JP2505857B2 - Movable magnet type multi-phase linear motor - Google Patents

Description

TECHNICAL FIELD The present invention relates to a movable magnet type linear motor, and more particularly to a movable magnet type linear motor used as a drive mechanism for ultra-precision equipment such as semiconductor manufacturing equipment and measuring equipment.

[Prior Art] Conventionally, a multi-phase linear motor has been known. FIG. 6 shows an example of a moving coil type multi-phase linear motor, and FIG. 6 (a) shows a mover B having coils 31a to 31b.
And (b) shows a stator A incorporating a mover B. Magnets 33 to 35 are provided on the stator A so as to sandwich the coils 31a to 31b of the mover B from above and below. Further, a movable magnet type multi-phase linear motor with both-side excitation is also known. FIG. 8 shows an example of such a linear motor. In this figure, 41a to 41f are coils on the side of the stator A whose back surface is fixed and supported by a supporting member 42,
45 and 46 are magnets provided on the mover B side.

[Problems to be Solved by the Invention] However, in such a conventional example, when the cooling of the coil is considered, the following problems occur. In the example of FIG. 6, (1) it is almost impossible to provide a cooling pipe line for flowing the cooling medium in the coil bobbin which is in contact with the coils 31a to 31c, and the heat generation of the coils 31a to 31c is efficiently performed. Cannot be absorbed. This is because even if a cooling pipe is provided in the coil bobbin, if a resin is used as the material of the bobbin as in the present situation, the resin almost acts as a heat insulating material, so the cooling effect can hardly be expected, while ,
If a metal is used as the material of the bobbin, the cooling effect can be expected, but the eddy current flowing in the bobbin itself will transiently significantly reduce the thrust characteristics of the linear motor.

(2) Further, as shown in FIG. 7, when the cooling pipe 29 is provided around the coils 31a to 31c, the rigidity of the entire mover is reduced and the size of the entire linear motor is increased. This is because in such a structure, the volume and weight occupied by the mover are increased, and the resonance point of the mover is lowered.

In the example of FIG. 8, (1) it is possible to provide the cooling pipe 43 in the support member 42, but in the case of this example, the support member 42 also serves as a yoke of the magnetic circuit and is made of an iron-based material. Since the material is limited, the structure and processing for providing the cooling pipe 43 are complicated.

(2) Since the support member 42 is plate-shaped, the cooling pipe 43
By providing, the plate thickness becomes thicker by that amount, and the type of the entire linear motor increases.

(3) The transient thrust characteristic of the linear motor deteriorates due to the iron loss due to the interlinkage magnetic flux of the coil, and the power efficiency also deteriorates. Therefore, a power source with a large capacity is required.

The present invention has been made in view of such circumstances, and an object thereof is to provide a small-sized movable magnet type multi-phase linear motor that can perform cooling efficiently and without any trouble.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention fixes the mover by fixing the mover-side magnet with thrust by a plurality of stator-side coils. In a movable magnet type multi-phase linear motor that moves relative to a child, both sides of the coils arranged in a predetermined direction are fixed by rod-shaped supporting members provided along the direction, and both sides of the coil are fixed. The magnet is arranged between the support members so as to face the coil, and a pipe line for flowing a coolant is provided inside the support member along the direction. By circulating the refrigerant through this pipe, it is possible to efficiently remove heat generated by the drive current applied to the coil and prevent eddy current from being generated in the stator. Further, in the present invention, by disposing the magnet between the supporting members, the total height of the linear motor is made approximately the same as that when the cooling pipeline is not provided. In this case, it is desirable that the height of the support member from the surface of the coil facing the magnet and the thickness of the magnet are approximately the same.

In the present invention, since the movable magnet type is adopted and the mover can be configured by the magnet and the yoke unit having the box-shaped structure, the coil can be cooled without lowering the rigidity of the mover. It is possible.

[Examples] Hereinafter, the present invention will be described in detail based on examples shown in the drawings.

FIG. 1 is a diagram showing an embodiment of a movable magnet type multi-phase linear motor of the present invention. In this figure, 1a to 1f are coils on the side of the stator A, and each of the coils 1a to 1f has a substantially rectangular shape. It is wound around a coil bobbin and arranged by the support member 2 along the Y-axis direction. The support member 2 is made of a non-magnetic material, for example, an aluminum-based material, and has a rod shape. As shown in FIG. 3, each of the support members 2 is formed with a figure hole 21 into which the side portion of the coil 1a to 1f is inserted, and the coil 1a to 1f has both side portions in the X direction. Each corresponding figure hole
After being inserted into 21, it is fixed with an adhesive. Further, as shown in FIG. 2, each of the support members 2 has a cooling pipe line 22 for flowing a cooling medium such as chlorofluorocarbon or water.
It is provided so as to penetrate along the direction. Two cooling pipes 22 are provided in each of the support members 2 so as to pass through the coil 1 inserted in the figure hole 21 above and below (Z direction).

