JP2016084894A - Linear motion table device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a linear motion table device which can be reduced in a manufacturing cost and size.SOLUTION: This device linearly moves a table on a base via a linear guide by the rotation of a feed screw shaft which is transmitted by a drive force of a drive motor. The device comprises: a drive nut and a fixed bracket which are screwed to a right screw part; a driven nut which is screwed to a left screw part; a first moving bracket which fixes the driven nut to the table, is engaged with the linear guide, and moves along the feed screw shaft; an intermediate support part; and a screw shaft support part. The intermediate support part and the screw shaft support part are different in structures, and arranged on the base. Then, a bearing is arranged between a bearing holding hole formed at a second moving bracket which moves along the feed screw shaft, and an intermediate cylinder part which penetrates the bearing holding hole is arranged at the intermediate support part. The bearing is fixed to the bearing holding hole by a bearing fixing member which fits a pair of tapering parts to the axial direction, and performs the diameter expansion of an outside diameter cylinder face and the diameter contraction of an inside diameter cylinder face.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a linear motion table device used in a machine tool, a semiconductor manufacturing apparatus, or the like.

  In machine tools, semiconductor manufacturing apparatuses, etc., for example, a linear motion table apparatus shown in FIG. In this device, both ends in the longitudinal direction of the screw shaft 3 are rotatably supported by bearings 2 a and 2 b disposed at both ends in the longitudinal direction of the base 1, and a nut 4 is screwed onto the outer periphery of the screw shaft 3. On the base 1, a pair of table guides 5 b are provided extending in the longitudinal direction in parallel with the depth direction of the paper surface. A table mounting member 6 a fixed to the movable table 6 is attached to the pair of table guides 5 b. 6b is engaged. A nut housing 7 is fixed to the moving table 6, and the nut 4 described above is held in the nut housing 7 so as not to rotate. Then, when the rotational driving force of the motor 8 fixed on the base 1 is transmitted to the screw shaft 3, the rotational force of the screw shaft 3 is transmitted as a linear driving force to the moving table 6 via the nut 4, and the moving table. 6 is adapted to move in the longitudinal direction of the base 1 while being supported by the table guides 5a and 5b.

In the linear motion table device of FIG. 5, when the rotational speed of the screw shaft 3 rotated at a high speed approaches the radial natural frequency (hereinafter referred to as the natural frequency), the screw shaft 3 is excited by the rotational whirling force. Then, there is a possibility that resonance will occur and it vibrates vigorously with a large amplitude, making it impossible to feed at high speed.
For this reason, a technique is known that enables high-speed feeding by providing an intermediate support that supports the middle part of the screw shaft, shortening the distance between attachments, and increasing the natural frequency so as not to cause resonance. (For example, patent document 1).

  As shown in FIGS. 6 (a) and 6 (b), the linear motion table device of Patent Document 1 has one end 10a, which is a right-hand thread portion made of a right-hand thread groove and a left-hand thread portion made of a left-hand thread groove, on one end side. And a first nut that is screwed into one of the right and left screw portions of the screw shaft 10 and the other one of the right and left screw portions 10b. 11, a first nut bracket 13 that fixes the first nut 11 to the base 12, a second nut 14 that is screwed into the other 10 b of the right screw portion and the left screw portion of the screw shaft 10, and a second A second nut bracket 16 that fixes the nut 14 to the moving table 15, a drive motor 17 that transmits a rotational driving force to the screw shaft 10, and a ball screw that rotatably supports both ends and a center portion of the screw shaft 10 in the longitudinal direction. And a support unit 18.

  The ball screw support portion 18 is a rectangular parallelepiped member that moves in the longitudinal direction of the base 13 while being supported by a linear guide 19 provided on the base 12, and a moving table 15 is disposed above the ball screw support portion 18. A linear guide 20 is provided for moving the guide in the longitudinal direction. Further, the ball screw support portion 18 includes a bearing 21 that rotatably supports an end portion of the right screw portion and the left screw portion of the screw shaft 10 on the other 10b side, and a right screw portion and a left screw portion of the screw shaft 10. On the other hand, a bearing 22 that rotatably supports the end portion on the side of 10a and a bearing 23 as an intermediate support that rotatably supports the outer periphery 10c that is not formed with a screw at the central portion in the longitudinal direction of the screw shaft 10 are disposed. ing.

