JP5426232B2 - Electric motor cooling jacket - Google Patents

Description

  The present invention relates to an electric motor cooling jacket for cooling an electric motor.

  Conventionally, a liquid cooling motor is known in which a cylindrical casing is provided outside the stator core so as to cover the entire circumference, and a cooling passage through which a refrigerant flows is processed in the casing to cool the electric motor (for example, Patent Documents). 1). However, in the liquid-cooled motor described in Patent Document 1, since the cylindrical casing is provided outside the stator core, the electric motor becomes larger than necessary.

  On the other hand, there is known a cooling jacket in which a cooling pipe through which a refrigerant flows is arranged around an electric motor so as to cool the electric motor (see, for example, Patent Document 2). In the cooling jacket described in Patent Document 2, a plate in which a recessed groove is formed is arranged around the electric motor, and the cooling tube is accommodated and supported in the recessed groove, and the outside of the cooling tube is covered with the plate facing the plate. Then, the resin having thermal conductivity is filled between the plate and the lid.

Japanese Patent No. 2661805 Japanese Patent No. 3759097

  However, in the configuration in which the cooling pipes are arranged around the electric motor as in the cooling jacket described in Patent Document 2, not only the number of parts increases and the cost increases, but also the cooling efficiency is poor.

The present invention is a cooling jacket for an electric motor that cools an electric motor, and includes a plurality of casings arranged in a circumferential direction in close contact with the outer peripheral surface of the electric motor so as to surround the electric motor, and a plurality of casings on the outer peripheral surface of the electric motor. A cooling passage through which a cooling medium passes , and each casing includes a first casing provided with a plurality of first cooling passages penetrating through the casing; It is joined to the end portion of the first casing, a second cooling passage for communicating the first cooling passage to each other and wherein Rukoto that having a second casing provided.

  According to the present invention, the cooling passages are provided in the plurality of casings arranged in close contact with the outer peripheral surface of the electric motor, so that the number of parts can be reduced. As a result, an increase in cost can be suppressed and cooling efficiency can be improved.

It is a perspective view which shows the whole structure of the electric motor cooling jacket which concerns on embodiment of this invention. It is the II-II sectional view taken on the line of FIG. It is a perspective view which shows the principal part structure of FIG. It is a figure which shows the cooling channel | path of the cooling jacket which concerns on this Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view showing an overall configuration of an electric motor cooling jacket 10 according to the present embodiment, and FIG. 2 is a cross-sectional view taken along the line II-II in FIG. 1 and 2, the cooling jacket 10 is disposed around the electric motor M. In FIG. 2, the configurations of the electric motor M and the cooling jacket 10 are schematically shown, and the detailed configuration is not shown.

  The electric motor M is a three-phase induction motor used for driving a spindle of a machine tool such as a machining center. The electric motor M includes a cylindrical stator 1 and a rotor 2 that is rotatably supported in the stator 1. Although not shown, the stator 1 has a stator core formed by laminating magnetic materials such as thin steel plates, and a winding wound around the stator core, and rotates around the rotor 2 by a supply current to the winding. A magnetic field is formed and the rotor 2 is rotated. The motor M according to the present embodiment is not provided with a casing that surrounds and supports the outer periphery of the stator core around the motor M.

  Such an electric motor M generates heat due to iron loss of the stator core and copper loss of the winding. In particular, in the motor M for driving the spindle of the machine tool, if the spindle of the machine tool is thermally deformed by heat transfer, the machining accuracy is adversely affected. Therefore, it is necessary to cool the motor M and suppress the heat generation of the motor M. In the present embodiment, the electric motor M is cooled by the following cooling jacket 10.

  The cooling jacket 10 is disposed so as to surround the stator 1, and a plurality of (here, four) casings 11 in which cooling passages 20 are formed, and a connecting bar 12 that connects the casings 11 adjacent to each other in the circumferential direction. Have As shown in FIG. 2, the outer shape of the stator 1 has a substantially rectangular shape, strictly speaking, an octagonal shape with chamfered corners, and the casing 11 is disposed in close contact with the four wall surfaces of the stator 1. Each casing 11 is integrated by being connected by a connecting bar 12 and is supported in close contact with the outer wall surface of the stator 1.

