JP5622614B2 - Rotating shaft device - Google Patents

Description

  The present invention relates to a rotary shaft device that enables balance correction when a rotary shaft rotates.

For example, in a machine tool, one of a tool and a workpiece is attached to a main shaft serving as a rotating shaft, and machining is performed while making a relative movement with the other of the tool or the workpiece. With the recent demand for higher speed and higher efficiency of machining, the spindle rotation speed has been increased, but on the other hand, the vibration generated during rotation due to the unbalance of the spindle has increased, which has deteriorated machining accuracy and damaged the bearing. It is becoming a problem as it leads to
Under such circumstances, in order to remove the unbalance of the main shaft, for example, in Patent Document 1, a screw hole is formed in the front end surface of the main shaft, and a necessary weight is set in the screw hole according to the length. And a structure for adjusting the balance by screwing a weight including a screw portion screwed into the screw hole.

JP-A-8-174370

  However, in the invention of Patent Document 1, since the weight is determined by the length of the mass portion, it is necessary to prepare a plurality of weights having different lengths of the mass portion, and when the required weight is different, screw holes The weight must be extracted from the screw and another weight must be screwed together, which takes time and effort to adjust the balance.

  Therefore, the present invention has an object to provide a rotary shaft device that can easily perform balance adjustment in a short time even when using such a weight and is excellent in workability related to balance adjustment. .

In order to achieve the above object, the invention described in claim 1 is a rotary shaft device that supports a rotary shaft that is rotationally driven,
A plurality of holes extending in parallel to the axis of the rotary shaft from at least one end surface of the rotary shaft and having a female screw portion on the inner periphery on the opening side are arranged at equal intervals in the circumferential direction concentrically with the axis. And a rod-shaped weight member having a male screw part that can be screwed into the female screw part at the end thereof is inserted into the hole, and the screwing depth of the male screw part with respect to the female screw part is set to the weight. By setting for each member, it is possible to adjust the balance of the rotating shaft by moving the weight member in the axial direction, and further screwing a screw member into the female screw portion into which the weight member is inserted, The weight member is fixed by bringing a screw member into contact with an end face of the weight member .
According to a second aspect of the present invention, in the configuration of the first aspect, the end of the hole is disposed between a plurality of bearings that are arranged at predetermined intervals in the axial direction of the rotary shaft and support the rotary shaft. It is characterized by being positioned.
According to a third aspect of the present invention, in the configuration of the first or second aspect , the length of the screw member is changed in accordance with the screwing depth of the weight member.
According to a fourth aspect of the present invention, in the configuration according to any one of the first to third aspects, the female screw portion is screwed with a back side portion where the male screw portion of the weight member is screwed with the screw member. It is divided into an opening side portion, and the lead of the screw is made different between the back side portion and the opening side portion.
According to a fifth aspect of the present invention, in the configuration according to any one of the first to fourth aspects, the female screw portion is screwed with a back side portion where the male screw portion of the weight member is screwed with the screw member. It divides | segments into the opening side part, The said opening side part was formed in the eccentric position with respect to the said back side part, It is characterized by the above-mentioned.

According to the first aspect of the present invention, the balance can be adjusted simply by screwing an arbitrary weight member back and forth. Therefore, the balance adjustment can be easily performed in a short time, and the workability related to the balance adjustment is excellent. Further, since the work from the end face of the rotating shaft is sufficient, it is effective in a structure in which the unbalance of the rotating shaft can be corrected only from one end face.
Further, the adoption of the screw member eliminates the possibility that the weight member will accidentally move from the set screw-in depth, thereby increasing the reliability of the balance adjustment.
According to the second aspect of the present invention, in addition to the effect of the first aspect, the imbalance between the bearings can be efficiently corrected, and the unbalance vibration and rotational runout during high-speed rotation can be efficiently reduced. .
According to the third aspect of the invention, in addition to the effect of the first or second aspect, by adjusting the length of the screw member, the balance adjustment on the back side can be performed without changing the balance on the end face side of the rotating shaft. It becomes possible.
According to the inventions of claims 4 and 5 , in addition to the above effects, there is a possibility that the weight member may be rotated even if the screw member screwed in when the weight member is fixed by the screw member contacts the weight member. Disappear.

