuum dry pump of the present invention comprises: a pump chamber through which a gas passes; an oil chamber disposed adjacent to the pump chamber; and an oil chamber that penetrates the pump chamber and protrudes inside the oil chamber; a rotating body that is disposed around the rotating shaft and that rotates in conjunction with the rotation of the rotating shaft; and a boundary portion between the pumping chamber and the oil chamber is disposed around the rotating shaft, and is coupled to the rotating shaft Rotating and rotating, having a plurality of holes partially disposed on the surface thereof and penetrating in the thickness direction, prevents oil from leaking from the oil chamber to the disk-shaped oil seal member of the pump chamber.

In the vacuum dry pump of the present invention, the plurality of holes are preferably arranged to surround the rotating shaft.

In the vacuum dry pump of the present invention, the plurality of holes are formed in a circular shape, and it is preferable to form a crank shape in a cross section in the thickness direction of the oil seal member.

In the vacuum dry pumping of the present invention, the plurality of holes are formed in a circular shape and are preferably disposed to extend obliquely with respect to the thickness direction of the oil seal member.

In the vacuum dry pump of the present invention, preferably, the plurality of holes include: a plurality of outer holes disposed at a position close to an outer circumference of the oil seal member and formed in a circular shape, and disposed adjacent to the foregoing a plurality of inner holes formed in a circular shape at a position of a center of the oil seal member, wherein each of the plurality of outer holes has a size larger than a size of each of the plurality of inner holes, and the plurality of outer holes and the plurality of inner holes are arranged concentrically Round shape.

In the vacuum dry pumping of the present invention, the plurality of holes are preferably formed such that the opening width of the hole gradually increases from the center of the oil seal member toward the radially outer side of the outer periphery.

In the vacuum dry pumping of the present invention, it is preferable that the inside of the plurality of holes is provided with a sintered metal or mesh so as to close the holes.

According to the vacuum dry pump of the present invention, a disk-shaped oil seal member that rotates in conjunction with the rotation of the rotating shaft is provided, and a plurality of holes penetrating in the thickness direction are partially disposed on the surface of the oil seal member. The oil seal member prevents oil from leaking from the oil chamber to the pump chamber. The oil seal member having such a configuration has a gas permeable structure. By the flow of the gas, the oil particles or the oil vapor are adsorbed on the oil sealing member while passing through the oil sealing member in rotation. The oil adsorbed on the oil seal member is scattered toward the periphery of the oil seal member by the centrifugal force caused by the rotation of the oil seal member.

Therefore, according to the present invention, it is possible to provide a vacuum dry pump having a simple configuration to prevent oil leakage.

Hereinafter, the best mode of the vacuum dry pump of the present invention will be described based on the drawings.

Further, in each of the drawings used in the following description, in order to make each member recognizable, the scale of each member is appropriately changed.

(First embodiment)

Fig. 1 is a view schematically showing a vacuum dry pump according to a first embodiment of the present embodiment, and Figs. 1A and 1B are longitudinal cross-sectional views, and Fig. 1C is a cross-sectional view.

The vacuum dry pump 1 includes pump chambers 10A to 10E, an oil chamber 20, rotating shafts 30 and 30, a rotor 40 (rotating body), and an oil seal member 50.

In the pump chambers 10A to 10E, the gas is discharged into the vacuum dry pump 1 and discharged from the vacuum dry pump 1. The oil chamber 20 is disposed adjacent to the pump chamber 10E, and oil is present in the oil chamber 20. The rotating shafts 30 and 30 are provided so as to penetrate through the pumping chambers 10A to 10E and protrude inside the oil chamber 20. The rotor 40 is disposed around the rotating shafts 30 and 30 in the pump chambers 10A to 10E, and rotates in conjunction with the rotation of the rotating shafts 30 and 30. The oil seal member 50 is provided around the rotating shafts 30, 30 at a boundary portion between the pump chamber 10E and the oil chamber 20. The oil seal member 50 is formed in a disk shape and rotates in conjunction with the rotational motion of the rotating shafts 30, 30, thereby preventing oil from leaking from the oil chamber 20 to the pump chambers 10A to 10E.

