CN217036984U - Motor - Google Patents
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- CN217036984U CN217036984U CN202220469689.2U CN202220469689U CN217036984U CN 217036984 U CN217036984 U CN 217036984U CN 202220469689 U CN202220469689 U CN 202220469689U CN 217036984 U CN217036984 U CN 217036984U
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- displacement meter
- displacement
- rotor core
- calculation unit
- evaluation
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Abstract
The utility model provides a motor. The motor includes a displacement meter for an evaluation portion for measuring an axial displacement of the evaluation portion located at a radially outer portion of the rotor core, a displacement meter for a reference portion for measuring an axial displacement of a reference portion located at a radially inner portion of the rotor core, and a deformation amount calculation unit for calculating a deformation amount of the evaluation portion in an axial direction based on a measurement result of each of the displacement meters, the displacement meter for the reference portion includes three displacement meters for measuring axial displacements of three reference portions set at the radially inner portion of the rotor core, and the deformation amount calculation unit includes a distance calculation unit for calculating a distance between a reference plane passing through each of the reference portions and the evaluation portion based on the measurement results of the three displacement meters and the measurement result of the displacement meter for the evaluation portion; and a difference calculation unit for calculating a difference between the distance at the time of rotation and the distance at the time of stop calculated by the distance calculation unit. Based on this structure, can measure the deflection of rotor core itself accurately.
Description
Technical Field
The present invention relates to a motor, and more particularly, to a motor capable of accurately measuring a deformation amount of a rotor core when a rotor rotates.
Background
Conventionally, there is a technique for measuring the amount of deformation generated when various rotating bodies rotate. For example, in the case where the rotor is a rotor provided in a turbine or the like and having rotor blades fixed around a rotation shaft, the tip portions of the rotor blades are twisted with respect to the root when viewed in the radial direction, and therefore, when the rotation shaft rotates, the tip portions of the rotor blades try to return in the root direction under the influence of centrifugal force, and torsional deformation occurs in the rotor blades. In order to measure the amount of back-twist of such torsional deformation, electromagnetic pickup devices as displacement meters are often provided near the leading end and the root of the rotary wing, respectively.
With the above configuration, in the electromagnetic pickup device provided at the leading end portion where torsional deformation occurs, the electromotive force is a total value obtained by adding the electromotive force corresponding to the amount of torsional deformation and the electromotive force corresponding to the rotational speed of the rotor blade; in contrast, in the electromagnetic pickup device provided at the root portion where no torsional deformation is generated, the electromotive force is only the electromotive force corresponding to the rotational speed of the rotor blade. Therefore, by subtracting the electromotive force of the electromagnetic pickup device provided at the root (i.e., the difference between the two electromotive forces) from the electromotive force of the electromagnetic pickup device provided at the tip, the amount of torque back of the rotor can be measured. The technique is also applicable to a rotor provided in a motor.
However, when the above-described technique is applied to a motor rotor in the related art, there is a problem that the amount of deformation generated when the rotor rotates cannot be accurately measured. Specifically, since the rotary shaft of the rotor is rotatably supported by the bearing, an appropriate gap is provided between the rotary shaft and the bearing to suppress friction, vibration, and the like. This clearance means that the rotating shaft is allowed to tilt or axially displace relative to the centre line of the bearing by an amount corresponding to said clearance. In this way, the electromagnetic pickup device for measuring the deformation amount of the rotor core measures the deformation amount due to the influence of the inclination of the rotary shaft or the axial displacement as the deformation amount of the rotor core. Therefore, it is difficult to accurately measure the amount of deformation of the rotor core itself.
SUMMERY OF THE UTILITY MODEL
In view of the above circumstances, an object of the present invention is to provide a motor capable of accurately measuring the amount of deformation of a rotor core itself while eliminating the influence of inclination of a rotating shaft or axial displacement.
