JP4685617B2 - Rotating electric machine - Google Patents

Description

  The present invention relates to an air supply / exhaust structure for preventing dust generation in a rotating electrical machine such as a generator or an electric motor.

  One type of electrical equipment that converts electrical energy into mechanical energy is an electric motor, also called a motor. In this motor, the electrical system and mechanical system are coupled, and the relative motion between the magnetic field and the conductor, the magnetic field and the current The energy is converted by using electromagnetic force between them, attractive force between magnets and repulsive force.

  One type of electric motor is a rotating electrical machine such as a direct current motor or an alternating current motor in which mechanical energy is extracted as a rotational motion. Therefore, a conventional example of this rotating electrical machine will be described with reference to FIG. 7. First, the rotating electrical machine shown in FIG. 7 is a kind of electric motor called an AC servo motor. In this example, details are shown in FIG. As shown, the armature core 1 and the armature winding 2 are molded by a resin mold 9.

  The resin-molded armature is fixed to the substantially cylindrical housing 3 by shrink-fitting or press-fitting, and a rotor 4 having permanent magnets 3 as magnetic poles is combined with the armature. The end bracket 6a and the end bracket 6b on the anti-load side are assembled.

  At this time, the armature is obtained by integrating a stack of electric iron plates called silicon steel plate by means such as caulking or laser welding to form an armature core 1, and armature winding is provided in a groove portion of the armature core 1. The wire 2 is applied, and the silicon steel plate at this time is usually a belt-like one, and an electric iron plate stamped and formed into a shape necessary for the armature is used as a laminate.

  The shape of the armature core 1 at this time includes a main body portion functioning as a magnetic circuit, and portions provided with bolt holes 15a and 15b for fixing the armature to the end brackets 6a and 6b via the housing. It is common to have one.

  On the other hand, the rotor 4 has a rotating shaft 8, which is rotatably held by the end brackets 6a and 6b by bearings 7a and 7b. In addition, in this FIG. 7, although the case where the rotating shaft 8 is a hollow shaft specification is shown as an example, a solid shaft may be sufficient.

  At this time, the load side end bracket 6a is provided with a bolt hole 15a, and is fixed to the housing 5 through the bolt 14a. The load side end bracket 6a is provided with an external mounting bolt hole (not shown) so that the load side end bracket 6a can be attached to an external device by the external mounting bolt.

  Further, the end bracket 6b on the opposite side of the load also has a bolt hole 15b and is fixed to the housing 5 by the bolt 14b. An end cover 12 is attached to the end bracket 6b on the side opposite to the load, and an encoder 11 is provided therein, so that the position and speed necessary for the servo motor can be detected.

  Here, the encoder 11 is fixed to the end bracket 6b on the load side, and the end cover 12 is fixed to the end bracket 6b on the side opposite to the load from the bolt hole 15c and the bolt 14c. The housing 3 is provided with a terminal box 13 from which a motor lead wire is taken out.

  By the way, such a rotating electrical machine requires a bearing, and naturally, this servomotor also includes bearings 7a and 7b. These usually require lubrication, but when a lubricant such as grease is used, generation of dust, so-called dust generation, becomes a problem.

  In particular, in recent years, rotating electric machines such as electric motors have come to be used in many precision devices that do not like dust, such as semiconductor manufacturing devices. As a result, the drive system is becoming more direct drive. In this case, the drive source is often installed near the workpiece such as a semiconductor wafer to be handled. Dust generation from electric machines has become a severe problem.

Here, in the case of such a rotating electric machine, the main cause of the dust generation is the lubricating grease sealed in the bearing as described above. Therefore, in order to suppress this dust generation, the conventional technology pays attention to the fact that the components generated from the bearings and wear particles are scattered mainly from the gap between the rotating shaft and the end bracket on the load side. A method is proposed in which a dust generation component or the like is prevented from leaking to the outside by using a sealing structure such as (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 05-227693

  In the above prior art, it cannot be said that consideration is given to the fact that the components generated from the rotating electric machine are particles with extremely small diameters, so-called particles. There was a problem that dissatisfaction remained in the point to plan.