The vacuum dry pump 1 having such a configuration rotates the rotor 40 based on the rotation of the rotating shafts 30 and 30, and the gas existing inside the pumping chambers 10A to 10E is directed from the suction port 16 by the rotation of the rotor 40. The discharge port 17 moves, and the gas is discharged to the outside of the vacuum dry pump 1.

In the vacuum dry pump 1 according to the first embodiment of the present invention, the disk-shaped oil seal member 50 is partially disposed on the surface of the oil seal member 50 and penetrates in the thickness direction of the oil seal member 50. A plurality of holes 51.

In the vacuum dry pump 1 according to the first embodiment of the present invention, since the oil seal member 50 is provided with a plurality of holes 51 as described above, the oil seal member 50 has a structure through which gas can pass.

The flow of the gas generated by the oil seal member 50 is adsorbed to the oil seal member 50 when the oil fine particles or the oil vapor passes through the oil seal member 50 that is rotating.

Here, on the oil adsorbed on the oil seal member 50, there is a centrifugal force caused by the rotation of the oil seal member 50. The oil adsorbed to the oil seal member 50 by the centrifugal force is scattered toward the periphery of the oil seal member 50 (toward the radially outer side of the oil seal member 50).

Therefore, the vacuum dry pump 1 according to the first embodiment of the present invention has a simple structure and can prevent oil leakage.

In the casing 2 of the vacuum dry pump 1, a plurality of (in the present embodiment, for example, five stages) pump chambers 10A to 10E are connected in series via a pipe 15 along the longitudinal direction thereof.

In the pumping chambers 10A to 10E, a suction port 16 is provided in the pumping chamber 10A located at the most upstream, and a discharge port 17 is provided in the pumping chamber 10E located at the most downstream. By the pumping action of the vacuum dry pump 1, the gas is supplied to the suction port 16, passes through the pumping chambers 10A to 10E and the pipe 15, and is discharged from the discharge port 17.

In the casing 2 of the vacuum dry pump 1, the rotating shafts 30 and 30 which penetrate the pumping chambers 10A to 10E and protrude inside the oil chamber 20 provided adjacent to the pumping chamber 10E are disposed.

As shown in FIG. 1A, the two rotating shafts 30 and 30 (the first rotating shaft and the second rotating shaft) are rotatably supported by the bearings 31 and 32, and are passed through a gear 33 provided at one end of the two rotating shafts 30 and 30 (timing) Gears are connected to each other. Further, the rotation shaft of one of the two rotating shafts 30 and 30 is coupled to the motor 35 via the coupling 34.

Between the bearings 31 and 32, a plurality of rotors 40 disposed in the respective pumping chambers 10A to 10E are disposed along the axial direction of the rotating shafts 30 and 30. A plurality of rotors 40 are disposed in the respective pumping chambers 10A to 10E and are disposed around the rotating shafts 30 and 30. The plurality of rotors 40 are rotatable in conjunction with the rotation of the rotating shafts 30, 30. The rotor 40 is a gas transfer body that transfers gas.

The oil chamber 20 is provided adjacent to the pump chamber 10E as an oil-preserving region that is sealed so that oil does not leak outside the vacuum dry pump 1. The oil 21 (lubricating oil) is stored in the oil chamber 20, and the gear 33 constituting the rotating mechanism of the rotating shafts 30 and 30 is accommodated. The oil 21 in the oil chamber 20 can be raised by the rotation of the gear to maintain the gear 33 in a lubricating state.

A disk-shaped oil seal member 50 is provided around the rotating shafts 30 and 30 at a boundary portion between the pump chamber 10E and the oil chamber 20. The oil seal member 50 is rotated in conjunction with the rotation of the rotating shafts 30 and 30 to prevent oil from leaking from the oil chamber 20 to the pump chambers 10A to 10E.

In the vacuum dry pump 1 according to the first embodiment of the present invention, the oil seal member 50 has a plurality of holes 51 penetrating in the thickness direction of the oil seal member 50. The hole 51 is partially disposed on the surface of the oil seal member 50.

On the other hand, in the prior vacuum dry pumping, a gap (gap) is provided outside the rotating oil seal member 50, and gas is allowed to pass through the gap.

