JP3691002B2 - Rotating shaft device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rotary shaft device, and more particularly to a rotary shaft device suitable for high-speed rotation of a motor, a machine tool, an industrial machine, or the like.
[0002]
[Prior art]
In general, a rotary shaft device of a machine tool, an industrial machine, or the like is configured such that a rotary shaft that is rotatably supported by a housing is driven to rotate by a motor. In such a rotary shaft device, for the purpose of downsizing the device, reducing the number of parts, etc., the inner peripheral portion of the housing facing the rotor and the rotor mounted on the outer peripheral portion of the rotary shaft that is rotatably supported by the housing. A so-called built-in motor having a stator fixed to the head is employed.
[0003]
As an example of such a rotary shaft device, there is a rolling bearing device disclosed in Japanese Patent Publication No. 58-33934. Referring to FIG. 1, in the rolling bearing device, the front part (left part in FIG. 1) of the rotating shaft 1 is rotatably supported by the housing 4 by the fixed bearing 2, and the rear part (in FIG. 1). The free side bearing 3 is rotatably supported by the lid 41 of the housing 4 via the sleeve 5. A so-called built-in motor in which a rotor is mounted on the outer peripheral portion of the central portion of the rotating shaft 1 and a stator is fixed to the inner peripheral portion of the housing 4 so as to face the rotor is employed.
[0004]
As another example, there is a spindle unit for a milling and drilling machine disclosed in Japanese Patent Laid-Open No. 2-71946. Referring to FIG. 1, in this spindle unit, the front part (the left part in FIG. 1) of the work spindle 9 is rotatably supported by the bearing 15 via the bearing sleeve 12 on the outer side 1, and the rear side of the work spindle 9. The portion (right side in FIG. 1) is rotatably supported by the bearing 1 via the bearing sleeve 12. A rotor 10 is mounted on the outer peripheral portion of the center portion of the work spindle 9 via a bush 11 and a bearing sleeve 12, and a stator is provided on the inner peripheral portion of the outer 1 facing the rotor 10 via an intermediate layer 7. A so-called built-in motor in which 8 is fixed is employed.
[0005]
As a motor employed in the rotary shaft device, there are an induction motor having a rotor in which a coil is wound around a silicon steel plate, a synchronous motor using a permanent magnet for the rotor, and the like. Such a motor converts electric energy into rotational kinetic energy using a force generated by the action of a magnetic field. That is, a rotational motion is imparted to the rotating shaft by a magnetic field generated between the stator fixed to the inner peripheral portion of the housing and the rotor mounted on the outer peripheral portion of the rotating shaft.
[0006]
[Problems to be solved by the invention]
As described above, in the conventional rotating shaft device, the rotor is mounted on the outer peripheral portion of the rotating shaft, and the rotor mounting portion has a large diameter with respect to the rotating shaft, and centrifugal force and inertia at the time of high-speed rotation of the rotating shaft device. As a result, the rotational characteristics of the rotating shaft became inconvenient.
[0007]
The present invention has a technical problem to solve the above-described problems of the prior art, and reduces the outer diameter of the rotating part including the rotor of the rotating shaft device, and at the same time without reducing the rigidity of the rotating shaft. An object of the present invention is to provide a rotary shaft device with improved rotational characteristics during rotation.
[0008]
[Means for Solving the Problems]
In view of the above-described object, in the present invention, the rotor mounting portion of the rotating shaft is formed to be narrower than the outer peripheral portion of the rotating shaft, and the rotor is mounted thereon, so that the outer diameter of the rotor is reduced. At that time, a nonmagnetic gap must be provided between the rotary shaft and both sides of the rotor, stress concentrates in the gap and the rigidity of the rotary shaft decreases. Therefore, a non-magnetic member is interposed between the rotating shaft and both sides of the rotor and fixed integrally.
