US20080064543A1 - Three axis drive apparatus - Google Patents

Abstract

A pulley drive mechanism26 for driving a second pulley23 includes: a spline shaft27 rotated integrally with the second pulley23, for supporting the second pulley so that the second pulley can be moved in the direction of Y-axis in the drawing; a third pulley28 arranged at one end portion of the spline shaft27; and a third belt drive mechanism29 for driving the spline shaft27 through the third pulley28.

Description

BACKGROUND OF THE INVENTION
• 1. Field of the Invention
• The present invention relates to a three axis drive apparatus used for an automatic analyzer, an electronic parts mounting device, various processing machines and a conveying device.
• 2. Description of Related Art
• As an example, in an automatic analyzer for analyzing a specimen of blood or urine which has been collected into a reaction container such as a well plate, it is necessary to conduct positioning by moving a distribution nozzle, which distributes liquid such as chemical into a reaction container, in three directions of X-axis, Y-axis and Z-axis.
• Conventionally a positioning device which determines position of the distribution nozzle in the three directions of X-axis, Y-axis and Z-axis has an X-direction positioning mechanism for positioning in X-axis direction, a Y-direction positioning mechanism for positioning in Y-axis direction and a Z-direction positioning mechanism for positioning in Z-axis direction. The distribution nozzle is positioned at a predetermined position by operating these positioning mechanisms.
• However, in the conventional device, a positioning mechanism for moving the distribution nozzle in the three axial directions is formed out of a combination of a linear guide with a ball screw. Therefore, at least two drive motors in the three drive motors for driving the ball screws are moved integrally with the distribution nozzle. Therefore, when the distribution nozzle is moved in the three axial directions, a Cable Bear (registered trademark in Japan) for protecting an electric power cable connected to the drive motor is dragged. Therefore, noise and dust are generated. Since at least two drive motors in the three drive motors are mounted on a movable portion of the mechanism portion, a weight of the movable portion is increased and it is difficult to move a member to be driven such as a distribution nozzle in the three axial directions at high speed.
SUMMARY OF THE INVENTION
• The present invention has been accomplished to solve the above problems. An object of the present invention is to provide a three axis drive apparatus capable of suppressing a generation of noise and dust from the Cable Bear.
• In order to accomplish the above object, according to a first aspect of the invention, there is provided a three axis drive apparatus (1) for driving a driven member in first (X-direction), second (Y-direction) and third (Z-direction) directions perpendicular to each other, comprising:
• a base (2,101) comprising a first support portion (50,60,105) fixed thereon;
• a first guide mechanism comprising:
• • a first guide member (4,36,121a) supported by the first support portion; and
  • a first slider (5,121b,121c) guided by the first guide member in the first direction;
• a second guide mechanism comprising:
• • a second guide member (3a,131a) extending in the second direction from the first slider; and
  • a second slider (3b,131b) guided by the second guide member in the second direction;
• a third guide mechanism that is provided on the second slider and guides the driven member to the third direction;
• a first belt drive mechanism comprising:
• • a first slider drive transmission belt (8,107) that slides the first slider; and
  • a first motor (11,113) that drives the first slider drive transmission belt through a plurality of first pulleys (9,10,108a,108b);
• a second belt drive mechanism comprising:
• • a second slider drive transmission belt (14,109) that slides the second slider; and
  • a second motor (20,114) that drives the second slider drive transmission belt through a plurality of second pulleys (15,16,17,18,19,110a,110b,110c,110d,110e); and
• a driven member drive mechanism comprising:
• • at least one of driven member drive transmission belt (25,30,111) that slides the driven member; and
  • a third motor (35,115) that drives the driven member in the third direction through a plurality of driven member pulleys (22,23,28,31,32,33,34,112a,112b,112c,112d112e,112f,112h,112g),
