JP5763358B2 - Vacuum pump - Google Patents

Description

  The present invention relates to a vacuum pump called a mechanical booster pump or a roots type vacuum pump.

  The mechanical booster pump is a volume transfer type vacuum pump that transfers gas from an intake port to an exhaust port by synchronously rotating two mayu type rotors arranged in a casing in opposite directions. Mechanical booster pumps have very little mechanical loss because there is no contact between both rotors and between each rotor and casing, and are driven compared to vacuum pumps with large frictional work such as oil rotary vacuum pumps. Has the advantage of reducing the energy required for.

  The mechanical booster pump does not require lubricating oil in the pump chamber that accommodates both rotors, so that there is little contamination of the vacuum with oil. On the other hand, since it is necessary to always maintain the rotational phase of both rotors and the center of each rotor shaft accurately during pump operation, gears for rotating each rotor synchronously, bearings for supporting each rotor's rotating shaft, etc. However, lubrication is required. For this reason, lubricating oil is stored in a gear chamber that houses the gear, and each part is lubricated during operation (see, for example, Patent Document 1 below).

  In the mechanical booster pump, a gear chamber that houses the gear and a drive chamber that houses a drive shaft that rotates one rotor are disposed adjacent to the pump chamber. In order to improve the sealing performance in the pump chamber, the gear chamber and the drive chamber communicate with the pump chamber, respectively, so that the pressure in each chamber is equalized during operation of the pump.

  For example, Patent Document 2 below includes a pump chamber that houses a pair of rotors, a first lubrication chamber that houses gears that rotate the rotors synchronously, and a second lubrication chamber that rotatably supports the rotor shaft. A lubrication chamber exhaust system for a rotary vacuum pump is described. The vacuum pump includes a first deaeration passage provided between the first lubrication chamber and the second lubrication chamber, and a second degassing second passage provided between the second lubrication chamber and the pump chamber. And a passage. This prevents the oil in the first lubrication chamber from flowing directly into the pump chamber and prevents contamination of the pump chamber with oil.

Japanese Patent Laid-Open No. 6-185383 Japanese Patent Laid-Open No. 5-187375

  However, in the vacuum pump described in Patent Document 2, the lubricating oil that has reached the deaeration passage cannot be returned from the deaeration passage to the first lubrication chamber side, particularly when the pump is started. There was a problem that the lubricating oil became deficient. As a result, there is a possibility that stable lubrication of the gear mechanism cannot be ensured.

  In view of the circumstances as described above, an object of the present invention is to provide a vacuum pump that can ensure stable lubrication of a gear mechanism.

In order to achieve the above object, a vacuum pump according to an embodiment of the present invention includes a pump unit, a drive unit, a rotation transmission unit, and a regulating member.
The pump unit includes a first rotor that can rotate in a first direction, and a second rotor that is disposed close to the first rotor and that can rotate in a second direction opposite to the first direction. And a first chamber for housing the first rotor and the second rotor.
The drive unit includes a drive mechanism that rotates the first rotor, a second chamber that houses the drive mechanism, and a first deaeration passage that communicates the first chamber and the second chamber. And have.
The rotation transmission unit includes a gear mechanism that synchronously rotates the first rotor and the second rotor, a third chamber that stores the gear mechanism and stores lubricating oil that lubricates the gear mechanism, And a second degassing passage for communicating the third chamber with the second chamber or the first chamber.
The restricting member is provided in the second degassing passage and has a restricting portion that restricts the flow of the lubricating oil from the third chamber to the second chamber.

It is a schematic sectional drawing of the vacuum pump which concerns on one Embodiment of this invention. It is sectional drawing which shows the structure of the pump part of the said vacuum pump. It is principal part sectional drawing explaining the structure of the deaeration channel | path of the said vacuum pump.

