JP6032717B2 - air compressor - Google Patents

Description

  The present invention relates to an air compressor in which a non-contact visco seal is provided in a gap in a portion where a rotating shaft of an electric motor passes through a partition wall that partitions an internal space of a gear casing and an internal space of an electric motor casing.

  A compressor body that compresses air, an electric motor that is a power source of the compressor body, a gear mechanism that transmits the power of the motor to the compressor body, and a connection between the casing of the compressor body and the casing of the motor An air compressor including a gear casing that houses a gear mechanism or the like is known (see, for example, Patent Document 1). This air compressor has a partition wall (part of the gear casing in Patent Document 1) that partitions the internal space of the gear casing and the internal space of the motor casing. A non-contact visco seal is provided in the gap between the penetrating portions. The visco seal has a thread groove formed on the inner peripheral surface thereof, and generates a flow from the motor casing side to the gear casing side by the rotation of the rotating shaft of the motor. Thereby, the lubricating oil in the gear casing is prevented from entering the casing of the electric motor.

JP 2000-97186 A

  However, there is room for improvement in the prior art described above. That is, in the above-described prior art, a visco seal is provided in a gap in a portion where the rotating shaft of the motor penetrates in the partition wall partitioning the internal space of the gear casing and the internal space of the motor, Thus, a flow from the motor casing side to the gear casing side is generated. For this reason, the electric motor side becomes negative pressure from the visco seal, and the internal space of the electric motor casing becomes negative pressure. If there is a minute gap in the casing of the motor, outside air (atmosphere) is sucked into the inner space of the casing of the motor, and dust contained in the outside air accumulates over a long period of time, causing problems such as overheating. May occur.

  An object of the present invention is to provide an air compressor that can prevent dust from entering a motor casing and can improve reliability.

(1) To achieve the above object, a compressor main body that compresses air, an electric motor that is a power source of the compressor main body, a gear mechanism that transmits the power of the electric motor to the compressor main body, and the compression A gear casing connected between the casing of the machine main body and the casing of the electric motor and housing the gear mechanism; a partition wall partitioning an internal space of the gear casing and an internal space of the casing of the motor; and the partition wall portion And a non-contact visco seal that is provided in a through-hole through which the rotating shaft of the electric motor passes, and that generates a flow from the casing side of the electric motor to the gear casing side by rotation of the rotating shaft of the electric motor. In the compressor, the electric motor has a bearing provided to support the rotating shaft between the non-contact visco seal and the gear mechanism, and the electric motor Are those rotor is overhanging in the direction of the rotational axis counter-load side relative to the bearing, the partition wall portion, a gap formed in the vicinity of the motor side of the visco seal said through hole of said air compressor The outside has a communication hole that communicates without passing through the internal space of the casing of the motor.

  (2) In the above (1), the lubricating oil stored in the gear casing has a lubricating oil supply path for supplying the lubricating oil to the bearing.

  In the present invention, the Bisco seal generates a flow from the motor casing side to the gear casing side by the rotation of the rotating shaft of the motor. At this time, outside air can be supplied to the gap on the electric motor side from the Bisco seal in the partition wall portion through the communication hole, and negative pressure can be prevented in the internal space of the casing of the electric motor. Therefore, even if a minute gap is generated in the casing of the electric motor, dust can be prevented from entering the electric motor casing, and reliability can be improved.

It is a figure showing sectional structure of an air compressor in a 1st embodiment of the present invention with an air system and an oil system. It is a figure showing sectional structure of an air compressor in a 2nd embodiment of the present invention with an air system and an oil system.

  A first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a diagram illustrating a cross-sectional structure of an air compressor according to this embodiment together with an air system and an oil system.

  In FIG. 1, an air compressor includes a compressor main body 1 that compresses air, an electric motor (for example, a permanent magnet electric motor) 2 that is a power source of the compressor main body 1, and the power of the electric motor 2 as a compressor main body 1. A gear mechanism 3 for transmitting to the gear, and a gear casing 4 for housing the gear mechanism 3 and the like.