[0009]
According to the present invention, there is provided a rotary shaft device incorporating a stator fixed to the housing so as to face the rotor with a rotor fitted rotating shaft rotatably supported in the housing, the maximum outside of said rotary shaft Two ring members made of a rotor having an outer diameter substantially the same as the diameter, a rotating shaft having a small-diameter portion formed by narrowing the outer shape of the portion on which the rotor is mounted, and a nonmagnetic material having an outer diameter substantially the same as the outer diameter of the rotor And fitting one of the two ring members to the small-diameter portion of the rotating shaft, and subsequently fitting the other of the rotor and the ring member to the small-diameter portion of the rotating shaft in this order, There is provided a rotary shaft device that presses one of the ring member, the rotor, and the other of the ring member in the axial direction from a small diameter portion side of the shaft toward a portion having a large outer diameter of the rotary shaft.
Furthermore, according to the present invention, there is provided a rotary shaft device including a rotor mounted on a rotary shaft rotatably supported by a housing and a stator fixed to the housing so as to face the rotor, A rotor having a substantially same outer diameter as the maximum outer diameter, a rotary shaft having a small-diameter portion formed with a thin outer shape of a portion on which the rotor is mounted, and two non-magnetic bodies having an outer diameter substantially the same as the outer diameter of the rotor A ring member and a pressing member having an outer diameter substantially the same as the outer diameter of the rotor, one of the two ring members is fitted into a small diameter portion of the rotating shaft, and the rotor is adjusted to a small diameter of the rotating shaft. The other end of the ring member is fitted to the small-diameter portion of the rotary shaft, and then the presser member is screwed into the small-diameter portion of the rotary shaft, and the presser member is used to The outer diameter of the rotating shaft is thicker from the small diameter side One of said ring member axially towards the rotary shaft device for pressing the other rotor and the ring member.
Further, the ring member can be formed of a nonmagnetic material such as ceramics, graphite, reinforced plastic, tempered glass, and stainless steel.
[0010]
[Action]
Since the rotor is attached to the part where the rotating shaft is narrowed and the outer diameter of the rotor is reduced, centrifugal force and inertia are reduced. Further, it is not necessary to provide a non-magnetic gap portion by interposing and fixing a non-magnetic member between the rotating shaft and both side portions of the rotor.
In addition, since a non-magnetic member is interposed between the rotating shaft and both sides of the rotor, the magnetic force is not transmitted from the rotor to the rotating shaft, and the magnetic field is not disturbed, which may adversely affect the rotation characteristics of the rotating shaft. Absent.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a cross-sectional view showing a rotary shaft device of the present invention, and FIG. 2 is an enlarged cross-sectional view of a main part showing a fixing portion of a rotor and a ring member of the rotary shaft device of the present invention.
Referring to FIG. 1, in the rotating shaft device 1 of the present invention, the front portion (left portion in the figure) of the rotating shaft 3 is rotatably supported by the front housing 7 with a pair of bearings 5, 5. The part (the right part in the figure) is rotatably supported by the rear housing 13 with a pair of bearings 11 and 11 through a sleeve 9. Collars 15, 17 are inserted between the front bearings 5, 5, the inner ring is fixed to the rotary shaft 3 by the bearing retainer 19, and the outer ring is fixed to the front housing 7 by the bearing retainer 21. Further, collars 23 and 25 are inserted between the rear bearings 11 and 11, the inner ring is fastened and fixed to the rotary shaft 3 via the collar 29 by the nut member 27, and the outer ring is fixed to the sleeve 9. The rear lid 31 is fixed to the rear housing 13, and spring members 33 and 33 are provided between the rear lid 31 and the rear housing 13, and when the rotary shaft 3 is thermally expanded, the rear bearings 11 and 11 and the sleeve 9 are arranged. Is moved in the axial direction of the rotary shaft 3, and the elongation of the rotary shaft 3 is absorbed by the spring members 33 and 33. The rotating shaft referred to here is, for example, a main shaft on which a tool is mounted in a machine tool, and an output shaft in a single motor.
[0012]
A rotor 35 is mounted on the small-diameter outer peripheral portion 3a at the center of the rotating shaft 3, and the rotor 35 is fixed to the rotating shaft 3 via ring members 37 made of a nonmagnetic material on both sides thereof. A stator 39 is fixed to the inner peripheral portion of the front housing 7 so as to face the rotor 35. The rotor 35 and the stator 39 form a built-in motor. The pressing member 41 is for fixing the rotor 35 and the ring member 37 to the rotating shaft 3.