A vacuum pump according to an embodiment of the present invention includes a pump unit, a drive unit, a rotation transmission unit, and a regulating member.
The pump unit includes a first rotor that can rotate in a first direction, and a second rotor that is disposed close to the first rotor and that can rotate in a second direction opposite to the first direction. And a first chamber for housing the first rotor and the second rotor.
The drive unit includes a drive mechanism that rotates the first rotor, a second chamber that houses the drive mechanism, and a first deaeration passage that communicates the first chamber and the second chamber. And have.
The rotation transmission unit includes a gear mechanism that synchronously rotates the first rotor and the second rotor, a third chamber that stores the gear mechanism and stores lubricating oil that lubricates the gear mechanism, And a second degassing passage for communicating the third chamber with the second chamber or the first chamber.
The restricting member is provided in the second degassing passage and has a restricting portion that restricts the flow of the lubricating oil from the third chamber to the second chamber.

  In the vacuum pump, the first rotor receives a driving force from the driving mechanism and rotates in the first direction. The rotation of the first rotor is transmitted to the second rotor via the gear mechanism, so that the second rotor rotates in the second direction. As a result, the first chamber is evacuated, and the second chamber containing the drive mechanism and the third chamber containing the gear mechanism are also evacuated via the first deaeration passage and the second deaeration passage, respectively. Is done.

  In the vacuum pump, the second degassing passage includes a regulating member having a regulating portion that regulates the flow of the lubricating oil from the third chamber to the second chamber. For this reason, it is possible to suppress a decrease in the amount of lubricating oil in the third chamber and to ensure stable lubrication of the gear mechanism.

The rotation transmission unit may further include a casing that partitions the third chamber. In this case, the second deaeration passage includes a passage portion formed inside the casing, and the restriction member is configured to shield a part of the flow path of the passage portion by the restriction portion. Attached to.
As a result, the lubricating oil that has entered the second degassing passage is returned to the third chamber, so that the amount of the lubricating oil in the third chamber can be stably maintained.

The said channel | path part may have a 1st flow path and a 2nd flow path. The first flow path has an axial direction parallel to the direction of gravity and faces the third chamber. The second flow path has a second axial direction that intersects the first axial direction. In this case, the restriction member is formed of a cylindrical body mounted on the second flow path, and the cylindrical body has a first end portion located in the first flow path as the restriction portion. .
This makes it difficult for the lubricating oil to enter the second flow path, so that the outflow of the lubricating oil to the second chamber side is effectively inhibited. Further, the lubricating oil that has collided with the restricting portion can be efficiently returned to the third chamber by the gravitational action.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic sectional view showing a vacuum pump according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing an internal configuration of the pump unit. In each figure, the X-axis direction and the Y-axis direction indicate horizontal directions orthogonal to each other, and the Z-axis direction indicates a vertical direction (gravity direction) orthogonal to these.

  The vacuum pump 1 of the present embodiment is configured with a single-stage mechanical booster pump. The vacuum pump 1 includes a pump unit 2, a drive unit 3, and a rotation transmission unit 4.

  The pump unit 2 includes a first casing 20 that forms a pump chamber 23. The first casing 20 has an intake port 201 that communicates with a vacuum chamber (not shown), and an exhaust port 202 that communicates with a pump device at a subsequent stage (for example, a rotary pump). The intake port 201 and the exhaust port 202 are each in communication with the pump chamber 23. The pump chamber 23 is defined by the first casing 20 and partition walls 24 and 25 that are airtightly attached to both sides of the first casing 20.

  The pump unit 2 includes a pair of rotors 21 and 22. The rotors 21 and 22 have rotating shafts 210 and 220 that extend in parallel to the Y-axis direction, respectively. The rotors 21 and 22 have a cocoon-shaped cross section, and are disposed close to each other and accommodated in the pump chamber 23 as shown in FIG. There are slight gaps (for example, about 0.02 to 0.04 mm) between the rotors 21 and 22, between the rotors 21 and 22 and the first casing 20, and between the rotors 21 and 22 and the partition walls 24 and 25. Is maintained.

  The rotary shafts 210 and 220 pass through the partition walls 24 and 25, respectively, and one end of the rotary shafts 210 and 220 is located in the motor chamber 33 in the drive unit 3. The other ends of the rotating shafts 210 and 220 are located in the gear chamber 43 in the rotation transmitting unit 4.

  The drive unit 3 includes a second casing 30 that is airtightly attached to the partition wall 24, and the motor chamber 33 is formed inside the second casing 30. A bearing 31 and a shaft seal 32 that rotatably support the rotating shafts 210 and 220 are respectively installed on the partition wall 24 on the motor chamber 33 side.