For this reason, in the related art, a structure in which the number of slits is increased and the size of the slit is reduced (thinned) has been employed. However, it is difficult to process and fix the components of the oil seal member, and the manufacturing cost is increased.

In the first embodiment of the present invention, the through hole 51 is provided in the disk portion of the oil seal member 50, and the gas can pass through the oil seal member 50.

2A and 2B are views showing the oil seal member 50 according to the first embodiment of the present invention, and Fig. 2A is a plan view, and Fig. 2B is a cross-sectional view.

For example, in the oil seal member 50A (50) shown in FIGS. 2A and 2B, a plurality of holes 51A (51) are formed in a circular shape and provided to surround the aforementioned rotating shafts 30, 30. Further, the oil seal member 50A (50) has a first surface 60 and a second surface 61 opposite to the first surface 60. The hole 51A is formed between the first surface 60 and the second surface 61, that is, formed so as to penetrate the oil seal member 50A.

Regarding the flow of the gas passing through the oil seal member 50, the air guide of the oil seal member 50 (the total air guide defined by the plurality of holes 51A) is larger than the air guide formed in the gap around the oil seal member 50. The flow rate of the gas passing through the plurality of holes 51A formed in a disk shape is increased.

When the oil fine particles or the oil vapor passes through the hole 51 of the oil seal member 50 that is rotating, it collides with the periphery of the hole 51 to be adsorbed. If the oil is adsorbed (adhered) on the oil (oil film, oil droplet) adsorbed on the oil seal member 50, if the oil accumulates on the oil adsorbed first, the oil adsorbed on the oil seal member 50 (oil film, oil droplet) The amount will increase. Further, the centrifugal force caused by the rotation of the oil seal member 50 acts on it, by which the oil adsorbed on the oil seal member 50 will face the periphery of the oil seal member 50 (toward the radial direction of the oil seal member 50). The outside is scattered.

In recent years, vacuum dry pumping that achieves high speed rotation has been used to date. In the vacuum dry pump 1 of the present embodiment, it is conceivable that the rotating shafts 30 and 30 are rotated at a speed of 5000 cycles/min or more, and the probability of capturing oil particles in this configuration is increased.

In order to make the air guide formed in the gap around the oil seal member 50 smaller than the total air guide formed in the plurality of holes 51A of the oil seal member 50, it is necessary to pass the gas through the plurality of holes 51A of the oil seal member 50. The total area is set to be large. Further, it is necessary to set the size of the gap formed around the oil seal member 50 to be small. When the temperature of the oil seal member 50 is higher than the temperature of the pump body, it is caused by thermal expansion, and the gap at a high temperature compared with the gap at normal temperature is smaller. Therefore, the structure having a small gap (gap structure) has a limit. Therefore, a labyrinth structure and a gap structure may be required and constructed. However, in the structure of the first embodiment of the present invention, the effect of preventing oil leakage by a simple structure can be obtained as compared with the prior structure (design) using only the labyrinth seal.

In the case of the prior art (for example, refer to Japanese Laid-Open Patent Publication No. 2002-257070), which is applied to the shaft sealing ring body to prevent oil leakage, the first shaft is applied to the case of the two-axis dry vacuum pumping, the first shaft. The direction of rotation of the (one axis) is opposite to the direction of rotation of the second axis (the other axis). Therefore, two shaft sealing rings of different shapes may be required, that is, two shaft sealing rings having shapes symmetrical to each other are required.

On the other hand, in the vacuum dry pump 1 according to the first embodiment of the present invention, the oil seal member 50 having the same shape can be used regardless of the direction of the shaft rotation. Therefore, the types of parts can be reduced and the management cost can be reduced. Moreover, according to the first embodiment of the present invention, it is possible to avoid errors in assembly work that is assembled on the second shaft by erroneously assembling the components assembled on the first shaft.

Further, in an oil chamber, an MBP, or the like exposed to a vacuum atmosphere such as a vacuum dry pumping, and in a vacuum chamber, the oil chamber pressure rises rapidly by a pumping action in one direction. The pressure drop rate is slow under this condition, which causes a decrease in discharge performance. Specifically, for example, the pressure reduction of the load lock chamber is repeated, or the pressure of the load lock chamber is set to a pressure higher than the vacuum (for example, atmospheric pressure). Underneath, it will cause a decline in exhaust performance.

