JP2008295214A - Electric motor and compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric motor wherein a permanent magnet or a shaft member can be press-fit easily into a sleeve and a rotor having a desired length in the axial direction can be formed. <P>SOLUTION: The electric motor 1 includes the rotor 10 placed inside a stator 20. The rotor 10 is formed of: a permanent magnet 11, shaft members 12, 13 provided at the ends 11a, 11b of the permanent magnet 11; and the sleeve 14 covering the outer circumferential surface 11c of the permanent magnet 11. The permanent magnet 11 has a through hole 11d, formed for discharging gas, in a space formed by the inner circumferential surface 14a of the sleeve 14, the permanent magnet 11, and the shaft member 12, to outside the rotor 10, when the permanent magnet 11 is press-fit into the sleeve 14. The shaft member 13 has a through hole 13c formed for discharging gas in the space, formed by the inner circumferential surface 14a of the sleeve 14, the permanent magnet 11, and the shaft member 13, to the outside of the rotor 10, when the shaft member 13 is press-fit into the sleeve 14. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a stator and an electric motor including a rotor which is disposed inside the stator and is formed by press-fitting a permanent magnet and a shaft member into a sleeve. The present invention also relates to a compressor using an electric motor as a drive source.

  2. Description of the Related Art Conventionally, as an electric motor that includes a stator and a rotor disposed inside the stator and is required to have a small size and high output, the rotor includes a permanent magnet, a shaft member provided at an end of the permanent magnet, and a permanent magnet. What is formed by the cylindrical sleeve which covers the outer peripheral surface of this is known. Such an electric motor is used in a compressor or the like. More specifically, the rotor of the electric motor has a cylindrical permanent magnet and a permanent in the axial direction (that is, a direction parallel to the rotation axis of the rotor). A cylindrical shaft member provided at the end of the magnet and a cylindrical sleeve that covers the permanent magnet and the shaft member are formed (see, for example, Patent Document 1).

  In the rotor described above, as a method for fixing the shaft member to the permanent magnet, the permanent magnet may be press-fitted into the sleeve and the shaft member may be directly fixed to the end of the permanent magnet by welding or the like. From the viewpoint of simplifying the assembly process, it is desirable to press-fit the permanent magnet and the shaft member into the sleeve. That is, by pressing the permanent magnet and the shaft member into the sleeve, the permanent magnet is fixed to the sleeve and the shaft member is fixed to the sleeve to which the permanent magnet is fixed. Is fixed. In this case, as a method for press-fitting the permanent magnet and the shaft member into the sleeve, by heating the sleeve to a predetermined temperature, the sleeve is expanded so that the inner diameter of the sleeve is widened. A so-called shrink fit that press fits into the sleeve is used.

Further, as a step of forming the rotor by press-fitting the permanent magnet and the shaft member into the sleeve, the sleeve is heated to a predetermined temperature at which shrink fitting can be performed. For example, as shown in FIG. The shaft member 112 is moved in the direction of the arrow X1 in the drawing so that the shaft member 112 is press-fitted into the sleeve 114 from the end portion 114a of the sleeve 114. Next, as shown in FIG. 8B, the permanent magnet 111 is moved in the direction of the arrow X2 in the drawing so that the permanent magnet 111 is press-fitted into the sleeve 114 from the end 114b of the sleeve 114. Then, as shown in FIG. 8C, the shaft member 113 is moved in the direction of the arrow X3 in the drawing so that the shaft member 113 is press-fitted into the sleeve 114 from the end 114b of the sleeve 114. In this manner, the permanent magnet 111 and the shaft members 112 and 113 are press-fitted into the sleeve 114, and the sleeve 114 is contracted by stopping the heating of the sleeve 114, whereby the rotor 110 is formed as shown in FIG. Is done.
JP 11-234975 A

  However, the permanent magnet 111, the shaft members 112 and 113, and the sleeve 114 that form the rotor 110 of the above-described electric motor are designed with very high accuracy so that no gap is generated in the sleeve 114. Therefore, when the permanent magnet 111 and the shaft member 113 are sequentially press-fitted into the sleeve 114, the permanent magnet in the sleeve 114 is caused by the repulsive force of the gas in the sleeve 114 compressed by the permanent magnet 111 and the shaft members 112 and 113. It is difficult to bring the shaft members 112 and 113 closer to 111. Therefore, in the rotor 110 of the electric motor described above, when the permanent magnet 111 and the shaft member 113 are sequentially press-fitted into the sleeve 114, it is difficult to press-fit into the sleeve 114, or a desired axial direction is desired. There is a problem that the rotor 110 having a length may not be formed.

