JP2008271654A - Electric motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a hot air to be discharged from the inside of an electric motor from directly blowing to the structure of a machine tool, even when the air outside the electric motor is blown to the inside of the electric motor to cool the electric motor. <P>SOLUTION: The electric motor 11 for a machine tool is provided with a housing 13 having an attaching end to be attached on the structure 33 of the machine tool, an output shaft 15 supported by the housing 13 so as to be rotatable around a rotary shaft line O, an air passage 45 extending in the housing 13 in a direction of the rotary shaft line O of the output shaft 15 and having a discharge port 47 on the attaching end side of the housing 13, and a blower 51 for circulating ambient air through the air passage 45. The electric motor 11 is further provided with a wind shield member 55 between the discharge port 47 of the air passage 45 and the structure 33 of the machine tool so that the air to be discharged from the discharge port 47 of the air passage 45 may not be directly blown to the structure 33 of the machine tool. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electric motor attached to a structure of a machine tool.

  In a machine tool, an electric motor is used to move or rotate a spindle or table. Such motors for machine tools often require high output. However, when the output of the electric motor increases, the amount of heat generation increases, so it is necessary to cool the electric motor using cooling water or air. For example, in an air-cooled electric motor, an air passage is provided inside the electric motor, and a blower is attached to one end of the electric motor to forcibly generate an air flow in the air passage of the electric motor, thereby cooling the inside of the electric motor. Yes.

  In an air-cooled electric motor using such a blower, a mode in which the blower is attached so as to blow air inside the motor toward the outside of the motor, and a blower is attached so that ambient air outside the motor is blown toward the inside of the motor. There are cases. For example, in the machine tool with a built-in motor spindle stock disclosed in Patent Document 1, a blower is attached to the spindle stock placed on the bed, and the air suction opening provided near the head stock mounting position of the bed enters the spindle stock. The spindle head and the motor (motor) are cooled by sucking air into the formed air passage and discharging the air in the air passage to the outside of the spindle head from the upper surface opening. However, since the temperature inside the structure is higher than the temperature of the ambient air outside the machine tool, the air discharged inside the structure after being blown into the motor is discharged outside the motor. In general, the cooling efficiency is inferior compared to a mode in which the ambient air is blown toward the inside. Therefore, from the viewpoint of cooling efficiency, a mode in which ambient air outside the motor is blown toward the inside of the motor is preferable.

Japanese Patent Laid-Open No. 11-48087

  An electric motor used for a machine tool is attached with an end portion (hereinafter referred to as an attachment end portion) from which an output shaft protrudes facing an outer surface of a machine tool structure. Therefore, in order to blow ambient air outside the motor toward the inside of the motor, the blower is attached to the end of the motor opposite to the mounting end of the motor. As a result, when air outside the motor is blown into the motor by the blower, the air that has passed through the motor in the direction of the rotation axis of the output shaft is discharged from the mounting end side of the motor toward the structure of the machine tool. Become. However, since the air discharged from the inside of the electric motor absorbs heat from the electric motor and has a high temperature, when it hits the machine tool, the temperature of the structure of the machine tool is raised to cause thermal deformation of the structure. Such thermal deformation of the machine tool structure causes a problem of lowering the machining accuracy of the machine tool.

  The present invention has been made to solve the above-described problems, and the object of the present invention is to provide a high temperature exhausted from the inside of the motor even when air outside the motor is blown into the motor for cooling the motor. It is to prevent air from hitting the machine tool structure.

  In order to achieve the above-mentioned object, in an electric motor attached to a machine structure, a housing having an attachment end attached to the machine structure, and extending through the housing, is discharged to the attachment end side of the housing. An air passage having an outlet, a blower that circulates air through the air passage, discharges the air from the discharge port, and cools the housing; and air discharged from the discharge port of the air passage directly There is provided an electric motor including a windbreak member provided between the discharge port of the air passage and the machine structure so as not to hit the machine structure.

  According to the above-described electric motor, the high-temperature air discharged from the discharge port of the air passage of the motor hits the windbreak member provided between the discharge port and the machine structure, and does not directly hit the machine structure. . Therefore, it is suppressed that the mechanical structure is thermally deformed by the high-temperature air discharged from the electric motor.

  In the electric motor, the windbreak member is formed in a direction away from the machine structure so as to guide the air discharged from the discharge port of the air passage to the opposite side of the machine structure. Preferably it is. Thereby, the high-temperature air discharged from the electric motor is guided in a direction away from the machine structure, and as a result, it is possible to suppress an increase in temperature in the vicinity of the machine structure.

  As described above, according to the present invention, by providing the windbreak member between the discharge port of the ventilation passage of the electric motor and the machine structure, the air discharged from the electric motor hits the windbreak member and directly forms the machine structure. If it hits, it will disappear. Therefore, it is possible to prevent the temperature of the machine structure from being raised by the high-temperature air discharged from the electric motor, and to prevent thermal deformation of the structure.