  Here, the term “particle” refers to a fine particle of 10 μm or less that floats in a gas or a liquid and does not easily settle. For this particle, a device that continuously measures the size and number of fine particles floating in the air. Can be measured by a particle counter known as

  The performance of the particle counter at this time is usually measurable if the particle size is 0.1 μm or more. At this time, the measurement is performed in units of 1 minute under an air supply flow rate of 28 NL / min (NL: normal liter). It is possible to count the number of particles according to the particle size in six stages over time. Therefore, normally, the cleanliness is defined by the number of particles measured by the particle counter. The normal liter is a volume (L) at a normal temperature and constant pressure.

  Therefore, using this particle counter, for example, in the conventional rotating electric machine of FIG. 7, instead of a general urea grease, a low dust generation grease with a small dust generation amount is applied, and then the rotating shaft 8 and the load side are used. The nozzle of the particle counter was installed in the vicinity of the gap of the end bracket 6a, and the amount of dust generated scattered from this portion to the outside was measured.

  As a result, in the case of the low dust generation grease used this time, it was confirmed that the dust generation amount was suppressed to a level of a few tenths as a whole compared with a general urea grease. However, it was found that particles with a particle size of about 0.1 μm are on the order of several hundreds per minute, and it is impossible to keep them to zero.

  Therefore, when the conventional techniques 1 and 2 cannot cope with the conventional techniques 1 and 4, the system including the apparatus becomes complicated and the size cannot be reduced. Will occur.

  An object of the present invention is to provide a rotating electrical machine that can reduce the size of equipment by suppressing scattering of dust containing particles with a simple configuration.

The object is to use a rotor combined with a rotating shaft, a first bearing and a second bearing that use grease for lubrication, and rotatably hold the rotating shaft, and disposed outside the rotor. And the stator fixed to the housing, the first flow path provided between the first bearing and the stator, and the first flow path connected to the rotor and the fixed A second flow path provided between the second bearing, the third flow path connected to the second flow path, and provided between the second bearing and the stator; 4 is connected to the second flow path, is provided on the opposite side to the third flow path and the second bearing, and discharges air that has passed through the second bearing from the second flow path. Air in the order of the first flow path, the first flow path, and the second flow path, and the fourth flow along with the third flow path. By passing in is achieved by providing a discharge means for discharging said first bearing and particles generated from the second bearing from the third flow path and the fourth flow path.

At this time, the first bearing is installed on the anti-load side of the rotating electrical machine,
The second bearing may be installed on the load side of the rotating electrical machine , and then the discharge means includes a first pump that sucks air from the third flow path to the outside, and the You may make it be comprised with the 2nd pump which sucks out air from the 4th flow path outside.
Here, the discharging means is constituted by a third pump for sending air to the first flow path in addition to the first pump and the second pump. Similarly, among the air discharged by the discharge means, the air discharged from the fourth flow path may be more than the air discharged from the third flow path.
Then, further wherein, it may be assumed with an encoder for detecting a rotational position of the rotary shaft in the counter-load side relative to the first bearing.

  According to the present invention, the dust generated by the rotating electrical machine is discharged by the circulation of air or the like, so that the scattering of dust containing particles can be suppressed with a simple configuration, and the device using the rotating electrical machine can be downsized. be able to.

  In order to reduce the size of the device, it is effective to suppress dust generation in the vicinity of the rotating electrical machine used for the device. Therefore, according to the present invention, the size of the device can be further reduced.

  In addition, according to the present invention, since it can be applied to a semiconductor manufacturing apparatus to prevent dust components from adhering to the target workpiece, further cleaning can be realized, thereby suppressing dust generation. Therefore, a structure that complicates the structure, such as a labyrinth structure, is not required, and an inexpensive rotating electrical machine can be provided.

  Furthermore, according to the present invention, the structure can be simplified, the reliability can be easily improved, and it is possible to contribute to avoiding the complexity of the rotating device itself and the system to be applied. Further downsizing of mechanical equipment and the like is possible, which can contribute to downsizing.