  The present invention has been made in view of such circumstances, and an object of the present invention is to easily press-fit a permanent magnet or a shaft member into a sleeve in a rotor of an electric motor, and to achieve a desired length in the axial direction. An object of the present invention is to provide an electric motor capable of forming a rotor having the same and a compressor using the electric motor as a drive source.

  The invention according to claim 1 is an electric motor including a stator and a rotor disposed inside the stator. The rotor includes a permanent magnet, a shaft member provided at an end of the permanent magnet, and an outer periphery of the permanent magnet. And at least one of the permanent magnet, the shaft member, and the sleeve when the permanent magnet or the shaft member is press-fitted into the sleeve, the inner peripheral surface of the sleeve, the permanent magnet, and the shaft. A discharge portion for discharging the gas in the space formed by the member to the outside of the rotor is formed.

  According to this configuration, when at least one of the permanent magnet, the shaft member, and the sleeve is press-fitted into the sleeve, the space formed by the inner peripheral surface of the sleeve, the permanent magnet, and the shaft member. A discharge part for discharging the gas in the part to the outside of the rotor is formed. For this reason, when the permanent magnet or the shaft member is press-fitted into the sleeve, the gas in the space formed by the inner peripheral surface of the sleeve, the permanent magnet, and the shaft member can be discharged to the outside of the rotor. Accordingly, the gas in the space formed by the inner peripheral surface of the sleeve, the permanent magnet, and the shaft member can be removed, and the permanent magnet or the shaft member can be easily press-fitted into the sleeve, and a desired length can be obtained in the axial direction. A rotor having the same can be formed.

  Invention of Claim 2 is an electric motor of Claim 1, Comprising: A shaft member is comprised by the 1st shaft member and 2nd shaft member which are provided in the both ends of a permanent magnet, and discharge part Is formed in the first shaft member, and when the permanent magnet or the first shaft member is press-fitted into the sleeve, the gas in the space formed by the inner peripheral surface of the sleeve, the permanent magnet, and the first shaft member Is formed in the second shaft member and the permanent magnet or the second shaft member when the permanent magnet or the second shaft member is press-fitted into the sleeve. It is characterized by comprising the 2nd discharge part for discharging | emitting the gas of the space part formed by a magnet and a 2nd shaft member to the exterior of a rotor.

  Invention of Claim 3 is an electric motor of Claim 1, Comprising: A shaft member is comprised by the 1st shaft member and 2nd shaft member which are provided in the both ends of a permanent magnet, and discharge part Is formed in the sleeve, and when the permanent magnet or the first shaft member is press-fitted into the sleeve, the gas in the space formed by the inner peripheral surface of the sleeve, the permanent magnet, and the first shaft member is transferred to the rotor. A first discharge portion for discharging to the outside and a sleeve, and when the permanent magnet or the second shaft member is press-fitted into the sleeve, the inner peripheral surface of the sleeve, the permanent magnet, and the second shaft member It is characterized by comprising the 2nd discharge part for discharging | emitting the gas of the space part formed to the exterior of a rotor.

  Invention of Claim 4 is an electric motor of Claim 1, Comprising: A shaft member is comprised by the 1st shaft member and the 2nd shaft member which are provided in the both ends of a permanent magnet, and discharge part Is formed in the permanent magnet, and when the permanent magnet or the first shaft member is press-fitted into the sleeve, the gas in the space formed by the inner peripheral surface of the sleeve, the permanent magnet, and the first shaft member is transferred to the rotor. A first discharge portion for discharging to the outside of the sleeve, and a second shaft member. When the permanent magnet or the second shaft member is press-fitted into the sleeve, the inner peripheral surface of the sleeve, the permanent magnet, It is characterized by comprising the 2nd discharge part for discharging | emitting the gas of the space part formed of 2 shaft members to the exterior of a rotor.