• wherein the first pulleys, at least one of the second pulleys, at least one of the driven member pulleys, the first motor, the second motor and the third motor are fixed on the first support portion.
• According to a second aspect of the invention, as set forth in the first aspect of the invention, it is preferable that the second belt drive mechanism further comprises three second pulleys that are supported on the first slider and draws a part of the second belt along with second direction.
• According to a third aspect of the invention, as set forth in the first aspect of the invention, it is preferable that the third drive mechanism further comprises:
• a spline shaft that is supported on the first slider so as to extend in the second direction and is rotated by at least one of the third transmission belt;
• a pair of third pulleys that is rotatably driven by the spline shaft and provided so as to be movable in an axial direction of the spline shaft;
• a secondary driven member drive transmission belt that moves the driven member in the third direction by the pair of the third pulleys.
• According to a fourth aspect of the invention, as set forth in the first aspect of the invention, it is preferable that the driven member drive mechanism comprises:
• a feed screw shaft supported on the second slider so as to extend in the third direction and rotatably driven by the driven member drive transmission belt;
• a nut that is connected to the driven member, is screwed to the feed screw shaft and is moved in the third direction by rotation of the feed screw shaft.
• According to a fifth aspect of the invention, as set forth in the fourth aspect of the invention, it is preferable that the driven member drive mechanism comprises:
• a second direction drawing pulley that is supported on the first slider and draws a part of the second slider drive transmission belt in the second direction;
• three first direction drawing pulleys that are supported on the second slider and draw a part of the second slider drive transmission belt in the second direction which is drawn in the second direction by the second direction drawing pulley,
• wherein one of the first direction drawing pulley, which is engaged with an end part of the second slider drive transmission belt drawn in the first direction, is fixed on the feed screw shaft.
• According to a sixth aspect of the invention, as set forth in the fourth aspect of the invention, it is preferable that the driven member drive mechanism comprises:
• a third slider comprising a nut portion screwed on the feed screw shaft,
• a slider support member that supports the third slider so as to be movable in an axial direction of the feed screw shaft.
• According to a seventh aspect of the invention, as set forth in the first aspect of the invention, it is preferable that the third guide mechanism comprising:
• a screw shaft (143) rotated by the driven member drive transmission belt;
• a movable body (146) engaged with the screw shaft directly or indirectly;
• a guide rail (147) that is provided so as to be parallel to the screw shaft and guides the movable body in a longitudinal direction of the guide rail;
• wherein the movable body is driven by the screw shaft and guided by the guide rail.
• According to the invention, since the first pulleys, at least one of the second pulleys, at least one of the driven member pulleys, the first motor, the second motor and the third motor are fixed on the first support portion, when moving the driven member in one of the three directions, there are not any fears that Cable Bear is dragged. Accordingly, there are no fears that the noise or the dust is generated.
• Furthermore, the first motor, second motor and third motor are mounted on the first support portion, the second guide mechanism or the driven member drive mechanism can be lightweight, thus, the driven member can be moved quickly.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a perspective view showing an outline of the structure of the three axis drive apparatus of the first embodiment of the present invention;
• FIG. 2 is a sectional view showing a portion of the three axis drive apparatus shown inFIG. 1;
• FIG. 3 is a perspective view showing an outline of the structure of the three axis drive apparatus of the second embodiment of the present invention;
• FIG. 4 is a perspective view showing an outline of the structure of the three axis drive unit of the third embodiment of the present invention;
• FIG. 5 is a plan view showing the three axis drive unit of the third embodiment of the present invention;
