JP3368559B2 - motor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor used in an industrial machine or machine tool for precision work, in which vibration is not transmitted to the machine.

[0002]

2. Description of the Related Art Conventionally, in an industrial machine or a machine tool which is required to prevent vibration, each element constituting the machine is machined and used with high precision. In particular, the rotating part is used with static balance and dynamic balance. As a motor used in these machines, one having a good mechanical balance is adopted. That is, in the motor, the rotary shaft is processed with high precision, a precision round nut is used for mounting the bearing, or the key groove is processed on the circumference in a balanced manner. When the rotor portion composed of the iron core and the short-circuit rod is attached to the rotary shaft, the rotation balance is achieved in this attached state. The bearings used are ultra-precision grade bearings. Furthermore, the rotation balance is maintained even when the motor is assembled. Also, the coupling portion with another rotating body connected to the rotating shaft is well balanced.

A normal motor has the property of automatically moving in the axial direction in the direction in which the magnetic centers of the rotor and the stator coincide with each other due to the magnetic force when the motor is started. For this reason, there is a method in which a spring similar to a spring washer is attached to the outer sides of the outer rings of the bearings that support the rotating shaft to which the rotor is attached so that the magnetic centers are automatically aligned to prevent magnetic vibration. Further, conventionally, the rotor magnetic center of the motor has been known by measuring the dimension from the end face of the motor case flange of the assembled motor to the end face of the intermediate rotating shaft. However, measures against magnetic vibration using this have not been taken.

[0004]

The motor vibration prevention measures described in the prior art mainly consider the mechanical balance of the motor, and take positive measures against the vibration caused by the magnetism of the motor. There was nothing. In the conventional motor, which uses the property that the rotor and stator automatically move in the direction in which the magnetic centers coincide, the rotor automatically moves in the direction in which the magnetic centers coincide within the allowable movement range of the spring. Therefore, there is a problem that the disagreement beyond this range cannot be resolved. Further, there is a problem that the vibration in the radial direction cannot be eliminated. In addition, this has a problem that the axial position of the rotary shaft is not stable. Therefore, in a precision motor that requires high precision, there is a problem that it is necessary to take sufficient measures against vibrations in the radial direction and the axial direction due to magnetism particularly when the motor rotates.

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to provide a precision motor having little magnetic vibration in both the radial direction and the axial direction of the rotating shaft. Is.

[0006]

In order to achieve the above object, a motor according to the present invention according to claim 1 is provided with elastically deformable mounting portions axially projecting from outer circumferences of both ends of a stator core of the motor. Provided on the inner circumference of the motor frame
Large diameter with a dimension width longer than the axial dimension of the stator core
The fitting parts of the mounting part are provided on both outer sides of the relief part of
, The inner circumference of both ends in the axial direction of the large diameter relief of the motor frame
Position between the shaft and the outer peripheral positions of both ends of the stator core in the axial direction.
Supported by the fitting part with a gap that deforms and absorbs vibration
It has been done. The motor of the present invention as defined in claim 2 is a motor cylinder having a right cylindrical shape with no escape on the inner peripheral surface.
The frame and the outer peripheral surface are fitted to the motor frame.
The width of the stator core in the axial direction
Wide and shallow groove is formed on the circumference to fit the stator core
Mounting a thin-walled cylindrical stator housing.
The axial direction of the inner end surface of the fitting part and the stator core
A space that absorbs vibration by elastically deforming between the outer peripheral positions of both ends of
And is supported by the fitting portion . According to the invention described above, since none so as to absorb the magnetic vibrations by providing an elastically deformable mounting portion protruding respectively axially from both ends periphery of the stator core, the vibration motor off
It is less likely to be transmitted to the ram and therefore does not have a detrimental effect on the machine in which this motor is installed.

According to a third aspect of the motor of the present invention, the stator of the motor and the rotor of the motor are provided so as to be relatively movable in the axial direction, and means for moving the stator or the rotor in the axial direction is provided. The deviation of the magnetic center in the axial direction between the rotor and the stator can be corrected. Here, the means for moving the stator or rotor in the axial direction is an adjusting screw or pin and an eccentric cam. According to the above-described invention, the positional deviation between the magnetic centers of the stator and the rotor is corrected by relatively moving the stator and the rotor in the axial direction. Therefore, the magnetic vibration generated by the disagreement of the magnetic centers in the axial direction is eliminated, and the axial vibration of the motor frame is eliminated. The adverse effect of axial vibration on the machine in which this motor is installed is eliminated.