  According to the structure in any one of Claims 2 thru | or 4, the effect similar to the invention in Claim 1 can be acquired. In particular, according to the configuration of the second or third aspect, since it is not necessary to form the discharge portion in the permanent magnet, the discharge portion can be formed without affecting the permanent magnet.

The invention according to claim 5 is the electric motor according to claim 4, characterized in that the first discharge portion and the second discharge portion are in communication.
According to this configuration, since the first discharge portion and the second discharge portion are in communication, the space portion formed by the inner peripheral surface of the sleeve, the permanent magnet, and the first shaft member or the second shaft member. The gas can be effectively removed.

  A sixth aspect of the present invention is the electric motor according to the second or fourth aspect, wherein the rotation axis of the rotor is a central axis of the cylindrical sleeve, and the first discharge portion is the rotor of the rotor. The first through hole extends in a direction substantially parallel to the rotation axis, and the second discharge portion is a second through hole that extends in a direction substantially parallel to the rotation axis of the rotor. The center line of the two through holes coincides with the central axis of the sleeve.

  According to this configuration, the rotation axis of the rotor is the central axis of the cylindrical sleeve, the first discharge portion is a first through hole extending in a direction substantially parallel to the rotation axis of the rotor, and the second The discharge portion is a second through hole extending in a direction substantially parallel to the rotation axis of the rotor. Since the center lines of the first through hole and the second through hole coincide with the central axis of the sleeve, the center of gravity of the rotor can be easily set on the rotation axis of the rotor. Therefore, vibration due to rotation of the rotor can be suppressed. The center line of the through hole is a line passing through the center of the cross section of the through hole in the direction perpendicular to the rotation axis of the rotor.

A seventh aspect of the present invention is the electric motor according to the first aspect, wherein the shaft member is integrally formed with a sleeve.
According to this configuration, since the sleeve is integrally formed on the shaft member, the number of parts of the rotor is reduced. Further, since the sleeve is formed integrally with the shaft member, it is not necessary to press-fit the shaft member into the sleeve, and the rotor can be easily assembled.

The invention described in claim 8 is a compressor characterized in that the electric motor according to any one of claims 1 to 7 is used as a drive source, and gas is pumped by rotation of the rotor.
According to this configuration, since the electric motor according to any one of claims 1 to 7 is used as a drive source, the same effect as the electric motor according to any one of claims 1 to 7 is obtained, Gas can be pumped.

  According to the present invention, a permanent magnet or a shaft member can be easily press-fitted into a sleeve, and a rotor having a desired length in the axial direction can be formed.

  Hereinafter, an embodiment of an electric motor according to the present invention will be described with reference to FIG. FIG. 1 is a cross-sectional view showing a centrifugal compressor using the electric motor 1 according to the present invention as a drive source, and FIG. 2 is a cross-sectional view showing a rotor 10 of the electric motor 1 according to the present invention.

  As shown in FIG. 1, the centrifugal compressor includes an electric motor 1 as a drive source. The electric motor 1 includes a rotating rotor 10, a stator 20 for rotating the rotor 10, and the rotor 10 and the stator 20. Housings 31, 32 and 33 for protection and bearings 41 and 42 for rotatably supporting the rotor 10 are provided.

  As shown in FIG. 1, the rotor 10 is disposed at a predetermined interval inside the stator 20, and is formed by a permanent magnet 11, shaft members 12 and 13, and a sleeve 14. Since the permanent magnet 11 and the shaft members 12 and 13 are press-fitted into the sleeve 14 and fixed, the permanent magnet 11, the shaft members 12 and 13 and the sleeve 14 (that is, the rotor 10) are shown by a one-dot chain line in FIG. Rotates integrally with R as a rotation axis.