• FIG. 6 is a front view showing the three axis drive unit of the third embodiment of the present invention;
• FIG. 7 is a rear view showing the three axis drive unit of the third embodiment of the present invention;
• FIG. 8 is a sectional view taken on line VIII-VIII inFIG. 5;
• FIG. 9 is a sectional view taken on line IX-IX inFIG. 5; and
• FIG. 10 is a perspective view showing an outline of the structure of the three axis drive unit of the fourth embodiment of the present invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTION EMBODIMENTSFirst Embodiment
• Referring to the drawings, an embodiment of the present invention will be explained below.
• FIG. 1 is a view showing an overall arrangement of the three axis drive apparatus of the first embodiment of the present invention.
• As shown in the drawing, the threeaxis drive apparatus1 of the first embodiment of the present invention is provided with a plate-shapedbase2. On thebase2, anX-direction support portion50 is provided. TheX-direction support portion50 is provided with twocolumns50a,50band twobeams50c50d, of which ends are fixed to thecolumns50a,50b. Twobeams50c,50dsupports twoguide rods4. Above this plate-shapedbase2, alinear guide3 is provided as a second guide mechanism. Thislinear guide3 is used for moving a drivenmember24 in the second axial direction (the direction of Y-axis) perpendicular to the first axial direction (the direction of X-axis). Thisguide rail3aof thelinear guide3 is fixed to theguide rail support5 so that an extending direction of theguide rail3acan be laid along the direction of Y-axis (the second axial direction) in the drawing.
• The X-axis slider (first slider)5 includes: a pair ofblocks5arespectively internally engaged with a substantially cylindrical bearing (not shown) guided by two guide rods (first guide member)4 arranged above thebase2; aplate5bprovided between the pair ofblocks5a; and arail support member5cfixed to theplate5b. Theguide rail3ais fixed to therail support member5c.
• The first guide mechanism includes: a pair ofguide rods4; and at least one bearing (not shown). Due to the above structure, the guide rail support5 (Y-direction support portion) is supported so as to be moved in the direction of X-axis (the first axial direction). Theguide rail support5 and others compose the first movable portion.
• Theguide rail3aof the linear guide (second guide member)3 is driven in the direction of X-axis in the drawing by the firstbelt drive mechanism6 through theguide rail support5.
• This firstbelt drive mechanism6 includes: abelt attaching member7 attached to theguide rail support5, composing the first movable portion; a timing belt8 (a first slider drive transmission belt) for driving theguide rail support5 through thebelt attaching member7 in the direction of X-axis in the drawing; and a motor11 (first motor) for driving thistiming belt8 through thepulleys9,10.
• On the other hand, a slider (second slider)3bof thelinear guide3 is driven in the direction of Y-axis in the drawing by the secondbelt drive mechanism12.
• This secondbelt drive mechanism12 includes: abelt attaching member13 attached to theslider3bof thelinear guide3; atiming belt14, which is a transmission belt, for driving theslider3bthrough the attachingmember13 in the direction of Y-axis in the drawing; and a motor20 (second motor) for driving thistiming belt14 throughpulleys15,16,17,18,19.
• The threeaxis drive apparatus1 of the first embodiment includes: afirst pulley22 pivotally supported by theslider3bof thelinear guide3 through thebracket21 composing the second movable portion together with thebelt attaching member13; asecond pulley23 arranged in parallel with thefirst pulley22; atiming belt25 which is a transmission belt for driving a drivenmember24 in the third axial direction (the direction of Z-axis) perpendicular to the first and the second axial direction in cooperation with thesepulleys22,23; and a pulley drive mechanism26 (shown inFIG. 1) for driving thesecond pulley23.
• In this case, thepulley drive mechanism26 includes: aspline shaft27 rotated together with thesecond pulley23, for supporting thesecond pulley23 so that thesecond pulley23 can be moved in the direction of Y-axis in the drawing; athird pulley28 arranged at one end portion of thisspline shaft27; and a thirdbelt drive mechanism29 for driving thespline shaft27 through thethird pulley28. The thirdbelt drive mechanism29 includes: atiming belt30 which is a transmission belt for driving thethird pulley28; and amotor35 for driving thistiming belt30 through thepulleys31,32,33,34.
