JP4533525B2 - Drive unit with linear motor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a driving device using a linear motor that moves a moving body with respect to a fixed body using a linear motor.
[0002]
[Prior art]
This conventional apparatus will be described with reference to FIG. 3. A table 1 as a moving body has a concave cross-sectional shape in a direction perpendicular to the moving direction of the table 1 (perpendicular to the plane of the drawing). The guides 2 and 3 are held in a base 4 which is a fixed body having guides 2 and 3 projecting in the directions, respectively, and are attached movably in a straddling state. A coil attachment member 5 is fixed to a lower center portion of the table 1, and a cooling jacket 6 and a coil 7 for a linear motor are attached.
[0003]
Permanent magnets 8 are attached to both concave inner wall portions A of the base 4 so as to face the coil 7, and a linear motor 9 for moving the table 1 is formed. Further, a moving position sensing device 12 including a scale 10 and a reading sensor 11 for sensing the moving position of the table 1 is provided between any one of the concave outer wall portions B and the table 1.
[0004]
As shown in FIG. 4 (only the guide 2 will be described), the pressure fluid of the hydrostatic bearing acts on the guides 2 and 3 provided on the base 4 from the directions of arrows a, b and c. The table 1 can be moved smoothly by eliminating the friction between the two.
[0005]
[Problems to be solved by the invention]
However, since the concave base 4 has the linear motor 9 inside, the dimension W in the width direction of the base 4 becomes large. As a result, the width of the table 1 also becomes large, and the size is increased to a medium-sized or larger mechanical structure. It is expensive and the installation area of the machine becomes large, making it unsuitable for small machine structures.
Further, as shown in FIG. 4, when the pressure fluid of the hydrostatic bearing from the directions of arrows b and c acts on the guide 2, the portion of the table 1 that encloses the guide 2 is deformed as indicated by a chain line, and the guide 2 There is a drawback in that it causes galling due to contact with the guide surface or affects the accuracy of the moving position sensing device 12 mounted between the outer surface of the base 4 and the moving body.
[0006]
The object of the present invention is that the conventional fixed body has a large base and is not suitable for a small mechanical structure, and the pressure fluid of the hydrostatic bearing from the directions of arrows b and c acts on the guide. When removing the drawback of affecting the accuracy of the moving position sensing device, reducing the size of the stationary body in the width direction, making the stationary body smaller, and the hydrostatic bearing from the direction of arrows b and c on the guide. It is an object of the present invention to provide a driving device using a linear motor that does not affect the accuracy of a moving position sensing device even when a pressure fluid is applied.
[0007]
[Means for Solving the Problems]
In order to achieve the above-described object, the present invention provides a linear motor driving device that provides a linear motor between a fixed body and a moving body, and moves the moving body using a linear motor. A substantially T-shaped fixed body having a central member whose cross-sectional shape extends in the vertical direction, and a pair of guides protruding in the left and right lateral directions at the upper portion of the side surface of the central member, and a state straddling the upper portion of the fixed body And a pair of mounting plates at positions opposite to the side surfaces of the central member of the fixed body, respectively, while moving along the pair of guides and projecting downward at both ends perpendicular to the moving direction. And a permanent magnet for a linear motor attached to both sides of the central member of the fixed body, and a permanent magnet for each permanent magnet on both sides. And a moving position sensing device for sensing the position of the moving body. .
[0008]
The fixed body guide is a linear motor in which the hydrostatic bearing pressure fluid from the moving body is applied and the moving body is provided with a cooling jacket for cooling the coil for driving. A driving device was used.
[0009]
As a result, the conventional fixed body becomes large and unsuitable for a small mechanical structure, and the moving position is detected even if the hydrostatic bearing pressure fluid from the directions of arrows b and c acts on the guide. The accuracy of the device is no longer affected.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to FIG.
The fixed body 20 includes a central member 21 whose cross-sectional shape perpendicular to the moving direction of the moving body extends in the vertical direction, and guides 22 and 23 projecting laterally on the two side surfaces C of the central member 21 respectively. It has a substantially T-shape. The moving body 24 straddles the upper part of the fixed body 20 and moves along the guides 22 and 23 in a state of embracing the guides 22 and 23, and protrudes downward at both ends in a direction perpendicular to the moving direction. A pair of mounting plates 25 and 26 facing the side surface C of the central member 21 of the fixed body 20 are provided.