  The best mode for carrying out the present invention will be described with reference to the accompanying drawings. FIG. 1 is a longitudinal sectional view of an electric motor according to the present invention. FIG. 2 is a schematic view showing the overall configuration of a machine tool using the electric motor of the present invention.

  First, an example of the structure of the machine tool 101 that can use the electric motor of the present invention will be described with reference to FIG. The machine tool 101 is a machining center, and includes a bed 103 installed on the floor, a column 105 installed upright on the bed 103, and a movably supported on the column 105 in the X-axis direction (perpendicular to the plane of FIG. 2). 2) and a spindle head 107 driven in the Y-axis direction (vertical direction in FIG. 2), a spindle 109 rotatably supported on the spindle head 107 and mounted with the tool T, and movable on the bed 103. And a table 111 driven in the Z-axis direction (left-right direction in FIG. 2). The machine tool 101 may be another type of machine tool such as a drilling machine or a lathe. An electric motor 113 for driving the spindle head 107 in the X-axis direction and the Y-axis direction is attached to the upper surface of the column 105 of the machine tool 101, and a table 111 is attached to the side surface of the bed 103 of the machine tool 101. An electric motor 115 for driving in the axial direction is attached.

Details of the electric motor 113 or 115 attached to the structure of the machine tool such as the column 105 or the bed 103 are shown as the electric motor 11 in FIG.
The electric motor 11 includes a housing 13 and an output shaft 15 to which a rotor 17 is attached and is rotatably supported by the housing 13. Specifically, the housing 13 includes a stator core 19 installed so as to surround the rotor 17 with a space from the outer peripheral surface of the rotor 17 fixed to the output shaft 15, and the stator core 19 so as to sandwich the stator core 19. The front cover 23 and the rear cover 25 are disposed at both ends in the axial direction and rotatably support the output shaft 15 via bearings 21. In addition, a plurality of grooves extending substantially parallel to the output shaft 15 are formed in the inner peripheral portion of the stator core 19, and the stator 31 is configured by mounting the windings 29 in the grooves. .

  The front cover 23 has a flange portion 23a for attaching to the structure 33 (in this case, the column 105 or the bed 103) of the machine tool 101. The flange portion 23a and the structure are connected with a fastener 35 such as a screw. The electric motor 11 can be attached to the structure by fastening. That is, the flange portion 23 a of the front cover 23 forms an attachment end portion of the housing 13 of the electric motor 11. The output shaft 15 extends through the front cover 23. The front end portion of the output shaft 15 is connected to a power transmission member 37 provided in the structure 33 via a coupling or clutch, and the driving force of the electric motor 11 is transmitted through the power transmission member 37 to the spindle head 107 or the like. The spindle head 107 and the table 111 are driven by being transmitted to the table 111.

  A concave portion 25a is formed on the outer end surface of the rear cover 25, and the rear end portion of the output shaft 15 extends through the rear cover 25 into the concave portion 25a. A rotation detector 39 is attached to the recess 25a of the rear cover 25 so that the rotation of the detected body 41 such as an encoder plate attached to the rear end of the output shaft 15 can be detected. Further, the recess 25 a of the rear cover 25 is completely covered by an end plate 43 attached to the outer side in the axial direction of the rear cover 25.

  A plurality of air passages 45 extending in the direction of the rotation axis O of the output shaft 15 are formed in the outer peripheral portions of the front cover 23, the stator core 19, and the rear cover 25. The front end of each air passage 45 opens to a portion of the front cover 23 that is not closed by the structure 33 even when the front cover 23 is attached to the structure 33, thereby forming a discharge port 47. On the other hand, the rear end of each air passage 45 opens to a portion of the rear cover 25 that is not covered by the end plate 43, thereby forming a suction port 49.

  A blower 51 for allowing air outside the motor (hereinafter referred to as ambient air) to flow through the air passage 45 is further attached to the rear side of the rear cover 25 of the housing 13. For example, an axial fan is used as the blower 51, but is not particularly limited as long as ambient air can be circulated through the air passage 45. The housing 53 of the blower 51 has a cup shape and is attached to the rear cover 25 so as to cover the entire rear end surface of the rear cover 25 of the electric motor 11. The rear end wall of the housing 53 of the blower 51 is provided with a ventilation opening (not shown) covered with a mesh member (not shown) that allows passage of ambient air from the outside to the inside, Ambient air can be taken into the blower 51.

  In the electric motor 11 of the present invention, a windbreak member 55 is further attached between the discharge port 47 of the air passage 45 of the electric motor 11 and the surface of the structure 33 of the machine tool 101, and the discharge port 47 of the air passage 45. The air discharged from the air strikes the windbreak member 55 so that it does not directly hit the surface of the structure 33 of the machine tool 101. The windbreak member 55 is provided at least near the position facing the discharge port 47 of the air passage 45 between the discharge port 47 of the air passage 45 of the electric motor 11 and the surface of the structure 33 of the machine tool 101. Just do it. However, in order to ensure that the air discharged from the discharge port 47 of the air passage 45 does not directly hit the surface of the structure 33 of the machine tool 101, the discharge port 47 of the air passage 45 of the electric motor 11 and the machine tool 101 It is preferable to be provided over the entire circumference of the front cover 23 of the electric motor 11 between the surface of the structure 33.