  Hereinafter, a rotating electrical machine according to the present invention will be described in detail with reference to embodiments shown in the drawings.

  First, FIG. 1 shows a rotating electrical machine according to the first embodiment of the present invention. This is the same as the case of the prior art explained in FIG. In one embodiment, in FIG. 1, the entire AC servomotor is indicated by M. In this AC servomotor M, 10a is an intake port, 10b and 10c are exhaust ports, and other than these are the same as the AC servomotor according to the prior art of FIG.

  Therefore, the components other than the intake port 10a and the exhaust ports 10b and 10c will be briefly described. First, the AC servo motor M according to this embodiment also includes an armature composed of the armature core 1 and the armature winding 2, The rotor 4 and end brackets 6a and 6b are combined.

  At this time, the armature core 1 and the armature winding 2 are molded by the resin mold 9 as already described with reference to FIG. 8, and the molded armature is fixed to the substantially cylindrical housing 3. A rotor 4 having a permanent magnet 3 as a magnetic pole is combined, and is assembled by a load-side end bracket 6a and an anti-load-side end bracket 6b.

  Also in this case, the rotor 4 has a rotating shaft 8, which is rotatably held by the end brackets 6a and 6b by bearings 7a and 7b. The load side end bracket 6a is fixed to the housing 5 by bolts 14a, and the anti-load side end bracket 6b is also fixed to the housing 5 by bolts 14b. At this time, the rotating shaft 8 is also hollow as shown in the figure. Not only the shaft specification but also a solid shaft may be used.

  Furthermore, an encoder 11 is provided in the end cover 12 so that the position and speed necessary for the servo motor can be detected. This encoder 11 is also fixed to the end bracket 6b on the anti-load side. The end cover 12 is also fixed to the end bracket 6b on the side opposite to the load side from the bolt hole 15c and the bolt 14c. The housing 3 is provided with a terminal box 13 from which a motor lead wire is taken out.

  The above is the same as in the case of the prior art of FIG. 7, but in the case of the embodiment of FIG. 1, as described above, the intake port 10a and the exhaust ports 10b and 10c are further provided. It is very different from the case.

  First, the intake port 10a is formed as a terminal box inside the housing 5 as a hole connected to the space A between the armature consisting of the armature core 1 and the armature winding 2 and the bearing 7b on the anti-load side. 13 is formed with a passage (intake passage) for communicating the space A to the outside.

  Next, as shown in detail in FIG. 2, the exhaust port 10b is left inside the end bracket 6a, between the armature consisting of the armature core 1 and the armature winding 1, and the load-side bearing 7a. The hole connected to the space B is provided in the end bracket 6a and forms a passage (first exhaust passage) for communicating the space B to the outside.

  At this time, the exhaust port 10b is formed in the end bracket 6a as a hole extending in a direction perpendicular to the rotation shaft 4, and further, the exhaust port 10b is formed in a predetermined direction along the circumferential direction of the housing 5. A plurality of, for example, four, are provided independently with an interval, for example, an angle of 90 °.

  Further, as shown in FIG. 2 in detail, the exhaust port 10c is a surface of a portion where the rotary shaft 8 protrudes outward from the bearing 7a on the load side and penetrates a hole in the center of the end bracket 6a. Is provided in the end bracket 6a as a hole continuous with the portion C, and forms a passage (second exhaust passage) for communicating the portion C to the outside. .

  Here, the exhaust port 10c is also formed in the end bracket 6a as a hole extending in a direction perpendicular to the rotating shaft 4. Further, the exhaust port 10c is also formed in a predetermined direction along the circumferential direction of the housing 5. A plurality of, for example, four, are provided independently with an interval, for example, an angle of 90 °.

  Further, as shown in the drawing, pipe tapping for connecting pipes is applied to the opening ends of the intake port 10a, the exhaust port 10b, and the exhaust port 10c so that pipes such as pipes can be connected thereto.