In order to solve the above-described problems, the present invention provides a motor including a rotating shaft rotatably supported by a bearing, and a rotor core fixed to a circumferential surface of the rotating shaft, the rotor core being made of a magnetic material, and a stator coil being arranged radially outside the rotor core, the motor including: the displacement gauge for the reference portion includes a first displacement gauge, a second displacement gauge, and a third displacement gauge that respectively measure axial displacements of three different reference portions set in a radially inner portion of the rotor core, and the deformation amount calculation unit includes a displacement gauge for the evaluation portion that measures an axial displacement of the evaluation portion located in a radially outer portion of the rotor core, a displacement gauge for the reference portion that measures an axial displacement of a reference portion located in a radially inner portion of the rotor core, and a deformation amount calculation unit that calculates a deformation amount of the evaluation portion in an axial direction based on a measurement result of the displacement gauge for the evaluation portion and a measurement result of the displacement gauge for the reference portion, a distance calculating unit for calculating distances between a reference plane passing through three different reference portions and the evaluation portion; and a difference calculation unit that calculates a difference between the distance at the time of rotation calculated by the distance calculation unit when the rotation shaft rotates and the distance at the time of stop calculated by the distance calculation unit when the rotation shaft stops rotating.
The motor of the present invention has an advantage in that the deformation of the rotor core itself can be accurately measured while eliminating the influence of the inclination or axial displacement of the rotating shaft.
In the motor according to the present invention, it is preferable that the motor further includes a rotation angle detector for detecting a rotation angle of the rotating shaft; and a displacement meter control unit that, when the rotation axis rotates, causes the measurement to be performed by the evaluation-site displacement meter and the reference-site displacement meter if a detection result of the rotation angle detector matches a previously stored measurement value.
Drawings
Fig. 1 is a schematic cross-sectional view showing a structure of a motor 1 according to an embodiment of the present invention.
Fig. 2 is a schematic plan view of the rotor 2 in fig. 1 viewed from the axial direction.
Fig. 3 is a block diagram showing a configuration of the control device 7 in fig. 1.
Fig. 4 is a schematic diagram for explaining the operation and effect of the motor 1.
Fig. 5 is a flowchart showing a process performed by the control device 7.
Detailed Description
Embodiments of the present invention will be described below with reference to the drawings.
< Structure of motor >
Fig. 1 is a schematic sectional view showing a structure of a motor 1 according to the present embodiment. As shown in fig. 1, the motor 1 includes a rotor 2, a stator 3, a rotation angle detector 4, a displacement meter for evaluation site 5, a displacement meter for reference site 6, a control device 7, and the like.
As shown in fig. 1, the rotor 2 includes a rotary shaft 8 and a rotor core 9. The rotary shaft 8 is a round bar-shaped output shaft, and is rotatably supported by a bearing 11 attached to a motor housing 10. The rotor core 9 (not shown in detail) is a cylindrical member made of electromagnetic steel plates and contains permanent magnets (not shown). Further, rotor core 9 is fixed to the circumferential surface of rotating shaft 8.
Fig. 2 is a schematic plan view of the rotor 2 viewed from the axial direction. As shown in fig. 1 and 2, an evaluation portion 12 and a reference portion 13 are set in the rotor core 9, respectively.
The evaluation portion 12 is a portion to be evaluated for the amount of deformation in the axial direction. The evaluation portion 12 is set at one portion of the radially outer portion of the end face 9a of the rotor core 9.
The reference site 13 is a site to be compared used for evaluating the evaluation site 12. The reference portion 13 includes a first reference portion 13a, a second reference portion 13b, and a third reference portion 13c that are respectively set at three portions in a radially inner portion of the end surface 9a of the rotor core 9.
In fig. 1 and 2, the evaluation portion 12 and each reference portion 13 are shown in an exaggerated manner for convenience.
The stator 3 generates electromagnetic force that rotates the rotor 2. As shown in fig. 1, the stator 3 includes a stator core 14 and a stator coil 15. The stator core 14 is a cylindrical member made of an electromagnetic steel plate or the like, and the stator core 14 surrounds the rotor core 9 with a gap from the rotor core 9. The stator coils 15 are wound around the stator core 14 and arranged at three positions (not shown in detail) in the circumferential direction of the rotor core 9. With this configuration, when a three-phase ac current flows through the stator coil 15 under the control of the control device 7, a rotating magnetic field is generated in the center of the stator core 14, and the rotor core 9 and the rotating shaft 8 fixed thereto are integrally rotated.
The rotation angle detector 4 detects a rotation angle of the rotation shaft 8 with respect to an origin position (not shown). As the rotation angle detector 4, a known rotary encoder or the like that detects a rotation angle by a photoelectric method, a magnetic method, or the like can be used. As shown in fig. 1, the detection result of the rotation angle detector 4 is input to the control device 7.
