JP2008290219A - Spindle device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spindle device capable of preventing foreign matter from intruding in the device, allowing unrestricted installing position for a balance correction plane, conducting the balance correction on multiple planes, and substantially reducing vibration and noise of the device. <P>SOLUTION: The spindle device is provided with a plurality of rolling bearings 13, a spindle 12 rotatably supported by the rolling bearings 13, a balancer mounting holes 20, 20 provided on a central axis CL of the spindle 12 from its end face sides, and a plurality of balancers 30, 30 etc., fit and mounted in the balancer mounting holes 20, 20. The plurality of balancers 30, 30 etc. are mounted at arbitrary positions in the axial direction of the balancer mounting holes 20, 20. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a spindle device, and more particularly to a spindle device that can effectively reduce vibration in a high-speed rotation region.

  In a spindle device of a machine tool that rotates at high speed, balance correction is performed in order to reduce vibration that has an important effect on machining accuracy. Conventionally, the balance correction is performed by handling the main shaft as a rigid rotor (assuming that the main shaft is not deformed even if there is an unbalance) and by correcting the balance of the two surfaces after the main shaft is assembled (two-surface correction) (for example, Patent Document 1). Since this balance correction can be performed on the front and rear end faces of the main shaft, there is an advantage that the work is easy. However, in recent years, there is a tendency to rotate the machine tool main shaft at a high speed in order to improve machining efficiency, and the main shaft may be deformed with an increase in the number of rotations, and vibration may be generated due to unbalance caused by the deformation. Therefore, the main shaft is treated as an elastic rotor, and in addition to correcting the balance on the front and rear sides of the main shaft, a multi-surface correction is proposed that corrects the balance on three or more surfaces with a new balance correction surface in the middle. (For example, see Patent Documents 2 and 3).

Japanese Patent Laid-Open No. 06-126588 Japanese Patent Laid-Open No. 2003-127041 Japanese Patent Laid-Open No. 2006-82165

  Further, in order to reduce vibrations at high speed rotation, it is not sufficient to correct the balance with the main spindle alone, and it is required to perform the balance correction after assembling the main spindle device. For this reason, in order to perform multi-face correction, it is necessary to provide a structure that allows external access (balance correction) to a new balance correction face located between the front side and the rear side. In the spindle device described in Patent Document 2, the bearing cooling groove and the motor cooling groove are separated, an adjustment screw mounting hole is provided in the middle, and the balance correction hole is provided from the mounting hole. Screws can be inserted and fixed to the main shaft. Further, in the spindle device described in Patent Document 3, a balancer made of resin is provided at both axial ends and the center of the spindle, and a balance is obtained by scraping a part of the resin at the center from the opening provided in the housing. It has been corrected.

  However, in the spindle device described in Patent Document 2, the mounting hole and the opening provided for accessing the center balance correction surface must avoid interference with the motor rotor and the stator. Since there is a restriction on the installation position, there is a possibility that sufficient balance correction cannot be performed. Further, in the spindle device described in Patent Document 3, foreign matter may enter the device when accessing the balancer from the opening provided in the housing or when cutting the balancer, and abnormal vibration of the device, There is a possibility that the bearing may cause damage to the device or shorten the life of the device due to the foreign matter.

  The present invention has been made to eliminate such inconveniences, and its purpose is to prevent foreign matter from entering the apparatus, and there is no restriction on the position where the balance correction surface is installed. An object of the present invention is to provide a spindle apparatus that can perform balance correction and can significantly reduce vibration and noise of the apparatus.

The above object of the present invention can be achieved by the following constitution.
(1) A main shaft device comprising a plurality of rolling bearings and a main shaft rotatably supported by the rolling bearing, wherein at least one balancer mounting hole provided from an end surface on the central axis of the main shaft, and a balancer mounting hole And a balancer attached to the balancer attachment hole at an arbitrary position in the axial direction.
(2) The balancer includes a plurality of female screw portions that are arranged at substantially equal intervals in the circumferential direction and are formed along the axial direction, and a screw weight that is screwed onto at least one of the plurality of female screw portions. The spindle device according to (1), wherein screw spindles are screwed onto the plurality of female screw portions to give the spindle an unbalance amount necessary for correcting the rotational balance of the spindle.