  Next, the operation of this embodiment will be described. In this case, first, pipes (pipes) are connected to the intake port 10a, the exhaust port 10b, and the exhaust port 10c, and the pipe connected to the intake port 10a is used for air introduction. The pipes connected to the exhaust port 10b and the exhaust port 10c are air discharge pipes, respectively.

  At this time, even in the case of the AC servomotor M, lubricating grease is applied to the bearings 7a and 7b. Accordingly, if the AC servo motor M is rotated, dust is generated from the bearings 7a and 7b, and particles are generated. The generated particles try to scatter mainly from the gap G between the rotary shaft 8 and the load side end bracket 6a.

Therefore, in this AC servo motor M, air or N ₂ gas (hereinafter referred to as air or the like) is sent from an air introduction conduit connected to the intake port 10a, and is connected to the exhaust port 10b and the exhaust port 10c. Air or the like is discharged from the air discharge pipe, and thereby, a flow of air or the like is created in the AC servomotor M as indicated by arrows in FIGS. 3 and 4.

  Here, FIG. 4 is a partially enlarged view of FIG. 3. As indicated by arrows in these drawings, the air or the like flowing into the space A from the intake port 10a is in the vicinity of the bearing 7b on the anti-load side. After passing through, it enters the gap between the stator core 1 and the rotor 4, and enters here the space B. Then, since the exhaust port 10b is connected here, most of the air etc. which entered this space B are discharged | emitted from the exhaust port 10b, and are discharged | emitted as it is outside.

  At this time, part of the air or the like that has entered the space B enters the bearing 7a on the load side and escapes to the space C, but since the exhaust port 10c is communicated there, The entered air or the like is discharged through the exhaust port 10c and is also discharged to the outside.

  Then, even if dust is generated from the bearing 7b and the bearing 7a along with the rotation of the AC servo motor M at this time, among the particles due to this, first, the particles generated from the bearing 7b on the anti-load side are in space. When air or the like flows into B, the air is discharged through the exhaust port 10b, so that the air is discharged from the air discharge pipe connected to the exhaust port 10b to a place distant from the outside.

  Further, since particles generated from the load-side bearing 7a enter the space C together with air or the like, the particles are discharged through the exhaust port 10c. Therefore, the air discharge conduit connected to the exhaust port 10c is used. Will be discharged to a remote location.

  As already described, the particles at this time are fine particles of 10 μm or less that float in gas or liquid and are difficult to settle, so they can easily get on the flow of air and move with the flow. Can do.

  Therefore, the air exhaust pipe connected to the exhaust port 10b and the exhaust port 10c is extended to a place away from the AC servo motor M, and the air exhaust pipe is opened at the place, thereby the AC servo motor. It is possible to prevent dust including particles from being discharged in the vicinity of M and causing adverse effects.

  Therefore, according to this embodiment, it is possible to prevent dust containing particles from the AC servo motor M from being discharged from the AC servo motor M into the surrounding atmosphere. Can be removed.

  Next, a method of creating a flow of air or the like in this embodiment will be described. There are roughly the following three methods.

・ Method 1
Air or the like is exhausted from the exhaust port 10b and the exhaust port 10c, and the intake port 10a is opened to an appropriate atmosphere.

・ Method 2
Air or the like is sent from the intake port 10a, and the exhaust port 10b and the exhaust port 10c are opened to the outside atmosphere.

・ Method 3
Air or the like is sent from the intake port 10a, and air or the like is discharged from the exhaust port 10b and the exhaust port 10c.

  First, in the case of Method 1, an appropriate pump such as an ejector (discharge fluid pump) is connected to the exhaust port 10b and the exhaust port 10c to suck out air and the like, and if necessary, escape to the outside through a filter. I will do it. At this time, the intake port 10a may be configured to suck in air from either inside or outside the casing of the device equipped with the AC servo motor M, and may pass through a filter if necessary.

  Next, in the case of the method 2, an appropriate pump such as an injector (pressurizing fluid pump) is connected to the intake port 10a, air is taken in from the atmosphere and pressurized, and the pressurized air or the like is taken into the intake port 10a. To be supplied to. At this time, a filter may be used if necessary.