The evaluation portion displacement meter 5 detects the displacement of the evaluation portion 12 of the rotor core 9 in the axial direction. As the displacement meter 5 for an evaluation portion, a known displacement sensor for detecting a distance to an object in a non-contact manner by a laser method, a capacitance method, or the like can be used. As shown in fig. 1, the displacement meter 5 for evaluation portion is provided at a position outside the motor case 10 where the evaluation portion 12 of the rotor core 9 can be detected through an outer measurement window 16 formed by penetrating the motor case 10. The evaluation site displacement meter 5 operates under the control of the control device 7, and the measurement result is input to the control device 7.
The reference portion displacement meter 6 is used to detect the displacement of the reference portion 13 of the rotor core 9 in the axial direction. As the displacement meter 6 for reference portion, a known displacement sensor that contactlessly measures the distance to the object by a laser method, a capacitance method, or the like can be used. As shown in fig. 1, the reference portion displacement meter 6 is provided outside the motor case 10, and includes a first displacement meter 6a, a second displacement meter 6b, and a third displacement meter 6 c. The first displacement meter 6a measures the displacement of the first reference point 13a in the axial direction through a first inside measurement window 17 formed by penetrating the motor housing 10. The second displacement meter 6b measures the displacement of the second reference point 13b in the axial direction through a second inside measurement window 18 formed by penetrating the motor housing 10. The third displacement meter 6c measures the displacement of the third reference point 13c in the axial direction through a third inside measurement window 19 formed by penetrating the motor housing 10. The first displacement meter 6a, the second displacement meter 6b, and the third displacement meter 6c are operated under the control of the control device 7, and the measurement results are input to the control device 7. The position of the reference portion displacement gauge 6 may be changed to the inside of the motor case 10.
The control device 7 controls each component. Fig. 3 is a block diagram showing the configuration of the control device 7. As shown in fig. 3, the control device 7 includes a deformation amount calculation unit 20, a storage unit 21, and a displacement meter control unit 22.
The deformation amount calculation unit 20 calculates the amount of deformation of the evaluation portion 12 in the axial direction from the measurement result of the evaluation portion displacement meter 5 and the measurement result of the reference portion displacement meter 6. The deformation amount calculation unit 20 includes a distance calculation unit 23 and a difference calculation unit 24. The distance calculation unit 23 calculates an equation of a reference plane passing through the first reference portion 13a, the second reference portion 13b, and the third reference portion 13c based on the measurement results of the first displacement meter 6a, the second displacement meter 6b, and the third displacement meter 6c and the measurement result of the displacement meter for evaluation portion 5, and calculates a distance between the reference plane and the evaluation portion 12. In the present embodiment, the distance between the reference surface and the evaluation site 12 corresponds to the length of a perpendicular line drawn from the evaluation site 12 toward the reference surface.
The storage unit 21 stores various data and programs. In the present embodiment, the storage unit 21 stores the rotation angle of the rotating shaft 8 to be measured by the displacement meter for evaluation portion 5 and the displacement meter for reference portion 6, that is, "measured value to be performed".
The displacement meter control unit 22 controls the operation of the evaluation-site displacement meter 5 and the reference-site displacement meter 6 based on the detection result of the rotation angle detector 4.
< effect >
Next, the operation and effect of the motor 1 according to the embodiment of the present invention will be described. Fig. 4 is a schematic diagram for explaining the operation and effect of the motor 1, and fig. 5 is a flowchart showing a control process (a process of measuring the evaluation portion 12 and the reference portion 13 of the rotor core 9) performed by the control device 7.
As shown in fig. 5, after the start of the measurement process, in step S1, the control device 7 appropriately rotates the rotary shaft 8 by energizing the stator coil 15, thereby moving the evaluation site 12 of the rotor core 9 to a predetermined measurement position, that is, the position of the evaluation site 12 that can be measured by the evaluation site displacement gauge 5 through the outer measurement window 16.
In step S2, the control device 7 acquires the detection result of the rotation angle detector 4 in a rotation stop state in which the evaluation portion 12 is stopped at the measurement position.
In step S3, the detection result is stored in the storage unit 21 as an implementation measurement value (see fig. 3).
