JP6147565B2 - Ball screw feeder - Google Patents

Description

  The present invention relates to a ball screw feeding device, and more particularly to a ball screw feeding device capable of preventing occurrence of abnormal vibration due to high-speed rotation in a ball screw shaft having a long stroke.

  The ball screw feeding device is usually arranged between a pair of bearings rotatably supporting the ball screw shaft, the ball screw shaft, and the ball screw shaft via a plurality of balls for the ball screw shaft. The nut is screwed together, and the nut is linearly moved in the axial direction of the ball screw shaft by rotating the ball screw shaft.

  In such a ball screw feeder, when the rotational speed of the ball screw shaft becomes high and approaches the natural frequency of the ball screw shaft, abnormal vibration occurs in the ball screw shaft due to resonance, and the ball and the bearing are damaged. There is a fear. For this reason, it is necessary to rotate the ball screw shaft at a rotational speed (dangerous speed) or less corresponding to this resonance point, whereby the upper limit of the linear movement (feed) speed of the nut is determined.

The maximum permissible rotational speed n _c (rpm) corresponding to the critical speed of the ball screw shaft is determined by a constant f determined by the support method of the ball screw shaft, a distance L (mm) between the support points of the ball screw shaft, and a valley diameter d of the ball screw shaft. It is known that it can be determined by the following equation (1) based on _r (mm).
n _c = f (d _r / L ² ) × 10 ⁷ (1)

For fast feed nuts, in the above equation (1), by increasing the root diameter d _r of the ball screw shaft, it is possible to increase the maximum allowable speed n _c. However, increasing the root diameter d _r of the ball screw shaft, a load inertia to (moment of inertia) is increased, it becomes necessary large torque in the rotation of the ball screw shaft. In addition, as the root diameter d _r of the ball screw shaft is larger, will also up the price of the ball screw shaft.

Further, in order to realize a high-speed feeding of the nut, the lead by increasing the (pitch of the thread groove on the ball screw shaft), lowering the rotation speed required for the ball screw shaft below the maximum allowable speed n _c Can do. However, when the lead is enlarged, the feeding accuracy of the nut is lowered.

  Patent Document 1 further includes a moving support body having a pair of brackets arranged between a pair of bearings and slidably penetrating the ball screw shaft, and a connecting portion for connecting the pair of brackets to each other, A ball screw feeder in which a nut is disposed between the pair of brackets is described.

The ball screw shaft of such a device is fixedly supported by each of the pair of bearings and nuts, and is simply supported by each of the pair of brackets. For this reason, the constant f determined by the support method is smaller between the bearing and the bracket and between the bracket and the nut than when the movable support body is not provided (specifically, (15.1 / 2. 9 =) 0.69 times), however, the distance L between the support points is shortened (specifically, as shown in FIG. by the made) that times the maximum allowable speed n _c of the ball screw shaft is much compared to the case without a moving support member (specifically (0.69 / 0.5 2 ⁼⁾ about 2. up to 7-fold) can be raised (since the maximum allowable speed n _c of the ball screw shaft which is inversely proportional to the square of the distance L between the supporting points, the greater its effect).

Japanese Utility Model Publication No. 61-28900

  However, in order to realize high-speed feed of the nut on the ball screw shaft having a long stroke, the maximum allowable rotational speed is about 2.7 times that when the moving support body is not provided as in the apparatus described in Patent Document 1. Even so, the number of rotations required for the ball screw shaft may be insufficient.

  The present invention has been created based on the above findings. An object of the present invention is to provide a ball screw feeding device that can effectively prevent occurrence of abnormal vibration due to high-speed rotation in a ball screw shaft having a long stroke.

  The present invention includes a ball screw shaft, a pair of bearings rotatably supporting the ball screw shaft, a pair of first brackets disposed between the pair of bearings and slidably penetrating the ball screw shaft, A first moving support body having a first connecting portion for connecting the pair of first brackets to each other; and a pair of second support members disposed between the pair of first brackets and slidably penetrating the ball screw shaft. A second moving support body having a bracket and a second connecting portion for connecting the pair of second brackets to each other; and a plurality of the ball screw shafts arranged between the pair of second brackets for the ball screw shaft. A nut screwed through the ball, and when one of the pair of second brackets comes into contact with one of the pair of first brackets, the pair of second brackets The other is a ball screw feed device, characterized in that in the state of being spaced from the other of said pair of first bracket.

According to the present invention, the ball screw shaft is fixedly supported by each of the pair of bearings and nuts and is simply supported by each of the pair of first brackets and the pair of second brackets. In the meantime, the constant f determined by the support method is even smaller (specifically, (9.7 / 21.9 =) 0.443 times) than when no moving support is provided. The distance L between the support points is further shortened (specifically, when the critical speeds between the support points are equalized as shown in FIG. 4, the distance L is 0.286 times). As a result, with reference to the above equation (1), the maximum allowable speed n _c of the ball screw shaft is more greatly (specifically as compared with a case without the mobile support member (0.443 / 0.286 ² =) up to about 5.4 times). Thereby, even in a ball screw shaft having a long stroke, it is possible to effectively prevent occurrence of abnormal vibration due to high-speed rotation.

  Preferably, the nut is in contact with one of the pair of second brackets, one of the pair of second brackets is in contact with one of the pair of first brackets, and one of the pair of first brackets is In a state as close as possible to one of the pair of bearings, in the linear coordinates parallel to the axis of the ball screw shaft, the other center coordinate of the pair of bearings is 0, and the center coordinate of the nut is 1. The other center coordinate of the pair of first brackets is in the range of 0.3 to 0.4, and the other center coordinate of the pair of second brackets is in the range of 0.6 to 0.7. Is in. According to such an aspect, the critical speeds between the bearing and the first bracket, between the first bracket and the second bracket, and between the second bracket and the nut are substantially equal, and thereby, the maximum allowable ball screw shaft is allowed. The rotation speed can be increased effectively.

  Preferably, each of the pair of second brackets supports the first connecting portion. According to such an aspect, even when the distance between the pair of first brackets is designed to correspond to the ball screw shaft having a long stroke, the first brackets that connect the pair of first brackets to each other are designed. The bending deformation of the one connecting portion can be effectively prevented by each of the pair of second brackets.

  Preferably, each of the pair of second brackets is a cylindrical second sleeve portion that passes through the ball screw shaft, and is disposed coaxially with the second sleeve portion outside the second sleeve portion. A second bracket portion rotatably supported on the second sleeve portion via a rotary bearing, and the second bracket portion and the nut can come into contact with each other. Each of the brackets has a cylindrical first sleeve portion that passes through the ball screw shaft, and is arranged coaxially with the first sleeve portion outside the first sleeve portion, and a rotary bearing is provided in the first sleeve portion. A first bracket portion rotatably supported, and the first bracket portion and the second bracket portion of the second bracket can contact each other. According to such an aspect, even if the first bracket and / or the second bracket contacts the rotating ball screw shaft, the first sleeve portion and / or the second sleeve portion are rotated together with the ball screw shaft, The first bracket portion and the second bracket portion are stationary with respect to the rotation direction. Thereby, generation | occurrence | production of the rubbing in a rotation direction in a contact location is suppressed, and the malfunction (for example, generation | occurrence | production of friction powder) by generation | occurrence | production of rubbing can be prevented.