In the case of N ₂ gas, nitrogen may be injected into the intake port 10a from a pressurized container such as a gas cylinder through a pressure regulating valve. In this case, a pressurizing pump is not necessary.

  In the case of method 3, an appropriate pump is connected to the intake port 10a, air is taken in from the atmosphere and pressurized, and the pressurized air is supplied to the intake port 10a. An appropriate pump is also connected to the exhaust port 10c and the exhaust port 10c to suck out air or the like.

Also in this case, in the case of N ₂ gas, the gas may be press-fitted into the intake port 10a from a pressurized container such as a gas cylinder through a pressure regulating valve. In this case, a pump is not necessary for the intake port 10a. is there.

  Here, in the case of a rotating electrical machine such as an AC servo motor M, if the internal pressure is larger than the external pressure, there is a possibility that the generated components may be scattered outside. When the internal pressure is smaller than the external pressure, there is a risk that external foreign matter may enter with the atmosphere.

  At this time, if the pressure inside and outside the rotating electrical machine is almost the same, dust generation will not scatter to the outside and external foreign matter will not enter, so this state is ideal, but When the rotating electrical machine is operated, the internal pressure generally increases. In this case, normally, the generated components leak out of the rotating electrical machine.

  Therefore, as an embodiment of the present invention, it is desirable that the pressure in the rotating electrical machine such as the AC servo motor M is kept slightly lower than the external pressure. In this case, from the actual evaluation experiment results, it is desirable that the air supply port 10a is at one place and the exhaust ports 10b and 10c are around 2 to 4 places on the entire circumference.

  In addition, it is confirmed that the flow rate of air or the like at this time is very small, and particles leaking from a rotating electrical machine such as the AC servo motor M cannot be detected even at a flow rate of several liters per minute, for example. At this time, it is effective to install the exhaust ports 10b and 10c as close as possible to the dust generation source, that is, in the vicinity of the bearings 7a and 7b. At this time, the gap G between the bearing 7a and the rotary shaft 8 is made as small as possible. It is also effective.

  At this time, in FIG. 3, the flow distribution of air or the like to the exhaust ports 10b and 10c is performed by, for example, changing the thickness of the exhaust ports 10b and 10c, or installing orifices (throttles) in the exhaust ports 10b and 10c. It can be set arbitrarily by adjusting.

  By the way, in the above embodiment, the case where the dust generation source is the bearings 7a and 7b has been described. However, this embodiment is similarly applied to the case where there is a dust generation source other than the bearings 7a and 7b in the rotating electrical machine. The effect of the above can be obtained, and the generation of dust can be suppressed.

  Next, another embodiment of the present invention will be described with reference to FIG. 5. Here, FIG. 5 shows a second embodiment of the present invention, in which the exhaust is discharged in the vicinity of the bearing 7b on the opposite side of the load. Ports 10d and 10e are provided, and other configurations are the same as those of the first embodiment described with reference to FIG.

  At this time, first, the discharge port 10d is connected to the space A inside the housing 5, and is provided in the end bracket 6b on the anti-load side as a hole opened as close as possible to the vicinity of the bearing 7b on the anti-load side. In other words, a passage (third exhaust passage) for communicating the space A with the outside is formed.

  The exhaust port 10d is formed in the end bracket 6b as a hole extending in a direction perpendicular to the rotating shaft 4. Further, the exhaust port 10d is also a predetermined along the circumferential direction of the end bracket 6b. A plurality of, for example, four, for example, 90 ° angles are provided independently.

  Next, in the exhaust port 10e, the rotary shaft 8 is directed from the bearing 7b on the anti-load side toward the end cover 12 where the encoder 11 is installed, and passes through the hole in the center of the end bracket 6b on the anti-load side. Is formed in the end bracket 6a as a hole connected to the portion E, and forms a passage (fourth exhaust passage) for communicating the portion C to the outside. It is what.

  Here, the exhaust port 10e is also formed in the end bracket 6b as a hole extending in a direction perpendicular to the rotating shaft 4, but the exhaust port 10e is also predetermined along the circumferential direction of the end bracket 6b. A plurality of, for example, four, are provided independently with an interval of, for example, an angle of 90 °.