  The permanent magnet 11 is formed in a substantially cylindrical shape, and as shown in FIGS. 1 and 2, the permanent magnet 11 is in the axial direction (that is, the direction parallel to the rotation axis R of the rotor 10 and indicated by the arrow A in the figure). ), The length of the permanent magnet 11 is shorter than the length of the sleeve 14, so that the entire permanent magnet 11 is press-fitted into the sleeve 14.

  In the present embodiment, the shaft member includes a shaft member 12 as a first shaft member and a shaft member 13 as a second shaft member. These shaft members 12 and 13 are formed in a substantially cylindrical shape, and are respectively provided at the end portions 11a and 11b of the permanent magnet 11 in the axial direction A as shown in FIGS. As shown in FIG. 2, the shaft member 12 includes a large-diameter portion 12a having the same diameter as the permanent magnet 11, and an end portion 12b that is rotatably supported by a bearing 42. A hole 12c is formed. Further, as shown in FIG. 2, the shaft member 13 includes a large-diameter portion 13a having the same diameter as the permanent magnet 11 and an end portion 13b rotatably supported by the bearing 41. A part is press-fitted into the sleeve 14. The end portions 12 b and 13 b of these shaft members 12 and 13 are also end portions of the rotor 10.

  Further, the sleeve 14 is formed in a cylindrical shape so as to cover the outer peripheral surface 11c of the permanent magnet 11, and in this embodiment, is formed integrally with the shaft member 12 as shown in FIGS. More specifically, the sleeve 14 is integrally formed outside the large-diameter portion 12a of the shaft member 12, and is formed in a cylindrical shape so that the permanent magnet 11 and the shaft member 13 can be press-fitted.

  As shown in FIG. 1, the stator 20 is disposed outside the rotor 10 at a predetermined interval so as not to come into contact with the sleeve 14, and includes a stator core 21 and a coil 22 made of a conductive wire wound around the stator core 21. It consists of and. Accordingly, the rotating magnetic field generated by the energized coil 22 rotates the permanent magnet 11, the sleeve 14 fixed to the permanent magnet 11, and the shaft members 12 and 13 fixed to the sleeve 14.

  The housing 31 is formed in a substantially cylindrical shape, and covers the stator 20 by being provided outside the stator 20 as shown in FIG. As shown in FIG. 1, the housing 32 is provided on the end 13 b side of the shaft member 13 and covers the ends of the rotor 10 and the stator 20 in the axial direction A, and the housing 33 is the end of the shaft member 12. It is provided on the side of the part 12b and covers the end of the stator 20 in the axial direction A. The housings 32 and 33 are fixed to the housing 31 by a fixing tool (not shown) such as a bolt.

  As shown in FIG. 1, the bearing 41 is accommodated in a bearing accommodating portion 32 a formed in the housing 32, and the bearing 42 is accommodated in a bearing accommodating portion 33 a formed in the housing 33. These bearings 41 and 42 rotatably support end portions 13b and 12b, which are end portions of the rotor 10, respectively.

  By providing the impeller 61 and the volute 62 in the electric motor 1 configured as described above, a centrifugal compressor using the electric motor 1 as a drive source is formed. That is, the centrifugal compressor includes the electric motor 1, the impeller 61, and the volute 62.

  The impeller 61 is fixed to the rotor 10 of the electric motor 1 using screws 70. More specifically, the screw 70 penetrating the impeller 61 is screwed into the screw hole 12c of the shaft member 12 that forms the rotor 10 so that the rotor 10 and the impeller 61 rotate integrally. On the other hand, the impeller 61 is fixed. Accordingly, when the impeller 61 rotates integrally with the rotor 10, the impeller 61 applies centrifugal force to the gas flowing in from the axial direction A and blows air in the centrifugal direction (the direction of arrow C in the figure).

  The volute 62 forms a flow path 62 a for pressure-feeding the gas blown in the centrifugal direction by the impeller 61 to a discharge unit (not shown), and a bolt or the like is fixed to the housing 33 of the electric motor 1. It is fixed by a tool (not shown). The volute 62 is integrally formed with a suction port 62b so that gas flows from the axial direction A into the impeller 61. The centrifugal compressor configured as described above sucks and pumps the gas in the suction port 62b by the rotation of the rotor 10.