  The motor chamber 33 communicates with the pump chamber 23 via the first deaeration passage P1. Thereby, the motor chamber 33 can be deaerated through the first deaeration passage P <b> 1, and is equalized with the pressure of the pump chamber 23 when the vacuum pump 1 is operated. In the present embodiment, the first degassing passage P1 is formed by a passage that penetrates the partition wall 24 in the Y-axis direction.

  The drive unit 3 includes a motor 35 that rotates the rotating shaft 210 of the rotor 21. The motor 35 has a drive shaft 350 that is fixed to the second casing 30 and that is coupled to the rotary shaft 210 via the magnet coupling mechanism 50. The magnet coupling mechanism 50 includes an annular inner peripheral magnet 51 fixed around the rotating shaft 210 and an annular outer peripheral magnet 52 fixed around the drive shaft 350, and these magnets 51, 52. The rotary shaft 210 and the drive shaft 350 are connected to each other by the magnetic coupling between the two.

  The inner peripheral side magnet 51 is disposed on the outer peripheral portion of the support member 53 fixed to the tip of the rotating shaft 210, and the outer peripheral side magnet 52 is disposed on the inner peripheral portion of the support member 54 fixed to the drive shaft 350. Yes. The inner circumference side magnet 51 and the outer circumference side magnet 52 are opposed to each other via the partition member 55. The peripheral edge portion of the partition member 55 is airtightly fixed to an annular convex portion 30 a formed on the inner peripheral surface of the second casing 30. The motor chamber 33 in which the inner peripheral side magnet 51 is disposed and the atmospheric chamber 34 in which the outer peripheral side magnet 52 is disposed are separated by a partition member 55.

  The rotation transmission unit 4 includes a third casing 40 that is airtightly attached to the partition wall 25, and the gear chamber 43 is formed inside the third casing 40. A bearing 45 and a shaft seal 46 that rotatably support the rotating shafts 210 and 220 are respectively installed on the side of the partition wall 25 facing the gear chamber 43.

  The third casing 40 forms a gear chamber 43 that houses a gear mechanism that synchronously rotates the rotors 21 and 22 in opposite directions. The gear mechanism has a synchronous gear 41 fixed to the end of the rotating shaft 210 and a synchronous gear 42 fixed to the end of the rotating shaft 220. Thereby, when one rotating shaft 210 rotates around the axis by driving the motor 35, the rotational force is transmitted to the other rotating shaft 220 through the synchronous gears 41 and 42. At this time, the rotating shaft 220 is rotated in the opposite direction to the rotating shaft 210.

  Lubricating oil G for lubricating the gear mechanism is stored in the gear chamber 43. A plate 47 for scooping up the lubricating oil G is fixed to the tips of the synchronous gears 41 and 42, and the lubricating oil G is supplied to the synchronous gears 41 and 42, the bearing 45 and the like by rotating together with the synchronous gears 41 and 42. . Thus, the rotors 21 and 22 can be properly rotated while maintaining the relative positions. The third casing 40 is provided with a window 44 for confirming the amount of lubricating oil G stored in the gear chamber 43. The gear chamber 43 is provided with a shield 48 in order to suppress scattering of the lubricating oil G due to rotation of the synchronous gears 41 and 42. The shield 48 has a substantially flat plate shape attached to the partition wall 25 so as to cover the upper portions of the synchronous gears 41 and 42.

  The gear chamber 43 communicates with the motor chamber 33 via the second deaeration passage P2. Thereby, the gear chamber 43 can be deaerated through the second deaeration passage P <b> 2, and is equalized with the pressures of the motor chamber 33 and the pump chamber 23 when the vacuum pump 1 is operated.

  In the present embodiment, the second deaeration passage P <b> 2 connects the gear chamber 43 to the motor chamber 33 through the third casing 40, the partition wall 25, the first casing 20, and the partition wall 24. The second degassing passage P2 is mainly formed by the main passage portion P21 penetrating the first casing 20, the partition walls 24 and 25 in the Y-axis direction, and the communication passage portion P22 formed in the third casing 40. The In addition, you may connect the main channel | path part P21 and the motor chamber 33 mutually by forming the same communication channel | path part also in the 2nd casing 30. FIG.