• In this structure, when themotor35 of the thirdbelt drive mechanism29 is driven, thesecond pulley23 is rotated integrally with thespline shaft27. When themotor20 of the secondbelt drive mechanism12 is driven, thesecond pulley23 is moved in the axial direction of thespline shaft27 integrally with theslider3b.
• Accordingly, in the first embodiment described above, thepulley drive mechanism26 for driving thesecond pulley23 includes: aspline shaft27 rotated integrally with thesecond pulley23, for supporting thesecond pulley23 so that thesecond pulley23 can be moved in the direction of Y-axis (the second axial direction); athird pulley28 arranged at one end portion of thespline shaft27; and a thirdbelt drive mechanism29 for driving thespline shaft27 through thethird pulley28.
• Due to the above structure, thesecond pulley23 can be rotated under the condition that the thirdbelt drive mechanism29 is fixed at a predetermined position. Accordingly, it is unnecessary to mount thepulley drive mechanism26, which drives thesecond pulley23, on theslider3bof thelinear guide3. Further, a weight of the device can be reduced.
Second Embodiment
• In this connection, it should be noted that the present invention is not limited to the above specific embodiment. For example, in the first embodiment described above, the first guide mechanism for supporting the guide rail support (the first movable portion)5 for supporting theguide rail3aof the linear guide is supported by the twoguide rods4 and the cylindrical bearing.
• However, as shown in a second embodiment illustrated inFIG. 3, it is possible that theguide rail support5 also uses a linear guide and is supported by theguide rail36 different from theguide rail3aof thelinear guide3. AnX-direction support portion60 is provided on thebase2. The X-direction support portion is provided withcolumns60a,60bandbeam60csupported by thecolumns60a,60b. Aguide rail36 is provided on thebeam60c. Further, it is possible that the bearing to support the driven member is replaced with a substantially cylindrical bearing.
• In the same manner, the second guide mechanism is not limited to the above guide mechanism, instead of thelinear guide3, for example, it is possible to employ a combination of the guide rod with the substantially cylindrical bearing. In any case, the guide mechanism is not limited to a rolling bearing but it is possible to use a sliding bearing. Alternatively, it is possible to use a non-contact type guide such as a static pressure guide.
Third Embodiment
• Referring toFIGS. 4 to 10, a third embodiment of the present invention will be explained below.
• FIG. 4 is a perspective view showing an outline of the structure of the three axis drive unit of the third embodiment of the present invention,FIG. 5 is a plan view showing the three axis drive unit of the third embodiment,FIG. 6 is a front view showing the three axis drive unit of the third embodiment,FIG. 7 is a rear view showing the three axis drive unit of the third embodiment,FIG. 8 is a sectional view taken on line VIII-VIII inFIG. 5, andFIG. 9 is a sectional view taken on line IX-IX inFIG. 5. The three axis drive unit of the third embodiment includes: a base101, afirst guide mechanism102, asecond guide mechanism103 and a Z-direction positioning mechanism104.
• The first guide mechanism, which will be referred to as “an X-direction linear guide” hereinafter, includes: aguide rail121awhich is an X-direction guide member horizontally supported bysupport columns105a,105b, which are vertically arranged on an upper face portion of thebase101, and also supported by abeam member105c, both end portions of which are fixed to upper end portions of both supportcolumns105a,105b; and X-axis sliders (bearing blocks)121b,121c(shown inFIG. 6) guided by theguide rail121ain the direction of X-axis. Thesupport columns105a,105band thebeam member105ccompose an X-direction support portion105 (shown inFIG. 6). To upper face portions of theX-axis sliders121b,121c, abase end portion122aof theX-axis plate122 described later is fixed. To abase end portion122aof theX-axis plate122, an X-axis belt attaching portion123 (shown inFIGS. 5 and 9) is fixed. To an X-axisbelt attaching member123, atiming belt107, which is a first slider drive transmission belt, is fixed. Due to the above structure, theX-axis sliders121b,121care driven and slid by thetiming belt107.
• Thetiming belt107 has an inner circumferential face on which teeth are formed being meshed with teeth provided on outer circumferential faces ofpulleys108a,108b(shown inFIG. 7) described later.