  According to the spindle device of the present invention, the balancer mounting hole has at least one balancer mounting hole provided from the end surface on the central axis of the spindle and at least one balancer fitted and attached to the balancer mounting hole. Since the balancer is attached at an arbitrary position in the axial direction, not only the balance correction at both ends of the main shaft but also the balance correction at an arbitrary position in the axial direction of the main shaft can be performed. Thereby, since balance correction (multi-surface correction) can be performed on three or more surfaces, the vibration and noise of the apparatus can be greatly reduced. In addition, since the balancer can be installed in the balancer mounting hole and the balancer can be installed from the end face side of the device, the balancer can be moved freely in the axial direction of the main shaft without being restricted by the position of the motor or cooling hole. It can be arranged at the position. Furthermore, since the balancer mounting hole is provided from the end surface of the main shaft, even if the balancer is shaved with the balancer assembled to the main shaft, foreign matter does not enter the apparatus (such as a bearing).

  Hereinafter, embodiments of a spindle device according to the present invention will be described in detail with reference to the drawings.

(First embodiment)
First, a first embodiment of a spindle device according to the present invention will be described with reference to FIGS.
1 is a schematic configuration diagram for explaining a first embodiment of a spindle device according to the present invention, FIG. 2 is an enlarged cross-sectional view of a portion A in FIG. 1, and FIG. 3 is a view of the balancer shown in FIG. FIG.

  As shown in FIG. 1, the spindle device 10 of the present embodiment includes a housing 11, a spindle 12, a pair of ball bearings (rolling bearings) 13 and 13 that rotatably support the spindle 12 with respect to the housing 11, Is provided. The ball bearings 13 are respectively arranged on the front side and the rear side of the main shaft 12, the outer ring 14 is fitted on the inner peripheral surface of the housing 11, and the inner ring 15 is fitted on the outer peripheral surface of the main shaft 12.

  A motor unit 16 is disposed at a substantially central portion in the axial direction of the spindle device 10. The motor unit 16 includes a rotor 17 fixed to the outer peripheral surface of the main shaft 12, and the rotor 17 in the radial direction. And a stator 18 that is disposed to face and is fixed to the inner peripheral surface of the housing 11.

  In the present embodiment, as shown in FIGS. 1 to 3, balancer mounting holes 20 and 20 are formed on the central axis CL of the main shaft 12 from the front end surface 12 f and the rear end surface 12 r toward the center. . The balancer mounting hole 20 has three holes 21a, 21b, and 21c having diameters that are gradually reduced from the end surface and having different diameters. The inner end surface in the axial direction of the inner peripheral surface of the holes 21a, 21b, and 21c The female screw portion 22 is formed. Further, the balancer 30 is attached to the holes 21a, 21b, 21c of the balancer attachment hole 20, respectively.

  As shown in FIGS. 2 and 3, the balancer 30 is a substantially columnar member, and is arranged along the axial direction with the male screw portions 31 formed on the outer peripheral surface, arranged at substantially equal intervals in the circumferential direction. And a plurality of screw weights 33 screwed to the plurality of female screw portions 32. The plurality of screw weights 33 are balance adjusting weights each adjusted to a predetermined mass, and a screw portion (not shown) that is screwed with the plurality of female screw portions 32 is formed on the outer peripheral surface thereof. If the balancer 30 is balanced without screwing the screw weight 33, the screw weight 33 may not be used for the balancer 30.

  The balancer 30 is fixed to the main shaft 12 by screwing the male screw portion 31 into the female screw portion 22 of each hole 21a, 21b, 21c. Further, when the balancer 30 is fixed, the balancer 30 abuts against the end faces of the holes 21a, 21b, and 21c of the balancer mounting hole 20, so that the phase in the rotation direction of the balancer 30 is always constant. For this reason, even if the balancer 30 is removed once, the same phase is reproduced by reattaching it.