[0008] motor of the present invention described in claim 4, wherein the motor frame through the elastic body in the middle of the supporting position of the mounting portion protruding on both sides of the stator core
At least one intermediate support portion between the stator and the stator core is provided. According to the above-described invention, even in a motor that is long in the axial direction, since the elastic support portion exists in the intermediate portion, the vibration can have a node and the vibration can be damped.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [Embodiment 1] Embodiment 1 of the present invention will be described below with reference to the drawings.

FIG. 1 is a structural diagram of a motor of the present invention. The rotating shaft 1 of the motor is rotatably supported by bearings 5 and 6 by a front end bracket 3 and a rear end bracket 4 fixed to both sides of a cylindrical motor frame 2. And the motor frame 2 and the front end bracket 3
Motake vinegar and the rear-end bracket 4 (not shown)
Is configured.

A rotor 8 is fixed to the central portion of the central rotating shaft 1. A cylindrical stator 9 is provided so as to surround the outer periphery of the rotor 8 with a predetermined gap from the rotor 8. The axial dimension of the stator core 10 of the stator 9 is substantially the same as the axial dimension of the rotor 8.

The inner periphery of the cylindrical motor frame 2 is provided with large-diameter relief portions 2b having a dimension width longer than the axial dimension of the stator core 10, leaving fitting portions 2a at both ends. The outer circumference of the stator core 10 is longer than the axial dimension of the stator core 10 and has a length sufficient to be inserted into and supported by the respective fitting portions 2a of the motor frame 2 and is elastically deformable as a mounting portion of the stator 9. A thin cylindrical stator housing 11 is fixed. The stator housing 11 fitted in the fitting portion 2a of the motor frame 2 is fitted and supported so as to be movable in the axial direction. Inner peripheral positions 2c of both axial ends of the large diameter relief portion 2b of the motor frame 2 and outer peripheral positions 10a of both axial ends of the stator core 10.
There is a gap of dimension L between and.

During this interval, the stator housing 11 elastically deforms and bends in response to vibrations of the motor in the radial direction, and exerts a buffering function of absorbing the vibrations. That is, the stator core 10 is attached to the motor frame 2 with the buffer portions having the axial dimension L on both sides. At this time, the two end surfaces of the stator housing 11 and the inner end surfaces of the front and rear end brackets 3 and 4 have a space dimension m shorter than the dimension L, respectively. When the stator housing 11 is moved in the axial direction, as will be described later, the dimension L on one side gradually decreases. At this time, first, the end face of the stator housing 11 comes into contact with the inner end face of the end bracket, and even if the dimension m becomes zero, the buffer portion of the dimension L still exists, so that the dimension m is set smaller than the dimension L.

At positions facing the both end surfaces of the thin-walled cylindrical stator housing 11, front and rear end brackets 3 and 4 are provided with screw holes 3a and 4a for set screws at a plurality of positions balanced on the same circumference. It is provided. Then, the adjusting screw 1 is provided in each of these screw holes 3a and 4a.
The screws 2 and 13 are screwed into contact with the respective end surfaces of the stator housing 11 to enable the axial position adjustment of the stator housing 11.

A fitting portion 2 is provided on the outer periphery of the motor frame 2.
Screw hole 2d for the set screw in the radial direction from the outer periphery at the position of a
Is provided. And set screw 1 into this screw hole 2d
4 is screwed to fix the stator housing 11 so as not to move carelessly after the axial position adjustment.

When the axial dimension of the motor is somewhat long, the axial dimension of the motor frame 2 becomes large. At this time, when the dimension of the large-diameter relief portion 2b in the axial direction becomes long, the intermediate support portion 2e is provided at an appropriate number of locations and at least one location at an appropriate interval in the axial direction. A circumferential groove 2f is provided on the inner periphery of the intermediate support portion 2e, and an elastic body 15 such as an O-ring,
The coil spring is housed in a state of protruding inward from the circumferential groove 2f.

The inner peripheral surface of the intermediate support portion 2e has a gap δ between it and the outer peripheral surface of the stator housing 11. The outer peripheral surface of the stator housing 11 is in contact with and supported by the inner peripheral surface of the elastic body 15. In this way, when the support portion 2e is provided in the middle of the escape portion 2b, the stator housing is supported by the elastic body 15 at the intermediate position, and the support position of the elastic body 15 serves as a node of vibration, and the damping property against vibration is provided. Will be improved.

[Axial Position Adjustment] Referring to FIG.
Is the magnetic center of A-A 'and the magnetic center of the stator 9 is B-B
It is assumed that the two magnetic centers have a positional deviation of dimension n in the axial direction. At this time, due to the disagreement between the two magnetic centers, magnetic vibration occurs in the motor in the axial direction. Motor case 7
The motor is started in a state where is fixed and the rotating shaft 1 is rotated to measure the vibration of the motor.