• TheX-axis plate122 includes an extendingportion122b(shown inFIGS. 4 and 5) which extends from thebase end portion122ain the Y-direction. On a side of this extendingportion122blaid along the direction of Y-axis, a plate-shaped Y-axis rail support member124 (shown inFIGS. 5 and 8) is fixed. TheX-axis plate122 and the Y-axisrail support member124 compose a Y-axis support portion125 (shown inFIG. 8).
• Thesecond guide mechanism103, which will be referred to as “a Y-direction linear guide” hereinafter, includes: aguide rail131awhich is a Y-direction guide member fixed onto a side of the Y-axisrail support member124; and a Y-axis slider131bguided by the guide rail131 in the direction of Y-axis. A Y-axis plate132 described later is fixed to the Y-axis slider131b. Further, a Y-axisbelt attaching member133 is fixed onto the Y-axis plate132. Atiming belt109, which is a second slider drive transmission belt, is fixed to the Y-axisbelt attaching member133. Due to the above structure, the Y-axis slider131bis driven and slid by thetiming belt109.
• Thetiming belt109 has an inner circumferential face on which teeth are formed being meshed with teeth provided on outer circumferential faces ofpulleys110a,110c,110e(shown inFIG. 5) described later.
• The Z-axis positioning mechanism104 includes: feed screwshaft support members141,142 (shown inFIG. 6) fixed to the Y-axis plate132; and afeed screw shaft143 perpendicularly, pivotally supported by the feed screwshaft support members141,142. Thefeed screw shaft143 is driven and rotated by the timing belt111 (the feed screw shaft drive transmission belt) throughpulleys112a,112b,112c,112d,112e,112f,112g,112h(shown inFIG. 5, thepulley112eis shown inFIG. 6) described later. On an inner circumferential face of thetiming belt111, teeth are provided which are meshed with the teeth provided on outer circumferential faces of thepulleys112a,112b,112e,112g. The Z-direction positioning mechanism104 includes: anut144 screwed to thefeed screw shaft143; and a nutsupport mechanism portion145 for supporting thenut144 so that thenut144 can be moved in the axial direction of thefeed screw shaft143.
• Further, the nutsupport mechanism portion145 of the Z-direction positioning mechanism104 includes: a guide rod support plate451 (shown inFIG. 6) fixed to thenut144; aguide rod452 perpendicularly supported by the guiderod support plate451; and guidesleeves453,454 for guiding theguide rod452 in the direction of Z-axis. These guidesleeves453,454 are fixed to the feed screwshaft support members141,142. An object to be positioned, which is theguide rod452 itself, or an object fixed to a portion of theguide rod452 such as a foreword end of the guide rod moved together with the guide rod, corresponds to a member to be driven.
• The sliderdrive timing belt107 is driven by thedrive motor113 through thepulleys108a,108b. The sliderdrive timing belt109 is driven by thedrive motor114 through thepulleys110a,110b,110c,110d,110e. The feed screwdrive timing belt111 is driven by thedrive motor115 through thepulleys112a,112b,112c,112d,112e,112f,112g,112h. Thedrive motor113, which is one of thesedrive motors113,114,115, is fixed to thesupport column105aso that a rotary shaft of thedrive motor113 can be horizontally supported. Thedrive motors114,115 are fixed to thesupport column105bso that rotary shafts of thedrive motors114,115 can be perpendicularly supported.
• Thepulleys108a,108bare timing pulleys (pulleys having teeth). Thepulley108afunctioning as a drive pulley is fixed to the rotary shaft of thedrive motor113. Thepulley108bfunctioning as an idle pulley is attached to thesupport column105bso that a pulley shaft of thepulley108bcan be set horizontally with respect to thebase101.
• Thepulleys110a,110c,110eare timing pulleys (pulleys having teeth). Thepulley110a, which is one of thesepulleys110a,110c,110e, is fixed to a rotary shaft of thedrive motor114 and functions as a drive pulley. Thepulley110cis arranged at a foreword end portion of the extendingportion122bof theX-axis plate122 so that a pulley shaft of thepulley110ccan be perpendicular to thebase101. Thepulley110eis attached to thesupport column105aso that a pulley shaft of thepulley110ecan be perpendicular to thebase101.
• Thepulleys110b,110dare pulleys having no teeth. Thesepulleys110b,110dare arranged in abase end portion122aof theX-axis plate122 so that pulley shafts of thepulleys110b,110dcan be perpendicular to thebase101.