  More preferably, at least a part of the end surface on the nut side of the second bracket portion is provided with a first abutting buffer body that protrudes toward the nut side from the end surface on the nut side of the second sleeve portion. And at least a part of the end surface of the first bracket portion on the second bracket side protrudes toward the second bracket side from the end surface of the first sleeve portion on the second bracket side. A buffer is provided. According to such an aspect, the nut is in contact with the second bracket portion via the first contact buffer, and the second bracket portion is in contact with the first bracket portion via the second contact buffer. Is done. Thereby, even when the nut is fed at a high speed, for example, the impact due to the contact is effectively absorbed by the first contact buffer and / or the second contact buffer, and damage due to the impact can be prevented.

  Alternatively, at least a part of the nut-side end surface of the second bracket portion is provided with a first abutting buffer that protrudes toward the nut side from the nut-side end surface of the second sleeve portion. And a second abutting shock absorber projecting toward the first bracket side of the end surface of the second sleeve portion from the end surface of the first bracket side of at least a part of the end surface of the second bracket portion on the first bracket side. Is provided. Also in such an aspect, the nut is brought into contact with the second bracket part via the first contact buffer, and the second bracket part is brought into contact with the first bracket part via the second contact buffer. The Thereby, even when the nut is fed at a high speed, for example, the impact due to the contact is effectively absorbed by the first contact buffer and / or the second contact buffer, and damage due to the impact can be prevented.

  Alternatively, at least a part of the end surface of the nut facing the second bracket portion of the end surface on the second bracket side protrudes closer to the second bracket than the portion facing the second sleeve portion. One abutting buffer is provided, and at least a part of the end surface of the first bracket portion on the second bracket side is more than the end surface of the first sleeve portion on the second bracket side. A second abutting buffer that protrudes to the side may be provided. Also in such an aspect, the nut is brought into contact with the second bracket part via the first contact buffer, and the second bracket part is brought into contact with the first bracket part via the second contact buffer. The Thereby, even when the nut is fed at a high speed, for example, the impact due to the contact is effectively absorbed by the first contact buffer and / or the second contact buffer, and damage due to the impact can be prevented.

  Alternatively, at least a part of the end surface of the nut facing the second bracket portion of the end surface on the second bracket side protrudes closer to the second bracket than the portion facing the second sleeve portion. One abutting buffer is provided, and at least a part of the end surface of the second bracket portion on the first bracket side is more than the end surface of the second sleeve portion on the first bracket side. A second abutting buffer that protrudes to the side may be provided. Also in such an aspect, the nut is brought into contact with the second bracket part via the first contact buffer, and the second bracket part is brought into contact with the first bracket part via the second contact buffer. The Thereby, even when the nut is fed at a high speed, for example, the impact due to the contact is effectively absorbed by the first contact buffer and / or the second contact buffer, and damage due to the impact can be prevented.

  Specifically, for example, the distance between the centers of the pair of bearings is 8000 mm to 12000 mm, and the valley diameter of the ball screw shaft is 60 mm to 100 mm.

  The present invention also includes a ball screw shaft, a pair of bearings that rotatably support the ball screw shaft, and a pair of first brackets that are disposed between the pair of bearings and slidably penetrate the ball screw shaft. A first moving support body having a first connecting portion that connects the pair of first brackets to each other, and a pair of sliding members that are disposed between the pair of first brackets and slidably penetrate the ball screw shaft. A second moving support body having a second bracket and a second connecting portion for connecting the pair of second brackets to each other; and being arranged between the pair of second brackets so that the ball screw shaft can slide. A third moving support body having a pair of third brackets to be penetrated, and a third connecting portion for connecting the pair of third brackets to each other, and disposed between the pair of third brackets. A nut screwed to the ball screw shaft via a plurality of balls for the ball screw shaft, and when one of the pair of third brackets is brought into contact with one of the pair of second brackets, When the other of the pair of third brackets is separated from the other of the pair of second brackets, and when one of the pair of second brackets comes into contact with one of the pair of first brackets, the pair of third brackets The other of the second brackets is a ball screw feeding device characterized in that the second bracket is separated from the other of the pair of first brackets.

According to the present invention, the ball screw shaft is fixedly supported by each of the pair of bearings and nuts and is simply supported by each of the pair of first brackets, the pair of second brackets, and the pair of third brackets. The constant f determined by the support method is further smaller between the one bracket and the second bracket and between the second and third brackets than when the movable support body is not provided (specifically, (9. 7 / 21.9 =) 0.443 times), but the distance L between the support points is further shortened (specifically, when the critical speeds between the support points are equalized as shown in FIG. 12). Is 0.222 times). As a result, with reference to the above equation (1), the maximum allowable speed n _c of the ball screw shaft is more greatly (specifically as compared with a case without the mobile support member (0.443 / 0.222 ² =) up to about 9.0 times). Thereby, even in a ball screw shaft having a long stroke, it is possible to effectively prevent occurrence of abnormal vibration due to high-speed rotation.

  Preferably, the nut is in contact with one of the pair of third brackets, one of the pair of third brackets is in contact with one of the pair of second brackets, and one of the pair of second brackets is In a state of being in contact with one of the pair of first brackets and one of the pair of first brackets being as close as possible to one of the pair of bearings, in a linear coordinate parallel to the axis of the ball screw shaft When the other center coordinate of the pair of bearings is 0 and the center coordinate of the nut is 1, the other center coordinate of the pair of first brackets is in the range of 0.23 to 0.33, The other center coordinate of the pair of second brackets is in the range of 0.45 to 0.55, and the other center coordinate of the pair of third brackets is in the range of 0.67 to 0.77. is there. According to such an aspect, the critical speeds are substantially equal between the bearing and the first bracket, between the first bracket and the second bracket, between the second bracket and the third bracket, and between the third bracket and the nut. Thus, the maximum allowable rotational speed of the ball screw shaft can be effectively increased.

  Preferably, each of the pair of second brackets is configured to support the first connection part, and each of the pair of third brackets includes the first connection part and the second connection part. Has come to support. According to such an aspect, even when the distance between the pair of first brackets is designed to correspond to the ball screw shaft having a long stroke, the first brackets that connect the pair of first brackets to each other are designed. Deflection of one connecting part can be effectively prevented by each of the pair of second brackets and the pair of third brackets. Further, the bending deformation of the second connecting portion that connects the pair of second brackets to each other can be effectively prevented by each of the pair of third brackets.

  Preferably, each of the pair of third brackets is a cylindrical third sleeve portion that passes through the ball screw shaft, and is arranged coaxially with the third sleeve portion outside the third sleeve portion. A third bracket portion rotatably supported by the third sleeve portion via a rotary bearing, and the third bracket portion and the nut can come into contact with each other. Each of the brackets has a cylindrical second sleeve portion that passes through the ball screw shaft, and is disposed coaxially with the second sleeve portion on the outside of the second sleeve portion. A second bracket portion rotatably supported by the second bracket portion, and the second bracket portion and the third bracket portion of the third bracket can come into contact with each other. Each is A cylindrical first sleeve portion that penetrates the ball screw shaft, and is arranged coaxially with the first sleeve portion outside the first sleeve portion and rotatably supported by the first sleeve portion via a rotary bearing A first bracket portion, and the first bracket portion and the second bracket portion of the second bracket can contact each other. According to such an aspect, even if the first bracket and / or the second bracket and / or the third bracket come into contact with the rotating ball screw shaft, the first sleeve portion and / or the second sleeve portion and / or the first bracket portion are used. The three sleeve portions are rotated together with the ball screw shaft, and the first bracket portion, the second bracket portion, and the third bracket portion are stationary with respect to the rotation direction. Thereby, generation | occurrence | production of the rubbing in a rotation direction in a contact location is suppressed, and the malfunction (for example, generation | occurrence | production of friction powder) by generation | occurrence | production of rubbing can be prevented.