However, according to the configuration of the first embodiment of the present invention, the gas flow is not directional, and the oil can be efficiently captured in proportion to the size of the air conduction.

In the above-described embodiment, a plurality of circular holes 51 are formed in the oil seal member 50, and a structure in which the holes 51 are provided so as to surround the rotating shafts 30 and 30 is described. However, the present invention is not limited to the embodiment. Holes 51 having various shapes can also be used.

Hereinafter, the second embodiment to the seventh embodiment of the present invention will be described. In the second embodiment to the seventh embodiment, the same members as those in the first embodiment are denoted by the same reference numerals, and their description will be omitted or simplified.

(Second embodiment)

3A and 3B are views showing an oil seal member 50 according to a second embodiment of the present invention. 3A is a plan view, and FIG. 3B is a cross-sectional view.

First, in the configuration shown in Figs. 3A and 3B, the hole 51B (51) is formed in a circular shape, and in the cross section in the thickness direction of the oil seal member 50B (50), the hole 51B (51) is formed in a crank shape. Specifically, the hole 51B is connected to the first hole 62 having a specific depth formed on the first surface 60 of the oil seal member 50B and the second hole having a specific depth formed on the second surface 61 of the oil seal member 50B. Formed by 63. Further, the center of the second hole 63 is deviated from the center of the first hole 62 on the outer side in the radial direction of the oil seal member 50B.

Since the hole 51 is formed in a cross section of the oil seal member 50B in a crankshaft shape, the effect of the pumping action by the centrifugal force can be expected. However, the pumping action caused by the centrifugal force is ultimately utilized to increase the probability that the oil molecules collide with the oil seal member 50 (supplementary probability).

(Third embodiment)

4A and 4B are views showing an oil seal member 50 according to a third embodiment of the present invention, and Fig. 4A is a plan view, and Fig. 4B is a cross-sectional view.

Further, in the structure of FIGS. 4A and 4B, the hole 51C (51) is formed in a circular shape, and is provided to extend obliquely upward in the thickness direction in the cross section in the thickness direction of the oil seal member 50C (50). In addition, the position of the second opening 65 formed in the second surface 61 is shifted from the position of the first opening 64 formed in the first surface 60 on the outer side in the radial direction of the oil seal member 50C.

By forming the hole 51 in the oblique direction with respect to the thickness direction, the effect of the pumping action by the centrifugal force can be expected. However, the pumping action caused by the centrifugal force is ultimately utilized to increase the probability that the oil molecules collide with the oil seal member 50 (supplementary probability).

(Fourth embodiment)

5A and 5B are views showing an oil seal member 50 according to a fourth embodiment of the present invention, and Fig. 5A is a plan view and Fig. 5B is a cross-sectional view.

Further, in the structure of FIGS. 5A and 5B, the hole 51D (51) has a plurality of inner holes 151D (51) and outer holes 251D (51) formed in a circular shape. Specifically, the outer hole 251D (51) is provided at a position close to the outer circumference of the oil seal member 50D (50). The inner hole 151D (51) is provided on the inner side in the radial direction of the oil seal member 50B at a position close to the center. Further, the diameter (size) of the outer hole 251D (51) is larger than the diameter (size) of the inner hole 151D (51).

Further, the center of the plurality of outer holes 251D (51) is located on the circumference of the circle, and the center of the plurality of inner holes 151D (51) is located on the circumference of the circle, and is arranged concentrically. That is, the plurality of outer holes 251D (51) and the plurality of inner holes 151D (51) are arranged concentrically.

As described above, the configuration in which the hole 51 having the large opening diameter is disposed at a position close to the outer periphery of the faster peripheral speed is effective in attempting to increase the air conduction.

Further, in the fourth embodiment, the hole group having two diameters, the first group including the plurality of inner holes 151D, and the second group including the plurality of outer holes 251D are arranged on the oil sealing member 50. The structure has been described, but the present invention is not limited to this configuration.