It is explanatory drawing of a main axis | shaft apparatus, (A) shows the longitudinal cross-section of an upper half, (B) shows the rear-end surface of a main axis | shaft, respectively. (A) is explanatory drawing of a weight member, (B) is explanatory drawing of a screw member. (A) (B) is explanatory drawing which shows the insertion state of the weight member. (A) (B) is explanatory drawing which shows the example of a change which changed the lead of the screw. It is explanatory drawing which shows the example of a change which made the opening side part of the internal thread part eccentric.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an example of the rotary shaft device. This is a spindle device of a machine tool that performs machining by rotating a tool such as a machining center, where (A) shows a vertical section of the upper half, and (B) shows a rear end surface of the spindle. In the main shaft device 1, a main shaft 3 is rotatably supported in a cylindrical housing 2 via a plurality of bearings 4, 4,. This spindle device 1 has a so-called built-in motor structure. A rotor 6 constituting a motor 5 is assembled on the outer circumference of the spindle 3, and a stator 7 is assembled on the outer circumference of the housing 2 on the inner circumference of the housing 2. 3 is configured to rotate as an output shaft of the motor 5.

  A tool holder 8 can be attached to the front end of the main shaft 3 (the left side of FIG. 1A is the front). This tool holder 8 is held via a holding mechanism (not shown) provided at the front end of the draw bar 9 by drawing a draw bar 9 that can be moved back and forth around the axis of the main shaft 3 by a disc spring 10, 10. Is done.

On the other hand, a hole 11 formed in the main shaft 3 from the rear end surface to the front and having a terminal end reaching the inside of the rotor 6 between the bearings 4 and 4 is concentric with the shaft center of the main shaft 3 at equal intervals in the circumferential direction. 6 places are provided. A female screw portion 12 is formed on the inner periphery of each hole 11 on the inlet side.
A weight member 13 and a screw member 16 as shown in FIG. 2 can be inserted into each hole 11. First, the weight member 13 is a shaft body having a male screw portion 14 on the outer periphery of the rear end, and a hexagonal hole 15 is formed on the rear end surface. The male screw portion 14 is formed with a dimension slightly shorter than half of the axial length of the female screw portion 12 of the hole 11.

Next, the screw member 16 is a shaft body in which the male screw portion 17 is formed over the entire length in the axial direction, and a hexagonal hole 18 is formed in the rear end surface. The screw member 16 is also formed with a dimension slightly shorter than half of the axial length of the female screw portion 12 of the hole 11.
Therefore, the weight member 13 is inserted into the hole 11 from the front end without the male screw portion 14, the male screw portion 14 is screwed into the female screw portion 12, and the screw member 13 is screwed with a hexagonal bar wrench using the hexagonal hole 15. Thus, it can be moved in the axial direction within the hole 11. If the weight member 13 is screwed into the hole 11 in this way, then the screw member 16 is screwed into the female screw portion 12 and screwed with a hexagonal bar wrench using the hexagonal hole 18 as shown in FIG. ), The screw member 16 can contact the weight member 13 to fix the weight member 13.

The spindle device 1 configured as described above is used in a state where the weight member 13 and the screw member 16 are accommodated in all the holes 11. When there is an unbalance between the rear bearings 4 and 4, the screw member 16 is first removed in the hole 11 having an appropriate phase, and the exposed weight member 13 is rotated according to the unbalance amount to be axially moved. Move back and forth. The weight corresponding to the space generated by this back-and-forth movement can be matched with the unbalance amount to be corrected. If the screw member 16 is screwed in again after the correction and the weight member 13 is fixed, the balance adjustment is completed.
At this time, as shown in FIG. 3B, the screw member 16 is adapted to the depth on the inlet side of the hole 11 changed by the back-and-forth movement of the weight member 13, so that the rear end of the spindle 1 is used. The unbalance amount may not be changed. On the contrary, it is possible to correct the balance at the rear end of the main shaft 1 by changing the length of the screw member 16.

  As described above, according to the spindle device 1 of the above-described form, the hole 11 that extends in parallel to the axis of the spindle 3 from the rear end surface and has the female screw portion 12 on the inner periphery on the opening side is concentric with the axis. In the rod shape, a plurality of positions are provided at equal intervals in the circumferential direction, and a male screw portion 14 is formed at the end of the hole 11 and can be screwed into the female screw portion 12 and has a shorter axial length than the female screw portion 12. Can be adjusted by moving the weight member 13 in the axial direction by setting the screwing depth of the male screw portion 14 with respect to the female screw portion 12 for each weight member 13. Thus, the balance can be adjusted simply by screwing the arbitrary weight member 13 back and forth. Therefore, the balance adjustment can be easily performed in a short time, and the workability related to the balance adjustment is excellent. Further, since the work from the end surface of the main shaft 1 is sufficient, it is effective in a structure in which the unbalance of the main shaft 1 can be corrected only from one end surface.

Particularly, since the end of the hole 11 is positioned between the plurality of bearings 4 and 4 that support the main shaft 3, the imbalance between the bearings 4 and 4 can be corrected efficiently, and at high speed rotation. It is possible to efficiently reduce unbalanced vibration and rotational vibration.
Further, since the screw member 16 is further screwed into the female screw portion 12 and the screw member 16 is brought into contact with the weight member 13 to fix the weight member 13, the weight member 13 is accidentally formed from the set screwing depth. There is no risk of moving to the balance, and the reliability of the balance adjustment is increased.

