JP2009201307A - Double-sided pulse motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a double-sided pulse motor capable of positioning the directions of X, Y and θ. <P>SOLUTION: The double-sided pulse motor includes: a moving member frame with a moving member core having teeth with a prescribed pitch formed in X axial direction and Y axial direction on the upper face and the lower face parallel to the travelling direction; a stator frame with a pair of stator cores having teeth in X axial direction and Y axial direction, facing to the teeth formed on the upper face and the lower face of the moving member core in the X axial direction and the Y axial direction; an exciting winding arranged at least the moving member core or the stator core; and an air bearing means for forming a prescribed air gap between the moving member core and the pair of stator cores against magnetic suction force generated through excitation current supply to the exciting winding. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a double-sided pulse motor in which a stator core and a mover core are opposed to each other via an air bearing means.

  An XY stage for controlling the position of a slider (movable frame) levitated by air bearing means in a two-dimensional direction on the upper surface of a platen (stator frame) with teeth formed at a predetermined pitch, and a pulse motor used in this stage Details of the structure and the position control of the slider are disclosed in Patent Document 1.

  A mover frame having a mover core having teeth of a predetermined pitch formed on the upper and lower surfaces parallel to the traveling direction, and a pair of fixed members having teeth facing the teeth of the mover core sandwiched between the mover frames A configuration of a uniaxial double-sided pulse motor including a stator frame including a child core is disclosed in Patent Document 2.

  FIG. 4 is a longitudinal sectional view of a uniaxial double-sided pulse motor described in Patent Document 2. As shown in FIG. The mover frame 10 includes mover cores 21 and 22 in which teeth having a predetermined pitch are formed on an upper surface and a lower surface parallel to the traveling direction P. Stator frames 31 and 32 are arranged opposite to each other with the mover frame 10 interposed therebetween.

  The stator frame 31 supports the stator core 41. Similarly, the stator frame 32 supports the stator core 42. The stator core 41 is formed with teeth facing the teeth formed on the upper surface of the mover core 21. Similarly, the stator core 42 is formed with teeth that face teeth formed on the lower surface of the mover core 22.

  The stator core 41 includes an excitation winding 51 wound around the yoke. Similarly, the stator core 42 includes an excitation winding 52 wound around its yoke. In order to realize a predetermined gap between the pair of mover cores and the pair of stator cores against the magnetic attraction generated by supplying the excitation current to these excitation windings, the stator core is moved from the mover frame 10 side. Air bearing means for ejecting compressed air A is provided on both sides of 41 and 42.

  5 is a cross-sectional side view taken along the line BB in FIG. The mover cores 21 and 22 attached to the upper and lower surfaces of the mover frame 10 have the positional relationship with each other accurately in the longitudinal direction and the width direction in order to balance the magnetic attractive force.

  The upper and lower stator frames 31 and 32 are precisely aligned with each other in the longitudinal direction and the width direction via the spacer member 60 in order to balance the magnetic attractive force. If the positional relationship between the mover core and the stator core is ideal, the magnetic attraction force can be balanced at the top and bottom, so that the mover frame 10 is not deformed by the attraction force.

  The spacer member 60 is for fixing the upper and lower stator frames 31 and 32 to each other. The thickness of the spacer member 60 is set to be about 30 to 40 μm larger than the thickness of the mover frame 10 in accordance with the minute gap at the time of flying by the air bearing.

  By designing the air bearing using numerical calculation (DF method, etc.) so as to balance the magnetic attractive force, it is possible to hold a small gap of about 15-20 μm between the stator core and the mover core. it can.

  The guide member 70 is disposed in contact with the mover frame 10 and the spacer member 60 in the moving direction of the mover frame 10 (perpendicular to the paper surface), and restricts blurring in a direction perpendicular to the moving direction of the mover frame 10. is doing.

  In the double-sided pulse motor having such a configuration, in order to reduce the weight of the movable frame 10, the exciting coils 51 and 52 are provided on the stator cores 41 and 42 side, and a current is supplied to the exciting coils to thereby move the movable element. A lightweight mover frame 10 composed only of the cores 21 and 22 is moved to operate as an actuator.

  In the double-sided pulse motor with such a configuration, the thruster frame 10 is sandwiched between the stator frames 31 and 32 from above and below, so that it is possible to obtain a thrust twice that of excitation on only one side as in a general motor. it can.