[0013]
Next, a method for fixing the rotor 35 and the ring member 37 to the rotating shaft 3 will be described with reference to FIG. The ring member 37 is fixed to both sides of the rotor 35 such that the rotor 35 and the ring member 37 are integrated with the rotating shaft 3 and the rigidity of the rotating shaft 3 is improved. The method which can be pressed and fixed with respect to a part is preferable.
First, the ring member 37, the rotor 35, and the ring member 37 are inserted in this order into the small-diameter outer peripheral portion 3 a formed at the center of the rotating shaft 3. At this time, the rotor 35 is shrink-fitted onto the small-diameter outer peripheral portion 3a of the rotating shaft 3. Thereafter, the presser member 41 is shrink-fitted from the outside of the ring member 37, pressed in the axial direction of the rotary shaft 3 at a desired pressure (for example, 1.5 tons), and then cooled down, whereby the small-diameter outer peripheral portion 3a of the rotary shaft 3 is removed. The rotor 35 is fixed to both sides thereof via ring members 37. It is desirable that the outer diameters of the rotor 35, the ring member 37, and the pressing member 41 are substantially the same as the maximum outer diameter of the rotating shaft 3 when fixed to the rotating shaft 3.
Thereby, the space | gap part of the both sides of the rotor 35 can be eliminated, the rotor 35 and the rotating shaft 3 can be integrated via the ring member 37, and the rigidity of the rotating shaft 3 can be improved.
[0014]
Even if the ring member 37 is integrated with the rotating shaft 3 and the rotor 35 and directly fixed to the rotating shaft 3, the ring member 37 is made of a non-magnetic material, so that no magnetic force is transmitted from the rotor 35 to the rotating shaft 3, and a magnetic field is generated. There is no disturbance, and the rotational characteristics of the rotating shaft 3 are not adversely affected. The ring member 37 is made of a material such as ceramics, graphite, reinforced plastic, tempered glass, and stainless steel. The ring member 37 is preferably made of a highly rigid material.
[0015]
Next, another method for fixing the rotor 35 and the ring member 37 to the rotating shaft 3 will be described with reference to FIG. The difference from the method shown in FIG. 1 is that the presser member 41 is not a shrink fit, but the presser member 41 is a nut member.
In this case, a screw groove 3 b is formed on the insertion side of the rotor 35 and the ring member 37 of the small-diameter outer peripheral portion 3 a formed at the center of the rotary shaft 3, and the ring member 37 is formed on the small-diameter outer peripheral portion 3 a of the rotary shaft 3. The rotor 35 and the ring member 37 are inserted in this order. At this time, the rotor 35 is shrink-fitted onto the small-diameter outer peripheral portion 3a of the rotating shaft 3. Thereafter, the presser member 41, which is a nut member, is tightened from the outside of the ring member 37, whereby the rotor 35 and the ring member 37 are fixed to the small-diameter outer peripheral portion 3 a of the rotating shaft 3. It is desirable that the outer diameters of the rotor 35, the ring member 37, and the pressing member 41 are substantially the same as the maximum outer diameter of the rotating shaft 3 when fixed to the rotating shaft 3. The method shown in FIG. It is the same. Here, if the small-diameter outer peripheral portion 3 a of the rotating shaft 3 is formed in a tapered shape, the ring member 37 and the rotor 35 can be firmly fixed to the small-diameter outer peripheral portion 3 a of the rotating shaft 3 with a pressing member 41 as a nut member. .
[0016]
Other methods for fixing the rotor 35 and the ring member 37 to the rotary shaft 3 include a method of directly bonding the presser member 41 to the small-diameter outer peripheral portion 3a of the rotary shaft 3, or omitting the presser member 41 and attaching the ring member 37 to the rotor 35. Various fixing methods such as a method of directly adhering to the rotating shafts 3 on both sides of the head are conceivable.
[0017]
Here, the material of the ring member 37 differs depending on the type of motor employed in the rotary shaft device. In the case of an induction motor, generally, it has a rotor in which a coil is wound around a silicon steel plate, and a loop current flows from the stator to the rotor. Therefore, the ring member 37 is made of a nonmagnetic and nonconductive material such as ceramics, reinforced plastic, It is preferable to employ a material such as tempered glass. However, the outermost part of the rotor of the induction motor is often subjected to insulation treatment. In this case, it is not necessary to use a non-conductive material, and materials such as graphite and stainless steel can also be employed.