• Thepulleys112a,112b,112e,112gare timing pulleys (pulleys having teeth). Thepulley112a, which is one of thesepulleys112a,112b,112e,112g, is fixed to a rotary shaft of thedrive motor115 and functions as a drive pulley. Thepulley112bis attached to thesupport column105aso that a pulley shaft of thepulley112bcan be perpendicular to thebase101. Thepulley112eis arranged on thefeed screw shaft143. Thepulley112gis attached to apulley support member122c, which is arranged in an upper face foreword end portion of the extendingportion122bof theX-axis plate122, so that a pulley shaft of thepulley112gcan be perpendicular to thebase101.
• Thepulleys112c,112d,112f,112hare pulleys having no teeth. Thepulleys112d,112fin thesepulleys112c,112d,112f,112hare attached to the Y-axis plate132 so that pulley shafts of thepulleys112d,112fcan be perpendicular to thebase101.
• A lower end portion of the pulley support member126 (shown inFIG. 9) is fixed onto an upper face portion of thebase end portion122aof theX-axis plate122. Thepulley support member126 has ahorizontal plate portion126a(shown inFIGS. 4 and 9) which is located above the X-axisbelt attaching member123. In an upper face portion of thishorizontal plate portion126a, pulley shafts of thepulleys112c,112hare perpendicularly arranged.
• In the above structure, for example, when thedrive motors113,114,115 are synchronously driven so as to make therespective timing belts107,109,111 run in a predetermined direction, the member to be driven is moved in the direction of X-axis in the drawing. When thedrive motors114,115 are synchronously driven so as to make therespective timing belts109,111 run in a predetermined direction, the member to be driven is moved in the direction of Y-axis in the drawing. When thedrive motor115 is driven so as to make thetiming belt111 run, the member to be driven is moved in the direction of Z-axis in the drawing.
• Accordingly, since thedrive motors113,114,115, which are used as a mechanism portion to move the member to be driven in three axial directions of X-axis, Y-axis and Z-axis, are respectively fixed to any of thesupport columns105aand105bwhich are not moved, it is unnecessary to provide the Cable Bear. Therefore, at the time of moving the member to be driven in three axial directions, no Cable Bear is dragged. Accordingly, it is possible to suppress generations of noise and dust.
• It is unnecessary to mount a drive motor on theslider131bof the Y-directionlinear guide103 or the Z-direction positioning mechanism104. Therefore, a weight of the Y-directionlinear guide103 or the Z-direction positioning mechanism104 can be reduced. Due to the reduction of the weight, the member be driven can be moved in the three axial directions at high speed. Accordingly, it is possible to reduce the time necessary for positioning.
• Further, since the Z-direction positioning mechanism104 having thefeed screw143 is used for positioning the member to be positioned in the Z-direction, no pulley is rotated by an inertial force when thedrive motor114 is stopped, which is unlike the structure in which the Z-direction positioning mechanism104 is provided with a pulley and a timing belt. Accordingly, it is unnecessary to separately provide a brake mechanism.
• In the third embodiment described above, the X-direction guide member of the X-directionlinear guide102 and the Y-direction guide member of the Y-directionlinear guide103 are respectively formed out of a guide rail. However, instead of the guide rail, it is possible to use a guide rod.
• In the third embodiment, thedrive motor113 for driving the sliderdrive timing belt107 is fixed to thesupport column105a. However, thedrive motor113 may be fixed to thesupport column105b. Further, thedrive motor114 for driving the sliderdrive timing belt109 is fixed to thesupport column105b. However, thedrive motor114 may be fixed to thesupport column105a. Furthermore, thedrive motor115 for driving the feed screw shaftdrive timing belt111 is fixed to thesupport column105b. However, thedrive motor115 may be fixed to thesupport column105a.
Fourth Embodiment
• In the third embodiment described above, the Z-direction positioning mechanism includes: afeed screw shaft143 perpendicularly supported by the Y-axis plate132; anut144 screwed to thefeed screw shaft143; and a nutsupport mechanism portion145 for supporting thenut144 so that thenut144 can be moved in the axial direction of thescrew shaft143.