  Here, each predetermined mass of the screw weight 33 is a mass necessary and sufficient for correcting the rotational balance of the main shaft 12 in total, and a part of the screw weight 33 is cut or The mass is adjusted by appropriate means, such as forming with different materials. Then, by adjusting and screwing the screw weights 33 having different masses to appropriate positions of the plurality of female screw portions 32 of the balancer 30, the rotational balance of the main shaft 12 can be adjusted to a position opposite to the unbalance phase of the main shaft 12. An unbalance amount necessary for correcting the rotation is given, and the rotational balance of the main shaft 12 is corrected with high accuracy. The screw weight 33 can be attached to and detached from the female screw portion 32 of the balancer 30 in either a state where the balancer 30 is attached to the balancer attachment hole 20 or a state where it is removed.

  As described above, according to the spindle device 10 of the present embodiment, the balancer mounting holes 20, 20 provided from the end surface on the central axis CL of the spindle 12, and a plurality of fittings fitted to the balancer mounting holes 20. In order to mount a plurality of balancers 30, 30... At any position in the axial direction of the balancer mounting hole 20, the balancer 30, 30. The balance can be corrected at an arbitrary position in the axial direction of the main shaft 12. Thereby, since balance correction (multi-surface correction) can be performed on three or more surfaces, the vibration and noise of the apparatus 10 can be greatly reduced.

  Further, according to the spindle device 10 of the present embodiment, the balancer 30 can be disposed in the balancer mounting hole 20 and the installation work of the balancer 30 can be performed from the end surface side of the device 10. Without being limited to the position, the balancer 30 can be arranged at an arbitrary position in the axial direction of the main shaft 12, and the balance correction work can be easily performed.

  In addition, according to the spindle device 10 of the present embodiment, the balancer mounting holes 20 and 20 are provided from the end face of the spindle 12, so even if the balancer 30 is shaved with the balancer 30 assembled to the spindle 12, Foreign matter does not enter the bearing 13 or the like.

  In addition, according to the spindle device 10 of the present embodiment, since the mass of the screw weight 33 is cut and adjusted, the mass of the screw weight 33 can be easily adjusted. An unbalance amount necessary for correcting the rotational balance can be accurately given.

  Further, according to the spindle device 10 of the present embodiment, the balancer 30 has the male screw portion 31 formed on the outer peripheral surface, and the male screw portion 31 is screwed into the female screw portion 22 formed in the balancer mounting hole 20. Since it is fixed to the main shaft 12, the balancer 30 can be easily attached and detached, so that the balance correction work can be performed efficiently.

(Second Embodiment)
Next, a second embodiment of the spindle device according to the present invention will be described with reference to FIGS. Note that portions that are the same as or equivalent to those of the first embodiment are denoted by the same reference numerals in the drawings, and description thereof is omitted or simplified.
FIG. 4 is a view for explaining a second embodiment of the spindle device according to the present invention, and is a schematic view showing a state before a plurality of balancers are assembled into balancer mounting holes of the spindle, and FIG. 5 is a plurality of drawings shown in FIG. FIG. 6 is a diagram of the balancer shown in FIG. 4 as viewed from the rear in the axial direction.

  As shown in FIGS. 4 to 6, in the present embodiment, the balancer mounting holes 40 and 40 are formed on the central axis CL of the main shaft 12 from the front end surface 12 f and the rear end surface 12 r toward the center portion, The balancer mounting hole 40 is a straight hole, and a female thread portion 41 is formed at the axially outer end portion of the inner peripheral surface thereof.

  In the present embodiment, the balancer mounting hole 40 includes an inner balancer 51 disposed at the innermost portion of the balancer mounting hole 40, an outer balancer 53 disposed at the outermost portion of the balancer mounting hole 40, and an inner balancer 51. A plurality (seven in this embodiment) of intermediate balancers 52, 52... Disposed between the outer balancer 53 and the outer balancer 53 are attached.

