JPH09154272A - Cooling structure of linear motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sufficiently control the temperature rise of a motor by providing a non-magnetic coil cooling member having high thermal conductivity between the magnetic pole of the rotor side and a coil to cool the coolant a little. SOLUTION: When a coil 9 of a linear motor 1 receives electric power, a repulsion force is generated at a rotor 1a and thereby a slider 4 is driven linearly. Generated heat is sequentially transferred, before it is transmitted to a projected magnetic pole 7, to a bobbin 8, a flange 11 and a cooling member 10 having higher thermal conductivity. Thereafter, heat is extracted to external side via the coolant flowing into the piping 13 for cooling. As a result, before heat of the coil 9 is spread to the projected magnetic pole 7 having a large thermal capacity, it is transmitted effectively to the bobbin 8, the flange 11 and cooling member 10, effective cooling can be realized and the temperature rise of the motor can also be controlled to improve the rated repulsion force. Moreover, since the bobbin 8 is cooled effectively, heat is not easily transmitted to the projected magnetic pole 7 and thermal expansion of the slider 4 can be reduced to improve positioning accuracy and linear performance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear motor cooling structure.

[0002]

2. Description of the Related Art FIG. 13 shows an example of a conventional linear motor. This linear motor linearly drives a slider c that is bridged between bearings b of two linear guides a that are arranged in parallel to each other, and a mover-side magnetic pole portion d attached to the lower portion of the slider c. Equipped with. A coil f is wound around the magnetic pole portion d via an insulating portion e, and a stator g is arranged below the magnetic pole portion d so as to face each other in a non-contact manner.

By the way, in such a linear motor, since the rated thrust is limited by the temperature rise value of the motor, a plate h with a cooling liquid pipe is interposed between the magnetic pole portion d and the slider c, and the coil f is used. The heat transferred to the magnetic pole part d through the insulating part e is released to the outside through the cooling liquid, thereby suppressing the temperature rise of the motor and preventing the rated thrust from decreasing.

[0004]

However, in such a conventional linear motor, the coil f to the insulating portion e are not used.
The heat transferred to the magnetic pole part d via the magnetic pole part d is diffused because the heat capacity of the magnetic pole part d is large, and as a result, the temperature difference between the magnetic pole part d and the cooling liquid flowing in the plate h with the cooling liquid pipe is small. Therefore, there is a disadvantage that the cooling efficiency is deteriorated and the temperature rise of the motor cannot be sufficiently suppressed.

Further, from the viewpoint of accurately transmitting the thrust of the motor to the slider c, the slider c, the plate h with the cooling liquid pipe, and the magnetic pole portion d are integrally and firmly fixed, so that the cooling efficiency of the motor is poor. As a result, heat is likely to be transferred from the plate h with the cooling liquid pipe to the slider c, and the temperature of the slider c rises. As a result, the thermal expansion of the slider c causes a disadvantage that positioning accuracy and rectilinear performance are significantly reduced. .

Further, since the plate h with the cooling liquid pipe is sandwiched between the slider c and the magnetic pole portion d, the plate h with the cooling liquid pipe is springy when the thrust of the motor is transmitted to the slider c. Resonance or the like is likely to occur as a factor that causes play or play, resulting in inferior controllability. The present invention has been made to solve such inconvenience, and provides a cooling structure for a linear motor, which can improve the rated thrust of the motor and can improve the positioning accuracy and the straight traveling performance. With the goal.

[0007]

In order to achieve the above object, a cooling structure for a linear motor according to the present invention is provided with a magnetic pole between a magnetic pole portion on a mover side and a coil wound around the magnetic pole portion. A non-magnetic coil cooling member having a higher thermal conductivity than that of the section is interposed, and a cooling unit for cooling the coil cooling member via a cooling liquid is provided.

[0008]

According to the present invention, a non-magnetic coil cooling member having a higher thermal conductivity than that of the magnetic pole portion is interposed between the magnetic pole portion on the mover side and the coil, and the coil cooling member is passed through the cooling liquid. By cooling, the coil cooling member is cooled while the temperature difference from the cooling liquid is set higher than before before the heat of the coil is transferred to the magnetic poles and diffused, thereby improving the cooling efficiency of the motor. To enable.

[0009]

DETAILED DESCRIPTION OF THE INVENTION An example of an embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is an explanatory schematic diagram for explaining a cooling structure of a linear motor that is an example of an embodiment of the present invention, FIG. 2 is an overall perspective view of a mover of the linear motor, and FIG. 3 is AA of FIG. A line sectional view, and FIG. 4 is an overall perspective view of the bobbin.

