JP2008067492A - Linear motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress temperature rise and thermal expansion of a slide table, while improving the heat-dissipation performance of a moving element of a linear motor. <P>SOLUTION: A heat-dissipating member, connecting between the slide table 16 and the moving member 19, comprises a large number of heat-dissipating plates 18 arranged substantially in parallel with a rail 15. By this, it is possible to increase a heat-dissipation area, by increasing the number of the heat-dissipating plates 18 while each heat-dissipating plate 18 is formed thin. A sufficient temperature gradient is imparted to a temperature distribution of each heat-dissipating plate 18 due to thickness reduction of each heat-dissipating plate 18 so that a temperature on the side of the slide table 16 becomes low. It is possible to suppress the temperature rise and the thermal expansion of the slide table 16 with this configuration, even if the moving member 19 expands thermally, merely an interval on the side of the moving member 19 is changed in the interval between each heat-dissipating plate 18; and it is possible to prevent the slide table 16 from deforming due to a thermal-expansion difference between the moving member 19 and the slide table 16. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a linear motor in which a mover is connected to a slide member slidably supported on a rail via a heat radiating member.

  In general, a linear motor is provided so that a pair of rails extend in parallel along both sides of a linearly extending stator, and a slide table is slidably supported by both rails, and a movable element fixed to the slide table is fixed. The movable element and the slide table are integrally slid along the rail by switching the energization to each coil of the movable element in accordance with the moving position of the movable element. While this linear motor is in operation, heat is generated by energizing the coil of the mover, so this heat is transmitted from the mover to the slide table, and the temperature of the slide table rises. Since the dimension of the slide table in the rail width direction changes, there is a problem that the sliding resistance of the sliding portion between the slide table and the rail increases, wear increases, and the life is shortened. In addition, there is a problem in that the positioning accuracy of the positioning object on the slide table is reduced due to a dimensional change due to thermal expansion of the slide table.

  In order to solve these problems, as described in Patent Document 1 (Japanese Patent Application Laid-Open No. 2004-88981), a heat insulating material is interposed between the slide table and the mover, and the slide table is moved from the mover to the slide table. There is one in which heat transfer to is prevented by a heat insulating material.

However, in this configuration, since the heat dissipation of the mover is poor and the coil temperature of the mover is excessively increased, in another embodiment described in Patent Document 1, there is a problem between the slide table and the mover. A heat sink is provided between them to ensure the heat dissipation of the mover, and a heat-absorbing deformation absorbing member (laminated glass epoxy) is interposed at the joint between the heat sink and the slide table, so that the heat from the heat sink to the slide table While the transmission is prevented by the heat-insulating deformation absorbing member, the deformation absorbing member is deformed according to the difference in thermal expansion between the heat sink and the slide table, thereby preventing the slide table from being deformed by the heat expansion of the heat sink. ing.
JP 2004-88981 A (first page, page 12 to page 14)

  However, in the above configuration, the temperature of the mover moves up and down every time the linear motor is started / stopped, and the heat sink expands / shrinks, and the deformation absorbing member is repeatedly deformed each time. There is a possibility that fatigue failure may occur, and there is a problem in durability. Moreover, since the heat sink and the slide table are fastened and fixed with bolts with the deformation absorbing member sandwiched between them in order to secure the mounting strength, if the bolt is tightened strongly, the deformability of the deformation absorbing member is hindered by the bolt. On the other hand, if the bolt is tightened loosely, the bolt is easily loosened by vibration, and it is difficult to achieve both the securing of the deformability of the deformation absorbing member and the securing of the mounting strength. Furthermore, there is a drawback that the connection structure between the heat sink and the slide table is complicated.

  The present invention has been made in consideration of such circumstances. Therefore, the object of the present invention is to suppress the temperature rise and thermal expansion of the slide member (slide table) while improving the heat dissipation of the mover, and to achieve durability. An object of the present invention is to provide a linear motor that can satisfy the demands for improving the performance, securing the mounting strength, and simplifying the configuration.

  In order to achieve the above object, the invention according to claim 1 includes a linearly extending stator, a slide member slidably supported by a pair of rails extending in parallel along both sides of the stator, and the slide In a linear motor having a movable element connected to a member via a heat dissipation member and facing the stator, the heat dissipation member is constituted by a plurality of heat dissipation plates arranged substantially parallel to the rail. is there.