  6 (a) and 6 (b), when the rotational driving force of the drive motor 17 is transmitted to the screw shaft 10, the moving table is moved simultaneously with the left (or right) movement of the ball screw support portion 18. 15 also moves to the left (or right) and performs high-speed feed with a stroke twice that of the apparatus shown in FIG. And since the bearing 23 as an intermediate support is supporting the outer periphery 10c of the longitudinal center part of the screw shaft 10, the natural frequency can be increased to such an extent that resonance does not occur.

JP 2003-127044 A

Incidentally, the drive motor 17 of the linear motion table device shown in FIGS. 6A and 6B requires a large drive torque because the ball screw support portion 18 having a large weight is moved. Therefore, a large drive motor that generates a large drive torque must be provided, which increases manufacturing costs and may result in a large apparatus.
Accordingly, the present invention has been made paying attention to the unsolved problems of the above-described conventional example, and an object thereof is to provide a linear motion table device capable of reducing the manufacturing cost and downsizing the device. Yes.

In order to achieve the above object, one aspect of the linear motion table device is a linear motion table in which a table provided on a base via a linear guide is linearly moved by rotation of a feed screw shaft by driving force transmission of a drive motor. The feed screw shaft is formed with a right-hand thread portion having a right-hand thread groove on one end side with an intermediate cylindrical portion at an axially central portion as a boundary, and a left-hand thread portion having a left-hand thread groove on the other end side. A drive nut that is screwed into one of the right screw portion and the left screw portion, a fixing bracket that fixes the drive nut on the base, the right screw portion, and the left screw portion. A driven nut that is screwed to the other of the first moving bracket, a first moving bracket that is fixed to the table, engages with the linear guide and moves along the front feed screw shaft, and an intermediate cylindrical portion of the feed screw shaft Is supported rotatably An intermediate support portion that is movably provided on the base along the front feed screw shaft and both ends of the feed screw shaft are rotatably supported, and can be moved on the base along the front feed screw shaft. A screw shaft support portion provided on the base, and the intermediate support portion and the screw shaft support portion are provided on the base in a separate structure. The intermediate support portion includes a bearing holding hole provided in a second moving bracket that moves along the feed screw shaft, and a bearing fixing member interposed between the bearing holding hole and the bearing. Prepared,
The bearing is composed of a plurality of rolling elements arranged to freely roll between a plurality of inner rings, a plurality of outer rings, the plurality of inner rings and the plurality of outer rings,
The bearing fixing member has an outer diameter cylindrical surface fitted to the inner diameter surface of the bearing holding hole, and an inner diameter cylindrical surface fitted to the outer ring outer diameter surface of the bearing, and has tapered surfaces that contact each other. Each of the taper ring members is composed of a pair of taper rings, and the taper ring members are fitted in the axial direction to increase the diameter of the outer cylindrical surface and the diameter of the inner cylindrical surface of the bearing fixing member. By performing, the said bearing is fixed to the said bearing holding hole.

  Further, in the linear motion table device, the screw shaft support portion includes one end side support portion that supports an end portion on one end side of the feed screw shaft, and another end portion on the other end side of the feed screw shaft. You may provide on the said base with the separate structure which consists of an end side support part.

  According to the linear motion table device of the present invention, the intermediate support portion and the screw shaft support portion are provided on the base with separate structures, and the weight of the support member that moves together with the feed screw shaft is reduced. Therefore, the manufacturing cost can be reduced and the apparatus can be reduced in size.

BRIEF DESCRIPTION OF THE DRAWINGS The linear motion table apparatus which concerns on this invention is shown, (a) is a side view, (b) is a top view. It is a figure which shows the structure of the intermediate | middle cylindrical part of the feed screw shaft which concerns on this invention. It is a figure which shows the structure of the intermediate support part which concerns on this invention. It is a principal part enlarged view of FIG. It is a figure which shows the structure of the conventional linear motion table apparatus. It is a figure which shows the structure of the other conventional linear motion table apparatus, (a) is a side view, (b) is an AA arrow directional view of (a).

Hereinafter, embodiments of a linear motion table apparatus according to the present invention will be described in detail with reference to the drawings.
1A and 1B show an embodiment of a linear motion table device according to the present invention, in which FIG. 1A is a side view and FIG. 1B is a plan view.
The linear motion table device according to the present embodiment is a device that linearly moves the first and second tables 27 and 28 provided on the base 25 via the linear guide 26. The linear guide 26 is fixed to a pair of guide walls 29 extending in parallel to each other in the longitudinal direction of the base 25 and a pair of rails 26a, and is fixed to the lower surface of the first table 27 so as to move on the rail 26a. The slider 26b slides and the slider 26c is fixed to the lower surface of the second table 28 and slides on the rail 26a.