  Specifically, for example, the distance between the centers of the pair of bearings is 10600 mm to 16000 mm, and the valley diameter of the ball screw shaft is 60 mm to 100 mm.

According to one aspect of the present invention, the ball screw shaft is fixedly supported by each of the pair of bearings and nuts and is simply supported by each of the pair of first brackets and the pair of second brackets. Between the second brackets, the constant f determined by the support method is further reduced (specifically, 0.443 times) as compared with the case where no moving support body is provided, but the distance L between the support points is also further shortened by (specifically, when aligned equally critical speed between each support point, in becomes 0.286 times) that the maximum permissible speed n _c of the ball screw shaft is provided with a moving support member Compared to the case where there is not, it can be increased significantly (specifically, up to about 5.4 times). Thereby, even in a ball screw shaft having a long stroke, it is possible to effectively prevent occurrence of abnormal vibration due to high-speed rotation.

According to another aspect of the present invention, the ball screw shaft is fixedly supported by each of the pair of bearings and nuts, and is simply supported by each of the pair of first brackets, the pair of second brackets, and the pair of third brackets. Therefore, in particular, between the first bracket and the second bracket, and between the second and third brackets, the constant f determined by the support method is further reduced as compared with the case where the moving support body is not provided (specifically, However, the distance L between the support points is further shortened (specifically, when the critical speeds between the support points are equalized, the ball screw is increased by 0.222 times). the maximum allowable speed n _c axis can further significantly raised (specifically, up to about 9.0-fold) as compared with the case without a moving support member. Thereby, even in a ball screw shaft having a long stroke, it is possible to effectively prevent occurrence of abnormal vibration due to high-speed rotation.

It is a schematic side view which shows the ball screw feeder by the 1st Embodiment of this invention. It is a schematic plan view which shows the ball screw feeder of FIG. FIG. 4 is a side sectional view for explaining a first example of the device configuration of the first and second brackets in the ball screw feeder of FIG. 1. It is a schematic diagram for demonstrating the distance L between support points when the critical speed between each support point is equal in the ball screw feeder of FIG. It is a schematic diagram for demonstrating operation | movement of the ball screw feeder of FIG. FIG. 4 is a side sectional view for explaining a second example of the device configuration of the first and second brackets in the ball screw feeder of FIG. 1. FIG. 6 is a side sectional view for explaining a third example of the device configuration of the first and second brackets in the ball screw feeder of FIG. 1. FIG. 6 is a side sectional view for explaining a fourth example of the device configuration of the first and second brackets in the ball screw feeder of FIG. 1. It is a schematic side view which shows the ball screw feeder by the 2nd Embodiment of this invention. It is a schematic plan view which shows the ball screw feeder of FIG. FIG. 10 is a side sectional view for explaining an example of the device configuration of the first to third brackets in the ball screw feeder of FIG. 9. FIG. 10 is a schematic diagram for explaining a distance L between support points when the critical speeds between the support points are equal in the ball screw feeder of FIG. 9. It is a schematic diagram for demonstrating operation | movement of the ball screw feeder of FIG. It is a schematic diagram for demonstrating the shortest distance between support points in case the critical speed between each support point is equal in the ball screw feeder of patent document 1. FIG.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

  FIG. 1 is a schematic side view showing a ball screw feeding device according to an embodiment of the present invention, and FIG. 2 is a schematic plan view showing the ball screw feeding device.

  As shown in FIGS. 1 and 2, the ball screw feeder 10 according to the present embodiment includes a ball screw shaft 16, a pair of bearings 11a and 11b that rotatably support the ball screw shaft 16, and a pair of bearings 11a and 11b. A first moving support body having a pair of first brackets 13a, 13b disposed between them and slidably penetrating the ball screw shaft 16 and a first connecting portion 13c for connecting the pair of first brackets 13a, 13b to each other. 13 and a pair of second brackets 14a, 14b disposed between the pair of first brackets 13a, 13b and slidably penetrating the ball screw shaft 16 and the pair of second brackets 14a, 14b are connected to each other. A ball screw shaft disposed between the second moving support body 14 having the two connecting portions 14c and the pair of second brackets 14a and 14b. A plurality of balls for the ball screw shaft 6 is provided with a nut 12 screwed via a (not shown), a.

  As shown in FIG. 1, in this embodiment, each of the pair of bearings 11a and 11b is fixed on a horizontal bed 18, and the ball screw shaft 16 is rotatably supported by the pair of bearings 11a and 11b. A rotational drive device 17 (for example, a motor) is connected to one end of the motor. Specifically, for example, the distance between the centers of the pair of bearings 11a and 11b is 8000 mm to 12000 mm, and the valley diameter of the ball screw shaft is 60 mm to 100 mm.

  As shown in FIG. 1, a table 19 is fixed horizontally on the nut 12. When the ball screw shaft 16 is rotated by the rotation driving device 17, the nut 12 and the table 19 screwed to the ball screw shaft 16 via the ball are linearly moved in the axial direction of the ball screw shaft 16. It has become.

  As shown in FIG. 1, the pair of first brackets 13 a and 13 b and the pair of second brackets 14 b and 14 b are slidably disposed on the bed 18.

  In the present embodiment, the device configuration of the first and second brackets 13a and 14a on the left side in FIG. 1 and FIG. 2 is the same as the device configuration of the first and second brackets 13b and 14b on the right side. The device configuration of the first and second brackets 13a and 14a will be described as a representative. FIG. 3 is a side sectional view for explaining an example of the device configuration of the first and second brackets 13a and 14a.

  As shown in FIG. 3, the first bracket 13 a is a cylindrical first sleeve portion 131 that penetrates the ball screw shaft 16, and is arranged coaxially with the first sleeve portion 131 outside the first sleeve portion 131. And a first bracket portion 132 supported rotatably on the first sleeve portion 131 via a rotary bearing 133. Further, the second bracket 14 a is a cylindrical second sleeve portion 141 that penetrates the ball screw shaft 16, and is disposed coaxially with the second sleeve portion 141 outside the second sleeve portion 141. And a second bracket part 142 rotatably supported by the part 141 via a rotary bearing 143. As shown in FIG. 3, the first bracket portion 132 and the second bracket portion 142 can come into contact with each other, and the second bracket portion 142 and the nut 12 can come into contact with each other.

  Specifically, each of the first and second sleeve portions 131 and 141 has an inner diameter slightly larger than the outer diameter of the ball screw shaft 16, and simply supports the ball screw shaft 16. The shaft 16 is slidable in the axial direction and the rotational direction, but is substantially immovable in the radial direction. On the other hand, each of the first and second bracket portions 132 and 142 is rotatably supported by the first and second sleeve portions 131 and 141 via the rotary bearings 133 and 143, and the first and second sleeve portions. Although it can move in the axial direction together with 131 and 141, it is stationary with respect to the rotational direction.