JP 2000-065970 A JP 2007-267497 A

The conventional double-sided pulse motor has the following problems.
(1) Since the moving direction of the movable frame 10 is only one axis, the two-dimensional position control of XY-θ (rotation angle around the Z axis) cannot be performed unlike the XY stage of Patent Document 1.

(2) In the case of using the uniaxial movement, an auxiliary member such as the guide member 70 for restricting the shake in the direction orthogonal to the moving direction of the mover frame 10 is required.

  The present invention has been made to solve the above-described problems, and aims to realize a double-sided pulse motor that enables positioning in the X, Y, and θ directions.

In order to achieve such a problem, the invention of claim 1
A mover frame comprising a mover core in which teeth of a predetermined pitch are formed in the X-axis direction and the Y-axis direction on the upper surface and the lower surface parallel to the traveling direction;
A pair of stators having teeth in the X-axis direction and the Y-axis direction facing the teeth in the X-axis direction and the Y-axis direction formed on the upper and lower surfaces of the mover core with the mover frame interposed therebetween A stator frame with a core;
An excitation winding provided in at least one of the mover core or the stator core;
Air bearing means for forming a predetermined gap between the mover core and the pair of stator cores against a magnetic attractive force generated by supplying an excitation current to the excitation winding;
A double-sided pulse motor comprising:

The invention of claim 2 is the double-sided pulse motor according to claim 1,
The mover core is formed on an upper surface and a lower surface of the mover frame of an integral member.

Invention of Claim 3 is the double-sided pulse motor of Claim 1 or 2,
The mover frame includes independent position sensors in the X-axis direction and the Y-axis direction.

  The invention of claim 4 is the double-sided pulse motor according to any one of claims 1 to 3, wherein a plurality of the position sensors are provided at a predetermined distance in the X-axis direction or the Y-axis direction of the mover frame. The rotation angle around the Z axis of the mover frame is detected based on each detection value.

According to the configuration of the present invention, the following effects can be expected.
(1) A double-sided pulse motor capable of positioning in the X, Y, and θ directions can be realized by providing a stator core and a mover core not only in a uniaxial direction but also in a direction perpendicular thereto.

(2) If position detection sensors in the X and Y axis directions are used, it is possible to move to correct these deviations due to disturbance. For this reason, it is possible to suppress misalignment without an auxiliary member such as a guide member.

  Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a longitudinal sectional view (in the position BB in FIG. 2) showing an embodiment of a double-sided pulse motor to which the present invention is applied. 2A is a side cross-sectional view of the Y-axis, and FIG. 2B is a plan view seen from the direction of the arrows AA.

  The constitutional feature of the present invention is that in addition to the conventional stator core and mover core in the uniaxial direction (which is referred to as the Y-axis direction), the stator core and mover in the X-axis direction orthogonal thereto The core is arranged. The basic structure of each double-sided pulse motor of each axis is the same as that of the single-axis double-sided pulse motor described with reference to FIGS.

  However, the sizes, shapes, windings, and the like of the stator core and the mover core in each axial direction need not be the same in the X-axis direction and the Y-axis direction. Depending on the required stroke and thrust, it can be designed independently according to the specifications of each axis.

  In the longitudinal cross-sectional view of FIG. 1, the mover frame 100 includes mover cores 201X, 202X and Y axis for X axis in which teeth of a predetermined pitch are formed on the upper and lower surfaces parallel to the traveling direction of the X and Y axes. Mover cores 201Y and 202Y. Stator frames 301 and 302 are arranged opposite to each other with the mover frame interposed therebetween.

  The stator frame 301 supports the X-axis stator core 401X and the Y-axis stator core 401Y. Similarly, the stator frame 302 supports an X-axis stator core 402X and a Y-axis stator core 402Y.

  The X-axis stator core 401X and the Y-axis stator core 401Y include excitation windings 501X and 501Y wound around respective yokes. Similarly, the X-axis stator core 402X and the Y-axis stator core 402Y include excitation windings 502X and 502Y wound around respective yokes. By providing the excitation winding on the stator side, there is an advantage that the mover can be reduced in size and weight.

  In order to realize a predetermined gap between the pair of mover cores and the pair of stator cores against the magnetic attractive force generated by the supply of the excitation current to these excitation windings, the stator core from the mover frame 100 side is realized. Air bearing means (not shown) for jetting compressed air is provided on both sides of 401X, 401Y and 402X, 402Y.