  In this configuration, the heat dissipating area (contact area with air) can be sufficiently increased by thinly forming a plurality of heat dissipating plates constituting the heat dissipating member and increasing the number of heat dissipating plates. It is possible to suppress the temperature rise of the mover by securing the property, and it is possible to have a sufficient temperature gradient so that the temperature distribution of each heat radiating plate becomes lower in the temperature distribution of each heat radiating plate by reducing the thickness of each heat radiating plate, Temperature rise and thermal expansion of the slide member can be suppressed. In addition, since each heat dissipating plate is arranged substantially parallel to the rail, even if the mover is thermally expanded and its dimension in the rail width direction is changed, the distance between the heat dissipating plates is changed on the slide member side. In this case, only the distance on the movable element side is changed due to the thermal expansion of the movable element, and it is possible to prevent the slide member from being deformed due to the thermal expansion difference between the movable element and the sliding member. Moreover, since each heat radiating plate is arranged substantially parallel to the rail, the load at the time of acceleration / deceleration of the slide member (load acting in a direction parallel to the rail) can be stably supported by each heat radiating plate, and Since the deformation absorbing member as in Patent Document 1 is not required, it is possible to solve the problems caused by the above-described deformation absorbing member, and to satisfy the demands for durability improvement, securing of mounting strength, and configuration simplification. it can.

  In the present invention, a plurality of heat dissipation plates constituting the heat dissipation member may be formed separately. However, as in claim 2, the plurality of heat dissipation plates are arranged on the movable element side and / or the slide member side. You may make it form integrally so that an edge part may connect. In this way, there is an advantage that the assembly work of the linear motor is simplified and the productivity can be improved.

  Further, as in claim 3, a heat insulating member is interposed between the plurality of heat radiating plates and the slide member so that heat transfer from each heat radiating plate to the slide member is prevented by the heat insulating member. good. In this case, since the heat insulating member does not need to be deformed, the problem as in Patent Document 1 that requires deformation does not occur.

  Further, as in claim 4, the heat dissipating member may be configured in a plurality of stages via a heat insulating member, and a predetermined number of heat dissipating plates may be arranged in each stage. Thereby, the heat transfer prevention effect to a slide member can be improved, improving heat dissipation.

  Moreover, you may make it form a radiation fin in each radiation plate like Claim 5. Thereby, heat dissipation can further be improved.

  Hereinafter, five examples 1 to 5 embodying the best mode for carrying out the present invention will be described.

A first embodiment of the present invention will be described with reference to FIGS.
Here, FIG. 1 is a longitudinal front view of the linear motor, FIG. 2 is a longitudinal side view of the linear motor, and FIG. 3 is a longitudinal front view for explaining the action when the mover of the linear motor is thermally expanded.

  A linearly extending stator 12 is provided on the bottom surface of the U-shaped base 11. The stator 12 is configured by arranging a large number of permanent magnets 14 on a core 13 such as an iron plate so that N-pole and S-pole magnetic fields are alternately formed.

  A pair of rails 15 extending in parallel along both sides of the stator 12 are attached to the upper ends of both side walls of the base 11. Slide guides 17 are attached to both sides of the lower surface of the slide table 16 (slide member), and each slide guide 17 is slidably fitted to each rail 15 so that the slide table 16 is attached to the pair of rails 15. It is slidably supported.

  On the lower surface of the slide table 16, a large number of heat radiating plates 18 constituting a heat radiating member are mounted at equal intervals and substantially parallel to the rail 15 and downward, and a mover 19 is attached to the lower end of each heat radiating plate 18. The movable element 19 faces the stator 12 via a predetermined air gap. The mover 19 is configured by mounting a coil on an armature core.

  Each heat dissipating plate 18 is made of a nonmagnetic material having high thermal conductivity (for example, copper, aluminum, silver, etc.), and is sufficiently thin as long as the connection strength between the slide table 16 and the mover 19 can be secured. Has been. By making the heat dissipation plate 18 thinner, (1) the number of the heat dissipation plates 18 is increased to increase the heat dissipation area (contact area with air), and (2) the temperature distribution of each heat dissipation plate 18 is changed to the slide table 16. It is possible to provide a sufficient temperature gradient so that the temperature on the side becomes low.

  For example, a structure in which each heat radiating plate 18 is fixed to the slide table 16 and the movable element 19 is formed with fitting grooves in the slide table 16 and the movable element 19, and the heat radiating plates 18 are fitted in the respective fitting grooves. It may be fixed by attaching or screwing.