  As a result, even if the first bracket 13a and / or the second bracket 14b are in contact with the rotating ball screw shaft 16, the first sleeve portion 131 and / or the second sleeve portion 141 that are in contact with the ball screw shaft 16 are The first bracket part 132 and the second bracket part 142 are stationary with respect to the rotation direction. Thereby, generation | occurrence | production of the rubbing in a rotation direction in a contact location is suppressed, and the malfunction (for example, generation | occurrence | production of friction powder) by generation | occurrence | production of rubbing can be prevented.

  Further, as shown in FIG. 3, in the present embodiment, at least a part of the end surface of the second bracket portion 142 on the nut 12 side is closer to the nut 12 side than the end surface of the second sleeve portion 141 on the nut 12 side. A projecting first abutting buffer 21 is provided. Further, at least part of the end surface of the first bracket portion 132 on the second bracket 14a side is a second abutting buffer that protrudes further toward the second bracket 14a side than the end surface of the first sleeve portion 131 on the second bracket 14a side. A body 22 is provided. The first and second contact buffer bodies 21 and 22 are specifically cushion rubbers, but may be other damper mechanisms.

  Since the first abutting buffer 21 protrudes toward the nut 12 side from the end surface of the second sleeve portion 141 on the nut 12 side, the nut 12 moved in the axial direction is interposed via the first abutting buffer 21. The second bracket portion 142 is in contact with the second sleeve portion 141 and is not in contact with the second sleeve portion 141. Further, the second abutment buffer 22 protrudes toward the second bracket 14a from the end surface of the first sleeve 131 on the second bracket 14a side, so that the second bracket 14a moved in the axial direction is second. The bracket portion 142 is in contact with the first bracket portion 132 via the second contact buffer 22 and is not in contact with the first sleeve portion 131. Thereby, even when the nut 12 is fed at a high speed, for example, the impact caused by the contact is effectively absorbed by the first contact buffer 21 and / or the second contact buffer 22, and damage due to the impact is prevented. It is prevented.

  Returning to FIG. 1 and FIG. 2, the first connecting portion 13 c and the second connecting portion 14 c are specifically elongated members having rigidity. The first connecting part 13c is configured to maintain a predetermined distance between the pair of first brackets 13a and 13b, and the second connecting part 14c is provided between the pair of second brackets 14a and 14b. The interval is maintained at a predetermined distance.

  In the present embodiment, each of the pair of second brackets 14a and 14b supports the first connecting portion 13c. Specifically, stepped portions are provided on both side edge portions of each of the bracket portions 142 of the pair of second brackets 14a and 14b, and the upper surface of the stepped portion is in contact with the lower surface of the first connecting portion 13c. .

  As shown in FIG.1 and FIG.2, the space | interval between each outer side end surface of a pair of 2nd bracket 14a, 14b becomes shorter than the space | interval between each inner side end surface of a pair of 1st bracket 13a, 13b. Yes. Thereby, when one second bracket 14a is brought into contact with one first bracket 13a, the other second bracket 14b is separated from the other first bracket 13b.

  In the present embodiment, as shown in FIGS. 1 and 2, the nut 12 is brought into contact with one second bracket 14a, the one second bracket 14a is brought into contact with one first bracket 13a, In a state where one first bracket 13a is as close as possible to one bearing 11a, in the linear coordinates parallel to the axis of the ball screw shaft 16, the center coordinate of the other bearing 11b is 0, and the center coordinate of the nut 12 is When 1, the center coordinate of the other first bracket 13b is in the range of 0.3 to 0.4, and the center coordinate of the other second bracket 14b is in the range of 0.6 to 0.7. It is in. More preferably, the center coordinate of the other first bracket 13b is in the range of 0.34 to 0.38, and the center coordinate of the other second bracket 14b is in the range of 0.62 to 0.66. is there. That is, the ratio of the distance L1 between the centers of the bearing 11b and the first bracket 13b, the distance L2 between the centers of the first bracket 13b and the second bracket 14b, and the distance L3 between the centers of the second bracket 14b and the nut 12 (L1: L2: L3) is substantially equal to 1.25: 1: 1.25.

In this case, the ball screw shaft 16 is fixedly supported by each of the pair of bearings 11a and 11b and the nut 12, and is simply supported by each of the pair of first brackets 13a and 13b and the pair of second brackets 14a and 14b. The constant f determined by the support method is 15.1 between the bearing 11b and the first bracket 13b and between the second bracket 14b and the nut 12, and between the first bracket 13b and the second bracket 14b is 9.7. In view of the fact, as shown in FIG. 5, the critical speeds between the bearing 11b and the first bracket 13b, between the first bracket 13b and the second bracket 14b, and between the second bracket 14b and the nut 12 are substantially equal. Are equal. Thus, it is possible to increase the maximum allowable speed n _c of the ball screw shaft 16 effectively.

Specifically, between the first bracket 13b and the second bracket 14b, the constant f determined by the support method is (9.7 /) compared with the case where the first and second movement support bodies 13 and 14 are not provided. 21.9 =) 0.443 times, but the support point distance L is (1 / (1.25 + 1 + 1.25) compared to the case where the first and second moving support bodies 13 and 14 are not provided. =) by has become 0.286 times, with reference to the above equation (1), the maximum allowable speed _{n c} of the ball screw shaft 16, if the first, does not include the second moving support members 13, 14 (0.443 / 0.286 ² =) can be increased up to about 5.4 times. Thereby, even in the ball screw shaft 16 having a long stroke, it is possible to effectively prevent occurrence of abnormal vibration due to high-speed rotation.

  Next, the operation of the present embodiment as described above will be described.

  As shown in FIGS. 1 and 2, the nut 12 is in contact with the left second bracket 14a, the left second bracket 14a is in contact with the left first bracket 13a, and the left first bracket 13a. When the ball screw shaft 16 is rotated by the rotation driving device 17 in a state where the nut 12 is as close as possible to the left bearing 11a, the nut 12 is moved rightward in the axial direction. Here, even if the pair of first brackets 13a and 13b and / or the pair of second brackets 14a and 14b come into contact with the rotating ball screw shaft 16, the respective sleeve portions 131 and 141 rotate together with the ball screw shaft 16. By doing so, the occurrence of rubbing at the contact location is suppressed, and problems due to the occurrence of rubbing (for example, generation of friction powder) can be prevented.

  Next, as shown in FIG. 4A, the nut 12 that is moved to the right in the axial direction by the rotation of the ball screw shaft 16 is brought into contact with the right second bracket 14b. Specifically, the nut 12 is brought into contact with the second bracket portion 142 of the second bracket 14 b via the first contact buffer 21. In the present embodiment, the impact due to the contact is effectively absorbed by the first contact buffer 21, so that damage due to the impact is prevented even when the nut 12 is moved at a high speed. Thereafter, the nut 12 that is moved rightward in the axial direction by the rotation of the ball screw shaft 16 pushes the abutted right second bracket 14b rightward in the axial direction. Thereby, the second movement support body 14 is moved to the right in the axial direction together with the nut 12.

  Next, as shown in FIG. 4B, the second movement support body 14 that is moved to the right in the axial direction together with the nut 12 by the rotation of the ball screw shaft 16 is brought into contact with the first bracket 13b on the right side. . Specifically, the second bracket portion 142 of the right second bracket 14b is brought into contact with the first bracket portion 132 of the first bracket 13b via the second contact buffer 22. In the present embodiment, since the impact due to the contact is effectively absorbed by the second contact buffer 22, even if the nut 12 and the second movement support body 14 are moved at high speed, the impact Damage due to is prevented. Thereafter, the second moving support body 14 that is moved to the right in the axial direction together with the nut 12 by the rotation of the ball screw shaft 16 pushes the abutted right first bracket 13b to the right in the axial direction. Thereby, the first movement support body 13 is moved rightward in the axial direction together with the second movement support body 14 and the nut 12.