  FIG. 3 is a perspective view showing the configuration of the casing 11. The casing 11 has a substantially rectangular central casing 13 that extends in the longitudinal direction (rotational axis direction of the rotor 2), and a pair of end casings 14 and 15 that are disposed at both ends of the central casing 13. The central casing 13 and the end casings 14 and 15 are joined by sealing the contact surfaces with an adhesive, for example, and the casing 11 is integrated. The central casing 13 and the end casings 14 and 15 can also be joined by fastening with bolts via a sealing material such as an O-ring. The widths of the central casing 13 and the end casings 14 and 15 are equal to each other, and the casing 11 has a substantially rectangular shape as a whole. The central casing 13 and the end casings 14 and 15 are each made of a material having good thermal conductivity.

  The central casing 13 is provided with a plurality of (here, ten) through-holes 16 penetrating linearly in the longitudinal direction, and openings 17 and 18 are arranged at both ends of the central casing 13 in the width direction. It is installed. On the upper surface of the central casing 13, a recess 19 in which the end of the connecting bar 12 is fitted is provided, and a screw hole 20 is provided in the recess 19. Bolts 21 (FIG. 1) penetrating through the connecting bar 12 are screwed into the screw holes 20, whereby the connecting bar 12 is fastened to the casing 11.

  One end casing 14 is provided with a plurality of (in this case, five) bottomed holes 22 which are slotted counterbore facing the opening 17 so as to straddle the adjacent openings 17. . For this reason, when the end casing 14 and the central casing 13 are joined, the adjacent through holes 16 of the central casing 13 communicate with each other through the bottomed hole 22. That is, the first and second through holes 16, the third and fourth through holes 16,... Communicate with each other through the bottomed holes 22.

  The other end casing 15 is provided with through holes 23 at both ends in the width direction so as to coincide with the openings 18 at both ends in the width direction of the central casing 13. Inside the through hole 23, a plurality (four in this case) of bottomed holes 24 that are slotted counterbore faces the opening 18 so as to straddle the adjacent openings 18. Therefore, when the end casing 15 and the central casing 13 are joined, the through holes 23 at both ends of the end casing 15 and the through holes 16 at both ends of the central casing 13 communicate with each other, and the low holes 24 are interposed. The adjacent through holes 16 of the central casing 13 communicate with each other. That is, the through hole 23 and the first and tenth through holes 16 of the central casing 13 communicate with each other, and the second and third through holes 16, the fourth and fifth through holes 16,. It communicates through the bottomed hole 24.

  As a result, as shown in FIG. 4, a linear cooling passage PS <b> 1 is formed in the central casing 13, and a substantially U-shaped cooling passage PS <b> 2 is formed in the end casings 14 and 15. When the through holes 23 at both ends of the end casing 14 are respectively referred to as an inlet portion 25 and an outlet portion 26, a cooling passage PS is formed in the casing 11 from the inlet portion 25 to the outlet portion 26 in a substantially zigzag manner. The

  As shown in FIG. 1, the inlet 25 of the casing 110 and the outlet 26 of the casing 111 adjacent to the casing 110 are connected by a flexible resin tube 27. Thereby, the cooling passages PS of the adjacent casings 11 communicate with each other via the tube 27.

  Not all the inlet portions 25 are connected to the outlet portion 26. As shown in FIG. 1, a refrigerant inflow joint 28 is connected to one inlet portion 25, and a refrigerant outlet is connected to one outlet portion 26. A joint 29 is connected. Although illustration is omitted, outside the electric motor M, a refrigerant supply device that supplies a refrigerant such as a coolant and a refrigerant processing device that processes the return refrigerant are provided.

  The refrigerant from the refrigerant supply device is supplied into the casing 11 via the joint 28. The supplied refrigerant passes through the cooling passages PS in the respective casings 11 and then is discharged to the refrigerant processing apparatus via the joint 29. At this time, the flow of the refrigerant removes heat from the surface of the stator 1 and cools the electric motor M. In the refrigerant processing apparatus, the refrigerant is cooled and sent to the refrigerant supply apparatus to circulate the refrigerant.