Next, during operation of the motor, the set screw 14 is loosened to loosen the adjustment screws 12 and 13 alternately, and screwing is repeated to move the stator housing 11 left and right in the axial direction, and the vibration value during measurement becomes small. The stator housing 11 is adjusted and moved in the direction. During this movement, the adjustment is finished at the position where the vibration is minimized and the movement is stopped. Firmly clamp the stator housing 11 from both sides with adjusting screws. This corrects the axial displacement of the magnetic center. After that, the set screw 14 is screwed in and the stator housing 11 is fixed to the motor frame 2 to complete the attachment.

[Operation] When the motor is operated after the above-mentioned attachment adjustment is performed, the motor is moved to the magnetic center AA ′ of the rotor 9.
Since the positional deviation amount n between the magnetic center of the stator and the magnetic center BB ′ of the stator is zero or very close to zero, it is possible to suppress the generation of harmful vibrations due to the positional deviation of the magnetic center. Further, there is a distance of an axial dimension L between the axially opposite end positions 10a of the stator core 10 and the inner end position 2c of the inner peripheral fitting portion 2a of the motor frame 2. Therefore, the vibration in the radial direction is prevented from being directly transmitted to the motor case 7 by elastically deforming between the dimensions L.

[Second Embodiment] Next, a second embodiment of the stator housing will be described with reference to FIG. Figure 1
The same parts as those in FIG. The motor frame 21 that supports the stator of the motor has a straight cylindrical shape with no clearance in the inner peripheral portion. The stator housing 22 mounted on the outer periphery of the stator core 10
Has a thin cylindrical shape, but the outer peripheral surface is provided with wide and shallow grooves 22b on the circumference, leaving both end portions 22a for fitting with the motor frame 21. When the shallow groove 22b has a large axial dimension, an intermediate support portion 22c is provided at an appropriate number of locations in the axial direction at least at a suitable location. A circumferential groove 22d is provided on the outer periphery of the intermediate support portion 22c, and the elastic body 2
3 For example, an O-ring and a coil spring are housed in a state of protruding outward from the circumferential groove 22d. The outer peripheral surface of the intermediate support portion 22 has a gap δ between it and the inner peripheral surface of the motor frame 21. The inner peripheral surface of the motor frame 21 has an elastic body 2
The stator housing 22 is supported in contact with the outer peripheral surface of the stator 3. In this case, the support position of the elastic body 23 serves as a node of vibration and imparts damping properties to the vibration.

[Third Embodiment] Next, a third embodiment of the adjusting movement mechanism of the stator housing will be described with reference to FIG. The same parts as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted. Front end bracket 3 of motor case 7
1 and the rear end bracket 32 are provided with pin holes 31a and 32a at a plurality of positions balanced on the same circumference at positions facing both end surfaces of the stator housing 11. The pin 3 is placed in the pin holes 31a and 32a.
3 is inserted.

An eccentric cam 34 is provided at a position where the pins 33 on both sides are pushed in, and the operation shaft 35 of the eccentric cam 34 is radially arranged in the front end bracket 31 and the rear end bracket 3.
2 is projected to the outside. A disk-shaped groove is formed in the front end bracket 31 and the rear end bracket 32 so that the eccentric cam 34 can rotate around the operation shaft 35. A bush 36 is attached to the front end bracket 31 and the rear end bracket 32 to support the operation shaft 35 of the eccentric cam 34.

When the stator housing 11 is adjusted and moved, the set screw 14 is loosened during the vibration measurement of the motor, and both operation shafts 35 provided on the end brackets 31, 32 on both sides are operated to move the eccentric cams on both sides. 34 is rotated to move the stator housing 11 left and right in the axial direction via the pin 33. Then, the stator housing 11 is adjusted and moved in a direction in which vibration during measurement is reduced. During this adjustment movement, the adjustment is finished at the position where the vibration is minimized and the movement is stopped. The eccentric cam 34 is pressed against the stator housing 11 from both sides via pins 33 to sandwich the eccentric cam 34.
This corrects the axial displacement of the magnetic center.
After that, set screw 14 is screwed into stator housing 11
Is fixed to the motor frame 2 and the mounting is completed.

[Fourth Embodiment] Next, a fourth embodiment of the mounting portion for mounting the stator on the motor frame 2 will be described with reference to FIG. The same parts as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted.