  Next, as shown in FIG. 4C, the first movement support body 13 that is moved to the right in the axial direction together with the nut 12 and the second movement support body 14 by the rotation of the ball screw shaft 16 is the right bearing 11b. As close as possible.

As described above, according to the present embodiment, the ball screw shaft 16 is fixedly supported by each of the pair of bearings 11a and 11b and the nut 12, and the pair of first brackets 13a and 13b and the pair of second brackets 14a, 14b, the first bracket 13a (13b) and the second bracket 14a (14b), in particular, are constants determined by the support method compared to the case where the movable support bodies 13 and 14 are not provided. Although f is small (specifically, (9.7 / 21.9 =) is 0.443 times), the distance L between the support points is also short (specifically, as shown in FIG. (If the critical speeds between the support points are equal, 0.286 times). As a result, with reference to the above equation (1), the maximum allowable speed _{n c} of the ball screw shaft 16, even more significantly (specifically as compared with the case without a moving support members 13, 14 (0.443 /0.286 ² =) up to about 5.4 times). Thereby, even in the ball screw shaft 16 having a long stroke, it is possible to effectively prevent occurrence of abnormal vibration due to high-speed rotation.

  Further, according to the present embodiment, the nut 12 is brought into contact with one second bracket 14a (14b), and the one second bracket 14a (14b) is brought into contact with one first bracket 13a (13b). In the state where the one first bracket 13a (13b) is as close as possible to the one bearing 11a (11b), the other bearing 11b (11a) is in a linear coordinate parallel to the axis of the ball screw shaft 16. When the center coordinate of the nut 12 is 0 and the center coordinate of the nut 12 is 1, the center coordinate of the other first bracket 13b (13a) is in the range of 0.3 to 0.4, and the other second bracket 14b Since the center coordinates of (14a) are within the range of 0.6 to 0.7, the distance between the bearing 11b (11a) and the first bracket 13b (13a), the first bracket 13b (13a) and the second bracket During 4b (14a), and a second bracket 14b (14a) - critical speed at each between the nut 12 is substantially equal. Thereby, the maximum permissible rotational speed of the ball screw shaft 16 can be effectively increased.

  Further, according to the present embodiment, since each of the pair of second brackets 14a and 14b supports the first connecting portion 13c, the pair of second brackets 14a and 14b corresponds to the ball screw shaft 16 having a long stroke. Even when the distance between the brackets 13a and 13b is designed to be wide, the bending deformation due to gravity of the first connecting portion 13c connecting the pair of first brackets 13a and 13b to each other is caused by the pair of second brackets 13a and 13b. Each of the brackets 14a and 14b can be effectively prevented.

  In this embodiment, as shown in FIG. 3, at least part of the end surface of the second bracket portion 142 on the nut 12 side is closer to the nut 12 than the end surface of the second sleeve portion 141 on the nut 12 side. A protruding first abutting buffer 21 is provided, and at least part of the end surface of the first bracket portion 132 on the second bracket 14a side is more than the end surface of the first sleeve portion 131 on the second bracket 14a side. Although the 2nd contact buffer 22 which protrudes in the 2nd bracket 14a side is provided, it is not limited to this, As shown in FIG. 5, at least one part of the end surface by the side of the nut 12 of the 2nd bracket part 142 is provided. Is provided with a first abutment buffer 21 projecting toward the nut 12 side of the end surface of the second sleeve portion 141 on the nut 12 side, and an end surface of the second bracket portion 142 on the first bracket 13a side. At least in part, the end face of the first bracket 13a side second contact cushion 21 'projecting to the first bracket 13a side may be provided in the second sleeve portion 141. Alternatively, as shown in FIG. 6, at least a part of the end face of the nut 12 on the second bracket 14 a side facing the second bracket part 142 is second than the part facing the second sleeve part 141. A first abutting buffer 21 ′ protruding toward the bracket 14a is provided, and the second bracket 14a of the first sleeve 131 is provided on at least part of the end surface of the first bracket 132 on the second bracket 14a side. The 2nd contact | abutting buffer 22 which protrudes in the 2nd bracket 14a side rather than the end surface of the side may be provided. Alternatively, at least a part of the end surface of the nut 12 facing the second bracket 14a on the second bracket 14a side protrudes more toward the second bracket 14a than the portion facing the second sleeve 141. One abutting shock absorber 21 'is provided, and at least a part of the end surface of the second bracket portion 142 on the first bracket 13a side is first than the end surface of the second sleeve portion 141 on the first bracket 13a side. A second abutting buffer 22 ′ protruding toward the bracket 13a may be provided. Also in such an aspect, the nut 12 is brought into contact with the second bracket portion 142 via the first contact buffer 21 (21 ′), and the second bracket portion 142 is in contact with the second contact buffer 22 ( 22 ′) to contact the first bracket portion 132, for example, even when the nut 12 is fed at a high speed, the impact caused by the contact is affected by the first contact buffer 21 (21 ′) and It can be effectively absorbed by the second abutting buffer 22 (22 ′), and damage due to impact can be prevented.

  Further, in the present embodiment, stepped portions are provided at both side edge portions of the bracket portions 142 of the pair of second brackets 14a and 14b, and the upper surface of the stepped portion is brought into contact with the lower surface of the first connecting portion 13c. However, the present invention is not limited to this as long as each of the pair of second brackets 14a and 14b supports the first connecting portion 13c. For example, a through-hole may be provided in both side edges of each bracket portion 142 of the pair of second brackets 14a and 14b, and the first connecting portion 13c may be inserted through the through-hole.

  Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 9 is a schematic side view showing a ball screw feeding device according to a second embodiment of the present invention, and FIG. 10 is a schematic plan view showing the ball screw feeding device.

  As shown in FIGS. 9 and 10, in the ball screw feeder 20 according to the second embodiment, a pair of first screws that are arranged between the pair of second brackets 14 a and 14 b and slidably penetrate the ball screw shaft 16. A third moving support body 15 having three brackets 15a and 15b and a third connecting portion 15c for connecting the pair of third brackets 15a and 15b to each other is further provided, and the nut 12 has a pair of third brackets 15a, 15b, and is screwed to the ball screw shaft 16 via a plurality of balls (not shown) for the ball screw shaft.

  Other configurations are substantially the same as those of the first embodiment shown in FIGS. 9 and 10, the same parts as those in the first embodiment shown in FIGS. 1 and 2 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 1, the pair of third brackets 15a and 15b are slidably disposed on the bed 18 like the pair of first brackets 13a and 13b and the pair of second brackets 14b and 14b. .

  In the present embodiment, the device configuration of the first through third brackets 13a to 15a on the left side and the device configuration of the first to third brackets 13b to 15b on the right side in FIGS. The device configuration of the first to third brackets 13a to 15a will be described as a representative. FIG. 11 is a side sectional view for explaining an example of the device configuration of the first to third brackets 13a to 15a.

  As shown in FIG. 11, the third bracket 15 a is a cylindrical third sleeve portion 151 that penetrates the ball screw shaft 16, and is arranged coaxially with the third sleeve portion 151 outside the third sleeve portion 151. And a third bracket portion 152 rotatably supported by the third sleeve portion 151 via a rotary bearing 153. As shown in FIG. 11, the third bracket portion 152 can come into contact with each of the second bracket portion 142 and the nut 12.