In the above configuration, the weight member and the screw member are screwed into the same female screw portion. However, when the screw member is screwed in, the weight member rotates (accompanying the weight member). The balance of adjustment may be lost.
As a solution to this, the structure shown in FIG. This is because a bottomed hole 19 having a diameter larger than that of the hole 11 is formed on the rear end surface of the main shaft 3 and the hole 11 is formed from the bottom of the bottomed hole 19, and is coaxial and the same diameter as the hole 11. A separate ring-shaped member 20 having a female screw portion 21 having a larger lead than the portion 12 is assembled, and a screw member 16a having a male screw portion 17a of the same lead is screwed into the female screw portion 21. That is, the female screw portion is divided into a female screw portion 12 in the back side portion and a female screw portion 21 in the opening side portion, and the lead of the screw is made different in the back side portion and the opening side portion. .

As described above, the screw member 16a screwed into the weight member 13 when the weight member 13 is fixed by the screw member 16a is divided into the female screw portions 12 and 21 and the lead of each screw is made different. There is no possibility that the weight member 13 will rotate with the contact. Also in this case, as shown in FIG. 4B, the length of the screw member 16a may be changed in accordance with the screwing position of the weight member 13, or the magnitude relationship of the leads may be reversed.
Further, as another solution, as shown in FIG. 5, it is conceivable to provide the female screw portion 21 provided in the ring-shaped member 20 at a position eccentric from the hole 11 by a predetermined distance S. Also in this case, the accompanying weight member 13 can be prevented. The screw leads of the weight member 13 and the screw member 16 may be the same or different.
4 and 5, in order to facilitate the insertion of the tool into the hexagonal hole 15 in the configuration including the ring-shaped member 20 having the female screw portion 21 into which the screw member 16a is screwed. The male screw portion 14 of the weight member 13 may be longer than the female screw portion 12 of the main shaft 3 and protrude into the bottomed hole 19.

In addition, the position and number of the holes are not limited to the above-described form, and may be increased or decreased as appropriate, and the number of weight members and screw members may be increased or decreased accordingly. Further, the end of the hole may be further extended if possible. Further, it is possible to omit the screw member and adjust the balance only with the weight member.
Moreover, in the said form, although a hole is formed only from the rear-end surface of a main axis | shaft and insertion of a weight member is possible, it is good also as a hole formed also in a front-end surface, and enabling a weight member to be inserted. In this case, the holes may be the same phase before and after to form one through hole.

  1 .. Main shaft device, 2 .. Housing, 3 .. Main shaft, 4 .. Bearing, 5 .. Motor, 6 .. Rotor, 7 .. Stator, 9 .. Drawbar, 11. -Female thread part, 13 ... Weight member, 14 ... Male screw part, 16, 16a ... Screw member, 17, 17a ... Male thread part, 19 ... Bottomed hole, 20 ... Ring-shaped member.

Claims (5)

A rotary shaft device that supports a rotary shaft that is driven to rotate,
A plurality of holes extending in parallel to the axis of the rotary shaft from at least one end surface of the rotary shaft and having a female screw portion on the inner periphery on the opening side are arranged at equal intervals in the circumferential direction concentrically with the axis. And a rod-shaped weight member having a male screw part that can be screwed into the female screw part at the end thereof is inserted into the hole, and the screwing depth of the male screw part with respect to the female screw part is set to the weight. By setting for each member, it is possible to adjust the balance of the rotating shaft by moving the weight member in the axial direction, and further screwing a screw member into the female screw portion into which the weight member is inserted, A rotary shaft device , wherein a screw member is brought into contact with an end surface of the weight member to fix the weight member .   2. The rotating shaft according to claim 1, wherein the end of the hole is positioned between a plurality of bearings arranged at predetermined intervals in the axial direction of the rotating shaft and supporting the rotating shaft. apparatus. Rotating shaft apparatus according to claim 1 or 2, characterized in that the length of the screw member, was changed to fit the screwing depth of the weight member. The female screw portion is divided into a back side portion into which the male screw portion of the weight member is screwed and an opening side portion into which the screw member is screwed, and the screw portion is divided into the back side portion and the opening side portion. rotary shaft device according to any one of claims 1 to 3, characterized in that with different lead. The female screw portion is divided into a back side portion into which the male screw portion of the weight member is screwed and an opening side portion into which the screw member is screwed, and the opening side portion is eccentric with respect to the back side portion. The rotary shaft device according to claim 1 , wherein the rotary shaft device is formed as described above.

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