  Each heat dissipating plate 18 is arranged in parallel at equal intervals, so that a flat air passage is formed between each heat dissipating plate 18, and an electric fan 20 (see FIG. 2) is attached to one end side thereof. The air is forced to flow through the air passages between the heat radiating plates 18 by 20 so as to forcibly cool the heat radiating plates 18.

  According to the first embodiment described above, the heat radiating member that connects the slide table 16 and the mover 19 is constituted by the plurality of heat radiating plates 18 arranged substantially in parallel with the rails 15. By forming it sufficiently thin and increasing the number of heat radiating plates 18, the heat radiating area (contact area with air) can be sufficiently increased. Thereby, the heat dissipation of the mover 19 can be secured, the temperature rise of the mover 19 can be suppressed, a large current can be passed through the coil of the mover 19, and the power performance of the linear motor can be fully exploited. .

  In addition, the thickness of each heat radiating plate 18 can make the temperature distribution of each heat radiating plate 18 have a sufficient temperature gradient so that the temperature on the slide table 16 side is lowered. Can be suppressed. And since each heat sink 18 is arrange | positioned substantially parallel to the rail 15, even if the needle | mover 19 thermally expands and the dimension of the rail width direction changes, the space | interval of each heat sink 18 is shown in FIG. As shown, the distance on the slide table 16 side does not change, only the distance on the mover 19 side changes due to the thermal expansion of the mover 19, and the slide is caused by the difference in thermal expansion between the mover 19 and the slide table 16. It is possible to prevent the table 16 from being deformed.

  Furthermore, by arranging each heat radiating plate 18 substantially in parallel with the rail 15, the load during acceleration / deceleration of the slide table 16 (load acting in a direction parallel to the rail 15) can be stably supported by each heat radiating plate 18. In addition, since the deformation absorbing member as in Patent Document 1 is not required, the problems caused by the above-described deformation absorbing member can be solved, and there is a demand for improvement in durability, securing of installation strength, and simplification of configuration. Can be met.

  In the first embodiment, the heat radiating plate 18 is forcibly cooled by the electric fan 20 to improve the cooling performance of the mover 19. However, the electric fan 20 is omitted and the heat radiating plate 18 is formed by natural convection of air. It is good also as a structure which produces heat dissipation.

  In the first embodiment, the multiple heat dissipation plates 18 constituting the heat dissipation member are formed separately, but in the second embodiment of the present invention shown in FIG. 4, the multiple heat dissipation plates 21 constituting the heat dissipation member are provided. The ends of the movable element 19 and the slide table 16 are integrally formed so as to be connected by connecting pieces 22 and 23, and the connecting pieces 22 and 23 are brazed and fixed to the movable element 19 and the slide table 16 by screwing or the like. Like to do. Also in this case, as in the first embodiment, each heat radiating plate 21 is formed substantially in parallel with the rails 15 at equal intervals using a nonmagnetic material having high thermal conductivity (for example, copper, aluminum, silver, etc.) In addition, the slide table 16 and the movable element 19 are sufficiently thin as long as the connection strength can be secured. Other configurations are the same as those of the first embodiment.

  In the second embodiment, a large number of the heat radiating plates 21 are integrally formed so that the end portions on the movable element 19 side and the slide table 16 side are connected by the connecting pieces 22, 23. The temperature distribution of each heat radiating plate 21 can have a sufficient temperature gradient so that the temperature on the slide table 16 side is lowered. Therefore, even if the connecting piece 22 on the movable element 19 side of each heat radiating plate 21 expands integrally with the movable element 19 due to the heat generated by the movable element 19, the slide table of each radiating plate 21 is caused by the temperature gradient of each radiating plate 21. The connection piece 23 on the 16 side is kept in a state in which the temperature rise is suppressed and thermal expansion does not occur. As a result, as in the first embodiment, even when the mover 19 is thermally expanded and the dimension in the rail width direction is changed, the distance between the heat radiation plates 21 is not changed on the slide table 16 side. Only the distance on the side of the mover 19 changes due to the thermal expansion of the mover 19, and it is possible to prevent the slide table 16 from being deformed by the difference in thermal expansion between the mover 19 and the slide table 16.

  In addition, in the second embodiment, since a large number of heat radiation plates 21 constituting the heat radiation member are integrally formed so as to be connected by the connecting pieces 22 and 23, the assembly work of the linear motor is simplified and the productivity is improved. There are advantages you can do.

In addition, the same effects as those of the first embodiment can be obtained.
In the second embodiment, the end portions on both sides of each heat radiation plate 21 are integrally formed so as to be connected by the connecting pieces 22 and 23, but only one of the movable element 19 side and the slide table 16 side is provided. May be integrally formed so as to be connected by a connecting piece.