  Each of the inner balancer 51, the intermediate balancer 52, and the outer balancer 53 is a substantially cylindrical member, and the inner balancer 51 is formed with a concave section 54 having a hexagonal cross section on the rear end face in the axial direction. Further, the intermediate balancer 52 is formed with a hexagonal cross-section convex portion 55 fitted to the concave portion 54 of the inner balancer 51 on the axial front end surface, and a hexagonal cross-sectional recess portion 54 formed on the axial rear end surface. The Further, the outer balancer 53 is formed with a hexagonal convex portion 55 that fits with the concave portion 54 of the intermediate balancer 52 on the front end surface in the axial direction, and a male screw portion 56 is formed on the outer peripheral surface. The relative phase of the inner balancer 51, the intermediate balancer 52, and the outer balancer 53 is fixed by fitting the concave portions 54 and the convex portions 55 to each other.

  Further, as shown in FIG. 6, the inner balancer 51, the intermediate balancer 52, and the outer balancer 53 are arranged at substantially equal intervals in the circumferential direction, and are formed with a plurality of female screw portions 32 formed along the axial direction (this embodiment). In the embodiment, there are 8 pieces at intervals of 45 °) and a plurality of screw weights 33 screwed to the plurality of female screw portions 32. Note that it is not necessary to attach the screw weight 33 to all of the inner balancer 51, the intermediate balancer 52, and the outer balancer 53, and it may be appropriately attached according to the number of balance correction surfaces.

  The inner balancer 51, the intermediate balancer 52, and the outer balancer 53 are first inserted into the balancer mounting holes 40 after the masses of the inner balancer 51, the intermediate balancer 52, and the outer balancer 53 are adjusted by the screw weight 33. The Next, the male screw portion 56 of the outer balancer 53 is screwed into the female screw portion 41 of the balancer mounting hole 40, and the inner balancer 51 and the intermediate balancer 52 are pressed by the outer balancer 53, thereby being fixed to the main shaft 12. At this time, the relative phases of the inner balancer 51, the intermediate balancer 52, and the outer balancer 53 are fixed by the concave portion 54 and the convex portion 55 that are fitted to each other.

  As described above, according to the spindle device 10 of the present embodiment, the balancer mounting holes 40, 40 provided from the end surface on the central axis CL of the spindle 12, and a plurality of fittings fitted to the balancer mounting holes 40. The balancers 51, 52, 53 are inserted into the balancer mounting holes 40 in a stacked state and fixed to the main shaft 12. Therefore, the balancers 51, 52, 53 are fixed to the main shaft 12. Not only the balance correction but also the balance correction at an arbitrary position in the axial direction of the main shaft 12 can be performed. Thereby, since balance correction (multi-surface correction) can be performed on three or more surfaces, the vibration and noise of the apparatus 10 can be greatly reduced.

  Further, according to the spindle device 10 of the present embodiment, the plurality of balancers 51, 52, 53 are arranged in the balancer mounting hole 20, and the installation work of the plurality of balancers 51, 52, 53 is performed from the end face side of the device 10. Therefore, the balancers 51, 52, and 53 can be arranged at arbitrary positions in the axial direction of the main shaft 12 without being limited to the positions of the motor, the cooling hole, and the like. Can be easily performed.

Further, according to the spindle device 10 of the present embodiment, the balancers 51 and 52 can be attached and detached simply by attaching and detaching the balancer 53 arranged at the outermost part of the balancer attachment hole 40, so that the balance correction work is performed. Can be done efficiently.
Other configurations and operational effects are the same as those of the first embodiment.