• However, as shown in a fourth embodiment shown inFIG. 10, the Z-direction positioning mechanism104 may includes: afeed screw shaft143 perpendicularly supported by the Y-axis plate132; a Z-direction slider (movable body)146 having a nut portion (not shown) screwed to thisfeed screw shaft143; and a slider support body (guide rail)147 for supporting the Z-direction slider146 so that the Z-direction slider146 can be moved in the Z-axis direction. In this case, the Z-direction slider146 or the object to be positioned, which is fixed to the Z-direction slider146, is a member to be driven.
• In this embodiment, rolling elements, such as balls or rollers (not shown) are disposed between thefeed screw shaft143 and the nut portion of theslider146, and also between theslider146 and theslider support body147 so as to allow relative movement each other.
• Thefeed screw shaft143 is rotated by thetransmission belt111 through thepulley112earranged on the end portion of thescrew shaft143.
• Theslider support body147 guides the Z-direction slider146 or the object to be positioned in the Z-direction. In this embodiment, theslider support body147 is provided so as to be parallel to thefeed screw shaft143;
• The Z-direction slider146 moves along with theslider support body147.
• For an example, instead of direct engagement between thefeed screw shaft143 and Z-direction slider146, when balls may be disposed between thefeed screw shaft143 and the Z-direction slider146 and between theslider support body147 and the Z-direction slider146. According to this structure, relative movement among thefeed screw shaft143 and the Z-direction slider146 is allowed.
• According to the above structure, the Z-direction slider146 is driven by rotation of thefeed screw shaft143, and guided by theslider support body147. Thus, the Z-direction slider146 moves in the Z-direction.
• In each embodiment described above, the Z-axis direction is set to be in the perpendicular direction. The X-axis direction and the Y-axis direction, which are perpendicular to the Z-axis direction, are set in the horizontal direction. However, it should be noted that the present invention is not limited to the above specific embodiment. The present invention can be applied even to a case in which the three axial directions are determined in a different manner from that of the case described above.
• The structure of theX-direction support portion50,60,105 and that of the Y-direction support portion5,125 are not restricted by the structure of each embodiment described above. For example, as long as theX-direction support portion105 is composed as follows, any structure may be employed. TheX-direction support portion105 is composed so that it can not be relative moved with respect to thebase101. TheX-direction support portion105 supports theguide rail121a, which is an X-direction guide member, and thedrive motors113 to115. As long as the Y-direction support portion125 is composed as follows, any structure may be employed. The Y-direction support portion125 is provided so that the Y-direction support portion125 can not be relatively moved with respect to theX-axis sliders121b,121c. The Y-direction support portion125 supports theguide rail131awhich is a Y-direction guide member.
• Further, in each embodiment described above, the slider drive transmission belt is formed out of a timing belt, on the inner circumferential face of which teeth are provided. The pulley engaged with the inner circumferential face of the timing belt is formed out of a timing pulley. However, it should be noted that the present invention is not limited to the above specific structure. For example, in the case where there is no possibility of the occurrence of slippage, it is possible to use a combination of a transmission belt having no teeth with a pulley having no teeth. Alternatively, in addition to the inner circumferential face on which teeth are provided, a timing belt, on the outer circumferential face of which teeth are provided, may be used, that is, all the pulleys may be timing pulleys.
• Concerning the guide mechanisms, it is possible to use appropriate bearings such as various rolling guide bearings, sliding guide bearings and statistic pressure guide bearings. In the same manner, concerning the feed screw mechanisms, it is possible to use appropriate screw mechanisms such as ball screws, roller screws and slide screws.
• While the invention has been described in connection with the exemplary embodiments, it will be obvious to those skilled in the art that various changes and modification may be made therein without departing from the present invention, and it is aimed, therefore, to cover in the appended claim all such changes and modifications as fall within the true spirit and scope of the present invention.