First, the structure will be described with reference to FIGS. 1 to 4. A linear motor 1 linearly drives a slider 4 which is bridged between bearings 3 of two linear guides 2 arranged in parallel with each other. The movable element 1a is attached to the lower part of the slider 4 and the stator (magnet or secondary side plate) 1b is disposed below the movable element 1a so as to face each other in a non-contact manner.

The mover 1a is provided with a yoke 5 formed by laminating electromagnetic steel plates. The yoke 5 is a plate-like slider mounting portion 6 which is a mounting portion for the slider 4, and the slider mounting portion 6 It has a plurality of projecting magnetic pole portions (mover-side magnetic pole portions) 7 that project. In this embodiment, the salient magnetic pole portions 7 are arranged in parallel with six poles along the longitudinal direction of the slider mounting portion 6 (moving direction of the slider 4), but the number of the salient magnetic pole portions 7 is not particularly limited. A coil 9 is wound around each salient magnetic pole portion 7 via a bobbin (coil cooling member) 8.

The bobbin 8 is cylindrically formed of a non-magnetic metal such as aluminum or copper having a higher thermal conductivity than the salient magnetic pole portion 7, and is externally fitted to the salient magnetic pole portion 7. A coil 9 is provided on the outer peripheral portion of the bobbin 8. Insulation coating is applied for electrical insulation with the.
In addition, at the end of the bobbin 8 on the slider mounting portion 6 side, as shown in FIG.
As shown in FIG. 4, a flange 11 is formed, and block-shaped cooling members (cooling means) 10 are provided on both sides of the flange 11 respectively on both sides in the width direction of the slider mounting portion 6. There is. Like the bobbin 8, the flange 11 and the cooling member 10 are made of a non-magnetic metal such as aluminum or copper having a higher thermal conductivity than the salient magnetic pole portion 7. In this case, synthetic resin can be used as the material of the bobbin 8, the flange 11, and the cooling member 10 instead of the non-magnetic metal, but the non-magnetic metal has higher thermal conductivity to the salient magnetic pole portion 7 than the synthetic resin. Therefore, a non-magnetic metal is preferable in order to expect more cooling effect. Further, the bobbin 8, the flange 11 and the cooling member 10 may be integrally formed or processed with the same material, or the same or different materials may be welded to each other. In FIG. 4, reference numeral 14 denotes an outer peripheral portion of the bobbin 8 to prevent a secondary current from flowing to the bobbin 8 when a current is passed through the coil 9 when a non-magnetic metal is used as the material of the bobbin 8. Is a slit that cuts along the axial direction.

Through holes 12 are formed in the cooling member 10 along the sides of the slider mounting portion 6. Cooling pipes (cooling means) through which the cooling liquid flows through the through holes 12 of the cooling members 10 arranged in parallel along the longitudinal direction of the slider mounting portion 6.
13 is inserted and arranged. The cooling pipe 13 is formed of a metal tube such as aluminum or copper having excellent heat conductivity, and the heat transferred from the coil 9 to the cooling member 10 via the bobbin 8 is released to the outside through the cooling liquid. Has been done. In this case, silicon or the like may be applied to the contact portion between the inner peripheral surface of the through hole 12 and the outer peripheral surface of the cooling pipe 13 in order to improve heat conductivity. In addition, in this embodiment, the case where the cooling pipes 13 are arranged one by one in the cooling member 10 is taken as an example, but the invention is not limited to this, and two or more cooling pipes 13 may be arranged. You may
Further, the through hole 12 is formed in the cooling member 10 to form the through hole 1.
Although the cooling pipe 13 is arranged to be inserted through the 2
Instead of this, a groove (not shown) may be formed in the cooling member 10 and the cooling pipe 13 may be embedded in the groove.

In the linear motor 1 having such a structure,
By energizing the coil 9, a thrust is generated in the mover 1a and the slider 4 is linearly driven. At this time, the heat generated in the coil 9 is transferred to the salient magnetic pole portion 7 before being transferred to the salient magnetic pole portion 7.
It is sequentially transferred to the bobbin 8, the flange 11 and the cooling member 10 having higher thermal conductivity, and then taken out to the outside via the cooling liquid flowing through the cooling pipe 13 in the cooling member 10. As a result, the heat of the coil 9 is transferred to the bobbin (coil cooling member) 8, the flange 11 and the cooling member 10 before being diffused to the salient magnetic pole portion 7 having a large heat capacity. It is possible to efficiently cool the bobbin 8, the flange 11 and the cooling member 10 in a state where the difference is set higher than in the conventional case, and as a result, the temperature rise of the motor is suppressed more than in the conventional case and the rated thrust can be improved.