  The electric motor 2 includes a rotating shaft 5, a rotor 6 attached to the rotating shaft 5, a stator 7 disposed on the outer peripheral side of the rotor 6, and an electric motor main casing 8 to which the stator 7 is fixed. And a load-side casing 9 connected to the rotation axis direction load side (left side in FIG. 1) of the electric motor main casing 8 and a rotation side in the rotation axis direction of the electric motor main casing 8 (right side in FIG. 1). And an anti-load side casing 10. The load side casing 9 is connected to one side (right side in FIG. 1) of the gear casing 4.

  The load-side end of the rotating shaft 5 extends through the load-side casing 9 to the inside of the gear casing 4 and is rotated by a bearing 11A provided in the load-side casing 9 and a bearing 11B provided in the gear casing 4. Supported as possible. That is, the rotor 6 located in the electric motor main casing 8 is overhanging with respect to the bearings 11A and 11B. A driving gear 12 is provided at the load side end of the rotating shaft 5. The load side casing 9 is provided with a bearing cover 13 for covering the bearing 11A.

  The screw-type compressor main body 1 includes a male rotor 14A and a female rotor 14B that rotate so that their axial directions are substantially parallel to each other, and a compressor main casing 15 that houses the teeth of the male rotor 14A and the female rotor 14B. And a discharge casing 16 connected to the discharge side (left side in FIG. 1) of the compressor main casing 15 in the rotor axial direction. The compressor main casing 15 is connected to the other side (left side in FIG. 1) of the gear casing 4.

  Shaft portions on the discharge side (left side in FIG. 1) and suction side (right side in FIG. 1) of the male rotor 14A are rotatably supported by a bearing (not shown). Similarly, the shaft portions on the discharge side and the suction side of the female rotor 14B are rotatably supported by a bearing (not shown). Timing gears 17A and 17B are provided on the discharge side shafts of the male rotor 14A and the female rotor 14B, so that the male rotor 14A and the female rotor 14B rotate synchronously in a non-contact state. Further, the suction side shaft portion of the male rotor 14 </ b> A extends from the compressor main casing 15 to the inside of the gear casing 4, and a driven gear 18 is provided.

  The gear mechanism 3 is configured by meshing the drive gear 12 and the driven gear 18 described above. Then, the rotational force of the electric motor 2 is transmitted to the male rotor 14A through the gear mechanism 3 to rotate the male rotor 14A, and the female rotor 14B also rotates through the timing gears 17A and 17B. Then, as the male rotor 14A and the female rotor 14B rotate, the working chamber moves to the rotor axial discharge side and the volume changes. As a result, air is sucked from the suction flow path 19 and compressed, and the compressed air is discharged to the discharge flow path 20.

  Lubricating oil is stored in the lower portion of the gear casing 4, and an oil system for supplying the lubricating oil to the timing gears 17A and 17B, the gear mechanism 3, the bearings 11A and 11B, and the like is provided. This oil system includes an oil pump 21, an oil pipe 22 </ b> A connected between the suction side of the oil pump 21 and the lower part of the gear casing 4, a discharge side of the oil pump 21, and a discharge casing 16 of the compressor body 1. , An oil pipe 22C connected between the discharge casing 16 of the compressor body 1 and the lower part of the gear casing 4, and an upper part of the gear casing 4 branched from the oil pipe 22B. And an oil pipe 22D connected to the. Note that a communication hole (not shown) for taking outside air (atmosphere) is formed in the upper part of the gear casing 4 so that the internal pressure of the gear casing 4 is kept below the atmospheric pressure.

  Incidentally, a visco seal 23 is provided in a gap (specifically, on the side of the electric motor 2 from the bearing 11 </ b> A) where the rotary shaft 5 of the electric motor 2 penetrates in the load-side casing 9. A seal cover 24 made of, for example, aluminum is attached to the load-side casing 9. The visco seal 23 has a thread groove formed on the inner peripheral surface thereof, and generates a flow from the motor main casing 8 side to the gear casing 4 side by the rotation of the rotating shaft 5. This prevents the lubricating oil in the gear casing 4 from entering the electric motor main casing 8. However, at this time, since the electric motor 2 side becomes negative pressure from the Bisco seal 23, the internal space of the electric motor main casing 8 may become negative pressure as it is.