  Further, as shown in the drawing, pipe tapping for connecting pipes is applied to the open ends of the exhaust port 10d and the exhaust port 10e so that pipes such as pipes can be connected thereto.

  Next, the operation of the second embodiment will be described. In this case as well, a pipe (pipe) is connected to the intake port 10a, the exhaust port 10b, and the exhaust port 10c, and the pipe connected to the intake port 10a is air. The introduction pipes and the pipes connected to the exhaust port 10b and the exhaust port 10c are respectively air discharge pipes. At this time, pipes (pipes) are also provided to the exhaust port 10d and the exhaust port 10e. Connect to air discharge pipe.

  At this time, even in the case of the AC servomotor M according to the second embodiment of FIG. 5, since the grease for lubrication is applied to the bearings 7a and 7b, if the AC servomotor M is rotated, the bearings 7a and 7b generate dust and particles are generated. At this time, air or the like is sent from the air introduction conduit connected to the intake port 10a, and not only the exhaust port 10b and the exhaust port 10c, but also Air or the like is also discharged from the air discharge pipe connected to the exhaust port 10d and the exhaust port 10e, and a flow of air or the like is created as indicated by an arrow in FIG.

  Then, even if dust is generated from the bearing 7a with the rotation of the AC servo motor M at this time, the particles generated from this are discharged by the exhaust port 10b when air or the like flows into the space B, and this The air is discharged to the outside from the air discharge pipe connected to the exhaust port 10b.

  At this time, even if dust is generated from the bearing 7b, particles generated from the bearing 7b are discharged by the exhaust port 10d opened near the bearing 7b, and the air discharged from the exhaust port 10d is discharged. It will be discharged to the outside from the pipeline.

  Further, a part of the air or the like that has entered the space A at this time enters the bearing 7b on the anti-load side and escapes to the space E, but since the exhaust port 10e is communicated there, the space C The entered air or the like is discharged through the exhaust port 10e.

  Therefore, even if particles generated from the bearing 7b and particles generated from the dust are discharged into the space E, they are discharged to the outside from the air discharge pipe connected to the exhaust port 10e.

  Therefore, the air exhaust pipe connected to the exhaust port 10b and the exhaust port 10c is extended to a place away from the AC servo motor M, and the air exhaust pipe connected to the exhaust port 10d and the exhaust port 10e is also connected to the AC servo motor M. It is possible to prevent the dust including particles from being discharged in the vicinity of the AC servo motor M from being adversely affected by extending to a place away from the air and opening the air discharge conduit at that place. .

  As a result, the dust component containing particles is prevented from leaking through the gap E from the bearing 7b on the anti-load side, so there is no concern that the encoder 11 is contaminated by the dust component containing particles. According to the second embodiment, there is no possibility that the reliability of the encoder 11 is impaired.

  Normally, an optical encoder using a light source and a light detection element is used as the encoder 11, so that it is vulnerable to contamination by dust components and the like, and it is difficult to maintain reliability. According to the second embodiment, Therefore, it is possible to eliminate the possibility of problems in the reliability of the encoder 11 and to extend the service life.

  As a result, there is no risk that dust components including particles will be scattered to the outside through the gap between the rotary shaft 8 and the end cover 12. Therefore, according to the second embodiment, dust including particles from the AC servo motor M is also generated. The discharge from the AC servo motor M into the ambient atmosphere can be suppressed.

  In the second embodiment, the distribution of the flow rate of air and the flow rate setting shown in FIG. 6 may be the same as those in the first embodiment already described.

  As an example of application of the present invention, the present embodiment is not limited to the present embodiment even at the location of the air supply / exhaust passage, and any number or location of the air supply / exhaust passage can be used if the gist of the invention can be realized. May be. For example, an exhaust passage for cleaning dust generation such as near the dust generation source or near the encoder is provided.