Claims (7)

1. A three axis drive apparatus for driving a driven member in first, second and third directions perpendicular to each other, comprising:

a base comprising a first support portion fixed thereon;

a first guide mechanism comprising:

a first guide member supported by the first support portion; and

a first slider guided by the first guide member in the first direction;

a second guide mechanism comprising:

a second guide member extending in the second direction from the first slider; and

a second slider guided by the second guide member in the second direction;

a third guide mechanism that is provided on the second slider and guides the driven member to the third direction;

a first belt drive mechanism comprising:

a first slider drive transmission belt that slides the first slider; and

a first motor that drives the first slider drive transmission belt through a plurality of first pulleys;

a second belt drive mechanism comprising:

a second slider drive transmission belt that slides the second slider; and

a second motor that drives the second slider drive transmission belt through a plurality of second pulleys; and

a driven member drive mechanism comprising:

at least one of driven member drive transmission belt that slides the driven member; and

a third motor that drives the driven member in the third direction through a plurality of driven member pulleys,

wherein the first pulleys, at least one of the second pulleys, at least one of the driven member pulleys, the first motor, the second motor and the third motor are fixed on the first support portion.

2. The three axis drive apparatus, according toclaim 1, wherein in the second belt drive mechanism, three pulleys of the second pulleys are supported on the first slider and draw a part of the second belt along with second direction.

3. The three axis drive apparatus, according toclaim 1, wherein the driven member drive mechanism further comprises:

a spline shaft that is supported on the first slider so as to extend in the second direction and is rotated by at least one of the driven member drive transmission belt;

a pair of third pulleys that is rotatably driven by the spline shaft and provided so as to be movable in an axial direction of the spline shaft;

a secondary driven member drive transmission belt that moves the driven member in the third direction by the pair of the third pulleys.

4. The three axis drive apparatus, according toclaim 1, wherein the driven member drive mechanism comprises:

a feed screw shaft supported on the second slider so as to extend in the third direction and rotatably driven by the driven member drive transmission belt;

a nut that is connected to the driven member, is screwed to the feed screw shaft and is moved in the third direction by rotation of the feed screw shaft.

5. The three axis drive apparatus, according toclaim 4, wherein the driven member drive mechanism comprises:

a second direction drawing pulley that is supported on the first slider and draws a part of the driven member drive transmission belt in the second direction;

three first direction drawing pulleys that are supported on the second slider and draw a part of the driven member slider drive transmission belt in the second direction which is drawn in the first direction by the second direction drawing pulley,

wherein one of the first direction drawing pulley, which is engaged with an end part of the driven member drive transmission belt drawn in the first direction, is fixed on the feed screw shaft.

6. The three axis drive apparatus, according toclaim 4, wherein the driven member drive mechanism comprises:

a third slider comprising a nut portion screwed on the feed screw shaft,

a slider support member that supports the third slider so as to be movable in an axial direction of the feed screw shaft.

7. The three axis drive apparatus, according toclaim 1, wherein the third guide mechanism comprising:

a screw shaft rotated by the driven member drive transmission belt;

a movable body engaged with the screw shaft directly or indirectly;

a guide rail that is provided so as to be parallel to the screw shaft and guides the movable body in a longitudinal direction of the guide rail;

wherein the movable body is driven by the screw shaft and guided by the guide rail.

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