  Specifically, the third sleeve portion 151 has an inner diameter slightly larger than the outer diameter of the ball screw shaft 16, and simply supports the ball screw shaft 16. It is slidable in the direction, but substantially immovable in the radial direction. On the other hand, the third bracket portion 152 is rotatably supported by the third sleeve portion 151 via the rotary bearing 153 and can move in the axial direction together with the third sleeve portion 151. Are now stationary.

  Thereby, even if the third bracket 15a contacts the rotating ball screw shaft 16, the third sleeve portion 151 contacting the ball screw shaft 16 is rotated together with the ball screw shaft 16, and the third bracket portion 152 rotates. Still with respect to direction. Thereby, generation | occurrence | production of the rubbing in a rotation direction in a contact location is suppressed, and the malfunction (for example, generation | occurrence | production of friction powder) by generation | occurrence | production of rubbing can be prevented.

  As shown in FIG. 11, in the present embodiment, at least a part of the end surface of the third bracket portion 152 on the nut 12 side is closer to the nut 12 side than the end surface of the third sleeve portion 151 on the nut 12 side. A projecting third abutting buffer 23 is provided. The third contact buffer 23 is specifically a cushion rubber, but may be another damper mechanism.

  Since the third abutment buffer 23 protrudes toward the nut 12 side from the end surface of the third sleeve portion 151 on the nut 12 side, the nut 12 moved in the axial direction is interposed via the third abutment buffer 23. The third bracket portion 152 is in contact with the third sleeve portion 151 and is not in contact with the third sleeve portion 151. Thereby, even when the nut 12 is fed at a high speed, for example, the impact due to the contact is effectively absorbed by the third contact buffer 23, and damage due to the impact is prevented.

  Returning to FIG. 9 and FIG. 10, the third connecting portion 15c is specifically an elongated member having rigidity, and maintains the distance between the pair of third brackets 15a and 15b at a predetermined distance. ing.

  In the present embodiment, each of the pair of third brackets 15a and 15b supports the first connecting portion 13c and the second connecting portion 14c. Specifically, two stepped portions are provided on both side edge portions of the bracket portions 152 of the pair of third brackets 15a and 15b, and the upper surface of the first stepped portion is the lower surface of the first connecting portion 13c. The upper surface of the second stepped portion is in contact with the lower surface of the second connecting portion 14c.

  As shown in FIGS. 9 and 10, the distance between the outer end faces of each of the pair of third brackets 15a and 15b is shorter than the distance between the inner end faces of each of the pair of second brackets 14a and 14b. Yes. Thereby, when one third bracket 15a is brought into contact with one second bracket 14a, the other third bracket 15b is separated from the other second bracket 14b.

  In the present embodiment, as shown in FIGS. 9 and 10, the nut 12 is brought into contact with one third bracket 15a, the one third bracket 15a is brought into contact with one second bracket 14a, In a state where one second bracket 14a is in contact with one first bracket 13a and the one first bracket 13a is as close as possible to one bearing 11a, a straight line parallel to the axis of the ball screw shaft 16 In the coordinates, when the center coordinate of the other bearing 11b is 0 and the center coordinate of the nut 12 is 1, the center coordinate of the other first bracket 13b is in the range of 0.23 to 0.33, and the other The center coordinate of the second bracket 14b is in the range of 0.45 to 0.55, and the center coordinate of the other third bracket 15b is in the range of 0.67 to 0.77. More preferably, the center coordinate of the other first bracket 13b is in the range of 0.26 to 0.30, and the center coordinate of the other second bracket 14b is in the range of 0.48 to 0.52. Yes, the center coordinates of the other third bracket 15b are in the range of 0.70 to 0.74. That is, the center-to-center distance L1 between the bearing 11b and the first bracket 13b, the center-to-center distance L2 between the first bracket 13b and the second bracket 14b, the center-to-center distance L3 between the second bracket 14b and the third bracket 15b, and the third A ratio (L1: L2: L3: L4) between the bracket 15b and the center-to-center distance L4 of the nut 12 is substantially equal to 1.25: 1: 1: 1.25.

In this case, the ball screw shaft 16 is fixedly supported by each of the pair of bearings 11a and 11b and the nut 12, and the pair of first brackets 13a and 13b, the pair of second brackets 14a and 14b, and the pair of third brackets 15a. 15b, the constant f determined by the support method is 15.1 between the bearing 11b and the first bracket 13b and between the third bracket 15b and the nut 12, and the first bracket 13b- In view of 9.7 between the second bracket 14b and between the second bracket 14b and the third bracket 15b, as shown in FIG. 12, between the bearing 11b and the first bracket 13b, the first bracket 13b- Between the second bracket 14b, between the second bracket 14b and the third bracket 15b, and the third bracket Critical speed at each between Tsu preparative 15b- nut 12 is substantially equal. Thus, it is possible to increase the maximum allowable speed n _c of the ball screw shaft 16 effectively.

Specifically, the constant f determined by the support method between the first bracket 13b and the second bracket 14b and between the second bracket 14b and the third bracket 15b is the first to third movement support bodies 13 to 15. (9.7 / 21.9 =) 0.443 times as compared with the case where the first to third moving support bodies 13 to 15 are not provided. by has been to (1 / (1.25 + 1 + 1 + 1.25) =) 0.222 times that, with reference to the above equation (1), the maximum allowable speed _{n c} of the ball screw shaft 16, first to Compared with the case where the third moving support bodies 13 to 15 are not provided, the speed can be increased to about 9.0 times (0.443 / 0.222 ² =). Thereby, even in the ball screw shaft 16 having a long stroke, it is possible to effectively prevent occurrence of abnormal vibration due to high-speed rotation.

  Next, the operation of the present embodiment as described above will be described.

  As shown in FIGS. 9 and 10, the nut 12 is in contact with the left third bracket 15a, the left third bracket 15a is in contact with the left second bracket 14a, and the left second bracket 14a. Is brought into contact with the left first bracket 13a, and the ball screw shaft 16 is rotated by the rotation driving device 17 in a state where the left first bracket 13a is as close as possible to the left bearing 11a. The nut 12 is moved rightward in the axial direction. Here, even if the pair of first brackets 13a and 13b and / or the pair of second brackets 14a and 14b and / or the pair of third brackets 15a and 15c come into contact with the rotating ball screw shaft 16, each sleeve portion By rotating 131, 141, 151 together with the ball screw shaft 16, the occurrence of rubbing at the contact location is suppressed, and problems due to the occurrence of rubbing (for example, generation of friction powder) can be prevented.

  Next, as shown in FIG. 13A, the nut 12 that is moved to the right in the axial direction by the rotation of the ball screw shaft 16 is brought into contact with the right third bracket 15b. Specifically, the nut 12 is brought into contact with the third bracket portion 152 of the third bracket 15 b via the third contact buffer 23. In the present embodiment, the impact due to the contact is effectively absorbed by the first contact buffer 23, so that damage due to the impact is prevented even when the nut 12 is moved at a high speed. Thereafter, the nut 12 that is moved to the right in the axial direction by the rotation of the ball screw shaft 16 pushes the abutted right third bracket 15b to the right in the axial direction. Thereby, the third movement support body 15 is moved to the right in the axial direction together with the nut 12.