  FIG. 3 is an enlarged view of a main part showing details of the communication passage part P22. The communication passage portion P22 includes a first flow path P221 and a second flow path P222. The first flow path P <b> 221 has an axial direction in the Z-axis direction, and one end thereof faces the gear chamber 43. The second flow path P222 has an axial direction in the Y-axis direction, and communicates between the first flow path P221 and the main passage portion P21.

  The vacuum pump 1 of the present embodiment has a regulating member 60. In the present embodiment, the regulating member 60 has a cylindrical shape, one end of which is fitted into the second flow path P222, and the other end is shielded from a part of the first flow path P221. Are located in the first flow path P221. The other end of the restricting member 60 functions as a restricting portion 61 that restricts the flow of the lubricating oil G from the gear chamber 43 to the motor chamber 33.

  The material of the regulating member 60 is not particularly limited, and may be a resin material or a metal material. In the present embodiment, the regulating member 60 is formed of stainless steel, aluminum alloy, or the like.

  Next, operation | movement of the vacuum pump 1 comprised as mentioned above is demonstrated.

  With reference to FIG. 1, the rotation of the rotating shaft 210 together with the drive shaft 350 through the magnet coupling mechanism 50 by the operation of the motor 35 causes the rotor 21 to rotate in the pump chamber 23. Further, the rotational force of the rotating shaft 210 is transmitted to the rotating shaft 220 of the rotor 22 in the rotation transmitting unit 4, whereby the rotor 22 rotates in the direction opposite to the rotor 21 in synchronization with the rotor 21. By the rotation of the rotors 21 and 22, the pump unit 2 performs a predetermined pumping action for discharging the gas sucked from the intake port 201 toward the exhaust port 202.

  The motor chamber 33 and the gear chamber 43 are depressurized through the first and second deaeration passages P1 and P2 as the pressure in the pump chamber 23 decreases. As a result, the differential pressure between the pump chamber 23 and the motor chamber 33 and the gear chamber 43 adjacent to the pump chamber 23 is reduced, so that a decrease in pump performance due to leakage of the pump chamber 23 is prevented.

  When the rotors 21 and 22 rotate, the synchronous gears 41 and 42 are lubricated by the lubricating oil G stored in the gear chamber 43. As described above, the gear chamber 43 is exhausted together with the pump chamber 23. At this time, the lubricating oil G is also degassed, and the degassed gas is exhausted to the motor chamber 33 side via the second degassing passage P2. At this time, the lubricating oil G bubbles vigorously by degassing, and the splashing of the lubricating oil scatters inside the gear chamber 43 with the stirring action by the rotation of the plate 47. The shield 48 suppresses the scattering of the lubricating oil G. However, when the foaming of the lubricating oil is intense, for example, when the pump is started, the shield 48 may pass through the shield 48 and reach the deaeration passage P2. When the lubricating oil scattered in the gear chamber 43 reaches the deaeration passage P2, it flows out to the motor chamber 33 side together with the residual gas in the gear chamber 43. If this state is left as it is, the stored flow rate of the lubricating oil G decreases, and the lubricating action of the synchronous gears 41 and 42 and the bearing 45 may not be stably maintained.

  Therefore, in the present embodiment, the regulating member 60 is provided in the deaeration passage P2. The restriction portion 61 of the restriction member 60 is attached to the second flow path P222 so as to shield a part of the first flow path P221 as shown in FIG. Thereby, the splash of the lubricating oil G that has entered the first flow path P221 is received by the restricting portion 61, and the intrusion of the lubricating oil G into the second flow path P222 is restricted. As a result, it is possible to prevent the lubricating oil G from flowing out from the gear chamber 43 to the motor chamber 33, and to ensure a stable lubricating action of the synchronous gears 41, 42, the bearing 45, and the like.

  Further, since the restricting member 60 is formed of a cylindrical body, the residual gas in the gear chamber 43 can be efficiently guided to the second flow path P222 through the inside of the restricting member 60.

  Furthermore, according to the present embodiment, since the communication passage portion P22 of the deaeration passage P2 is composed of the first flow path P221 and the second flow path P222, the lubricating oil G received by the restriction portion 61 is reduced by gravity. By the action, the gear chamber 43 can be efficiently returned. Thereby, the stagnation of the lubricating oil G in the communication passage part P22 can be prevented.