On the other hand, in the case of a synchronous motor, since a permanent magnet is generally used for the rotor, the ring member 37 must be a nonmagnetic material. In the case of a synchronous motor, since electricity does not flow from the stator to the rotor, it is not necessary to use a non-conductive material. That is, examples of materials that can be used as the material of the ring member 37 include ceramics, graphite, reinforced plastic, tempered glass, and stainless steel.
[0018]
The motor employed in the rotary shaft device of the present invention is not limited to an induction motor or a synchronous motor. The rotary shaft device of the present invention is not limited to machine tools, industrial machines, and the like, and can be applied to various machines and devices having a built-in motor. The method of fixing the rotor and ring member in the present invention can also be applied to a single motor.
[0019]
【The invention's effect】
As described above, according to the present invention, the rotor is attached to the part where the rotating shaft is narrowed, and the outer diameter of the rotor is reduced, so that centrifugal force and inertia are reduced, and the rotating characteristics at high speed rotation of the rotating shaft are improved. did. And by interposing and fixing the non-magnetic material member between the rotating shaft and both sides of the rotor, it is not necessary to provide a gap on both sides of the rotor existing in the conventional rotating shaft device, The rigidity of the rotating shaft has increased.
Therefore, a small and highly rigid rotary shaft device suitable for high speed rotation was obtained.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a rotary shaft device of the present invention.
FIG. 2 is an enlarged sectional view of a main part showing a fixing part of a rotor and a ring member of the rotary shaft device of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Rotating shaft apparatus 3 ... Rotating shaft 3a ... Small diameter outer peripheral part 5 ... Bearing 7 ... Front housing 11 ... Bearing 13 ... Rear housing 35 ... Rotor 37 ... Ring member 39 ... Stator 41 ... Holding member

Claims (3)

A rotary shaft device including a rotor mounted on a rotary shaft rotatably supported by a housing and a stator fixed to the housing so as to face the rotor;
A rotor having an outer diameter substantially the same as the maximum outer diameter of the rotating shaft;
A rotating shaft having a small-diameter portion formed with a thin outer shape of a portion to which the rotor is mounted;
Two ring members made of a non-magnetic material having an outer diameter substantially the same as the outer diameter of the rotor;
A pressing member having an outer diameter substantially the same as the outer diameter of the rotor;
Comprising
One of the two ring members is fitted into the small-diameter portion of the rotating shaft, the rotor is fitted into the small-diameter portion of the rotating shaft and shrink-fitted, and the other of the ring members is fitted into the small-diameter portion of the rotating shaft. Then, the presser member is fitted into the small diameter portion of the rotary shaft and shrink-fitted, and the presser member is axially moved from the small diameter portion side of the rotary shaft toward the thick portion of the outer diameter of the rotary shaft. A rotating shaft device that presses one of a ring member, the other of a rotor and a ring member . A rotary shaft device including a rotor mounted on a rotary shaft rotatably supported by a housing and a stator fixed to the housing so as to face the rotor;
A rotor having an outer diameter substantially the same as the maximum outer diameter of the rotating shaft;
A rotating shaft having a small-diameter portion formed with a thin outer shape of a portion to which the rotor is mounted;
Two ring members made of a non-magnetic material having an outer diameter substantially the same as the outer diameter of the rotor;
A pressing member having an outer diameter substantially the same as the outer diameter of the rotor;
Comprising
One of the two ring members is fitted into the small-diameter portion of the rotating shaft, the rotor is fitted into the small-diameter portion of the rotating shaft and shrink-fitted, and the other of the ring members is fitted into the small-diameter portion of the rotating shaft. Then, the holding member is screwed into the small diameter portion of the rotating shaft, and the ring member is axially moved from the small diameter side of the rotating shaft toward the thick outer portion of the rotating shaft by the holding member. On the other hand, a rotating shaft device that presses the other of the rotor and the ring member . The rotary shaft device according to claim 1, wherein the ring member is made of a nonmagnetic material such as ceramics, graphite, reinforced plastic, tempered glass, and stainless steel.

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