  Next, as shown in FIG. 13B, the third movement support body 15 that is moved to the right in the axial direction together with the nut 12 by the rotation of the ball screw shaft 16 is brought into contact with the second bracket 14b on the right side. . Specifically, the third bracket portion 152 of the right third bracket 15b is brought into contact with the second bracket portion 142 of the second bracket 14b via the first contact buffer 21. In the present embodiment, since the impact due to the contact is effectively absorbed by the first contact buffer 21, even if the nut 12 and the third movement support body 15 are moved at high speed, the impact Damage due to is prevented. Thereafter, the third movement support body 15 moved to the right in the axial direction together with the nut 12 by the rotation of the ball screw shaft 16 pushes the abutted right second bracket 14b in the right direction in the axial direction. Thereby, the second movement support body 14 is moved rightward in the axial direction together with the third movement support body 15 and the nut 12.

  Next, as shown in FIG. 13C, the second movement support body 14 that is moved axially right together with the nut 12 and the third movement support body 15 by the rotation of the ball screw shaft 16 is It abuts on the bracket 13b. Specifically, the second bracket portion 142 of the right second bracket 14b is brought into contact with the first bracket portion 132 of the first bracket 13b via the second contact buffer 22. In the present embodiment, since the impact caused by the contact is effectively absorbed by the second contact buffer 22, the nut 12, the third movement support body 15, and the second movement support body 14 are moved at high speed. Even in this case, damage due to impact is prevented. After that, the second movement support body 14 that is moved to the right in the axial direction together with the nut 12 and the third movement support body 15 by the rotation of the ball screw shaft 16 moves the abutted right first bracket 13b to the right in the axial direction. Push it. Accordingly, the first movement support body 13 is moved rightward in the axial direction together with the second movement support body 14, the third movement support body 15, and the nut 12.

  Next, as shown in FIG. 13 (d), the first movement support body moved rightward in the axial direction together with the nut 12, the third movement support body 15, and the second movement support body 14 by the rotation of the ball screw shaft 16. 13 is as close as possible to the right bearing 11b.

As described above, according to the present embodiment, the ball screw shaft 16 is fixedly supported by each of the pair of bearings 11a and 11b and the nut 12, and the pair of first brackets 13a and 13b and the pair of second brackets 14a. 14b and each of the pair of third brackets 15a and 15b, in particular, between the first bracket 13a (13b) and the second bracket 14a (14b) and between the second bracket 14a (14b) and the third bracket 15a. Between (15b), the constant f determined by the support method is smaller than when the moving support bodies 13 and 14 are not provided (specifically, (9.7 / 21.9 =) 0.443 times). However, the distance L between the support points is also shortened (specifically, the critical speeds between the support points are equalized as shown in FIG. 12). The case, made to 0.222 times). As a result, with reference to the above equation (1), the maximum allowable speed n _c of the ball screw shaft 16, the more significant (specifically as compared with a case without the mobile support member (0.443 / 0. 222 ² =) up to about 9.0 times). Thereby, even in the ball screw shaft 16 having a long stroke, it is possible to effectively prevent occurrence of abnormal vibration due to high-speed rotation.

  Further, according to the present embodiment, the nut 12 is brought into contact with one third bracket 15a (15b), and the one third bracket 15a (15b) is brought into contact with one second bracket 14a (14b). The one second bracket 14a (14b) is brought into contact with the one first bracket 13a (13b), and the one first bracket 13a (13b) is made as close as possible to the one bearing 11a (11b). In the close state, when the center coordinate of the other bearing 11b (11a) is 0 and the center coordinate of the nut 12 is 1 in the linear coordinates parallel to the axis of the ball screw shaft 16, the other first bracket 13b (13a ) Is in the range of 0.23 to 0.33, and the center coordinate of the other second bracket 14b (14a) is in the range of 0.45 to 0.55. Since the center coordinates of the bracket 15b (15a) are in the range of 0.67 to 0.77, the distance between the bearing 11b (11a) and the first bracket 13b (13a), the first bracket 13b (13a) and the second bracket The critical speeds are substantially equal between 14b (14a), between the second bracket 14b (14a) and the third bracket 15b (15a), and between the third bracket 15b (15a) and the nut 12. Thereby, the maximum permissible rotational speed of the ball screw shaft 16 can be effectively increased.

  Further, according to the present embodiment, each of the pair of second brackets 14a, 14b supports the first connecting portion 13c, and each of the pair of third brackets 15a, 15b Since the connecting portion 13c and the second connecting portion 14c are supported, the distance between the pair of first brackets 13a and 13b is designed to be wide corresponding to the ball screw shaft 16 having a long stroke. Even if it exists, the bending deformation by the gravity of the 1st connection part 13c which connects the pair of said 1st brackets 13a and 13b mutually is effective by each of a pair of 2nd brackets 14a and 14b and a pair of 3rd brackets 15a and 15b. Can be prevented. Further, the deformation of the second connecting portion 14c that connects the pair of second brackets 14a and 14b due to gravity can be effectively prevented by each of the pair of third brackets 15a and 15b.

  In the present embodiment, as shown in FIG. 11, at least part of the end surface of the third bracket portion 152 on the nut 12 side is closer to the nut 12 side than the end surface of the third sleeve portion 151 on the nut 12 side. The protruding third abutting buffer 23 is provided, but is not limited to this, and at least a part of the end surface of the nut 12 facing the third bracket 15a on the third bracket 15a side, A third abutting buffer that protrudes further toward the third bracket 15a than a portion facing the third sleeve portion 151 may be provided. Also according to such an aspect, the nut 12 is brought into contact with the third bracket portion 152 via the third contact buffer, so that, for example, even when the nut 12 is fed at a high speed, the impact caused by the contact. Is effectively absorbed by the third contact buffer, and damage due to impact can be prevented.

  In the present embodiment, two stepped portions are provided on both side edges of the bracket portions 152 of the pair of third brackets 15a and 15b, and the upper surface of the first stepped portion is the first connecting portion 13c. The upper surface of the second step portion is in contact with the lower surface of the second connecting portion 14c, but each of the pair of third brackets 15a and 15b is connected to the first connecting portion 13c. And as long as it supports the 2nd connection part 14c, it is not limited to this. For example, two through holes are provided in both side edge portions of each of the bracket portions 152 of the pair of third brackets 15a and 15b, the first connecting portion 13c is inserted into one through hole, and the other through hole is provided. The 2nd connection part 14c may be penetrated by the hole.