The linear motion table device of this embodiment includes a screw shaft 30. The screw shaft 30 is formed with a right screw portion 30a formed of a right screw groove on the outer periphery on one end side, and on the outer periphery of the other end side from a left screw groove having the same outer diameter and the same screw pitch with respect to the right screw portion 30a. The left screw portion 30b is formed.
Further, as shown in FIG. 2, an intermediate cylindrical portion 30c having an outer diameter larger than that of the right screw portion 30a and the left screw portion 30b is formed on the outer periphery of the central portion in the longitudinal direction of the boundary between the right screw portion 30a and the left screw portion 30b. Has been.

  The linear motion table device of the present embodiment supports the drive motor 31 coupled to the end of the screw shaft 30 on the right screw portion 30a side and the right screw portion 30a on the center side in the longitudinal direction of the screw shaft 30. A support portion 32, a second support portion 33 that rotatably supports an end portion on the right screw portion 30a side of the screw shaft 30, and a third portion that rotatably supports an end portion on the left screw portion 30b side of the screw shaft 30. While supporting the support portion 34, the fourth support portion 35 fixed to the first table 27 while supporting the intermediate cylindrical portion 30 c of the screw shaft 30, and the left screw 30 b at the center in the longitudinal direction of the screw shaft 30, 2 and a fifth support portion 36 connected to the table 28.

The first support portion 32 is disposed on the first nut bracket 32a by being screwed to the first nut bracket 32a fixed to the approximate center in the longitudinal direction of the upper surface of the base 25 and the right screw portion 30a of the screw shaft 30. And the first nut 32b.
The second support portion 33 includes a pair of rails 33a arranged in the longitudinal direction on the base 25 on the right screw portion 30a side (the right side in FIG. 1A) of the screw shaft 30, and the rails 33a. The second support frame 33b, which is placed on the slider 33d and is movable in the longitudinal direction of the base 25, and the end on the right screw portion 30a side of the screw shaft 30 are rotatably supported. The drive motor 31 connected to the end of the screw shaft 30 on the right screw portion 30a side is disposed on the second support frame 33b. .

  The third support portion 34 includes a pair of rails 34a extending in the longitudinal direction on the base 25 on the left screw portion 30b side (the left side in FIG. 1A) of the screw shaft 30, and the rails 34a. Are supported via a slider 34d, and are rotatably supported by a third support frame 34b that is movable in the longitudinal direction of the base 25 and the left screw 30b side end of the screw shaft 30. 3 and a bearing 34c disposed on the support frame 34b.

The fifth support portion 36 is disposed on the fifth nut bracket 36a by screwing into a fifth nut bracket 36a fixed to the lower surface of the second table 28 and a left screw 30b on the center side in the longitudinal direction of the screw shaft 30. And a fifth nut 36b.
The fourth support portion 35 includes a bracket 37 that is fixed to the lower surface of the first table 27, and a bearing 38 that is disposed on the bracket 37 so as to rotatably support the intermediate cylindrical portion 30 c of the screw shaft 30. .

FIG. 3 shows a specific structure of the fourth support portion 35. FIG. 4 is an enlarged view of a main part of FIG.
As shown in FIG. 3 and FIG. 4, the bearing 38 is constituted by two rows of ball bearings, and is arranged between one outer ring 38 a, two inner rings 38 b, and between the outer ring 38 a and the inner ring 38 b so as to be able to roll. It comprises a plurality of rolling elements 38c. That is, the bearing 38 has a configuration in which the outer ring 38a is integrated with a conventional two-row ball bearing constituted by two outer rings 38a, two inner rings 38b, and a plurality of rolling elements 38c. . In the present embodiment, the number of inner rings 38b (the number of raceways) is not limited to two, and the bearings 38 can roll between one outer ring 38a, a plurality of inner rings 38b, and the outer ring 38a and the inner ring 38b. What is necessary is just to be comprised with the arrange | positioned several rolling element 38c.
A bearing holding hole 39 is formed in the bracket 37. The bearing holding hole 39 is formed so that the inner peripheral surface 39a faces the outer peripheral surface of the outer ring 38a of the bearing 38 with a predetermined gap. Further, a bearing fixing member 45 is interposed between the inner peripheral surface 39a of the bearing holding hole 39 and the outer peripheral surface of the outer ring 38a.