(Third embodiment)
Next, a third embodiment of the spindle apparatus according to the present invention will be described with reference to FIGS. Note that the same or equivalent parts as those in the first and second embodiments are denoted by the same reference numerals in the drawings, and the description thereof is omitted or simplified.
FIG. 7 is a view for explaining a third embodiment of the main spindle device according to the present invention. FIG. 7 is a schematic view showing a state before a plurality of balancers are assembled in the balancer mounting holes of the main spindle, and FIG. FIG. 9 is a diagram for explaining a modification of the third embodiment of the main spindle device according to the present invention, in which a plurality of balancers are arranged on the main spindle. It is the schematic which shows the state after incorporating in the balancer attachment hole.

  As shown in FIGS. 7 and 8, in the present embodiment, the balancer mounting holes 60, 60 are formed on the central axis CL of the main shaft 12 from the front end surface 12f and the rear end surface 12r toward the center, respectively. The balancer mounting hole 60 is a straight hole, and an internal thread portion 61 is formed at the axially outer end portion of the inner peripheral surface thereof, and a convex portion 62 having a hexagonal cross section is formed at the axially inner end wall. The

  In this embodiment, the balancer mounting hole 60 includes a plurality of (seven in this embodiment) inner balancers 71, 71... Disposed from the innermost portion of the balancer mounting hole 60 and the balancer mounting hole 60. An outer balancer 73 arranged at the outermost part and an intermediate balancer 72 arranged between the inner balancers 71, 71... And the outer balancer 73 are attached.

  Each of the inner balancer 71, the intermediate balancer 72, and the outer balancer 73 is a substantially cylindrical member, and the inner balancer 71 has a hexagonal concave section that fits with the convex section 62 of the balancer mounting hole 60 on the front end surface in the axial direction. 74 is formed, and a convex portion 75 having a hexagonal cross section is formed on the rear end surface in the axial direction. The intermediate balancer 72 is formed with a recess 74 having a hexagonal cross section that fits with the protrusion 75 of the inner balancer 71 on the front end surface in the axial direction. The outer balancer 73 is formed with a male screw portion 76 on the outer peripheral surface. The inner balancer 71, the intermediate balancer 72, and the outer balancer 73 have their relative phases fixed by fitting the convex portions 62 of the balancer mounting holes 60 and the concave portions 74 and the convex portions 75 of each other.

  Similarly to the second embodiment, the inner balancer 71, the intermediate balancer 72, and the outer balancer 73 are arranged at substantially equal intervals in the circumferential direction and are formed with a plurality of female screw portions 32 (this In the embodiment, there are 8 pieces at intervals of 45 °) and a plurality of screw weights 33 screwed to the plurality of female screw portions 32 (see FIG. 6).

The inner balancer 71, the intermediate balancer 72, and the outer balancer 73 are inserted into the balancer mounting hole 60 after the masses of the inner balancer 71, the intermediate balancer 72, and the outer balancer 73 are first adjusted by the screw weight 33. The concave portion 74 of the inner balancer 71 disposed at the innermost portion is fitted into the convex portion 62 of the balancer mounting hole 60. Next, the external threader 76 of the outer balancer 73 is screwed into the female threaded part 61 of the balancer mounting hole 60, and the inner balancer 71 and the intermediate balancer 72 are pressed by the outer balancer 73, thereby being fixed to the main shaft 12. At this time, the relative phases of the inner balancer 71, the intermediate balancer 72, and the outer balancer 73 are fixed by the convex portion 62 of the balancer mounting hole 60, and the concave portion 74 and the convex portion 75 that are fitted to each other.
Other configurations and operational effects are the same as those of the first and second embodiments.

  As a modification of the present embodiment, as shown in FIG. 9, the balance of the main shaft 12 may be adjusted by the plurality of inner balancers 71, 71... And the outer balancer 73 without using the intermediate balancer 72. . In this case, a concave section 77 having a circular cross section is formed on the front end surface in the axial direction of the outer balancer 73 so that the convex section 75 having a hexagonal cross section of the inner balancer 71 is rotatably fitted therein. In this modification, only the convex portion 75 of the inner balancer 71 that engages with the outer balancer 73 may be formed in a circular cross section so as to be fitted to the concave portion 77.