  Here, the present embodiment is characterized in that discharge portions are formed in the permanent magnet 11 and the shaft member 13. In the present embodiment, the discharge unit is composed of a first discharge unit and a second discharge unit.

  More specifically, when the permanent magnet 11 is press-fitted into the sleeve 14, the gas in the space formed by the inner peripheral surface 14 a of the sleeve 14, the permanent magnet 11, and the shaft member 12 is given to the permanent magnet 11. A feature is that a first through-hole 11d is formed as a discharge portion (first discharge portion) for discharging to the outside of the rotor 10. Therefore, in the step of forming the rotor 10 shown in FIG. 3, when the permanent magnet 11 is press-fitted into the sleeve 14, the space portion 81 formed by the inner peripheral surface 14 a of the sleeve 14, the permanent magnet 11, and the shaft member 12. Can be discharged to the outside 90 of the rotor 10. More specifically, as a step of forming the rotor 10 by press-fitting the permanent magnet 11 and the shaft member 13 into the sleeve 14, the sleeve 14 is heated to a predetermined temperature at which shrink fitting can be performed, and FIG. As shown in FIG. 2, the permanent magnet 11 is moved in the direction of the arrow S1 in the drawing so that the permanent magnet 11 is press-fitted into the sleeve 14. When the permanent magnet 11 is press-fitted into the sleeve 14, as shown in FIG. 3B, a space portion 81 is formed by the inner peripheral surface 14 a of the sleeve 14, the permanent magnet 11, and the shaft member 12. The gas in the portion 81 passes through the through hole 11d and is discharged to the outside 90 of the rotor 10.

  Further, when the shaft member 13 is press-fitted into the sleeve 14, the gas in the space formed by the inner peripheral surface 14 a of the sleeve 14, the permanent magnet 11, and the shaft member 13 is transferred to the outside of the rotor 10. A second through-hole 13c is formed as a discharge portion (second discharge portion) for discharging to the bottom. Therefore, in the step of forming the rotor 10 shown in FIG. 3, when the shaft member 13 is press-fitted into the sleeve 14, the space portion 82 formed by the inner peripheral surface 14 a of the sleeve 14, the permanent magnet 11, and the shaft member 13. Can be discharged to the outside 90 of the rotor 10. More specifically, as shown in FIG. 3C, the shaft member 13 is moved in the direction of the arrow S2 in the drawing so that the shaft member 13 is press-fitted into the sleeve. When the shaft member 13 is press-fitted into the sleeve 14, as shown in FIG. 3D, a space 82 is formed by the inner peripheral surface 14 a of the sleeve 14, the permanent magnet 11, and the shaft member 13. The gas in the part 82 passes through the through hole 13 c and is discharged to the outside 90 of the rotor 10. Then, the heating of the sleeve 14 into which the permanent magnet 11 and the shaft members 12 and 13 are press-fitted is stopped and the sleeve 14 is contracted, whereby the rotor 10 is formed as shown in FIG.

  In the present embodiment, the through hole 11d and the through hole 13c communicate with each other. Therefore, in the step of forming the rotor 10 shown in FIG. 3, when the shaft member 13 is press-fitted into the sleeve 14, the space portion 82 formed by the inner peripheral surface 14 a of the sleeve 14, the permanent magnet 11, and the shaft member 13. This gas can be discharged to the outside 90 of the rotor 10 without being compressed in the through hole 11d.

  In the present embodiment, the rotation axis R of the rotor 10 is the central axis of the cylindrical sleeve 14, and the first discharge portion is a through hole 11 d that extends in a direction substantially parallel to the rotation axis R of the rotor 10. The second discharge portion is a through hole 13c extending in a direction substantially parallel to the rotation axis R of the rotor 10. The center lines of the through hole 11 d and the through hole 13 c coincide with the center axis of the sleeve 14. For this reason, the center of gravity of the rotor 10 can be easily set on the rotation axis R of the rotor 10. The center lines of the through holes 11d and the through holes 13c are lines passing through the centers of the cross sections of the through holes 11d and 13c in the direction perpendicular to the rotation axis R of the rotor 10.