  Further, as shown by a solid line in FIG. 1, the windbreak member 55 is directed away from the structure 53 in order to guide the air discharged from the air passage 45 to flow away from the structure 33. Are preferably curved so as to have a substantially L-shaped cross section. However, if the air discharged from the discharge port 47 of the air passage 45 does not directly hit the surface of the structure 33 of the machine tool 101, the windbreak member 55 can take any shape. For example, it may have a flat plate shape as shown by a one-dot chain line in FIG. 1, and as shown by a dotted line in FIG. 1, the tip portion of the windbreak member 55 is oriented in an arbitrary direction. It may be.

  In the embodiment shown in FIG. 1, the windbreak member 55 is formed as a separate member from the front cover 23 of the electric motor 11, and is attached to the flange portion 23 a of the front cover 23 by a fastener 35 such as a screw. . However, the windbreak member 55 may be formed integrally with the front cover 23 of the electric motor 11 or may be attached to the side surface or the structure 33 of the front cover 23. Further, when the windbreak member 55 is attached to the flange portion 23 a of the front cover 23, it may be attached to the side or the side facing the structure 33 of the machine tool 101 or may be attached to the side away from the structure 33. Further, between the windbreak member 55 and the structure 33 of the machine tool 101, the heat of the windbreak member 55 that has been heated by the high-temperature air discharged from the discharge port 47 of the air passage 45 is the structure 33 of the machine tool 101. In order to prevent transmission to the heat sink, it is preferable to interpose a heat insulating material (not shown) between the windbreak member 55 and the structure 33 of the machine tool 101.

Next, the operation of the electric motor 11 shown in FIG. 1 will be described.
The blower 51 is activated simultaneously with the activation of the electric motor 11 or at any time thereafter. When the blower 51 is activated, ambient air is sucked from the rear end wall of the blower 51, and air blowing to the air passage 45 formed in the housing 13 of the electric motor 11 is started. When air having a relatively low temperature flows through the air passage 45 of the housing 13 of the electric transmitter 11, heat is taken away from the housing 13 of the electric motor 11 that has become relatively hot due to heat generated by the stator 31 and / or the rotor 17. Then, the housing 13 of the electric motor 11 and the stator 31 and the rotor 17 therein are cooled.

  On the other hand, the air in the air passage 45 that has become hot due to heat absorption from the housing 13 of the electric motor 11 is discharged from the discharge port 47 of the air passage 45 toward the structure 33 of the machine tool 101. However, since the windbreak member 55 is provided between the discharge port 47 of the air passage 45 and the structure 33 of the machine tool 101, the high-temperature air discharged from the discharge port 47 of the air passage 45 is removed from the machine tool. 101 does not directly hit the structure 33. In particular, as shown by a solid line in FIG. 1, when the windbreak member 55 is curved in a substantially L-shaped cross section, the high-temperature air discharged from the discharge port 47 of the air passage 45 is 55 is guided in a direction away from the structure 33 of the machine tool 101 to suppress an increase in temperature near the surface of the structure 33 of the machine tool 101.

  As described above, according to the electric motor of the present invention, it is avoided that the air discharged from the air passage 45 of the electric motor 11 after being used for cooling the electric motor 11 directly hits the structure 33 of the machine tool 101. The temperature of the structure 33 of the machine tool 101 is prevented from rising due to the high-temperature air discharged from the air passage 45, and the thermal deformation of the structure 33 of the machine tool 101 can be reduced. As a result, it is possible to suppress a decrease in machining accuracy of the machine tool 101 due to thermal deformation of the structure 33 of the machine tool 101.

  As mentioned above, although this invention was demonstrated based on embodiment shown in figure, this invention is not limited to the said embodiment. For example, in the above-described embodiment, the case where an axial fan is used as the blower 51 has been described, but other types of blowers such as a centrifugal turbofan may be used.

It is a longitudinal cross-sectional view of the electric motor of this invention. It is the schematic which shows the whole structure of the machine tool using the electric motor of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Electric motor 13 Housing 15 Output shaft 33 Structure 45 Air passage 47 Outlet 51 Blower 55 Windbreak member

Claims (2)

In an electric motor attached to a machine structure,
A housing having an attachment end attached to the structure of the machine;
An air passage extending through the housing and having a discharge port on the mounting end side of the housing;
A blower for circulating air in the air passage and discharging the air from the outlet to cool the housing;
A windbreak member provided between the discharge port of the air passage and the structure of the machine so that the air discharged from the discharge port of the air passage does not directly hit the structure of the machine;
An electric motor comprising:   2. The windbreak member according to claim 1, wherein the windbreak member is formed in a direction away from the machine structure so as to guide the air discharged from the discharge port of the air passage to the opposite side of the machine structure. The electric motor described.

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