  Therefore, in the present embodiment, the seal cover 24 has a substantially circular groove 25 larger than the through hole through which the rotary shaft 5 passes, and extends downward from the groove 25 (in other words, radially outward). A communication groove (communication hole) 26 is formed. The gap between the side surface (inner peripheral surface) of the groove 25 in the seal cover 24 and the outer peripheral surface of the rotary shaft 5 is the same as the inner peripheral surface of the portion on the motor 2 side of the groove 25 in the seal cover 24 and the rotary shaft 5. It is larger than the gap between the outer peripheral surface. In addition, the flow path cross section of the communication groove 26 of the seal cover 24 is larger than the gap between the inner peripheral surface of the portion of the seal cover 24 closer to the electric motor 2 than the groove 25 and the outer peripheral surface of the rotary shaft 5. The load-side casing 9 is formed with a communication hole 27 that communicates with the communication groove 26 of the seal cover 24 and opens downward and communicates with the outside.

  That is, in the present embodiment, the load-side casing 9 and the seal cover 24 constitute a partition wall that partitions the internal space of the gear casing 4 and the internal space of the electric motor main casing 8, and from the Bisco seal 23 in this partition wall portion. The gap on the electric motor 2 side (in other words, the space in the groove 25) and the outside of the air compressor are communicated with each other through the communication holes 26 and 27 without passing through the internal space of the electric motor main casing 8. Thereby, outside air can be supplied to the clearance on the motor 2 side from the Bisco seal 23 via the communication holes 26 and 27, and the internal space of the motor main casing 8 can be prevented from becoming negative pressure. Therefore, even if a minute gap is generated in the casing of the electric motor 2 (as a specific example, even if a minute gap is generated in the connecting portion between the electric motor main casing 8 and the load side casing 9), the electric motor main casing It is possible to prevent dust from entering the inside 8, and to improve the reliability.

  In the first embodiment, as shown in the drawing, the structure in which the anti-load side end portion of the rotating shaft 5 of the electric motor 2 does not penetrate the anti-load side casing 10 is shown as an example, but the present invention is not limited to this. That is, for example, the anti-load side end of the rotating shaft 5 of the electric motor 2 extends through the anti-load side casing 10 to the outside, and the anti-load side casing 10 (or the anti-load side attached thereto) You may provide a contact-type seal | sticker in the clearance gap between the penetration parts of the rotating shaft 5 in a seal cover. In such a case, the same effect as described above can be obtained.

  A second embodiment of the present invention will be described with reference to FIG. FIG. 2 is a diagram illustrating the structure of the air compressor in the present embodiment together with an air system and an oil system. In FIG. 2, the same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  In this embodiment, the anti-load side end portion of the rotating shaft 5A of the electric motor 2 extends through the anti-load side casing 10A to the outside. An anti-load-side seal cover 28 made of, for example, aluminum is attached to the anti-load-side casing 10A, and a contact-type seal 29 is provided in the clearance between the rotation shaft 5A in the anti-load-side seal cover 28. Yes.

  The load-side seal cover 24A is formed with a substantially circular groove 25 larger than the through hole through which the rotary shaft 5 passes, as in the first embodiment. And inside the rotating shaft 5A, a plurality of radial communicating holes 30a communicating with the groove 25 of the seal cover 24A, and communicating with these communicating holes 30a, and extending to the opposite end face of the rotating shaft 5A. An axial communication hole 30b is formed.

  That is, in the present embodiment, the load-side casing 9 and the seal cover 24A constitute a partition portion that divides the internal space of the gear casing 4 and the internal space of the electric motor main casing 8, and from the Bisco seal 23 in this partition portion. The gap on the electric motor 2 side (in other words, the space in the groove 25) and the outside of the air compressor are communicated with each other through the communication holes 30a and 30b without passing through the internal space of the electric motor main casing 8. Thereby, outside air can be supplied to the gap on the motor 2 side from the Bisco seal 23 via the communication holes 30a and 30b, and the internal space of the motor main casing 8 can be prevented from becoming negative pressure. Therefore, even if a minute gap is generated in the casing of the electric motor 2, dust can be prevented from entering the electric motor main casing 8, and reliability can be improved.