  The amount of protrusion of the restricting portion 61 that protrudes from the second flow path P222 to the first flow path P221 is not particularly limited. For example, the volume of the gear chamber 43, the cross-sectional area of the deaeration passage P2, the storage amount of the lubricating oil G, It can be set accordingly.

  The embodiment of the present invention has been described above, but the present invention is not limited to this, and various modifications can be made based on the technical idea of the present invention.

  For example, in the above embodiment, the second flow path P222 of the communication path portion P22 is formed in a direction orthogonal to the first flow path P221. However, the present invention is not limited to this. One channel P221 may be formed with an upward slope toward the main passage portion P21.

  Moreover, in the above embodiment, although the control part 61 was formed in the edge part of a cylinder, it is not restricted to this, A planar board part may be sufficient. Moreover, the form by which the hole for deaeration was formed in the said board part by one or more may be sufficient. In this case, the said board part may be arrange | positioned in the whole region of a 1st flow path.

  Further, in the above embodiment, the first degassing passage P1 is formed in the partition wall 24, but the degassing passage P1 may be configured by a separate piping member that communicates the pump chamber 23 and the motor chamber 33. . Further, the first degassing passage P1 is not limited to the case where the motor chamber 33 is directly communicated with the pump chamber 23, and may be communicated with the intake side or the exhaust side of the pump chamber 23.

  Similarly, the second degassing passage P <b> 2 may be configured by a separate piping member that connects the gear chamber 43 and the motor chamber 33. Further, the second degassing passage P <b> 2 may be configured to directly connect the gear chamber 43 to the pump chamber 23 without passing through the motor chamber 33. By installing the regulating member 60, the intrusion of the lubricating oil into the pump chamber 23 can be suppressed, and the pump chamber 23 can be maintained in a clean state.

  Further, in the above embodiment, an example in which the present invention is applied to a single-stage mechanical booster pump has been described. However, the present invention is not limited to this, and the present invention can also be applied to other vacuum pumps such as a multi-stage type root pump. It is.

DESCRIPTION OF SYMBOLS 1 ... Vacuum pump 2 ... Pump part 3 ... Drive part 4 ... Rotation transmission part 20, 30, 40 ... Casing 21,22 ... Rotor 23 ... Pump room 33 ... Motor room 41, 42 ... Synchronous gear 43 ... Gear room 60 ... Restriction Member 61 ... Restriction part G ... Lubricating oil P1 ... 1st deaeration passage P2 ... 2nd deaeration passage P22 ... Communication passage part P221 ... 1st flow path P222 ... 2nd flow path

Claims (1)

A first rotor rotatable in a first direction; a second rotor disposed adjacent to the first rotor and rotatable in a second direction opposite to the first direction; and the first A first chamber that accommodates the rotor and the second rotor, a first casing that forms the first chamber, a first partition that is attached to one end of the first casing, A pump unit having a second partition wall attached to the other end of the first casing ;
A drive mechanism that rotates the first rotor; a second chamber that houses the drive mechanism; a second casing that divides the second chamber by the first partition; and the first partition A drive unit having a first deaeration passage formed to communicate with the first chamber and the second chamber;
A gear mechanism that synchronously rotates the first rotor and the second rotor, a third chamber that can store the lubricating oil that houses the gear mechanism and lubricates the gear mechanism, and the third chamber A rotation transmission portion having a third casing partitioned by the second partition ;
A main passage formed through the first partition, the first casing, the second partition, and the second casing and passing through the first partition, the first casing, and the second partition. And a second flow passage formed in the third casing and having a first axial direction parallel to the direction of gravity and facing the third chamber, and a second crossing the first axial direction. A communication passage portion having a second flow passage that communicates between the first flow passage and the main passage portion, and the third chamber is the second chamber. Or a second degassing passage communicating with the first chamber;
One end is fitted into the second flow path, and the other end is a cylindrical regulating member that shields a part of the first flow path, and the other end is removed from the third chamber. A vacuum pump comprising: a regulating member serving as a regulating portion that prevents the lubricating oil from flowing out into the second chamber or the first chamber .

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