Both ends of the outer periphery of the stator core 10 are protruded outwardly so as to be fitted to both sides of the motor frame 2.
An elastically deformable thin-walled cylindrical ring 41 having a length to be inserted therein is fixed. There is a gap of dimension L between the outer peripheral positions 10a on both ends of the stator core 10 to which the rings 41 are fixed and the inner peripheral positions 2c on both ends in the axial direction of the large diameter relief portion 2b of the motor frame 2. During this gap, the rings 41 on both sides are not affected by the radial vibration of the motor.
Elastically deforms to exert a flexure buffering effect. That is, the stator core 10 is attached to the motor frame 2 with the buffer portions having the axial dimension L on both sides. At this time, the outer end surfaces of the two rings 41 and the inner end surfaces of the two end brackets 3 and 4 each have a spacing dimension m shorter than the dimension L.

The axial dimension of the motor frame 2 is large,
When the large-diameter relief portion 2b has a long axial dimension, the motor frame 2 is provided with an intermediate support portion 2e at a proper number of locations and at least one location at suitable intervals in the axial direction. A ring 42 is fixed to the outer periphery of the stator core 10 in the same axial relationship as the intermediate support portion 2e and corresponding to the intermediate support portion 2e. There is a gap δ between the inner peripheral surface of the intermediate support portion 2e and the outer peripheral surface of the ring 42. An inner peripheral groove 2f is provided in the intermediate support portion 2e, and an elastic body 15, for example, an O-ring coil spring is accommodated therein.

[Fifth Embodiment] Next, a fifth embodiment of the mounting portion for mounting the stator on the motor frame 2 will be described with reference to FIG. The same parts as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted.

The stator core 51 is integrally formed with elastically deformable thin-walled cylindrical rings each having a length to be axially outwardly protruded from both ends of the stator core 51 and to be inserted into both side fitting portions 2a of the motor frame 2. The part 51a is formed. There is a distance L between the outer peripheral positions 51b of both ends of the stator core 51 integrally formed with the ring portion 51a and the inner peripheral positions 2c of both ends of the large-diameter relief portion 2b of the motor frame 2 in the axial direction. Then, during this interval, the ring portions 51a on both sides are elastically deformed against the vibration of the motor in the radial direction, so that a bending cushioning action is generated. That is, the stator core 51
Will be attached to the motor frame 2 with a buffer portion having an axial dimension L on both sides. At this time, both outer end surfaces of the two ring portions 51a and the two end brackets 3, 4
Each of the inner end surfaces has a space dimension m shorter than the dimension L.

The axial dimension of the motor frame 2 is large,
When the large-diameter relief portion 2b has a long axial dimension, the motor frame 2 is provided with an intermediate support portion 2e at a proper number of locations and at least one location at suitable intervals in the axial direction. A ring-shaped outer radial projection 51c corresponding to the intermediate support 2e
Are integrally formed with the stator core 51. The inner peripheral surface of the intermediate support portion 2e has a gap δ between the inner peripheral surface and the ring-shaped outer radial protrusion 51c. An inner peripheral groove 2f is provided in the intermediate support portion 2e, and an elastic body 15, for example, an O-ring coil spring is accommodated therein.

[Sixth Embodiment] Next, a sixth embodiment of the mechanism for adjusting and moving the rotor 8 in the axial direction will be described with reference to FIG. The same parts as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted.

Of the bearings 5 and 6 that rotatably support the rotating shaft 1 in the front and rear, the bearing 5 has a wavy spring washer for bearing so as to come into contact with the inner end surface of the bearing 5 in the front end bracket 3. I wear 61. Further, a plurality of screw holes 62a are provided in the bearing pressing lid 62, which fixes the outer ring of the bearing 5 from the outer left end, at positions circumferentially balanced so as to face the outer ring of the bearing 5. And this screw hole 62a
Two setscrews 63 and 64 are screwed in series inside. Of the two setscrews 63, 64, the deepest set screw (for adjustment) 63 is for pressing the outer ring of the bearing 5, and the outer set screw 64 is for locking.

Regarding the bearing 6, a wavy spring washer 6 for the bearing is provided in the rear end bracket 4 so as to contact the inner end surface of the bearing 6.
I am wearing 5. Further, a plurality of screw holes 65a are provided at a circumferentially balanced position on the bearing holding cover 66 that holds the outer ring of the bearing 6 from the outer right end, facing the outer ring of the bearing 6. Then, two setscrews 67, 68 are screwed in series in the screw hole 65a. Two setscrews 6
The set screw (for adjustment) 67 at the back of 7, 68 is for pressing the outer ring of the bearing 6, and the set screw 68 for the outside is for locking.