  The upper and lower stator frames 301 and 302 are aligned with respect to each other in the longitudinal direction and the width direction with a spacer member 600 in order to balance the magnetic attractive force. If the positional relationship between the mover core and the stator core is ideal, the magnetic attraction force can be balanced at the top and bottom, so that the mover frame 100 is not deformed by the attraction force.

  The spacer member 600 is for fixing the upper and lower stator frames 301 and 302 to each other. The thickness of the spacer member 600 is set to be about 30 to 40 μm larger than the thickness of the mover frame 100 in accordance with the minute gap at the time of flying by the air bearing.

  2A is a side sectional view of the Y-axis, and FIG. 2B is a plan view seen from the arrow AA in FIG. 2A. The side sectional view of each axis is the same as that of the single-sided double-sided pulse motor shown in FIG. 4, but the mover 100 includes a Y-axis position sensor 800Y and an X-axis position sensor 800X. It is attached.

  In such a configuration, the magnetic circuit is excited by passing a current through the excitation winding of each stator core, and the mover frame 100 is controlled to move in the X-axis and Y-axis directions to operate as an XY stage. it can.

  If independent non-contact position detection sensors (laser interferometer, resolver, etc.) are used as the position sensors 800X and 800Y, highly accurate two-dimensional position control can be realized by servo operation. Thereby, position shift can be suppressed without auxiliary members, such as a guide member. However, a contact-type position sensor can be used depending on conditions. Details regarding the position servo control of the X and Y axes are disclosed in Patent Document 1.

  For example, the rotation angle θ about the Z axis of the mover frame can be detected by detecting the position of the mover frame 100 at a predetermined distance in the X axis direction at two or more locations. If a plurality of stator cores in the X-axis direction are arranged so that excitation at different phases can be performed individually, a minute positional deviation in the θ direction can be corrected based on this information. The details of the θ direction control by the two position sensors are also disclosed in Patent Document 1.

  FIG. 3 is a side sectional view showing a vertical usage pattern of a double-sided pulse motor to which the present invention is applied. In the vertical usage mode, when there is only one axis, an auxiliary mechanism such as the guide member 70 of FIG. 5 is required so that the mover frame does not fall due to gravity. However, in the double-sided pulse motor of the present invention, Since the two-axis drive is possible, the lightweight mover frame 100 can be self-held so as not to fall, and an auxiliary member is not required.

1 is a longitudinal sectional view showing an embodiment of a double-sided pulse motor to which the present invention is applied. It is the sectional side view and top view of a double-sided pulse motor to which the present invention was applied. It is a sectional side view which shows the usage type of the vertical type of the double-sided pulse motor to which this invention was applied. It is a longitudinal cross-sectional view of the double-sided pulse motor described in Patent Document 2. It is a sectional side view in the BB position of FIG.

Explanation of symbols

100 mover frame 201X, 202X X-axis mover core 201Y, 202Y Y-axis mover core 301, 302 stator frame 401X, 402X X-axis stator core 401Y, 402Y Y-axis stator core 501X, 502X X-axis excitation winding 501Y, 502Y Y-axis excitation winding 600 Spacer member 800Y Y-axis position sensor

Claims (4)

A mover frame comprising a mover core in which teeth of a predetermined pitch are formed in the X-axis direction and the Y-axis direction on the upper surface and the lower surface parallel to the traveling direction;
A pair of stators having teeth formed in the X-axis direction and the Y-axis direction so as to face the teeth in the X-axis direction and the Y-axis direction formed on the upper and lower surfaces of the mover core with the mover frame interposed therebetween. A stator frame with a core;
An excitation winding provided in at least one of the mover core or the stator core;
Air bearing means for forming a predetermined gap between the mover core and the pair of stator cores against a magnetic attractive force generated by supplying an exciting current to the exciting winding;
A double-sided pulse motor comprising:   The double-sided pulse motor according to claim 1, wherein the mover core is formed on an upper surface and a lower surface of the mover frame of an integral member.   The double-sided pulse motor according to claim 1, wherein the mover frame includes position sensors independent in the X-axis direction and the Y-axis direction.   A plurality of the position sensors are provided at a predetermined distance in the X-axis direction or the Y-axis direction of the mover frame, and detect the rotation angle around the Z-axis of the mover frame based on the respective detection values. The double-sided pulse motor according to any one of claims 1 to 3.

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