Further, after the screw shaft 30 is inserted so that the intermediate cylindrical portion 30 c is positioned in the bearing holding hole 39 of the bracket 37, the outer peripheral surface of the outer ring 38 a faces the inner peripheral surface 39 a of the bearing holding hole 39, It arrange | positions so that the internal peripheral surface of the inner ring | wheel 38b may contact | abut to the outer peripheral surface of the intermediate | middle cylindrical part 30c.
The outer peripheral surface 45a of the bearing fixing member 45 is disposed so as to contact the inner peripheral surface 39a of the bearing holding hole 39, and the inner peripheral surface 45b of the bearing fixing member 45 is disposed to contact the outer peripheral surface of the outer ring 38a of the bearing 38. Yes. As shown in FIG. 4, the bearing fixing member 45 includes a pair of tapered rings 46 and 47. The taper rings 46 and 47 are deformed by pulling them together in the axial direction with a screw 48, and the outer diameter 45a of the bearing fixing member 45 is expanded, and the inner diameter 45b is reduced, thereby fixing the bearing 38 to the housing 37. To do. Thereby, the bearing 38 can be reliably fixed to the bearing fixing hole 39 of the housing 37. Further, since the outer ring of the bearing 38 is pressed in the axial direction by the bearing fixing member 45, pressure is applied, so that the cores of the intermediate cylindrical portion 30c and the bearing fixing hole 39 can be accurately aligned. Further, the axial fixed positions of the housing 37 and the bearing 38 with respect to the position intermediate cylindrical portion 30c can be easily adjusted.

  According to the linear motion table device of the present embodiment, when a clockwise rotational force is transmitted from the drive motor 31 to the screw shaft 30, the screw shaft 30 in which the right screw portion 30 a is screwed with the first support portion 32. 1, the second support portion 33, the third support portion 34, and the fourth support portion 35 are also moved in the left direction of FIG. Further, when the screw shaft 30 is driven to feed in the left direction in FIG. 1, the fifth nut 36 b of the fifth support portion 36 screwed into the left screw portion 30 b of the screw shaft 30 is moved in the stroke of the screw shaft 30. On the other hand, the second table 28 that moves to the left with a double stroke and is connected to the fifth nut 36b via the fifth nut bracket 36a moves to the left at a high speed.

  On the other hand, when a counterclockwise rotational force is transmitted from the drive motor 31 to the screw shaft 30, the screw shaft 30 is fed and driven in the right direction in FIG. 1, and the second support portion 33, the third support portion 34 and the fourth support portion are driven. The part 35 also moves to the right in FIG. When the screw shaft 30 is driven to the right in FIG. 1, the fifth nut 36 b of the fifth support portion 36 moves to the right with a stroke twice that of the screw shaft 30. 2 The table 28 moves to the right at high speed.

Next, the effect of the linear motion table device of this embodiment will be described.
In the linear motion table device of the present embodiment, since the fourth support portion 35 supports the longitudinal center portion (intermediate cylindrical portion 30c) of the screw shaft 30, the natural frequency is increased to such an extent that resonance does not occur. Can do.
In addition, the fourth support portion 35 that supports the central portion in the longitudinal direction of the screw shaft 30 is separate from the second support portion 33 and the third support portion 34 that support both ends in the longitudinal direction of the screw shaft 30. The second support part 33 and the third support part 34 are also supported by the base 25 in a separate structure so as to be movable. The apparatus of this embodiment is There is no heavy support member that moves with the screw shaft 30. Therefore, the supporting member that moves together with the screw shaft 30 can be reduced in weight, so that the small driving motor 31 with a small driving torque can be obtained, so that the manufacturing cost can be reduced and the apparatus can be downsized.

  Further, after the screw shaft 30 is inserted so that the intermediate cylindrical portion 30 c is positioned in the bearing holding hole 39 of the bracket 37, the outer peripheral surface of the outer ring 38 a faces the inner peripheral surface 39 a of the bearing holding hole 39, It arrange | positions so that the internal peripheral surface of the inner ring | wheel 38b may contact | abut to the outer peripheral surface of the intermediate | middle cylindrical part 30c. The outer peripheral surface 45a of the bearing fixing member 45 is disposed so as to contact the inner peripheral surface 39a of the bearing holding hole 39, and the inner peripheral surface 45b of the bearing fixing member 45 is disposed to contact the outer peripheral surface of the outer ring 38a of the bearing 38. Yes. As shown in FIG. 4, the bearing fixing member 45 includes a pair of tapered rings 46 and 47. The taper rings 46 and 47 are deformed by pulling them together in the axial direction with a screw 48, and the outer diameter 45a of the bearing fixing member 45 is expanded, and the inner diameter 45b is reduced, thereby fixing the bearing 38 to the housing 37. To do. Thereby, the bearing 38 can be reliably fixed to the bearing fixing hole 39 of the housing 37. Further, since the outer ring of the bearing 38 is pressed in the axial direction by the bearing fixing member 45, pressure is applied, so that the cores of the intermediate cylindrical portion 30c and the bearing fixing hole 39 can be accurately aligned. Further, the axial fixed positions of the housing 37 and the bearing 38 with respect to the position intermediate cylindrical portion 30c can be easily adjusted.