According to the electric motor or the centrifugal compressor of the above embodiment, the following effects can be obtained.
(1) When the permanent magnet 11 is press-fitted into the sleeve 14, the gas in the space 81 formed by the inner peripheral surface 14 a of the sleeve 14, the permanent magnet 11, and the shaft member 12 is transferred to the rotor 10. A through hole 11d for discharging to the outside 90 is formed. For this reason, when the permanent magnet 11 is press-fitted into the sleeve 14, the gas in the space 81 formed by the inner peripheral surface 14 a of the sleeve 14, the permanent magnet 11, and the shaft member 12 is discharged to the outside 90 of the rotor 10. Can do. Therefore, the gas in the space 81 formed by the inner peripheral surface 14 a of the sleeve 14, the permanent magnet 11, and the shaft member 12 can be removed and the permanent magnet 11 can be easily press-fitted into the sleeve 14. Further, when the shaft member 13 is press-fitted into the sleeve 14, the gas in the space 82 formed by the inner peripheral surface 14 a of the sleeve 14, the permanent magnet 11, and the shaft member 13 is transferred to the shaft 10. A through hole 13c for discharging to the outside 90 is formed. For this reason, when the shaft member 13 is press-fitted into the sleeve 14, the gas in the space 82 formed by the inner peripheral surface 14 a of the sleeve 14, the permanent magnet 11, and the shaft member 13 is discharged to the outside 90 of the rotor 10. Can do. Therefore, the gas in the space 82 formed by the inner peripheral surface 14 a of the sleeve 14, the permanent magnet 11, and the shaft member 13 can be removed and the shaft member 13 can be easily press-fitted into the sleeve 14. Then, the rotor 10 having a desired length in the axial direction A can be formed.

  (2) The through hole 11d and the through hole 13c communicate with each other. Therefore, when the shaft member 13 is press-fitted into the sleeve 14, the gas in the space 82 formed by the inner peripheral surface 14 a of the sleeve 14, the permanent magnet 11, and the shaft member 13 is not compressed in the through hole 11 d. , And can be discharged to the outside 90 of the rotor 10. Therefore, the gas in the space 82 formed by the inner peripheral surface 14 a of the sleeve 14, the permanent magnet 11, and the shaft member 13 can be effectively removed.

  (3) The rotation axis R of the rotor 10 is the central axis of the cylindrical sleeve 14, and the first discharge portion is a through hole 11 d extending in a direction substantially parallel to the rotation axis R of the rotor 10, and the second The discharge portion is a through hole 13 c extending in a direction substantially parallel to the rotation axis R of the rotor 10. Since the center lines of the through hole 11d and the through hole 13c coincide with the center axis of the sleeve 14, the center of gravity of the rotor 10 can be easily set on the rotation axis R of the rotor 10. Therefore, vibration due to rotation of the rotor can be suppressed.

  (4) A sleeve 14 is formed integrally with the shaft member 12. For this reason, the number of parts of the rotor 10 is reduced. Further, since the sleeve 14 is formed integrally with the shaft member 12, there is no need to press-fit the shaft member 12 into the sleeve 14, and the rotor 10 can be easily assembled.

  (5) Since the centrifugal compressor uses the electric motor 1 as a drive source, gas is pumped by the rotation of the rotor 10. For this reason, gas can be pumped using the electric motor which can acquire the effect of said (1) thru | or (4).

  In addition, this invention is not limited to the said embodiment, A various design change is possible based on the meaning of this invention, and they are not excluded from the scope of the present invention. For example, the above embodiment may be modified as follows.