According to the present embodiment, the following operational effects can be achieved.
(1) A cooling passage PS is formed in a zigzag shape in the casing 11 by the through-holes 16 and the bottomed holes 22 and 24, and a plurality of circumferentially close contacts with the outer wall surface of the stator 1 so as to surround the motor M. The casing 11 was arranged. Accordingly, the motor M can be efficiently cooled by the flow of the refrigerant in the plurality of casings 11 without increasing the size of the motor M more than necessary, and the heat generation of the motor M can be suppressed.
(2) Since the holes 16, 22, and 24 are opened in the casing 11 and the cooling passage PS is formed directly in the casing, the number of parts can be reduced. That is, since it is not necessary to dispose a cooling pipe around the motor, there is no need for a plate that supports the cooling pipe, a lid that covers the outside of the cooling pipe, or a filler that is filled between the plates. As a result, the cost can be reduced, the thermal conductivity is good, and the cooling efficiency can be improved. Therefore, it is suitable for use in the spindle motor M for machine tools.

(3) The casing 11 is constituted by the central casing 13 and the end casings 14 and 15 at both ends thereof, and a plurality of linear cooling passages PS1 penetrating through the central casing 13 are provided in the end casings 14 and 15. Since the communication is made by the substantially U-shaped cooling passage PS2, the cooling passage PS can be formed in a zigzag shape over almost the entire area of the casing 11, and the entire electric motor can be cooled well.
(4) Since the inlet portion 25 and the outlet portion 26 of the cooling passage PS are respectively provided in the casing 11 and the inlet portion 25 and the outlet portion 26 of the adjacent casing 11 are connected by the tube 27, the cooling passages PS of different casings 11 are connected to each other. Easy connection.
(5) Since the adjacent casings 11 are connected by the connecting bar 12, the plurality of casings 11 can be easily fixed around the motor M.

  In the above embodiment, the four casings 11 are arranged in the circumferential direction in close contact with the main surfaces around the electric motor M. However, the casings 11 are in close contact with the respective surfaces around the electric motor M. It may be arranged. The outer shape of the electric motor M is not limited to that described above, but may be other polygonal shapes or circular shapes. When the outer shape of the electric motor M is circular, the surface of the casing 11 may be formed in a curved surface according to the shape.

  A cooling passage PS1 (first cooling passage) penetrating through the central casing 13 is provided in the central casing 13 as the first casing, and the cooling passages PS1 are provided in the end casings 14 and 15 as the second casing. However, the configuration of the casing 11 is not limited to this. Therefore, the shape of the cooling passage PS may not be zigzag.

  Although the cooling passage PS of the different casing 11 is communicated with the tube 27, other pipe members such as metal pipes may be used. Although the casing 11 is fixed by connecting the plurality of casings 11 with the connecting bar 12, any fixing means for fixing the casing 11 may be used. The through hole of the connection bar 12 may be a long hole so that the fastening position of the connection bar 12 can be adjusted. The cooling medium flowing in the casing 11 is not limited to liquid but may be gas.

  In the above embodiment, the example used for the electric motor for driving the spindle of the machine tool has been described. However, the present invention can be similarly applied to an electric motor other than the machine tool. That is, the present invention is not limited to the cooling jacket for an electric motor according to the embodiment as long as the features and functions of the present invention can be realized.

DESCRIPTION OF SYMBOLS 10 Cooling jacket 11 Casing 12 Connecting bar 13 Central casing 14, 15 End casing 27 Tube PS, PS1, PS2 Cooling passage

Claims (1)

A cooling jacket for an electric motor that cools the electric motor,
A plurality of casings arranged in the circumferential direction in close contact with the outer peripheral surface of the electric motor so as to surround the electric motor;
Fixing means for fixing the plurality of casings to the outer peripheral surface of the electric motor;
A cooling passage through which a cooling medium passes is provided in each casing ,
Each casing is
A first casing provided with a plurality of first cooling passages penetrating through the casing;
Wherein is joined to an end portion of the first casing, the first second casing and the electric motor cooling jacket, characterized in Rukoto of having a the second cooling passage is provided to communicate the cooling passages to each other.

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