[0011]
The mounting plates 25 and 26 are each provided with a coil 28 via a cooling jacket 27 on a surface facing the side surface C of the central member 21 of the fixed body 20 and fixed by a permanent magnet 29 attached to the side surface C of the central member 21. A linear motor 30 is formed between the body 20 and the mounting plates 25 and 26, that is, the moving body 24. The pressure fluid of the hydrostatic bearing acts on the guides 22 and 23 from the directions of arrows a, b and c, respectively.
In addition, a sensor 31 for sensing the position of the moving body 24 is provided immediately below the moving body 24 in the center of the fixed body 20, and a scale 32 is provided on the upper part of the central member 21 facing the sensor 31, thereby moving position sensing device 33. Is configured.
[0012]
The present invention is configured as described above, and by attaching a linear motor to the outer surface of the fixed body, the conventional linear motor is inside the fixed body and the width of the fixed body is increased. As shown in FIG. 2, since the pressure fluid of the hydrostatic bearing from the direction of arrows b and c acts, the member that holds the guide of the moving body is deformed, and the permanent magnet and coil of the linear motor are removed. It can be offset or decreased as shown by arrow D by the suction force of.
In addition, a sensor for detecting the position of the moving body is provided directly below the central portion of the moving body, so that there is little influence from the outside, and it is compact. In addition, since the linear motor is provided outside the fixed body, not only maintenance is easy, but also the cooling effect is increased because the coil cooling jacket can be enlarged.
[0013]
【The invention's effect】
As described above, in the present invention, the base which is a conventional fixed body is large, and is not suitable for a small mechanical structure, and the pressure fluid of the hydrostatic bearing from the directions of arrows b and c to the guide. The effect of affecting the accuracy of the moving position sensing device is removed, and the dimension of the fixed body in the width direction is reduced, the fixed body is reduced in size, and the guide from the directions of arrows b and c is removed. It has become possible to provide a linear motor driving device that does not affect the accuracy of the moving position sensing device even when the pressure fluid of the hydrostatic bearing is applied.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a driving apparatus using a linear motor according to an embodiment of the present invention.
FIG. 2 is a diagram of a linear motor driving apparatus showing an embodiment of the present invention, in which a guide is used to cancel or reduce deformation of a moving body due to pressure fluid of a hydrostatic bearing from the directions of arrows b and c. It is explanatory drawing.
FIG. 3 is an explanatory diagram of a conventional linear motor driving device.
FIG. 4 is a diagram of a conventional linear motor driving device, and is a diagram illustrating deformation of a moving body due to pressure fluid of a hydrostatic bearing from the directions of arrows b and c on a guide.
[Explanation of symbols]
20 fixed body 21 central member 22, 23 guide 24 moving body 25, 26 mounting plate 27 cooling jacket 28 coil 29 permanent magnet 30 linear motor 31 sensor 32 scale 33 moving position sensing device

Claims (2)

In a linear motor driving device that provides a linear motor between a fixed body and a moving body and moves the moving body by a linear motor,
Central member perpendicular sectional shape extending longitudinally with respect to the moving direction of the moving body, and fixing a substantially T-shaped having a pair of guides, projecting both laterally left and right in the upper portion of the side surface of the central member Body,
With moving along the pair of guide in a state of straddling the upper part of the fixed body, projecting downward at both ends of a direction perpendicular to the moving direction, and at a position opposite to the side surface of the central member of the fixed body A moving body having a pair of mounting plates;
A permanent magnet for a linear motor attached to both side surfaces of the central member of the fixed body;
A coil for constituting a linear motor together with the permanent magnets provided to face the permanent magnets on both side surfaces,
A moving position sensing device installed at the center of the fixed body and the center of the moving body, for sensing the position of the moving body;
A drive device using a linear motor. A pressure fluid of a hydrostatic bearing from the moving body acts on the guide of the fixed body , and
The moving body is provided with a cooling jacket for cooling the coil for driving,
The linear motor driving apparatus according to claim 1.

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