  In the above embodiment, the permanent magnet 11 has the through hole 11 d that discharges the gas in the space 81 formed by the inner peripheral surface 14 a of the sleeve 14, the permanent magnet 11, and the shaft member 12 to the outside 90 of the rotor 10. Although formed, a through hole as a discharge portion may be formed in the shaft member 12. That is, as shown in FIG. 4, when the permanent magnet 11 is press-fitted into the shaft member 12 into the sleeve 14, the space portion 81 formed by the inner peripheral surface 14 a of the sleeve 14, the permanent magnet 11, and the shaft member 12. A through hole 12d may be formed as a discharge portion (first discharge portion) for discharging the gas to the outside 90 of the rotor 10. Even if it does in this way, the effect of said (1) can be acquired. Moreover, since it is not necessary to form the through-hole 11d in the permanent magnet 11, the discharge part (through-hole 12d) can be formed without affecting the permanent magnet 11.

  In the above embodiment, the permanent magnet 11 is formed with the through hole 11d as the discharge portion, and the shaft member 13 is formed with the through hole 13c as the discharge portion. However, the discharge portion is not a through hole but a groove. Good. That is, as shown in FIG. 5, when the permanent magnet 11 is press-fitted into the sleeve 14 into the permanent magnet 11, the space 81 formed by the inner peripheral surface 14 a of the sleeve 14, the permanent magnet 11, and the shaft member 12. A groove 11e may be formed as a discharge portion (first discharge portion) for discharging the gas to the outside 90 of the rotor 10. Further, when the shaft member 13 is press-fitted into the sleeve 14 into the shaft member 13, the gas in the space 82 formed by the inner peripheral surface 14 a of the sleeve 14, the permanent magnet 11, and the shaft member 13 is transferred to the outside of the rotor 10. A groove 13d as a discharge portion (second discharge portion) for discharging to 90 may be formed. Even if it does in this way, the effect of said (1) can be acquired.

  In the above embodiment, the permanent magnet 11 is formed with the through hole 11d as the discharge portion, and the shaft member 13 is formed with the through hole 13c as the discharge portion. However, the through hole as the discharge portion is formed in the sleeve 14. It may be formed. That is, as shown in FIG. 6, when the permanent magnet 11 is press-fitted into the sleeve 14 into the sleeve 14, the gas in the space 81 formed by the inner peripheral surface 14 a of the sleeve 14, the permanent magnet 11, and the shaft member 12. May be formed as a discharge portion (first discharge portion) for discharging the air to the outside 90 of the rotor 10. Further, when the shaft member 13 is press-fitted into the sleeve 14, the gas in the space 82 formed by the inner peripheral surface 14 a of the sleeve 14, the permanent magnet 11, and the shaft member 13 is transferred to the outside 90 of the rotor 10. A through-hole 14c may be formed as a discharge portion (second discharge portion) for discharging to the bottom. Even if it does in this way, the effect of said (1) can be acquired. In addition, since it is not necessary to form the through hole 11d in the permanent magnet 11, the discharge portions (through holes 14a and 14b) can be formed without affecting the permanent magnet 11.

  In the embodiment described above, the sleeve 14 is integrally formed with the shaft member 12, but as shown in FIG. 7, these may not be integrally formed. Even if it does in this way, the effect of said (1) can be acquired.

  In the above embodiment, the centrifugal compressor is the one that uses the electric motor 1 as a drive source, but it may not be a centrifugal compressor. That is, an axial flow compressor that pumps gas by rotation of the rotor 10 using the electric motor 1 as a drive source may be used. Even if it does in this way, the effect of said (5) can be acquired.

Sectional drawing which shows the centrifugal compressor which used the electric motor which concerns on embodiment of this invention as a drive source. Sectional drawing which shows the rotor of the electric motor which concerns on embodiment of this invention. (A)-(e) Sectional drawing which shows the process of forming the rotor of the electric motor which concerns on embodiment of this invention. Sectional drawing which shows the rotor of the electric motor which concerns on the modification of this invention. Sectional drawing which shows the rotor of the electric motor which concerns on the modification of this invention. Sectional drawing which shows the rotor of the electric motor which concerns on the modification of this invention. Sectional drawing which shows the rotor of the electric motor which concerns on the modification of this invention. (A)-(d) Sectional drawing which shows the process of forming the rotor of the conventional electric motor.