Further, since the bobbin 8 can be cooled efficiently, the heat of the coil 9 is less likely to be transferred to the salient magnetic pole portion 7, and as a result, the temperature rise of the slider 4 and the detector (not shown) can be suppressed low. Therefore, the thermal expansion of the slider 4 can be reduced, and the positioning accuracy and the straight traveling performance can be improved. Further, since it is not necessary to interpose a conventional plate h with cooling liquid piping between the slider mounting portion 6 of the yoke 5 and the slider 4, the plate with cooling liquid piping when transmitting the thrust of the motor to the slider 4. It is possible to eliminate the spring property and play due to h, and it is possible to make resonance less likely to occur.

In the above embodiment, the cooling liquid is caused to flow through the cooling pipe 13 inserted through the through hole 12 of the cooling member 10. However, this is not always necessary, and the slider mounting portion is not always necessary. The cooling members 10 arranged side by side along the longitudinal direction of 6 may be joined to each other to connect the through holes 12 of the cooling members 10 to form a cooling liquid flow path. In this case, as a result, the cooling pipe 13 becomes unnecessary.

Further, in the above embodiment, the cooling member 10 is used.
Although the flow path for the cooling liquid is formed only in the above, as shown in FIG. 5, both sides of the bobbin 8 around which the coil 9 is wound are made thicker to form the cooling liquid flow path 15 in the thick portion. , The cooling liquid channel 1
The cooling efficiency may be further improved by opening both ends of the cooling member 5 in the cooling member 10. Further, in some cases, a conventional plate h with cooling liquid piping may be interposed between the slider mounting portion 6 of the yoke 5 and the slider 4.

Next, another embodiment of the present invention will be described with reference to FIGS. 6 is an explanatory schematic view for explaining a cooling structure of a linear motor according to another embodiment of the present invention, FIG. 7 is an overall perspective view of a mover of the linear motor shown in FIG. 6, and FIG. 9 is a sectional view taken along line BB of FIG. 9, and FIG. 9 is an overall perspective view of the bobbin. First, the configuration will be described with reference to FIGS. 6 to 9. The linear motor 20 linearly drives the slider 4 bridged between the bearings 3 of the two linear guides 2 arranged in parallel with each other. A mover 21a attached to the lower part of the slider 4, and a mover 21
It is constituted by a stator (magnet or secondary side plate) 21b which is arranged in a non-contacting and opposed manner to a position below a.

The mover 21a is provided with a yoke 22 formed by laminating electromagnetic steel sheets. The yoke 22 has a plate-like slider mounting portion 23 which is a mounting portion for the slider 4.
It has a five-pole salient magnetic pole portion (mover-side magnetic pole portion) 24 protruding from the slider mounting portion 23. Each salient pole portion 24 has
As shown in FIGS. 7 and 8, a coil 26 is wound via a bobbin (coil cooling member) 25.

The bobbin 25 is cylindrically formed of a non-magnetic metal such as aluminum or copper having a higher thermal conductivity than that of the salient magnetic pole portion 24, and is externally fitted to the salient magnetic pole portion 24. Insulation coating is applied for electrical insulation with the. In addition, as shown in FIGS. 8 and 9, the bobbin 25
Flanges 27a, 27b on both axial ends of
Are formed, and cooling members (cooling means) 28 are arranged on both sides in the width direction of the slider attachment portion 23 of the flanges 27a and 27b. Flange 27a, 27b
Similarly to the bobbin 25, the cooling member 28 includes the salient magnetic pole portion 24.
It is made of a non-magnetic metal such as aluminum or copper having a higher thermal conductivity.

The cooling member 28 connects the contact pieces 29a and 29b with the contact pieces 29a and 29b which come into surface contact with the outer surfaces of the flanges 27a and 27b arranged in parallel along the longitudinal direction of the slider mounting portion 23. The connecting piece 30 is formed with a substantially U-shaped cross section, and the connecting piece 30 has two through holes 31 as a flow path of the cooling liquid.
Are formed along the longitudinal direction. The heat transmitted from the coil 26 to the cooling member 28 via the bobbin 25 and the flanges 27a and 27b via the cooling liquid flowing through the through hole 31 is released to the outside. In this case, in order to further improve the heat transfer property, silicon or the like may be applied to the contact portions between the outer surfaces of the flanges 27a and 27b and the contact pieces 29a and 29b, and the flanges 27a and 27b and the contact pieces 29a and 29b. 29b may be joined by welding or the like. In FIG. 9, reference numeral 32 is a slit that cuts the outer peripheral portion of the bobbin 25 along the axial direction in order to prevent a secondary current from flowing to the bobbin 25 when a current is passed through the coil 26.