In step S4, the displacement meter control unit 22 (see fig. 3) included in the control device 7 causes the displacement meter for evaluation portion 5 and the displacement meter for reference portion 6 to measure the displacement while the rotor 2 is stopped from rotating. Specifically, the displacement meter control unit 22 causes the evaluation site displacement meter 5 to measure the axial displacement of the evaluation site 12 and obtains the measurement result. On the other hand, the displacement meter control section 22 causes the first displacement meter 6a to measure the axial displacement of the first reference site 13a, causes the second displacement meter 6b to measure the axial displacement of the second reference site 13b, and causes the third displacement meter 6c to measure the axial displacement of the third reference site 13c, and then obtains the measurement results thereof.
In step S5, the distance calculation unit 23 (see fig. 3) included in the control device 7 calculates the distance between the reference surface and the evaluation portion 12 at the time of stopping the rotation of the rotor 2. Specifically, first, the distance calculation unit 23 solves the equation of the reference plane at the time of stop passing through the three points of the first reference portion 13a, the second reference portion 13b, and the third reference portion 13c, based on the measurement results of the first displacement meter 6a, the second displacement meter 6b, and the third displacement meter 6c obtained in the state where the rotation of the rotor 2 is stopped. Then, the distance calculation unit 23 calculates the distance between the reference surface and the evaluation point 12 at the time of stopping, that is, the distance at the time of stopping, based on the measurement result of the displacement meter for evaluation point 5 obtained in the state where the rotor 2 stops rotating.
In step S6, the controller 7 starts rotation of the rotor 2 by energizing the stator coil 15.
In step S7, the displacement meter control unit 22 included in the control device 7 causes the displacement meter for evaluation portion 5 and the displacement meter for reference portion 6 to measure the displacement while rotating the rotor 2. Specifically, if the detection result of the rotation angle detector 4 does not match the measured value stored in the storage unit 21 (no in step S7), the displacement meter control unit 22 is in a standby state; when the detection result of the rotation angle detector 4 matches the measurement value (yes in step S7), the measurement is performed by the displacement meter for evaluation region 5 and the displacement meter for reference region 6 (step S8).
Step S8 is the same as step S4 described above, and thus a detailed description thereof is omitted here.
In step S9, the distance calculation unit 23 included in the control device 7 calculates the distance during rotation between the reference surface and the evaluation site 12 during rotation of the rotor 2. Specifically, first, the distance calculation unit 23 solves the equation of the reference plane during rotation passing through the three points of the first reference portion 13a, the second reference portion 13b, and the third reference portion 13c, based on the measurement results of the first displacement meter 6a, the second displacement meter 6b, and the third displacement meter 6c obtained while the rotor 2 is rotating. Then, the distance calculation unit 23 calculates the distance between the reference surface and the evaluation portion 12 during rotation, that is, the distance during rotation, based on the measurement result of the displacement meter for evaluation portion 5 obtained while the rotor 2 is rotated.
Finally, in step S10, the difference calculation unit 24 (see fig. 3) provided in the control device 7 calculates the amount of deformation of the evaluation portion 12 in the axial direction when the rotor 2 rotates. Specifically, the difference calculation unit 24 calculates the amount of deformation of the evaluation portion 12 in the axial direction when the rotor 2 rotates by calculating the difference between the distance at the time of rotation calculated in step S9 and the distance at the time of stop calculated in step S5. Then, the measurement processing is ended.
Based on the above measurement processing, the influence of the inclination and axial displacement of the rotary shaft 8 can be eliminated, and the amount of deformation of the rotor core 9 itself in the axial direction can be accurately calculated. In general, as described above, since a gap is provided between the rotary shaft 8 and the bearing 11, it means that the rotary shaft 8 is allowed to tilt with respect to the center line of the bearing 11 or to be displaced in the axial direction by an amount corresponding to the gap. However, when the rotating shaft 8 is inclined, for example, a large displacement occurs in the axial direction at the evaluation portion 12 set in the radially outer portion of the rotor core 9, while the three reference portions 13 set in the radially inner portion of the rotor core 9 are not substantially displaced in the axial direction. Therefore, as shown in fig. 4, the distance d1 at the time of stopping calculated in step S5 represents the axial displacement generated radially outward of the rotor core 9 due to the inclination of the rotary shaft 8 or the like. In fig. 4, the broken line shows the center line of the bearing 11, and the solid line shows the rotating shaft 8 in which the inclination occurs.