  Therefore, according to the embodiment of the present invention, since the dust generated by the rotating electrical machine is discharged by circulation of air or the like, scattering of dust containing particles can be suppressed with a simple configuration, and the rotating electrical machine is used. Miniaturization of equipment can be achieved.

  As a result, according to the embodiment, the component generated from the rotating electrical machine can be discharged at an arbitrary location away from the rotating electrical machine. There is no possibility of components adhering, and further cleaning can be achieved.

  Furthermore, as a result, according to the above-described embodiment, a labyrinth structure for suppressing dust generation is not necessary, so that the structure is not complicated, an inexpensive rotating electrical machine can be provided, and the structure can be simplified. Improvement of the rotating electrical machine itself and the system configuration can be avoided, and when the rotating electrical machine is used for direct drive drive, the mechanical equipment can be made more compact and contribute to downsizing. be able to.

It is sectional drawing which shows 1st Embodiment of the rotary electric machine by this invention. It is a partial expanded sectional view of the 1st Embodiment of this invention. It is sectional drawing for demonstrating the distribution | circulation conditions, such as air by the 1st Embodiment of this invention. It is a partial expanded sectional view for demonstrating the distribution | circulation conditions, such as air by the 1st Embodiment of this invention. It is sectional drawing which shows 2nd Embodiment of the rotary electric machine by this invention. It is sectional drawing for demonstrating the distribution | circulation conditions, such as air by the 2nd Embodiment of this invention. It is sectional drawing which shows an example of the rotary electric machine by a prior art. It is sectional drawing which shows an example of the molded armature.

Explanation of symbols

M: AC servo motor (an example of rotating electrical machine)
1: Armature core 2: Armature winding 3: Permanent magnet 4: Rotor 5: Housing 6a: End bracket on the load side 6b: End bracket on the anti-load side 7a: Bearing on the load side 7b: Bearing on the anti-load side 8: Rotating shaft 9: Resin mold 10a: Air supply port (intake passage)
10b: Exhaust port (first exhaust passage)
10c: Exhaust port (second exhaust passage)
10d: Exhaust port (third exhaust passage)
10e: Exhaust port (fourth exhaust passage)
11: Encoder 12: End cover 13: Terminal box 14a: Fixing bolt 14b: Fixing bolt 14c: Fixing bolt 15a: Bolt hole 15b: Bolt hole 15c: Bolt hole

Claims (6)

A rotor combined with a rotating shaft;
A first bearing and a second bearing in which grease for lubrication is used and the rotating shaft is rotatably held;
A stator disposed outside the rotor and fixed to the housing;
A first flow path provided between the first bearing and the stator;
A second flow path connected to the first flow path and provided between the rotor and the stator;
A third flow path connected to the second flow path and provided between the second bearing and the stator;
Connected to the second flow path, provided on the opposite side to the third flow path and the second bearing, and exhausts air that has passed through the second bearing from the second flow path. A fourth flow path;
By flowing air in the order of the first flow path and the second flow path, and further flowing the air through the fourth flow path together with the third flow path, the first bearing and the second flow path. A rotating electrical machine comprising: discharge means for discharging particles generated from the bearings from the third flow path and the fourth flow path . In the rotating electrical machine according to claim 1,
The first bearing is installed on a non-load side of the rotating electrical machine;
The rotating electrical machine, wherein the second bearing is installed on a load side of the rotating electrical machine. In the rotating electrical machine according to claim 1 or 2,
The discharge means is constituted by a first pump that sucks air from the third flow path to the outside and a second pump that sucks air from the fourth flow path to the outside. Electric. In the rotating electrical machine according to claim 3,
  The rotary electric machine is characterized in that the discharging means is constituted by a third pump for feeding air into the first flow path in addition to the first pump and the second pump. In the rotating electrical machine according to any one of claims 1 to 4,
A rotating electrical machine characterized in that, of the air discharged by the discharge means, the air discharged from the fourth flow path is more than the air discharged from the third flow path. In the rotating electrical machine according to any one of claims 1 to 4,
An electrical rotating machine comprising an encoder for detecting a rotational position of the rotary shaft on the side opposite to the load with respect to the first bearing.

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