The guide 3 provided on the support member 2 includes coils 1a to 1f.
The lead wires from each of the above are guided to the connector 7 fixed to the end portion of the support member 2 to enable connection between the two. The connectors 4 and 5 for piping are fixed to each end of the support member 2 in order to connect the cooling conduit 22 of the support member 2 and the pipes 8 and 9 for cooling guide. The pipes 8 and 9 are each made of a flexible material. Each of the pipes 8 and 9 is connected to the connectors 4 and 5 via the nipple 6. Attachments 10 for attaching the stator A to a base (not shown) are fixed to respective ends of the support member 2 and hold the two support members 2 in the illustrated state.

The mover B includes an upper yoke 13 having magnets 11a to 11d and a magnet.
The upper and lower yokes 14 having 12a to 12d are connected by a side plate 15 to form a box shape. Magnets 11a-11d and magnet 12a
.About.12d are arranged so that the magnets facing each other have different polarities. In addition, the polarities are different between the adjacent magnets in the Y direction. The yokes 13 and 14 are made of an iron material, and the side plate 15 is made of a non-magnetic material. The mover B is assembled to the stator A as shown in FIG. At this time, the magnets 11 and 12 are located between the support members 2 in the X direction. Further, in this embodiment, in order to enable such a structure, the height (Z direction) T1 of the support member 2 from the magnet facing surface of the coil 1 and the thickness T2 of the magnets 11 and 12 are set.
Are almost equal.

When a current is supplied to the coils 1a to 1f from a power source (not shown) through the connector 7, the mover B moves in the Y direction with respect to the stator A. As is well known, the drive sequence at this time is
A relative position of the mover B with respect to the stator A is detected by a position detector (not shown), for example, a side length device using a laser interferometer, and one of the coils 1a to 1f is selected according to the detected value. It is controlled by passing a current in a direction determined according to the value. Due to this current, the magnets 11 and 12 receive thrust in a predetermined direction and are driven in the Y direction. At this time, coil 1a ~
The Joule heat generated from 1f is transferred to the refrigerant flowing through the pipe 22 inside the support member 2 by heat conduction, and is carried away to the outside of the linear motor by this refrigerant. The refrigerant is constantly supplied from a supply source (not shown).

[Other Embodiments] FIG. 4 shows another embodiment of the present invention.
Both side portions of 1f are held and fixed by two supporting members 2a and 2b, respectively. The support members 2a, 2b are hollow and are made of extruded aluminum to form a conduit.
In this embodiment, the coils 1a to 1f are composed of two supporting members 2a and 2b.
By grasping, it is not necessary to machine the figure hole 21 as in the previous embodiment.

Further, FIG. 5 shows still another embodiment of the present invention, in which each of the supporting members 2 is composed of three bent pipes of aluminum or copper. In this embodiment, like the embodiment shown in FIG. 4, it is not necessary to machine the figure hole 21, and the cooling pipes 8 and 9 can be installed on only one side.

[Effect of the Invention] As described above, according to the present invention, in the movable magnet type multi-phase linear motor, the heat generated from the coil can be efficiently cooled. Further, in this case, the thrust characteristics of the linear motor are not hindered. Further, there is an effect that the overall height of the linear motor can be reduced and the structure of the coil unit can be simplified.

[Brief description of drawings]

FIG. 1 is a view showing an embodiment of a movable magnet type multi-phase linear motor of the present invention, FIG. 2 is a view showing a cross section of the embodiment of FIG. 1, and FIG. 3 is a fixing of the embodiment of FIG. FIG. 4 is a diagram showing a child in detail, FIGS. 4 and 5 are diagrams showing other embodiments of the present invention, and FIGS. 6, 7 and 8 are diagrams showing conventional examples. 1 (a to f) ... coil, 2 ... support member, 11, 12 (a
~ F) ... Magnet, 21 ... Figure hole, 22 ... Cooling conduit, A ...
Stator, B ... Movable element

Claims (2)

(57) [Claims] 1. A movable magnet type multi-phase linear motor that moves the mover relative to the stator by applying thrust to a magnet on the mover side by a plurality of coils on the side of the stator, and arranged in a predetermined direction. The two sides of the coil are fixed by rod-shaped support members provided along the direction, and the magnets are arranged so as to face the coil between the support members that fix each side of the coil, A movable magnet type multi-phase linear motor characterized in that a pipeline for flowing a refrigerant is provided inside the support member along the direction. 2. The movable magnet type multi-phase linear motor according to claim 1, wherein the support member is made of a non-magnetic material.