On the other hand, when the rotor 2 rotates, a three-phase alternating current in the stator coil 15 forms a magnetic field, and the rotor core 9 made of electromagnetic steel plates is deformed in the axial direction by the magnetic field. Regarding this deformation, a large deformation occurs around the evaluation portion 12 set in the radially outer portion of the rotor core 9, while substantially no deformation occurs around the three reference portions 13 set in the radially inner portion of the rotor core 9. Therefore, as shown in fig. 4, the distance d2 during rotation calculated in step S9 is a total value obtained by adding the axial displacement generated in the radially outer portion due to the inclination of the rotary shaft 8 or the like and the axial deformation amount generated in the radially outer portion of the rotor core 9 due to the action of the magnetic field.
Therefore, as shown in fig. 4, the difference between the distance d2 during rotation and the distance d1 during stoppage calculated in step S10 corresponds to the amount of axial deformation d3 generated on the radially outer portion of the rotor core 9 by the action of the magnetic field during rotation of the rotor 2, that is, the amount of axial deformation of the rotor core 9 itself. This makes it possible to accurately measure and evaluate the amount d3 of axial deformation of the rotor core 9 itself caused only by the action of the magnetic field when the rotor 2 rotates, while excluding the influence of the inclination of the rotating shaft 8 and the like.
< modification example >
The technical scope of the present invention is not limited to the contents described in the above embodiments, and various modifications are possible within the scope defined by the claims. For example, the following modifications may be made to the above embodiment.
In the above embodiment, the evaluation portion 12 and the three reference portions 13 are set at the positions shown in fig. 2, respectively, but the evaluation portion 12 may be set at any position on the radially outer portion of the rotor core 9, and the three reference portions 13 may be set at any position on the radially inner portion of the rotor core 9, respectively.
In the above embodiment, the reference points 13 are set at three positions of the rotor core 9. However, the reference portions 13 may be set at four or more positions of the rotor core 9 within a range in which one reference surface can be obtained. In this case, the number of the displacement meters 6 for reference portions can be appropriately changed according to the number of the reference portions 13.
In the above embodiment, the control device 7 causes the displacement meter for evaluation region 5 and the displacement meter for reference region 6 to perform measurement based on the rotation angle of the rotating shaft 8 detected by the rotation angle detector 4. Alternatively, the control device 7 may cause the displacement meter for evaluation portion 5 and the displacement meter for reference portion 6 to perform measurement based on, for example, an elapsed time from the start of rotation measured by a timer.
Claims (2)
1. A motor including a rotating shaft rotatably supported by a bearing, and a rotor core fixed to a circumferential surface of the rotating shaft, the rotor core being made of a magnetic material, and a stator coil being arranged radially outside the rotor core, characterized in that:
the rotor core deformation amount calculation device includes an evaluation portion displacement meter for measuring an axial displacement of an evaluation portion located at a radially outer portion of the rotor core, a reference portion displacement meter for measuring an axial displacement of a reference portion located at a radially inner portion of the rotor core, and a deformation amount calculation unit for calculating a deformation amount of the evaluation portion in an axial direction based on a measurement result of the evaluation portion displacement meter and a measurement result of the reference portion displacement meter,
the displacement meters for reference portions include a first displacement meter, a second displacement meter, and a third displacement meter that measure axial displacements of three different reference portions set in a radially inner portion of the rotor core,
the deformation amount calculation unit includes a distance calculation unit that calculates distances between a reference surface passing through three different reference portions and the evaluation portion based on the measurement results of the first displacement meter, the second displacement meter, and the third displacement meter and the measurement result of the evaluation portion displacement meter; and a difference calculation unit that calculates a difference between the distance at the time of rotation calculated by the distance calculation unit when the rotation shaft rotates and the distance at the time of stop calculated by the distance calculation unit when the rotation shaft stops rotating.
2. The motor of claim 1, wherein:
a rotation angle detector for detecting a rotation angle of the rotation shaft; and a displacement meter control unit that, when the rotation axis rotates, causes the rotation angle detector to perform measurement using the displacement meter for the evaluation portion and the displacement meter for the reference portion when a detection result of the rotation angle detector matches a previously stored measurement value.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202220469689.2U CN217036984U (en) | 2022-03-03 | 2022-03-03 | Motor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202220469689.2U CN217036984U (en) | 2022-03-03 | 2022-03-03 | Motor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN217036984U true CN217036984U (en) | 2022-07-22 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202220469689.2U Active CN217036984U (en) | 2022-03-03 | 2022-03-03 | Motor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN217036984U (en) |
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2022
- 2022-03-03 CN CN202220469689.2U patent/CN217036984U/en active Active
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