Explanation of symbols

  A ... axial direction, R ... rotating shaft, 1 ... electric motor, 10 ... rotor, 11 ... permanent magnet, 11a, 11b ... end, 11d ... through-hole (first discharge part), 11e ... groove (first Discharge part), 12 ... shaft member (first shaft member), 12d ... through hole (first discharge part), 13 ... shaft member (second shaft member), 13c ... through hole (second discharge part) ), 13d ... groove (second discharge portion), 14 ... sleeve, 14a ... inner peripheral surface, 14b ... through hole (first discharge portion), 14c ... through hole (second discharge portion), 20 ... stator , 81, 82 ... space part, 90 ... outside.

Claims (8)

In an electric motor comprising a stator and a rotor disposed inside the stator,
The rotor is formed by a permanent magnet, a shaft member provided at an end of the permanent magnet, and a cylindrical sleeve that covers an outer peripheral surface of the permanent magnet,
At least one of the permanent magnet, the shaft member, and the sleeve is formed by the inner peripheral surface of the sleeve, the permanent magnet, and the shaft member when the permanent magnet or the shaft member is press-fitted into the sleeve. The electric motor is characterized in that a discharge portion is formed for discharging the gas in the space portion to the outside of the rotor. The shaft member is composed of a first shaft member and a second shaft member provided at both ends of the permanent magnet,
The discharge portion is formed on the first shaft member, and when the permanent magnet or the first shaft member is press-fitted into the sleeve, the inner peripheral surface of the sleeve, the permanent magnet, and the first magnet A first discharge part for discharging the gas in the space formed by the shaft member to the outside of the rotor and the second shaft member, and the permanent magnet or the second shaft member is When press-fitted into the sleeve, the second discharge portion for discharging the gas in the space formed by the inner peripheral surface of the sleeve, the permanent magnet, and the second shaft member to the outside of the rotor. The electric motor according to claim 1, wherein the electric motor is configured. The shaft member is composed of a first shaft member and a second shaft member provided at both ends of the permanent magnet,
The discharge portion is formed in the sleeve, and is formed by the inner peripheral surface of the sleeve, the permanent magnet, and the first shaft member when the permanent magnet or the first shaft member is press-fitted into the sleeve. A first discharge portion for discharging the gas in the space portion to the outside of the rotor and the sleeve, and when the permanent magnet or the second shaft member is press-fitted into the sleeve, It is comprised by the 2nd discharge part for discharging | emitting the gas of the space part formed by the internal peripheral surface of the said sleeve, the said permanent magnet, and the said 2nd shaft member to the exterior of the said rotor. The electric motor according to claim 1. The shaft member is composed of a first shaft member and a second shaft member provided at both ends of the permanent magnet,
The discharge portion is formed in the permanent magnet, and when the permanent magnet or the first shaft member is press-fitted into the sleeve, the inner peripheral surface of the sleeve, the permanent magnet, and the first shaft member Formed in the first exhaust part for exhausting the gas in the formed space part to the outside of the rotor and the second shaft member, and the permanent magnet or the second shaft member into the sleeve When press-fitted, a second discharge portion is formed for discharging the gas in the space formed by the inner peripheral surface of the sleeve, the permanent magnet, and the second shaft member to the outside of the rotor. The electric motor according to claim 1.   The electric motor according to claim 4, wherein the first discharge unit and the second discharge unit communicate with each other. The rotational axis of the rotor is a central axis of the cylindrical sleeve,
The first discharge portion is a first through hole extending in a direction substantially parallel to the rotation axis of the rotor,
The second discharge portion is a second through hole extending in a direction substantially parallel to the rotation axis of the rotor,
5. The electric motor according to claim 2, wherein center lines of the first through hole and the second through hole coincide with a center axis of the sleeve.   The electric motor according to claim 1, wherein the sleeve is formed integrally with the shaft member.   A compressor, wherein the electric motor according to any one of claims 1 to 7 is used as a drive source, and gas is pumped by rotation of the rotor.

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