A structure in which a group of holes having three or more diameters, that is, a group other than the above-described first group and the second group, and a third group of holes are arranged on the oil sealing member may be employed. In this case, the third hole group is formed by a plurality of holes having a larger diameter than the inner hole 151D and smaller than the diameter of the outer hole 251D, and the third hole group is disposed in the first group ( The inner hole 151D) is between the inner hole 151D) and the second group (outer hole 251D). That is, a configuration is adopted in which the hole diameter is gradually increased from the center toward the radially outer side of the outer circumference. Even in such a structure, the first group, the second group, and the third group are arranged in a concentric shape.

(Fifth Embodiment)

6A and 6B are views showing an oil seal member 50 according to a fifth embodiment of the present invention, and Fig. 6A is a plan view, and Fig. 6B is a cross-sectional view.

Further, in the configuration shown in Figs. 6A and 6B, the opening width of the hole 51E of the hole 51E (51) increases on the radially outer side of the oil seal member 50E (50). The shape of the hole 51E may also be non-circular.

As described above, by providing the hole 51 having an increased opening width in the radial direction of the oil seal member 50E (50), it is possible to realize a structure in which the opening area at a position close to the outer circumference of the peripheral speed is increased. This configuration is effective when an attempt is made to increase the air conduction.

(Sixth embodiment)

7A and 7B are views showing an oil seal member 50 according to a sixth embodiment of the present invention, and Fig. 7A is a plan view, and Fig. 7B is a cross-sectional view.

Further, in the structure shown in FIGS. 7A and 7B, a sintered metal or mesh 52 is disposed inside the hole 51F (51) so as to close the hole 51F.

In the inside of the hole 51, by arranging the sintered metal or the mesh 52, the action of the supplementary oil particles can be enhanced.

The experiment using the vacuum pump for the experiment having the configuration shown in Fig. 1 was carried out to compare the case where the previous oil seal member was assembled and the case where the oil seal member of the present invention was assembled. In this experiment, a vacuum pump different from the experimental vacuum pump was prepared, and the vacuum pump was used to decompress the experimental vacuum pump, and the oil was supplied to the oil chamber to measure the amount of oil retained in the pump chamber. .

In the vacuum pump using the previous oil seal member in which no pores were formed, the amount of oil retained in the pump chamber was 2.12 g. On the other hand, in the vacuum pump using the oil seal member of the present invention in which the hole was formed, the amount of oil remaining in the pump chamber was 0.32 g.

From this result, it was confirmed that by using the vacuum pump of the present invention, the amount of oil leakage to the pumping chamber was reduced to 15% of the previous leakage amount.

In the above, the vacuum dry pump of the present invention has been described. However, the technical scope of the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit and scope of the invention.

The invention is broadly applicable to mechanical vacuum dry pumps where oil or liquid is not used in a vacuum chamber.

1. . . Vacuum dry pump

2. . . case

10A~10E. . . Pump room

15. . . Piping

16. . . suction point

17. . . Spit

20. . . Oil room

twenty one. . . oil

30. . . Rotating shaft

31, 32. . . Bearing

33. . . gear

34. . . Coupling

35. . . motor

40. . . Rotor (rotating body)

50A~50F(50). . . Oil sealing member

51A~51F(51). . . hole

251D (51). . . Outer hole

151D (51). . . Inner hole

52. . . Sintered metal or mesh

60. . . First side

61. . . Second side

62. . . First hole

63. . . 2nd hole

64. . . First opening

65. . . Second opening

Fig. 1A is a vertical longitudinal sectional view showing the configuration of a vacuum dry pump according to a first embodiment of the present invention.

Fig. 1B is a vertical longitudinal sectional view showing a configuration of a vacuum dry pump according to a first embodiment of the present invention.

Fig. 1C is a vertical cross-sectional view schematically showing the configuration of a vacuum dry pump according to the first embodiment of the present invention.

Fig. 2A is a plan view schematically showing an oil sealing member in a vacuum dry pumping according to a first embodiment of the present invention.

Fig. 2B is a cross-sectional view schematically showing an oil seal member in a vacuum dry pump according to the first embodiment of the present invention.

Fig. 3A is a plan view schematically showing an oil seal member in a vacuum dry pump according to a second embodiment of the present invention.