  The linear guide of the present invention corresponds to the linear guide 26, the table of the present invention corresponds to the second table 28, the feed screw shaft of the present invention corresponds to the screw shaft 30, and the drive nut of the present invention is the first. Corresponding to the nut 32b, the fixed bracket of the present invention corresponds to the nut bracket 32a, the driven nut of the present invention corresponds to the fifth nut 36b, and the first moving bracket of the present invention corresponds to the nut bracket 36a. The intermediate support portion corresponds to the fourth support portion 35, the screw shaft support portion of the present invention corresponds to the second support portion 33 and the third support portion 34, and the one end side support portion of the present invention corresponds to the second support portion 33. The other end side support portion of the present invention corresponds to the other of the second support portion 33 and the third support portion 34.

  25 ... Base, 26 ... Linear guide, 26a ... Rail, 26b ... Slider, 26c ... Slider, 27 ... First table, 28 ... Second table, 29 ... Guide wall, 30 ... Screw shaft, 30a ... Right screw part, 30b ... Left screw part, 30c ... Intermediate cylindrical part, 31 ... Drive motor, 32 ... First support part, 32a ... Nut bracket, 32b ... First nut, 33 ... Second support part, 33a ... Rail, 33b ... , 33c ... bearing, 33d ... slider, 34 ... third support, 34a ... rail, 34b ... support frame, 34c ... bearing, 34d ... slider, 35 ... fourth support, 36 ... fifth support, 36a ... nut Bracket, 36b ... fifth nut, 37 ... bracket, 38 ... bearing, 38a ... outer ring, 38b ... inner ring, 38c ... rolling element, 39 ... bearing retaining hole, 39a ... inner peripheral surface, 39b ... outer ring locking 40, outer ring holding portion, 41, bolt, 42, collar, 43, lock nut, 45, bearing fixing member

Claims (2)

A linear motion table device that linearly moves a table provided on a base via a linear guide by rotation of a feed screw shaft by driving force transmission of a drive motor,
A shaft in which the feed screw shaft is formed with a right-hand thread portion having a right-hand thread groove on one end side with respect to the intermediate cylindrical portion in the axially central portion and the other of the left-hand thread portion having a left-hand thread groove on the other end side. age,
A drive nut screwed into one of the right screw portion and the left screw portion, a fixing bracket for fixing the drive nut on the base,
A driven nut that is screwed to the other of the right screw portion and the left screw portion, a first moving bracket that is fixed to the table, engages with the linear guide, and moves along the forward feed screw shaft; ,
An intermediate support portion that rotatably supports the intermediate cylindrical portion of the feed screw shaft, and that is movably provided on the base along the front feed screw shaft;
A screw shaft support portion that rotatably supports both ends of the feed screw shaft, and is provided on the base so as to be movable along the front feed screw shaft;
The intermediate support part and the screw shaft support part are provided on the base in separate structures from each other,
The intermediate support part is interposed between a bearing holding hole provided in a second moving bracket that moves along the feed screw shaft, a bearing through which the intermediate cylindrical part is inserted, and the bearing holding hole and the bearing. A bearing fixing member to be mounted,
The bearing is composed of a plurality of rolling elements arranged to freely roll between a plurality of inner rings, a plurality of outer rings, the plurality of inner rings and the plurality of outer rings,
The bearing fixing member has an outer diameter cylindrical surface fitted to the inner diameter surface of the bearing holding hole, and an inner diameter cylindrical surface fitted to the outer ring outer diameter surface of the bearing, and has tapered surfaces that contact each other. Each of the taper ring members is composed of a pair of taper rings, and the taper ring members are fitted in the axial direction to increase the diameter of the outer cylindrical surface and the diameter of the inner cylindrical surface of the bearing fixing member. By performing, the said linear bearing table apparatus characterized by fixing the said bearing to the said bearing holding hole.   The screw shaft support portion is a separate body composed of one end side support portion that supports an end portion on one end side of the feed screw shaft and another end side support portion that supports an end portion on the other end side of the feed screw shaft. The linear motion table device according to claim 1, wherein the linear motion table device is provided on the base in a structure.

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