  In the first and second embodiments, the load-side casing 9 and the seal cover 24 (or 24A) are described as separate members. However, the present invention is not limited to this. That is, for example, the load-side casing 9 and the seal cover 24 (or 24A) may be integrally formed as the same member. Moreover, in the said 1st and 2nd embodiment, although the load side casing 9 was demonstrated as a part of casing of the electric motor 2 for convenience, you may consider it as a part of gear casing 4. FIG. For example, the load side casing 9 and the gear casing 4 may be integrally formed as the same member. In such a case, the same effect as described above can be obtained.

  In the first and second embodiments, the rotating shaft 5 (or 5A) of the electric motor 2 is rotatably supported by bearings 11A and 11B provided in the gear casing 4 and the load side casing 9. The rotor 6 located in the electric motor main casing 8 has been described as an example of a structure that overhangs the bearings 11A and 11B, but is not limited thereto. That is, for example, the rotating shaft 5 (or 5A) may be rotatably supported by bearings provided in the load-side casing 9 and the anti-load-side casing 10 (or 10A). In this case, the same effect as described above can be obtained.

  Moreover, in the said 1st and 2nd embodiment, although the gear mechanism 3 demonstrated taking the case where it comprised by a pair of gears 12 and 18, as an example, it is not restricted to this. That is, for example, it may be configured by two pairs of gears. Specifically, the driving gear provided at the load side end of the rotating shaft 5 (or 5A) of the electric motor 2 and the first intermediate gear meshing with the driving gear and the shaft of the male rotor 14A of the compressor body 1 are provided. You may provide a driven gear, the 2nd intermediate gear meshing with this, and the intermediate shaft which attached the 1st and 2nd intermediate gear. Further, the suction side shaft portion of the female rotor 14B may extend from the compressor main casing 15 to the inside of the gear casing 4 instead of the suction side shaft portion of the male rotor 14A, and a driven gear may be provided. In such a case, the same effect as described above can be obtained.

  Moreover, in the said 1st and 2nd embodiment, although the case where the one-stage compressor main body 1 was provided was demonstrated as an example, it is not restricted to this. In other words, two or more stages of compressor bodies may be provided. In such a case, the same effect as described above can be obtained.

DESCRIPTION OF SYMBOLS 1 Compressor body 2 Electric motor 3 Gear mechanism 4 Gear casing 5 Rotating shaft 5A Rotating shaft 8 Motor main casing 9 Load side casing (partition wall)
DESCRIPTION OF SYMBOLS 10 Anti-load side casing 10A Anti-load side casing 15 Compressor main casing 16 Discharge casing 23 Visco seal 24 Seal cover (partition part)
24A Seal cover (partition wall)
25 groove 26 communication groove (communication hole)
27 Communication hole 28 Anti-load side seal cover 29 Contact type seal 30a Communication hole 30b Communication hole

Claims (2)

A compressor body for compressing air;
An electric motor as a power source of the compressor body;
A gear mechanism for transmitting the power of the electric motor to the compressor body;
A gear casing that is connected between the casing of the compressor body and the casing of the electric motor and houses the gear mechanism;
A partition wall partitioning the internal space of the gear casing and the internal space of the casing of the motor;
A non-contact visco seal that is provided in a through-hole through which the rotating shaft of the electric motor penetrates in the partition wall and generates a flow from the casing side of the electric motor to the gear casing side by rotation of the rotating shaft of the electric motor; In the air compressor provided,
In the electric motor, a bearing for supporting the rotating shaft is provided between the non-contact type Bisco seal and the gear mechanism, and the rotor of the electric motor is overloaded to the opposite side of the rotating shaft direction with respect to the bearing. Hangs,
The partition wall has a communication hole that communicates a gap formed near the motor side with respect to the visco seal of the through hole and the outside of the air compressor without passing through the internal space of the casing of the motor. The air compressor that is what. The air compressor according to claim 1,
An air compressor having a lubricating oil supply path for supplying lubricating oil stored in the gear casing to the bearing.

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