Fig. 3B is a cross-sectional view schematically showing an oil seal member in a vacuum dry pump according to a second embodiment of the present invention.

Fig. 4A is a plan view schematically showing an oil seal member in a vacuum dry pump according to a third embodiment of the present invention.

Fig. 4B is a cross-sectional view schematically showing an oil seal member in a vacuum dry pump according to a third embodiment of the present invention.

Fig. 5A is a plan view schematically showing an oil seal member in a vacuum dry pump according to a fourth embodiment of the present invention.

Fig. 5B is a cross-sectional view schematically showing an oil seal member in a vacuum dry pump according to a fourth embodiment of the present invention.

Fig. 6A is a plan view schematically showing an oil seal member in a vacuum dry pump according to a fifth embodiment of the present invention.

Fig. 6B is a cross-sectional view schematically showing an oil seal member in a vacuum dry pump according to a fifth embodiment of the present invention.

Fig. 7A is a plan view schematically showing an oil sealing member in a vacuum dry pumping according to a sixth embodiment of the present invention.

Fig. 7B is a cross-sectional view schematically showing an oil seal member in a vacuum dry pumping according to a sixth embodiment of the present invention.

1. . . Vacuum dry pump

2. . . case

10A~10E. . . Pump room

15. . . Piping

16. . . suction point

17. . . Spit

20. . . Oil room

twenty one. . . oil

30. . . Rotating shaft

31, 32. . . Bearing

33. . . gear

34. . . Coupling

35. . . motor

40. . . Rotor (rotating body)

50. . . Oil sealing member

51. . . hole

Claims (6)

A vacuum dry pump, comprising: a pump chamber through which a gas passes; an oil chamber disposed adjacent to the pump chamber and containing oil; and a rotating shaft penetrating the pump chamber to protrude inside the oil chamber; a pump body disposed around the rotating shaft and coupled to the rotating body that rotates in rotation of the rotating shaft; and a boundary portion between the pump chamber and the oil chamber is disposed around the rotating shaft to rotate the rotating shaft And rotating, and having a plurality of holes partially disposed on the surface thereof and penetrating in the thickness direction, preventing gas from leaking from the oil chamber to the disk-shaped plate of the pump chamber by allowing gas to pass through the plurality of holes An oil sealing member; and the plurality of holes include: a plurality of outer holes that are disposed at a position close to an outer circumference of the oil seal member and formed in a circular shape; and are disposed at a position close to a center of the oil seal member and formed into a circular shape a plurality of inner holes; each of the plurality of outer holes has a size larger than a size of each of the plurality of inner holes, and the plurality of outer holes and the plurality of inner holes Are arranged concentrically; and non-directional flow through the gas lines of the plurality of holes. The vacuum dry pump of claim 1, wherein the plurality of holes are disposed to surround the aforementioned rotating shaft. The vacuum dry pump of claim 1, wherein the plurality of holes are formed in a circular shape, and the oil seal is formed The cross section in the thickness direction of the piece is formed in a crank shape. The vacuum dry pumping of claim 1, wherein the plurality of holes are formed in a circular shape and are disposed to extend obliquely with respect to a thickness direction of the oil seal member. A vacuum dry pump, comprising: a pump chamber through which a gas passes; an oil chamber disposed adjacent to the pump chamber and containing oil; and a rotating shaft penetrating the pump chamber to protrude inside the oil chamber; a pump body disposed around the rotating shaft and coupled to the rotating body that rotates in rotation of the rotating shaft; and a boundary portion between the pump chamber and the oil chamber is disposed around the rotating shaft to rotate the rotating shaft And rotating, and having a plurality of holes partially disposed on the surface thereof and penetrating in the thickness direction, preventing gas from leaking from the oil chamber to the disk-shaped plate of the pump chamber by allowing gas to pass through the plurality of holes An oil sealing member; and the plurality of holes are formed such that an opening width of the hole gradually increases from a center of the oil sealing member toward a radially outer side of the outer periphery; and the flow of the gas through the plurality of holes does not have Directionality. A vacuum dry pump according to claim 1 or claim 5, wherein a sintered metal or mesh is disposed inside the plurality of holes to close the holes.