In addition, this invention is not limited to what was illustrated by said each embodiment, In the range which does not deviate from the summary of this invention, it can change suitably.
For example, in each of the embodiments described above, two balancer mounting holes are formed on the main shaft, but there may be one hole penetrating on the central axis of the main shaft, and the number of the balancer mounting holes is not particularly limited.
In each of the above embodiments, the balancer corrects the balance by attaching a screw weight. However, the present invention is not limited to this, and the balance may be corrected by cutting the balancer itself.
In the first embodiment, a total of six balancers are used, and the balance of the main shaft is corrected on six surfaces. However, if the balance of the main shaft can be corrected on three or more surfaces, the number of balancers is not particularly limited. Absent.
In the second embodiment, seven intermediate balancers are used. However, the number of spindles is not particularly limited as long as the balance of the main shaft can be corrected on three or more surfaces.
Moreover, in the said 2nd Embodiment, although the recessed part and the convex part are formed in the cross-sectional hexagon, if it is a shape which can fix the relative phase of an inner side balancer, an intermediate | middle balancer, and an outer side balancer, it will be arbitrary shapes (for example, , Triangles, quadrilaterals, pentagons, male screws, female screws, etc.).
The balancer mounting hole may also be used as a mounting hole such as a quill or a through hole.
Furthermore, the spindle device of the present invention may be combined with other balance correction mechanisms.

It is a schematic block diagram for demonstrating 1st Embodiment of the main axis | shaft apparatus which concerns on this invention. It is an expanded sectional view of the A section of FIG. It is the figure which looked at the balancer single item shown in FIG. 2 from the axial direction back. It is a figure for demonstrating 2nd Embodiment of the main axis | shaft apparatus which concerns on this invention, and is the schematic which shows the state before a some balancer is integrated in the balancer attachment hole of a main axis | shaft. It is the schematic which shows the state after the several balancer shown in FIG. 4 was integrated in the balancer attachment hole of a main axis | shaft. It is the figure which looked at the balancer single item shown in FIG. 4 from the axial direction back. It is a figure for demonstrating 3rd Embodiment of the main axis | shaft apparatus which concerns on this invention, and is the schematic which shows the state before a some balancer is integrated in the balancer attachment hole of a main axis | shaft. It is the schematic which shows the state after the several balancer shown in FIG. 7 was integrated in the balancer attachment hole of a main axis | shaft. It is a figure for demonstrating the modification of 3rd Embodiment of the main axis | shaft apparatus which concerns on this invention, and is the schematic which shows the state after a several balancer was integrated in the balancer attachment hole of a main axis | shaft.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Main shaft apparatus 11 Housing 12 Main shaft 12f Front end surface 12r Rear end surface 13 Ball bearing (rolling bearing)
20 balancer mounting holes 21a, 21b, 21c holes 22 female threaded portion 30 balancer 31 male threaded portion 32 female threaded portion 33 screw weight 40, 60 balancer mounting hole 41, 61 female threaded portion 51, 71 inner balancer (balancer)
52,72 Intermediate balancer (balancer)
53,73 Outer balancer (balancer)
54,74 Concave part 55,75 Convex part 56,76 Male thread part 62 Convex part 77 Concave part

Claims (2)

A spindle device comprising a plurality of rolling bearings and a spindle that is rotatably supported by the rolling bearings,
And at least one balancer mounting hole provided from an end surface on the central axis of the main shaft, and at least one balancer fitted and attached to the balancer mounting hole,
The main spindle apparatus, wherein the balancer is attached to an arbitrary position in the axial direction of the balancer attachment hole. The balancer includes a plurality of female screw portions that are arranged at substantially equal intervals in the circumferential direction and are formed along the axial direction, and a screw weight that is screwed onto at least one of the plurality of female screw portions. ,
2. The spindle device according to claim 1, wherein the screw spindle is screwed onto the plurality of female screw portions, and an unbalance amount necessary for correcting the rotational balance of the spindle is imparted to the spindle.

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