In the linear motor 20 having such a structure, when the coil 26 is energized, a thrust is generated in the mover 21a to linearly drive the slider 4. At this time, the heat generated in the coil 26 is sequentially transferred to the bobbin 25, the flanges 27a and 27b, and the cooling member 28, which have higher thermal conductivity than the salient magnetic pole portion 24, before being transferred to the salient magnetic pole portion 24, and then cooled. It is taken out to the outside via the cooling liquid flowing through the through hole 31 in the member 28. As a result, the heat of the coil 26 is transferred to the bobbin (coil cooling member) 25, the flanges 27a and 27b, and the cooling member 28 before being diffused to the salient magnetic pole portion 24 having a large heat capacity. Bobbin 25 with the temperature difference of
The flanges 27a and 27b and the cooling member 28 can be efficiently cooled, and as a result, the temperature rise of the motor can be suppressed more than before and the rated thrust can be improved.

Further, since the bobbin 25 can be cooled efficiently, the heat of the coil 26 is less likely to be transferred to the salient magnetic pole portion 24, and as a result, the temperature rise of the slider 4, the detector (not shown) and the like can be suppressed low. Therefore, the thermal expansion of the slider 4 can be reduced, and the positioning accuracy and the straight traveling performance can be improved. Further, since it is not necessary to interpose a conventional plate h with cooling liquid piping between the slider mounting portion 23 of the yoke 22 and the slider 4, the plate with cooling liquid piping when transmitting the thrust of the motor to the slider 4. It is possible to eliminate the spring property and play due to h, and it is possible to make resonance less likely to occur.

As a modified example of the bobbin 25, FIGS.
As shown in FIG. 12, the bobbin 2 around which the coil 26 is wound.
5, the entire wall portion 5 is made thick, and the cooling liquid passage 32 is formed in the thick portion.
May be formed and the cooling pipe 33 may be connected to the cooling liquid flow path 32 to further improve the cooling efficiency.

[0025]

As is apparent from the above description, according to the present invention, the coil cooling is performed in a state in which the temperature difference between the heat of the coil and the cooling liquid is set higher than that of the prior art before being diffused to the magnetic pole portion having a large heat capacity. Since the cooling member can be efficiently cooled and the cooling efficiency can be increased, it is possible to obtain an effect that the temperature rise of the motor is suppressed more than in the past and the rated thrust can be improved.

Further, since the coil cooling member can be cooled efficiently, the heat of the coil is less likely to be transferred to the magnetic pole portion, so that the temperature rise of the slider can be suppressed low and the thermal expansion of the slider can be suppressed. It is possible to reduce the number, and it is possible to obtain the effect that the positioning accuracy and the straight traveling performance can be improved. Furthermore, since it is not necessary to interpose a conventional plate with cooling liquid piping between the magnetic pole portion and the slider, when the thrust of the motor is transmitted to the slider, the spring property and play caused by the plate with cooling liquid piping are eliminated. This can be eliminated, and the effect that resonance or the like is less likely to occur can be obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory schematic diagram for explaining a cooling structure for a linear motor that is an example of an embodiment of the present invention.

FIG. 2 is an overall perspective view of a mover of a linear motor.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is an overall perspective view of a bobbin.

FIG. 5 is an overall perspective view showing a modified example of the bobbin.

FIG. 6 is an explanatory schematic diagram for explaining a cooling structure for a linear motor that is another embodiment of the present invention.

FIG. 7 is an overall perspective view of a mover of a linear motor.

FIG. 8 is a sectional view taken along line BB of FIG. 7;

FIG. 9 is an overall perspective view of a bobbin.

FIG. 10 is an explanatory plan view for explaining a modified example of the bobbin.

FIG. 11 is a left side view of FIG.

12 is a cross-sectional view taken along the line CC of FIG.

FIG. 13 is an explanatory schematic diagram for explaining a conventional cooling structure for a linear motor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Linear motor 1a ... Mover 7 ... Salient magnetic pole part (mover side magnetic pole part) 8 ... Bobbin (coil cooling member) 9 ... Coil 10 ... Cooling member (cooling means) 13 ... Cooling piping (cooling means)

Claims (1)

[Claims] 1. A non-magnetic coil cooling member having a thermal conductivity higher than that of the magnetic pole portion is interposed between a magnetic pole portion on the mover side and a coil wound around the magnetic pole portion, and the coil cooling member is provided. A cooling structure for a linear motor, comprising: a cooling unit that cools the liquid via a cooling liquid.