  In the third embodiment of the present invention shown in FIG. 5, a heat insulating member 31 formed of a heat insulating resin or the like is interposed between the plurality of heat dissipating plates 18 constituting the heat dissipating member and the slide table 16, and each heat dissipating plate. Heat transfer from the 18 to the slide table 16 is prevented by the heat insulating member 31. Furthermore, a temperature sensor 32 is provided on the slide table 16 so that when the temperature of the slide table 16 rises above a predetermined temperature, the speed of the linear motor is reduced or stopped. Other configurations are the same as those of the first embodiment.

  In the third embodiment, the heat insulating member 31 interposed between each heat radiating plate 18 and the slide table 16 can prevent heat transfer from each heat radiating plate 18 to the slide table 16. , Thermal expansion can be more reliably suppressed. In this case, since the heat insulating member 31 does not need to be deformed, the problem as in Patent Document 1 that requires deformation does not occur.

  In the configuration of the second embodiment, a heat insulating member may be interposed between the connecting piece 23 of the heat radiating plate 21 and the slide table 16.

  In the fourth embodiment of the present invention shown in FIG. 6, heat radiation fins 41 are integrally formed on each heat radiation plate 18 so as to improve heat radiation. Other configurations are the same as those of the third embodiment.

  In the configuration of the first and second embodiments, the heat radiating fins may be formed integrally with the heat radiating plates 18 and 21, respectively.

  In the fifth embodiment of the present invention shown in FIG. 7, the heat dissipating member for connecting the slide table 16 and the mover 19 is configured in a plurality of stages via the heat insulating members 51 and 52, and the heat dissipating plate 53 is provided for each stage. A predetermined number of sheets are arranged. The heat insulating members 51 and 52 are formed of a heat insulating resin or the like, and each heat radiating plate 53 is made of a nonmagnetic material (for example, copper, aluminum, silver, etc.) having a high thermal conductivity, as in the first embodiment. It is formed so as to be substantially parallel to the rail 15 at an interval and sufficiently thin as long as the connection strength between the slide table 16 and the movable element 19 can be secured. Other configurations are the same as those of the first embodiment.

  In the fifth embodiment, since a large number of heat radiating plates 53 are assembled in a plurality of stages via the heat insulating members 51 and 52, the effect of preventing heat transfer to the slide table 16 can be enhanced while improving the heat radiating performance. it can.

In the configuration example of FIG. 7, the number of assembly stages of the heat radiation plate 53 is three, but it may be assembled in two stages or four or more stages.
In addition, it goes without saying that the present invention can be implemented with various changes such as the configuration of each part of the linear motor may be appropriately changed.

It is a vertical front view of the linear motor of Example 1 of the present invention. It is a vertical side view of the linear motor of Example 1 of the present invention. It is a vertical front view for demonstrating an effect | action when the needle | mover of the linear motor of Example 1 of this invention thermally expands. It is a vertical front view of the linear motor of Example 2 of the present invention. It is a vertical front view of the linear motor of Example 3 of the present invention. It is a vertical front view of the linear motor of Example 4 of the present invention. It is a vertical front view of the linear motor of Example 5 of the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Base, 12 ... Stator, 14 ... Permanent magnet, 15 ... Rail, 16 ... Slide table (slide member), 17 ... Slide guide, 18 ... Radiation plate, 19 ... Movable element, 20 ... Electric fan, 21 ... Radiation Plate, 22, 23 ... Connecting piece, 31 ... Thermal insulation member, 41 ... Radiation fin, 51, 52 ... Thermal insulation member, 53 ... Radiation plate

Claims (5)

A linearly extending stator, a slide member slidably supported by a pair of rails extending in parallel along both sides of the stator, and coupled to the slide member via a heat radiating member to face the stator In a linear motor with a mover,
The linear motor is characterized in that the heat radiating member is composed of a plurality of heat radiating plates arranged substantially parallel to the rail.   2. The linear motor according to claim 1, wherein the plurality of heat radiation plates are integrally formed so that end portions on the movable element side and / or the slide member side are connected to each other.   The linear motor according to claim 1, wherein a heat insulating member is interposed between the plurality of heat radiation plates and the slide member.   4. The linear motor according to claim 1, wherein the heat radiating member is formed in a plurality of stages through a heat insulating member, and a predetermined number of the heat radiating plates are arranged in each stage. .   The linear motor according to claim 1, wherein the heat radiating plate is formed with heat radiating fins.

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