10 ball screw feeder 11a bearing 11b bearing 12 nut 13 first movement support body 13a first bracket 13b first bracket 13c first connection part 131 first sleeve part 132 first bracket part 133 rotary bearing 14 second movement support body 14a first Two brackets 14b Second bracket 14c Second connecting portion 141 Second sleeve portion 142 Second bracket portion 143 Rotating bearing 15 Third movement support body 15a Third bracket 15b Third bracket 15c Third connecting portion 151 Third sleeve portion 152 First Three bracket portion 153 Rotating bearing 16 Ball screw shaft 17 Rotating drive portion 18 Bed 19 Table 20 Ball screw feeder 21 First abutting buffer 21 ′ First abutting buffer 22 Second abutting buffer 22 ′ Second abutting buffer Body 23 Third contact buffer

Claims (14)

A ball screw shaft;
A pair of bearings rotatably supporting the ball screw shaft;
A pair of first brackets disposed between the pair of bearings and slidably penetrating the ball screw shaft, and the pair of first brackets so as to maintain a predetermined distance between the pair of first brackets A first connecting part for connecting the two to each other, and a first moving support body,
A pair of second brackets disposed between the pair of first brackets and slidably penetrating the ball screw shaft, and the pair of second brackets so as to maintain a predetermined distance between the pair of second brackets . A second moving support body having a second connecting portion for connecting the two brackets to each other;
A nut disposed between the pair of second brackets and screwed to the ball screw shaft via a plurality of balls for the ball screw shaft;
With
The first movement support body and the second movement support body are movable independently of each other;
When one of the pair of second brackets comes into contact with one of the pair of first brackets, the other of the pair of second brackets is separated from the other of the pair of first brackets. A ball screw feeding device. The nut is in contact with one of the pair of second brackets, one of the pair of second brackets is in contact with one of the pair of first brackets, and one of the pair of first brackets is in the pair of pairs When as close as possible to one of the bearings,
In a linear coordinate parallel to the axis of the ball screw shaft, when the other center coordinate of the pair of bearings is 0 and the center coordinate of the nut is 1,
The other center coordinate of the pair of first brackets is in the range of 0.3 to 0.4,
2. The ball screw feeder according to claim 1, wherein a center coordinate of the other of the pair of second brackets is in a range of 0.6 to 0.7. The ball screw feeder according to claim 1, wherein each of the pair of second brackets is configured to support the first connecting portion. Each of the pair of second brackets includes a cylindrical second sleeve portion that passes through the ball screw shaft, and the second sleeve portion is disposed coaxially with the second sleeve portion outside the second sleeve portion. A second bracket part rotatably supported via a rotary bearing, and the second bracket part and the nut can come into contact with each other.
Each of the pair of first brackets includes a cylindrical first sleeve portion that passes through the ball screw shaft, and the first sleeve portion is disposed outside the first sleeve portion and coaxially with the first sleeve portion. A first bracket portion rotatably supported via a rotary bearing, and the first bracket portion and the second bracket portion of the second bracket can be brought into contact with each other. The ball screw feeder according to any one of claims 1 to 3. At least a part of the end surface on the nut side of the second bracket portion is provided with a first abutting buffer that protrudes toward the nut side from the end surface on the nut side of the second sleeve portion,
At least a part of the end surface of the first bracket portion on the second bracket side is provided with a second contact buffer that protrudes toward the second bracket side from the end surface of the first sleeve portion on the second bracket side. The ball screw feeder according to claim 4, wherein the ball screw feeder is provided. At least a part of the end surface on the nut side of the second bracket portion is provided with a first abutting buffer that protrudes toward the nut side from the end surface on the nut side of the second sleeve portion,
At least a part of the end surface of the second bracket portion on the first bracket side is provided with a second abutting buffer that protrudes closer to the first bracket side than the end surface of the second sleeve portion on the first bracket side. The ball screw feeder according to claim 4, wherein the ball screw feeder is provided. At least a part of the end surface of the nut facing the second bracket portion of the end surface on the second bracket side protrudes toward the second bracket side from the portion facing the second sleeve portion. A contact buffer is provided,
At least a part of the end surface of the first bracket portion on the second bracket side is provided with a second contact buffer that protrudes toward the second bracket side from the end surface of the first sleeve portion on the second bracket side. The ball screw feeder according to claim 4, wherein the ball screw feeder is provided. At least a part of the end surface of the nut facing the second bracket portion of the end surface on the second bracket side protrudes toward the second bracket side from the portion facing the second sleeve portion. A contact buffer is provided,
At least a part of the end surface of the second bracket portion on the first bracket side is provided with a second abutting buffer that protrudes closer to the first bracket side than the end surface of the second sleeve portion on the first bracket side. The ball screw feeder according to claim 4, wherein the ball screw feeder is provided. The distance between the centers of the pair of bearings is 8000 mm to 12000 mm,
The ball screw feeder according to any one of claims 1 to 8, wherein a valley diameter of the ball screw shaft is 60 mm to 100 mm. A ball screw shaft;
A pair of bearings rotatably supporting the ball screw shaft;
A pair of first brackets disposed between the pair of bearings and slidably penetrating the ball screw shaft, and the pair of first brackets so as to maintain a predetermined distance between the pair of first brackets A first connecting part for connecting the two to each other, and a first moving support body,
A pair of second brackets disposed between the pair of first brackets and slidably penetrating the ball screw shaft, and the pair of second brackets so as to maintain a predetermined distance between the pair of second brackets . A second moving support body having a second connecting portion for connecting the two brackets to each other;
A pair of third brackets disposed between the pair of second brackets and slidably penetrating the ball screw shaft, and the pair of first brackets so as to maintain a predetermined distance between the pair of third brackets . A third moving support body having a third connecting portion for connecting the three brackets to each other;
A nut disposed between the pair of third brackets and screwed to the ball screw shaft via a plurality of balls for the ball screw shaft;
With
The first movement support body, the second movement support body and the third movement support body are movable independently of each other;
When one of the pair of third brackets comes into contact with one of the pair of second brackets, the other of the pair of third brackets is separated from the other of the pair of second brackets,
When one of the pair of second brackets comes into contact with one of the pair of first brackets, the other of the pair of second brackets is separated from the other of the pair of first brackets. A ball screw feeding device. The nut is in contact with one of the pair of third brackets, one of the pair of third brackets is in contact with one of the pair of second brackets, and one of the pair of second brackets is in the pair of pairs In a state in which one of the first brackets is in contact with one of the pair of bearings as close as possible to one of the first brackets,
In a linear coordinate parallel to the axis of the ball screw shaft, when the other center coordinate of the pair of bearings is 0 and the center coordinate of the nut is 1,
The other center coordinate of the pair of first brackets is in the range of 0.23 to 0.33, and the other center coordinate of the pair of second brackets is in the range of 0.45 to 0.55. The ball screw feeder according to claim 10, wherein the center coordinates of the other of the pair of third brackets are within a range of 0.67 to 0.77. Each of the pair of second brackets is adapted to support the first connecting portion,
The ball screw feeder according to claim 10 or 11, wherein each of the pair of third brackets supports the first connecting portion and the second connecting portion. Each of the pair of third brackets includes a cylindrical third sleeve portion that passes through the ball screw shaft, and the third sleeve portion is disposed coaxially with the third sleeve portion outside the third sleeve portion. A third bracket portion rotatably supported via a rotary bearing, and the third bracket portion and the nut can come into contact with each other.
Each of the pair of second brackets includes a cylindrical second sleeve portion that passes through the ball screw shaft, and the second sleeve portion is disposed coaxially with the second sleeve portion outside the second sleeve portion. A second bracket portion rotatably supported via a rotary bearing, and the second bracket portion and the third bracket portion of the third bracket can contact each other,
Each of the pair of first brackets includes a cylindrical first sleeve portion that passes through the ball screw shaft, and the first sleeve portion is disposed outside the first sleeve portion and coaxially with the first sleeve portion. A first bracket portion rotatably supported via a rotary bearing, and the first bracket portion and the second bracket portion of the second bracket can be brought into contact with each other. The ball screw feeder according to any one of claims 10 to 12. The distance between the centers of the pair of bearings is 10600 mm to 16000 mm,
The ball screw feeder according to any one of claims 10 to 13, wherein a valley diameter of the ball screw shaft is 60 mm to 100 mm.

Images