The magnetic center AA 'of the rotor 8 and the stator 9
It is assumed that there is a positional deviation of the dimension n in the axial direction from the magnetic center B-B '. When the position of the rotary shaft 1 is adjusted in the axial direction in this state, the motor is started to rotate the rotary shaft 1 and the vibration of the motor is measured. Next, set screws 63, 64, 67, 68 pressing the two bearings 5, 6 during motor operation.
Of these, the outer locking setscrews 64 and 68 are removed.

After that, the set screws 63 and 67 on the inner sides of both sides are alternately loosened and screwed in repeatedly to move the rotor 8 left and right in the axial direction, and the rotor 8 is adjusted and moved in the direction in which the vibration value during measurement becomes small. . During the movement, the adjustment movement is completed at the position where the vibration is minimized and the movement is stopped so that both setscrews are surely brought into contact with the bearing outer ring. Then, the locking screws 64 and 68 on both outer sides are screwed to lock the locking screws at the back, and the work is completed. This corrects the axial displacement of the magnetic center.

In the above description of each embodiment, the present invention is described as being applied to an ordinary motor, but it is also applicable to a so-called built-in motor mounted on the spindle of a machine tool.

[0037]

Since the motor of the present invention is constructed as described above, it has the following effects.

According to the motors of claims 1 and 2 , the elastically deformable mounting portions axially projecting from the outer circumferences of both ends of the stator core are provided to absorb the magnetic vibrations. There is less transmission, so that the machine on which this motor is installed is not adversely affected by vibration.

In the motor of claim 3 , the stator and the rotor are allowed to move relative to each other in the axial direction, and the positional deviation of the magnetic centers of the stator and the rotor in the axial direction is corrected. Therefore, the magnetic vibration generated by the mismatch of the magnetic centers in the axial direction disappears,
Vibration in the axial direction of the motor frame is eliminated. The adverse effect of axial vibration on the machine in which this motor is installed is eliminated.

According to the motor of the fourth aspect, even if the motor is long in the axial direction, since the elastic supporting portion is present in the middle portion, the vibration can have nodes and the vibration can be damped.

[Brief description of drawings]

FIG. 1 is a sectional view illustrating the structure of a motor of the present invention.

FIG. 2 is an explanatory cross-sectional view of another embodiment of the stator housing of the motor of the present invention.

FIG. 3 is an enlarged explanatory view of another embodiment of the axial movement mechanism of the motor of the present invention.

FIG. 4 is an explanatory cross-sectional view of another embodiment of the stator housing of the motor of the present invention.

FIG. 5 is an explanatory sectional view of another embodiment of the stator housing of the motor of the present invention.

FIG. 6 is an explanatory sectional view of a rotating shaft moving mechanism of the motor of the present invention.

[Explanation of symbols]

1 rotation axis 2 motor frame 2e, 22c Intermediate support part 8 rotor 9 stator 10,51 Stator core 11,22 Stator housing 12, 13 adjusting screw 63, 64, 67, 68 Set screw 15,23 elastic body 33 pin 34 Eccentric cam 41,42 ring 61,65 Wavy spring washers

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Claims (4)

(57) [Claims] 1. A stator core of a motor is provided with elastically deformable mounting portions projecting axially from the outer peripheries of both ends thereof, and the axial dimension of the stator core is provided on the inner perimeter of the motor frame.
On the outside of both ends of the large diameter relief with a dimension width longer than
The fitting part of the mounting part is provided,
Inner circumferential position of both ends of large diameter relief part in axial direction and axial direction of stator core
Absorbs vibration by elastically deforming between the outer peripheral position
A motor having a gap and supported by the fitting portion . 2. A right cylindrical motor hood having no escape on its inner peripheral surface.
The frame and the outer peripheral surface are fitted to the motor frame.
The width of the stator core in the axial direction
Wide and shallow groove is formed on the circumference to fit the stator core
Mounting a thin-walled cylindrical stator housing.
The axial direction of the inner end surface of the fitting part and the stator core
A space that absorbs vibration by elastically deforming between the outer peripheral positions of both ends of
And is supported by the fitting portion.
Motor. 3. A stator of the motor and a rotor of the motor are provided so as to be relatively movable in the axial direction, a means for moving the stator or the rotor in the axial direction is provided, and an axial magnetic center of the rotor and the stator is provided. the motor according to claim 1 or 2 the deviation was correctable. 4. Any of Claims 1 to 3 intermediate support is provided at least one point of the said motor frame via an elastic body in the middle of the supporting position of the mounting portion protruding to both sides of the stator core stator core Or the motor described in paragraph 1 .